RESUMO
The development of resistance to EGFR Tyrosine kinase inhibitors (TKIs) in NSCLC with activating EGFR mutations is a critical limitation of this therapy. In addition to genetic alterations such as EGFR secondary mutation causing EGFR-TKI resistance, compensatory activation of signaling pathways without interruption of genome integrity remains to be defined. In this study, we identified S6K1/MDM2 signaling axis as a novel bypass mechanism for the development of EGFR-TKI resistance. The observation of S6K1 as a candidate mechanism for resistance to EGFR TKI therapy was investigated by interrogation of public databases and a clinical cohort to establish S6K1 expression as a prognostic/predictive biomarker. The role of S6K1 in TKI resistance was determined in in vitro gain-and-loss of function studies and confirmed in subcutaneous and orthotopic mouse lung cancer models. Blockade of S6K1 by a specific inhibitor PF-4708671 synergistically enhanced the efficacy of TKI without showing toxicity. The mechanistic study showed the inhibition of EGFR caused nuclear translocation of S6K1 for binding with MDM2 in resistant cells. MDM2 is a downstream effector of S6K1-mediated TKI resistance. Taken together, we present evidence for the reversal of resistance to EGFR TKI by the addition of small molecule S6K1/MDM2 antagonists that could have clinical benefit.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/patologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Neoplasias Pulmonares/patologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Quinases S6 Ribossômicas 70-kDa/antagonistas & inibidores , Adulto , Animais , Linhagem Celular Tumoral , Transformação Celular Neoplásica , Receptores ErbB/antagonistas & inibidores , Humanos , Masculino , Camundongos , Mutação , Prognóstico , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacosRESUMO
The apoptosis that occurs in the immature testis under physiological conditions is necessary for male germ cell development, whereas improper activation of apoptosis can impair spermatogenesis and cause defects in reproduction. We previously demonstrated that in mice, the makorin-2 (Mkrn 2) gene is expressed exclusively in the testis and its deletion leads to male infertility. To understand the potential molecular mechanism, in this study, we found that levels of apoptosis in the testis were abnormally high in the absence of Mkrn 2. To identify specific gene(s) involved, we performed digital gene expression profiling (DGE) and pathway analysis via gene set enrichment analysis (GSEA) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, and we found that MKRN2 inhibits p53 apoptosis effector related to PMP22 (PERP) expression and that levels of the protein in sperm samples have an inverse correlation with infertility levels. GSEA additionally indicated that PERP is a negative regulator of spermatogenesis and that its ectopic expression induces male infertility. Further, Gene Expression Omnibus (GEO) dataset analysis showed that p53, upstream of PERP, was upregulated in oligoasthenoteratozoospermia (OAT). These observations suggest that Mkrn 2 is crucial for protecting germ cells from excessive apoptosis and implicate Mkrn 2-based suppression of the p53/PERP signaling pathway in spermatogenesis and male fertility.
Assuntos
Apoptose/genética , Infertilidade Masculina/genética , Ribonucleoproteínas/genética , Espermatogênese/genética , Animais , Células Cultivadas , Fibroblastos , Perfilação da Expressão Gênica , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Knockout , Oligospermia/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Teratozoospermia , Testículo , Proteína Supressora de Tumor p53/metabolismoRESUMO
PURPOSE: Glioblastoma multiforme (GBM) is one of the deadliest tumors, which is involved in numerous dysregulated microRNAs including miR-137. However, the mechanism of how miR-137 suppression associated with cancer progression and chemoresistance still remains to be elucidated. METHODS: Quantitative reverse transcriptase-PCR (qRT-PCR), DNA methylation analysis, cell proliferation assay, flow cytometric analysis, invasion assay, in situ tumor formation experiment were performed to test the expression levels and functions of miR-137 in GBM. Bioinformatics analysis, luciferase reporter assay, qRT-PCR, immunoblotting, immunofluorescence, and immunohistochemistry assay were used to identify and verify the target of miR-137. RESULTS: We found that miR-137 was downregulated in primary and recurrent GBM compared with normal brain tissues. Overexpression of miR-137 inhibited cell invasion and enhanced cell chemosensitivity to temozolomide (TMZ) by directly targeting low-density lipoprotein receptor-related protein 6 (LRP6) in GBM. Forced expression of LRP6 cDNA without its 3'-UTR region partly restored the effects of miR-137 in vitro and in vivo. Hypoxia-induced miR-137 methylation was responsible for the miR-137 suppression, leading to the cell chemoresistance and poor prognosis of GBM. CONCLUSIONS: These findings demonstrated the detailed molecular mechanism of miR-137 in regulating GBM growth and chemoresistance in hypoxia microenvironment, suggesting the potentiality of miR-137 as a therapeutic target for GBM.
