Long noncoding RNAs (lncRNAs) play crucial roles in melanoma initiation and development, serving as potential therapeutic targets and prognostic markers for melanoma. lncRNA survival-associated mitochondrial melanoma-specific oncogenic noncoding RNA (SAMMSON) is upregulated in many types of human cancers. However, the functions of SAMMSON in melanoma have not been fully elucidated. This study is aimed at investigating the expression and functions of SAMMSON in melanoma development. Bioinformatics analysis was performed to determine the expression of SAMMSON and its correlation with the 10-year overall survival (OS) in melanoma patients. Cell proliferation, migration, invasion, and tumorigenesis were detected by MTT, colony formation, Transwell assays, and mouse xenograft model. The expression of cell cycle-related factors, epithelial-to-mesenchymal transition (EMT) makers, and matrix metalloproteinases (MMPs) was assessed by RT-qPCR and western blotting analysis. The results demonstrated that SAMMSON expression was upregulated in melanoma tissues and cells, and lower SAMMSON expression was correlated with longer 10-year OS. SAMMSON knockdown decreased the proliferation, migration, and invasion of melanoma cells by regulating the expression of proliferation-related genes, EMT factors, and MMPs, respectively. Additionally, Forkhead box protein A2 (FOXA2) was confirmed to be a target of SAMMSON, and the biological effects induced by FOXA2 overexpression were similar to those induced by SAMMSON silencing in melanoma cells. Further studies showed that SAMMSON downregulated FOXA2 expression in melanoma cells by modulating the EZH2/H3K27me3 axis. Taken together, our data indicate that SAMMSON plays an important role in melanoma progression and can be a valuable biomarker and therapeutic target in melanoma.

Background: Glucose 6-phosphate dehydrogenase (G6PD) serves key roles in cancer cell metabolic reprogramming, and has been reported to be involved in certain carcinogenesis. Previous results from our laboratory demonstrated that overexpressed G6PD was a potential prognostic biomarker in clear cell renal cell carcinoma (ccRCC), the most common subtype of kidney cancer. G6PD could stimulate ccRCC growth and invasion through facilitating reactive oxygen species (ROS)-phosphorylated signal transducer and activator of transcription 3 (pSTAT3) activation and ROS-MAPK-MMP2 axis pathway, respectively. However, the reasons for ectopic G6PD overexpression and the proliferation repressive effect of G6PD inhibition in ccRCC are still unclear. Methods: The impact of ROS accumulation on NF-κB signaling pathway and G6PD expression was determined by real-time RT-PCR and Western blot in ccRCC cells following treatment with ROS stimulator or scavenger. The regulatory function of NF-κB signaling pathway in G6PD transcription was analyzed by real-time RT-PCR, Western blot, luciferase and ChIP assay in ccRCC cells following treatment with NF-κB signaling activator/inhibitor or lentivirus infection. ChIP and Co-IP assay was performed to demonstrate protein-DNA and protein-protein interaction of NF-κB and pSTAT3, respectively. MTS assay, human tissue detection and xenograft model were conducted to characterize the association between NF-κB, pSTAT3, G6PD expression level and proliferation functions. Results: ROS-stimulated NF-κB and pSTAT3 signaling over-activation could activate each other, and exhibit cross-talks in G6PD aberrant transcriptional regulation. The underlying mechanism was that NF-κB signaling pathway facilitated G6PD transcription via direct DNA–protein interaction with p65 instead of p50. p65 and pSTAT3 formed a p65/pSTAT3 complex, occupied the pSTAT3-binding site on G6PD promoter, and contributed to ccRCC proliferation following facilitated G6PD overexpression. G6PD, pSTAT3, and p65 were highly expressed and positively correlated with each other in ccRCC tissues, confirming that NF-κB and pSTAT3 synergistically promote G6PD overexpression. Moreover, G6PD inhibitor exhibited tumor-suppressor activities in ccRCC and attenuated the growth of ccRCC cells both in vitro and in vivo . Conclusion: ROS-stimulated aberrations of NF-κB and pSTAT3 signaling pathway synergistically drive G6PD transcription through forming a p65/pSTAT3 complex. Moreover, G6PD activity inhibition may be a promising therapeutic strategy for ccRCC treatment.

