Showing posts with label research. Show all posts
Showing posts with label research. Show all posts

Wednesday, 26 April 2017

Myc, Models and Tumour Growth

When I wrote the NEATG model of tumour growth, published in the journal PeerJ (https://peerj.com/articles/2176/), I focused on the behaviour of individual cells and on the role of cell competition and cell death in tumour growth. All models have to simplify and abstract, and the NEATG model does exactly that. The model steered clear of the molecular basis for the behaviour of the cells – my working assumption was that cells produce soluble factors and signalling proteins that mediate their cell-cell and cell-tissue interactions. It was one of the reasons I called the model NEATG (Non-physiological Evolutionary Algorithm for Tumour Growth – though as Sebastien Benzekry pointed out to me, the fact that the model has cells and tissues already makes it fairly physiological… ).

Despite the level of abstraction, the model clearly does show cellular behaviours that mimic aspects of tumour growth and response to cytotoxic chemotherapy.  A surprise for me was that the model showed that accelerated tumour regrowth following chemotherapy is driven by cell competition and the levels of cell death. I spent time looking at the research literature on these topics and found that my results were actually in line with clinically relevant phenomena – which is what makes the model interesting.

A recent paper from a group of researchers from the University of Bologna entitled MYC, CellCompetition, and Cell Death in Cancer: The Inseparable Triad  (available open access from the journal genes – it’s well worth a read), casts some interesting light on the topic. C-Myc is one of the most important of the master genes involved in cell cycle progression and tissue growth. It’s a transcription factor, which means it regulates the activity of other genes, and is often switched on permanently in tumours rather than coming on and off as required. It’s widely associated with a whole range of different cancers.

In this paper the authors review recent evidence from Drosophilia (fruit fly) models of cancer and how they are implicated in cell growth, cell death and cell competition. They outline the way that competition selects for cells that are ‘fittest’ and that less fit cells are effectively killed off – in just the way that they do in software in my model. The evidence that they outline suggests that one of the drivers for the behaviour of these cells is c-Myc, making it an important component at the physiological level missing from NEATG.The authors themselves make note of the results from the NEATG model:

Our findings suggest that CC [cell competition] is an innate process governing both cancer initiation and progression, where cell death fuels the clonal expansion of the fittest cells in the context. CC and apoptosis thus appear to be strictly linked one another, and emerge as fundamental cancer drivers also in a computational model of tumour growth, where several parameters of malignancy such as intra-tumour heterogeneity and accelerated repopulation have been taken into account.

For the next stage of work on this model I will be investigating the metabolic impact of cell growth in tumour growth, and the impact that cell death has on this. My prediction is that the model will show that populations of ‘super-feeders’ will emerge during tumour growth – and that chemotherapy helps to select for these populations of cells. However, as this stage I don’t really know that that’s what happens – I have to wait and see what the data tells me…

In the meantime I’ll finish with some final words from the team at Bologna :

Cells cooperate to build an organ and, in a similar way, they cooperate to build a cancer. Although the contexts are impressively distant, MYC-mediated cell competition seems to be at work in both cases with the same basic, sequential elements: cell–cell disparity in MYC contents, death of the cells with lower MYC levels, and proliferation of the cells with higher MYC levels. This stereotypical module shapes organ development and, possibly, cancer evolution. In growing tumours, an excess of dying cells is known to contribute to mass expansion, but the implication of MYC-mediated cell competition in this cancer trait has just begun to be investigated. Further research is warranted on the intricate “life and death” signals exchanged by confronting cell populations within the cancer community.


Tuesday, 6 December 2016

Aspirin as an anti-metastatic drug - in 1977

Working on drug repurposing often involves an element of historical research. Drugs like cimetidine, nitroglycerin and propranolol have been around for decades and there’s a lot of good data that we can extract from old articles, clinical trials and retrospective studies. One of the best known examples of old drugs is aspirin - which is attracting a huge amount of attention from clinical researchers in oncology. There is a huge literature on aspirin, with much more on the way as clinical trials are designed, run and reported.

One of the most intriguing things about aspirin is the data that suggests that it might work as an anti-metastatic agent. There is data that shows that aspirin may be effective in reducing the risk of metastatic spread in breast, prostate and colon cancer (for example this recent meta-analysis reported a relative risk of metastasis of 0.77 with aspirin).

That we’ve known about the anti-cancer potential of aspirin for a long time isn’t a surprise – but I have to admit to being surprised to come across a paper from 1977 arguing the case that aspirin might be an effective anti-metastatic drug. The paper is Aspirin for reducing cancer metastases? by Henschke, Luande and Choppala (J Natl Med Assoc. 1977 Aug;69(8):581-4). The paper is available open access (here), and while the data is old, the arguments it makes are still vital and relevant. It really begs the question, how is that things haven’t moved forward more quickly? And, more crucially, how can we make sure that things move forward more quickly in the future. Not just for aspirin but for so many of the other old drugs that have good data in their favour.

