TRIM33 Overexpression Inhibits The Progression Of Clear Cell Renal Cell Carcinoma In Vivo And In Vitro

Research Background:Globally,clear-cell renal cell carcinoma(ccRCC)is one of the most common malignancies in the genitourinary system.Although a number of omics studies demonstrated the various causes and potential mechanisms for the occurrence and development of ccRCC,the morbidity and mortality of ccRCC have been high worldwide in the past few decades.Similar to other solid tumors,the occurrence and development of ccRCC are characterized by abnormal genetics and protein expression.The occurrence and development of ccRCC results from the accumulation of cellular and molecular aberrations,including abnormalities in epigenetics,transcriptomics,miRNA,proteomics,and metabolomics.ccRCC has significant molecular heterogeneity and involves many changes in genetics and protein levels.At present,the molecular properties of ccRCC have not been extensively studied.Exploring the underlying molecular mechanism of the occurrence and development of ccRCC may be of great help in developing better ccRCC treatment methods and diagnosis.Tripartite motif-containing 33(TRIM33)is a protein molecule with multiple biological functions.It has a RING domain,two B-boxes,and a coiled-coil domain at the N end.TRIM33 can be involved in the regulation of various biological processes of vertebrate embryos and hematogenesis,DNA repair,mitosis,transcription elongation,and carcinogenesis.Therefore,TRIM33 has complex biological functions in the occurrence and development of various tumors.TRIM33 can act as a tumor suppressor or tumor promoter in different tumor cells.It suppresses the growth of tumors in patients with breast cancer,non-small cell lung cancer,renal clear cell carcinoma,and glioma.However,it can prevent the apoptosis of tumor cells in pancreatic cancer,B lymphoblastic leukemia,and cervical cancer and can promote tumor growth.This indicates that TRIM33 may affect tumor progression through a variety of biological pathways.In addition,studies have shown that TRIM33 can participate in the TGF-βsignaling pathway by binding to phosphorylated SMAD2/3 or monoubiquitinated SMAD4 in hepatocellular carcinoma,human chronic myeloid leukemia,and pancreatic cancer.In addition,its tumor suppressor function may not be associated with SMAD4,indicating that the TGF-β signal transduction pathway may not be the main pathway for TRIM33 to inhibit tumorigenesis.Researchers paid too much attention to the TGF-βsignaling pathway and ignored the role of TRIM33 in other cancer pathways.Studies on mouse embryonic stem cells have shown that TRIM33 regulates Wnt/β-catenin signaling,which is independent of the E3 ligase activity in its RING domain.Similarly,in human glioblastoma,TRIM33 can inhibit the proliferation and tumorigenicity of tumor cells by degrading β-catenin.However,it is unclear whether TRIM33 can affect tumor progression through the Wnt/β-catenin pathway in ccRCC.Research Purposes:In order to evaluate the expression of TRIM33 in ccRCC tissues and to explore the biological impact of TRIM33 on the progress of ccRCC.Research Methods:The Cancer Genome Atlas(TCGA)database is used to examine the mRNA expression level of TRIM33 in ccRCC tissues and its clinical significance.Subsequently,an immunohistochemical staining experiment was performed to evaluate the expression level of TRIM33 in ccRCC tissues obtained from our hospital.In addition,the correlation between the expression level of TRIM33 and the clinicopathological characteristics of patients was also studied.The effects of overexpression of TRIM33 on the proliferation of ccRCC cell lines were examined by CCK-8 and cell colony formation experiments.Through wound healing and transwell experiments,as well as the use of Wnt signaling pathway agonists in rescue experiments,the effects of overexpression of TRIM33 on the migration and invasion of ccRCC cell lines were explored.Western blotting was used to assess the potential mechanism of TRIM33 in ccRCC cell lines.Finally,a xenograft model was used to explore the effect of overexpression of TRIM33 on tumor growth in vivo.Research Results:Bioinformatics analysis showed that the expression level of TRIM33 mRNA in ccRCC tissues was significantly downregulated compared with that in normal kidney tissues,and the low expression of TRIM33 was associated with the poor prognosis of patients with ccRCC.Consistently,in the immunohistochemical staining experiment,the TRIM33 expression level detected in human ccRCC tissue is also significantly lower than that in normal kidney tissue.The level of TRIM33 expression is correlated to clinicopatho logical characteristics,including tumor size and Furman grade.In addition,overexpression of TRIM33 can inhibit the proliferation,migration,and invasion of 786-O and ACHN renal cancer cell lines.The results of the rescue experiment showed that after adding Wnt signaling pathway agonists to the two renal cancer cell lines overexpressing TRIM33,the initially inhibited migration and invasion capabilities were restored.In Western blot experiments,overexpression of TRIM33 can reduce the expression levels of β-catenin,cyclin D1,and c-myc in both renal cancer cell lines.In a xenograft model,overexpression of TRIM33 can inhibit tumor growth in vivo.Research Conclusion:TRIM33 showed abnormally low expression in human ccRCC tissues compared to that in normal kidney tissues.TRIM33 can be used as a potential therapeutic target and prognostic marker of ccRCC.