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BACKGROUND: Prostate cancer is a leading cause of cancer-related deaths in men worldwide. Despite advances in treatment strategies, there is still a need for novel therapeutic targets and approaches. Ferroptosis has emerged as a critical process in the development and progression of several cancers, including prostate cancer (PCA). In this study, we investigate the role of MT1G, a gene implicated in immune responses and ferroptosis, in the pathogenesis of PCA. Our objective is to elucidate its prognostic significance and its impact on the tumor microenvironment, while exploring its potential in enhancing the sensitivity to immune checkpoint inhibitor (ICI) therapy. METHODS: We utilized a combination of in silico analysis and experimental techniques to investigate the role of MT1G in PCA. First, we analyzed large-scale genomic datasets to assess the expression pattern and prognostic significance of MT1G in PCA patients. Subsequently, we performed functional assays to explore the impact of MT1G in PCA and its potential involvement in modulating immune responses. In addition, we conducted in vivo experiments to evaluate the effect of MT1G on tumor growth and response to ICI therapy. RESULTS: Our analysis revealed that MT1G expression is significantly downregulated in PCA tissues compared to normal prostate tissues and is associated with poor prognosis. Furthermore, MT1G overexpression inhibited the growth of PCA cells in vitro and in vivo. Importantly, we found that MT1G regulates the tumor microenvironment by modulating immune cell infiltration and inhibiting immunosuppressive factors. Furthermore, our study reveals a significant correlation between MT1G expression levels and the response to immune checkpoint inhibitor (ICI) therapy in prostate cancer (PCA) patients, as MT1G upregulation leads to an increase in PDL-1 expression. These findings underscore the potential of MT1G as a promising predictive biomarker for ICI therapy response in PCA patients. CONCLUSION: Our study elucidates the pivotal role played by MT1G in the pathogenesis of prostate cancer (PCA) and its profound implications for prognosis. Moreover, it raises the intriguing possibility that MT1G could pave the way for novel therapeutic approaches in PCA treatment. This potential arises from its ability to orchestrate immune infiltration within the tumor microenvironment, consequently enhancing sensitivity to immune checkpoint inhibitor (ICI) therapy. Therefore, our findings hold substantial promise for advancing our comprehension of PCA and exploring innovative therapeutic strategies.
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Ferroptose , Neoplasias da Próstata , Masculino , Humanos , Prognóstico , Ferroptose/genética , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Imunoterapia , Neoplasias da Próstata/genética , Neoplasias da Próstata/terapia , Microambiente Tumoral , MetalotioneínaRESUMO
Sorafenib, a multikinase inhibitor, has been widely used as a first-line anticancer drug for advanced hepatocellular carcinoma (HCC). However, the development of drug resistance to sorafenib is frequently observed in clinical applications. Potential nonkinase targets of sorafenib have not been well documented and may provide insights into reversing drug resistance and enhancing drug efficacy. Herein, we report that sorafenib exerts its anticancer effects by activating metallothionein 1 G (MT1G) expression. MT1G is a novel marker in HCC that correlates well with patient survival. MT1G overexpression suppressed the cellular proliferation, migration, invasion, and tumour formation of HCC and sensitised cells to sorafenib treatment. However, the disruption of MT1G attenuated the anticancer effects of sorafenib. Mechanistically, sorafenib upregulated MT1G expression via hypomethylation of its promoter region by binding and inhibiting DNA methyltransferase 1 (DNMT1) and increasing its promoter accessibility in HCC cells. Activation of MT1G also inhibited CA9 transcription through the suppression of HIF1A as mediated by KLF4. Our collective data revealed that sorafenib exerts its anticancer effects through epigenetic regulation of the DNMT1/MT1G/KLF4/CA9 axis in HCC and the activation of MT1G might constitute a strategy for enhancing the effect of sorafenib to suppress HCC cells.
