GCIP/CCNDBP1, a helix-loop-helix protein, suppresses tumorigenesis

Short-chain fatty acids in cancer pathogenesis

Cancer is a multi-step process that can be viewed as a cellular and immunological shift away from homeostasis in response to selected infectious agents, mutations, diet, and environmental carcinogens. Homeostasis, which contributes importantly to the definition of "health," is maintained, in part by the production of short-chain fatty acids (SCFAs), which are metabolites of specific gut bacteria. Alteration in the composition of gut bacteria, or dysbiosis, is often a major risk factor for some two dozen tumor types. Dysbiosis is often characterized by diminished levels of SCFAs in the stool, and the presence of a "leaky gut," permitting the penetration of microbes and microbial derived molecules (e.g., lipopolysaccharides) through the gut wall, thereby triggering chronic inflammation. SCFAs attenuate inflammation by inhibiting the activation of nuclear factor kappa B, by decreasing the expression of pro-inflammatory cytokines such as tumor necrosis factor alpha, by stimulating the expression of anti-inflammatory cytokines such as interleukin-10 and transforming growth factor beta, and by promoting the differentiation of naïve T cells into T regulatory cells, which down-regulate immune responses by immunomodulation. SCFA function epigenetically by inhibiting selected histone acetyltransferases that alter the expression of multiple genes and the activity of many signaling pathways (e.g., Wnt, Hedgehog, Hippo, and Notch) that contribute to the pathogenesis of cancer. SCFAs block cancer stem cell proliferation, thereby potentially delaying or inhibiting cancer development or relapse by targeting genes and pathways that are mutated in tumors (e.g., epidermal growth factor receptor, hepatocyte growth factor, and MET) and by promoting the expression of tumor suppressors (e.g., by up-regulating PTEN and p53). When administered properly, SCFAs have many advantages compared to probiotic bacteria and fecal transplants. In carcinogenesis, SCFAs are toxic against tumor cells but not to surrounding tissue due to differences in their metabolic fate. Multiple hallmarks of cancer are also targets of SCFAs. These data suggest that SCFAs may re-establish homeostasis without overt toxicity and either delay or prevent the development of various tumor types.

FOXG1 targets BMP repressors and cell cycle inhibitors in human neural progenitor cells

FOXG1 is a critical transcription factor in human brain where loss-of-function mutations cause a severe neurodevelopmental disorder, while increased FOXG1 expression is frequently observed in glioblastoma. FOXG1 is an inhibitor of cell patterning and an activator of cell proliferation in chordate model organisms but different mechanisms have been proposed as to how this occurs. To identify genomic targets of FOXG1 in human neural progenitor cells (NPCs), we engineered a cleavable reporter construct in endogenous FOXG1 and performed chromatin immunoprecipitation (ChIP) sequencing. We also performed deep RNA sequencing of NPCs from two females with loss-of-function mutations in FOXG1 and their healthy biological mothers. Integrative analyses of RNA and ChIP sequencing data showed that cell cycle regulation and Bone Morphogenic Protein (BMP) repression gene ontology categories were over-represented as FOXG1 targets. Using engineered brain cell lines, we show that FOXG1 specifically activates SMAD7 and represses CDKN1B. Activation of SMAD7 which inhibits BMP signaling may be one way that FOXG1 patterns the forebrain, while repression of cell cycle regulators such as CDKN1B may be one way that FOXG1 expands the NPC pool to ensure proper brain size. Our data reveal novel mechanisms on how FOXG1 may control forebrain patterning and cell proliferation in human brain development.

Dissecting Molecular Heterogeneity of Circulating Tumor Cells (CTCs) from Metastatic Breast Cancer Patients through Copy Number Aberration (CNA) and Single Nucleotide Variant (SNV) Single Cell Analysis

Circulating tumor cells' (CTCs) heterogeneity contributes to counteract their introduction in clinical practice. Through single-cell sequencing we aim at exploring CTC heterogeneity in metastatic breast cancer (MBC) patients. Single CTCs were isolated using DEPArray NxT. After whole genome amplification, libraries were prepared for copy number aberration (CNA) and single nucleotide variant (SNV) analysis and sequenced using Ion GeneStudio S5 and Illumina MiSeq, respectively. CTCs demonstrate distinctive mutational signatures but retain molecular traces of their common origin. CNA profiling identifies frequent aberrations involving critical genes in pathogenesis: gains of 1q (CCND1) and 11q (WNT3A), loss of 22q (CHEK2). The longitudinal single-CTC analysis allows tracking of clonal selection and the emergence of resistance-associated aberrations, such as gain of a region in 12q (CDK4). A group composed of CTCs from different patients sharing common traits emerges. Further analyses identify losses of 15q and enrichment of terms associated with pseudopodium formation as frequent and exclusive events. CTCs from MBC patients are heterogeneous, especially concerning their mutational status. The single-cell analysis allows the identification of aberrations associated with resistance, and is a candidate tool to better address treatment strategy. The translational significance of the group populated by similar CTCs should be elucidated.

Cyclin D1 Binding Protein 1 Responds to DNA Damage through the ATM–CHK2 Pathway

Cyclin D1 binding protein 1 (CCNDBP1) is considered a tumor suppressor, and when expressed in tumor cells, CCNDBP1 can contribute to the viability of cancer cells by rescuing these cells from chemotherapy-induced DNA damage. Therefore, this study focused on investigating the function of CCNDBP1, which is directly related to the survival of cancer cells by escaping DNA damage and chemoresistance. Hepatocellular carcinoma (HCC) cells and tissues obtained from Ccndbp1 knockout mice were used for the in vitro and in vivo examination of the molecular mechanisms of CCNDBP1 associated with the recovery of cells from DNA damage. Subsequently, gene and protein expression changes associated with the upregulation, downregulation, and irradiation of CCNDBP1 were assessed. The overexpression of CCNDBP1 in HCC cells stimulated cell growth and showed resistance to X-ray-induced DNA damage. Gene expression analysis of CCNDBP1-overexpressed cells and Ccndbp1 knockout mice revealed that Ccndbp1 activated the Atm–Chk2 pathway through the inhibition of Ezh2 expression, accounting for resistance to DNA damage. Our study demonstrated that by inhibiting EZH2, CCNDBP1 contributed to the activation of the ATM–CHK2 pathway to alleviate DNA damage, leading to chemoresistance.

