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Disruption of the CDKN2A (INK4A/ARF) and B (INK4B) genes, which encode three function-independent tumor suppressors, is one of the most common events in human cancer. Because their relative importance in tumor prevention appears to be species- and context-specific, studying their regulation can shed light on mechanisms by which they are bypassed in malignant transformation. We previously unveiled a new pathway in which TGFβ selectively induces Arf at mouse Cdkn2a in eye development and cultured fibroblasts. As TGFβ signaling is often derailed in cancer development or progression, we investigated its control of CDKN2A/B in human cancer. Computational analyses of sequencing and array data from nearly 11,000 patients with cancer in TCGA showed discordant expression of ARF and INK4A in most cancer subtypes, with gene copy-number loss and promoter methylation involved in only a subset. Using HeLa cells as a model, we found that exogenous TGFβ induced ARF mRNA and protein, and ARF knockdown limited TGFβ-mediated growth suppression. TGFβ-mediated ARF mRNA induction required SMAD2/3, p38MAPK, and SP1, and ARF mRNA was induced without added RNAPII recruitment. Chromatin immunoprecipitation unveiled a remote enhancer element engaged by TGFβ by a mechanism that partially depended on p38MAPK. CRISPR-based editing of this enhancer limited induction of ARF and INK4B by TGFβ, but not by oncogenic RAS.Implications:Our findings reveal new molecular mechanisms by which CDKN2A/B regulation is coupled to external cues, and those findings represent entry points to further explore pharmacologic strategies to restore their expression in cancer.

Supplementary Table S1. Sequences of siRNAs, sgRNAs and primers for regular PCR, qRT-PCR and ChIP-qPCR Figure S1. Global analysis of ARF regulation from The Cancer Genome Atlas (TCGA). Figure S2. The status of DNA methylation at promoter regions of CDKN2A/B from DNA methylation data in ENCODE. Figure S3. Induction of ARF by TGFbeta in HeLa cells but not other cervical cancer cell lines. Figure S4. Transcriptional regulation of ARF by TGFbeta in HeLa cells. Figure S5. ARF induction by TGFbeta requires SMAD, p38MAPK and SP1. Figure S6. Deletion of CAD risk interval reflects the long-range gene regulation in Chr4Î"70kb/Î"70kb MEFs. Figure S7. CDKN2A/B expression in response to TGFbetaï�¢ induction in HeLaÎ"20kb-PD cells.

Introduction: Cancer cells often develop a program of metabolic adaptability and epigenetic remodelling to promote gene expression changes causing cancerous cell proliferation and invasion. The metabolic-epigenetic axis as a an underlying mechanism of carcinogenesis could lead to new approaches to cancer treatment. Nicotinamide N-Methyl Transferase (NNMT) is a metabolic enzyme that catalyzes the transfer of a methyl group from S-Adenosyl methionine (SAM) to nicotinamide, thereby decreasing the overall methyl pools for RNA, histone and DNA methylation. High NNMT expression has been previously associated with a poor outcome in TNBC. Hypothesis: We hypothesized that high versus low NNMT activity and resulting oncogenic gene expression in TNBC may alter histone methylation is association with altered metabolic pathway activation. Methods: We used two TNBC cell lines models, MDA-MB 231 and SUM159, to study the association between high versus low NNMT activity and metabolic pathway activation. Surprisingly, we identified gene expression pathways suggestive of increased free cholesterol biosynthesis gene expression with low NNMT, and then used biochemical assays and filipin to measure free cholesterol in both total high and low NNMT TNBC cell lysates and relative cholesterol expression in the High vs Low NNMT cell membranes. Results: In vitro, NNMT knockdown resulted in increased cholesterol synthetic pathway enzyme expression in both TNBC cell lines. In vivo studies also showed that protein expression of cholesterol synthesis enzymes was also increased in NNMT-depleted MDA-MB 231 xenografted tumors. Interestingly, the increased cholesterol level upon NNMT depletion was mainly localized at the plasma membrane via Filipin III staining, suggesting a possible association with less cellular membrane fluidity and a decreased oncogenic phenotype. In ongoing experiments, we are evaluating whether changes in histone methylation in high vs low NNMT cells are associated with differential expression of cholesterol biosynthetic genes, and free cholesterol production. We hypothesize that NNMT might epigenetically decrease the methylation of histones regulating cholesterol production in TNBC. Citation Format: Woei-Yaw Chee, Deniz Nesli Dolcen, Lynda Bennett, Suzanne D. Conzen. Modulation of Nicotinamide N-Methyl Transferase (NNMT) expression in TNBC is associated with altered cell membrane cholesterol levels. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3697.

Elevated levels of immunosuppressive myeloid-derived suppressor cells (MDSCs) circulate in the peripheral blood or infiltrate the tumors as well as ascites in ovarian cancer patients, however the cause for this observed phenotype is unknown. MDSCs contribute to tumor immune tolerance primarily via inhibition of cytotoxic T-cells or by activation of immunosuppressive T-regulatory cells. We previously showed that high tumor cell glucocorticoid receptor (GR) expression is associated with a relatively poor prognosis in ovarian cancer patients. Additionally, using primary tumor data retrieved from the ovarian cancer TCGA dataset, we show high tumor GR expression is associated with significantly higher expression of Foxp3, a marker of immunosuppressive T-regulatory cells, as well as CD33, a marker of immunosuppressive myeloid cells, further suggesting an immunosuppressive phenotype in ovarian cancer patients. We thus hypothesize that tumor-intrinsic GR activation in ovarian cancer is associated with increased MDSC infiltration into the tumor microenvironment in part via modulating tumor cell cytokine secretion. To determine whether tumor-cell GR activation modulates the cytokine secretome, we previously showed that GR activation in ovarian cancer cells upregulated secretion of immunomodulatory factors including G-CSF, TGFb and CXCL5. Moreover, co-treatment of cells with a selective GR modulator (SGRM), reverses this secretome effect. Considering that elevated levels of these cytokines are necessary for the production and recruitment of MDSCs, these data highlight the relevance of this evident glucocorticoid receptor-cytokine circuit in ovarian cancer tumor cells. Furthermore, we show that this tumor-cell cytokine secretome has the capacity to promote differentiation of MDSCs from precursor myeloid cells in healthy PBMCs. Importantly, measuring expression of activation markers such as Arginase-1 and NOS2 illustrated that these MDSCs are in their functional state. To our knowledge this is the first evidence that a nuclear receptor in ovarian cancer tumor cells is actively driving MDSC differentiation. Finally, employing ovarian cancer xenograft models as well as a syngeneic ID8 tumor model, treatment with SGRMs demonstrated reduced levels of circulating MDSCs in the peripheral blood as well as tumor infiltrated MDSCs. Using neutralizing antibodies for cytokines, we will now identify key mechanisms, specifically, identify which targetable immunomodulatory factors are contributing to immune suppression. Based on the insight provided by these data, we propose to determine whether targeting ovarian tumor cell-intrinsic GR activation and resulting MDSC infiltration contributes to improved anti-tumor immune response. Citation Format: Manisha Taya, Eleanore LeBlanc, Lynda Bennett, Suzanne D. Conzen. Ovarian cancer-cell glucocorticoid receptor activity modulates cytokine secretion promoting infiltration of immunosuppressive cells into the tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 654.

