Objective:To investigate the regulatory mechanism and clinical significance of RASSF5 in cutaneous melanoma.Methods:We used GEPIA and HPA online tools and TCGA and GSE53118 data sets for differential expression analysis and prognosis analysis; cBioPortal was applied to analyze the correlation between RASSF5 expression and gene mutation and methylation; "limma" R package was used to screen differential genes for GO analysis, KEGG analysis and protein-protein interaction analysis, and we also performed GSEA analysis on all genes; finally we used ESTIMATE and CIBERSORTx online tools to evaluate immune cell infiltration. The kruskal test was used to compare the differences between the groups for measurement data, the Kaplan-Meier method was used to draw the survival curve, and the Cox proportional hazard regression model was used for univariate and multivariate analysis.Results:This study found that in cutaneous melanoma, the expression level of RASSF5 was significantly lower than that of normal tissues, and the methylation level was negatively correlated. KEGG analysis and GSEA analysis showed that RASSF5 can be related to multiple signaling pathways such as immune regulation, KRAS, and P53. Further analysis showed that the expression level of RASSF5 was positively correlated with the degree of infiltration of a variety of tumor immune cells. Survival analysis found that the expression level of RASSF5 was correlated with the overall survival rate of patients with cutaneous melanoma, and multivariate regression analysis found that RASSF5 was an independent predictor of cutaneous melanoma. Finally, using the GSE53118 dataset to verify again, RASSF5 is related to the overall survival rate of patients with cutaneous melanoma and can be used as an independent predictor.Conclusions:RASSF5 may regulate the occurrence and development of cutaneous melanoma cells through a variety of ways. It is a potential biological prognostic marker and therapeutic target.

Objective:To investigate the regulatory mechanism and clinical significance of RASSF5 in cutaneous melanoma.Methods:We used GEPIA and HPA online tools and TCGA and GSE53118 data sets for differential expression analysis and prognosis analysis; cBioPortal was applied to analyze the correlation between RASSF5 expression and gene mutation and methylation; "limma" R package was used to screen differential genes for GO analysis, KEGG analysis and protein-protein interaction analysis, and we also performed GSEA analysis on all genes; finally we used ESTIMATE and CIBERSORTx online tools to evaluate immune cell infiltration. The kruskal test was used to compare the differences between the groups for measurement data, the Kaplan-Meier method was used to draw the survival curve, and the Cox proportional hazard regression model was used for univariate and multivariate analysis.Results:This study found that in cutaneous melanoma, the expression level of RASSF5 was significantly lower than that of normal tissues, and the methylation level was negatively correlated. KEGG analysis and GSEA analysis showed that RASSF5 can be related to multiple signaling pathways such as immune regulation, KRAS, and P53. Further analysis showed that the expression level of RASSF5 was positively correlated with the degree of infiltration of a variety of tumor immune cells. Survival analysis found that the expression level of RASSF5 was correlated with the overall survival rate of patients with cutaneous melanoma, and multivariate regression analysis found that RASSF5 was an independent predictor of cutaneous melanoma. Finally, using the GSE53118 dataset to verify again, RASSF5 is related to the overall survival rate of patients with cutaneous melanoma and can be used as an independent predictor.Conclusions:RASSF5 may regulate the occurrence and development of cutaneous melanoma cells through a variety of ways. It is a potential biological prognostic marker and therapeutic target.

It is critical to regulate the senescence-associated secretory phenotype (SASP) due to its effect on promoting malignant phenotypes and limiting the efficiency of cancer therapy. In this study, we demonstrated that marchantin M (Mar-M, a naturally occurring bisbibenzyl) suppressed pro-inflammatory SASP components which were elevated in chemotherapy-resistant cells. Mar-M treatment attenuated the pro-tumorigenic effects of SASP and enhanced survival in drug-resistant mouse models. No toxicity was detected on normal fibroblast cells or in animals following this treatment. Inactivation of transcription factor EB (TFEB) and nuclear factor-B (NF-B) by Mar-M significantly accounted for its suppression on the components of SASP. Furthermore, inhibition of SASP by Mar-M contributed to a synergistic effect during co-treatment with doxorubicin to lower toxicity and enhance antitumor efficacy. Thus, chemotherapy-driven pro-inflammatory activity, seen to contribute to drug-resistance, is an important target for Mar-M. By decreasing SASP, Mar-M may be a potential approach to overcome tumor malignancy.