Overexpression of cyclin D1 and interaction between p27Kip1 and tumour thickness predict lymph node metastases occurrence in lower lip squamous cell carcinoma

We have attempted to identify those subgroups of patients most likely to develop lymph node metastases from squamous cell carcinoma of the lower lip (LLSSC). A total of 97 subjects, who did not undergo elective neck dissection, were recruited into the 60-month disease-free survival study. After univariate analysis, tumour size, histological grading, maximal thickness, perineural invasion and immunoreactivity to cyclin D1 and p27Kip1 proteins proved to be significant factors. Tests of the effect of interaction between p27Kip1 LI and tumour thickness yielded that the impact of tumour thickness on the risk of lymph node metastases was modified by the percentage of p27Kip1 positive cells. Subsequent to models of multivariate analysis, tumour size, positive cyclin D1 protein expression, maximal thickness (> 5 mm), p27Kip1 LI (%) and the interaction term between p27Kip1 LI and tumour thickness retained strong independent predictive values for lymph node metastases. We suggest that immunohistochemistry for cyclin D1 and p27Kip1 may prove to be valuable ancillary tests for identifying LLSSC with metastatic potential.     

Reduced expression of p27(Kip1) protein in relation to salivary adenoid cystic carcinoma metastasis.

BACKGROUND: Adenoid cystic carcinoma (ACC) is a malignant tumor of salivary gland origin. It tends to grow slowly but shows frequent recurrence and metastasis, ultimately with a poor outcome. Reduced expression of a cyclin-dependent kinase inhibitor, p27(Kip1), has been reported to correlate with poor survival for patients with various types of carcinoma. However, there has been no previous study reported of p27(Kip1) expression in ACC, to the authors' knowledge. METHODS: To evaluate p27(Kip1) as a prognostic marker, the authors examined the immunohistochemical expression of p27(Kip1) protein in 29 ACCs and correlated its expression with clinicopathologic findings. Eleven pleomorphic adenomas (PAs) were also examined to compare the p27(Kip1) expression in benign and malignant salivary gland tumors. RESULTS: All PAs expressed p27(Kip1) at high levels, whereas 83% of ACCs (24 of 29) showed reduced expression of this protein. Furthermore, the expression levels were significantly lower in ACCs with metastasis than in those without metastasis. The authors also examined the expression of p27(Kip1) in 2 ACC cell lines (ACCh and ACC3) by Northern and Western blot analysis to elucidate the possible mechanism of p27(Kip1) reduction in ACC. Both ACCh and ACC3 expressed p27(Kip1) mRNA, but ACCh did not produce p27(Kip1) protein. In ACCh, the expression of p27(Kip1) protein was induced by treatment with a proteasome inhibitor. CONCLUSIONS: Overall, these findings suggest that reduced expression of p27(Kip1) may correlate with the development and progression of salivary ACC and can be an indicator of its malignant behavior. They also suggest that increased proteasome-mediated degradation may play an important role in this reduction of p27(Kip1) expression.     

p27Kip1、PLK1在食管鳞癌中表达的临床意义

目的:探讨p27Kip1(p27)、polo-like kinase1(PLK1)在食管鳞癌(ESCC)与其癌旁组织中的差异表达及其相关性,分析其基因表达差异与ESCC的临床病理特点及蛋白表达与预后的关系。方法:RT-PCR和免疫组化检测70对ESCC与其癌旁组织中p27、PLK1的mRNA和蛋白表达情况。结果:比较70对ESCC与其癌旁组织中p27及PLK1的相对表达,p27在46例(66%)癌组织中相对表达下降,24例(34%)癌组织中相对表达增高,比较有统计学差异(P＜0.01);而PLK1在63例(90%)癌组织中相对表达增高,7例(10%)癌组织中相对表达下降,比较有统计学差异(P＜0.01);且癌组织中PLK1及p27相对低表达与患者的病理进展、淋巴结的转移和临床分期相一致(P＜0.05);癌组织中PLK1伴p27胞浆表达阳性的患者与癌组织中PLK1伴p27胞核表达阳性的患者比较,术后生存期明显缩短(P＜0.01)。结论:p27与PLK1在ESCC组织中的差异性表达与患者的临床病理特点密切相关,癌组织中PLK1伴胞浆p27表达阳性的患者预后更差。     

