NUCKS1 overexpression is a novel biomarker for recurrence-free survival in cervical squamous cell carcinoma

Acts as a Promising Novel Biomarker for the Prognosis of Patients with Hepatocellular Carcinoma

Objective: Nuclear casein kinase and cyclin-dependent kinase substrate 1 (NUCKS1) is highly expressed in some tumors, including hepatocellular carcinoma (HCC). However, its clinical significance in HCC prognosis is still unclear. The aim of this study was to explore the expression and prognostic value of NUCKS1 in HCC. Materials and Methods: Quantitative real-time polymerase chain reaction was used to detect relative expression of NUCKS1 mRNA in HCC tissues and corresponding adjacent normal tissues. The relationship between NUCKS1 expression and clinical characteristics of patients was analyzed by χ2 test. Kaplan-Meier method and Cox regression analysis were applied to estimate prognostic value of NUCKS1 in HCC. Results: Compared with normal ones, the expression of NUCKS1 mRNA was significantly upregulated in HCC tissues (p < 0.001). Besides, NUCKS1 expression was closely associated with tumor differentiation, tumor node metastasis stage, vascular invasion, and metastasis (p < 0.05). Kaplan-Meier analysis revealed that overall survival was obviously longer in HCC patients with low expression of NUCKS1 than those with high NUCKS1 expression (log rank test, p = 0.001). NUCKS1 might be an independent prognostic factor for HCC patients (HR = 1.905, 95% CI = 1.106-3.283, p = 0.020). Conclusions: NUCKS1 may be correlated with the progression of HCC and serve as a potential predictive factor for the prognosis of this disease.

Roles of increased NUCKS1 expression in endometriosis

BACKGROUND

Endometriosis is still a difficult problem for women. The Nuclear Ubiquitous Casein and cyclin-dependent Kinase Substrate 1 (NUCKS1) gene is located on human chromosome 1q32.1. It encodes the NUCKS1 protein, a 27 kDa nuclear DNA binding protein that plays an important role in cell growth and proliferation. NUCKS1 plays an important role in the development of many diseases. However, its role in endometriosis is unclear.

METHODS

Ectopic endometrial tissues and normal tissue specimens were collected, and the expression of NUCKS1, NF-κB and PI3K was detected by RT-qPCR and immunohistochemistry. Inhibition of NUCKS1 in hEM15A cells, study the changes in cell viability, apoptosis, migration and protein expression by CCK8 assay, flow cytometry, wound-healing assay, western blot and ELISA techniques. The comparison of differences between the two groups was implemented using unpaired sample t test or Mann-whitney U test. One-way analysis of variance or Kruskal-wallis test was used for comparisons among the three groups.

RESULTS

(1) NUCKS1 is highly expressed in endometriosis tissues. (2) Inhibition of NUCKS1 decreases cell viability and capability of migration, and increases apoptosis in endometriosis cells. (3) Expressions of NF-κB and PI3K are increased in endometriosis tissues, and inhibition of NUCKS1 decreases the expression levels of PI3K and NF-κB in endometriosis cells. (4) Inhibition of NUCKS1 decreases the expression of VEGF.

CONCLUSION

(1) NUCKS1 is overexpressed in endometriosis, and inhibition of NUCKS1 inhibits cell viability and capability of migration, and increases apoptosis. (2) NUCKS1 promotes the progress of endometriosis through activating PI3K and NF-κB pathways, and VEFG is also involved in this process.

NUCKS1, a LINC00629-upregulated gene, facilitated osteosarcoma progression and metastasis by elevating asparagine synthesis

