جستجوی مقالات مرتبط با کلیدواژه « Oct4 » در نشریات گروه « پزشکی »

Cancer stem cells are a subpopulation of tumor cells with self-renewal capacity that promote tumorigenesis, resistance to chemotherapy, and metastasis. Sox2, Oct4, and Nanog are three pluripotent transcription factors expressed in embryonic stem cells and cancer stem cells. This study aimed to evaluate the expression of Sox2, Nanog, and Oct4, and analyze their clinical significance in human non-small-cell lung cancer (NSCLC). Expression of Sox2, Nanog, and Oct4 was assayed in cancer tissues and their corresponding paracancerous tissues from 30 patients with NSCLC. RT-PCR was used to analyze the expression of these genes. The correlation between the expression of these three genes and clinical parameters including disease stage, smoking, lymph node, and cancer subgroups (adenocarcinoma and squamous) were analyzed. All three genes were expressed simultaneously in 76.6% of tumor samples. A significant correlation was observed between the expression of Sox2, Nanog, and Oct4 in the cancer tissues in comparison to the paracancerous tissues (P<0.000). Expression of Sox2 and Oct4 gene had a positive correlation with the stage of cancer (Sox2 P=0.01, Oct4 P=0.0007), while the expression profile of Nanog showed a significant positive correlation with sex (P=0.0063), smoking (P=0.0253), tumor stages (P=0.0003), and tumor type (P=0.0085). Evaluating the expression of Sox2, Nanog, and Oct4 genes in NSCLC might have some implications for diagnosis and prognosis; they might be also promising treatment targets. The correlations between prognosis and pathological features and Nanog overexpression in NSCLC suggest Nanog is a potential indicator of the early stage of NSCLC.

So far, many studies have been conducted on the importance of expressing different genes in humans and zebrafish. In this regard, the expression of OCT4, HOX and SOX genes as influential genes in the embryonic period is very thought-provoking. At different embryonic stages, including morula, middle blastula, gastrula, and segmentation, the expression of these genes is very important in the growth, immunity, tissue repair, and viability of different cells. The aim of this study was to investigate the expression of common genes between humans and zebrafish in the embryonic period and their efficiency in different parts of the body.

Over 90% of oral cancers including oral squamous cell carcinoma (OSCC), originate from the oral cavity epithelium. Early detection for this lesion is as important. Evaluating cancer stem cell markers can improve the accuracy of early diagnosis, and be used as an OSCC prognostic indicator. We aimed to evaluate SOX2 and OCT4 gene expression among different grades of OSCC and oral epithelial dysplasia (OED) lesions.

Sixty samples that contains 45 OSCC and 15 OED samples were retrieved from the pathology department archives at the dental school of Mashhad. Demographic and pathological patient data including the tumor stage and tumor grade were assessed. Finally, SOX2 and OCT4 expression was examined using qRT-PCR.

There was a significant difference in SOX2 and OCT4 expression between OSCC and OED samples (p< 0.001). The mean expression of SOX2 and OCT4 in OSCC samples were significantly higher than in the OED group (p< 0.001). The mean expression of SOX2 and OCT4 was higher in grade II and grade III OSCC compared to grade I. There was no significant relationship between the gene expression of SOX2 or OCT4 to the demographic, site and stage of tumors. The correlation between SOX2 and OCT4 expression (p= 0.001) was significant in grade III OSCC specimens compared to other grades (p= 0.005, r= 0.68).

The increased expression of SOX2 and OCT4 in higher grades and the significant correlation of these genes with each other among OSCC specimens could suggest the role of SOX2 or OCT4 in oral mucosal carcinogenesis.

Vitrification is increasingly used in assisted reproductive technology (ART) laboratories worldwide. In this study the effect of vitrification on the expression and modifications of H3 histones of Igf2 and Oct4 was investigated in blastocysts cultured from vitrified and non-vitrified two-cell embryos.
In this experimental study, two-cell embryos were cultured in KSOM medium to reach the blastocyst stage. Expression of Igf2 and Oct4 and modifications of H3 histones in regulatory regions of both genes were compared with in vivo blastocysts, which comprise the control group. To gene expression evaluation, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and the ChIP assay method were carried out to assess expression and histone modifications of the two genes.
The expression level of Igf2 was significantly higher in both experimental groups than the control group. In the regulatory region of Igf2, H3K9 methylation decreased whereas H3K9 acetylation increased in the experimental group compared with the control group. In contrast, the expression level of Oct4 was significantly lower in experimental groups. The Oct4 gene promoter showed a significant increase in H3K9 methylation and decrease in H3K9 acetylation (P According to our results, both vitrification and cultivation conditions may lead to changes in expression level and modification of histones in Igf2 and Oct4. However, these effects were the same in vitrified and non-vitrified groups. Indeed, the embryo is most affected by culture environment and in vitro culture. Therefore, vitrification may be used as a low-risk technique for embryo cryopreservation in ART.