RESUMO
Glioma is the most malignant brain tumors in the world, the function and molecular mechanism of microRNA-199a (miR-199a) in glioma is not fully understood. Our research aims to investigate miR-199a/K-RAS axis in regulation of glioma tumor growth and chemoresistance. The function of miR-199a in glioma was investigated through in vitro and in vivo assays. We found that miR-199a in tumor tissues of glioma patients was significantly downregulated in this study. Kinase suppressor of ras 1 (K-RAS), was indicated as a direct target of miR-199a, as well as expression levels of K-RAS were inversely correlated with expression levels of miR-199a in human glioma specimens. Forced expression of miR-199a suppressed AKT and ERK activation, decreased HIF-1α and VEGF expression, inhibited cell proliferation and cell migration, forced expression of K-RAS restored the inhibitory effect of miR-199a on cell proliferation and cell migration. Moreover, miR-199a renders tumor cells more sensitive to temozolomide (TMZ) via targeting K-RAS. In vivo experiment validated that miR-199a functioned as a tumor suppressor, inhibited tumor growth by targeting K-RAS and suppressed activation of AKT, ERK and HIF-1α expression. Taken together, these findings indicated that miR-199a inhibits tumor growth and chemoresistance by regulating K-RAS, and the miR-199a/K-RAS axis is a potential therapeutic target for clinical intervention in glioma.
RESUMO
BACKGROUND: Estrogen plays a critical role in breast cancer (BC) progression through estrogen receptor (ER)-mediated gene regulation. Emerging studies suggest that the malignant progress of BC cells is influenced by the cross talk between microRNAs (miRNAs) and ER-α signaling. However, the mechanism and functional linkage between estrogen and miRNAs remain unclear. METHODS: The expression levels of miR-196a and SPRED1 in BC were tested by qRT-PCR in 46 paired BC and adjacent tissues and by the GEO datasets. The role of miR-196a in estrogen-induced BC development was examined by CCK-8 assay, wound healing assay, Matrigel invasion assay and tumorigenicity assay in nude mice. The binding site of ER-α in miR-196a promoter region was analyzed by ChIP-seq, ChIP assay and luciferase reporter assay. The potential targets of miR-196a in BC cells were explored using the luciferase reporter assay and western blot analysis, and the correlation between miR-196a and SPRED1 was analyzed by Spearman's correlation analysis in BC specimens and GEO dataset. TCGA BRCA data was used to characterize the ESR1 signatures according to MSigDB gene set. RESULTS: The expression levels of miR-196a were higher in ER-positive (ER+) breast tumors compared to ER-negative (ER-) tumor tissue samples. Besides, miR-196a was involved in estrogen-induced BC cell proliferation, migration and invasion. Notably, the up-regulation of miR-196a was mediated by a direct interaction with estrogen receptor α (ER-α) but not estrogen receptor ß (ER-ß) in its promoter region, and miR-196a expression levels were positively correlated to ER-α signature scores. Furthermore, SPRED1 was a new direct target of miR-196a which participated in miR-196a-promoted BC development and was suppressed by ligand-activated ER-α signal pathway. Finally, forced expression of miR-196a induced tumor growth of MCF7 cells, while inhibition of miR-196a significantly suppressed the tumor progress in vivo. CONCLUSIONS: Overall, the identification of estrogen/miR-196a/SPRED1 cascade will shed light on new molecular mechanism of estrogen signaling in BC development and therapy.
