Caudal Type Homeobox Research Articles

Methylation of the CDX2 promoter in Helicobacter pylori-infected gastric mucosa increases with age and its rapid demethylation in gastric tumors is associated with upregulated gene expression.

Pathological changes in the epigenetic landscape of chromatin are hallmarks of cancer. The caudal-type homeobox gene CDX2 is not expressed in normal gastric epithelia but rather in adult intestinal epithelia, and it is overexpressed in intestinal metaplasia (IM). However, it remains unclear how CDX2 transcription is suppressed in normal gastric epithelial cells and overexpressed in IM. Here, we demonstrate that methylation of the CDX2 promoter increases with age in Helicobacter pylori-positive, noncancerous gastric tissue, whereas the promoter is demethylated in paired gastric tumors in which CDX2 is upregulated. Moreover, we also found that the CDX2 promoter is demethylated in IM as well as gastric tumor. Immunohistochemistry revealed that CDX2 is present in foci of parts of the gastric mucosae but highly expressed in IM as well as in gastric tumors, suggesting that the elevated level of CDX2 in IM and gastric tumors may be attributable to promoter demethylation. Our data suggest that CDX2 repression may be associated with promoter methylation in noncancerous H. pylori-positive mucosa but its upregulation might be attributable to increased promoter activity mediated by chromatin remodeling during gastric carcinogenesis.

TGR5-HNF4\u03b1 axis contributes to bile acid-induced gastric intestinal metaplasia markers expression

Intestinal metaplasia (IM) increases the risk of gastric cancer. Our previous results indicated that bile acids (BAs) reflux promotes gastric IM development through kruppel-like factor 4 (KLF4) and caudal-type homeobox 2 (CDX2) activation. However, the underlying mechanisms remain largely elusive. Herein, we verified that secondary BAs responsive G-protein-coupled bile acid receptor 1 (GPBAR1, also known as TGR5) was increased significantly in IM specimens. Moreover, TGR5 contributed to deoxycholic acid (DCA)-induced metaplastic phenotype through positively regulating KLF4 and CDX2 at transcriptional level. Then we employed PCR array and identified hepatocyte nuclear factor 4α (HNF4α) as a candidate mediator. Mechanically, DCA treatment could induce HNF4α expression through TGR5 and following ERK1/2 pathway activation. Furthermore, HNF4α mediated the effects of DCA treatment through directly regulating KLF4 and CDX2. Finally, high TGR5 levels were correlated with high HNF4α, KLF4, and CDX2 levels in IM tissues. These findings highlight the TGR5-ERK1/2-HNF4α axis during IM development in patients with BAs reflux, which may help to understand the mechanism underlying IM development and provide prospective strategies for IM treatment.

Trophoblast lineage specification in the mammalian preimplantation embryo.

BackgroundThe establishment of the trophectoderm (TE) and the inner cell mass (ICM) is the first cell lineage segregation that occurs in mammalian preimplantation development. TE will contribute to the placenta while ICM cells give rise to the epiblast (EPI) and primitive endoderm (PrE). There are two historical models for TE/ICM segregation: the positional (inside‐outside) model and the polarity model, but both models alone cannot explain the mechanism of TE/ICM segregation.MethodsThis article discusses a current possible model based on recent studies including the finding through live‐cell imaging of the expression patterns of caudal type homeobox 2 (Cdx2), a key transcription factor of TE differentiation in the mouse embryo.ResultsIt was observed that a part of outer Cdx2‐expressing blastomeres was internalized at the around 20‐ to 30‐cell stage, downregulates Cdx2, ceases TE differentiation, and participates in ICM lineages.ConclusionThe early blastomere, which starts differentiation toward the TE cell fate, still has plasticity and can change its fate. Differentiation potency of all blastomeres until approximately the 32‐cell stage is presumably not irreversibly restricted even if they show heterogeneity in their epigenetic modifications or gene expression patterns.

SO-36 The prognostic impact of mismatch repair phenotype in colon cancer is highly stage-dependent

Mismatch repair deficiency (dMMR) is associated with an improved prognosis in stage II colon cancer, as reflected in current treatment guidelines. However, for patients with colon cancer stage IV, dMMR is a marker of poor prognosis in many studies. The reason for this stage-dependent function of MMR phenotype is not known. In this study, we assess whether the prognostic impact of dMMR differs between stage II and stage III colon cancer, adjusting for possible confounders including density of tumor-infiltrating CD3+ and CD8+ lymphocytes (TILs), expression of caudal-type homeobox transcription factor 2 (CDX2), and administration of adjuvant chemotherapy.

