Immunohistochemical expression of the p53, mdm2, p21/Waf-1, Rb, p16, Ki67, cyclin D1, cyclin A and cyclin B1 proteins and apoptotic index in T-cell lymphomas

Fifty-seven cases of T-cell lymphomas (TCL) including 5 lymphoblastic (T-LBL) and 52 peripheral TCL (PTCL) were analyzed by immunohistochemistry for the expression of p53, mdm2, p21, Rb, cyclin D1, cyclin A, cyclin B1, and Ki67/MIB1 proteins and 39/52 PTCL were also analyzed for the expression of p16 protein and for the presence of apoptotic cells by the TUNEL method. The aim was to search for abnormal immunoprofiles of p53 and Rb growth control pathways and to determine the proliferative activity and the apoptotic index of TCL. Abnormal overexpression of p53, p21 and mdm2, in comparison to normal lymph nodes, was found in 12/57, 10/57 and 2/57 cases of TCL, respectively. Abnormal loss of Rb and p16 expression was found in 1/57 and 2/39 cases, respectively, whereas abnormal overexpression of cyclin D1 was not detected in any of the 57 cases. Our data revealed entity-related p53/p21/mdm2 phenotypes. Indeed, most nodal and cutaneous CD30+ anaplastic large cell lymphomas (ALCL) showed concomitant overexpression of p53 and p21 proteins (7/8 cases), and mdm2 was overexpressed in 2 p53-positive nodal ALCL. In contrast, overexpression of p53 was found in 3/17 cases of nodal peripheral TCL unspecified (PTCL-UC) and 2/7 non-ALCL cutaneous pleomorphic TCL. Overexpression of p21 protein was detected in 2/3 p53-positive PTCL-UC and in 1/2 p53-positive non-ALCL cutaneous pleomorphic TCL. Finally, all the remaining 25 cases of TCL did not show p53 and p21 overexpression. Overall, the p53+/p21+ phenotype in 10/57 TCL suggests wild-type p53 capable of inducing p21 expression. The highest apoptotic index (AI) was found in ALCL and a positive correlation between apoptotic index and Ki67 index (p<0.001) was detected. Ki67, cyclin A and cyclin B1 expression was found in all 57 TCL and on the basis of the combined use of these 3 variables, 3 groups of proliferative activity could be determined: a) high in ALCL and T-LBL, b) low in mycosis fungoides (MF) and gammadelta hepatosplenic TCL, and c) intermediate in the remaining TCL entities. The proliferative activity in the 12 p53 overexpressing cases was higher in comparison to the 45 p53-negative cases. Ki67 expresion in more than 25% of tumour cells showed significant correlation with p53 overexpression (p<0.001). Rb expression tended to be parallel to Ki67, cyclin A and cyclin B1 expression in all but one case of nodal PTCL-UC which displayed loss of RB expression. Interestingly, this case was p53-negative, whereas the p53-positive cases were Rb-positive. These findings suggest that different pathogenetic routes may function in some TCL, involving either the p53 or, less frequently, the Rb pathways.     

Cyclin A but not cyclin D1 is essential for c-myc-modulated cell-cycle progression

The proto-oncogene c-myc is a key player in cell-cycle regulation and is deregulated in a broad range of human cancers and cell proliferation disorders. Here we reported that overexpression of c-myc in human embryonic lung fibroblasts (HEL) that have low endogenous c-myc enriched S phase cells with increased expression of cyclin D3, E, A, Cdk2, and Cdk4, and decreased expression of p21 and p27. To the opposite, using RNAi to downregulate c-myc expression in A549 cells that have high endogenous c-myc enriched G1 phase cells with decreased expression of cyclin D3, E, A, Cdk2, Cdk4, and increased expression of p21 and p27. We found that cyclin A expression was the most susceptive to changes in c-myc levels and essential in c-myc-modulated cell cycle pathway via co-transfection, however, cyclin D1 showed no change between treated and control groups in either HEL or A549 cells. Our results indicated that upregulation of c-myc expression promotes cell cycling in HEL cells, whereas downregulation of c-myc expression causes G1 phase arrest in A549 cells, and the c-myc-mediated cell-cycle regulation pathway was dependent on cyclin A and involved cyclin D3, E, Cdk2, Cdk4, p21, and p27, but not cyclin D1.     

