bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5245: Peretinoin prevents the accumulation of somatic gene mutations and reverts neoplastic lesions to normal liver-like in platelet-derived growth factor-c transgenic mice
Authors: Yamashita Taro , Okada Hikari , Honda Masao , Kaneko Shuichi
Published: July 2017

Hepatocellular carcinoma (HCC) develops with progressive accumulation of multiple genetic changes. An acyclic retinoid peretinoin is reported to suppress the development of HCC, but the molecular mechanism in detail remains to be obscure. Here we evaluated the effect of peretinoin on preneoplastic nodules and HCC developed in platelet derived growth factor-c (PDGF-C) transgenic mice liver by gadolinium ethoxybenzyl diethylenetriamide pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) and whole exome sequence analysis. We confirmed the progressive accumulation of somatic mutations in hypervascular liver cancer tissues compared with hypovascular precancerous tissues and non-cancerous background liver tissues in PDGF-C transgenic mice. Surprisingly, peretinoin treatment in HCC as well as preneoplastic nodules resulted in the accumulation of less gene mutations compared with vehicle. Gd-EOB-DTPA uptake capacity and its transporter OATP1 was confirmed to be re-activated in peretinoin treated nodules in mice. Gene and protein expression analysis indicated the inactivation of cell cycle with low Ki-67 labeling indexes in peretinoin treated nodules. The reversion of Gd-EOB-DTPA uptake capacity was confirmed in preneoplastic nodules and a subset of classical hypervascular HCCs. Notably, peretinoin supplementation induced the expression of OATP1B3 in mature hepatocyte-like HCC cell lines in vitro, whereas supplementation of tretinoin (all-trans retinoic acid) had no such effects and rather suppressed OATP1B3. Taken together, our data suggested the utility of peretinoin to revert the malignant transformation processes of hepatocytes by preventing accumulation of gene mutations especially in early stages of hepatocarcinogenesis. Peretinoin but not tretinoin can induce the expression of a mature hepatocyte marker OATP1B3, suggesting that peretinoin may exert its anti-tumor effect with hepatocytic differentiation capacity independently of the activation of retinoic acid signaling.

Note: This abstract was not presented at the meeting.

Citation Format: Taro Yamashita, Hikari Okada, Masao Honda, Shuichi Kaneko. Peretinoin prevents the accumulation of somatic gene mutations and reverts neoplastic lesions to normal liver-like in platelet-derived growth factor-c transgenic mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5245. doi:10.1158/1538-7445.AM2017-5245
Abstract 5246: Effects of bazedoxifene either alone or in combination with letrozole in the prevention of chemically induced mammary cancers
Authors: Dunn Barbara K. , Suen Chen , Lubet Ronald A. , Steele Vernon E. , Grubbs Clinton J.
Published: July 2017

Bazedoxifene is a third-generation selective estrogen receptor modulator (SERM) that has been clinically approved in Europe for the prevention and treatment of postmenopausal osteoporosis. The agent has also been shown to have therapeutic activity against estrogen receptor positive (ER+) breast cancer. Our laboratory is currently evaluating bazedoxifene for chemopreventive efficacy when given alone or in combination with the aromatase inhibitor (AI) letrozole. Initially, the agents were evaluated alone to determine effective chemopreventive doses in the methylnitrosourea (MNU) ER+mammary cancer model using female Sprague-Dawley rats. Bazedoxifene was mixed directly into a standard (Teklad, 4% fat) diet, while letrozole was gavaged 7x/week (vehicle was ethanol: PEG 400, 10:90, v/v). When evaluated alone in rats receiving MNU at 50 days of age, bazedoxifene (started one week after MNU) at doses of 100 and 30 mg/kg diet decreased mammary cancer multiplicity by 93 and 88%, respectively. In a similar protocol, letrozole at a dose of 0.1 mg/kg BW/day reduced cancer number (multiplicity) by 89%, while a dose of 0.05 mg/kg BW/day reduced the number by 47%. In a separate study evaluating lower doses (MNU also given to rats at 50 days of age), bazedoxifene at a dose of 5 mg/kg diet and letrozole at a dose of 0.04 mg/kg BW/day both decreased mammary tumor multiplicity by 73%. When the agents were given in combination at these lower dose levels, cancer number was reduced by 91%. An additional study was done in which the agents were given to rats receiving MNU at an older age (100 days). Rats receiving the agents at the original doses beginning one week after MNU (bazedoxifene at 30 mg/kg diet; letrozole at 0.1 mg/kg BW/day) had identical decreases in mammary tumor development (96%). It is obvious that bazedoxifene is as effective as letrozole in the prevention of mammary cancers even when initiated in older rats. Furthermore, administration of the agents in combination suggests an additive effect. The large increase in body weight gain generally noted in letrozole treated rats was not observed in rats receiving bazedoxifene; of interest, rats receiving the combination also had no increase in body weights. These studies indicate that bazedoxifene may be superior to other SERMs in that chemopreventive efficacy is achieved at low doses, which may be associated with less toxicity. Supported by NCI contract HHSN261201200021I, Task Order HHSN26100007.