Sinonasal renal cell-like adenocarcinoma with EGFR overexpression of the maxillary sinus: Report of a high-grade case and a review of the literature

Sinonasal renal cell-like adenocarcinoma (SRCLA), which is an extremely rare but established entity, belongs to the non-salivary gland type of low-grade adenocarcinomas arising from the sinonasal tract. We report a case of high-grade SRCLA. The patient was a 63-year-old Japanese male, who complained of nasal obstruction. Histologically, the tumor exhibited solid nests and sheet-like structures composed of atypical clear or eosinophilic cells with central necrosis. The tumor cells contained periodic acid Schiff-positive glycogen. Immunohistochemically, they were positive for cytokeratin (CK)7, CD10, carbonic anhydrase (CA)-IX, the epidermal growth factor receptor (EGFR), mucin 1, and cancer antigen 125, whereas they were negative for CK20, caudal type homeobox 2, CK5/6, p40, vimentin, S-100, a renal cell carcinoma marker, paired box gene 8, and the human epidermal growth factor receptor 2. Both local recurrence and late lymph node metastases arose in this case. Therefore, the tumor was considered to be clinically aggressive and was diagnosed as a high-grade SRCLA. Immunostaining of CD10 and CA-IX was very diagnostically useful. Although 14 cases of SRCLA have been reported previously, all of them involved low-grade malignancies, and no descriptions of their EGFR statuses were provided. This is the first report about a high-grade SRCLA exhibiting EGFR overexpression.

Nanoparticle technology improves in-vitro attachment of cattle (Bos taurus) trophectoderm cells.

The bovine cell line, cow trophectoderm-1 (CT-1), provides an excellent in-vitro cell culture model to study early embryonic development. Obtaining consistent attachment and outgrowth, however, is difficult because enzymatic disassociation into single cells is detrimental; therefore, CT-1 cells must be passaged in clumps, which do not attach readily to the surface of the dish. We tested whether magnetic nanoparticles, NanoShuttle™-PL, could be used to improve cell attachment and subsequent proliferation of the cattle trophectoderm cell line without altering cellular metabolism or immunofluorescent detection of the lineage marker Caudal Type Homeobox 2 (CDX2). Confluency was achieved more consistently by using the NanoShuttle™-PL system to magnetically force attachment (75-100% of wells) as compared to the control (11%). Moreover, there were no alterations in characteristic morphology, nuclear-localized expression of the trophectoderm marker CDX2, or glycolytic metabolism. By enhancing attachment, magnetic nanoparticles improved culture efficiency and reproducibility in an anchorage-dependent cell line that otherwise was recalcitrant to efficient passaging.

Functional genomics analysis of human colon organoids identifies key transcription factors.

Organoids are a valuable three-dimensional (3D) model to study the differentiated functions of the human intestinal epithelium. They are a particularly powerful tool to measure epithelial transport processes in health and disease. Though biological assays such as organoid swelling and intraluminal pH measurements are well established, their underlying functional genomics are not well characterized. Here we combine genome-wide analysis of open chromatin by ATAC-Seq with transcriptome mapping by RNA-Seq to define the genomic signature of human intestinal organoids (HIOs). These data provide an important tool for investigating key physiological and biochemical processes in the intestinal epithelium. We next compared the transcriptome and open chromatin profiles of HIOs with equivalent data sets from the Caco2 colorectal carcinoma line, which is an important two-dimensional (2D) model of the intestinal epithelium. Our results define common features of the intestinal epithelium in HIO and Caco2 and further illustrate the cancer-associated program of the cell line. Generation of Caco2 cysts enabled interrogation of the molecular divergence of the 2D and 3D cultures. Overrepresented motif analysis of open chromatin peaks identified caudal type homeobox 2 (CDX2) as a key activating transcription factor in HIO, but not in monolayer cultures of Caco2. However, the CDX2 motif becomes overrepresented in open chromatin from Caco2 cysts, reinforcing the importance of this factor in intestinal epithelial differentiation and function. Intersection of the HIO and Caco2 transcriptomes further showed functional overlap in pathways of ion transport and tight junction integrity, among others. These data contribute to understanding human intestinal organoid biology.