Nuclear ubiquitous casein and cyclin-dependent kinase substrate 1 (NUCKS1) has been reported to play an oncogenic role in several cancers. However, the biological functions and regulatory mechanism of NUCKS1 in osteosarcoma have not been fully understood. In this study, we reported that NUCKS1 was significantly increased in osteosarcoma. Depletion of NUCKS1 decreased osteosarcoma cell proliferation and metastasis in vivo and in vitro. Overexpression of NUCKS1 accelerated osteosarcoma cell aggressiveness. Mechanistically, NUCKS1 facilitated asparagine (Asn) synthesis by transcriptionally upregulating asparagine synthetase (ASNS) expression and elevating the levels of Asn in osteosarcoma cells, leading to increased cell growth and metastasis. Inhibition of ASNS or reduction of Asn decreased osteosarcoma cell aggressiveness and impaired the promoting effects of NUCKS1 on tumorigenesis and metastasis. Furthermore, we also found that by acting as a sponge for miR-4768-3p, LINC00629 promoted NUCKS1 expression. Collectively, our findings highlight the role of NUCKS1 in regulating asparagine metabolism and reveal that LINC00629 is an important regulator of NUCKS1 that contributes to NUCKS1 upregulation in osteosarcoma.

NUCKS1 is a highly modified, chromatin-associated protein involved in a diverse set of biological and pathophysiological processes

The Nuclear Casein and Cyclin-dependent Kinase Substrate 1 (NUCKS1) protein is highly conserved in vertebrates, predominantly localized to the nucleus and one of the most heavily modified proteins in the human proteome. NUCKS1 expression is high in stem cells and the brain, developmentally regulated in mice and associated with several diverse malignancies in humans, including cancer, metabolic syndrome and Parkinson's disease. NUCKS1 function has been linked to modulating chromatin architecture and transcription, DNA repair and cell cycle regulation. In this review, we summarize and discuss the published information on NUCKS1 and highlight the questions that remain to be addressed to better understand the complex biology of this multifaceted protein.

Hsa_circ_0001550 facilitates colorectal cancer progression through mediating microRNA-4262/nuclear casein kinase and cyclin-dependent kinase substrate 1 cascade

Background

Circular RNAs (circRNAs) play important roles in various malignancies, such as colorectal cancer (CRC). However, the function of hsa_circ_0001550 in CRC remains to be elucidated.

Methods

The expression levels of hsa_circ_0001550, microRNA (miR)‐4262, and nuclear casein kinase and cyclin‐dependent kinase substrate 1 (NUCKS1) were determined by real‐time qPCR. Cell biological behaviors were evaluated via colony formation assay, transwell assay, flow cytometry, and sphere formation assays. The target relationship was validated via dual‐luciferase reporter and RNA pull‐down assays. Protein expression was analyzed by western blot. Xenograft tumor model was adopted to evaluate hsa_circ_0001550 function in vivo.

Results

Hsa_circ_0001550 enrichment was enhanced in CRC tissue specimens and cell lines. Hsa_circ_0001550 absence hindered CRC cell proliferation, metastasis, stemness, and caused apoptosis. Hsa_circ_0001550 targeted miR‐4262, and hsa_circ_0001550 absence‐caused impacts were diminished by anti‐miR‐4262. MiR‐4262 targeted NUCKS1. Hsa_circ_0001550 had positive regulation on NUCKS1 expression. NUCKS1 overexpression overturned the influences of hsa_circ_0001550 silencingon CRC cell progression. Hsa_circ_0001550 interference notably blocked in vivo xenograft tumor growth.

Conclusion

Hsa_circ_0001550 facilitated CRC progression by binding to miR‐4262 to positively regulate NUCKS1 abundance.

CircRNA circ_0008037 facilitates tumor growth and the Warburg effect via upregulating NUCKS1 by binding to miR-433-3p in non-small cell lung cancer

BACKGROUND

Circular RNAs (circRNAs) participate in the genesis and progression of tumors, including non-small cell lung cancer (NSCLC). At present, the role and regulatory mechanisms of circRNAs in NSCLC have not been fully elucidated. The aim of this study was to explore the role and regulatory mechanism of circRNA hsa_circ_0008037 (circ_0008037) in NSCLC.

METHODS

Expression of circ_0008037 in NSCLC tissues and cells was detected by quantitative real-time polymerase chain reaction (RT-qPCR). Loss-of-function experiments were performed to analyze the influence of circ_0008037 knockdown on proliferation, migration, invasion, and the Warburg effect of NSCLC cells. Western blotting was utilized for protein analysis. The regulatory mechanism of circ_0008037 was surveyed by bioinformatics analysis, RNA pulldown assay, and dual-luciferase reporter assay. Xenograft assay was used to validate the oncogenicity of circ_0008037 in NSCLC in vivo.