Assuntos
Neoplasias da Mama/patologia , Estrogênios/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas de Membrana/genética , MicroRNAs/genética , Regulação para Cima , Proteínas Adaptadoras de Transdução de Sinal , Animais , Sítios de Ligação , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Receptor alfa de Estrogênio/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Células MCF-7 , Camundongos , MicroRNAs/química , Metástase Neoplásica , Transplante de Neoplasias , Transdução de SinaisRESUMO
Dysregulation of miRNAs is important in breast cancer initiation and malignant progression. Recently we showed that miR-152 downregulation is associated with breast cancer development, yet the underlying mechanism of miR-152 remains to be well elucidated. In this study, we identified ß-catenin as a new direct target of miR-152. MiR-152 inhibited cell proliferation by targeting and inhibiting both ß-catenin and PKM2 expression. We found that miR-152 expression sensitized the breast cancer cells to paclitaxel treatment by inhibiting ß-catenin and PKM2 expression. Intriguingly, IGF-1 induced ß-catenin and PKM2 expression and enhanced ß-catenin and PKM2 interaction. Subsequently, IGF-1-induced ß-catenin and PKM2 complex translocated into the nucleus, which in turn activated expression of miR-152. These results suggested a regulatory circuit between miR-152, ß-catenin and PKM2 in breast cancer. By using human clinical specimens, we also showed that miR-152 expression levels were negatively correlated with ß-catenin and PKM2 levels in breast cancer tissues. Our findings provide new insights into a mechanism of miR-152 involved in ß-catenin and PKM2 inhibition which would have clinical implication for the cancer development and new treatment option in the future.
Assuntos
Neoplasias da Mama/genética , Proteínas de Transporte/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Proteínas de Membrana/metabolismo , MicroRNAs/metabolismo , Hormônios Tireóideos/metabolismo , beta Catenina/metabolismo , Sequência de Bases , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Proliferação de Células/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , MicroRNAs/genética , Paclitaxel/farmacologia , Ligação Proteica/efeitos dos fármacos , Proteínas de Ligação a Hormônio da TireoideRESUMO
Although recent studies have shed insights on some of the potential causes of male infertility, new underlining molecular mechanisms still remain to be elucidated. Makorin-2 (Mkrn2) is an evolutionarily conserved gene whose biological functions are not fully known. We developed an Mrkn2 knockout mouse model to study the role of this gene, and found that deletion of Mkrn2 in mice led to male infertility. Mkrn2 knockout mice produced abnormal sperms characterized by low number, poor motility, and aberrant morphology. Disruption of Mkrn2 also caused failure of sperm release (spermiation failure) and misarrangement of ectoplasmic specialization (ES) in testes, thus impairing spermiogenesis and spermiation. To understand the molecular mechanism, we found that expression of Odf2, a vital protein in spermatogenesis, was significantly decreased. In addition, we found that expression levels of Odf2 were decreased in Mkrn2 knockout mice. We also found that MKRN2 was prominently expressed in the sperm of normal men, but was significantly reduced in infertile men. This result indicates that our finding is clinically relevant. The results of our study provided insights into a new mechanism of male infertility caused by the MKRN2 downregulation.
