Cyclin D1 In Breast Cancer Research Articles

HSulf‑1 and palbociclib exert synergistic antitumor effects on RB‑positive triple‑negative breast cancer.

Human sulfatase-1 (HSulf-1) is emerging as a novel prognostic biomarker in breast cancer. Previous studies demonstrated HSulf-1 to function as a negative regulator of cyclin D1 in breast cancer. Accumulating preclinical evidence is supporting the efficacy of cyclin-dependent kinase (CDK) 4/6 inhibitors against the luminal androgen receptor sub-type of triple-negative breast cancer (TNBC). It was therefore hypothesized that HSulf-1 may cooperate with CDK4/6 inhibitors to control cell cycle progression in breast cancer cells. HSulf-1 expression was found to be downregulated in TNBC tissues and cell lines compared with that in healthy tissues and non-breast cancer cell lines, respectively. High levels of HSulf-1 expression was also found to be associated with increased progression-free survival and overall survival in patients with TNBC. Functionally, it was demonstrated that HSulf-1 served as tumor suppressor in TNBC by inducing cell cycle arrest and apoptosis whilst inhibiting proliferation, epithelial-mesenchymal transition, migration and invasion. Subsequent overexpression of HSulf-1 coupled with treatment with the CDK4/6 inhibitor palbociclib exhibited a synergistic antitumor effect on retinoblastoma (RB)-positive TNBC. Further studies revealed the mechanism underlying this cooperative antiproliferative effect involved to be due to the prohibitive effects of HSulf-1 on the palbociclib-induced accumulation of cyclin D1 through AKT/STAT3 and ERK1/2/STAT3 signaling. Taken together, findings from the present study not only suggest that HSulf-1 may be a potential therapeutic target for TNBC, but also indicate that combinatorial treatment could be an alternative therapeutic option for RB-positive TNBC, which may open novel perspectives.

Association of different patterns of expression of beta-catenin and cyclin D1 with pathogenesis of breast carcinoma.

Beta-catenin and cyclin D1 have attracted considerable attention in recent studies as potential proto-oncogenes in many human cancers especially colonic cancer. Beta-catenin plays multiple roles within the cell such as canonical Wnt signaling where cyclin D1 has been identified as one of its target genes. The role of beta-catenin and cyclin D1 in breast cancer has been evaluated in many studies but not established yet. The expression of beta-catenin and cyclin D1 was evaluated in 82 cases of breast carcinoma (BCa) and 32 cases of ductal carcinoma in situ(DCIS) by immunohistochemistry (IHC). Their relationship with clinicopathological features was also investigated. Statistical analysis was done to establish an association. Abnormal expression of beta-catenin (ABE) was seen in 80.2% cases of invasive ductal carcinoma (IDC) and 47% cases of DCIS, while the cyclin D1 positive expression rate was 60.9% and 50%, respectively. In the cases showing ABE, cyclin D1 positivity was 88.1%. ABE showed significant association with high-grade BCa. The most common pattern of ABE was loss of membrane with nuclear positivity which is associated with worst prognosis. In addition, ABE in cases of BCa and DCIS showed concordant patterns. Therefore, an association exists between ABE and cyclin D1 in BCa and its precursor lesions implying that Wnt/beta-catenin oncogenic pathway may have a definite role in breast carcinogenesis and can be used for targeted therapy. Also, different patterns of beta-catenin expression may have prognostic and predictive value.

D-type Cyclins are important downstream effectors of cytokine signaling that regulate the proliferation of normal and neoplastic mammary epithelial cells

In response to the ligand-mediated activation of cytokine receptors, cells decide whether to proliferate or to undergo differentiation. D-type Cyclins (Cyclin D1, D2, or D3) and their associated Cyclin-dependent kinases (CDK4, CDK6) connect signals from cytokines to the cell cycle machinery, and they propel cells through the G1 restriction point and into the S phase, after which growth factor stimulation is no longer essential to complete cell division. D-type Cyclins are upregulated in many human malignancies including breast cancer to promote an uncontrolled proliferation of cancer cells. After summarizing important aspects of the cytokine-mediated transcriptional regulation and the posttranslational modification of D-type Cyclins, this review will highlight the physiological significance of these cell cycle regulators during normal mammary gland development as well as the initiation and promotion of breast cancer. Although the vast majority of published reports focus almost exclusively on the role of Cyclin D1 in breast cancer, we summarize here previous and recent findings that demonstrate an important contribution of the remaining two members of this Cyclin family, in particular Cyclin D3, for the growth of ErbB2-associated breast cancer cells in humans and in mouse models. New data from genetically engineered models as well as the pharmacological inhibition of CDK4/6 suggest that targeting the combined functions of D-type Cyclins could be a suitable strategy for the treatment of ErbB2-positive and potentially other types of breast cancer.

