The Clinical Significance And Relationship Of Midkine MRNA Expression In Peripheral Blood Mononuclear Cells In Primary Non-small Cell Lung Cancer

Objective: Midkine (MK) mRNA was highly expressed in various human cancer tissues and cells. The present study aimed to investigate whether MK mRNA level in peripheral blood mononuclear cells (PBMC) could serve as a diagnostic biomarker for patients having primary non-small cell lung cancer (NSCLC).Methods:MK mRNA level in PBMC from87patients with primary NSCLC,35patients with lung benign lesion (LEL), and30healthy volunteers was analyzed by realtime quantitative RT-PCR. The levels of serum carcinoembryonic antigen, carbohydrate antigen125(CA125), and neuron-specific enolase were detected by chemiluminescent microparticle enzyme immunoassay.Results:PBMC MK mRNA level was significantly higher in patients with primary NSCLC than that in other groups (P<0.001), while there was no significant difference between LEL patients and healthy volunteers (P>0.05). Higher MK mRNA level was correlated with clinical stages (P=0.026), differentiation (P=0.025), and lymph node metastasis (P=0.022) of NSCLC. Using a cut off of0.0063, the sensitivity and specificity of MK mRNA levels to differentiate between patients with NSCLC and patients with LEL were57.47and93.33%,and it were56.32and93.33%for patients with NSCLC and healthy volunteers, respectively. Furthermore, multivariate analysis indicated that PBMC MK mRNA level above the cutoff value presented a chance of11-fold higher for NSCLC occurrence.Conclusions:MK mRNA level in PBMC may be a potential non-invasive molecular marker for the diagnosis of primary NSCLC. Evaluated MK mRNA expression in peripheral blood mononuclear cells in primary non-small cell lung cancer is an independent risk factor for NSCLC disease.