@article{oai:nagasaki-u.repo.nii.ac.jp:00022069, author = {Hirose, Kiyoto}, issue = {1-3}, journal = {Acta medica Nagasakiensia}, month = {Oct}, note = {To determine the clinical significance of the MDR1 gene and its transcript P-glycoprotein (PGP) expression in lung cancer, ninety-one surgical lung cancer samples and normal lung tissues were analyzed. They consisted of 85 NSCLC (84 untreated and one treated) and 6 SCLC (three untreated and three treated). MDR1 messenger RNA (mRNA) levels in all surgical samples were determined by Northern blotting and compared with anticancer drug-sensitive and -resistant cell lines. The transcript PGP was detected in frozen sections by immunohistochemical staining. There was a strong correlation between the levels of MDR1 mRNA and PGP expression in the tumors. No normal lung tissues expressed the MDR1 gene in Northern blots. Fifteen percent (13/87) of the untreated tumors were positive for the MDR1 gene at low levels, which did not relate to any pathologic factors such as histologic type, tumor extensions, and differentiation grade. All three treated SCLC expressed high levels of the MDR1 gene, although all three untreated SCLC did not. Furthermore, only SCLC negative for MDR1 gene tended to respond to chemotherapy. The MDRI gene is thought to be related to multidrug resistance in SCLC. A prospective study in a large number of patients should be attempted to clarify the clinical significance of the MDR1 gene in the treatment of SCLC., Acta medica Nagasakiensia. 1994, 39(1-3), p.59-64}, pages = {59--64}, title = {The MDR1 gene and Its Transcript P-glycoprotein Expressions in Lung Cancer}, volume = {39}, year = {1994} }