Citations

Key Points HERC4 is the first identified ubiquitin ligase that mediates c-Maf ubiquitination and degradation. HERC4 suppresses MM cell proliferation and delays MM tumor growth.

Abstract Introduction: The use of multi-drug regimens, including taxanes (T), has increased survival for breast cancer patients. However, T-induced neuropathy, one of the most common side effects, cannot be predicted, prevented or effectively treated. Using genome wide analyses (GWA), we sought to identify common genetic variants that infer susceptibility to clinical and self-reported neuropathy. Methods: Women with high risk breast cancer were enrolled in SWOG 0221, a trial of dosing schedules for AC and T. Genotyping was performed using the Illumina 1M chip and SNPs examined in relation to CTCAE grade 3 and 4 neurotoxicity and self-reported symptoms (FACT-TAXANE) among women providing blood samples. Significant associations were tested for replication in CALGB40101. Results: Among 1269 European Americans (EA) and 139 African Americans (AA) in S0221, there were 147 and 31 grade 3+ neuropathies, respectively. In CALGB40101, grade 3 toxicity was less frequent (59/855 EA and 15/117 AA). In S0221 EA patients, loci on chromosomes 7, 10, 16 and 17 showed associations with grades 3 and 4 neuropathy at p<5×10e-06, with the most significant genetic association on chromosome 17, rs910920, p = 6.8×10e-08, odds ratio (OR) = 0.44 (95% confidence interval (CI), 0.32-0.61); this SNP is a cis eQTL, thought likely to affect transcription factor binding and linked to expression of VPS53 in lymphoblastoid cell lines. While the rs910920 association was specific to EA, the A allele in rs1858826 on chromosome 7 was associated with reduced odds of neuropathy in both EA (p = 7×10e-07) and AA (p = .02) groups. The S0221 associations at p<5×10e-06 did not replicate in CALGB40101. A subset of patients (n = 677 EA and n = 42 AA) completed the FACT-TAXANE. The most significant associations with this neuropathy phenotype (p<5×10e-07) were on chromosomes 2 (rs4267555 and rs4443044) and 3 (rs2421468). Of the 168 SNPs tested for association with neuropathy in previous studies, rs1695 in GSTP1 (p = 0.0009) and rs228591 in ATM (p = 0.0006), showed some evidence of association with FACT-TAXANE scores; the latter SNP was significant at p = .005 in ordinal regression analysis of neuropathy grades 0-4 in CALGB40101. None of these SNPs were significantly associated with grade 3 CTCAE neuropathy at p<.05, nor were the top CTCAE associations in relation to FACT-TAXANE scores. Replication of the most significant S0221 FACT-TAXANE findings in CALGB40101 is ongoing. Conclusions: Failure to replicate S0221 in CALGB40101, and the lack of coherence between self-report and clinical grade in S0221 could be attributable to differences in trial designs as well as differences in defining a complex phenotype. Larger homogeneous trials with similar dosing and criteria for defining neuropathy are needed to assess the relationship of genetics and the neuropathy symptom spectrum. Citation Format: Lara Sucheston-Campbell, Alyssa Clay, William E. Barlow, G Thomas Budd, Dan Stram, Chris Haiman, Li Yan, Gary Zirpoli, Song Yao, Dawn Hershman, Kathy S. Albain, Daniel F. Hayes, Halle Moore, Timothy J. Hobday, James A. Stewart, Claudine Isaacs, Muhammad Salim, Julie R. Gralow, Gabriel N. Hortobagyi, Robert B. Livingston, Xin Sheng, Deanna L. Kroetz, Christine B. Ambrosone. A genome-wide association study identifies novel loci associated with taxane-related sensory neuropathy in breast cancer patients enrolled in a cooperative group clinical trial (SWOG S0221). [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5489. doi:10.1158/1538-7445.AM2015-5489