A primary neuroendocrine tumor of the left ventricle presenting with diarrhea\u2014an unusual experience and literature review

BackgroundNeuroendocrine tumors (NETs) can secrete bioactive amines in the bloodstream, resulting in the carcinoid syndrome characterized by diarrhea and flushing. The frequency of occurrence of primary cardiac neuroendocrine neoplasms is lesser than that of metastases, and hence, metastases must be adequately ruled out before diagnosis. Cardiac tumors, both primary and metastatic, mainly result in heart-related symptoms, such as heart failure and acquired valvular dysfunction. Here, we report a unique case of a primary left ventricular neuroendocrine tumor presenting with diarrhea.Case presentationA 51-year-old female complaining of intermittent diarrhea for 2 years was admitted to our hospital. Enhancement of total abdominal computed tomography scan, echocardiography, and magnetic resonance imaging indicated a mass in the left ventricle. The indexes of myocardial enzymes were normal. Histologically, round cells with well-differentiated neuroendocrine morphology were arranged in typical pseudo-glandular, trabecular, ribbon-like, and solid nest patterns. Immunohistochemically, the tumor cells were positive for cytokeratin, chromogranin, synaptophysin, and CD56. However, they were negative for caudal type homeobox 2, S100, paired box gene 8, thyroid transcription factor 1, and CD20, which ruled out the origin of gastrointestinal, pancreatic, lung, and Merkel cell carcinomas. The symptoms of diarrhea disappeared after the operation. The patient was asymptomatic at the 9-month follow-up.ConclusionCardiac neuroendocrine tumors with diarrhea are considerably rare and related clinical research is limited. We presented a case and reviewed related articles to improve the identification, diagnosis, and management of patients with cardiac neuroendocrine tumors. The site of origin of a neuroendocrine tumor is clinically vital, and identification of an occult primary tumor using imaging modalities is necessary. Immunohistochemistry is well-suited to indicate the origin of the tumor. Regular follow-up is necessary for both poorly differentiated and well-differentiated cardiac neuroendocrine tumors. It is suggested to detect some neuroendocrinal markers for patients with unexplained reasons of diarrhea.

CDX2: A Prognostic Marker in Metastatic Colorectal Cancer Defining a Better BRAF Mutated and a Worse KRAS Mutated Subgroup.

Background: Survival of metastatic colorectal cancer (mCRC) patients has improved, but mainly for trial patients. New predictive and prognostic biomarkers validated in the general mCRC population are needed. Caudal-type homeobox 2 (CDX2) is an intestine-specific transcription factor with potential prognostic and predictive effect, but the importance in mCRC has not been fully investigated.Methods: Immunohistochemistry analysis of CDX2 was performed in a Scandinavian population-based cohort of mCRC (n = 796). Frequency, clinical and tumor characteristics, response rate, progression-free survival, and overall survival (OS) were estimated.Results: Loss of CDX2 expression was found in 87 (19%) of 452 stained cases, in 53% if BRAF mutated (BRAFmut) and in 9% if KRAS mutated (KRASmut). CDX2 loss was associated with microsatellite instability, BRAFmut, and poor differentiation and inversely associated with KRASmut. Patients with CDX2 loss received less first-line (53 vs. 64%, p = 0.050) and second-line (23 vs. 39%, p = 0.006) chemotherapy and secondary surgery (1 vs. 9%, p = 0.019). Median progression-free survival and OS for patients given first-line combination chemotherapy was 4 and 10 months if CDX2 loss vs. 9 and 24 months if CDX2 expressed (p = 0.001, p < 0.001). Immediate progression on first-line combination chemotherapy was seen in 35% of patients with CDX2 loss vs. 10% if CDX2 expressed (p = 0.003). Median OS in patients with BRAFmut or KRASmut and CDX2 expressed in tumor (both 21 months) was comparable to wild-type patients (27 months). However, if CDX2 loss, median OS was only 8 and 11 months in BRAFmut and KRASmut cases, respectively, and 10 months in double wild-type patients. In multivariate analysis, CDX2 loss (hazard ratio: 1.50, p = 0.027) and BRAFmut (hazard ratio: 1.62, p = 0.012) were independent poor prognostic markers for OS.Conclusion: In a population-based cohort of mCRC patients, CDX2 loss is an independent poor prognostic marker. Expression of CDX2 defines a new subgroup of BRAFmut cases with a much better prognosis. Loss of CDX2 defines a small group of KRASmut cases with a worse prognosis. Patients with CDX2 loss receive less palliative chemotherapy with less benefit and rarely reach secondary surgery.

