Bmal1 upregulates ATG5 expression to promote autophagy in skin cutaneous melanoma

Background

Skin cutaneous melanoma (SKCM) is a highly aggressive and malignant tumor that arises from the malignant transformation of melanocytes. In light of the limitations of existing treatment modalities, there is a pressing need to identify new drug targets for SKCM. Aryl-hydrocarbon receptor nuclear translocator-like (ARNTL), also known as Bmal1, is a gene that has been linked to the onset and progression of cancer. However, its role in SKCM remains understudied.

Methods

The expression of Bmal1 mRNA and protein was detected using TCGA, GTEx, CCLE, and ULCAN databases. Moreover, survival analysis was performed to investigate the association between Bmal1 and immune invasion and gene expression in immune infiltrating cells via CIBERSORT, R programming, TIMER, Sangerbox, Kaplan-Meier. The study also explored the role of proteins associated with Bmal1 by using R programming and databases (STRING and GSEA). Both in vitro and in vivo studies were conducted to examine the potential role of Bmal1 in SKCM.

Results

Compared to normal tissues, the expression level of Bmal1 was significantly reduced in SKCM. Which has been associated with its poor prognosis. Similarly, its expression in SKCM was substantially correlated with immune infiltration, while biogenic analysis indicated that it could potentially influence the tumor immune microenvironment (TME) by influencing tumor-associated neutrophils (TANs). Moreover, Bmal1 overexpression suppressed the proliferation and invasion of melanoma cells and enhanced apoptosis, migration, and cell colony formation.

Conclusion

This study concluded that Bmal1 is a novel biomarker that functions as both a diagnostic and prognostic indicator for the progression of SKCM.