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Antineoplásicos , Carcinoma Hepatocelular , Neoplasias Hepáticas , Sorafenibe , Antígenos de Neoplasias , Antineoplásicos/farmacologia , Anidrase Carbônica IX/genética , Anidrase Carbônica IX/metabolismo , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células , DNA (Citosina-5-)-Metiltransferase 1/genética , DNA (Citosina-5-)-Metiltransferase 1/metabolismo , Resistencia a Medicamentos Antineoplásicos , Epigênese Genética , Humanos , Fator 4 Semelhante a Kruppel/genética , Fator 4 Semelhante a Kruppel/metabolismo , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Metalotioneína/genética , Metalotioneína/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sorafenibe/farmacologiaRESUMO
Diffuse Large B-cell lymphoma (DLBCL) is an aggressive disease with heterogeneous outcome and marked variable response to chemotherapy. We assessed promoter hypermethylation (PM) for a panel of tumor suppressor genes in 75 DLBCLs compared to 20 lymphoid hyperplasia (LH) and 30 normal control, using methylation specific PCR. Results were correlated to patients' clinic-pathological characteristics, immunophenotyping, and patients' outcome. DAPK1, RUNX3, MT1G, MGMT, CDH1 and p16 PM were detected in 38.7% (29/75), 49.3% (37/75), 46.7% (35/75), 44% (33/75), 49.3% (37/75) and 42.7% (32/75);respectively, of DLBCL patients compared to LH group (P < 0.05). Aberrant PM of RUNX3, MGMT, CDH1 and p16 was significantly higher in non-germinal central B-cell like (non-GCB) compared to GCB (58.3% vs. 33.3%, 56.2% vs. 22.2, 62.5% vs. 25.9, and 56.2% vs. 18.5%, respectively). PM of studies genes in DLBCL associated significantly with worse survival outcome and resistance to chemotherapy (P ≤ 0.01). In non-GCB group, DAPK1, MT1G, RUNX3, CDH1 and p16 PM associated significantly with reduced DFS (P ≤ 0.004) and OS (P ≤ 0.015). Multivariate analysis indicated that RUNX3 and CDH1 PM were independent prognostic factors for OS (P = 0.03 and 0.04; respectively), while DAPK1, RUNX3 and MT1G PM were independent prognostic factors for DFS (P = 0.002, 0.037& 0.007; respectively). DAPK1, RUNX3, MT1G, CDH1 and p16 PM are promising prognostic and/or predictive markers for non-GCB independent of IPI. Upregulation of those genes using new demethylating agents is a promising approach that sensitize chemoresistant DLBCL patients, especially the non-GCB subtype.
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Metilação de DNA/genética , Genes Supressores de Tumor/fisiologia , Linfoma Difuso de Grandes Células B/genética , Adulto , Idoso , Antígenos CD/genética , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Caderinas/genética , Subunidade alfa 3 de Fator de Ligação ao Core/genética , Proteínas Quinases Associadas com Morte Celular/genética , Intervalo Livre de Doença , Doxorrubicina/uso terapêutico , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Linfoma Difuso de Grandes Células B/metabolismo , Masculino , Metalotioneína/genética , Pessoa de Meia-Idade , Prognóstico , Regiões Promotoras Genéticas/genética , Estudos Retrospectivos , Análise de SobrevidaRESUMO
BACKGROUND: Osteosarcoma (OS) is a primary malignant bone tumor arising from mesenchymal cells. The standard clinical treatment for OS involves extensive tumor resection combined with neoadjuvant chemotherapy or radiotherapy. OS's invasiveness, lung metastasis, and drug resistance contribute to a low cure rate and poor prognosis with this treatment. Metallothionein 1G (MT1G), observed in various cancers, may serve as a potential therapeutic target for OS. METHODS: OS samples in GSE33382 and TARGET datasets were selected as the test cohorts. As the external validation cohort, 13 OS tissues and 13 adjacent cancerous tissues from The Second Affiliated Hospital of Nanchang University were collected. Patients with OS were divided into high and low MT1G mRNA-expression groups; differentially expressed genes (DEGs) were identified as MT1G-related genes. The biological function of MT1G was annotated using Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO) and gene set enrichment analysis (GSEA). Gene expression correlation analysis and competing endogenous RNA (ceRNA) regulatory network construction were used to determine potential biological regulatory relationships of DEGs. Survival analysis assessed the prognostic value of MT1G. RESULTS: MT1G expression increased in OS samples and presented higher in metastatic OS compared with non-metastatic OS. Functional analyses indicated that MT1G was mainly associated with spliceosome. A ceRNA network with DEGs was constructed. MT1G is an effective biomarker predicting survival and correlated with increased recurrence rates and poorer survival. CONCLUSIONS: This research identified MT1G as a potential biomarker for OS prognosis, highlighting its potential as a therapy target.