RESULTS

Circ_0008037 was upregulated in NSCLC tissues and cells. Circ_0008037 downregulation reduced tumor growth in vivo and repressed proliferation, migration, invasion, and decreased the Warburg effect of NSCLC cells in vitro. Mechanically, circ_0008037 regulated nuclear ubiquitous casein kinase and cyclin-dependent kinase substrate 1 (NUCKS1) expression via sponging miR-433-3p. Furthermore, MiR-433-3p inhibitor reversed the inhibiting influence of circ_0008037 silencing on proliferation, migration, invasion, and the Warburg effect of NSCLC cells. Also, NUCKS1 elevation overturned the repressive influence of miR-433-3p mimic on proliferation, migration, invasion, and the Warburg effect of NSCLC cells.

CONCLUSION

Circ_0008037 accelerated tumor growth and elevated the Warburg effect via regulating NUCKS1 expression by adsorbing miR-433-3p, providing an underlying target for NSCLC treatment.

The NUCKS1-SKP2-p21/p27 axis controls S phase entry

Efficient entry into S phase of the cell cycle is necessary for embryonic development and tissue homoeostasis. However, unscheduled S phase entry triggers DNA damage and promotes oncogenesis, underlining the requirement for strict control. Here, we identify the NUCKS1-SKP2-p21/p27 axis as a checkpoint pathway for the G1/S transition. In response to mitogenic stimulation, NUCKS1, a transcription factor, is recruited to chromatin to activate expression of SKP2, the F-box component of the SCFSKP2 ubiquitin ligase, leading to degradation of p21 and p27 and promoting progression into S phase. In contrast, DNA damage induces p53-dependent transcriptional repression of NUCKS1, leading to SKP2 downregulation, p21/p27 upregulation, and cell cycle arrest. We propose that the NUCKS1-SKP2-p21/p27 axis integrates mitogenic and DNA damage signalling to control S phase entry. The Cancer Genome Atlas (TCGA) data reveal that this mechanism is hijacked in many cancers, potentially allowing cancer cells to sustain uncontrolled proliferation.

Upregulation of NUCKS1 in Lung Adenocarcinoma is Associated with a Poor Prognosis

To evaluate the clinicopathologic features and survival analysis of NUCKS1 expression in human lung adenocarcinoma (LA), we used bioinformatic methods to obtain NUCKS1 gene status and correlated it with prognosis in LA. We compared NUCKS1 expression in 70 samples of LA with intrinsically normal lung alveoli (NLA) by immunohistochemistry, and analyzed their clinicopathologic features. NUCKS1 was overexpressed in LA components(LACs) relative to NLA, and was significantly correlated to patient with 5-year disease-free survival (DFS) and overall survival(OS). Elevated NUCKS1 expression in LACs was shown to be an independent prognostic indicator for OS and a biomarker in LA.

NUCKS1 Promotes Proliferation, Invasion and Migration of Non-Small Cell Lung Cancer by Upregulating CDK1 Expression

Background

Non-small cell lung cancer (NSCLC) is a predominant type of lung cancer with a high mortality rate.

Objective

The aim of this study is to investigate the roles of nuclear casein kinase and cyclin-dependent kinase substrate 1 (NUCKS1) in NSCLC and to identify the potential mechanisms.

Materials and Methods

The expression of NUCKS1 in several NSCLC cells was detected firstly. Then, NUCKS1 was overexpressed or silenced in both A549 and NCI-H460 cells, where cell proliferation, invasion and migration were, respectively, determined, using CCK-8, colony formation assay, transwell and wound healing assays. Cell cycle analysis was performed, and the expression-associated proteins were detected by Western blotting. Subsequently, NCI-H460 cells with NUCKS1 overexpression for the subsequent tumor-bearing experiment. And the NUCKS1 expression in tumor tissues was measured by means of immunohistochemistry and Western blotting. Additionally, the STRING database predicted that Cyclin-Dependent Kinase 1 (CDK1) would bind to NUSK1, which was verified by the co-immunoprecipitation assay. Then, CDK1 was silenced by transfection with short hairpin RNA (shRNA)-CDK-1 or by exposure to CDK1 inhibitor p2767-00. And the biological characteristics of proliferation, invasion and migration were examined.

