Objective: To evaluate the expression of MRP gene and its relation to pathological features in lung carcinoma.
Methods: A series of 35 resected primary lung cancer tissues from 9 post-chemotherapy and 26 untreated patients and adjacent normal lung tissues and 28 lymph node tissues were analyzed for MRP gene expression by RT-PCR method.
Results: Positive expression rate of MRP gene was 54% in 35 cases with primary lung cancer, 14% in tissues adjacent to the carcinoma site and the difference was significant (P < 0.005), the positive rate of MRP gene expression in metastatic lymph node tissues was 53%. In 9 cases of pre-operative chemotherapy, the positive expression rate of MRP gene was higher than that in 26 cases without chemotherapy. Nineteen of 35 tumors were found to show positive expression of MRP gene, comprising 11 of 18 adenocarcinoma, 9 of 15 squamous cell cancer. The relapse or metastasis rate with MRP-positive cases was higher(55%) than that with MRP-negative (15%) by follow-up of these patients.
Conclusions: There are overexpression of MRP gene in primary lung cancer tissues. Preoperative chemotherapy may play inductive role in lung cancer multidrug resistance. The positive expression of MRP gene in lung cancer tissues is in accord with its lymph node tissues. Positive expression of MRP gene does not necessarily be associated with tumor size, clinical type and TNM stages, but it could be regarded as one poor prognostic factor.