Disruption of the CDKN2A (INK4A/ARF) and B (INK4B) genes, which encode three function-independent tumor suppressors, is one of the most common events in human cancer. Because their relative importance in tumor prevention appears to be species- and context-specific, studying their regulation can shed light on mechanisms by which they are bypassed in malignant transformation. We previously unveiled a new pathway in which TGFβ selectively induces Arf at mouse Cdkn2a in eye development and cultured fibroblasts. As TGFβ signaling is often derailed in cancer development or progression, we investigated its control of CDKN2A/B in human cancer. Computational analyses of sequencing and array data from nearly 11,000 patients with cancer in TCGA showed discordant expression of ARF and INK4A in most cancer subtypes, with gene copy-number loss and promoter methylation involved in only a subset. Using HeLa cells as a model, we found that exogenous TGFβ induced ARF mRNA and protein, and ARF knockdown limited TGFβ-mediated growth suppression. TGFβ-mediated ARF mRNA induction required SMAD2/3, p38MAPK, and SP1, and ARF mRNA was induced without added RNAPII recruitment. Chromatin immunoprecipitation unveiled a remote enhancer element engaged by TGFβ by a mechanism that partially depended on p38MAPK. CRISPR-based editing of this enhancer limited induction of ARF and INK4B by TGFβ, but not by oncogenic RAS. Implications: Our findings reveal new molecular mechanisms by which CDKN2A/B regulation is coupled to external cues, and those findings represent entry points to further explore pharmacologic strategies to restore their expression in cancer.

While considered uncommon, there are an estimated 39,000 new invasive lobular carcinoma (ILC) cases in the US yearly, making it the sixth most common among all tumor types. ILC is recognized for unique metastatic organotropism. Its propensity to metastasize to serosal surfaces lining the gut (peritoneum) and lung (pleura) make it particularly challenging to diagnose and consequently is associated with overall unfavorable prognosis. We hypothesize that GR activation will slow cell proliferation and reduce metastatic potential of ILC cells in vitro and in vivo. Using transcriptome data from 142 ILC tumors with long-term follow up clinical data from the METABRIC dataset we found a trend towards improved overall patient survival with increased GR (NR3C1) expression (and presumably activity). Preliminary in vitro data showed slowed cell proliferation in an ILC cell line (MDA-MB-134IV) treated with GR agonist dexamethasone relative to vehicle control. ILC cell lines (MDA-MB-134IV and SUM44PE) have dramatically different adhesion preference for extracellular components and we will study whether GR mediates the metastatic organotrophism of ILC cells. Preliminary transcriptome data lends insight into the proliferative and adhesive gene expression changes elicited by both ER and GR activation. Two GR+ ILC patient derived organoid lines have GR dependent proliferative and adhesive phenotypes. In future studies we will utilize an in vivo mouse model that recapitulates ILC progression from an in situ to invasive breast carcinoma and finally to metastatic colonization of distant organs to determine the role of GR activity in proliferation and metastasis to the serosal surfaces. Citation Format: Candace Frerich, Ishrat Durdana, Ariella Hanker, Carlos L. Arteaga, Lynda Bennett, Suzanne Conzen. Glucocorticoid receptor biology in lobular breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2699.

Immunosuppressive cells abundantly infiltrate tumors during cancer progression. Notably, immunosuppressive myeloid-derived suppressor cells (MDSCs) have recently been identified as a heterogeneous cell population that expand during tumor-associated inflammation and are significantly increased in the tumor, peripheral blood, as well as ascites of ovarian cancer patients. MDSCs contribute to tumor immune tolerance via inhibition of T-cell proliferation and activation. Signals from the tumor microenvironment in the form of soluble cytokines are proposed to lead to MDSC infiltration. It is also known that high tumor cell glucocorticoid receptor (GR) expression is associated with a relatively poor prognosis in ovarian cancer patients. We hypothesized that ovarian cancer cell GR expression and activity may modulate tumor cell cytokine secretion thereby leading to increased MDSC generation and recruitment to the tumor, eventually creating an immunosuppressive environment. Our preliminary data confirm that GR activation in two high-grade ovarian cancer cell lines (HEYA8 and SKOV3) modulates the cytokine secretome. Our results demonstrate GR-mediated secretion of several pro-tumorigenic and immunosuppressive proteins including G-CSF, M-CSF, TGF-β, and MCP-1 in those ovarian cancer models. We also observed downregulation of potent cytotoxic T-cell activating cytokines required for anti-tumor T-cell function including IL-2, IFN-γ and MIP1 upon GR activation. Importantly, treatment of cells with a competitive GR antagonist reverses this immunosuppressive secretome effect. Furthermore, upon culturing healthy peripheral blood mononuclear cells (PBMCs) with tumor conditioned media from GR activated ovarian cancer cells, we show that secreted immunomodulatory factors have the capacity to promote differentiation of human MDSCs from PBMCs. The resulting MDSC population was characterized via expression of activation markers including Arginase-1, iNOS, VEGF and TGF-β. Most importantly, the suppressive function of these MDSCs is being evaluated by determining their inhibitory potential on cytotoxic T-cell proliferation and/or activation. Based on the insight provided by these data, we propose to determine whether ovarian tumor cell-intrinsic GR activation and resulting MDSC generation contributes to earlier relapse of GR-positive ovarian cancers, and eventually whether this mechanism may be targeted to improve patient outcomes in this subset of ovarian cancers. Citation Format: Manisha Taya, Janet Gonzalez, Lynda Bennett, Suzanne D. Conzen. Ovarian cancer cell glucocorticoid receptor activity is associated with cytokine secretion promoting infiltration of immunosuppressive cells into the tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1335.

Significance Beclin 1, an essential autophagy protein, is important for tumor suppression in mice, as well as in human breast and ovarian cancers. However, it is not well understood how Beclin 1 acts as a tumor suppressor. By performing a genetic screen to identify genes whose loss blocks the ability of Beclin 1 to inhibit the growth of breast cancer cells and follow-up biological analyses, we have identified a mechanism by which Beclin 1 prevents breast cancer growth. We found that Beclin 1 promotes the plasma membrane localization of E-cadherin, a breast tumor-suppressor molecule that restricts tumor growth and metastases only when present at the cell surface. These findings have important implications for understanding the cell biology of human breast cancer., Beclin 1, an autophagy and haploinsufficient tumor-suppressor protein, is frequently monoallelically deleted in breast and ovarian cancers. However, the precise mechanisms by which Beclin 1 inhibits tumor growth remain largely unknown. To address this question, we performed a genome-wide CRISPR/Cas9 screen in MCF7 breast cancer cells to identify genes whose loss of function reverse Beclin 1-dependent inhibition of cellular proliferation. Small guide RNAs targeting CDH1 and CTNNA1, tumor-suppressor genes that encode cadherin/catenin complex members E-cadherin and alpha-catenin, respectively, were highly enriched in the screen. CRISPR/Cas9-mediated knockout of CDH1 or CTNNA1 reversed Beclin 1-dependent suppression of breast cancer cell proliferation and anchorage-independent growth. Moreover, deletion of CDH1 or CTNNA1 inhibited the tumor-suppressor effects of Beclin 1 in breast cancer xenografts. Enforced Beclin 1 expression in MCF7 cells and tumor xenografts increased cell surface localization of E-cadherin and decreased expression of mesenchymal markers and beta-catenin/Wnt target genes. Furthermore, CRISPR/Cas9-mediated knockout of BECN1 and the autophagy class III phosphatidylinositol kinase complex 2 (PI3KC3-C2) gene, UVRAG, but not PI3KC3-C1–specific ATG14 or other autophagy genes ATG13, ATG5, or ATG7, resulted in decreased E-cadherin plasma membrane and increased cytoplasmic E-cadherin localization. Taken together, these data reveal previously unrecognized cooperation between Beclin 1 and E-cadherin–mediated tumor suppression in breast cancer cells.

