Silencing LINC00665 inhibits cutaneous melanoma in vitro progression and induces apoptosis via the miR-339-3p/TUBB.

BACKGROUND: LncRNAs are closely related to cutaneous melanoma (CM) tumorigenesis and metastasis, and it can affect the progression of CM by regulating cell proliferation, migration, invasion, apoptosis, and other cellular mechanisms. This study investigated the role of LINC00665 in CM. METHODS: Expressions of LINC00665, miR-339-3p, and tubulin beta chain (TUBB) in CM cells were analyzed by qRT-PCR and/or Western blot. The LINC00665/miR-339-3p/TUBB targeting network was predicted by bioinformatics tools, screened out by Venn diagrams and analyzed by Pearson's correlation coefficients, followed by validation via dual-luciferase reporter assay and/or pull-down assay. Transfection of siLINC00665 or miR-339-3p inhibitor/mimic was conducted with CM cells whose viability, proliferation, migration, invasion, cell cycle progression, and apoptosis were measured by CCK-8 assay, colony formation assay, wound healing assay, Transwell assay, and flow cytometry. The associations of TUBB with tumor biological characteristics and other proteins were analyzed by CanserSEA and String, respectively. RESULTS: High-expressed LINC00665 was detected in CM cells. Silencing LINC00665 decreased CM cell viability; inhibited colony formation, cell cycle progression, migration and invasion; enhanced apoptosis; and upregulated miR-339-3p. LINC00665 targeted miR-339-3p which targeted TUBB. MiR-339-3p upregulation induced effects similar to the LINC00665-silencing-induced effects and could downregulate TUBB, which was associated with malignant behaviors and related to other five proteins. MiR-339-3p downregulation induced the opposite effects of what miR-339-3p upregulation induced, and the miR-339-3p downregulation-induced effects could be reversed by LINC00665 silencing. CONCLUSION: Silencing LINC00665 inhibits in vitro CM progression and induces apoptosis via the miR-339-3p/TUBB axis.

MiR-217 is down-regulated in psoriasis and promotes keratinocyte differentiation via targeting GRHL2.

MiR-217 is a well-known tumor suppressor, and its down-regulation has been shown in a wide range of solid and leukaemic cancers. However, the biological role of miR-217 in psoriasis pathogenesis, especially in keratinocyte hyperproliferation and differentiation, is not clearly understood. In this study, we found the expression of miR-217 was markedly down-regulated in psoriasis keratinocytes of psoriatic patients. In addition, overexpression of miR-217 inhibited the proliferation and promoted the differentiation of primary human keratinocytes. On the contrary, inhibition of endogenous miR-217 increased cell proliferation and delayed differentiation. Furthermore, Grainyhead-like 2 (GRHL2) was identified as a direct target of miR-217 by luciferase reporter assay. The expression of miR-217 and GRHL2 was inversely correlated in both transfected keratinocytes and in psoriasis lesional skin. Moreover, knocking down GRHL2 expression by siRNA enhanced keratinocyte differentiation. Taken together, our results demonstrate a role for miR-217 in the regulation of keratinocyte differentiation, partially through the regulation of GRHL2.