Analysis of Cyclin D1 in Breast Cancer: A Call to Arms

The oncogenic capabilities of the cell cycle protein cyclin D1 have long been established in a breast cancer setting. The CCND1 gene is amplified in up to 15 % of breast tumors, with overexpression of its corresponding protein found in up to 50 % of cases. While gene amplification is consistently associated with reduced patient survival times and treatment resistance, repeated attempts to clarify the prognostic and predictive impact of the cyclin D1 protein in breast cancer have yielded contrasting results. Here, we recommend that any examination of cyclin D1 in a patient cohort should begin by determining CCND1 copy number, with subsequent removal and separate analysis of amplified cases. Next, the remaining tumors should be examined for cyclin D1 protein expression in the context of well-defined breast cancer subgroups. Only in this manner can the true clinical value of cyclin D1 be fully elucidated.

Age dependent switching role of cyclin D1 in breast cancer.

Background: Cyclin D1 gene (CCND1) plays pivotal roles in the development of several human cancers, including breast cancer, functioning as an oncogene. The aim of this study was to better understand the molecular dynamics of ductal carcinomas with regard to proliferation and the ageing process.Methods: 130 cases of ductal breast cancer in postmenopausal women, aged 52–96 in 3 age classes were selected. Tumoral tissues preserved in formaldehyde solution and subsequently embedded in paraffin were subjected to analysis Fluorescence in situ Hybridization (FISH), Reverse Transcription-Polymerase Chain Reaction (RT- PCR) and immuno-histochemical tests. The molecular variables studied were estimated in relation to the patients’ age.Results: The results obtained suggest that the increment of the levels of cyclin D1 in intra-ductal breast tumors in older woman that we have examined is significantly associated with a lower proliferation rate.Conclusion: Cyclin D1, which characterizes tumor in young women as molecular director involved in strengthening tumoral proliferation mechanisms, may be seen as a potential blocking molecular switch in corresponding tumours in old women.

Examining the Role of Cyclin D1 in Breast Cancer

Cyclin D1 overexpression is found in more than 50% of human breast cancers and causes mammary cancer in transgenic mice. Dysregulation of cyclin D1 gene expression or function contributes to the loss of normal cell cycle control during tumorigenesis. Recent studies have demonstrated that cyclin D1 conducts additional specific functions to regulate gene expression in the context of local chromatin, promote cellular migration and inhibit mitochondrial metabolism. It is anticipated that these additional functions contribute to the pathology associated with dysregulated cyclin D1 abundance. This article discusses evidence that examines the significance of cyclin D1 in breast cancer with emphasis on its role in breast cancer stem cell expansion.

Abstract P4-04-01: Proliferation, Migration, Stem Cell Activity and the Role of Cyclin D1 in Breast Cancer

