RESUMO
BACKGROUND & AIMS: The liver is a common site of cancer metastasis, most commonly from colorectal cancer, and primary liver cancers that have metastasized are associated with poor outcomes. The underlying mechanisms by which the liver defends against these processes are largely unknown. Prohibitin 1 (PHB1) and methionine adenosyltransferase 1A (MAT1A) are highly expressed in the liver. They positively regulate each other and their deletion results in primary liver cancer. Here we investigated their roles in primary and secondary liver cancer metastasis. METHODS: We identified common target genes of PHB1 and MAT1A using a metastasis array, and measured promoter activity and transcription factor binding using luciferase reporter assays and chromatin immunoprecipitation, respectively. We examined how PHB1 or MAT1A loss promotes liver cancer metastasis and whether their loss sensitizes to colorectal liver metastasis (CRLM). RESULTS: Matrix metalloproteinase-7 (MMP-7) is a common target of MAT1A and PHB1 and its induction is responsible for increased migration and invasion when MAT1A or PHB1 is silenced. Mechanistically, PHB1 and MAT1A negatively regulate MMP7 promoter activity via an AP-1 site by repressing the MAFG-FOSB complex. Loss of MAT1A or PHB1 also increased MMP-7 in extracellular vesicles, which were internalized by colon and pancreatic cancer cells to enhance their oncogenicity. Low hepatic MAT1A or PHB1 expression sensitized to CRLM, but not if endogenous hepatic MMP-7 was knocked down first, which lowered CD4+ T cells while increasing CD8+ T cells in the tumor microenvironment. Hepatocytes co-cultured with colorectal cancer cells express less MAT1A/PHB1 but more MMP-7. Consistently, CRLM raised distant hepatocytes' MMP-7 expression in mice and humans. CONCLUSION: We have identified a PHB1/MAT1A-MAFG/FOSB-MMP-7 axis that controls primary liver cancer metastasis and sensitization to CRLM. IMPACT AND IMPLICATIONS: Primary and secondary liver cancer metastasis is associated with poor outcomes but whether the liver has underlying defense mechanism(s) against metastasis is unknown. Here we examined the hypothesis that hepatic prohibitin 1 (PHB1) and methionine adenosyltransferase 1A (MAT1A) cooperate to defend the liver against metastasis. Our studies found PHB1 and MAT1A form a complex that suppresses matrix metalloproteinase-7 (MMP-7) at the transcriptional level and loss of either PHB1 or MAT1A sensitizes the liver to metastasis via MMP-7 induction. Strategies that target the PHB1/MAT1A-MMP-7 axis may be a promising approach for the treatment of primary and secondary liver cancer metastasis.
Assuntos
Neoplasias Colorretais , Neoplasias Hepáticas , Animais , Humanos , Camundongos , Linfócitos T CD8-Positivos/metabolismo , Neoplasias Colorretais/genética , Neoplasias Hepáticas/patologia , Metaloproteinase 7 da Matriz/genética , Metionina Adenosiltransferase/genética , Metionina Adenosiltransferase/metabolismo , Proibitinas , Microambiente TumoralRESUMO
Behcet's disease (BD) is a multisystem disease with altered Toll-like receptors (TLRs) on macrophages. Long noncoding RNA Maternally expressed gene 3 (lncRNA MEG3) and lncRNA Musculoaponeurotic fibrosarcoma oncogene family, protein G antisense 1 (MAFG-AS1) are regulators of microRNA (miRNA) 147-b, which is induced upon TLR stimulation. We included fifty BD patients, and fifty age and sex-matched controls. Real-time polymerase chain reaction (PCR) was used to measure the expression levels of serum lncRNA MEG3, lncRNA MAFG-AS1, and miRNA 147-b. LncRNA MEG3 and lncRNA MAFG-AS1 were significantly downregulated while miRNA 147-b was significantly upregulated in the BD patients' serum compared to the controls with p-value <0.001. Receiver operation characteristics (ROC) curve analysis revealed that the three biomarkers can discriminate between BD and control subjects with 76%, 100%, and 70% sensitivity respectively, and 100% specificity for all of them. There was a lower expression level of lnc RNA MEG3 among patients who had new eye involvement in the last month in comparison to those without new eye involvement (p-value=0.017). So, LncRNA MEG3, lncRNA MAFG-AS1, and miRNA147-b are promising diagnostic markers and therapeutic targets for BD patients. LncRNA MEG3 can be used as a predictor for new BD ocular involvement.
