Differential expression of cdk inhibitors p16, p21cip1, p27kip1, and cyclin E in cervical cytological smears prepared by the ThinPrep method

Our objective was to correlate p16, p21cip1, p27kip1, and cyclin E protein expression with the degree of dysplasia on ThinPrep Papanicolaou (Pap) smears using a modified immunoperoxidase staining. Smears read as normal, atypical squamous cells of undetermined significance (ASC-US), low-grade squamous intraepithelial lesion (LSIL), or high-grade SIL (HSIL) were identified and tested for high-risk human papillomavirus (HR-HPV). Additional smears were processed for immunoperoxidase for p16, p21cip1, p27kip1, and cyclin E. Thirty-four smears were satisfactory for study. The p16 was positive in all nine HSIL, in four of nine LSIL, and in one of seven ASC-US. The p27kip1 was positive in all nine HSIL, in eight of nine LSIL, and in one of seven ASC-US. The p21cip1 was positive in all nine HSIL, in one of nine LSIL, and in one of seven ASC-US. Cyclin E was positive in seven of nine HSIL and in one of nine LSIL and in none of the ASC-US smears. Normal smears were negative for all the antigens. There was poor correlation of protein expression and HR-HPV infection. We concluded that p16, p21cip1, p27kip1, and cyclin E can be demonstrated on Pap smears and they are expressed differentially in dysplastic cells, with highest expression in HSIL. The p21cip1 and cyclin E showed the greatest correlation with HSIL.     

Expression of p21Waf1, p27Kip1 and cyclin D1 proteins in breast ductal carcinoma in situ: Relation with clinicopathologic characteristics and with p53 expression and estrogen receptor status

p21Waf1 (p21), p27Kip1 (p27) and cyclin D1 have recently been reported as useful prognostic markers for patients with breast carcinoma. However, studies on these cell cycle regulators in ductal carcinoma in situ (DCIS) have been extremely limited. Therefore, we studied the immunohistochemical expression of p21, p27 and cyclin D1 proteins in 49 DCIS cases and compared the findings with the clinicopathologic parameters (age, tumor size, gross type, histologic type, histologic grade, necrosis and mitotic index), p53 and estrogen receptor (ER) status. A significant correlation was found between positive p21 immunoreactivity (67.3% of the cases) and well-differentiated histologic grade, non-comedo type, ER-positive and p53-negative (p53-) status. DCIS with p21+/p53- is likely to be the non-comedo type. The overexpression of cyclin D1 (59.2% of the cases) correlated positively with the ER expression (P = 0.001). The p27 protein expression (46.9% of the cases) correlated with the cyclin D1 immunopositivity (P = 0.0003) and ER expression (P = 0.005). No significant associations were seen in the p27 or cyclin D1 expression and other clinicopathologic parameters. Our results suggest that p21 might be more related to the useful biologic markers in DCIS than p27 or cyclin D1. The significant positive association between p21, p27 or cyclin D1 and ER status, and close association of p27 and cyclin D1 expression might be implicated in the tumor biology of DCIS.     

nm23—H1与p21、p53蛋白在人卵巢癌中表达的相关性研究

目的：研究人卵巢癌组织中肿瘤转移抑制基因nm23-H1、抑癌基因p21^WAFI及p53蛋白的表达,探讨它们在卵巢癌发生、发展中的作用。方法：采用免疫印迹技术,对74例卵巢癌组织及21例卵巢非癌组织中nm23-H1p21^WAFI及p53蛋白进行检测。结果：在卵巢癌中nm23-H1、p53蛋白的表达高于卵巢非癌组织,p21^WAFI蛋白的表达呈下调;肿瘤发生转移时卵巢癌组织中nm23-H1和p21WAF蛋白表达显著低于未发生肿瘤转移的癌组织。p53蛋白表达与肿瘤转移无关。nm23-H1 \p21^WAFI 蛋白与卵巢癌组织类型无关,但与卵巢癌的临床分期相关。p53蛋白的表达与卵巢癌组织类型及卵巢癌的临床分期无关。nm23-H1与p53、p21^WAFI蛋白间表达在卵巢癌中呈相关性。结论：nm23-H1、p53、p21^WAFI 基因在卵巢癌发生、发展中起一定的作用,nm23-H1与p53、p21^WAFI基因在卵巢癌发生、发展中可能起协同作用。     