Wednesday, 23 November 2016

Innovative new brain tumour trial kicks off

The Anticancer Fund is pleased to announce that on Tuesday 15th November 2016, the first patient was enrolled in a clinical trial called CUSP9v3 for recurrent glioblastoma at the Department of Neurosurgery, University Hospital of Ulm, Germany. This is a phase 1 clinical trial. The study treatment will be given to 10 patients to assess safety and tolerability.

Glioblastoma is the most frequent type of malignant brain tumour in adults. In Europe and North America, there are 3-4 new cases per 100,000 inhabitants per year. Even when all visible tumour is surgically removed, glioblastoma almost always returns within a year. Therefore, after surgery patients are treated with radiotherapy and chemotherapy. Despite this additional treatment, glioblastomas usually regrow and at some point can no longer be effectively treated, often resulting in death 1-2 years after the initial diagnosis.

 "For decades, researchers have been looking for new experimental therapies for our patients with no real success yet" says Professor Marc-Eric Halatsch, the neurosurgeon leading the trial. "Together with Dr Richard Kast (USA), we sought to address the problem that glioblastomas usually find a way to escape the action of a single drug. In 2013, we teamed up with an international group of researchers to propose a treatment that would act on multiple mechanisms used by glioblastoma cells to grow. This treatment consists of 9 drugs that are currently on the market for other indications than cancer (‘repurposed’ drugs). These nine drugs have ancillary attributes that block several of the mechanisms glioblastoma cells use to grow. These drugs had remarkable effects in preventing growth of glioblastoma cells in preclinical studies. A clinical trial was warranted."

In addition to contributing to the design and set-up of the trial, the Anticancer Fund will provide €300,000 for this study. "This type of treatment is not developed by the pharma industry because the 9 drugs are from different companies and all are off-patent and mostly available as generics" says Lydie Meheus, director of the Anticancer Fund. "This implies that the treatment, if successful, will not generate substantial additional financial return for the manufacturers of the drugs. Since the treatment can benefit patients and the healthcare system, it must be developed with the support of philanthropy and governments."

Patients participating in the trial will receive CUSP9v3 for one year. When all patients have completed 2 months of treatment, a first analysis will be done on the safety and tolerability of the combined treatment.

If the combination is well tolerated, a larger multi-centre study will be initiated to evaluate the treatment’s efficacy.

Further information on the CUSP9v3 trial can be found on www.anticancerfund.org or on www.clinicaltrials.gov (NCT02770378).

Wednesday, 22 June 2016

Guest Post - Crowdfunding for Pediatric Cancers

Cesare Spadoni, founder of aPODD (accelerate Paediatric Oncology Drug Development), talks to Pan Pantziarka about the problems in drug development in children's cancers, and about the crowdfunding campaign to find a new treatment for Medulloblastoma.

Pan: What is the aPODD foundation aiming to do?
Cesare: aPODD (accelerate Paediatric Oncology Drug Development) was set up with the mission to speed up the development of better and safer treatments for children with cancer. This is a cause that is very close to my heart. I lost my first daughter to cancer a few years ago. That is when I began thinking about doing something for children with cancer.

Obviously, you can have a positive impact on sick children and their families in many different ways. In my case, because of my professional background in drug development, I felt compelled to do something to address the major problem preventing any further clinical improvement for children and adolescents with cancer: the lack of therapeutic options and the delayed access to the most innovative treatments.

Specific anti-cancer drugs are not developed for younger patients because it is not profitable for industry to do so. This is an area where patients’ organisations may play a vital role. Drug repurposing is certainly an area we are very much interested in. By looking at existing drugs we may be in a position to identify possible new treatments much faster and at a fraction of the cost and risk of new drug development

Pan: How is this campaign different to others?
Cesare: We are looking to identify a potential new treatment for Medulloblastoma, a rather aggressive form of brain cancer that is more frequent in children and adolescents. The current therapeutic options for this cancer are limited and very harsh, including high dose chemotherapy and radiotherapy. The impact on patients may be devastating as the lucky survivors may face severe health problems later in life.

For this project we are partnering with Healx, a company based in Cambridge (UK), which offers very advanced technologies and strong expertise in drug re-purposing. Healx is applying advanced computational biology tools, data analytics and machine learning to make sense of complex biological data sets and match those with the profiles of known drugs.

We are now in the process of finalising a list of drugs that we would like to test experimentally in Medulloblastoma cell lines in view of progressing further with the most promising ones.
We are very excited by these early results and we are really hope that this crowdfunding is successful so that we can proceed as fast as we can.

Monday, 14 December 2015

NEATG - A software model of cancer

For a huge chunk of my working life I have built computer models which were used to assess operational activities in different industries. The combination of mathematics and software can provide enormous power to help understand and assess complex processes. My doctorate put these skills to good use in that I used software implementations of evolutionary processes to build a system that evolved mathematical models which could validate the correctness, or otherwise, of large data sets. In plain English I used genetic algorithms to discover mathematical models which could pick out incorrect data values in large volumes of data. Think of a system that could take the largest Excel spreadsheets and automatically flag those rows of data which were most likely to be in error – all without knowing what the spreadsheet data represented or who had put it together or why.