Acorus calamus (A. calamus) has been used as a medicinal plant in Asia for its effects on digestive system for the last 2000 years. To investigate the anti-cancer activity of rhizome of A. calamus, the ethanolic and methanolic extracts and essential oil of the rhizome were prepared and their effects were assessed on human gastric cancer cell line (AGS).
The viability of cells which were treated with the extracts and the essential oil was assessed by MTT assay. To evaluate the anti-angiogenic property of the extracts, in vitro tube formation assay was done. Cell cycle distribution and the expression of Oct4 and Nucleostemin, after treatments, were checked by flowcytometry and quantitative RT-PCR, respectively. Furthermore, analysis of essential oil from A.calamus was done by GC-MS.
Our results showed that the growth of AGS cells was inhibited by the extracts and essential oil and the extracts inhibited the angiogenesis in HUVEC cells. Our data revealed that the extracts and essential oil of A. calamus caused G1 arrest in AGS cells and downregulation of Oct4 and NS after treatment. By GC-MS analysis, we found new compoundssuch as epiprezizaene, valencene and isocyclocitral in essential oil of A.
All together, our results showed that the extracts of A. calamus have anti-proliferative and anti-angiogenic effects on cancer cells.

Cancer stem cells have been isolated and characterized in all common cancers. SOX2 and OCT4 are important genes to enhance the self-renewal ability as activate stem cells and inhibit the genes that start differentiation and thus maintain the self-renewal ability of stem cells. Also, the aim of this study is "Comparison of gene expression of SOX2 and OCT4 in normal tissue, polyps, and colon adenocarcinoma using immunohistochemical staining."

This cross-sectional study conducted on 20 patients so that for each patient, a sample of healthy tissue, dysplastic polyp tissue, and colon adenocarcinoma were provided as microscopic sections and staining on each tissue was performed through immunohistochemistry method by markers OCT4 and SOX2. The collected data were interred into SPSS version 18.0, (SPSS Inc., Chicago, IL, USA) software and the level of significance were considered as <0.05.

The study sample consisted of 20 patients including 11 men (55%) and 9 women (45%) with a mean age of 55.6 ± 9.88 years. There was no association between Oct4 and colorectal cancer (CRC) patients (P > 0.05), but there was a significant correlation between Sox2 expression and CRC (P < 0.05). Patients in many aspects such as race, type of polyp, presence of lymph node, grade and intensity of Sox2 in different types of patients' tissues (P < 0.05).

Regarding our findings, the expression of Sox2 would be a liable marker for evaluating of cancer progression and could be a treatment target of CRC cells.

Every cell type is characterized by a specific transcriptional profile together with a unique epigenetic landscape. Reprogramming factors such as Oct4, Klf4, Sox2 and c-Myc enable somatic cells to change their transcriptional profile and convert them to pluripotent cells. Small molecules such as BIX-01294, Bay K8644, RG-108 and valproic acid (VPA) are reported as effective molecules for enhancing induction of pluripotency in vitro, however, their effects during in vivo reprogramming are addressed in this experimental study. In this experimental study, Oct4 expressing lentiviral particles and small molecules BIX-01294, Bay K8644 and RG-108 were injected into the right ventricle of mice brain and VPA was systematically administered as oral gavages. Animals treated with different combinations of small molecules for 7 or 14 days in concomitant with Oct4 exogenous expression were compared for expression of pluripotency markers. Total RNA was isolated from the rims of the injected ventricle and quantitative polymerase chain reaction (PCR) was performed to evaluate the expression of endogenous Oct4, Nanog, c-Myc, klf4 and Sox2 as pluripotency markers, and Pax6 and Sox1 as neural stem cell (NSC) markers. Results showed that Oct4 exogenous expression for 7 days induced pluripotency slightly as it was detected by significant enhancement in expression of Nanog (p<0.05). Combinatorial administration of Oct4 expressing vector and BIX-01294, Bay K8644 and RG-108 did not affect the expression of pluripotency and NSC markers, but VPA treatment along with Oct4 exogenous expression induced Nanog, Klf4 and c-Myc (p<0.001). VPA treatment before the induction of exogenous Oct4 was more effective and significantly increased the expression of endogenous Oct4, Nanog, Klf4, c-Myc (p<0.01), Pax6 and Sox1 (p<0.001). These results suggest VPA as the best enhancer of pluripotency among the chemicals tested, especially when applied prior to pluripotency induction by Oct4.