CCNDBP1, a Prognostic Marker Regulated by DNA Methylation, Inhibits Aggressive Behavior in Dedifferentiated Liposarcoma via Repressing Epithelial Mesenchymal Transition

The present study aimed to explore the prognostic value, function, and mechanism of CCNDBP1 in dedifferentiated liposarcoma (DDL). Immunohistochemistry staining was used to analyze the protein expression of CCNDBP1 in tissue specimens. After silencing CCNDBP1 in LPS853 and overexpressing CCNDBP1 in LPS510, CCK-8, clone formation, transwell migration, and invasion assays were used to detect cell proliferation, migration, and invasion ability. CCNDBP1-induced cell apoptosis was analyzed by flow cytometry. The altered expression of epithelial-mesenchymal transition (EMT)-related proteins were detected by Western blot. The methylation, gene expression, and clinical data of 58 samples with DDL were analyzed using the cancer genome atlas (TCGA) database. Low expression of CCNDBP1 was associated with a poor prognosis of patients with DDL and was considered an independent prognostic factor of the progression-free survival (PFS). CCNDBP1 significantly inhibited the clone formation, proliferation, migration, and invasion of cancer cells in vitro and promoted cancer cell apoptosis. CCNDBP1 could repress the pathological EMT, thereby inhibiting the malignant behaviors of DDL cells. The high degree of DNA methylation sites cg05194114 and cg22184989 could decrease the expression of CCNDBP1 and worsen the prognosis of DDL patients. This is the first study reporting that CCNDBP1 is a tumor suppressor gene of DDL and putative prognostic marker in DDL patients. CCNDBP1 might inhibit the ability of cell proliferation and invasion by repressing pathological EMT, and the expression of CCNDBP1 could be regulated by DNA methylation in DDL.

Genetic program activity delineates risk, relapse, and therapy responsiveness in multiple myeloma

Despite recent advancements in the treatment of multiple myeloma (MM), nearly all patients ultimately relapse and many become refractory to multiple lines of therapies. Therefore, we not only need the ability to predict which patients are at high risk for disease progression but also a means to understand the mechanisms underlying their risk. Here, we report a transcriptional regulatory network (TRN) for MM inferred from cross-sectional multi-omics data from 881 patients that predicts how 124 chromosomal abnormalities and somatic mutations causally perturb 392 transcription regulators of 8549 genes to manifest in distinct clinical phenotypes and outcomes. We identified 141 genetic programs whose activity profiles stratify patients into 25 distinct transcriptional states and proved to be more predictive of outcomes than did mutations. The coherence of these programs and accuracy of our network-based risk prediction was validated in two independent datasets. We observed subtype-specific vulnerabilities to interventions with existing drugs and revealed plausible mechanisms for relapse, including the establishment of an immunosuppressive microenvironment. Investigation of the t(4;14) clinical subtype using the TRN revealed that 16% of these patients exhibit an extreme-risk combination of genetic programs (median progression-free survival of 5 months) that create a distinct phenotype with targetable genes and pathways.

Multi-omics analysis based on integrated genomics, epigenomics and transcriptomics in pancreatic cancer

Aim: Integrated analysis of genomics, epigenomics, transcriptomics and clinical information contributes to identify specific molecular subgroups and find novel biomarkers for pancreatic cancer. Materials & methods: The DNA copy number variation, the simple nucleotide variation, methylation and mRNA data of pancreatic cancer patients were obtained from The Cancer Genome Atlas. Four molecular subgroups (iC1, iC2, iC3 and iC4) of pancreatic cancer were identified by integrating analysis. Results: The iC1 subgroup harbors better prognosis, higher immune score, lesser DNA copy number variation mutations and better genomic stability compared with iC2, iC3 and iC4 subgroups. Three new genes (GRAP2, ICAM3 and A2ML1) correlated with prognosis were identified. Conclusion: Integrated multi-omics analysis provides fresh insight into molecular classification of pancreatic cancer, which may help discover new prognostic biomarkers and reveal the underlying mechanism of pancreatic cancer.

MEK2 is a critical modulating mechanism to down-regulate GCIP stability and function in cancer cells

Loss of tumor suppressor activity and upregulation of oncogenic pathways simultaneously contribute to tumorigenesis. Expression of the tumor suppressor, GCIP (Grap2- and cyclin D1-interacting protein), is usually reduced or lost in advanced cancers, as seen in both mouse tumor models and human cancer patients. However, no previous study has examined how cancer cells down-regulate GCIP expression. In this study, we first validate the tumor suppressive function of GCIP using clinical gastric cancer tissues and online database analysis. We then reveal a novel mechanism whereby MEK2 directly interacts with and phosphorylates GCIP at its Ser313 and Ser356 residues to promote the turnover of GCIP by ubiquitin-mediated proteasomal degradation. We also reveal that decreased GCIP stability enhances cell proliferation and promotes cancer cell migration and invasion. Taken together, these findings provide a more comprehensive view of GCIP in tumorigenesis and suggest that the oncogenic MEK/ERK signaling pathway negatively regulates the protein level of GCIP to promote cell proliferation and migration.

Sodium Butyrate as a Histone Deacetylase Inhibitor Affects Toll-Like Receptor 4 Expression in Colorectal Cancer Cell Lines

We assessed the effect of sodium butyrate (SB) as a histone deacetylase inhibitor (HDACi) on Toll-like receptor 4 (TLR4) gene expression levels, in low TLR4 expressing (HCT116) and high TLR4 expressing (SW480) colorectal cancer cells. The cytotoxic effect of SB was assessed by culturing SW480 and HCT116 cell lines using a broad spectrum of times and concentrations of SB. The MTT assay was done to check the cytotoxic properties of different SB concentrations. Gene expression levels of TLR4 was then evaluated for non-cytotoxic SB concentrations. Morphological analysis and MTT assay confirmed that SB concentrations equal to or less than 5mM were not cytotoxic for both cell lines. At 5mM concentration of SB in SW480 cell line and 1mM concentration of SB in HCT116 cell line, TLR4 gene expression level significantly increased from 24 to 48 hrs and decreased significantly from 48 to 72 hrs with an "early increased and late decreased pattern". At 1mM concentration of SB in SW480 cell line and 5mM concentration of SB in HCT116 cell line, TLR4 expression had a "gradually increased pattern". This study focuses on the dose-time-effect of SB in the pathogenesis of colorectal cancer. SB alters the expression level of TLR4 in colorectal cancer cells. This effect may depend on the cell type, treatment duration and SB concentration. The alterations in TLR4 expression may be due to the direct effect of SB on TLR4 and/or the expression changes of in other genes which may indirectly affect the TLR4 expression. Abbreviations: TLR4: Toll-like receptor 4; HDACi: histone deacetylase inhibitor; SB: sodium Butyrate; CRC: colorectal cancer; SCFA: short-chain fatty acid; hrs: hours.

