Cyclin-dependent Kinase 2-associated Protein Research Articles

The deleted in oral cancer (DOC1 aka CDK2AP1) tumor suppressor gene is downregulated in oral squamous cell carcinoma by multiple microRNAs

Cyclin-dependent kinase 2-associated protein 1 (CDK2AP1; also known as deleted in oral cancer or DOC1) is a tumor suppressor gene known to play functional roles in both cell cycle regulation and in the epigenetic control of embryonic stem cell differentiation, the latter as a core subunit of the nucleosome remodeling and histone deacetylation (NuRD) complex. In the vast majority of oral squamous cell carcinomas (OSCC), expression of the CDK2AP1 protein is reduced or lost. Notwithstanding the latter (and the DOC1 acronym), mutations or deletions in its coding sequence are extremely rare. Accordingly, CDK2AP1 protein-deficient oral cancer cell lines express as much CDK2AP1 mRNA as proficient cell lines. Here, by combining in silico and in vitro approaches, and by taking advantage of patient-derived data and tumor material in the analysis of loss of CDK2AP1 expression, we identified a set of microRNAs, namely miR-21-5p, miR-23b-3p, miR-26b-5p, miR-93-5p, and miR-155-5p, which inhibit its translation in both cell lines and patient-derived OSCCs. Of note, no synergistic effects were observed of the different miRs on the CDK2AP1–3-UTR common target. We also developed a novel approach to the combined ISH/IF tissue microarray analysis to study the expression patterns of miRs and their target genes in the context of tumor architecture. Last, we show that CDK2AP1 loss, as the result of miRNA expression, correlates with overall survival, thus highlighting the clinical relevance of these processes for carcinomas of the oral cavity.

The Association between Cyclin Dependent Kinase 2 Associated Protein 1 (CDK2AP1) and Molecular Subtypes of Lethal Prostate Cancer.

Prostate cancer (PCa) is one of the most commonly diagnosed types of malignancy and is the second leading cause of cancer-related death in men in developed countries. Cyclin dependent kinase 2 associate protein 1(CDK2AP1) is an epigenetic and cell cycle regulator gene which has been downregulated in several malignancies, but its involvement in PCa has not yet been investigated in a clinical setting. We assessed the prognostic value of CDK2AP1 expression in a cohort of men diagnosed with PCa (n = 275) treated non-surgically by transurethral resection of the prostate (TURP) and studied the relationship between CDK2AP1 expression to various PCa molecular subtypes (ERG, PTEN, p53 and AR) and evaluated the association with clinical outcome. Further, we used bioinformatic tools to analyze the available TCGA PRAD transcriptomic data to explore the underlying mechanism. Our data confirmed increased expression of CDK2AP1 with higher Gleason Grade Group (GG) and metastatic PCa (p <0.0001). High CDK2AP1 expression was associated with worse overall survival (OS) (HR: 1.62, CI: 1.19-2.21, p = 0.002) and cause-specific survival (CSS) (HR: 2.012, CI 1.29-3.13, p = 0.002) using univariate analysis. When compared to each sub-molecular type. High CDK2AP1/PTEN-loss, abnormal AR or p53 expression showed even worse association to poorer OS and CCS and remained significant when adjusted for GG. Our data indicates that CDK2AP1 directly binds to p53 using the Co-Immunoprecipitation (Co-IP) technique, which was validated using molecular docking tools. This suggests that these two proteins have a significant association through several binding features and correlates with our observed clinical data. In conclusion, our results indicated that the CDK2AP1 overexpression is associate with worse OS and CSS when combined with certain PCa molecular subtypes; interaction between p53 stands out as the most prominent candidate which directly interacts with CDK2AP1.

CDK2AP1 influences immune infiltrates and serves as a prognostic indicator for hepatocellular carcinoma.