p73基因在卵巢上皮性肿瘤中的表达及甲基化研究

目的 探讨卵巢上皮性肿瘤中p73蛋白的表达和基因启动子的甲基化情况,并观察其与临床病理学特征的关系.方法 制备包括68例卵巢癌、37例卵巢交界性肿瘤和21例卵巢良性肿瘤的组织芯片,用免疫组织化学EnVision法检测上述组织中p73蛋白表达情况,用亚硫酸氧盐修饰后测序法检测13例新鲜卵巢癌组织及5例新鲜卵巢交界性肿瘤组织的p73基因启动子甲基化情况.结果 92.6％ (63/68)的卵巢癌表达p73,p73蛋白总体表达率均值为32％(p73表达率指p73阳性细胞数所占的百分比),其中浆液性癌( 26/26)的表达率均值为40％,高于其他组织类型的癌(P=0.006).按照卵巢癌发病模式区分,Ⅱ型卵巢癌p73表达率均值(40％)高于Ⅰ型卵巢癌(24％),P=0.010.卵巢癌中p73的表达与临床分期及组织学分级无相关性(均P＞0.05).卵巢交界性肿瘤组(30/37)和良性肿瘤组(12/21)p73的总体表达率均值分别为16％和15％,该两组肿瘤中浆液性肿瘤表达率均值均高于黏液性肿瘤(P-0.003,P=0.026).卵巢癌组的p73阳性表达率均值明显高于交界性肿瘤组和良性肿瘤组(均P ＜0.05),交界性肿瘤组与良性肿瘤组比较差异无统计学意义(P＞0.05).浆液性肿瘤( 49/53)中,卵巢癌组(26/26) p73阳性表达率均值明显高于交界性肿瘤组(12/14)和良性肿瘤组(11/13;P =0.024和P=0.002),而卵巢交界性肿瘤组和良性肿瘤组比较差异无统计学意义(P=0.428).黏液性肿瘤(15/27)中,卵巢癌组(6/7)p73阳性表达率均值高于良性肿瘤组( 1/8;p=0.032),而卵巢癌组与卵巢交界性肿瘤组(8/12)、交界性肿瘤组与良性肿瘤组比较,差异均无统计学意义(P=0.234和P=0.201).p73启动子的甲基化结果显示,13例卵巢癌有8例发生甲基化,但每例样本甲基化频率有所不同,总体甲基化频率均值为8.0％.5例交界性肿瘤有2例发生甲基化,总体甲基化频率均值为9.0％,两组比较差异无统计学意义(P＞0.05).卵巢癌组p73甲基化额率与组织类型、发病模式、组织学分级及临床分期均无相关性(均P＞0.05).结论 卵巢上皮性肿瘤多数表达p73,卵巢癌p73的表达率均值明显高于交界性肿瘤和良性肿瘤,浆液性肿瘤高于其他组织类型;p73蛋白表达率与p73基因甲基化程度不存在简单线性相关关系.     

Expression of cell cycle regulatory proteins in the multistep process of oesophageal carcinogenesis: stepwise over-expression of cyclin E and p53, reduction of p21(WAF1/CIP1) and dysregulation of cyclin D1 and p27(KIP1)

AIMS: Cell cycle regulatory proteins were analysed by immunohistochemistry in order to clarify how their expression changes with the degree of atypia as oesophageal surface squamous epithelium progresses from normal mucosa, through reactive change, low-grade dysplasia, and high-grade dysplasia to mucosal invasive carcinoma. METHODS AND RESULTS: Immunostaining for cyclin D1, cyclin E, p21, p27, p53 and Ki67 proteins was performed using 22 normal mucosa, 17 reactive change, 22 low-grade dysplasia, 15 high-grade dysplasia and 22 mucosal invasive carcinoma specimens. Normal mucosa, low-grade dysplasia and high-grade dysplasia samples were taken from patients without any oesophageal invasive carcinoma by endoscopic biopsy or endoscopic mucosal resection, and reactive change and mucosal invasive carcinoma were obtained from oesophagectomy material. Stepwise over-expression of cyclin E (P < 0.0001) and p53 (P < 0.0001), reduction of p21 (P=0.0189) and dysregulation of cyclin D1 and p27 were observed in the multistep process of oesophageal carcinogenesis. Significant differences in expression of p27 (P < 0.0001), p53 (P=0.0299) and Ki67 (P=0.0101) were observed between reactive change and low-grade dysplasia. Furthermore, expression of cyclin D1, cyclin E, p27 and p53 in mucosal invasive carcinoma were significantly different from those in high-grade dysplasia (P=0.0079, P=0.0237, P=0.0042 and P= 0.0299, respectively). CONCLUSIONS: Cell cycle regulatory proteins, cyclin E, p53 and p21 show stepwise over-expression or reduction with progression of oesophageal carcinogenesis, correlating with the increased cell proliferation observed with Ki67 labelling. We conclude that immunohistochemical analysis for p27, p53 and Ki67 is practically useful for the discrimination between low-grade dysplasia and reactive change. Cyclin D1, cyclin E, p27 and p53 help to distinguish high-grade dysplasia from mucosal invasive carcinoma.     