Abstract Background: Proliferation, migration, and stem cell (SC) activity have all been implicated in the development and progression of breast cancer. Growing evidence suggests a relationship between these cellular characteristics, which are tightly regulated by complex signalling pathways. The oncogene cyclin D1 is an essential cell cycle protein that regulates G1 to S phase transition and is overexpressed in many breast cancers. Despite the proliferation activating properties of cyclin D1 it has been linked to a less malignant phenotype. Aim: The aim is to investigate the relationship between migration, proliferation and SC activity in breast cancer and to determine the molecular mechanisms that control these processes focusing on cyclin D1. Methods and Results: To establish a link between proliferation and migration two breast cancer cell lines (MDAMB231 and MDAMB468) were quiesced and proliferation assessed by Ki67 and migration by transwell migration assays. G0/G1 cells displayed an increased migratory capacity (2.9 ±0.15 fold) compared to cycling cells. Next we downregulated cyclin D1 in actively cycling cells using siRNA which resulted in significantly decreased proliferation and the novel observation of increased migration (1.7±0. 19 fold). Having established a link between proliferation and migration the next aim was to investigate relationships with SC activity. To achieve this, cells were sorted following Hoechst 33342 and 7AAD labelling into three populations G0/G1, S, and G2/M. SC-like activity was assessed using a non-adherent mammosphere culture system where single cells are seeded at a density of 500 cells per cm2 for cultured for 7 days. The data clearly demonstrated that G0/G1 cells had increased migratory capacity and also SC-like activity (1.5±0.2 fold) compared to actively cycling cells. Interestingly, down-regulation of cyclin D1 increased both migratory and SC-like activity with most significant effects observed in G0/G1 and S phase of the cell cycle indicating that cyclin D1 is a key protein in the regulation of these cellular processes. When downregulating the cyclin D1 associated kinases CDK4/6 no effect on migration or SC activity was observed suggesting that cyclin D1 affects these cellular processes independent of CDK activation. Finally, when analysing a large set of premenopausal breast cancers we observed an inverse, proliferation-independent link between cyclin D1 and cancer recurrence as well as tumour size (p=0.03), validating that the protein might abrogate infiltrative and malignant behaviour in vivo. Conclusion: These novel functions of cyclin D1 illustrates the interplay between tumor proliferation and migration and SC activity and may explain the lessened malignant behaviour in cyclin D1 high breast cancers. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-04-01.

Expression and amplification of Her2, EGFR and cyclin D1 in breast cancer: Immunohistochemistry and chromogenic in situ hybridization

Determination of Her2, epidermal growth factor receptor (EGFR) and cyclin D1 status is now of major clinical importance due to the development of molecule-targeting drugs in anticancer therapy. Immunohistochemistry (IHC) and chromogenic in situ hybridization (CISH) are the most simple and convenient methods for evaluating gene alterations and their protein consequences. The purpose of the present study was to investigate the status of Her2, EGFR and cyclin D1 on both IHC and CISH in 95 primary breast carcinomas. There was substantial consistency between the IHC and CISH results of Her2 and EGFR, showing fair agreement between protein overexpression and gene amplification. However, cyclin D amplification was not related to protein overexpression. Moreover, there was no correlation between Her2, EGFR and cyclin D1. Her2 protein overexpression and amplification were positively associated with histological grade, nuclear grade and inversely correlated with the expression of estrogen receptor (ER) and progesterone receptor (PR). In ER-negative and postmenopausal patients, EGFR gene amplification was strongly associated with worse recurrence-free survival (P = 0.0087, P = 0.0149, respectively). Overall, the present findings suggest that EGFR gene amplification is important in predicting prognosis and this should be evaluated in breast carcinoma in addition to Her2 status in routine pathological practice.

Cyclin D1 and breast cancer

Cyclin D1 is one of the frequently overexpressed proteins and one of the commonly amplified genes in breast cancer. This article reviews the roles of cyclin D1 in cell-cycle regulation (normal and abnormal), mammary gland development and carcinogenesis and the relationship to oestrogen in breast tissues. It concludes by presenting the clinical, prognostic and therapeutic implications of our current knowledge of cyclin D1 in breast cancer.

Peroxisome Proliferator-Activated Receptor γ-Independent Ablation of Cyclin D1 by Thiazolidinediones and Their Derivatives in Breast Cancer Cells