Assuntos
Proteínas de Choque Térmico/biossíntese , Infertilidade Masculina , Ribonucleoproteínas/deficiência , Espermatogênese , Animais , Perfilação da Expressão Gênica , Masculino , Camundongos Knockout , Espermatozoides/citologia , Espermatozoides/fisiologiaRESUMO
Pancreatic adenocarcinoma is one of the most leading causes of cancer-related deaths worldwide. Although recent advances provide various treatment options, pancreatic adenocarcinoma has poor prognosis due to its late diagnosis and ineffective therapeutic multimodality. Gemcitabine is the effective first-line drug in pancreatic adenocarcinoma treatment. However, gemcitabine chemoresistance of pancreatic adenocarcinoma cells has been a major obstacle for limiting its treatment effect. Our study found that p70S6K1 plays an important role in gemcitabine chemoresistence. MiR-145 is a tumor suppressor which directly targets p70S6K1 for inhibiting its expression in pancreatic adenocarcinoma, providing new therapeutic scheme. Our findings revealed a new mechanism underlying gemcitabine chemoresistance in pancreatic adenocarcinoma cells.
Assuntos
Adenocarcinoma/genética , Antimetabólitos Antineoplásicos/farmacologia , Desoxicitidina/análogos & derivados , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica , MicroRNAs/metabolismo , Neoplasias Pancreáticas/genética , Proteínas Quinases S6 Ribossômicas 70-kDa/genética , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/patologia , Antimetabólitos Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Desoxicitidina/farmacologia , Desoxicitidina/uso terapêutico , Genes Supressores de Tumor , Humanos , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Gencitabina , Neoplasias PancreáticasRESUMO
It is currently known that estrogen plays an important role in breast cancer (BC) development, but the underlying molecular mechanism remains to be elucidated. Accumulating evidence has revealed important roles of microRNAs in various kinds of human cancers, including BC. In this study, we found that among the microRNAs regulated by estrogen, miR-124 was the most prominent downregulated miRNA. miR-124 was downregulated by estradiol (E2) treatment in estrogen receptor (ER) positive BC cells, miR-124 overexpression suppressed cell proliferation, migration and invasion in BC cells; while the suppression of miR-124 using Anti-miR-124 inhibitor had opposite cellular functions. Under the E2 treatment, miR-124 had stronger effect to inhibit cellular functions in MCF7 cells than that in MDA-MB-231 cells. In addition, we identified that ERα, but not ERß, was required for E2-induced miR-124 downregulation. Furthermore, AKT2, a known oncogene, was a novel direct target of miR-124. AKT2 expression levels were inversely correlated with miR-124 expression levels in human breast cancer specimens. AKT2 was overexpressed in BC specimens, and its expression levels were much higher in ERα positive cancer tissues than those ERα negative cancer tissues. Consistent with miR-124 suppression, E2 treatment increased AKT2 expression levels in MCF7 cells via ERα. Finally, overexpression of miR-124 in MCF7 cells significantly suppressed tumor growth and angiogenesis by targeting AKT2. Our results provide a mechanistic insight into a functional role of new ERα/miR-124/AKT2 signaling pathway in BC development. miR-124 and AKT2 may be used as biomarkers for ERα positive BC and therapeutic effect in the future.