Assuntos
Síndrome de Behçet , MicroRNAs , RNA Longo não Codificante , Humanos , RNA Longo não Codificante/genética , RNA Longo não Codificante/sangue , Síndrome de Behçet/genética , Síndrome de Behçet/sangue , MicroRNAs/genética , MicroRNAs/sangue , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Biomarcadores/sangue , Estudos de Casos e Controles , Curva ROCRESUMO
We investigated the mechanism of ETS-translocation variant 1 (ETV1)/lncRNA-MAFG-AS1 in pancreatic cancer (PC). MAFG-AS1 and ETV1 levels in PC cell lines and HPNE cells were determined using reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blotting (WB). After transfection with sh-MAFG-AS1, PC cell invasion, migration, proliferation, and epithelial-mesenchymal transition (EMT)-related proteins were measured by 5-ethynyl-2'-deoxyuridine (EdU), Transwell assay, and WB. The binding between ETV1 and MAFG-AS1 was studied using dual-luciferase assay and chromatin immunoprecipitation. The interactions between MAFG-AS1, IGF2BP2, and ETV1 were tested. Combined experiments were further performed using sh-MAFG-AS1 and pcDNA-ETV1 simultaneously. ETV1/MAFG-AS1 was highly expressed in PC cells. Blocking MAFG-AS1 inhibited the malignant behaviors of PC cells. ETV1 induced MAFG-AS1 transcription in PC cells. MAFG-AS1 stabilized ETV1 mRNA by recruiting IGF2BP2. ETV1 overexpression partially antagonized the suppression of silencing MAFG-AS1 on PC cells. ETV1-induced MAFG-AS1 stabilized the ETV1 expression by recruiting IGF2BP2 and promoted PC cell migration, invasion, proliferation, and EMT.
Assuntos
MicroRNAs , Neoplasias Pancreáticas , RNA Longo não Codificante , Humanos , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Transição Epitelial-Mesenquimal/genética , Proliferação de Células/genética , Linhagem Celular Tumoral , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , MicroRNAs/genética , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Movimento Celular/genética , Regulação Neoplásica da Expressão Gênica , Proteínas Repressoras/genética , Fator de Transcrição MafG/genética , Fator de Transcrição MafG/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Neoplasias PancreáticasRESUMO
PURPOSE: We aimed to explore the function and competing endogenous RNA (ceRNA) pathway of MAFG-AS1 in breast cancer. METHODS: qRT-PCR assay identified the expression of MAFG-AS1, miR-3612 and FKBP4. We used Western blot analysis to test the autophagy related protein levels in breast cancer cells. Functional assays such as Cell Counting Kit-8 (CCK8) assay, BrdU proliferation assay, Caspase-3 activity detection were used to identify the function of MAFG-AS1, miR-3612 and FKBP4 in breast cancer cells. Mechanism assays were used to verify the interacting relationship among MAFG-AS1, miR-3612 and FKBP4, including RNA pull down assay, RNA immunoprecipitation (RIP) assay and luciferase reporter assay. RESULTS: MAFG-AS1 and FKBP4 were both up-regulated in breast cancer tissues. MAFG-AS1 could function as an oncogene in breast cancer to activate cell proliferation, and inhibit cell apoptosis and autophagy. Meanwhile, MAFG-AS1 could sponge miR-3612 to elevate the expression of FKBP4. Besides, FKBP4 could activate the cell proliferation and inhibit cell apoptosis and autophagy, which could relieve the inhibitory effect of miR-3612 on breast cancer cells. CONCLUSION: MAFG-AS1 could activate breast cancer progression via modulating miR-3612/FKBP4 axis in vitro.
