Ravid Straussman, MD, PhD

Tumors are very complex, comprising not only cancer cells but also many other components, including immune cells, blood vessels, fibroblasts, and nerves. The Straussman lab is looking at one of those elements – bacteria and fungi – to understand what they’re up to and how they affect tumor biology. The researchers hope to understand how the complexity of tumors affects the way patients respond to anti-cancer therapies.  

Can you tell us about your research? 

Our lab is studying cancer biology. Specifically, we’re trying to understand how the complexity of tumors affects the way patients respond to anti-cancer therapies. Tumors are very complex. They not only have cancer cells but many other things like immune cells, blood vessels, fibroblasts, and nerves. Our lab is looking into another very interesting component, which is bacteria and fungi that we and others have found to be present inside tumors. Our research is trying to characterize these bacteria and fungi in these tumors, but mostly to understand what their functions are. How do they affect tumor biology? How do they affect the way patients respond to therapy? We hope that by studying this, we can come up with novel ways to treat patients because the more we study it, the more we understand that these microbiomes — or bacteria and fungi, as we call them — really affect the way patients respond to therapy, and if we can modulate them, we can make patients respond better to therapy. 

What excites you most about your research? 
The most exciting thing is the fact that even though cancer has been studied for a long time, we didn’t really recognize the fact that there are bacteria and fungi, and viruses inside tumors. This angle of cancer biology has not been thoroughly studied, and only in the last few years has it become more and more clear that intra-tumor bacteria and fungi can affect cancer biology. There are a lot of new things to understand and lots of low-hanging fruit. By studying this for almost the very first time, we can really uncover a truly exciting piece of new biology and find completely novel ways to affect patients’ responses to therapy. 

Where do you hope this will lead in practical terms? 

I think that the more we learn, the more opportunities we will find to modulate the response to therapy. One way to think about it is that we can kill bacteria by adding antibiotics to other treatment options. But there’s another way to think about it, and this is that maybe we do not have to kill the bacteria but rather modulate the activity of these bacteria. One can think of targeted therapies that are not directed to human proteins, as is usually done, but directed to bacterial proteins in order to modulate specific activities of the bacteria, which in turn will modulate cancer and affect the way patients respond to therapy. So, new targets are emerging, and the scientific community will have the opportunity to generate new drugs for these targets and thus find completely novel ways of treating cancer. 

Please tell us a little bit more about how you became interested in this aspect of cancer research. 

The way I became interested in cancer bacteria was complete serendipity. I was looking at the way that stromal cells – a type of normal cells that are present inside tumors — affect cancer cells’ response to therapy. I was co-culturing (meaning putting together) cancer cells and normal cells and testing how the normal cells affect the way cancer cells respond to drugs. I found a case in which cells that came from the skin of a woman, protected pancreatic cancer cells from chemotherapy. I was looking for the mechanism, and after a lot of research, we found out that the skin cells were infected with bacteria and that it was actually the bacteria that protected the cancer cells from chemotherapy. That made us think: how can bacteria change the sensitivity of cancer cells to anti-cancer drugs? And- are there bacteria in pancreatic cancer that can protect cancer cells from drugs? That made us look into pancreatic cancer, and indeed, we discovered that there are bacteria in pancreatic cancer and started exploring this area. So it’s really completely serendipity 

What has receiving an ICRF grant meant to you and your career? 

Receiving any grant is really great, and the ICRF grant was really great news for us because, without going into much detail, we have suggested, a high-risk, high-gain project, and it’s always more difficult to raise money for these high-risk projects. We truly believe in this project, and we think that we can find something really exciting there. Getting the funds from ICRF for this specific project gives us the opportunity to pursue our curiosity and our hypothesis, and hopefully, a few years from now, we can make some significant discoveries based on this. ICRF funding has been fantastic news as it allowed us to explore completely novel directions.

View Grant Recipient Profile