MiR-182 promotes cell proliferation by suppressing FBXW7 and FBXW11 in non-small cell lung cancer.

OBJECTIVE: MicroRNAs have been found to be deregulated in lung cancers, which play crucial roles in tumorigenesis and progression. FBXW7 and FBXW11, two important F-box proteins of the ubiquitin-proteasome system (UPS), can target multiple substrates for degradation, in order to regulate cell proliferation and survival in cancers. In the present study, we aimed to explore the potential role and regulating mechanism of miR-182 in non-small cell lung cancer (NSCLC). METHODS: MiRNA expression was evaluated by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). FBXW7, FBXW11, c-Jun, c-Myc and cyclin D protein levels were detected by western blot. Cell growth was determined using cell counting kit (CCK)-8 reagent and colony formation experiment. Then, cell apoptosis and the cell cycle were analyzed on flow cytometry. The target binding activity of miR-182 with FBXW7 or FBXW11 was evaluated through the Dual-Luciferase Reporter Assay System. RESULTS: It was confirmed that miR-182 was significantly upregulated in tumor tissues, compared with adjacent normal tissues, and this was inversely correlated to the protein levels of FBXW7 and FBXW11. The overexpression of miR-182 in NSCLC cells dramatically promoted cell growth, colony formation capacity and cell cycle progression, and inhibited apoptosis in NSCLC cells. In contrast, the downregulation of miR-182 significantly alleviated these properties in vitro. Furthermore, we demonstrated that miR-182 exerted an oncogenic role in NSCLC by directly targeting FBXW7 and FBXW11. CONCLUSION: These results bring new insights into the oncogenic role of miR-182 in NSCLC, indicating that miR-182 might be a novel biomarker for the diagnosis and prognosis of NSCLC.

MicroRNA-378 is associated with non-small cell lung cancer brain metastasis by promoting cell migration, invasion and tumor angiogenesis.

Lung cancer is the leading cause of cancer deaths in the world. Brain metastasis (BM) can affect about 25% of non-small cell lung cancer (NSCLC) patients during their lifetime. Efforts to characterize patients that will develop BM have been disappointing. MicroRNAs (miRNAs) play a role in regulating a variety of targets and, consequently, multiple pathways, which make them a powerful tool for early detection of disease, risk assessment and prognosis. In this study, using RT-PCR and further northern blot validation, we confirmed that miR-378 was significantly differentially expressed in the matched NSCLC from 8 patients with BM and 21 without BM. Our study showed evidences that miR-378 is associated with non-small cell lung cancer brain metastasis by promoting cell migration, invasion and tumor angiogenesis. MiR-378 may be a potential biomarker for characterizing non-small cell lung cancer brain metastasis and assisting clinicians in stratifying the high-risk patients on a clinical trial for either prophylactic cranial irradiation or a new intervention that may mitigate BM development, ultimately leading to a new standard of care for NSCLC patients.

[Effect of cisplatin on the expression of Pokemon gene: experiment with different human lung cancer cells].

OBJECTIVE: To investigate the correlation between Pokemon gene and cisplatin mechanism. METHODS: Human lung adenocarcinoma cells of the lines A549 and AGZY83-a, human lung squamous carcinoma cells of the line HE-99, and human giant cell lung cancer cells of the line 95D were cultured and cisplatin was added into the medium. Other lung cancer cells of the above mentioned lines were cultured in the medium without cisplatin and were used as control groups. RT-PCR and Western blotting were used to detect the mRNA and protein expression of Pokemon. RESULTS: Pokemon mRNA and protein were expressed highly in all the 4 cell lines. The Pokemon gene expression did not changed significantly after cisplatin treatment groups. There were not significant differences in the mRNA and protein expression of Pokemon among the 4 experiment groups and the control groups (all P > 0.05). CONCLUSION: Cisplatin has no effect on the Pokemon gene expression of the human lung cancer cells.

Overexpression of Pokemon in non-small cell lung cancer and foreshowing tumor biological behavior as well as clinical results.

