Establishment of three cisplatin-resistant endometrial cancer cell lines using two methods of cisplatin exposure.
Using the endometrial cancer cell line EI established in our department, we attempted to establish cisplatin (CDDP)-resistant cell lines by incremental exposure and high concentration exposure methods. Three CDDP-resistant cell lines were isolated, which could be distinguished by morphological differences. 1. Upon acquiring CDDP resistance, the cells tended to become small and grow in a floating state. This tendency was especially marked when using incremental exposure method. Using the incremental exposure method, a cell line obtained by isolating and culturing only adherent cells was designated EICR-Ia, and a cell line established by culturing only floating cells was designated EICR-If. A cell line obtained by the high concentration exposure method was designated EICR-II. 2. Upon acquiring CDDP resistance, tumor markers such as TPA and LDH increased, while proliferative capability of the cells was lowered. 3. The invasion capability was diminished in EICR-If cells, but was increased in EICR-Ia and EICR-II cells. 4. Following exposure to CDDP, the intracellular platinum concentrations were markedly elevated in EI and EICR-If cells, whereas the increase was mild in EICR-Ia and EICR-II cells and the concentration was lower than that in parent EI cells. 5. Studies of drug resistance gene expression revealed increased expression of MDR1, GSTπ, and Topo-II in EICR-If cells; increased expression of GSTπ in EICR-II cells; but no expression of any of the genes in EICR-Ia cells. 6. Analyses of cancer- and apoptosis-related genes showed increased expressions of Bcl-2, c-Myc, p53, and ICE in EICR-If cells. 7. Upon acquiring CDDP resistance, sensitivity to mitomycin and adriamycin decreased, but sensitivity to etoposide and 5-fluorouracil increased. The findings indicate that the mechanisms of CDDP resistance are different in the three cell lines.
Department of Obstetrics and Gynecology, Tokyo Medical University, Tokyo, Japan.
Yasukazu
Y
Sagawa
Atsuya
A
Fujitoh
Hirotaka
H
Nishi
Hiroe
H
Ito
Tamaki
T
Yudate
Keiichi
K
Isaka
D000970:Antineoplastic Agents / Q000627:therapeutic use*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002945:Cisplatin / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004317:Doxorubicin / Q000627:therapeutic use; D019008:Drug Resistance, Neoplasm; D016889:Endometrial Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D016685:Mitomycin / Q000627:therapeutic use; D009361:Neoplasm Invasiveness / Q000473:pathology; D010984:Platinum / Q000378:metabolism
D000970:Antineoplastic Agents; D010984:Platinum; D016685:Mitomycin; D004317:Doxorubicin; D002945:Cisplatin