In light of the clinical relevance of targeting cyclin D1 in breast cancer, we have investigated the mechanism underlying the effect of the peroxisome proliferator-activated receptor-gamma (PPARgamma) agonists troglitazone and ciglitazone on cyclin D1 repression. We obtain evidence that the ability of high doses of troglitazone and ciglitazone to repress cyclin D1 is independent of PPARgamma activation. PPARgamma-inactive troglitazone and ciglitazone analogs 5-[4-(6-hydroxy-2,5,7,8-tetramethyl-chroman-2-yl-methoxy)-benzylidene]-2,4-thiazolidinedione (Delta2-TG) and 5-[4-(1-methyl-cyclohexylmethoxy)-benzylidene]-thiazolidine-2,4-dione are able to facilitate cyclin D1 ablation with potency similar to that of troglitazone and ciglitazone in MCF-7 cells. Reverse transcription-polymerase chain reaction shows that the mRNA level of cyclin D1 remains unaltered in drug-treated cells, indicating the repression is mediated at the post-transcriptional level. Moreover, the ablative effect of these agents is specific to cyclin D1, in that the expression levels of many other cyclins and cyclin-dependent kinases examined remain unchanged after drug treatment. Our data indicate that troglitazone- and Delta2-TG-induced cyclin D1 repression is mediated via proteasome-facilitated proteolysis because it is inhibited by different proteasome inhibitors, including N-carbobenzoxy-l-leucinyl-l-leucinyl-l-norleucinal (MG132), lactacystin, and epoxomicin, and is preceded by increased ubiquitination. The dissociation of these two pharmacological activities (i.e., PPARgamma activation and cyclin D1 ablation) provides a molecular basis to use Delta2-TG as a scaffold to develop a novel class of cyclin D1-ablative agents. Therefore, a series of Delta2-TG derivatives have been synthesized. Among them, 5-[4-(6-allyoxy-2,5,7,8-tetramethyl-chroman-2-yl-methoxy)-benzylidene]-2,4-thiazolidinedione represents a structurally optimized agent with potency that is an order of magnitude higher than that of Delta2-TG in cyclin D1 repression and MCF-7 cell growth inhibition.

Prognostic significance of cyclin D1 overexpression in patients (pts) with primary breast cancer (BC)

9714 Background: Cyclin D1, a key cell cycle regulator, is overexpressed in approximately 50% of BCs. Previous studies yielded conflicting results on the prognostic importance of cyclin D1 in BC. In this study, we evaluated overexpression of cyclin D1 in primary BC to determine any relation to clinicopathologic factors and its impact on survival. Methods: Formalin fixed tissue samples from 119 pts diagnosed with primary BC in 1996 and 1997 were analyzed for cyclin D1 expression by immunohistochemistry (IHC). A scoring system based on intensity and proportion of staining cells was used to judge cyclin D1 overexpression. ER, PR, Her2-Neu, p53 and Ki-67 expression by IHC and nuclear grade (NG) and histologic grade were determined at the time of diagnosis. OS and DFS curves were estimated by the method of Kaplan-Meier using log rank statistics. Clinicopathologic variables were included in Cox proportional hazards model to determine significance. Results: Cyclin D1 overexpression was observed in 68 of the 119 pts (57%). There was a positive correlation between cyclin D1 overexpression and ER expression (p=0.005) and an inverse correlation between cyclin D1 overexpression and both TNM stage and tumor size (p=0.009 and 0.042). Median follow up was 57 months. In univariate analysis, younger age, nodal involvement and higher NG were associated with poorer DFS (p=0.016, 0.001 and 0.026) and OS (p<0.001, p=0.016 and 0.036). Cyclin D1 had no influence on DFS or OS regardless of the cut point used to define overexpression. Among the ER positive subgroup however, there was a trend for improved OS in pts with cyclin D1 negative tumors (p=0.08). In contrast, cyclin D1 expression did not influence OS in ER negative subset. When ER positive pts with ductal carcinoma histology were considered, cyclin D1 negativity was associated with a better prognosis (p=0.053). In multivariate analyses of DFS and OS, only the nodal status (p=0.031 and 0.023) and NG (p=0.029 and 0.039) remained statistically significant. Conclusions: Cyclin D1 overexpression is not an independent predictor of prognosis in BC. In ER positive subgroup however, there is a trend for improved survival in cyclin D1 negative pts. No significant financial relationships to disclose.

