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Supplementary Figures 1-4 from Long-term Epigenetic Therapy with Oral Zebularine Has Minimal Side Effects and Prevents Intestinal Tumors in Mice

Recent successes in the application of epigenetic drugs for the treatment of myelodysplastic syndrome have raised questions on the safety of long-term administration of DNA methylation inhibitors. We treated preweaned cancer prone ApcMin/+ (Min) mice continuously with the DNA methylation inhibitor zebularine in their drinking water to determine the effects of the drug on normal mouse development as well as cancer prevention. Zebularine caused a tissue-specific reduction in DNA methylation at B1 short interspersed nucleotide elements in the small and large intestines of female Min mice but not in other organs examined after chronic oral treatment. No significant difference in the average weights of mice was observed during the treatment. In addition, analysis of global gene expression of colonic epithelial cells from the females indicated that only 3% to 6% of the genes were affected in their expression. We did not detect toxicity and abnormalities from the histopathologic analysis of liver and intestinal tissues. Lastly, we tested whether prevention of tumorigenesis can be achieved with chronic oral administration of zebularine in Min mice. The average number of polyps in Min females decreased from 58 to 1, whereas the average polyp number remained unaffected in Min males possibly due to differential activity of aldehyde oxidase. Taken together, our results show for the first time that long-term oral administration of zebularine causes a gender-specific abrogation of intestinal tumors while causing a tissue-specific DNA demethylation. Importantly, prolonged treatment of mice with epigenetic drugs resulted in only minor developmental and histologic changes.

Supplementary Figure 7. Pathological evaluation of tissues following chronic treatment of NEO212

Perspective from Long-term Epigenetic Therapy with Oral Zebularine Has Minimal Side Effects and Prevents Intestinal Tumors in Mice

Patients with glioblastoma multiforme (GBM), a malignant primary brain tumor, inevitably develop resistance to standard-of-care chemotherapy, temozolomide. This study explores the effects of the novel agent NEO212, a conjugate of temozolomide to perillyl alcohol, on temozolomide-resistant gliomas. NEO212 was tested for cytotoxic activity on three human temozolomide-resistant glioma cell lines, which were resistant to temozolomide based on overexpression of the base excision repair (BER) pathway, mismatch repair (MMR) deficiency, or overexpression of O6 methyl-guanine-DNA methyltransferase (MGMT). BER expression was evaluated by Western blotting and PARP activity. MMR deficiency was determined by Western blotting and microsatellite instability. MGMT overexpression was evaluated by Western blotting and O6-benzylguanine (O6BG) inhibition. For in vivo evaluation of NEO212, temozolomide-resistant glioma cells were implanted into immune-incompetent mice, and NEO212 was administered. NEO212, at equimolar concentrations of temozolomide, was more cytotoxic for temozolomide-resistant cells than temozolomide and not toxic to normal cells. NEO212-induced cell death in temozolomide-resistant glioma cells was independent of such mechanisms of resistance as high levels of MGMT, MMR deficiencies, or overexpression of BER proteins. NEO212 functions as a DNA alkylating agent, similar to temozolomide; however, this novel conjugate is unique for it may induce endoplasmic reticulum (ER) stress and inhibits autophagy. In vivo studies show that NEO212 reduces intracranial tumor growth and increases animal survival without significant toxicity. These results demonstrate that NEO212 is an effective drug against malignant gliomas that can be used for a broad range of newly diagnosed and temozolomide-resistant gliomas. Mol Cancer Ther; 13(8); 2004–17. ©2014 AACR.

Epithelial ovarian cancer (EOC) is a leading cause of cancer-related mortality in the United States due to the late-stage disease at diagnosis. Overexpression of GRP78 and PDI following endoplasmic reticulum (ER) stress and activation of the unfolded protein response (UPR) promote growth and invasion in cancer. To identify novel prognostic biomarkers in EOC, here we determined the expression of ER stress-associated proteins (GRP78, ATF6 and PERK) and correlated with clinical outcome in EOC. Tissue microarray (TMA) samples from 415 tissues collected from three cancer centers (UM, USC, and KCCRI) were used to assess the expression levels of ER-associated proteins using immunohistochemistry (IHC). We observed that the expression levels of GRP78 (p p p p p = 0.03), while low expression of combined GRP78 and PDI correlated with better survival (p = 0.01) in high-grade serous. The increased expression of ER stress-associated proteins in EOC suggests a role for ER stress and the UPR in EOC. More importantly, our results demonstrate that GRP78 and PDI are potential biomarkers for EOC and could be used as dual prognostic markers.

The two homologous estrogen receptors ERα and ERβ exert distinct effects on their cognate tissues. Previous work from our laboratory identified an ERβ-specific phosphotyrosine residue that regulates ERβ transcriptional activity and antitumor function in breast cancer cells. To determine the physiological role of the ERβ phosphotyrosine residue in normal tissue development and function, we investigated a mutant mouse model (Y55F) whereby this particular tyrosine residue in endogenous mouse ERβ is mutated to phenylalanine. While grossly indistinguishable from their wild-type littermates, mutant female mice displayed reduced fertility, decreased ovarian follicular cell proliferation, and lower progesterone levels. Moreover, mutant ERβ from female mice during superovulation is defective in activating promoters of its target genes in ovarian tissues. Thus, our findings provide compelling genetic and molecular evidence for a role of isotype-specific ERβ phosphorylation in mouse ovarian development and function.

