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Background: Embryonic pluripotency markers are recognized for their role in ER− BC aggressiveness, but their significance in ER+ BC remains unclear. This study aims to investigate the prevalence of expression of pluripotency markers in ER+ BC and their effect on survival and prognostic indicators. Methods: We analyzed data of ER+ BC patients from three large cancer datasets to assess the expression of three pluripotency markers (NANOG, SOX‐2, and OCT4), and the stem cell marker ALDH1A1. Additionally, we investigated associations between gene expression, through mRNA‐Seq analysis, and overall survival (OS). The prevalence of mutational variants within these genes was explored. Using immunohistochemistry (IHC), we examined the expression and associations with clinicopathologic prognostic indicators of the four markers in 81 ER+ BC patients. Results: Through computational analysis, NANOG and ALDH1A1 genes were significantly upregulated in ER+ BC compared to ER‐ BC patients (p < 0.001), while POU5F1 (OCT4) was downregulated (p < 0.001). NANOG showed an adverse impact on OS whereas ALDH1A1 was associated with a highly significant improved survival in ER+ BC (p = 4.7e‐6), except for the PR− and HER2+ subgroups. Copy number alterations (CNAs) ranged from 0.4% to 1.6% in these genes, with the highest rate detected in SOX2. In the IHC study, approximately one‐third of tumors showed moderate to strong expression of each of the four markers, with 2–4 markers strongly co‐expressed in 56.8% of cases. OCT‐4 and ALDH1A1 showed a significant association with a high KI‐67 index (p = 0.009 and 0.008, respectively), while SOX2 showed a significant association with perinodal fat invasion (p = 0.017). Conclusion: Pluripotency markers and ALDH1A1 are substantially expressed in ER+ BC tumors with different, yet significant, associations with prognostic and survival outcomes. This study suggests these markers as targets for prospective clinical validation studies of their prognostic value and their possible therapeutic roles. [ABSTRACT FROM AUTHOR]

Testicular germ cell tumours (TGCTs), the most frequent solid tumour of the young men, originate from the primitive germ cells. They share some pluripotency stem-cell markers which may help to distinguish between seminoma, the most frequent TGCTs and non-seminoma tumours, such as embryonal carcinoma, teratocarcinoma or choriocarcinoma. Due probably to the propensity of seminoma to apoptosis, only two cell lines originated from pure testicular seminoma, TCam-2 and JKT-1 have been up to now, established, maintained and proposed as representative models of human testicular seminoma. However, both seem, following recent reports, to be able to drift. Thus, the molecular signature of embryonic stem-cell markers of the JKT-1 cells cultured in our laboratory, were studied by RT-PCR, Western blot and immunofluorescence (IF). JKT-1 cells analysed after 30 passages, expressed placenta alkaline phosphatase but not alphafoetoprotein (αFP) nor beta-human chorionic gonadotropin. JKT-1 cells also expressed markers of pluripotency such as NANOG and OCT3/4 and more specific seminoma markers, such as AP2γ and HIWI. However, protein expression of OCT3/4 and AP2y was weak and these JKT-1 cells expressed SOX2, a marker of embryonal carcinoma and did not express c-KIT usually expressed in most seminoma. Possible derivation through in vitro culture conditions was supported by looking at later passages (61) which showed a decrease of NANOG and HIWI protein expression. JKT-1 cells express a signature of markers which is still near from the one express by seminoma cells, allowing carcinogenetic studies. However, because of their great ability to drift as shown for TCam-2, it is recommended to verify and to precise this molecular signature before reporting functional results. [ABSTRACT FROM AUTHOR]

Embryonic stem (ES) cells are a valuable system to study early development of mammals. A lot of researchers are dedicated to comprehensive study of the ES cells. Today ES cells have been isolated from mice, human and some other mammalian species. A set of the American mink ES cell lines had been isolated from mink morulas and blastocysts in our group. The formation of embryoid bodies and teratomas in athymic mice suggested that these cells are pluripotent. It is known that several transcription factors are essential for the ES cell identity, including two homeodomain proteins, Nanog and Oct-4, and a HMG factor, Sox-2. These factors influence on other transcription factors and control expression of each other establishing regulatory network that maintains ES cell pluripotency and self-renewal. In this study, we analyzed the expression of the Oct-4 and Sox-2 genes in the American mink ES cells and determined their chromosomal localization. First we determined the primary structure of the American mink Oct-4 and Sox-2 gene fragments. Using the Chinese hamster-American mink somatic cell hybrids panel, consisting of 14 clones, we localized Oct-4 and Sox-2 genes to mink chromosomes one and six, respectively, with 100% concordance between the marker and the specific chromosome. To analyze the expression of Oct-4 in the mink ES cell lines (MES-12, MES-12neo and MES-13) we used RT-PCR analysis and immunostaining. Both methods revealed that the ES cells expressed Oct-4. As for Sox-2 with use of RT-PCR we have found the low level of expression in the ES cells. The expression of pluripotency markers confirms the pluripotent capacities of examined ES cells. [ABSTRACT FROM AUTHOR]