Long non-coding RNAs (lncRNAs) have emerged as important regulators of cancer progression. Super enhancers (SE) play a role in tumorigenesis and regulate the expression of specific lncRNAs. We examined the role of BRD3OS, also named LINC00094, in cutaneous squamous cell carcinoma (cSCC). Elevated BRD3OS (LINC00094) expression was detected in cSCC cells, and expression was downregulated by SE inhibitors THZ1 and JQ1 and via the MEK1/ERK1/2 pathway. Increased expression of BRD3OS (LINC00094) was noted in tumor cells in cSCCs and their metastases compared to normal skin, actinic keratoses, and cSCCs in situ. Higher BRD3OS (LINC00094) expression was noted in metastatic cSCCs than in non-metastatic cSCCs. RNA-seq analysis after BRD3OS (LINC00094) knockdown revealed significantly regulated GO terms Cell-matrix adhesion, Basement membrane, Metalloendopeptidase activity, and KEGG pathway Extracellular matrix-receptor interaction. Among the top-regulated genes were MMP1, MMP10, and MMP13. Knockdown of BRD3OS (LINC00094) resulted in decreased production of MMP-1 and MMP-13 by cSCC cells, suppressed invasion of cSCC cells through collagen I, and growth of human cSCC xenografts in vivo. Based on these observations, BRD3OS (LINC00094) was named SERLOC (super enhancer and ERK1/2-Regulated Long Intergenic non-protein coding transcript Overexpressed in Carcinomas). These results reveal the role of SERLOC in cSCC invasion and identify it as a potential therapeutic target in advanced cSCC.
Keywords: long non-coding RNA; matrix metalloproteinase; metastasis; skin cancer; squamous cell carcinoma; super enhancer.