Human Chromosome 11p15 Research Articles

Pedigree-Defined Haplotypes and Their Applications to Genetic Studies.

A haplotype is a string of nucleotides or alleles at nearby loci on one chromosome, usually inherited as a unit. Within the major histocompatibility complex (MHC) region on human chromosome 6p, independent population studies of multiple families have identified conserved extended haplotypes (CEHs) that segregate as long stretches (≥1 megabase) of essentially identical DNA sequence at relatively high (≥0.5 %) population frequency ("genetic fixity"). CEHs were first identified through segregation analysis in the early 1980s. In European Caucasian populations, the most frequent 30 CEHs account for at least one-third of all MHC haplotypes. These CEHs provide all of the known individual MHC susceptibility and protective genetic markers within those populations for several complex genetic diseases. Haplotypes are rigorously determined directly by sequencing single chromosomes or by Mendelian segregation analysis using families with informative genotypes. Four parental haplotypes are assigned unambiguously using genotypes from the two parents and from two of their haploidentical (to each other) children. However, the most common current technique to phase haplotypes is probabilistic statistical imputation, using unrelated subjects. Such probabilistic techniques have failed to detect CEHs and are thus of questionable value in identifying long-range haplotype structure and, consequently, genetic structure-function relationships. Finally, with haplotypes rigorously defined, association studies can determine frequencies of alleles among unrelated patient haplotypes vs. those among only unaffected family members (i.e., control alleles/haplotypes). Such studies reduce, as much as possible, the confounding effects of population stratification common to all genetic studies.

Regulating RNA Binding Motif 5 Gene Expression- A Novel Therapeutic Target for Lung Cancer.

RNA-binding motif protein 5 (RBM5), also known as LUCA-15/H37, is a gene that maps to human chromosome 3p21.3, a critical region that is deleted in a large number of human cancers, of which the majority are lung cancers, and that is predicted to contain one or more tumor suppressor genes (TSGs). RBM5 is a tumor suppressor gene and is most frequently deleted at the earliest stage of lung cancer development. It represents a significant area of recent progress in cancer genomic, cytogenetic, and molecular biological research because of its role in the induction of cell cycle arrest and apoptosis and the regulation of inhibition of in lung cancer metastasis. RBM5 is involved in the suppression of epidermal growth factor receptor (EGFR) expression, thus preventing proliferation, angiogenesis, invasion, and metastasis of lung cancer. In this way it exhibits its tumor suppressive capacity during lung cancer progression. Exploration of RBM5's potential importance in inhibiting tumor metastasis includes downstream players in the RBM5-mediated metastasis suppressor pathway(s). This review highlights the differential expression of the RBM5 tumor suppressor gene which impacts cell proliferation and apoptosis control during lung cancer progression. Regulating RBM5 expression may be a novel therapeutic target for lung cancer.

PinX1: structure, regulation and its functions in cancer.

PIN2/TRF1-interacting telomerase inhibitor 1 (PinX1) is a novel cloned gene located at human chromosome 8p23, playing a vital role in maintaining telomeres length and chromosome stability. It has been demonstrated to be involved in tumor genesis and progression in most malignancies. However, some researches showed opposing molecular status of PinX1 gene and its expression patterns in several other types of tumors. The pathogenic mechanism of PinX1 expression in human malignancy is not yet clear. Moreover, emerging evidence suggest that PinX1 (especially its TID domain) might be a potential new target cancer treatment. Therefore, PinX1 may be a new potential diagnostic biomarker and therapeutic target for human cancers, and may play different roles in different human cancers. The functions and the mechanisms of PinX1 in various human cancers remain unclear, suggesting the necessity of further extensive works of its role in tumor genesis and progression.