Assuntos
Neoplasias da Mama , MicroRNAs , RNA Longo não Codificante , Proteínas de Ligação a Tacrolimo , Autofagia/genética , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proliferação de Células/genética , Progressão da Doença , Feminino , Humanos , Fator de Transcrição MafG/genética , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Proteínas Repressoras/metabolismoRESUMO
To identify hepatitis B virus (HBV)-related lncRNA(s), we previously examined the transcription profiles of the HBV-transgenic cell line HepG2-4D14 and parental HepG2 cells by RNA deep sequencing and identified 38 upregulated long noncoding RNAs (lncRNAs). In the present study, the lncRNA MAFG-AS1 is investigated in detail because its gene is located adjacent to the MAFG gene, which is an important transcription factor involved in cell proliferation. The level of MAFG-AS1 is significantly higher in HCC tissue than in nontumor tissues. TCGA data show that the expression level of MAFG-AS1 is negatively correlated with survival of HCC patients. GEO cohort data show that compared with healthy tissues, the expression level of MAFG-AS1 is significantly higher in HBV-infected liver tissues. Real-time PCR and luciferase reporter assay data show that HBx can enhance the transcription of MAFG-AS1. Gain-of-function and loss-of-function experiments indicate that MAFG-AS1 promotes proliferation, migration, and invasion of HCC cells. Tumor formation assay results demonstrate that knockdown of MAFG-AS1 significantly inhibits cell proliferation in nude mice. Furthermore, MAFG-AS1 enhances the transcription of adjacent MAFG via E2F1. Additionally, MAFG-AS1 interacts with three subunits (MYH9, MYL12B, and MYL6) of nonmuscle myosin IIA (NM IIA). Knockdown of MAFG-AS1 inhibits ATPase activity of MYH9, interaction of NM IIA subunits, and cell cycle progression. Thus, the lncRNA MAFG-AS1 is upregulated by HBV and promotes proliferation and migration of HCC cells. Our findings suggest that MAFG-AS1 is a potential oncogene that may contribute to HBV-related HCC development.
Assuntos
Carcinoma Hepatocelular/patologia , Movimento Celular , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Fator de Transcrição MafG/metabolismo , Miosina não Muscular Tipo IIA/química , Proteínas Repressoras/metabolismo , Transativadores/metabolismo , Proteínas Virais Reguladoras e Acessórias/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Fator de Transcrição MafG/antagonistas & inibidores , Fator de Transcrição MafG/genética , Miosina não Muscular Tipo IIA/genética , Miosina não Muscular Tipo IIA/metabolismo , Oligonucleotídeos Antissenso/genética , Proteínas Repressoras/antagonistas & inibidores , Proteínas Repressoras/genética , Transativadores/genética , Proteínas Virais Reguladoras e Acessórias/genéticaRESUMO
Microgravity and radiation exposure-induced bone damage is one of the most significant alterations in astronauts after long-term spaceflight. However, the underlying mechanism is still largely unknown. Recent ground-based simulation studies have suggested that this impairment is likely mediated by increased production of reactive oxygen species (ROS) during spaceflight. The small Maf protein MafG is a basic-region leucine zipper-type transcription factor, and it globally contributes to regulation of antioxidant and metabolic networks. Our research investigated the role of MafG in the process of apoptosis induced by simulated microgravity and radiation in MC3T3-E1 cells. We found that simulated microgravity or radiation alone decreased MafG expression and elevated apoptosis in MC3T3-E1 cells, and combined simulated microgravity and radiation treatment aggravated apoptosis. Meanwhile, under normal conditions, increased ROS levels facilitated apoptosis and downregulated the expression of MafG in MC3T3-E1 cells. Overexpression of MafG decreased apoptosis induced by simulated microgravity and radiation. These findings provide new insight into the mechanism of bone damage induced by microgravity and radiation during space flight.
Assuntos
Apoptose/efeitos da radiação , Fator de Transcrição MafG/metabolismo , Osteoblastos/citologia , Osteoblastos/efeitos da radiação , Proteínas Repressoras/metabolismo , Apoptose/fisiologia , Linhagem Celular , Regulação para Baixo , Regulação da Expressão Gênica/efeitos da radiação , Humanos , Fator de Transcrição MafG/genética , Osteoblastos/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Proteínas Repressoras/genética , Simulação de Ausência de Peso , Raios XRESUMO
Amounting evidence suggested that long non coding RNAs (lncRNAs) played vital roles in the progression of various cancers. The aim of this study is to examine the biological roles and underlying mechanisms of lncRNA MAFG-AS1 in the tumorigenesis of breast cancer (BC) cells. Here we showed that downregulation of MAFG-AS1 inhibited the viability, migration, and invasion of BC cells. Mechanism investigation showed that inhibition of MAFG-AS1 induced apoptosis via the intrinsic apoptotic pathway and overexpression of Bcl-2 could inhibited it. Further, MAFG-AS1 acts as a sponge of miR-574-5p which directly binds to SOD2 mRNA. Re-expression of SOD2 using a 3'-UTR mutant SOD2 reversed the effects of silencing of MAFG-AS1 on BC cells. Finally, downregulation of MAFG-AS1 inhibited the growth of tumour in vivo. Together, MAFG-AS1 acts as an oncogene via regulation of miR-574-5p/SOD2 axis in BC cells.
