Downregulated miR-100 Result in High Expression Levels of Chemokine (CXC Motif) Receptor 7 That Predict Recurrence of Lung Cancer

MicroRNAs (miRs) have been proved to play significant role in both the tumorigenesis and recurrence of lung cancer (LA). However, the identification of which miR participated in the recurrence of LA, as well as the underlying mechanism are poorly understood. Here in our article, quantitative analysis of the miR-100 expression in non-recurrent and recurrent LA tissues using real-time PCR (RT-qPCR) revealed that, compared to non-recurrent LA, the expression of miR-100 was significantly downregulated in recurrent ones. Especially, the chemokine (CXC motif) receptor 7 (CXCR7) level was negatively correlated with the expression of miR-100 in both non-recurrent and recurrent LA cell lines derived from corresponding LA tissues. The following in vitro experiments also confirmed that either miR-100 overexpression or CXCR7 depletion decreased proliferation of recurrent LA cells. In conclusion, miR-100 may act as a recurrence suppressor in LA through the regulation of CXCR7 expression, which might be a promising target for the prevention of LA recurrence.