Cyclin I is expressed in human breast cancer and closely associated with VEGF and KDR expression

Moderate levels of dietary arachidonic acid reduced lipid accumulation and tended to inhibit cell cycle progression in the liver of Japanese seabass Lateolabrax japonicus

To investigate the physiological roles of dietary arachidonic acid (ARA) in fish, a feeding trial with Japanese seabass was conducted, followed by a hepatic transcriptome assay. Six experimental diets differing basically in ARA level (0.05%, 0.22%, 0.37%, 0.60%, 1.38% and 2.32% of dry matter) were used in the feeding trial. Liver samples from fish fed diets with 0.05% and 0.37% ARA were subjected to transcriptomic assay, generating a total of 139 differently expressed unigenes, which were primarily enriched in lipid metabolism and cell cycle-related signaling pathways. Then, qRT-PCR validation on lipid metabolism and cell cycle-related genes as well as corresponding enzyme-linked immunosorbent assay of selected proteins were conducted with liver samples from all six groups. Moderated ARA levels reduced lipogenesis and stimulated β-oxidation concurrently, but high ARA levels seemed to affect lipid metabolism in complicated ways. Both gene expression and protein concentration of cell cycle-related proteins were decreased by moderate levels of dietary ARA. The lipid content and fatty acid composition in fish confirmed the transcription and protein concentration results related to lipid metabolism. In conclusion, moderate levels of dietary ARA (0.37% and 0.60%) reduced lipid accumulation and tended to inhibit cell cycle progression in the liver of Japanese seabass.

Multifaceted Nucleolin Protein and Its Molecular Partners in Oncogenesis

Discovered in 1973, nucleolin is one of the most abundant phosphoproteins of the nucleolus. The ability of nucleolin to be involved in many cellular processes is probably related to its structural organization and its capability to form many different interactions with other proteins. Many functions of nucleolin affect cellular processes involved in oncogenesis-for instance: in ribosome biogenesis; in DNA repair, remodeling, and genome stability; in cell division and cell survival; in chemokine and growth factor signaling pathways; in angiogenesis and lymphangiogenesis; in epithelial-mesenchymal transition; and in stemness. In this review, we will describe the different functions of nucleolin in oncogenesis through its interaction with other proteins.

A systematic analysis of orphan cyclins reveals CNTD2 as a new oncogenic driver in lung cancer

As lung cancer has increased to the most common cause of cancer death worldwide, prognostic biomarkers and effective targeted treatments remain lacking despite advances based on patients’ stratification. Multiple core cyclins, best known as drivers of cell proliferation, are commonly deregulated in lung cancer where they may serve as oncogenes. The recent expansion of the cyclin family raises the question whether new members might play oncogenic roles as well. Here, we investigated the protein levels of eight atypical cyclins in lung cancer cell lines and formalin-fixed and paraffin-embedded (FFPE) human tumors, as well as their functional role in lung cancer cells. Of the new cyclins evaluated, CNTD2 was significantly overexpressed in lung cancer compared to adjacent normal tissue, and exhibited a predominant nuclear location. CNTD2 overexpression increased lung cancer cell viability, Ki-67 intensity and clonogenicity and promoted lung cancer cell migration. Accordingly, CNTD2 enhanced tumor growth in vivo on A549 xenograft models. Finally, the analysis of gene expression data revealed a high correlation between elevated levels of CNTD2 and decreased overall survival in lung cancer patients. Our results reveal CNTD2 as a new oncogenic driver in lung cancer, suggesting value as a prognostic biomarker and therapeutic target in this disease.

Role of CDK5/cyclin complexes in ischemia-induced death and survival of renal tubular cells

Ischemia reperfusion processes induce damage in renal tubules and compromise the viability of kidney transplants. Understanding the molecular events responsible for tubule damage and recovery would help to develop new strategies for organ preservation. CDK5 has been traditionally considered a neuronal kinase with dual roles in cell death and survival. Here, we demonstrate that CDK5 and their regulators p35/p25 and cyclin I are also expressed in renal tubular cells. We show that treatment with CDK inhibitors promotes the formation of pro-survival CDK5/cyclin I complexes and enhances cell survival upon an ischemia reperfusion pro-apoptotic insult. These findings support the benefit of treating with CDK inhibitors for renal preservation, assisting renal tubule protection.