Results

Results indicated that NUCKS1 was overly expressed in NSCLC cells, and its overexpression promoted proliferation, invasion and migration of both A549 and NCI-H460 cells while NUCKS1 knockdown displayed the opposite effects. Moreover, the results of the xenograft experiments revealed that NUCKS1-upregulation promoted the tumor growth. Furthermore, the immunoprecipitation assay verified CDK1’s interaction with NUCKS1, and CDK1 knockdown alleviates the impact of NUCKS1 overexpression on NSCLC cell proliferation, invasion and migration.

Conclusion

Taken together, these findings demonstrated that NUCKS1 promotes proliferation, invasion and migration of NSCLC by upregulating CDK1, providing a novel putative target for the clinical treatment of NSCLC.

Novel targets identified by integrated proteomic and phosphoproteomic analysis in spermatogenesis of swamp buffalo (Bubalus bubalis)

To understand mechanisms of spermatogenesis, the proteome and the phosphoproteome in prepubertal and pubertal swamp buffalo (Bubalus bubalis) testes were analyzed using tandem mass tag (TMT) coupled with liquid chromatography-tandem mass spectrometry (LC–MS/MS). In prepubertal testes, 80 proteins were overexpressed, 148 proteins were underexpressed, and 139 and 142 protein sites had higher and lower phosphorylation, respectively, compared to the levels in pubertal testes. Several of these proteins were associated with reproductive processes such as sexual reproduction, spermatogenesis, fertilization, and spermatid development. In particular, outer dense fiber protein 1 (ODF1), protein maelstrom homolog (MAEL), actin-like protein 7B (ACTL7B), tyrosine-(Y)-phosphorylation regulated (CABYR), and tripartite motif containing 36 (TRIM36) were upregulated with age at both the proteome and phosphoproteome levels. Combining proteome and phosphoproteome analysis can be effectively applied to study the protein/phosphorylation patterns of buffalo testes. These data provide new regulatory candidates and evidence for a complex network in spermatogenesis in buffalo testes, and serve as an important resource for exploring the physiological mechanism of spermatogenesis in mammals.

A Selection of Important Genes and Their Correlated Behavior in Alzheimer's Disease

In 2017, approximately 5 million Americans were living with Alzheimer’s disease (AD), and it is estimated that by 2050 this number could increase to 16 million. In this study, we apply mathematical optimization to approach microarray analysis to detect differentially expressed genes and determine the most correlated structure among their expression changes. The analysis of GSE4757 microarray dataset, which compares expression between AD neurons without neurofibrillary tangles (controls) and with neurofibrillary tangles (cases), was casted as a multiple criteria optimization (MCO) problem. Through the analysis it was possible to determine a series of Pareto efficient frontiers to find the most differentially expressed genes, which are here proposed as potential AD biomarkers. The Traveling Sales Problem (TSP) model was used to find the cyclical path of maximal correlation between the expression changes among the genes deemed important from the previous stage. This leads to a structure capable of guiding biological exploration with enhanced precision and repeatability. Ten genes were selected (FTL, GFAP, HNRNPA3, COX1, ND2, ND3, ND4, NUCKS1, RPL41, and RPS10) and their most correlated cyclic structure was found in our analyses. The biological functions of their products were found to be linked to inflammation and neurodegenerative diseases and some of them had not been reported for AD before. The TSP path connects genes coding for mitochondrial electron transfer proteins. Some of these proteins are closely related to other electron transport proteins already reported as important for AD.

