The role of TGF-β and antimicrobial peptides in basal cell carcinoma: a systematic review.

Introduction: Basal cell carcinoma (BCC) is the most common skin cancer in humans, occurring in more than 50% of Caucasians during their lifetime, with a frequency rate that is continually increasing. Material and methods: We present a systematic review summarizing the role of transforming growth factor β (TGF-β), cathelicidin, and human β-defensins (HBDs) in the pathogenesis of BCC. The major online databases including PubMed, Scopus, Embase, Web of Science, Cochrane Library, and Google Scholar were searched to extract studies regarding the levels of TGF-β, HBD, and cathelicidin in BCC. Results: A total of 14 studies met the inclusion criteria and were included in this systematic review. There were 6 studies that included initially established levels of TGF-β in BCCs. A total of 87 BCCs were analysed, and a common result was that the TGF-β levels increase in the BCCs compared to the control groups. Analogously, 2 studies contained numerical data on HBD levels but with a different in methodology. The level of cathelicidin was established in 108 BCCs and was significantly higher in the BCC group than in the control group. Conclusions: The presented review shows evidence that proteins like TGF-β, HBD, and cathelicidin play a role in developing BCC. Protein levels or their expression are elevated in patients with BCC. Furthermore, a critical review of the literature was presented and discussed, highlighting its shortcomings.