Background: Glucose 6-phosphate dehydrogenase (G6PD) serves key roles in cancer cell metabolic reprogramming, and has been reported to be involved in certain carcinogenesis. Previous results from our laboratory demonstrated that overexpressed G6PD was a potential prognostic biomarker in clear cell renal cell carcinoma (ccRCC), the most common subtype of kidney cancer. G6PD could stimulate ccRCC growth and invasion through facilitating reactive oxygen species (ROS)-phosphorylated signal transducer and activator of transcription 3 (pSTAT3) activation and ROS-MAPK-MMP2 axis pathway, respectively. However, the reasons for ectopic G6PD overexpression and the proliferation repressive effect of G6PD inhibition in ccRCC are still unclear. Methods: The impact of ROS accumulation on NF-κB signaling pathway and G6PD expression was determined by real-time RT-PCR and Western blot in ccRCC cells following treatment with ROS stimulator or scavenger. The regulatory function of NF-κB signaling pathway in G6PD transcription was analyzed by real-time RT-PCR, Western blot, luciferase and ChIP assay in ccRCC cells following treatment with NF-κB signaling activator/inhibitor or lentivirus infection. ChIP and Co-IP assay was performed to demonstrate protein-DNA and protein-protein interaction of NF-κB and pSTAT3, respectively. MTS assay, human tissue detection and xenograft model were conducted to characterize the association between NF-κB, pSTAT3, G6PD expression level and proliferation functions. Results: ROS-stimulated NF-κB and pSTAT3 signaling over-activation could activate each other, and exhibit cross-talks in G6PD aberrant transcriptional regulation. The underlying mechanism was that NF-κB signaling pathway facilitated G6PD transcription via direct DNA–protein interaction with p65 instead of p50. p65 and pSTAT3 formed a p65/pSTAT3 complex, occupied the pSTAT3-binding site on G6PD promoter, and contributed to ccRCC proliferation following facilitated G6PD overexpression. G6PD, pSTAT3, and p65 were highly expressed and positively correlated with each other in ccRCC tissues, confirming that NF-κB and pSTAT3 synergistically promote G6PD overexpression. Moreover, G6PD inhibitor exhibited tumor-suppressor activities in ccRCC and attenuated the growth of ccRCC cells both in vitro and in vivo . Conclusion: ROS-stimulated aberrations of NF-κB and pSTAT3 signaling pathway synergistically drive G6PD transcription through forming a p65/pSTAT3 complex. Moreover, G6PD activity inhibition may be a promising therapeutic strategy for ccRCC treatment.

