The Role Of Rab23in Cell Invasion Of Cutaneous Squamous Cell Carcinoma And The Mechanism

Cutaneous squamous cell carcinoma (cSCC) is the second most commonform of non-melanoma skin cancer (behind basal cell carcinoma (BCC)). It isusually localized, but it can metastasize. Recent years, the research abouttumorigenesis, development, invasion, and metastasis is the point ofdermatology.Rab23, a member of Ras-related small GTPase family, is mutated in openbrain mice. It is a Rab-GTPase vesicular transport protein, which appears toantagonize sonic hedgehog (Shh)-mediated signaling during mouse development,was recently found associated with several kinds of human cancers. Ourprevious study found that Rab23expressed in cSCC sections, while the role ofRab23in SCC invasion and mechanism were not known. In this study, we firstlyinvestigated the expression of Rab23in AKs, Bowen’s disease, invasive SCCand normal skin by immunohistochemistry; then studied the role and mechanismof Rab23in cSCC invasion.Method:①The expression of Rab23in AKs, SCC in situ, invasive SCC and normal skin was detected by immunohistochemistry. Logistic regression analysis wasused to analyse the relationship between Rab23and clinical-pathologicalcharacteristics by SPSS11.5.②Western blotting was used to investigate theexpression of Rab23in HSC-2、HSQ-89，Sa-3，Tca, and Hacat.③SCC cellinvasion ability was detected by transwell assay.④The migration ability wasdetected by cell scratch assay.⑤mRNA relative level of MMP2, MMP9, Ptch1,Gli1, Gli2was detected by real time RT-PCR.⑥Rac1expression was detectedby western blotting.Result:①Rab23expression in cSCC, AK, Bowen’s disease and normal skin byimmunohistochemistry: Positively stained cells were found in cSCC, AK, andBowen’s disease; Rab23protein was absent in normal epidermis or dermis. IncSCC sections, moderately to poorly tumor differentiation and nonexposedpositions are the risk factors of Rab23positive staining.②Rab23expression in SCC cell lines and Hacat cell line by westernblotting: Rab23expressed in four SCC cell lines but Hacat.③SCC cell invasion ability by invasion assays using transwell filters: Cellinvasion ability decreased when Rab23silenced by siRNA in HSQ-89; Cellinvasion ability increased when Rab23was overexpressed in Sa-3cells.④Migration ability by cell scratch assay: silencing or overexpression ofRab23had no effect on SCC cell migration.⑤Real time RT-PCR: mRNA level of MMP2, MMP9, Gli2wassignificantly reduced by siRNA silencing of RAB23in Hsq-89cells, whereassignificantly enhanced by overexpression of RAB23in Sa-3cells. Ptch1andGli1was significantly enhanced by siRNA silencing of RAB23in Hsq-89cells,whereas significantly reduced by overexpression of RAB23in Sa-3cells. ⑥Rac1expression by western blotting: Rac1expression was significantlyreduced by siRNA silencing of RAB23in Hsq-89cells, whereas significantlyenhanced by overexpression of RAB23in Sa-3cells.Conclusions:①Rab23expresses in AK, Bowen’s disease, cSCC sections, and SCC celllines, suggesting a role of Rab23in tumorigenesis of SCC.②Rab23promotes SCC cell invasion, but has no effect on SCC cellmigration.③Rab23enhances cell invasion may by promoting Rac1, MMP2, MMP9expression, but not hedgehog signaling pathway.