Non-small Cell Lung Cancer Patients With Blood Cell Mirna Expression Spectrum To Establish Its Characteristics

Background & Objective:Lung cancer is one of malignant tumors which threat human health seriously. The government has invested a great deal of resources in the lung cancer therapy every year, however, because of its high malignancy, low diagnosis rate and inefficiency of current clinical treatment, the prognosis of lung cancer is very poor. In addition, many patients missed the best time for therapy because lung cancer is hard to be detected in the early stage. Therefore, improving the efficiency of lung cancer clinical diagnosis is the key point for the future research. MicroRNA (miRNA) is a class of small non-protein-coding RNAs with 18-25 nucleotides in length. They can regulate the expression level of special genes either by decreasing the stability of mRNA or by translational inhibition. They are also involved in diverse processes, including cellular differentiation, proliferation and apoptosis. If miRNA express abnormally, it will cause tumor and other kinds of disease. Now, it was reported that miRNA in the lung cancer played an important role in the mechanism of pathogenesis, but it is still a doubt whether miRNAs in blood cells could be recognized as a biomarker of the lung cancer.In our study, the massively parallel sequencing (Solexa) was used to screen the differentially expressed miRNA in NSCLC, and we also compared the results to the miRNAs in lung cancer tissues. The results of this study can not only help us further reveal the mechanism of miRNAs regulating NSCLC development, but also provide evidence that miRNA patterns can be used to detect human cancers from blood cells.Methods:7 pairs of blood cell samples from NSCLC patients and normal controls were collected.5ml venous blood per sample was used for the small RNA extraction. Then, two groups of the small RNA libraries were constructed respectively. Massively parallel sequencing was used to screen the differentially expressed miRNAs, and miRNAs expression profile of NSCLC was established. Lastly, we compared the differentially miRNAs expression pattern between the blood cells and the tissues with NSCLC. Results:miRNA expression profile of NSCLC was established.5,780.071 miRNA reads and 409 miRNAs were detected in NSCLC patients. We found 142 significantly dysregulated miRNAs expressed in blood cells of lung cancer patients compared to the controls. And there were 105 up-regulated miRNAs and 37 down-regulated miRNAs in NSCLC. In a comparison,24 miRNAs expression patterns of blood cells were consistent with that of the lung cancer tissue.Conclusions:1 The method of small RNA sequencing was successfully established in our laboratory.2 miRNA expression profile of NSCLC was established. Both the sequencing throughput and the detected miRNAs numbers are higher than other research. And the results also suggested that there is a significant difference between the expression pattern of miRNAs in cases and controls.3 The characteristic of miRNAs expression pattern in blood cells are partially consistent with the expression pattern in lung cancer tissue. The results of this study can not only help us further reveal the mechanism of miRNAs regulating NSCLC development, but also provide potential molecular biomarkers for clinical diagnosis of NSCLC.