Background Glucose 6-phosphate dehydrogenase (G6PD) serves key roles in cancer cell metabolic reprogramming, and has been reported to be involved in certain carcinogenesis. Previous results from our laboratory demonstrated that overexpressed G6PD was a potential prognostic biomarker in clear cell renal cell carcinoma (ccRCC), the most common subtype of kidney cancer. G6PD could stimulate ccRCC growth and invasion through facilitating reactive oxygen species (ROS)-phosphorylated signal transducer and activator of transcription 3 (pSTAT3) activation and ROS-MAPK-MMP2 axis pathway, respectively. However, the reasons for ectopic G6PD overexpression and the proliferation repressive effect of G6PD inhibition in ccRCC are still unclear. Methods The impact of ROS accumulation on NK-κB signaling pathway and G6PD expression was determined by real-time RT-PCR and Western blot in ccRCC cells following treatment with ROS stimulator or scavenger. The regulatory function of NK-κB signaling pathway in G6PD transcription was analyzed by real-time RT-PCR, Western blot, luciferase and ChIP assay in ccRCC cells following treatment with NK-κB signaling activator/inhibitor or lentivirus infection. ChIP and Co-IP assay was performed to demonstrate protein-DNA and protein-protein interaction of NK-κB and pSTAT3, respectively. MTS assay, human tissue detection and xenograft model were conducted to characterize the association between NK-κB, pSTAT3, G6PD expression level and proliferation functions. Results ROS-stimulated NF-κB and pSTAT3 signaling over-activation could activate each other, and exhibit cross-talks in G6PD aberrant transcriptional regulation. The underlying mechanism was that NF-κB signaling pathway facilitated G6PD transcription via direct DNA–protein interaction with p65 instead of p50. p65 and pSTAT3 formed a p65/pSTAT3 complex, occupied the pSTAT3-binding site on G6PD promoter, and contributed to ccRCC proliferation following facilitated G6PD overexpression. G6PD, pSTAT3, and p65 were highly expressed and positively correlated with each other in ccRCC tissues, confirming that NF-κB and pSTAT3 synergistically promote G6PD overexpression. Moreover, G6PD inhibitor exhibited tumor-suppressor activities in ccRCC and attenuated the growth of ccRCC cells both in vitro and in vivo . Conclusion ROS-stimulated aberrations of NF-κB and pSTAT3 signaling pathway synergistically drive G6PD transcription through forming a p65/pSTAT3 complex and occupy the pSTAT3-binding site on G6PD promoter. Moreover, G6PD activity inhibition may be a promising therapeutic strategy for ccRCC treatment.

Background: Glucose 6-phosphate dehydrogenase (G6PD) serves key roles in cancer cell metabolic reprogramming, and has been reported to be involved in certain carcinogenesis. Previous results from our laboratory demonstrated that overexpressed G6PD was a potential prognostic biomarker in clear cell renal cell carcinoma (ccRCC), the most common subtype of kidney cancer. G6PD could stimulate ccRCC growth and invasion through facilitating reactive oxygen species (ROS)-phosphorylated signal transducer and activator of transcription 3 (pSTAT3) activation and ROS-MAPK-MMP2 axis pathway, respectively. However, the reasons for ectopic G6PD overexpression and the proliferation repressive effect of G6PD inhibition in ccRCC are still unclear. Methods: The impact of ROS accumulation on NF-κB signaling pathway and G6PD expression was determined by real-time RT-PCR and Western blot in ccRCC cells following treatment with ROS stimulator or scavenger. The regulatory function of NF-κB signaling pathway in G6PD transcription was analyzed by real-time RT-PCR, Western blot, luciferase and ChIP assay in ccRCC cells following treatment with NF-κB signaling activator/inhibitor or lentivirus infection. ChIP and Co-IP assay was performed to demonstrate protein-DNA and protein-protein interaction of NF-κB and pSTAT3, respectively. MTS assay, human tissue detection and xenograft model were conducted to characterize the association between NF-κB, pSTAT3, G6PD expression level and proliferation functions.Results: ROS-stimulated NF-κB and pSTAT3 signaling over-activation could activate each other, and exhibit cross-talks in G6PD aberrant transcriptional regulation. The underlying mechanism was that NF-κB signaling pathway facilitated G6PD transcription via direct DNA–protein interaction with p65 instead of p50. p65 and pSTAT3 formed a p65/pSTAT3 complex, occupied the pSTAT3-binding site on G6PD promoter, and contributed to ccRCC proliferation following facilitated G6PD overexpression. G6PD, pSTAT3, and p65 were highly expressed and positively correlated with each other in ccRCC tissues, confirming that NF-κB and pSTAT3 synergistically promote G6PD overexpression. Moreover, G6PD inhibitor exhibited tumor-suppressor activities in ccRCC and attenuated the growth of ccRCC cells both in vitro and in vivo. Conclusion: ROS-stimulated aberrations of NF-κB and pSTAT3 signaling pathway synergistically drive G6PD transcription through forming a p65/pSTAT3 complex. Moreover, G6PD activity inhibition may be a promising therapeutic strategy for ccRCC treatment.