Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0007097 (carcinoma)
 152,788 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The modifying effects of 22-oxa-calcitriol (OCT), a synthetic analog of 1 alpha,25-dihydroxyvitamin D3, were assessed in a multi-organ carcinogenesis model using male F344 rats initially treated with five kinds of carcinogens. In experiment 1 the rats were given OCT intraperitoneally at doses of 30 micrograms/kg (25 rats) or 3 micrograms/kg (25 rats), three times a week for 24 weeks after initial carcinogen exposure over 4 weeks and a 2 week non-treatment period. Twenty-two rats received the five carcinogens and were given the vehicle intraperitoneally as a control. A further group of 10 rats was given the 30 micrograms/kg dose of OCT without prior carcinogen application. At the end of the total observation period of 30 weeks the carcinoma incidence in the small intestine of rats given 30 micrograms/kg OCT after carcinogen treatment was 0%. This incidence was significantly smaller when compared with the control group. The incidence of large intestine carcinomas in the 30 micrograms/kg OCT group showed a tendency to decrease. The numbers of small and large intestinal carcinomas per rat were also significantly lower in the group given 30 micrograms/kg OCT than after 3 micrograms/kg OCT or carcinogens alone. Attention was, therefore, focused on colon carcinogenesis and in experiment 2 30 micrograms/kg OCT administered six times a week to rats for 8 weeks after the last injection of N,N'-dimethylhydrazine (DMH) exposure. OCT significantly reduced the formation of DMH-induced aberrant crypt foci, considered to be putative preneoplastic lesions. In experiment 3 30 micrograms/kg OCT was administered six times a week to rats for 4 weeks without prior carcinogen treatment. The proliferating cell nuclear antigen labeling index for the colonic epithelium of rats given 30 micrograms/kg OCT was decreased. Ornithine decarboxylase and spermidine/spermine N1-acetyltransferase activities in colonic epithelium, assayed as indicators of cell proliferation, were not significantly decreased as compared with control group values. Furthermore, vitamin D receptors in colonic epithelium were not significantly increased. Thus the present study indicates that OCT can exert inhibitory effects on tumor development in the small and large intestines, although the mechanism is unclear.
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PMID:Inhibition of intestinal tumor development in rat multi-organ carcinogenesis and aberrant crypt foci in rat colon carcinogenesis by 22-oxa-calcitriol, a synthetic analogue of 1 alpha, 25-dihydroxyvitamin D3. 755 59

Proliferation of some cultured human tumor cell lines bearing high numbers of epidermal growth factor (EGF) receptors is paradoxically inhibited by EGF in nanomolar concentrations. In the present study, we have investigated the biochemical mechanism of growth inhibition in A431 human squamous carcinoma cells exposed to exogenous EGF. In parallel, we studied a selected subpopulation, A431-F, which is resistant to EGF-mediated growth inhibition. We observed a marked reduction in cyclin-dependent kinase-2 (CDK2) activity when A431 and A431-F cells were cultured with 20 nM EGF for 4 h. After further continuous exposure of A431 cells to EGF, the CDK2 activity remained at a low level and was accompanied by persistent G1 arrest. In contrast, the early reduced CDK2 activity and G1 accumulation in A431-F cells was only transient. We found that, at early time points (4-8 h), EGF induces p21Cip1/WAF1 mRNA and protein expression in both EGF-sensitive A431 cells and EGF-resistant A431-F cells. But only in A431 cells, was p21Cip1/WAF1 expression sustained at a significantly increased level for up to 5 d after addition of EGF. Induction of p21Cip1/WAF1 by EGF could be inhibited by a specific EGF receptor tyrosine kinase inhibitor, tyrphostin AG1478, suggesting that p21Cip1/WAF1 induction was a consequence of receptor tyrosine kinase activation by EGF. We also demonstrated that the increased p21Cip1/WAF1 was associated with both CDK2 and proliferating cell nuclear antigen (PCNA). Taken together, our results demonstrate that p21Cip1/WAF1 is an important mediator of EGF-induced G1 arrest and growth inhibition in A431 cells.
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PMID:Prolonged induction of p21Cip1/WAF1/CDK2/PCNA complex by epidermal growth factor receptor activation mediates ligand-induced A431 cell growth inhibition. 755 80