Of course cancer is the ultimate in evolutionary systems – if you wanted to design a system to illustrate the evolution at work you’d come up with something pretty much like it. When we look at cancer and see that some treatments have fantastic initial responses, with tumours shrinking away to almost nothing, followed by a rebound in which the cancer comes back more aggressive and resistant to the treatment then we’re seeing evolution at work.

Given my background in computer modelling and my current work in oncology it should be no surprise that I’ve worked on a software model of tumour growth. I’ve called it NEATG – for Non-physiological Evolutionary Algorithm for Tumour Growth. It’s a computational model – it’s about algorithms rather than about trying to recreate in software the vast complexities and details of cells, proteins, signals and pathways. Although it’s a simple model by design, it does illustrate some interesting behaviour that brings to mind the behaviour of real tumour growth.

Tumour growth in NEATG

For example, the NEATG system can model the growth of a tumour mass (in two dimensions), it can model the rise of genetically different sub-populations of cancer cells, and it can model different interventions such as chemotherapy or nutrient deprivation. What is more it displays emergent behaviour – such as a more aggressive growth pattern following the cessation of treatment. This is behaviour that emerges naturally from the interactions between cells and tissues, not behaviour that has been explicitly programmed into the system as a set of predefined rules.

For now NEATG is a tool that can be used to explore different algorithmic scenarios – you can play try out different thought experiments to see what happens. It’s good for thinking about some of the most fundamental aspects of cancer without getting bogged down in the molecular biology. For example, while most people think of cancer as primarily a disease of disordered genes – a view known as the ‘somatic mutation theory’ of cancer – there is an alternative theory called the ‘tissue organisation field theory’ of cancer. In this theory disordered genes are more of a by-product than a cause of cancer, and it places more emphasis at the disordered tissue environment. Simplistically we can ask: is it the delinquent cell or the bad neighbourhood that causes cancer? This is a good question to explore using a suitable software model – and I hope that NEATG can be applied to this.

While it’s still early days for this piece of work, I have written a paper on it which is available as a preprint (i.e. prior to peer review) at PeerJ. If you’re interested please take a look.

Tuesday, 6 October 2015

Crowdfunding Against Cancer

One of the many problems associated with repurposing off-patent drugs for new uses in cancer is that there is no commercial sponsor involved in the process of getting the drug into clinical use. On the face of it this might seem like a good thing – surely it means that there will be nobody jacking the price up to make huge profits from previously cheap drugs. But in practice this means that the very expensive process of gaining evidence of efficacy in clinical trials though to applying for a new licence is hamstrung due to lack of funding. Clinical trials, especially the larger pivotal trials which convince clinicians that a treatment is effective, are expensive to design and run. For a new drug anywhere up to 75% of the billion dollar cost of getting it to market is spent on the trials process.

This is a significant problem but not an insurmountable one. The Anticancer Fund, for example, is funding a number of clinical trials using a range of repurposed drugs – for example a trial of the pain-killer ketorolac in breast cancer, or a mix of drugs in recurrent osteosarcoma. Another notable example is the Add-Aspirin trial, which is part funded by Cancer Research UK. Clearly there is a role for the not-for-profit sector to step in – but is there also a role for a more direct role for the public?

The Neo-Art trial is looking at using the generic drug artesunate – a commonly used ant-malarial drug – as a treatment in colorectal cancer. Like the ketorolac in breast cancer trial, this one is looking to reduce the rate of post-surgical relapse. Remember, it’s most often metastatic disease which kills cancer patients. Any intervention which can stop metastatic disease in its tracks can have huge impact on overall survival. This is an idea which we urgently need to explore in a range of cancers, including osteosarcoma, as I have suggested in the past.

In the case of the Neo-Art trial, the team at St George’s Hospital have already got preliminary data in patients suggesting that two weeks of artesunate prior to surgery can have a major impact on the relapse rate. The new trial is aiming to prove that this is the case in a larger population of patients – 140 in all. Much of the funding for the trial is coming from a small charity called Bowel Diseases UK, but there’s an additional £50,000 required – and this is where the public can have a direct role.

In a pioneering move, the St George’s team are working with a crowdfunding platform called FutSci to appeal directly to patients, families and members of the public to raise the funds required to make the trial happen. So far the results have been impressive and the appeal is nearly 70% of the way there – but that still leaves around £15,000 to be raised. So, if you have ever been touched by bowel cancer, or want to be part of something that could be truly groundbreaking -  then please go ahead and make a donation.

Thursday, 28 May 2015

LFS - Primed for cancer - Interview

The excellent Living LFS blog has a new piece which covers my latest  paper on Li Fraumeni Syndrome...

http://livinglfs.blogspot.co.uk/2015/05/primed-for-cancer-with-pan-pantziarka.html

This explains the core details of the paper in very non-technical language and explains what it may mean in practice. So, if the technical nature of the original paper gets in the way, then this is certainly a good alternative.

Friday, 22 May 2015

Press release - Primed for cancer?

Li Fraumeni Syndrome (LFS), a rare genetic condition that predisposes sufferers to cancer development, is associated with mutations in the TP53 tumour suppressor gene. Although rare, LFS sufferers have a highly elevated risk of developing one or more cancers, with some estimates putting the life-time risk at 70% for males and 100% for females. However, new research published today in leading online oncology journal ecancermedicalscience, suggests that cancer development may be due to more than a mutated tumour suppressor function.

