| Background and aimsOCT-4(octamer binding factor 4) is a transcription factor that is specifically expressed in cells participating in the generation of the germline lineage, which also is a control gene or the transcription factor for an early developmental. Oct4 encoded by the POU5F1 gene.Oct4, also known as OCT3, OTF3, and POU5F1(POU domain, class 5, transcription factor 1), is an 18-kDa POU-domain transcription factor encoded in an open reading frame corresponding to a 324-aminoacid protein, which located on human chromosome 6p21.3.Transcription factors of the POU, as a binding protein, are able to activate genes bearing cis-acting elements containing an Octameric sequence within their promoter and enhancer region to transcription. They bind to the consensus sequence ATGCAAAT. The DNA-binding domain provides for nucleotide sequence-directed localization to target genes, while the regulatory domain interacts with one or more components of the basal transcription complex to mediate activation or repression of gene expression. They role are to maintain the totipotency of the cells.Oct4 is expressed not only in the embryonic stem cell and embryonic germ cell, but also in the embryonal carcinoma and seminomas. Here, we convincingly show that embryonal carcinoma cells, germinomas, testicular CIS, Gonadoblastomas, dysgerminomas, seminoma, and embryonal carcinoma components of both pure and mixed nonseminomas (and representative cell lines) are consistently positive for POU5F1, In contrast, none of the differentiated nonseminomatous derivatives (teratoma, yolk sac tumor, and choriocarcinoma) stained positive.Oct4 expression in human breast weakly tumorigenic and highly tumorigenic cell line, the pancreatic cancer cell lines Capan-2 and Pan-1, and liver cancer cell line Mahlava, as well as the classic cancer cell lines HeLa and MCF-7, all exhibited Oct4 expression. Looijenga et al also find one kidney carcinoma and two lung carcinomas (1 of 50 squamous and 1 of 47 large cell carcinomas analyzed), the pancreatic cancers in the hamster, the poorly differentiated (insular) carcinoma of the thyroid gland exhibited Oct4 expression. Be similar to the embryonal carcinoma cells and germinomas, Oct4 also down-regulation in the differentiated components of the tumors from adult tissues. HeLa and MCF-7 cells exhibited heterogeneous expression of Oct4. It was noticed that when these two classic cancer cell lines were grown in the medium induced some differentiation of the cells, thereby reducing expression of Oct4.Nowadays, the study of Oct4 expression in tumor from adult tissues is fewer than in the embryonal carcinoma cells and germinomas. Except the classic cell lines of adult tissues exhibit Oct4 expression, other tumors from adult tissues have the lower expression ratio of Oct4. Moreover, not all the tumors from adult tissues have reported exhibit Oct4 expression. So we want to find if all the tumors from adult tissues have Oct4 expression, and then find the regularity of Oct4 expression in them. Finally, we hope to find if the tumor cells expression Oct4 have relationship with the tumor stem cells. If the cells expression Oct4 are tumor stem cells, we could find the other way to eliminate the cancer completely.Urinary bladder cancer ranks 5th cancer among cancers in men and women, and ranks 2nd cancer result in patients to die among all the cancers in genitourinary tract. In china, urinary bladder cancer is the highest disease incidence of cancer invades the urinary tract, which is about 20 percentages incidence rate in all the tumors. Recently, urinary bladder cancer has the higher disease incidence than past, and also has the higher recurrence rate and easy to get acquired drug-resistance.The pathogenesis and the specical tumor marker of urinary bladder cancer are still uncertainty. Oct4 is considered as a marker of the totipotent stem cells or pluripotent stem cells, which expresses in the minority tumors from adult tissues. So it maybe also expresses in the urinary bladder cancer. If high recurrence rate of bladder cancer is relationship with the Oct4? Moreover, the Oct4 expression-cells are tumor stem cells? These questions need to resolve. Because the transitional cell carcinoma of the bladder are the majority of the bladder cancers, the investigations only for the transitional cell carcinoma of the bladder can help us to understand the most parts of the bladder cancer. So this study is a basic investigation to search weather the transitional cell carcinoma of the bladder exhibit Oct4 expression or not. If exhibit the Oct4 expression, next we would find how the Oct4 expression in the transitional cell carcinoma of the bladder and what the relation of the Oct4 with the malignancy of the tumor. And then we want to find the treatment to cure the transitional cell carcinoma of the bladder.Materials and MethodsMaterialsFrom July 2002 to December 2005, a total of 46 cases(34 males and 12 females, age from 30 to 84) carcinoma of urinary bladder and 2 cases atypical hyperplasia(males, age is 48 and 50) were collected from Henan Province, which was located in the mid part of China and the largest population of hinterland province. At the same time, nineteen samples of marginal tissue of tumor, fifteen cases normal mucous membrane of urinary bladder were collected for contrast. All the patients