Expression Levels Of Cyclin D3 Research Articles

Early pregnancy exposure to beta-cypermethrin compromises endometrial decidualisation in mice via downregulation of cyclin D3, CDK4/6, and p21.

Beta-cypermethrin (β-CYP) is a highly effective broad-spectrum insecticide that can potentially affect female reproduction. However, little is known about the effect of β-CYP on uterine decidualisation, which is a vital process by which the uterus provides a suitable microenvironment for pregnancy maintenance. Therefore, we focused on the effect and mechanism of β-CYP on endometrial decidualisation during early pregnancy in mice. The results indicated that the expression levels of HOXA10, BMP2, and IGFBP1 was significantly downregulated in the decidual tissue and primary endometrial stromal cells of pregnant and pseudopregnant mice following β-CYP treatment. Serum E2 concentration was significantly increased, whereas P4 concentration and oestrogen receptor (ERα) and progesterone receptor (PRA) expression were significantly downregulated following β-CYP exposure. The number of polyploid decidual cells was lower in the β-CYP-treated group. Furthermore, β-CYP significantly downregulated the protein expression levels of CDK4 and CDK6, and the mRNA expression levels of cyclin D3 and p21. The number of foetuses per female in the first litter was markedly reduced following exposure to β-CYP. In summary, early pregnancy exposure to β-CYP may result in defective endometrial decidualisation via compromised proliferation of uterine stromal cells and reduced expressions of cyclin D3, CDK4/6, and p21 in mice.

Abemaciclib, a CDK4/6 inhibitor, exerts preclinical activity against aggressive germinal center-derived B-cell lymphomas.

The revised WHO classification newly defined the entities “High‐grade B‐cell lymphoma with MYC and BCL2, and/or BCL6 rearrangements (HGBL‐DH/TH)” and “HGBL, NOS.” Standard immunochemotherapy for diffuse large B‐cell lymphoma (DLBCL), R‐CHOP, is insufficient for HGBL patients, and there are currently no optimized therapeutic regimens for HGBL. We previously reported that CCND3, which encodes cyclin D3, harbored high mutation rates in Burkitt lymphoma (BL), HGBL and a subset of DLBCL. Furthermore, the knockdown of cyclin D3 expression was toxic to germinal center (GC)‐derived B‐cell lymphomas. Thus, the fundamental function of cyclin D3 is important for the pathogenesis of GC‐derived B‐cell lymphoma. We herein used two structurally different CDK4/6 inhibitors, palbociclib and abemaciclib, and examined their suppressive effects on cell proliferation and their ability to induce apoptosis in various aggressive B‐cell lymphoma cell lines. The results obtained demonstrated that abemaciclib more strongly suppressed cell proliferation and induced apoptosis in GC‐derived B‐cell lymphoma cell lines than the control, but only slightly inhibited those features in activated B‐cell (ABC)‐like DLBCL cell lines. Palbociclib exerted partial or incomplete effects compared with the control and the effect was intermediate between abemaciclib and the control. Moreover, the effects of abemaciclib appeared to depend on cyclin D3 expression levels based on the results of the expression analysis of primary aggressive B‐cell lymphoma samples. Therefore, abemaciclib has potential as a therapeutic agent for aggressive GC‐derived B‐cell lymphomas.

Identification of a novel interaction between the M2 proton channel of influenza A virus and cyclin D3: consequences for cell cycle progression

To define cellular factors involved in the life cycle of influenza virus, we have used a genome-wide yeast-two-hybrid screening approach. Interestingly, we have identified a novel interaction between the 54 amino-acid cytosolic tail of influenza A virus M2 proton channel protein and the cyclin D3 cellular protein, a key regulator of the cell cycle G1-S transition. Very little is known about crosstalks between influenza A virus and the cellular machineries that regulate the cell cycle. We confirmed the physical interaction between M2 and Cyclin D3, by co-immunoprecipitation studies in human epithelial cells. We then conducted immunofluorescence assays to analyze the relative distribution of cyclin D3 and M2 in infected A549 lung epithelial cells. Interestingly, we observed that cyclin D3 is relocated to or retained at the Golgi apparatus, where M2 is concentrated, at 5 hours post infection. In contrast, cyclin D3 was mainly present in the nucleus, with occasional localization in the cytoplasm, in non-infected cells. More importantly, at 10 hours post infection cyclin D3 was detected in the cytoplasm and at 24 hours post infection expression levels were much reduced. To further study the consequences of influenza virus infection on cyclin D3 expression levels, we infected A549 cells for increasing time points and MOI and analyzed protein levels by western blotting. We found that level of expressed cyclin D3 is decreased upon infection and that this effect is dependent on both time of infection and MOI used. Those data suggest that cyclin D3 is either degraded or its expression down regulated upon influenza virus infection. Interestingly, protein levels of downstream effectors, namely cyclin dependent kinases CDK4 and 6, retinoblastoma protein RB, and cyclin E and A, were also diminished upon infection. By contrast, levels of the CDK inhibitors P15 and P16, which are upstream regulators of the G1-S transition, were unchanged. Together, our data strongly suggest that influenza virus infection alters normal cell cycle progression by interfering with expression levels of cell cycle regulators. Most likely, the newly identified interaction between influenza M2 proton channel and cyclin D3 is involved in this process. We will further investigate the effects of infection on the cell cycle progression by flow cytometry and decipher the molecular mechanism responsible for the down-regulation of cell cycle regulators in influenza infected cells. We will determine whether alteration of cell cycle progression is a strategy used by influenza virus to better replicate in host cells.