Background: Hepatocellular carcinoma (HCC) is a tumor with high malignancy and poor 5-years survival rate. Excellent tumor markers are very important for early clinical diagnosis and prognosis evaluation. Previous studies have shown that CDK2AP1 (Cyclin-dependent kinase 2-associated protein 1) is involved in cell-cycle and epigenetic regulation. In the present study, we assess CDK2AP1 expression, prognostic value, immunomodulatory and possible influencing pathways in HCC. Method: The Cancer Genome Atlas (TCGA) database was used to analyse gene expression, clinicopathology and prognosis. The protein level of CDK2AP1 in HCC tissues was detected in the Human Protein Atlas (HPA) database. The immune score in HCC to CDKAP1 expression were analyzed using ESTIMATE. Furthermore, we use Tumor IMmune Estimation Resource (TIMER) database to study CDK2AP1 expression and Immune Infiltration Levels in HCC. Co-expressed genes of CDK2AP1 were predicted and elaborated by LinkedOmics. Results: In normal liver tissues, the expression of CDK2AP1 was significantly lower than tumor tissues, and was correlated with the level of clinical stage and histologic grade in HCC patients. Patients with high expression of CDK2AP1 have a poor prognosis than patients with low CDK2AP1 expression. CDK2AP1 expression level exhibits significantly positive correlations with the number of infiltrating B cells, CD4+ T cells, CD8+ T cells, Macrophages, Neutrophils, and DCs in HCC tissues. KEGG enrichment analysis showed that the related pathways affected by CDK2AP1 mainly include: Fc gamma R-mediated phagocytosis, Th1 and Th2 cell differentiation, Cell cycle, etc. Both in vitro and in vivo experiments confirmed that CDK2AP1 promotes the proliferation and metastasis in hepatocellular carcinoma. Our results highlight the role of CDK2AP1 as an important prognostic indicator and immunotherapy target for HCC patients. Conclusion: We found CDK2AP1 as a new prognostic biomarker for HCC, which could help explain changes in the biological processes and immune environment lead to liver cancer development. Therefore, CDK2AP1 is a potential new target for HCC therapy.

Computational study to evaluate the potency of phytochemicals in Boerhavia diffusa and the impact of point mutation on cyclin-dependent kinase 2-associated protein 1

A protein's function is closely related to its structural properties. Mutations can affect the functionality of a protein. Different cancer tissues have found disordered expression of the cyclin-dependent kinase 2-associated Protein 1 (CDK2AP1) gene. A protein molecule's conformational flexibility affects its interaction with phytochemicals and their biological partners at various levels. Boerhavia diffusa has been investigated most extensively for its medicinal activities like anticancer properties. It contains many bioactive compounds like Boeravinone A, Boeravinone B, Boeravinone C, Boeravinone D, Boeravinone E, Boeravinone F, Boeravinone G, Boeravinone H, Boeravinone I and Boeravinone J. We have studied to analyse the binding efficacy properties as well as essential dynamic behaviour, free energy landscape of both the native and mutant protein CDK2AP1 with bioactive compounds from Boerhavia diffusa plant extracts through computational approaches by homology modelling, docking and molecular dynamics simulation. From the molecular docking study, we found that. Boeravinone J have best binding affinity (–7.9 kcal/mol) towards the native protein of CDKAP1 compared to others phytochemicals. However, we found the binding energy for H23R and C105R (mutation point) −7.8 and −7.6 kcal/mol, respectively. A single minima energy point (from 100 ns molecular dynamics simulation study) was found in the H23R mutant with Boeravinone J complex suggested that minimum structural changes with less conformational mobility compared C105A mutant model. Communicated by Ramaswamy H. Sarma

Experimental and theoretical corroboration of antimicrobial and anticancer activities of two pseudohalides induced structurally diverse Cd (II)-Salen complexes

Two new cadmium (II) complexes, viz., [Cd4(L1)2(ƞ1-NCS)2(µ2-ƞ2:ƞ1-OAc)2] (C1) and [Cd4(L2)2(µ1,1-N3)4]n (C2) (H2L1= N, N’-ethylene bis(3-methoxysalicylaldimine), H2L2= N, N’-ethylene bis(3-ethoxysalicylaldimine) were impeccably synthesized and structurally characterized using various sophisticated analytical techniques including SCXRD. X-ray diffraction confirmed complexes possess Cd4 structural motifs with two distinctive geometrical arrangements displayed around the central Cd (II) ion. Supramolecular architecture and multi-dimensional polymer formation reunited through the utilization of all anionic forms of ligands taken after by bridging bolster of pseudo-halide ions. Supramolecular interactions are more easily discernible through Hirshfeld surfaces and fingerprint plots. Herein, we demonstrated the potential role of the as-synthesized complexes towards the antimicrobial and anticancer activity. To address the issue, compounds are tested for antibacterial and antifungal activities against the bacteria Staphylococcus aureus (ATCC 25923), Bacillus subtilis (ATCC 6635), Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 25922), and fungal Candida albicans (ATCC 10231). The antimicrobial screening revealed that C1-C2 demonstrated higher action over ligands (L1-L2), thus, simply signifies the endowment of the compound's structural environment on these biological movements. Further, compounds anticancer activity was determined against A549 (Human lung carcinoma) and Panc-1 (Human pancreatic) lines using MTT assay. Molecular docking was performed to correlate the experimental binding results between complexes and the targeted proteins responsible for bacterial or cancerous features. Herewith, E. coli enzyme MurB (PDB ID: 2q85), B. subtilis SMC head domain (PDB ID: 5h67), cyclin-dependent kinase 2-associated protein 1 (PDB ID: 2kw6), and Epidermal Growth Factor Receptor (EGFR) tyrosine kinase domain (PDB ID: 1m17) have been selected to identify the true binding modes and docking poses, which are responsible for this superior biological activity. Subsequently, the current research puts in an exertion to crack a new Cd (II)-mediated complex as an antibacterial and anticancer drug which may demonstrate to be a moo fetched pharmaceutical.