Downregulation of Skp2 and p27/Kip1 synergistically induces apoptosis in T98G glioblastoma cells

S-Phase kinase associated protein (Skp) 2 is an F-box protein required for substrate recognition of the SCF^Skp2 ubiquitin ligase complex. Skp2 is often overexpressed in transformed cells and in various types of tumors. Downregulation or inhibition of Skp2 inhibits growth of breast cancer cells and small-cell lung carcinoma cells. We downregulated Skp2 in T98G glioblastoma cells using small interfering RNA (siRNA). Downregulation induced p27 and caused growth arrest and apoptosis. Downregulation of both Skp2 and p27 increased apoptosis synergistically. Cyclin E levels and cyclin E-CDK2 kinase activity increased dramatically when both Skp2 and p27 were downregulated. Coincidently, Bcl-2 but not Bcl-xL expression decreased, and caspase-3 was activated. Inhibition of cyclin E-CDK2 kinase activity by forced expression of p21 reversed these effects. Moreover, stable expression of Bcl-2 also abrogated apoptosis induced by downregulation of Skp2 and p27. We suggest that Skp2 in tumor cells suppresses apoptosis through Bcl-2 expression, potentially through regulation of cyclin E-CDK2 activity.     

细胞周期素E和p53在乳腺癌中表达及意义

目的 探讨细胞周期素E(cyclin E)和p53在乳腺癌中表达的意义和相瓦关系.方法 采用免疫组化方法 (SP法)观察82例乳腺癌、15例乳腺良性肿瘤与15例正常乳腺组织的eyclin E和p53的表达.结果 正常乳腺组织和良性肿瘤中cyclin E和p53无表达,乳腺癌组织中cyclin E和p53的阳性表达率分别为56.10%和60.98%(P<0.05),cyclin E和p53的阳性表达与乳腺癌的临床分期密切相关(P<0.05);cyclin E和p53在乳腺癌的阳性表达具有相关(P<0.05),共同阳性表达的患者5年生存率明显低于阴性者(P<0.05).结论 cyclin E在乳腺癌中的表达与p53的表达呈明显的一致性,并在肿瘤的进展中起一定的作用,cyclin E和p53在乳腺癌中的共同阳性表达可作为乳腺癌预后的有效指标.     

Correlation of cyclin D1 and E1 expression with bladder cancer presence, invasion, progression, and metastasis

The objective of this study was to determine the correlation of the expression of cyclin D1 and E1 with the expression of commonly altered cell cycle regulators and bladder cancer presence, staging, and clinical outcomes. We performed immunohistochemical staining for cyclin D1, cyclin E1, p53, p21, p27, and retinoblastoma protein (pRB) on serial cuts from normal urothelium from 9 controls, radical cystectomy specimens from 226 consecutive patients with advanced transitional cell carcinoma, and lymph nodes with metastasis from 50 of the 226 cystectomy patients. Cyclin D1 and E1 immunoreactivity were considered low when samples demonstrated less than 10% and 30% nuclear reactivity, respectively. Normal bladder urothelium from all 9 control patients showed uniformly intense expression of cyclin D1 and E1. Cyclin D1 expression was low in 99 (43.8%) of 226 cystectomy specimens and 25 (50.0%) of 50 metastatic lymph node specimens. Cyclin D1 immunoreactivity was not associated with any pathologic characteristics or clinical outcomes. Cyclin E1 expression was low in 125 (55.3%) of 226 cystectomy specimens and 22 (44.0%) of 50 metastatic lymph node specimens. Low cyclin E1 expression was significantly associated with advanced pathologic stage, lymphovascular invasion, and lymph node metastases. In multivariate analyses, low cyclin E1 expression was significantly associated with bladder cancer-specific mortality (P = .048), but not disease recurrence (P = .056). Low cyclin E1 expression was significantly associated with altered expression of pRB, p27, and cyclin D1. Low cyclin D1 expression was significantly associated with altered expression of pRB, p21, and cyclin E1. Cyclin E1 expression stratifies patients with bladder transitional cell carcinoma into those with more "indolent" behavior and those with features of biologically and clinically aggressive disease.     

