Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It was found in our previous study that oxidative modification LDL (Ox-LDL) could stimulate the proliferation of cultured human arterial smooth muscle cells (SMC). Yet, the mechanism responsible for the SMC proliferation induced by Ox-LDL is not clear. Proliferating cell nuclear antiger (PCNA), P53 and P27 are the key regulatory factors of cell replication. In order to observe the effects of Ox-LDL on cell cycling phase and PCNA, P53, P27 and c-erb B-2 expression in SMC, we used the flow cytometric method in the present study on the proliferation of cultured human SMC induced by Ox-LDL. The results showed a relation between the Ox-LDL mediated SMC proliferation and the cycling phase shifting. The relative number of S phase cells in the Ox-LDL group was higher than that of the control group (22.9% vs 15.7%). Ox-LDL mediated SMC proliferation was accompanied with the increasing expression of PCNA. The percentage of specific PCNA positive FITC cells in the Ox-LDL group was significantly higher than that of the control group (12.6% vs 6.5%). PMA, an activitor of protein kinase C (PKC), stimulated SMC proliferation and increased the PCNA exression in cultured SMC, while the PKC inhibitor, F109203X, significantly decreased the PCNA expression in SMC (PCNA positive cells 13.4% vs 0.4%). No changes were observed in the expression of P53, P27 and c-erb B-2 in the cultured proliferating SMC induced by Ox-LDL. In all, the results suggest that the OX-LDL mediated SMC proliferation is related to increasing S Phase Cells and involved in the PCNA expression which might undergo the PKC cellular signal transduction pathway.
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PMID:[Effect of Ox-LDL on cell cycling phases and PCNA, P53, P27 and c-erbB-2 expression in cultured human arterial smooth muscle cells]. 1074 36

Se-allylselenocysteine (ASC) has been shown to inhibit mammary carcinogenesis in vivo and cell growth in vitro. However, little is known about the molecular events that account for these effects. The goal of the present study was to use a mouse hyperplastic mammary epithelial cell line, TM12, to investigate the underlying mechanism(s) associated with ASC regulation of cell proliferation and apoptosis. Cells were treated with 50 microM ASC and assessed after 3, 6 and 12 h of exposure. A significant inhibition of cell proliferation, as measured by BrdU incorporation into DNA, was observed within 3 h of ASC treatment. This inhibitory effect was slightly magnified at the later time points. The induction of apoptosis was also rapid, and progressed from a 1.3-fold increase at 3 h to a 4.4-fold increase at 12 h. Consistent with these cellular events, the levels of phosphorylated Rb protein were greatly reduced at all times points. The other accompanying changes included increases in P53, P21 and P27. Collectively, the results demonstrate for the first time that ASC is able to cause an immediate response in the expression of cell cycle regulatory proteins that favor an arrest in proliferation and an augmentation in apoptosis.
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PMID:Molecular mechanisms associated with Se-allylselenocysteine regulation of cell proliferation and apoptosis. 1114 22

The immunohistochemical expression of p53, p21, Rb, p16, cyclin D1, Ki67, cyclin A, cyclin B1, p27, bcl2, bax, and bak proteins and the apoptotic index (Al) were investigated in 20 normal thymuses (8 adults, 3 adolescents, 5 infants and 4 newborns). The expressions of Rb, Ki67, cyclin A and cyclin B1 were overlapping, being high in the cortex with a tendency for decreased expression toward the medulla. Apoptotic cells were mainly detected in the cortex and the corticomedullary junction, rarely being present in Hassall's corpuscles. The mean values of Ki67, cyclin A, and cyclin B1 expression in thymuses were 77.2%, 32.2% and 21.4% (newborns), 62.4%, 33.7% and 18.5% (infants), 56.9%, 23.4% and 18.9% (adolescents) and 38.7%, 21.7% and 14.6% (adults), respectively. The mean values of AI in thymuses from newborns, infants, adolescents and adults were 1.4%, 2.9%, 2.7% and 3.8%, respectively. This decrease in proliferation and increase in apoptosis may account for the process of thymic involution. P16 expression was widespread with most of Hassall's corpuscles being p16-positive. P16-positive cells and Hassall's corpuscles increased with the increase in age, in keeping with the suggested role of p16 in cellular senescence. P27 expression was undetectable in subcapsular thymocytes with a tendency for increased expression toward the medulla. The expressions of Ki67, cyclin A and cyclin B1 were inversly related with that of p27, consistent with previous evidence that p27 concentration is reduced when the cell-cycle progresses. P21 and much less frequently p53 proteins were mainly detected in a part of the subcapsular cortical epithelial cells. These findings suggest that a) in thymocytes, the apoptotic pathway is mostly p53-independent and the function of p21 as a negative regulator of the cell cycle must be redundant to other negative regulators, such as p16 and p27 which were abundantly detected in thymocytes and b) in some thymic epithelial cells, the p21 expression may be induced by p53, but in most of them seems to be p53-independent. Most of Hassall's corpuscles were p21-positive, consistent with previous evidence that these structures represent end stages of maturation of thymic medullary epithelium and that p21 protein is involved in the process of terminal differentiation. Cyclin D1 positivity was found in some macrophages. Bcl2 expression was mainly seen in medullary thymocytes, reflecting the surviving thymocytes in this region. The expressions of Bax and bak were more widespread in both the medulla and cortex, suggesting that these proteins play a broader role than bcl2 in the regulation of thymic apoptosis.
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PMID:Immunohistochemical expression of p53, p21/waf1, rb, p16, cyclin D1, p27, Ki67, cyclin A, cyclin B1, bcl2, bax and bak proteins and apoptotic index in normal thymus. 1164 19

