Correlation between reduced p21(WAF1/CIP1) expression and abnormal p53 expression in esophageal carcinomas

Direct gene transfer into somatic tissue iii vivo is a developing technology with potential application for cancer gene therapy. In this study, recombinant vaccinia virus encoding human IL-2 gene (rVV-IL-2) was used as a candidate vector in mediating iii vivo gene therapy. After rVV-IL-2 was expanded in VERO cells for 72 h, high titer (10(8)-10(10) PFU/ml) rVV-IL-2 were harvested. When 10(6) murine melanoma cells (F16-F10) were infected with rVV-IL-2, about 200 U/ml IL-2 activity was detected in the supernatants at 8 h, and the up-regulation of ICAM-1 and MHC-I expressions on the melanoma cells were observed. The treatment of murine melanoma model by local injection of rVV-IL-2 into the tumor site showed that rVV-IL-2 transfection significantly inhibited the tumor growth and prolonged the survival time of tumor-bearing mice. The splenocytes from rVV-IL-2 treated mice showed higher cytotoxicities of NK, LAK and CTL in comparison with those from the controls. These results suggest that in vivo transfection mediated by rVV-IL-2 has potential effectiveness in enhancing host immunity and would be a useful approach to cancer gene therapy.     

p21WAF1/CIP1 protein expression in primary ovarian cancer

p21WAF1/CIP1 protein is a cyclin-dependent kinase inhibitor, able to prevent the CDK2/cyclin E induced retinoblastoma protein (pRB) phosphorylation, thus inhibiting cell cycle progression at G1 phase. p21WAF1/CIP1 protein levels were examined in a series of 102 ovarian tissue samples including normal ovary, primary ovarian tumors, omental metastasis, recurrent disease and residual tumor after chemotherapy exposure, by Western blot analysis. The association of p21WAF1/CIP1 status with clinicopathological parameters and clinical outcome was also investigated. p21WAF1/CIP1 protein was detectable in 76 out of 102 (74%) ovarian tissue samples. We observed a significant trend of p21 levels to gradually increase from normal ovarian tissues (median 0 a.u.) through primary ovarian cancers (median 0.19 a.u.), omental metastases (median 0.33 a.u.) and recurrence of disease (median 0.44 a.u.) (p=0.015). In the group of stage III-IV ovarian cancer patients, p21-positive cases showed a more favourable prognosis with respect to p21-negative cases: the 3-year time to progression (TTP) rate was 58% for p21-positive compared with 33% of p21-negative cases (p=0.036). In conclusion, p21WAF1/CIP1 expression levels seem to be correlated with tumor status at the time of diagnosis and can predict TTP in a selected group of patients.     

p53和p21WAF1/CIP1基因在上皮性卵巢癌中的表达及临床意义

目的探讨联合检测p53和p21蛋白表达与上皮性卵巢癌预后的关系.方法 108例上皮性卵巢癌标本用于研究,每个标本同时用免疫组化的方法检测p53和p21蛋白表达.结果 p53(－)和p53( )患者的5年生存率分别为60.47%和29.43%,差异有显著性(P=0.0228).p21(－)和p21( )患者的5年生存率分别为31.58%和47.14%,差异有显著性(P=0.0246).p53(－)而p21( )患者的预后明显优于其他患者(P=0.0013).多因素分析显示p53、p21蛋白联合表达状态是判断上皮性卵巢癌预后的独立因子. 53蛋白表达与p21蛋白表达呈负相关(P=0.0003).结论联合检测p53、p21蛋白表达在判断上皮性卵巢癌预后上的意义优于单纯检测p53或p21蛋白表达,对临床有指导意义.     

Relationship between expression of p21WAF1/CIP1 and radioresistance in human gliomas.

The role of p21WAF1/CIP1 (p21) in DNA repair and apoptosis following gamma-irradiation remains controversial. In this study the influence of p21 on the radiosensitivity of human brain tumors was investigated. Resected tumors were stained immunohistochemically for p21. Expression of p21 in astrocytic tumors was high, but it was low in medulloblastomas, germinomas, and primary malignant lymphomas. Glioma and medulloblastoma cell lines were transfected with pcDNA/p21 to cause p21 overexpression, then tumor-cell colony formation and apoptosis were assessed following gamma-irradiation of the transfected and nontransfected cells. Overexpression of p21 enhanced clonogenic survival and suppressed apoptosis after gamma-irradiation in human brain tumor cell lines with or without p53 protein deficiency. Radioresistance was acquired when p21 was overproduced in the glioma cell lines irrespective of p53 status.     