Citation Format: Barbara K. Dunn, Chen Suen, Ronald A. Lubet, Vernon E. Steele, Clinton J. Grubbs. Effects of bazedoxifene either alone or in combination with letrozole in the prevention of chemically induced mammary cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5246. doi:10.1158/1538-7445.AM2017-5246
Abstract 5251: Amentoflavone regulate Hh-Gli1 signaling pathway and inhibits tumorsphere formation in U251 glioblastoma cells
Authors: Chen Jing , Bao Cheng , Lee Hong Jin
Published: July 2017

Cancer stem cells represent a rare population of cells with a self-renewal capacity, and potentially are involved in tumor progression, tumor relapse, and resistance to cancer chemotherapies. In this study, we investigated the effect of an active ingredient of chamaecyaris obtuse, amentoflavone, on stemness of U251 glioblastoma cells. We first found that amentoflavone from 1 to10 μM suppressed tumorsphere formation and inhibited the expression of glioblastoma stem cell markers CD133 and ALDH1 in a dose dependent manner. In addition, amentoflavone significantly reduced the expression of Nanog involved in cancer stem cells maintenance in tumorsphere culture. As an upstream modulator, Hedgehog (Hh) signaling mediator Gli1 was confirmed to be highly expressed in tumorsphere culture where the suppression of Gli1 by the treatment of Hh inhibitors (vismodegib and GANT 61) or Gli1-siRNA significantly suppressed the expression of stem cell markers CD133, ALDH1, and Nanog as well as tumorsphere formation in U251 glioblastoma cells. These results indicate that Hh signaling plays an important role in maintaining tumorsphere and stemness of U251 glioblastoma cells. Next, we also found that the treatment of amentoflavone from 1 to10 μM inhibited the expression of Gli1 and its downstream mediator Nanog in tumorsphere culture of U251 glioblastoma cells. Taken together, amentoflavone significantly suppressed Hh/Gli1 signaling which results in inhibition of stemness of U251 glioblastoma cells.

Citation Format: Jing Chen, Cheng Bao, Hong Jin Lee. Amentoflavone regulate Hh-Gli1 signaling pathway and inhibits tumorsphere formation in U251 glioblastoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5251. doi:10.1158/1538-7445.AM2017-5251
Abstract 5253: Arctigenin inhibits prostate tumor growth in vitro and in vivo in obese state
Authors: Wang Piwen , Diaz Tanya , Henning Susanne , Vadgama Jaydutt
Published: July 2017

Arctigenin is a novel anti-inflammatory lignan derived mainly from the seeds of Arctium lappa which is an herb widely used in traditional Chinese medicine to treat inflammation related diseases. We previously demonstrated that arctigenin strongly inhibited prostate tumor cell growth in cell culture and mouse models in non-obese state. The present study investigated the tumor inhibitory effect of arctigenin in obese state. An in vitro obese setting was created by co-culture of mouse adipocytes 3T3-L1 with androgen-sensitive LAPC-4 and LNCaP prostate cancer cells. An ELISA analysis of 3T3-L1 conditioned medium revealed that three cytokines/growth factors were prominently secreted by 3T3-L1 cells, including IGF-1, VEGF, and MCP-1, and the sensitivity of prostate cancer cells to arctigenin was decreased in the obese state. However, arctigenin at a moderate concentration (10 µM) significantly inhibited the proliferation of both LAPC-4 and LNCaP cell by 40-50% at 96h in the co-culture system. Male severe combined immunodeficiency (SCID) mice was implanted subcutaneously with LAPC-4 xenograft tumors to confirm the tumor-inhibitory effect of arctigenin in vivo. Mice were fed high-fat diet containing 45% energy from fat, and treated with arctigenin at 50mg/kg b.w. orally or vehicle control for 6 weeks (n=10 per group). The tumor growth in arctigenin group was significantly inhibited by 40% compared to control, along with decreased blood concentrations of several cytokines including IGF-1, VEGF, and MCP-1. Immunohistochemistry analysis is ongoing to determine the molecular changes involved in tumor cell proliferation and apoptosis in response to arctigenin treatment. This study provides a promising natural compound to enhance chemoprevention of prostate cancer especially in obese patients. These results warrant future clinical trial studies to confirm the anti-carcinogenic effect of arctigenin in humans.

Citation Format: Piwen Wang, Tanya Diaz, Susanne Henning, Jaydutt Vadgama. Arctigenin inhibits prostate tumor growth in vitro and in vivo in obese state [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5253. doi:10.1158/1538-7445.AM2017-5253
Abstract 5258: Benzyl isothiocyanate prevents breast cancer-induced bone erosion in vivo
Authors: Pore Subrata K. , Singh Shivendra V.
Published: July 2017

Bone is one of the metastatic sites for advanced breast cancer. Nearly 70% of breast cancer patients experience metastasis to bone due to enhanced osteoclastogenesis and formation of osteoclasts leading to bone resorption. We have shown previously that benzyl isothiocyanate (BITC), a constituent of edible cruciferous vegetables such as garden cress, is a potent inhibitor of breast cancer cells in vitro and in vivo. The present study was designed to determine the effect of BITC on breast cancer-induced osteoclastogenesis. Co-culture of murine RAW 264.7 macrophages with human breast cancer cells resulted in genesis of osteoclasts in vitro that was suppressed significantly in the presence of BITC. Runx2, a transcription factor, is abnormally expressed in breast cancer and contributes to osteoclastogenesis by regulating receptor activator of NF-κB ligand (RANKL). BITC treatment downregulated expression of Runx2 in breast cancer cells at the mRNA and protein levels. Osteoclastogenesis was increased in Runx2 overexpressing MDA-MB-231 cells, whereas conditional knockdown of Runx2 in T47D cells attenuated this process. To determine the in vivo efficacy of BITC, MDA-MB-231-Luc cells were injected into the left ventricle of nude mice. BITC was administrated orally at 10 mg per kg body weight. Micro-CT X-ray analysis showed that bone metastases and erosion was decreased by about 50% upon BITC treatment when compared with vehicle control. Cathepsin K and total RANKL levels were lower in the plasma of BITC-treated mice when compared to the control group. Altogether, this study demonstrates, for the first time, that BITC is a potent inhibitor of breast cancer-induced osteoclastogenesis in vivo. This study was supported by the grant RO1 CA129347-09 awarded by the national Cancer Institute.