Distinctive patterns of Her-2/neu, c-myc, and cyclin D1 gene amplification by fluorescence in situ hybridization in primary human breast cancers.

Background: Human solid tumors undergo clonal evolution as they progress, but evidence for specific sequences of genetic changes that occur in individual tumors and are recapitulated in other tumors is difficult to obtain. Methods: Patterns of amplification of Her-2/neu, c-myc, and cyclin D1 were determined by fluorescence in situ hybridization (FISH) in relation to the presence of p53 dysfunction and ploidy in 60 primary human breast cancers. Results: We show that there are clusters of genophenotypic abnormalities that distinguish lobular breast cancers from nonlobular tumors; that cyclin D1 amplification occurs prior to the divergence of lobular breast cancers from nonlobular cancers; that p53 dysfunction, Her-2/neu amplification, and c-myc amplification are characteristic features of nonlobular breast cancers, but not of lobular breast cancers; and that the frequencies of amplification of all three oncogenes examined increase progressively with increasing aneuploidy, but that each gene exhibits a different profile of increasing amplification in relation to tumor progression. Early amplification of c-myc appears to be an especially prominent feature of hypertetraploid/hypertetrasomic tumors. Conclusions: The data suggest that in tumors containing multiple abnormalities, these abnormalities often accumulate in the same cells within each tumor. Furthermore, the same patterns of accumulation of multiple genophenotypic abnormalities are recapitulated in different tumors.     

Expression of cyclin D3 and cyclin E and identification of distinct clusters of proliferation and apoptosis in diffuse large B-cell lymphomas

In the present study 79 cases of de novo Diffuse Large B-cell Lymphomas (DLBCL) were studied in order: a) to analyse the expression of cyclin D3, cyclin E and cyclin D1 in relation to other proliferative features (expression of Ki67, cyclin A and cyclin B1), the apoptosis status and the expression of p53, Rb, p16 and p27; and b) to determine whether distinct clusters of proliferation and apoptosis could be identified in DLBCL. Overexpression of cyclin D3 and cyclin E was found in 35/79 (43%) and 18/79 (22%) cases, respectively, whereas overexpression of cyclin D1 was not detected in any case. In most cases (39/46) overexpression of cyclin D3 and cyclin E was mutually exclusive possibly reflecting different underlying pathways inducing deregulated expression of these cyclins. In most cases (29/35) overexpression of cyclin D3 was mutually exclusive with Rb/p16 aberrant expression status supporting an oncogenic role for cyclin D3 and suggesting that the pathogenetic effect of cyclin D3 overexpression occurs through perturbation of the Rb1 pathway. Combined alterations of the P53 and the Rb/p16/cyclin D3 expression status were significantly associated with higher mean values of cyclin A (p=0.023) and cyclin B1 (p=0.033) indicating that concurrent impairment of the p53 and Rb1 pathways induces increased tumour cell proliferation in DLBCL. Cluster analysis of the apoptosis and the proliferation status permitted separation of DLBCL into distinct groups with low (44 cases) and high (18 cases) apoptotic activity and into distinct groups with low (32 cases), intermediate (36 cases) and high (11 cases) proliferative activity. The identification of distinct clusters with respect to the proliferation and the apoptosis status indicates that groups with distinct cellular kinetic properties can be defined in the histological group of DLBCL.     

Effect of elevated levels of ornithine decarboxylase on cell cycle progression in skin.

By crossing TG.AC v-Ha-ras and K6/ODC transgenic mice, we found previously that an activated ras and follicular ornithine decarboxylase (ODC) overexpression cooperate to generate spontaneous tumors in the skin. Cellular proliferation was dramatically increased in the K6/ODC transgenic skin, as evidenced by elevated proliferating cell nuclear antigen and Ki67 expression compared with nontransgenic littermates. Keratinocytes isolated from transgenic skin also displayed increased clonal growth. Paradoxically, expression of the growth inhibition-associated proteins p53, p21Waf1, p27Klp1, and Bax was increased with ODC overexpression in the skin. ODC overexpression did not affect cyclin D/cyclin-dependent kinase 4 (Cdk4)-dependent phosphorylation of retinoblastoma protein but stimulated cyclin E/Cdk2 and cyclin A/Cdk2-associated kinase activity, with minimal effect on the levels of these proteins. Thus, ODC/polyamine-induced activation of cyclin E/Cdk2 and cyclin A/Cdk2-associated kinase activity may cooperate with the ras induction of cyclin D/Cdk4/6-associated retinoblastoma protein phosphorylation to not only stimulate proliferation but ultimately contribute to tumor development.     