Cathepsin L interacts with CDK2-AP1 as a potential predictor of prognosis in patients with breast cancer.

Cathepsin L (CTSL) is a lysosomal acid cysteine protease that has been implicated in tumorigenesis and malignant progression. In the present study, the role of CTSL in tumorigenesis and prognosis of breast cancer was evaluated. The prognostic value of CTSL was analyzed using immunohistochemistry in patients with breast cancer, as well as online microarray datasets. CTSL expression was knocked down in the breast cancer cell line T-47D using RNA interference. MTT and colony formation assays were performed to assess the role of CTSL in the proliferation of breast cancer cells. Cell cycle progression and apoptosis were measured using flow cytometry. A physical interaction of CTSL and cyclin dependent kinase 2 associated protein 1 (CDK2-AP1) was determined using a glutathione S-transferase pull-down assay. Endogenous CTSL expression was high in breast cancer cells and exhibited an inverse association with CDK2-AP1 expression; aberrant expression of CTSL in breast cancer tissues predicted an improved clinical outcome and prognosis. In addition, CTSL knockdown decelerated the progression of breast cancer cells by arresting cell cycle progression and increasing apoptosis. Thus, CTSL may be a potential therapeutic target for treating patients with breast cancer.

Knockdown of CDK2AP1 in human embryonic stem cells reduces the threshold of differentiation.

Recent studies have suggested a role for the Cyclin Dependent Kinase-2 Associated Protein 1 (CDK2AP1) in stem cell differentiation and self-renewal. In studies with mouse embryonic stem cells (mESCs) derived from generated mice embryos with targeted deletion of the Cdk2ap1 gene, CDK2AP1 was shown to be required for epigenetic silencing of Oct4 during differentiation, with deletion resulting in persistent self-renewal and reduced differentiation potential. Differentiation capacity was restored in these cells following the introduction of a non-phosphorylatible form of the retinoblastoma protein (pRb) or exogenous Cdk2ap1. In this study, we investigated the role of CDK2AP1 in human embryonic stem cells (hESCs). Using a shRNA to reduce its expression in hESCs, we found that CDK2AP1 knockdown resulted in a significant reduction in the expression of the pluripotency genes, OCT4 and NANOG. We also found that CDK2AP1 knockdown increased the number of embryoid bodies (EBs) formed when differentiation was induced. In addition, the generated EBs had significantly higher expression of markers of all three germ layers, indicating that CDK2AP1 knockdown enhanced differentiation. CDK2AP1 knockdown also resulted in reduced proliferation and reduced the percentage of cells in the S phase and increased cells in the G2/M phase of the cell cycle. Further investigation revealed that a higher level of p53 protein was present in the CDK2AP1 knockdown hESCs. In hESCs in which p53 and CDK2AP1 were simultaneously downregulated, OCT4 and NANOG expression was not affected and percentage of cells in the S phase of the cell cycle was not reduced. Taken together, our results indicate that the knockdown of CDK2AP1 in hESCs results in increased p53 and enhances differentiation and favors it over a self-renewal fate.

MRNA Expression of CDK2AP1 in Human Breast Cancer: Correlation with Clinical and Pathological Parameters.