Abstract Genome-wide association studies (GWAS) of multiple myeloma (MM) in Northern Europeans have identified seven novel risk loci (2p23.3, 3p22.1, 3q26.2, 6p21.33, 7p15.3, 17p11.2, 22q13.1). We performed a multiethnic meta-analysis of these regions in 1,274 MM patients and 1,486 controls of European ancestry (EA) and 1,049 MM patients and 7,080 controls of African ancestry (AA), leveraging the differential linkage-disequilibrium of these populations in order to better localize the putative functional variants. We observed directionally consistent effects for all seven index SNPs in both populations, with four significantly associated (p<0.05) with risk in EAs (3p22.1, 7p15.3, 17p11.2, 22q13.1), and two significantly associated with risk in AAs (7p15.3 and 22q13.1). In a fixed effects meta-analysis of six regions (excluding the HLA region on chromosome 6), variation in five of the regions (2p33.3, 3p22.1, 7p15.3, 17p11.2, 22q13.1) had statistically significant associations with risk (Table 1). In one region, the index variant had the strongest association [rs4487645 at 7p15.3, (OR = 1.30, p = 8.7×10−8)]. Five of the six most significantly associated variants identified in the multiethnic analyses overlapped with biologically relevant features indicating regulatory activity based on CD20+ (B lymphocyte) cells, showing evidence of potential function; those included a missense variant in (17p11.2, rs34562254, Pro251Leu) in TNFRSF13B, which encodes a lymphocyte-specific protein in the tumor necrosis factor receptor family that interacts with the NF-kb pathway. Our study shows that these regions are important in MM risk across ethnicities and further supports the use of multiple ethnic groups in genetic studies to enhance identification of risk variants. Table 1.Most significant associations for each region in the multiethnic meta-analysis.Individuals of European AncestryIndividuals of African AncestryMulitethnic Metar2 with IndexcCHRSNPRAaFreqbORP-valueFreqbORP-valueORP-valueP-het2rs732075G0.591.222.0×10−30.621.122.0×10−21.162.6×10−40.280.09/0.283rs73069394A0.191.243.0×10−30.621.181.5×10−21.201.3×10−50.550.77/0.963rs12637184G0.761.136.0×10−20.921.192.7×10−11.151.0×10−20.640.94/1.007rs4487645C0.671.237.0×10−40.891.485.5×10−51.308.7×10−80.07-d17rs34562254A0.121.452.4×10−50.131.212.2×10−31.312.5×10−60.120.33/0.9022rs139400T0.491.224.0×10−40.531.172.1×10−31.191.2×10−60.630.63/0.96aRisk allelebFrequency of the risk allele in European and African ancestry studiescr2 metrics based on 1000 Genomes Project AFR/EUR populationsdIndex SNP Citation Format: Kristin A. Rand, Chi Song, Eric Dean, Daniel Serie, Karen Curtin, Dennis Hazelett, Amie E. Hwang, Xin Sheng, Alex Stram, David J. Van Den Berg, Carol Ann Huff, Leon Bernal-Mizrachi, Michael H. Tomasson, Sikander Ailawadhi, Anneclaire De Roos, Seema Singhal, Karen Pawlish, Edward Peters, Catherine Bock, David V. Conti, Graham Colditz, Todd Zimmerman, Scott Huntsman, John Graff, African Ancestry Prostate Cancer GWAS Consortium,African Ancestry Breast Cancer GWAS Consortium, Stephen J. Chanock, Michael Lieber, Jayesh Mehta, Eric A. Klein, Nalini Janakiraman, Richard K. Severson, Angela R. Brooks-Wilson, Vincent Rajkumar, Elizabeth E. Brown, Laurence Kolonel, Susan Slager, Brian E. Henderson, Graham G. Giles, John J. Spinelli, Brian Chiu, Kenneth C. Anderson, Jeffrey Zonder, Robert Z. Orlowski, Sagar Lonial, Nicola Camp, Celine Vachon, Elad Ziv, Dan O. Stram, Christopher A. Haiman, Wendy Cozen. Multiple myeloma susceptibility loci examined in African and European ancestry populations. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4629. doi:10.1158/1538-7445.AM2015-4629

Abstract Inhibitors of the proteasome-ubiquitin system have been found to be effective in the clinical management of multiple myeloma. We here describe the compound VLX1570, an optimized lead of the 19S deubiquitinase inhibitor b- AP15. VLX1570 was shown to inhibit the enzymatic activities of both USP14 and UCHL5 in vitro, and was shown to induce accumulation of high molecular weight polyubiquitinated proteins in multiple myeloma cells. The compound showed limited inhibitory activity of a panel of kinases. VLX1570 induces apoptosis and cell death of multiple myeloma cell lines at submicromolar concentrations. Importantly, a multiple myeloma cell line selected for bortezomib resistance was found to be sensitive to VLX1570. VLX1570 was found to be able to overcome apoptosis resistance by these cells. Induction of the phosphorylation of stress-activated kinases (JNK and p38) and inhibition of ERK phosphorylation was observed in multiple myeloma cells. We finally showed that VLX1570 confers antineoplastic activity in two different myeloma xenograft models and conclude that VLX1570 is a candidate agent for treatment of multiple myeloma. Citation Format: Xin Wang, Chitralehka Mohanty, Padraig D'Arcy, Maria Hägg Olofsson, Felicitas Bossler, Asher Chanan-Khan, Stig Linder. Development of the proteasome deubiquitinase inhibitor VLX1570 for treatment of multiple myeloma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4557A. doi:10.1158/1538-7445.AM2015-4557A

