Identification of a linear B-cell epitope on the avian leukosis virus P27 protein using monoclonal antibodies.

Avian leukosis virus (ALV) is an avian oncogenic retrovirus that can induce various clinical tumors. The capsid protein P27 is the group-specific antigen of ALV and has many viral antigen sites that are easy to detect. In this study, we produced a monoclonal antibody (mAb), 3A9, that is specific for the P27 protein. A series of partially overlapping peptides were screened to define (181)PPSAR(185) as the minimal linear epitope recognized by mAb 3A9. The identified epitope could be recognized by chicken anti-ALV and mouse anti-ALV P27 sera. The epitope was highly conserved among a number of ALV-A, ALV-B and ALV-J strains. MAb 3A9 might be a valuable tool for the development of new immunodiagnostic approaches for ALV, and the defined linear epitope might help further our understanding of the antigenic structure of the P27 protein.

Development of an antigen-capture ELISA for the detection of the p27-CA protein of HERV-K(HML-2).

The detection or quantification of retroviruses is often achieved using an antigen-capture ELISA (AC-ELISA) that targets the Gag capsid (CA) protein. We report here the development of an AC-ELISA specific for the p27-CA protein of HERV-K(HML-2). A monoclonal p27-specific antibody is used for capture and a polyclonal anti-p27-CA immune serum generated in rabbits serves for detection. The assay was shown to be specific for HERV-K(HML-2), showing no evidence of cross reactivity with the human retroviruses HIV-1, HIV-2 and HTLV-1 or with XMRV (as a model non-human gammaretrovirus). Using purified recombinant antigen, the limit of detection was shown to be 130pg/ml. The AC-ELISA can be used to quantify HERV-K(HML-2) expression in teratocarcinoma cell lines and to normalize HERV particles generated by transfecting HEK 293T cells with full-length molecular clones. This novel AC-ELISA also proved useful in studies of virus regulation, for example in demonstrating that HERV-K(HML-2) expression is dramatically enhanced by overexpression of Staufen-1, a binding partner of the HERV-K(HML-2) Rec protein. This specific and sensitive HERV-K(HML-2) AC-ELISA will be a useful tool for investigating many aspects of endogenous retroviruses, from basic research to the role they may play in human diseases or as a surrogate marker for particular diseases.

Effect of Resveratrol on the Expression of Survivin and p27 Protein in Human Renal Cell Carcinoma 786-0 Cells / 医药导报

Objective To investigate the effect of resveratrol ( Res ) on the expression of survivin, p27 protein in human renal cell carcinoma 786-0 cells. Methods The cell cycle and apoptosis of 786-0 cells were detected by flow cytometry, and the expression of survivin and p27 protein of 786-0 cells was detected by Western blotting at time point of 12, 24 and 48 h after human renal cell carcinoma 786-0 cells were cultured with Res ( 25μmol·L-1 ) and blank medium, respectively. Results The ratio in G1 phase [(64.87±3.76)%] and G2 phase [(9.91±0.82)%] in the experimental group decreased significantly (P<0.05), and the ratio of S phase [(25.05±3.12)%] increased significantly (P<0.05).The apoptosis rate of experimental group at 12, 24 and 48 h [(5.12±0.64)%, (5.71±0.49)%, (5.84±0.30)%] was significantly higher than that of the control group [ ( 0. 72 ± 0. 27 )%, ( 0. 93 ± 0. 25 )%, ( 1. 12 ± 0. 21 )%, P<0. 05 ] . The expression of survivin protein in experimental group was significantly higher than that of the control group ( P<0. 05 ) , and the expression was significantly increased with time prolonging (P<0.05).The expression of p27 protein in experimental group was significantly lower than that of the control group (P<0.05), and the expression level was significantly decreased in time-dependent manner (P<0.05).There was a negative correlation between the expression of survivin and p27 protein in the experimental group ( P<0.05) . Conclusion Res could inhibit the expression of p27 protein and up-regulate survivin expression level, and promote the apoptosis of renal cell carcinoma 786-0 cells.