Bcl-2 and p53 protein expression, apoptosis, and p53 mutation in human epithelial ovarian cancers

Bcl-2 and p53 gene products have been both linked to cell death by apoptosis. In the present study, we examined the relationship of Bcl-2 and p53 protein expression, p53 mutation and apoptosis in normal human ovaries and different types of human ovarian epithelial tumors by immunohistochemical localization, in situ terminal transferase-mediated dUTP nick end labeling and polymerase chain reaction-single strand conformation polymorphism. It was found that Bcl-2 expressed strongly in the surface epithelium of normal ovaries and benign and borderline ovarian tumors but weakly in the malignant tumors. On the contrary, strong protein expression of p53 was found in 54% (25/46) of the malignant epithelial tumors examined but similar expression of p53 was not observed in borderline and benign tumors and normal ovarian surface epithelium. A significant inverse correlation between Bcl-2 and p53 expression was found in the malignant ovarian tumors examined. p53 gene mutation at exons 5-11 was however not a pre-requisite for p53 expression in both borderline and malignant tumors. Apoptotic activities, as reflected by apoptotic indices, were low in normal ovarian surface epithelium and benign tumors but were increased in borderline and malignant tumors, with the highest average apoptotic index found in grade III malignant tumors. Statistical analyses showed a positive correlation between apoptosis and p53 expression, but similar correlation was not found between apoptosis and Bcl-2 expression. Our results also indicate that although expression of Bcl-2 is important during ovarian carcinogenesis, the Bcl-2 protein may have other roles to play apart from being a modulator of apoptosis in human ovarian epithelial cancers.     

Expression of differentiation and proliferation related proteins in epithelium of prophylactically removed ovaries from women with a hereditary female adnexal cancer predisposition

AIMS: To investigate the occurrence of preinvasive neoplastic lesions in ovarian surface epithelium and ovarian inclusion cyst epithelium of women with a hereditary predisposition to the development of female adnexal (ovarian and fallopian tube) carcinoma and to assess the expression of differentiation and proliferation related proteins within putative sites of origin of serous ovarian carcinoma, the ovarian surface epithelium and ovarian inclusion cyst epithelium. METHODS: Twenty-one ovaries, prophylactically removed from 11 women predisposed to the development of female adnexal cancer (cases) were compared with 22 ovaries from 11 women without such predisposition (controls). Archival histological specimens were screened for hyperplastic and dysplastic epithelial lesions. In both the ovarian surface and inclusion cyst epithelia, the percentage of cells was determined that stained positively for Ki67, p21, p27, p53, cyclin A, cyclin D1, bcl-2 and the presence of HER-2/neu, oestrogen (ER-alpha) and progesterone receptors (PR). RESULTS: No preinvasive neoplastic lesions were detected. However, hyperplastic areas were found in three cases and in four controls (NS). ER-alpha (P = 0.013), PR (P < 0.001), bcl-2 (P = 0.008), p21 (P = 0.046) and p27 (P = 0.008) were expressed in a significantly higher percentage of cells in inclusion cyst epithelium than in ovarian surface epithelium (both groups). The latter showed higher bcl-2 expression in cases (P = 0.05) compared with controls. The inclusion cyst epithelium of cases showed higher expression of bcl-2 (P = 0.006) and PR (P = 0.039) compared with controls. Proliferation was low in both cases and controls as reflected by low Ki67 expression. Over-expression of p53, cyclin D1 and HER-2/neu was not detected. CONCLUSIONS: Premalignant changes are not a common feature of ovaries removed prophylactically from women predisposed to the development of female adnexal carcinoma. Increased expression of p21, p27, and ER-alpha is seen in inclusion cyst compared with ovarian surface epithelium of women with and without an inherited risk of adnexal carcinoma. This is most probably caused by the different intraovarian hormonal milieu of inclusion cyst epithelium. However, the increased expression of bcl-2 and PR in the inclusion cyst epithelium of patients with a hereditary predisposition may reflect early disruption of hormonal balance and growth control.     