Assuntos
Neoplasias da Mama/genética , Regulação Neoplásica da Expressão Gênica , MicroRNAs/metabolismo , RNA Longo não Codificante/metabolismo , Superóxido Dismutase/genética , Animais , Apoptose , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Carcinogênese , Caspases/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Sobrevivência Celular , Feminino , Humanos , Camundongos SCID , Invasividade Neoplásica , Superóxido Dismutase/metabolismoRESUMO
Proteomic analysis requires protein tags that enable high-throughput handling; however, versatile tags that can be used in in vitro expression systems are currently lacking. In this study, we developed an insoluble protein tag, INSOL-tag, derived from human transcription factor MafG. The INSOL-tagged target protein is expressed in a eukaryotic in vitro expression system and recovered as a pellet following centrifugation at 19,000 × g for 20 min. Comparisons of the target protein recovery rates of GST-tag and INSOL-tag using 111 cytoplasmic proteins revealed a fourfold increase in the yield of INSOL-tagged proteins. Using 267 cancer antigens purified with INSOL-tag, we subsequently developed an INSOL-CTA array method, for profiling autoantibodies in sera of cancer patients. The detection limit of the array was approximately 11.1 pg IgG, and the correlation with ELISA was high (R2 = .993, .955). Moreover, when autoantibody profiling of digestive cancer patient sera was performed, antigen spreading was observed. These data suggest that INSOL-tag is a versatile tag that can insolubilize a wide range of target proteins. It is therefore expected to become a powerful tool in comprehensive protein preparation for protein arrays, antibody production, and mass spectrometry.
Assuntos
Fator de Transcrição MafG/isolamento & purificação , Fator de Transcrição MafG/metabolismo , Proteômica/métodos , Proteínas Repressoras/isolamento & purificação , Proteínas Repressoras/metabolismo , Ensaios de Triagem em Larga Escala/métodos , Humanos , Fator de Transcrição MafG/genética , Espectrometria de Massas/métodos , Análise Serial de Proteínas/métodos , Engenharia de Proteínas/métodos , Proteoma/genética , Proteínas Repressoras/genética , Fatores de Transcrição/metabolismoRESUMO
BACKGROUND: A host of researches have demonstrated the regulation of long non-coding RNAs (lncRNAs) in the progression of pancreatic cancers (PC). In this study, our main task was to analyze the function of MAF bZIP transcription factor G antisense RNA 1 (MAFG-AS1) in PC. METHODS: RT-qPCR measured gene expression. Functional experiments, including EdU assay, flow cytometry analysis, TUNEL assay and transwell assay, assessed the biological changes of PC cells. RNA pull down assay, luciferase reporter assay and RIP assay verified the interaction between RNAs. RESULTS: MAFG-AS1 was lowly expressed in normal pancreatic samples but up-regulated in PC tissues and cell lines. Besides, MAFG-AS1 silence suppressed cell proliferation and migration whereas promoted cell apoptosis in PC. Mechanism assays verified that miR-3196 could bind with MAFG-AS1. Moreover, miR-3196 was discovered to be lowly expressed in PC cell lines, and its overexpression inhibited PC cell growth and migration. Importantly, nuclear factor I X (NFIX), overexpressed in PC cell lines, was validated to be positively modulated by MAFG-AS1 through absorbing miR-3196. Moreover, overexpression of NFIX could countervail the restraining effects of MAFG-AS1 knockdown on the growth and migration of PC cells. CONCLUSION: MAFG-AS1 had an oncogenic function in the progression of PC via regulating miR-3196/NFIX pathway, and decreasing MAFG-AS1 expression could attenuate PC progression.