Fe3O4 Nanopowders: Genomic and Apoptotic Evaluations on A549 Lung Adenocarcinoma Cell Line

The magnetite nanoparticles are progressively used in a wide range of biological applications. In the present study, we purposed to show apoptosis-inducing ability of Fe₃O₄ nanopowders on A549 cells. In addition, the toxic effects of Fe₃O₄ nanopowders were researched on L929 cells. The cytotoxicity of Fe₃O₄ nanopowders were evaluated on A549 and L929 cells by MTT assay and inhibited cell proliferation by time and dose-dependent manner on A549 cells but was not toxic on L929 cells. According to these findings, IC₃₀ value of Fe₃O₄ nanopowders was determined as 5 µM. The early and late apoptotic cells were detected by Annexin V-FITC/PI assay using IC₃₀ concentration of Fe₃O₄ nanopowders. Furthermore, The IC₃₀ value of Fe₃O₄ nanopowders was not effective in the activation of caspase-3 but was effective on loss of mitochondrial membrane potential. The apoptotic index of A549 cells was investigated and found out to increase by IC₃₀ value of Fe₃O₄ nanopowders using TUNEL, BrdU, Bcl-2 immunocytochemical assays. The upregulated and downregulated genes were profiled and the presence of some apoptotic genes was determined with administration of IC₃₀ value of Fe₃O₄ nanopowders by microarray assay. This work suggests that Fe₃O₄ nanopowders could be a good candidate for therapy of lung adenocarcinoma cells.

Identification of Novel Susceptibility Loci and Genes for Prostate Cancer Risk: A Transcriptome-Wide Association Study in Over 140,000 European Descendants

Genome-wide association study-identified prostate cancer risk variants explain only a relatively small fraction of its familial relative risk, and the genes responsible for many of these identified associations remain unknown. To discover novel prostate cancer genetic loci and possible causal genes at previously identified risk loci, we performed a transcriptome-wide association study in 79,194 cases and 61,112 controls of European ancestry. Using data from the Genotype-Tissue Expression Project, we established genetic models to predict gene expression across the transcriptome for both prostate models and cross-tissue models and evaluated model performance using two independent datasets. We identified significant associations for 137 genes at P < 2.61 × 10-6, a Bonferroni-corrected threshold, including nine genes that remained significant at P < 2.61 × 10-6 after adjusting for all known prostate cancer risk variants in nearby regions. Of the 128 remaining associated genes, 94 have not yet been reported as potential target genes at known loci. We silenced 14 genes and many showed a consistent effect on viability and colony-forming efficiency in three cell lines. Our study provides substantial new information to advance our understanding of prostate cancer genetics and biology. SIGNIFICANCE: This study identifies novel prostate cancer genetic loci and possible causal genes, advancing our understanding of the molecular mechanisms that drive prostate cancer.

A microRNA profile of pediatric glioblastoma: The role of NUCKS1 upregulation

MicroRNAs (miRNAs/miRs) are a novel class of gene regulators that may be involved in tumor chemoresistance. Recently, specific miRNA expression profiles have been identified in adult glioblastoma (aGBM), but there are only limited data available on the role of miRNAs in pediatric GBM (pGBM). In the present study, the expression profile of miRNAs was examined in seven pGBMs and three human GBM cell lines (U87MG, A172 and T98G), compared with a non-tumoral pool of pediatric cerebral cortex samples by microarray analysis. A set of differentially expressed miRNAs was identified, including miR-490, miR-876-3p, miR-876-5p, miR-448 and miR-137 (downregulated), as well as miR-501-3p (upregulated). Through bioinformatics analysis, a series of target genes was predicted. In addition, similar gene expression patterns in pGBMs and cell lines was confirmed. Of note, drug resistant T98G cells had upregulated nuclear casein kinase and cyclin-dependent kinase substrate 1 (NUCKS1) expression, a protein overexpressed in many tumors that serves an important role in cell proliferation and progression. On the basis of the present preliminary report, it could be intriguing to further investigate the relationship between each of the identified differentially expressed miRNAs and NUCKS1, in order to clarify their involvement in the multi-drug resistance mechanism of pGBMs.