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Neoplasias Ósseas , Biologia Computacional , Regulação Neoplásica da Expressão Gênica , Células-Tronco Mesenquimais , Metalotioneína , Osteossarcoma , Feminino , Humanos , Masculino , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/mortalidade , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Células-Tronco Mesenquimais/metabolismo , Metalotioneína/genética , Metalotioneína/metabolismo , Osteossarcoma/genética , Osteossarcoma/patologia , PrognósticoRESUMO
Betulinic acid (BA) is a pentacyclic triterpene found in many plant species and has a broad-spectrum anti-tumor effect in various cancers, including colon cancer (CRC). However, its anticancer mechanism in CRC is no clear. RNA sequencing and bioinformatics analysis showed BA up-regulated 378 genes and down-regulated 137 genes in HT29 cells, while 2303 up-regulated and 1041 down-regulated genes were found in SW480 cells. KEGG enrichment analysis showed BA significantly stimulated the expression of metallothionein 1 (MT1) family genes in both HT29 and SW480 cells. Metallothionein 1G (MT1G) was the gene with the highest upregulation of MT1 family genes induced by BA dose-dependently. High MT1G expression enhanced the sensitivity of CRC cells to BA, whereas, MT1G knockdown had the opposite effect in vitro and in vivo. GSEA and GSCA showed genes affected by BA treatment were involved in cell cycle and G2/M checkpoint in CRC. Flow cytometry further exhibited BA reduced the percentage of G0/G1 cells and increased the percentage of G2/M cells in a dose-dependent manner, which could be rescued by MT1G knockdown. Moreover, MT1G also counteracted the BA-induced changes in cell cycle-related proteins (CDK2 and CDK4) and p-Rb. In summary, we have revealed a new anti-tumor mechanism that BA altered the cell cycle progression of CRC cells by upregulating MT1G gene, thereby inhibiting the proliferation of CRC cells.
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INTRODUCTION: Colon cancer is a common and malignant cancer featuring high morbidity and poor prognosis. AIMS: This study was performed to explore the regulatory role of MT1G in colon cancer as well as its unconcealed molecular mechanism. METHODS: The expressions of MT1G, c-MYC, and p53 were assessed with the application of RT-qPCR and western blot. The impacts of MT1G overexpression on the proliferative ability of HCT116 and LoVo cells were measured by CCK-8 and BrdU incorporation assays. Additionally, transwell wound healing, and flow cytometry assays were employed to evaluate the invasive and migrative capacities as well as the apoptosis level of HCT116 and LoVo cells. Moreover, the activity of the P53 promoter region was assessed with the help of a luciferase reporter assay. RESULTS: It was found that the expressions of MT1G at both mRNA and protein levels were greatly decreased in human colon cancer cell lines, particularly in HCT116 and LoVo cell lines. After transfection, it was discovered that the MT1G overexpression suppressed the proliferation, migration and invasion but promoted the apoptosis of HCT116 and LoVo cells, which were then partially reversed after overexpressing c-MYC. Additionally, MT1G overexpression reduced c-MYC expression but enhanced the p53 expression, revealing that the MT1G overexpression could regulate c-MYC/P53 signal. Elsewhere, it was also shown that c-MYC overexpression suppressed the regulatory effects of MT1G on P53. CONCLUSION: To conclude, MT1G was verified to regulate c-MYC/P53 signal to repress the proliferation, migration and invasion but promote the apoptosis of colon cancer cells, which might offer a novel targeted-therapy for the improvement of colon cancer.
