RESUMO
Circular RNAs (circRNAs) are a class of noncoding RNAs that are widely expressed in cancer tissues and play a pro- or anticancer role in modulating cancer progression. This work is aimed to probe the biological role of circ_0000317 in colorectal cancer (CRC) and its underlying mechanism. Circ_0000317 was selected from the circRNA microarray datasets (GSE121895). Quantitative real-time polymerase chain reaction was utilized to examine circ_0000317, microRNA (miR)-520g, and homeobox D10 (HOXD10) mRNA expression in CRC. Cell Counting Kit-8 and Transwell experiments were conducted to examine the effects of circ_0000317 on proliferation, migration, and invasion of CRC cells. Bioinformatic analysis and dual-luciferase reporter gene experiments were implemented to predict and validate the targeting relationship between circ_0000317 and miR-520g, miR-520g, and HOXD10. Western blot was employed to examine HOXD10 expression at protein level in CRC cells. Circ_0000317 and HOXD10 mRNA expression were unveiled to be down-modulated and miR-520g expression was up-modulated in CRC. Functionally, circ_0000317 overexpression repressed CRC cell proliferation, migration, and invasion. Mechanistically, miR-520g was a direct target of circ_0000317 and miR-520g specifically modulated HOXD10 expression. Furthermore, miR-520g mimics partially counteracted the suppressing effect of circ_0000317 on malignant phenotype of CRC cells. Circ_0000317 represses CRC progression by targeting miR-520g and modulating HOXD10 expression. Hence, circ_0000317 may be a promising diagnostic biomarker and a therapeutic target for CRC.
Assuntos
Adenocarcinoma/genética , Neoplasias Colorretais/genética , Proteínas de Homeodomínio/genética , MicroRNAs/genética , RNA Circular/genética , Fatores de Transcrição/genética , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Idoso , Pareamento de Bases , Sequência de Bases , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Biologia Computacional/métodos , Feminino , Regulação Neoplásica da Expressão Gênica , Genes Reporter , Células HT29 , Proteínas de Homeodomínio/metabolismo , Humanos , Luciferases/genética , Luciferases/metabolismo , Masculino , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , RNA Circular/metabolismo , Transdução de Sinais , Fatores de Transcrição/metabolismoRESUMO
BACKGROUND: Recurrent miscarriage (RM) is a distressing reproductive issue worldwide. Dysfunction of trophoblasts can trigger numerous unfavorable pregnant outcomes such as RM, stillbirth, and fetal malformation. METHODS: In this text, the roles and molecular basis of long non-coding RNA insulin growth factor 2 antisense (IGF2-AS) in the development of trophoblast cells were further investigated. IGF2-AS, microRNA-520g (miR-520g), and N-cadherin levels were measured by RT-qPCR assay. Cell viability, the number of colonies, cell apoptosis, migration, and invasion were measured by CCK-8 assay, colony formation assay, flow cytometry, transwell migration, and invasion assays, respectively. The relative proteins expression was detected by western blot. RESULTS: The interaction between miR-520g and IGF2-AS or N-cadherin was tested by bioinformatics prediction analysis, and confirmed by dual-luciferase reporter assay, RNA pull-down assay, and RNA immunoprecipitation (RIP) assay. Our data revealed that IGF2-AS and N-cadherin levels were notably decreased, and miR-520g was strikingly increased in the placentas from RM patients. IGF2-AS overexpression promoted cell proliferation, migration, invasion, epithelial-mesenchymal transition (EMT), and hampered cell apoptosis in trophoblast cells, while IGF2-AS deletion exhibited opposite results. Moreover, miR-520g was a target gene of IGF2-AS and negatively regulated by IGF2-AS. MiR-520g inhibitor enhanced the proliferation, migration, and invasion capability of trophoblast cells, suppressed cell apoptosis, and promoted the EMT process. Moreover, the effects of IGF2-AS overexpression on trophoblast cells were reversed by miR-520g upregulation. CONCLUSIONS: These findings indicated that IGF2-AS facilitated trophoblast cell proliferation, migration, invasion, EMT, and suppressed cell apoptosis by regulating miR-520g/N-cadherin axis, providing potential biomarkers for RM.