In a new paper by Pan Pantziarka PhD, a scientist working for the Anticancer Fund and co-ordinator of the Repurposing Drugs in Oncology(ReDO) project, it is suggested that there are other important functions of the TP53 gene that contribute to this elevated cancer risk. 'Our knowledge of the multi-faceted functions of TP53 has grown enormously in the last few years,' Pantziarka says, 'yet much of this new information has yet to be integrated into our understanding of the disease process in people with LFS'.

Sue Armstrong, author of 'p53: The Gene that Cracked the Cancer Code', points out that: 'TP53 is the most commonly mutated gene in human cancer. Indeed it’s probably fair to say that if this key tumour suppressor is functioning properly, it’s almost impossible for cancer to develop. It follows that to be born with mutant - and therefore malfunctioning - TP53 in every cell in the body is to be extremely vulnerable to cancer. This is the tragic fate of people with Li Fraumeni Syndrome, for whom conventional therapies rarely offer more than temporary respite. So, new ways of looking at, and treating, cancer are sorely needed.'

Known as the 'guardian of the genome', the p53 protein is at the heart of an array of signalling networks involved in responding to DNA damage, metabolic stress, immunity, senescence and ageing. In people with normal p53 function, the kinds of damage that cause cells to become cancerous trigger a damage response that normally leads to the cell self-destructing before it can proliferate, a process called apoptosis. But in people born with a mutated TP53 gene this process does not take place. However, there is more to cancer than delinquent cells, increasingly we understand that cancer also involves a supporting micro-environment to provide a blood supply, nutrients, protection from an immune response and so on. These factors may also involve p53, and Pantziarka's hypothesis suggests that people with LFS are born 'primed for cancer' because many of these cancer-support systems are already in place thanks to the mutation.

Pantziarka has first-hand knowledge of this disease process himself, having lost his first wife and his teenage son, George, to cancers due to LFS. George, for example, developed his first cancer at the age of two and subsequently developed two further primary cancers before succumbing to metastatic sarcoma in 2011. The story is told in a recent book, 'For The Love of George' by Irene Kappes, available from Amazon and other booksellers. The family have also established the George Pantziarka TP53 Trust (www.tp53.org.uk) to provide support for other families and to promote research into the condition.

This new hypothesis does more than provide a more nuanced view of cancer development in people with LFS, it also suggests that many of these additional factors may be amenable to drug treatment. 'By expanding our view of carcinogenesis in LFS we may also be broadening the range of interventions available to us to change things. The key thing,' Pantziarka underlines, 'is to start looking at active measures we can take to reduce this risk. Drugs such as metformin may hold the promise of reducing that life-time risk by some significant margin.'

In perhaps the most radical section of the paper, it is suggested that some other cancer predisposition syndromes, caused by mutations in other genes, may share some of the same features of LFS despite the different genetic drivers. If this is the case, as the paper suggests, then perhaps some of the active measures which warrant investigation in LFS may also apply to a range of different genetic cancer predisposition syndromes. In such a case the prospect of a clinical trial that targets multiple high-risk patient populations is an alluring prospect. 'With limited population sizes it is difficult to design cancer-prevention trials because the sample sizes are too low,' Pantziarka explains, 'but if my theory is correct then we can pool different populations into the same trial and look for reduced cancer incidence across the board.'

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Links/Contacts:
The George Pantziarka TP53 Trust – www.tp53.org.uk
Original paper (publication date 21/05/15): ‘Primed for cancer: Li Fraumeni Syndrome and the pre-cancerous niche’ -http://ecancer.org/journal/9/541-primed-for-cancer-li-fraumeni-syndrome-and-the-pre-cancerous-niche.php

Wednesday, 18 March 2015

Exercise and Breast Cancer

I was alerted today to an interesting new paper in the Journal of the National Cancer Institute that looked at the effect of exercise on tumour blood supply and the response to chemotherapy in breast cancer. Now this is a topic which is worth paying attention to – there is lots of evidence that daily exercise can reduce breast cancer recurrence, have positive effects on physical status and may even improve overall survival in women with breast cancer. With that in mind, what does this new paper tell us?

Firstly, it’s important to note that this isn’t a study in people – this is a study in mice. But these are mice with intact immune systems and they are bearing mouse tumours. It means that although this is an animal model we can trust the evidence a bit more than we can when dealing with immune deficient mice implanted with human tumours. Secondly we should note that these mice were not forced to do exercise – so there was no additional stress involved and there were no enforced amounts of exercise that had to be performed. Basically the mice were given an environment which gave them an exercise wheel they could use, whereas the comparison group didn’t have the opportunity to exercise. Finally, some of the mice had ER+ and some ER- tumours, matching human tumours in hormone responsive and non-responsive sub-types.

What the study showed was that the mice doing the exercise had a reduced the tumour growth rate, an increased the rate of cancer cell death (apoptosis), increased the maturity of the tumour blood vessels, increased tumour blood flow and reduced the areas that were starved of oxygen (hypoxia). These are all things which are positive and which we definitely would want to achieve clinically. Basically these results show that exercise normalises the tumour blood supply. This is a good thing.