Myeloid-derived suppressor cells (MDSCs) have been identified as a heterogeneous cell population that expand during tumor progression and infiltrate the tumor, peripheral blood, as well as ascites of ovarian cancer patients. MDSCs contribute to tumor immune tolerance via inhibition of T-cell proliferation/activation. It is also known that high tumor cell glucocorticoid receptor (GR) expression is associated with a relatively poor prognosis in ovarian cancer patients. We hypothesized that ovarian tumor cell GR expression and activity may modulate tumor cell cytokine secretion thereby leading to increased MDSC generation and recruitment, thus creating an immunosuppressive tumor microenvironment. Our preliminary data confirms GR-mediated secretion of pro-tumorigenic cytokines including G-CSF, TGF-b, and MCP-1 in high-grade ovarian cancer models. We also observed GR-mediated downregulation of IL-2 and IFN-g, cytokines required for anti-tumor T-cell function. Importantly, treatment of cells with a competitive GR antagonist reversed this immunosuppressive secretome effect. Moreover, culturing healthy peripheral blood mononuclear cells (PBMCs) with tumor conditioned media from GR activated ovarian cancer cells demonstrated that secreted immunomodulatory factors have the capacity to promote differentiation of human MDSCs from PBMCs. Based on the insight provided by these data, we propose to determine whether ovarian tumor cell-intrinsic GR activation and resulting MDSC generation has an inhibitory effect on cytotoxic T-cell function, contributing to earlier relapse of GR-positive ovarian cancers, and eventually whether this mechanism may be targeted to improve patient outcomes in this subset of ovarian cancers. Supported by grant from CPRIT

A key mediator of macroautophagy/autophagy induction is the class III phosphatidylinositol 3-kinase complex I (PtdIns3K-C1) consisting of PIK3C3/VPS34, PIK3R4/VPS15, BECN1, and ATG14. Although several proteins are known to enhance or decrease PtdIns3K-C1 activity, our understanding of the molecular regulation of PtdIns3K-C1 is still incomplete. Previously, we identified a Golgi-associated protein, GLIPR2, in a screen for proteins that interact with amino acids 267–284 of BECN1, a region of BECN1 sufficient to induce autophagy when fused to a cell penetrating leader sequence. In this study, we used CRISPR-Cas9-mediated depletion of GLIPR2 in cells and mice to investigate the role of GLIPR2 in the regulation of autophagy and PtdIns3K-C1 activity. Depletion of GLIPR2 in HeLa cells increased autelophagic flux and generation of phosphatidylinositol 3-phosphate (PtdIns3P). GLIPR2 knockout resulted in less compact Golgi structures, which was also observed in autophagy-inducing conditions such as amino acid starvation or Tat-BECN1 peptide treatment. Importantly, the binding of GLIPR2 to purified PtdIns3K-C1 inhibited the in vitro lipid kinase activity of PtdIns3K-C1. Moreover, the tissues of glipr2 knockout mice had increased basal autophagic flux as well as increased recruitment of the PtdIns3P-binding protein, WIPI2. Taken together, our findings demonstrate that GLIPR2 is a negative regulator of PtdIns3K-C1 activity and basal autophagy. Abbreviations: ATG14: autophagy related 14; Baf A1: bafilomycin A1; BARA: β-α repeated, autophagy-specific; CQ: chloroquine; GFP: green fluorescent protein; GLIPR2: GLI pathogenesis related 2; HBSS: Hanks’ balanced salt solution; KO: knockout; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; PBS: phosphate-buffered saline; PtdIns3K-C1: phosphatidylinositol 3-kinase complex I; PtdIns3P: phosphatidylinositol-3-phosphate; SEM: standard error of the mean; WIPI2: WD repeat domain, phosphoinositide interacting 2

While considered a relatively uncommon breast cancer (BC) subtype, there are an estimated 39,000 new invasive lobular carcinoma (ILC) cases in the US yearly, making it the sixth most common among all tumor types. Yet, ILC remains understudied and, consequently, the mechanisms driving tumor growth and progression remain elusive. Hallmark E-Cadherin mutations resulting in defective cell-to-cell adhesion are believed to result in ILC’s single-file, discontinuous phenotype. ILC has also long been recognized for unique metastatic organotropism. Notably, its propensity to metastasize to serosal surfaces lining the gut (peritoneum) and lung (pleura) make it particularly challenging to diagnose and consequently is associated with an overall unfavorable prognosis. Indeed, ILC has significantly worse long-term prognosis than invasive ductal carcinoma (IDC) due to its poor response to endocrine therapy, and deadly, late occurring metastases. Thus, ILC patients are in dire need for improved therapies that can prevent tumor growth and progression five or more years after diagnosis. We previously found that selective GR modulators (SGRMs) that bind to the body's stress hormone receptor - the glucocorticoid receptor (GR) - can inhibit estrogen receptor positive (ER+) IDC growth in vivo. SGRMs are appealing clinically because they are (1) already in clinical trials and (2) well-tolerated by patients. Thus, SGRMs could be rapidly mobilized in the clinical setting if proven effective against ILC. We hypothesize that if SGRMs can slow ILC growth, as they do in IDC, GR modulation in ILC might improve patient outcome by slowing tumor growth and preventing serosal metastases. Using transcriptome data for 142 ILC tumors with long-term follow up clinical data from the METABRIC dataset we found a trend towards improved overall patient survival with increased NR3C1 (GR) expression. Our preliminary in vitro data also demonstrate slowed cell proliferation in an ILC cell line (MM134) relative to vehicle control. ILC cell lines have dramatically different adhesion preference for extracellular components of serosal surfaces. Preliminary transcriptome data lend insight into the proliferative and adhesive gene expression changes elicited by both ER and GR activation. We have found two CDK4/6 inhibitor-resistant GR+ ILC patient-derived organoids that may have GR-dependent proliferative and adhesive phenotypes. Future studies will use an in vivo mammary intraductal mouse model of metastatic colonization of distant organs to determine the role of tumor cell GR activation in proliferation and metastases to serosal surfaces. Citation Format: Candace Frerich, Ishrat Durdana, Sumanta Chatterjee, Ariella Hanker, Lynda Bennett, Carlos L. Arteaga, Suzanne D. Conzen. Modulation of glucocorticoid receptor activity in invasive lobular carcinoma progression [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-04-02.