Lung cancer is the leading cause of cancer mortality worldwide and KRAS is the most commonly mutated gene in lung adenocarcinoma (LUAD). The 78-kDa glucose-regulated protein GRP78/BiP is a key endoplasmic reticulum (ER) chaperone protein and a major pro-survival effector of the unfolded protein response (UPR). Analysis of the Cancer Genome Altas (TCGA) database and immunostain of patient tissues revealed that compared to normal lung, GRP78 expression is generally elevated in human lung cancers, including tumors bearing the KRAS(G12D) mutation. To test the requirement of GRP78 in human lung oncogenesis, we generated mouse models containing floxed Grp78 and Kras Lox-Stop-Lox G12D (Kras(LSL-G12D)) alleles. Simultaneous activation of the Kras(G12D) allele and knockout of the Grp78 alleles were achieved in the whole lung or selectively in lung alveolar epithelial type 2 cells known to be precursors for adenomas which progress to LUAD. Here we report that GRP78 haploinsufficiency is sufficient to suppress Kras(G12D)-mediated lung tumor progression and prolong survival. Furthermore, GRP78 knockdown in human lung cancer cell line A427 (Kras(G12D/+)) leads to activation of UPR and apoptotic markers and loss of cell viability. Our studies provide evidence that targeting GRP78 represents a novel therapeutic approach to suppress mutant KRAS-mediated lung tumorigenesis.

Women-specific cancers are a major health issue, particularly those associated with the BRCA1 germline mutation carrier state, which include triple-negative basal breast carcinomas and high-grade serous ovarian carcinomas (referred to as extra-uterine Müllerian carcinomas). Whereas many chronic diseases can currently be prevented (e.g., cardiovascular diseases), no recent tangible progress was made in cancer prevention of BRCA1 mutation carriers apart from surgical resections of at-risk organs. This lack of progress is largely due to (1) poor understanding of the initiating events triggered by known risk factors in the development of these cancers, (2) the fact that current preventive measures rely on evidence obtained from adjuvant breast cancer treatment that fail to protect against poor prognostic cancers, and (3) problems with using cancer incidence in high-risk women as an ethically justifiable endpoint in cancer prevention trials. Here, we propose that cancer predisposition in BRCA1 mutation carriers is driven, at least in part, by cell-nonautonomous mechanisms (i.e., driven by consequences of this carrier state on hormonal and other systemic factors controlled in organs other than those that are cancer-prone) and that biomarkers of epigenomic reprogramming, hypothesized to be a direct consequence of such cell-nonautonomous mechanisms, are attractive as intermediate surrogate endpoints to assess the efficacy of cancer risk-reducing strategies targeting these mechanisms.

AXL is one of the TAM (TYRO3, AXL and MERTK) receptor tyrosine kinases and may be involved in airway inflammation. Little is known about how epigenetic changes in AXL may affect lung development du...

We previously described an in vitro model in which serous ovarian cystadenomas were transfected with SV40 large T antigen, resulting in loss of RB and P53 functions and thus mimicking genetic defects present in early high-grade serous extra-uterine Mullerian (traditionally called high-grade serous ovarian) carcinomas including those associated with the BRCA1 mutation carrier state. We showed that replicative aging in this cell culture model leads to a mitotic arrest at the spindle assembly checkpoint. Here we show that this arrest is due to a reduction in microtubule anchoring that coincides with decreased expression of the BUB1 kinase and of the phosphorylated form of its substrate, BUB3. The ensuing prolonged mitotic arrest leads to cohesion fatigue resulting in cell death or, in cells that recover from this arrest, in cytokinesis failure and polyploidy. Down-regulation of BRCA1 to levels similar to those present in BRCA1 mutation carriers leads to increased and uncontrolled microtubule anchoring to the kinetochore resulting in overcoming the spindle assembly checkpoint. Progression to anaphase under those conditions is associated with formation of chromatin bridges between chromosomal plates due to abnormal attachments to the kinetochore, significantly increasing the risk of cytokinesis failure. The dependence of this scenario on accelerated replicative aging can, at least in part, account for the site specificity of the cancers associated with the BRCA1 mutation carrier state, as epithelia of the mammary gland and of the reproductive tract are targets of cell-nonautonomous consequences of this carrier state on cellular proliferation associated with menstrual cycle progressions.

Background Epigenetic modifications, including DNA methylation, act as one potential mechanism underlying the detrimental effects associated with prenatal tobacco smoke (PTS) exposure. Methylation in a gene called AXL was previously reported to differ in response to PTS. Methods We investigated the association between PTS and epigenetic changes in AXL and how this was related to childhood asthma phenotypes. We tested the association between PTS and DNA methylation at multiple CpG loci of AXL at birth using Pyrosequencing in two separate study populations, the Children’s Health Study (CHS, n = 799) and the Newborn Epigenetic Study (NEST, n = 592). Plasma cotinine concentration was used to validate findings with self-reported smoking status. The inter-relationships among AXL mRNA and miR-199a1 expression, PTS, and AXL methylation were examined. Lastly, we evaluated the joint effects of AXL methylation and PTS on the risk of asthma and related symptoms at age 10 years old. Results PTS was associated with higher methylation level in the AXL gene body in both CHS and NEST subjects. In the pooled analysis, exposed subjects had a 0.51% higher methylation level in this region compared to unexposed subjects (95% CI 0.29, 0.74; p

