Thyrotrophin receptor protein expression in normal and adenomatous human pituitary

Thyrotrophin (TSH) synthesis and secretion is under the positive control of thyrotrophin releasing hormone and under the negative control of the thyroid hormones. However, it is hypothesised that TSH has a direct effect on the regulation of its own synthesis through an intrapituitary loop mediated by pituitary TSH receptors (TSH-R). The aim of this investigation was to study the expression of TSH-R in normal human pituitary at mRNA and protein levels, and to compare the pattern of protein expression between different pituitary adenomas. Using RT-PCR we were able to detect TSH-R mRNA in the normal pituitary, and immunohistochemical studies showed TSH-R protein expression in distinct areas of the anterior pituitary. Double immunostaining with antibodies against each of the intrapituitary hormones and S100 revealed that TSH-R protein is present in thyrotrophs and folliculostellate cells. Examination of 58 pituitary adenomas, including two clinically active and two clinically inactive thyrotroph adenomas, revealed TSH-R immunopositivity in only the two clinically inactive thyrotroph adenomas. This study shows, for the first time, the presence of TSH-R protein in the normal anterior pituitary and in a subset of thyrotroph adenomas. The expression of TSH-R in the thyrotroph and folliculostellate cell subpopulations provides preliminary evidence of a role for TSH in autocrine and paracrine regulatory pathways within the anterior pituitary gland.     

Cyclin E, a redundant cyclin in breast cancer

Cyclin E is an important regulator of cell cycle progression that together with cyclin-dependent kinase (cdk) 2 is crucial for the G₁/S transition during the mammalian cell cycle. Previously, we showed that severe overexpression of cyclin E protein in tumor cells and tissues results in the appearance of lower molecular weight isoforms of cyclin E, which together with cdk2 can form a kinase complex active throughout the cell cycle. In this study, we report that one of the substrates of this constitutively active cyclin E/cdk2 complex is retinoblastoma susceptibility gene product (pRb) in populations of breast cancer cells and tissues that also overexpress p16. In these tumor cells and tissues, we show that the expression of p16 and pRb is not mutually exclusive. Overexpression of p16 in these cells results in sequestering of cdk4 and cdk6, rendering cyclin D1/cdk complexes inactive. However, pRb appears to be phosphorylated throughout the cell cycle following an initial lag, revealing a time course similar to phosphorylation of glutathione S-transferase retinoblastoma by cyclin E immunoprecipitates prepared from these synchronized cells. Hence, cyclin E kinase complexes can function redundantly and replace the loss of cyclin D-dependent kinase complexes that functionally inactivate pRb. In addition, the constitutively overexpressed cyclin E is also the predominant cyclin found in p107/E2F complexes throughout the tumor, but not the normal, cell cycle. These observations suggest that overexpression of cyclin E in tumor cells, which also overexpress p16, can bypass the cyclin D/cdk4-cdk6/p16/pRb feedback loop, providing yet another mechanism by which tumors can gain a growth advantage.     

胃癌组织中P27表达与cyclin D1、cyclin E表达的相关性

目的:检测胃癌组织中P27的表达及其与cyclin D_1、cyclin E表达的相关性,并探讨其意义.方法:临床病理资料齐全的胃癌蜡块标本54例,正常胃黏膜标本15例,采用SP免疫组化方法检测P27、cyclin D和cyclin E在其中的表达.结果:胃癌组织54例中有20例P27表达阳性(37.0%),正常胃组织中15例有11例P27呈阳性表达(73.3%),胃癌组织与正常胃组织相比,P27的表达有明显差异(P<0.05),胃癌组织中P27的表达与患者的性别、年龄及肿瘤大小,浸润深度,分化程度无相关性(P>0.05),而与TNM分期及有无淋巴结转移明显相关(P<0.05),P27的表达与cyclin D_1的表达呈负相关(r=-0.332),而与cyclin E的表达无明显相关性(p>0.05).结论:胃癌组织中P27表达与正常胃组织有显著差异,胃癌组织中P27蛋白表达与淋巴结转移及临床分期密切相关,与cyclin E的表达呈负相关.     

