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BACKGROUND@#Ovarian cancer is one of the most widespread malignant diseases of the female reproductive system worldwide. The plurality of ovarian cancer is diagnosed with metastasis in the abdominal cavity. Epithelial-mesenchymal transition (EMT) exerts a vital role in tumor cell metastasis. However, it remains unclear whether long non-coding RNA (lncRNA) are implicated in EMT and influence ovarian cancer cell invasion and metastasis. This study was designed to investigate the impacts of lncRNA AC005224.4 on ovarian cancer.@*METHODS@#LncRNA AC005224.4, miR-140-3p, and snail family transcriptional repressor 2 ( SNAI2 ) expression levels in ovarian cancer and normal ovarian tissues were determined using real-time quantitative polymerase chain reaction (qRT-PCR). Cell Counting Kit-8 (CCK-8) and Transwell (migration and invasion) assays were conducted to measure SKOV3 and CAOV-3 cell proliferation and metastasis. E-cadherin, N-cadherin, Snail, and Vimentin contents were detected using Western blot. Nude mouse xenograft assay was utilized to validate AC005224.4 effects in vivo . Dual-luciferase reporter gene assay confirmed the targeted relationship between miR-140-3p and AC005224.4 or SNAI2 .@*RESULTS@#AC005224.4 and SNAI2 upregulation and miR-140-3p downregulation were observed in ovarian cancer tissues and cells. Silencing of AC005224.4 observably moderated SKOV3 and CAOV-3 cell proliferation, migration, invasion, and EMT process in vitro and impaired the tumorigenesis in vivo . miR-140-3p was a target of AC005224.4 and its reduced expression level was mediated by AC005224.4. miR-140-3p mimics decreased the proliferation, migration, and invasion of ovarian cancer cells. SNAI2 was identified as a novel target of miR-140-3p and its expression level was promoted by either AC005224.4 overexpression or miR-140-3p knockdown. Overexpression of SNAI2 also facilitated ovarian cancer cell viability and metastasis.@*CONCLUSION@#AC005224.4 was confirmed as an oncogene via sponging miR-140-3p and promoted SNAI2 expression, contributing to better understanding of ovarian cancer pathogenesis and shedding light on exploiting the novel lncRNA-directed therapy against ovarian cancer.
Subject(s)
Animals , Mice , Humans , Female , MicroRNAs/metabolism , RNA, Long Noncoding/metabolism , Ovarian Neoplasms/metabolism , Cell Line, Tumor , Epithelial-Mesenchymal Transition/genetics , Cell Movement/genetics , Cell Proliferation/genetics , Gene Expression Regulation, Neoplastic/genetics , Snail Family Transcription Factors/metabolismABSTRACT
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 prepare centromere-associated protein E(CENP-E)polyclonal antibody with specificity by using New Zealand white rabbits.Methods Prokaryotic expression plasmid of pHis-CENPEC410 was constructed by molecular cloning technique and then transformed into competent cells of E.coli BL-21 (DE3).HisCENPEC410 fusion protein was induced by isopropyl β-D-thiogalactoside (IPTG) and purified by affinity chromatography using Ni-NTA beads.The purified protein was used as antigen to immune New Zealand white rabbits to produce spccific polyclonal antibody of CENP-E.The antibodies serum was detected by immunoblotting and co-immunoprecipitation,and the purified antibodies were detected by immunofluorescene staining.Results The results of immunoblotting and co-immunoprecipitation demonstrated that the antibody serum was effective and the purified antibody could be applied to immunofluorescene test.Conclusions CENP-E polyclonal antibody with high specificity and sensitivity was obtained,which lay the foundation for the follow-up study of CENP-E.
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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 KIF18A is a protein that has close relation with mitotic regulation and tumor development.This study aimed to establish KIF18A protein expression system in baculovirus,which may help to realize high efficient synthesis of KIF1 8A protein in vitro.Methods Transfer vector was constructed with molecular cloning method,and recombinant baculovirus were obtained through gene transposition.KIF18A protein was expressed by transforming recombinant baculovirus into infected insect Sf-9 cells to realize the synthesis efficiency.Results It was confirmed by DNA sequencing,microscopic observation and Western Blot that the KIF18A protein expression system in baculovirus was successfully established.Conclusions Conditions for transfer vector and recombinant virus transfection are defined,and high efficient KIF18A protein baculovirus expression system are successfully constructed.
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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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Objective Mitotic spindle and midbody are both microtubule-based temporary structures during cell growth and play essential roles in mitosis.The purpose of this study was to establish a mature and efficient method to extract mitotic spindle and midbody.Methods Through the cell cycle synchronization method,mitotic spindle or midbody was made appear inside cells.Low permeability swelling and glycerol gradient centrifugation principles were then used to extract spindle and midbody.Results By Western Blot and immunofluorescence staining,the extracts were identified as mitotic spindle and midbody.Conclusions The successful extraction of mitotic spindle and midbody from synchronized Hela cells will provide foundation for identifying the proteins located in cell during mitosis,and be of great significance to the study of molecular regulation mechanisms of mitosis and tumorigenesis.
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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.