RESUMO
AIMS: MicroRNA served as inhibitor for gene expression in various cancers. This study aimed to investigate the role of miR-605 and EN2 in prostate cancer (PCa). MATERIALS AND METHODS: In this research, the expression of miR-605 and EN2 protein in PCa tissues and cells were determined by qRT-PCR and western blot, respectively. The cell proliferation was measured by Cell Counting Kit-8 (CCK-8) and the tumor cell invasion assay was accomplished with transwell system. Flow cytometry was used to analyze the cell cycle. The endogenous expression of miR-605 and EN2 was modulated by recombinant plasmids and cell transfection. Dual luciferase reporter assay was performed to determine the interaction between miR-605 and EN2 in PCa cells. KEY FINDINGS: The expression of miR-605 was lower in PCa tissue and cells than that in normal tissues and cells, while the expression of EN2 was just the opposite. Down-regulation of the EN2 by siRNA inhibited the proliferation and invasion of PC3 cells, and the cell cycle was arrested in G0/G1 phase. EN2 regulated the expression of E-cadherin and Vimentin through Snail and EN2 regulated the cell cycle and cell proliferation via PI3K/AKT pathway. MiR-605 inhibited the proliferation and invasion of PCa cells through targeting EN2. SIGNIFICANCE: EN2 is negatively regulated by miR-605, and down-regulation of miR-605 promotes the proliferation and invasion of PCa cells by up-regulating EN2, which leads to PCa development and progression.
Assuntos
Proliferação de Células/genética , Proteínas de Homeodomínio/genética , MicroRNAs/genética , Proteínas do Tecido Nervoso/genética , Neoplasias da Próstata/genética , Western Blotting , Ciclo Celular , Linhagem Celular Tumoral , Progressão da Doença , Regulação para Baixo , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Invasividade Neoplásica/genética , Fosfatidilinositol 3-Quinases , Neoplasias da Próstata/patologia , Proteínas Proto-Oncogênicas c-akt , RNA Interferente Pequeno/administração & dosagem , Reação em Cadeia da Polimerase em Tempo Real , Regulação para CimaRESUMO
OBJECTIVE: To dynamically investigate the morphology of human gastric cancer SGC-7901 cell clones, and then compare the tumorigenic ability of different clones in order to identify the tumor stem cell clones. METHODS: Clones derived from gastric cancer SGC-7901 cells were assessed by morphological observation, and the clone formation rate and proportion of each clone were calculated. The expression of CD44 and CDX2 in different clones was detected by immunofluorescence microscopy and Western blot. Furthermore, different clones were isolated and cultured, and their self-renewal property was assayed. Cells of different clones were subcutaneously inoculated into nude mice and the tumorigenic ability of each group was determined. RESULTS: Clones derived from gastric cancer SGC-7901 cells had three types, i.e. clones of tight, transitional and loose types. The total clone formation rate was (9.80 ± 1.07)%, and the proportion of tight, transitional and loose type clones was 10.2%, 56.0% and 33.8%, respectively. The results of immunofluorescence microscopic examination showed that the signal of CD44 was significantly stronger in the tight clones than in the transitional and loose clones, however, the signal of CDX2 was weakest in the tight colonies. The results of Western blot were consistent with that of immunofluorescence microscopic observation. SGC-7901 cells of tight clones possessed strong ability of self-renewal and in vivo tumorigenicity in the nude mice. CONCLUSION: SGC-7901 cell clones vary in morphology and differentiation, and the tight type clones may include rich gastric cancer stem cells.
Assuntos
Diferenciação Celular , Células-Tronco Neoplásicas/citologia , Neoplasias Gástricas/patologia , Animais , Fator de Transcrição CDX2 , Linhagem Celular Tumoral , Proliferação de Células , Células Clonais/classificação , Feminino , Proteínas de Homeodomínio/metabolismo , Humanos , Receptores de Hialuronatos/metabolismo , Camundongos , Camundongos Nus , Transplante de Neoplasias , Células-Tronco Neoplásicas/metabolismo , Distribuição Aleatória , Neoplasias Gástricas/metabolismoRESUMO
The androgen receptor, like other nuclear receptors, activates target genes by binding to hormone-responsive enhancers. Here we demonstrate that androgen induces robust recruitment of androgen receptor, members of the p160 coactivator family, and CREB-binding protein p300 specifically at the distant enhancer of prostate-specific antigen (PSA) gene. Unexpectedly, we found that RNA polymerase II (Pol II) is directly recruited to the enhancer in a hormone-dependent manner, independent of the proximal promoter, and that the isolated PSA enhancer can mediate efficient androgen induction of transcription. Inhibition of the Pol II carboxyl-terminal domain kinase activity with low concentrations of flavopiridol blocks Pol II transfer from the enhancer to the promoter and selectively abolishes PSA induction by androgen. Moreover, elevated levels of the p160 coactivator ACTR/AIB1 increase both androgen-dependent and -independent PSA expression, by facilitating Pol II recruitment to the enhancer. These results support a model in which nuclear receptors and their coactivators mediate hormone induction by serving as a staging platform for Pol II recruitment.