Stimulatory effect of estrogen on the growth of endometrial cancer cells is regulated by cell-cycle regulators

Estrogen is known as a major risk factor in tumorigenesis of the endometrium. The aim of this study is to establish stable estrogen-responsive endometrial cancer cell lines and to investigate the mechanism of estrogen action, focusing on cell-cycle regulation. Human wild-type estrogen receptor cDNA was transfected into endometrial cancer cells (Ishikawa) and estrogen-responsive cell lines were cloned. Their estrogen responsiveness was evaluated by the effect of estrogen on cellular growth and progesterone receptor expression. It was quantitatively estimated by immunocytochemistry or immunoblotting how the expression of cell-cycle regulators such as cyclin D1, cyclin E, Cyclin A, p53, p21 and p27 was regulated by estrogen. A cell line stably responsive to estrogen was established, and cells proliferated and the glandular structure was formed by estrogen stimulation. Cyclin D1 expression increased at 6–24 h and cyclin A gradually increased until 48 h of estrogen treatment compared with untreated cells. On the other hand, p53 and p21 expressions decreased at 6–24 h, and p27 gradually decreased until 24 h by estrogen. Our results show that the stimulatory effect of estrogen on cell proliferation may be regulated by the up-regulation of cyclin D1 and cyclin A, and down-regulation of p53, p21 and p27. This cell line is useful to clarify the molecular mechanism of estrogen action on endometrial cancer.     

cyclin D1, cyclin E 在乳腺良、恶性病变中的表达及其与p16,p21waf1及Rb 蛋白的关系

为探讨cyclinD1,cyclinE在乳腺癌发生发展中的作用及其与细胞周期调控相关基因蛋白的关系,采用免疫组化检测17例非增生乳腺导管上皮、19例不同程度增生的导管上皮及59例乳腺癌中cyclinD1,cyclinE,p16,p21waf1及Rb基因蛋白的表达.结果显示1.非增生乳腺导管上皮除1例cyclinE过表达外均无cyclinD1和cyclinE的过表达.乳腺癌的cyclinD1和cyclinE的过表达率均明显高于良性乳腺组织(P<0.05).2.乳腺癌cyclinD1过表达与淋巴结转移呈正相关(P<0.05),瘤体直径大于5cm者cyclinE过表达呈增加趋势,但差异无显著性意义.3.CyclinD1和cyclinE的过表达呈正相关(P<0.05).4.从非增生乳腺导管上皮到增生直至乳腺癌,p16,p21与cyclinD1,cyclinE含量的比值逐渐递减,而p21含量高于cyclinD1的乳腺癌体积小、淋巴结转移率低(P<0.05).p21阳性率与cyclinD1过表达呈正相关(P<0.01),也随cyclinE的过表达呈上升趋势.Rb基因蛋白的强表达与cyclinD1过表达呈正相关(P<0.01).结果表明CyclinD1和cyclinE蛋白过表达频发于乳腺癌早期,它们可能与p16、p21waf1、pRb共同参与了乳腺癌的发生发展.     

食管癌前细胞DNA、端粒酶含量及多基因表达产物的定量检测

为探讨食管癌高发区人群食管上皮癌变过程中的早期分子改变及早期癌变机理.应用流式细胞术和免疫荧光技术及碘化丙啶DNA荧光染色方法,对食管上皮癌前细胞的DNA含量、端粒酶含量和多个基因p53、p16、cyclin D1蛋白质表达进行了定量检测.检测结果发现,DNA含量在癌变形成时明显增加,异倍体率为87.9%;p53蛋白积聚发生在癌变早期,在癌细胞组的阳性率为100%（5/5）;抑癌基因p16在癌变早期有明显缺失;癌基因cyclin D1及端粒酶阳性率在癌细胞组都为100%（分别为6/6,7/7）.研究结果表明：在癌变早期,DNA含量及异倍体率增加,癌基因cyclin D1表达增高,抑癌基因p16缺失及p53蛋白积聚,端粒酶含量也明显增高,在癌形成时已有多个分子事件发生.     