Effect of simvastatin and atorvastatin on the expression of p 27 protein in mesangial cells of rat under high glucose / 重庆医学

Objective To explore the effect of simvastatin and atorvastatin on the level of p 27 protein in mesangial cells of rat under high glucose .Methods Cultured rat mesangial cells in vitro were divided into four groups :normal glucose(5 .6 mmol/L glu-cose) ,high glucose(30 mmol/L glucose) ,high glucose(30 mmol/L glucose) plus simvastatin(10 μmol/L) ,high glucose(30mmol/L glucose) plus atorvastatin(10 μmol/L) .After treatment for 24 ,48 ,72 120 hours ,the cells were collected .The protein level of p27 was detected by Western blotting and the mRNA level of p27 was detected by RT-PCR .Results Compared to the normal glucose group ,the levels of p27 protein and mRNA in the high glucose group had a significant increase(P<0 .05) .Compared to the high glucose group ,the level of p27 protein and mRNA in the high glucose plus simvastatin or atorvastatin group both had a significant decrease(P<0 .05) .Conclusion By modulating the expression of P27 in mesangial cells ,statins could become the independent lipid-decreasing drug to prevent kidney .

The expresssion of p53 and p27 in lung cancer and its clinical significance / 中国医师进修杂志

Objective To investigate the expression and clinical significance of p53 and p27 in lung cancer.Methods From December 2011 to December 2012,100 cases of patients with lung cancer were enrolled in this study.Another 40 person without lung cancer were collected as normal control.The protein expression of p53 and p27 was detected by immunohistochemistry.Results The positive rate of p53 in normal control was lower than that in lung cancer patients [27.5％ (11/40) vs.66.0％ (66/100)] (P ＜ 0.05).The positive rate of p27 in normal control group was higher than that in lung cancer group [87.5％(35/40) vs.41.0％(41/100)] (P ＜ 0.05).The expression of p53 and p27 had no relationship with the gander and rumor tissue type in lung cancer patients (P ＞ 0.05),but had relationship with the clinical pathologic stage (P ＜0.05).Spearman correlation analysis showed that the expression of p53 and p27 protein in lung cancer tissue had significantly negative correlation (r =-0.516,P＜ 0.05).Conclusion The abnormal expression of p53 and p27 may be involved in the occurrence and development of lung cancer,and their joint detection may be used as the new molecular marker in the diagnosis and prognosis assessment of lung cancer.

Expression of p27, C-myc protein in lung squamous cell carcinoma and adenocarcinoma / 中国医师进修杂志

Objective To investigate the clinical pathology characteristics of the p27 and C-myc protein expression in lung squamous cell carcinoma and adenecarcinoma as well as the correlation between the expressions of them. Method The expressions of p27 and C-mye protein in tumor tissue of 35 cases excised during pulmonectomy for lung squamous cell carcinoma and adenocarcinoma patients were examined using immunochemical method,and compared with 10 cases of normal lung tissue. Results The total positive rate of p27 protein was 17.1%(6/35 ) in 35 eases of tumor tissue, but 90.0%(9/10) in normal lung tissue, and there was significant difference (P 0.05 ). The total positive rate of C-myc protein was 85.7% (30/35) in tumor tissue, but no expression existed in normal lung tissue (P 0.05). The expression of p27 and C-myc in lung squamous cell carcinoma and adenecareinoma showed negative correlation.Conclusions The expression of p27 protein is positive in normal lung tissue, but shows outstanding decrease in lung squamous cell carcinoma and adenocarcinoma tissue. Its expression correlates with the differentiated degree. The expression of C-myc is negative in normal lung tissue but shows significant increase in lung squamous cell carcinoma and adenocareinoma tissue and its expression correlates with lymph nodes metastasis. C-myc may be a valuable marker in evaluating prognosis.