Controversial Impact of Sirtuins in Chronic Non-Transmissible Diseases and Rehabilitation Medicine

A large body of evidence reports about the positive effects of physical activity in pathophysiological conditions associated with aging. Physical exercise, alone or in combination with other medical therapies, unquestionably causes reduction of symptoms in chronic non-transmissible diseases often leading to significant amelioration or complete healing. The molecular basis of this exciting outcome—however, remain largely obscure. Epigenetics, exploring at the interface between environmental signals and the remodeling of chromatin structure, promises to shed light on this intriguing matter possibly contributing to the identification of novel therapeutic targets. In this review, we shall focalize on the role of sirtuins (Sirts) a class III histone deacetylases (HDACs), which function has been frequently associated, often with a controversial role, to the pathogenesis of aging-associated pathophysiological conditions, including cancer, cardiovascular, muscular, neurodegenerative, bones and respiratory diseases. Numerous studies, in fact, demonstrate that Sirt-dependent pathways are activated upon physical and cognitive exercises linking mitochondrial function, DNA structure remodeling and gene expression regulation to designed medical therapies leading to tangible beneficial outcomes. However, in similar conditions, other studies assign to sirtuins a negative pathophysiological role. In spite of this controversial effect, it is doubtless that studying sirtuins in chronic diseases might lead to an unprecedented improvement of life quality in the elderly.

CDKN2A Depletion Causes Aneuploidy and Enhances Cell Proliferation in Non-Immortalized Normal Human Cells

Aneuploidy is a common feature of cancer cells and may contribute to cellular transformation and cancer development. In this study, we found that significant down-regulation of CDKN2A, CHEK2, CDCA8, TP53BP1, and CCNDBP1 led to chromosome imbalances in two diploid non-immortalized human cell lines; however, only CDKN2A inhibition enhanced cell proliferation and additionally up-regulated three cell cycle control genes: CDCA8, AURKA, and CCND. These results confirm that CDKN2A is a tumor suppressor gene driving human cancer development by inducing cell aneuploidy and cell cycle up-regulation.

Prognostic factors and survival outcomes in patients with chronic myeloid leukemia in blast phase in the tyrosine kinase inhibitor era: Cohort study of 477 patients

BACKGROUND

Outcomes in patients with chronic myeloid leukemia in blast phase (CML-BP) are historically dismal. Herein, the authors sought to analyze the characteristics, prognostic factors, and survival outcomes in patients with CML-BP in the tyrosine kinase inhibitor (TKI) era.

METHODS

A total of 477 patients with CML-BP were treated with a TKI at some point during the course of their CML. Cox proportional hazard models identified characteristics that were predictive of survival. Overall survival and failure-free survival were assessed. Optimal cutoff points for specific parameters were identified using classification and regression tree (CART) analysis.

RESULTS

The median age of the patients was 53 years (range, 16-84 years) and 64% were male. Approximately 80% of patients initially were diagnosed in the chronic phase of CML at a median of 41 months (range, 0.7-298 months) before transformation to CML-BP. De novo CML-BP occurred in 71 patients. Approximately 72% of patients received TKI therapy before CML-BP. The initial therapy for CML-BP included a TKI alone (35%), a TKI with chemotherapy (46%), and non-TKI therapies (19%). The median overall survival was 12 months and the median failure-free survival was 5 months. In multivariate analysis, myeloid immunophenotype, prior TKI, age ≥58 years, lactate dehydrogenase level ≥1227 IU/L, platelet count < 102 K/μL, no history of stem cell transplantation, transition to BP from chronic phase/accelerated phase, and the presence of chromosome 15 aberrations predicted for a significantly increased risk of death. Achievement of major hematologic response and/or complete cytogenetic response to first-line treatment was found to be predictive of better survival. The combination of a TKI with intensive chemotherapy followed by stem cell transplantation appeared to confer the best outcome.

CONCLUSIONS

Patients with CML-BP continue to pose a therapeutic challenge, have dismal outcomes, and require newer treatment approaches. Cancer 2017;123:4391-402. © 2017 American Cancer Society.

Overexpression of SYF2 promotes cell proliferation and correlates with poor prognosis in human breast cancer

SYF2, a known cell cycle regulator, is reported to be involved in cell cycle arrest by interacting with cyclin-D-type binding protein 1. In the present study, we investigated the role of SYF2 in human breast cancer (BC) progression. SYF2 was highly upregulated in BC tissues and cell lines, as per Western blot and immunohistochemistry analysis. The SYF2 expression level had a significant correlation with the tumor grade and Ki-67 expression. In vitro starvation-refeeding experiment and SYF2-siRNA transfection assay demonstrated that SYF2 could promote proliferation of BC cells, while SYF2 knockdown resulted in cells cycle arrest at G1/S phase, reducing the cell growth rate of BC cells. These results indicated that SYF2 promotes human BC progression by accelerating the BC cells’ proliferation. SYF2 could be a novel therapeutic target in human BC therapies.

Identification of Predictive DNA Methylation Biomarkers for Chemotherapy Response in Colorectal Cancer

Resistance to 5-Fluorouracil (5-FU) is a major obstacle to the successful treatment of colorectal cancer (CRC) and posed an increased risk of recurrence. DNA methylation has been suggested as one of the underlying mechanisms for recurrent disease and its contribution to the development of drug resistance remains to be clarified. This study aimed to determine the methylation phenotype in CRC for identification of predictive markers for chemotherapy response. We performed DNA methylation profiling on 43 non-recurrent and five recurrent CRC patients using the Illumina Infinium HumanMethylation450 Beadchip assay. In addition, CRC cells with different genetic backgrounds, response to 5-FU and global methylation levels (HT29 and SW48) were treated with 5-FU and DNA methylation inhibitor 5-aza-2′-deoxycytidine (5-azadC). The singular and combined effects of these two drug classes on cell viability and global methylation profiles were investigated. Our genome-wide methylation study on the clinical specimens showed that recurrent CRCs exhibited higher methylation levels compared to non-recurrent CRCs. We identified 4787 significantly differentially methylated genes (P < 0.05); 3112 genes were hyper- while 1675 genes were hypomethylated in the recurrent group compared to the non-recurrent. Fifty eight and 47 of the significantly hypermethylated and hypomethylated genes have an absolute recurrent/non-recurrent methylation difference of ≥20%. Most of the hypermethylated genes were involved in the MAPK signaling pathway which is a key regulator for apoptosis while the hypomethylated genes were involved in the PI3K-AKT signaling pathway and proliferation process. We also demonstrate that 5-azadC treatment enhanced response to 5-FU which resulted in significant growth inhibition compared to 5-FU alone in hypermethylated cell lines SW48. In conclusion, we found the evidence of five potentially biologically important genes in recurrent CRCs that could possibly serve as a new potential therapeutic targets for patients with chemoresistance. We postulate that aberrant methylation of CCNEI, CCNDBP1, PON3, DDX43, and CHL1 in CRC might be associated with the recurrence of CRC and 5-azadC-mediated restoration of 5-FU sensitivity is mediated at least in part by MAPK signaling pathway.

