ABSTRACT
Objective To evaluate the effect of downregulation of microRNA (miR)-373 expression on cell cycle and apoptosis of a cutaneous squamous cell carcinoma (CSCC) cell line A431.Methods A431 cells at exponential growth phase were classified into 3 groups:miR-373 inhibitor group and negative control group transfected with miR-373 inhibitor and negative control miRNA respectively,and untreated group receiving no treatment.At 48 hours after the transfection,real-time PCR was performed to determine the expression of miR-373 in the above 3 groups,cell counting kit-8 (CCK-8) assay to evaluate the effect of downregulated expression of miR-373 on the proliferation of A431 cells,flow cytometry to investigate the distribution of cell cycle and changes in apoptosis of A431 cells in different treatment groups,and colorimetric analysis to detect the changes in caspase-3 activity in different treatment groups.Statistical analysis was carried out with SPSS 17.0 software by using two-sample t test for the comparison between two groups,one-way analysis of variance (ANOVA) for the comparison among 3 groups,and least significant difference (LSD)-t test for multiple comparisons.Results The expression of miR-373 was significantly lower in the miR-373 inhibitor group (0.120 ± 0.036) than in the untreated group (1.002 ± 0.022) and negative control group (1.037 ± 0.028,LSD-t =36.21,34.83,respectively,both P ＜ 0.001).At 48,72 and 96 hours,the miR-373 inhibitor group showed significantly decreased proliferative activity of A375 cells compared with the untreated group and negative control group (F =10.805,13.720 and 30.907 respectively,P =0.038,0.010 and 0.001 respectively).The proportion of A375 cells in G0/G1 phase was significantly higher in the miR-373 inhibitor group (64.69％ ± 1.18％) than in the untreated group (52.74％ ± 0.66％,t =15.51,P ＜ 0.001) and negative control group (53.80％ ± 0.80％,t =13.24,P ＜ 0.001).The proportion of total apoptotic cells and activity of caspase-3 in the miR-373 inhibitor group were 22.69％ ± 1.24％ and 1.238 ± 0.057 respectively,which were significantly higher than those in the untreated group (9.62％ ± 1.14％,0.413 ± 0.028 respectively,both P ＜ 0.001)and negative control group (9.66％ ± 0.97％,0.437 ± 0.036 respectively,both P ＜ 0.001).Conclusion MiR-373 may play an important role in the regulation of cell cycle and induction of apoptosis of the CSCC cell line A431.
ABSTRACT
Objective To investigate the expression of microRNA-373 (miR-373) in cutaneous squamous cell carcinoma (CSCC) tissues and cells,and to explore its effects on cell invasion.Methods Real-time PCR was performed to determine the expression of miR-373 in CSCC tissues and paralesional normal skin tissues,as well as in CSCC cell lines (A431 and SCL-1) and HaCaT cells.A431 cells were divided into 4 groups:miR-373 mimic group,miR-373 inhibitor group and negative control group which were transfected with miR-373 mimic,miR-373 inhibitor and negative control miRNA respectively,and untreated group receiving no treatment.Cell invasion assay was performed to evaluate effects of miR-373 downregulation on cell invasion.Western blot analysis was conducted to assess effects of miR-373 downregulation on the protein expression of matrix metalloproteinase-2 (MMP-2) and MMP-9.Results Expression of miR-373 was significantly higher in the CSCC tissues (2.465 ± 0.218) than in the paralesional normal skin tissues (1.000 ± 0.000,P ＜ 0.05),and higher in SCL-1 cells (1.864 ± 0.178) and A431 cells (2.919 ± 0.277) than in HaCaT cells (1.000 ± 0.000,P ＜ 0.05).Most notably,miR-373 expression was also markedly higher in metastatic CSCC tissues than in non-metastatic CSCC tissues (3.323 ± 0.344 vs.1.914 ± 0.161,t =4.158,P =0.000 4).Compared with the untreated group and negative control group,the miR-373 mimic group showed significantly increased miR-373 expression and invasive ability,while the miR-373 inhibitor group showed markedly decreased miR-373 expression and invasive ability (all P ＜ 0.05).Conclusion MiR-373 downregulation can significantly suppress the invasion of A431 cells,and obviously decrease the protein expression of MMP-2 and MMP-9.
ABSTRACT
Objective To investigate the expression of microRNA-373 (miR-373) in cutaneous squamous cell carcinoma (CSCC) tissues and cells,and to explore its effects on cell invasion.Methods Real-time PCR was performed to determine the expression of miR-373 in CSCC tissues and paralesional normal skin tissues,as well as in CSCC cell lines (A431 and SCL-1) and HaCaT cells.A431 cells were divided into 4 groups:miR-373 mimic group,miR-373 inhibitor group and negative control group which were transfected with miR-373 mimic,miR-373 inhibitor and negative control miRNA respectively,and untreated group receiving no treatment.Cell invasion assay was performed to evaluate effects of miR-373 downregulation on cell invasion.Western blot analysis was conducted to assess effects of miR-373 downregulation on the protein expression of matrix metalloproteinase-2 (MMP-2) and MMP-9.Results Expression of miR-373 was significantly higher in the CSCC tissues (2.465 ± 0.218) than in the paralesional normal skin tissues (1.000 ± 0.000,P ＜ 0.05),and higher in SCL-1 cells (1.864 ± 0.178) and A431 cells (2.919 ± 0.277) than in HaCaT cells (1.000 ± 0.000,P ＜ 0.05).Most notably,miR-373 expression was also markedly higher in metastatic CSCC tissues than in non-metastatic CSCC tissues (3.323 ± 0.344 vs.1.914 ± 0.161,t =4.158,P =0.000 4).Compared with the untreated group and negative control group,the miR-373 mimic group showed significantly increased miR-373 expression and invasive ability,while the miR-373 inhibitor group showed markedly decreased miR-373 expression and invasive ability (all P ＜ 0.05).Conclusion MiR-373 downregulation can significantly suppress the invasion of A431 cells,and obviously decrease the protein expression of MMP-2 and MMP-9.
ABSTRACT
Objective To investigate the inhibitory effect of 5-fluorouracil (5-FU) on hepatocellular carcinoma (HCC) cell growth and to elucidate its potential molecular mechanism.Methods Real-time PCR analysis was conducted to determine the expression of miR-373 in HCC tissue specimens and HCC cell lines.The expression of miR-373 was also evaluated in HepG2 cells after 5-FU treatment.Western blot analysis was performed to detect the protein levels of PPP6C,a verified target of miR-373,with transfection of miR-373 mimics or 5-FU treatment.A rescue assay was conducted to investigate the cell growth in HepG2 cells by using CCK-8.Results miR-373 expression was up-regulated in both HCC tissues and cell lines.miR-373 expression depicted about 2.94-fold augment in HepG2 cells as compared to normal liver cells control (P ＜0.01).5-FU treatment led to a significant decrease of miR-373 levels (approximately 50％,P ＜0.01,48 h) and resulted in a marked increase of PPP6C protein (approximately 2.1-fold,48 h) in HepG2 cells.The overexpression of miR-373 could prevent the impact of 5-FU treatment on cell growth in HepG2 cells and CCK-8 assay showed that HepG2 cell growth was rescued approximately 81％ and 84％ at 24 h (P ＜ 0.05) and 48 h (P ＜ 0.01),respectively.Conclusion 5-FU can repress endogenous miR-373 level,which activates the expression of downstream targeted gene PPP6C,thereby exerting an inhibitory effect on HepG2 cells.