Low p27Kip1 expression is associated with poor prognosis in oral squamous cell carcinoma

BACKGROUND: p27Kip1 is a cyclin-dependent kinase inhibitor which regulates the progression of cells from the G1-into the S-phase in a cell cycle. Loss of p27Kip1 is associated with disease progression and an unfavorable outcome in several malignancies. The purpose of this study was to determine whether p27Kip1 expression can be a useful prognostic factor in oral squamous cell carcinoma (SCC) patients. PATIENTS AND METHODS: p27Kip1 expression was investigated by immunohistochemistry in tissue samples from 81 patients with oral SCC. The associations between p27Kip1 expression and clinicopathological characteristics and patient survival were also analyzed. RESULTS: Significant associations were found between p27Kip1 expression and histological grade (p = 0.010), therapeutic effect (p = 0.004) and patient outcome (p = 0.005). The 5-year survival rates of p27Kip1 high- and low-expression tumours were 80.4% and 56.7%, respectively, this difference being significant (p = 0.009) by log-rank test. Multivariate analysis revealed that reduced term survival was related to low levels of p27Kip1 expression (p = 0.008) and advanced stage (stages III and IV) (p = 0.003). CONCLUSION: These results suggest that reduction of p27Kip1 plays an important role in the progression of oral SCC and is considered to be a useful prognostic factor in oral SCC patients.     

Prognostic role of p27(Kip1) expression in oral squamous cell carcinoma in Taiwan

The cyclin-dependent kinase inhibitor p27(Kip1) can inhibit the G1 to S transition of the cell cycle and is a putative tumor suppressor. Decreased expression of p27(Kip1) protein has been correlated with poor prognosis in a variety of human tumors. We examined the expression of p27(Kip1) in oral squamous cell carcinoma (SCC), epithelial dysplasia (ED) and normal oral mucosa (NOM) using antibodies to p27(Kip1). Positive p27(Kip1) nuclear staining was detected in all the specimems from ED and NOM, whereas positive p27(Kip1) staining was observed in 16 of the 63 (25%) cases of oral SCC. The labeling index for p27(Kip1) protein was significantly reduced from NOM through ED to oral SCCs, indicating that changes of p27(Kip1) protein expression may be an early event in oral carcinogenesis in Taiwan. The Kaplan-Meier analysis showed patients with p27(Kip1)-positive tumors had significantly higher overall survival than those with p27(Kip1)-negative tumors in a total of 63 patients (P=0.015) and 47 patients with areca quid chewing habit (P=0.026). Multivariate analysis showed decreased p27(Kip1) protein expression was an independent significant predictor of poor overall survival in the patients with oral SCCs. These results indicate that p27(Kip1) protein expression may serve as a putative new adjuvant prognostic marker for routine assessment of oral SCC patients.     

Inverse relationship between E-cadherin and p27Kip1 expression in renal cell carcinoma

The cell-cell adhesion system plays a pivotal role in the maintenance of tissue structure and cell-cell communication. E-cadherin is a major adhesion protein of the epithelial cells, and E-cadherin expression may be involved in the regulation of cell proliferation or differentiation. To address the relationship between cell-cell adhesion and cell proliferation, we focused on the alteration of p27Kip1 (p27), a cyclin-dependent kinase inhibitor, by E-cadherin-mediated adhesion. In an immunohistochemical study of 76 cases of renal cell carcinoma (RCC), the p27-labeling index (LI) was 67% in E-cadherin-reduced RCC, but only 28% in E-cadherin-preserved RCC. E-cadherin-expressing cells rarely expressed p27 in various cancers including those of the breast, colon, liver and prostate. In a subconfluent monolayer culture, the E-cadherin levels were increased steadily in the E-cadherin positive RCC cell line ACHN, whereas the p27 levels were decreased. Subsequent exposure of ACHN cells to the E-cadherin-specific function-blocking antibody reduced the growth associated with the increase in p27 and the decrease in phosphorylated epidermal growth factor receptor (EGFR). In the E-cadherin negative RCC cell line Caki-1, these effects were not observed. These results suggest that E-cadherin-mediated adhesion may be involved in the contact stimulation for cell proliferation in part through the downregulation of p27 and the activation of EGFR in human cancers.     