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Neoplasias do Colo , Proteína Supressora de Tumor p53 , Humanos , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/genética , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Apoptose/genética , Movimento Celular/genética , Regulação Neoplásica da Expressão Gênica , Metalotioneína/genética , Metalotioneína/metabolismo , Metalotioneína/farmacologiaRESUMO
Hepatocellular carcinoma (HCC), one of the most prevalent cancers globally, is closely associated with tumor-associated macrophages (TAMs), including monocyte-derived macrophages and liver-resident Kupffer cells. Understanding TAM heterogeneity at the cellular level is crucial for developing effective HCC prevention and treatment strategies. In this study, we conducted an integrated single-cell analysis of four cohorts (GSE140228, GSE125449, GSE149614 and GSE156625) to elucidate the TAM landscape in HCC. We identified 284 gene markers, termed Panmyeloid markers, that characterize myeloid cells within this context. Our analysis distinguished six clusters of monocyte-derived macrophages (Macro1-Macro6) and four clusters of Kupffer cells (Kupffer1-Kupffer4). Notably, CXCL10 + macrophages and MT1G + Kupffer cells, predominantly located within tumor tissues, exhibited distinct functional characteristics relevant to HCC. We also explored cellular communication between TAMs and T cells, uncovering potential signaling pathways such as the CXCL10/CXCL11-CXCR3 and CXCL12-CXCR4 networks. These findings enhance our understanding of TAMs in HCC and open new avenues for targeted therapeutic interventions.
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Ferroptosis, a newly discovered way of cell death, has been proved to be involved in the oncogenesis and development of cancers, including colorectal cancer (CRC). Here, by identifying the differentially expressed genes (DEGs) from three CRC transcriptome microarray datasets (GSE20842, GSE23878, and GSE25070), we found that the expression of MT1G was significantly decreased in CRC tissues, and the patients with a high level of MT1G displayed a poor prognosis. Quantitative PCR (qPCR) further confirmed the downregulated MT1G in two CRC cells, HCT8 and HCT116. The colony-forming assay indicated that the MT1G overexpression exhibited a remarkable inhibition of cell proliferation in HCT8 and HCT116 cells. In addition, we explored the co-expressed genes of MT1G to gain a better understanding of its potential signaling pathways. Aberrantly expressed MT1G also affected the immune response of CRC patients. Collectively, these findings might deepen our comprehension on the potential biological implications of MT1G in CRC.
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Naringenin (Nar) is a flavanone that has been suggested to provide human health benefits such as anti-inflammatory, anti-oxidant and anti-cancer properties. However, the mechanisms underlying these benefits are complex and still not fully understood. In this study, we investigated the effect of Nar on the inflammatory response of macrophages and its underlying mechanism. In lipopolysaccharide (LPS)-stimulated human macrophages, Nar inhibited the activation of NF-κB pathway and suppressed the downstream expression of pro-inflammatory factors. In addition, Nar was also able to induce metallothionein 1 G (MT1G) expression, and the inhibitory effects of Nar on the production of pro-inflammatory cytokines was dependent on MT1G. Mechanistically, we found that MT1G-mediated inhibition of pro-inflammatory cytokines responses might be through repressing NF-κB activation via zinc chelation. Overall, this study reveals a novel mechanism of Nar on inflammatory responses, the suppression of NF-κB activation through upregulation of MT1G.