Abstract 2767: Expression of miR-1252 and its target PRR4 gene in laryngeal carcinoma

Abstract Head and neck squamous cell carcinoma (HNSCC) is the sixth most frequent cancer worldwide and includes neoplasias of the paranasal sinuses, the oral cavity, the trachea, the pharynx and the larynx. The most important risk factors are tobacco use, alcohol consumption and infection with human papillomavirus (HPV). Besides the exogenous risk factors, genetic factors may play a key role in the development of the HNSCC. Cancer of the larynx accounts for 25% of all head and neck malignancies. The PRR4 (Prolin Rich Protein 4) gene is localized on human chromosome 12p13 and encodes a protein which is secreted from the acinar cells of the lacrimal gland, the submandibular gland, the parotis and the sublingual glands. Recent studies have demonstrated that PRR4 may play an important role as an antimicrobial protein to protect the ocular surface and the oral cavity. Additionally, it has been shown that PRR4 is highly expressed in the human submucosal glands. microRNAs are small non-coding RNAs which regulate gene expression at the post-transcriptional level. They bind to their target RNA with their seed sequence complementary to the 3’UTR region. This interaction results in either up- or down-regulation of the target messenger RNA. To understand the role of the PRR4 gene in laryngeal carcinogenesis, we investigated its mRNA expression levels in laryngeal tumor tissue and adjacent non-cancerous tissue samples from 90 patients by quantitative real-time PCR. As a complementary region between the seed sequence of miR-1252 and 3’UTR region of PRR4 gene exists, we also analyzed whether miR-1252 binds to this region and regulates the expression of PRR4. We found that PRR4 gene expression was decreased in 65 (72.2%) and increased in 24 (26.7%) of 90 tumor tissues when compared to normal tissue. Statistically significant downregulation of the PRR4 mRNA was observed in laryngeal tumors (p<0.001). No significant correlation was found between PRR4 gene expression and clinicopathological parameters including age, sex, stage, histological grade and tumor location (p>0.05). We also analyzed miR-1252 expression levels in a subset of tumor samples. miR-1252 upregulation was observed only in 24% of tumor tissues compared to non-cancerous tissue. The miR-1252 level was same in the 62.5% of the remaining samples. We did not observe any correlation between the PRR4 and miR-1252 expression levels. Our results indicate that the PRR4 gene may have an impact in the progression of laryngeal carcinoma. Citation Format: NUR BUYRU, SEDA EKIZOGLU, JALAL GULIYEV, EMIN KARAMAN, TURGUT ULUTIN. Expression of miR-1252 and its target PRR4 gene in laryngeal carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2767.

Abstract 3429: Evidence chronic inflammation is a risk factor for histiocytic sarcoma in Bernese mountain dogs - implications for human histiocytic sarcoma

Abstract The purpose of this study was to evaluate exposure variables associated with development of histiocytic sarcoma (HS), a rare but aggressive malignancy, using the canine spontaneous tumor model. The domestic dog has been shown to be an excellent model to investigate risk of occurrence of complex diseases in humans, especially cancers. This is due in part to the limited genetic heterogeneity within specific dog breeds. HS, though rare in most breeds of dogs, is a common malignancy in Bernese mountain dogs (BMD) with up to 25% of the population of dogs being diagnosed with HS during their lifetime. The frequency of HS diagnosis in BMDs is thought to be due to a heritable mutation in a single gene region analogous to the human chromosome 9p21. For this study, owners of BMDs registered with a non-profit breed registry, the Berner-Garde Foundation, were recruited for participation in an internet-based cross-sectional survey. Data were collected for a total of 216 BMDs. Of the total population of BMDs enrolled in the study 118 dogs were sibling-sets representing a case and a non-case that originated from the same litter. Mixed effects logistic regression (MELR) and conditional logistic regression (CLR) were used in parallel to examine associations between potential risk factors and the occurrence of HS. When controlling for litter of origin (as a marker of relatedness), dogs diagnosed with orthopedic conditions were found to be more likely to develop HS (MELR, OR: 2.5, 95% CI: 1.5, 5.2; CLR, OR: 2.81, 95% CI: 1.1, 7.3), while dogs receiving prescription anti-inflammatory medications were found to be at a considerably lower risk of developing this disease (MELR, OR: 0.43, 95% CI: 0.2, 0.8; CLR, OR: 0.32, 95% CI: 0.1, 0.8). These data suggest inflammation may be a modifiable risk factor for the development of HS. Therefore, identification and treatment of conditions that promote inflammatory mechanisms may reduce future risk of developing HS in dogs and people. Results of logistic regression models examining risk factors associated with development of histiocyRisk factorCategoryOdds ratio (MELR), n = 21695% CIP-ValueOdds ratio (CLR), n = 11895% CIP-ValueOrthopedic conditionYes2.491.21, 5.140.0142.811.08, 7.260.034NoReferenceReferenceNon-prescription medication useYes2.101.05, 4.180.0362.881.04, 7.900.041NoReferenceReferenceLong-term prescription medication useYes0.430.22, 0.810.0100.320.12, 0.830.020NoReferenceReference Citation Format: Audrey Ruple-Czerniak, Paul S. Morley. Evidence chronic inflammation is a risk factor for histiocytic sarcoma in Bernese mountain dogs - implications for human histiocytic sarcoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3429.