Endogenous p21WAF1/CIP1 status predicts the response of human tumor cells to wild-type p53 and p21WAF1/CIP1 overexpression

Expression of exogenous wild-type (wt) p53 protein can suppress the growth and/or induce apoptosis in different tumor cells. The effect of exogenous p21(WAF1/CIP1) expression is more controversial: while it can induce apoptosis in some cells, it can protect against p53-mediated apoptosis in others. We used adenoviral vectors to introduce p53 and p21(WAF1/CIP1) genes into human tumor cell lines with different p53 and/or p21(WAF1/CIP1) status. The cell growth inhibition and the induction of apoptosis were measured. Overexpression of wt p53 induced more efficient growth inhibition and apoptosis in SW 620 (mutant p53) and HeLa (inactivated p53 protein) than in MCF-7 (wt p53) and CaCo-2 cell line, which was the most resistant to p53 overexpression despite the p53 mutation. Unlike HeLa and SW 620 cells, the basal p21 protein level was readily detected in CaCo-2 and MCF-7 cells. Overexpression of p21(WAF1/CIP1) gene induced somewhat less pronounced growth inhibition of all cell lines tested, but it also induced apoptosis in HeLa and SW 620 cells. These results suggest that the basal, but not the inducible, levels of p21(WAF1/CIP1) protein in tumor cells could protect from p53-mediated apoptosis. On the other hand, overexpression of p21(WAF1/CIP1) gene itself can induce apoptosis in cells with no basal p21(WAF1/CIP1) protein level. Possible mechanisms of the differential response to these genes are discussed.     

胃肠道类癌中生长抑素和p21^WAF1/CIP1蛋白表达的意义

目的探讨生长抑素和p21WAF1/CIP1蛋白阳性表达与胃肠道类癌的组织分化、浸润和转移的关系.方法采用免疫组化S-P法对36例胃肠道类癌组织生长抑素和p21WAF1/CIP1蛋白的表达进行检测.结果 36例类癌组织中,生长抑素和p21WAF1/CIP1蛋白较多表达于高分化类癌组(P＜0.05),随着肿瘤的浸润和淋巴结转移,生长抑素阳性表达率显著降低(P＜0.01),p21WAF1/CIP1阳性表达差异有显著性(P＜0.05).结论生长抑素和p21WAF1/CIP1低表达在类癌的组织分化和发展中起着重要作用,可用于临床对患者进行预后判断.     

Loss of p21WAF1/CIP1 expression correlates with disease progression in gastric carcinoma.

Previous studies have shown that tumour-suppressor genes play an important role in the progression of solid tumours. Recently, the p21WAF1/CIP1 tumour-suppressor protein has been reported to work as a critical downstream effector of p53 and a potent inhibitor of cyclin-dependent kinases. Thus, the p21WAF1/CIP1 gene is thought to play a central role in tumour suppression. In this study we investigated p21 protein expression in gastric carcinomas. A total of 172 primary gastric carcinoma specimens were immunohistochemically stained for p21 protein expression. Correlations between p21 expression and clinicopathological features were examined. Loss of p21 expression was observed in 104 of 172 tumour tissues (60.4%), and the frequency of p21 loss increased as the stage progressed. Expression of p21 in the primary tumour was frequently lost in patients with either lymph node, liver or peritoneal metastases as compared with patients without metastases. In patients with p21-negative tumours, the risk of recurrence following curative surgery was significantly higher, and the prognosis was significantly poorer than in patients with p21-positive tumours. Loss of p21 expression in primary gastric carcinoma correlates with disease progression. The status of p21 gene expression may have prognostic value in this disease.     

Expression of p53 and p21CIP1/WAF1 proteins in oral epithelial dysplasias and squamous cell carcinomas

The expression of tumor suppressor gene, p53 and cyclin-dependent kinase inhibitor, p21 in oral epithelial dysplasia and oral squamous cell carcinoma (OSCC) was examined immunohistochemically and its relationship with clinicopathological findings was analyzed. Among 24 epithelial dysplasias, 4 cases (17%) expressed p53 protein and 23 cases (96%) expressed p21 protein. On the other hand, expression of p53 was observed in 64% of OSCCs, and expression of p21 was observed in 77% of OSCCs. In the analyses of the correlation between the expression of p53 and p21 in epithelial dysplasia and OSCC, 79% of epithelial dysplasias were p53-negative and p21-positive, compared to 25% of the OSCCs. p21 expression did not correlate with p53 expression. These results were also demonstrated in OSCC cell lines by western blot analysis. Cumulative survival rate of the patients p53-negative and p21-positive was higher than those p53-positive and p21-negative, those p53-negative and p21-negative and those p53-positive and p21-positive. These findings suggest that p53 expression and p21 negative expression may involve in neoplastic transformation of oral epithelium. In the present study, we did not observe correlation between the expression of p53 and p21 proteins in OSCC. p21 expression may be regulated by p53-independent pathways as well as p53-dependent ones. However, combination of the p21 and p53 expression may be useful as a prognostic marker.     