Cyclin-dependent kinase 2-associated protein 1 (CDK2AP1) interacts with CDK2AP2, modulates the actions of transforming growth factor-B1, cyclin-dependent kinase 2 and retinoblastoma protein, and closely interacts with micro-RNA21 and micro-RNA25. Our objective was to determine if CDK2AP1 mRNA expression levels were consistent with tumour-suppressive functions in breast cancer. A total of 134 samples were analysed. CDK2AP1 mRNA levels were measured using quantitative polymerase chain reaction (RT-PCR) and normalised against glyceraldehyde 3-phosphate dehydrogenase mRNA. Levels in breast cancer and adjacent non-cancerous breast tissue were analysed against pathological and clinical parameters (TNM staging, survival over a 10-year follow-up period). Normalised CDK2AP1 expression was 38-fold higher in adjacent non-cancerous breast tissue than in breast cancer. CDK2AP1 expression in disease-free patients at 10 years was more than threefold that of patients who died of breast cancer. However, neither of these differences in expression levels reached statistical significance. CDK2AP1 mRNA levels were higher in TNM1 compared to TNM3 (p=0.016) and with TNM4 (p=0.016). There were no significant associations between CDK2AP1 expression and estrogen receptor status, tumour grade and tumour type. There was no significant difference in overall survival between patients with high and those with low CDK2AP1 mRNA levels after a median follow-up of 10 years (Kaplan-Meier analysis, p=0.872). To our knowledge, this is the first study in the literature to examine the mRNA expression of CDK2AP1 in human breast cancer over a long-term follow-up period. A compelling relationship exists between high CDK2AP1 mRNA expression and lower TNM classification of breast cancer, which is consistent with CDK2AP1 having a tumour-suppressive function.

MiRNA-21 ablation protects against liver injury and necroptosis in cholestasis.

Inhibition of microRNA-21 (miR-21) prevents necroptosis in the mouse pancreas. Necroptosis contributes to hepatic necro-inflammation in the common bile duct ligation (BDL) murine model. We aimed to evaluate the role of miR-21 in mediating deleterious processes associated with cholestasis. Mechanistic studies established a functional link between miR-21 and necroptosis through cyclin-dependent kinase 2-associated protein 1 (CDK2AP1). miR-21 expression increased in the liver of primary biliary cholangitis (PBC) patients and BDL wild-type (WT) mice at both 3 and 14 days. Notably, under BDL, miR-21 -/- mice displayed decreased liver injury markers in serum compared with WT mice, accompanied by reduced hepatocellular degeneration, oxidative stress and fibrosis. Hallmarks of necroptosis were decreased in the liver of BDL miR-21 -/- mice, via relieved repression of CDK2AP1. Further, miR-21 -/- mice displayed improved adaptive response of bile acid homeostasis. In conclusion, miR-21 ablation ameliorates liver damage and necroptosis in BDL mice. Inhibition of miR-21 should arise as a promising approach to treat cholestasis.

MiR-205 promotes proliferation and invasion of laryngeal squamous cell carcinoma by suppressing CDK2AP1 expression.

BackgroundThe aberrant expression of microRNAs (miRNAs) has been found in various types of cancer. miR-205 was reported to be upregulated in laryngeal squamous cell carcinoma (LSCC) tissues, however, the mechanisms by which miR-205 functions as a regulator of LSCC are largely unknown.ResultsIn this study, Real-time qPCR and Western blot assay showed that expression of miR-205 was upregulated and expression of cyclin-dependent kinase 2-associated protein 1 (CDK2AP1) was downregulated in LSCC tissues. The expression levels of miR-205 were negatively related to those of CDK2AP1 in LSCC tissues and cell lines. Moreover, we found that miR-205 was the upstream regulator of CDK2AP1 and could suppress the CDK2AP1 expression in LSCC cells. 3-(4,5-dimethylthiazal-2-yl)-2,5-diphenyl-tetrazolium bromide assays and transwell invasion assay were performed to test the proliferation and invasion of LSCC cells. Gelatin zymography was used to detect the activity of MMP2 and MMP9. CDK2AP1, c-Myc and CyclinD1 expression in cells was assessed with Western blotting. We found that miR-205 was the upstream regulator of CDK2AP1 and could suppress the expression of CDK2AP1 in LSCC cells. In addition, miR-205 significantly induced cell proliferation and invasion by suppressing CDK2AP1 expression. Consistent with miR-205 inhibitors, overexpressed CDK2AP1 suppressed the activity of MMP2 and MMP9 and c-Myc and CyclinD1 expression in LSCC cells.ConclusionThese findings help us to better elucidate the molecular mechanisms of LSCC progression and provide a new theoretical basis to further investigate miR-205 as a potential biomarker and a promising approach for LSCC treatment.