Deletions linked to TP53 loss drive cancer through p53-independent mechanisms.

Mutations disabling the TP53 tumour suppressor gene represent the most frequent events in human cancer and typically occur through a two-hit mechanism involving a missense mutation in one allele and a 'loss of heterozygosity' deletion encompassing the other. While TP53 missense mutations can also contribute gain-of-function activities that impact tumour progression, it remains unclear whether the deletion event, which frequently includes many genes, impacts tumorigenesis beyond TP53 loss alone. Here we show that somatic heterozygous deletion of mouse chromosome 11B3, a 4-megabase region syntenic to human 17p13.1, produces a greater effect on lymphoma and leukaemia development than Trp53 deletion. Mechanistically, the effect of 11B3 loss on tumorigenesis involves co-deleted genes such as Eif5a and Alox15b (also known as Alox8), the suppression of which cooperates with Trp53 loss to produce more aggressive disease. Our results imply that the selective advantage produced by human chromosome 17p deletion reflects the combined impact of TP53 loss and the reduced dosage of linked tumour suppressor genes.

Mice Homozygous for a Deletion in the Glaucoma Susceptibility Locus INK4 Show Increased Vulnerability of Retinal Ganglion Cells to Elevated Intraocular Pressure

A genomic region located on chromosome 9p21 is associated with primary open-angle glaucoma and normal tension glaucoma in genome-wide association studies. The genomic region contains the gene for a long noncoding RNA called CDKN2B-AS, two genes that code for cyclin-dependent kinase inhibitors 2A and 2B (CDKN2A/p16(INK4A) and CDKN2B/p15(INK4B)) and an additional protein (p14(ARF)). We used a transgenic mouse model in which 70 kb of murine chromosome 4, syntenic to human chromosome 9p21, are deleted to study whether this deletion leads to a discernible phenotype in ocular structures implicated in glaucoma. Homozygous mice of this strain were previously reported to show persistent hyperplastic primary vitreous. Fundus photography and optical coherence tomography confirmed that finding but showed no abnormalities for heterozygous mice. Optokinetic response, eletroretinogram, and histology indicated that the heterozygous and mutant retinas were normal functionally and morphologically, whereas glial cells were activated in the retina and optic nerve head of mutant eyes. In quantitative PCR, CDKN2B expression was reduced by approximately 50% in the heterozygous mice and by 90% in the homozygous mice, which suggested that the CDKN2B knock down had no deleterious consequences for the retina under normal conditions. However, compared with wild-type and heterozygous animals, the homozygous mice are more vulnerable to retinal ganglion cell loss in response to elevated intraocular pressure.

Abstract A60: DOK1 gene may act as a tumor suppressor in breast cancer

Abstract The DOK1 (Downstream of Tyrosine kinase 1) gene is a putative tumor suppressor gene located on human chromosome 2p13 which is frequently rearranged in leukaemia and other human tumours. The DOK1 protein is a member of the Dok protein family comprising seven members. It inhibits MAP kinase activity and displays anti-proliferative activities. The DOK1 gene may act as a tumor suppressor gene in ovarian cancer, Burkitt lymphoma, head and neck cancer (HNC), chronic lymphocytic leukaemia (CLL) and lung cancer by inhibiting cell proliferation. So far there is no study in the literature analyzing the relationship between the DOK1 gene and breast cancer. The aim of this study was to investigate the role of the DOK1 gene in breast cancer. The tumors and adjacent normal tissues were collected from 50 patients who underwent surgery for breast cancer at the Bezmialem Vakif University Medical Faculty. For expression analysis, after isolation of RNA cDNA was been obtained. Gene expression levels in the tumors and adjacent normal tissues were determined by quantitative RT-PCR using the 2-ΔΔCT method. The results were normalized using the G6PD gene as reference. For mutation analysis, DNA was isolated and analyzed by cycle sequencing to detect mutations. The SPSS 21.0 software package was used for statistical analysis. P<0.05 was considered significant. When the DOK1 expression levels in the tumors and adjacent normal tissues were compared we observed that DOK1 expression was decreased in 31 (62%) patients and increased in 16 (32%) patients. The decrease of DOK1 expression was associated with age (p=0.031), menopausal status (p=0.017), histologic type, (p=0.015) and stage (p=0.017). We identified 11 different alterations in the non-coding regions of the gene. One of these alterations was in the 5'-UTR and the remaining 10 were located in the introns 1 and 4. We did not observe any significant association between the mutations and expression level of the DOK1 gene. Our results, suggest that the DOK1 gene might act as a tumor suppressor in breast cancer. Citation Format: Nur Buyru, Esin Tuna, Filiz Ozdemir, Pelin Bulut, Nejat Dalay. DOK1 gene may act as a tumor suppressor in breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr A60.