// Stefan Kiechl 1 , Daniel Schramek 2,3 , Martin Widschwendter 4 , Evangelia-Ourania Fourkala 4 , Alexey Zaikin 4,5 , Allison Jones 5 , Bernadette Jaeger 4 , Brigitte Rack 4 , Wolfgang Janni 6 , Christoph Scholz 7 , Johann Willeit 1 , Siegfried Weger 8 , Agnes Mayr 8 , Andrew Teschendorff 9 , Adam Rosenthal 10 , Lindsay Fraser 5 , Susan Philpott 5 , Louis Dubeau 11 , Mohammed Keshtgar 12 , Rebecca Roylance 10 , Ian J. Jacobs 4,13 , Usha Menon 4 , Georg Schett 14 and Josef M. Penninger 2 1 Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria 2 IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria 3 The Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada 4 Department of Women’s Cancer, EGA Institute of Women’s Health, University College London, London, United Kingdom 5 Department of Mathematics, University College London, London, United Kingdom 6 Department of Gynecology and Obstetrics, University Duesseldorf, Duesseldorf, Germany 7 Heinrich-Heine-University Dusseldorf, Dusseldorf, Germany 8 Department of Internal Medicine, Bruneck Hospital, Bruneck, Italy 9 Statistical Genomics Group, Paul O’Gorman Building, UCL Cancer Institute, University College London, London, United Kingdom 10 Barts Cancer Institute CR UK Centre of Excellence, Queen Mary University of London, Charterhouse Square, London, United Kingdom 11 Department of Pathology, USC/Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, USA 12 Department of Surgery, Royal Free and University College London Medical School, London, United Kingdom 13 UNSW Australia, Sydney, New South Wales, Australia 14 Department of Internal Medicine 3, University of Erlangen-Nuremberg, Erlangen, Germany Correspondence to: Josef M. Penninger, email: // Keywords : breast cancer, RANKL/RANK, Gerotarget Received : October 10, 2016 Accepted : December 05, 2016 Published : December 18, 2016 Abstract Breast cancer is the most common female cancer, affecting approximately one in eight women during their lifetime in North America and Europe. Receptor Activator of NF-kB Ligand (RANKL), its receptor RANK and the natural antagonist osteoprotegerin (OPG) are essential regulators of bone resorption. We have initially shown that RANKL/RANK are essential for hormone-driven mammary epithelial proliferation in pregnancy and RANKL/RANK have been implicated in mammary stem cell biology. Using genetic mouse-models, we and others identified the RANKL/RANK system as a key regulator of sex hormone, BRCA1 -mutation, and oncogene-driven breast cancer and we proposed that RANKL/RANK might be involved in the initiation of breast tumors. We now report that in postmenopausal women without known genetic predisposition, high RANKL and progesterone serum levels stratify a subpopulation of women at high risk of developing breast cancer 12-24 months before diagnosis (5.33-fold risk, 95%CI 1.5-25.4; P= 0.02). In women with established breast cancer, we demonstrate that RANKL/OPG ratios change dependent on the presence of circulating tumor cells (CTCs). Finally, we show in a prospective human breast cancer cohort that alterations in RANKL/OPG ratios are significantly associated with breast cancer manifestation. These data indicate that the RANKL/RANK/OPG system is deregulated in post-menopausal women at high risk for breast cancer and in women with circulating tumor cells. Thus, serum levels of RANKL/OPG are potentially indicative of predisposition and progression of breast cancer in humans. Advancement of our findings towards clinical application awaits prior validation in independent patient cohorts.

// Jieli Shen 1 , Lijing Yao 1 , Yvonne G. Lin 2 , Francesco J. DeMayo 3 , John P. Lydon 3 , Louis Dubeau 4 , Amy S. Lee 1 1 Department of Biochemistry and Molecular Biology, USC Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA 2 Division of Gynecologic Oncology, Department of Obstetrics-Gynecology, USC Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA 3 Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA 4 Department of Pathology, USC Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA Correspondence to: Amy S. Lee, e-mail: amylee@usc.edu Keywords: endometrial cancer, PTEN, glucose-regulated protein 94 (GRP94), squamous cell metaplasia, β-catenin Received: December 23, 2015 Accepted: January 30, 2016 Published: February 17, 2016 ABSTRACT Endometrial carcinoma is the most prevalent gynecologic cancer in the United States. The tumor suppressor gene Pten (phosphatase and tensin homolog) is commonly mutated in the more common type 1 (endometrioid) subtype. The glucose-regulated protein 94 (GRP94) is emerging as a novel regulator for cancer development. Here we report that expression profiles from the Cancer Genome Atlas (TCGA) showed significantly increased Grp94 mRNA levels in endometrial tumor versus normal tissues, correlating with highly elevated GRP94 protein expression in patient samples and the requirement of GRP94 for maintaining viability of human endometrioid adenocarcinoma (EAC) cell lines. Through generation of uterus-specific knockout mouse models with deletion of Grp94 alone ( c94 f/f ) or in combination with Pten ( cP f/f 94 f/f ), we discovered that c94 f/f uteri induced squamous cell metaplasia (SCM) and reduced active nuclear β-catenin. The cP f/f 94 f/f uteri showed accelerated SCM and suppression of PTEN-null driven EAC, with reduced cellular proliferation, attenuated β-catenin signaling and decreased AKT/S6 activation in the SCM. In contrast to single PTEN knockout uteri ( cP f/f ), cP f/f 94 f/f uteri showed no decrease in E-cadherin level and no invasive lesion. Collectively, our study implies that GRP94 downregulation induces SCM in EAC and suppresses AKT/S6 signaling, providing a novel mechanism for suppressing EAC progression.

