Pathogens and Carcinogenesis: A Review

Abstract

Cancer is a global health problem associated with genetics and unhealthy lifestyles. Increasingly, pathogenic infections have also been identified as contributors to human cancer initiation and progression. Most pathogens (bacteria, viruses, fungi, and parasites) associated with human cancers are categorized as Group I human carcinogens by the International Agency for Research on Cancer, IARC. These pathogens cause carcinogenesis via three known mechanisms: persistent infection that cause inflammation and DNA damage, initiation of oncogene expression, and immunosuppression activity of the host. In this review, we discuss the carcinogenesis mechanism of ten pathogens, their implications, and some future considerations for better management of the disease. The pathogens and cancers described are Helicobacter pylori (gastric cancer), Epstein-Barr virus (gastric cancer and lymphoma), Hepatitis B and C viruses (liver cancer), Aspergillus spp. (liver cancer), Opisthorchis viverrine (bile duct cancer), Clonorchis sinensis (bile duct cancer), Fusobacterium nucleatum (colorectal cancer), Schistosoma haematobium (bladder cancer); Human Papillomavirus (cervical cancer), and Kaposi’s Sarcoma Herpes Virus (Kaposi’s sarcoma).

Risk factors of hepatocellular carcinoma in type 2 diabetes patients: A two-centre study in a developing country

“…Moreover, viral hepatitis and DM development were influenced by genetic and ethnic variances [ 42 , 43 ]. In the viral hepatitis infection, the viral-host genome integration causes chromosomal instability, mutagenesis, and activation of tumour-associated genes, resulting in uncontrolled proliferation of faulty hepatocytes that vary depending on genetic influences [ 44 , 45 ]. Aside from the genetic-environmental influence, risk factors prevention, dietary composition, behavioural and biological factors differ greatly between ethnicities [ 46 ].…”

Urinary bladder Schistosoma haematobium-related squamous cell carcinoma: a report of two fatal cases and literature review

“…The mechanisms of bladder malignant transformation by Schistosoma heamatobium is mainly thought to be indirect rather than direct. The eggs deposition by adult worms in tissues induces intense chronic inflammatory reaction with subsequent release of growth factors and other biochemical substances with carcinogenic effects [ 5 , 9 , 20 ]. Also, this chronic inflammation alter the host local immune system leading to co-infections by bacterial and viral agents that promote malignant transformation of the bladder epithelium.…”

Editorial: Autoimmunity, Infection and Cancer, an Inflammatory Relationship With Intimate Implication to Cancer Prevention and Immunotherapy

“…In animal models, autoimmunity can cause cancer (Nguyen et al, 2013;Miska et al, 2018). A number of infectious agents have long been known for their oncogenic potential (Hatta et al, 2021). This Research Topic, with multi-disciplinary contributions, seeks to examine the molecular and cellular mechanisms underlining autoimmunity, infection and their links to cancer, and the implications of their complex relationship to interventions against autoimmune diseases and cancer.…”