Cyclin D1 expression in acute leukemia

BACKGROUND: Disorders of the cell cycle regulatory machinery play a key role in the pathogenesis of cancer. Over expression of cyclin D1 protein has been reported in several solid tumors and certain lymphoid malignancies, but little is known about the involvement of cyclin D1 in acute leukemia. PATIENTS AND METHODS: In this study, we analyzed the expression of cyclin D1 at protein level in, 40 newly diagnosed patients with acute myeloid leukemia (AML), 10 patients with acute lymphoblastic leukemia (ALL), and 11 normal controls using flow cytometry. RESULTS: The expression of cyclin D1 was not significantly different in AML group as compared to normal controls. On the other hand, over expression of cyclin D1 was evident in ALL group (4/10) as compared to that in healthy control. The ALL cases with cyclin D1 over expression were significantly correlated to blast cell counts in the peripheral blood and bone marrow (BM) but not with hemoglobin level, WBC, and platelets count. The ALL group with lymphadenopathy and organomegaly express significantly higher cyclin D1 over expression as compared to those without. CONCLUSION: The biological value of cyclin D1 over expression might be different in AML and ALL.     

Cyclin D1 expression in acute leukemia

Background: Disorders of the cell cycle regulatory machinery play a key role in the pathogenesis of cancer. Over expression of cyclin D1 protein has been reported in several solid tumors and certain lymphoid malignancies, but little is known about the involvement of cyclin D1 in acute leukemia.

Patients and methods: In this study, we analyzed the expression of cyclin D1 at protein level in, 40 newly diagnosed patients with acute myeloid leukemia (AML), 10 patients with acute lymphoblastic leukemia (ALL), and 11 normal controls using flow cytometry.

Results: The expression of cyclin D1 was not significantly different in AML group as compared to normal controls. On the other hand, over expression of cyclin D1 was evident in ALL group (4/10) as compared to that in healthy control. The ALL cases with cyclin D1 over expression were significantly correlated to blast cell counts in the peripheral blood and bone marrow (BM) but not with hemoglobin level, WBC, and platelets count. The ALL group with lymphadenopathy and organomegaly express significantly higher cyclin D1 over expression as compared to those without.

Conclusion: The biological value of cyclin D1 over expression might be different in AML and ALL.     

Cyclin A and cyclin D1 as significant prognostic markers in colorectal cancer patients

Background  

Colorectal cancer is a common cancer all over the world. Aberrations in the cell cycle checkpoints have been shown to be of prognostic significance in colorectal cancer.     

Cyclin A1 expression in leukemia and normal hematopoietic cells

Human cyclin A1 is a newly cloned, tissue-specific cyclin that is prominently expressed in normal testis. In this study, we showed that cyclin A1 was highly expressed in a subset of leukemia samples from patients. The highest frequency of cyclin A1 overexpression was observed in acute myelocytic leukemias, especially those that were at the promyelocyte (M3) and myeloblast (M2) stages of development. Cyclin A1 expression was also detected in normal CD34(+) progenitor cells. The expression of cyclin A1 increased when these cells were stimulated to undergo myeloid differentiation in vitro. Taken together, our observations suggest that cyclin A1 may have a role in hematopoiesis. High levels of cyclin A1 expression are especially associated with certain leukemias blocked at the myeloblast and promyelocyte stages of differentiation.     

