RESUMO
Uterine fibroids, also known as uterine leiomyomas, are a benign tumor of the human uterus and the commonest estrogen-dependent benign tumor found in women. Myocardin is an important transcriptional regulator in smooth and cardiac muscle development. The role of myocardin and its relationship with ERα in uterine fibroids have barely been addressed. We noticed that the expression of myocardin was markedly reduced in human uterine fibroid tissue compared with corresponding normal or adjacent myometrium tissue. Here we reported that myocardin induced the transcription and expression of differentiation markers SM22α and alpha smooth muscle actin (α-SMA) in rat primary uterine smooth muscle cells (USMCs) and this effect was inhibited by ERα. Notably, we showed that, ERα induced expression of proliferation markers PCNA and ki-67 in rat primary USMCs. We also found ERα interacted with myocardin and formed complex to bind to CArG box and inhibit the SM22α promoter activity. Furthermore, ERα inhibited the transcription and expression of myocardin, and reduced the levels of transcription and expression of downstream target SM22α, a SMC differentiation marker. Our data thus provided important and novel insights into how ERα and myocardin interact to control the cell differentiation and proliferation of USMCs. Thus, it may provide potential therapeutic target for uterine fibroids.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Receptor alfa de Estrogênio/metabolismo , Leiomioma/metabolismo , Proteínas Nucleares/farmacologia , Transativadores/farmacologia , Animais , Diferenciação Celular/fisiologia , Regulação da Expressão Gênica/genética , Humanos , Leiomioma/induzido quimicamente , Leiomioma/tratamento farmacológico , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/metabolismo , Proteínas Nucleares/metabolismo , Regiões Promotoras Genéticas/genética , Ratos , Fator de Resposta Sérica/metabolismo , Transativadores/metabolismoRESUMO
Epithelial-mesenchymal transition (EMT) plays an important role in breast cancer cell metastasis. Both (megakaryoblastic leukemia)/myocardin-like 1 (MKL-1) and Signal transducer and activator of transcription 3 (STAT3) have been implicated in the control of cellular metabolism, survival and growth. Our previous study has shown that cooperativity of MKL-1 and STAT3 promoted breast cancer cell migration. Herein, we demonstrate a requirement for MKL-1 and STAT3 in miRNA-mediated cellular EMT to affect breast cancer cell migration. Here we show that cooperativity of MKL-1 and STAT3 promoted the EMT of MCF-7 cells. Importantly, MKL-1 and STAT3 promoted the expression of Vimentin via its promoter CArG box. Interestingly, miR-93-5p inhibits the EMT of breast cancer cells through suppressing the expression of MKL-1 and STAT3 via targeted their 3'UTR. These results demonstrated a novel pathway through which miR-93-5p regulates MKL-1 and STAT3 to affect EMT controlling breast cancer cell migration.
Assuntos
Neoplasias da Mama/genética , Transição Epitelial-Mesenquimal/fisiologia , Regulação Neoplásica da Expressão Gênica/genética , MicroRNAs/genética , Fator de Transcrição STAT3/genética , Transativadores/genética , Neoplasias da Mama/metabolismo , Humanos , Células MCF-7 , Regiões Promotoras Genéticas/genéticaRESUMO
Myocardin is frequently repressed during human malignant transformation, and restoration of myocardin expression in sarcoma cells contributes to the inhibition of malignant growth. However, its role in breast carcinoma has barely been addressed. Here, we reported that myocardin could inhibit the proliferation of MCF-7 cells. Notably, we show that myocardin inhibited ERα-mediated proliferation of breast cancer MCF-7 via impairing ER-dependent transcriptional activation, mainly through the inhibition of the activity of ERα. Importantly, the molecular mechanism for the inhibition of the ERα-mediated proliferation is that myocardin inhibited the transcription and expression of ERα-induced PCNA, Ki-67, and E2F1 to impair ERα-mediated proliferation of breast cancer MCF-7. Interestingly, myocardin significantly enhanced the transcription and expression of miR-885 depending on the CArG box in miR-885 promoter, and miR-885 targeted the 3' untranslated regions (UTR) of E2F1 to silence the expression of E2F1. Thus, our data provided important and novel insights into how myocardin may deeply influence ERα-mediated breast cancer proliferation. In conclusion, myocardin could be seen as a breast cancer tumor suppressor so that it will provide new ideas for the treatment of breast cancer. © 2016 IUBMB Life, 68(6):477-487, 2016.
Assuntos
Neoplasias da Mama/genética , Receptor alfa de Estrogênio/metabolismo , MicroRNAs/genética , Proteínas Nucleares/metabolismo , Transativadores/metabolismo , Regiões 3' não Traduzidas , Neoplasias da Mama/patologia , Proliferação de Células/genética , Fator de Transcrição E2F1/genética , Fator de Transcrição E2F1/metabolismo , Receptor alfa de Estrogênio/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Antígeno Ki-67/genética , Antígeno Ki-67/metabolismo , Células MCF-7 , Proteínas Nucleares/genética , Antígeno Nuclear de Célula em Proliferação/genética , Antígeno Nuclear de Célula em Proliferação/metabolismo , Transativadores/genéticaRESUMO
Signal transducer and activator of transcription 3 (Stat3) and Myocardin regulate cardiomyocyte differentiation, proliferation, and apoptosis. We report a novel aspect of the cellular function of Myocardin and Stat3 in the regulation of cardiomyocyte apoptosis. Myocardin and Stat3 showed anti-apoptotic function by increasing the expression of Bcl-2 while reducing expression of the pro-apoptotic genes Bax, Apaf-1, caspase-9, and caspase-3. Moreover, myocardin/Stat3-mediated activation of Bcl-2 and Mcl-1 transcription is contingent on the CArG box. Myocardin and Stat3 synergistically inhibited staurosporine-induced cardiomyocyte apoptosis by up-regulating expression of anti-apoptotic Bcl-2 and Mcl-1 in neonatal rat cardiomyocytes. These results describe a novel anti-apoptotic Myocardin/Stat3 signaling pathway operating during cardiomyocyte apoptosis. This provides a molecular explanation for cardiomyocyte apoptosis inhibition as a critical component of myocardial protection.
