Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0596263 (carcinogenesis)
 64,820 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We examined the effect of S-allylcysteine (SAC), a water-soluble garlic constituent, on cytokeratin expression, a sensitive and specific marker for differentiation status during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis in male Syrian hamsters. Hamsters were divided into four groups of six animals each. Animals in group 1 were painted with a 0.5% solution of DMBA in liquid paraffin on the right buccal pouches three times a week for 14 weeks. Group 2 animals were painted with DMBA as in group I, and in addition they received orally 200 mg/kg of SAC on days alternate to DMBA application. Group 3 animals received SAC as in group 2. Group 4 animals received neither DMBA nor SAC and served as the control. The hamsters were killed after an experimental period of 14 weeks. Cytokeratin expression was detected by Western blot analysis using monoclonal antibodies AE1 and AE3. In DMBA-induced HBP tumors, the decreased expression of high molecular weight cytokeratins of molecular mass between 55-70 kDa was observed. Administration of SAC (200 mg/kg) to animals painted with DMBA suppressed the incidence of DMBA-induced carcinomas and was associated with restoration of normal cytokeratin expression. The results of the present study suggest that inhibition of HBP tumorigenesis by SAC may be due to its regulatory effects on differentiation, tumor invasiveness, and its ability to migrate and form metastases.
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PMID:Altered cytokeratin expression during chemoprevention of hamster buccal pouch carcinogenesis by S-allylcysteine. 1470 76

In a process seeking out a good model cell line for Epstein-Barr virus (EBV)-associated gastric cancer, we found that one previously established gastric adenocarcinoma cell line is infected with type 1 EBV. This SNU-719 cell line from a Korean patient expressed cytokeratin without CD19 or CD21 expression. In SNU-719, EBNA1 and LMP2A were expressed, while LMP1 and EBNA2 were not. None of the tested lytic EBV proteins were detected in this cell line unless stimulated with phorbol ester. EBV infection was also shown in the original carcinoma tissue of SNU-719 cell line. Our results support the possibility of a CD21-independent EBV infection of gastric epithelial cells in vivo. As the latent EBV gene expression pattern of SNU-719 closely resembles that of the EBV-associated gastric cancer, this naturally derived cell line may serve as a valuable model system to clarify the precise role of EBV in gastric carcinogenesis.
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PMID:A naturally derived gastric cancer cell line shows latency I Epstein-Barr virus infection closely resembling EBV-associated gastric cancer. 1501 54

In order to evaluate the significance of altered expression of mucin and cytokeratin during gallbladder carcinogenesis, we characterized the expressional profiles of MUC1, MUC2, MUC5AC, MUC6, CK7 and CK20 in 33 normal mucosa, 31 adenomas, 55 dysplasias and 131 carcinomas of the gallbladder. In normal gallbladder mucosa, the expressions of MUC5AC and MUC6 were diffuse and MUC1 expression was absent. However, in adenomas, dysplasias and carcinomas, the expressions of MUC5AC and MUC6 tended to decrease, whereas MUC1 expression was elevated. MUC2 and CK20 were infrequently expressed in all of the gallbladder epithelia, but adenomas expressing MUC2 and/or CK20 were more frequently associated with carcinomas and showed a higher grade of atypia than those without these antigens. In carcinomas, MUC1 expression was related to invasive growth, lymph node metastasis and a non-papillotubular type, whereas MUC6 expression was related to non-invasive growth. CK7 was diffusely expressed in almost all lesions, but carcinomas with a loss of CK7 expression showed poor survival. In conclusion, normal gallbladder mucosa has a gastric phenotype, but during carcinogenesis and tumor progression, the gastric phenotype is gradually lost and the aberrant expression of MUC1 occurs. The intestinal phenotype is not common in the gallbladder.
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PMID:Phenotypic alterations of mucins and cytokeratins during gallbladder carcinogenesis. 1526 Aug 48

