| | |  | | | | Record from Web of Science® | | | | | | |
| p53-dependent apoptosis in melanoma cells after treatment with camptothecin |
|
|
| Author(s): Li G, Bush JA, Ho VC |
| Source: JOURNAL OF INVESTIGATIVE DERMATOLOGY Volume: 114 Issue: 3 Pages: 514-519 Published: MAR 2000 |
| Times Cited: 38 References: 44 |
| Abstract: Cutaneous malignant melanoma is a life-threatening cancer with poor prognosis due to a high metastasis potential. The main obstacle in treatment of metastatic melanoma is the resistance to chemotherapy. Recent studies indicated that apoptosis is a common mechanism of action for various cytotoxic agents. As p53 plays an important part in apoptosis, we investigated the role of p53 in chemosensitivity of melanoma cells. Previously, we found that melanoma cell lines containing wild-type p53 have significantly higher response rates to chemotherapy than cell lines with a mutant p53 gene. To confirm the role of p53 in melanoma chemosensitivity further, we transfected an expression vector, pED1, which carries a mutant p53 gene, into a wild-type p53 melanoma cell line, MMAN. We examined the effect of mutant p53 on camptothecin-induced apoptosis and the expression of genes which are known to be involved in apoptosis or drug resistance, such as bcl-2, bax, bak, p21(waf1), and P-glycoprotein. Our results indicate that overexpression of the mutant p53 increased the growth rate of MMAN cells, reduced the sensitivity to camptothecin, and lowered drug-induced apoptosis by 2-3-fold. Flow cytometry indicated that the camptothecin-induced apoptosis is not associated with G(1) arrest. Furthermore, camptothecin treatment reduced bcl-2 and P-glycoprotein expression in wild-type p53 MMAN cells, but not cells overexpressing mutant p53. These results demonstrate that p53 mutational status is a determinant of melanoma chemosensitivity. p53 may downregulate bcl-2 and P-glycoprotein to induce apoptosis in melanoma cells after chemotherapy. |
| Document Type: Article |
| Language: English |
| Reprint Address: Li, G (reprint author), Jack Bell Res Ctr, 2660 Oak St, Vancouver, BC V6H 3Z6 Canada |
Addresses:
1. Univ British Columbia, Vancouver Hosp & Hlth Sci Ctr, Dept Med, Div Dermatol, Vancouver, BC V5Z 1M9 Canada |
| Publisher: BLACKWELL SCIENCE INC, 350 MAIN ST, MALDEN, MA 02148 USA |
| Subject Category: Dermatology |
| IDS Number: 299DT |
| ISSN: 0022-202X |
|
| | | | | | | | | Record from Web of Science® | | | | | | | | | |