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BACKGROUND: Colorectal cancer (CRC) is considered as the second common death-induced cancer. More recently, association of long non-coding RNAs (lncRNAs) with CRC has been extensively investigated. Therefore, the present study was performed to determine whether lncRNA MAF BZIP Transcription Factor G Antisense RNA 1 (MAFG-AS1) could regulate biological activities of CRC cells and unravel the underlying mechanisms. METHODS: CRC and corresponding adjacent tissues were collected to determine the expression of lncRNA MAFG-AS1, microRNA-149-3p (miR-149-3p) and homeobox B8 (HOXB8) by RT-qPCR. Dual luciferase reporter gene assay was used to explore the targeting relationship between miR-149-3p and lncRNA MAFG-AS1 and between miR-149-3p and HOXB8, followed by RNA immunoprecipitation for verification. Migration, proliferation, invasion, and apoptosis of HCT116 and LoVo cells were examined when lncRNA MAFG-AS1 was silenced or miR-149-3p was overexpressed. Furthermore, tumorigenicity of HCT116 and LoVo cells was measured in vivo by tumor xenograft in nude mice. RESULTS: LncRNA MAFG-AS1 and HOXB8 were found to be highly expressed in CRC tissues and cells, while miR-149-3p was under-expressed. LncRNA MAFG-AS1 negatively regulated miR-149-3p while miR-149-3p downregulated HOXB8. In addition, lncRNA MAFG-AS1 silencing by shRNA or miR-149-3p upregulation by mimic suppressed the migration, proliferation, invasion and tumorigenesis but promoted the apoptosis of HCT116 and LoVo cells. CONCLUSION: Taken together, lncRNA MAFG-AS1 downregulation inhibits the malignant behaviors of CRC cells by upregulating miR-149-3p and downregulating HOXB8, providing a potential therapeutic target for CRC treatment.
RESUMO
BACKGROUND: Long noncoding RNAs (lncRNAs) are potential biomarkers that are very important for the development of cancer. Studies show that lncRNAs are significantly correlated with the carcinogenesis and progression of bladder cancer (BLCA). In this research, we aimed at probing into the role of lncRNA MAFG-AS1 in the tumorigenesis of BLCA. METHODS: RT-qPCR was employed to detect MAFG-AS1 expression in BLCA tissues and cells. MAFG-AS1 siRNA and overexpression plasmid were transfected into 5637 and T24 BLCA cell lines to inhibit or upregulate MAFG-AS1 expression, respectively, and then the regulatory functions of MAFG-AS1 on BLCA cell proliferation, migration, and invasion were assessed using cell counting kit-8 (CCK-8) assay, EdU method, and Transwell experiments, respectively. Dual-luciferase reporter assay and RNA immunoprecipitation were conducted to validate the targeting relationships between MAFG-AS1 and miR-143-3p, and miR-143-3p and COX-2. In addition, miR-143-3p was repressed in MAFG-AS1-silenced 5637 and T24 cell lines, and the function of MAFG-AS1/miR-143-3p axis in BLCA cells was further evaluated. The regulatory effects of MAFG-AS1 and miR-143-3p on the expression of COX-2 protein were detected by Western blot. RESULTS: MAFG-AS1 was remarkably upregulated in BLCA patient tissues and cell lines, and its high expression was closely related to histological grade, tumor size, and lymph node metastasis. Silencing of MAFG-AS1 inhibited BLCA cell proliferation, metastasis, and invasion, while overexpression of MAFG-AS1 in BLCA cells had opposite biological effects. MAFG-AS1 was proved to target miR-143-3p to repress its expression. Moreover, it was confirmed that MAFG-AS1 and miR-143-3p could modulate COX-2 expression. CONCLUSION: The MAFG-AS1/miR-143-3p/COX-2 axis contributes to BLCA progression.
Assuntos
Ciclo-Oxigenase 2/metabolismo , Progressão da Doença , Fator de Transcrição MafG/genética , MicroRNAs/metabolismo , RNA Longo não Codificante/genética , Proteínas Repressoras/genética , Neoplasias da Bexiga Urinária/genética , Adulto , Linhagem Celular Tumoral , Proliferação de Células/genética , Ciclo-Oxigenase 2/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , MicroRNAs/classificação , MicroRNAs/genética , Pessoa de Meia-Idade , Invasividade Neoplásica , Regulação para CimaRESUMO
LncRNA MAFG-AS1 is predicted to interact with miR-146a, which can target Toll-like receptor 4 (TLR4), a key player in periodontitis. This study aimed to investigate the roles of MAFG-AS1 in periodontitis. It was observed that MAFG-AS1 was downregulated in the human periodontal ligament stem cells (PDLSCs) derived from periodontitis-affected teeth. Dual-luciferase assay revealed that co-transfection of MAFG-AS1 expression vector and miR-146a mimic showed significantly lower relative luciferase activity comparing to co-transfection of MAFG-AS1 expression vector and negative control (NC) miRNA. However, MAFG-AS1 and miR-146a failed to affect each other. Interestingly, MAFG-AS1 overexpression led to the upregulated TLR4. In addition, MAFG-AS1 overexpression also led to the inhibited proliferation of PDLSCs. Therefore, MAFG-AS1 may regulate the proliferation of PDLSCs and the expression of TLR4 to participate in periodontitis.