The Long-Lasting Rodenticide Brodifacoum Induces Neuropathology in Adult Male Rats

Superwarfarins are very long-lasting rodenticides effective in warfarin-resistant rodents at extremely low doses. The consequences of chronic superwarfarin levels in tissues, due to biological half-lives on the order of 20 days, have not been examined. We now characterized the neurological effects of brodifacoum (BDF), one of the most widely used superwarfarins, in adult male Sprague Dawley rats. Dosing curves established the acute oral lethal dose for BDF as 221 ± 14 μg/kg. Measurement of tissue BDF levels showed accumulation throughout the body, including the central nervous system, with levels diminishing over several days. Immunocytochemical staining showed that both astrocyte and microglial activation was increased 4 days after BDF administration, as were levels of carbonylated proteins, and neuronal damage assessed by fluorojade B staining. Direct toxic effects of BDF on neurons and glia were observed using enriched cultures of cerebellar neurons and cortical astrocytes. Proteomic analysis of cerebellar lysates revealed that BDF altered expression of 667 proteins in adult rats. Gene ontology and pathway analysis identified changes in several functional pathways including cell metabolism, mitochondria function, and RNA handling with ribosomal proteins comprising the largest group. In vitro studies using primary astrocytes showed that BDF suppressed de novo protein synthesis. These findings demonstrate that superwarfarin accumulation increases indices of neuroinflammation and neuropathology in adult rodents, suggesting that methods which minimize BDF toxicity may not address delayed neurological sequelae.

Nucks1 synergizes with Trp53 to promote radiation lymphomagenesis in mice

NUCKS1 is a 27 kD vertebrate-specific protein, with a role in the DNA damage response. Here, we show that after 4 Gy total-body X-irradiation, Trp53+/− Nucks1+/− mice more rapidly developed tumors, particularly thymic lymphoma (TL), than Trp53+/− mice. TLs in both cohorts showed loss of heterozygosity (LOH) of the Trp53+ allele in essentially all cases. In contrast, LOH of the Nucks1+ allele was rare. Nucks1 expression correlated well with Nucks1 gene dosage in normal thymi, but was increased in the majority of TLs from Trp53+/− Nucks1+/− mice, suggesting that elevated Nucks1 message may be associated with progression towards malignancy in vivo. Trp53+/− Nucks1+/− mice frequently succumbed to CD4- CD8- TLs harboring translocations involving Igh but not Tcra/d, indicating TLs in Trp53+/− Nucks1+/− mice mostly originated prior to the double positive stage and at earlier lineage than TLs in Trp53+/- mice. Monoclonal rearrangements at Tcrb were more prevalent in TLs from Trp53+/− Nucks1+/− mice, as was infiltration of primary TL cells to distant organs (liver, kidney and spleen). We propose that, in the context of Trp53 deficiency, wild type levels of Nucks1 are required to suppress radiation-induced TL, likely through the role of the NUCKS1 protein in the DNA damage response.

Roles of NUCKS1 in Diseases: Susceptibility, Potential Biomarker, and Regulatory Mechanisms

Nuclear casein kinase and cyclin-dependent kinase substrate 1 (NUCKS1) is a 27 kD chromosomal, highly conserved, and vertebrate-specific protein. NUCKS1 gene encodes a nuclear protein and the conserved regions of NUCKS1 contain several consensus phosphorylation sites for casein kinase II (CK2) and cyclin-dependent kinases (Cdk) and a basic DNA-binding domain. NUCKS1 is similar to the high mobility group (HMG) family which dominates chromatin remodeling and regulates gene transcription. Meanwhile, NUCKS1 is a RAD51 associated protein 1 (RAD51AP1) paralog that is significant for homologous recombination (HR) and genome stability and also a transcriptional regulator of the insulin signaling components. NUCKS1 plays an important role in DNA damage response and metabolism, participates in inflammatory immune response, and correlates with microRNA. Although there is still not enough functional information on NUCKS1, evidences suggest that NUCKS1 can be used as the biomarker of several cancers. This review summarizes the latest research on NUCKS1 about its susceptibility in diseases, expression levels, and regulatory mechanisms as well as the possible functions in reference to diseases.