Understanding of molecular genetic mechanisms underlying prostate carcinogenesis would be greatly advanced by in vitro models of prostate tumors representing primary tumors. We have successfully established a neoplastic immortalized human prostate epithelial (HPE) clonal culture derived from a primary tumor of a prostate cancer patient (RC-58T) with hTERT, the catalytic subunit of telomerase. The early passage RC-58T cells derived from a radical prostatectomy specimen of a 52-year-old white male patient was transduced through infection with a retrovirus vector expressing the hTERT for the establishment of the RC-58T/hTERT cell line. One clonal line, soft-agar derived from the RC-58T/hTERT cell line, was isolated and further characterized phenotypically and genetically. These clonal (RC-58T/hTERT SA#4) cells are currently growing well at passage 70 and exhibit transformed morphology. The RC-58T/hTERT SA#4 line expressed a high level of telomerase activity and showed anchorage-independent growth in soft agar. The clonal line like the untransduced RC-58T cells (passage 3) expressed prostate specific antigen (PSA), androgen receptor (AR), prostate stem cell antigen (PSCA), and an androgen-regulated prostate specific gene NKX3.1, P16, and cytokeratin (CK) 8. Growth is slightly stimulated by dihydrotestosterone (DHT), and lyates are immunoreactive with AR antibody by Western blot analysis. More importantly, this clonal line produced adenocarcinomas when transplanted into SCID mice. A number of chromosome alterations were observed including the loss of chromosome Y, 1q, 2p, 3p, 4q, 8p, 11p, 14p, 17p and 18q. Our results demonstrate that this primary tumor-derived HPE cell line retained its neoplastic phenotypes and its prostate specific markers and should allow elucidating molecular and genetic alterations involved in prostate cancer. This is the first documented case of an AR and PSA expressing telomerase established human prostate cancer cell line with neoplastic phenotypes from a primary tumor of a prostate cancer patient.
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PMID:A telomerase-immortalized primary human prostate cancer clonal cell line with neoplastic phenotypes. 1537 56

Squamous cell carcinoma (SCC) is the most common form of oral malignancy and is often preceded by premalignant lesions, some of which are more likely to progress to carcinoma than others. In this study, a panel of monoclonal antibodies (AE1/AE3, cytokeratin [CK] 14, Ki-67 and p53) is applied to 10 cases of human oral tissue in each of six categories to establish staining patterns indicative of which lesions are more likely to progress to malignancy. The six tissue categories are normal tissue; abnormal benign lesions; mild, moderate and severe dysplasia; and SCC. A statistical analysis of Ki-67 and p53 immunoexpression is performed. The results showed that AE1/AE3 and CK 14 expression was reduced as a late event in oral carcinogenesis, particularly in poorly differentiated SCC. Expression of Ki-67 and p53 proved to be a weak but statistically significant predictor of malignant progression in oral tissue.
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PMID:Immunocytochemical analysis of AE1/AE3, CK 14, Ki-67 and p53 expression in benign, premalignant and malignant oral tissue to establish putative markers for progression of oral carcinoma. 1546 55

Human ovarian cancer is predominantly of epithelial cell origin (>90% of malignant tumors) and most often presents at an advanced stage with poor prognosis. Most animal models of ovarian carcinoma yield thecal/granulosa cell tumors, rather than adenocarcinomas. Induction of adenocarcinoma in 10-45% of rats following an ovarian implantation of 7,12-dimethylbenz[a]anthracene (DMBA) coated silk suture has been reported. Here, DMBA of 99% purity was melted at 124 degrees C to impregnate a 1 cm length of sterile suture for direct ovarian implantation in Wistar Furth rats at 7 weeks of age. DMBA-treated ovaries showed a nearly complete loss of primary follicles and degeneration of granulosa cells at 16 weeks, consistent with the known toxic response of the ovary to direct DMBA application. No tumors were present. Untreated right ovaries and sham dimethyl sulfoxide-treated ovaries were normal. Ovarian tumors in DMBA-treated rats were first noted at 26 weeks post implantation reaching a cumulative tumor incidence of 77% (23/30) at 52 weeks. Controls showed no evidence of tumor at 52 weeks (0/31). Tumor histology was distributed as well differentiated adenocarcinoma (1/23), poorly differentiated adenocarcinoma (8/23), thecal/granulosa cell tumor (8/23), undifferentiated sarcoma (5/23) and one undifferentiated carcinoma with no adeno character. Tumors occasionally seeded to peritoneal mesentery, spleen and abdominal wall. Adenocarcinomas appeared to originate from the ovarian surface epithelium, with focal papillary extension into cystic space. Epithelial derived tumor cells positively react with antibodies to cytokeratin (8/8), epithelial cell adhesion molecule (Ep-CAM 5/5) and prostaglandin synthetase-1 (COX-1 4/4). Vimentin positive epithelial cells when present in adenocarcinomas (4/7), showed perinuclear staining, quite distinct from the uniformly stained stromal cells in thecal/granulosa cell tumors (8/8). The thecal/granulosa cell tumors were Ep-CAM negative (0/5) and weakly COX-1 positive (4/4). Thus, the DMBA suture model in rats yields epithelial derived tumors histologically similar to humans and should prove suitable for the testing of preventive or therapeutic agents.
Carcinogenesis 2005 May
PMID:Characterization of rat ovarian adenocarcinomas developed in response to direct instillation of 7,12-dimethylbenz[a]anthracene (DMBA) coated suture. 1569 34

