RESUMO
BACKGROUND: The incidence of colorectal cancer (CRC) has increased in recent years. Identification of accurate tumor markers has become the focus of CRC research. Early and frequent DNA methylation tends to occur in cancer. Thus, identifying accurate methylation biomarkers would improve the efficacy of CRC treatment. Neuroglobin (NGB) is involved in neurological and oncological diseases. However, there are currently no reports on epigenetic regulation involvement of NGB in CRC. RESULTS: NGB was downregulated or silenced in majority CRC tissues and cell lines. The hypermethylation of NGB was detected in tumor tissue, but no or a very low methylation frequency in normal tissues. Overexpression of NGB induced G2/M phase arrest and apoptosis, suppressed proliferation, migration, invasion in vitro, and inhibited CRC tumor growth and angiogenesis in vivo. Isobaric tag for relative and absolute quantitation (Itraq)-based proteomics identified approximately 40% proteins related to cell-cell adhesion, invasion, and tumor vessel formation in the tumor microenvironment, among which GPR35 was proved critical for NGB-regulated tumor angiogenesis suppression in CRC. CONCLUSIONS: NGB, an epigenetically silenced factor, inhibits metastasis through the GPR35 in CRC. It is expected to grow into a potential cancer risk assessment factor and a valuable biomarker for early diagnosis and prognosis assessment of CRC.
Assuntos
Neoplasias Colorretais , Metilação de DNA , Humanos , Neuroglobina/genética , Neuroglobina/metabolismo , Epigênese Genética , Linhagem Celular Tumoral , Neoplasias Colorretais/patologia , Biomarcadores/metabolismo , Regulação Neoplásica da Expressão Gênica , Proliferação de Células , Microambiente Tumoral , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismoRESUMO
BACKGROUND AND AIM: The high mortality and poor prognosis of hepatocellular carcinoma (HCC) have raised the public attention. Gene therapy is considered as a promising treatment option for cancer; thus, finding a new therapeutic target for HCC is urgently needed. GATA4 is a tumor suppressor gene in multiple cancers, but its role in HCC is unclear. In this study, we explored the function of GATA4 in HCC. METHODS: Reverse transcription-polymerase chain reaction and quantitative polymerase chain reaction were used to detect the mRNA expression of GATA4 in HCC cells and tissues. Cell viability, transwell, colony formation, and flow cytometry assays were applied to examine different aspects of biological effects of GATA4 in vitro. Xenografts, immunohistochemistry, and terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling assays were performed to evaluate the effect of GATA4 on tumorigenicity in vivo. Western blotting, immunofluorescence, and ß-galactosidase staining were used to investigate the mechanism underlying the function of GATA4. RESULTS: We found that GATA4 was silenced in 15/19 (79%) HCC tissues. Restoring the expression of GATA4 induced G0 /G1 phase arrest, promoted apoptosis, suppressed HCC proliferation in vitro, and inhibited HCC tumor growth in vivo. Our data further showed that the ectopic expression of GATA4 induced cellular senescence through regulating nuclear factor-κB and inducing mesenchymal-to-epithelial transition. CONCLUSIONS: Our data demonstrated that by inducing cellular senescence and mesenchymal-to-epithelial transition, GATA4 plays a crucial role as a tumor suppressor in HCC. It may thus be a potential cancer therapeutic target for HCC.
Assuntos
Carcinoma Hepatocelular/patologia , Senescência Celular/fisiologia , Fator de Transcrição GATA4/fisiologia , Neoplasias Hepáticas/patologia , Animais , Apoptose/genética , Apoptose/fisiologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Pontos de Checagem do Ciclo Celular/genética , Pontos de Checagem do Ciclo Celular/fisiologia , Proliferação de Células/genética , Proliferação de Células/fisiologia , Senescência Celular/genética , Regulação para Baixo/fisiologia , Transição Epitelial-Mesenquimal/genética , Transição Epitelial-Mesenquimal/fisiologia , Fator de Transcrição GATA4/genética , Regulação Neoplásica da Expressão Gênica/fisiologia , Inativação Gênica , Xenoenxertos , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Masculino , Camundongos Nus , NF-kappa B/fisiologia , Invasividade Neoplásica , Transplante de Neoplasias , RNA Mensageiro/genética , RNA Neoplásico/genética , Transdução de Sinais/fisiologia , Células Tumorais CultivadasRESUMO
Colon cancer is the main cause of cancer mortality worldwide. Its poor prognosis is mainly ascribed to high recurrence rates. Identifying novel prognostic biomarkers and therapeutic key points for management is crucial and important. Long non-coding RNAs (lncRNAs) are a class of RNAs, which have various roles in carcinogenicity and molecular mechanisms. The lncRNA small nucleolar RNA host gene 1 (SNHG1) contributes to the promotion of tumor development, however, the connections between SNHG1 and colon cancer are still unclear. The aim of the present study was to investigate the clinical significance, the biological functions, and the potential mechanism of SNHG1 in colon cancer. In the present study, we referred to the Oncomine database and used RT-qPCR to determine that SNHG1 expression was significantly higher both in colon cancer tissues and cancerous cell lines than in normal samples. Cell functional experiments were performed after knockdown of SNHG1, including Cell Counting Kit-8 assay, colony formation assay, Transwell® assay, and flow cytometric analyses of cell apoptosis, which suggested that SNHG1 stimulated colon cancer cell proliferation, promoted cell invasion and migration, and inhibited apoptosis. Immunohistochemical staining and western blotting experiments revealed that in colon cancer cells with SNHG1 knockdown, ß-catenin, c-Myc and cyclin D1 protein levels were decreased, while E-cadherin was increased, which suggested that SNHG1 promoted colon cancer cell proliferation, migration and invasion through the Wnt/ß-catenin signaling pathway. Our results indicated that SNHG1 and its interrelated components may be future therapeutic targets of carcinoma of the colon.
Assuntos
Carcinogênese/genética , Neoplasias do Colo/genética , Prognóstico , RNA Longo não Codificante/genética , Apoptose/genética , Caderinas/genética , Movimento Celular/genética , Proliferação de Células/genética , Neoplasias do Colo/patologia , Ciclina D1/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas c-myc/genética , Via de Sinalização Wnt , beta Catenina/genéticaRESUMO
Our previous study showed that PLCD1 significantly decreases cell proliferation and affects cell cycle progression in breast cancer cells. In the present study, we aimed to investigate its functional and molecular mechanisms, and whether or not can become a new target for gene therapies. We found reduced PLCD1 protein expression in breast tumor tissues compared with paired surgical margin tissues. PLCD1 promoter CpG methylation was detected in 55 of 96 (57%) primary breast tumors, but not in surgical-margin tissues and normal breast tissues. Ectopic expression of PLCD1 inhibited breast tumor cell proliferation in vivo by inducing apoptosis and suppressed tumor cell migration by regulating cytoskeletal reorganization proteins including RhoA and phospho-cofilin. Furthermore, we found that PLCD1 induced p53 accumulation, increased p27 and p21 protein levels, and cleaved PARP. Finally, we constructed an adenoviral vector expressing PLCD1 (AdH5-PLCD1), which exhibited strong cytotoxicity in breast cancer cells. Our findings provide insights into the development of PLCD1 gene therapies for breast cancer and perhaps, other human cancers.