CyclinD1、CyclinE、CDK6在原发性肝细胞癌中的表达

探讨细胞周期调控因子CyclinD1、CyclinE、CDK6在原发性肝细胞癌中的表达及意义。应用免疫组织化学、原位分子杂交和细胞图象分析技术检测原发性肝细胞癌组织及其对应的癌旁肝组织(各20例)、正常肝组织(5例)中CyclinD1、CyclinE和CDK6mRNA表达情况。结果显示:CyclinD1、CyclinE和CDK6mRNA在肝细胞癌组织中呈阳性表达,阳性率分别为70%、75%和25%,正常肝组织呈阴性表达;肝细胞癌组织中CyclinD1和CyclinE的阳性表达与癌旁肝组织、正常肝组织相比,差异均有显著性意义(P<0.05);CyclinD1和CyclinE的过表达在肝细胞癌的发生和发展中起着重要作用。     

胃癌组织cyclinE表达的临床病理意义

目的　Ｃｙｃｌｉｎ Ｅ 蛋白在细胞周期的Ｇ１ 晚期起作用,加速Ｇ１Ｓ期转化,与人类肿瘤有关． 本研究探讨ｃｙｃｌｉｎ Ｅ 蛋白在胃癌的意义．方法　用敏感而特异的免疫组化ＳＰ 法测定胃癌石蜡切片中ｃｙｃｌｉｎ Ｅ蛋白的异常表达．结果　Ｃｙｃｌｉｎ Ｅ 在胃癌中表达６２ ％ （ｎ ＝ ６０ ,Ｍ＝ ４３ ,Ｆ＝ １７ ,３２岁～７３ 岁） ,与癌旁组织２６ ％ 相比有显著差异（ Ｐ＜ ０－０５） ．Ｃｙｃｌｉｎ Ｅ表达与组织病理分化程度呈负相关． 分化差的胃癌组织ｃｙｃｌｉｎ Ｅ蛋白表达越强,ｃｙｃｌｉｎ Ｅ与肿瘤侵袭、淋巴结转移、远处转移无明显关系．结论　Ｃｙｃｌｉｎ Ｅ 蛋白与胃癌发生有关,与胃癌进展无关．ＣｙｃｌｉｎＥ 蛋白可做为胃癌的一个潜在的诊断和判断预后的指标．     

Rapamycin-induced G1 arrest in cycling B-CLL cells is associated with reduced expression of cyclin D3, cyclin E,cyclin A,and survivin

In B-cell chronic lymphocytic leukemia (B-CLL), malignant cells seem to be arrested in the G(0)/early G(1) phase of the cell cycle, and defective apoptosis might be involved in disease progression. However, increasing evidence exists that B-CLL is more than a disease consisting of slowly accumulating resting B cells: a proliferating pool of cells has been described in lymph nodes and bone marrow and might feed the accumulating pool in the blood. Rapamycin has been reported to inhibit cell cycle progression in a variety of cell types, including human B cells, and has shown activity against a broad range of human tumor cell lines. Therefore, we investigated the ability of rapamycin to block cell cycle progression in proliferating B-CLL cells. We have recently demonstrated that stimulation with CpG-oligonucleotides and interleukin-2 provides a valuable model for studying cell cycle regulation in malignant B cells. In our present study, we demonstrated that rapamycin induced cell cycle arrest in proliferating B-CLL cells and inhibited phosphorylation of p70s6 kinase (p70(s6k)). In contrast to previous reports on nonmalignant B cells, the expression of the cell cycle inhibitor p27 was not changed in rapamycin-treated leukemic cells. Treatment with rapamycin prevented retinoblastoma protein (RB) phosphorylation in B-CLL cells without affecting the expression of cyclin D2, but cyclin D3 was no longer detectable in rapamycin-treated B-CLL cells. In addition, rapamycin treatment inhibited cyclin-dependent kinase 2 activity by preventing up-regulation of cyclin E and cyclin A. Interestingly, survivin, which is expressed in the proliferation centers of B-CLL patients in vivo, is not up-regulated in rapamycin-treated cells. Therefore, rapamycin interferes with the expression of many critical molecules for cell cycle regulation in cycling B-CLL cells. We conclude from our study that rapamycin might be an attractive substance for therapy for B-CLL patients by inducing a G(1) arrest in proliferating tumor cells.     