"Stealth dissemination" of macrophage-tumor cell fusions cultured from blood of patients with pancreatic ductal adenocarcinoma

Here we describe isolation and characterization of macrophage-tumor cell fusions (MTFs) from the blood of pancreatic ductal adenocarcinoma (PDAC) patients. The MTFs were generally aneuploidy, and immunophenotypic characterizations showed that the MTFs express markers characteristic of PDAC and stem cells, as well as M2-polarized macrophages. Single cell RNASeq analyses showed that the MTFs express many transcripts implicated in cancer progression, LINE1 retrotransposons, and very high levels of several long non-coding transcripts involved in metastasis (such as MALAT1). When cultured MTFs were transplanted orthotopically into mouse pancreas, they grew as obvious well-differentiated islands of cells, but they also disseminated widely throughout multiple tissues in "stealth" fashion. They were found distributed throughout multiple organs at 4, 8, or 12 weeks after transplantation (including liver, spleen, lung), occurring as single cells or small groups of cells, without formation of obvious tumors or any apparent progression over the 4 to 12 week period. We suggest that MTFs form continually during PDAC development, and that they disseminate early in cancer progression, forming "niches" at distant sites for subsequent colonization by metastasis-initiating cells.

NUCKS nuclear elevated expression indicates progression and prognosis of ovarian cancer

NUCKS (nuclear, casein kinase, and cyclin-dependent kinase substrate) is implicated in the tumorigenesis of several human malignancies, but its role in ovarian cancer remains unknown. We aim to investigate NUCKS expression and its clinical significance in ovarian cancer. The messenger RNA expression of NUCKS was determined in normal and malignant ovarian tissues using quantitative polymerase chain reaction assay. Immunohistochemistry was applied to detect the status of NUCKS protein expression in 121 ovarian cancer tissues. NUCKS protein high expression was detected in 52 (43.0%) of 121 patients. NUCKS messenger RNA expression was gradually upregulated in non-metastatic ovarian cancers ( n = 20), metastatic ovarian cancers ( n = 20), and its matched metastatic lesions ( n = 20) in comparison with that in normal ovarian tissues ( n = 10; p < 0.05). Elevated expression of NUCKS in ovarian cancer was associated significantly with the Federation of Gynecology and Obstetrics stage ( p = 0.037), histological grade ( p = 0.003), residual disease ( p = 0.013), lymph node metastasis ( p = 0.002), response to chemotherapy ( p < 0.001), and recurrence ( p = 0.013). In the multivariate Cox analysis, NUCKS expression was an independent prognostic marker for overall survival and disease-free survival in ovarian cancer with p values of <0.001 for both. Especially, NUCKS overexpression had prognostic potential for overall survival and disease-free survival ( p < 0.001 for both) in advanced ovarian cancers and only for disease-free survival in early ovarian cancers ( p = 0.017). Our data suggest that NUCKS overexpression may contribute to progression and poor prognosis in ovarian cancer especially in advanced ovarian cancer.

Identification of kinases phosphorylating 13 sites in the nuclear, DNA-binding protein NUCKS

NUCKS is a vertebrate specific, nuclear and DNA-binding phospho protein. The protein is highly expressed in rapidly dividing cells, and is overexpressed in a number of cancer tissues. The phosphorylation of NUCKS is cell cycle and DNA-damage regulated, but little is known about the responsible kinases. By utilizing in vitro and in vivo phosphorylation assays using isolated NUCKS as well as synthetic NUCKS-derived peptides in combination with mass spectrometry, phosphopeptide mapping, phosphphoamino acid analyses, phosphospecific antibodies and the use of specific kinase inhibitors, we found that NUCKS is phosphorylated on 11 sites by CK2. At least 7 of the CK2 sites are phosphorylated in vivo. We also found that NUCKS is phosphorylated on two sites by ATM kinase and DNA-PK in vitro, and is phosphorylated in vivo by ATM kinase in γ-irradiated cells. All together, we identified three kinases phosphorylating 13 out of 39 in vivo phosphorylated sites in mammalian NUCKS. The identification of CK2 and PIKK kinases as kinases phosphorylating NUCKS in vivo provide further evidence for the involvement of NUCKS in cell cycle control and DNA repair.