Role of SOX7 in Hematopoietic System Development and Hematological Malignancies--Review

The sex-determining region Y-box 7 (Sox7) is a important member of SOX family containing high mobi- lity group (HMG), mapped to human chromosome 8p23.1. Wnt/β-catenin signaling pathway plays an important role in cell survival, differentiation, self-renewal, proliferation and apoptosis, and is closely related with carcinogenesis. SOX7 gene is likely to be a tumor suppressor gene in MDS and other hematological malignancies. As a negative regulator of the WNT/β-catenin signaling pathway, the function loss of this gene can lead to carcinogenesis. The methylation of SOX7 gene leads to the silence of this gene, resulting in tumorigenesis. The decision of hematopoietic stem cells to self-renew or differentiate is a stochastic process, but SOX7 can promote the differentiation into all blood cell types. This review focuses on the role of SOX7 in hematopoietic system development and hematological malignancies.

Complete Genome Sequence of Germline Chromosomally Integrated Human Herpesvirus 6A and Analyses Integration Sites Define a New Human Endogenous Virus with Potential to Reactivate as an Emerging Infection.

Human herpesvirus-6A and B (HHV-6A, HHV-6B) have recently defined endogenous genomes, resulting from integration into the germline: chromosomally-integrated “CiHHV-6A/B”. These affect approximately 1.0% of human populations, giving potential for virus gene expression in every cell. We previously showed that CiHHV-6A was more divergent than CiHHV-6B by examining four genes in 44 European CiHHV-6A/B cardiac/haematology patients. There was evidence for gene expression/reactivation, implying functional non-defective genomes. To further define the relationship between HHV-6A and CiHHV-6A we used next-generation sequencing to characterize genomes from three CiHHV-6A cardiac patients. Comparisons to known exogenous HHV-6A showed CiHHV-6A genomes formed a separate clade; including all 85 non-interrupted genes and necessary cis-acting signals for reactivation as infectious virus. Greater single nucleotide polymorphism (SNP) density was defined in 16 genes and the direct repeats (DR) terminal regions. Using these SNPs, deep sequencing analyses demonstrated superinfection with exogenous HHV-6A in two of the CiHHV-6A patients with recurrent cardiac disease. Characterisation of the integration sites in twelve patients identified the human chromosome 17p subtelomere as a prevalent site, which had specific repeat structures and phylogenetically related CiHHV-6A coding sequences indicating common ancestral origins. Overall CiHHV-6A genomes were similar, but distinct from known exogenous HHV-6A virus, and have the capacity to reactivate as emerging virus infections.

Genetic architecture of early pre-inflammatory stage transcription signatures of autoimmune diabetes in the pancreatic lymph nodes of the NOD mouse reveals significant gene enrichment on chromosomes 6 and 7