AXL is one of the TAM (TYRO3, AXL and MERTK) receptor tyrosine kinases and may be involved in airway inflammation. Little is known about how epigenetic changes in AXL may affect lung development during adolescence. We investigated the association between AXL DNA methylation at birth and lung function growth from 10 to 18 years of age in 923 subjects from the Children’s Health Study (CHS). DNA methylation from newborn bloodspots was measured at multiple CpG loci across the regulatory regions of AXL using Pyrosequencing. Linear spline mixed-effects models were fitted to assess the association between DNA methylation and 8-year lung function growth. Findings were evaluated for replication in a separate population of 237 CHS subjects using methylation data from the Illumina HumanMethylation450 (HM450) array when possible. A 5% higher average methylation level of the AXL promoter region at birth was associated with a 48.4 ml decrease in mean FEV(1) growth from 10 to 18 years of age in the primary study population (95% CI: −100.2, 3.4), and a 53.9 ml decrease in mean FEV(1) growth from 11 to 15 years of age in the replication population (95% CI: −104.3, −3.5). One CpG locus in the promoter region, cg10564498, was significantly associated with decreased growth in FEV(1), FVC and MMEF from 10 to 18 years of age and the negative associations were observed in a similar age range in the replication population. These findings suggest a potential association between AXL promoter methylation at birth and lower lung function growth during adolescence.

// Soma Samanta 1 , Shuzo Tamura 1 , Louis Dubeau 2 , Paulette Mhawech-Fauceglia 2 , Yohei Miyagi 3 , Hisamori Kato 3 , Rich Lieberman 4 , Ronald J. Buckanovich 4, 5 , Yvonne G. Lin 2, 6 and Nouri Neamati 1 1 Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 2 USC/Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA 3 Kanagawa Cancer Center Research Institute, Yokohama, Japan 4 Department of Internal Medicine, Division of Hematology Oncology, Division of Gynecologic Oncology, University of Michigan, Ann Arbor, Michigan 5 Current/Present affiliation: Magee-Womens Research Institute, University of Pittsburgh, Pittsburgh, PA, USA 6 Current/Present affiliation: Genentech-Roche, South San Francisco, California, USA Correspondence to: Nouri Neamati, email: neamati@umich.edu Keywords: tissue microarray (TMA), ovarian cancer, PDI family proteins, clinical outcome, patient survival Received: June 04, 2017 Accepted: September 07, 2017 Published: October 06, 2017 ABSTRACT Objective: Protein disulfide isomerase (PDI) is an oxidoreductase that is overexpressed in several cancers. PDI family members (PDIs) play a role in various diseases including cancer. Select PDIs were reported as useful markers in other cancers but their expression in ovarian cancer has not been thoroughly assessed. We sought to evaluate the expression of PDI, PDIA6, PDIR, ERp57, ERp72 and AGR3 in ovarian cancer patient samples and examine their prognostic significance. Methods: TMA samples from 415 tissues collected from three cancer centers (UM, USC, and KCCRI) were used to assess the expression levels of PDI family proteins using IHC. Results: We observed significant increases in PDI ( p = 9.16E-36), PDIA6 ( p = 5.51E-33), PDIR ( p = 1.81E-12), ERp57 ( p = 9.13E-07), ERp72 ( p = 3.65E-22), and AGR3 ( p = 4.56E-24) expression in ovarian cancers compared to normal tissues. Expression of PDI family members also increases during disease progression ( p

Pancreatic ductal adenocarcinoma (PDAC) remains a highly lethal disease in critical need of new therapeutic strategies. Here, we report that the stress-inducible 78-kDa glucose-regulated protein (GRP78/HSPA5), a key regulator of endoplasmic reticulum homeostasis and PI3K/AKT signaling, is overexpressed in the acini and PDAC of Pdx1-Cre;KrasG12D/+;p53f/+ (PKC) mice as early as 2 mo, suggesting that GRP78 could exert a protective effect on acinar cells under stress, as during PDAC development. The PKC pancreata bearing wild-type Grp78 showed detectable PDAC by 3 mo and rapid subsequent tumor growth. In contrast, the PKC pancreata bearing a Grp78f/+ allele (PKC78f/+ mice) expressing about 50% of GRP78 maintained normal sizes during the early months, with reduced proliferation and suppression of AKT, S6, ERK, and STAT3 activation. Acinar-to-ductal metaplasia (ADM) has been identified as a key tumor initiation mechanism of PDAC. Compared with PKC, the PKC78f/+ pancreata showed substantial reduction of ADM as well as pancreatic intraepithelial neoplasia-1 (PanIN-1), PanIN-2, and PanIN-3 and delayed onset of PDAC. ADM in response to transforming growth factor α was also suppressed in ex vivo cultures of acinar cell clusters isolated from mouse pancreas bearing targeted heterozygous knockout of Grp78 (c78f/+ ) and subjected to 3D culture in collagen. We further discovered that GRP78 haploinsufficiency in both the PKC78f/+ and c78f/+ pancreata leads to reduction of epidermal growth factor receptor, which is critical for ADM initiation. Collectively, our studies establish a role for GRP78 in ADM and PDAC development.