Citation Format: Subrata K. Pore, Shivendra V. Singh. Benzyl isothiocyanate prevents breast cancer-induced bone erosion in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5258. doi:10.1158/1538-7445.AM2017-5258
Abstract 526: NFκB p65 overexpression promotes bladder cancer migration via FBW7-mediated degradation of RhoGDIα protein
Authors: Li Yang , Zhu Junlan , Li Jingxia , Huang Chuanshu
Published: July 2017

Since bladder cancer (BC) is one of the most lethal urological malignant tumors worldwide, understanding the molecular mechanisms that trigger the migration, invasion and metastasis of BC has great significance in reducing the mortality of this disease. RelA/p65, a member of the NF-kappa B transcription factor family, is increasingly recognized as a crucial player in many steps of cancer initiation and progression. In this study, we unexpectedly found that p65 protein expression increased in the bladder carcinogen N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN)-induced high invasive bladder tumor tissues, and in human bladder cancer cell lines. We also observed that p65 overexpression promoted bladder cancer cell migration by inhibiting RhoGDIα expression. We further demonstrate that the regulatory effect of p65 on RhoGDIα expression is mediated by its upregulation of FBW7, which specifically interacted with RhoGDIα and promoted RhoGDIα ubiquitination and degradation. Mechanistic studies revealed that p65 stabilizing the E3 ligase FBW7 protein was mediated by its attenuating Pten transcription. Taken together, p65 overexpression results in Pten downregulation, and FBW7 protein degradation, and in turn leading to RhoGDIα protein degration and promotings human BC cell migration. The identification of p65/PTEN/FBW7/RhoGDIα axis provides a significant insight into understanding the nature of BC migration.

Note: This abstract was not presented at the meeting.

Citation Format: Yang Li, Junlan Zhu, Jingxia Li, Chuanshu Huang. NFκB p65 overexpression promotes bladder cancer migration via FBW7-mediated degradation of RhoGDIα protein [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 526. doi:10.1158/1538-7445.AM2017-526
Abstract 5265: Breast cancer stem cell inhibition by benzyl isothiocyanate is hampered by induction of Kruppel-like factor 4
Authors: Kim Su-Hyeong , Wan Yong , Singh Shivendra V.
Published: July 2017

Breast cancer is a leading cause of cancer-related deaths among women in the United States. Over the last decade, breast cancer stem cells (bCSC) have been identified and characterized as a key player in breast cancer progression and recurrence. Benzyl isothiocyanate (BITC) is a highly promising cancer chemopreventive constituent of edible cruciferous vegetables such as garden cress. We have shown previously that BITC inhibits bCSC in cultured breast cancer cells (MCF-7 and SUM159 cells) and in spontaneous tumors of mouse mammary tumor virus-neu (MMTV-neu) mice in vivo. Krüppel-like factor 4 (KLF4), a zinc finger transcription factor, is known as both oncogene and tumor suppressor in various types of human cancers and plays an important role in reprogramming differentiated somatic cells into induced pluripotent stem cells. The present study demonstrates that KLF4 impedes bCSC inhibition by BITC. Exposure of breast cancer cells (MCF-7, MDA-MB-231, and SUM159) to pharmacological concentrations of BITC (2.5 and 5 µM) resulted in induction of KLF4 protein, which was accompanied by increase of its transcription. In addition, BITC treatment increased nuclear level of KLF4 in breast cancer cells. KLF4 protein expression was also higher in tumors form BITC-treated MMTV-neu mice compared with the control group. Ectopic expression of KLF4 in MCF-7 cells conferred marked protection against BITC-mediated inhibition of bCSC as evidenced by aldehyde dehydrogenase 1 (ALDH1) activity. Consistent with these observations, BITC-mediated inhibition of bCSC in MCF-7, MDA-MB-231 and SUM159 cells was significantly augmented by RNA interference of KLF4 as evidenced by ALDH1 activity and frequency of mammospheres. KLF4 overexpression also increased cell migration capacity of MCF-7 cells. Furthermore knockdown of KLF4 augmented BITC-mediated inhibition of cell migration in SUM159 cells. These results suggest that anticancer activity of BITC may be enhanced by KLF4 inhibition or knockdown in breast cancer cells. This study was supported by the grant RO1 CA129347-09 awarded by the National Cancer Institute.

Citation Format: Su-Hyeong Kim, Yong Wan, Shivendra V. Singh. Breast cancer stem cell inhibition by benzyl isothiocyanate is hampered by induction of Kruppel-like factor 4 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5265. doi:10.1158/1538-7445.AM2017-5265
Abstract 527: Integrated genomic cfDNA/cfRNA profiling for AR-V7 liquid biopsy test in prostate cancer
Authors: Jia Shidong
Published: July 2017

The growth and survival of prostate cancer tumors relies primarily on the functioning of the androgen receptor (AR) signaling pathway. Recent studies suggested that the presence of AR-V7, a c-terminal truncated form of AR, in circulating tumor cells (CTCs) of patients with castration-resistant prostate cancer (CRPC) is associated with inherent and/or acquired resistance to enzalutamide and abiraterone, the stand of care androgen deprivation therapies in prostate cancer. A series of data also indicate that AR-Vs (eg, including AR-V7, ARv567es, AR-T878A, AR-F876L etc) may drive resistance in CRPC. Expression of AR-V7 has been shown to correlate with disease progression and shortened survival. Considering that truncated AR splicing variants with C-terminal loss lack a functional ligand-bingding domain (LBD) and are constitutively active, C-terminal AR-directed therapies may not be effective for patients with AR splicing variants. Circulating tumor cell (CTC)-based AR-V7 tests are currently being tested in the clinic. However, nearly half of the CRPC patients do not have enough CTCs for AR-V7 test, raising the request for a complementary, non-CTC platform to detect AR variants as well as other resistance markers in circulation.