Knockdown of CDK2AP1 in primary human fibroblasts induces p53 dependent senescence.

Cyclin Dependent Kinase-2 Associated Protein-1 (CDK2AP1) is known to be a tumor suppressor that plays a role in cell cycle regulation by sequestering monomeric CDK2, and targeting it for proteolysis. A reduction of CDK2AP1 expression is considered to be a negative prognostic indicator in patients with oral squamous cell carcinoma and also associated with increased invasion in human gastric cancer tissue. CDK2AP1 overexpression was shown to inhibit growth, reduce invasion and increase apoptosis in prostate cancer cell lines. In this study, we investigated the effect of CDK2AP1 downregulation in primary human dermal fibroblasts. Using a short-hairpin RNA to reduce its expression, we found that knockdown of CDK2AP1in primary human fibroblasts resulted in reduced proliferation and in the induction of senescence associated beta-galactosidase activity. CDK2AP1 knockdown also resulted in a significant reduction in the percentage of cells in the S phase and an accumulation of cells in the G1 phase of the cell cycle. Immunocytochemical analysis also revealed that the CDK2AP1 knockdown significantly increased the percentage of cells that exhibited γ-H2AX foci, which could indicate presence of DNA damage. CDK2AP1 knockdown also resulted in increased mRNA levels of p53, p21, BAX and PUMA and p53 protein levels. In primary human fibroblasts in which p53 and CDK2AP1 were simultaneously downregulated, there was: (a) no increase in senescence associated beta-galactosidase activity, (b) decrease in the number of cells in the G1-phase and increase in number of cells in the S-phase of the cell cycle, and (c) decrease in the mRNA levels of p21, BAX and PUMA when compared with CDK2AP1 knockdown only fibroblasts. Taken together, this suggests that the observed phenotype is p53 dependent. We also observed a prominent increase in the levels of ARF protein in the CDK2AP1 knockdown cells, which suggests a possible role of ARF in p53 stabilization following CDK2AP1 knockdown. Altogether, our results show that knockdown of CDK2AP1 in primary human fibroblasts reduced proliferation and induced premature senescence, with the observed phenotype being p53 dependent.

Association of oral tumor suppressor gene deleted in oral cancer-1 (DOC-1) in progression of oral precancer to cancer

IntroductionDeleted in oral cancer-1 (DOC-1), a highly conserved tumor suppressor gene, encodes a specific cyclin-dependent kinase 2-associated protein 1 (p12DOC-1). The protein DOC-1 arrests the cells in the G1 phase of the cell cycle and regulates DNA replication in the S phase of the cell cycle. It is known that DOC-1 is downregulated in head and neck cancer. Hence, the aim of the study was to analyze the messenger RNA (mRNA) expressions of DOC-1 in patients with oral lichen planus (OLP), leukoplakia (LPK), oral submucous fibrosis (OSF), and oral squamous cell carcinoma (OSCC) in comparison to normal control subjects, and these were correlated with differential oral habits and duration of exposure. Materials and methodsSemiquantitative one-step reverse transcriptase polymerase chain reaction (RT-PCR) was used to assess the potential role of DOC-1 in differential oral conditions. ResultsThe expression of DOC-1 at the transcriptional level was found to be consistently reduced (39.13%) or non-detectable (60.87%) in OSCC cases; LPK cases also showed reduced (26.19%) or non-detectable (59.52%) DOC-1 expression, and overexpression of DOC-1 was observed in patients with OSF (42.3%) and OLP (35.29%) as compared to the normal control groups. A marked reduction in DOC-1 expression was observed in patients who smoke bidi and chew tobacco compared to patients who smoke cigarettes and chew pan. An overall reduced expression of DOC-1 with an increase in the duration of exposure was observed. ConclusionsThe overexpression of DOC-1 in oral premalignant disease groups with reduced or loss of expression in OSCC groups suggests its association in the progression of oral carcinogenesis, suggesting DOC-1 to be an important prognostic indicator for oral cancer.