Changes in expression of pRb, p16 and cyclin D1 in non-small cell lung cancer: an immunohistochemical study

Aberrations in the pathway composed of p16, cyclin D1/CDK4,6 and pRb (pRb pathway) which controls the transition from G1 to S phase occur frequently in various types of tumors. In the present study we analyzed immunohistochemically the expression of pRb, p16 and cyclin D1 in 1 12 primary non-small cell lung carcinomas (NSCLC). Loss of expression of pRb and p16 proteins was demonstrated in 15/112 cases and 64/112 cases, respectively. Inverse expression of pRb and p16 proteins was observed in 61 cases and was statistically correlated with advanced stage of the disease (p=0.03). Overexpression of cyclin D1 was detected in 34 cases and was more frequently observed in stage I than in stage III of the disease (p=0.02). Concomitant overexpression of cyclin D1 and lack of p16 was observed in 57% of cyclin D1-positive tumors. In summary, 82 of 112 analyzed cases showed an aberrant expression of at least one of the investigated proteins. These results indicate that although pRb protein expression is altered only in a small percentage of NSCLCs, the pRb pathway is disrupted very frequently in this type of tumor. There were no statistically significant correlations between changes in protein expression and histological type of tumor, gender, smoking habits and occupation of patients.     

Analysis of wild-type and mutant p21WAF-1 gene activities.

The p21WAF-1 gene is positively regulated by the wild-type p53 protein. p21WAF-1 has been shown to interact with several cyclin-dependent kinase complexes and block the activity of G1 cyclin-dependent kinases (cdks). Mutational analysis with the p21WAF-1 gene localized a site, at amino acid residues 21 and 24 in the amino terminus of the protein, for p21WAF-1 binding to cyclins D and E. This region of the protein is conserved (residues 21 to 26) in other p21WAF-1 family members, p27kip-1 and p57kip-2. The same p21WAF-121,24 mutant also fails to bind to cyclin D1-cdk 4 or cyclin E-cdk 2 complexes in vitro, suggesting that amino acid residues 21 and 24 are important for p21WAF-1-cdk-cyclin trimeric complex interactions. The p21WAF-1 wild-type protein will suppress tumor cell growth in culture while p21WAF-1 mutant proteins with defects in residues 21 and 24 fail to suppress tumor cell growth. The overexpression of cyclin D or E in these cells will partially overcome the growth suppression of wild-type p21WAF-1 protein in cells. These results provide evidence that p21WAF-1 acts through cyclin D1-cdk4 and cyclin E-cdk2 complexes in vivo to induce the growth suppression. The p21WAF-1 binding sites for cyclins (residues 21 to 26), cdk2 (residues 49 to 71), and proliferating-cell nuclear antigen (residues 124 to 164) have all been mapped to discrete sites on the protein.     

Abrogation of p53 by its antisense in MCF-7 breast carcinoma cells increases cyclin D1 via activation of Akt and promotion of cell proliferation

The p53 protein has been a subject of intense research interest since its discovery as about 50% of human cancers carry p53 mutations. Mutations in the p53 gene are the most frequent genetic lesions in breast cancers suggesting a critical role of p53 in breast cancer development, growth and chemosensitivity. This report describes the derivation and characterization of MCF-7As53, an isogenic cell line derived from MCF-7 breast carcinoma cells in which p53 was abrogated by antisense p53 cDNA. Similar to MCF-7 and simultaneously selected hygromycin resistant MCF-7H cells, MCF-7As53 cells have consistent basal epithelial phenotype, morphology, and estrogen receptor expression levels at normal growth conditions. Present work documents investigation of molecular variations, growth kinetics, and cell cycle related studies in relation to absence of wild-type p53 protein and its transactivation potential as well. Even though wild-type tumor suppressor p53 is an activator of cell growth arrest and apoptosis-mediator genes such as p21, Bax, and GADD45 in MCF-7As53 cells, no alterations in expression levels of these genes were detected. The doubling time of these cells decreased due to depletion of G0/G1 cell phase because of constitutive activation of Akt and increase in cyclin D1 protein levels. This proliferative property was abrogated by wortmannin, an inhibitor of PI3-K/Akt signaling pathway. Therefore this p53 null cell line indicates that p53 is an indispensable component of cellular signaling system which is regulated by caveolin-1 expression, involving Akt activation and increase in cyclin D1, thereby promoting proliferation of breast cancer cells.     