The expression of the cyclin-dependent kinase inhibitor (CDKI) p27 protein was investigated in relation to (1) the expression of the cell cycle regulators p53, Rb and p16 and (2) the proliferation profile as determined by the expression of Ki67, cyclin A, and cyclin B1 in 80 cases of de novo diffuse large B-cell lymphomas (DLBCL). P27 expression was low/null in large tumor cells in 58/80 cases and intermediate/high in 22/80 cases. Increased expression of p53 protein was observed in 39/80 cases. Decreased expression of Rb and p16 proteins was mutually exclusive and was observed in 5/80 and 14/80 cases, respectively. The analysis of the p27 expression status (low/null versus intermediate/high) with respect to the p53 and/or Rb/p16 expression status showed that low/null p27 expression was significantly correlated with increased p53 expression (P =.018) and showed a strong trend for correlation with concurrent increased p53 expression and decreased Rb or p16 expression (P =.050). These findings suggest a tendency for concurrent alterations of the cell cycle regulators p27, p53, and Rb or p16 in DLBCL, which might result in impaired tumor growth control. Indeed, the analysis of the combined p27/p53/Rb/p16 expression status with respect to the proliferation profile showed that (1) three alterations in the combined p27/p53/Rb/p16 status (i.e., low/null P27 expression, increased expression of p53, and decreased expression of Rb or p16) were significantly correlated with increased expression of cyclin B1 (P =.005) and (2) two or three alterations were significantly correlated with increased expression of cyclin A (P =.014). These findings suggest combined impairment of a complex cell-cycle control network involving the CDK inhibitor p27, the P53 pathway, and the Rb1 pathway, which exerts a cooperative effect resulting in enhanced tumor cell proliferation.
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PMID:Low expression of p27 protein combined with altered p53 and Rb/p16 expression status is associated with increased expression of cyclin A and cyclin B1 in diffuse large B-cell lymphomas. 1170 71

P27 expression was examined on paraffin-embedded specimens in proliferative, secretory, hyperplastic and neoplastic human endometrium by immunohistochemistry. The results of p27 immunoreactivity in endometrial carcinomas were compared with clinicopathological indicators as well as with p53 expression. Thirty-eight cases of endometrial carcinoma, 30 normal functional (15 proliferative, 15 secretory), 24 hyperplastic endometrium (12 without atypia, 12 with atypia) specimens were studied by using monoclonal p27 and p53 antibodies. The streptavidin-biotin-peroxidase detection system was used and the intensity and the distribution of immunoreactivity was evaluated semiquantitatively. p27 expression was present both in the proliferative and secretory phases; the expression being stronger in the secretory period. In complex hyperplasia with atypia, p27 expression was even higher and it was significantly reduced in the endometrial carcinoma group (p<0.05). No significant correlation was found between p27 expression and any of the clinicopathologic prognostic parameters (p>0.05). Nuclear p53 expression was detected in 13 (34.2%) patients with endometrial carcinoma and was higher in non-endometrioid carcinomas and in tumors with increasing FIGO grade (p<0.05). High expression of p53 was not found to be a significant prognostic indicator of survival (p>0.05). No p53 expression was detected in the endometria with proliferation, secretion or hyperplasia either simple without atypia or complex with atypia. Surprisingly, tumors with absent/low p27 expression showed absent/low p53 expression. Our data suggest that p27 is necessary to control the proliferation of endometrium and its loss of expression seems to play a role in some aspects of endometrial carcinogenesis.
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PMID:Significantly decreased P27 expression in endometrial carcinoma compared to complex hyperplasia with atypia (correlation with p53 expression). 1518 25

