Laboratory of GI Injury and Cancer

Long Beach, CA, United States

Laboratory of GI Injury and Cancer

Long Beach, CA, United States
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Chai J.,Laboratory of GI Injury and Cancer | Jamal M.M.,University of California at Irvine
World Journal of Gastroenterology | Year: 2012

Metastasis is the main reason for cancer-related death. S100A4 is one of the key molecules involved in this event. Several studies have shown that overexpression of S100A4 in non-metastatic cancer cells can make them become metastatic, and knockdown of S100A4 in metastatic cancer cells can curtail their invasive nature. A study by Chen et al[2] published in the World J Gastroenterol 18(9): 915-922, 2012 is a typical example. This study showed in vitro and in vivo evidence that S100A4 expression level determines the invasiveness of esophageal squamous carcinoma. Considering the fact that more than half of the cancer-related deaths are caused by malignancies derived from the digestive system and esophageal cancer is the 4th top contributor to this fraction, this study warrants more attention. © 2012 Baishideng.


Chai J.,Laboratory of GI Injury and Cancer | Chai J.,University of California at Irvine | Norng M.,Laboratory of GI Injury and Cancer | Modak C.,Laboratory of GI Injury and Cancer | And 4 more authors.
Laboratory Investigation | Year: 2010

CCN1 is a matricellular protein that activates many genes related to wound healing and tissue remodeling in fibroblasts, but its effect on epithelial cells remains unclear. This study examined the role of CCN1 in epithelial wound healing using rat gastric epithelial cells and rat stomach ulcer as in vitro and in vivo models, respectively. We found that CCN1 expression is highly upregulated in the epithelial cells adjacent to a wound and remains high until the wound is healed. Upregulation of CCN1 activates a transient epithelial-mesenchymal transition in the epithelial cells at the migrating front and drives wound closure. Once the wound is healed, these epithelial cells and their progeny can resume their original epithelial phenotype. We also found that CCN1-induced E-cadherin loss is not due to transcriptional regulation but rather protein degradation due to the collapse of adherens junctions, which is contributed by Β-catenin translocation. CCN1-activated integrin-linked kinase mediates this process. Finally, our in vivo study showed that locally neutralizing CCN1 drastically impairs wound closure, whereas local injection of recombinant CCN1 protein induces expression of vimentin and smooth muscle α-actin in normal gastric mucosal epithelial cells and accelerates re-epithelialization during ulcer healing. In conclusion, our study indicates that CCN1 can induce reversible epithelial-mesenchymal transition, and this feature may have great value for clinical wound healing. © 2010 USCAP, Inc All rights reserved.


PubMed | Laboratory of GI Injury and Cancer
Type: | Journal: ISRN gastroenterology | Year: 2012

Aims. Nuclear translocation of -catenin is common in many cancers including esophageal squamous cell carcinoma (ESCC). As a mediator of Wnt signaling pathway, nuclear -catenin can activate many growth-related genes including CCN1, which in turn can induce -catenin translocation. CCN1, a matricellular protein, signals through various integrin receptors in a cell-dependent manner to regulate cell adhesion, proliferation, and survival. Its elevation has been reported in ESCC as well as other esophageal abnormalities such as Barretts esophagus. The aim of this study is to examine the relationship between CCN1 and -catenin in ESCC. Methods and Results. The expression and correlation between CCN1 and -catenin in ESCC tissue were examined through immunohistochemistry and further analyzed in both normal esophageal epithelial cells and ESCC cells through microarray, functional blocking and in situ protein ligation. We found that nuclear translocation of -catenin in ESCC cells required high level of CCN1 as knockdown of CCN1 in ESCC cells reduced -catenin expression and translocation. Furthermore, we found that integrin (11) was highly expressed in ESCC tumor tissue and functional blocking integrin (11) diminished CCN1-induced -catenin elevation and translocation. Conclusions. Integrin (11) mediated the effect of CCN1 on -catenin in esophageal epithelial cells.


PubMed | Laboratory of GI Injury and Cancer
Type: Journal Article | Journal: World journal of gastroenterology | Year: 2012

Metastasis is the main reason for cancer-related death. S100A4 is one of the key molecules involved in this event. Several studies have shown that overexpression of S100A4 in non-metastatic cancer cells can make them become metastatic, and knockdown of S100A4 in metastatic cancer cells can curtail their invasive nature. A study by Chen et al([2]) published in the World J Gastroenterol 18(9): 915-922, 2012 is a typical example. This study showed in vitro and in vivo evidence that S100A4 expression level determines the invasiveness of esophageal squamous carcinoma. Considering the fact that more than half of the cancer-related deaths are caused by malignancies derived from the digestive system and esophageal cancer is the 4th top contributor to this fraction, this study warrants more attention.

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