p14ARF Post-Transcriptional Regulation of Nuclear Cyclin D1 in MCF-7 Breast Cancer Cells: Discrimination between a Good and Bad Prognosis?

As part of a cell's inherent protection against carcinogenesis, p14ARF is upregulated in response to hyperproliferative signalling to induce cell cycle arrest. This property makes p14ARF a leading candidate for cancer therapy. This study explores the consequences of reactivating p14ARF in breast cancer and the potential of targeting p14ARF in breast cancer treatment. Our results show that activation of the p14ARF-p53-p21-Rb pathway in the estrogen sensitive MCF-7 breast cancer cells induces many hallmarks of senescence including a large flat cell morphology, multinucleation, senescence-associated-β-gal staining, and rapid G1 and G2/M phase cell cycle arrest. P14ARF also induces the expression of the proto-oncogene cyclin D1, which is most often associated with a transition from G1-S phase and is highly expressed in breast cancers with poor clinical prognosis. In this study, siRNA knockdown of cyclin D1, p21 and p53 show p21 plays a pivotal role in the maintenance of high cyclin D1 expression, cell cycle and growth arrest post-p14ARF induction. High p53 and p14ARF expression and low p21/cyclin D1 did not cause cell-cycle arrest. Knockdown of cyclin D1 stops proliferation but does not reverse senescence-associated cell growth. Furthermore, cyclin D1 accumulation in the nucleus post-p14ARF activation correlated with a rapid loss of nucleolar Ki-67 protein and inhibition of DNA synthesis. Latent effects of the p14ARF-induced cellular processes resulting from high nuclear cyclin D1 accumulation included a redistribution of Ki-67 into the nucleoli, aberrant nuclear growth (multinucleation), and cell proliferation. Lastly, downregulation of cyclin D1 through inhibition of ER abrogated latent recurrence. The mediation of these latent effects by continuous expression of p14ARF further suggests a novel mechanism whereby dysregulation of cyclin D1 could have a double-edged effect. Our results suggest that p14ARF induced-senescence is related to late-onset breast cancer in estrogen responsive breast cancers and/or the recurrence of more aggressive breast cancer post-therapy.     

细胞周期相关蛋白cyclin D1、p53和p21WAF1/Cip1在食管鳞癌中的表达改变及其病理学意义

食管鳞状细胞癌(Esophageal squamous cell carcinoma, ESCC)是我国常见的恶性肿瘤之一, 虽然临床诊治手段正逐步改进, 但中晚期患者5年生存率仍然很低。目前认为细胞周期调控异常与肿瘤发生发展关系密切, 然而相关周期调节蛋白在食管癌患者中的表达改变、临床意义及其应用价值还没有明确结论。文章应用组织微阵列联合免疫组织化学技术(TMA-IHC), 对148例食管鳞癌组织标本中细胞G₁/S期调控蛋白cyclin D1、p53和p21^WAF1/Cip1的表达进行检测, 分析其与临床病理参数之间的相关性。结果显示, cyclin D1与p53蛋白在食管癌细胞中表达升高, p53表达阳性率与区域淋巴结转移显著相关(P = 0.001)。p21^WAF1/Cip1蛋白在肿瘤组织中表达降低, 且p21WAF1/Cip1表达阴性患者的术后生存时间显著短于表达阳性的患者(P = 0.001)。多因素生存分析显示p21WAF1/Cip1是一个独立的预后因素(相对危险度为0.418, P<0.001)。微阵列比较基因组杂交(array-CGH)检测进一步表明45.4%的食管癌患者存在cyclin D1基因扩增。以上结果提示食管鳞癌中存在细胞周期G1/S期调控异常, p21^WAF1/Cip1蛋白可能是一个有应用价值的预后因子。     