Ccndbp1 is a new positive regulator of skeletal myogenesis

Skeletal myogenesis is a multistep process in which basic helix-loop-helix (bHLH) transcription factors, such as MyoD (also known as MyoD1), bind to E-boxes and activate downstream genes. Ccndbp1 is a HLH protein that lacks a DNA-binding region, and its function in skeletal myogenesis is currently unknown. We generated Ccndbp1-null mice by using CRISPR-Cas9. Notably, in Ccndbp1-null mice, the cross sectional area of the skeletal tibialis anterior muscle was smaller, and muscle regeneration ability and grip strength were impaired, compared with those of wild type. This phenotype resembled that of myofiber hypotrophy in some human myopathies or amyoplasia. Ccndbp1 expression was upregulated during C2C12 myogenesis. Ccndbp1 overexpression promoted myogenesis, whereas knockdown of Ccndbp1 inhibited myogenic differentiation. Co-transfection of Ccndbp1 with MyoD and/or E47 (encoded by TCF3) significantly enhanced E-box-dependent transcription. Furthermore, Ccndbp1 physically associated with MyoD but not E47. These data suggest that Ccndbp1 regulates muscle differentiation by interacting with MyoD and enhancing its binding to target genes. Our study newly identifies Ccndbp1 as a positive modulator of skeletal myogenic differentiation in vivo and in vitro, providing new insights in order to decipher the complex network involved in skeletal myogenic development and related diseases.

SePIA: RNA and small RNA sequence processing, integration, and analysis

Background

Large-scale sequencing experiments are complex and require a wide spectrum of computational tools to extract and interpret relevant biological information. This is especially true in projects where individual processing and integrated analysis of both small RNA and complementary RNA data is needed. Such studies would benefit from a computational workflow that is easy to implement and standardizes the processing and analysis of both sequenced data types.

Results

We developed SePIA (Sequence Processing, Integration, and Analysis), a comprehensive small RNA and RNA workflow. It provides ready execution for over 20 commonly known RNA-seq tools on top of an established workflow engine and provides dynamic pipeline architecture to manage, individually analyze, and integrate both small RNA and RNA data. Implementation with Docker makes SePIA portable and easy to run. We demonstrate the workflow’s extensive utility with two case studies involving three breast cancer datasets. SePIA is straightforward to configure and organizes results into a perusable HTML report. Furthermore, the underlying pipeline engine supports computational resource management for optimal performance.

Conclusion

SePIA is an open-source workflow introducing standardized processing and analysis of RNA and small RNA data. SePIA’s modular design enables robust customization to a given experiment while maintaining overall workflow structure. It is available at http://anduril.org/sepia.

Electronic supplementary material

The online version of this article (doi:10.1186/s13040-016-0099-z) contains supplementary material, which is available to authorized users.

Pooled-matrix protein interaction screens using Barcode Fusion Genetics

High‐throughput binary protein interaction mapping is continuing to extend our understanding of cellular function and disease mechanisms. However, we remain one or two orders of magnitude away from a complete interaction map for humans and other major model organisms. Completion will require screening at substantially larger scales with many complementary assays, requiring further efficiency gains in proteome‐scale interaction mapping. Here, we report Barcode Fusion Genetics‐Yeast Two‐Hybrid (BFG‐Y2H), by which a full matrix of protein pairs can be screened in a single multiplexed strain pool. BFG‐Y2H uses Cre recombination to fuse DNA barcodes from distinct plasmids, generating chimeric protein‐pair barcodes that can be quantified via next‐generation sequencing. We applied BFG‐Y2H to four different matrices ranging in scale from ~25 K to 2.5 M protein pairs. The results show that BFG‐Y2H increases the efficiency of protein matrix screening, with quality that is on par with state‐of‐the‐art Y2H methods.

The role of sirtuins in aging and age-related diseases

Sirtuins, initially described as histone deacetylases and gene silencers in yeast, are now known to have much more functions and to be much more abundant in living organisms. Sirtuins gained much attention when they were first acknowledged to be responsible for some beneficial and longevity-promoting effects of calorie restriction in many species of animals - from fruit flies to mammals. In this paper, we discuss some detailed molecular mechanisms of inducing these effects, and wonder if they could be possibly mimicked without actually applying calorie restriction, through induction of sirtuin activity. It is known now that sirtuins, when adjusting the pattern of cellular metabolism to nutrient availability, can regulate many metabolic functions significant from the standpoint of aging research - including DNA repair, genome stability, inflammatory response, apoptosis, cell cycle, and mitochondrial functions. While carrying out these regulations, sirtuins cooperate with many transcription factors, including PGC-1a, NFKB, p53 and FoxO. This paper contains some considerations about possible use of facilitating activity of the sirtuins in prevention of aging, metabolic syndrome, chronic inflammation, and other diseases.

Overexpression of SYF2 correlates with enhanced cell growth and poor prognosis in human hepatocellular carcinoma

SYF2, also known as p29/NTC31/CBPIN, encodes a nuclear protein that interacts with Cyclin D-type binding-protein 1. SYF2 has been reported to be involved in pre-mRNA splicing and cell cycle regulation. In the present study, we observed that SYF2 was obviously upregulated in HCC tumor tissues and cell lines, and its level was positively correlated with the tumor grade and Ki-67 expression, as well as poor prognosis of HCC. In vitro, using serum starvation-refeeding experiment, our results suggested that SYF2 was upregulated in proliferating HCC cells, and was positive correlated with the expression of PCNA and Cyclin D1. In addition, depletion of SYF2 decreased PCNA and Cyclin D1 levels. Accordingly, interference of SYF2 resulted in cells cycle arrest at G1/S phase in Huh7 HCC cells. Furthermore, we found that SYF2 might interact with Cyclin D1 and could confer doxorubicin resistance in HCC cells. These findings revealed that SYF2 might play a regulatory role in the proliferation of HCC cells. In summary, SYF2 may be a novel prognostic marker and serve as a potential therapeutic target in HCC.