GRP78, a multifunctional protein with potent cytoprotective properties, is an emerging therapeutic target to combat cancer development, progression and drug resistance. The biological consequences of prolonged reduction in expression of this essential chaperone which so far has been studied primarily in young mice, was investigated in older mice, as older individuals are likely to be important recipients of anti-GRP78 therapy. We followed cohorts of Grp78+/+ and Grp78+/− male and female mice up to 2 years of age in three different genetic backgrounds and characterized them with respect to body weight, organ integrity, behavioral and memory performance, cancer, inflammation and chemotoxic response. Our results reveal that body weight, organ development and integrity were not impaired in aged Grp78+/− mice. No significant effect on cancer incidence and inflammation was observed in aging mice. Interestingly, our studies detected some subtle differential trends between the WT and Grp78+/− mice in some test parameters dependent on gender and genetic background. Our studies provide the first evidence that GRP78 haploinsufficiency for up to 2 years of age has no major deleterious effect in rodents of different genetic background, supporting the merit of anti-GRP78 drugs in treatment of cancer and other diseases affecting the elderly.

Patients with glioblastoma multiforme (GBM), a malignant primary brain tumor, inevitably develop resistance to standard-of-care chemotherapy, temozolomide. This study explores the effects of the novel agent NEO212, a conjugate of temozolomide to perillyl alcohol, on temozolomide-resistant gliomas. NEO212 was tested for cytotoxic activity on three human temozolomide-resistant glioma cell lines, which were resistant to temozolomide based on overexpression of the base excision repair (BER) pathway, mismatch repair (MMR) deficiency, or overexpression of O6 methyl-guanine-DNA methyltransferase (MGMT). BER expression was evaluated by Western blotting and PARP activity. MMR deficiency was determined by Western blotting and microsatellite instability. MGMT overexpression was evaluated by Western blotting and O6-benzylguanine (O6BG) inhibition. For in vivo evaluation of NEO212, temozolomide-resistant glioma cells were implanted into immune-incompetent mice, and NEO212 was administered. NEO212, at equimolar concentrations of temozolomide, was more cytotoxic for temozolomide-resistant cells than temozolomide and not toxic to normal cells. NEO212-induced cell death in temozolomide-resistant glioma cells was independent of such mechanisms of resistance as high levels of MGMT, MMR deficiencies, or overexpression of BER proteins. NEO212 functions as a DNA alkylating agent, similar to temozolomide; however, this novel conjugate is unique for it may induce endoplasmic reticulum (ER) stress and inhibits autophagy. In vivo studies show that NEO212 reduces intracranial tumor growth and increases animal survival without significant toxicity. These results demonstrate that NEO212 is an effective drug against malignant gliomas that can be used for a broad range of newly diagnosed and temozolomide-resistant gliomas. Mol Cancer Ther; 13(8); 2004–17. ©2014 AACR.

No present therapy effectively impacts overall survival of advanced ovarian cancer (OC). The current standard-of-care includes surgical debulking followed by combination intravenous (IV) or intraperitoneal (IP) chemotherapy. Although there is increasing interest in IP chemotherapy, side effects from cytotoxic agents result in a significant percentage of women discontinuing treatment. We propose to examine the efficacy of IP administration of a novel non-cytotoxic, non-immunogenic, anti-invasive peptide called vicrostatin (Mol. Wt. 7,146). We investigated the clinical translational potential of this disintegrin, which was conceived, produced and developed in our laboratory. Vicrostatin is produced recombinantly using a bacterial system in amounts sufficient for clinical trials. It has high binding affinity for a number of RGD (Arg-Gly-Asp)-integrins, including αvβ3, αvβ5, α5β1 and αIIbβ3. Vicrostatin disruption of the actin cytoskeleton, which occurs exclusively in motile cells (cancer and angiogenic endothelial cells), accounts for its mechanism of action. We showed lack of toxicity following vicrostatin introduction into rodents. We used several different experimental animal models to demonstrate the efficacy of vicrostatin in ovarian cancer. We compared saline and Oxiplex formulations for IP delivery of vicrostatin in mouse models. Oxiplex, a hydrogel composed of polyethylene oxide and carboxymethyl cellulose, stabilized by CaCl2, is impregnated with vicrostatin; incorporation of vicrostatin at 2-10 mg/ml results in its sustained release for 10-12 days. We eventually settled on a 5 mg/week (250mg/kg) dose per mouse and compared efficacies of Oxiplex versus saline in animals harboring IP xenografts (10 animals per group) of SKOV3GFP/LUC spheroids (2x106 cell equivalents); the spheroids were allowed to implant for 4 days before treatment with weekly IP injections of either 5 mg of vicrostatin in 1 ml saline, 5mg of vicrostatin in 1 ml of Oxiplex, or 1 ml of Oxiplex alone (control). After one-month animals in Oxiplex alone group showed extensive and widespread cancer cell dissemination based on bioluminescent imaging and findings at autopsy. Vicrostatin-saline and vicrostatin-Oxiplex treatments resulted in dramatically less or, in some animals, no grossly visible tumor foci and in ~95-98% reduction in bioluminescent signals. These results were reproduced in three independent experiments and suggest that both delivery modalities are similarly effective. An advantage of the Oxiplex formulation is its ability to prevent post-surgical adhesions, a frequent complication of gynecological surgery. We are presently using RNAseq technologies to investigate changes in expression of genes involved in intracellular pathways suspected to represent predictive biomarkers of ovarian cancer response to vicrostatin therapy in xenografts of SKOV3 ovarian cancer cells. The results will enhance our understanding of pathways targeted by vicrostatin and provide biomarkers of clinical responsiveness in future clinical trials. Citation Format: Franics S Markland, Steve Swenson, Radu Minea, Louis Dubeau. A novel integrin-targeted therapeutic agent for ovarian cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr C032. doi:10.1158/1535-7163.TARG-19-C032

