Evaluation of Aquaporin-3 Role in Nonmelanoma Skin Cancer: An Immunohistochemical Study.

Aquaporin-3 (AQP3), is an aquaglyceroporin, that plays a role in cell proliferation, tumorigenesis, and cell migration. This study aimed at evaluating the possible role of AQP3 in nonmelanoma skin cancer (NMSC) pathogenesis through its immunohistochemical expression in skin biopsies of these diseases. One-hundred and thirty cutaneous specimens were studied. These included 60 cases of NMSC and 40 normal skin and 30 psoriasis samples, from age- and gender-matched subjects, as a control group. AQP3 was expressed in 66.7% of basal cell carcinoma (BCC) cases and in 93.3% of squamous cell carcinoma (SCC) cases. Higher AQP3 expression (p = .01), expression percentage (p = .01), and H score (p = .04) were significantly associated with SCC compared to BCC. Normal skin and psoriasis showed significantly higher AQP3 expression (p = .001, p < .001, respectively), expression percentage (p < .001 for both), and H score values (p < .001, p = .001, respectively) compared to NMSC. Higher H score values in BCC were significantly associated with female gender (p = .02) and with nodular lesions (p > .001). Higher H score values in SCC were significantly associated with grade III tumors (p = .04) and AQP3 percentage of expression was significantly correlated with grade III tumors (r = .48, p = .009). In conclusion, AQP3 may play a role in NMSC pathogenesis. This probably occurs through aquaporin-mediated glycerol transport and ATP generation. Its downregulation, observed in the current work, is mostly a result of excessive proliferation. Further studies are needed to investigate the therapeutic effect of its inhibition in NMSC treatment.