Chromatin remodeling plays a critical role in tumor suppression as demonstrated by 20% of human cancers bearing inactivating mutations in SWI/SNF chromatin remodeling complex members. Mutations in different SWI/SNF subunits drive a variety of adult and pediatric tumor types, including non-small cell lung cancers, rhabdoid tumors, medulloblastomas, and ovarian cancers. Small cell carcinoma of the ovary hypercalcemic type (SCCOHT) is an aggressive subtype of ovarian cancer occurring in young women. Nearly all (>98%) SCCOHTs have inactivating mutations inSMARCA4, which encodes 1 of 2 mutually exclusive catalytic subunits of the SWI/SNF complex. Less than half of SCCOHT patients survive 5 years despite aggressive surgery and multimodal chemotherapy. Empirical support for effective SCCOHT treatments is scarce, in part because of the poor understanding of SCCOHT tumorigenesis. To gain insight into the functional consequences of SWI/SNF subunit loss, we defined SWI/SNF composition and its protein-protein interactions (PPIs) by immunoprecipitation and mass spectrometry (IP-MS) of SWI/SNF subunits in 3 SCCOHT cell lines. Comparing these results to a cell line containing a wild-type SWI/SNF complex, the interaction of most canonical core SWI/SNF subunits was observed in all SCCOHT cell lines at a lower abundance. The SCCOHT SWI/SNF also lacked ATPase module subunits and showed a drastic reduction in PBAF-specific subunit interactions. The wild-type and SCCOHT SWI/SNF subunits immunoprecipitated a shared set of 26 proteins, including core SWI/SNF subunits and RNA processing proteins. We observed 131 proteins exclusively interacting with the wild-type SWI/SNF complex including isoform-specific SWI/SNF subunits, members of the NuRD complex, and members of the MLL3/4 complex. We observed 60 PPIs exclusive to the SCCOHT residual SWI/SNF shared in at least 2 of the 3 SCCOHT cell lines, including many proteins involved in RNA processing. Differential interactions with the residual SWI/SNF complex in SCCOHT may further elucidate altered functional consequences of SMARCA4 mutations in these tumors as well as identify synthetic lethal targets that translate to other SWI/SNF-deficient tumors.

CDKN2A is an evolutionarily conserved gene encoding proteins implicated in tumor suppression, ocular development, aging, and metabolic diseases. Like the human form, mouse Cdkn2a encodes two distinct proteins – p16(lnk4a), which blocks cyclin-dependent kinase activity, and p19(Arf), which is best known as a positive regulator of the p53 tumor suppressor – and their functions have been well-studied in genetically engineered mouse models. Relatively little is known about how expression of the two transcripts is controlled in normal development and in certain disease states. To better understand their coordinate and transcript-specific expression in situ, we used a transposase-aided approach to generate a new BAC transgenic mouse model in which the first exons encoding Arf and Ink4a are replaced by fluorescent reporters. We show that mouse embryo fibroblasts (MEFs) generated from the transgenic lines faithfully display induction of each transgenic reporter in cell culture models, and we demonstrate the expected expression of the Arf reporter in the normal testis, one of the few places where that promoter is normally expressed. Interestingly, the TGFβ-2-dependent induction of the Arf reporter in the eye - a process essential for normal eye development - does not occur. Our findings illustrate the value of BAC transgenesis in mapping key regulatory elements in the mouse by revealing the genomic DNA required for Cdkn2a induction in cultured cells and the developing testis, and the apparent lack of elements driving expression in the developing eye.

Disruption of the CDKN2A (INK4A/ARF) and B (INK4B) genes, which encode three function-independent tumor suppressors, is one of the most common events in human cancer. Because their relative importance in tumor prevention appears to be species- and context-specific, studying their regulation can shed light on mechanisms by which they are bypassed in malignant transformation. We previously unveiled a new pathway in which TGFβ selectively induces Arf at mouse Cdkn2a in eye development and cultured fibroblasts. As TGFβ signaling is often derailed in cancer development or progression, we investigated its control of CDKN2A/B in human cancer. Computational analyses of sequencing and array data from nearly 11,000 cancer patients in TCGA showed discordant expression of ARF and INK4A in most cancer subtypes, with gene copy-number loss and promoter methylation involved in only a subset. Using HeLa cells as a model, we found that exogenous TGFβ induced ARF mRNA and protein, and ARF knockdown limited TGFβ-mediated growth suppression. TGFβ-mediated ARF mRNA induction required SMAD2/3, p38MAPK, and SP1, and ARF mRNA was induced without added RNAPII recruitment. Chromatin immunoprecipitation unveiled a remote enhancer element engaged by TGFβ by a mechanism that partially depended on p38MAPK. CRISPR-based editing of this enhancer limited induction of ARF and INK4B by TGFβ, but not by oncogenic RAS. IMPLICATIONS: Our findings reveal new molecular mechanisms by which CDKN2A/B regulation is coupled to external cues, and those findings represent entry points to further explore pharmacological strategies to restore their expression in cancer.

Chromatin remodeling plays a critical role in tumor suppression as demonstrated by 20% of human cancers bearing inactivating mutations in SWI/SNF chromatin remodeling complex members. Mutations in different SWI/SNF subunits drive a variety of adult and pediatric tumor types, including non-small cell lung cancers, rhabdoid tumors, medulloblastomas, and ovarian cancers. Small cell carcinoma of the ovary hypercalcemic type (SCCOHT) is an aggressive subtype of ovarian cancer occurring in young women. Nearly all (>98%) SCCOHTs have inactivating mutations in SMARCA4, which encodes 1 of 2 mutually exclusive catalytic subunits of the SWI/SNF complex. Less than half of SCCOHT patients survive 5 years despite aggressive surgery and multimodal chemotherapy. Empirical support for effective SCCOHT treatments is scarce, in part because of the poor understanding of SCCOHT tumorigenesis. To gain insight into the functional consequences of SWI/SNF subunit loss, we defined SWI/SNF composition and its protein-protein interactions (PPIs) by immunoprecipitation and mass spectrometry (IP-MS) of SWI/SNF subunits in 3 SCCOHT cell lines. Comparing these results to a cell line containing a wild-type SWI/SNF complex, the interaction of most canonical core SWI/SNF subunits was observed in all SCCOHT cell lines at a lower abundance. The SCCOHT SWI/SNF also lacked ATPase module subunits and showed a drastic reduction in PBAF-specific subunit interactions. The wild-type and SCCOHT SWI/SNF subunits immunoprecipitated a shared set of 26 proteins, including core SWI/SNF subunits and RNA processing proteins. We observed 131 proteins exclusively interacting with the wild-type SWI/SNF complex including isoform-specific SWI/SNF subunits, members of the NuRD complex, and members of the MLL3/4 complex. We observed 60 PPIs exclusive to the SCCOHT residual SWI/SNF shared in at least 2 of the 3 SCCOHT cell lines, including many proteins involved in RNA processing. Differential interactions with the residual SWI/SNF complex in SCCOHT may further elucidate altered functional consequences of SMARCA4 mutations in these tumors as well as identify synthetic lethal targets that translate to other SWI/SNF-deficient tumors. Citation Format: Elizabeth Raupach, Krystine Garcia-Mansfield, Ritin Sharma, Apurva Hegde, Victoria David-Dirgo, Yemin Wang, Chae Young Shin, Lan Tao, Salvatore Facista, Rayvon Moore, Jessica Lang, Victoria Zismann, Krystal Orlando, Monique Spillman, Anthony Karnezis, Lynda Bennett, David Huntsman, Jeffrey Trent, William Hendricks, Bernard Weissman, Patrick Pirrotte. Novel functional insights revealed by distinct protein-protein interactions of the residual SWI/SNF complex in SMARCA4-deficient small cell carcinoma of the ovary, hypercalcemic type [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr LB-038.