Incessant menstrual cycle activity, uninterrupted by either pregnancy or oral contraceptive use, is the most important risk factor for sporadic ovarian cancer. Menstrual cycle progression is partly controlled by steroid hormones such as estrogens and others that are secreted by the ovarian granulosa cells. We showed earlier that mice carrying a homozygous granulosa cell-specific knockout of Brca1, the homolog of BRCA1 that is associated with familial ovarian cancer predisposition in humans, develop benign epithelial tumors in their reproductive tract. These tumors are driven, at least in part, by a prolongation of the proestrus phase of the estrus cycle (equivalent to the follicular phase of the menstrual cycle) in Brca1 mutant mice, resulting in prolonged unopposed estrogen stimulation. Mutant mice synchronized in proestrus also showed increased circulating estradiol levels, but the possibility that this change also has a role in tumor predisposition was not investigated. We sought to determine whether these changes in hormonal stimulation result in measurable changes in tissues targeted by estrogen outside the ovary. Here we show that mice carrying a Brca1 mutation in their ovarian granulosa cells show increased endometrial proliferation during proestrus, implying that the effects of Brca1 inactivation on estrogen stimulation have short-term consequences, at least on this target organ. We further show that mutant mice develop increased femoral trabecular thickness and femoral length, which are well-known consequences of chronic estrogen stimulation. Estrogen biosynthesis by granulosa cells was increased not only in mice carrying a homozygous Brca1 mutation, but also in heterozygous mutants mimicking the mutational status in granulosa cells of human BRCA1 mutation carriers. The results suggest that human germline BRCA1 mutations, although associated with increased cancer risk, may also have beneficial consequences, such as increased bone strength, that may have contributed to the maintenance of mutated BRCA1 alleles in the human gene pool.

Cancers that develop in BRCA1 mutation carriers are usually near tetraploid/polyploid. This led us to hypothesize that BRCA1 controls the mitotic checkpoint complex, as loss of such control could lead to mitotic errors resulting in tetraploidy/polyploidy and subsequent aneuploidy. We used an in vitro system mimicking premalignant conditions, consisting of cell strains derived from the benign counterparts of serous ovarian carcinomas (cystadenomas) and expressing SV40 large T antigen, conferring the equivalent of a p53 mutation. We previously showed that such cells undergo one or several doublings of their DNA content, as they age in culture and approach the phenomenon of in vitro crisis. Here, we show that such increase in DNA content reflects a cell cycle arrest possibly at the anaphase promoting complex, as evidenced by decreased BrdU incorporation and increased expression of the mitotic checkpoint complex. Down-regulation of BRCA1 in cells undergoing crisis leads to activation of the anaphase promoting complex and resumption of growth kinetics similar to those seen in cells before they reach crisis. Cells recovering from crisis after BRCA1 down-regulation become multinucleated, suggesting that reduced BRCA1 expression may lead to initiation of a new cell cycle without completion of cytokinesis. This is the first demonstration that BRCA1 controls a physiological arrest at the M phase apart from its established role in DNA damage response, a role that could represent an important mechanism for acquisition of aneuploidy during tumor development. This may be particularly relevant to cancers that have a near tetraploid/polyploid number of chromosomes.

The immunophenotype of BRCA-associated breast cancer has been studied in predominantly non-Hispanic whites (NHW). We evaluated the pathological characteristics of BRCA-associated invasive breast cancer in Hispanics. A case–control study was conducted on breast cancers from Hispanic and NHW women who enrolled in an IRB-approved registry and underwent BRCA gene analysis. BRCA negative controls (41 Hispanic, 39 NHW) were matched on age and ethnicity to BRCA positive cases (39 Hispanic, 35 NHW). A tissue array was constructed to characterize the expression of estrogen receptor (ER), progesterone receptor (PR), HER2, Ki-67 and p53 by immunohistochemistry. Mean age at diagnosis was 37.1 years (range 24–59) for Hispanics (80% with Mexican ancestry) and 40.1 years (range 21–63) for NHW (P = 0.03). Hispanic BRCA1 cases were more likely than BRCA negative controls to have tumors that were ER-negative (P