Asiatic Acid Promotes p21WAF1/CIP1 Protein Stability through Attenuation of NDR1/2 Dependent Phosphorylation of p21WAF1/CIP1 in HepG2 Human Hepatoma Cells

Previous studies have suggested anti-tumor effects of asiatic acid in some human cancer cell lines. This agent isreported to increase the levels of p21WAF1/CIP1 in human breast cancer cell lines. However, the molecular mechanismshave not been established. Here we report that asiatic acid up-regulates p21WAF1/CIP1 protein expression but notthe level of p21WAF1/CIP1 mRNA in HepG2 human hepatoma cells. Furthermore, we found that the asiatic acidinduced increase of p21WAF1/CIP1 protein was associated with decreased phosphorylation (ser-146) of p21WAF1/CIP1.Knockdown of NDR1/2 kinase, which directly phosphorylates p21WAF1/CIP1 protein at ser-146 and enhances itsproteasomal degradation, increased the levels of p21WAF1/CIP1 protein and eliminated the regulation of p21WAF1/CIP1 stability by asiatic acid. At the same time, the expression of NDR1/2 kinase decreased during treatment withasiatic acid in HepG2 cells. Moreover, asiatic acid inhibited the proliferation of HepG2 cells, this being attenuatedby knockdown of p21WAF1/CIP1. In conclusion, we propose that asiatic acid inhibits the expression NDR1/2 kinaseand promotes the stability of p21WAF1/CIP1 protein through attenuating NDR1/2 dependent phosphorylation ofp21WAF1/CIP1 in HepG2 cells.     

Expression of p21 (WAF1/CIP1) protein in clinical thyroid tissues.

p21 (WAF1/CIP1) protein expression in various thyroid tissues, including thyroid carcinoma, was studied by means of immunohistochemistry using anti-p21 monoclonal antibody. Normal follicles and hyperplasias rarely expressed p21, whereas immunohistochemically positive cells were also too rarely found in follicular adenomas to justify these cases being classified as positive. Twenty eight of the 93 carcinomas examined (30.1%), however, were positive for p21. Of the p21-positive cases, 80% of the undifferentiated and 28.6% of the poorly differentiated carcinomas showed lesions co-expressing p21 and p53. If diffuse immunoreactivity of p53 reflects the p53 mutation, our results indicate that p21 in these carcinomas can be induced by p53-independent as well as by p53-dependent pathways. On the other hand, well-differentiated carcinomas did not co-express these two proteins and it therefore remains unclear whether p53-independent or p53-dependent pathways are predominant in this type of carcinoma. The incidence of expression of p21 was very similar in undifferentiated (26.3%), poorly (28.0%) and well-differentiated carcinomas (32.7%), even though they are characterised by different degree of malignancy. Furthermore, no correlation between p21 expression and either clinical parameters or patient''s prognosis could be established. These results suggest that p21 is only marginally related to the characteristics of thyroid carcinoma and can play only an adjuvant role in regulating the progression of this carcinoma.     

p21WAF1/CIP1和p53蛋白表达在胃癌发生发展过程中的研究

目的研究p21WAF1/CIP1和p53蛋白在胃癌发生发展过程中的作用及表达的临床病理意义.方法采用免疫组化SP法对正常胃粘膜、萎缩性胃炎伴肠上皮化生、萎缩性胃炎伴不典型增生组织各20例和78例胃癌组织标本进行p21WAF1/CIP1和p53蛋白检测.结果胃癌组织中p53蛋白阳性表达率高于正常胃粘膜、萎缩性胃炎伴肠上皮化生和不典型增生组(P＜0.05),而p21WAF1/CIP1蛋白阳性表达低于正常胃粘膜、萎缩性胃炎伴肠上皮化生组(P＜0.01)p21WAF1/CIP1、p53蛋白表达与胃癌的分化程度相关(P＜0.05);有淋巴结转移组p21WAF1/CIP1蛋白表达率低于无淋巴结转移组(P＜0.05),而有淋巴结转移组p53蛋白表达率高于无淋巴结转移组(P＜0.05);p53蛋白表达与胃癌浸润深度有关.结论p53蛋白高表达与p21WAF1/CIP1蛋白失表达可能参与胃癌的发生发展过程;检测p53和p21WAF1/CIP1蛋白作为反映胃癌病理学特点的参考指标可能有一定意义;p21WAF1/CIP1蛋白表达在胃癌可能存在非p53诱导表达途径.     