The ability to use archival tissue to test externally valid hypotheses of carcinogenesis is dependent on the availability of population-based samples of cancer tissue. Tissue microarrays (TMAs) provide an efficient format for developing population-based samples of tissue. A TMA was constructed consisting of archival tissue from patients diagnosed with invasive colorectal cancer in the state of Hawaii in 1995. The population representativeness of the TMA was evaluated by comparing patient and clinical characteristics of TMA cases to that of all cases of colorectal carcinoma diagnosed statewide in 1995. Cytokeratin 20 (CK20) and cytokeratin 7 (CK7) immunohistochemistry was used to validate the utility of the TMA, and the expression of these proteins was correlated with patient and tumor characteristics. The TMA comprised tissue specimens from 286 patients representing 47% of all invasive cases diagnosed statewide in 1995. TMA cases were comparable to all invasive colorectal cases statewide with respect to age, sex, race/ethnicity, anatomic site, and survival. There were some differences between TMA cases and all cases with respect to tumor stage, histological classification, and treatment. There were significant differences in the relative expression of CK20 and CK7 proteins between malignant and normal tissues and by tumor stage. Advanced cancers were more likely to have CK20+/cytokeratin 7+ (CK7+) profiles than early-stage cancers, which were predominantly CK20+/cytokeratin 7- (CK7-). CK7+ expression was not correlated with anatomic location of carcinomas. This well-characterized TMA offers a powerful tool for testing hypotheses regarding colorectal carcinogenesis, including the identification of potential markers of neoplastic development and progression.
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PMID:CK20 and CK7 protein expression in colorectal cancer: demonstration of the utility of a population-based tissue microarray. 1964 96

Stem cells of the human prostate gland have not yet been identified utilizing a structural biomarker. We have discovered a new prostatic epithelial cell phenotype-expressing cytokeratin 6a (Ck6a+ cells). The Ck6a+ cells are present within a specialized niche in the basal cell compartment in fetal, juvenile and adult prostate tissue, and within the stem cell-enriched urogenital sinus. In adult normal prostate tissue, the average abundance of Ck6a+ cells was 4.9%. With proliferative stimuli in the prostate organ culture model, in which the epithelial-stromal interaction was maintained, a remarkable increase of Ck6a expression was noticed to up to 64.9%. The difference in cytokeratin 6a expression between the normal adult prostate and the prostate organ culture model was statistically significant (p<0.0001). Within the prostate organ culture model the increase of cytokeratin 6a-expressing cells significantly correlated with increased proliferation index (r = 0.7616, p = 0.0467). The Ck6a+ cells were capable of differentiation as indicated by their expression of luminal cell markers such as ZO-1 and prostate specific antigen (PSA). Our data indicate that Ck6a+ cells represent a prostatic epithelial stem cell candidate possessing high potential for proliferation and differentiation. Since the development of benign prostatic hyperplasia and prostate carcinogenesis are disorders of proliferation and differentiation, the Ck6a+ cells may represent a major element in the development of these diseases.
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PMID:Identification of a stem cell candidate in the normal human prostate gland. 1581 12

