%T Cancer-Inducing Mechanisms of Representative Sexually-
Transmitted Infection Pathogens
%K Sexually Transmitted Infections, Cancer, Oncogene, Inflammation
%D 2020
%R doi: 10.11648/j.cb.20200801.13
%P 12-21
%L eprints16855
%V 8
%X The causal organisms of the numerous sexually transmitted infections (STIs) may be bacteria, viruses,
fungi or protozoa. Apart from the known STIs these organisms cause, along with their accompanying
physical, psychological and social effects, these organisms have also been implicated in oncogenesis.
Each pathogen has its unique mechanisms of action, however, one representative organism was
examined for each of the groups of microbes that cause STIs, namely: viruses, bacteria, fungi and
protozoa, to show their oncogenic association. The human papillomavirus, which causes genital warts, is
associated with oropharyngeal, cervical, anogenital, testicular and prostate cancer by the actions of the
E5, E6 and E7 oncogenes, which have different functions. Chlamydia trachomatis, the etiological agent
of Chlamydia infection, is linked to lymphogranuloma venereum, trachoma, cervical, and ovarian cancers
by squamous cell metaplasia, and by the inhibition of apoptosis factors: caspase 3 and mitcochondrial
cytochrome c; which consequently inhibits apoptosis. Candida albicans, the causal organism of thrush in
the mouth and the vagina, could cause cancer by producing carcinogenic by-products, triggering
inflammation, molecular mimicry, and induction of the TH17 response. Trichomonas vaginalis, the
protozoon which causes trichomoniasis, is known to cause the influx of pro-inflammatory molecules:
chemoattractant protein-1, interleukin-8, and leukotriene B4, d neutrophils, and IL-6, and this may play a
role in carcinogenesis. Expression of the oncogenes PIM1, HMGA1, and COX-2 by T. vaginalis has also
been associated with the onset of cancer. Vaccination, healthy lifestyles, a mutually-monogamous sexual
relationship, completing treatment regimen, use of sterile medical equipment, and not sharing sharp or
invasive materials, are recommended in prevention and control of the STI pathogens and consequently,
the cancers they cause.
%A Emmanuel Sokefu
%A Olayemi O. Akinnola
%J Cell Biology
%N 1