Regulation of Cell Cycle Regulators by SIRT1 Contributes to Resveratrol-Mediated Prevention of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a major cause of morbidity and mortality in rheumatic diseases. Vascular remodeling due to the proliferation of pulmonary arterial smooth muscle cells (PASMCs) is central to the development of PAH. To date, it is still unclear if Silence Information Regulator 1 (SIRT1) regulates cell cycle regulators in the proliferation of PASMCs and contributes to prevention of PAH by resveratrol. In this study, we found that a significant decrease of SIRT1 expression levels in platelet-derived growth factor BB (PDGF-BB) treated human PASMCs (HPASMCs) and in monocrotaline (MCT) induced PAH rat. Overexpression of SIRT1 induced G1 phase arrest and increased p21 expression but decreased cyclin D1 expression in PDGF-BB treated HPASMCs. Moreover, resveratrol attenuated pulmonary arterial remodeling, decreased pulmonary arterial pressure, and upregulated SIRT1 and p21 expression but downregulated cyclin D1 expression in MCT induced PAH rat. Notably, knockdown of SIRT1 eliminated the regulation of resveratrol on p21 and cyclin D1 expression in PDGF-BB treated HPASMCs. These results demonstrated that SIRT1 mediated the regulation of resveratrol on the expression of cell cycle regulatory molecules. It suggests that SIRT1 exerts a protective role in PAH associated with rheumatic diseases and can be a potential treatment target.

Maid is a negative regulator of transforming growth factor-β-induced cell migration

Maternal Id-like molecule (Maid) is a dominant negative helix-loop-helix protein that has been implicated in regulating gene expression as well as cell-cycle progression. Overexpressed Maid was previously shown to inhibit certain cellular responses induced by transforming growth factor-β (TGF-β), such as TGF-β-induced cytostasis and cell motility, but not epithelial-mesenchymal transition (EMT). The role of endogenous Maid in regulating TGF-β signalling, however, has not been elucidated. We have found evidence that endogenous Maid negatively regulates TGF-β-induced cell motility. Maid knockdown enhanced TGF-β-induced cell motility as measured by chamber migration and wound healing assays but did not affect cell motility induced by bone morphogenetic protein (BMP)-4. Endogenous Maid does not appear to be involved in regulating TGF-β-induced cytostasis, resistance to apoptosis or EMT. Notably, Maid expression was induced in the delayed phase (later than 24 h) after TGF-β stimulation whereas the expression of two other negative feedback regulators, Smad7 and SnoN, was induced as early as 1 h after stimulation. These findings indicate that Maid is a unique negative feedback regulator of TGF-β signalling in its mode of action as well as the timing of its induction.

GCIP functions as a tumor suppressor in non-small cell lung cancer by suppressing Id1-mediated tumor promotion

Grap2 and cyclin D1 interacting protein (GCIP) has been recognized as a putative tumor suppressor, but the molecular mechanisms underlying its anti-tumor properties remain undefined. Here, we report that GCIP is frequently downregulated in non-small cell lung cancer (NSCLC) tissues. Binding assays indicated that inhibitor of DNA binding/differentiation 1 (Id1) interacts with GCIP in the nucleus. Ectopic GCIP expression in the highly invasive NSCLC cell line, H1299, inhibited proliferation, colony formation, invasion and migration, and increased susceptibility to anticancer drugs. Conversely, silencing GCIP expression in the minimally invasive NSCLS cell line, A549, increased proliferation, colony formation, invasion, and migration in vitro, and increased survival and resistance to anticancer drugs. GCIP also suppresses tumorigenicity of NSCLC cells in vivo and GCIP suppresses NSCLC progression is mediated in part by interfering with Id1 signaling, which was confirmed in conditionally induced stable cell lines. In addition, GCIP downregulates the expression of Id1, and GCIP and Id1 are inversely expressed in NSCLC cell lines and specimens. Taken together, these results suggest that GCIP is a potential tumor suppressor in NSCLC and that suppression of Id1-mediated oncogenic properties may be a key mechanism by which GCIP can potently suppress NSCLC tumor progression.

Upregulation of SYF2 in esophageal squamous cell carcinoma promotes tumor cell proliferation and predicts poor prognosis

SYF2, also known as CCNDBP1-interactor or p29, is reported in pre-mRNA splicing and cell cycle progression. However, the role of SYF2 in esophageal squamous cell carcinoma (ESCC) development remains elusive. In the present study, Western blot and immunohistochemistry assays demonstrated that SYF2 was overexpressed in ESCC tumor tissues and cell lines. In addition, immunohistochemistry analysis revealed that SYF2 expression was positively correlated with tumor grade and predicted poor prognosis of ESCC. In vitro studies using serum starvation-refeeding experiment and SYF2-siRNA transfection assay demonstrated that SYF2 expression promoted proliferation of ESCC cells, while SYF2 knockdown led to decreased cell growth rate and colony formation resulted from growth arrest of cell cycle at G0/G1 phase. Furthermore, our results indicated that SYF2 can down-regulate the sensitivity of ESCC cells for cisplatin. Our findings for the first time supported that SYF2 might play an important role in the regulation of ESCC proliferation and would provide a novel therapeutic strategy against human ESCC.

Upregulation of SYF2 is associated with neuronal apoptosis caused by reactive astrogliosis to neuroinflammation

SYF2, known as CCNDBP1-interactor or p29, is likely involved in pre-mRNA splicing and cell cycle progression. The present study was designed to elucidate dynamic changes in SYF2 expression and distribution in the cerebral cortex in a lipopolysaccharide (LPS)-induced neuroinflammation rat model. It was found that SYF2 expression was induced strongly in active astrocytes after LPS injection. In vitro studies showed that the upregulation of SYF2 might be involved in the activation of C6 cells after LPS challenge and the neuronal apoptosis after conditioned media challenge. In addition, with silencing of SYF2 in C6 and PC12 cells by siRNA, the results indicated that SYF2 was required for astrocyte activation and neuronal apoptosis induced by LPS. Our findings on the cellular signaling pathway may provide a new therapeutic strategy against neuroinflammation in the CNS.