Correlation of enhanced cell turnover with prognosis of gastrointestinal stromal tumors of the stomach: relevance of cellularity and p27kip1

The aim of the present study was to determine whether expression of molecules associated with cell cycle regulation and apoptosis might reflect tumor grade and patients' prognosis of gastrointestinal stromal tumor (GIST). Forty-nine cases of gastric GIST were divided into three grades; low, intermediate, and high risk. Ki-67, cyclin A, cyclin D1, cyclin E, p16(Ink4), p21(Waf1), p27(Kip1), cyclin-dependent kinase (cdk)2, cdk4 and single-strand DNA (ssDNA) were immunohistochemically stained and assessed. Ki-67, ssDNA, cyclin A and cdk2 had higher labeling indices (LI) in high-risk than in low-risk cases. Cyclin E expression was greater in the intermediate- than in the low-risk grade. On Kaplan-Meier analysis, tumor size, necrosis, cellularity, Ki-67, ssDNA, and cyclin A LI were significantly correlated with disease-free survival. Necrosis, cellularity, and Ki-67 LI were significant as prognostic factors on univariate, and Ki-67 LI on multivariate Cox hazard tests. Within the high-risk grade, high cellularity and low p27(Kip1) subgroups had the worst prognosis. The histological grade is related to cell turnover, assessed in terms of Ki-67, ssDNA, cyclin A, cyclin E, and cdk2 levels. Ki-67, ssDNA, and cyclin A are useful for prediction of prognosis, with cellularity and p27(Kip1) expression as further prognostic factors in high-risk cases.     

Increased cyclin D3 expression significantly correlates with p27 nuclear positivity in gastrointestinal stromal tumors

Gastrointestinal stromal tumors, the most common mesenchymal tumors of the gastrointestinal tract, are characterized by strong expression of c-Kit protein. Recently, it has been shown that gastrointestinal stromal tumors may also contain alterations of genes involved in the regulation of cell cycle. In this study, we evaluate the prevalence and clinical significance of cyclin D1 and D3, Ki-67, p27, and retinoblastoma protein expression in a group of 50 human gastrointestinal stromal tumors selected from the files of the Moffitt Cancer Center. Tissue sections from each case were subjected to immunostaining using the avidin-biotin complex method. Cyclin D1 nuclear positivity was detected in 21 of 50 (42%) and cyclin D3 in 24 of 50 (48%) cases. p27 high immunoreactivity and negative or decreased retinoblastoma protein expression were identified in 33 of 50 (66%) gastrointestinal stromal tumors. In 19 of 50 (38%) tumors, Ki-67 had high labeling index. Direct correlation was observed between cyclin D3 and p27 expression (P < .0001), and between cyclin D1 and retinoblastoma protein (P = .03). Coexpression of cyclin D3 and p27 was demonstrated by immunofluorescence. The p27 protein expression inversely correlated with tumor size (P = .004), but was not correlated with tumor grade (P = .12). Ki-67 directly correlated with both tumor size (P = .03) and tumor grade (P = .008). We report a direct correlation between cyclin D3 and p27 expression in gastrointestinal stromal tumors. Additional alterations in cyclin D1, Ki-67, and retinoblastoma protein expression indicate a disregulated cell cycle in these tumors.     

Loss of Cell Cycle Regulators p27Kip1 and Cyclin E in Transitional Cell Carcinoma of the Bladder Correlates with Tumor Grade and Patient Survival