672 Background: While there is accumulating evidence that tumor specific mutations can be accurately detected in cfDNA, the determination of MSI status in cfDNA has not been investigated, perhaps because the complexity of detecting tumor instability embedded within stutter amplification patterns generated from normal cfDNA was considered too challenging to allow the detection of altered microsatellite profiles. We explored the possibility of detecting MSI in cfDNA. Methods: Circulating cfDNA was isolated from Streck tubes from 13 patients with CRC; 6 pts had serial collections. Isolation and testing of cfDNA for MSI was performed using kits purchased from Promega. Microsatellite alterations were scored by comparing the amplicon stutter profiles of 5 mononucleotide markers generated from cfDNA to those present in genomic DNA extracted from buffy coats from the same pts. MSI was diagnosed based on a shift in the size of a predominant stutter peak together with a commensurate shift in the stutter profile resulting in the appearance of at least one new stutter in tumor-derived DNA compared to matched germline DNA. MSI was scored high when 30% or more of the markers showed MSI or low if present in less than 30% of the biomarkers examined. Results: No MSI was detected in 3 pts with microsatellite stable tumors and 2 Lynch syndrome pts with no evidence of disease. Five of six pts with MSI high tumors (sporadic and Lynch syndrome) had a detectable MSI high biomarker profile in cfDNA at baseline. Four pts with positive MSI in cfDNA started immunotherapy and had a decline in the relative amounts of tumor-derived microsatellite alleles in their subsequent specimens. The pt with MSI high in the primary tumor and no MSI in cfDNA had rapid progression on immunotherapy. Two other pts with MSI high who responded deeply to check point inhibitors had no evidence of MSI in cfDNA at the time of their specimen collection. In each case with MSI in cfDNA, the electrophoretic profile matched that in the respective primary tumor. Conclusions: Detection of MSI in cfDNA is feasible and may be reflective of burden of the disease. A prospective study to establish the validity of cfDNA in the diagnosis and follow up care in pts with metastatic CRC is planned.

Neurodegenerative diseases are often associated with dysfunction in protein quality control. The endoplasmic reticulum (ER), a key site for protein synthesis, senses stressful conditions by activating the unfolded protein response (UPR). In this study we report the creation of a novel mouse model in which GRP78/BiP, a major ER chaperone and master regulator of UPR, is specifically eliminated in Purkinje cells (PCs). GRP78-depleted PCs activate UPR including the induction of GRP94, PDI, CHOP and GADD34, feedback suppression of eIF2alpha phosphorylation and apoptotic cell death. In contrast to current models of protein misfolding in which an abnormal accumulation of ubiquitinated protein is prominent, cytosolic ubiquitin staining is dramatically reduced in GRP78-null PCs. Ultrastructural evaluation reveals that the ER shows prominent dilatation with focal accumulation of electron-dense material within the ER. The mice show retarded growth and severe motor coordination defect by week 5 and cerebellar atrophy by week 13. Our studies uncover a novel link between GRP78 depletion and reduction in cytosolic ubiquitination and establish a novel mouse model of accelerated cerebellar degeneration with basic and clinical applications.

Hypomethylation of DNA repeats, including satellite 2 DNA (Sat2), is one of the most frequent epigenetic changes in cancer. We examined ovarian epithelial tumors and diverse control tissues for methylation on only one strand (hemimethylation), both strands (symmetrical methylation), or neither strand at Sat2 CpG dyads using hairpin genomic sequencing. Analysis of the resulting cloned DNA molecules indicated that although carcinomas displayed much symmetrical hypomethylation of CpG dyads, there was cancer-linked hypermethylation at one of the thirteen dyads in the examined 0.2 kb Sat2 region. Hemimethylated sites were seen in both carcinomas and controls but, importantly, in carcinoma DNA molecules, they were significantly more likely to occur in clusters displaying the same orientation (the same strand methylated). Our data suggest that hemimethylated CpG dyads are intermediates in active demethylation during carcinogenesis and not just due to a failure of maintenance methylation during replicative DNA synthesis. Constitutive heterochromatin may be especially suitable for providing a snapshot of demethylation intermediates because hemimethylation might be more long-lived in heterochromatin due to its highly condensed state.

Although ovarian epithelial tumors are widely believed to arise in the coelomic epithelium that covers the ovarian surface, it was also suggested that they could instead arise from tissues that are embryologically derived from the mullerian ducts. This article revisits this debate based on recent epidemiological and molecular biological observations as well as evidence based on histopathological observations of surgical specimens from individuals with familial ovarian cancer predisposition. Morphological, embryological, and molecular biological characteristics of ovarian epithelial tumors that must be accounted for in formulating a theory about their cell of origin are reviewed, followed by comments about the ability of these two hypotheses to account for each of these characteristics. An argument is made that primary ovarian epithelial tumors fallopian tube carcinomas, and primary peritoneal carcinomas are all mullerian in nature and could therefore be regarded as a single disease entity. Although a significant proportion of cancers presently regarded as of primary ovarian origin arise in the fimbriated end of the fallopian tube, this site cannot account for an equally significant proportion of these tumors, which are most likely derived from components of the secondary mullerian system.

Cell cultures of ovarian cystadenomas transfected with SV40 large T antigen are not immortal because they invariably reach a phenomenon called crisis, which is triggered in part by telomere attrition. Recovery from crisis may be an integral component of the malignant transformation process. We reported earlier that such ovarian cystadenoma cell cultures undergo severe changes in DNA ploidy as they approach crisis and that such changes are an important determinant of crisis independent of telomere attrition. Here, we show that in sharp contrast to these benign ovarian tumours, the DNA content of ovarian tumours of low malignant potential (LMP) was remarkably stable as they approached crisis, suggesting that telomere attrition was the main determinant of this mortality checkpoint. Lack of a ploidy-based crisis was not due to loss of expression of a functional SV40 large T antigen protein. We conclude that ovarian LMP tumours are characterised by increased numerical chromosomal stability compared to cystadenomas. This might account for the fact that most LMP tumours are diploid or near diploid in vivo. This fundamental difference in chromosomal stability between ovarian cystadenomas and LMP tumours also suggests potential differences in predisposition to progression to malignancy between these two ovarian tumour subtypes.