Here we report the development, validation and clinical application of PrediSeq-Prostate, a non-invasive next generation sequencing-based diagnostics platform that offers integrated genomic cell-free DNA (cfDNA) and cell-free RNA (cfRNA) profiling of prostate cancer, identifying known (such as AR-V7, AR-V9, AR-V2, etc) and novel AR splicing variants, point mutation, copy number, and translocation (such as TMPRSS2-ERG) using a single tube of blood. Using plasma samples from mCRPC patients that developed resistance to enzalutamide and/or abiraterone, PrediSeq-Prostate NGS test identified AR-V7, AR-V2, AR-V3, AR-V4 and other splicing variants that impact diagnosis and therapeutic selection. We also developed a Bio-Rad digital PCR assay measuring AR-V7 and AR-FL (full length) simultaneously. Collectively, PrediSeq NGS and ddPCR assays offer comprehensive genomic profiling of both cfDNA and cfRNA in all patients with prostate cancer, regardless of their status of CTC enumeration. The successful development and clinical validation of these tests has potential to enable precision medicine in prostate cancer.

Citation Format: Shidong Jia. Integrated genomic cfDNA/cfRNA profiling for AR-V7 liquid biopsy test in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 527. doi:10.1158/1538-7445.AM2017-527
Abstract 5271: Prostate cancer chemoprevention by dietary isothiocyanates is associated with suppression of lipogenesis
Authors: Singh Krishna B. , Singh Shivendra V.
Published: July 2017

Isothiocyanates (ITCs), including sulforaphane (SFN) and phenethyl isothiocyanate (PEITC), have been studied extensively for chemoprevention of prostate cancer using both in vitro and in vivo models, but the underlying mechanism is not fully understood. Dependence on fatty acid metabolism is progressively recognized as a unique trait of prostate cancer. Using in vitro and in vivo prostate cancer models, we demonstrate for the first time, that prostate cancer chemoprevention by ITCs is associated with suppression of fatty acid metabolism. Exposure of human prostate cancer cells to plasma achievable concentrations of SFN resulted in a marked decrease in levels of key fatty acid metabolism proteins, including acetyl-CoA carboxylase 1 (ACC1), fatty acid synthase (FASN), and carnitine palmitoyl transferase 1A (CPT1A), that was accompanied by suppression of their transcription. Consistent with the in vitro results, oral administration of prostate cancer chemopreventive concentrations of SFN (6 µmol per mouse, three times per week) resulted in downregulation of ACC1, FASN, and CPT1A proteins in prostate adenocarcinoma of TRAMP transgenic mice when compared with control. Levels of fatty acid metabolites (free fatty acid, triglycerides and phospholipids), lactate, and acetyl-CoA were also lower in the plasma and/or prostate adenocarcinoma of SFN-treated TRAMP mice in comparison with controls. Because fatty acid oxidation is an important step to supply energy to the prostate cancer cells, we explored the possibility of whether SFN could affect the fatty acid oxidation in prostate cancer cells. Indeed, SFN exposure significantly decreased the level of proteins involved in fatty acid oxidation in prostate cancer cells. Many of these changes were also observed with PEITC. In conclusion, it is reasonable to propose that suppression of fatty acid metabolism is an important mechanism in prostate cancer chemoprevention by ITCs. This study was supported by the grants RO1 CA115498-10 and RO1 CA101753-12 awarded by the National Cancer Institute.

Citation Format: Krishna B. Singh, Shivendra V. Singh. Prostate cancer chemoprevention by dietary isothiocyanates is associated with suppression of lipogenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5271. doi:10.1158/1538-7445.AM2017-5271
Abstract 5283: Association between body mass index and prostate cancer among African American men
Authors: Pichardo Margaret S. , Smith Cheryl J. , Tang Wei , Dorsey Tiffany , Ambs Stefan
Published: July 2017

Prostate cancer (PCa) is a leading cause of cancer death in US men. Yet, the etiology of prostate cancer remains poorly understood, with only older age, African ancestry, family history of the disease, and multiple germline genetic variations being established disease risk factors. Prostate cancer occurs more often in African-American (AA) men and Caribbean men of African descent than in men of other race/ethnicities. While it has been previously suggested that obesity (measured using body mass index [BMI, kg/m2]) may worsen disease-related outcomes among prostate cancer patients, the relationship of obesity and prostate cancer risk, using race as a predictor, has not been fully explored. Using multivariable logistic regression, we estimated the risk of total PCa for 976 cases and 1,032 age-matched controls, with equal proportions of European-American (EA) and AA men. Among men in the NCI Maryland Prostate Cancer Case-Control Study, BMI was inversely associated with disease outcomes in AA men, but not among EA men. Consistent with previous literature, BMI in EA men was shown to be positively associated with overall prostate cancer risk. Our findings suggest an obesity paradox, where obesity may protect against incidence of PCa among AA men. Studies are needed to elucidate the underlying mechanisms responsible for the differential effects of obesity in AA and EA men with prostate cancer.

