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Objective To investigate the clinical values of detection of plasma miRNA-544a (miR-544a) expression level in the diagnosis and treatment of lung cancer.Methods A total of 110 patients diagnosed with lung cancer in Ⅰ-Ⅱ stage from June 2017 to March 2018 in Shiyan Taihe Hospital were collected,and 35 patients with benign pulmonary nodules and 64 healthy people were also collected as the controls.Realtime quantitative polymerase chain reaction (RT-qPCR) was used to detect the level of miR-S44a in plasma of 64 healthy people,110 patients with lung cancer (50 newly diagnosed patients without anti-tumor treatment,33 patients one week after radical resection,27 patients after one week chemotherapy with the same dose) and 35 patients with benign pulmonary nodules.Of the 50 newly diagnosed patients,42 cases were non-small cell lung cancer and 8 cases were small cell lung cancer.The plasma expression level of miR-544a in each group was compared by using Mann-Whitney U test,and the efficacy of miR-544a in the diagnosis of lung cancer was evaluated by the receiver operationg characteristic (ROC) curve and the area under the curve (AUC).Results The plasma expression levels of miR-544a in the newly diagnosed untreated lung cancer group,one week after operation group,one week chemotherapy group,healthy control group and benign pulmonary nodule group were 1.40 nmol/L (0.55 nmol/L,8.76 nmol/L),33.52 nmol/L (3.64 nmol/L,250.47 nmo/L),8.87 nmol/L (0.68 nmol/L,125.43 nmol/L),0.31 nmol/L (0.17 nmol/L,1.19 nmol/L),1.04 nmol/L (0.31 nmol/L,4.62 nmol/L),respectively,and the differences between untreated lung cancer group and the other 4 groups were statistically significant (Z =-4.483,P ＜ 0.001;Z =-4.274,P ＜ 0.001;Z =-2.562,P =0.01;Z =-2.152,P =0.031).The expression levels of miR-544a in non-small cell lung cancer group and small cell lung cancer group were 1.40 nmol/L (0.66 nmol/L,8.76 nmol/L) and 1.37 nmol/L (0.26 nmol/L,36.97 nmol/L),respectively.The differences between non-small cell lung cancer group and healthy control group and benign pulmonary nodule group were statistically significant (Z =-4.463,P ＜ 0.001;Z =-2.026,P =0.043).Compared with the healthy people,the AUC of miR-544a for diagnosing the lung cancer was 0.841,the sensitivity was 87.5 ％,and the specificity was 68.0 ％.Compared with the benign pulmonary nodule,the AUC for diagnosing lung cancer was 0.638,the sensitive was 45.7 ％,and the specificity was 80.0 ％.Conclusions The plasma expression level of miR-544a has certain significances in the differential diagnosis of early stage lung cancer and benign pulmonary nodules and healthy people,and it can be used as a potential biomarker for diagnosing early stage lung cancer,especially for the non-small cell lung cancer.The plasma expression of miR-544a is increased after surgery or chemotherapy,suggesting that its expression may be related to the occurrence and development of lung cancer,and miR-544a may become a new target for cancer treatment.
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Objective To investigate the effects of 5-Aza-2'-deoxycytidine (5-Aza-CdR) on the apoptosis of A549/DDP cells and the expression of hMLH1 gene.Methods A549/DDP cells were treated with 5-Aza-CdR at 0.5,5,50 μmol/L.The growth curve of A549/DDP cells was investigated by MTT assay.The methylation status of hMLH1 gene was detected by methylation specific PCR (MSP).The expression of hMLH1 mRNA was evaluated by FQ-PCR.The apoptosis rate of A549/DDP cells was analyzed by flow cytometry.Results A549/DDP cells treated with 5-Aza-CdR showed a slow growth in comparison with the control cells,and the growth rates were decreased with the increasing of 5-Aza-CdR concentration.The apoptosis rate after treatment was higher than that before treatment in A549/DDP cells (P ＜ 0.05),and had a positive correlation with 5-Aza-CdR dose (P ＜ 0.001).hMLH1 mRNA expression level was increased in a 5-Aza-CdR concentration dependent manner (P ＜ 0.05).hMLH1 promoter in A549/DDP cells was methylated and hMLH1 mRNA was negatively expressed before treatment,but the mRNA was positively expressed after treatment with 5-Aza-CdR.Conclusions 5-Aza-2'-CdR can induce apoptosis of A549/DDP cells by inducing demethylation of hMLH1 promoter and thereby enhancing hMLH1 gene expression and its tumor suppressor function.
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Objective To investigate the status and diagnostic value of aberrant phosphatase and tensin homology deleted on chromosometen(PTEN) gene promoter in tissues, peripheral plasma and BALF of lung cancer patients. Methods We analyzed the methylation of PTEN gene in tissues, peripheral plasma and BALF by methylation specific-PCR. Results The frequency of methylation of promoter of PTEN gene was 26.67%(12/45) in lung cancer tissues, 15.56%(7/45) in peripheral plasma, 22.22%(10/45) in BALF, no methylation product was found in lung tissues without cancer, normal plasma and BALF controls (P