食管鳞癌nm23-H1蛋白表达及DNA倍体与淋巴结转移关系

目的研究食管鳞癌nm23-H1蛋白表达及DNA倍体状态与区域淋巴结转移的关系.方法应用流式细胞仪检测食管癌患者新鲜手术标本包括食管癌组织(癌)、食管癌旁粘膜(癌旁)、食管正常粘膜(切缘)及食管癌区域淋巴结(淋巴结)中nm23-H1蛋白表达水平及DNA倍体状态.结果无论有、无淋巴结转移,nm23-H1蛋白表达在癌与癌旁、癌与切缘之间差异有显著性(P＜0.05),癌与淋巴结之间差异无显著性(P＞0.05);DNA指数(DI)在癌组织与癌旁、切缘、淋巴结之间比较差异均有显著性(P＜0.05),癌旁、切缘、淋巴结之间DI差异无显著性(P＞0.05);nm23-H1蛋白表达在有、无淋巴结转移两组对应组织间比较差异均有显著性(P＜0.05);两组对应组织比较DI差异无显著性(P＞0.05);DI在不同病理分级间差异有显著性(P＜0.05),DI及nm23-H1蛋白表达在性别、肿瘤部位、病理类型、浸润深度间差异无显著性(P＞0.05).结论nm23-H1蛋白高表达对食管癌转移有一定的抑制作用,结合DNA倍体检测有助于了解食管鳞癌的生物学行为和预后判断.     

乳腺癌组织p27Kip1的表达及其与细胞增殖的关系

目的:研究乳腺癌组织中细胞周期抑制剂p27Kip1的表达及其意义,并探讨其与细胞增殖的关系.方法:应用免疫组化SP法检测80例乳腺癌和20例癌旁正常组织中p27Kip1和增殖细胞核抗原(pro-liferative cell nuclear antigen,PCNA)的表达.结果:乳腺癌组织中p27Kip1高表达率为53.75%(43/80),明显低于癌旁正常组织(P<0.01).p27Kip1表达与组织学分级、TNM分期及淋巴结转移均相关,P<0.05.乳腺癌组织中p27Kip1的表达与PCNA LI呈负相关,r=-0.372,P<0.05.p27Kip1高表达的乳腺癌术后5年无病生存率(DFS)明显高于p27Kip1低表达者(P<0.05).结论:p27Kip1表达缺失可促进肿瘤细胞增殖,是判断乳腺癌发生、发展及预后的有效生物学指标.     

Prognostic implications of expression of the cell cycle inhibitor protein p27Kip1

Mitogenic and growth inhibitory signals influence the activity of a family of cyclin dependent kinases (cdks). p27 is an important cdk inhibitor, acting in G1 to inhibit cyclin-cdks. As negative growth regulators, the cdk inhibitors may function as tumor suppressors. While the p16 gene plays a tumor suppressor role in cancers, p27 gene mutations have been identified only rarely. While high levels of p27 protein are expressed in normal human mammary epithelium, loss of p27 is frequent and is of independent prognostic significance in breast cancers. Low p27 is also a poor prognostic factor in colon, gastric, esophageal, lung, and prostate carcinomas, and enhanced proteasomal degradation may underlie loss of p27 in tumor cells. Loss of p27 has not been significantly correlated with tumor proliferation in a number of studies and may reflect alterations in differentiation and adhesion-dependent growth regulation germane to oncogenesis and tumor progression. Efforts to confirm the prognostic value of p27 are under way in a number of large breast cancer studies. These studies may also indicate whether loss of p27 in association with other traditional or novel markers has greater prognostic potential than each factor alone. p27 immunostaining is inexpensive and reliable and may become part of the routine histopathologic processing of tumors in the near future. Widespread application of p27 in prognostic testing will require greater uniformity in scoring techniques and determination of the cut off levels which distinguish individuals at high and low risk of cancer recurrence and death. Finally, the greatest utility of p27 may lie in the information it sheds on the biology of aberrant growth regulation in breast cancer and the potential to use this in the generation of novel therapeutic strategies.     