Autoimmune diseases are characterized by the stimulation of an excessive immune response to self-tissues by inner and/or outer organism factors. Common characteristics in their etiology include a complex genetic predisposition and environmental triggers as well as the implication of the major histocompatibility (MHC) locus on human chromosome 6p21. A restraint number of non-MHC susceptibility genes, part of the genetic component of type 1 diabetes have been identified in human and in animal models, while the complete spectrum of genes involved remains unknown. We elaborate herein patterns of chromosomal organization of 162 genes differentially expressed in the pancreatic lymph nodes of Non-Obese Diabetic mice, carefully selected by early sub-phenotypic evaluation (presence or absence of insulin autoantibodies). Chromosomal assignment of these genes revealed a non-random distribution on five chromosomes (47%). Significant gene enrichment was observed in particular for two chromosomes, 6 and 7. While a subset of these genes coding for secreted proteins showed significant enrichment on both chromosomes, the overall pool of genes was significantly enriched on chromosome 7. The significance of this unexpected gene distribution on the mouse genome is discussed in the light of novel findings indicating that genes affecting common diseases map to recombination “hotspot” regions of mammalian genomes. The genetic architecture of transcripts differentially expressed in specific stages of autoimmune diabetes offers novel venues towards our understanding of patterns of inheritance potentially affecting the pathological disease mechanisms.

Phenotype Prediction of Pathogenic Nonsynonymous Single Nucleotide Polymorphisms in WFS1.

Wolfram syndrome (WS) is a rare, progressive, neurodegenerative disorder that has an autosomal recessive pattern of inheritance. The gene for WS, wolfram syndrome 1 gene (WFS1), is located on human chromosome 4p16.1 and encodes a transmembrane protein. To date, approximately 230 mutations in WFS1 have been confirmed, in which nonsynonymous single nucleotide polymorphisms (nsSNPs) are the most common forms of genetic variation. Nonetheless, there is poor knowledge on the relationship between SNP genotype and phenotype in other nsSNPs of the WFS1 gene. Here, we analysed 395 nsSNPs associated with the WFS1 gene using different computational methods and identified 20 nsSNPs to be potentially pathogenic. Furthermore, to identify the amino acid distributions and significances of pathogenic nsSNPs in the protein of WFS1, its transmembrane domain was constructed by the TMHMM server, which suggested that mutations outside of the TMhelix could have more effects on protein function. The predicted pathogenic mutations for the nsSNPs of the WFS1 gene provide an excellent guide for screening pathogenic mutations.

Long non-coding RNA Loc554202 induces apoptosis in colorectal cancer cells via the caspase cleavage cascades.

BackgroundAberrant expression of long noncoding RNAs (lncRNAs) has frequently been reported in cancer studies, including those of colorectal cancer (CRC). Increasing evidence suggests that lncRNAs are significantly correlated with the pathogenesis, development and metastasis of cancer. Loc554202 is a 2166-bp transcript on human chromosome 9p21.3, the expression of which is dysregulated in breast and lung cancer cells. However, its role in CRC remains under investigation.MethodsQuantitative real-time polymerase chain reaction (qRT-PCR) was carried out to assess the relative expression of Loc554202 in CRC cell lines and tissues. Gain and/or loss of function approaches were used to investigate the potential functional roles in cell proliferation and apoptosis in vitro and in vivo. qRT-PCR, western-blotting and immunohistochemistry were used to evaluate the mRNA and protein expression of apoptosis-related factors.ResultsLoc554202 was significantly downregulated in cancerous tissues and CRC cell lines compared with adjacent normal tissue and a normal human intestinal epithelial cell line. Low Loc554202 expression was closely associated with advanced pathologic stage and a larger tumor size. The overexpression of Loc554202 decreased the cell proliferation and induced apoptosis in vitro and hindered tumorigenesis in vivo. Loc554202 regulated cell apoptosis partly through the activation of specific caspase cleavage cascades.ConclusionOur results suggest that Loc554202 may play an important role in the progression of CRC and could be a candidate prognostic biomarker or a target for new cancer therapies.Electronic supplementary materialThe online version of this article (doi:10.1186/s13046-015-0217-7) contains supplementary material, which is available to authorized users.

