OCT4 spliced variant OCT4B1 is expressed in human colorectal cancer

Abstract

OCT4, a POU-domain transcription factor is considered to be a key factor in maintaining the pluripotency of stem cells. Several OCT4 isoforms are differentially expressed in human pluripotent and non-pluripotent cells. Reactivation of OCT4 expression is postulated to occur in differentiated cells that have undergone tumorigenesis. To examine OCT4 expression in colorectal cancer (CRC) tissues, and to assess the efficacy of OCT4 as a potential biomarker for CRC, in this study, we investigated its expression in CRC tissues, evaluated its relationship to various clinicopathological parameters and defined the isoform of OCT4 that was found to be expressed in CRC cases. Primary tumor tissues and matching adjacent non-cancerous tissues were obtained from 84 CRC patients. OCT4 expression and isoform determination were documented by reverse transcription-PCR and real-time PCR. OCT4, Sox-2, and NANOG localization were performed using immunohistochemistry. The isoforms expressed in the studied cases were confirmed by sequencing. Twenty biopsy specimens representing healthy tissues, retrieved from colonoscopy were studied in parallel as controls. OCT4 expression levels were higher in CRC tissues compared to matching, adjacent non-cancerous tissues, and healthy controls. Additionally, the levels of OCT4 expression in CRC tissues correlated with tumor stage. OCT4 and Sox-2 were localized in the nuclei and the cytoplasm of CRC cells. In all CRC cases, we found that the OCT4B1 isoform is expressed. Over-expression of OCT4B1 was found in poorly and moderately differentiated CRC tissues. In conclusion, the data imply that OCT4B1 isoform may represent a potential biomarker for the initiation, progression, and differentiation of CRC.

Nonsyndromic cleft lip with or without cleft palate and cancer: Evaluation of a possible common genetic background through the analysis of GWAS data

“…Notably, the BMP4 pathway is involved in mammalian palatogenesis [71], and mutations in BMP4 have been associated with human NSCL/P [12], [58], [59]. Research has shown that OCT4 is overexpressed in cancer cell lines and in diverse cancer entities [24], [37], [67], suggesting that aberrant transcriptional regulation of OCT4 might be a mechanism in cancer susceptibility. Thus, a plausible hypothesis is that rs6457327 regulates OCT4 expression, and that this regulation is a possible common process in oncogenesis and the development of NSCL/P.…”

Preoperative low dose NSAID treatment influences the genes for stemness, growth, invasion and metastasis in colorectal cancer

“…Overexpression of OCT4B1 has been related to poor prognosis in cancer in several studies. Expression of OCT4B1 was upregulated in CRC tissues, compared to adjacent non-cancerous tissues, which suggested OCT4B1 to represent a potential biomarker for the initiation, progression and differentiation of CRC (26). Like OCT4B1, SOX2 is reported to act as an oncogene, being upregulated in CRC, and in esophageal squamous cell carcinoma, where it correlated to poor clinical outcome (27,28).…”

Suppressive Effect of Crocin and Cisplatin on Pluripotency Genes Expression in Human Cervical Cancer Cells

“…A large amount of data has showed up-regulation of key stemness factors, like Sox2 and Nanog in several types of cancer cells and the importance of targeting these regulators in cancer therapy (2)(3)(4)(5)(6)(7)(8). Sox2 and Nanog are transcription factors that are essential for maintaining self-renewal or pluripotency of undifferentiated embryonic stem cells (17).…”