Effect of Cdx2 Polymorphism on the Relationship between Dietary Calcium Intake and Peak Bone Mass in Young Japanese Women.

Studies investigating the effect of the caudal-type homeobox protein 2 (Cdx2) polymorphism in the vitamin D receptor gene and calcium intake on bone mass have shown inconsistent results. This study investigated whether the effect of calcium intake on peak bone mass is affected by Cdx2 polymorphism in young Japanese women. A cross-sectional study of 500 young women was conducted. Dietary intake was assessed by the Food Frequency Questionnaire. The osteo sono-assessment index (OSI), assessed by the qualitative ultrasound method, was used as a bone mass index. The subjects were divided into two groups by the median calcium intake. The OSI was not different among Cdx2 genotypes and between calcium groups (p = 0.960, p = 0.191, respectively). The interaction between calcium and Cdx2 genotypes on the OSI approached significance (GG versus GA and AA genotypes, p = 0.092). The difference in the OSI between calcium groups was significant in the GG genotype (p = 0.028), but not in the GA or AA genotypes (p = 0.501, p = 0.306, respectively). Adjustment for covariates (body mass index and physical activity) did not change the results. In conclusion, the relationship between dietary calcium intake and peak bone mass may vary according to Cdx2 polymorphism.

Clinical, histopathological and immunohistochemical features of brain metastases originating in colorectal cancer: a series of 27 consecutive cases.

Introduction: Brain metastases (BMs) originating in colorectal cancer (CRC) have a significant importance for patients’ survival. Because in literature there are only isolated case reports and only few series published on this issue, we aimed to assess the incidence of BMs from CRC, to identify patient’s characteristics and BMs clinical, histopathological (HP) and immunohistochemical (IHC) features, and to compare the data we obtained with those from literature. Patients, Materials and Methods: We present a retrospective study of 27 histologically confirmed cases of BMs from CRC among all 1040 patients who received metastasectomy in the Department of Neurosurgery, Prof. Dr. Nicolae Oblu Emergency Clinical Hospital, Iaşi, Romania, in an eight-year period (January 2011 to December 2018). Patients’ characteristics (gender, age), primary tumor location, time from primary tumor surgery to BMs surgery and BMs features (number, location and HP characteristics) were investigated. Histochemical [Alcian Blue (AB) and Periodic Acid–Schiff (PAS)] staining and IHC stainings for cytokeratin (CK) 7, CK20, caudal-type homeobox 2 (CDX2) and human epidermal growth factor receptor 2 (HER2)/neu were performed on all available BMs specimens. Results: There were 27 consecutive patients with BMs from CRC, corresponding to 2.59% of all patients with BMs during the eight-year period we have studied, most of them being diagnosed and treated in 2016. Male:female ratio was 1.45. The mean age for all patients at diagnosis of the BMs was 62.25 years (range: 40–79 years). The origin of the primary cancer was mainly the colon (62.96% of all cases). Of all 27 patients, only two (7.4%) presented neurological symptoms without a diagnosis of CRC. BMs were identified in a period ranging from six months to 70 months after the initial diagnosis. The average time between diagnosis of the primary tumor and of the BMs was 25.92 months. At the moment of the diagnosis of BMs, 17 (62.96%) patients also had other systemic metastases. Most of the cases (55.55%) were situated in the supratentorial compartment. IHC stainings were negative for CK7 and positive for CK20 and CDX2 in all BMs from colonic adenocarcinomas (ADCs), a profile consistent with a non-neuronal and gastric origin. AB and PAS stainings revealed pools of extracellular mucin, especially in cases of mucinous ADC. Ki67 labeling index ranged between 90% and 100%. IHC staining with anti-HER2/neu antibody showed in 25 (96.15%) cases a strong and diffuse aberrant nuclear staining. Conclusions: BMs originating in CRC represent a rare pathology and have particular clinical and IHC features that could vary from one series to another series. In a few cases, BMs may be diagnosed in the absence of a known CRC diagnosis and in these situations, the correct diagnosis is of interest. However, a panel of antibodies can help in establishing a correct diagnosis. Our study was among the first to analyze the HER2/neu expression pattern in BMs from CRC and we found a strong aberrant nuclear expression of this molecular marker on IHC investigation. Related to the data published so far in the literature, it is possible that HER2/neu aberrant expression in the tumor nuclei of the BMs from our series may express the metastatic tumor cell phenotype that was previously subjected to cytostatics and radiation therapies. As such, we suggest that HER2/neu aberrant expression in BMs originating in CRC could represent a proof for the worst prognosis of these patients.