Cyclins condition the course of a cell cycle through the activation of appropriate serine-threonine kinases. Any variation in the cyclins' expression result in pathologies of the cell division, including neoplastic proliferation. Activity of the complexes of cyclins D1 and E with appropriate cyclin-dependent kinases may be inhibited by protein P21 (WAF1/CIP1) which functions as a cell growth cycle inhibitor. As yet, there have been rather few reports on the prognostic value of this cyclin expression assessment in gastric cancer, the kind of neoplasm still characterized by very poor prognosis. The study aimed at the assessment of expression levels of cyclins D1 and E in surgically removed gastric cancers, including the analysis of this prognostic value parameter, and attempted to determine some correlations between the expression of the examined cyclins and selected histoclinical and molecular parameters such as: patients' age and gender, histological type according to the Lauren classification, cancer stage (TNM), degree of histological malignancy (G) and level of expression of the cell-cycle regulatory genes protein products--P53, P21, P27. Immunohistochemical analysis was performed on specimens obtained from radical stomach resections of 80 patients treated in the period 1992-1997 for gastric cancer stage I-IIIB (TNM-UICC) at the Department of Surgical Oncology, Medical University of Lodz. For immunohistochemical examinations, the LSAB system was used, designed for assessment of antigen expression. In statistical analysis, Fisher's exact test was applied to evaluate correlations between the analyzed variables and Mantel-Haenschel's test to evaluate their collinearity. For the evaluation of the effect of the analyzed variables on postoperation survival and recurrence-free survival the Cox regression model was used. When analyzing the prognostic value and survival period in association to the cyclins D1 and E expression levels, a statistically significant correlation was found only in relation to cyclin E expression: a survival period of minimum 5 year duration was significantly higher in the group displaying a negative, or only faintly positive, reaction to the presence of cyclin E, than in the group with a strongly positive response. Moreover, the analysis showed statistically significant non-linear dependence between the histological type of cancer in the Lauren classification as well as a degree of histological malignancy and the level of cyclin E expression, and a negative correlation between the level of cyclin E expression and the stage of cancer; In addition, a positive correlation between the level of P53 and cyclin E expression as well as statistically significant non-linear correlation between the level of cyclin E expression and the level of protein P21 expression was observed. However, no statistically significant correlations were found between the level of expression of the two cyclins and the level of protein P27 expression or between the levels of cyclin D1 and E expression in gastric cancer. Out of the two types of evaluated cyclins only cyclin E can be considered a significant regulatory factor and a useful prognostic parameter in gastric cancer.
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PMID:A study on the prognostic value of cyclins D1 and E expression levels in resectable gastric cancer and on some correlations between cyclins expression, histoclinical parameters and selected protein products of cell-cycle regulatory genes. 1627 May 27

The mutation status and usage of specific VH genes such as V3-21 and V1-69 are potentially independent pathogenic and prognostic factors in chronic lymphocytic leukemia (CLL). To investigate the role of antigenic stimulation, we analyzed the expression of genes involved in B-cell receptor (BCR) signaling/activation, cell cycle, and apoptosis control in CLL using these specific VH genes compared to VH mutated (VH-MUT) and VH unmutated (VH-UM) CLL not using these VH genes. V3-21 cases showed characteristic expression differences compared to VH-MUT (up: ZAP70 [or ZAP-70]; down: CCND2, P27) and VH-UM (down: PI3K, CCND2, P27, CDK4, BAX) involving several BCR-related genes. Similarly, there was a marked difference between VH unmutated cases using the V1-69 gene and VH-UM (up: FOS; down: BLNK, SYK, CDK4, TP53). Therefore, usage of specific VH genes appears to have a strong influence on the gene expression pattern pointing to antigen recognition and ongoing BCR stimulation as a pathogenic factor in these CLL subgroups.
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PMID:Distinct gene expression patterns in chronic lymphocytic leukemia defined by usage of specific VH genes. 1632 80

