Here is another large body mammal that just cannot seem to get cancer as often as it should. Whales are gigantic animals, with a lot more cells than humans that can potentially become cancerous. This makes it very hard to explain why they are actually 1000 times less likely to develop cancer than we are.

Does size really matter in biology? Being larger has its benefits in the food chain, but it also imposes a biological risk: the bigger you are, the more likely it is for you to develop cancer. The reason is very straightforward: larger bodies contain more cells that can potentially turn into cancerous cells. At least, that is the theory. In practice, there are exceptions. Elephants are very big sized animals, but they rarely get cancer. What is their secret?

The tumor builds around itself a "wall" of immunosuppressive cells or physical and chemical factors that seal off or weaken immune cells. Researchers managed to “hack” and reprogram the tumor microenvironment (TME) using a special “Trojan Horse”. A gene making IFNα was inserted in a cell population within the tumor, imposing an immunostimulatory program to the TME.

In some animal species, cancer is worse than what we are accustomed to, because it is contagious…and no virus has anything to do with it! Cancer cells themselves are “parasitic agents” able to spread from one individual to another. We mentioned the example of Tasmanian devil, whose transmissible facial tumor is decimating wild populations (if you missed it, look at here https://goo.gl/qvm1eN), but there are also cases reported in dogs and hamsters. Furthermore, transmissible tumors also concern animals that do not resemble us at all, like marine bivalves. These organisms are “simpler” than mammals, but not enough to escape cancer: they fall with a leukaemia-like cancer called disseminated, or hemic, neoplasia.

Insulin is probably the most famous hormone, as it regulates glucose metabolism and is associated with diabetes. Insulin promotes glucose uptake by cells and tissues, especially liver and muscle, therefore sustaining their metabolism. Who else needs energy and nutrients? Immune cells spend many resources fighting against pathogens and might need a little energetic “kick-start”. Researchers described for the first time the mechanism through which insulin and its receptor boost the immune system during infection and inflammation.

Every cancer is different, so why should therapy be one? Personalized medicine is the new frontier in immunotherapy and aims at targeting tumour specific mutations, which differ between patients. Researchers from the University of Pennsylvania developed a personalized vaccine against ovarian cancer, which is safe and induces a broad antitumor immunity. Further clinical investigations are required to assess the efficacy of such vaccine: in the meantime, aren’t you curious to find out which strategy they used?

Natural Killer cells (NK) are part of the innate immunity, the first line of defence against several pathogens and cancer. Epigenetics regulates both NK functions and vulnerability of cancer cells to immune clearance. The job of researchers is to “play” with the epigenetic switches, in order to make the scales always tip in favour of tumour eradication. There is in fact an increasing interest in combining NK-based immunotherapies with epigenetic modulators, in order to improve their efficacy.

The undisputed protagonists of most immunotherapic strategies are cytotoxic lymphocytes (CTL) that can recognize and eliminate tumor cells, impairing cancer progression and metastasis dissemination. However, CTL are not the only immune population interacting with the tumor. The cancer “immune landscape” is far more complex and includes a mosaic of different cells that exert both anti- and pro-tumor functions. Each patient has its own immune landscape, which explains the variability in responses to therapy and can become a target for new drugs. What is in there besides lymphocytes?