RESUMO
Signal transducer and activator of transcription 3 (STAT3) controls cell survival, growth, migration, and invasion. Here, we observed that STAT3 exerted anti-apoptotic effects in breast cancer cells. On the other hand, miR-17-5p induced apoptosis in breast cancer cells, and overexpression of miR-17-5p sensitized MCF-7 cells to paclitaxel-induced apoptosis via STAT3. Overexpression of STAT3 in MCF-7 cells decreased paclitaxel-induced apoptosis, but STAT3 knockout abolished the miR-17-5p-induced increases in apoptosis. Finally, miR-17-5p promoted apoptosis by increasing p53 expression, which was inhibited by STAT3. These results demonstrate a novel pathway via which miR-17-5p inhibits STAT3 and increases p53 expression to promote apoptosis in breast cancer cells.
Assuntos
Apoptose/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Paclitaxel/farmacologia , Fator de Transcrição STAT3/genética , Regiões 3' não Traduzidas/genética , Antineoplásicos Fitogênicos/farmacologia , Apoptose/genética , Western Blotting , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Antagonistas de Estrogênios/farmacologia , Feminino , Humanos , Células MCF-7 , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Transcrição STAT3/metabolismo , Tamoxifeno/farmacologia , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
Myocardin is regarded as a key mediator for the change of smooth muscle phenotype. The gap junction protein connexin 43 (Cx43) has been shown to be involved in vascular smooth muscle cells (VSMCs) proliferation and the development of atherosclerosis. However, the role of myocardin on gap junction of cell communication and the relation between myocardin and Cx43 in VSMC phenotypic switch has not been investigated. The goal of the present study is to investigate the molecular mechanism by which myocardin affects Cx43-regulated VSMC proliferation. Data presented in this study demonstrated that inhibition of the Cx43 activation process impaired VSMC proliferation. On the other hand, overexpression miR-206 inhibited VSMC proliferation. In additon, miR-206 silences the expression of Cx43 via targeting Cx43 3' Untranslated Regions. Importantly, myocardin can significantly promote the expression of miR-206. Cx43 regulates VSMCs' proliferation and metastasis through miR-206, which could be promoted by myocardin and used as a marker for diagnosis and a target for therapeutic intervention. Thus myocardin affected the gap junction by inhibited Cx43 and myocardin-miR-206-Cx43 formed a loop to regulate VSMC phenotypic switch.
Assuntos
Conexina 43/genética , MicroRNAs/genética , Músculo Liso Vascular/citologia , Proteínas Nucleares/metabolismo , Transativadores/metabolismo , Regiões 3' não Traduzidas , Diferenciação Celular , Linhagem Celular , Proliferação de Células , Conexina 43/metabolismo , Humanos , Músculo Liso Vascular/metabolismo , FenótipoRESUMO
OBJECTIVE@#To propose a kind of robotic ankle-foot rehabilitation system for children with cerebral palsy and to preliminarily verify its feasibility in clinical application.@*METHODS@#A robot assisted ankle-foot rehabilitation system was specially designed and developed for children with cerebral palsy and a preliminary clinical study was conducted in Department of Rehabilitation Medicine, Peking University First Hospital. Modified Tardieu Scale and joint biomechanical properties (ankle plantar flexion resistance torque under different ankle dorsiflexion angles) were measured to analyze the muscle tone and soft tissue compliance of the ankle plantar flexors pre- and post-robotic training intervention. Six children with cerebral palsy (4 girls and 2 boys, mean age: 7 years) were recruited in this study. Each subject received 5 session robotic training and each session included 10-cycle passive stretching and static hold. SPSS 19.0 software was used for data statistical analysis.@*RESULTS@#Both R1 and R2 angles of Modified Tardieu Scale for ankle plantar flexors after training were significantly higher than those before the treatments (Gastrocnemius: PR1=0.003, PR2=0.029; Soleus: PR1=0.002, PR2=0.034). The difference between R2 and R1 was of no statistical difference before and after the training (P=0.067 and P=0.067, respectively). After training, the ankle plantar flexion resistance torque under different dorsiflexion angles (0°, 10°, 20°, 30°) were significantly reduced than those before training (P=0.001, P=0.001, P=0.014, P=0.002, respectively).@*CONCLUSION@#The robot assisted ankle-foot rehabilitation system can improve the contracture and soft tissue compliance of cerebral palsy children's ankle plantar flexors. All the children in the study were well tolerated and interested with the training, easy to accept and cooperate with it. This device may be suitable for application in the rehabilitation of children with cerebral palsy. However, further randomized clinical trials with larger sample size are still needed to verify the long term efficacy of this device.