ABSTRACT
Gastric stem cells are adult stem cells found in the gastric tissues,which possess high self-renewal capability,proliferation rate and multiple differentiation capability.They can regenerate all the gastric mucosa epithelial cells.Gastric stem cells play an important role in the self-renewal and injury repair,making epithelium of gastric mucosa in the dynamic balance and maintaining the integrity of gastric mucosa.With the constant deepening of stem cell research,the application of gastric stem cells provides a new means for the study of gastric physiology and diseases.Since the first report by Barker in 2010,gastric organoids have soon become a model of interest and are highly desirable as tools for studying gastric diseases.As an optimal experimental model,gastric organoids are superior to animal model and conventional cell culture.Gastric organoids are comprised of all major types of gastric epithelial cells,represent the architecture and function remarkably similar to those of the gastric epithelium,faithfully recapitulating the functional gastric epithelium ex vivo.Especially gastric organoids derived from the human body,which allow the investigation of the function of human stomach in the ex vivo setting.In this review,research progresses of gastric stem cells and their application in establishment of gastric organoids are summarized.
ABSTRACT
The gastric epithelium is continuously regenerated by gastric stem cells, which give rise to various kinds of daughter cells, including parietal cells, chief cells, surface mucous cells, mucous neck cells, and enteroendocrine cells. The self-renewal and differentiation of gastric stem cells need delicate regulation to maintain the normal physiology of the stomach. Recently, it was hypothesized that cancer stem cells drive the cancer growth and metastasis. In contrast to conventional clonal evolution hypothesis, only cancer stem cells can initiate tumor formation, self-renew, and differentiate into various kinds of daughter cells. Because gastric cancer can originate from gastric stem cells and their self-renewal mechanism can be used by gastric cancer stem cells, we review here how critical signaling pathways, including hedgehog, Wnt, Notch, epidermal growth factor, and bone morphogenetic protein signaling, may regulate the self-renewal and differentiation of gastric stem cells and gastric cancer stem cells. In addition, the precancerous change of the gastric epithelium and the status of isolating gastric cancer stem cells from patients are reviewed.