子宫内膜癌p21WAF1/CIP1蛋白的表达及其意义

背景与目的:探讨p21WAF1/CIP1蛋白在子宫内膜癌中的表达情况及其意义.材料与方法:应用免疫组织化学SP法检测30例正常子宫内膜,20例单纯性增生性宫内膜,22例不典型增生性宫内膜,57例子宫内膜癌(高分化32例,中分化12例,低分化13例)中p21WAF1/CIP1蛋白的表达. 结果:p21WAF1/CIP1蛋白表达于细胞核,子宫内膜癌中p21WAF1/CIP1蛋白的表达明显低于正常子宫内膜和单纯性增生性子宫内膜(P＜0.01),且p21WAF1/CIP1蛋白的表达与子宫内膜癌组织有无肌层浸润及临床分期明显相关(P均＜0.05).结论:p21WAF1/CIP1蛋白表达降低可能在子宫内膜癌的发生发展及判断预后方面具有重要作用.     

P21WAF1/CLP1在甲状腺癌组织的表达及临床意义

[目的]探讨p21WAF/CLP与p53基因在甲状腺癌中的表达与病理类型和分化程度的关系。[方法］应用免疫组化技术检测甲状腺癌组织中的抑癌基因p2lWAF/CLPl及p53基因的表达。统计学采用x2检验。[结果]甲状腺腺瘤(TT),甲状腺乳头状癌(PTC)、滤泡状癌(FTC)、未分化癌(UDC)组织p21蛋白阳性率分别为66.7％、62 5％、58.3％、50.0％,各组之间无显著差别(P＞0.05);高分化癌(WDC)、低分化癌(PDC)、UDC组织p21蛋白阳性率分别为67.7％、46.2％、50.0％,各组之间无显著差别(P＞0.05);PTC、FTC、UDC组织p53蛋白阳性率分别为31.3％、25.0％、64.3％,UDC与PTC、FTC之间存在显著差别(P＜0 05);WDC、PDC、UDC组织p53蛋白阳性率分别为l6.1％、61.5％、64.3％,WDC的阳性率明显低于PDC、UDC(P＜0.05);p53蛋白阳性的癌组织p21蛋白阳性率为40.9％(9/22),p53蛋白阴性的癌组织p21蛋白阳性率为69.4％(25/36),两者之间存在显者差异(P＜0 05)。[结论］甲状腺癌中p21WAF/CLP的表达与其病理类型和分化程度无关,而p53基因的表达与甲状腺癌病理类型和分化程度有关,p2WAFl/CLPl作为一新的抑癌基因,其表达相当程度上依赖于p53蛋白。     

Aberrant expression of p21(WAF1/CIP1) and p27(KIP1) in cervical carcinoma

An immuno-histochemical study of p21 and p27 expression in cervical carcinoma was performed in 73 patients. Positive p21 and p27 staining was detected in 35.6 and 11% of tumour tissues, respectively. p21 expression was significantly correlated with advanced disease stage and negative human papilloma virus infection whilst positive p27 staining was not correlated with any clinical and pathological parameters studied. Kaplan-Meier estimation indicated that survival might be related to disease stage, tumour grade and p21 expression. Cox regression analysis confirmed that advanced stage disease and poorly differentiated tumour are independent prognostic factors for cervical carcinoma.     

Cytoplasmic expression of p21CIP1/WAF1 is correlated with IKKbeta overexpression in human breast cancers

Regulation of cytoplasmic p21CIP/WAF1 (p21) is of great clinical significance in molecular oncology due to its identification as an antiapoptotic factor, a poor survival predictor as well as a drug-resistance inducer. A retrospective study of the immunohistochemical (IHC) profiles of 128 human primary breast cancers showed that increased total and cytoplasmic p21 expression were highly associated with the expression of IkappaB kinase beta (IKKbeta), the major catalytic subunit of the IKK complex and another crucial player in tumorigenesis and drug resistance. The causal relationship study based on cultured cell lines, MDA-MB-453 and MCF-7, confirmed that IKKbeta overexpression did upregulate protein levels of total and cytoplasmic p21. Mechanistic investigation demonstrated that IKKbeta increased p21 expression through upregulation of p21 mRNA level. Moreover, by Western blotting, IKKbeta was found to be able to upregulate Akt phosphorylation on Ser 473. This novel finding indicated that IKKbeta could mediate cytoplasmic p21 accumulation via activation of its downstream target Akt, which was known to phosphorylate p21 and lead to cytoplasmic localization of p21.     