Normally the tumour blood supply is chaotic – vessels are immature, leaky, misconnected. This chaotic blood supply has a number of downsides. Firstly it means that the drugs we give cancer patients to kill the tumour often don’t make it into the interior of the tumour – not good because if they don’t in they won’t work. Secondly the chaos causes areas of the tumour to become starved of oxygen and nutrients – this in turn causes the cancer cells to become more aggressive and dangerous as they adapt to these harsh conditions.

So, normalising the blood supply means that tumours are not forced to become more aggressive and, as we see in these results, this can lead to a slower growth rate. It also means that when drugs are administered they can make it into a greater portion of the tumour. And this is where the second lot of results come in. Mice treated with the chemotherapy drug cyclophosphamide had greater response if they were exercising compared to the sedentary mice. Interestingly, mice who did exercise alone (no chemo) showed a similar response to mice treated with chemo alone. But the best response came from mice who had chemo and did exercise.

These are positive results but we do have to keep in mind that this is in mice. However, it backs up what we know from evidence in humans and suggests reasons for why we’ve seen these results. The take home from this is that exercise has a positive effect in breast cancer – and most likely in other cancers too. It doesn’t have to be running a marathon every week either – a study in women with breast cancer back in 2005 found that walking at an average pace for 3 – 5 hours per week had positive effects on survival.

Tuesday, 24 February 2015

Clarithromycin - a repurposed anticancer drug?

An antibiotic may join the ranks of drugs suitable for repurposing as anti-cancer treatments, according to new research from the Repurposing Drugs in Oncology (ReDO) project published in ecancermedicalscience.

Clarithromycin is a very common and effective antibiotic. It is traditionally used for many types of bacterial infections, treatment of Lyme disease and eradication of gastric infection with Helicobacter pylori. It is noted in the World Health Organisation’s list of essential medicines, ensuring it will remain available worldwide at low cost. Dr. Vikas P. Sukhatme of the ReDO project and GlobalCures says "The multiple mechanisms of action of this drug make it particularly attractive for repurposing."

“Clarithromycin is a canonical example of a drug that may have limited antitumor activity on its own, but is extremely valuable against cancer in combination with other drugs,“ says An Van Nuffel, PhD, lead author of the paper and member of the ReDo project and the Anticancer Fund.

An international collaboration between anticancer researchers from across the world, the ReDO project is dedicated to promoting the cause of common medicines which may represent an untapped source of novel therapies for cancer.

In partnership with ecancer, the ReDO project is publishing a series of papers on drugs with enough evidence to be taken to clinical trials. Future papers will address the potential anti-cancer uses of nitroglycerin, itraconazole and diclofenac.

Dr Gauthier Bouche of the ReDO project and the Anticancer Fund describes a serendipitous use of clarithromycin for the treatment of chronic myeloid leukaemia (CML).

In 2012, Italian doctors led by Dr Carella prescribed clarithromycin for an infection in a patient with CML. The patient had developed resistance to his treatment, which reversed after treatment with clarithromycin, reinstalled when the drug was discontinued and then reversed again after re-challenge.

Low- and middle-income countries (LMIC) may pave the way for drug repurposing. The latest randomised trial done with clarithromycin was done in Egypt, demonstrating that patients with a certain form of lymphoma lived longer when clarithromycin was added to chemotherapy.

The faster development of new - but expensive - drugs in High Income Countries may create a role for LMIC to further develop drug repurposing in oncology. Could LMIC with no access to the recent drugs perform trials with clarithromycin?

“If clarithromycin were a new drug with the anticancer potential that it has, we would see companies pushing hard for clinical trials and aiming to get to market quickly,” says Pan Pantziarka, PhD, member of the ReDO project and the Anticancer Fund. “Why isn't that happening now in multiple myeloma or resistant leukaemias?”

Monday, 22 December 2014

When less is more

The conventional approach to chemotherapy treatment for cancer is to give the patient a cocktail of different chemo drugs at the maximum tolerated dose (MTD). The idea of MTD treatment is to hit the cancer with the most toxic treatment the patient can stand in the hope that it causes the maximum damage to the disease. Normally a treatment consists of a number of cycles of chemo using a mix of drugs, with the idea that each drug will attack the tumour in a different way – reducing the chance of the tumour surviving the onslaught. And it’s an onslaught for the person receiving the treatment too – most chemotherapy drugs are toxic to a wide range of cells, not just cancer cells. Hence the hair loss, the nausea, the immune suppression, fatigue and the rest of the side effects that makes chemo so hard.

Of necessity a person needs recovery time after each cycle of chemotherapy. Blood counts need to recover, sickness needs to pass, people need to regain some strength. Unfortunately that’s recovery time that tumours can also use to recover. The highest rates of tumour kill tend to be at the least cycles, the later cycles tend to be less effective, particularly if resistance starts to kick in.

