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Objective:To investigate the expression of silencing kinesin KIF4A in thyroid cancer tissues and its relationship with clinicopathological characteristics of thyroid cancer patients, and to assess the role of KIF4A in the progression of thyroid cancer.Methods:The expression of KIF4A in normal thyroid tissues and the thyroid cancer population and its relationship with disease-free survival of patients were analyzed online by gene expression interaction analysis (GEPIA) database, and the expression of KIF4A in tumor tissues and paraneoplastic tissues of thyroid cancer patients was assessed by immunohistochemical assays. The patients were divided into high- and low-expression groups according to the staining intensity, and the correlation between the expression of KIF4A and clinicopathological features was analyzed. The effect of KIF4A on the proliferation of thyroid cancer cells was explored by a clone formation assay and an MTT assay.Results:According to the analysis of the web-based database, KIF4A showed significantly high expression in human thyroid cancer tissues, and disease-free survival was significantly lower in highly expressed patients. The results of the case analysis showed that the correlation between KIF4A expression intensity and gender, age, and lymph node metastasis in thyroid cancer patients was not statistically significant (all P>0.05), and the correlation with TNM stage and intraglandular dissemination was statistically significant (all P<0.05). The results of the colony formation assay and the MTT assay showed that the expression of KIF4A promoted the proliferation of thyroid cancer cells ( P<0.05). Conclusions:KIF4A can promote the progression of thyroid cancer and has the potential to become a new therapeutic target for thyroid cancer.
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Objective To explore the role of chromokinesin KIF4A in gastric cancer cell invasion using gastric cancer cells SGC-7901 and chromokinesin KIF4A deficient gastric cancer cells (SGC-shKIF4A).Methods Expression levels of KIF4A in controlling gastric cancer cells (SGC-shNC) and SGC-shKIF4A cells were determined by Western Blot.Invasion of gastric cancer cells were assessed using Transwell invasion assay and the number of cells passing through the matrigel was counted.Changing numbers of cortactin in SGC-7901,SGC-shNC,and SGC-shKIF4A cells were analyzed by immunofluorescence staining.Results Compared to the SGC-shNC cells,invasion ability of SGC-shKIF4A cells was increased.Compared to other cells,the numbers of cortactin in SGC-shKlF4A cells was also increased suggesting invadopodia in these cells was increased(P＜0.01).Conclusions Chromokinesin KIF4A acts as a tumor suppressor by inhibiting gastric cancer cells invasion and the results provides strong evidences for KIF4A serving as one of potent targets for gastric cancer prognostics and treatment in clinic.
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Objective To investigate the process that chromosome kinesin KIF4A promote cisplatin resistance in lung cancer cells.Methods Reverse transcription PCR (RT-PCR) and Western Blot experiments were performed to analyze the expression of KIF4A in lung cancer cells A549 and cisplatin (DDP) resistant cells A549/ DDP.Cell transfection, RNA interference (RNAi) experiments and thiazolyl blue tetrazolium bromide (MTT) assays were carried out to examine cell proliferation of A549 cells with overexpression of exogenous KIF4A and A549/DDP cells with depletion of endogenous KIF4A after cisplatin treatment.Results Expression of KIF4A in A549/DDP cells was higher than that in A549 cells.With overexpression of exogenous KIF4A, A549 cells displayed drug resistance to cisplatin.On the contrary, depletion of endogenous KIF4A in A549/DDP cells resulted in cisplatin sensitivity.Conclusions Chromosome kinesin KIF4A involves in the regulation of cisplatin resistance in lung cancer cells and KIF4A may be a potential and effective new biological target for treatment of lung cancer cisplatin resistance.
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Objective To construct stable chromokinesin KIF4A knockdown gastric cancer cell lines (SGC-7901) and study the mitotic spindle midzone formation in these cells.Methods Short hairpin RNA (shRNA) expression plasmids of pGPU-GFP-shKIF4A,pGPU-GFP-shNC specific targetting KIF4A and non-sense DNA sequences were constructed respectively and then transfected into SGC-7901 cells.The cells were cultured in selection medium containing G418 to form single clones.Stable KIF4A shRNA expressing SGC-7901 cells were picked up under an fluoroscent microscope and identified by Western Blot.The spindle midzone in these cells was analyzed after immunofluorescence staining.Results Three cell lines stably expressing KIF4A shRNA and one with shNC were successfully constructed.Compare to the control cell line,KIF4A knockdown cell lines represented remarkable elongation of spindle midzone and the less the KIF4A,the longer spindle midzone.Conclusions Stable KIF4A knockdown SGC-7901 cell lines were successfully constructed that can serve for further study of KIF4A ' s function and its role in proliferation and development of gastric cancer.
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Background and purpose:Chemotherapy is the important way of breast cancer treatment, but the drug-resistance has attracted special attention. The emergence of drug resistance is closely related to the abnormal enhancement of DNA-damage repair. Both Kif4A and PARP-1 are important molecules of DNA repair. The research investigated the function of Kif4A in epirubicin up-regulating the activity of PARP-1 in breast cancer cells and possible significance. Methods:Western blot was used to detect the expression of Kif4A and PARP-1 after treatment with epirubicin in MDA-MB-231 and MCF-7 cells; the expression of PARP-1 and its activity were detected after high expression of Kif4A and treatment with epirubicin;FCM was used to detect cell apoptosis after treatment with epirubicin combined with PARP-1 inhibitor 3-ABA. Results:Epirubicin up-regulated PARP-1 activity and induced low expression of Kif4A in breast cancer cells, both of them showed dose-dependent and time-dependent. After high expression of Kif4A, the activity of PARP-1 was inhibited and the apoptosis of cells increased, epirubicin partially reversed the activity of PARP-1 inhibited by high Kif4A expression. Both of epirubicin and 3-ABA induced cell apoptosis, combination of them further increased cell apoptosis compared with alone used (P<0.05). The results also showed the apoptosis rate of MDA-MB-231 cells induced by epirubicin, PARP-1 inhibitor 3-ABA and high expression Kif4A was higher than that of MCF-7 cells (P<0.05). Conclusion:Epirubicin increases the activity of PARP-1 dependent on the low expression of Kif4A in breast cancer cells. Kif4A might become a novel target for overcoming resistance of epirubicin.
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Objective To establish KIF4A 3'UTR esiRNA library and analyze the advantage of method in studying the function of KIF4A in SGC-7901 cells.Methods The GST-fusion protein of Escherichia coli endoribonuclease Ⅲ (GST-RNase Ⅲ) was used to digest the double strand RNA (dsRNA),which was transcribed in vitro from a 502bp template of KIF4A genome (T7-KIF4A 3'UTR).The KIF4A esiRNA library generated from the above method and chemically synthesized KIF4A siRNA were then used to transfect SGC-7901 cells at 10 nmol/L and 20 nmol/L.Real-time quantitative PCR and Western Blot were used to detect the mRNA and protein level of KIF4A,respectively.Results The KIF4A esiRNA library was effectively established from dsRNA digestion using GST-RNase Ⅲ.KIF4A expression was significantly reduced in SGC-7901 cells transfected with KIF4A esiRNA or siRNA.In addition,the inhibitory effect of KIF4A esiRNA was more effective than that of chemically synthesized siRNA.Conclusion KIF4A esiRNA library which was obtained using biological method can more effectively inhibited the expression of KIF4A more effectively in SGC-7901 cells than chemically synthesized siRNA.Therefore,esiRNA library can be used as a new and more effective method in studying the function of KIF4A in SGC-7901 cells.