An exploration of immunohistochemistry-based prognostic markers in patients undergoing curative resections for colon cancer

Background The immune system recognizes and destroys cancer cells. However, cancer cells develop mechanisms to avoid detection by expressing cell surface proteins. Specific tumour cell surface proteins (e.g. HLA-G, PD-L1, CDX2) either alone or in combination with the relative presence of immune cells (CD3 and CD8 positive T-cells) in the tumour tissue may describe the cancer cells’ ability to escape eradication by the immune system. The aim was to investigate the prognostic value of immunohistochemical markers in patients with colon cancer. Methods We conducted a retrospective study including patients diagnosed with pT3 and pT4 colon cancers. Immunohistochemical staining with HLA-G, PD-L1, CDX2, CD3, and CD8 was performed on tissue samples with representation of the invasive margin. PD-L1 expression in tumour cells and immune cells was reported conjointly. The expression of CD3 and CD8 was reported as a merged score based on the expression of both markers in the invasive margin and the tumour centre. Subsequently, a combined marker score was established based on all of the markers. Each marker added one point to the score when unfavourable immunohistochemical features was present, and the score was categorized as low, intermediate or high depending on the number of unfavourable stains. Hazard ratios for recurrence, disease-free survival and mortality were calculated. Results We included 188 patients undergoing colon cancer resections in 2011–2012. The median follow-up was 41.7 months, during which 41 (21.8%) patients had recurrence and 74 (39.4%) died. In multivariable regression analysis positive HLA-G expression (HR = 3.37, 95%CI [1.64–6.93]) was associated with higher recurrence rates, while a preserved CDX2 expression (HR = 0.23, 95%CI [0.06–0.85]) was associated with a lower risk of recurrence. An intermediate or high combined marker score was associated with increased recurrence rates (HR = 20.53, 95%CI [2.68–157.32] and HR = 7.56, 95%CI [1.06–54.16], respectively). Neither high expression of PD-L1 nor high CD3-CD8 score was significantly associated with recurrence rates. Patients with a high CD3-CD8 score had a significantly longer DFS and OS. Conclusions In tumour cells, expression of HLA-G and loss of CDX2 expression were associated with cancer recurrence. In addition, a combination of certain tumour tissue biomarkers was associated with colorectal cancer recurrence.

Transcription factor-mediated intestinal metaplasia and the role of a shadow enhancer

Barrett's esophagus (BE) and gastric intestinal metaplasia are related premalignant conditions in which areas of human stomach epithelium express mixed gastric and intestinal features. Intestinal transcription factors (TFs) are expressed in both conditions, with unclear causal roles and cis-regulatory mechanisms. Ectopic CDX2 reprogrammed isogenic mouse stomach organoid lines to a hybrid stomach–intestinal state transcriptionally similar to clinical metaplasia; squamous esophageal organoids resisted this CDX2-mediated effect. Reprogramming was associated with induced activity at thousands of previously inaccessible intestine-restricted enhancers, where CDX2 occupied DNA directly. HNF4A, a TF recently implicated in BE pathogenesis, induced weaker intestinalization by binding a novel shadow Cdx2 enhancer and hence activating Cdx2 expression. CRISPR/Cas9-mediated germline deletion of that cis-element demonstrated its requirement in Cdx2 induction and in the resulting activation of intestinal genes in stomach cells. dCas9-conjugated KRAB repression mapped this activity to the shadow enhancer's HNF4A binding site. Altogether, we show extensive but selective recruitment of intestinal enhancers by CDX2 in gastric cells and that HNF4A-mediated ectopic CDX2 expression in the stomach occurs through a conserved shadow cis-element. These findings identify mechanisms for TF-driven intestinal metaplasia and a likely pathogenic TF hierarchy.

Loss of SATB2 Occurs More Frequently Than CDX2 Loss in Colorectal Carcinoma and Identifies Particularly Aggressive Cancers in High-Risk Subgroups