Assuntos
Neoplasias da Mama/patologia , Estradiol/metabolismo , Receptor alfa de Estrogênio/metabolismo , Regulação Neoplásica da Expressão Gênica/fisiologia , MicroRNAs/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Neoplasias da Mama/genética , Movimento Celular/genética , Estradiol/farmacologia , Feminino , Xenoenxertos , Humanos , Camundongos , Camundongos Nus , MicroRNAs/genética , Invasividade Neoplásica/genética , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Proteínas Proto-Oncogênicas c-akt/genéticaRESUMO
Chemotherapy resistance frequently drives tumour progression. However, the underlying molecular mechanisms are poorly characterized. In this study, we explored miR-137's role in the chemosensitivity of lung cancer. We found that the expression level of miR-137 is down-regulated in the human lung cancer tissues and the resistant cells strains: A549/paclitaxel(A549/PTX) and A549/cisplatin (A549/CDDP) when compared with lung cancer A549 cells. Moreover, we found that overe-expression of miR-137 inhibited cell proliferation, migration, cell survival and arrest the cell cycle in G1 phase in A549/PTX and A549/CDDP. Furthermore, Repression of miR-137 significantly promoted cell growth, migration, cell survival and cell cycle G1/S transition in A549 cells. We further demonstrated that the tumor suppressive role of miR-137 was mediated by negatively regulating Nuclear casein kinase and cyclin-dependent kinase substrate1(NUCKS1) protein expression. Importantly, miR-137 inhibits A549/PTX, A549/CDDP growth and angiogenesis in vivo. Our study is the first to identify the tumor suppressive role of over-expressed miR-137 in chemosensitivity. Identification of a novel miRNA-mediated pathway that regulates chemosensitivity in lung cancer will facilitate the development of novel therapeutic strategies in the future.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Biomarcadores Tumorais/genética , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Pulmonares/patologia , MicroRNAs/genética , Proteínas Nucleares/metabolismo , Fosfoproteínas/metabolismo , Animais , Apoptose , Biomarcadores Tumorais/metabolismo , Proliferação de Células , Cisplatino/administração & dosagem , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas Nucleares/genética , Paclitaxel/administração & dosagem , Fosfoproteínas/genética , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Colorectal cancer (CRC) is one of the leading cancer-related causes of death in the world. Recently, downregulation of microRNA-497 (miR-497) has been observed in CRC tissues. In this study, we found that miR-497 expression levels were downregulated in human CRC specimens compared to the adjacent normal tissues. MiR-497 expression levels were strongly correlated with clinical stages and lymph node metastases. Furthermore, kinase suppressor of ras 1 (KSR1), a known oncogene, was a direct target of miR-497, and KSR1 expression levels were inversely correlated with miR-497 expression levels in human CRC specimens. Overexpression of miR-497 inhibited cell proliferation, migration, invasion and increased chemosensitivity to 5-fluorouracil treatment, whereas forced expression of KSR1 had the opposite effect. Taken together, these results revealed that lower miR-497 levels in human CRC tissues induce KSR1 expression which is associated with CRC cancer occurrence, advanced stages, metastasis and chemoresistance. Lower miR-497 levels may be a potential biomarker for CRC advanced stages and treatment response.
Assuntos
Neoplasias Colorretais/prevenção & controle , Resistencia a Medicamentos Antineoplásicos/genética , Fluoruracila/farmacologia , MicroRNAs/genética , Proteínas Quinases/química , Animais , Antimetabólitos Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Western Blotting , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Humanos , Metástase Linfática , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Gradação de Tumores , Invasividade Neoplásica , Estadiamento de Neoplasias , Prognóstico , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Therapeutic applications of microRNAs (miRNAs) in RAS-driven glioma were valuable, but their specific roles and functions have yet to be fully elucidated. Here, we firstly report that miR-143 directly targets the neuroblastoma RAS viral oncogene homolog (N-RAS) and functions as a tumor-suppressor in glioma. Overexpression of miR-143 decreased the expression of N-RAS, inhibited PI3K/AKT, MAPK/ERK signaling, and attenuated the accumulation of p65 in nucleus of glioma cells. In human clinical specimens, miR-143 was downregulated where an adverse with N-RAS expression was observed. Furthermore, overexpression of miR-143 decreased glioma cell migration, invasion, tube formation and slowed tumor growth and angiogenesis in a manner associated with N-RAS downregulation in vitro and in vivo. Finally, miR-143 also sensitizes glioma cells to temozolomide (TMZ),the first-line drug for glioma treatment. Taken together, for the first time, our results demonstrate that miR-143 plays a significant role in inactivating the RAS signaling pathway through the inhibition of N-RAS, which may provide a novel therapeutic strategy for treatment of glioma and other RAS-driven cancers.
