Stable blood based
miRNA species have allowed for the differentiation of patients with various types of
cancer. Therefore, specific blood-based
miRNA might be considered as a methodology which could be informative of the presence of
cancer potentially from multiple distinct organ sites. Recently, miR-21 has been identified as an "oncomir" in various
tumors while miR-152 as a
tumor suppressor. In this study, we investigated whether circulating miR-21 and miR-152 can be used for early detection of
lung cancer (LuCa),
colorectal carcinoma (CRC),
breast cancer (BrCa) and
prostate cancer (PCa), with distinguishing
cancer from various benign lesions on these organ sites. We measured the two
miRNA levels by using real-time RT-PCR in plasma samples from a total of 204
cancer patients, 159 various benign lesions, and 228 normal subjects. We observed significantly elevated expression of miR-21 and miR-152 in LuCa, CRC, and BrCa when compared with normal controls. We also found upregulation of plasma miR-21 and miR-152 levels in patients with benign lesions of lung and breast, as compared to normal controls, respectively. No significant expression variation of the two
miRNAs was observed in PCa or prostatic benign lesions as compared to healthy controls. Receiver operating characteristic (ROC) analyses revealed that miR-21 and/or miR-152 can discriminate LuCa, CRC and BrCa from normal controls. Our results suggest that plasma miR-21 and miR-152 may serve as non-specific noninvasive
biomarkers for early screening of LuCa, CRC, and BrCa, but not PCa.