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Anti-Inflamatórios/farmacologia , Citocinas/metabolismo , Flavanonas/farmacologia , Inflamação/tratamento farmacológico , Macrófagos/efeitos dos fármacos , NF-kappa B/metabolismo , Antioxidantes/farmacologia , Células Cultivadas , Células HEK293 , Humanos , Inflamação/metabolismo , Lipopolissacarídeos/farmacologia , Macrófagos/metabolismo , Metalotioneína/farmacologia , Transdução de Sinais/efeitos dos fármacos , Células THP-1/efeitos dos fármacos , Células THP-1/metabolismo , Regulação para Cima/efeitos dos fármacosRESUMO
BACKGROUND: Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related death. Traditional Chinese medicine (TCM) has special advantages in relieving HCC, while Astragalus membranaceus is commonly used in TCM treatment. However, its underlying mechanisms for treatment of HCC are unclear. METHODS: Differentially expressed genes (DEGs) of Astragalus membranaceus treatment in HepG2 cells were identified, and Astragalus membranaceus-gene network was constructed. The hub genes were then obtained via protein-protein interaction (PPI) analysis. Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), and Gene Set Enrichment Analysis (GSEA) were subsequently performed. Furthermore, prognosis genes related to HCC from The Cancer Genome Atlas Program (TCGA) was identified to explore the correlation between Astragalus membranaceus treatment and prognosis of HCC. Finally, Astragalus membranaceus-component-target network was established through SymMap. RESULTS: Twenty five DEGs (15 up-regulated and 10 down-regulated) of Astragalus membranaceus treatment in HepG2 cells were identified. Among the 25 genes, MT1F, MT1G, MT1X and HMOX1 may play essential roles. Astragalus membranaceus mainly affects the Mineral absorption pathway in HCC. A total of 256 genes (p < 0.01) related to prognosis of HCC were identified, and MT1G is a common gene between prognosis genes and DEGs. Furthermore, Astragalus membranaceus may directly down-regulate MT1G through daidzein to promote ferroptosis of HCC cells and improve prognosis for HCC. CONCLUSION: Our study provided new understandings of the pharmacological mechanisms by which Astragalus membranaceus improves the prognosis of HCC, and showed that the combination of transcriptomics and network pharmacology is helpful to explore mechanisms of TCM and traditional medicines from other nations.
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Astragalus propinquus , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Medicina Tradicional Chinesa/métodos , Regulação para Baixo , Ontologia Genética , Terapia Genética , Células Hep G2 , Humanos , Farmacologia em Rede , Mapas de Interação de Proteínas , Transcriptoma , Regulação para CimaRESUMO
Resistance to chemotherapy is a long-standing problem in the management of cancer, and cancer stem cells are regarded as the main source of this resistance. This study aimed to investigate metallothionein (MT)-1G involvement in the regulation of cancer stemness and provide a strategy to overcome chemoresistance in pancreatic ductal adenocarcinoma (PDAC). Methods: MT1G was identified as a critical factor related with gemcitabine resistance in PDAC cells by mRNA microarray. Its effects on PDAC stemness were evaluated through sphere formation and tumorigenicity. LC-MS/MS analysis of conditional medium revealed that activin A, a NF-κB target, was a major protein secreted from gemcitabine resistant PDAC cells. Both loss-of-function and gain-of-function approaches were used to validate that MT1G inhibited NF-κB-activin A pathway. Orthotopic pancreatic tumor model was employed to explore the effects on gemcitabine resistance with recombinant follistatin to block activin A. Results: Downregulation of MT1G due to hypermethylation of its promoter is related with pancreatic cancer stemness. Secretome analysis revealed that activin A, a NF-κB target, was highly secreted by drug resistant cells. It promotes pancreatic cancer stemness in Smad4-dependent or independent manners. Mechanistically, MT1G negatively regulates NF-κB signaling and promotes the degradation of NF-κB p65 subunit by enhancing the expression of E3 ligase TRAF7. Blockade of activin A signaling with follistatin could overcome gemcitabine resistance. Conclusions: MT1G suppresses PDAC stemness by limiting activin A secretion via NF-κB inhibition. The blockade of the activin A signaling with follistatin may provide a promising therapeutic strategy for overcoming gemcitabine resistance in PDAC.
