Modeling the integration of bacterial rRNA fragments into the human cancer genome

Bacterial Extracellular Vesicles in Gastrointestinal Tract Cancer: An Unexplored Territory

Bacterial extracellular vesicles are membrane-enclosed, lipid bi-layer nanostructures that carry different classes of biomolecules, such as nucleic acids, lipids, proteins, and diverse types of small molecular metabolites, as their cargo. Almost all of the bacteria in the gut secrete extracellular vesicles to assist them in competition, survival, material exchange, host immune modulation, infection, and invasion. The role of gut microbiota in the development, progression, and pathogenesis of gastrointestinal tract (GIT) cancer has been well documented. However, the possible involvement of bacterial extracellular vesicles (bEVs) in GIT cancer pathophysiology has not been given due attention. Studies have illustrated the ability of bEVs to cross physiological barriers, selectively accumulate near tumor cells, and possibly alter the tumor microenvironment (TME). A systematic search of original published works related to bacterial extracellular vesicles on gastrointestinal cancer was performed for this review. The current systemic review outlines the possible impact of gut microbiota derived bEVs in GIT cancer in light of present-day understanding. The necessity of using advanced sequencing technologies, such as genetic, proteomic, and metabolomic investigation methodologies, to facilitate an understanding of the interrelationship between cancer-associated bacterial vesicles and gastrointestinal cancer is also emphasized. We further discuss the clinical and pharmaceutical potential of bEVs, along with future efforts needed to understand the mechanism of interaction of bEVs in GIT cancer pathogenesis.

Role of Bacteria in the Incidence of Common GIT Cancers: The Dialectical Role of Integrated Bacterial DNA in Human Carcinogenesis

Despite the wide medical knowledge about the direct role of many viruses in the pathogenesis of certain cancers, there is still ambiguity and hazy vision about the direct role of bacteria in cancer incidence. Understanding the role of bacteria in carcinogenesis is no longer a scientific luxury, but it has become an urgent and extremely important necessity to realize the pathogenesis of cancer caused by oncogenic bacteria as an attempt to overcome the oncogenic mechanisms exhibited by these oncogenic bacteria. This review shed the light on the indirect role of the host's inflammatory and immunological responses in the pathogenesis of bacteria-induced cancer. Also, this review discussed the indirect role of the bacterial toxins and virulence factors in the induction of common gastrointestinal cancers, such as gallbladder cancer (GBC), colorectal cancer (CRC), and gastric cancer (GC). Finally, this review dealt with the debate about the possibility of bacterial DNA integration into the human genome and cancer incidence.

Lateral gene transfer between prokaryotes and eukaryotes

Lateral gene transfer (LGT) is an all-encompassing term for the movement of DNA between diverse organisms. LGT is synonymous with horizontal gene transfer, and the terms are used interchangeably throughout the scientific literature. While LGT has been recognized within the bacteria domain of life for decades, inter-domain LGTs are being increasingly described. LGTs between bacteria and complex multicellular organisms are of interest because they challenge the long-held dogma that such transfers could only occur in closely-related, single-celled organisms. Scientists will continue to challenge our understanding of LGT as we sequence more, diverse organisms, as we sequence more endosymbiont-colonized arthropods, and as we continue to appreciate LGT events, both young and old.