Assuntos
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/terapia , Dacarbazina/análogos & derivados , Genes ras , Glioma/genética , Glioma/terapia , MicroRNAs/genética , Animais , Antineoplásicos Alquilantes/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Dacarbazina/farmacologia , Regulação para Baixo , Genes Supressores de Tumor , Glioma/tratamento farmacológico , Glioma/patologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Terapia de Alvo Molecular , Transdução de Sinais , Temozolomida , Transfecção , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUNDS AND AIMS: Glioma accounts for the majority of primary malignant brain tumors in adults. Upregulation of microRNA-26a (miR-26a) has been observed in glioma. However, the biological function and molecular mechanism of miR-26a in glioma remain to be elucidated. METHODS: Glioma cells stably overexpressing or down-expressing miR-26a were analyzed for both in vitro and in vivo biological functions. Novel target of miR-26a was identified by bioinformatics searching and molecular biological assays. Glioma specimens and normal brain tissues were analyzed for both expression levels of miR-26a and its target. RESULTS: Forced expression of miR-26a in glioma cells significantly increased both growth rate and colony formation in vitro and tumor growth and angiogenesis in vivo, while reduced expression of miR-26a played opposite roles. MiR-26a directly targeted prohibitin (PHB) whose expression levels were downregulated in glioma specimens. The levels of miR-26a were inversely correlated with PHB expression levels in glioma samples and strongly correlated with clinical WHO grades of glioma. CONCLUSION: These results reveal that miR-26a regulates PHB and promotes glioma progression both in vitro and in vivo and that miR-26a and its target PHB are associated with glioma development, which can be helpful in developing microRNA-based treatment for glioma in the future.
Assuntos
Progressão da Doença , Glioma/metabolismo , MicroRNAs/biossíntese , Neovascularização Patológica/metabolismo , Proteínas Repressoras/biossíntese , Animais , Linhagem Celular Tumoral , Proliferação de Células , Glioma/patologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proibitinas , Receptor EphB3RESUMO
Insulin is known to regulate multiple cellular functions and is used for the treatment of diabetes. MicroRNAs have been demonstrated to be involved in many human diseases, including Type 2 diabetes. In this study, we showed that insulin decreased miR-99a expression levels, but induced glucose consumption and lactate production, and increased the expression of mTOR, HIF-1α and PKM2 in HepG2 and HL7702 cells. Forced expression of miR-99a or rapamycin treatment blocked insulin-induced PKM2 and HIF-1α expression, and glucose consumption and lactate production. Meanwhile, knockdown of HIF-1α inhibited PKM2 expression and insulin-induced glucose consumption. Taken together, these findings will reveal the role and mechanism of insulin in regulating glycolytic activities via miR-99a/mTOR.
Assuntos
Proteínas de Transporte/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glucose/metabolismo , Insulina/farmacologia , Neoplasias Hepáticas/genética , Proteínas de Membrana/metabolismo , MicroRNAs/genética , Serina-Treonina Quinases TOR/metabolismo , Hormônios Tireóideos/metabolismo , Antibióticos Antineoplásicos/farmacologia , Western Blotting , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Proteínas de Transporte/genética , Células Cultivadas , Humanos , Hipoglicemiantes/farmacologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/antagonistas & inibidores , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Lactatos/metabolismo , Fígado/metabolismo , Fígado/patologia , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/metabolismo , Luciferases/metabolismo , Proteínas de Membrana/genética , Fosforilação , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/efeitos dos fármacos , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/genética , Hormônios Tireóideos/genética , Proteínas de Ligação a Hormônio da TireoideRESUMO
Colorectal cancer (CRC) is one of the leading cancer-related causes of death in the world. Recently, downregulation of microRNA-143 (miR-143) has been observed in CRC tissues. Here in this study, we found that miR-143 expression was downregulated both in CRC patients' blood samples and tumor specimens. MiR-143 expression levels were strongly correlated with clinical stages and lymph node metastasis. Furthermore, insulin-like growth factor-I receptor (IGF-IR), a known oncogene, was a novel direct target of miR-143, whose expression levels were inversely correlated with miR-143 expression in human CRC specimens. Overexpression of miR-143 inhibited cell proliferation, migration, tumor growth and angiogenesis and increased chemosensitivity to oxaliplatin treatment in an IGF-IR-dependent manner. Taken together, these results revealed that miR-143 levels in human blood and tumor tissues are associated with CRC cancer occurrence, metastasis and drug resistance, and miR-143 levels may be used as a new diagnostic marker and therapeutic target for CRC in the future.