Peroxisome proliferator activated receptor α ligands as anticancer drugs targeting mitochondrial metabolism

Tumor cells show metabolic features distinctive from normal tissues, with characteristically enhanced aerobic glycolysis, glutaminolysis and lipid synthesis. Peroxisome proliferator activated receptor α (PPAR α) is activated by nutrients (fatty acids and their derivatives) and influences these metabolic pathways acting antagonistically to oncogenic Akt and c-Myc. Therefore PPAR α can be regarded as a candidate target molecule in supplementary anticancer pharmacotherapy as well as dietary therapeutic approach. This idea is based on hitting the cancer cell metabolic weak points through PPAR α mediated stimulation of mitochondrial fatty acid oxidation and ketogenesis with simultaneous reduction of glucose and glutamine consumption. PPAR α activity is induced by fasting and its molecular consequences overlap with the effects of calorie restriction and ketogenic diet (CRKD). CRKD induces increase of NAD+/NADH ratio and drop in ATP/AMP ratio. The first one is the main stimulus for enhanced protein deacetylase SIRT1 activity; the second one activates AMP-dependent protein kinase (AMPK). Both SIRT1 and AMPK exert their major metabolic activities such as fatty acid oxidation and block of glycolysis and protein, nucleotide and fatty acid synthesis through the effector protein peroxisome proliferator activated receptor gamma 1 α coactivator (PGC-1α). PGC-1α cooperates with PPAR α and their activities might contribute to potential anticancer effects of CRKD, which were reported for various brain tumors. Therefore, PPAR α activation can engage molecular interplay among SIRT1, AMPK, and PGC-1α that provides a new, low toxicity dietary approach supplementing traditional anticancer regimen.

The protein-protein interaction network of the human Sirtuin family

Protein-protein interaction networks are useful for studying human diseases and to look for possible health care through a holistic approach. Networks are playing an increasing and important role in the understanding of physiological processes such as homeostasis, signaling, spatial and temporal organizations, and pathological conditions. In this article we show the complex system of interactions determined by human Sirtuins (Sirt) largely involved in many metabolic processes as well as in different diseases. The Sirtuin family consists of seven homologous Sirt-s having structurally similar cores but different terminal segments, being rather variable in length and/or intrinsically disordered. Many studies have determined their cellular location as well as biological functions although molecular mechanisms through which they act are actually little known therefore, the aim of this work was to define, explore and understand the Sirtuin-related human interactome. As a first step, we have integrated the experimentally determined protein-protein interactions of the Sirtuin-family as well as their first and second neighbors to a Sirtuin-related sub-interactome. Our data showed that the second-neighbor network of Sirtuins encompasses 25% of the entire human interactome, and exhibits a scale-free degree distribution and interconnectedness among top degree nodes. Moreover, the Sirtuin sub interactome showed a modular structure around the core comprising mixed functions. Finally, we extracted from the Sirtuin sub-interactome subnets related to cancer, aging and post-translational modifications for information on key nodes and topological space of the subnets in the Sirt family network.

SIRT6: a master epigenetic gatekeeper of glucose metabolism

Sirtuins are the mammalian homologs of the yeast histone deacetylase Sir2. In recent years, an ever-expanding picture has emerged indicating that these proteins (SIRT1-7) play broad functions in cellular stress resistance, genomic stability, energy metabolism, aging and tumorigenesis. Among members of this family, SIRT6 appears to have particular significance in regulating metabolism, DNA repair and lifespan. In this context, new research from our lab has established SIRT6 as a key regulator of glucose homeostasis. In this Point of View article, we will first highlight our recent findings, and then provide an in-depth discussion of their implications in cancer and aging.

Chromosome 15q21-22-related polymorphisms and haplotypes are associated with susceptibility to type-2 diabetic nonproliferative retinopathy

OBJECTIVE

Diabetic retinopathy (DR) is a microvascular complication of diabetes with a complex multifactorial pathogenesis. We aimed to investigate whether chromosome 15q21-22-related gene polymorphisms could be used as markers of DR susceptibility in type 2 diabetic (T2D) individuals.

METHODS

Individuals were divided into three groups: (1) T2D with nonproliferative DR (NPDR; n=102); (2) T2D with proliferative DR (PDR; n=72); (3) T2D without DR (n=573). Six single-nucleotide polymorphisms (SNPs) (rs7174997, rs3751624, rs8025011, rs17818837, rs2922220, and rs2414520) lying within chromosome 15q21-22 region were genotyped by using Illumina HumanHap550-Duo BeadChips. Genotypes/allelic frequencies and haplotypes for these polymorphisms in each group were compared.

RESULTS

The MYO5C related SNP (rs3751624)*A related genotype and allele are associated with higher susceptibilities to DR, including PDR and NPDR. The rs3751624*GG/AA+AG percentages in each group are (1) 75.5%/24.5%, (2) 73.6%/26.4%, and (3) 82.5%/17.5%. In contrast, the other five SNPs in each group were not significantly different. One haplotype (G-A-G-G-T-G) appears significantly different between T2D individuals with and without DR. Other haplotype distributions were not significantly different between each group.

CONCLUSION

The MYO5C related SNP (rs3751624)*A related genotype/allele and haplotype (G-A-G-G-T-G) might be associated with susceptibility for retinopathy in T2D individuals. Some chromosome 15q21-22* related genetic variations might contribute to the pathogenesis of DR.

A systems biology approach identifies SART1 as a novel determinant of both 5-fluorouracil and SN38 drug resistance in colorectal cancer

Chemotherapy response rates for advanced colorectal cancer remain disappointingly low, primarily because of drug resistance, so there is an urgent need to improve current treatment strategies. To identify novel determinants of resistance to the clinically relevant drugs 5-fluorouracil (5-FU) and SN38 (the active metabolite of irinotecan), transcriptional profiling experiments were carried out on pretreatment metastatic colorectal cancer biopsies and HCT116 parental and chemotherapy-resistant cell line models using a disease-specific DNA microarray. To enrich for potential chemoresistance-determining genes, an unsupervised bioinformatics approach was used, and 50 genes were selected and then functionally assessed using custom-designed short interfering RNA (siRNA) screens. In the primary siRNA screen, silencing of 21 genes sensitized HCT116 cells to either 5-FU or SN38 treatment. Three genes (RAPGEF2, PTRF, and SART1) were selected for further analysis in a panel of 5 colorectal cancer cell lines. Silencing SART1 sensitized all 5 cell lines to 5-FU treatment and 4/5 cell lines to SN38 treatment. However, silencing of RAPGEF2 or PTRF had no significant effect on 5-FU or SN38 sensitivity in the wider cell line panel. Further functional analysis of SART1 showed that its silencing induced apoptosis that was caspase-8 dependent. Furthermore, silencing of SART1 led to a downregulation of the caspase-8 inhibitor, c-FLIP, which we have previously shown is a key determinant of drug resistance in colorectal cancer. This study shows the power of systems biology approaches for identifying novel genes that regulate drug resistance and identifies SART1 as a previously unidentified regulator of c-FLIP and drug-induced activation of caspase-8.