Positive correlation between P27Kip1 expression and progression of human esophageal squamous cell carcinoma

p27^Kip1, one of the cyclin-dependent kinase (CDK) inhibitors (CDKIs), blocks progression from G₁ to S phase by binding cyclin D1-CDK4 and/or cyclin E-CDK2 and inhibiting their activities. Reflecting the function of p27 as a CDKIin vitro, a reduced expression of protein p27 has recently been reported to be associated with tumor aggressiveness in some types of human cancers. In the present study, we examined the relationships between immunohistochemically detected expression of p27, cyclin D1, cyclin E proteins and clinico-pathological findings in 77 patients with esophageal squamous cell carcinoma (SCC). Using specific monoclonal antibodies to p27, cyclin D1 and cyclin E proteins, positive immunostaining in the nuclei was observed in 32.5% (25/77), 27.3% (21/77) and 29.6% (21/71) of patients, respectively. There were no statistically significant relationships among the expressions of these 3 proteins. Using the Kaplan-Meier's method, p27 and cyclin D1 expressions were found to be independently associated with poor prognosis. When all parameters were combined into a multivariate regression analysis using the Cox model, the expressions of p27 and cyclin D1 retained a predictive value for survival. In contrast to former reports supporting a tumor-suppressive function of p27, our results suggest that altered expression of p27 and cyclin D1 may be associated with the progression of human esophageal SCC, in which cyclin E may well not play any central role. Int. J. Cancer (Pred. Oncol.) 79:439–443, 1998. © 1998 Wiley-Liss, Inc.     

食管鳞状细胞癌组织中细胞凋亡与P27Kip1、PCNA同步表达的关系

目的 :探讨食管鳞状细胞癌组织中细胞凋亡、细胞增殖相关基因PCNA及P2 7Kip1相互之间的关系 ,以及与食管鳞癌发生、发展及预后的关系。方法 :4 7例原发性食管鳞状细胞癌手术切除标本为一组 ,2 0例正常食管粘膜组织为对照组。采用免疫组织化学方法 (S ABC法 )对两组的PCNA、P2 7Kip1的表达水平进行检测 ,采用TdT介导的脱氧尿苷酸缺口末端标记法 (TUNEL法 )对两组的细胞凋亡进行检测。结果 :4 7例食管鳞癌组织中 ,P2 7Kip1阳性表达率、平均增殖指数 (PI)、平均凋亡指数 (AI)、PI/AI均较正常食管粘膜组有明显差异 (P <0 .0 5 )。P2 7Kip1蛋白的表达及PI与食管鳞癌的病理分级、淋巴结转移、肿瘤的浸润深度以及临床分期有关 (P <0 .0 5 ) ,而与肿瘤的部位和病变范围无关。AI则与肿瘤病理分级有关 (P <0 .0 5 )。PI/AI比值与肿瘤病理分级、淋巴结转移有关 (P <0 .0 5 )。P2 7Kip1蛋白表达阳性组食管鳞癌术后五年生存率显著高于表达阴性组 ;PCNA低表达组食管鳞癌术后五年生存率显著高于高表达组 (P <0 .0 5 )。结论 :PCNA的异常表达状态能够较好的反映食管鳞癌的浸润、转移能力 ,有一定的预后判定价值。增殖与凋亡的失衡贯穿于食管鳞癌的发生、发展过程。P2 7Kip1在食管鳞癌中表达的缺失与肿瘤的病理分级、浸润     

Expression of the cell cycle regulator p27(Kip1) in normal squamous epithelium, cervical intraepithelial neoplasia, and invasive squamous cell carcinoma of the uterine cervix. Immunohistochemistry and functional aspects of p27(Kip1).

