Expression Of MicroRNA-34a And MicroRNA-101 In Serum In Patients With Lung Cancer And Its Potential Clinical Significance

Objective:micro RNA(mi RNA) is a class of endogenous micro RNA, about 20-24 nucleotides long, and found in eukaryotic microorganisms. mi RNA has several important roles in cells. mi RNA can be used as a tumor suppressor gene to reduce oncogene activity, but also can be used as a cancer gene to reduce tumor suppressor gene activity. Its mutation, deletion, translocation and mutual regulation abnormality, can lead to abnormal expression of related genes. Research of mi RNA to explore the molecular mechanism of the occurrence and development of tumor will provide new targets for clinical diagnosis and treatment. mi RNA can stably exist in serum/plasma, and can be used as a potential biomarker of tumor or other diseases. The purpose of this study is to determine the expression levels of micro RNA-34a(mi R-34a) and micro RNA-101(mi R-101) in serum of lung cancer patients, in order to investigate their expression characteristics, the correlation with CEA level, and the relationship with diagnosis and pathogenesis of lung cancer.Methods:Collect 111 serum samples from lung cancer group and 101 serum samples from health control group. Extract small fragments of RNA from serum, conduct RT-PCR using mi R-34 a and mi R-101 specific reverse transcription primers,and detect the expression levels of mi R-34 a and mi R-101 by Real-time PCR, validate the abnormal expression of mi R-34 a and mi R-101 in serum of patients with lung cancer. Then select the smoking group and no smoking group, detect the expression level of mi R-34 a and mi R-101 in serum of two groups by Real-time PCR. Statistical analysis was performed on the expression of mi R-34 a and mi R-101 between the two groups, to explore the relationship between the mi RNA and the pathogenesis of lung cancer. Then a group of patients with lung cancer were detected for the expression of mi R-34 a and mi R-101 by Real-time PCR, and the level of CEA using Access CEA two site sandwich enzyme immunoassay(Sandwich) method, finally perform correlation analysis of mi RNA and CEA.Results:1.the expression levels of mi R-34 a and mi R-101 were up-regulated in serum samples from lung cancer patients, the expression levels of mi R-34 a and mi R-101 in patients group were significantly higher than normal control group(p<0.05), with statistical significance. 2. There were no significant differences in expression levels of mi R-34 a between smoking group and no smoking group(p>0.05), with no statistical significance. But there were significant differences in expression levels of mi R-101 between the tow groups. 3. mi R-34 a and CEA levels were positively correlated(r2=0.69, P = 0.036); Mi R-101 and CEA levels were positively correlated(r2 = 0.76, P =0.023).Conclusions:1. By Real-time PCR, it was confirmed that the expression levels of mi R-34 a and mi R-101 in serum sample of lung cancer patients were up-regulated. And according to further analysis, mi R-34 a and mi R-101 in serum from lung cancer patients were significantly higher expressed than from normal control group. The results may demonstrate that mi R-34 a and mi R-101 have close relationship with the occurrence of lung cancer. 2. By Real-time PCR, it was confirmed that the expression levels of mi R-34 a were up-regulated in serum samples of smoking lung cancer group and no smoking lung cancer group, but there were no significant differences in expression levels between the two groups. It was consistent with the previous research data, the mi R-34 a was significantly up-regulated in the serum of patients with multifarious malignant tumor; mi R-101 was up-regulated in serum samples of smoking lung cancer group and no smoking lung cancer group, and there were significant differences with statistical significance in expression levels between the groups. The analytic results may demonstrate that, different induction effects of different mi RNAs may result in relevant gene mutation and eventually lead to the same type of cancer. So there may be various molecular mechanisms of the occurrence and development of lung cancer. 3. The expression levels of mi R-34 a and mi R-101 were positively correlated with CEA level in serum sample of lung cancer patients. So combined detection of mi R-34 a, mi R-101 and CEA for lung cancer diagnosis will be better.