Cyclin D1 expression in B-cell non Hodgkin lymphoma

Disorders of the cell cycle regulatory machinery playa key role in the pathogenesis of cancer. Over-expression of cyclin D1 protein has been reported in several solid tumors and certain lymphoid malignancies, but little is known about the effect of its expression on clinical behavior and outcome in B-cell Non-Hodgkin lymphoma (NHL).

In this study, we investigated the expression of cyclin D1 in group of patients with NHL and correlated the results with the clinical and laboratory data. The degree of expression of cyclin D1 protein was evaluated by flow cytometry in a group of NHL patients (n = 46) and in normal control group (n = 10). Cyclin D1 over expression was detected in 10 out of 46 (21.7%) patients; they were 5/5-mantle cell lymphoma (MCL) (100%) and 5/28 large B-cell lymphoma (17.8%). All other NHL subtypes showed normal cyclin D1 expression. The clinical signs (hepatomegaly, splenomegaly and B-symptoms, clinical staging) and laboratory data (hemoglobin, white cell count (WBCs), platelet count, and bone marrow infiltration) were not significantly different between NHL subgroup with cyclin D1 over expression and that with normal cyclin D1 expression. Serum lactic dehydrogenase (LDH) levels and lymphadenopathy were significantly higher in NHL group with cyclin D1 over expression as compared to those without. Also, cyclin Dl over expression is associated with poor outcome of NHL patients.

Cyclin D1 over expression was evident among all cases of MCL and few cases of large B-cell lymphoma. Cyclin D1 over expression might be used as adjuvant tool for diagnosis of MCL; has role in NHL biology and is bad prognostic index in NHL.     

细胞周期蛋白E和生存素在结直肠癌中表达意义的探讨

目的研究结直肠癌中细胞周期蛋白E和生存素基因的表达,探讨其与结直肠癌的临床病理因素间的关系。方法采用免疫组织化学SP法检测67例结直肠癌组织石蜡切片中细胞周期蛋白E和生存素蛋白的表达情况。结果①细胞周期蛋白E和生存素蛋白在结直肠癌中阳性表达率分别为44.77%(30/67)和49.25%(33/67);②细胞周期蛋白E和生存素蛋白的表达率及表达强度均分别与结直肠癌的细胞分化和淋巴结转移密切相关(P均<0.05);③结直肠癌中细胞周期蛋白E和生存素蛋白的表达未见明显相关性(P>0.05)。结论①细胞周期蛋白E可能作为一种细胞周期调节蛋白在结直肠癌细胞中特异性表达,其高表达的癌细胞常分化差,进展快且易发生转移,常为TNM晚期,因此细胞周期蛋白E具有癌基因的性质;②生存素作为一种癌蛋白,特异性表达于结直肠癌细胞中,与肿瘤的分化和转移密切相关,其高表达的癌细胞常分化差,易转移,预后差;③结直肠癌形成发展多步骤过程是多因素协同作用的结果,癌基因生存素和细胞周期蛋白E激活并上调蛋白的表达;④生存素和细胞周期蛋白E表达强度间无显著相关性,细胞周期蛋白E过表达导致结直肠癌细胞的细胞周期从G1期转化为S期,DNA合成增加,而生存素过表达则使DNA合成后的细胞从G2期转化为M期,癌细胞分裂活跃,两者的协同作用反映在癌生长和浸润转移的生物学表型特征上。     

Cyclin D1 expression in typical chronic lymphocytic leukaemia

Demonstration of cyclin D1 expression by immunohistochemistry in a CD5‐positive small B‐cell proliferation is extremely helpful in the diagnosis of mantle cell lymphoma in tissue samples, including bone marrow trephine biopsies (BMTB) and in differentiating them from chronic lymphocytic leukaemia (CLL). Following the identification of cyclin D1 expression in one case of CLL on BMTB, 64 additional cases, which included 25 lymph nodes, one tonsillar lesion, one skin lesion and 37 BMTBs were systematically reviewed for presence of cyclin D1 overexpression. Overall, in seven of 65 samples (～10%) of CLL, a minority of the leukaemic cells in the proliferation centres expressed cyclin D1. Cytogenetic analysis had been performed in three of seven cases and there was no evidence of translocation involving CCND1 locus. Our findings suggest that a small subset of CLL overexpresses cyclin D1 in amounts that can be demonstrated by immunohistochemistry. Our observation has impact on the diagnosis of small B‐cell lymphomas in BMTB and other tissue samples.     