Significance of E-cadherin/β-catenin complex and cyclin D1 in breast cancer

E-cadherin and beta-catenin are important epithelial adhesion molecules in normal epithelium. Loss of E-cadherin - beta-catenin adhesion is an important step in the progression of many epithelial malignancies. beta-catenin plays also a role in intracellular signaling and can function as an oncogene when binds to the T-cell factor 4 (Tcf4)-binding site in the promotor region of cyclin D1 and transactivates genes after translocation to the nucleus. We evaluated the immunohistochemical expression pattern of E-cadherin, beta-catenin in relationship with cyclin D1 overexpression, tumor stage, clinicopathologic parameters and patient survival in 128 mammary infiltrating duct carcinomas. The expression of E-cadherin/beta-catenin complex and beta-catenin/cyclin D1 double staining with confocal scanning laser microscope was evaluated. There were aberrant expressions in 78% of E-cadherin, 79% of beta-catenin, and 66% of cyclin D1 in breast cancer. There was correlation of aberrant expression of E-cadherin or beta-catenin with lymph node metastasis, survival rate, and survival length. However, there was no correlation of cyclin D1 overexpression with aberrant expression of E-cadherin or beta-catenin. No death was found in normal expression of beta-catenin, however lowest survival (50%) was found in nuclear beta-catenin expression. There was correlation of overexpression of cyclin D1 with survival rate and survival length. The highest survival rate and survival length were found in membranous normal beta-catenin expression group, however significant decrement of survival length was found in the groups of aberrant expression one or both of E-cadherin or/and beta-catenin. These results suggest that aberrant expression of E-cadherin, beta-catenin, and cyclin D1 may be involved in tumor metastasis, and analysis of the degree or the pattern of E-cadherin, beta-catenin, cyclin D1, and E-cadherin/beta-catenin complex may be good prognostic markers of mammary infiltrating duct carcinoma.

Cyclin D1in breast cancer is not associated with Ki67 but with ER

Cyclin D1in breast cancer is not associated with Ki67 but with ER

A novel activity of cyclin D1 in breast cancer

A novel activity of cyclin D1 in breast cancer

Cyclin D1 in breast cancer.

Cyclin D1 protein plays an important part in regulating the progress of the cell during the G1 phase of the cell cycle. The cyclin D1 gene, CCND1, is amplified in approximately 20% of mammary carcinomas, and the protein is over-expressed in approximately 50% of cases. This has led to intensive study to ascertain whether cyclin D1 is a biological marker in breast cancer; however, the clinical work has produced unexpected results. Work in cell lines and in transgenic mice indicate that CCND1 is a weak oncogene and it was expected that, like c-erbB-2, over-expression of cyclin D1 protein would be associated with a poor prognosis. Early immunohistochemical prognostic studies produced equivocal results but we, and others, have recently shown that strong staining for cyclin D1 is more likely to be seen in well differentiated, estrogen receptor positive carcinomas. Furthermore, we have found that over-expression of cyclin D1 is actually associated with a good outcome, both in terms of prognosis and response to endocrine treatment. Cyclin D1 is frequently over-expressed in ductal carcinoma in situ but not in benign breast disease, including atypical ductal hyperplasia; hence its expression appears to be closely linked with carcinogenesis. In order to help explain the apparent beneficial effects of cyclin D1 over-expression, a number of closely associated cell cycle proteins have also been evaluated, including the cyclin dependent kinase inhibitor p27, which blocks the activating effects of cyclin D1. Initial reports show that high levels of p27 are associated with a good prognosis and we have shown a positive association between p27 and cyclin D1 expression. These clinical results of cyclin D1 are an example of how information obtained from basic cell biology studies needs to be complemented by clinical studies to ascertain the true worth of a prognostic marker.

Inhibition of cyclin D expression in human breast carcinoma cells by retinoids in vitro.

Transfection and transgenic mouse experiments supported an oncogenic role for cyclin D1 in breast cancer. We recently reported that noninvasive carcinoma in situ lesions of the human breast overexpress cyclin D, suggesting that this molecular event may represent a valuable target for chemoprevention. The purpose of the present series of investigations was to identify agents which could reduce the cyclin D expression of breast cells. We report that 9-cis retinoic acid (9-cis RA) and all trans retinoic acid (tRA) inhibited the cyclin D1 and D3 expression levels of human MCF-7, ZR-75 and T-47D breast carcinoma cells in vitro. Where detectable, similar trends were observed in the immortalized, HBL-100 and MCF-10A breast cell lines. Cyclin D2 was undetectable. The effect of retinoids was both dose- and time-dependent, and correlated with altered cell cycle kinetics and proliferative status. Retinoids were also found to inhibit the expression levels of other cell cycle related proteins, including Cdk2 and Cdk4, resulting in lower kinase activities. In contrast to other breast prevention studies, no synergistic effect was observed with retinoids and tamoxifen. The data indicate that retinoids can potently reduce cyclin D expression levels in a variety of breast cell lines in vitro, and suggest further consideration of this mechanism for the chemoprevention of breast cancer.