In vitro cell cycle dynamics of primitive hematopoietic cells from human umbilical cord blood

The goal of the present study was to investigate the specific way in which recombinant stimulatory cytokines modulate the cell cycle dynamics of primitive hematopoietic cells in vitro. A human cord blood-derived cell population, enriched for CD34+ Lin− cells, was obtained by negative selection and cultured in liquid cultures, in the absence or presence of recombinant stimulatory cytokines. The proportion of cells in each phase of the cell cycle, as well as the expression of cyclin D3, cyclin-dependent kinase-4 (cdk4), p16, p21 and p27, was determined at different time points. At the onset of culture, the vast majority of the cells were in the G0/G1 phase of the cell cycle. In the absence of cytokines, most cells remained in such a phase and no cell cycle activity was detected throughout the culture period, which correlated with the absence of population doublings. In the presence of cytokines, approximately four cell cycles, with a proportionate population doubling, were observed within the first 4 days of culture. In cultures incorporating cytokines, expression levels of cyclin D3 and cdk4 were higher than in their absence; in contrast, the levels of the cell cycle inhibitors p16 and p21 were higher in cultures without cytokines. Levels of p27 were also higher in the presence of cytokines. Our results indicate that the proliferation of primitive hematopoietic cells in liquid culture is promoted by recombinant cytokines via the induction of specific positive regulators of the cell cycle and down-regulation of particular cell cycle inhibitors.

Cyclin D1 and D3 overexpression predicts malignant behavior in thyroid fine‐needle aspirates suspicious for Hurthle cell neoplasms

Thyroid fine-needle aspiration (FNA) samples that feature a follicular-patterned, monotonous Hurthle (oncocytic) cell population cannot be diagnosed reliably. The authors of this report recently identified cyclin D3 overexpression on histologic sections of Hurthle cell carcinoma. In this study, they assessed the diagnostic value of cyclin D3 immunohistochemistry added to routine cytology. Fifty-one FNA samples that were suspicious for Hurtle cell neoplasia and that had histologic follow-up (19 malignant cases) were examined. Cyclin D3 expression levels were evaluated in cell block preparations and were compared with levels of the closely related cyclin D1 protein. Greater than 25% positive cells were used as the cutoff point, as suggested by previous studies. Cyclin D1 and cyclin D3 were highly specific (100% for both) and fairly accurate (75% and 92%, respectively) in distinguishing between benign and malignant oncocytic lesions; the positive predictive value (PPV) for each was 100%. However, both cyclins D1 and D3 had low sensitivity (32% and 79%, respectively) and low negative predictive value (NPV) (71% and 89%, respectively). In contrast, by adopting balanced receiver operating characteristic-derived positive cutoff values, cyclin D1 (>or=6.5%) and cyclin D3 (>or=7.5%) were found to be highly sensitive (100% for both) and accurate (90% and 94%, respectively); and the NPV was 100% for both. In contrast, cyclins D1 and D3 had low specificity (84% and 91%, respectively) and a low PPV (79% and 86%, respectively); however, these values improved in samples that were positive for both cyclins (sensitivity, 100%; specificity, 94%; PPV, 90%; NPV, 100%; and accuracy, 96%). Cyclin D3 increased the suspicion of malignancy in indeterminate oncocytic lesions; its diagnostic performance depended on the cutoff point used and was enhanced further when combined with cyclin D1.