This study was undertaken to determine the extent of apoptosis in lung carcinoma and to evaluate it as a prognostic marker. A series of 75 lung carcinomas (47 squamous cell carcinomas, 24 adenocarcinomas, 3 small cell carcinomas, and 1 large cell carcinoma) was analyzed for the extent of apoptosis by using the 3' end-labeling method of DNA in tissue sections. Apoptosis was correlated with the rate of cell proliferation, the immunohistochemically detectable p53 and bcl-2, the extent of tumor necrosis, and the survival data. The end-labeling method allowed a precise evaluation of the extent of apoptosis. In tumor tissue, the number of apoptotic bodies was roughly 2-fold greater than the number of apoptotic cells, whereas in nonneoplastic control tissues, the ratio was 1:1. The apoptotic indexes (percentages of apoptotic cells and bodies among tumor cells) were slightly higher in adenocarcinoma than in squamous cell carcinoma. There was no association between the extent of apoptosis and the expression of proliferating cell nuclear antigen or p53. On the other hand, tumor necrosis correlated significantly with proliferating cell nuclear antigen and p53 positivity (P = 0.00025 and 0.00087, respectively). Surprisingly, the extent of apoptosis was also found to be independent of the expression of bcl-2. Patients with apoptotic indexes greater than 1.5% had significantly shorter survival time than patients with apoptotic indexes equal to 1.50% or less (P < 0.01 by log rank). Aberrant p53 positivity also predicted a poor prognosis (P < 0.002 by log rank). By multivariate analysis, enhanced apoptosis showed a 1.9-fold risk (P = 0.04), and p53 positivity showed a 2.3-fold risk (P = 0.005) for a shortened survival. We conclude that both enhanced apoptosis and p53 positivity are independent prognostic markers in non-small cell lung carcinoma, predicting shortened survival time of the patients.
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PMID:Enhanced apoptosis predicts shortened survival in non-small cell lung carcinoma. 758 40

The modifying effect of dietary administration of protocatechuic acid (PCA) during the initiation and postinitiation phases on N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN)-induced bladder carcinogenesis was investigated in male F344 rats. Animals were divided into nine groups and groups 1-7 were given 0.05% BBN in drinking water for 6 weeks to induce bladder neoplasms. Rats in groups 2, 3 and 4 were fed diets containing 500, 1000 and 2000 p.p.m. PCA respectively for 8 weeks, starting 1 week before BBN exposure. Groups 5, 6 and 7 were fed the PCA-containing diets at three dose levels for 33 weeks. Group 8 was fed the diet containing 2000 p.p.m. PCA alone throughout the study. Group 9 was given tap water without BBN and the basal diet without PCA and served as an untreated control. At 41 weeks after the start, all animals were killed. The incidence of bladder tumors and preneoplastic lesions, and cell proliferation activity estimated by the numbers of silver-stained nucleolar organizer regions proteins (AgNORs) and proliferating cell nuclear antigen (PCNA)-immunoreactive cells were compared among the groups. PCA administration at 1000 and 2000 p.p.m. during the initiation and postinitiation phases significantly decreased the carcinoma incidence in a dose-dependent manner. Also, PCA at all doses given during either initiation or postinitiation phases reduced the development of the preneoplastic lesions. PCA feeding significantly reduced the numbers of AgNORs and PCNA-positive cells in the non-lesional transitional epithelium, preneoplasms, and neoplasms in the urinary bladder of rats treated with BBN. These results indicate that dietary administration of PCA is quite effective in preventing BBN-induced bladder carcinogenesis.
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PMID:Chemoprevention of urinary bladder carcinogenesis by the natural phenolic compound protocatechuic acid in rats. 758 32

We assessed cellular proliferation of sebaceous neoplasms by AgNOR counts and the immunohistochemical demonstration of proliferating cell nuclear antigen (PCNA) and Ki-67, using formalin-fixed and paraffin-embedded tissue specimens. We used three categories of sebaceous neoplasms: four cases of sebaceoma, three cases of basal cell carcinoma with sebaceous differentiation (BCSD), and seven cases of sebaceous carcinoma (SC). Significant differences were noted between SC and non-SC tumors (sebaceoma and BCSD) in AgNOR counts and semi-quantitative grading of PCNA and Ki-67 labelling indices (P < 0.01). When a cut-off value of 6 was chosen, the AgNOR value discriminated SC from non-SC tumors with high specificity and sensitivity. When a cut-off value of 25% was chosen, PCNA and Ki-67 labelling indices also discriminated between these tumors. Significant differences were not observed between sebaceoma and BCSD with PCNA and Ki-67 labelling indices. AgNOR counts of BCSD were a little higher than those of sebaceoma, but the number of cases was too small to perform statistical assessment. We consider AgNOR counts and semi-quantitative grading of PCNA and Ki-67 labelling indices to be useful in differentiating SC from BCSD and sebaceoma.
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PMID:Assessment of cellular proliferation of sebaceous neoplasms by AgNOR counts and immunohistochemical demonstrations of PCNA and Ki-67. 760 80

