Inhibition of farnesoid X receptor controls esophageal cancer cell growth in vitro and in nude mouse xenografts

Abstract

BACKGROUND Gastroesophageal reflux is a risk factor for esophageal adenocarcinoma and bile acid and its farnesoid X receptor (FXR) have been implicated in esophageal tumorigenesis. We investigated the role of FXR expression and activity in esophageal cancer initiation and growth. METHODS FXR expression in esophageal adenocarcinoma tissues was assessed by immunohistochemistry. Knockdown of FXR expression in esophageal cancer cells in vitro and in nude mice xenografts was suppressed by FXR shRNA and guggulsterone (a natural FXR inhibitor). Esophageal cancer cells were treated with bile acids to show their effects on growth-promoting genes. RESULTS FXR was expressed in 48 of 59 esophageal adenocarcinoma tissues (81.3%), and this overexpression was associated with higher tumor grade, greater tumor size, and lymph node metastasis, but was inversely associated with RAR-β2 expression. Knockdown of FXR expression suppressed tumor cell growth in vitro and in nude mouse xenografts. Guggulsterone reduced viability of esophageal cancer cells in a time- and dose-dependent manner, whereas this effect was diminished after knockdown of FXR expression. Guggulsterone induced apoptosis through activation of caspases-8, -9, and -3 in tumor cells. FXR mediated bile acid–induced alterations of gene expression, e.g., RAR-β2 and COX-2. CONCLUSION Inhibition of FXR by FXR shRNA or guggulsterone suppressed tumor cell viability and induced apoptosis in vitro and reduced tumor formation and growth in nude mouse xenografts. FXR mediated bile acid–induced alterations of cell growth-related genes in esophageal cancer cells.

Guggulsterone inhibits human cholangiocarcinoma Sk-ChA-1 and Mz-ChA-1 cell growth by inducing caspase-dependent apoptosis and downregulation of survivin and Bcl-2 expression

“…Flow cytometry analysis was performed as previously described (18). In brief, the cells treated with Z-guggulsterone or DMSO were harvested and fixed with 75% ethanol at -20˚C.…”

“…Previous studies have reported that guggulsterone possesses anticancer potential due to the anti-proliferative and apoptosis-inducing effects exerted by this agent on a panel of human cancers, including leukemia, breast carcinoma, prostate cancer, colorectal cancer, pancreatic carcinoma and esophageal cancer (13)(14)(15)(16)(17)(18).…”

Farnesoid X receptor regulates the growth of renal adenocarcinoma cells without affecting that of a normal renal cell-derived cell line

“…Since our previous study in HepG2 cells (Fujino et al, 2012) and the present study have been performed in the medium containing 10% FCS sufficient for cell growth, our data is not comparable with the data obtained from Guo et al Consistent with our previous study (Fujino et al, 2012), Xie et al (2016) have reported FXR ligand GW4064 stimulates cell proliferation of HepG2 cells by analyzing DNA synthesis. As similar to hepatocellular and renal carcinoma cells, FXR knockdown inhibits cell proliferation of esophageal cancer cells (Guan et al, 2013). They have shown Ki-67 expression, cell proliferation marker, is down-regulated by FXR knockdown.…”

“…Thus, the stimulation of growth of renal adenocarcinoma cells by FXR ligand may arise from the down-regulation of p53 translation in a miR-21-dependent manner. There are several reports that state FXR regulates the proliferation of hepatocellular and other carcinoma cells (Zhang et al, 2012;He et al, 2015;Guo et al, 2015;Guan et al, 2013;Xie et al, 2016). Zhang et al (2012) and He et al (2015) have reported FXR inhibits the proliferation of hepatocellular carcinoma cell line HepG2 based on the data showing FXR ligand GW4064 reduced the value of MTT assay.…”

Microenvironmental Influences on Metastasis Suppressor Expression and Function during a Metastatic Cell’s Journey

“…All of these results implicate a place for FXR as a metastasis suppressor, but the in vitro data is at odds with clinical data in some cancers. For example, FXR expression in pancreatic and esophageal cancers is correlated with poor patient prognosis [171][172][173]. As with other metastasis suppressors, designation in this category is cell type dependent.…”