Gastric cancer is one of the most frequent cancers,and it ranks the third most common cancer in China.The most recently caudal-related homeobox transcription factor 2(CDX2)is expressed in a large number of human gastr...Gastric cancer is one of the most frequent cancers,and it ranks the third most common cancer in China.The most recently caudal-related homeobox transcription factor 2(CDX2)is expressed in a large number of human gastrointestinal cancers.In addition,gastric epithelial cell mutations in CDX2 result in tumor promotion,which is characterized by cellular drug resistance and a high proclivity for developing cancer.A series of publications over the past years suggests a mechanism by which CDX2 overexpression results in multidrug resistance.CDX2 appears to forward control regenerating Ⅳand the multidrug resistance 1 expression signaling pathway for regulation of cell drug resistance.展开更多
Barrett's esophagus (BE) is characterized by intestinal metaplasia with the differentiated epithelium replaced by another type of epithelium morphologically similar to normal intestinal epithelium. The metaplasia ...Barrett's esophagus (BE) is characterized by intestinal metaplasia with the differentiated epithelium replaced by another type of epithelium morphologically similar to normal intestinal epithelium. The metaplasia is preceded by bile and acid reflux into the esophagus. BE is a premalignant condition associated with increased risk of esophageal cancer, especially esophageal adenocarcinoma. The Caudal-related homeodomain transcription factors Caudal-related homeodomain transcription factor CDX1 and CDX2 are expressed exclusively in the small and large intestine, playing important roles in proliferation and differentiation of intestinal epithelial cells. Ectopic expression of CDX1 and CDX2 occurs in BE. The apical sodium-dependent bile acid transporter (ASBT) is expressed primarily in terminal ileum where it is a key factor for intestinal reabsorption of bile salts. In addition to upregulation of CDX1 and CDX2, ASBT expression is up-regulated in BE. Furthermore, both CDX1/CDX2 and ASBT expressions are down-regulated in high-grade esophageal dysplasia. The alteration of the above-mentioned factors calls for attention: what is the relationship between CDXs and ASBT aberrant expression in BE? In this commentary, we discuss this issue on basis of the recent study done by Ma et al .展开更多
AIM: To investigate the ability of a genetically altered embryonic stem (ES) cell line to generate insulin-producing cells in vitro following transfer of the Nkx2.2 gene.METHODS: Hamster Nkx2.2 genes were transferred ...AIM: To investigate the ability of a genetically altered embryonic stem (ES) cell line to generate insulin-producing cells in vitro following transfer of the Nkx2.2 gene.METHODS: Hamster Nkx2.2 genes were transferred into mouse ES cells. Parental and Nkx2.2-transfected ES cells were initiated toward differentiation in embryoid body (EB)culture for 5 d and the resulting EBs were transferred to an attached culture system. Dithizone (DTZ), a zincchelating agent known to selectively stain pancreatic beta cells, was used to detect insulin-producing cells.The outgrowths were incubated in DTZ solution (final concentration, 100 μg/mL) for 15 min before being examined microscopically. Gene expression of the endocrine pancreatic markers was also analyzed by RT-PCR. In addition, insulin production was determined immunohistochemically and its secretion was examined using an ELISA.RESULTS: DTZ-stained cellular clusters appeared after approximately 14 d in the culture of Nkx2.2-transfected ES cells (Nkx-ES cells), which was as much as 2 wk earlier, than those in the culture of parental ES cells (wt-ES). The frequency of DTZ-positive cells among total cultured cells on day 28 accounted for approximately 1.0% and 0.1% of the Nkx-ES- and wt-ES-derived EB outgrowths, respectively. The DTZ-positive cellular clusters were found to be immunoreactive to insulin, while the gene expressions of pancreatic-duodenal homeobox 1(PDX1), proinsulin 1 and proinsulin 2 were observed in the cultures that contained DTZ-positive cellular clusters.Insulin secretion was also confirmed by ELISA, whereas glucose-dependent secretion was not demonstrated.CONCLUSION: Nkx2.2-transfected ES cells showed an ability to differentiate into insulin-producing cells.展开更多
The Arabidopsis （Arabidopsis thaliana L.） genome encodes for four distinct classes of homeodomain leucinezipper （HD-ZIP） transcription factors （HD-ZIPI to HD-ZIPIV）, which are all organized in multi-gene familie...The Arabidopsis （Arabidopsis thaliana L.） genome encodes for four distinct classes of homeodomain leucinezipper （HD-ZIP） transcription factors （HD-ZIPI to HD-ZIPIV）, which are all organized in multi-gene families. HD-ZIP transcription factors act as sequence-specific DNA-binding proteins that are able to control the expression level of target genes. While HD-ZIPI and HD-ZIPII proteins are mainly associated with environmental responses, HD-ZIPIII and HD- ZIPIV are primarily known to act as patterning factors. Recent studies have challenged this view. It appears that several of the different HD-ZlP families interact genetically to align both morphogenesis and environmental responses, most likely by modulating phytohormone-signaling networks.展开更多
基金Supported by The National Natural Science Foundation of China,No.81060201Natural Science Foundation of Guangxi Zhuang Autonomous Region of China,No.2011GXNS-FA018273 and No.2013GXNSFAA019163the Key Health Science Fund of Guangxi Zhuang Autonomous Region of China,No.1298003-2-6
文摘Gastric cancer is one of the most frequent cancers,and it ranks the third most common cancer in China.The most recently caudal-related homeobox transcription factor 2(CDX2)is expressed in a large number of human gastrointestinal cancers.In addition,gastric epithelial cell mutations in CDX2 result in tumor promotion,which is characterized by cellular drug resistance and a high proclivity for developing cancer.A series of publications over the past years suggests a mechanism by which CDX2 overexpression results in multidrug resistance.CDX2 appears to forward control regenerating Ⅳand the multidrug resistance 1 expression signaling pathway for regulation of cell drug resistance.