BACKGROUND: Abnormality of cell cycle regulators and tumor suppressors, such as cyclin dependent kinase inhibitors (cdkIs), has been reported in malignant tumors. The current study was undertaken to examine the involvement of a cdkI, p27(Kip1) (p27), in the neoplastic process of the uterine cervical epithelium. METHODS: Immunohistochemical staining of p27 was performed in samples of normal cervical tissue (30 samples), cervical intraepithelial neoplasias (CINs; 17 samples), and invasive squamous cell carcinoma (SCC; 25 samples). The results were compared with the expression levels of Ki-67, cdk2, and cyclin E. The functional aspects of the p27 protein, such as its ability to bind to cdk2 and the phosphorylation activity of p27-bound cdk2, also were evaluated with an immunoprecipitation and histone H1 kinase assay. RESULTS: In normal cervical epithelia, the expression of p27 was strong in the intermediate and superficial cells but very weak in the parabasal cells. In CIN samples, the expression of p27 was negligible. The expression of p27 in these tissues showed an inverse topologic correlation to that of Ki-67, cdk2, and cyclin E. However, it is noteworthy that the number of p27 positive cells increased in SCC samples that also showed increased expression of Ki-67, cdk2, and cyclin E. The p27 protein in SCC samples was bound to cdk2 and cyclin E. However, cdk2 that was bound to p27 still possessed histone H1 kinase activity. CONCLUSIONS: The expression of p27 may be involved in the growth regulation of the normal squamous epithelium in the uterine cervix. However, aberrant function of p27 expression may occur in invasive SCC of the cervix.     

Up-regulation of GPR48 induced by down-regulation of p27Kip1 enhances carcinoma cell invasiveness and metastasis

A reduced expression level of the cyclin-dependent kinase inhibitor p27(Kip1) is associated with increased tumor malignancy and poor prognosis in individuals with various types of cancer. To investigate the basis for this relation, we applied microarray analysis to screen for genes differentially expressed between p27(+/-) and parental (p27(+/+)) HCT116 human colon carcinoma cells. Expression of the gene for G protein-coupled receptor 48 (GPR48) was increased in the p27(+/-) cells. Forced expression of GPR48 increased both in vitro invasive activity and lung metastasis potency of HCT116 cells. In contrast, depletion of endogenous GPR48 by RNA interference reduced the invasive potential of HeLa and Lewis lung carcinoma cells not only in vitro but also in vivo. Moreover, GPR48 expression was significantly associated with lymph node metastasis and inversely correlated with p27 expression in human colon carcinomas. GPR48 may thus play an important role in invasiveness and metastasis of carcinoma and might therefore represent a potential prognostic marker or therapeutic target.     

Reduced expression of p27(Kip1) correlates with an early stage of cancer invasion in oral squamous cell carcinoma

Down-regulation of p27(Kip1) has been reported to correlate with poor survival of various carcinoma patients including oral squamous cell carcinomas (OSCCs). It is still unclear, however, at what stage of oral carcinogenesis the down-regulation of this protein occurs. In this study, therefore, we evaluated immunoexpression of p27(Kip1) protein in 17 cases of oral epithelial dysplasia and succeeding invasive OSCC in the same patient. We reported here that 88% cases showed high p27(Kip1) expression in dysplastic lesions, whereas 82% cases of succeeding invasive OSCC exhibited reduced expression. The reduction of p27(Kip1) expression was also observed in 16 of 19 (84%) early invasive lesions and well correlated with Ki-67 expression which is good indicator of cell proliferation. We also investigated immunoexpression of p53 protein of which abnormality has been known to occur during the early stage of OSCC development. Overexpression of p53 protein was demonstrated in 29% of dysplastic lesions, 42% of early invasive and 71% of invasive OSCCs. These findings suggest that abnormalities of both p53 and p27(Kip1) are involved in the carcinogenesis of OSCC, but they seem to play their role at different stages of oral cancer development, respectively. Reduced expression of p27(Kip1) may concern the cancer invasion directly or indirectly as well as abnormal proliferation.     

Inactivation of PTEN is associated with a low p27Kip1 protein expression in breast carcinoma