The cyclin-dependent kinase inhibitor p27(Kip1) is a powerful molecular determinant of cell cycle progression. Loss of expression of p27(Kip1) has been shown to be predictive of disease progression in several human malignancies. In this study we investigated the expression of two key cell cycle regulators, p27(Kip1) and cyclin E, in the progression of transitional cell carcinoma of the bladder. An immunohistochemical analysis was conducted in a series of 50 bladder tumor specimens, including 3 metastatic lymph nodes, and 7 normal bladder specimens, using specific antibodies against the two regulators of the cell cycle, p27(Kip1) and cyclin E. The degree of immunoreactivity was correlated with the pathological tumor grade, stage, and patient survival. A uniformly intense immunoreactivity for p27(Kip1) and cyclin E was observed in epithelial cells of normal bladder tissue. Malignant bladder tissue demonstrated a heterogeneous pattern of significantly reduced p27(Kip1) and cyclin E immunoreactivity, compared with normal urothelium (P < 0.01). In addition, there was progressive loss of expression of both cell cycle proteins with increasing tumor grade and pathological stage. Expression of p27(Kip1) was significantly lower in the poorly differentiated tumors (grades III) compared to well and moderately differentiated (grades I and II) tumors (P = 0.004). Moreover, the expression of cyclin E was lower in grade III tumors compared to grade I and II lesions, although this difference failed to reach statistical significance. Most significantly, Kaplan-Meier plots of patient survival show increased mortality risk associated with low levels of p27(Kip1) (P = 0.001) and cyclin E (P = 0.002) expression. This is the first evidence that loss of expression of p27(Kip1) and cyclin E in human bladder transitional cell carcinoma cells correlates with advancing histological aggressiveness and poor patient survival. These results have clinical importance, because they support a role for p27(Kip1) and cyclin E as novel predictive markers of the biological potential of bladder tumors that will enable identification of those tumors most likely to progress to muscle invasive disease and of patient survival.     

Expression of cell cycle regulators p57(KIP2), cyclin D1, and cyclin E in epithelial ovarian tumors and survival

The search for new prognostic indicators is especially important in the diagnosis and treatment of ovarian cancer because clinicopathologic criteria currently used to predict survival are largely inadequate. We examined 2 groups of patients with epithelial ovarian cancer, 1 group of long-term survivors (>5 years), and 1 group of short-term survivors (<2 years) for levels of expression of the cell cycle regulators p57(KIP2), cyclin D1, and cyclin E and their relationship with survival. Our findings show that p57(KIP2) is not associated with prognosis, in contrast to p27(KIP1) expression, which is previously shown to be positively associated with long-term survival in univariate analysis (P =.001). Cyclin E expression, in contrast to cyclin D1 expression, is marginally associated with short-term survival in univariate analysis for a group of 53 women. Among the short-term survivors, 15 (65%) of 23 were positive for cyclin E expression, compared with only 11 (37%) of 30 long-term survivors (P = 0.054). This association remained significant (P =.04) in a logistic regression analysis adjusted simultaneously for performance status and extent of residual disease, the 2 strongest predictors of survival in our study. We also found a significant difference in the frequency of the cyclin E staining pattern between nonserous and serous ovarian tumor subtypes (P =.0002). Immunostaining for levels of cyclin E and p27(KIP1) expression may have potential as prognostic markers in the management of ovarian cancer.     

Prognostic implications of cyclin B1, p34cdc2, p27(Kip1) and p53 expression in gastric cancer

PURPOSE: Cell cycle progression is regulated by interactions of specific cyclins and cyclin dependent kinases (CDKs) at the G1-S and G2-M checkpoints and cell cycle deregulation plays a major role in carcinogenesis of human cancers. PATIENTS AND METHODS: To investigate the role of cell cycle regulators in the pathogenesis and progression of human gastric cancers, 23 cases of gastric carcinomas were examined for the expression of cyclin B1, p34cdc2, p27(Kip1) and p53 by immunohistochemical methods, and gene expression was correlated with various clinicopathologic findings. RESULTS: Out of 23 cases studied, cyclin B1 was diffusely expressed in 20 cases (87.0%), p34cdc2 in 14 cases (60.9%) and p53 in 12 cases (52.2%), whereas in normal gastric tissues, cyclin B1 and p34cdc2 were weakly expressed and p53 was not expressed. In contrast, p27(Kip1) was expressed in only 8.7% of gastric carcinomas compared with 78.3% of normal gastric tissues. There was correlation between the expression of cyclin B1 and expression of p34cdc2 (p=0.002), between the expression of cyclin B1 and loss of p27(Kip1) (p=0.025), and between the expression of p34cdc2 and loss of p27(Kip1) (p=0.065). In addition, expression of cyclin B1 was correlated with regional lymph node metastasis (p=0.032). CONCLUSION: Our results indicate that cyclin B1 and p34cdc2 are involved in the genesis or progression of gastric cancers. Furthermore, overexpression of cyclin B1 may play an important role in lymph node metastatic potential of gastric cancer. Thus, abnormal expression of cyclin B1 and CDKs, overexpression of p53 and loss of p27(Kip1) expression may play important roles in human gastric carcinogenesis.     