Tea polyphenols can restrict benzo[a]pyrene-induced lung carcinogenesis by altered expression of p53-associated genes and H-ras, c-myc and cyclin D1

The modulatory influence of tea polyphenols (epigallocatechin gallate, epicatechin gallate and theaflavin) on benzo[a]pyrene (B[a]P)-induced lung carcinogenesis in mice was analyzed using histopathological and molecular parameters. Progression of lung lesions was restricted at the hyperplastic stage by tea polyphenols. A significant reduction in cellular proliferative index and an increase in apoptotic index were noted in the restricted lung lesions. High expression of H-ras, c-myc, cyclin D1 and p53 genes was seen at the inflammatory stage (9th week) and in subsequent premalignant lesions, but down-regulation of H-ras at the hyperplastic stage (17th week). Expression of bcl-2 was high in hyperplastic lesions, whereas the expression of mdm2 and bcl-xl increased only at the moderately dysplastic stage (36th week). The tea polyphenols inhibited inflammatory response in the lung lesions on the 9th week, when decreased expression of H-ras and c-myc and increased expression of bax were noted. Prolonged treatment (>9th week) with tea polyphenols resulted in changes in the expression of some additional genes, such as reduced expression of cyclin D1 (from the 17th week), bcl-2 (from the 26th week; mild dysplasia) and p21 (on the 36th week), and high expression of p53 (from the 17th week) and p27 (on the 36th week). These observations indicate that the tea polyphenols can restrict B[a]P-induced lung carcinogenesis by differential modulation of the expression of p53 and its associated genes such as bax, bcl-2, mdm2, p21 and p27, along with H-ras, c-myc and cyclin D1, at different time points.     

Oncogene expression in a medullary thyroid carcinoma

We report the expression of Ha-ras, fos, c-myc and N-myc mRNA in a human medullary carcinoma of the thyroid gland, both in primary tumor and lymph node metastasis, as demonstrated by in situ hybridization and Northern blot analysis. A significant difference in the oncogene expression in the primary tumor and the metastasis was not observed. Tumor tissue revealed a significant overexpression of Ha-ras, c-myc and N-myc mRNA as compared to the normal thyroid gland. The amount of fos mRNA expression in non tumorous thyroid gland did not significantly differ from tumor tissue, sis, fms and abl mRNA expression was not detectable in tumor tissue and non tumorous thyroid gland. We conclude, that the (over)expression of the oncogenes Ha-ras, c-myc and N-myc may be associated with initiation and progression of medullary thyroid carcinoma. Similar studies on additional cases of human medullary thyroid carcinoma will be necessary to reveal further information.     

Tumor growth fraction, expression of estrogen and progesterone receptors, p53, bcl-2 and cathepsin D activity in primary ductal invasive breast carcinoma and their axillary lymph node metastases

The aim of this paper is to determine similarities and differences between tumor cell subclones in cases of ductal invasive breast carcinoma, and which occupy primary tumor and local axillary lymph metastases. The tumor growth fraction evaluated by Ki-67 was analyzed along with the expression level of estrogen and progesterone receptors, protein p53, proto-oncogene protein bcl-2 and cathepsin D in 60 patients. Metastatic lymph node in axilla has a higher growth fraction of the tumor cells than the primary tumor (p = 0.045), as well as the higher level of bcl-2 overexpression (p = 0.014). No statistically significant difference was found in the presence of immunohistochemically identified estrogen receptors (p = 0.161) and progesterone receptors (p = 0.081) between the primary tumor and the metastatic lymph node in axilla. Likewise, no difference was found between the immunohistochemical evaluation of p53 (p = 0.356) and cathepsin D activity (p = 0.928). A higher growth fraction of the tumor cells and the higher level of bcl-2 overexpression in metastatic tumor cells indicate the more aggressive cell subclones. This study does not support the routine testing of both primary tumor and locoregional metastasis to evaluate the breast cancer hormone receptor status.