Comparative Analysis Of LUNX　mRNA, CK19 MRNA And CEA MRNA In The Detection Of Micrometastasis In Lymph Nodes And Peripheral Bloods Of Patients With NSCLC

Objective To detect the expression of LUNX mRNA, CK19 mRNA and CEA mRNA in the lymph nodes and peripheral bloods of patients with NSCLC (non-small cell lung cancer ) by RT-PCR(reverse transcriptase polymerase chain reaction). By comparative analysis, it is to indicate the early diagnosis of micrometastasis of NSCLC and to investigate the correlation between micrometastasis and the prognosis of NSCLC patients.Methods RT-PCR was used to detect the LUNX mRNA, CK19 mRNA and nested RT-PCR was used to detect CEA mRNA in peripheral bloods of 56 NSCLC patients before their operations. 20 patients with stage Ⅳ NSCLC were served as the positive controls. Moreover, 30 patients with stage IV malignant tumors except lung cancer, 15 patients with benign lung diseases and 20 healthy volunteers were served as the negative controls. Tumor tissues and 103 regional lymph nodes (mainly paratracheal nodes) were exscinded from the 56 NSCLC patients. 35 lymph nodes were exscinded from the 15 benign lung diseases as controls. All the samples were semi-qualitatively determined with the ratio of LUNX (or CK19, or CEA) band intensity to the β-actin band intensity. Meanwhile, all lymph nodes were also examined by conventionalpathological method.Results ?In the 56 tumor tissues, the expression rate of LUNX mRNA, CK19 mRNA and CEA mRNA was 100% (56/56), 96.4% (54/56) and 89.2% (48/56) respectively. ?In the 76 peripheral blood samples from NSCLC patients, LUNX mRNA, CK19 mRNA and CEA mRNA was detected in 42 patients (55.3%), 32(42.1%), 43(56.6%), respectively. In the 30 blood samples from stage IV malignant tumors except lung cancer, the positive rate of LUNX mRNA, CK19 mRNA and CEA mRNA was 0% (0/30), 23.3%(7/30), 40.0% (11/30),respectively. In the 15 blood samples from patients with benign lung diseases, 2 expressed CK1-9 (13. 3%), 3 expressed CEA (20. 0%), but none was positive for LUNX. In the 20 healthy volunteers, LUNX mRNA was negative, the positive rate of CK19 mRNA and CEA mRNA was 10.0% (2/20) and 15.5% (3/20) respectively. ?The positive detection rate of LUNX mRNA, CK19 mRNA and CEA mRNA in 103 lymph nodes for non-small cell lung cancer patients was 45. 6% (47/103), 32.0 % (33/103), 31.1% (32/103), (P<0. 05), respectively. In the benign pulmonary lesion group, none of LUNX mRNA was observed in all the 35 lymph nodes, CK19 mRNA expression was detected in 5 lymph nodes (14. 3%) and CEA mRNA expression was observed in 3 lymph nodes (8.6%). ?In the 103 regional lymph nodes, 23 nodes were observed to have micrometastasis by conventional pathological method, the positive rate was significantly lower than that examined by RT-PCR (/><0. 05) . ?No significant differences have been found in the LUNX mRNA and CK19 mRNA positive rates in regional lymph nodes and the peripheral blood samples among groups arranged in according to histopathology types (squamous carcinoma; adenocarcinoma; other types of NSCLC)(/>>0. 05), but CEA mRNA expressed significantly highly in adenocarcinoma (P<0. 05). ?All NSCLC were arranged into groups according to the TNM stage (I , II , III, IV), the results of LUNX mRNA detection in lymph nodes and peripheral blood samples indicated that the positive rates increased along with the stage, but the expression of CK19 mRNA and CEA mRNA had no correlation with TNM stage (P<0. 05).Conclusion ?LUNX and CK19 are appropriately targeted genes for the detection of micrometastasis in NSCLC. According to the results of our study, LUNX mRNA is the better molecular marker both in sensitivity and specificity; but CEA mRNA has significantly lower expression in cancer tissues than the two formers so that it can not be solely used as a molecular marker for the detection of the micrometastasis in NSCLC. (2) Compared with conventional pathological method, RT-PCT has superior sensitivity. (3) For LUNX mRNA and CK19 mRNA, no correlation is found between positive rates of micrometastasis with any of the histopathological type of lung cancer; but the positive rate of CEA mRNA in adenocarcinoma is significantly higher than any other types of NSCLC which indicates that CEA mRNA can help to estimate the pathological types of NSCLC. ? For LUNX mRNA, the positive rates of micrometastasis in lymph nodes and peripheral blood samples increase along with the stage of TNM.