However, this isn't the only way of delivering treatment. An alternative approach to chemotherapy has been developing for some time. Low dose metronomic chemotherapy involves many of the same drugs as MTD chemo, but delivered at low doses, often in tablet form, but with no treatment breaks. The continuous dosing is possible because at these low doses the drugs work in very different ways to when they are delivered at MTD levels. The side effects are minimal as the drugs are no longer acting as potent toxins to massively kill cells.

Friday, 12 December 2014

Not All Journals Are Created Equal

An increasing hazard in science publishing is the increasing number of 'predatory journals'. The term refers to low-quality scientific journals which exist solely to make easy money under the 'author pays' model of publishing. These journals pretend to do peer review and they look and feel like proper academic journals, but in reality they will publish anything to harvest those publication fees. It's a scam, and a successful one given the growth of the number of these journals. The way the scam works is for these journals to solicit papers, to claim they do peer review, then to accept the papers. The authors are billed the article processing and publication fees, and then the paper is published online.

There are multiple dangers in this process. The first and most obvious is that the authors are ripped off - they have effectively just paid for someone to turn there text into a web page. There has been no peer review, no proper scrutiny of the content and the chances are that the paper will be ignored by other academics. If you have a limited budget for publication fees you've just wasted it. If you are starting out in your research career publishing in these journals may seem an easy route to getting some papers to your name, but more knowledgeable colleagues will know what you've done and so the risk is that you damage your career, not enhance it. It is also possible that unscrupulous academics will deliberately use predatory journals to beef up a CV to impress people who don't know about predatory journals - all of which sound eminently respectable to the unsuspecting.

However, the biggest danger is not with academics, but with the general public. Most people are impressed by a paper that is published in a scientific journal. Scammers and snake-oil salesmen can use this to peddle fake medical treatments to desperate patients. Shoddy papers that sound scientifically plausible can be published in predatory journals and then used to convince people that there's some real science behind the scam. If you're not a scientist or someone versed in the medical literature a paper that claims to treat late stage cancer patients and to have miraculous results can be very convincing. The best examples of this are the scammers selling GcMAF as a miracle cure for cancer, autism, AIDS and just about everything else.

How can you, as a reader, verify that the journal paper you are reading is not a piece of junk published in exchange for a few hundred dollars?

Thursday, 27 November 2014

Alveolar Soft Part Sarcoma - The Reverse Warburg Effect In Action?

Alveolar soft part sarcoma (ASPS) is a rare cancer - rare even among soft tissue sarcomas - that is slow growing but hard to treat. When the disease metastasises the prognosis is generally grim and there are few options for treatment if surgical resection is not possible. A new paper, published in the journal Cancer Cell, describes work in a mouse model of the disease which may ultimately have important therapeutic consequences.

A team at the University of Utah have created a mouse model of ASPS, by fusing two strands of DNA to create a fusion gene which forms tumours in the mice in which it is implanted. What's more the resulting disease behaves very much like ASPS in humans, including producing very similar genetic profiles. Intriguingly the mouse tumours formed preferentially in areas of the body which had high concentrations of lactate. In humans this tends to be in the skeletal muscles as lactate is a by-product when our muscles are straining for energy in low oxygen conditions. In the mice the areas with the highest lactate concentrations were in the skull.

Generally tumours are believed to generate excess lactate as a by-product of their metabolism - this is known as the Warburg effect. And yet here the tumours seem to be feeding off the lactate produced by non-cancer cells. As one of the researchers, Kevin Jones explains: "It's unusual to find a cancer using lactate this way. The ASPS cells grow preferentially where they are bathed in high concentrations of lactate."

The most likely explanation is that this is yet another example of the reverse Warburg effect, first described by Michael Lisanti and his team. This is a topic of huge importance as it revises what has been seen as a core component of our understanding of cancer. In this model of cancer, the tumour cells act on non-cancer cells to change their metabolism so that they emit lactate and glutamine, which the tumour cells use as a more powerful fuel source.

This does open up opportunities for intervention, however. If we can interrupt that 'metabolic shuttle' between lactate consuming tumour cells and stromal cells they are 'farming' then we can starve the cancer cells and so slow - or possibly even halt - tumour growth.

Cimetidine as an anticancer drug - New ReDO paper

The latest paper from the ReDO project has just been published. Our focus for this paper is the well-known antacid cimetidine (trade name Tagamet, but now available as a generic). The paper summarises the extensive pre-clinical and clinical evidence that shows cimetidine has huge potential in cancer treatment. It has multiple mechanisms of action and there is clinical trial evidence that it is associated with a survival in colorectal cancers.

The paper is published as open access at the journal ecancer.

The press release provides a few more details:

How a common antacid could lead to cheaper anti-cancer drugs

The cancer solution in your medicine cabinet

A popular indigestion medication can increase survival in colorectal cancer, according to research published in ecancermedicalscience. But in fact, scientists have studied this for years - and a group of cancer advocates want to know why this research isn't more widely used.

"Cimetidine is an interesting drug as it's very safe, very well-known, and has clinical results in cancer that have been confirmed in a number of trials," says Pan Pantziarka, lead author of the paper and member of the Repurposing Drugs in Oncology (ReDO) project.