Citation Format: Margaret S. Pichardo, Cheryl J. Smith, Wei Tang, Tiffany Dorsey, Stefan Ambs. Association between body mass index and prostate cancer among African American men [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5283. doi:10.1158/1538-7445.AM2017-5283
Abstract 5287: Recent trends in racial and regional disparities in cervical cancer incidence and mortality
Authors: Yoo Wonsuk , Kim Sangmi , Coughlin Steven , Bae Sejong , Partridge Edward , Huh Warner , Dilley Sarah , Chung Yunmi
Published: July 2017

Background: Although black and Hispanic women experienced greater cervical cancer rate reduction in recent years, they continue to have higher incidence rates than whites. Great variations also exist among geographic regions of the US, with the South having both the highest incidence and mortality rates compared to other regions. The present study explores the question of whether living in the South is associated with greater racial disparity in cervical cancer incidence and mortality by examining race- and region-specific rates and the trend between 2000 and 2012.

Methods: The Surveillance, Epidemiology, and End Results (SEER) 18 Program data was used. Incidence and mortality rates, annual percent changes, and disparity ratios of cervical cancer were calculated using SEER*Stat software and Joinpoint regression for four groups: US14-Non-Hispanic White (NHW), US14-Non-Hispanic Black (NHB), South-NHW, and South-NHB, where the South included 4 registries from Georgia and Louisiana.

Results: The incidence and mortality rates were much higher among NHB women compared to NHW in the South and the US. The degree of racial disparities between NHB and NHW women was greater in terms of mortality rates than incidence rates. For all age groups, NHB women in the South consistently had higher incidence rates than NHB women in the US14 region. The mortality disparity ratios was highest among NHB women, followed by NHW women in the South, NHW women in US14, and finally NHB women in the South.

Conclusions: Although racial disparity has been narrowed in recent years, there has been little change or even a growing gap between white women in the South and their counterparts in the US14 region. Age-specific analysis further indicated that the emerging regional gap observed among white women might be attributable to the excess number of new cases and deaths among young women.

Citation Format: Wonsuk Yoo, Sangmi Kim, Steven Coughlin, Sejong Bae, Edward Partridge, Warner Huh, Sarah Dilley, Yunmi Chung. Recent trends in racial and regional disparities in cervical cancer incidence and mortality [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5287. doi:10.1158/1538-7445.AM2017-5287
Abstract 5292: Multitarget fecal miRNA test combined with fecal occult blood test and fecal miRNA test for colorectal cancer screening
Authors: Koga Yoshikatsu , Yamazaki Nobuyoshi , Kakugawa Yasuo , Matsuda Takahisa , Ito Masaaki , Saito Yutaka , Saito Hiroshi , Matsumura Yasuhiro
Published: July 2017

Background & Aims: The fecal immunochemical test (FIT) is used for colorectal cancer (CRC) screening worldwide. However, there are several issues of the false-positive and the false-negative. To overcome these problems, various molecular biological tests have been combined to FIT. In this context, multitarget fecal DNA test was approved by FDA in August 2014. In addition, multitarget fecal microbiota has been recently reported. We have reported the usefulness of fecal miRNA analysis to detect CRC. Here, we investigated the applicability of multitarget fecal miRNA test combined with FIT and fecal miRNA test using fecal RNA extracted from FIT residua.

Methods: In this study, 57 patients with invasive CRC, 33 patients with advanced adenoma, and 60 healthy individuals were enrolled. Each participant collected 10 mg fecal samples using the FIT sampling container for 2 days. After FIT was performed, total RNA was extracted from the residuum and miRNA expression was analyzed by using real-time RT-PCR. The sensitivity and specificity of the multitarget fecal miRNA test combined with FIT and fecal miRNA test was analyzed by using the decision tree analysis.

Results: Approximately 1μg RNA was extracted from 10 mg fecal sample. The expressions of miR-16, miR-92a, miR-106a, miR-142-3p, miR-223, and miR-451 in fecal samples were significantly higher in the patients with advanced neoplasm (including invasive CRC and advanced adenoma) than in the healthy individuals (P<0.05). The sensitivity and the specificity of the FIT alone were 74.4% (67/90) and 93.3% (56/60), whereas those of the multitarget fecal miRNA test were 93.3% (83/90) and 91.7% (55/60). Moreover the multitarget fecal miRNA test could detect 81.8% of patients with advanced adenoma (27/33).

Conclusions: Multitarget fecal miRNA test combined with FIT and fecal miRNA test may be a useful new CRC screening method.

