In vitro effects of 2‐methoxyestradiol on cell numbers, morphology, cell cycle progression, and apoptosis induction in oesophageal carcinoma cells

Abstract

The influence of 2-methoxyestradiol (2-ME) was investigated on cell numbers, morphology, cell cycle progression, and apoptosis induction in an oesophageal carcinoma cell line (WHCO3). Dose-dependent studies (1 x 10(-9)M-1 x 10(-6)M) revealed that 2-ME significantly reduced cell numbers to 60% in WHCO3 after 72 h of exposure at a concentration of 1 x 10(-6)M compared to vehicle-treated cells. Morphological studies entailing light-, fluorescent-, as well as transmission electron microscopy (TEM) confirmed 2-ME's antimitotic effects. These results indicated hallmarks of apoptosis including cell shrinkage, hypercondensation of chromatin, cell membrane blebbing, and apoptotic bodies in treated cells. Flow cytometric analyses demonstrated an increase in the G(2)/M-phase after 2-ME exposure; thus preventing cells from proceeding through the cell cycle. beta-tubulin immunofluorescence revealed that 2-ME caused spindle disruption. In addition, increased expression of death receptor 5 protein was observed further supporting the proposed mechanism of apoptosis induction via the extrinsic pathway in 2-ME-exposed oesophageal carcinoma cells.

2-Methoxyestradiol: New perspectives in colon carcinoma treatment

“…In particular, our data indicated an involvement of caspase-8 and not of caspase-9 in the apoptotic cascade proteolysis, thus suggesting the activation of the extrinsic pathway. However, our evidence that mitochondria from 2-ME treated cells have an altered distribution, in line with the reported increase in mitochondria aggregating around the nuclear envelope (Thaver et al 2009), could support an effect of the drug on mitochondria. In fact, it has been reported that 2-ME promotes the release of cytochrome c and the translocation of Bax protein to mitochondria in pancreatic cancer cells (Qanungo et al 2002).…”

“…In fact, given that drug resistance of cancer cells is often correlated with the evasion of apoptosis, a major goal in cancer research is to selectively increase the susceptibility of cancer cells to apoptosis-based strategies (Giansanti and Scovassi 2008). Previous studies have reported the ability of 2-ME to induce apoptosis in various human cancer cell lines, by triggering both the extrinsic (Pribluda et al 2000;LaValle et al 2003;Mooberry et al 2003;Shimada et al 2004;Kato et al 2008;Thaver et al 2009) and intrinsic pathway (Yue et al 1997;Attalla et al 1998, Schumacher andNeuhaus 2001;Bu et al 2002;Mooberry 2003;Shimada et al 2003;Gao et al 2005;Zou et al 2006;Fukui and Zhu 2009). The activation of caspase-independent apoptosis by 2-ME has also been explored.…”

Sulphamoylated estradiol analogue induces antiproliferative activity and apoptosis in breast cell lines

“…2ME failed to advance to United States Food and Drug Administration approval because of its low efficacy [1][2][3][4]. It also shows rapid metabolic degradation and has limited bioavailability.…”

FGF8b oncogene mediates proliferation and invasion of Epstein–Barr virus-associated nasopharyngeal carcinoma cells: implication for viral-mediated FGF8b upregulation

“…Although the molecular mechanisms for FGF8b overexpression in prostate and breast cancers are not fully understood, the human sex hormone androgen (Tanaka et al, 1992) is known to play a key role, even in the case of breast cancer (Castellano et al, 2010Park et al, 2010 (in addition to prostate cancer (Gnanapragasam et al, 2002)). Similar findings in esophageal cancer, which has recently found to be androgen-related (Yamashita et al, 1989;Awan et al, 2007;Thaver et al, 2009), also revealed that FGF8b overexpression is linked to androgen signaling (Tanaka et al, 2001;Awan et al, 2007). With the limited number of cancer types being investigated thus far, it is unclear whether FGF8b is involved in the carcinogenesis of other human malignancies, especially in those hormone-unrelated cancers.…”