Gut microbiome extracellular vesicles in solid tumour patients

Cancer is a disease with around 19.3 million annual incident cases and ~10 million yearly deaths across the world according to the Global Cancer Observatory (2020). During cancer immunotherapy targeting programmed death 1, some patients exhibit primary or acquired resistance. It is essential to address drug resistance to improve the efficacy of cancer immunotherapy. (Walton, G. E. 2020). The microbiome, influences multiple physiological functions and pathological processes especially metabolism, inflammation, and immunity - both locally and systemically. There is increasing evidence indicating that the gut microbiome variations could also be affecting immunotherapy, playing an important role in clinical outcomes. This study aims to understand if extracellular vesicles in the gut affect the immune system in cancer patients through. The study plans to do so by analysing the protein cargo of extracellular vesicles extracted from the faecal samples of 28 patients diagnosed with lung carcinomas or solid tumours who are yet to undergo immunotherapy. 19 healthy persons matched with age and gender were treated as controls.

There have been thought-provoking findings from nanoparticle size analysis leading us to believe that the general size of the cancer EVs is larger than those in healthy groups. Also, the mass spectrometry and protein analysis points to larger protein cargos in cancer patients as compared to healthy patients, despite a lower gut microbial diversity. This is an important finding that supports the hypothesis that gut microbiota play a role in cancer pathophysiology. Therefore, there is a need to explore gut microbial dysbiosis in cancer to enhance the understanding of the disease. In the future, the protein data obtained in this MSc thesis will be cross-analysed with clinical therapy response and disease relapse data from patients after a 2-year follow-up.