SIRT6 overexpression induces massive apoptosis in cancer cells but not in normal cells

Emerging evidence suggests that Sirtuin 6 (SIRT6) functions as a longevity assurance gene by promoting genomic stability, regulating metabolic processes and attenuating inflammation. Here, we examine the effect of SIRT6 activation on cancer cells. We show that SIRT6 overexpression induces massive apoptosis in a variety of cancer cell lines but not in normal, non-transformed cells. This cell death requires the mono-ADP-ribosyltransferase but not the deacetylase activity of SIRT6 and is mediated by the activation of both the p53 and p73 apoptotic signaling cascades in cancer cells by SIRT6. These results suggest that SIRT6 is an attractive target for pharmacological activation in cancer treatment.

Sirtuins, bioageing, and cancer

The Sirtuins are a family of orthologues of yeast Sir2 found in a wide range of organisms from bacteria to man. They display a high degree of conservation between species, in both sequence and function, indicative of their key biochemical roles. Sirtuins are heavily implicated in cell cycle, cell division, transcription regulation, and metabolism, which places the various family members at critical junctures in cellular metabolism. Typically, Sirtuins have been implicated in the preservation of genomic stability and in the prolongation of lifespan though many of their target interactions remain unknown. Sirtuins play key roles in tumourigenesis, as some have tumour-suppressor functions and others influence tumours through their control of the metabolic state of the cell. Their links to ageing have also highlighted involvement in various age-related and degenerative diseases. Here, we discuss the current understanding of the role of Sirtuins in age-related diseases while taking a closer look at their roles and functions in maintaining genomic stability and their influence on telomerase and telomere function.

Characterization of nuclear sirtuins: molecular mechanisms and physiological relevance

Sirtuins are protein deacetylases/mono-ADP-ribosyltransferases found in organisms ranging from bacteria to humans. This group of enzymes relies on nicotinamide adenine dinucleotide (NAD(+)) as a cofactor linking their activity to the cellular metabolic status. Originally found in yeast, Sir2 was discovered as a silencing factor and has been shown to mediate the effects of calorie restriction on lifespan extension. In mammals seven homologs (SIRT1-7) exist which evolved to have specific biological outcomes depending on the particular cellular context, their interacting proteins, and the genomic loci to where they are actively targeted. Sirtuins biological roles are highlighted in the early lethal phenotypes observed in the deficient murine models. In this chapter, we summarize current concepts on non-metabolic functions for sirtuins, depicting this broad family from yeast to mammals.

The sirtuins in the pathogenesis of cancer

Aging is the natural trace that time leaves behind on life during blossom and maturation, culminating in senescence and death. This process is accompanied by a decline in the healthy function of multiple organ systems, leading to increased incidence and mortality from diseases such as diabetes, cancer, cardiovascular disease, and neurodegeneration. Based on the fact that both sirtuin expression and activity appear to be upregulated in some types of cancer while they are being downregulated in others, there is quite some controversy stirring up as to the role of sirtuins, acting as cancer suppressors in some cases while under other circumstances they may promote cellular malignancy. It is therefore currently quite unclear as to what extent and under which particular circumstances sirtuin activators and/or inhibitors will find their place in the treatment of age-related disease and cancer. In this review, we take an effort to bring together the highlights of sirtuin research in order to shed some light on the mechanistic impact that sirtuins have on the pathogenesis of cellular malignancy.

Aging and cancer: are sirtuins the link?

Classically, aging has been defined as a general degeneration process that leads to the loss of corporal function. The loss of function caused by degeneration limits the maximum lifespan of all organisms and is linked to disease and cancer. Nevertheless, the molecular mechanisms behind aging and their connection to cancer are not well understood. NAD-dependent protein deacetylase enzymes, sirtuins, are emerging as a novel molecular link between aging and cancer due to their specific role in cell cycle regulation, antistress response and cell survival. This article reviews the contribution of sirtuins and environmental factors to ontogenic development, senescence and cancer.

A novel senescence-evasion mechanism involving Grap2 and Cyclin D interacting protein inactivation by Ras associated with diabetes in cancer cells under doxorubicin treatment

Ras associated with diabetes (Rad) is a Ras-related GTPase that promotes cell growth by accelerating cell cycle transitions. Rad knockdown induced cell cycle arrest and premature senescence without additional cellular stress in multiple cancer cell lines, indicating that Rad expression might be critical for the cell cycle in these cells. To investigate the precise function of Rad in this process, we used human Rad as bait in a yeast two-hybrid screening system and sought Rad-interacting proteins. We identified the Grap2 and cyclin D interacting protein (GCIP)/DIP1/CCNDBP1/HHM, a cell cycle-inhibitory molecule, as a binding partner of Rad. Further analyses revealed that Rad binds directly to GCIP in vitro and coimmunoprecipitates with GCIP from cell lysates. Rad translocates GCIP from the nucleus to the cytoplasm, thereby inhibiting the tumor suppressor activity of GCIP, which occurs in the nucleus. Furthermore, in the presence of Rad, GCIP loses its ability to reduce retinoblastoma phosphorylation and inhibit cyclin D1 activity. The function of Rad in transformation is also evidenced by increased telomerase activity and colony formation according to Rad expression level. In vivo tumorigenesis analyses revealed that tumors derived from Rad knockdown cells were significantly smaller than those from control cells (P = 0.0131) and the preestablished tumors are reduced in size after the injection of siRad (P = 0.0064). Therefore, we propose for the first time that Rad may promote carcinogenesis at least in part by inhibiting GCIP-mediated tumor suppression.

Mammalian sirtuins: biological insights and disease relevance

Aging is accompanied by a decline in the healthy function of multiple organ systems, leading to increased incidence and mortality from diseases such as type II diabetes mellitus, neurodegenerative diseases, cancer, and cardiovascular disease. Historically, researchers have focused on investigating individual pathways in isolated organs as a strategy to identify the root cause of a disease, with hopes of designing better drugs. Studies of aging in yeast led to the discovery of a family of conserved enzymes known as the sirtuins, which affect multiple pathways that increase the life span and the overall health of organisms. Since the discovery of the first known mammalian sirtuin, SIRT1, 10 years ago, there have been major advances in our understanding of the enzymology of sirtuins, their regulation, and their ability to broadly improve mammalian physiology and health span. This review summarizes and discusses the advances of the past decade and the challenges that will confront the field in the coming years.