RESUMO
Non-small-cell carcinoma (NSCLC) is the most common cancer along with high mortality rate worldwide. In the present study, our data showed that lncRNA MAF BZIP Transcription Factor G Antisense RNA 1 (MAFG-AS1) was over-expressed in NSCLC tissues and cell lines. Overexpression of MAFG-AS1 promoted the migration, invasion and enhanced epithelial-mesenchymal transition (EMT) of NSCLC cell. In addition, miR-339-5p was predicted to be a target of MAFG-AS1 and the level of miR-339-5p was down-regulated in NSCLC. Over-expression of MAFG-AS1 significantly decreased the level of miR-339-5p in NSCLC cell. Moreover, the matrix metalloproteinase 15 (MMP15) was identified to be a target of miR-339-5p. The level of MMP15 was negatively regulated by miR-339-5p whereas positively controlled by MAFG-AS1. In addition, up-regulation of miR-339-5p neutralized the promoting impact of MAFG-AS1 on the migration, invasion and EMT of NSCLC cell. Finally, the xenograft model suggested that MAFG-AS1 promoted the metastasis of NSCLC cell in vivo. Altogether, we proved that MAFG-AS1-miR-339-5p-MMP15 axis might be a promising therapeutic target for the treatment of patients with NSCLC.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Pulmonares/genética , Metaloproteinase 15 da Matriz/metabolismo , MicroRNAs/metabolismo , RNA Antissenso/metabolismo , Animais , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Transição Epitelial-Mesenquimal/genética , Xenoenxertos , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Fator de Transcrição MafG/genética , Fator de Transcrição MafG/metabolismo , Metaloproteinase 15 da Matriz/genética , Camundongos , Camundongos Endogâmicos BALB C , MicroRNAs/genética , Invasividade Neoplásica , RNA Antissenso/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismoRESUMO
During cancer development, it is well established that many genes, including tumor suppressor genes, are hypermethylated and transcriptionally repressed, a phenomenon referred to as epigenetic silencing. In general, the factors involved in, and the mechanistic basis of, epigenetic silencing during cancer development are not well understood. We have recently described an epigenetic silencing pathway, directed by the oncogenic B-Raf proto-oncogene (BRAF) variant BRAF(V600E), that mediates widespread epigenetic silencing in colorectal cancer (CRC). Notably, the BRAF(V600E) mutation is also present in 50-70% of melanomas. Here, we show that the same pathway we identified in CRC also directs epigenetic silencing of a similar set of genes in BRAF-positive melanoma. In both CRC and melanoma, BRAF(V600E) promotes epigenetic silencing through up-regulation of v-maf avian musculoaponeurotic fibrosarcoma oncogene homolog G (MAFG), a transcriptional repressor with sequence-specific DNA-binding activity. The elevated concentration of MAFG drives DNA binding on the promoter. Promoter-bound MAFG recruits a set of corepressors that includes its heterodimeric partner BTB and CNC homology 1, basic leucine zipper transcription factor 1 (BACH1), the chromatin remodeling factor chromodomain helicase DNA-binding protein 8 (CHD8), and the DNA methyltransferase DNMT3B, resulting in hypermethylation and transcriptional silencing. Our results reveal a common BRAF(V600E)-directed transcriptional regulatory pathway that mediates epigenetic silencing in unrelated solid tumors and provide strong support for an instructive model of oncoprotein-directed epigenetic silencing.