Citation Format: Yoshikatsu Koga, Nobuyoshi Yamazaki, Yasuo Kakugawa, Takahisa Matsuda, Masaaki Ito, Yutaka Saito, Hiroshi Saito, Yasuhiro Matsumura. Multitarget fecal miRNA test combined with fecal occult blood test and fecal miRNA test for colorectal cancer screening [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5292. doi:10.1158/1538-7445.AM2017-5292
Abstract 53: Antibody-drug conjugates (ADCs) of peptide-linked Indolino-Benzodiazepine (IGN) DNA-alkylator provides improved anti-tumor activity over that of a crosslinker
Authors: Miller Michael L. , Shizuka Manami , Ponte Jose F. , Lanieri Leanne , Vitharana Dilrukshi , Qiu Qifeng , Reid Emily E. , Archer Katie E. , Wu Rui , Maloney Erin K. , Ab Olga , Pinkas Jan , Chari Ravi V.
Published: July 2017

We recently disclosed highly active antibody-drug conjugates (ADCs) that incorporated the novel DNA alkylating indolino-benzodiazepine (termed IGN) dimer, DGN549 (IGN-P1). The stereochemistry of the alanyl moiety of the protease-cleavable alanine-alanine linker used was shown to impact ADC catabolism, bystander killing activity, and in vivo efficacy (Shizuka, et al., AACR 2016 #2959). Building upon these results, here we describe preclinical results from a head-to-head comparison of ADCs of the mono-imine containing DGN549 with its corresponding DNA cross-linking diimine version, IGN-P1 diimine. IGN-P1 diimine and DGN549 were conjugated to a folate receptor-α (FRα)-binding antibody and an EpCAM-binding antibody. The resulting ADCs demonstrated similar high in vitro potency (IC50 ~3-100 pM) and specificity towards several cancer cell lines. Further in vitro studies revealed that the DNA alkylating anti-FRα-DGN549 ADC demonstrated superior bystander cell-killing activity compared to its DNA crosslinking counterpart, anti-FRα-IGN-P1 diimine. In vivo, this improved bystander killing ability translated into better in vivo activity for the DNA alkylating ADC. In an endometrial tumor xenograft model established with Ishikawa cells, the anti-FRα-DGN549 induced complete regressions at a single dose of 140 µg/kg Ab dose (equivalent to 5 µg/kg linked IGN). The cross-linking anti-FRα-IGN-P1 diimine had to be used at twice the dose to achieve the same level of anti-tumor activity. The in vivo tolerability in CD-1 mice also displayed differences in the two ADCs. We found that the ADC of the DNA crosslinker was at least two-fold less tolerated than the corresponding ADC of the DNA alkylator. These results indicate that a ~4 fold greater therapeutic index can be achieved when using a DNA alkylating mono-imine DGN549 ADC as compared to the DNA crosslinking IGN-P1 diimine ADC.

Citation Format: Michael L. Miller, Manami Shizuka, Jose F. Ponte, Leanne Lanieri, Dilrukshi Vitharana, Qifeng Qiu, Emily E. Reid, Katie E. Archer, Rui Wu, Erin K. Maloney, Olga Ab, Jan Pinkas, Ravi V. Chari. Antibody-drug conjugates (ADCs) of peptide-linked Indolino-Benzodiazepine (IGN) DNA-alkylator provides improved anti-tumor activity over that of a crosslinker [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 53. doi:10.1158/1538-7445.AM2017-53
Abstract 5304: A serological biopsy using five stomach-specific circulating biomarkers for gastric cancer risk assessment: a multi-phase study
Authors: Tu Huakang , Sun Liping , Dong Xiao , Gong Yuehua , Xu Qian , Jing Jingjing , Bostick Roberd M. , Wu Xifeng , Yuan Yuan
Published: July 2017

Objective: We aimed to assess a serological biopsy using five stomach-specific circulating biomarkers—pepsinogen I (PGI), PGII, PGI/II ratio, anti-Helicobacter pylori (H. pylori) antibody, and gastrin-17 (G-17)—for identifying high-risk individuals and predicting risk of developing gastric cancer (GC).

Methods: Among 12112 participants with prospective follow-up from an ongoing population-based screening program using both serology and gastroscopy in China, we conducted a multi-phase study involving a cross-sectional analysis, a follow-up analysis, and an integrative risk prediction modeling analysis.

Results: In the cross-sectional analysis, the five biomarkers (especially PGII, the PGI/II ratio, and H. pylori sero-positivity) were associated with the presence of precancerous gastric lesions or GC at enrollment. In the follow-up analysis, low PGI levels and PGI/II ratios were associated with higher risk of developing GC, and both low (<0.5 pmol/L) and high (2.0-4.7 or >4.7 pmol/L) G-17 levels were associated with higher risk of developing GC, suggesting a J-shaped association. In the risk prediction modeling analysis, the five biomarkers combined yielded a C statistic of 0.801 (95% CI=0.787-0.815) and improved prediction beyond traditional risk factors (C statistic from 0.580 to 0.811, P<0.001) for identifying precancerous lesions at enrollment, and higher serological biopsy score based on the five biomarkers at enrollment were associated with higher risk of developing GC during follow-up (P for trend <0.001).

Conclusions: A serological biopsy composed of the five stomach-specific circulating biomarkers could be used to identify high-risk individuals for further diagnostic gastroscopy, and to stratify individuals’ risk of developing GC and thus to guide targeted screening/precision prevention.

Citation Format: Huakang Tu, Liping Sun, Xiao Dong, Yuehua Gong, Qian Xu, Jingjing Jing, Roberd M. Bostick, Xifeng Wu, Yuan Yuan. A serological biopsy using five stomach-specific circulating biomarkers for gastric cancer risk assessment: a multi-phase study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5304. doi:10.1158/1538-7445.AM2017-5304
Abstract 5313: Associations of calcium and dairy product intakes with colorectal cancer risk among older women: the Iowa Women's Health Study
Authors: Um Caroline , Prizment Anna , Lazovich DeAnn , Bostick Roberd M.
Published: July 2017

Calcium has been consistently modestly associated with lower risk of colorectal cancer, which remains the second leading cause of cancer deaths among men and women combined in the United States. Dairy products, a major source of dietary calcium, have also been consistently inversely associated with colorectal cancer, although inconsistencies in relation to high-fat dairy products have been noted. Limited evidence suggests that dairy products may contain components other than calcium and fat, such as insulin-like growth factor 1 (IGF-1), that may be independently directly associated with risk of colorectal and other cancers.

