CDX2 mRNA Levels Research Articles

Development of a novel oncolytic adenovirus controlled by CDX2 promoter for esophageal adenocarcinoma therapy.

Prognosis of esophageal adenocarcinoma (EAC) is still poor. Therefore, the development of novel therapeutic modalities is necessary to improve therapeutic outcomes in EAC. Here, we report a novel promoter-controlled oncolytic adenovirus targeting CDX2 (Ad5/3-pCDX2) and its specific anticancer effect for EAC. We used OE19, OE33, HT29, MKN28, RH30, and HEL299 cell lines. To establish CDX2 overexpressing OE19 cells, pCMV-GLI1 plasmid was transfected to OE19 (OE19 + GLI1). The virus replication and cytocidal effect of replication competent Ad5/3-pCDX2 were analyzed in vitro. Antitumor effect of Ad5/3-pCDX2 was assessed in xenograft mouse models by intratumoral injection of the viruses. Finally, efficacy of combination therapy with Ad5/3-pCDX2 and 5FU was evaluated. EAC cells and HT29 showed high mRNA levels of CDX2, but not MKN28, RH30, and HEL299. We confirmed that deoxycholic acid (DCA) exposure enhanced CDX2 expression in EAC cells and OE19 + GLI1 had persistent CDX2 overexpression without DCA. Ad5/3-pCDX2 showed stronger cytocidal effect in OE19 + GLI1 than OE19, whereas Ad5/3-pCDX2 did not kill CDX2-negative cells. Ad5/3-pCDX2 was significantly replicated in EAC cells and the virus replication was higher in OE19 + GLI1 and OE19 with DCA compared to OE19 without DCA exposure. In vivo, Ad5/3-pCDX2 significantly suppressed OE19 tumor growth and the antitumor effect was enhanced in OE19 + GLI1 tumor. In contrast, Ad5/3-pCDX2 did not show significant antitumor effect in MKN28 tumor. Moreover, Ad5/3-pCDX2 significantly increased the efficacy of 5FU in vitro and in vivo. Ad5/3-pCDX2 showed specific anticancer effect for EAC, which was enhanced by bile acid exposure. Ad5/3-pCDX2 has promising potential for EAC therapy in the clinical setting.

Methylation of CDX2 as a Predictor in Poor Clinical Outcome of Patients with Colorectal Cancer

Increased DNA methylation within the promoter regions of tumor suppressor genes has been associated with gene silencing in various cancers. CDX2, a caudal-related homeobox transcription factor, represents a key tumor suppressor in colorectal cancer. However, the pathological role of its promoter methylation has not yet been well defined in colorectal cancer. We measured CDX2 promoter methylation by methylation-specific PCR (MSP) and CDX2 mRNA levels by real-time quantitative reverse transcription-PCR in both tumor and normal control tissues collected from 108 colorectal cancer patients and then performed correlation analyses. We also determined whether CDX2 promoter methylation status was associated with any clinicopathological features and prognosis in these patients. CDX2 was expressed in all normal mucosa, but only in 38 (35.2%) tumor tissues. CDX2 promoter methylation was detected in 43 (39.8%) tumor samples, but in none of the normal tissue specimens. DNA methylation correlated with decreased mRNA level in these tumors (p < 0.05). The methylation of the CDX2 promoter was associated with enhanced lymph node metastases and shorter survival time (p = 0.0273), but was independent of tumor stage, tumor differentiation, gender, and age. Enhanced CDX2 promoter methylation is associated with gene silencing in a subgroup of colorectal cancer patients with lymph node metastasis and shorter survival times.

Expression and Functional Role of Cdx2 in Intestinal Metaplasia of Cystitis Glandularis