Background: Special AT-rich sequence-binding protein 2 (SATB2) has emerged as an alternative immunohistochemical marker to CDX2 for colorectal differentiation. However, the distribution and prognostic relevance of SATB2 expression in colorectal carcinoma (CRC) have to be further elucidated. Methods: SATB2 expression was analysed in 1039 CRCs and correlated with clinicopathological and morphological factors, CDX2 expression as well as survival parameters within the overall cohort and in clinicopathological subgroups. Results: SATB2 loss was a strong prognosticator in univariate analyses of the overall cohort (p < 0.001 for all survival comparisons) and in numerous subcohorts including high-risk scenarios (UICC stage III/high tumour budding). SATB2 retained its prognostic relevance in multivariate analyses of these high-risk scenarios (e.g., UICC stage III: DSS: p = 0.007, HR: 1.95), but not in the overall cohort (DSS: p = 0.1, HR: 1.25). SATB2 loss was more frequent than CDX2 loss (22.2% vs. 10.2%, p < 0.001) and of higher prognostic relevance with only moderate overlap between SATB2/CDX2 expression groups. Conclusions: SATB2 loss is able to identify especially aggressive CRCs in high-risk subgroups. While SATB2 is the prognostically superior immunohistochemical parameter compared to CDX2 in univariate analyses, it appears to be the less sensitive marker for colorectal differentiation as it is lost more frequently.

Loss of CDX2 in colorectal cancer is associated with histopathologic subtypes and microsatellite instability but is prognostically inferior to hematoxylin–eosin-based morphologic parameters from the WHO classification

Background Immunohistochemical loss of CDX2 has been proposed as a biomarker of dismal survival in colorectal carcinoma (CRC), especially in UICC Stage II/III. However, it remains unclear, how CDX2 expression is related to central hematoxylin–eosin (HE)-based morphologic parameters defined by 2019 WHO classification and how its prognostic relevance is compared to these parameters. Methods We evaluated CDX2 expression in 1003 CRCs and explored its prognostic relevance compared to CRC subtypes, tumour budding and WHO grade in the overall cohort and in specific subgroups. Results CDX2-low/absent CRCs were enriched in specific morphologic subtypes, right-sided and microsatellite-instable (MSI-H) CRCs (P < 0.001) and showed worse survival characteristics in the overall cohort/UICC Stage II/III (e.g. DFS: P = 0.005) and in microsatellite stable and left-sided CRCs, but not in MSI-H or right-sided CRCs. Compared with CDX2, all HE-based markers showed a significantly better prognostic discrimination in all scenarios. In multivariate analyses including all morphologic parameters, CDX2 was not an independent prognostic factor. Conclusion CDX2 loss has some prognostic impact in univariate analyses, but its prognostic relevance is considerably lower compared to central HE-based morphologic parameters defined by the WHO classification and vanishes in multivariate analyses incorporating these factors.

385 MIR-24-3P REGULATES CDX2 DURING THE PROCESS OF INTESTINALIZATION OF THE CARDIAC-TYPE EPITHELIUM IN A HUMAN MODEL OF BARRETT’S ESOPHAGUS

Cardiac-type epithelium has been proposed as an intermediate stage between normal squamous epithelium and intestinal metaplasia in the development of Barrett’s esophagus. Deregulation of certain miRNAs and their effects on CDX2 expression might contribute to the intestinalization process of cardiac-type epithelium. The aim of this study was to identify miRNAs differentially expressed between CDX2 positive and negative glands of Barrett’s esophagus and to examine the function of specific miRNAs on the regulation of CDX2. Methods miRNA expression profiling using OpenArrayTM analysis in microdissected cardiac-type glands with and without fully CDX2 expression was performed in biopsies from patients who developed cardiac-type epithelium in the remnant esophagus after esophagectomy. Data were validated using real-time PCR in esophageal adenocarcinoma cell lines and in situ and real-time PCR miRNA/CDX2/MUC2 co-expression analysis in cardiac-type mucosa samples. The effect of miR-24-3p precursor transfection on CDX2 expression was assessed in the esophageal adenocarcinoma cell lines FLO-1 and KYAE-1. Results CDX2 positive glands were characterized by an unique miRNA profile with a significant downregulation of miR-24-3p, miR-520e-3p, miR-548a-1, miR-597-5p, miR-133a-3p, miR-30a-5p, miR-638, miR-625-3p, miR-1255b-1, miR-1260a and upregulation of miR-590 (Figure 1A). miRNA-24-3p was identified as potential regulator of CDX2 gene expression in three bioinformatics algorithms, and this was confirmed in esophageal adenocarcinoma cell lines (Figure 1C). Furthermore, miR-24-3p expression negatively correlates with CDX2 in cardiac-type mucosa samples with different stages of mucosal intestinalization (Figure 1B). Conclusion These results imply that miRNA-24-3p directly targets CDX2, and downregulation of miRNA-24-3p is associated with the acquisition of an intestinal phenotype in cardiac-type epithelium.