急性白血病患者细胞周期蛋白E及依赖激酶抑制剂表达的意义

目的：探讨细胞周期蛋白E（cyclin E)、细胞周期蛋白依赖激酶抑制剂（p27KIP1)对成人初治急性白血病（AL）发展及预后的作用。方法：用流式细胞术检测60例AL及17例对照cyclin E、p27 KIP1、多药耐药基因蛋白p170表达及细胞周期分布;逆转录－聚合酶链反应检测46例成人AL患者及17例对照的骨髓cyclin E、p27KIP1、多药耐药蛋白的mRNA水平。结果：60例AL患者全周期及G2／M期cyclinE表达均高于对照组（＜0．01或0．05）;p27KIP1全周期表达亦均高于对照组,但G2／M期差异无显著性（P＞0．05）;cyclinE与p27KIP1的表达呈正相关;AL患者cyclin E高表达组缓解率（44．8％）低于正常表达组（77．4％）（P＜0．01）;复发率（92．3％）高于正常表达组（41．7％）（P＝0．003;p27KIP1表达对AL缓解率、复发率的影响无统计学意义（P＞0．05,P＝0．89）。结论：cyclinE在成人AL有异常高表达,并可能促使AL的发展,是AL缓解率、复发率的重要危险因素。     

细胞周期蛋白E、B1在胃肠癌中的表达及意义

目的 探讨细胞周期蛋白E、B1在胃肠癌中的表达及意义。方法 用间接免疫荧光双标法在激光扫描共聚焦显微镜下检测49例胃肠癌组织中cyclin E和cylcin Bl的表达。结果 胃肠癌中cyclin E和cylcin Bl的阳性表达率分别为48.9％和40.8％,正常组织未见表达,有显著性差异(P<0.05);cyclin E和cylcin Bl在胃肠癌中的表达与肿瘤的生长方式和分化程度相关,在膨胀性生长和高中分化肿瘤中的表达阳性率显著高于浸润性生长和低分化的肿瘤(P<0.05),cyclin Bl在有远处转移的胃肠癌中的表达阳性率显著高于无远处转移的肿瘤组织(P<0.05)。结论cyclin E和cyclin Bl在胃肠肿瘤的发生、发展中起重要作用。     

Cyclin D1 expression and novel mutational findings in Rosai-Dorfman disease

Rosai-Dorfman disease (RDD) is an enigmatic histiocytic disorder classically diagnosed by a distinctive combination of pathological features: emperipolesis, or migration of intact haematological cells through the voluminous cytoplasm of lesional histiocytes, and expression of S100 by these histiocytes. The pathogenesis has long been elusive until the recent detection of recurrent and mutually exclusive mutations in several oncogenes in the mitogen-activated protein kinase (MAPK) pathway. Based on these findings, we investigated a cohort of 21 RDD patients and found that the lesional histiocytes in 86% (18/21) of patients exhibited strong and diffuse nuclear Cyclin D1 expression, which not only may provide a diagnostic marker for this sometimes pathologically challenging disease, but also probably reflects constitutive MAPK pathway activation because we additionally identified phosphorylated-ERK expression in 90% (19/21) of cases. Further, we performed massively parallel sequencing on a subset (6/18) of the CyclinD1 positive cases, identifying several mutations that have not been previously reported in RDD. Taken together, our findings bolster the concept of RDD as a disease of MAPK activation in a substantial percentage of cases and enhance the current understanding of the pathogenesis of RDD.