ZCCHC9 promotes proliferation and invasion of lung cancer through regulating the JNK pathway

ZCCHC9 is a type of CCHC type zinc-finger containing protein which was found to be expressed in some tissues including brain and testicles in mice. Expression and function of ZCCHC9 in human tissues including cancer was largely unknown. In this study, we investigated the expression and function of ZCCHC9 in human non-small cell lung cancer (NSCLC) and the related molecular mechanism. Immunochemistrical standing showed that ZCCHC9 was mainly located in the nucleus in bronchial epithelial cells and epithelial cells of submucosal glands (58.3% 14/24]). But in NSCLC cells ZCCHC9 was mainly located in the cytoplasm and the positive rate was 54.5% (60/110). Ectopic cytoplasmic expression of ZCCHC9 in cancer tissues was significantly associated with advanced TNM stages (III+IV), lymph node metastasis, and poor clinical outcome (P < 0.05). Overexpression of cytoplasmic ZCCHC9 using transfection of ZCCHC9 cDNA in A549 and NCI-H1299 cells significantly upregulated the proliferation and invasion of these cancer cells in vitro (P < 0.05). Western blot study showed that overexpression of cytoplasmic ZCCHC9 significantly upregulated expression of p-JNK, Cyclin D1, and MMP7 (P < 0.05). Next we used the inhibitor of JNK pathway to inhibit the activity of the JNK pathway and the results showed that co-addition of SP600125 significantly abolished the function of ZCCHC9 to promote the proliferation and invasion of cancer cells. These results indicate that cytoplasmic ZCCHC9 could promote the proliferation and invasion of NSCLC through the JNK pathway and may be a promising cancer maker.