View Single Post
Old 05-23-2014, 11:31 AM   #1
'lizbeth
Senior Member
 
'lizbeth's Avatar
 
Join Date: Apr 2008
Location: Sunny San Diego
Posts: 2,214
Post herb-drug interference in human breast cancer cells treated with tamoxifen and trastu

Menopause. 2013 Jun;20(6):646-54. doi: 10.1097/gme.0b013e31827b2240.
In vivo and in vitro demonstration of herb-drug interference in human breast cancer cells treated with tamoxifen and trastuzumab.

Chen JL1, Wang JY, Tsai YF, Lin YH, Tseng LM, Chang WC, King KL, Chen WS, Chiu JH, Shyr YM.
Author information


Abstract

OBJECTIVE:

In recent trends, patients with breast cancer seek integrative medical treatment when receiving either hormonal (tamoxifen [Tam]) or target (trastuzumab) therapy. Our previous in vitro studies demonstrated that the Chinese medicine Si-Wu-Tang (SWT) stimulates MCF-7 cell growth via activation of estrogen receptor α and human epidermal growth factor receptor 2 (HER2) signaling. The present study demonstrates herb-drug interference with cell proliferation in tumor-bearing mice treated with SWT and Tam in vivo and with proliferation capacity in breast cancer cells treated with SWT and trastuzumab in vitro.
METHODS:

To assess in vivo SWT + Tam interference, we randomly separated female MCF-7-implanted athymic nude mice into five groups, namely, vehicle (n = 11), estradiol (n = 8), SWT (n = 8), Tam (n = 11), and SWT + Tam (n = 8). All mice were killed after 21 days of treatment. Body weight, uterine weight, tumor volume, and tumor weight were measured. To assess in vitro SWT-trastuzumab interference, we cotreated BT-474 and SK-BR-3 breast cancer cells with SWT and trastuzumab. This was followed by (4,5-cimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assays and cell cycle analysis to measure cell proliferation and by Western blot analysis to analyze protein expression in growth-related signal pathways.
RESULTS:

SWT reversed Tam-induced antiproliferative effects on tumor weight and tumor volume and increased estrogen receptor α and N-cadherin expression in the SWT + Tam-treated group compared with the Tam-treated group. Furthermore, SWT reversed trastuzumab-induced antiproliferative activity in HER2 cell lines (SK-BR-3 and BT-474) through increased phosphorylation of the cell cycle regulatory protein p27(Kip1) and possibly of the antiapoptosis protein P38.
CONCLUSIONS:

Based on the in vivo and in vitro demonstration of herb-drug interference in breast cancer cells, we conclude that physicians should pay more attention to such interference when treating patients with receptor-positive (estrogen receptor-positive, progesterone receptor-positive, or HER2) breast cancers.
'lizbeth is offline   Reply With Quote