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Ativinas/metabolismo , Metalotioneína/metabolismo , Células-Tronco Neoplásicas/metabolismo , Animais , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , China , Cromatografia Líquida , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Humanos , Metalotioneína/genética , Camundongos Endogâmicos C57BL , Camundongos Nus , NF-kappa B/metabolismo , Células-Tronco Neoplásicas/fisiologia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Transdução de Sinais/efeitos dos fármacos , Espectrometria de Massas em Tandem , Fator de Transcrição RelA/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Neoplasias PancreáticasRESUMO
Identification of toxicants that underlie neurological diseases is a neglected area awaiting a valid strategy to identify such toxicants. We sought biomarkers that respond to known neurotoxicants in LUHMES immortalized neurons and evaluated these biomarkers for use in screening libraries of environmental toxicants. LUHMES immortalized human dopaminergic neurons were surveyed by RNA sequencing following challenge with parkinsonian toxicants rotenone, 6-hydroxydopamine, MPP+, and ziram (zinc dimethyldithiocarbamate; Zn2+DDC2), as well as additional toxicants paraquat, MS275, and methylmercury. The metallothionein gene MT1G was the most dynamic gene expression response to all seven toxicants. Multiple toxicants also increased transcripts for SLC30A1 and SLC30A2 zinc secretion transporters, the SLC7A11 xCT cystine/glutamate antiporter important for glutathione synthesis, DNA damage inducible transcript 3 (DDIT3), and secreted growth factors FIBIN and CXCL12, whereas several toxicants decreased expression of the apelin growth factor (APLN). These biomarker genes revealed stress responses to many toxicants at sub-cytotoxic concentrations. Since several of these biomarker genes and prior neurological disease studies implicated disruption of metal distribution, we tested metal chelator thiram (dimethyldithiocarbamate, DDC), ziram, and several other metals and metal chelates for cytotoxicity and induction of MT1G expression. Metals and chelators that caused dynamic increases in MT1G expression also caused cytotoxicity, except Ni2+DDC2 induced MT1G at 5 µM, but lacked cytotoxicity up to 100 µM. These results bolster prior work suggesting that neurons are characteristically sensitive to depletion of glutathione or to disruption of cellular metal distribution and provide biomarkers to search for such neurotoxicants in chemical libraries.
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Substâncias Perigosas/toxicidade , Metalotioneína/biossíntese , Metalotioneína/genética , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Biomarcadores/metabolismo , Linhagem Celular Transformada , Relação Dose-Resposta a Droga , Guanidinas/toxicidade , Humanos , Neonicotinoides/toxicidade , Nitrocompostos/toxicidadeRESUMO
BACKGROUND: Mechanisms underlying hepatocellular carcinoma (HCC) development are largely unknown. The role of trace elements and proteins regulating metal ions homeostasis, i.e. metallothioneins (MTs), recently gained an increased interest. Object of the study was to investigate the role of promoter DNA methylation in MTs transcriptional regulation and the possible prognostic significance of serum trace elements in HCC. METHODS: Forty-nine HCC patients were enrolled and clinically characterized. Cu, Se, and Zn contents were measured by Inductively Coupled Plasma Mass Spectrometry in the serum and, for a subset of 27 patients, in HCC and homologous non-neoplastic liver (N) tissues. MT1G and MT1H gene expression in hepatic tissues was assessed by Real-Time RT-PCR and the specific promoter DNA methylation by Bisulfite-Amplicon Sequencing. RESULTS: Patients with Cu serum concentration above the 80th percentile had a significantly decreased survival rate (P < 0.001) with a marked increased hazard ratio for mortality (HR 6.88 with 95% CI 2.60-18.23, P < 0.001). Se and Zn levels were significantly lower in HCC as compared to N tissues (P < 0.0001). MT1G and MT1H gene expression was significantly down-regulated in HCC as compared to N tissues (P < 0.05). MTs promoter was hypermethylated in 9 out of the 19 HCC tissues showing MTs down-regulation and methylation levels of three specific CpGs paralleled to an increased mortality rate among the 23 patients analyzed (P = 0.015). CONCLUSIONS: MT1G and MT1H act as potential tumor suppressor genes regulated through promoter DNA methylation and, together with serum Cu concentrations, be related to survival rate in HCC.