Cdx2 is an essential transcription factor in intestinal epithelial cell differentiation and proliferation. However, to our knowledge the expression and role of Cdx2 in the development of intestinal cystitis glandularis, a metaplastic lesion induced by chronic inflammation, remained to be explored. Real-time polymerase chain reaction was used to examine Cdx2, LI-cadherin and villin expression in typical and intestinal cystitis glandularis, and normal bladder tissue. Cdx2 cDNA was subcloned to the retroviral vector pLNCX2 for subsequent transfection into human bladder urothelium cells and rat bladder urothelium. Cdx2 mRNA and protein levels, and cell morphology and proliferation were assessed after transfection using real-time polymerase chain reaction, phase contrast microscopy, transmission electron microscopy and MTT assay, respectively. Higher mRNA levels of Cdx2, villin and LI-cadherin were detected in intestinal cystitis glandularis compared to normal bladder and typical cystitis glandularis. Only Cdx2 groups attained statistical significance (p <0.001). Retroviral over expression of Cdx2 resulted in increased mRNA and protein expression of Cdx2 as well as villin and LI-cadherin levels, and increased cell proliferation. A distinct change in cellular morphology, in which cells resembled intestinal-like cells, was also observed in vitro and in vivo. Cdx2 may have a critical role in regulating intestinal metaplasia in cystitis glandularis. Further studies are planned to assess the potential of using Cdx2 as a marker and therapeutic target for cystitis glandularis.

Activation of the BMP4 Pathway and Early Expression of CDX2 Characterize Non-specialized Columnar Metaplasia in a Human Model of Barrett’s Esophagus

BackgroundA human model of gastroesophageal reflux disease was used to examine the contribution of a non-specialized columnar type of metaplasia (NSCM) and key molecular events (BMP4 and CDX2) in the development of Barrett’s esophagus. MethodsBiopsies of the remnant esophagus from 18 patients undergoing esophagectomy with gastric preservation were taken at 6–36-month intervals postoperatively and examined for activation of the BMP pathway (BMP4/P-Smad 1/5/8) and CDX2 and CDX1 expression by imunohistochemistry, quantitative real-time PCR, Western blot, and in situ hybridization. ResultsA short segment (mean 15.6 mm) of NSCM was detected in 10 (56%) patients, with an increasing prevalence from 17% at 6 months to 62% at 36 months. Nuclear expression of P-Smad 1/5/8 in the squamous epithelium close to the anastomosis with strong expression in all epithelial cells of NSCM areas was found. Forty-eight (63%) biopsies with NSCM showed scattered nuclear expression of CDX2. Two cases showed isolated glands at 18, 24, and 36 months that fully expressed CDX2 and co-expressed CDX1. BMP4 mRNA and CDX2 mRNA levels were significantly greater in NSCM than in squamous epithelium. ConclusionsBMP4 activation in NSCM and early expression of CDX2 are involved in the columnar epithelial differentiation of Barrett’s esophagus.

Insulin deficiency induces abnormal increase in intestinal disaccharidase activities and expression under diabetic states, evidences from in vivo and in vitro study

Structural and functional alterations in the gastrointestinal tract of diabetic patients are often accompanied by increase in absorption of intestinal glucose and activities of brush-border disaccharidases. The purpose of this study was to investigate the role of insulin in regulating intestinal disaccharidases using in vivo and in vitro experiments. Streptozotocin-induced diabetic rats and normal rats received protamine zinc insulin (10IU/kg) subcutaneously twice daily for 5 weeks. Disaccharidase activities and sucrase–isomaltase (SI) complex protein and mRNA expression in intestinal regions were assessed. In addition, Caco-2 cells were cultured in medium containing glucose, insulin or insulin plus some pharmacological inhibitors for 7 days, disaccharidase activities, sucrase–isomaltase (SI) complex and Cdx2 mRNA levels were measured. The animal experiments showed that diabetes increased intestinal disaccharidase activities, accompanied by high mRNA and protein expression of SI complex. Insulin treatment reversed the increases induced by diabetes. The cellular results showed that insulin suppressed disaccharidase activities and down-regulated SI complex and Cdx2 mRNA expression in a concentration-dependent manner. The inhibitor of MAPK signal pathway PD-98059 blocked the suppression of disaccharidase activities and expression of SI complex and Cdx2 mRNA induced by insulin. In conclusion, insulin deficiency induces abnormal increase in intestinal disaccharidase activities and expression under diabetic states. Insulin plays an essential role in regulation disaccharidase activities and expression, at least in part, via the MAPK-dependent pathway.

