RESUMO
MicroRNA, an endogenous noncoding RNA modulating gene expression, is a key molecule that by its dysregulation plays roles in inflammatory-driven carcinogenesis. This study aimed to investigate the role of oncomiR miR-21 and its target, the programmed cell death 4 (PDCD4) in tumor growth and metastasis of the liver fluke Opisthorchis viverrini-associated cholangiocarcinoma (CCA). The expression levels of miR-21 and PDCD4 were analyzed using the TaqMan miRNA expression assay and immunohistochemistry in liver tissues of both O. viverrini plus N-nitrosodimethylamine (NDMA)-treated hamsters and human CCA samples (n=23 cases). The functional assay for miR-21 was performed in CCA cell lines by the anti-miR-21 and pre-miR-21 transfection procedures. The peak of miR-21 levels were reached at 2 (hyperplastic lesions) and 6 (CCA) months of the O. viverrini plus NDMA-induced group and had a reverse response with its target PDCD4 proteins. In human CCA, miR-21 was overexpressed in tumor tissues when compared with nontumor tissues (P=0.0034) and had a negative correlation with PDCD4 protein (P=0.026). It was also found that high expression of miR-21 was significantly correlated with shorter survival (P<0.05) and lymph node metastasis (P=0.037) of CCA patients. Transient transfection of pre-miR-21 reduced the PDCD4 level and resulted in an increase of M213 CCA cell growth and wound-induced migration ability. These results indicated that miR-21 plays a role in the carcinogenesis and metastasis of O. viverrini-associated CCA by suppressing the function of PDCD4. Modulation of aberrantly expressed miR-21 may be a useful strategy to inhibit tumor cell phenotypes or improve response to chemotherapy.
Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Neoplasias dos Ductos Biliares/etiologia , Ductos Biliares Intra-Hepáticos/metabolismo , Proliferação de Células , Colangiocarcinoma/etiologia , Fasciolíase/complicações , MicroRNAs/genética , Proteínas de Ligação a RNA/metabolismo , Animais , Apoptose , Proteínas Reguladoras de Apoptose/genética , Neoplasias dos Ductos Biliares/metabolismo , Neoplasias dos Ductos Biliares/patologia , Ductos Biliares/parasitologia , Ductos Biliares/patologia , Ductos Biliares Intra-Hepáticos/parasitologia , Ductos Biliares Intra-Hepáticos/patologia , Western Blotting , Movimento Celular , Colangiocarcinoma/metabolismo , Colangiocarcinoma/secundário , Cricetinae , Fasciola hepatica/patogenicidade , Fasciolíase/genética , Fasciolíase/parasitologia , Feminino , Humanos , Técnicas Imunoenzimáticas , Masculino , Mesocricetus , Pessoa de Meia-Idade , Opistorquíase/genética , Opistorquíase/parasitologia , Opistorquíase/patologia , Opisthorchis/patogenicidade , RNA Mensageiro/genética , Proteínas de Ligação a RNA/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais CultivadasRESUMO
Altered miRNA expression could be a determinant of cancer development and/or progression. We aimed to study the role of oncomir miR-21 and tumor suppressor let-7a in the genesis of Opisthorchiasis-associated cholangiocarcinoma (CCA). The results showed that miR-21 was up-regulated while let-7a was down-regulated during cholangiocarcinogenesis in the hamster model and also in human CCA samples. The expression level of miR-21 had an inverse correlation with the mRNA level of its target RECK, a metastasis suppressor, in human CCA. Knockdown of miR-21 of KKU100 CCA cells significantly increased the mRNA level of RECK and suppressed the wound-induced migration of CCA cells. Our data suggest that miR-21 is one key molecule playing crucial roles in the CCA growth and metastasis. Manipulation of miRNA expression offers a potential avenue of CCA therapy.
