| Objective: Lung cancer is one of the most common human cancers worldwide. Thecombined modality therapy of lung cancer includes surgical operation, chemotherapy,radiotherapy and targeted therapy. A better understanding of the molecularmechanisms underlying lung cancer formation and progression should be helpful indeveloping more effective treatments for this disease. TRIM29has been reported tobe overexpressed in variety of different cancers, but the exact function of TRIM29incancers is not fully understood. The aim of this study was to investigate the effect ofTRIM29on cell proliferation, invasion and cisplatin chemotherapy in non small celllung cancer (NSCLC).Methods:(1)The specimens were divided into non small cell lung cancer and normallung tissues. The expressions of TRIM29in NSCLC and normal lung tissues weredetected by immunochemical method. The relationship between TRIM29expressionand clinicopathological was analyzed.(2) We transformed TRIM29siRNA intoNCI-H520cells. Real time reverse transcriptase polymerase chain reaction andWestern blotting assay were employed to determine TRIM29messenger (m)RNA andprotein expressions. MTT assay was used to determine the cell proliferation.Transwell invasion assay was used to determine the cell invasion.(3)TRIM29siRNAwas used to suppress the expression of TRIM29. We analysed the protein expressionof Bax and Bcl-2with Western blotting assay. An Annexin V-propidium iodide(AnnV/PI) staining apoptosis test was used for detecting apoptosis.Results:(1) An overexpression of TRIM29was noted in63out of100NSCLC specimens. NO or weak staining signals were detected in the normal lung tissues. Theexpression of TRIM29was significantly correlated with histological subtypes, TNMstaging and lymph node metastasis. However, there was no significant differencebetween age and gender.(2) In our assay, three TRIM29siRNAs (TRIM29siRNA1,TRIM29siRNA2, TRIM29siRNA3) were used to suppress TRIM29expression,TRIM29mRNA and protein were measured by quantitative real-time PCR andWestern blotting, respectively. Compared with TRIM29siRNA1and2, TRIM29siRNA3could mostly specifically and efficiently suppress TRIM29expression atboth mRNA and protein levels. Therefore, we chose TRIM29siRNA3to fulfill ourassay. We used an MTT assay kit to evaluate the effect of TRIM29-RNAi on cellgrowth. The growth curves of TRIM29knockdown cells were significantly lowerthan those of the control cells for the five days of incubation. We studied the effect ofTRIM29knockdown on the invasion of NCI-H520cells using the transwell invasionassay. The results showed that invasion was significantly inhibited in the TRIM29knockdown cells compared with the untreated group, or the siCONTROL group.(3)We examined the effect of TRIM29suppression on NCI-H520cell apoptosis withflow cytometric analysis. After transfection with TRIM29siRNA, cell apoptosis wasinduced. Furthermore, cell apoptosis was increased when cells were treated with5?g/mL cisplatin. The apoptosis rate in the siRNA group (0.32±0.005) wassignificantly higher than the untreated group (0.22±0.026) and the siCONTROLgroup(0.20±0.015). We further studied the protein expression of Bax and Bcl-2. Theresults showed that after suppressing the expression of TRIM29, the expression ofBax was up-regulated and the expression of Bcl-2was down-regulated.Conclusion: Our study has systematically investigated the expression of TRIM29inNSCLC tissues and the role of TRIM29in proliferation, invasion and cisplatinchemotherapy of NCI-H520cells. Our data have shown that TRIM29was significantly correlated with histological subtypes, TNM staging and lymph nodemetastasis in NSCLC. Moreover, downregulation of TRIM29by siRNA could inhibitthe proliferation and invasion of NCI-H520cells, up-regulate the expression of Baxand down-regulate the expression of Bcl-2, increase cell chemosensitivity to cisplatin.These findings suggest that TRIM29may have a wide therapeutic application in thetreatment of human lung cancer. |
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