High expression level of human TLR8 in mice results in spontaneous, multiorgan inflammation attributable in part to increased DC activation., Studies on the role of the RNA receptor TLR8 in inflammation have been limited by its different function in human versus rodents. We have generated multiple lines of transgenic mice expressing different levels of human TLR8. The high copy number chimeras were unable to pass germline; developed severe inflammation targeting the pancreas, salivary glands, and joints; and the severity of the specific phenotypes closely correlated with the huTLR8 expression levels. Mice with relatively low expression levels survived and bred successfully but had increased susceptibility to collagen-induced arthritis, and the levels of huTLR8 correlated with proinflammatory cytokines in the joints of the animals. At the cellular level, huTLR8 signaling exerted a DC-intrinsic effect leading to up-regulation of co-stimulatory molecules and subsequent T cell activation. A pathogenic role for TLR8 in human diseases was suggested by its increased expression in patients with systemic arthritis and the correlation of TLR8 expression with the elevation of IL-1β levels and disease status. We found that the consequence of self-recognition via TLR8 results in a constellation of diseases, strikingly distinct from those related to TLR7 signaling, and points to specific inflammatory diseases that may benefit from inhibition of TLR8 in humans.

Purpose of review The purpose of review is to describe the recent advances in the field of human epigenetics. Recent findings With the completion of the genome project in 2003, high expectations existed for the DNA sequence information to provide answers about the causative mutations for common diseases. However, this was not completely the case. Another interesting finding that resulted from the genome project was that the perceived level of complexity of humans was not accompanied with a relative increase in the number of genes when compared to ‘lower species’. Epigenetics is able to provide answers to previously unanswered health-related questions and can explain differences in level of complexity between organisms. Epigenetic studies accomplished in the last few years have exposed a very complex multilayered regulatory mechanism that is able to answer previously puzzling questions in biology. Summary Understanding and interpretation of the role for epigenetic modifications in the human genome has progressed rapidly over the past decade with the advancement of microarray-based and sequence-based technologies. The complex interaction between DNA methylation, histone modifications, protein complexes and microRNAs has become better appreciated in the context of both local and long range epigenetic control of transcription in both normal cellular differentiation and tumorigenesis.

Certain WNT and WNT network target genes are expressed at higher or lower levels in chronic lymphocytic leukemia compared with normal B-cells. This includes upregulation of nuclear complex genes, as well as genes for cytoplasmic proteins and WNT ligands and their cognate receptors. In addition, epigenetic silencing of several negative regulators of the WNT pathway have been identified. The balance between epigenetic downregulation of negative effector genes and increased expression of positive effector genes demonstrate that the epigenetic downregulation of WNT antagonists is one mechanism, perhaps the main mechanism, that is permissive to active WNT signaling in chronic lymphocytic leukemia. Moreover, constitutive activation of the WNT network and target genes is likely to impact on additional interacting signaling pathways. Based on published studies, we propose a model of WNT signaling that involves mainly permissive expression, and sometimes overexpression, of positive effectors and downregulation of negative regulators in the network. In this model, DNA methylation, histone modifications and altered expression of microRNA molecules interact to allow continuous WNT signaling.

Aims: B-cell chronic lymphocytic leukemia (CLL) is a heterogeneous malignancy that clinically ranges from indolent to rapidly progressive. CLL, like other cancers, can be affected by epigenetic alterations. Materials & methods: A microarray discovery-based study was initiated to determine DNA methylation in CLL cases with a range of CD38 expression (1–92%). Results: Many loci were either methylated or unmethylated across all CD38 levels, but differential methylation was also observed for some genes. Genomic sequencing of DLEU7 confirmed extensive cytosine methylation preferentially in patient samples with low CD38 expression, whereas NRP2, SFRP2 and ADAM12 were more commonly methylated in those with high CD38 expression. Conclusion: This study demonstrates that CLL is affected by CpG island methylation in some genes that segregate with CD38 expression levels, while most others show similar methylation patterns across all levels. The CpG island methylation in certain functional gene groups and pathway-associated genes that are known to be deregulated in CLL provides additional insights into the CLL methylome and epigenetic contribution to cellular dysfunction. It will now be useful to investigate the effectiveness of epigenetic therapeutic reversal of these alterations to develop effective treatments for the disease.

High-throughput microarray technologies were used to study DNA methylation accompanied by transcriptional changes in follicular lymphoma (FL). Using Methylated CpG Island Amplification with Microarrays (MCAM) to study CpG Island (CGI) DNA methylation in follicular lymphoma (FL) we discovered widespread hypermethylation of homeobox genes and previously identified targets of polycomb repressive complex 2 (PRC2) in cell lines and primary tumors, but not in benign follicular hyperplasia (BFH). DNA methylation for HOXA11, HOXD10, HOXB7, HOXC12, PAX6, LHX9, SFMBT2, EN2 and PAX7 was independently validated in the RL cell line and HOXA11, HOXD10, PAX6 and EN2 in primary tumors. Combined Bisulfite Restriction Analysis (COBRA) also established DNA methylation for the previously identified PRC2 targets DCC, DES, GAD2, AQP5, GPR61, GRIA4, GJD2 and AMPH in FL but not in BFH. Gene expression analyses revealed 411 genes that were hypermethylated and transcriptionally repressed in RL, 74% of which were re-activated by the demethylating agent 5-aza-2′-deoxycytidine (5-azaD) plus or minus the histone deacetylase inhibitor trichostatin A (TSA). Forty genes were also down-regulated in primary FL. Our results suggest that extensive hypermethylation in promoters of polycomb target genes is a characteristic of FL and that loss of expression of certain SUZ12 target genes could be functionally relevant for lymphomagenesis.

SummaryThe analysis of patient blood transcriptional profiles offers a means to investigate the immunological mechanisms relevant to human diseases on a genome-wide scale. In addition, such studies provide a basis for the discovery of clinically relevant biomarker signatures. We designed a strategy for microarray analysis that is based on the identification of transcriptional modules formed by genes coordinately expressed in multiple disease data sets. Mapping changes in gene expression at the module level generated disease-specific transcriptional fingerprints that provide a stable framework for the visualization and functional interpretation of microarray data. These transcriptional modules were used as a basis for the selection of biomarkers and the development of a multivariate transcriptional indicator of disease progression in patients with systemic lupus erythematosus. Thus, this work describes the implementation and application of a methodology designed to support systems-scale analysis of the human immune system in translational research settings.

Dendritic cells (DCs) loaded with killed allogeneic melanoma cells can cross-prime naive CD8+ T cells to differentiate into melanoma-specific CTLs in 3-wk cultures. In this study we show that DCs loaded with killed melanoma cells that were heated to 42°C before killing are more efficient in cross-priming of naive CD8+ T cells than DCs loaded with unheated killed melanoma cells. The enhanced cross-priming was demonstrated by several parameters: 1) induction of naive CD8+ T cell differentiation in 2-wk cultures, 2) enhanced killing of melanoma peptide-pulsed T2 cells, 3) enhanced killing of HLA-A*0201+ melanoma cells in a standard 4-h chromium release assay, and 4) enhanced capacity to prevent tumor growth in vitro in a tumor regression assay. Two mechanisms might explain the hyperthermia-induced enhanced cross-priming. First, heat-treated melanoma cells expressed increased levels of 70-kDa heat shock protein (HSP70), and enhanced cross-priming could be reproduced by overexpression of HSP70 in melanoma cells transduced with HSP70 encoding lentiviral vector. Second, hyperthermia resulted in the increased transcription of several tumor Ag-associated Ags, including MAGE-B3, -B4, -A8, and -A10. Thus, heat treatment of tumor cells permits enhanced cross-priming, possibly via up-regulation of both HSPs and tumor Ag expression.

