Intratumoral expression of macrophage migration inhibitory factor is correlated with serum C-reactive protein and interleukin-6 in patients with non-small cell lung cancer

Purpose. To investigate if macrophage migration inhibitory factor (MIF) affects systemic inflammatory response in patients with non-small cell lung cancer (NSCLC), we studied the relationship between intratumoral MIF expression and serum levels of C-reactive protein (CRP) and interleukin-6 (IL-6). Methods. mRNAs for MIF and β-actin, and 18S ribosomal RNA derived from tumor-bearing and nontumor-bearing tissues were quantified by a quantitative reverse transcription-polymerase chain reaction in 35 patients with NSCLC. Spearman's test was used to examine the correlation between the quantities of RNAs and the preoperative serum levels of CRP and IL-6 in the corresponding patients. Results. The intratumoral level of MIF mRNA was significantly correlated with the serum levels of CRP (ρ = 0.542, P = 0.0016) and IL-6 (ρ = 0.532, P = 0.0173). The level of MIF mRNA in the non-tumor-bearing lung also showed a positive, but relatively weak correlation with the serum CRP level (ρ = 0.418, P = 0.0148). Conclusion. Macrophage migration inhibitory factor expression in the tumor site may affect the systemic inflammatory response in patients with NSCLC.