OCT4 is a transcription factor required for pluripotency during early embryogenesis and the maintenance of identity of embryonic stem cells and pluripotent cells. Therefore, the effective expression regulation of this gene is highly critical. UTR regions are of great significance to gene regulation. In this study, we aimed to investigate the potential regulatory role played by 5´UTR and 3´UTR of the Oct4 gene in mouse BMSC and P19 cells. The Oct4 5´UTR and 3´UTR sequences were cloned into pGL3 luciferase plasmid which led to the generation of pGL3 5´-UTR, pGL3 5´&3´-UTRs and pGL3 3´-UTR vectors. The vectors were transfected into BMSC and P19 cells followed by luciferase assay. The assay of luciferase expression exhibited a direct link between the presence of Oct4 3´- UTR and the decrease of luciferase count in both cell lines; whereas 5´UTR indicated diverse behaviors in two cells. This discrepancy could be explained in view of the difference of cellular contexts in which the Oct4 UTRs act. This study sheds some light on the role of UTR regions of mouse Oct4 in regulating post-transcriptional gene expression in pluripotent cells. These data represent potential to be used for the development of novel therapeutic approaches for a variety of malignancies.

Embryo cryopreservation is the process that water is removed from the cell by cryoprotectant materials, and embryos are stored at temperature below zero. This process may affect the viability and developmental potential of embryos. In this study, the effect of the vitrification cryotop method on the expression level of Oct4 and Mest developmental genes in mouse blastocysts was examined. The collected 2-cell embryos of superovulated mouse by oviduct flushing were divided into non-vitrified and vitrified groups. These embryos were cultured to the blastocyst stage directly in the non-vitrified group and in the vitrified group, these embryos were cultured to 4-8 cell embryos, vitrified with cryotop in these stages and after 2-6 months, warmed and cultured to blastocyst embryos. Quantitative expression of two developmental genes, namely Oct4 and Mest, were performed in these groups, using RNA purification and Real-time RT-PCR. Quantitative PCR analysis showed that the expression level of both genes, Oct4 and Mest, was reduced significantly in the vitrified-warmed group relative to the control group (p=0.046 and p=0.001). This study revealed that morphologically normal embryos show a reduced amount of Oct4 and Mest transcripts which indicate that the vitrification method negatively effects the expression level of these two developmental genes.

The key transcriptional regulator Oct4 is one of the self-renewal and differentiation-related factors in cancer stem cells, where it maintains «stemness» state. Cancer stem cells have been identified in a variety of solid malignancies. They are a small population of tumor cells with stem cell characteristics, which are a likely cause of relapse in cancer patients. Due to high incidence, mortality, and recurrence rates of bladder cancer and the necessity of accurate prediction of malignant behavior of the tumors, we evaluated the prognostic value of Oct4 expression in formalin-fixed paraffin-embedded (FFPE) tissues of bladder cancer. In this study, Oct4 expression was evaluated in 52 (FFPE) tissues of bladder cancer. RNA extraction from samples of 30 patients from the archive of Labbafi-Nejad Medical Centre in Tehran was performed and Oct4 expression levels were examined by semi-quantitative RT-PCR. The intracellular distribution of Oct4 protein was also determined by immunohistochemistry (IHC). The results revealed a significant correlation between the expression level of Oct4 and the tumors’ grade and stage. A mostly cytoplasmic distribution of Oct4 protein was also confirmed by IHC. All together, our data indicate that the expression level of Oct4 gene is correlated with the clinical and histopathological prognostic indexes of tumors and thus can be considered as a potential prognostic tumor marker.