Identification of a new microRNA expression profile as a potential cancer screening tool

Abstract

Clin Invest Med 2010; 33 (2): E124-E132. AbstractPurpose: Small non-coding microRNAs (miRNAs) are key components of cancer development and are considered as potential biomarkers for cancer diagnosis and treatment monitoring. This study investigated miRNA expression profiles of human cancer cells in order to develop a screening method for lung cancer. Methods: A series of lung cancer related miRNAs (miR-21, miR-145, miR-155, miR-205, miR-210, miR-92, miR-17-5p, miR-143, miR-182, miR-372, let-7a) were selected as candidates for miRNA expression profiles of human lung cancer cell lines (A549, SK-mes-1). MicroRNA u6 was the endogenous control. Cancer cell lines for positive controls; breast MCF-7, prostate Du-145, and glioblastoma U118. The negative control was normal lung fibroblast cell line MRC-5. RT-PCR was performed on StepOnePlus (Applied Biosystem, USA). MiRNA expressions of malignant cells were compared with normal fibroblast cells as well as endogenous control (u6) using the thermal cycle at threshold. Assessment of miRNA expression profiles were then performed using agglomerative hierarchical cluster analysis software (SPSS13, USA). Results: We demonstrated that miR-21, miR-182 and let7-5a were over-expressed, and miR-145 and miR-155 were under-expressed in all cancer cell lines. Combined with the cluster analysis we were able to clearly distinguish cell lines for normal fibroblasts, breast cancer, prostate cancer, glioblastoma, and lung cancer. Conclusion:There is potential utility of screening for lung cancer with miRNA expression profiles. Future work will focus on the sensitivity of such miRNA expression profiles in screening sputum for lung cancer, which can be performed in real time.Lung cancer remains the leading cause of cancerrelated deaths in Canada, the United States and Europe. In fact, more people die from lung cancer each year than from breast, colon, and prostate cancers combined. 1,2,3 Conventionally-treated early stage lung cancer patients have a five year survival of approximately 60 to 70%. 4 One reason that lung cancer mortality is so high is the lack of effective standardized screening. As a result, most patients present with advanced stage disease and subsequent poor overall survival. One recent review states: "Overall, no single cheap and reliable test has yet been identified for the effective screening of lung cancer in large population studies, but work is in progress." 5 Effective and financially feasible screening for patients at a high risk of developing lung cancer is, therefore, a high research priority.

RNA Helicase DDX5 Regulates MicroRNA Expression and Contributes to Cytoskeletal Reorganization in Basal Breast Cancer Cells

“…However, we observed a positive correlation between miR-182 and miR-21 (r ϭ 0.77, p ϭ 0.003) (Fig. 4C), consistent with an earlier study showing that miR-21 and miR-182 are overexpressed and correlated in cancer cell lines (33).…”

Bio-barcode gel assay for microRNA

“…The real-time PCR-based results suggest that MDA-MB-231 overexpresses the miR-21 and miR-155 sequences, whereas miR-205 is decreased 32 . Although the miR-205 and miR-21 sequences are increased in A549, miR-155 is decreased 4,33 . For the bio-BaGel assay, 80% confluent cells were lysed with a cell lysis buffer that induces the rupture of cell membrane and inactivates RNase.…”

“…miRNA has been implicated in cancer of abnormal complex genetic diseases through their function as oncogenes or tumour suppressors 2,3 , and it will be highly beneficial to detect multiple miRNA sequences at a very low concentration for understanding and diagnosing cancers in reliable fashion 4,5 . Although many new types of miRNAdetection methods have been developed, polymerase chain reaction (PCR) based methods have been dominantly used for detecting an ultra-low amount of miRNA convincingly [5][6][7] .…”

Specific peripheral miRNA profiles for distinguishing lung cancer from COPD

“…While single markers show a rather low sensitivity and specificity for the identification of lung cancer and other cancers, complex marker signatures often reach a significantly higher degree of accuracy. Most recently, microRNA (miRNA) expression profiles have been proposed as potential biomarkers for cancer diagnosis and treatment monitoring [2]. MicroRNAs are small (17-24 nt) non-coding RNA transcripts, involved in physiological and pathophysiological processes including cancer development through the regulation of gene expression [3,4].…”