Data from the Iowa Women’s Health Study, a prospective cohort study, were used to investigate associations of calcium, dairy products, and the non-calcium component of dairy products with colorectal cancer incidence. Dietary data were collected using a semiquantitative food frequency questionnaire (FFQ) mailed to 55 – 69 year-old women in 1986 who had a valid Iowa driver’s license. Among participants with no history of cancer at baseline and who satisfactorily completed their FFQ (n=35,221), through follow up in 2012, 1,731 incident cases of colorectal cancer were documented via the Iowa SEER registry. To investigate total dairy and total, whole, and non-fat milks independent of their calcium components, we used the residuals from linear regression models of their associations with dietary calcium. Associations of the calcium and dairy product variables with colorectal cancer incidence were estimated using multivariable Cox proportional hazards regression.

For those in the highest relative to those in the lowest quintiles of intakes, the adjusted hazards ratios and 95% confidence intervals (CI) were 0.81 (CI 0.67-0.98; P-trend 0.004) for total calcium, 0.85 (CI 0.68-1.03; P-trend 0.07) for dietary calcium, and 0.85 (CI 0.68-1.06; P-trend 0.16) for supplemental calcium. For total dairy and total milk, the corresponding findings were 0.79 (CI 0.66-0.94; P-trend 0.01) and 0.82 (CI 0.69-0.96; P-trend 0.09), respectively. Low-fat dairy products, non-fat milk, and residuals of total dairy products and total and non-fat milk were not associated with colorectal cancer.

These results are consistent with previous findings of lower colorectal cancer risk with higher intakes of calcium and dairy products, but provide little support for the hypothesis that the non-calcium, non-fat component of dairy products may be associated with colorectal cancer.

Citation Format: Caroline Um, Anna Prizment, DeAnn Lazovich, Roberd M. Bostick. Associations of calcium and dairy product intakes with colorectal cancer risk among older women: the Iowa Women's Health Study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5313. doi:10.1158/1538-7445.AM2017-5313
Abstract 5325A: Fruit and vegetable intake and risk of breast cancer: Pooled analysis of the Nurses’ Health Study and the Nurses’ Health Study II
Authors: Farvid Maryam S. , Willett Walter C. , Eliassen A. Heather
Published: July 2017

Fruit and vegetable intake has been hypothesized to protect against breast cancer, but the overall evidence has not been supportive. Using pooled data from the Nurses’ Health Study and the Nurses’ Health Study II cohorts, we evaluated fruit and vegetable intake in relation to breast cancer risk. Diet was assessed every 4 years using semi-quantitative food frequency questionnaires. Cox proportional hazards regression, adjusting for multiple breast cancer risk factors, was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs)for each category, using the lowest quintile of intake as the reference category. Among 182,204 women aged 27 to 66 years, we prospectively identified 10,973 invasive breast cancer cases during follow-up from 1980 through 2012 for the Nurses’ Health Study and from 1991 through 2013 for the Nurses’ Health Study II. Fruit and vegetable intake was significantly associated with a lower risk of breast cancer. The pooled multivariate HR (95% CIs) for highest (3.2 servings/day) versus lowest (0.4 serving/day) quintile intake of total fruit intake was 0.93 (0.86-0.99; Ptrend=0.03) and for highest (4.9 servings/day) versus lowest (1.5 servings/day) quintile intake of total vegetable was 0.92 (0.86-0.99; Ptrend=0.02). We also observed that a higher intake of yellow/orange vegetables, cruciferous vegetable, fruits and vegetables rich in vitamin C, fruits and vegetables rich in α-carotene, fruits and vegetables rich in β-carotene, and fruits and vegetables rich in lutein was each associated with a lower breast cancer risk. In addition, the association with vegetable intake was stronger for both estrogen and progesterone receptor negative (HR=0.91; 95%CIs=0.87-0.95) than both estrogen and progesterone receptor positive cancers (HR=0.98; 95%CIs=0.96-1.00; Pheterogeneity=0.003). Our findings support an association of a higher fruit and vegetable intake with a lower breast cancer risk.

Citation Format: Maryam S. Farvid, Walter C. Willett, A. Heather Eliassen. Fruit and vegetable intake and risk of breast cancer: Pooled analysis of the Nurses’ Health Study and the Nurses’ Health Study II [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5325A. doi:10.1158/1538-7445.AM2017-5325A
Abstract 5326: EZH2 regulation through lysine 63 linked ubiquitination in prostate cancer
Authors: Lu Wenfu , Lu Shenji , Li Bo , Xie Yingqiu , Izban Michael G. , Ballard Billy R. , Sathyanarayana Sandeep A. , Adunyah Samuel E. , Matusik Robert J. , Chen Zhenbang
Published: July 2017