Abstract Immunomodulatory drugs (IMiDs) are therapeutically active compounds that bind to the E3 ubiquitin ligase substrate recruiter cereblon (CRBN) and induce many cellular responses, including cytotoxicity. We had found that the expression of CRBN in multiple myeloma (MM) cells provided the basis for their responses to IMiDs. In this report, we have identified argonaute 2 (AGO2) as a new member of CRBN-downstream binding protein and found that: 1) the steady-state levels of CRBN in IMiD-sensitive cells are significantly higher than in IMiD-resistant cells; 2) the steady-state levels of AGO2 in IMiD-sensitive cells are significantly less compared to IMiD-resistant cells, suggesting that CRBN plays a role in regulating AGO2. AGO2 is a component of microRNA (miRNA)-induced silencing complexes and plays an important role in miRNA maturation and function. The matured miRNAs are considered as key regulators of almost all cellular pathways. Treatment of IMiD-sensitive MM cells with lenalidomide, an IMiD, significantly increased CRBN, decreased both AGO2 and miRNAs and inhibited cell growth. In contrast, although treatment of IMiD-resistant MM cells with lenalidomide moderately increased CRBN and decreased both AGO2 and miRNAs, this treatment did not significantly inhibit cell growth. However, silencing of AGO2 with small hairpin RNA significantly decreased both AGO2 and miRNAs and inhibited cell growth regardless of whether the cells are sensitive or resistant to IMiDs. Therefore, AGO2 could be considered as a new drug target for overcoming IMiDs resistance in MM cells. Citation Format: Qinqin Xu, Yuexian Hou, Paul Langlais, Patrick Erickson, James Zhu, Changxin Shi, Moulun Luo, Yuanxiao Zhu, Lawrence Mandarino, Keith Stewart, Xiu-Bao Chang. Expression of CRBN binding protein AGO2 plays important roles for myeloma cell growth. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3625. doi:10.1158/1538-7445.AM2015-3625

Obesity and hypertension are major risk factors for cardiovascular diseases, and their growing coexistence accounts for an increase in adverse cardiac events, but the mechanisms are yet to be determined. We hypothesized that obesity exacerbates mitochondrial dysregulation imposed by hypertension and augments left ventricular dysfunction. Obesity-prone Ossabaw pigs were randomized to lean (standard diet) and obese (high-fat diet), without (Lean-sham and Obese-sham) or with renovascular hypertension (Lean-hypertension and Obese-hypertension), induced after 12 weeks of diet (n=7 each). Cardiac function, myocardial perfusion and oxygenation, and microvascular remodeling were assessed 4 weeks later. Mitochondrial biogenesis signals and structural proteins, respiratory chain complex activities, and mitochondrial self-degradation were examined, as was fibrosis. Obesity alone exerted no apparent effect on mitochondrial dynamics, but aggravated in hypertensive hearts the reduction of mitochondrial proteins, deoxyribonucleic acid content, and respiratory chain complex IV subunits activity, and amplified mitochondrial self-degradation. Synergistic interaction of obesity with hypertension also exacerbated myocardial fibrosis and left ventricular diastolic dysfunction. Mitochondrial content, respiratory chain complex IV subunits activity, and mitophagy were correlated with myocardial fibrosis. These findings suggest that obesity aggravates in renovascular hypertension cardiac mitochondrial aberrations. Mitochondrial function may regulate the progression of cardiac injury and functional deterioration in hypertension concomitant with obesity.

Obesity remains a prominent public health concern. Obesity not only contributes greatly to cardiovascular events but has also been identified to initiate and affect the progression of preexisting chronic kidney disease. The prevalence of renal artery stenosis is growing world-wide, especially in the elderly population and in individuals with atherosclerotic risk factors such as obesity. Prolonged renovascular disease causes inflammation and microvascular remodeling within the post-stenotic kidney, which promote tissue scarring and may account for irreversible renal damage. Obesity has been shown to aggravate kidney damage via several pathways, including exacerbation of microvascular regression and renal cell injury mediated by adipocytes and insulin resistance, thereby worsening the structural and functional outcomes of the kidney in renovascular disease. Dietary modification and inhibition of the renin-angiotensin-aldosterone system have been shown to alleviate obesity-induced tissue injury and remodeling. Possibly, angiogenic factors may boost microvascular repair in the ischemic kidney in the obesity milieu. Novel therapeutic interventions targeting deleterious pathways that are activated by obesity and responsible for kidney damage need to be explored in future studies.