Colorectal Carcinoma Presenting as Ovarian Metastasis: A Case Report

There is a common occurrence of colorectal adenocarcinoma metastasis to the ovary and in rare circumstances, these cases may present clinically as primary ovarian cancer and histologically as primary endometrioid carcinoma of the ovary. Approximately 3.6% to 7.4% of patients with colon cancer have ovarian metastasis at the time of initial presentation, of which, 45% are mistaken for primary ovarian tumors. The author reports the case of a 60-year-old female presenting with fatigue and pelvic pain secondary to a pelvic mass. Computed tomography (CT) revealed a lobulated, heterogeneous pelvic mass measuring 11.1 × 10.5 × 9.8 cm, and ultrasound (US) showed complex 13.8 × 8.2 × 12.3 cm mass posterior to the uterus. Upon examination of the specimen following debulking procedure, endometrioid carcinoma of the ovaries was initially considered. However, immunohistochemical stains were performed and showed malignant cells positive for cytokeratin (CK) 20, caudal type homeobox (CDX) 2, and specific AT-rich sequence binding (SATB) protein 2, consistent with metastatic colorectal carcinoma. This report highlights the diagnostic challenges arising with differentiation between primary endometrioid ovarian carcinoma and metastatic colorectal adenocarcinoma to the ovary and the potential clinical consequences of misdiagnosis.

Fucoidan suppresses the gastric cancer cell malignant phenotype and production of TGF-β1 via CLEC-2.

The sulfated polysaccharide fucoidan displays excellent anticancer properties with low toxicity in many kinds of cancers. However, its detailed pharmacological effect and mechanism of action in gastric carcinoma remains unclear. In this study, we found that fucoidan could suppress gastric cancer (GC) cell growth, as well as cell migration and invasion. A cytokine expression screen demonstrated that transforming growth factor beta 1 (TGF-β1) secretion was decreased in fucoidan-treated cells. Fucoidan has been reported to be a platelet agonist for the C-type lectin-like receptor 2 (CLEC-2), and our previous research found that upregulation of CLEC-2 inhibited GC progression. Here, we confirmed that fucoidan, combined with CLEC-2, significantly increased CLEC-2 expression in GC cells via the transcription factor caudal type homeobox transcription factor 2, an important regulator of gut homeostasis. In addition, the inhibitory effect of fucoidan on the GC cell malignant phenotype and TGF-β1 secretion could be restored by knocking down CLEC-2. Thus, our data suggest that fucoidan targets CLEC-2 to exert antitumorigenesis and antimetastatic activity, suggesting that fucoidan is a promising treatment for gastric carcinoma.

MicroRNA-9-5p-CDX2 Axis: A Useful Prognostic Biomarker for Patients with Stage II/III Colorectal Cancer.