Enhancer of zeste homolog 2 (EZH2) plays crucial roles on the development of cells and tissues as well as the progression of prostate cancer (PCa) and castration resistant prostate cancer (CRPC). EZH2 can upregulate and activate progenitor genes including androgen receptor (AR) and the target genes. However, the mechanisms by which EZH2 is regulated in PCa remain elusive. Literature reports that tumor necrosis factor (TNF) receptor associated factor 6 (TRAF6) is essential for both normal tissue development and regulation of oncogenic signaling pathways in cancers. In this study, we reported that EZH2 is regulated by PTEN and SKP2 network in PCa. Specifically, we showed that the aberrant upregulation of EZH2 and histone H3 lysine 27 trimethylation (H3K27me3) in both Pten null mouse embryonic fibroblasts (MEFs) in vitro and prostate tumors of Pten null mice in vivo, as compared to the controls. EZH2 levels were negatively correlated with TRAF6 in human PCa cells upon SKP2 dysregulation. Immunofluorescence (IF) staining results showed a co-localization of EZH2 and TRAF6 in nucleus of PC3 cells, and co-immunoprecipitation (co-IP) analysis further confirmed a physical binding of EZH2 and TRAF6 in PC3 cells. Ectopic expression of TRAF6 promoted the K63-linked polyubiquitination of EZH2 to decrease EZH2 and H3K27me3 levels in PCa cells. Conversely, TRAF6 knockdown resulted in a reduction of EZH2 polyubiquitination with an increase of EZH2 and H3K27me3 levels in PCa cells. Furthermore, the catalytically dead mutant TRAF6 C70A abolished the TRAF6-mediated polyubiquitination of human EZH2 in vivo in 293T cells and in vitro in the recombinant human EZH2 protein, as compared with TRAF6 WT. Together, we report for the first time a novel mechanism on EZH2 ubiquitination and an important signaling network of SKP2-TRAF6-EZH2-H3K27me3 in PCa cells. Our findings provide valuable clues on the mechanism and efficiency of targeting EZH2 in PCa and CRPC .

Note: This abstract was not presented at the meeting.

Citation Format: Wenfu Lu, Shenji Lu, Bo Li, Yingqiu Xie, Michael G. Izban, Billy R. Ballard, Sandeep A. Sathyanarayana, Samuel E. Adunyah, Robert J. Matusik, Zhenbang Chen. EZH2 regulation through lysine 63 linked ubiquitination in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5326. doi:10.1158/1538-7445.AM2017-5326
Abstract 5329: Glycyl-tRNA Synthetase is a novel target for cancer therapeutics
Authors: Mo Zhongying , Liu Ze , Yang Xiang-Lei
Published: July 2017

Neddylation, an ubiquitination-like, post-translational modification that controls cell cycle and proliferation, is strongly associated with cancer. Interestingly, we recently identified that glycyl-tRNA synthetase (GlyRS) as a critical chaperone for neddylation1. GlyRS is also an essential enzyme for protein synthesis, which is required for tumor growth. Therefore, the dual functional GlyRS may be a novel target for anti-cancer therapy. Consistent with this idea, we found strong positive correlation between the level of GlyRS and tumor progression in breast cancer. A proof-of-concept inhibitor of GlyRS for aminoacylation was able to suppress neddylation in breast cancer cells, and reduce their lung metastasis in a mouse model. Taken together, we propose that GlyRS is a novel and promising target for cancer treatment.

Reference:1. ZY Mo, Q Zhang, J Laurer, Z Liu, LT Sun, Y Shi, P Griffin, XL Yang. Nature Structural and Molecular biology. 2016 Jun 27. doi: 10.1038/nsmb.3250.

Citation Format: Zhongying Mo, Ze Liu, Xiang-Lei Yang. Glycyl-tRNA Synthetase is a novel target for cancer therapeutics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5329. doi:10.1158/1538-7445.AM2017-5329
Abstract 5334: Destabilization of EWS-Fli1 protein by deubiquitinase inhibition in Ewing Sarcoma
Authors: Wang Shan , Kittler Ralf
Published: July 2017

Background: Ewing Sarcoma is a malignant tumor in bone or soft tissue, and typically in teenagers and young adults. Genetically, 85% of Ewing’s Sarcoma contains the chromosomal translocation [t(11;22)(q24;q12)], which fuses EWSR1 gene from chromosome 11 and Fli1 gene from chromosome 22 and generates an aberrant chimeric protein EWS-Fli1. EWS-Fli1 is essential for cell growth and development in EWS-Fli1 positive Ewing Sarcoma cells. Therefore, targeting EWS-Fli1 could be a promising therapeutic strategy for Ewing Sarcoma.

Methods and Results: Currently, the compounds of targeting EWS-Fli1 mainly interfere its interaction with partner or DNA. However, it could be a more potent way to manipulate its protein stability. Firstly, the proteasome inhibitor MG132 could retard the degradation of EWS-Fli1 protein in EWS502 cells and A673 cells, and increase its ubiquitination, which hints the degradation of EWS-Fli1 is through the ubiquitin (Ub)-proteasome pathway (UPP). Then, to identify the protein that interact with EWS-Fli1 and modulate its stability, we selected the candidate deubiquitinase according to literatures and the protein homology. And by co-immunoprecipitation assay, we identified a deubiquitinating enzyme (DUB) binding to EWS-Fli1. RNAi-mediated knockdown or inhibition of EWS-Fli1-DUB with a small molecule compound caused a marked increase in EWS-Fli1 ubiquitination, decreased levels of EWS-Fli1 in a proteasome-dependent manner, and further inhibited the growth of Ewing Sarcoma cells.

Conclusion: The findings indicate that EWS-Fli1 could be ablated by inhibiting its specific deubiquitinase in Ewing Sarcoma, which could be a novel treatment approach for Ewing Sarcoma.

Citation Format: Shan Wang, Ralf Kittler. Destabilization of EWS-Fli1 protein by deubiquitinase inhibition in Ewing Sarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5334. doi:10.1158/1538-7445.AM2017-5334