Abstract 2029: Mcph1/Brit1 deficiency promotes genomic instability and tumor formation in a mouse model

Abstract MCPH1, also known as BRIT1, has recently been identified as a novel key regulatory gene of the DNA damage response pathway. MCPH1 is located on human chromosome 8p23.1, where human cancers frequently show loss of heterozygosity. As such, MCPH1 is aberrantly expressed in many malignancies, including breast and ovarian cancers, and the function of MCPH1 has been implicated in tumor suppression. However, it remains poorly understood whether MCPH1 deficiency leads to tumorigenesis. Here, we generated and studied both Mcph1−/− and Mcph1−/−p53−/− mice; we showed that Mcph1−/− mice developed tumors with long latency, and that primary lymphoma developed significantly earlier in Mcph1−/−p53−/− mice than in Mcph11+/+p53−/− and Mcph1+/−p53−/- mice. The Mcph1−/−p53−/− lymphomas and derived murine embryonic fibroblasts (MEFs) were both more sensitive to irradiation. Mcph1 deficiency resulted in remarkably increased chromosome and chromatid breaks in Mcph1−/−p53−/− lymphomas and MEFs, as determined by metaphase spread assay and spectral karyotyping analysis. Additionally, Mcph1 deficiency significantly enhanced aneuploidy as well as abnormal centrosome multiplication in Mcph1−/−p53−/− cells. Meanwhile, Mcph1 deficiency impaired double strand break (DSB) repair in Mcph1−/−p53−/− MEFs as demonstrated by neutral Comet assay. Compared with Mcph1+/+p53−/− MEFs, homologous recombination and non-homologous end joining activities were significantly decreased in Mcph1−/−p53−/− MEFs. Notably, reconstituted MCPH1 rescued the defects of DSB repair and alleviated chromosomal aberrations in Mcph1−/−p53−/- MEFs. Taken together, our data demonstrate MCPH1 deficiency promotes genomic instability and increases cancer susceptibility. Our study using knockout mouse models provides convincing genetic evidence that MCPH1 is a bona fide tumor suppressor gene. Its deficiency leading to defective DNA repair in tumors can be utilized to develop novel targeted cancer therapies in the future. Citation Format: Yulong Liang, Hong Gao, Shiaw-Yih Lin, John A. Goss, Chunying Du, Kaiyi Li. Mcph1/Brit1 deficiency promotes genomic instability and tumor formation in a mouse model. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2029. doi:10.1158/1538-7445.AM2015-2029

Abstract 1264: Conditional mouse and zebrafish models of INK4-mediated tumor suppression reveal ARF-independent regulation of cellular senescence

Abstract The INK4b-ARF-INK4a locus on human chromosome 9p21 is a hot spot genomic region that undergoes frequent inactivation or deletion in a wide spectrum of human cancers. The locus encodes three cell cycle inhibitory proteins: p15INK4b encoded by CDKN2b, p16INK4a encoded by CDKN2a and p14ARF (p19Arf in mice) encoded by an alternative reading frame (ARF) of CDKN2a. We have recently identified a homologous INK4 genomic locus in zebrafish that is surprisingly devoid of ARF sequences, and encodes a single zebrafish ink4ab gene that functions to activate stress-induced senescence. Therefore, evolution of the mammalian INK4 locus to include multiple tumor suppressors sharing regulatory features could attribute to stronger mechanisms of tumor suppression in these longer-lived vertebrates. Oxidative and/or oncogenic stress provokes cellular senescence involving the retinoblastoma (Rb) and ARF/p53 pathways, leading to silencing of growth-promoting genes by methylation of histone H3 lysine 9 (H3K9me) with the histone methyltransferase Suv39h1. We found that ink4ab deficient zebrafish had deregulated Rb signaling and senescence responses, and reduced suv39h1 expression levels that led to poor overall survival. Ink4ab deficient zebrafish had increased lymphocyte proliferation, splenomegaly, and developed multiple spontaneous tumors including metastatic melanoma, osteosarcoma, hepatocellular adenoma, leukemias and myelodysplastic disorders. Moreover, zebrafish heterozygous for both p53 and ink4ab mutations displayed significantly higher tumor incidence compared to p53 heterozygotes with wild-type ink4ab, indicating that ink4ab haploinsufficiency promotes tumorigenesis. To this end, the combined deficiency of ink4ab and p53 accelerates tumor latency, likely by reversing cellular senescence responses. To further examine ARF-independent senescence regulatory roles of INK4 products in a mammalian model, we have generated conditional mice deficient for all three INK4 open reading frames in the adult hematopoietic system. Within seven months, homozygous Ink4a/Ink4b/ARF-/- mice exhibited marked splenomegaly and developed spontaneous tumors, including leukemias and soft tissue sarcomas. Peripheral blood, splenic and bone marrow analyses of homozygous mutant mice showed deregulated lymphocyte development, uncontrolled proliferation, apoptosis and Suv39h1-dependent senescence when compared to heterozygous and wild type mice. These results identify ARF-independent and Suv39h1-dependent senescence regulatory and tumor suppressor mechanisms whose inactivation permits tumor formation in response to oncogenic and/or oxidative stress. Our models offer the opportunity to reveal novel paradigms for promoting cellular senescence as an alternative strategy for cancer prevention and therapy. Citation Format: Kathleen Flaherty, Daniel Jones, Shamila Yussuf, Stephani Davis, Eric Huselid, Wei Wang, Monica Bartucci, Hatem E. Sabaawy. Conditional mouse and zebrafish models of INK4-mediated tumor suppression reveal ARF-independent regulation of cellular senescence. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1264. doi:10.1158/1538-7445.AM2015-1264

