Effects of infections on the pathogenesis of cancer

Abstract

Several studies have shown an inverse relationship between acute infections and cancer development. On the other hand, there is a growing evidence that chronic infections may contribute significantly to the carcinogenesis. Factors responsible for increased susceptibility to infections may include modifications of normal defence mechanisms or impairment of host immunity due to altered immune function, genetic polymorphisms, ageing and malnourishment. Studies have demonstrated that children exposed to febrile infectious diseases show a subsequent reduced risk for ovarian cancer, melanoma and many other cancers, while common acute infections in adults are associated with reduced risks for melanoma, glioma, meningioma and multiple cancers. Chronic inflammation associated with certain infectious diseases has been suggested as a cause for the development of tumours. Mechanisms of carcinogenesis due to infections include cell proliferation and DNA replication by mitogen-activated protein kinase pathway, production of toxins that affect the cell cycle and lead to abnormal cell growth and inhibition of apoptosis. This review was aimed to summarize the available evidence on acute infections as a means of cancer prevention and on the role of chronic infections in the development and progression of cancer.

Incidence of Colorectal Cancer After Intestinal Infection Due to Clostridioides difficile

“…For one, although infections pose a significant and immediate stress on the body, the long-term effect of this stress may not be easily ascertained. In fact, numerous studies have demonstrated an inverse relationship between acute infection and cancer development [ 20 ]. This may be because acute infections are typically characterized by rapid onset and production of cytokines and acute phase reactants, signaling a robust immune response; conversely, a chronic infection may indicate a failure or retardation of the immune system, therefore increasing susceptibility for development of malignancy.…”

Significance of extracellular vesicles in orchestration of immune responses in Mycobacterium tuberculosis infection

“…However, a remarkable feature of an inflammatory microenvironment is that it has the core required elements to induce the changes for cancer development ( Alipoor et al., 2018 ; Komi and Redegeld, 2020 ; Liardo et al., 2021 ; Tian et al., 2022 ). In a chronic inflammatory site, the presence of several inflammatory cells and signaling molecules such as NF-KB, can increase the malignant progression of transformed cells due to their mutagenic predisposition.…”

“…During a chronic TB infection, EVs may play the main role in changing the game in favor of a tumor microenvironment. During chronic inflammation, the content of EVs undergoes various changes, which may close them to the tumorigenic EVs ( Liardo et al., 2021 ; Tian et al., 2022 ). These EVs shuttle a variety of different inflammatory molecules including noncoding RNAs or critical cancerous proteins in the inflammatory site that may change condition by different mechanisms including triggering tumorigenic pathways, epigenetic-related changes, macrophage polarization, TAM production, epithelial-mesenchymal transition (EMT), angiogenesis, etc ( Alipoor et al., 2018 ).…”

Hypoxia-induced cancer cell reprogramming: a review on how cancer stem cells arise

“…To illuminate this question, tumor cells can arise either from transformed differentiated cells or transformed resident stem cells ( 28 , 29 ). Transformation is likely to arise from environmental inputs such as tissue regeneration ( 30 ), infections ( 31 ), toxins ( 32 ), as well as intrinsic and non-intrinsic factors that lead to DNA mutations ( 33 ). As the transformation process progresses in differentiated cells, oncogenes are overexpressed while tumor suppresser genes are deactivated leading to the de-differentiation of cells, uncontrolled proliferation, and the acquisition of stem-like characteristics ( 26 ).…”