Identification of NUCKS1 as a putative oncogene and immunodiagnostic marker of hepatocellular carcinoma

Although the molecular mechanisms underpinning hepatocellular carcinoma (HCC) are unknown, gene copy number and associated mRNA expression changes are frequently reported. Comparative genomic hybridization arrays spotted with 4041 bacterial artificial chromosome clones were used to assess copy number changes in 45 HCC tissues. Seventy more HCC tissues were used to validate candidate genes by using western blots and immunohistochemistry. A total of 259 clones were associated with copy number changes that significantly differed between normal liver and HCC samples. The chromosomal region 1q32.1 containing the nuclear casein kinase and cyclin-dependent kinase substrate 1 (NUCKS1) gene was associated with tumor vascular invasion. Western blot analysis demonstrated that NUCKS1 was up-regulated in 37 of 70 (52.8%) HCC tissues compared with adjacent non-tumor tissues, and over-expressed in a vast majority of HCCs (44/52, 84.6%) as determined by immunohistochemical staining. Furthermore, immunostaining of both NUCKS1 and glypican-3 improved the diagnostic prediction of HCC. Knock-down of NUCKS1 by siRNA implied the decrease in cell viability of the Hep3B cell line and reduced tumor formation in a xenograft mouse model. NUCKS1 was identified as a potential oncogene at chromosomal 1q32.1 in patients with HCC, and it might be a valuable immunodiagnostic marker for HCC.

Integration of genome scale data for identifying new players in colorectal cancer

Colorectal cancers (CRCs) display a wide variety of genomic aberrations that may be either causally linked to their development and progression, or might serve as biomarkers for their presence. Recent advances in rapid high-throughput genetic and genomic analysis have helped to identify a plethora of alterations that can potentially serve as new cancer biomarkers, and thus help to improve CRC diagnosis, prognosis, and treatment. Each distinct data type (copy number variations, gene and microRNAs expression, CpG island methylation) provides an investigator with a different, partially independent, and complementary view of the entire genome. However, elucidation of gene function will require more information than can be provided by analyzing a single type of data. The integration of knowledge obtained from different sources is becoming increasingly essential for obtaining an interdisciplinary view of large amounts of information, and also for cross-validating experimental results. The integration of numerous types of genetic and genomic data derived from public sources, and via the use of ad-hoc bioinformatics tools and statistical methods facilitates the discovery and validation of novel, informative biomarkers. This combinatory approach will also enable researchers to more accurately and comprehensively understand the associations between different biologic pathways, mechanisms, and phenomena, and gain new insights into the etiology of CRC.

NUCKS1 is a novel RAD51AP1 paralog important for homologous recombination and genome stability

NUCKS1 (nuclear casein kinase and cyclin-dependent kinase substrate 1) is a 27 kD chromosomal, vertebrate-specific protein, for which limited functional data exist. Here, we demonstrate that NUCKS1 shares extensive sequence homology with RAD51AP1 (RAD51 associated protein 1), suggesting that these two proteins are paralogs. Similar to the phenotypic effects of RAD51AP1 knockdown, we find that depletion of NUCKS1 in human cells impairs DNA repair by homologous recombination (HR) and chromosome stability. Depletion of NUCKS1 also results in greatly increased cellular sensitivity to mitomycin C (MMC), and in increased levels of spontaneous and MMC-induced chromatid breaks. NUCKS1 is critical to maintaining wild type HR capacity, and, as observed for a number of proteins involved in the HR pathway, functional loss of NUCKS1 leads to a slow down in DNA replication fork progression with a concomitant increase in the utilization of new replication origins. Interestingly, recombinant NUCKS1 shares the same DNA binding preference as RAD51AP1, but binds to DNA with reduced affinity when compared to RAD51AP1. Our results show that NUCKS1 is a chromatin-associated protein with a role in the DNA damage response and in HR, a DNA repair pathway critical for tumor suppression.