Expression profiling of cell cycle genes in human pancreatic islets with and without type 2 diabetes

Microarray gene expression data were used to analyze the expression pattern of cyclin, cyclin-dependent kinase (CDKs) and cyclin-dependent kinase inhibitor (CDKIs) genes from human pancreatic islets with and without type 2 diabetes (T2D). Of the cyclin genes, CCNI was the most expressed. Data obtained from microarray and qRT-PCR showed higher expression of CCND1 in diabetic islets. Among the CDKs, CDK4, CDK8 and CDK9 were highly expressed, while CDK1 was expressed at low level. High expression of CDK18 was observed in diabetic islets. Of the CDKIs, CDKN1A expression was higher in diabetic islets in both microarray and qRT-PCR. Expression of CDKN1A, CDKN2A, CCNI2, CDK3 and CDK16 was correlated with age. Finally, eight SNPs in these genes were associated with T2D in the DIAGRAM database. Our data provide a comprehensive expression pattern of cell cycle genes in human islets. More human studies are required to confirm and reproduce animal studies.

Cyclin I is involved in the regulation of cell cycle progression

Cyclins control cell cycle progression by regulating the activity of cyclin-dependent kinases (Cdks). Cyclin I is a member of the cyclin family because of the presence of a cyclin box motif. It has been suggested that Cyclin I is involved in various biological processes, such as cell survival, angiogenesis, and cell differentiation. However, whether or not Cyclin I has a role in regulating the cell cycle similarly to other cyclins has yet to be clarified. Therefore, we investigated the role for Cyclin I in cell cycle progression. We showed that the protein level of Cyclin I oscillated during the cell cycle, and that Cyclin I was subjected to ubiquitination and degradation in cells. The interaction between Cyclin I and Cdk5 was detected in cells overexpressed with both proteins. Furthermore, depletion of Cyclin I by siRNAs prevented cell proliferation, suggesting the positive role of Cyclin I for the cell cycle progression. In addition, flow cytometric analysis revealed that cells depleted of Cyclin I were accumulated at G₂/M phases. By using HeLa.S-Fucci (fluorescent ubiquitination-based cell cycle indicator) cells, we further confirmed that knockdown of Cyclin I induced cell cycle arrest at S/G₂/M phases. These results strongly suggest that Cyclin I has the role in the regulation of cell cycle progression.

Cyclin I correlates with VEGFR-2 and cell proliferation in human epithelial ovarian cancer

OBJECTIVE

Ovarian cancer is the most lethal of all gynecologic malignancies. It is characterized by the spread of intraperitoneal tumors, accumulation of ascites, and formation of tumor blood vessels. Cyclin I has been linked with angiogenesis-related proteins, like vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR-2), in human breast cancer. We examined whether an association exists between expression of cyclin I, VEGFR-2, clinicopathologic parameters and survival of patients with epithelial ovarian cancer (EOC).

METHODS

Cyclin I and VEGFR-2 expressions were analyzed by immunohistochemistry in 55 human primary EOC tissue specimens.

RESULTS

Cyclin I immunoreactivity was significantly correlated with VEGFR-2 (R=0.4587, P=0.0004), and immunolabeling of cyclin I and VEGFR-2 significantly correlated with cancer cells' proliferative activity evaluated using cyclin A labeling index as a marker (R=0.3107, P=0.0209 and R=0.4183, P=0.0015, respectively). VEGFR-2 immunostaining was significantly higher in advanced, poorly differentiated, and suboptimally resected EOCs compared to their counterparts (P<0.05). Finally, higher VEGFR-2 expression was significantly associated with shorter disease-free survival (P=0.0437).