Genome-wide profiling using single-nucleotide polymorphism arrays identifies novel chromosomal imbalances in pediatric glioblastomas

Available data on genetic events in pediatric grade IV astrocytomas (glioblastoma [pGBM]) are scarce. This has traditionally been a major impediment in understanding the pathogenesis of this tumor and in developing ways for more effective management. Our aim is to chart DNA copy number aberrations (CNAs) and get insight into genetic pathways involved in pGBM. Using the Illumina Infinium Human-1 bead-chip-array (100K single-nucleotide polymorphisms [SNPs]), we genotyped 18 pediatric and 6 adult GBMs. Results were compared to BAC-array profiles harvested on 16 of the same pGBM, to an independent data set of 9 pediatric high-grade astrocytomas (HGAs) analyzed on Affymetrix 250K-SNP arrays, and to existing data sets on HGAs. CNAs were additionally validated by real-time qPCR in a set of genes in pGBM. Our results identify with nonrandom clustering of CNAs in several novel, previously not reported, genomic regions, suggesting that alterations in tumor suppressors and genes involved in the regulation of RNA processing and the cell cycle are major events in the pathogenesis of pGBM. Most regions were distinct from CNAs in aGBMs and show an unexpectedly low frequency of genetic amplification and homozygous deletions and a high frequency of loss of heterozygosity for a high-grade I rapidly dividing tumor. This first, complete, high-resolution profiling of the tumor cell genome fills an important gap in studies on pGBM. It ultimately guides the mapping of oncogenic networks unique to pGBM, identification of the related therapeutic predictors and targets, and development of more effective therapies. It further shows that, despite commonalities in a few CNAs, pGBM and aGBMs are two different diseases.

Calorie restriction and the exercise of chromatin

Since the earliest stages of evolution, organisms have faced the challenge of sensing and adapting to environmental changes for their survival under compromising conditions such as food depletion or stress. Implicit in these responses are mechanisms developed during evolution that include the targeting of chromatin to allow or prevent expression of fundamental genes and to protect genome integrity. Among the different approaches to study these mechanisms, the analysis of the response to a moderate reduction of energy intake, also known as calorie restriction (CR), has become one of the best sources of information regarding the factors and pathways involved in metabolic adaptation from lower to higher eukaryotes. Furthermore, responses to CR are involved in life span regulation-conserved from yeast to mammals-and therefore have garnered major research interest. Herein we review current knowledge of responses to CR at the molecular level and their functional link to chromatin.

del(15q) is a recurrent minor-route cytogenetic abnormality in the clonal evolution of chronic myelogenous leukemia

The del(15q) chromosomal abnormality is known to occur in acute leukemias, but has rarely been described in chronic myelogenous leukemia (CML). Described here are five cases of CML associated with del(15q): four men and one woman. Bone marrow aspirate smears showed increased blasts in all cases at the time of del(15q) detection, in accelerated phase in two cases and myeloid blast phase in three. Conventional cytogenetic analysis showed t(9;22) and del(15q), as well as other inconsistent clonal abnormalities. All patients received imatinib mesylate; four received additional chemotherapy, and two had allogeneic stem cell transplantation (ASCT). Of the three patients who did not receive ASCT, one died, one was in persistent blast phase, and one was in clinical remission with molecular evidence of residual disease at 16, 6, and 34 months, respectively, after identification of the del(15q). Of the two patients who had ASCT, one died and one was in clinical remission with molecular evidence of disease at 15 and 64 months, respectively, after identification of the del(15q). These findings indicate that del(15q) is a recurrent cytogenetic abnormality that may be seen at initial presentation of advanced disease or may emerge during disease progression. Del(15q) appears to be associated with a poor prognosis in CML.

Identification of genes putatively involved in the pathogenesis of diffuse large B-cell lymphomas by integrative genomics

Diffuse large B-cell lymphomas (DLBCL) are highly heterogeneous with regard to clinical presentation and outcome. DLBCL copy number aberrations have been identified previously, of which the deletion at 6q21-24 was significantly associated with a highly favorable clinical response to chemotherapy. In this study, we aimed to identify genes implicated in this and other genomic regions with recurrent losses and/or gains. To identify implicated genes, we superimposed array comparative genomic hybridization (aCGH) data onto a microarray expression dataset of 42 clinically well-characterized primary nodal DLBCL biopsies. We confirmed that loss of 6q21-24 is significantly associated with a highly favorable clinical response to chemotherapy. Our approach identified 316 significant genes restricted to 32 chromosomal regions, including 24 genes identified at 6q21-24. In an independent dataset, 18% of overexpressed genes in gained regions and 55% of down-regulated genes in deleted regions were validated. In summary, using integrative genomics novel onco and tumor suppressor genes were identified in DLBCL that were not recognized by expression profiling alone.

Immunohistochemical expression of GCIP in breast carcinoma: relationship with tumour grade, disease-free survival, mucinous differentiation and response to chemotherapy

AIMS

Grap2 and cyclin-D interacting protein (GCIP) is a putative tumour suppressor in human cancer. The aim was to investigate its prognostic significance in human breast carcinoma.

METHODS AND RESULTS

Immunohistochemical analysis of breast carcinoma specimens from 107 female patients was performed. Decreased cytoplasmic expression of GCIP was detected in breast carcinomas compared with normal ductal epithelium (P < 0.001). Higher GCIP scores were observed in patients with lower histological grade, mucinous carcinomas and better clinical outcome (P < 0.05). Disease-free survival was significantly longer in patients with high GCIP scores than in those with low GCIP scores (P = 0.010). However, GCIP expression was independent of the status of oestrogen receptor, progesterone receptor, Her-2/neu and cancer stage. Moreover, in patients receiving neoadjuvant chemotherapy, those with higher GCIP scores showed potentially more reduction of tumour size compared with those with lower GCIP scores (borderline significance, P = 0.053).

CONCLUSIONS

The current data provide evidence that decreased expression of GCIP in vivo is present in human breast carcinoma and indicate that GCIP is a potential indicator of good prognosis. In patients receiving neoadjuvant chemotherapy, it may also have predictive value for the chemotherapeutic response.