Lysophosphatidic Acid Accelerates Bovine In Vitro-Produced Blastocyst Formation through the Hippo/YAP Pathway

The segregation of trophectoderm (TE) and inner cell mass in early embryos is driven primarily by the transcription factor CDX2. The signals that trigger CDX2 activation are, however, less clear. In mouse embryos, the Hippo-YAP signaling pathway is important for the activation of CDX2 expression; it is less clear whether this relationship is conserved in other mammals. Lysophosphatidic acid (LPA) has been reported to increase YAP levels by inhibiting its degradation. In this study, we cultured bovine embryos in the presence of LPA and examined changes in gene and protein expression. LPA was found to accelerate the onset of blastocyst formation on days 5 and 6, without changing the TE/inner cell mass ratio. We further observed that the expression of TAZ and TEAD4 was up-regulated, and YAP was overexpressed, in LPA-treated day 6 embryos. However, LPA-induced up-regulation of CDX2 expression was only evident in day 8 embryos. Overall, our data suggest that the Hippo signaling pathway is involved in the initiation of bovine blastocyst formation, but does not affect the cell lineage constitution of blastocysts.

miR-24-3p regulates CDX2 during intestinalization of cardiac-type epithelium in a human model of Barrett’s esophagus

Summary Background Cardiac-type epithelium has been proposed as the precursor of intestinal metaplasia in the development of Barrett’s esophagus. Dysregulation of microRNAs (miRNAs) and their effects on CDX2 expression may contribute to intestinalization of cardiac-type epithelium. The aim of this study was to examine the possible effect of specific miRNAs on the regulation of CDX2 in a human model of Barrett’s esophagus. Methods Microdissection of cardiac-type glands was performed in biopsy samples from patients who underwent esophagectomy and developed cardiac-type epithelium in the remnant esophagus. OpenArray™ analysis was used to compare the miRNAs profiling of cardiac-type glands with negative or fully positive CDX2 expression. CDX2 was validated as a miR-24 messenger RNA target by the study of CDX2 expression upon transfection of miRNA mimics and inhibitors in esophageal adenocarcinoma cell lines. The CDX2/miR-24 regulation was finally validated by in situ miRNA/CDX2/MUC2 co-expression analysis in cardiac-type mucosa samples of Barrett’s esophagus. Results CDX2 positive glands were characterized by a unique miRNA profile with a significant downregulation of miR-24-3p, miR-30a-5p, miR-133a-3p, miR-520e-3p, miR-548a-1, miR-597-5p, miR-625-3p, miR-638, miR-1255b-1, and miR-1260a, as well as upregulation of miR-590-5p. miRNA-24-3p was identified as potential regulator of CDX2 gene expression in three databases and confirmed in esophageal adenocarcinoma cell lines. Furthermore, miR-24-3p expression showed a negative correlation with the expression of CDX2 in cardiac-type mucosa samples with different stages of mucosal intestinalization. Conclusion These results showed that miRNA-24-3p regulates CDX2 expression, and the downregulation of miRNA-24-3p was associated with the acquisition of the intestinal phenotype in esophageal cardiac-type epithelium.

Predictive Value of CDX2 and SOX2 in Chronic Gastritis and Intestinal-type Gastric Cancer

BACKGROUND: Worldwide gastric cancer (GC) ranks sixth in incidence and second in mortality among all malignancies. CDX2 has an essential role in the development and maintenance of intestinal differentiation in the gut and ectopic sites such as intestinal metaplasia (IM) of the stomach. SOX2 contributes to the cell lineages normally found in the stomach, suggesting contribution in gastric differentiation. AIM: The aim of the study was to assess the expression of CDX2 and SOX2 in chronic gastritis (CG) lesions associated with Helicobacter pylori, IM, or dysplasia as well as in intestinal-type GC. METHODS: Immunohistochemical staining for CDX2 and SOX2 were applied on archival paraffin blocks from 80 CG cases, 40 intestinal-type GC cases, and 10 controls. CG cases were either of non-specific inflammation or associated with H. pylori infection. GC cases were of intestinal-type only, excluding any other type of GC. Control cases were of minimal gastritis, negative for H. pylori, IM, and dysplasia. RESULTS: CDX2 expression was correlated with CG associated with H. pylori, IM, and dysplasia as well as with more differentiated and less invasive pattern of intestinal-type GC, while SOX2 expression was correlated with CG negative for H. pylori and IM as well as with less differentiated and more invasive intestinal-type GC. CONCLUSION: Both CDX2 and SOX2 could predict the behavior of CG disease over time and plan the suitable line of treatment and both proteins could be potential targets for novel therapeutic interventions.