BACKGROUND: Transcription factor Pokemon, a central regulation gene of the important tumor suppressor alternative reading frame (ARF), exerted its activity by acting upstream of many tumor-suppressing genes and proto-oncogenes. Its expression in non-small cell lung cancer (NSCLC) and its clinical significance remains unclear. The aim of this study was to investigate the expression of Pokemon in non-small cell lung cancer and to explore its correlation with the clinical pathological characteristics and its influence on patients' prognosis. AIM: Observe the expression of Pokemon in NSCLC and investigate its mechanism and clinical significance. METHODS: Determine the expression of Pokemon in human NSCLC cell lines as well as 55 cases of NSCLC tumor tissues, tumor adjacent tissues and surrounding tissues by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, and analyze the relationship between Pokemon expression in NSCLC tumor tissues and clinicopathological features. Determine 62 NSCLC tumor tissues (5 years ago) and p14(ARF) expression with immunohistochemical technique, discuss the correlation between them and assess the effect of Pokemon on prognosis of patients with lung cancer. RESULTS: Pokemon mRNA and protein took on high expression in lung cancer cell lines, and the expression difference between cancer tissues, tumor adjacent tissues and surrounding tissues had statistical significance (P<0.05). Pokemon expression and p14(ARF) expression were negatively correlated (r=-0.287). The expression of Pokemon was determined not to be associated with the patient's sex, age, smoking condition, tumor differentiation degree, histology and lymph node metastasis condition. However, its relationship with TNM staging was established (P<0.05). Furthermore, it was shown that the survival rate of patients with negative Pokemon expression was significantly higher than that of those with positive Pokemon expression (P=0.004), therefore, the expression of Pokemon is believed to be an independent factor affecting prognosis (P=0.034). CONCLUSION: There was high expression of Pokemon in NSCLC, Pokemon exerted carcinogenesis by inhibiting ARF and had some clinical significance for prognostic evaluation of the patients with NSCLC.

Expression of transcription factor Pokemon in non-small cell lung cancer and its clinical significance.

BACKGROUND: Transcription factor Pokemon, a central regulation gene of the important tumor suppressor ARF gene, exerted its activity by acting upstream of many tumor-suppressing genes and proto-oncogenes. Its expression in non-small cell lung cancer (NSCLC) and its clinical significance remains unclear. The aim of this study was to investigate the expression of Pokemon in NSCLC and to explore its correlation with the clinical pathological characteristics and its influence on patients' prognosis. METHODS: Fifty-five cases of NSCLC were involved in this study. The expression of Pokemon in the tumor tissue, the corresponding tumor adjacent tissue and the surrounding tissue was detected via reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting, with the aim of investigating the correlation between the expression of Pokemon in tumor tissue of NSCLC and its clinical pathological characteristics. Moreover, a prognostic analysis was carried out based upon the immunohistochemical (IHC) detection of the expression of Pokemon gene in archival tumor specimens (5 years ago) of 62 cases of NSCLC. RESULTS: Statistical significance of the expression of Pokemon mRNA and protein was determined in the tumor tissue, the tumor adjacent tissue and the surrounding tissue (P<0.05). The expression of Pokemon was determined not to be associated with the patients' sex, age, smoking condition, tumor differentiation degree, histology and lymph node metastasis condition. However, its relationship with TNM staging was established (P<0.05). Furthermore, it was shown that the survival rate of patients with negative Pokemon expression was significantly higher than that of those with positive Pokemon expression (P=0.004), therefore, the expression of Pokemon is believed to be an independent factor affecting prognosis (P=0.034). CONCLUSION: Pokemon was over-expressed in NSCLC tissue and the expression of Pokemon might be of clinical significance in non-small cell lung cancer prognostic evaluation.

[Suppression of RASSF1A gene on human esophageal carcinoma cells: experiments in vitro and in vivo].