The immune system is controlled by dendritic cells (DCs). Just as lymphocytes comprise different subsets, DCs comprise several subsets that differentially control lymphocyte function. In humans, the myeloid pathway includes Langerhans cells (LCs) and interstitial DCs (intDCs). While both subsets produce IL-12, only intDCs make IL-10 and induce B cell differentiation. Another pathway includes plasmacytoid DCs, which promptly secrete large amounts of IFN-alpha/beta viral encounter. Thus, insights into in vivo DC functions are important to understand the launching and modulation of immunity.

Blood monocytes from children with systemic lupus erythematosus (SLE) behave similar to dendritic cells (DCs), and SLE serum induces healthy monocytes to differentiate into DCs in a type I IFN–dependent manner. In this study, we found that these monocytes display significant transcriptional changes, including a prominent IFN signature, compared with healthy controls. Few of those changes, however, explain DC function. Exposure to allogeneic T cells in vitro reprograms SLE monocytes to acquire DC phenotype and function, and this correlates with both IFN-inducible (IP10) and proinflammatory cytokine (IL-1β and IL6) expression. Furthermore, we found that both IFN and SLE serum induce the upregulation of CCR7 transcription in these cells. CCR7 protein expression, however, requires a second signal provided by TLR agonists such as LPS. Thus, SLE serum “primes” a subset of monocytes to readily (

Objective To localize the gene for familial recurrent arthritis via a genome-wide linkage scan in an extended kindred with the disease. Methods A 3-generation family in which 9 members were diagnosed with juvenile idiopathic arthritis (JIA) was ascertained. In this family the disease was of very early onset and included episodic inflammation leading to eventual destruction of joints, muscle, and skin. We treated this disorder as a distinct clinical entity that we have named “familial recurrent arthritis.” A genome-wide linkage scan with polymorphic microsatellites at 10–15-cM resolution was initiated. Results The genome-wide scan generated a maximum 2-point logarithm of odds score with D15S211 (Zmax = 3.27 at θmax= 0.0010). Haplotype reconstruction defined a candidate region of ∼20 cM flanked proximally by D15S983 and distally by D15S127 on human chromosome 15. Conclusion A gene for familial recurrent arthritis was localized to 15q22-24, as a result of a genome-wide linkage scan in a large, multiply affected kindred. Identification of the altered gene will provide insights into the pathogenesis of autoimmune joint destruction that is reminiscent of JIA.

Familial partial lipodystrophy (FPLD), Dunnigan variety, is an autosomal dominant disorder characterized by marked loss of subcutaneous adipose tissue from the extremities and trunk but by excess fat deposition in the head and neck. The disease is frequently associated with profound insulin resistance, dyslipidemia, and diabetes. We have localized a gene for FPLD to chromosome 1q21-q23, and it has recently been proposed that nuclear lamin A/C is altered in FPLD, on the basis of a novel missense mutation (R482Q) in five Canadian probands. This gene had previously been shown to be altered in autosomal dominant Emery-Dreifuss muscular dystrophy (EDMD-AD) and in dilated cardiomyopathy and conduction-system disease. We examined 15 families with FPLD for mutations in lamin A/C. Five families harbored the R482Q alteration that segregated with the disease phenotype. Seven families harbored an R482W alteration, and one family harbored a G465D alteration. All these mutations lie within exon 8 of the lamin A/C gene-an exon that has also been shown to harbor different missense mutations that are responsible for EDMD-AD. Mutations could not be detected in lamin A/C in one FPLD family in which there was linkage to chromosome 1q21-q23. One family with atypical FPLD harbored an R582H alteration in exon 11 of lamin A. This exon does not comprise part of the lamin C coding region. All mutations in FPLD affect the globular C-terminal domain of the lamin A/C protein. In contrast, mutations responsible for dilated cardiomyopathy and conduction-system disease are observed in the rod domain of the protein. The FPLD mutations R482Q and R482W occurred on different haplotypes, indicating that they are likely to have arisen more than once.

Background Follicular lymphoma (FL) is a form of non-Hodgkin's lymphoma (NHL) that arises from germinal center (GC) B-cells. Despite the significant advances in immunotherapy, FL is still not curable. Beyond transcriptional profiling and genomics datasets, there currently is no epigenome-scale dataset or integrative biology approach that can adequately model this disease and therefore identify novel mechanisms and targets for successful prevention and treatment of FL. Methodology/Principal Findings We performed methylation-enriched genome-wide bisulfite sequencing of FL cells and normal CD19+ B-cells using 454 sequencing technology. The methylated DNA fragments were enriched with methyl-binding proteins, treated with bisulfite, and sequenced using the Roche-454 GS FLX sequencer. The total number of bases covered in the human genome was 18.2 and 49.3 million including 726,003 and 1.3 million CpGs in FL and CD19+ B-cells, respectively. 11,971 and 7,882 methylated regions of interest (MRIs) were identified respectively. The genome-wide distribution of these MRIs displayed significant differences between FL and normal B-cells. A reverse trend in the distribution of MRIs between the promoter and the gene body was observed in FL and CD19+ B-cells. The MRIs identified in FL cells also correlated well with transcriptomic data and ChIP-on-Chip analyses of genome-wide histone modifications such as tri-methyl-H3K27, and tri-methyl-H3K4, indicating a concerted epigenetic alteration in FL cells. Conclusions/Significance This study is the first to provide a large scale and comprehensive analysis of the DNA methylation sequence composition and distribution in the FL epigenome. These integrated approaches have led to the discovery of novel and frequent targets of aberrant epigenetic alterations. The genome-wide bisulfite sequencing approach developed here can be a useful tool for profiling DNA methylation in clinical samples.

Individuals of all ages can be detrimentally affected by cancer, albeit the disease is more prevalent in aging individuals. Epigenetic modulation is essential for normal development and becomes altered in cancer and aging. The most well-studied epigenetic elements include DNA methylation, histone modifications, miRNAs, and the binding of co-regulatory proteins such as Polycomb group and Trithorax proteins. Each of these “contributors” to the epigenetic landscape is subjected to aberrant events that are associated with aging and with cancer. We discuss the types of epigenetic modifications that are associated with cancers that affect the young and those that affect adults. It is known that erroneous DNA damage repair, inflammation, and proinflammatory signaling occur frequently in the elderly and that these processes can also result in aberrant epigenetic modifications. Acute lymphoblastic leukemia is one type of cancer that spans the entire lifetime from birth to the aged and demonstrates a number of age-related differences in clinical behavior. Therefore, ALL provides an excellent model to begin to decipher age-related epigenetic impacts on the disease. Finally, mechanistic scenarios are given which may explain the relationship between aging and the development of cancer, and future directions which will augment the elucidation of the complex relationship between cancer and aging are discussed.