Huntington disease is caused by the expansion of a CAG repeat encoding an extended glutamine tract in a protein called huntingtin. Here, we provide evidence supporting the hypothesis that somatic increases of mutation length play a role in the progressive nature and cell-selective aspects of HD pathogenesis. Results from micro-dissected tissue and individual laser-dissected cells obtained from human HD cases and knock-in HD mice indicate that the CAG repeat is unstable in all cell types tested although neurons tend to have longer mutation length gains than glia. Mutation length gains occur early in the disease process and continue to accumulate as the disease progresses. In keeping with observed patterns of cell loss, neuronal mutation length gains tend to be more prominent in the striatum than in the cortex of low-grade human HD cases, less so in more advanced cases. Interestingly, neuronal sub-populations of HD mice appear to have different propensities for mutation length gains; in particular, smaller mutation length gains occur in nitric oxide synthase-positive striatal interneurons (a relatively spared cell type in HD) compared with the pan-striatal neuronal population. More generally, the data demonstrate that neuronal changes in HD repeat length can be at least as great, if not greater, than those observed in the germline. The fact that significant CAG repeat length gains occur in non-replicating cells also argues that processes such as inappropriate mismatch repair rather than DNA replication are involved in generating mutation instability in HD brain tissue.

Serous extra-uterine Müllerian tumors include lesions previously classified either as serous ovarian, fimbrial, or primary peritoneal tumors. They should be distinguished from intra-uterine (endometrial) serous tumors in spite of their common Müllerian differentiation lineage due to distinctive clinical-pathological parameters. Increased risk for these cancers is driven primarily by cell non-autonomous hormonal factors associated with menstrual cycle progression, which can be accentuated by mutations in BRCA1/2. Additional factors, such as inflammatory conditions and others, may also contribute to elevated cancer risk in some individuals. The most consistent molecular alterations associated with serous extra-uterine Müllerian carcinomas, whether they arise in the context of familial predisposition or BRCA-independent hormonal factors, include severe aneuploidy superimposed on P53 mutations. Their near polyploid nature strongly suggests a role for mitotic errors associated with cytokinesis failure in their pathogenesis. A molecular mechanism is proposed involving a combination of both cell non-autonomous and cell autonomous factors in the development and progression of serous extra-uterine Müllerian tumors. Cell non-autonomous factors lead to increased cellular proliferation in extra-uterine serous Müllerian epithelium and contribute to the site-specificity of cancers associated with germline BRCA mutations. Cell autonomous factors in individuals with BRCA1 mutations lead to failure of cytokinesis following recovery from a cell cycle arrest at the mitotic spindle assembly checkpoint. In individuals with intact BRCA1/2 function, recovery from such arrest might be facilitated by CCNE1 amplification and ensuing centrosome duplication leading to increased microtubule anchoring, accounting for frequent amplification of this cyclin observed in tumors not associated with BRCA1/2 mutations. The cell non-autonomous factors provide an opportunity for using pharmacological means to control cancer incidence in individuals at elevated risk for these cancers such as BRCA1/2 mutation carriers, underscoring the importance of better understanding their determinants and downstream targets. The cell autonomous factors discussed here account for the molecular features of high-grade serous extra-uterine Müllerian carcinomas, which are regarded as a disease of chromosomes, and underscore the potential merit of targeting components of the spindle assembly checkpoint in their clinical management.

We compared the gene expression profiles of ovarian granulosa cells harboring either mutant or wild type Brca1 to follow up on our earlier observation that absence of a functional Brca1 in these important regulators of menstrual/estrous cycle progression leads to prolongation of the pre-ovulatory phase of the estrous cycle and to increased basal levels of circulating estradiol. Here we show that ovarian granulosa cells from mice carrying a conditional Brca1 gene knockout express substantially higher levels of olfactory receptor mRNA than granulosa cells from wild type littermates. This led us to hypothesize that reproductive functions in mutant female mice might be more sensitive to male-derived scent than in wild type female mice. Indeed, it is well established that isolation from males leads to complete cessation of mouse estrous cycle activity while exposure to olfactory receptor ligands present in male urine leads to resumption of such activity. We found that Brca1 -/- female mice rendered anovulatory by unisexual isolation resumed ovulatory activity more rapidly than their wild type littermates when exposed to bedding from cages where males had been housed. The prime mediator of this increased responsiveness appears to be the ovary and not olfactory neurons. This conclusion is supported by the fact that wild type mice in which endogenous ovaries had been replaced by Brca1-deficient ovarian transplants responded to male-derived scent more robustly than mutant mice in which ovaries had been replaced by wild type ovarian transplants. Our findings not only have important implications for our understanding of the influence of olfactory signals on reproductive functions, but also provide insights into mechanisms whereby genetic risk factors for breast and extra uterine Müllerian carcinomas may influence menstrual activity in human, which is itself an independent risk factor for these cancers.