were the first found the cancer, which were not accepted Chemotherapy and radiotherapy treatment. Only 3 cases infiltrate into the muscle in all the cancer, but none of them have metastasized to other tissues. According to the standard of pathology-classify of WTO, all the cancers was divided into 5 groups. Seven cases are grade I of transitional cell carcinoma of the bladder, twenty cases are grade II, 10cases are grade III, 1 case is adencarcinoma, 1 case is mixed carcinoma.MethodsSections cut at 4-μm thickness were stained with hematoxylin and eosin. The sections were obtained and deparaffinized for immunohistochemical studies. Antigen retrieval was carried out by heating sections in natrium citricum buffer solution of natrium citricum (pH 8.0) for 30 minutes. The endogenous peroxidase was blocked by 3% H2O2 in methanol for 15 minutes. Protein block was applied for 20 minutes for blocking of nonspecific background staining. A polyclonal goat anti-Oct4 antibody (Santa Cruz Biotechnology, Santa Cruz, CA), raised against the 2COOH terminus of the protein was used. The primary antibody was diluted (1:500) and incubated for 30 minutes at room temperature. The second antibody was used for 30 minutes at room temperature. And then, use DAB to colour and fix.Access the stain of cellsThe cell nucleus of positive cells was dyed into brown. We choose 10 high power fields to calculate the percentage of the positive cells. If the positive cells more than 75 percentages of the 10 high power fields were calculated 3 scores, if more than 50 percentages but less than 75 percentages were calculated 3 scores, if more than 5 percentages but less than 50 percentages were calculated 2 scores, and if less than 5 percentages were calculated 0 score. The strong stain of positive cells were calculated 3 scores, the midrange stain were calculated 2 scores and the weakly stain were calculated 1 score. Then, we use the scores of the stain area to multiplied by the scores of the stain intensity. If the scores get from them are equal to 0, the cancer should think negative, if equal to 1 or 2, the cancer should think weakly positive, if equal to 3 or 4, the cancer should think midrange positive, and if equal to from 6 to 9, the cancer should think strong positive.Statistical analysisStatistical analysis was carried out using the Statistical Package for Social Sciences (SPSS), version 10.0 for windows. The Chi-square test and Fisher's Exact Test was used to test the stain of Oct4. P-values <0.05 were considered to be statistically significant.Result1. Oct4 is expression in the bladder cancer, which expresses in the transitional cell carcinoma, adenocarcinoma and mixed carcinoma. The positive expression of the transitional cell carcinoma is 63.6% (28/44), but no expression in the atypical hyperplasia and normal mucous membrane of urinary bladder (P<0.05).2. The differentiation of the cancer is associated with expression and stain of Oct4 in bladder cancer. The poorly differentiated bladder cancers have higher expression and stronger stain of Oct4 than the well-differentiated (100% vs. 14.3%). The percentages of Oct4 expression in grade I, II and III of the transitional cell carcinoma are 14.3%, 63% and 100%, separately. The expression and stain of Oct4 in different grade of the transitional cell carcinoma have the statistical significance (p<0.05).3. The strong positive staining of Oct4 in the poorly differentiated transitional cell carcinoma of the bladder is significantly stronger than the well-differentiated (80% vs 14.3%). The percentages of strong expression of Oct4 in grade I, II and III of the transitional cell carcinoma are 14.3%, 33% and 80%, separately. The expression and stain of Oct4 in different grade of the transitional cell carcinoma also have the statistical significance (p<0.05).Conclusion1. Oct4 has the relationship with transitional cell carcinoma of the bladder, which maybe as a mark for searching for the carcinogenesis of the transitional cell carcinoma of the bladder and also as a mark for diagnosis the transitional cell carcinoma of the bladder.2. The study suggests expression and the expression extent of Oct4 are associated with the malignancy of the transitional cell carcinoma of the bladder. The higher expression of Oct4 in the bladder cancer maybe reveals the more malignancy of the bladder cancer. As well as, Oct4 has the stronger stain extent and more positive tumor cells in the malignant tumors.In all, from the above conclusion we can get imply that Oct4 expressing in the bladder cancer is associated with the malignancy of the bladder cancer. So if we would find the Oct4-expressing cells in the bladder cancer, which would be help for treatment and prognosis of transitional cell carcinoma of the bladder.3. Oct4 also expresses in the adencarcinoma and mixed carcinoma of the bladder cancer. which maybe also as a mark for searching for the carcinogenesis and as a mark for diagnosis the adencarcinoma and mixed carcinoma of the bladder cancer.4. The Oct4-expressing cells in the transitional cell carcinoma of the bladder maybe the tumor stem cells of the transitional cell carcinoma of the bladder. If this hypothesis is correct, we should treatment the bladder cancer with different way dependent on weather has expression of Oct4 or not. |
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