FUS1 acts as a tumor-suppressor gene by upregulating miR-197 in human glioblastoma

Glioblastoma is the most common primary malignancy of the adult central nervous system (CNS) and is associated with an exceptionally poor prognosis. Elucidation of the pathogenesis and molecular changes will help us to further understand the pathogenesis and progression of the disease and offer new therapeutic targets. FUS1 (TUSC2, tumor suppressor candidate 2) is a tumor-suppressor gene located on human chromosome 3p21. Restoration of FUS1 function in human non-small cell lung cancer (NSCLC) cells was found to significantly inhibit tumor cell growth and modulate the chemosensitivity of lung cancer cells. Yet, its role in human glioblastoma has rarely been addressed. In the present study, we demonstrated that low expression of FUS1 was detected in high-grade human glioma, implying that FUS1 expression is negatively associated with progression of the disease. Subsequent studies confirmed that FUS1 overexpression inhibited the proliferation, migration and invasion of human glioblastoma cells. In addition, we found that FUS1 overexpression significantly upregulated miR-197 expression in the glioblastoma cells. We also revealed that miR-197 suppressed the proliferation, migration and invasion of the cells as well as the silencing of miR-197 attenuated the biological functions of FUS1. Using human glioblastoma tissue samples, we demonstrated that miR-197 is negatively associated with metastasis. All the results demonstrated that FUS1 acts as a tumor-suppressor gene by upregulating miR-197 in human glioblastoma and implied that restoration of FUS1 and miR-197 could be new therapeutic strategies for glioblastoma.

Association Between PTPN22 Gene Polymorphism and Type1 Diabetes in Egyptian Population

The protein tyrosine phosphatase, nonreceptor 22 gene (PTPN22) maps at human chromosome 1p13.3which encodes an important negative regulator of T-cell activation, lymphoid-specific phosphatase(Lyp). The PTPN22 gene has been shown to associate with a risk for multiple autoimmune diseases,including type1 diabetes (T1DM). This study aimed to analyze the association of three PTPN22polymorphisms in Egyptian population .The single nucleotide polymorphisms (SNP) at positions -1123(rs#2488457), 1858 (rs#2476601), and +2740 (rs#1217412) were genotyped in 60 persons with T1DM,and 60 control persons, all three SNPs were genotyping using two technique, allele specific PCRtechnique and restriction fragment length polymorphism – PCR (RFLP-PCR). The 1858 C/T did notshow any significance differences between patients and control groups. (MCP=1.0) whereas, respectively-1123 G/C and +2740 A/G were significantly associated with T1DM disease (P≤0.0001) and(P=0.012).These results suggest that the PTPN22 gene of SNPs polymorphisms were associated withtype 1 diabetes in Egyptian population. The difference in the association of the aforementioned SNPsvariants with T1DM among different populations may be attributed to the presence of multiplesusceptibility alleles.

Pyrrole-imidazole polyamide-mediated silencing of KCNQ1OT1 expression induces cell death in Wilms' tumor cells.

