Background and purpose:MicroRNA (miRNA, miR) plays an important regulatory role in cancer. miR-222 is reported to be up-regulated in various tumors, but its role in renal cell carcinoma (RCC) remains unclear. In this study, we detected the expression of miR-222 in both RCC and adjacent tissue samples. The aim of this study was to investigate the role of miR-222 in RCC. Methods:The expression levels of miR-222 in RCC tissue samples were quantified by quantitative real-time polymerase chain reaction (qRT-PCR). DDIT4 and LC3-Ⅱ protein expressions were determined by Western blot. Dual luciferase assay was performed to verify the target of miR-222. EGFP-LC3 microscopy assay was performed to assess autophagy. Results:Results from qRT-PCR showed that the expression of miR-222 was up-regulated in RCC tissues. Knockdown of miR-222 with speciifc antagomiR decreased the cell viability of 786-O cells, whereas overexpression of miR-222 increased the cell viability (P<0.01). The levels of DDIT4 were up-regulated in 786-O cells transfected with miR-222 antagomiR, whereas overexpression of miR-222 induced the down-regulation of DDIT4 expression. Data from dual luciferase assay indicated that miR-222 directly targeted the expression of DDIT4. Consistently, the expression of DDIT4 in RCC tissues was down-regulated compared with adjacent tissues. Knockdown of miR-222 in 786-O cells induced a signiifcant increase of autophagosome formation and LC3 lipidation.These results supported that miR-222 could inhibit autophagy in RCC cells, which may affect the clinical characteristcs of RCC. Conclusion: miR-222 is up-regulated in RCC and can inhibit the autophagy of RCC cells through down-regulating the expression of DDIT4.

Objective: To investigate the effects of hinokitiol on the proliferative inhibition and apoptosis induction in human clear cell renal cancer 786-O cells. Methods:CCK-8 assays were performed to analyze the effects of hinokitiol on the proliferation of 786-O cells. The apoptosis rate was determined by flow cytometry. EGFP-LC3 microscopy assays were performed to assess the autoph-agy flux. Cleaved Caspase-3, LC3, and P62 were detected by Western blot. Results: Hinokitiol could inhibit the proliferation of the 786-O cells and could induce cell apoptosis via Caspase pathway. Hinokitiol induced the autophagy of 786-O cells, increased LC3 ex-pression, and downregulated P62 expression. Conclusion: Hinokitiol can inhibit the proliferation of 786-O cells and can induce cell apoptosis via autophagy induction.

Objective To explore the role of the DACT2 gene in the occurrence and development of renal cell carcinoma(RCC).Methods The samples of RCC tissues and corresponding tumor-adjacent tissues after radical operation and normal kidney tissues were collected.The methylation specific PCR (MSP) and real time fluorescence reverse transcriptase-PCR (RT-PCR) methods were adopted to detect the methylation status and mRNA expression of DACT2.The streptavidin-peroxidase (SP) method labeled by immunohistochemistry peroxidase was used to examine the expression of β-catenin protein.Then the relationship between DACT2 gene methylation status and mRNA expression with the clinicopathologic characteristics was analyzed.The relationship between DACT2 gene methylation with mRNA and β-catenin expression was analysed,as well.Results The DACT2 mRNA relative expression level in RCC tissues was 0.427±0.025,which was significantly lower than (0.801±0.047) in tumor-adjacent tissues and (0.872±0.022) in normal tissue,the positive rate of DACT2 gene methylation in RCC tissues was 45.76%,which was significantly higher than 6.78% in tumor-adjacent tissues and 5.08% in normal tissues,the difference was statistically significant (P<0.05),while the difference between tumor-adjacent tissues and normal tissues had no statistical significance (P>0.05).The DACT2 gene mRNA expression level in RCC tissues and promoter area methylation occurrence rate had no obvious correlation with the clinical data such as patients age,gender,tumor size,clinical stage and Fuhrman grade (P>0.05).The DACT2 gene mRNA relative level in the methylation group was lower than that in the non-methylation group,the difference was statistically significant (P<0.05).The expression rate of β-catenin protein in cytoplasma in RCC tissues was higher than that in the tumor-adjacent tissues and normal tissues,the difference was statistically significant (P<0.05),moreover,DACT2 gen methylation had a positive correlation with β-catenin protein expression (r=0.324,P=0.012).Conclusion The decrease of DACT2 gene promoter area methylation and mRNA relative expression level may participate in the RCC occurrence,but has no relationship with RCC clinical progression.Methylation occurred in DACT2 gene promoter area may be one of reasons causing mRNA relative expression decrase.DACT2 gene methylation occurrence in RCC tissue might be related to the high expression of β-catenin.

[Abstract] Objective：To investigate the expression of ITGB2 (integrinβ2) in renal cell carcinoma (RCC) tissues and cells (ACHN cells) and its effects on the proliferation, migration, invasion and cell cycle of ACHN cells. Methods: The expression level of ITGB2 in RCC tissues and para-cancerous tissues was analyzed by GEPIA database. The tissue samples of 66 RCC patients retained in the biological specimen bank of the Fourth Hospital of Hebei Medical University from 2016 to 2020 were selected for this study. The expression level of ITGB2 in 66 cases of RCC tissues and para-cancerous tissues was detected by immunohistochemical SP and qPCR, and the relationship between ITGB2 and clinical parameters was analyzed. The shRNA with ITGB2 knockdown was constructed and transfected into ACHN cells for functional experiments to detect its effect on the malignant biological behaviors of ACHN cells, and its effect on the cell cycle was detected by flow cytometry. WB was used to detect the effect of ITGB2 knockdown on ITGB2 protein expression in ACHN cells. Results: The relative expression of ITGB2 in RCC tissues was significantly higher than that in para-cancerous tissue (P<0.01), and the expression was related to the clinical stage of RCC (P<0.05). Transfection of shITGB2 into ACHN cells could knock down the gene and protein expression of ITGB2 (all P<0.01). Knockdown of ITGB2 could significantly inhibit the proliferation (P<0.05), migration(P<0.01) and invasion (P<0.05) of ACHN cells but had no significant effect on cell cycle (P>0.05). Conclusion: ITGB2 is highly expressed in RCC tissues and cells and is associated with the clinical stage of RCC. Knockdown of ITGB2 can inhibit the malignant biological behaviors of ACHN cells.