TY - JOUR
T1 - Differential expression of DNA topoisomerase I gene between CPT-11 acquired-and native-resistant human pancreatic tumor cell lines
T2 - Detected by RNA PCR-based quantitation assay
AU - Takeda, Sachi
AU - Shimazoe, Takao
AU - Sato, Keiki
AU - Sugimoto, Yoshikazu
AU - Tsuruo, Takashi
AU - Kono, Akira
N1 - Funding Information:
We thank Seiko Co. Ltd.(Fukuoka) was supported in part by a Grant-in-Aid for Cancer Control and a Grant-in-Aid Health and Welfare of Japan.
PY - 1992/4/30
Y1 - 1992/4/30
N2 - RNA PCR quantitation method was developed to determine DNA Topoisomerase I(Topo I)-specific mRNA in order to study its gene expression in CPT-11 sensitive, acquired- or native-resistant human pancreatic tumor cell lines. The results were supported by Northern blotting and Western blotting analyses. Acquired-resistant cells have shown decreased levels of Topo I mRNA, compared with their parental cells. On the contrary, in the wild type cells no correlation was shown between sensitivity and gene expression. On the other specific Topo I activity of the native resistant cell lines was fairly lower than that of sensitive cell lines, suggesting that immunoreactive Tope I protein contains low levels of active form enzyme which could be targets of CPT-11 in these native-resistant ones. Finally, the different mechanisms might be operative between acquired- and native-resistant tumor cells.
AB - RNA PCR quantitation method was developed to determine DNA Topoisomerase I(Topo I)-specific mRNA in order to study its gene expression in CPT-11 sensitive, acquired- or native-resistant human pancreatic tumor cell lines. The results were supported by Northern blotting and Western blotting analyses. Acquired-resistant cells have shown decreased levels of Topo I mRNA, compared with their parental cells. On the contrary, in the wild type cells no correlation was shown between sensitivity and gene expression. On the other specific Topo I activity of the native resistant cell lines was fairly lower than that of sensitive cell lines, suggesting that immunoreactive Tope I protein contains low levels of active form enzyme which could be targets of CPT-11 in these native-resistant ones. Finally, the different mechanisms might be operative between acquired- and native-resistant tumor cells.
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U2 - 10.1016/0006-291X(92)90634-W
DO - 10.1016/0006-291X(92)90634-W
M3 - Article
C2 - 1315526
AN - SCOPUS:0026683277
SN - 0006-291X
VL - 184
SP - 618
EP - 625
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 2
ER -