Monday, 17 November 2014

Bisphosphonates in non-bone tumours

Bisphosphonates are a class of bone-targeted drug that act to slow the turn-over of bone (bone resorption). These drugs, including zoledronate, ibandronate and others, are standard treatments for osteoporosis and other bone diseases. And, as I have mentioned previously on this blog they have increasingly found use in cancer treatment to help control bone-related problems - both from metastatic disease to the bone and in primary bone tumours. There is also increasing evidence that as well as controlling bone pain and reducing fractures, these drugs have some very positive effects on overall survival. For example there is now evidence that zoledronate (also called Zometa or zoledronic acid) gives a survival advantage even in early stage breast cancer. Now this is something of a surprise because the effects are there even when there are no bone metastases, so the drug must be acting on non-bone tumour tissue - how is this possible?

New light has been shed on the matter by some recent work that convincingly shows that zoledronic acid is taken up by cancer associated cells outside of bony metastases. Some clever lab work has shown that zoledronic acid attaches itself to tiny crystals of calcium (microcalcifications) outside of the bone. These microcalcifications are then eaten up by tumour associated macrophages, immune cells that actively encourage and support tumour growth. Once these macrophages have swallowed the microcalcifications with the zolderonic acid attached the drug can get to work and interfere with their function. In other words, the drug doesn't affect tumour cells directly, it affects the cells that provide some of the life-support that tumours require. The lab work on mice was also confirmed on a tumour sample from a breast cancer patient.

Thursday, 6 November 2014

The Burzynski Con

There is a lot wrong with current oncology practice and the research that underpins it. The pace of change is slow. Promised breakthroughs fail to deliver what they initially promised. The clinical trials process is slow and getting slower. Patient needs remain unmet and patients are dying while regulations multiply and conspire against change. But with that in mind, that doesn't mean that science is wrong, that clinical trials are wrong or that there are 'cures' out there which the drug companies are suppressing. As I have written before, there is no such thing as a miracle cure.

Unfortunately there are some people who take what are valid criticisms of the clinical trials process or the lack of progress in oncology and then imagine that there are conspiracies at work to deliberately stop progress happening. And of course there are some people out there who will use that to their advantage. Probably the most notorious example of this is a man called Stanislaw Burzynski.

Burzynki came up with the idea that there were chemicals in the body, which he called antineoplastons, which could be effective against cancer. His idea was that people with cancer were deficient in these antineoplastons, and that by taking them externally they could mount an effective defence against cancer. It's a simple idea, but rather than go through the normal process of testing, Burzynski set up a clinic and began treating patients very early on. He has been doing this for decades, and still there is no proof that his treatment works. In the years that he has been operating his Burzynski Clinic in Texas, he has treated many thousands of patients, at great financial cost to them. It's not a cheap treatment. And, despite what he says, it's not non-toxic either, patients have died from the side effects of his treatment. And still there is no evidence that this stuff works.

Thursday, 2 October 2014

Fecal Transplants And Cancer

Fecal transplantation is probably one of the most disgusting medical procedures in existence. It literally means taking a sample of fecal material (poop, in other words) from one person and transplanting it into another. Like I said, it's a pretty disgusting idea, but one that is receiving increasing attention. The more we learn about the role of our gut bacteria the more we understand that having a healthy gut ecosystem is essential to health. Gut bacteria play a big part in how we digest our food, with possibly a role in causing obesity, and in the development of our immune systems. It's the latter that has been explored the most in inflammatory bowel diseases - which is where fecal transplants have been used to treat conditions like Crohn's Disease and similar conditions.

When it comes to cancer there is also a possible role for our gut bacteria. I have previously written about the study that showed mice with a genetic predispostion to cancer and fed with a probiotic had fewer tumours and later onset of disease than similar mice not fed probiotic. Note that these mice were developing breast cancers, not colon, so the effect of feeding probiotics was systemic, not just restricted to the colon. This is really a stunning result and worth taking note of. But I think there is room to take this further...

There is now strong evidence that our gut bacteria are essential for a good response to chemotherapy - again this has been something of a surprising result, but the evidence is that without the right gut bacteria chemotherapy response is severely blunted. And we also know that having the wrong bacteria - gut dysbiosis in the terminology - is also associated with the development of colon cancer.

Where am I going with this? Well, if we know that fecal transplants can be effective in inflammatory bowel conditions, and we know that gut dysbiosis is a factor in colorectal and other cancers, then shouldn't we now be considering looking at fecal transplants as a possible cancer treatment?

Thursday, 25 September 2014

Nitroglycerin and cancer drug therapy

Following on from the paper on the anti-parasitic drug mebendazole (which I first discussed on this site a while ago) and the antacid cimetidine (paper not yet published), I've been working on another ReDO paper on the drug nitroglycerin. Like all the repurposed drugs we're looking at in the ReDO project this one is commonly used clinically for non-cancer uses, in this case it's a drug used to treat heart problems and blood pressure. Available as tablet you stick under the tongue, or a spray or even a transdermal patch, nitroglycerin is a drug that has been used for over a 100 years as a vasodilator - in other words it relaxes the blood vessels. It's partly this property that makes it interesting in terms of anti-cancer treatment.

