Transient activation of EGFR/AKT cell survival pathway and expression of survivin contribute to reduced sensitivity of human melanoma cells to betulinic acid
机构:[a]Department of OB/GYN, Renji Hospital, Shanghai Second Medical University, China[b]Department of Dermatology, Guangdong Provincial Hospital, Guangzhou, China[c]Department of Dermatology, Nanjing Medical University, China[d]Department of Biology, Providence College, 549 River Avenue, Providence, RI 02918, United States[e]Department of Surgical Oncology, Roger Williams Medical Center, Boston University, Providence, RI 02908, United States[f]Department of Biomedical Sciences, University of Rhode Island, Kingston, RI 02881, United States
Betulinic acid (BA), a pentacyclic triterpene first identified less than a decade ago, has served as a melanomaspecific cytotoxic agent, and yet its specificity is being challenged. Recently, we found that human melanoma cells exhibited less sensitivity to betulinic acid than human skin keratinocytes. This study was designed to investigate the cell signaling pathway leading human melanoma cells to increased resistance to betulinic acid treatment. In vitro experiments using cultured human melanoma cells indicated that betulinic acid transiently induced survivin expression. The expression of survivin started 30 min post-betulinic acid treatment, peaked at 2 h, remained elevated for 8 h and returned to basal level within 24 h. Similarly, epithelial growth factor (EGF) treatment induced expression of survivin in a time-dependent manner. Since epithelial growth factor receptor (EGFR) activation leads to the activation of cell signaling components that are important to cell survival, we next examined whether BA-induced survivin expression is mediated by the EGFR pathway. The results showed that BA induced EGFR tyrosine phosphorylation in a time-dependent manner. Further, BA strongly induced AKT phosphorylation in a similar pattern. AKT activation started 15 min post-treatment, peaked at approximately 1 h, remained elevated for 4 h and returned to basal level within 8 h. BA also induced ERK activation and, in contrast, weakly induced JNK and p38 activation. Pretreatment of EGFR inhibitor PD153035 blocked BAinduced EGFR phosphorylation, ERK and AKT activation, and survivin expression. Results of the MTT dye assay showed that a combination of PD 153035 and B A enhanced melanoma cell death. Collectively, we conclude that betulinic acid transiently activated the EGFR/AKT cell survival pathway and induced survivin expression, contributing to less sensitivity in human melanoma cells. The data suggest that a combination of the EGFR inhibitor and betulinic acid may be a better clinical option to treat human melanoma.
基金:
This research was supported in part by a grant from NIH
(P20 RRO16457 from the BRIN Program of the National
Center for Research Resources) and grants from Rhode
Island Foundation for biomedical research, the Committee on
Aid to Faculty Research from Providence College, and the
Slater Center for Environmental Biotechnology.
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外文
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无
最新[2025]版:
大类|3 区医学
小类|3 区肿瘤学
第一作者:
第一作者机构:[a]Department of OB/GYN, Renji Hospital, Shanghai Second Medical University, China
通讯作者:
通讯机构:[d]Department of Biology, Providence College, 549 River Avenue, Providence, RI 02918, United States[*1]Department of Biology, Providence College, 549 River Avenue, Providence, RI 02918, USA
推荐引用方式(GB/T 7714):
Qiu L,Wang Q,Di W,et al.Transient activation of EGFR/AKT cell survival pathway and expression of survivin contribute to reduced sensitivity of human melanoma cells to betulinic acid[J].International journal of oncology.2005,27(3):823-30.doi:10.3892/ijo.27.3.823.
APA:
Qiu, L,Wang, Q,Di, W,Jiang, Q,Schefeller, E...&Wan, Y.S.(2005).Transient activation of EGFR/AKT cell survival pathway and expression of survivin contribute to reduced sensitivity of human melanoma cells to betulinic acid.International journal of oncology,27,(3)
MLA:
Qiu, L,et al."Transient activation of EGFR/AKT cell survival pathway and expression of survivin contribute to reduced sensitivity of human melanoma cells to betulinic acid".International journal of oncology 27..3(2005):823-30