Whether miR‑21 inhibitor affects the anti‑cancer activity of doxorubicin assisted by c(RGDyK)‑modified liposome (DLN) in melanoma and the underlying mechanisms are largely unknown.
The molecular mechanism of miR-21-induced inhibitory activity on UV-ray-stimulated melanogenesis-regulating proteins was examined in A375.S2 human melanoma and B16F10 mouse melanoma cells.
Human melanoma A375 cells were divided into the Mock, negative control (NC), miR-21 inhibitors, miR-21 inhibitors + siRNA-SPRY1, miR-21 inhibitors + siRNA-PDCD4, and miR-21 inhibitors + siRNA-PTEN groups.
In a validation cohort (n=167), measured expression of miR-21-5p and miR-424-5p, not previously reported in melanoma, were significantly increased in invasive compared with in situ melanomas (P<0.0001).
We highlight pertinent studies involving common miRs implicated in the oncogenesis of melanoma including miR-21, miR-125b, miR-150, miR-155, miR-205, and miR-211.
It was therefore hypothesized that increased levels of miR-21 expression would lead to decreased expression of TIMP3 and thereby enhance the invasiveness of melanoma cells. miR-21 over-expression in the melanoma cell lines WM1552c, WM793b, A375 and MEL 39 was accomplished via transfection with pre-miR-21.
We firstly showed that increased levels of microRNA-21 expression were shown from dysplastic nevi to primary cutaneous melanomas to melanoma metastases.
To characterize the role of miR-21 in melanoma behavior, we transduced B16 cells with lentivirus encoding a miR-21 antagomir and isolated miR-21 knockdown B16 cells. miR-21 knockdown or IFN treatment alone inhibited B16 cell proliferation and migration in vitro, and in combination they had an enhanced effect.