Knockdown of CDK2AP1 by RNA interference inhibits cell growth and tumorigenesis of human glioma

Previous reports support the role of cyclin-dependent kinase 2-associated protein 1 (CDK2AP1) as a tumor suppressor that functions as a key player in cell cycle regulation. Although the misadjustment of CDK2AP1 has been revealed in several types of human malignancies, the functional role of CDK2AP1 in human glioma remains unknown. The present study was undertaken to investigate the effects of CDK2AP1 knockdown by RNA interference (RNAi) on glioma cell growth and tumorigenesis. We employed lentivirus-mediated RNAi to down-regulate CDK2AP1 expression in U251 and U373 cells. Knockdown of CDK2AP1 resulted in a significant reduction in U251 and U373 cell proliferation, as determined by MTT and colony formation assays. Cell cycle analysis showed CDK2AP1 silencing caused U251 cells arrest in G0/G1 phase, especially in the sub-G1 phase representing apoptotic cells. In vivo tumorigenesis was assessed using xenograft formation and CDK2AP1 depletion remarkably inhibited glioma growth and tumorigenesis. Taken together, these results suggest that CDK2AP1 siRNA may have an anti-tumorigenic effect on human glioma.

Interaction between p12CDK2AP1 and a novel unnamed protein product inhibits cell proliferation by regulating the cell cycle

Human p12CDK2AP1 protein is encoded by the cyclin‑dependent kinase 2‑associated protein1 (CDK2AP1) gene. This protein suppresses cell growth, differentiation and angiogenesis in numerous types of carcinoma by interacting with certain cell cycle proteins, including CDK2 and DNA polymerase α/primase. p12CDK2AP1 exerts its functions predominantly through protein‑protein interactions. Therefore, the identification of other p12CDK2AP1‑interacting proteins may clarify its role in cell cycle regulation and carcinogenesis. The aim of this study was to identify additional p12CDK2AP1‑interacting proteins. A novel unnamed protein product (UPP, BC006130) was identified through using a yeast two‑hybrid system. The interaction of p12CDK2AP1 with the UPP was further verified by glutathione S-transferase pull‑down and co‑immunoprecipitation experiments invitro. The qPCR results following overexpression and siRNA assays demonstrated that the expression levels of the UPP were mediated by the CDK2AP1 gene. Furthermore, overexpression of the UPP gene was shown to shorten the length of the G2/M phase of the cell cycle in normal and tumor cell lines in a flow cytometry assay. The results of human tumor xenografts experiments in Balb/c nude mice indicated that stable transfection with the UPP gene was able to inhibit tumor cell proliferation invivo. Overall, this study identified and characterized a novel interactive protein of p12CDK2AP1, which may inhibit cell proliferation by mediating the cell cycle. It expands the understanding of the mechanisms of p12CDK2AP1 and its potential as a cancer therapeutic target.

Cyclin-dependent kinase 2-associated protein 1 suppresses growth and tumorigenesis of lung cancer

Cyclin-dependent kinase 2-associated protein 1 (CDK2AP1), a growth suppressor that negatively regulates CDK2 activity, has been implicated in various types of cancer; yet its role in lung cancer remains unclear. In the present study, a lentivirus-based system was used to specifically downregulate or upregulate CDK2AP1 expression. A549 lung cancer cells were treated with RNAi (RNA interference) or lentiviral vectors for overexpression. Ectopic overexpression of CDK2AP1 in A549 cells in vitro greatly impaired their proliferation and colony-forming ability and enhanced their chemosensitivity to cisplatin and paclitaxel and caused cell cycle arrest at G1/S transition accompanied by the reduction of expression of CDK4 and CDK7. Injection of the ectopically CDK2AP1-overexpressing A549 cells into nude mice resulted in growth arrest of solid lung cancer tumors in vivo. Knockdown of CDK2AP1 in A549 cells, however, gave rise to the opposite effects including promoting cell proliferation/growth, cell cycling in vitro and enhancing tumorigenesis in vivo. These results suggest that CDK2AP1 plays an important role in modulating the growth and tumorigenesis of lung cancer cells and also has significant effects on the chemosensitivity of pulmonary malignancies to chemotherapeutics. Hence, this study extends our knowledge on the relationship between CDK2AP1 and oncogenesis of lung cancer, indicating that CDK2AP1 may serve as a new molecular target for future lung cancer therapy.