Assuntos
Antígenos CD , Caderinas , MicroRNAs , RNA Longo não Codificante , Antígenos CD/genética , Antígenos CD/metabolismo , Caderinas/genética , Caderinas/metabolismo , Movimento Celular , Proliferação de Células , Feminino , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Gravidez , Proteínas , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , TrofoblastosRESUMO
Circular RNAs (circRNAs) are a type of non-coding RNAs generated from back splicing to enhance or inhibit the progression of multiple human cancers including osteosarcoma (OS). Although circ_0102049 has been found to be highly expressed in OS cell lines, the role and specific mechanism of circ_0102049 in OS remains unclear. Here, we found that silence of circ_0102049 could significantly exacerbate the tumorigenesis of OS in vivo through sponging microRNA-520g-3p. Polo-like kinase 2 (PLK2) was predicted to be a target of miR-520g-3p, and luciferase reporter assay revealed that overexpression of miR-520g-3p dramatically suppressed the expression of PLK2, whereas miR-520g-3p inhibitor promoted the PLK2 expression. Moreover, the silence of circ_0102049 could markedly promote the proliferation, invasion, migration and cell-cycle promotion while inhibiting the apoptosis of OS cell line MG63 cells in vitro through regulating miR-520g-3p/PLK2 axis. Taken together, the present study indicated that circ_0102049 suppressed the progression of osteosarcoma via modulating miR-520g-3p/PLK2/TAp73 axis, providing a potential therapeutic target for OS.
Assuntos
Neoplasias Ósseas/patologia , MicroRNAs/metabolismo , Osteossarcoma/patologia , Proteínas Serina-Treonina Quinases/metabolismo , RNA Circular/metabolismo , Animais , Neoplasias Ósseas/genética , Neoplasias Ósseas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Progressão da Doença , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , MicroRNAs/genética , Osteossarcoma/genética , Osteossarcoma/metabolismo , Proteínas Serina-Treonina Quinases/genética , RNA Circular/genéticaRESUMO
The lack of efficient tumor progression and chemoresistance indicators leads to high mortality in epithelial ovarian cancer (EOC) patients. Dysregulated miR-520g expression is involved in these processes in hepatic and colorectal cancers. In this study, we found that miR-520g expression gradually increased across normal, benign, borderline and EOC tissues. High miR-520g expression promoted tumor progression and chemoresistance to platinum-based chemotherapy, and reduced survival in EOC patients. miR-520g upregulation increased EOC cell proliferation, induced cell cycle transition and promoted cell invasion, while miR-520g downregulation inhibited tumor-related functions. In vivo, overexpression or downregulation of miR-520g respectively generated larger or smaller subcutaneous xenografts in nude mice. Death-associated protein kinase 2 (DAPK2) was a direct target of miR-520g. In 116 EOC tissue samples, miR-520g expression was significantly lower following DAPK2 overexpression. DAPK2 overexpression or miR-520g knockdown reduced EOC cell proliferation, invasion, wound healing and chemoresistance. This study suggests that miR-520g contributes to tumor progression and drug resistance by post-transcriptionally downregulating DAPK2, and that miR-520g may be a valuable therapeutic target in patients with EOC.
Assuntos
Proteínas Quinases Associadas com Morte Celular/biossíntese , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica/genética , MicroRNAs/metabolismo , Neoplasias Epiteliais e Glandulares/patologia , Neoplasias Ovarianas/patologia , Adulto , Idoso , Animais , Carcinoma Epitelial do Ovário , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Proteínas Quinases Associadas com Morte Celular/genética , Progressão da Doença , Intervalo Livre de Doença , Regulação para Baixo , Feminino , Xenoenxertos , Humanos , Estimativa de Kaplan-Meier , Camundongos , Camundongos Nus , MicroRNAs/genética , Pessoa de Meia-Idade , Invasividade Neoplásica/genética , Neoplasias Epiteliais e Glandulares/genética , Neoplasias Epiteliais e Glandulares/mortalidade , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/mortalidade , Modelos de Riscos ProporcionaisRESUMO
Development of drug resistance is one of the major causes of colorectal cancer recurrence, yet mechanistic understanding and therapeutic options remain limited. Here, we show that expression of microRNA (miR)-520g is correlated with drug resistance of colon cancer cells. Ectopic expression of miR-520g conferred resistance to 5-fluorouracil (5-FU)- or oxaliplatin-induced apoptosis in vitro and reduced the effectiveness of 5-FU in the inhibition of tumor growth in a mouse xenograft model in vivo. Further studies indicated that miR-520g mediated drug resistance through down-regulation of p21 expression. Moreover, p53 suppressed miR-520g expression, and deletion of p53 up-regulated miR-520g expression. Inhibition of miR-520g in p53(-/-) cells increased their sensitivity to 5-FU treatment. Importantly, studies of patient samples indicated that expression of miR-520g correlated with chemoresistance in colorectal cancer. These findings indicate that the p53/miR-520g/p21 signaling axis plays an important role in the response of colorectal cancer to chemotherapy. A major implication of our studies is that inhibition of miR-520g or restoration of p21 expression may have considerable therapeutic potential to overcome drug resistance in colorectal cancer patients, especially in those with mutant p53.