Clinical significance of p21(WAF1/CIP1) and p53 expression in serous cystadenocarcinoma of the ovary

There have been many reports indicating that the down-regulation of p21(WAF1/CIP1) is related to carcinogenesis and the development of various tumors; nevertheless, its association with epithelial ovarian cancer (EOC) remains controversial. In this study, we focused on serous ovarian cancer, which is the most prevalent histological type, and performed immunohistochemical analysis to examine the expression of p21(WAF1/CIP1) and p53 in 43 cases of serous-type EOC sourced from a single University Hospital: 14 stage I, 4 stage II, 21 stage III, and 4 stage IV. Positive p21(WAF1/CIP1) was found in 24 of 43 cases (56%), and positive p53 was detected in 21 of 43 cases (49%). Among stage III/IV cases, positive p21(WAF1/CIP1) staining was found in 11 of 25 cases (44%), and positive p53 staining was detected in 13 of 25 cases (52%). Univariate survival analysis for the entire cohort revealed that positive p21(WAF1/CIP1) was associated with a survival benefit. The 10-year survival rates of p21(WAF1/CIP1)-positive staining and p21(WAF1/CIP1)-negative staining were 82.4 and 39.5%, respectively, and there was a significant difference between the two groups (p<0.01). Overall survival for p21(WAF1/CIP1)-positive with p53-negative staining [p21(+)/p53(-)] was significantly different from p21(WAF1/CIP1)-positive with p53-positive [p21(+)/p53(+)], p21(WAF1/CIP1)-negative with p53-positive staining [p21(-)/p53(+)], and p21(WAF1/CIP1)-negative with p53-negative staining [p21(-)/p53(-)] (p<0.05). When only III/IV cases were evaluated, overall survival for [p21(+)/p53(-)] was significantly different from [p21(+)/p53(+)], [p21(-)/p53(+)], and [p21(-)/p53(-)] (p<0.05). These results suggested that the overexpression of p21(WAF1/CIP1) in conjunction with the loss of p53 expression was a stronger predictor of survival benefit than either molecule alone in Japanese serous-type advanced ovarian cancers with more than 10-year follow-up.     

P21WAF1/CIP1蛋白表达与上皮性卵巢癌预后的关系

目的 探讨P21蛋白表达与上皮性卵巢癌预后的关系。方法 30例正常卵巢、30例良性卵巢肿瘤、108例上皮性卵巢癌标本用免疫组化的方法检测P21蛋白表达。结果 正常卵巢组、良性肿瘤组、卵巢癌组的P21蛋白阳性表达率分别为88．33％、80．00％、64．81％，恶性组阳性率低于其它两组(P=0．014)。P21(-)和P21( )患者的5年生存率分别为31．58％和47．14％，差异有显著性(P=0．0246)。结论 P21蛋白表达对判断上皮性卵巢癌预后有指导意义。     

Mutational analysis of the p21/WAF1/CIP1/SDI1 coding region in human tumor cell lines

p21/WAF1/CIP1/SDI1 is an important cell-cycle mediator with tumor suppressor gene capabilities, and its inactivation could potentially lead to tumor progression. Because tumor suppressor genes are commonly inactivated by somatic and germline mutations, we analyzed a variety of human tumor cell lines for p21 mutations. We used single-strand conformational analysis and direct sequencing to identify possible mutations in the p21 coding region. Two base-alterations were observed in 41 immortalized human tumor cell lines. A previously reported polymorphism that results in a serine-to-arginine amino-acid substitution at codon 31 was found in 24% (10 of 41) of the tumor cell lines but was also found in 10% (six of 62) of normal parental DNAs tested and 7% (three of 43) of normal DNAs from patients with primary endometrial tumors. Another nucleotide substitution found at codon 80 resulted in the replacement of threonine with methionine. Codon 80 changes were found in 7% (three of 41) of the tumor cell lines (all endometrial) and in 2% (one of 62) of the normal parental DNAs. (This article is a US Government work and, as such, is in the public domain in the United States of America.)