Proliferative rate is an important prognostic marker in breast carcinoma. However, the best measurement method has not been established. This study evaluated mitotic figure counts (MFC) as mitoses per 10 high power fields (HPF) and per 1,000 cells, S-phase fraction by flow cytometry, and Ki-67, MIB-1, and proliferating cell nuclear antigen (PCNA) positivity by immunohistochemistry in 135 breast carcinomas. There was strong correlation between the two MFC methods and significant correlation between MIB-1 positivity and all proliferation markers except Ki-67. S-phase fraction showed significant correlation with all proliferation markers except PCNA. Ki-67 positivity correlated only with S-phase fraction, and PCNA positivity only with MIB-1 and mitoses per 10 HPF. High MFC was associated with other prognostic factors: high histologic tumor grade, absence of biochemical and immunohistochemical hormone receptors, and DNA aneuploidy, but not lymph node involvement or tumor size. MIB-1 positivity was also associated with these parameters, except lymph node involvement, tumor size, and DNA aneuploidy. Mitotic figure count and MIB-1 positivity were associated strongly with disease-free survival, up to 46 months. The other proliferation markers were associated with fewer prognostic factors and showed weak or absent association with disease-free survival. The best proliferation markers are mitotic figure counting (either method) or MIB-1 positivity.
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PMID:Proliferation markers in breast carcinoma. Mitotic figure count, S-phase fraction, proliferating cell nuclear antigen, Ki-67 and MIB-1. 761 Nov 79

The present study was undertaken to elucidate the relationship between the distribution of potentially proliferative tumor cells and the organoid differentiation of tumor cells in gastric carcinomas. One hundred four specimens of surgically removed human gastric carcinomas, including 68 and 36 specimens of early and advanced carcinomas, respectively, were studied by using a battery of histochemical techniques. Serial 3-microns thick paraffin sections were stained by galactose oxidase-cold thionine Schiff-paradoxical concanavalin A staining (GOCTS-PCS), or were immunostained for pepsinogen types I and II, lysozyme, and proliferating cell nuclear antigen (PCNA). In addition, to identify proliferative tumor cells parts of fresh carcinoma tissues were incubated in a solution containing bromodeoxyuridine (BrdU), embedded in paraffin, and immunostained for BrdU. The results indicated that in intramucosal carcinoma tissues showing organoid differentiation the proliferative tumor cells were located predominantly between the covering epithelial cell type tumor cells and the glandular mucous cell type tumor cells, and the disturbance in the distribution of proliferative cells coincided with the submucosal invasion.
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PMID:Proliferative markers in gastric carcinoma and organoid differentiation. 762 43

Well-differentiated colorectal adenocarcinomas are subclassified into carcinoma with high-grade atypia (CAH) and carcinoma with low-grade atypia (CAL) based on their cellular atypia. It is proposed that CAH and CAL are different in histologic prognostic factors and that the former should be regarded as carcinoma with high-grade malignancy and the latter as low-grade malignancy. In this study, the differences in cell-proliferative activity between CAH and CAL were examined using a monoclonal antibody to the proliferating cell nuclear antigen (PCNA). The PCNA index and mitotic index of 27 early colorectal carcinomas (9 CAL, 5 CAH, and 13 carcinomas with mixed low- and high-grade atypia) was evaluated in relation to their depth of invasion. In intramucosal lesions, both indices were higher in CAH (78%, 0.89%) than in CAL (68%, 0.47%; P < 0.01). In lesions invading into the submucosa, the PCNA and mitotic indices were also higher in CAH (75%, 0.65%) than in CAL (35%, 0.19%; P < 0.01). A significant correlation was observed between the PCNA index and the mitotic index in the mucosal lesions (P < 0.05). These results indicate that CAH has a higher proliferative activity than CAL, and support the current authors' proposal that CAH is a high-grade malignancy and CAL low-grade malignancy.
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PMID:The proliferating cell nuclear antigen (PCNA) index correlates with the grade of cytologic atypia in well-differentiated early adenocarcinomas of the large intestine. 764 32

Laryngeal hyperkeratotic lesions can progress to fully developed malignant carcinoma in some cases. These premalignant lesions are proliferative disorders whose potential for further tumour progression is perhaps difficult to assess by mere histology. Immunostaining with PCNA, a protein correlated with cell proliferation, has been used to study tissue behavior in 30 cases of premalignant laryngeal vocal chord lesions treated by epithelial stripping in microlaryngoscopy, 15 of whom had no progression and 15 had recurrence and final development of full malignancy. The results showed a statistically significantly higher PCNA-index in the cases which underwent further tumour progression towards malignancy. PCNA testing may thus be suggested as a marker for tumour progression potential and help in determining clinical treatment choices.
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PMID:PCNA--a cell proliferation marker in vocal chord cancer. Part I: Premalignant laryngeal lesions. 765 40

Anti-PCNA monoclonal antibody and ABC staining were used to study the expressions of proliferating cell nuclear antigen/cyclin in patients with primary gallbladder carcinoma (31 cases), adenoma and tumor-like lesions of gallbladder (10 cases), and chronic cholecystitis (7 cases). The PCNA indices were 373.48 +/- 219.83, 94.9 +/- 93, and 56 +/- 28.63, respectively. This index was significantly higher in malignant lesions than in benign diseases (P < 0.01). There was a tendency that the higher the PCNA index, the lower differential degree of the gallbladder carcinoma (P < 0.01). But there were no significant correlations between the PCNA indices and the pathohistological types, the nevin classifications and the TNM classifications of the gallbladder carcinoma (P > 0.05).
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PMID:[The expressions of proliferating cell nuclear antigen (PCNA) in primary gallbladder carcinoma and its significance]. 765 96


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