肾癌中cyclinD1和p27kip1的表达及其意义

目的探讨cyc lin D1、p27k ip1在普通型肾细胞癌(renal cell carc inom a,RCC)发生、发展中的作用。方法用半定量RT-PCR方法检测25例普通型RCC和10例肿瘤远端的正常肾组织中cyc lin D1的mRNA含量,用免疫组化方法检测76例普通型RCC中cyc lin D1和p27k ip1蛋白的表达,并对cyc lin D1、p27k ip1蛋白表达与临床病理参数的关系进行分析。结果普通型RCC中cyc lin D1的mRNA含量0.488±0.399,高于正常对照组0.089±0.066(P<0.01)。cyc lin D1的表达与肿瘤体积大小有关,体积大者cyc lin D1高表达(P<0.05)。普通型RCC中p27k ip1表达低于正常对照组,随着p27k ip1表达的降低,肿瘤的细胞核Fu-hrm an分级、TNM分期增高。结论cyc lin D1高表达和p27k ip1的低表达与普通型RCC的发生有关;p27k ip1的低表达可能促进肿瘤的演进,p27k ip1的表达可作为评价普通型RCC预后的参考指标。     

非霍奇金淋巴瘤p27Kip1、p21WAF1及cyclin E表达的意义

目的 :探讨在非霍奇金淋巴瘤 (NHL)中 p2 7Kip1及其同族抑癌基因 p2 1WAF1、细胞周期素E(cyclinE)的表达意义。 方法 :应用免疫组化S P法检测 40例NHL患者受累淋巴结中 p2 7Kip1、p2 1WAF1、cyclinE蛋白表达情况 ,同时结合临床病理资料进行分析。结果 :40例NHL中 ,p2 7、p2 1、cyclinE蛋白阳性表达分别为 2 0例 (72 5 % )、8例 (2 0 % )、2 6例 (6 5 % )。 3种蛋白在NHL中的阳性表达与患者的性别、年龄及免疫分型无明显相关性 (P >0 0 5 ) ,但均与组织分化程度明显相关 (P <0 0 5 )。p2 7与cy clinE的表达水平间存在显著负相关 (r =- 0 2 7,P <0 0 1)。结论 :NHL患者淋巴组织中存在较高比例的 p2 7、p2 1蛋白阴性表达及较高比例的cyclinE阳性表达 ,说明在NHL的发生发展过程中 ,p2 7及其相关因素cyclinE ,同族基因 p2 1蛋白水平的异常变化起着重要作用 ,可作为NHL诊断标记物及预后指标。     

Expression of cyclooxygenase-2, p53 and Ki-67 in gastric cancer

It has been reported that p53 mutation may contribute to upregulate cyclooxygenase (COX)-2 expression that is observed in malignant tissues. These molecules are involved in carcinogenesis by affecting tumor cell proliferation. The aim of this study was to examine the relationship between COX-2 or p53 expression and clinico-pathological characteristics including tumor cell proliferation in gastric cancer. COX-2 and p53 expressions were investigated with immunostaining, in tissue specimens obtained from 119 patients who underwent surgery for gastric cancer. The Ki-67 labeling index (LI) was counted by Ki-67 immunostaining. COX-2 and p53 expressions correlated significantly with depth of tumor invasion. However, there was no association between COX-2 or p53 expression and survival. p53 expression did not correlate with COX-2 expression. There was no significant difference in various clinicopathological variables between Ki-67 LI subgroups. The mean Ki-67 LI value of COX-2 positive tumors was significantly higher than that of negative tumors. The mean Ki-67 LI value of p53 positive tumors was not significantly higher than that of negative tumors. The mean Ki-67 LI value of both COX-2 and p53 positive tumors was significantly higher than that of both negative tumors. These results imply that COX-2 expression is associated with tumor cell proliferation of gastric cancer.     