OBJECTIVE: To investigate the effect of Ras association domain family 1A (RASSF1A) gene, a new tumor suppressor gene (TSG), on tumorigenesis of human esophageal carcinoma cells. METHODS: pcDNA3.1 (+)-RASSF1A, a plasmid containing RASSF1A gene, and the blank plasmid pcDNA3.1 (+) were transfected into human esophageal carcinoma cells of the line EC9706. The expression of RASSF 1A protein was examined by Western blotting. The changes of cell cycle of stably-transfected cells were determined by flow cytometry (FCM), and the cellular proliferation was analyzed by MTT assay. Fifteen nude mice were randomly divided into 3 groups to be inoculated subcutaneously with EC9706 cells transfected with pcDNA3.1 (+)-RASSF1A, EC9706 cells transfected with pcDNA3.1 (+), and untransfected EC9706 cells respectively. Other 5 nude mice were used as controls. Four weeks later, the mice were killed to take out the carcinoma tissues. FCM was used to analyze the cell cycle. RESULTS: Western blotting showed that RASSF1A protein was expressed highly in the stably transfected cells. The cell viability and growing speed were decreased obviously in the cells expressing of RASSF1A (both P < 0.01); FCM showed that the proportion of cells at the G(1) phase of the EC9706 cells expressing RASSF1A was significantly higher than those in the blank plasmid group and untransfected group (both P < 0.01). The size of the EC9706 cells obtained from the nude mice inoculated with the EC9706 cells transfected with pcDNA3.1 (+)-RASSF1A was significantly smaller than those of the pcDNA3.1 (+) group and blank plasmid group (both P < 0.05). CONCLUSION: Expression of exogenous RASSF1A inhibits the progression of human esophageal carcinoma cells in vitro and in vivo. As a tumor suppressor gene, it plays an important role in origination, progression and metastasis of esophageal carcinoma.

[Hypermethylation of promoter region of RAS association domain family gene1A in esophageal squamous cell carcinoma and significance thereof].

OBJECTIVE: To investigate the hypermethylation of the promoter region of RAS association domain family gene1A (RASSF1A) and its relationship with esophageal squamous cell carcinoma. METHODS: Sixty-six patients with esophageal squamous carcinoma, 60 males and 6 females, aged 59 +/- 8 (44 - 76), underwent resection of the tumor. Methylation-specific PCR (MSP) was used to detect the hypermethylation of promoter region of RASSF1A in the carcinoma tissues and the adjacent normal tissues. RESULTS: The hypermethylation rate of RASSF1A promoter in the tumor tissues was 48. 5% (32/66), significantly higher than that in the adjacent normal tissues (6.1%, 4/66, P < 0.05). The hypermethylation rate of RASSF1A promoter of the patients with lymph node metastasis was 61.1%, significantly higher than that of the patients without lymph node metastasis (33.3%, chi(2) = 5.055, P = 0.025). The hypermethylation rate of RASSF1A promoter in the esophageal squamous cell carcinoma at advanced stages (stages III - IV) was 69.2%, significantly higher than that in the esophageal squamous cell carcinoma at early stages (stages I - II, 35.0%, chi(2) = 7.392, P = 0.007). The hypermethylation rates of RASSF1A promoter in the high, moderate, and low differentiation tumors were 61.5% (16/26), 46.2% (12/26), and 28.6% (4/14) respectively without significant differences among them (chi(2) = 4.053, P = 0.132). CONCLUSION: Abnormal methylation exists in the RASSF1A promoter in esophageal squamous cell carcinoma. The hypermethylation of RASSF1A promoter is related to lymph node metastasis and TNM stage.

[mRNA expression of RASSF1A in esophageal squamous cell carcinoma and clinical significance thereof].

OBJECTIVE: To investigate the mRNA expression of the new tumor suppressor gene, RASSF1A, in esophageal squamous cell carcinoma and its biological value. METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the mRNA expression of RASSF1A in the tumor tissues, tissues near tumor, and normal tissues, all obtained during operation, from 66 esophageal squamous cell carcinoma patients. RESULTS: The deletion rates of RASSF1A mRNA expression were 42.4% (28/66), 15.2% (10/66), and 0 in the tumor tissues, tissues near tumor, and normal tissues respectively. The deletion rates of RASSF1A mRNA expression in patients with lymph node metastasis was 61.1%, significantly higher than that of the patients without lymph node metastasis (20.0%, chi(2) = 11.323, P < 0.01); The deletion rates of RASSF1A mRNA expression in the esophageal squamous cell carcinoma at the advanced stages (stages III - IV) was 61.5%, significantly higher than that in the esophageal squamous cell carcinoma at the early stages (stages I - II, 30.0%, chi(2) = 6.417, P < 0.01). The deletion rages of RASSF1A mRNA in the highly, moderately, and lowly differentiation tumors were 38.5% (10/26), 38.5% (10/26), and 57.1% (8/14) respectively, However, there was no significant association between the differentiation degree of tumor and the grade the deletion rages of RASSF1A mRNA (chi(2) = 1.576, P = 0.455). CONCLUSION: The deletion of the mRNA expression of RASSF1A, a tumor suppressor gene, may play an important role in the tumorigenesis and influences the prognosis of esophageal squamous cell carcinoma.