Dados do Resumo

Título

The role of the Slc25a13 gene in promoting melanoma aggressiveness and therapy resistance and its regulation by novel lncRNA Slamon

Introdução

Melanomas are responsible for about 80% of all deaths related to skin cancers. Studies have revealed the central role of long non-coding RNAs (lncRNAs) in regulatory networks controlling cell behavior. The altered expression of lncRNAs can contribute to cancer development and progression. Our laboratory has developed a linear cellular model of melanoma progression composed of four cell lines: melan-a (melanocytes), 4C (pre-malignant melanocytes), 4C11- (undifferentiated and non-metastatic melanoma cells) and 4C11+ (differentiated and metastatic melanoma cells), which were analyzed for their lncRNA expression profile by RNAseq. Differentially expressed lncRNAs were selected by in silico analyses based on their proximity to differentially expressed coding-genes in the same melanoma model. Correlation analyses were performed between the expression of differentially expressed lncRNA neighboring genes and their melanoma patient survival, using two independent melanoma cohorts (TCGA and LMC). Among those lncRNA located near genes presenting prognostic value is the lncRNA Slamon, neighbor to Slc25a13 gene (mitochondrial aspartate/glutamate carrier gene), which high expression correlates with poor prognosis. Both Slamon lncRNA and Slc25a13 are highly expressed in the metastatic melanoma cells 4C11+ compared to melan-a, 4C and 4C11- cell lines.

Objetivo

This study aimed to analyze the mechanisms of action and role of lncRNA Slamon and Slc25a13 gene in melanoma progression.

Métodos

The knocking down of Slamon or Slc25a13 or the double silencing were performed in 4C11+ melanoma cells, followed by analyses of collective migration, clonogenicity, proliferation, anoikis resistance, dacarbazine and MEK inhibitor treatment, in vivo tumour appearance assay (CEUA nª 5757050224) and gene expression (qPCR). Also, we performed a coexpression analysis and an analysis of the methylation profile (ERRBS) in the promoter regions of Slamon and Slc25a13

Resultados

By knocking down Slc25a13 lead 4C11+ cells significantly less migratory, clonogenicity, proliferation and anoikis resistance capability, diminished sensitivity to dacarbazine and MEK inhibitor treatment, delayed the appearance of tumor and increased expression of Slamon lncRNA. 4C11+ melanoma cells knocked down for Slamon presented a low reduced migratory and resulted in increased expression of Slc25a13 gene. Also, knocking down both, surprisingly the cells do not present the behavior obtained with Slc25a13 silencing. The analysis of genes coexpressed with Slc25a13 revealed genes related to important axis for melanoma progression, as PI3K/AKT and MAPK. The association was confirmed by decresead expresssion of Pi3kcb, Sos2 of Pdgfrb in cells knock down for Slc25a13. Additionally, significant demethylation of the promoter region of these genes was observed in 4C11+.

Conclusões

Our results suggest the importance of Slc25a13 for the melanoma progression and therapy response. Also, we described a crucial role of the lncRNA Slamon and Slc25a13 that has never been described before. Slamon regulates tumor aggressiveness associated with Slc25a13, forming a regulatory network. These findings reveal the importance of lncRNAs in melanoma biology, potentially indicating transcripts that can serve as prognostic biomarkers and therapeutic targets in melanoma.

Financiador do resumo

FAPESP (2022/00322-7; 2021/06214-9), CAPES

Palavras Chave

Melanoma; lncRNA; biomarker