BACKGROUND: It was previously demonstrated that PTEN protein expression is reduced in 67 of 236 (28%) breast carcinomas. Recent experimental studies suggested that the cell cycle inhibitor p27Kip1 (p27) is a downstream mediator through which PTEN negatively regulates cell cycle progression. METHODS: The immunohistochemic expression of p27 and PTEN protein expression was evaluated in a series of 228 invasive ductal carcinomas of the breast. RESULTS: PTEN protein expression was found to have decreased in 65 of 228 (29%) cases, while the nuclear accumulation of p27 protein was low in 99 of 228 (43%) cases. A reduced PTEN protein expression correlated significantly (P = 0.0214) with a low p27 protein expression. Univariate analysis indicated that the patients demonstrating a combined decrease in PTEN and p27 protein expression have a significantly (P = 0.0044) worse disease-free survival (DFS) than those with other combinations of these two protein expression patterns, while multivariate analysis indicated that the lymph node status, MIB-1 counts, and the combination of PTEN/p27 protein expression (P = 0.0452) are independently significant prognostic factors for DFS. CONCLUSIONS: A reduced PTEN protein expression correlated significantly with a low p27 protein expression in breast carcinoma. The finding that the patients with a combined decrease in both protein expressions had a poor prognosis thus suggests that a combined loss of PTEN and p27 function is associated with an aggressive phenotype in breast carcinoma.     

Low expression of p27(Kip1) is associated with tumor size and poor prognosis in patients with renal cell carcinoma

BACKGROUND: Proliferative activity in tumors depends on regulation of the cell cycle. p27(Kip1) (p27) plays a pivotal role as a negative regulator of the cell cycle. A decrease in p27 expression has been reported in many kinds of tumors, but little is known regarding p27 in patients with renal cell carcinoma (RCC). METHODS: Expression of p27 and the related cyclins (cyclin A, cyclin E, and cyclin D1) was examined immunohistochemically in 67 patients with of clear cell RCC. The Ki-67 labeling index (MIB-1 LI) and clinicopathologic parameters related to a poor prognosis also were analyzed. To determine their prognostic significance, univariate and multivariate survival analyses were performed. RESULTS: In tumors, there was considerable immunoreactivity for cyclin A, cyclin D1, and MIB-1, and the mean values for each were 1.08%, 16.1%, and 1.5%, respectively. Cyclin E expression was rare. The expression of p27 was correlated strongly with the expression of cyclin A (correlation coefficient, 0.432; P < 0.0004) and cyclin D1 (correlation coefficient, 0.476; P < 0.0004). Also, an inverse correlation was present between p27 expression and tumor size (P = 0.0377). In univariate analysis, the unfavorable prognostic factors were high TNM stage (P < 0.0001), large tumor size (P = 0.0016), high histologic grade (P = 0.0104), and low p27 expression (P < 0.0001). In multivariate analysis, high TNM stage (P = 0.0035) and low p27 expression (P = 0.0235) were independent prognostic factors for disease specific survival in patients with RCC. CONCLUSIONS: The results of this study suggest that low p27 expression may be a significant and independent, unfavorable prognostic factor in patients with renal cell carcinoma.     

p27Kip1 accumulation by inhibition of proteasome function induces apoptosis in oral squamous cell carcinoma cells.

Ubiquitin-mediated proteolysis controls intracellular levels of various cell cycle regulatory proteins, and its inhibition has been shown to induce apoptosis in proliferating cells. In the present study, we examined induction of apoptosis in oral squamous cell carcinoma (OSCC) cells by treatment with specific proteasome inhibitors, carbobenzoxy-L-leucyl-L-leucyl-L-norvalinal and lactacystin. In all three OSCC cell lines examined, apoptotic changes such as apoptotic body formation and DNA fragmentation were observed at various degrees after 24 h of the carbobenzoxy-L-leucyl-L-leucyl-L-norvalinal or lactacystin treatment. HSC2 cells showed the most prominent apoptotic changes among the cell lines examined and demonstrated the highest level of accumulation of p27Kip1 protein after the treatment with proteasome inhibitor. Reduced expressions of cyclin D1 and phospho pRb were also observed after the treatment with proteasome inhibitor. Moreover, 12 h of treatment with the proteasome inhibitor inhibited cdk2/cyclin E kinase activity and increased the ratio of the cell cycle population at the G1 phase. The proteasome inhibitor led to inhibition of cell cycle progression. In addition, activation of CPP32 and reduced expression of Bcl-2 were observed. Because apoptosis induced by the proteasome inhibitor was inhibited by treatment with antisense p27Kip1 oligonucleotide, accumulation of the p27Kip1 protein might play an important role in the apoptosis induced by proteasome inhibitor. The present results suggest that inhibition of proteasome function may be used as a possible target of novel therapy for OSCC.