Differential expression of cyclin D3 in ALK+ and ALK− anaplastic large cell lymphoma

As defined in the World Health Organization classification, anaplastic large cell lymphoma (ALCL) is a distinct type of non-Hodgkin lymphoma of T/null cell lineage, a subset of which is associated with translocations involving 2p23 resulting in expression of anaplastic lymphoma kinase (ALK). The most common translocation, the t(2;5)(p23;q35), results in expression of nucleophosmin (NPM)-ALK. NPM-ALK has been shown to activate signal transducer and activator of transcription (STAT) 3, a transcriptional regulator of cyclin D3. In this study, we assessed cyclin D3 expression in 2 ALK+ ALCL cell lines (Karpas 299 and SU-DHL1) and 1 ALK- ALCL cell line (Mac2A) by Western blot analysis. We also assessed cyclin D3 expression in 52 ALCL tumors (32 ALK+, 20 ALK-) by immunohistochemistry using tissue microarrays. These results were compared with phosphorylated (activated) STAT3 (pSTAT3) expression. Both ALK+ ALCL cell lines, but not the ALK- ALCL cell line, expressed cyclin D3 and pSTAT3. Cyclin D3 was expressed in 25 (78%) of 32 ALK+ ALCL tumors and in 4 (20%) of 20 ALK- ALCL tumors (P < .001, Fisher exact test ). In ALK+ ALCL tumors, the mean percentage of cyclin D3-positive tumor cells was 40.6% compared with 5.1% in ALK- ALCL tumors (P < .001, Mann-Whitney U test). The percentages of cyclin D3-positive and pSTAT3-positive tumor cells were positively correlated (Spearman R = 0.35, P = .036). We conclude that cyclin D3 is differentially expressed in ALK+ and ALK- ALCL and that high expression levels of cyclin D3 in ALK+ ALCL may be attributable to STAT3 activation.

Increased expression of G1 cyclins and cyclin-dependent kinases during tumor progression of chemically induced mouse skin neoplasms

Cyclins and cyclin-dependent kinases (Cdks) are central to regulation of the cell cycle. Their abnormal expression may cause loss of cell-cycle control and result in autonomous cell growth, a critical feature of neoplasias. In this study, using immunoblotting, we analyzed the protein levels of several G1/S cyclins (cyclins D1, D2, D3, A, and E) and their respective Cdks (Cdk 2, 4, and 6) in 17 mouse squamous cell carcinomas (SCCs) and 18 mouse skin tumor cell lines. Overexpression of these cell cycle-related genes was frequent in tumors and cell lines. Of special interest was the fact that a group of cell lines that became more aggressive after animal passaging expressed more cyclins D2 and D3 than their respective parental lines did. In addition, SCCs had higher cyclin D3 expression levels than papillomas, and metastases had higher levels than the respective primary tumors, indicating that overexpression of cyclin D3 may be associated with increased aggressiveness of mouse SCC. Interestingly, overexpression of cyclin E was seen in most SCCs induced by a complete carcinogenesis protocol with benzo[a]pyrene (B(a)P) and only in a few SCCs induced by a two-stage carcinogenesis protocol using 7,12-dimethylbenz[a]anthracene as initiator. In contrast, more of the latter tumors overexpressed cyclin D1 and D2 than those induced by B(a)P. Thus, it is possible that different components of the cell-cycle machinery are involved in proliferative dysfunctions that take place during tumor development with different carcinogenesis protocols. Taken together, these results indicate that overexpression of G1 cyclins and their related Cdks is a significant molecular abnormality that could be involved in the process of tumor progression.

Increased expression of G1 cyclins and cyclin‐dependent kinases during tumor progression of chemically induced mouse skin neoplasms

Cyclins and cyclin-dependent kinases (Cdks) are central to regulation of the cell cycle. Their abnormal expression may cause loss of cell-cycle control and result in autonomous cell growth, a critical feature of neoplasias. In this study, using immunoblotting, we analyzed the protein levels of several G1/S cyclins (cycling D1, D2, D3, A, and E) and their respective Cdks (Cdk 2, 4, and 6) in 17 mouse squamous cell carcinomas (SCCs) and 18 mouse skin tumor cell lines. Overexpression of these cell cycle-related genes was frequent in tumors and cell lines. Of special interest was the fact that a group of cell lines that became more aggressive after animal passaging expressed more cyclins D2 and D3 than their respective parental lines did. In addition, SCCs had higher cyclin D3 expression levels than papillomas, and metastases had higher levels than the respective primary tumors, indicating that overexpression of cyclin D3 may be associated with increased aggressiveness of mouse SCC. Interestingly, overexpression of cyclin E was seen in most SCCs induced by a complete carcinogenesis protocol with benzo[a]pyrene (B(a)P) and only in a few SCCs induced by a two-stage carcinogenesis protocol using 7,12-dimethylbenz[a]anthracene as initiator. In contrast, more of the latter tumors overexpressed cyclin D1 and D2 than those induced by B(a)P. Thus, it is possible that different components of the cell-cycle machinery are involved in proliferative dysfunctions that take place during tumor development with different carcinogenesis protocols. Taken together, these results indicate that overexpression of G1 cyclins and their related Cdks is a significant molecular abnormality that could be involved in the process of tumor progression. Mol. Carcinog. 18:142–152, 1997. © 1997 Wiley-Liss, Inc.