The utilization of gene-expression microarrays in patient-based research creates new prospects for the discovery of diagnostic biomarkers and the identification of genes or pathways linked to pathogenesis. Gene-expression signatures in peripheral blood mononuclear cells isolated from over one hundred patients with conditions presenting a strong immunological component (patient with autoimmune, graft versus host and infectious diseases, as well as immunosuppressed transplant recipients) were generated. This dataset provides the opportunity to carry out comparative analyses and define disease signatures in a broader context. Transcriptional changes of 22,283 probe sets were evaluated through statistical group comparison performed systematically for seven diseases versus their respective healthy control group. Patterns of significance were generated by hierarchical clustering of P-values. This approach led to the identification of a SLE-specific "diagnostic signature," formed by genes that did not change compared to healthy subjects in the other six diseases. Conversely, a "sentinel signature" that was common to all seven diseases was characterized. These findings bring new perspectives for the application of blood leukocyte expression signatures for diagnosis and early disease detection.

Monocytes represent a large pool of circulating precursors of APCs, both macrophages and dendritic cells (DCs). It is thus important to identify the mechanisms by which microenvironment regulates monocyte differentiation. We have previously shown that, upon contact with resting stromal cells such as fibroblasts, monocytes differentiate into macrophages in an IL-6/M-CSF-dependent fashion. Yet, in the inflamed tissue, monocytes need to yield DCs for the adaptive immunity to be induced. Inasmuch as TNF and IL-1 are present at the site of inflammation, we tested their capacity to modulate monocyte differentiation into either macrophages or DCs. TNF, but not IL-1, induce monocytes to become DCs despite the presence of fibroblasts. TNF-induced DCs contain Langerin-positive cells and are able to induce allogenic T cell proliferation. Then, TNF was found to decrease the expression and internalization of the M-CSF receptor, thus overriding the IL-6/M-CSF pathway. Thus, TNF facilitates the induction of adaptive immunity by promoting DC differentiation not only from CD34+ progenitors but also from CD14+ blood precursors.

Distinct human dendritic cell (DC) subsets differentially control immunity. Thus, insights into their in vivo functions are important to understand the launching and modulation of immune responses. We show that nonobese diabetic/LtSz-scid/scid (NOD/SCID) mice engrafted with human CD34+ hematopoietic progenitors develop human myeloid and plasmacytoid DCs. The skin displays immature DCs expressing Langerin, while other tissues display interstitial DCs. Myeloid DCs from these mice induce proliferation of allogeneic CD4 T cells in vitro, and bone marrow human cells containing plasmacytoid DCs release interferon-α (IFN-α) upon influenza virus exposure. Injection of influenza virus into reconstituted mice triggers IFN-α release and maturation of mDCs. Thus, these mice may provide a model to study the pathophysiology of human DC subsets.

The immune system is controlled by dendritic cells (DCs). Just as lymphocytes comprise different subsets, DCs comprise several subsets that differentially control lymphocyte function. In humans, the myeloid pathway includes Langerhans cells (LCs) and interstitial DCs (intDCs). While both subsets produce IL-12, only intDCs make IL-10 and induce B cell differentiation. Another pathway includes plasmacytoid DCs, which promptly secrete large amounts of IFN-alpha/beta viral encounter. Thus, insights into in vivo DC functions are important to understand the launching and modulation of immunity.

Polymorphisms at di-, tri-, and tetranucleotide microsatellite loci have been analyzed in 14 worldwide populations. A statistical index of population expansion, denoted S(k), is introduced to detect historical changes in population size using the variation at the microsatellites. The index takes the value 0 at equilibrium with constant population size and is positive or negative according to whether the population is expanding or contracting, respectively. The use of S(k) requires estimation of properties of the mutation distribution for which we use both family data of Dib et al. for dinucleotide loci and our population data on tri- and tetranucleotide loci. Statistical estimates of the expansion index, as well as their confidence intervals from bootstrap resampling, are provided. In addition, a dynamical analysis of S(k) is presented under various assumptions on population growth or decline. The studied populations are classified as having high, intermediate, or low values of S(k) and genetic variation, and we use these to interpret the data in terms of possible population dynamics. Observed values of S(k) for samples of di-, tri-, and tetranucleotide data are compatible with population expansion earlier than 60,000 years ago in Africa, Asia, and Europe if the initial population size before the expansion was on the order of 500. Larger initial population sizes force the lower bound for the time since expansion to be much earlier. We find it unlikely that bottlenecks occurred in Central African, East Asian, or European populations, and the estimated expansion times are rather similar for all of these populations. This analysis presented here suggests that modern human populations departed from Africa long before they began to expand in size. Subsequently, the major groups (the African, East Asian, and European groups) started to grow at approximately same time. Populations of South America and Oceania show almost no growth. The Mbuti population from Zaire appears to have experienced a bottleneck during its expansion.

The short arm of human chromosome 21 (21p) contains many different types of repetitive sequences and is highly homologous to the short arms of other acrocentric chromosomes. Owing to its repetitive nature and the lack of chromosome 21p-specific molecular markers, most physical maps of chromosome 21 exclude this region. We constructed a physical map of chromosome 21p using sequence tagged site (STS) content mapping of yeast artificial chromosomes (YACs). To this end, 39 STSs located on the short arm or near the centromere of chromosome 21 were constructed, including four polymorphic simple tandem repeats (STRs) and two expressed sequence tags (ESTs). Thirty YACs were selected from the St. Louis YAC library, the chromosome 21-enriched ICRF YAC library, and the CEPH YAC and megaYAC libraries. These were assembled in a YAC contig map ranging from the centromere to the rDNA gene cluster at 21p12. The total size of the region covered by YACs is estimated between 2.9 and 5 Mb. The integrity of the YAC contig was confirmed by restriction enzyme fingerprinting and fluorescence in situ hybridization (FISH). One gap with an estimated size of 400 kb remained near the telomeric end of the contig. This YAC contig map of the short arm of human chromosome 21 constitutes a basic framework for further structural and functional studies of chromosome 21p.

Obesity is strongly implicated in the pathophysiology of insulin resistance, diabetes mellitus and dyslipidemia. The mechanisms, however, by which obesity causes these complications are not known. The study of single-gene disorders affecting adipose tissue may elucidate some of the mechanisms involved in these processes. Familial partial lipodystrophy, Dunnigan variety, (FPLD, OMIM 308980) is an autosomal-dominant condition characterized by marked loss of subcutaneous adipose tissue affecting the trunk and extremities but with excess fat deposition in the head and neck areas. Affected individuals show an increased preponderance of insulin resistance, diabetes mellitus, dyslipidemia and acanthosis nigricans. The genetic basis of FPLD is unknown. We carried out a genome-wide scan with a set of highly polymorphic short tandem-repeats (STR) in individuals from five well-characterized pedigrees and mapped the FPLD locus to chromosome 1q21-22. The maximum two-point lod score obtained with a highly polymorphic microsatellite at D1S2624 at theta(max)=0 was 5.84. Multipoint-linkage analysis yielded a peak lod score of 8.25 between D1S305 and D1S1600. There was no evidence for genetic heterogeneity (alpha=1) in the pedigrees.

