ABSTRACT
MicroRNAs (miRNAs) are a type of small non-coding RNAs that are often play important roles in carcinogenesis, but the carcinogenic mechanism of miRNAs is still unclear. This study will investigate the function and the mechanism of miR-638 in carcinoma (GC). The expression of miR-638 in GC and the DNA copy number of miR-638 were detected by real-time PCR. The effect of miR-638 on cell proliferation was measured by counting kit-8 assay. Different assays, including bioinformatics algorithms (TargetScan and miRanda), luciferase report assay and Western blotting, were used to identify the target gene of miR-638 in GC. The expression of miR-638 target gene in clinical CRC tissues was also validated by immunohistochemical assay. From this research, we found that miR-638 was downregulated in GC tissues compared with corresponding noncancerous tissues (NCTs), and the DNA copy number of miR-638 was lower in GC than NCTs, which may induce the corresponding downregulation of miR-638 in GC. Ectopic expression of miR-638 inhibited GC cell growth in vitro. Subsequently, we identified that PLD1 is the target gene of miR-638 in GC, and silencing PLD1 expression phenocopied the inhibitory effect of miR-638 on GC cell proliferation. Furthermore, we observed that PLD1 was overexpressed in GC tissues, and high expression of PLD1 in GC predicted poor overall survival. In summary, we revealed that miR-638 functions as a tumor suppressor in GC through inhibiting PLD1.
Subject(s)
Humans , 3' Untranslated Regions , Genetics , Apoptosis , Genetics , Base Sequence , Cell Line, Tumor , Cell Proliferation , Genetics , Down-Regulation , Genetics , MicroRNAs , Genetics , Phospholipase D , Genetics , Prognosis , Stomach Neoplasms , Diagnosis , Genetics , PathologyABSTRACT
MicroRNAs (miRNAs) that exert function by posttranscriptional suppression have recently brought insight in our understanding of the role of non-protein-coding RNAs in carcinogenesis and metastasis. In this study, we described the function and molecular mechanism of miR-139-5p in colorectal cancer (CRC) and its potential clinical application in CRC. We found that miR-139-5p was significantly downregulated in 73.8% CRC samples compared with adjacent noncancerous tissues (NCTs), and decreased miR-139-5p was associated with poor prognosis. Functional analyses demonstrated that ectopic expression of miR-139-5p suppressed CRC cell migration and invasion in vitro and metastasis in vivo. Mechanistic investigations revealed that miR-139-5p suppress CRC cell invasion and metastasis by targeting AMFR and NOTCH1. Knockdown of the two genes phenocopied the inhibitory effect of miR-139-5p on CRC metastasis. Furthermore, the protein levels of the two genes were upregulated in CRC samples compared with NCTs, and inversely correlated with the miR-139-5p expression. Increased NOTCH1 protein expression was correlated with poor prognosis of CRC patients. Together, our data indicate that miR-139-5p is a potential tumor suppressor and prognostic factor for CRC, and targeting miR-139-5p may repress the metastasis of CRC and improve survival.
Subject(s)
Animals , Female , Humans , Male , Middle Aged , Base Sequence , Cell Line, Tumor , Cell Movement , Genetics , Colorectal Neoplasms , Genetics , Pathology , Therapeutics , Down-Regulation , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , HCT116 Cells , HEK293 Cells , Mice, Inbred BALB C , Mice, Nude , MicroRNAs , Genetics , Neoplasm Invasiveness , RNA Interference , Receptor, Notch1 , Genetics , Metabolism , Receptors, Autocrine Motility Factor , Genetics , Metabolism , Reverse Transcriptase Polymerase Chain Reaction , Sequence Homology, Nucleic Acid , Survival Analysis , Xenograft Model Antitumor AssaysABSTRACT
Objective To investigate the association between the genetic polymorphisms in GSTA1 and the clinical outcome of breast cancer patients treated with cyclophosphamide-based adjuvant chemotherapy. Methods A total of 137 breast cancer patients receiving cyclophosphamide-based adjuvant chemotherapy were recruited ( 124 cases with infiltrative ductal carcinoma, 5 cases with infiltrative lobular carcinoma and 8 cases with other histological types). PCR-LDR method was used to detect the genotypes of GSTA1. Survival curves were generated by the Kaplan-Meier method, and verified by the log-rank test. Cox proportional hazards regression analysis was used to estimate the prognostic factors in multivariate analysis. Results Of the 137 breast cancer patients, the genotypic frequencies of the GSTA1 * A/* A,* A/* B and * B/* B were 67.2% ( 92/137 ), 31.4% ( 43/137 ) and 1.5% ( 2/137 ), respectively. No significant differences were found between the genotypic frequencies and groups categorization according to age, stage, lymph node metastasis, ER or PR status (x2 = 0. 722,1. 967, 3. 303, 0. 226 and 0. 709, all P ＞0. 05 ) ;through Fisher exact test, also no significant differences were found between the genotypic frequencies and group categorization according to tumor size, histological types and grading ( all P ＞ 0. 05 ) . The recurrence rates in patients with GSTA1 * A/* A and * A/* B or * B/* B genotypes were 47. 8% (44/92) and 31.1% ( 14/45 ), respectively, and the mortality rates were 22. 8% ( 21/92 ) and 17. 8% ( 8/45 ),respectively. Patients with GSTA1 * A/* B and * B/* B genotypes were significantly associated with reduced hazard of relapse (x2 =18.723, P＜0. 01)and mortality (x2 =7.352, P＜0.01), compared to cases with the common * A/* A genotypes, according to Kaplan-Meier survival analysis and log-rank test. Moreover,Cox multivariate analysis showed that GSTA1 polymorphisms appeared to be an independent risk factor for recurrence-free survival ( OR =0. 222, 95% CI:0. 108-0. 458, P ＜0. 01 ) and overall survival ( OR =0. 362,95% CI:0. 145-0. 902, P ＜ 0. 05 ). Conclusion These data indicate that GSTA1 polymorphism may be a potential prognostic factor for recurrence-free survival and overall survival in breast cancer patients treated with cyclophosphamide-based adjuvant chemotherapy.