Studies have revealed that Epstein-Barr virus (EBV) infection, genetic aberration, and environmental factors are of importance in the development of nasopharyngeal carcinoma (NPC), although the definite mechanism remains to be fully elucidated. The aim of our study is to investigate using tissue microarray analysis whether differential expression of EBV-encoded small RNA-1 (EBER-1) and several tumor-related genes were associated with NPC carcinogenesis. Immunohistochemistry and in situ hybridization were performed on tissue microarrays containing 148 NPCs and 164 noncancerous nasopharyngeal epithelia (NPE) with different morphologic features. We found that overexpressions of EBER-1 hybridization signals, p53, p21ras, and bcl-2 proteins and loss expressions of p16 and p27 proteins were significantly increased in NPC tissues compared with normal NPE and hyperplastic NPE (P </= .001). The overexpressions of EBER-1 and p53 (P < .001) and the loss expressions of P16 (P < .001) and P27 (P = .005) were also significantly higher and more frequently observed in NPC than in dysplastic NPE. The positive expression of EBER-1 hybridization signals in NPC had significant associations with overexpressions of p53 (P < .001), p21ras (P = .041), and bcl-2 proteins (P < .001) and loss expression of p16 protein (P = .001). Further analysis confirmed that the abnormal expression of p53, p16, and p27 proteins occurred in the earliest stage of nasopharyngeal epithelial carcinogenesis. In the final logistic regression analysis model, the positive hybridization signals of EBER-1 and the abnormal expression of p53, p16, and p27 proteins were independent contributions for nasopharyngeal carcinogenesis, and EBER-1 was the most significant, independent predictor of nasopharyngeal carcinogenesis (hazard ratio = 13.412, 95% confidence interval 6.179-29.111, P < .001). In conclusion, EBV infection, together with overexpressions of p53, and loss expressions of p16 and p27 proteins are involved in the multistep process of human nasopharyngeal epithelial carcinogenesis.
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PMID:Differential expression of Epstein-Barr virus-encoded RNA and several tumor-related genes in various types of nasopharyngeal epithelial lesions and nasopharyngeal carcinoma using tissue microarray analysis. 1664 58

The exact mechanism behind the effect of hypoxia-inducible factor-1alpha (HIF-1alpha) on the proliferation and/or apoptosis of carcinoma cells is still a matter of debate. We treated a human gastric carcinoma cell line, MKN-1 (mutant P53), with 500 microM CoCl(2). A dual-phase pattern of HIF-1alpha expression with an increase until 4 h followed by a decrease until 36 h was observed. Immunocytochemistry showed that nuclear translocation was maximal at 4 h of treatment, while trypan blue staining showed a dual-phase pattern. Instead of G1/S arrest, FACS showed an increase in the pre-G1 fraction and G(2)/M arrest that correlated with Cyclin-B1, SKP-2 and P27 expression. Starting at 6 h, the apoptotic index increased in a time-dependent manner, in correlation with the expression of HIF-1alpha, Bcl-2, Bcl-xL, Bax and cleaved-Caspase-9. Phosphorylation of Akt was inhibited by CoCl(2) treatment and LY294002 treatment inhibited HIF-1alpha expression in a dose-dependent manner. These results suggested that the alteration of CoCl(2)-induced HIF-1alpha expression correlated with proliferation and apoptosis in MKN-1 cells. A possible role for the PI3K/Akt pathway was indicated in this model of hypoxia.
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PMID:CoCl2-induced HIF-1alpha expression correlates with proliferation and apoptosis in MKN-1 cells: a possible role for the PI3K/Akt pathway. 1686 70

Study effect and mechanisms of growth-suppression of hepatocelluar carcinoma (HCC) in nude mice. The construction of the pAdeasy-1-pTrack-CMV-hIL-24 recombined adenovirus vector (Ad-hIL-24) was completed and lineared with PacI. Ad-hIL-24 were transfected into QBI-293 cells and obtained. 16 nude mice of the subcutaneous tumor models were established with SMMC-7721 HCC and were randomly divided into NS, 5-Fu, Ad and Ad-hIL-24 groups. Then 100 microL NS, Ad (10(7) pfu) and Ad-hIL-24 (10(7) pfu) for each one were given respectively QOD, and 5-Fu (20 microg/kg) were injected Q.D., for 5 times, with intratumor injections. After 15 d, 16 mice were sacrificed and subcutaneous tumors were taken out. The volumes (before administration, 1 week and 2weeks after administration) were measured and the weights of tumor were weighed and ratios of tumor-suppression were calculated. The morphological changes of apoptotic tumor cells were observed under microscope. Caspase3, P53 and P27, CD34 and VEGF were tested in immunohistochemistry. In tumor subcutaneous model, compared with NS group, the ratios of tumor-suppression of Ad-hIL-24 group and 5-Fu group were 68.52% (P < 0.01) and 65.64 (P < 0.01), respectively. Caspase3 protein in Ad-hIL-24 group was higher than other 3 groups significantly (P < 0.01). The expression of P27 also differed from NS group (P < 0.01). CD34 and VEGF protein in Ad-hIL-24 group can inhibit neovascularization obviously (P < 0.001), compared with NS and Ad groups. Ad-hIL-24 inhibits the growth of SMMC-7721 HCC on nude mice's. The mechanisms of tumor-suppression may be multi-pathways such as the induction of caspase3 pathway, P27 activities and the antiangiogenic mechanism.
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PMID:[The study of the growth-suppression and mechanisms of hepatocelluar carcinoma tumor in nude mice]. 1716 14


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