文摘Barrett's esophagus (BE) is characterized by intestinal metaplasia with the differentiated epithelium replaced by another type of epithelium morphologically similar to normal intestinal epithelium. The metaplasia is preceded by bile and acid reflux into the esophagus. BE is a premalignant condition associated with increased risk of esophageal cancer, especially esophageal adenocarcinoma. The Caudal-related homeodomain transcription factors Caudal-related homeodomain transcription factor CDX1 and CDX2 are expressed exclusively in the small and large intestine, playing important roles in proliferation and differentiation of intestinal epithelial cells. Ectopic expression of CDX1 and CDX2 occurs in BE. The apical sodium-dependent bile acid transporter (ASBT) is expressed primarily in terminal ileum where it is a key factor for intestinal reabsorption of bile salts. In addition to upregulation of CDX1 and CDX2, ASBT expression is up-regulated in BE. Furthermore, both CDX1/CDX2 and ASBT expressions are down-regulated in high-grade esophageal dysplasia. The alteration of the above-mentioned factors calls for attention: what is the relationship between CDXs and ASBT aberrant expression in BE? In this commentary, we discuss this issue on basis of the recent study done by Ma et al .
文摘AIM: To investigate the ability of a genetically altered embryonic stem (ES) cell line to generate insulin-producing cells in vitro following transfer of the Nkx2.2 gene.METHODS: Hamster Nkx2.2 genes were transferred into mouse ES cells. Parental and Nkx2.2-transfected ES cells were initiated toward differentiation in embryoid body (EB)culture for 5 d and the resulting EBs were transferred to an attached culture system. Dithizone (DTZ), a zincchelating agent known to selectively stain pancreatic beta cells, was used to detect insulin-producing cells.The outgrowths were incubated in DTZ solution (final concentration, 100 μg/mL) for 15 min before being examined microscopically. Gene expression of the endocrine pancreatic markers was also analyzed by RT-PCR. In addition, insulin production was determined immunohistochemically and its secretion was examined using an ELISA.RESULTS: DTZ-stained cellular clusters appeared after approximately 14 d in the culture of Nkx2.2-transfected ES cells (Nkx-ES cells), which was as much as 2 wk earlier, than those in the culture of parental ES cells (wt-ES). The frequency of DTZ-positive cells among total cultured cells on day 28 accounted for approximately 1.0% and 0.1% of the Nkx-ES- and wt-ES-derived EB outgrowths, respectively. The DTZ-positive cellular clusters were found to be immunoreactive to insulin, while the gene expressions of pancreatic-duodenal homeobox 1(PDX1), proinsulin 1 and proinsulin 2 were observed in the cultures that contained DTZ-positive cellular clusters.Insulin secretion was also confirmed by ELISA, whereas glucose-dependent secretion was not demonstrated.CONCLUSION: Nkx2.2-transfected ES cells showed an ability to differentiate into insulin-producing cells.
基金funded by the Deutsche Forschungsgemeinschaft, an International Reintegration Grant of the European Union, the European Research Council and the German Ministry for Agriculture
文摘The Arabidopsis （Arabidopsis thaliana L.） genome encodes for four distinct classes of homeodomain leucinezipper （HD-ZIP） transcription factors （HD-ZIPI to HD-ZIPIV）, which are all organized in multi-gene families. HD-ZIP transcription factors act as sequence-specific DNA-binding proteins that are able to control the expression level of target genes. While HD-ZIPI and HD-ZIPII proteins are mainly associated with environmental responses, HD-ZIPIII and HD- ZIPIV are primarily known to act as patterning factors. Recent studies have challenged this view. It appears that several of the different HD-ZlP families interact genetically to align both morphogenesis and environmental responses, most likely by modulating phytohormone-signaling networks.
