LncRNA SNHG1 promotes renal cell carcinoma progression through regulation of HMGA2 via sponging miR-103a.

BACKGROUND: Long noncoding RNAs (LncRNAs) plays a vital role in tumorigenesis and development. The molecular mechanism of SNHG1 in renal cell carcinoma (RCC) has not been illustrated. The aim of this research was to explore the expression and function of LncRNA SNHG1 in RCC. MATERIAL AND METHODS: The expression of SNHG1 in clinical tissues and RCC cell lines was detected. Luciferase reporter assay was performed to verify the correlation between SNHG1, miR-103a, and HMGA2. CCK-8 assay was performed to examine cell viability. Cell apoptosis was analyzed using flow cytometry. Cell invasion capacity was determined by Transwell assays. The protein level of HMGA2 was analyzed by Western blotting. RESULTS: The expression of SNHG1 markedly increased in RCC tissues and cell lines. Subsequent studies identified SNHG1 as a miRNA sponge for miR-103a. In addition, SNHG1 knockdown and miR-103a overexpression significantly inhibited progression of RCC. miR-103a also regulated HMGA2 levels. CONCLUSION: Our findings showed that SNHG1 was upregulated in RCC cells and tissues. SNHG1 promoted the malignant characteristics of RCC cells. Its regulatory effect may be regulation of HMGA2 by sponging miR-103a. Therefore, Our study facilitates the understanding of SNHG1 function in RCC.

Ubiquitin-specific peptidase 53 inhibits the occurrence and development of clear cell renal cell carcinoma through NF-κB pathway inactivation.

BACKGROUND: Clear cell renal cell carcinoma (ccRCC) is one of the most prevalent malignant diseases in the urinary system with more than 140,000 related deaths annually. Ubiquitination-deubiquitination homeostasis is an important factor in ccRCC progression; ubiquitin-specific peptidase 53 (USP53) belongs to the family of deubiquitinating enzymes, but its functions are rarely reported. METHODS: Databases obtained from GEO and TCGA were analyzed to reveal the role of USP53 in ccRCC. CCK-8/BrdU and EDU assays were used to detect the proliferation of ccRCC after USP53 overexpression or knockdown. A tumor xenograft experiment was used to verify the effect of the proliferation of ccRCC after USP53 knockdown. Transwell assays were used to detect the metastasis of ccRCC after USP53 overexpression or knockdown. RNA sequencing and western blot analysis were employed to detect the change in genes after USP53 overexpression and knockdown. Then we tested the effect of USP53 on IκBα protein stability through western blot analysis. Detect the effect of USP53 on IκBα ubiquitination in vitro by immunoprecipitation method. RESULTS: USP53 expression was downregulated in ccRCC tissues and USP53 expression was significantly negatively correlated with the tumor progression and clinical prognosis. The ability of growth and metastasis of ccRCC was inhibited after USP53 overexpression. In addition, USP53 knockdown promoted ccRCC growth and metastasis. Moreover, USP53 knockdown promoted the ability of clone formation of ccRCC in vivo. NF-κB signaling pathway significantly enriched and downregulated in USP53 overexpressed cells, and genes in the NF-κB pathway (such as IL1B, CXCL1-3, RELA, RELB, etc.) were obviously downregulated in USP53 overexpressed cells. USP53 overexpression decreased the phosphorylation of IKKß and P65 in both Caki-1 and 786-O cells, and the expression of IκBα was increased. Phosphorylation of IKKß and P65 was increased in both Caki-1 and 786-O cells after USP53 knockdown. As the expression of USP53 increases, the protein expression of IκBα was also gradually increased and USP53 reduced the ubiquitination of IκBα. CONCLUSION: In summary, our data indicate that USP53 inhibits the inactivation of the NF-κB pathway by reducing the ubiquitination of IκBα to further inhibit ccRCC proliferation and metastasis. These findings may help understand the pathogenesis of ccRCC and introduce new potential therapeutic targets for kidney cancer patients.

Ubiquitin-specific peptidase 46 (USP46) suppresses renal cell carcinoma tumorigenesis through AKT pathway inactivation.

USP46, a member of the ubiquitin-specific protease family, plays essential roles in cancer cell proliferation and metastasis and is used as a candidate target for cancer therapeutics. However, the effects of USP46 on renal cell carcinoma (RCC) and its underlying molecular mechanism remain unknown. In this study, the predictive and prognostic relevance of USP46 in RCC, patient-derived primary tissues, and normal liver tissues obtained from the TCGA dataset were analyzed for the USP46 mRNA levels or prognostic relevance. Gain-of-function or loss-of-function assays were used to evaluate the vital roles of USP46 in tumor cell proliferation and cell migration. As a result, the USP46 expression level in RCC is highly decreased compared to normal tissues, and the Kaplan-Meier curve showed that USP46 high expression patients had good prognoses. Functionally, the forced expression of USP46 significantly restrained tumor cell proliferation, colony formation, and cell migration. The shRNA mediated USP46 knockdown cells exhibited the opposite results. We further showed that ectopically expressed USP46 obviously inhibited the AKT signaling pathway in cancer cells, while USP46 depletion caused a dramatic increase in AKT activity reflected by phosphorylation in the serine and threonine residues of AKT or downstream p70S6K1. Importantly, MK2206, a specific AKT inhibitor, completely counteracted the effects on cell proliferation, cell migration, and AKT activity in the USP46 depletion cells. We thus revealed a novel mechanism of USP46 regulation in RCC, and our data indicate that USP46 is a tumor suppressor in RCC via AKT signaling pathway inactivation.