Bacteria-Mediated Oncogenesis and the Underlying Molecular Intricacies: What We Know So Far

Abstract

Cancers are known to have multifactorial etiology. Certain bacteria and viruses are proven carcinogens. Lately, there has been in-depth research investigating carcinogenic capabilities of some bacteria. Reports indicate that chronic inflammation and harmful bacterial metabolites to be strong promoters of neoplasticity. Helicobacter pylori-induced gastric adenocarcinoma is the best illustration of the chronic inflammation paradigm of oncogenesis. Chronic inflammation, which produces excessive reactive oxygen species (ROS) is hypothesized to cause cancerous cell proliferation. Other possible bacteria-dependent mechanisms and virulence factors have also been suspected of playing a vital role in the bacteria-induced-cancer(s). Numerous attempts have been made to explore and establish the possible relationship between the two. With the growing concerns on anti-microbial resistance and over-dependence of mankind on antibiotics to treat bacterial infections, it must be deemed critical to understand and identify carcinogenic bacteria, to establish their role in causing cancer.

Reactive oxygen species and gastric carcinogenesis: The complex interaction between Helicobacter pylori and host

“…Unfortunately, the infection carries a significant risk of developing disease, ranging from peptic ulcer to gastric adenocarcinoma 2 . Therefore, the bacterium has been characterized as a class I carcinogen by the World Health Organization, marking it as the first globally recognized bacterial carcinogen associated with gastritis and peptic ulcers 3 …”

“…However, H. pylori has evolved multiple defensive strategies to combat host defense and weaken the host's ability to eliminate bacteria, resulting in incomplete elimination and ongoing infection of bacterium. H. pylo ri is known to persist in the host for extended periods, exacerbating inflammation and increasing the likelihood of errors during DNA replication, leading to a vicious cycle of damage and ultimately cancer 3 …”

Editorial: Congruities between cancer and infectious diseases: Lessons to be learned from these distinct yet analogous fields

“…Recent studies show that microRNAs (miRNAs) and associated RNA-induced silencing complex (RISC) also play a major role in oncogenesis ( Yoo et al., 2011 ; Santhekadur and Kumar, 2019 ; Santhekadur et al., 2012 ). Infectious diseases are serious health disorders, and they are mainly caused by various unicellular or multicellular organisms such as bacteria, viruses, and fungi ( Prasad et al., 2022 ; José et al., 2020 ). Infectious human viruses like human papillomavirus (HPV) cause cervical cancer; Epstein–Barr virus (EBV) is known to cause nasopharyngeal cancer and Burkitt lymphoma.…”

“…Liver-associated human viruses like hepatitis B virus (HBV) and hepatitis C virus (HCV) cause hepatitis and induce hepatocellular carcinoma ( Liao, 2006 ). Bacteria, namely, Helicobacter pylori , are also known to cause gastric cancer ( Prasad et al., 2022 ). Some of the fungal secondary metabolites and toxic chemicals are known to trigger mutations and initiate cancer growth and development ( Ekwomadu et al., 2022 ).…”

“…Inflammation is a major contributor and a well-known hallmark of almost all of the infectious diseases and carcinogenesis. Inflammatory cytokines like tumor necrosis factor alpha (TNF-α) and transcription factor nuclear factor kappa B (NF-κB) act as master regulators of inflammation-associated infectious diseases and cancer ( Santhekadur et al., 2012 ; Prasad et al., 2022 ). Therefore, although distinct, there exists a strong congruity between cancer and infectious diseases.…”