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Using genome-wide screening and TCGA-based data analysis, we identified a DNA methylation-related gene named metallothionein-1G (MT1G), which may play an important role in hepatocellular carcinoma (HCC). In this study, we found that MT1G expression was silenced in 4/6 HCC cell lines and negatively related to aberrant promoter hypermethylation. Its mRNA level was restored with demethylation treatment. Moreover, MT1G downregulation at both the transcriptional and protein level was also detected in 8 pairs of clinical HCC samples compared with its expression in adjacent normal tissues. Ectopic expression of MT1G in silenced HCC cell lines inhibited colony formation, suppressed cell migration and invasion, and repressed xenograft tumor growth in nude mice. In contrast, knockdown of MT1G by short hairpin RNA showed the opposite effect on cell proliferation and the malignant phenotype. Moreover, our data showed that MT1G suppressed tumor invasion and metastasis mainly through regulating the expression of proteins in the matrix metalloproteinase family (MMP) and modulating the epithelial-mesenchymal transition (EMT) process. To our surprise, the data from TCGA showed that hypermethylation of MT1G is associated with good survival of HCC patients. In conclusion, our study demonstrated that MT1G acts as a tumor suppressor gene in HCC development, but its clinical potential in HCC requires further evaluation.
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The intake of cadmium contaminated fish was mimicked by incubating human hepatoblastoma cells (Cell line HepG2) with a combination of different levels of cadmium (0-5µM) plus the n-3 fatty acids docosahexaenoic acid and eicosapentaenoic acid, which are typical for fish. Uptake of cadmium, iron, copper and zinc was measured by ICP-MS. In addition mRNA expression of two metallothioneins (mt1 g and mt1 m) was evaluated by real-time PCR. The obtained data shows that the presence of cadmium increases the uptake of iron and zinc into the HepG2 cells while the uptake of copper remains unaffected. The presence of the chosen fatty acids did not affect the uptake of either cadmium or iron, zinc and copper. The presence of already 1µM cadmium increased the mRNA expression of mt1 g and mt1 m significantly, while the fatty acids did not interfere with the effect of cadmium.
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Metalotioneína/genética , Metais Pesados/farmacologia , Transporte Biológico/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ácidos Docosa-Hexaenoicos/farmacologia , Ácido Eicosapentaenoico/farmacologia , Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Humanos , RNA Mensageiro/metabolismoRESUMO
AIM: To investigate the potential of promoter methylation of two tumor suppressor genes (TSGs) as biomarkers for hepatocellular carcinoma (HCC). METHODS: A total of 189 subjects were included in this retrospective cohort, which contained 121 HCC patients without any history of curative treatment, 37 patients with chronic hepatitis B (CHB), and 31 normal controls (NCs). DNA samples were extracted from 400 µL of serum of each subject and then modified using bisulfite treatment. Methylation of the promoters of the TSGs (metallothionein 1M, MT1M; and metallothionein 1G, MT1G) was determined using methylation-specific polymerase chain reaction. The diagnostic value of combined MT1M and MT1G promoter methylation was evaluated using the area under the receiver operating characteristic curves. RESULTS: Our results indicated that the methylation status of serum MT1M (48.8%, 59/121) and MT1G (70.2%, 85/121) promoters in the HCC group was significantly higher than that in the CHB group (MT1M 5.4%, 2/37, P < 0.001; MT1G 16.2%, 6/37, P < 0.001) and NC group (MT1M 6.5%, 2/31, P < 0.001; MT1G 12.9%, 4/27, P < 0.001). Aberrant serum MT1M promoter methylation gave higher specificity to discriminate HCC from CHB (94.6%) and NCs (93.5%), whereas combined methylation of serum MT1M and MT1G promoters showed higher diagnostic sensitivity (90.9%), suggesting that they are potential markers for noninvasive detection of HCC. Furthermore, MT1M promoter methylation was positively correlated with tumor size (rs = 0.321, P < 0.001), and HCC patients with both MT1M and MT1G promoter methylation tended to show a higher incidence of vascular invasion or metastasis (P = 0.018). CONCLUSION: MT1M and MT1G promoter methylation may be used as serum biomarkers for noninvasive detection of HCC.