Introduction: An international consortium was established to create comprehensive methylomes of B-cell lymphoma cell lines representing multiple stages of B-cell differentiation. One of the consortium's long-term goals is to identify genes and pathways that are perturbed by methylation in these cell lines either individually, or wholly, so that this information may be utilized to identify novel targets of aberrant methylation in patient samples. Experimental procedures: The B-cell derived tumor cell lines included in this study represent the spectrum of B-cell development: chronic lymphocytic leukemia (Mec1); mantle cell lymphoma (Granta); diffuse large B-cell lymphoma (Val and Ly10); follicular lymphoma (RL); Burkitt's lymphoma (Raji); and multiple myeloma (U266B1). Three methods were employed in this study: 1) Methylated CpG island amplification (MCA) and Agilent CpG island arrays; 2) HpaII tiny fragment enrichment by ligation-mediated PCR (HELP) and Agilent CpG island arrays; and 3) Bisulfite treatment in conjunction with the Illumina Infinium Methylation BeadChip. Data summary: Comprehensive genome-wide methylation profiles were constructed for each tumor cell line using the data generated from three different methods. The number of detected differentially methylated probes, genes and gene promoters differed for each method. The number of unique methylated genes identified ranged from 25 for Granta to more than 200 for U266B1. Recurrent aberrant methylation was detected in ∼100 genes in all seven cell lines included in this study. Methylation of key miRNAs was identified in each of the cell lines. Gene lists that included genes with promoter methylation were submitted to the database for annotation, visualization and integrated discovery (DAVID) to identify enriched functional-related gene groups. Cell differentiation, transcription factor activity and HOX were among the top three functionally enriched gene groups in all cell lines. Genes associated with the Wnt, MAPK and Hedgehog pathways were also enriched in select cell lines. Conclusions: All approaches suffer from limitations in their ability to detect methylated sequences. The probes assayed on the Agilent CpG island array are limited to sequences that are contained within the restriction fragments produced in the MCA and HELP assays. The MCA method relies on the co-hybridization of a sample of interest to a “normal control” which may introduce biases if the “proper” control is not used. Finally, the Illumina Infinium BeadChip assays, on average, only 2 probes per gene and is the least informative of the detection assays. Despite these shortcomings, the combination of the data generated by each method has allowed the identification of novel genes and pathways that can be used to design screening assays for large numbers of patient samples. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 168.

Systemic onset juvenile idiopathic arthritis (SoJIA) represents up to 20% of juvenile idiopathic arthritis. We recently reported that interleukin (IL) 1 is an important mediator of this disease and that IL-1 blockade induces clinical remission. However, lack of specificity of the initial systemic manifestations leads to delays in diagnosis and initiation of therapy. To develop a specific diagnostic test, we analyzed leukocyte gene expression profiles of 44 pediatric SoJIA patients, 94 pediatric patients with acute viral and bacterial infections, 38 pediatric patients with systemic lupus erythematosus (SLE), 6 patients with PAPA syndrome, and 39 healthy children. Statistical group comparison and class prediction identified genes differentially expressed in SoJIA patients compared with healthy children. These genes, however, were also changed in patients with acute infections and SLE. An analysis of significance across all diagnostic groups identified 88 SoJIA-specific genes, 12 of which accurately classified an independent set of SoJIA patients with systemic disease. Transcripts that changed significantly in patients undergoing IL-1 blockade were also identified. Thus, leukocyte transcriptional signatures can be used to distinguish SoJIA from other febrile illnesses and to assess response to therapy. Availability of early diagnostic markers may allow prompt initiation of therapy and prevention of disabilities.

Systemic lupus erythematosus (SLE) is a prototype systemic autoimmune disease characterized by flares of high morbidity for which we have no predictors. We used oligonucleotide microarrays to analyze the genes expressed by blood mononuclear cells from active SLE patients, arthritis patients and healthy controls. Here we show that active SLE can be distinguished by a remarkably homogeneous gene expression pattern with overexpression of granulopoiesis-related and interferon (IFN)-induced genes. Using the most stringent statistical analysis (Bonferroni correction), 15 genes were found highly upregulated in SLE patients, 14 of which are either well-known or newly identified targets of IFN. The other gene is the defensin DEFA-3, a major product of immature granulocytes. A more liberal correction to the pairwise tests (Benjamini and Hochberg correction) yielded 16 additional genes, 12 of which are known to be IFN-regulated and four to be granulocyte specific. High-dose intravenous infusion of glucocorticoids, one of the standard treatments of disease flares, shuts down the IFN signature, further supporting the critical role of this cytokine in SLE. Furthermore, we have identified a set of 10 genes whose expression correlated with disease activity according to the SLE Disease Activity Index. The most striking correlation (P < 0.001, r = 0.55) was found with the formyl peptide receptor-like 1 protein that mediates chemotactic activities of defensins. Therefore, while the IFN signature confirms the central role of this cytokine in SLE, the microarray analysis of blood cells reveals that immature granulocytes may be involved in SLE pathogenesis.

Objective: To use genetic linkage analysis to localize a gene for paroxysmal kinesigenic dyskinesia (PKD) in a three generation African-American kindred. Background: PKD is a rare autosomal dominant disorder characterized by episodic choreiform or dystonic movements that are brought on or exacerbated by voluntary movement. There are individuals with the clinical features of PKD but with no family history of the disease, but whether these sporadic cases represent spontaneous mutations of PKD or have a distinct condition is unknown. Methods: A genome-wide linkage scan of polymorphic microsatellites at 25 cM resolution was performed to localize a gene for PKD in one African-American kindred. Pairwise multipoint linkage analyses were performed at different penetrance estimates. Results: Evidence for linkage of the kinesigenic form of paroxysmal dyskinesia to chromosome 16 was obtained. A maximum lod score of 4.40 at θ = 0 was obtained with D16S419. Critical recombinants place the PKD gene between D16S3100 and D16S771. Conclusions: A paroxysmal kinesigenic dyskinesia (PKD) locus lies within an 18 cM interval on 16p11.2-q11.2, between D16S3100 and D16S771. A gene for infantile convulsions with paroxysmal choreoathetosis has also been mapped to this region. These two regions overlap by approximately 6 cM. These two diseases could be caused by different mutations in the same gene or two distinct genes may lie within this region.

Compared with aerosol administration the Bennett's Intermittent Positive Pressure Respirator (I.P.P.R.) has been the most favoured method of Salbutamol administration in hospitals for the treatment of asthma or Chronic Obstructive Airways Disease (C.O.A.D.).

Objective: To clinically characterize affected individuals in families with paroxysmal kinesigenic dyskinesia (PKD), examine the association with infantile convulsions, and confirm linkage to a pericentromeric chromosome 16 locus.Background: PKD is characterized by frequent, recurrent attacks of involuntary movement or posturing in response to sudden movement, stress, or excitement. Recently, an autosomal dominant PKD locus on chromosome 16 was identified.Methods: The authors studied 11 previously unreported families of diverse ethnic background with PKD with or without infantile convulsions and performed linkage analysis with markers spanning the chromosome 16 locus. Detailed clinical questionnaires and interviews were conducted with affected and unaffected family members.Results: Clinical characterization and sampling of 95 individuals in 11 families revealed 44 individuals with paroxysmal dyskinesia, infantile convulsions, or both. Infantile convulsions were surprisingly common, occurring in 9 of 11 families. In only two individuals did generalized seizures occur in later childhood or adulthood. The authors defined a 26-cM region using linkage data in 11 families (maximum lod score 6.63 at θ = 0). Affected individuals in one family showed no evidence for a shared haplotype in this region, implying locus heterogeneity.Conclusions: Identification and characterization of the PKD/infantile convulsions gene will provide new insight into the pathophysiology of this disorder, which spans the phenotypic spectrum between epilepsy and movement disorder.