KvDMR (an intronic CpG island within the KCNQ1 gene) is one of the imprinting control regions on human chromosome 11p15.5. Since KvDMR exists within the promoter region of KCNQ1OT1 (antisense transcript of KCNQ1), it is likely that genomic alterations of this region including deletion, paternal uniparental disomy and de-methylation in maternal allele lead to aberrant overexpression of KCNQ1OT1. Indeed, de-methylation of KvDMR accompanied by uncontrolled overexpression of KCNQ1OT1 occurs frequently in Beckwith-Wiedemann syndrome (BWS), and around 10% of BWS patients developed embryonal tumors (Wilms' tumor or hepatoblastoma). These observations strongly suggest that silencing of KCNQ1OT1 expression might suppress its oncogenic potential. In the present study, we designed two pyrrole-imidazole (PI) polyamides, termed PI-a and PI-b, which might have the ability to bind to CCAAT boxes of the KCNQ1OT1 promoter region, and investigated their possible antitumor effect on Wilms' tumor-derived G401 cells. Gel retardation assay demonstrated that PI-a and PI-b specifically bind to their target sequences. Microscopic observations showed the efficient nuclear access of these PI polyamides. Quantitative real-time PCR analysis revealed that the expression level of KCNQ1OT1 was significantly decreased when treated with PI-a and PI-b simultaneously but not with either PI-a or PI-b single treatment. Consistent with these results, the combination of PI-a and PI-b resulted in a significant reduction in viability of G401 cells in a dose-dependent manner. Furthermore, FACS analysis demonstrated that combinatory treatment with PI-a and PI-b induces cell death as compared with control cells. Taken together, our present observations strongly suggest that the combinatory treatment with PI polyamides targeting KCNQ1OT1 might be a novel therapeutic strategy to cure patients with tumors over-expressing KCNQ1OT1.

Contribution of mGluR5 to pathophysiology in a mouse model of human chromosome 16p11.2 microdeletion.

Human chromosome 16p11.2 microdeletion is the most common gene copy number variation in autism, but the synaptic pathophysiology caused by this mutation is largely unknown. Here we show using a mouse with the same genetic deficiency that metabotropic glutamate receptor 5-(mGluR5-) dependent synaptic plasticity and protein synthesis is altered in the hippocampus, and that hippocampus-dependent memory is impaired. Remarkably, chronic treatment with a negative allosteric modulator of mGluR5 reverses the cognitive deficit.

PAX6 mRNA Transcript Analysis in Various Ocular/Non-Ocular Tissues

PAX6 is a critical regulatory gene located on human chromosome 11p13, is expressed in many ocular tissues, and non-ocular tissues like brain, and pancreas. The expression of mRNA transcript has been investigated in this study since PAX6 is likely to play a vital role in the development of eye. RNA was extracted from various ocular tissues including lens epithelium, retina, iris, non-ocular tissues Trabecular Meshwork cells (TM cell line), HeLa cells. Besides the mutant and wild type blood cells were also included and total RNAs were subjected to convert in to Complementary DNA (cDNA). The high sensitive reverse transcriptase polymerase chain reaction (RT-PCR) was performed to monitor the mRNA transcript level to detect the expression profiles of the ocular/non-ocular tissues taken for this study. The competitive RT-PCR analysis was carried out using the house keeping gene beta actin as a control in both the ocular and non-ocular tissues. The level of beta actin expression in ocular/non-ocular tissues was equal and showed 540bp amplification. Subsequently the PAX6 mRNA transcript was analysed in these tissues. The expression level of PAX6 was observed in the ocular tissues such as retina, iris and lens epithelium which expressed approximately 600, 855, 1013 and 1055bp amplification. In the non-ocular HeLa cells the PAX6 expression was abnormally high and showed approximately 1.2kb amplification. No PAX6 expression was observed in the wild type WBC cells; however the mutant WBC amplified an irrelevant transcript. Sequencing the irrelevant transcript revealed the homology hint to various chromosomes particularly of hypothetical LOC441763 mRNA. RT-PCR amplification confirms the presence of various PAX6 mRNA expressions in ocular and non-ocular tissues. Lens epithelium, retina and iris tissues have significant PAX6 expression while the retina contains an overwhelming majority of mRNAs encoding crystallins and other genes but still express PAX6 isoforms at high levels. HeLa is a fibroblast based cell line and it would not expect a fibroblast to express a lot of PAX6 However PAX6 gene expression might be high in these cells for some reason. The PAX6 gene partial expression was found in mutant WBC and not in wild type WBC cells, the real fact for this reason is unknown. PAX6 mutations should be analyzed with effective functional assays, which will be useful for future study.