Expression and clinical significance of p27 protein in stage Ⅱ colon cancer / 中华消化外科杂志

Objective To investigate the expression and clinical significance of p27 protein in stage Ⅱ colon cancer.Methods The expression of p27 protein in 57 samples of stage Ⅱ colon cancer tissue from BeijingCancer Hospital was detected by immunohistochemistry and tissue microarray technique.Survival was analyzed by the Kaplan-Meier method,and the correlation between the expression of p27 protein and the prognosis of patients was analyzed by Pearson chi-square test.Multivariate analysis was done by using Cox proportional hazard regression model.Results The rate of high expression of p27 protein in stage Ⅱ colon cancer was 60%(34/57).The differentiation.location and distal metastasis of the tumor were correlated with the expression of p27 protein(X2=5.97,5.93,5.05,P＜0.05);while age,tumor size,growth patterns of tumor were not correlated with the expression of p27 protein(X2=0.64,0.49,0.33,P＞0.05).The 5-year survival rate of the patients with high expression of p27 protein was 94%(32/34),which was significantly higher than the 78%(18/23)of the patients with low expression of p27 protein(X2=3.86,P＜0.05).Multivariate analysis showed that low expression of p27 protein and tumor penetrating serous membrane are the independent adverse prognostic factors for stage Ⅱ coloR cancer.Conclusions Low expression of p27 protein is one of the independent adverse prognostic factors for stage Ⅱ colon cancer,and the expression of p27 protein should be consulted when screening out the patients who are in the high risk group of stage Ⅱ colon cancer.

Expressions of S-Phase Kinase-Associated Protein 2 and p27 Protein in Gastric Carcinoma and Pericancerous Tissues / 中国普外基础与临床杂志

Objective To study the expressions of SKP2 and p27 in gastric carcinoma and pericancerous tissues and to detect the relationship between their expressions and clinicopathological features. Methods Forty-nine cases of gastric carcinoma spicemen and 20 cases of tissue adjacent to the carcinoma were cut and made into paraffin-embedded slices. The expressions of SKP2 and p27 were then detected by SP immunohistochemical method. Results The positive expression rate and score of SKP2 were both significantly higher in the gastric carcinoma tissues than those in pericancerous tissues (P

Expression Pattern of p27 Protein in Primary Gastric Lymphomas.

PURPOSE: To investigate the expression pattern of p27 protein in primary gastric lymphomas. MATERIALS AND METHODS: Immunostaining for the p27 protein was performed in 16 cases of low grade mucosa-associated lymphoid tissue (MALT) lymphomas and 16 cases of high grade B-cell lymphomas of the stomach. RESULTS: All low grade MALT lymphomas were positive, however all high grade lymphomas were negative forp27 protein. Most of the monocytoid cells in the low grade lymphoma were unstained. CONCLUSION: Loss of p27 protein expression is well correlated with histologic grade and appears to be associated with the high grade transformation seen in primary gastric lymphomas.

p27 protein expression in nodular goiter / 中国普通外科杂志

ObjectiveTo measure p27 protein expression in nodular goiter and study the relationship between p27 protein expression and clinicpathologic factors.MethodsImmunohistochemical method-SP was used to detect expression of p27 protein in 42 cases of nodular goiter, 32 cases of normal thyroid tissues and 30 cases of thyroid cancer.ResultsThe positive expression rate of p27 protein was 52%?29% in nodular goiter, 87%?7 2% in normal thyroid tissue and 14%?12% in thyroid cancer. p27 protein expression in different thyroid tissues was significantly different (R 1,2=576, R 1,3=1?998, R 2,3=1?422, P

Effects of combination of octreotide and wortmannin on proliferation of gastric carcinoma cell BGC-823 / 中国实用内科杂志

Objective To investigate the effect and mechanism of octreotide with or without wortmannin on the growth of gastric carcinoma cell BGC-823.Methods From June to August of 2007,in Remin Hospital of Wuhan University,cells were exposed to octreotide for four dilution(10-5、10-4、10-3、10-2g/L)with or without wortmannin(a special inhibitor of PI3'K/Akt pathway,the dilution is 40 nmol/L).And then the cytotoxicity was assessed by determining cell survival with MTT after 24 hours,with also were exposed to octreotide for the dilution of 10-3 g/L with or without Wortmannin in 12 h,24 h,36 h,48 h,then the cell survivral rate was accounted and the results were formulated in a table,and the cell cycle was checked-out with Flow Cytometer(FCM);the expression level of p27 gene and protein was determinated with RT-PCR and Western-bloting Test.Results The five groups within one reagent treating were compared with control group,and the results had difference,but the combination of two reagents group had significant difference(P

Expression Pattern of p27 Protein in Primary Gastric Lymphomas / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: To investigate the expression pattern of p27 protein in primary gastric lymphomas. MATERIALS AND METHODS: Immunostaining for the p27 protein was performed in 16 cases of low grade mucosa-associated lymphoid tissue (MALT) lymphomas and 16 cases of high grade B-cell lymphomas of the stomach. RESULTS: All low grade MALT lymphomas were positive, however all high grade lymphomas were negative forp27 protein. Most of the monocytoid cells in the low grade lymphoma were unstained. CONCLUSION: Loss of p27 protein expression is well correlated with histologic grade and appears to be associated with the high grade transformation seen in primary gastric lymphomas.

