OCT3 and SOX2 promote the transformation of Barrett's esophagus to adenocarcinoma by regulating the formation of tumor stem cells

Establishment of a monoclonal antibody against glycosylated CD271 specific for cancer cells in immunohistochemistry

Various proteins are highly expressed in cancer (e.g., epidermal growth factor receptor); however, the majority are also expressed in normal cells, although they may differ in expression intensity. Recently, we reported that CD271 (nerve growth factor receptor), a glycosylated protein, increases malignant behavior of cancer, particularly stemlike phenotypes in squamous cell carcinoma (SCC). CD271 is expressed in SCC and in normal epithelial basal cells. Glycosylation alterations generally occur in cancer cells; therefore, we attempted to establish a cancer‐specific anti‐glycosylated CD271 antibody. We purified recombinant glycosylated CD271 protein, immunized mice with the protein, and screened hybridomas using an ELISA assay with cancer cell lines. We established a clone G4B1 against CD271 which is glycosylated with O‐glycan and sialic acid. The G4B1 antibody reacted with the CD271 protein expressed in esophageal cancer, but not in normal esophageal basal cells. This specificity was confirmed in hypopharyngeal and cervical cancers. G4B1 antibody recognized the fetal esophageal epithelium and Barrett's esophagus, which possess stem cell–like characteristics. In conclusion, G4B1 antibody could be useful for precise identification of dysplasia and cancer cells in SCC.

The Modes of Dysregulation of the Proto-Oncogene T-Cell Leukemia/Lymphoma 1A

Simple Summary

T-cell leukemia/lymphoma 1A (TCL1A) is a proto-oncogene that is mainly expressed in embryonic and fetal tissues, as well as in some lymphatic cells. It is frequently overexpressed in a variety of T- and B-cell lymphomas and in some solid tumors. In chronic lymphocytic leukemia and in T-prolymphocytic leukemia, TCL1A has been implicated in the pathogenesis of these conditions, and high-level TCL1A expression correlates with more aggressive disease characteristics and poorer patient survival. Despite the modes of TCL1A (dys)regulation still being incompletely understood, there are recent advances in understanding its (post)transcriptional regulation. This review summarizes the current concepts of TCL1A’s multi-faceted modes of regulation. Understanding how TCL1A is deregulated and how this can lead to tumor initiation and sustenance can help in future approaches to interfere in its oncogenic actions.

Abstract

Incomplete biological concepts in lymphoid neoplasms still dictate to a large extent the limited availability of efficient targeted treatments, which entertains the mostly unsatisfactory clinical outcomes. Aberrant expression of the embryonal and lymphatic TCL1 family of oncogenes, i.e., the paradigmatic TCL1A, but also TML1 or MTCP1, is causally implicated in T- and B-lymphocyte transformation. TCL1A also carries prognostic information in these particular T-cell and B-cell tumors. More recently, the TCL1A oncogene has been observed also in epithelial tumors as part of oncofetal stemness signatures. Although the concepts on the modes of TCL1A dysregulation in lymphatic neoplasms and solid tumors are still incomplete, there are recent advances in defining the mechanisms of its (de)regulation. This review presents a comprehensive overview of TCL1A expression in tumors and the current understanding of its (dys)regulation via genomic aberrations, epigenetic modifications, or deregulation of TCL1A-targeting micro RNAs. We also summarize triggers that act through such transcriptional and translational regulation, i.e., altered signals by the tumor microenvironment. A refined mechanistic understanding of these modes of dysregulations together with improved concepts of TCL1A-associated malignant transformation can benefit future approaches to specifically interfere in TCL1A-initiated or -driven tumorigenesis.

Stem cell autocrine CXCL12/CXCR4 stimulates invasion and metastasis of esophageal cancer

Esophageal cancer is one of the most common malignant tumors of the digestive tract. The greatest obstacle to the curing of esophageal cancer is its propensity to spread and metastasize. Esophageal cancer stem cells are considered the source for recurrence and metastasis of the tumors. While clinical evidence suggested that continuous up-regulation of CXCL12/CXCR4 was significantly associated with poor prognosis in patients with esophageal cancer, but the role and mechanism of CXCL12/CXCR4 in the invasion and metastasis of esophageal cancer has not been reported by far. This study found that esophageal cancer stem cells not only autocrine a great amount of CXCL12, but also high expression of its corresponding receptor CXCR4. Most importantly, the ability of esophageal cancer stem cells to spread and metastasize could be inhibited by blockage of CXCR4 with inhibitors or shRNA approaches both in vivo and in vitro studies. The important role of CXCL12 in the invasion and metastasis of esophageal cancer stem cells was also confirmed by loss-of-function and gain-of-function strategies. Mechanistically, we demonstrated that CXCL12/CXCR4 activated the ERK1/2 pathway and thereby ultimately maintained the characteristics of high-level invasion and metastasis of esophageal cancer stem cells. Taken together, our findings suggested that autocrine CXCL12/CXCR4 was one of the major mechanisms underlying the metastatic property of esophageal cancer stem cells through ERK1/2 signaling pathway, and might serve as a therapeutic target for esophageal cancer patients.

T-cell leukemia/lymphoma-1A predicts the clinical outcome for patients with stage II/III colorectal cancer

T-cell leukemia/lymphoma-1A (TCL1A) as a stem cell marker is abundantly expressed in embryonic stem cells and has been identified as an oncogene in various hematological malignancies such as chronic lymphocytic leukemia and B-cell lymphoma. However, with regard to its role in solid tumors, few studies are available and less are for colorectal cancer (CRC). In this study, we aim to investigate the expression and clinical significance of TCL1A in a cohort of 278 stage II/III CRC patients. As a result, we find TCL1A expression is higher in CRC tissues than that in adjacent normal tissues, and significantly correlated with tumor differentiation, TNM stage and Ki-67 positive rate. The prognostic analysis suggests that TCL1A expression is an independent factor affecting CRC-specific and disease-free survival of these patients. Furthermore, we find stage II/III patients with high TCL1A expression have a significantly higher rate of postoperative local recurrence and metastasis than those with low TCL1A expression. Finally, through subgroup analysis, we find TCL1A expression can stratify the outcome of stage II/III patients who received standard adjuvant chemotherapy. Taken together, our findings suggest TCL1A is not only a useful biomarker for prognostic evaluation in stage II/III CRC patients, but also a promising therapeutic target for improving their clinical outcome.

Deoxycholic acid (DCA) confers an intestinal phenotype on esophageal squamous epithelium via induction of the stemness-associated reprogramming factors OCT4 and SOX2

Barrett's esophagus (BE) is essentially a metaplasia in which the normal stratified squamous epithelium is replaced by columnar epithelium. This study focuses on the involvement of OCT4 and SOX2, 2 key cell-reprogramming factors, in the deoxycholic acid (DCA)-induced expression of the intestinal hallmarks Cdx2 and MUC2 using both in vivo and in vitro models. Up-regulated expression of OCT4 and down-regulated expression of SOX2 were observed in BE compared with normal esophagus and esophagitis. Consistent with the data in vivo, DCA induced time-dependent expression of OCT4 at both the mRNA and protein levels and decreased nuclear expression of SOX2 in Het-1A cells. Down-regulation of OCT4 expression by siRNA abrogated DCA-induced expression of Cdx2 and MUC2, whereas siRNA against SOX2 significantly upregulated the expression of both Cdx2 and MUC2. Our data indicate that both OCT4 and SOX2 play important roles in the development of BE triggered by bile acid reflux.