Like other tissues, tumours need a blood supply for food and oxygen, and it is well-known that they release chemical signals that cause new blood vessels to form. This is the process called angiogenesis, and for many years scientists have been looking at ways to disrupt the process - with drugs like avastin (bevacizumab) developed to stop this happening. The idea is that with no blood supply tumours can't grow. However, even when angiogenesis does take place and tumours sprout the blood vessels they need, the vessels that are formed aren't normal. The blood supply is chaotic and the vessels are much leakier than normal. Back in the late 1980s some scientists started looking at how we could use this to our advantage. The idea is that you take advantage of the leakiness by using drugs that leak out into the tumours rather than spreading throughout the body (as normal chemo does). Hiroshi Maeda and his co-workers termed this the 'enhanced permeability and retention' (EPR) effect.

Nitroglycerin enters the picture as a way of making the leakiness worse by relaxing the blood vessels, thus encouraging large drug molecules to leak into the tumours. And once they've leaked out, the chaotic structure of the vessels means the drugs are retained in the tumour where they can have an effect. It is, in theory at least, a way of targeting anti-cancer drugs to the tumours and not to the rest of the body. It's an elegant idea and has lots of experimental evidence going for it. And the evidence includes some small trials in humans - primarily in lung and prostate cancers. There are more clinical trials on-going, and we can but hope that their results encourage more work in this area. To really work well we need to team up the nitroglycerin with some reworked chemotherapy drugs that are specifically designed to work with the EPR effect.

Thursday, 11 September 2014

Report from Metronomic Chemotherapy Conference



Chemotherapy remains at the core of much current cancer treatment. Along with radiotherapy and surgery, it’s one of the big three that nearly every cancer patient has to face in the treatment of disease. Many of the ‘classical’ chemotherapy drugs have been in clinical use for decades now, and you would think we would know all there is to know about how best to use them. Unfortunately it appears not... 

The most common approach to chemotherapy is the multi-drug maximum tolerate dose (MTD) protocol. Here you take a set of drugs that work in slightly different ways and then blast them into the patient in a fixed pattern and at the highest possible dose. These cocktails are incredibly toxic – they knock out cancer cells but at considerable collateral damage. Patients lose hair, suffer sickness, loss of immune system, suffer damage to the heart and other organs. It’s a horror and nobody looks forward to chemo. On the plus side there is often a considerable amount of tumour kill, at least at the beginning. But very often tumours develop resistance, the drugs stop being effective and the side effects continue.

However, there is an alternative approach to using these drugs called metronomic chemotherapy. This involves giving considerably lower doses of these drugs but much more frequently. Here, instead of blasting the patient with chemo and then leaving them for a couple of weeks while they recover from the blast – time in which the tumour can also recover – you give a steady drip-drip of the drugs instead. The side effects are considerably lower and quality of life is much higher – especially as the drugs are usually given in tablet form on an out-patient basis.

Friday, 5 September 2014

A new surgical technique for bone cancers



When it comes to bone cancers – such as osteosarcoma or Ewings sarcoma – surgical removal of the tumour-bearing bone is part of the standard treatment. Chemotherapy is part of the treatment, and sometimes radiotherapy, but resection of the bone is at the core of any curative program.  In days gone by this used to mean amputation of a limb, but these days a lot of work goes into limb-sparing surgery. And of course for those cases where the tumour is not in a limb, amputation isn’t an option any way.


In practice this means that very often surgery involves not just the removal of the effected bone, but also taking bone from another part of the body and slotting it into place a replacement. In my son’s case, George had three separate operations to treat the osteosarcoma in his jaw. The second and third time the ‘new’ mandible had to be replaced with a ‘newer’ one – in the end bone taken from his leg, his hip and a rib all to craft new jaw bones. While his was an extreme case, it shows what surgeons are capable off – but also gives an idea of how much trauma is involved to the patient. Some of the operations took more than 12 hours to complete. 


But what if there is a way to reduce the scale of the operation? What if the surgeons didn’t need to harvest new bone to replace the diseased one?


Surprisingly, such an approach does exist. It involves removing the diseased bone – making sure there are good margins as normal – and then the bone is treated to definitively kill the tumour cells. This is achieved by placing the resected bone in liquid nitrogen or bombarding it with very high doses of radiotherapy. Then the treated bone, now stripped of disease, is replaced in its original position. No need therefore to operate on other parts of the body to harvest bits of bone. No need for extensive remodelling.


Does this radical new treatment work? Recent papers show that the results are very good – there are lower rates of complications, low rates of disease recurrence, and of course lower risks of infection and faster recovery times.  For example in one study, published in the Bone and Joint Journal (http://www.bjj.boneandjoint.org.uk/content/96-B/4/555.abstract), no recurrences are reported at all in the grafted bones. 


That’s the good news. For patients in the UK the bad news is that this procedure, which was first used in Japan about 10 years ago, is not available. I remember asking for this for George, but got a blank look in return. So far as I know this is still not available in the UK – though I’d love to find out that someone, somewhere in the NHS has started doing this. It would make a huge difference to those people who’ve got primary bone cancers or bony metastases.