A lack of caudal-type homeobox transcription factor 2 (CDX2) protein expression has been proposed as a prognostic biomarker for colorectal cancer (CRC). However, the relationship between CDX2 levels and the survival of patients with stage II/III CRC along with the relationship between microRNAs (miRs) and CDX2 expression are unclear. Tissue samples were collected from patients with stage II/III CRC surgically treated at Kyoto University Hospital. CDX2 expression was semi-quantitatively evaluated by immunohistochemistry (IHC). The prognostic impacts of CDX2 expression on overall survival (OS) and relapse-free survival (RFS) were evaluated by multivariable statistical analysis. The expression of miRs regulating CDX2 expression and their prognostic impacts were analyzed using The Cancer Genome Atlas Program for CRC (TCGA-CRC). Eleven of 174 CRC tissues lacked CDX2 expression. The five-year OS and RFS rates of patients with CDX2-negative CRC were significantly lower than those of CDX2-positive patients. Multivariate analysis of clinicopathological features revealed that CDX2-negative status is an independent marker of poor prognosis in stage II/III CRC. miR-9-5p was shown to regulate CDX2 expression. TCGA-CRC analysis showed that high miR-9-5p expression was significantly associated with poor patient prognosis in stage II/III CRC. In conclusion, CDX2, the post-transcriptional target of microRNA-9-5p, is a useful prognostic biomarker in patients with stage II/III CRC.

DGCR8/ZFAT-AS1 Promotes CDX2 Transcription in a PRC2 Complex-Dependent Manner to Facilitate the Malignant Biological Behavior of Glioma Cells.

Studies have found that RNA-binding proteins (RBPs) and long non-coding RNAs (lncRNAs) are dysregulated and play an important regulatory role in the development of tumors. Based on The Cancer Genome Atlas (TCGA) database, our findings from experiments, and the evidence of previous studies, we screened DiGeorge syndrome critical region gene 8 (DGCR8), ZFAT antisense RNA 1 (ZFAT-AS1), and caudal type homeobox 2 (CDX2) as research candidates. In the present study, DGCR8 and CDX2 were highly expressed and ZFAT-AS1 was markedly downregulated in glioma tissues and cells. DGCR8 or CDX2 knockdown or ZFAT-AS1 overexpression suppressed glioma cell proliferation, migration, and invasion and facilitated apoptosis. DGCR8 might decrease ZFAT-AS1 expression by attenuating its stability in a manner of inducing its cleavage. Importantly, ZFAT-AS1 could inhibit CDX2 transcription by mediating the methylation of histone H3 on lysine 27 (H3K27me3) modification induced by PRC2 in the CDX2 promoter region. In addition, CDX2 transcriptionally activated DGCR8 expression by binding to its promoter regions, forming a positive feedback loop of DGCR8/ZFAT-AS1/CDX2. In conclusion, DGCR8/ZFAT-AS1 promotes CDX2 transcription in a PRC2 complex-dependent manner to facilitate the malignant biological behavior of glioma cells.

Caudal Type Homeobox 2 Is Required for Leukemogenesis but Not for Normal Hematopoieisis

Caudal Type Homeobox 2 (CDX2) is a caudal-related homeobox family transcription factor known to be developmental regulator involved in murine axial elongation and anteroposterior vertebral patterning and cell fate determination in the intestine. In adults, CDX2 expression is restricted to the small intestine and the colon. Interestingly, CDX2 is overexpressed in ~90% of human acute myeloid leukemias and the majority of acute lymphoblastic leukemias. Hence, aberrant expression of CDX2 may play a contributing role in leukemogenesis. The role of CDX2 in normal hematopoietic development is unknown. To assess the role of CDX2 in normal hematopoiesis we characterized hematopoietic development in Cdx2 fl/fl Mx1-Cre+ mice after poly (I:C)-mediated gene deletion compared to wildtype littermates. Under steady state conditions, no significant defects were identified in long-term hematopoietic stem cells (LT-HSCs), multipotent progenitors, myeloid progenitors, or mature cell lineages. To test if long-term hematopoietic stem cells were functionally impaired following Cdx2 deletion, competitive transplantation assays were performed. We found that CDX2 was not required for long-term hematopoietic reconstitution in the competitive transplant setting. Together, these data establish that CDX2 is not required for adult steady state hematopoiesis or LT-HSC function. We then asked whether or not CDX2 was essential for leukemogenesis. To interrogate this, Cdx2 fl/fl Mx1-Cre+, Cdx2 fl/+ Mx1-Cre+, and wildtype littermates were treated with poly (I:C) to facilitate gene deletion or for control purposes. Bone marrow cells from the mice were then transformed using well-established HOXA9/MEIS1 or MLL-AF10 leukemogenesis models. In both systems, Cdx2-deficiency prevented leukemia development, whereas wildtype controls succumbed to leukemia within 200 days. Cdx2 heterozygous knockout animals had a delayed onset of leukemia compared to wildtype animals. Taken together, these data indicate that CDX2 is not required for steady state adult hematopoiesis or LT-HSC function, but is necessary for the development of leukemia. Our findings suggest CDX2 has potential as a novel therapeutic target that could be exploited in the majority of AML and ALL patients across a broad mutational spectrum. The nomination of CDX2 as a key target for the majority of leukemias is significant, as current targeted treatment strategies are limited to only particular patient subsets. Disclosures No relevant conflicts of interest to declare.