Assuntos
Neoplasias Colorretais/genética , Epigênese Genética/fisiologia , Inativação Gênica , Fator de Transcrição MafG/fisiologia , Melanoma/genética , Proteínas Proto-Oncogênicas B-raf/fisiologia , Proteínas Repressoras/fisiologia , Linhagem Celular Tumoral , Metilação de DNA , Humanos , Proto-Oncogene Mas , Regulação para CimaRESUMO
Researchers have shown that long noncoding RNAs (lncRNAs) are closely associated with the pathogenesis of colorectal cancer (CRC). In here, we aimed to explore the function of lncRNA MAFG-AS1 in tumorigenesis of CRC. Firstly, we found that the expression of MAFG-AS1 was upregulated in CRC tissues and positively correlated with the advanced tumor stage. A reciprocal repression was found between MAFG-AS1 and miR-147b. The expression of miR-147b was downregulated in CRC tissues and inversely correlated with MAFG-AS1. Both the low-expression of miR-147b expression and the advanced tumor stage were independent factor for poor survival probability. Furthermore, overexpression of MAFG-AS1 promoted cell proliferation, cell cycle progression, and invasion, and inhibited apoptosis, while transduction of miR-147b partially reversed the effect of MAFG-AS1 on cellular processes. Consistently, stable over-expression of MAFG-AS1 contributed to the growth of colon cancer cell xenografts in vivo. NDUFA4 was identified as a direct target of miR-147b and knockdown of NDUFA4 abolished the oncogenic role of miR-147b inhibitor. Besides, MAFG-AS1 contributed to cell glycolysis by sponging miR-147b and activation of NDUFA4, causing an upregulation of PDK1, PFK1 and PKM2. Taken together, our study suggested that MAFG-AS1 functions as a novel oncogenic lncRNA in the development of CRC by regulating miR-147b/NDUFA4.
Assuntos
Neoplasias Colorretais/patologia , Progressão da Doença , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Fator de Transcrição MafG/genética , MicroRNAs/antagonistas & inibidores , RNA Longo não Codificante/fisiologia , Proteínas Repressoras/genética , Animais , Apoptose , Ciclo Celular , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Complexo IV da Cadeia de Transporte de Elétrons/antagonistas & inibidores , Glicólise , Xenoenxertos , Humanos , Camundongos , MicroRNAs/fisiologiaRESUMO
Chronic myeloid leukemia (CML) is one of the most frequent hematological neoplasia worldwide. The abnormal accumulation of reactive oxygen species may be an important factor in CML development. The transcription factor NRF2 can regulate the transcription of a battery of antioxidant and detoxificant genes after heterodimerizing with small-Maf proteins. Although the participation of NRF2 in the development of chronic degenerative diseases has been thoroughly studied, the role of small-Maf genes has not been documented. We have identified polymorphisms in the three MAF genes (F, G and K) and assessed their association with CML. Over 266 subjects with CML and 399 unrelated healthy donors have been studied. After sequencing each MAF gene by Sanger technology, we found 17 variants in MAFF gene, eight in MAFG and seven in MAFK. In the case-control study, the homozygote genotype CC for the rs9610915 SNP of MAFF was significantly associated with CML. The frequency of the ACC haplotype from MAFK was significantly lower than controls. After stratification by gender, the ACC and GTG haplotypes were associated only with males with CML. These novel data suggest an association between MAFF and MAFG and the development of CML.
Assuntos
Variação Genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Proteínas Proto-Oncogênicas c-maf/genética , Adulto , Alelos , Estudos de Casos e Controles , Biologia Computacional , Feminino , Frequência do Gene , Genótipo , Haplótipos , Humanos , Fator de Transcrição MafF/genética , Fator de Transcrição MafK/genética , Masculino , Pessoa de Meia-Idade , Proteínas Nucleares/genética , Razão de Chances , Polimorfismo de Nucleotídeo Único , Fatores SexuaisRESUMO
MAF bZIP transcription factor G (MAFG)-driven astrocytes have been reported to promote inflammation in the CNS. However, its function in depression, the primary cause of disability worldwide, has not been well characterized. This study investigated the possible perturbation of heme oxygenase 1 (HMOX1, also known as HO1) by the transcription factor MAFG as an underlying mechanism of the development of depression. The GSE98793 dataset was included for gene expression analysis of whole blood from donors with major depressive disorder and controls, and the target of MAFG was predicted by multiple database mining. Mouse and cellular models of depression were established by chronic unpredictable mild stress (CUMS) and lipopolysaccharide (LPS) treatment of astrocytes, which were treated with MAFG and HMOX1 knockdown plasmids. MAFG was highly expressed in the hippocampal tissues of CUMS-challenged mice and LPS-induced astrocytes. MAFG knockdown alleviated depression-like behaviors in mice. MAFG bound to the HMOX1 promoter and repressed its transcription. Knockdown of HMOX1 exacerbated neuroinflammation in astrocytes and accelerated depression-like behavior in mice. In conclusion, MAFG knockdown attenuated CUMS-stimulated depression-like behaviors in mice by astrocyte-mediated neuroinflammation via restoration of HMOX1.