Bottom-up cell proliferation with cyclin A and p27Kip1 expression in ulcerative colitis-associated dysplasia

To analyze the cell kinetics of ulcerative colitis (UC)-associated dysplasia, cyclin A, cyclin D1, cyclin E, cdk2, cdk4, p21(Waf1), and p27(Kip1) were immunohistochemically examined, in comparison with sporadic tubular adenomas. Immunohistochemical labeling indices for each marker in formalin-fixed paraffin-embedded tissue sections were assessed in a total of 23 low-grade dysplasias, 27 high-grade dysplasias, and 14 invasive adenocarcinomas associated with UC. For comparison, 21 sporadic tubular adenomas with low-grade dysplasia, 33 with high-grade dysplasia, and 21 invasive adenocarcinomas were also examined. In UC-associated dysplasias, cyclin A and p27(Kip1) were located in the lower parts of the crypts and p21(Waf1) in the upper regions. In tubular adenomas, cyclin A, cdk4, p27(Kip1), and p21(Waf1) were all expressed in the upper parts of the crypts. The expression levels of cyclin D1, cyclin E, and cdk2 were low. The cell proliferation zone in UC-associated dysplasia is located towards the bases of the crypts with the strong expression of cyclin A and p27(Kip1), in contrast to tubular adenomas, which have their cell proliferation zone in the upper parts of neoplastic crypts. It is considered that tumorigenesis with UC-associated dysplasia is of the bottom-up type, related to altered expression of cyclin A and p27(Kip1).     

Frequent loss of PTEN expression is linked to elevated phosphorylated Akt levels, but not associated with p27 and cyclin D1 expression, in primary epithelial ovarian carcinomas

PTEN (MMAC1/TEP1), a tumor suppressor gene on chromosome subband 10q23.3, is variably mutated and/or deleted in a variety of human cancers. Germline mutations in PTEN, which encode a dual-specificity phosphatase, have been implicated in at least two hamartoma tumor syndromes that exhibit some clinical overlap, Cowden syndrome and Bannayan-Riley-Ruvalcaba syndrome. Among several series of ovarian cancers, the frequency of loss of heterozygosity (LOH) of markers flanking and within PTEN, is approximately 30 to 50%, and the somatic intragenic PTEN mutation frequency is <10%. In this study, we screened primary adenocarcinomas of the ovary for LOH of polymorphic markers within and flanking the PTEN gene and for intragenic mutations of the PTEN gene and compared them to PTEN expression using immunohistochemistry. Furthermore, we sought to detect the expression of the presumed downstream targets of PTEN, such as P-Akt, p27, and cyclin D1 by immunohistochemistry. LOH at 10q23 was observed in 29 of 64 (45%) cases. Of the 117 samples, 6 somatic intragenic PTEN mutations, 1 germline mutation, and 1 novel polymorphism were found in 7 (6%) patients. Immunostaining of 49 ovarian cancer samples revealed that 13 (27%) were PTEN immunostain-negative, 25 (51%) had reduced staining, and the rest (22%) were PTEN expression-positive. Among the 44 informative tumors assessed for 10q23 LOH and PTEN immunostaining, there was an association between 10q23 LOH and decreased or absent staining (P = 0.0317). Of note, there were five (11%) tumors with neither mutation nor deletion that exhibited no PTEN expression and 10 (25%) others without mutation or deletion but had decreased PTEN expression. Among the 49 tumors available for immunohistochemistry, 28 (57%) showed P-Akt-positive staining, 24 (49%) had decreased p27 staining, and cyclin D1 was overexpressed in 35 (79%) cases. In general, P-Akt expression was inversely correlated with PTEN expression (P = 0.0083). These data suggest that disruption of PTEN by several mechanisms, allelic loss, intragenic mutation, or epigenetic silencing, all contribute to epithelial ovarian carcinogenesis, and that epigenetic silencing is a significant mechanism. The Akt pathway is prominently involved, but clearly not in all cases. Surprisingly, despite in vitro demonstration that p27 and cyclin D1 lies downstream of PTEN and Akt, there was no correlation between p27 and cyclin D1 expression and PTEN or P-Akt status. Thus, in vivo, although PTEN and Akt play a prominent role in ovarian carcinogenesis, p27 and cyclin D1 might not be the primary downstream targets. Alternatively, these observations could also suggest that pathways involving other than Akt, p27 and cyclin D1 that lie downstream of PTEN play roles in ovarian carcinogenesis.