ABSTRACT
Objective To examine the complement component 1 Q subcomponent-binding protein (C1QBP) gene expression in human resistance choriocarcinoma cell lines and its parental cell line JeG-3,and to investigate whether silence C 1QBP by small interference RNA could reverse the resistance of human resistance choriocarcinoma cell lines to its relevant chemotherapy drugs.Methods Expression of C1QBP mRNA and protein in cells were detected by real-time fluorogenic quantitative PCR and western blot,respectively.The difference of C 1QBP expression was compared between human resistance choriocarcinoma cell lines and its parental cell line JeG-3.Sub-cellular location was proved by confocal immunofluorescence microscopy.A lentiviral vector containing short hairpin RNA (shRNA) targeting C 1QBP was constructed and cotransfected with the packaging plasmid mixture into 293T cells by lipofectamine 2000.The human resistance choriocarcinoma cell lines were infected with the packaged lentivirus.Real-time fluorogenic quantitative PCR and western blot were used to validate whether the C 1QBP gene expression was silenced.The cell counting kit 8(CCK8)was used to determine the drug sensitivity.Results (1)The C1QBP mRNA expression levels among four human resistance choriocarcinoma cell lines[JeG-3/floxuridiuum (FUDR),JeG-3/methotrexate (MTX),JeG-3/etoposide (VP),JeG-3/dactinomycin (KSM)] were 2.520±0.680,1.770±0.230,1.940±0.090 and 1.740±0.350 folds compared to that in JeG-3 cells.The C1QBP protein was higher expression level in human resistance choriocarcinoma cell lines than that in JeG-3.The immunofluorescence methods and confocal analysis showed that C1QBP localized predominantly in the mitochondrial matrix.(2)The C1QBP mRNA expression in JeG-3/FUDR cells after infected with lentiviral vector were decreased by 93.1％ (P＜0.01).The protein expression of C 1QBP in JeG-3/FUDR cells after infected with lentiviral vector were almost completely suppressed.The resistance indexes of four human resistance choriocarcinoma cell lines(JeG-3/FUDR,JeG-3/MTX,JeG-3/VP,JeG-3/KSM) were respectively 86.3％,93.9％,92.8％ and 89.9％,which were decreased remarkably by knockdown the C 1QBP expression (P＜0.05).Conclusions C1QBP is overexpressed in human resistance choriocarcinoma cell lines compared with parental cell line JeG-3.Inhibition of C 1QBP by lentivirus-mediated small interference RNA could effectively reverses the resistance of human resistance choriocarcinoma cell lines to its relevant chemotherapy drugs.
ABSTRACT
Objective To establish human choriocarcinoma JeG-3 cell line resistant to floxuridine (FUDR)and describe the characteristics of this FUDR-resistant subline.The thymidylate synthase (TS) expression level in FUDR-resistant subline was also discussed.Methods The FUDR-resistant sub-line JeG-3/FUDRA was established by intermitted exposure to grads increased FUDR.Reversed microscope was used to observe the morphological changes in FUDR-resistant sub-line.Population doubling time was calculated and compared based on the growth curve of these two cell lines,cell cycles and chromosomal ploidy were assayed with flow cytometry methods.The chemo-luminescence assay was used to detect the hormone secretion by two kinds of cell lines.The resistant index (RI) was measured by cell counting kit-8 (CCK-8)assay.Quantitative RT-PCR was used to detect the mRNA expression level of TS and we also detected the TS mRNA expression level in different doses exposed subline.Results The RI of JeG-3/FUDRA was 31.62.Compared with the JeG-3 cell,the FUDR-resistant cell line had gross changes in morphological,cell growth,cell cycles and chromosomal numbers.The ability of human chorionic gonadotrop(hCG) and progesterone secretion was lower in JeG-3/FUDRA subline.The trend of TS mRNA expression was:while exposed to low concentration of FUDR,the TS mRNA expression level was downregulated,then followed the increasing dose of the drug,the expression level of TS mRNA ascended gradually.When the terminal concentration was reached,the expression level of TS mRNA in JeG-3/FUDRA subline was higher than that of JeG-3 cell line (P＜0.05).Conclusions We established the FUDR-resistant subline of JeG-3 successfully.The TS mRNA expression level is stage-related to the different concentration and different phase in FUDR exposure.Our data suggested that TS mRNA expression level may not be used as a biomarker to predict the chemosensitivity in FUDR-based chemotherapy.