CDX2 in the formation of the trophectoderm lineage in primate embryos

The first lineage decision during mammalian development is the establishment of the trophectoderm (TE) and the inner cell mass (ICM). The caudal-type homeodomain protein Cdx2 is implicated in the formation and maintenance of the TE in the mouse. However, the role of CDX2 during early embryonic development in primates is unknown. Here, we demonstrated that CDX2 mRNA levels were detectable in rhesus monkey oocytes, significantly upregulated in pronuclear stage zygotes, diminished in early cleaving embryos but restored again in compact morula and blastocyst stages. CDX2 protein was localized to the nucleus of TE cells but absent altogether in the ICM. Knockdown of CDX2 in monkey oocytes resulted in formation of early blastocyst-like embryos that failed to expand and ceased development. However, the ICM lineage of CDX2-deficient embryos supported the isolation of functional embryonic stem cells. These results provide evidence that CDX2 plays an essential role in functional TE formation during primate embryonic development.

Phosphatase activity of nuclear PTEN is required for CDX2-mediated intestinal differentiation of gastric carcinoma

The PTEN tumor suppressor localizes predominantly to the cytoplasm, where it negatively regulates the phosphatidylinositol 3-kinase-AKT signaling pathway; however, the biological significance of nuclear PTEN in gastric carcinoma (GC) remains unknown. In this study, transduction of recombinant PTEN into GC-derived TMK-1 cells promoted PTEN nuclear localization with increased mRNA levels of CDX2 and intestinal claudins ( CLDN3 and CLDN4), whereas the G129E phosphatase ‘dead’ mutant had no effect. In GC tissue samples, tumors with nuclear PTEN expression frequently demonstrated the intestinal-type claudin phenotype. Our results suggested that nuclear localization of PTEN is important for determining intestinal differentiation of GCs.

Intestinal capacity to digest and absorb carbohydrates is maintained in a rat model of cholestasis

Cholestasis is associated with systemic accumulation of bile salts and with deficiency of bile in the intestinal lumen. During the past years bile salts have been identified as signaling molecules that regulate lipid, glucose, and energy metabolism. Bile salts have also been shown to activate signaling routes leading to proliferation, apoptosis, or differentiation. It is unclear, however, whether cholestasis affects the constitution and absorptive capacity of the intestinal epithelium in vivo. We studied small intestinal morphology, proliferation, apoptosis, expression of intestine-specific genes, and carbohydrate absorption in cholestatic (1 wk bile duct ligation), bile-deficient (1 wk bile diversion), and control (sham) rats. Absorptive capacity was assessed by determination of plasma [(2)H]- and [(13)C]glucose concentrations after intraduodenal administration of [(2)H]glucose and naturally enriched [(13)C]sucrose, respectively. Small intestinal morphology, proliferation, apoptosis, and gene expression of intestinal transcription factors (mRNA levels of Cdx-2, Gata-4, and Hnf-1alpha, and Cdx-2 protein levels) were similar in cholestatic, bile-deficient, and control rats. The (unlabeled) blood glucose response after intraduodenal administration was delayed in cholestatic animals, but the absorption over 180 min was quantitatively similar between the groups. Plasma concentrations of [(2)H]glucose and [(13)C]glucose peaked to similar extents in all groups within 7.5 and 30 min, respectively. Absorption of [(2)H]glucose and [(13)C]glucose in plasma was similar in all groups. The present data indicate that neither accumulation of bile salts in the body, nor their intestinal deficiency, two characteristic features of cholestasis, affect rat small intestinal proliferation, differentiation, apoptosis, or its capacity to digest and absorb carbohydrates.

The transcription factor Cdx2 regulates the intestine-specific expression of human peptide transporter 1 through functional interaction with Sp1

H +/peptide cotransporter 1 (PEPT1, SLC15A1) localized at the brush-border membranes of intestinal epithelial cells plays important roles in the intestinal absorption of small peptides and a variety of peptidemimetic drugs. We previously demonstrated that transcription factor Sp1 functions as a basal transcriptional regulator of human PEPT1. However, the factor responsible for the intestine-specific expression of PEPT1 remains unknown. In the present study, we investigated the effect of the intestinal transcription factors on the transcription of the PEPT1 gene and found that only Cdx2 markedly trans-activated the PEPT1 promoter. However, the promoter region responsible for this effect lacked a typical Cdx2-binding sequence, but instead, possessed some Sp1-binding sites. In vitro experiments using Caco-2 cells showed that (1) mutation of the Sp1-binding site diminished the effect of Cdx2, (2) co-expression of Cdx2 and Sp1 synergistically trans-activated the PEPT1 promoter and (3) Sp1 protein was immunoprecipitated with Cdx2 protein. These results raise the possibility that Cdx2 modulates the PEPT1 promoter by interaction with Sp1. The significance of Cdx2 in vivo for PEPT1 regulation was shown by the determination of mRNA levels of Cdx2 and PEPT1 in human tissue. In gastric samples, some with intestinal metaplasia, the levels of PEPT1 and Cdx2 mRNA were highly correlated. Taken together, the present study suggests that Cdx2 plays a key role in the transcriptional regulation of the intestine-specific expression of PEPT1, possibly through interaction with Sp1.