CONCLUSIONS

Our results indicate that elevated expression of cyclin I and VEGFR-2 is likely to provide a proliferative advantage to the EOC cells, and that cyclin I may be linked with angiogenesis in EOC. Higher expression of VEGFR-2 is associated with more advanced disease. Further investigation of cyclin I in ovarian cancer is needed to evaluate if cyclin I may become a novel target for an anticancer therapy.

Development of transcriptomic biomarker signature in human saliva to detect lung cancer

Lung cancer is the leading cause of cancer death for both men and women worldwide. Since most of the symptoms found for lung cancer are nonspecific, diagnosis is mostly done at late and progressed stage with the consecutive poor therapy outcome. Effective early detection techniques are sorely needed. The emerging field of salivary diagnostics could provide scientifically credible, easy-to-use, non-invasive and cost-effective detection methods. Recent advances have allowed us to develop discriminatory salivary biomarkers for a variety of diseases from oral to systematic diseases. In this study, salivary transcriptomes of lung cancer patients were profiled and led to the discovery and pre-validation of seven highly discriminatory transcriptomic salivary biomarkers (BRAF, CCNI, EGRF, FGF19, FRS2, GREB1, and LZTS1). The logistic regression model combining five of the mRNA biomarkers (CCNI, EGFR, FGF19, FRS2, and GREB1) could differentiate lung cancer patients from normal control subjects, yielding AUC value of 0.925 with 93.75 % sensitivity and 82.81 % specificity in the pre-validation sample set. These salivary mRNA biomarkers possess the discriminatory power for the detection of lung cancer. This report provides the proof of concept of salivary biomarkers for the non-invasive detection of the systematic disease. These results poised the salivary biomarkers for the initiation of a multi-center validation in a definitive clinical context.

RNA-binding protein nucleolin in disease

Nucleolin is a multifunctional protein localized primarily in the nucleolus, but also found in the nucleoplasm, cytoplasm and cell membrane. It is involved in several aspects of DNA metabolism, and participates extensively in RNA regulatory mechanisms, including transcription, ribosome assembly, mRNA stability and translation, and microRNA processing. Nucleolin's implication in disease is linked to its ability to associate with target RNAs via its four RNA-binding domains and its arginine/glycin-rich domain. By modulating the post-transcriptional fate of target mRNAs, which typically bear AU-rich and/or G-rich elements, nucleolin has been linked to cellular events that influence disease, notably cell proliferation and protection against apoptotic death. Through its diverse RNA functions, nucleolin is increasingly implicated in pathological processes, particularly cancer and viral infection. Here, we review the RNA-binding activities of nucleolin, its influence on gene expression patterns, and its impact upon diseases. We also discuss the rising interest in targeting nucleolin therapeutically.

Serum proteomic-based analysis of pancreatic carcinoma for the identification of potential cancer biomarkers

To identify new biomarkers that improve the early diagnosis and lead to possible therapeutic targets in pancreatic carcinoma, we performed a proteomic approach to compare serum protein expression patterns of pancreatic carcinoma patients with that of gastric cancer patients, other pancreatic disease patients, and healthy volunteers. By two-dimensional gel electrophoresis (2-DE) analyses and mass spectroscopic identification, 10 protein spots were found significantly changed in pancreatic carcinoma and 5 proteins including cyclin I, Rab GDP dissociation inhibitor beta (GDI2), alpha-1 antitrypsin precursor, Haptoglobin precursor, and Serotransferrin precursor were successfully identified. The increased levels of cyclin I and GDI2 found to be associated with pancreatic carcinoma were further confirmed by Western blot analyses in an independent series of serum samples and/or pancreatic juice samples. Applying immunohistochemistry, we further validated expression of cyclin I and GDI2 in additional pancreatic carcinomas. These results indicate that cyclin I and GDI2 may be potential molecular targets for pancreatic cancer diagnostics and therapeutics.