Metachronous rectal metastasis from pulmonary adenocarcinoma after 11\u2009years of chemo-, immuno-, and radiotherapy for recurrent lesions: a case report

BackgroundRectal metastasis from pulmonary adenocarcinoma is rare, and it has been regarded as an end-stage phenomenon. Recently, however, advances in lung cancer treatment have improved the chance of long-term survival of patients with unresectable distant metastases. We describe the occurrence and management of metastatic spread of a pulmonary carcinoma to the rectum.Case presentationThe patient was a 79-year-old woman who had undergone thoracoscopic left lobectomy for pulmonary adenocarcinoma and then, over the next 11 years, various drugs (carboplatin + paclitaxel (as adjuvant therapy), gefitinib, gemcitabine + vinorelbine, S1 (an oral 5-fluorouracil-based drug), carboplatin + pemetrexed + bevacizumab, erlotinib, nivolumab, afatinib, and carboplatin+ S1) were administered, especially for hilar and mediastinal lymph node recurrences. During the eleventh postoperative year, left and right iliac bone metastases were detected, and radiation therapy was undertaken for local control of these lesions. When 18F-fluorodeoxyglucose positron emission tomography was performed for evaluation of the disease, tracer accumulation in the upper rectum was seen. Colonoscopic examination of the rectum revealed an intramural mass with central ulceration, and the mass was diagnosed histologically as an adenocarcinoma. The bone metastases appeared to be controlled, and the patient’s performance status was good, but she had suffered constipation for about a year and desired treatment. Thus, laparoscopic low anterior resection was performed. Histopathologic analysis revealed a moderately differentiated adenocarcinoma existing mainly between the submucosa and serosa, and immunohistochemical analysis showed the tumor to be positive for cytokeratin (CK) 7, negative for CK20, positive for thyroid transcription factor-1, and negative for special AT-rich sequence-binding protein 2 and caudal type homeobox 2, confirming the diagnosis of rectal metastasis from the primary pulmonary adenocarcinoma. The patient recovered well without any change in her functional status. Systemic chemotherapy was resumed, and she continues to do well, now 6 months after surgery.ConclusionsSurgery may be a good option for the management of an isolated rectal metastasis from pulmonary cancer in patients whose functional status is good.

CDX2 Protein Expression in Colorectal Cancer and ItsCorrelation with Clinical and Pathological Characteristics, Prognosis, and Survival Rate of Patients.

Caudal-type homeobox transcription factor 2 (CDX2) is expressed in the nucleus of the intestinal epithelial cells and is essential for embryonic formation and differentiation of the intestine, whose reduced expression can result in metastatic tumors. This study was to investigate the association of CDX2 expression level in colorectal cancer (CRC) with age, gender, microscopic histopathology, tumor staging, tumor grading, 3-year survival rate, and prognosis. After preparing paraffin tissue blocks, CDX2 protein expression was assayed by immunohistochemistry in 82 CRC patients. Hematoxylin and eosin staining was used to detect tumor histology, tumor grading, tumor staging, and blood-lymphatic, and neural invasion. The collected data includes age, gender, tumor site, and 3-year survival rate of patients after diagnosis. The CDX2 expression was significantly higher in men than in women, and it was significantly lower in right-sided tumors as in transverse colon and left-sided tumors. Also, the CDX2 expression was significantly higher in adenocarcinoma than in mucinous. In addition, a significant correlation was found between downregulated CDX2 and lymph node involvement. In tumor grading, there was a significant correlation between CDX2 downregulation and high-grade tumor. Moreover, there was a significant correlation between downregulated CDX2 expression and overall pathological staging. The downregulated CDX2 expression is associated with female gender, right-sided tumors, mucinous tumors, lymph node involvement, high-grade tumor, and advanced overall pathological staging and can be considered as a possible prognostic factor for patients follow-up. However, our study is a preliminary study and further studies with larger sample sizes in different ethnic groups are required.