RESUMO
The MAF bZIP transcription factor G-antisense RNA 1 (MAFG-AS1) is located on chromosome 17. MAFG-AS1 was upregulated in 15 human cancers. MAFG-AS1 not only suppresses 16 miRNAs but also directly impacts 22 protein-coding genes' expression. Notably, abnormal MAFG-AS1 expression is connected to clinicopathological characteristics and a worse prognosis in a variety of cancers. Moreover, MAFG-AS1 takes its part in the tumorigenesis and progression of various human malignancies by suppressing apoptosis and promoting proliferation, migration, invasion, aerobic glycolysis, ferroptosis, angiogenesis, EMT, and metastasis. Besides, it can predict treatment effectiveness in ER + breast cancer, urothelial bladder carcinoma, and liver cancer by functioning as a trigger of resistance to tamoxifen, sorafenib, and cisplatin. This study systematically presents the functions of MAFG-AS1 in various cancers, as well as the findings of bioinformatics analyses of the MAFG-AS1, which should give clear advice for future research.
Assuntos
Neoplasias da Mama , Neoplasias Hepáticas , MicroRNAs , RNA Longo não Codificante , Humanos , Feminino , Carcinógenos , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Antissenso/genética , Neoplasias Hepáticas/genética , Neoplasias da Mama/genética , Transformação Celular Neoplásica/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Linhagem Celular Tumoral , Movimento Celular/genética , Proteínas Repressoras/genética , Fator de Transcrição MafG/genética , Fator de Transcrição MafG/metabolismoRESUMO
Non-healing lesions in diabetic foot ulcers are a significant effect of poor angiogenesis. Epigenetic regulators, mainly lncRNA and miRNA, are recognized for their important roles in disease progression. We deciphered the regulation of lncRNA NEAT1 through the miR-146a-5p/mafG axis in the progression of DFU. A lowered expression of lncRNA NEAT1 was associated with dysregulated angiogenesis through the reduced expression of mafG, SDF-1α, and VEGF in chronic ulcer subjects compared to acute DFU. This was validated by silencing NEAT1 by SiRNA in the endothelial cells which resulted in the transcriptional repression of target genes. Our in silico analysis identified miR-146a-5p as a potential target of lncRNA NEAT1. Further, silencing NEAT1 led to an increase in the levels of miR-146a-5p in chronic DFU subjects. This research presents the role of the lncRNA NEAT1/miR-146a-5p/mafG axis in enhancing angiogenesis in DFU.
Assuntos
Pé Diabético , MicroRNAs , Neovascularização Fisiológica , RNA Longo não Codificante , Humanos , Pé Diabético/patologia , Células Endoteliais/metabolismo , MicroRNAs/genética , RNA Longo não Codificante/genéticaRESUMO
Long noncoding RNAs (lncRNAs) are RNA molecules of 200 nucleotides or more in length that are not translated into proteins. Their expression is tissue-specific, with the vast majority involved in the regulation of cellular processes and functions. Many human diseases, including cancer, have been shown to be associated with deregulated lncRNAs, rendering them potential therapeutic targets and biomarkers for differential diagnosis. The expression of lncRNAs in the nervous system varies in different cell types, implicated in mechanisms of neurons and glia, with effects on the development and functioning of the brain. Reports have also shown a link between changes in lncRNA molecules and the etiopathogenesis of brain neoplasia, including glioblastoma multiforme (GBM). GBM is an aggressive variant of brain cancer with an unfavourable prognosis and a median survival of 14-16 months. It is considered a brain-specific disease with the highly invasive malignant cells spreading throughout the neural tissue, impeding the complete resection, and leading to post-surgery recurrences, which are the prime cause of mortality. The early diagnosis of GBM could improve the treatment and extend survival, with the lncRNA profiling of biological fluids promising the detection of neoplastic changes at their initial stages and more effective therapeutic interventions. This review presents a systematic overview of GBM-associated deregulation of lncRNAs with a focus on lncRNA fingerprints in patients' blood.