Expression and clinical value of major histocompatibility complex class-I related chain A molecule in serum of patients with renal tumor

Objective To explore the expression and clinical value of major histocompatibility complex class-I related chain A (sMICA) molecule in serum of patients with renal tumor. Methods From March 2013 to July 2013, 60 patients with renal tumor, including 37 male patients and 23 female patients were enrolled in this study as experimental group. The mean age was 46 years (range 34-76 years). The pathological diagnosis included renal cell carcinoma in 48 cases and renal angiomyolipoma in 12 cases. The stage classification included T1 stage in 20 cases, T2 stage in 14 cases, T3 stage in 10 cases and T4 stage in 4 cases. Lymphatic metastases were found in 11 cases and metastases in other organs were found in 4 cases. Another 20 healthy volunteers were enrolled as control group, including 10 male and 10 female. The mean age was 31 years (range 24-50 years). The ELISA method was used to detect the soluble MICA′s (sMICA) level in serum. And the results were compared with tumor′s malice, TNM pathology stages, metastasis. In 15 cases with renal cell carcinoma, the expression of MICA molecule in tumor masses and paraneoplastic masses was measured by immunohistochemical (IHC) method. The quantitative expression of MICA-mRNA was detected by RT-PCR in 9 tumor masses and 3 paraneoplastic masses. Results The level of sMICA in renal malignant tumor group was (348.5±32.5) pg/ml, while the sMICA′s level in benign renal tumor groups was (289.3±30.4) pg/ml and that in the control group was (168.4±43.2) pg/ml. The level of sMICA in malignant group is statistically higher than that in benign group and control group (P 0.05). Significant difference in the sMICA level could also be observed between patients with other organ metastasis (373.4±45.4) pg/ml and those without metastasis (346.4±31.5) pg/ml (P<0.05). The IHC results revealed that high expression of MICA molecule in tumor cell. However , this oppsite result was demonstrated in cells located in paraneoplastic tissues. In the results of RT-PCR, the MICA-mRNA level (2.03) in tumor masses was significantly higher than that in pareneoplastic masses (0.77) (P<0.05). Conclusions MICA highly expressed in renal tumor, and its expression correlates with tumor′s malice, TNM pathologic stages, and metastasis. Key words: Renal tumor; Major histocompatibility complex class-I related chain A; Natural killer cell