Study On Detection For NMB-R Gene Expression In Peripheral Blood Of Patients Suffering From Small Cell Lung Cancer By RT-PCR And Its Application In Diagnosis Of Metastasis

Detection of tumor-specific or tumor-associated genes expression with high sensitivity is of great value for cancer diagnosis. In this work, reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the expression of NMB-R gene in peripheral blood (PB), which is a bombesin-like peptides(BLP) receptor gene and is reported to be highly expressed in the tissues of small cell lung cancer (SCLC). The peripheral blood samples were collected from 22 patients of SCLC and 10 healthy individuals. 18 out of 22 samples from the patients were showed positive signs of NMB-R mRNA, whereas 2 out of 10 subjects were positive in the control group. 5 out of the NMB-R gene positive patients were followed and 3 of them showed negative signs after chemotherapy. We also focused our attention on the sensitivity of this method and the results showed that the NMB-R gene was detectable at a density as low as 10 SCLC cells per 107 normal PBMNC (peripheral blood mononuclear cell).The survival time in SCLC patients whose NMB-R gene in PB was positive was significantly shorter than that in those with negative signs.Our observation suggests that this detection may be competent in diagnosing metastasis and monitoring minimal residual disease in SCLC patients.