In this translational study, we showed, for the first time, the prognostic value of PD-L1 expression in TGCTs and our data imply that the PD-1/PD-L1 pathway could be a novel therapeutic target in TGCTs.

Current evidence supporting probiotic use as adjunctive therapy to anticancer treatment is limited, especially in cancer patients treated with chemotherapy. Well designed clinical trials are needed to find true role of probiotics in oncology.

Increasing incidence and mortality of colorectal cancer brings the necessity to uncover new possibilities in the prevention, diagnosis and treatment. The microbiome as the collective genetic material of the microflora, overexceed the number of genes in the human genome and is unique for each individual. Due to the benefits providing for the host and mainly for immediate interaction with the host immune system, a gastrointestinal microflora can be considered "cardinal microbiome". Host-microbial relations includes symbiotic, pathogenic and competitive interactions. Causal role of gastrointestinal microflora in colorectal carcinogenesis is still not well determined. This minireview is focused on current evidence in understanding the role of bacteria in colorectal carcinogenesis, the impact of bacterial dysbiosis on tumor formation, and ability of probiotics and bacterial vectors to modulate the gastrointestinal microflora as prevention and therapy tool in colorectal cancer.

SummaryBackgroundFamilial adenomatous polyposis (FAP) is a hereditary disease induced by germ-line mutations in the tumor suppressor APC gene. These initiate the early stages of the adenoma-carcinoma sequence in familial, but also in sporadic (in 80% to 90%), colon tumorigenesis. We found the presence of APC-like sequences in bacteria of FAP patients.Material/MethodsWe analyzed bacteria isolated from FAP patients’ rectal swabs. Total bacterial DNA was isolated and analyzed for detection of APC-like sequences using PCR. We also tested DNA homology rate and APC-like protein production.ResultsWe collected blood samples and rectal swabs from patients with confirmed diagnosis of FAP. They were analyzed for presence of sections from exon 15 of the APC gene. Most positive results were found in sections located exactly in the area called the MCR (mutation cluster region), where the highest frequency of APC gene mutations were identified. By sequencing PCR products from bacteria in section F–G together with a patient’s DNA sample and human APC gene, we found a more than 90% DNA homology rate. We also confirmed production of APC-like protein using Western blotting.ConclusionsOur results suggested two hypotheses. The APC-like protein might have same function as a truncated APC product, which is synthesized in most cases of mutations of APC gene in the MCR region in colorectal cancer cells. Alternatively, we can consider the possible existence of horizontal transfer of genetic information between eukaryotic and prokaryotic cells. Our study can be considered as a pilot project. For confirmation of our hypotheses, further research is needed.