Expression of p21/WAF1/CIP1, p27/KIP1 and p57/KIP2 Proteins in Gastric Adendegrees Carcinoma / 대한암학회지

PURPOSE: p21/WAF1/CIP1, p27/KIP1 and p57/KIP2 are negative regulators of the cell division cycle. We evaluated the expressions of KIP CDK inhibitors and examined the relationship of clinicopathologic parameters and cell proliferation index in gastric adendegrees Carcinomas. MATERIALS AND METHODS: The study was carried by the TUNEL method for apoptosis, immuno histdegrees Chemical staining for PCNA, p53, p21/WAF1/CIP1, p27/KIP1, and p57/KIP2 proteins and Western blot for KIPs proteins of normal and cancer tissues of stomach. RESULTS: In normal gastric mucosa, p21/WAF1/CIP1 and p27/KIP1 proteins were expressed both mainly to the superficial portion of the glands with intestinal metaplasia and stromal cells. p57/KIP2 protein was also expressed normal crypt glandular epithelial and stromal cells. In gastric adendegrees Carcinoma, p21/WAF1/CIP1 was positive in 25 of 70 (35%) and showed significant decrease in deep tumor invasion (p=0.015) and the presence of angioinvasion (p=0.013). There was signi ficant inverse correlation between p27/KIP1 expression and cell proliferating index. p21/WAF1/ CIP1 expression was related to lower apoptotic index. Western blot analysis of KIP CDK inhibitors showed marked down-regulation of p21/WAF1/CIP1 protein in cancer than normal tissue, but alternative expression in p27/KIP1 and p57/KIP2 proteins. CONCLUSION: The above results indicated that the expression loss of KIP CDK inhibitors was contributed to tumor progression and aggressiveness in gastric adendegrees Carcinoma.

Expressions of P27 protein and PCNA in oral squamous cell carcinomas / 实用口腔医学杂志

Objective:To investigate the expressions of P27 protein and proliferating cell nuclear antigen(PCNA) in oral squamous cell carcinoma(OSCC) and to determine the relationship between them. Methods: SP immunohistochemistry was used to detect P27 protein and PCNA in 55 cases of OSCC, 5 biopsies of normal oral mucosa and 20 hyperplastic tissues. Results: The expression rate of P27 protein and PCNA in OSCC were 40.0%,80.0%,which were different from normal oral mucosa and hyperplasia tissues(P0.05). They correlated with malignant behaviors, clinical stages and whether there was lymphnode metastasis or not of the neoplasm(P0.05). Conclusion: Decrease of P27 protein expression and increase of PCNA expression may be important indicators which stand for malignant behavior of neoplasm. The results suggest that their inverse correlation between PCNA and P27 in various forms of oral squamous cell carcinomas may be of prognostic and therapy value.

Expression and significance of P27 in hepatocellular carcinomas / 重庆医科大学学报

Objective:To study the expression and its significance of P27 protein in hcpatocellular carcinomas(HCC).Methods:Expression of P27 protein is investigated by immunohistochemistry technique(SP) in 50 cases of hepatocellular carcinoma who had undergone surgery for HCC,22 cases of their adjacent noncancerous lesions and 9 cases normal liver control specimens.Results:The P27 LI in hepatocellular carcinomas was higher than that in the adjacent noncancerous lesions (P=0.002).Furthermore,the P27LI in adjacent noncancerous lesions was significantly highter than that in normal liver lesions (P=0.007).The expression of P27 was significantly correlated with tumor differentiation,stage,size,portal invasion,and intrahepatic metastasis.The post-operation survival time for patients with P27LI≥50% was longer than those with P27 LI