Curcumin Inhibits Cell Viability and Increases Apoptosis of SW620 Human Colon Adenocarcinoma Cells via the Caudal Type Homeobox-2 (CDX2)/Wnt/β-Catenin Pathway.

BackgroundCurcumin is a polyphenol compound extracted from the root of the herb Curcuma longa, which is used in traditional Chinese medicine (TCM). Worldwide, colorectal carcinoma (CRC) is an increasing cause of morbidity and mortality. This study aimed to investigate the effects of increasing concentrations of curcumin on cell viability, proliferation, and apoptosis of SW620 human colonic adenocarcinoma cells cultured in vitro, and the signaling pathways involved.Material/MethodsSW620 human colonic adenocarcinoma cells were cultured in curcumin at concentrations of 0, 4, 8, 16, and 32 μmol/l for 48 hours. Specific small interfering RNA (siRNA) was transfected into SW620 cells to silence the expression of caudal type homeobox-2 (CDX2). Cell viability was measured using the MTT assay. Flow cytometry evaluated cell apoptosis. Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR) were used to assess the nuclear translocation of β-catenin and the activation of Wnt signaling.ResultsCurcumin reduced cell viability and increased apoptosis of SW620 human colonic adenocarcinoma cells in a dose-dependent way, and increased the expression of CDX2 but decreased β-catenin nuclear translocation and the expression of Wnt3a, c-Myc, survivin, and cyclin D1. CDX2 silencing significantly reduced the effects of curcumin on SW620 human colonic adenocarcinoma cells. The nuclear translocation of β-catenin, and expression levels of Wnt3a, c-Myc, survivin, and cyclin D1 were significantly higher in CDX2-silenced SW620 cells.ConclusionsCurcumin reduced cell viability and increased apoptosis in SW620 human colonic adenocarcinoma cells by restoring CDX2, which inhibited the Wnt/β-catenin signaling pathway.

557P - Loss of CDX-2 expression is an independent poor prognostic biomarker in colorectal cancer

BackgroundLoss of caudal-type homeobox transcription factor-2 (CDX-2) expression in colorectal cancers (CRC) has recently been proposed as a predictive biomarker for response to chemotherapy and also prognosis. However, the data on relationship between alterations in CDX-2 expression and clinicopathological variables remain limited. We herein aimed to investigate the clinicopathological factors and prognostic implications associated with loss of CDX-2 expression in CRC patients. MethodsImmunohistochemistry for CDX-2 expression was performed on formalin-fixed, paraffin-embedded tissue samples from 427 patients with CRC. Correlation between CDX-2 expression and clinicopathological characteristics were evaluated. Univariate and multivariate survival analyses were performed to reveal the prognostic value of loss of CDX-2 expression. ResultsOf 427 patients, 85% were stage I-III. Seventy six percent had left-sided primary tumors. Deficient mismatch repair (dMMR) was found in 12%. CDX-2-negative expression was identified in 18 out of 427 (4.2%) patients. Loss of CDX-2 expression was more commonly found in patient with right-sided tumors rather than left-sided tumors (9.4% vs 2.8% respectively, p=0.005) and dMMR compared to proficient MMR (11.5% vs 3.3% respectively, p=0.006). There was no association between CDX-2 expression and sex, stage, histologic subtype, tumor differentiation and lymphovascular/perineural invasion. By univariate analysis, patients with CDX-2 loss of expression had significantly worse overall survival (OS) and disease free survival (DFS) than those with CDX-2 positive expression (median OS 1.6 vs 11.6 months (mo), p<0.001; median DFS 1.33mo vs NR, p=0.003). By multivariate analysis, loss of CDX-2 expression remained a negative prognostic factor for OS (hazard ratio 2.32; 95%CI 1.25-4.28, p=0.007). ConclusionsLoss of CDX-2 expression was associated with right-sided tumor and dMMR status. Moreover, loss of CDX-2 expression is a poor prognostic factor for OS, even among patients with dMMR tumors. Legal entity responsible for the studyThe authors. FundingFaculty of Medicine Siriraj Hospital. DisclosureAll authors have declared no conflicts of interest.