Most pancreatic neoplasia are of ductal lineage, characterized by tubule (gland), cyst, papilla, or mucin formation and expression of mucin-related glycoproteins and oncoproteins (eg, MUC1, CA19-9, CEA, DUPAN), as well as some subsets of cytokeratin (eg, CK19). Mutations of k-ras oncogene and DPC4 are also common in ductal neoplasia and generally not seen in nonductal tumors. A variety of pancreatic neoplasia fall under the heading of ductal neoplasia. Invasive ductal adenocarcinoma (DA) is the most important and constitutes the vast majority (>85%) of pancreatic tumors. DA is characterized by insidious infiltration and rapid dissemination, despite its relatively well-differentiated histologic appearance. In some variants of DA such as undifferentiated or sarcomatoid, evidence of ductal differentiation may be lacking or only focal. The presumed precursors of DA are microscopic intraductal proliferative changes that are now termed pancreatic intraepithelial neoplasia (PanIN). PanINs comprise a neoplastic transformation ranging from early mucinous change (PanIN-1A) to frank CIS (PanIN-3). A similar (in situ) neoplastic spectrum also characterizes intraductal papillary mucinous neoplasms and mucinous cystic neoplasms, which are cystic ductal-mucinous tumors with varying degrees of papilla formation, and may be associated with invasive carcinoma. As such, these can be regarded as mass-forming preinvasive neoplasia. Some intraductal papillary mucinous neoplasms are associated with invasive carcinoma of the colloid type. Colloid carcinoma of the pancreas appears to be a clinicopathologically distinct tumor with indolent behavior. Whereas most ductal pancreatic neoplasia are characterized by some degree of mucin formation, serous tumors, of which serous (microcystic) adenoma is the sole example, lack mucin formation, presumably because they recapitulate centroacinar ducts. They are typically benign tumors. It is recognized now that pancreatic carcinoma, like other malignant processes, is a genetic disease produced by progressive mutations in cancer-related genes. These alterations can be categorized as "early" such as k-ras mutation, HER-2/neu, PSCA, MUC5, and fascin overexpression; "intermediate" such as p16 inactivation, MUC1, and cyclin D1 overexpression; and finally as "late" such as p53 and DPC4 inactivation, BRCA2 mutation, and overexpression of ki-67, 14-3-3sigma, and mesothelin. Ductal neoplasia is the most important category among pancreatic tumors. It is important to appreciate the different types of ductal tumors because they vary greatly in their clinicopathologic characteristics and prognosis. Understanding the molecular mechanisms of ductal carcinogenesis will help develop more efficient prevention and therapy of these tumors.
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PMID:Ductal neoplasia of the pancreas: nosologic, clinicopathologic, and biologic aspects. 1618 79

Interactions between normal mammary epithelial cells and extracellular matrix (ECM) are important for mammary gland homeostasis. Loss of interactions between ECM and normal mammary epithelial cells are thought to be an early event in mammary carcinogenesis. CREB-binding protein (CBP) is an important regulator of proliferation and apoptosis but the role of CBP in ECM signaling is poorly characterized. CBP was suppressed in basal-cytokeratin-positive HMECs (CK5/6+, CK14+, CK8-, CK18-, CK19-). Suppression of CBP resulted in loss of reconstituted ECM-mediated growth control and apoptosis and loss of laminin-5 alpha3-chain expression. Suppression of CBP in normal human mammary epithelial cells (HMECs) resulted in loss of CBP occupancy of the LAMA3A promoter and decreased LAMA3A promoter activity and laminin-5 alpha-3 chain expression. Exogenous expression of CBP in CBP-negative HMECs that have lost reconstituted ECM-mediated growth regulation and apoptosis resulted in (1) CBP occupancy of the LAMA3A promoter, (2) increased LAMA3A activity and laminin-5 alpha3-chain expression, and (3) enhancement of reconstituted ECM-mediated growth regulation and apoptosis. Similarly, suppression of laminin-5 alpha3-chain expression in HMECs resulted in loss of reconstituted ECM-mediated growth control and apoptosis. These observations suggest that loss of CBP in basal-cytokeratin-positive HMECs results in loss of reconstituted ECM-mediated growth control and apoptosis through loss of LAMA3A activity and laminin-5 alpha3-chain expression. Results in these studies may provide insight into early events in basal-type mammary carcinogenesis.
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PMID:CREB-binding protein regulates apoptosis and growth of HMECs grown in reconstituted ECM via laminin-5. 1621 77


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