Crocin exerts anti-proliferative and apoptotic effects on cutaneous squamous cell carcinoma via miR-320a/ATG2B.

ABSTRACT

Cutaneous squamous cell carcinoma (cSCC) is a highly prevalent skin malignancy, and the effective therapy still remains a challenge. Crocin can be used for cSCC therapy. This study explored the effects of cSCC cells treatment with crocin in vitro and in vivo. The study used A431 and SCL-1 cells lines, cSCC human samples and BALB/C nude mice for investigations. Apoptosis was determined by MTT assays, while miR-320a and ATG2B expressions were validated through RT-qPCR. Interaction of miR-320a with ATG2B was examined via dual luciferase reporter assay. The autophagy and apoptosis proteins expressions were further confirmed through western blot and immunofluorescence staining assays. The results indicated a significantly upregulated miR-320a, but a down-regulated ATG2B expression in the cSCC clinical samples. Crocin significantly repressed cSCC cells growth, and induced apoptosis through autophagy. Furthermore, miR-320a expression was inhibited and ATG2B expression was increased. Dual luciferase reporter assay revealed that miR-320a regulated ATG2B expression directly. Additionally, the upregulation of ATG2B expression in cSCC cells inhibited cell proliferation and led to cell apoptosis. Crocin also reduced tumor growth and stimulated the apoptosis in vivo. In conclusion, miR-320a is upregulated and ATG2B is down-regulated in cSCC, Crocin suppresses the proliferation and induces apoptosis of cSCC cells. Further, Crocin increases autophagy while miR-320a hinders autophagy and the apoptotic effects of crocin on cSCC cells. MiR-320a binds ATG2B directly, and ATG2B expression is upregulated by crocin. Finally, Crocin triggers cSCC cells apoptosis in vivo. Crocin can target ATG2B/miR-320a and may be an effective alternative for cSCC treatment.