Solution NMR Structure of Cyclin-dependent kinase 2-associated protein 2 (CDK2AP2, DOC-1R) from Homo sapiens, Northeast Structural Genomics Consortium (NESG) Target HR8910C

Solution NMR Structure of Cyclin-dependent kinase 2-associated protein 2 (CDK2AP2, DOC-1R) from Homo sapiens, Northeast Structural Genomics Consortium (NESG) Target HR8910C

A Novel Regulatory Factor Recruits the Nucleosome Remodeling Complex to Wingless Integrated (Wnt) Signaling Gene Promoters in Mouse Embryonic Stem Cells

The nucleosome remodeling and deacetylation (NuRD) complex is required for modulating the transcription of essential pluripotency genes in ESC self-renewal. MBD3 is considered a key player in the formation of a functional NuRD complex. The recruitment of MBD3 to methylated promoters may require other prerequisite factors. We show that cyclin-dependent kinase 2-associated protein 1 (CDK2AP1), an essential gene for early embryonic development, plays a role in pluripotency of ESC by engaging MBD3 to the promoter region of Wnt signaling genes. The occupancy of MBD3 on several promoters of Wnt genes was significantly lost in the absence of CDK2AP1, resulting in hyperactivation of Wnt. We propose that the transcriptional modulation of the Wnt pathway mediated by NuRD requires the presence of essential auxiliary components such as CDK2AP1, which may aid the association of the complex with specific focal regions of the target promoters.

Effect of CDK2-AP1 gene over-expression on proliferation and cell cycle regulation of breast cancer cell line MCF-7

To over-express cyclin-dependent kinase 2-associated protein 1 (CDK2-AP1) gene, and investigate its effect on the proliferation and cell cycle regulation in breast cancer cell line MCF-7. CDK2-AP1 gene coding region was cloned into lentivirus vector. Lentivirus particles were infected into MCF-7 cells to upregulate the expression of CDK2-AP1 gene. The expression level of CDK2-AP1 was detected at both mRNA and protein levels by real-time PCR and Western blot. MTT assay, colony formatting assay, and flow cytometry were performed to detect the change of proliferation and cell cycle in MCF-7 cells. We examined the expression of cell cycle associated genes (CDK2, CDK4, P16Ink4A, and P21Cip1/Waf1) followed by CDK2-AP1 over-expression by Western blot. CDK2-AP1 gene was up-regulated significantly at both mRNA (6.94 folds) and protein level. MTT based growth curve, colony formatting assay and flow cytometry showed that CDK2-AP1 over-expression lentivirus inhibited the proliferation of MCF-7 cells with statistical difference (P<0.05). In addition, with CDK2-AP1 over-expression, MCF-7 cells were arrested in G1 phase accompanied by apoptosis. Western blot showed that the expression level of P21Cip1/Waf1 and P16 Ink4A was upregulated, while the expression level of CDK2 and CDK4, members of the CDK family, was downregulated. CDK2-AP1 gene plays a cancer suppressor role in breast cancer. Its function includes inhibiting the proliferation of MCF-7 cells and arresting the cell cycle in G1 phase.

Expression of cyclin-dependent kinase 2-associated protein 1 confers an independent prognosticator in nasopharyngeal carcinoma: a cohort study

Background and aimLow expression of cyclin-dependent kinase 2-associated protein (CDK2AP1) is associated with tumour progression in oral and oesophageal carcinomas, but is not well studied in patients with head and...

Human Cyclin-dependent Kinase 2-associated Protein 1 (CDK2AP1) Is Dimeric in Its Disulfide-reduced State, with Natively Disordered N-terminal Region

CDK2AP1 (cyclin-dependent kinase 2-associated protein 1), corresponding to the gene doc-1 (deleted in oral cancer 1), is a tumor suppressor protein. The doc-1 gene is absent or down-regulated in hamster oral cancer cells and in many other cancer cell types. The ubiquitously expressed CDK2AP1 protein is the only known specific inhibitor of CDK2, making it an important component of cell cycle regulation during G(1)-to-S phase transition. Here, we report the solution structure of CDK2AP1 by combined methods of solution state NMR and amide hydrogen/deuterium exchange measurements with mass spectrometry. The homodimeric structure of CDK2AP1 includes an intrinsically disordered 60-residue N-terminal region and a four-helix bundle dimeric structure with reduced Cys-105 in the C-terminal region. The Cys-105 residues are, however, poised for disulfide bond formation. CDK2AP1 is phosphorylated at a conserved Ser-46 site in the N-terminal "intrinsically disordered" region by IκB kinase ε.