Assuntos
Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , MicroRNAs/metabolismo , Neovascularização Patológica/genética , Compostos Organoplatínicos/uso terapêutico , Animais , Sequência de Bases , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/irrigação sanguínea , Neoplasias Colorretais/genética , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Camundongos , Camundongos Nus , MicroRNAs/genética , Dados de Sequência Molecular , Neovascularização Patológica/tratamento farmacológico , Compostos Organoplatínicos/farmacologia , Oxaliplatina , Receptor IGF Tipo 1/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
MicroRNAs (miRNAs) are single-stranded, 18- to 23-nt RNA molecules that function as regulators of gene expression. Previous studies have shown that microRNAs play important roles in human cancers, including gliomas. Here, we found that expression levels of miR-181b were decreased in gliomas, and we identified IGF-1R as a novel direct target of miR-181b. MiR-181b overexpression inhibited cell proliferation, migration, invasion, and tumorigenesis by targeting IGF-1R and its downstream signaling pathways, PI3K/AKT and MAPK/ERK1/2. Overexpression of IGF-1R rescued the inhibitory effects of miR-181b. In clinical specimens, IGF-1R was overexpressed, and its protein levels were inversely correlated with miR-181b expression. Taken together, our results indicate that miR-181b functions in gliomas to suppress growth by targeting the IGF-1R oncogene and that miR-181b may serve as a novel therapeutic target for gliomas.
Assuntos
Proliferação de Células , Transformação Celular Neoplásica , Glioma/metabolismo , Glioma/patologia , MicroRNAs/metabolismo , Receptor IGF Tipo 1/metabolismo , Inibidores da Angiogênese/metabolismo , Animais , Movimento Celular , Genes Supressores de Tumor , Humanos , Masculino , Camundongos , Camundongos Nus , MicroRNAs/genética , Transdução de SinaisRESUMO
OBJECTIVE: To investigate the Z scores for growth and development, physical fitness, and the relationship between them in preschool children in Yantai City, China, and to provide scientific evidence for health care in children. METHODS: A total of 362 children aged 3 to 4 years, whose data were recorded in the National Physical Fitness Survey in Yantai in 2010, were included in the study. Z scores for weight-for-age, height-for-age and body mass index-for-age were calculated. The relationship between Z scores and physical fitness was determined by Pearson's correlation analysis. RESULTS: The mean Z scores were all positive numbers. The prevalence rates of underweight and growth retardation were very low, but that of obesity was relatively high (up to 16.5% in 4-year-old boys). There were differences in physical fitness between children of different ages and between boys and girls (P<0.05). The Z scores showed correlation with some physical fitness indices (P<0.05), but they were not closely correlated as the value of r was not more than 0.30. CONCLUSIONS: Z scores for growth and development remain at relatively high levels in preschool children in Yantai. The physical fitness is associated with age and gender in these children. There are weak correlations between Z scores and some physical fitness indices. Effective measures should be taken to adjust dietary habits and promote exercise for children, thus preventing obesity and improving physical fitness.
Assuntos
Desenvolvimento Infantil , Aptidão Física , Estatura , Peso Corporal , Pré-Escolar , China , Feminino , Humanos , MasculinoRESUMO
Ku70 plays an important role in DNA double-strand break repair. Studies revealing conflicting results on the role of the Ku70-1310C/G promoter polymorphism on cancer risk led us to perform a meta-analysis to investigate this relationship. Ten case-control studies with 2566 cases and 3058 controls were identified. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of associations. The overall results suggested no association between the Ku70-1310C/G promoter polymorphism and total cancer risk. However, on stratified analysis, significantly increased risks were observed among the Asian population (GG vs. CC: OR=1.50, 95%CI=1.10-2.06; GG vs. CC/CG: OR=1.47, 95%CI=1.07-2.01) and population-based case- control studies (GG vs. CC: OR=1.57, 95%CI=1.12-2.22; CG vs. CC: OR=1.35, 95%CI=1.11-1.64; CG/GG vs. CC: OR=1.37, 95%CI=1.14-1.65). Additionally, variant genotypes were associated with a significantly increased breast cancer risk (GG vs. CC: OR=1.80, 95%CI=1.26-2.56; GG vs. CC/CG: OR=1.40, 95%CI=1.01-1.95).
