OCT‐4, an embryonic stem cell marker, is highly expressed in bladder cancer

Abstract

OCT‐4 (also known as POU5F1) is a key regulator of self‐renewal in embryonic stem cells. Regarding the new cancer stem cell concept, the expression of such genes is potentially correlated with tumorigenesis and can affect some aspects of tumor behavior, such as tumor recurrence or resistance to therapies. Although OCT‐4 has been introduced as a molecular marker for germ cell tumors, little is known about its expression in somatic cancers. Here, we have investigated the potential expression of OCT‐4 in bladder cancer. We used semiquantitative RT‐PCR to examine the expression of OCT‐4 in 32 tumors, 13 apparently nontumor tissues taken from the margin of tumors and 9 normal urothelial tissues. The expression of OCT‐4 at protein level was further determined by Western blotting and immunohistochemical (IHC) analysis. OCT‐4 expression was detected in almost all examined tumors (31/32), but at much lower level (p < 0.001) in some nonneoplastic samples (6/22). A significantly strong correlation of 0.6 has been observed between OCT‐4 expression and the presence of tumors (p < 0.001). Western blot analysis further confirmed the expression of OCT‐4 in tumor biopsies. According to IHC results, OCT‐4 is primarily localized in the nuclei of tumor cells, with no or low immunoreactivity in nontumor cells. Our study demonstrated, for the first time, the expression of OCT‐4 in bladder cancer and a further clue to the involvement of embryonic genes in carcinogenesis. © 2007 Wiley‐Liss, Inc.

Comparative Analysis of Oct4 in Different Histological Subtypes of Esophageal Squamous Cell Carcinomas in Different Clinical Conditions

“…It may also be interpreted that poorly differentiated ESCC exhibiting basaloid character possibly acquires stem cell property identified by Oct4 expression. Similar to the our observation, other groups also documented higher number of basaloid or poorly differentiated carcinoma cells expressing Oct4 in patients who either had residual or recurrent ESCC (Atlasi et al, 2006;Hu et al, 2008;Chen et al, 2009;Koukourakis et al, 2012). Koukourakis et al (2012) and Islam et al (2014) observed high percentages of Oct4 in recurrent oral, head and neck SCC.…”

“…There are two studies (Tai et al, 2005;He et al, 2012) who had reported Oct4 expression by dysplastic and hyperplastic esophageal mucosa confining to the proliferative zone, and not expressed by the normal mucosa. Oct4 positivity is reported in certain adult tissue including benign endometrial stromal cells (Atlasi et al, 2006;Cauffman et al, 2006;Mathai et al, 2006;Katona et al, 2007;Zangrossi et al, 2007;Atlasi et al, 2008;Forte et al, 2009). We observed slightly higher sensitivity by PCR technique than by the conventional immunohistochemistry method in detecting Oct4 expression, which is similar to other reported data (Atlasi et al, 2006;Xi et al, 2011;.…”

“…Oct4 positivity is reported in certain adult tissue including benign endometrial stromal cells (Atlasi et al, 2006;Cauffman et al, 2006;Mathai et al, 2006;Katona et al, 2007;Zangrossi et al, 2007;Atlasi et al, 2008;Forte et al, 2009). We observed slightly higher sensitivity by PCR technique than by the conventional immunohistochemistry method in detecting Oct4 expression, which is similar to other reported data (Atlasi et al, 2006;Xi et al, 2011;. This disparity could be due to the sensitivity of the technique used as PCR is observed to be more sensitive than immunohistochemsitry methods and also Oct4 is known to have two isoforms (Lee et al, 2006).…”

“…Oct4 is a member of POU-domain transcription factors and is expressed normally by pluripotent cells of embryonic tissue (Nichols et al, 1998) and adult stem cells (Niwa et al, 2000;Warthemann et al, 20012). Oct4 has important role in maintenance and controlling of embryonic stem cell pluripotency including childhood germ cell tumors (Jones et al, 2004) and a few adult carcinomas (Atlasi et al, 2006;Cheng et al, 2007; . Hu et al (2008) successfully inhibited tumor growth by decreasing cancer like stem cell population with the help of small interfering RNAs to knock down the Oct4 gene.…”

POU5F1, encoding a key regulator of stem cell pluripotency, is fused to EWSR1 in hidradenoma of the skin and mucoepidermoid carcinoma of the salivary glands

“…POU5F1 reactivation has been found to be implicated in human tumours; aberrant POU5F1 expression was detected in germ cell tumours [36,37] and recently in bladder cancer [38]. Furthermore, ectopic Pou5f1 expression in adult mice resulted in dysplastic growth of epithelial tissues [39].…”