Cdk2-dependent Phosphorylation of Homeobox Transcription Factor CDX2 Regulates Its Nuclear Translocation and Proteasome-mediated Degradation in Human Intestinal Epithelial Cells

By having demonstrated previously that p27(Kip1), a potent inhibitor of G(1) cyclin-cyclin-dependent kinases complexes, increases markedly during intestinal epithelial cell differentiation, we examined the effect of p27(Kip1) on the activity of the transcription factor CDX2. The present results revealed the following. 1) p27(Kip1) interacts with the CDX2 transcription factor. 2) In contrast to CDX2 mRNA levels, CDX2 protein expression levels significantly increased as soon as Caco-2/15 cells reached confluence, slowed their proliferation, and began their differentiation. The mechanism of CDX2 regulation is primarily related to protein stability, because inhibition of proteasome activity increased CDX2 levels. The half-life of CDX2 protein was significantly enhanced in differentiated versus undifferentiated proliferative intestinal epithelial cells. 3) Cdk2 interacted with CDX2 and phosphorylated CDX2, as determined by pull-down glutathione S-transferase and immunoprecipitation experiments with proliferating undifferentiated Caco-2/15 cell extracts. 4) Treatment of Caco-2/15 cells with MG132 (a proteasome inhibitor) and (R)-roscovitine (a specific Cdk2 inhibitor) induced an increase in CDX2 protein levels. 5) Conversely, ectopic expression of Cdk2 resulted in decreased expression of CDX2 protein. 6) Of note, treatment of proliferative Caco-2/15 cells with (R)-roscovitine or leptomycin (an inhibitor of nuclear export through CRM1) led to an accumulation of CDX2 into the nucleus. These data suggest that CDX2 undergoes CRM1-dependent nuclear export and cytoplasmic degradation in cells in which Cdk2 is activated, such as in proliferative intestinal epithelial cells. The targeted degradation of CDX2 following its phosphorylation by Cdk2 identifies a new mechanism through which CDX2 activity can be regulated in coordination with the cell cycle machinery.

Expression of the Cdx1and Cdx2Homeotic Genes Leads to Reduced Malignancy in Colon Cancer-derived Cells

We have previously described an inverse relationship between Cdx1 and Cdx2 mRNA levels and the extent of dysplasia and severity of clinical outcome in colorectal carcinoma, suggesting that altered expression of these genes was associated with colorectal carcinogenesis or tumor progression. To investigate further their involvement in the physiopathology of colorectal cancer, HT29 colon carcinoma cells that show very low Cdx expression were transfected with Cdx1 and/or Cdx2 cDNA to elicit their overexpression. Growth rate, tumorigenicity, resistance to apoptosis, and migration potential of the corresponding cells were analyzed. Growth rate of cells overexpressing Cdx2 decreased by half, whereas overexpression of Cdx1 had no effect. However, cells overexpressing both Cdxs had a growth rate reduced to 20% of control. In cells overexpressing Cdx1 or Cdx2, tumorigenicity and resistance to apoptosis induced by serum starvation, ceramide, or staurosporine were not changed compared with control cells; yet phorbol ester-stimulated cell migration was decreased by 50%. In cells overexpressing both Cdx1 and Cdx2, tumorigenicity was decreased by 50%, resistance to apoptosis was significantly lowered, and stimulated cell migration was further decreased to 15% of control compared with cells expressing Cdx1 or Cdx2. Finally, cells overexpressing both Cdxs showed strongly decreased Bcl-2 expression, which could account for their increased sensitivity to apoptosis. These findings show that, in HT29 cells, both Cdx1 and Cdx2 genes must be expressed to reduce tumorigenic potential, to increase sensitivity to apoptosis, and to reduce cell migration, suggesting that the two genes control the normal phenotype by independent pathways. This may explain why loss of Cdx1 or Cdx2 expression is associated with tumor development and invasiveness in colorectal tumors.