Assuntos
Antígenos Nucleares/genética , Proteínas de Ligação a DNA/genética , Neoplasias/genética , Polimorfismo Genético/genética , Regiões Promotoras Genéticas/genética , Estudos de Casos e Controles , Humanos , Autoantígeno Ku , Prognóstico , Fatores de RiscoRESUMO
MicroRNAs are a class of small noncoding RNAs that function as critical gene regulators through targeting mRNAs for translational repression or degradation. In this study, we showed that miR-128 expression levels were decreased in glioma, and identified p70S6K1 as a novel direct target of miR-128. Overexpression of miR-128 suppressed p70S6K1 and its downstream signaling molecules such as HIF-1 and VEGF expression, and attenuated cell proliferation, tumor growth and angiogenesis. Forced expression of p70S6K1 can partly rescue the inhibitory effect of miR-128 in the cells. Taken together, these findings will shed light to the role and mechanism of miR-128 in regulating glioma tumor angiogenesis via miR-128/p70S6K1 axis, and miR-128 may serve as a potential therapeutic target in glioma in the future.
Assuntos
Glioma/enzimologia , MicroRNAs/biossíntese , Neovascularização Patológica/enzimologia , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Animais , Linhagem Celular Tumoral , Glioma/genética , Glioma/terapia , Humanos , Fator 1 Induzível por Hipóxia/biossíntese , Fator 1 Induzível por Hipóxia/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/genética , Transplante de Neoplasias , Neovascularização Patológica/genética , Neovascularização Patológica/terapia , Proteínas Quinases S6 Ribossômicas 70-kDa/genética , Transdução de Sinais/genética , Transplante Heterólogo , Fator A de Crescimento do Endotélio Vascular/biossíntese , Fator A de Crescimento do Endotélio Vascular/genéticaRESUMO
PURPOSE: Recently, several microRNAs (miRNAs) were reported to be involved in the modulation of glioma development. The aim of our study was to determine the effect of miR-181d on the growth of glioma and to investigate whether this growth is modulated by targeting K-ras and Bcl-2. METHODS: Real-time PCR was used to analyze the expression of miR-181d in human glioma samples and glioma cell lines. Apoptosis, cell cycle, and proliferation (MTT) assays were performed to assess the phenotypic changes in glioma cells. Immunohistochemistry was used to determine the expression of K-ras and Bcl-2 in glioma tissues, and a luciferase reporter assay was carried out to confirm whether K-ras and Bcl-2 are direct targets of miR-181d. Western blotting was used to identify the potential signaling pathways affected glioma cell growth by miR-181d. In vivo, xenograft tumors were examined for an anti-glioma effect of miR-181d. RESULTS: MiR-181d was down-regulated in human glioma samples and up-regulated in transfected glioma cells. Ectopic expression of miR-181d suppressed proliferation and triggered cell cycle arrest and apoptosis in glioma cell lines. K-ras and Bcl-2 were identified as direct targets of miR-181d and were up-regulated in glioma samples. The results showed evidence linking the tumor suppressor activity of miR-181d in glioma cells with the K-ras-related PI3K/AKT and MAPK/ERK pathways. Furthermore, xenograft tumors from miR-181d-treated U251 cells were suppressed in vivo. CONCLUSION: MiR-181d may act as a glioma suppressor by targeting K-ras and Bcl-2.