bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1401: Deterring breast cancer progression. The critical role of a lipid-sphingolipid epigenetic mechanism of cell fate
Authors: Rossetti Stefano , Gagliostro Vincenzo , Sacchi Nicoletta
Published: July 2017

Genetic and environmental factors cooperate to assure precise genome-wide epigenetic regulation of the mammary epithelia cell transcriptome. Our interest in regulatory epigenetic mechanisms that, by determining mammary epithelial cell decisions, are pivotal to deter the onset and progression of breast cancer, let us identify a regulatory epigenetic mechanism of mammary morphogenesis that links a physiological regulatory lipid of environmental origin (all-trans retinoic acid, RA) with sphingolipids capable of determining either cell death (ceramide, CER) or cell life (sphingosine 1 phosphate, S1P).

Whenever RA, for different reasons, fails to perform the epigenetic transcriptional control of neutral sphingomyelinase 2 (nSMase2/SMDP3), involved in the synthesis of pro-apoptotic CER, S1P fosters both pro-proliferative and pro-invasive activity. Apparently, in the absence of epigenetic control of CER production by RA, S1P contributes to determine RA tumorigenic action. This study provides the rationale for combination therapeutic approaches with epigenetic drugs and inhibitors of either sphingosine kinase, the enzyme involved in S1P synthesis, or S1P receptors.

This study was supported by the NCI R01 CA127614 grant (NS).

Citation Format: Stefano Rossetti, Vincenzo Gagliostro, Nicoletta Sacchi. Deterring breast cancer progression. The critical role of a lipid-sphingolipid epigenetic mechanism of cell fate [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 1401. doi:10.1158/1538-7445.AM2017-1401
Abstract 1412: High EGFR somatic mutation frequency targeting the TK domain in colorectal cancer patients with microsatellite instability (MSI)
Authors: Deihimi Safoora , Slifker Michael , Ross Eric A. , El-Deiry Wafik S.
Published: July 2017

CRCs arise through genetic changes that impact various driver genes and in some tumors increased mutation rate in microsatellite unstable tumors. The hypermutable phenotype associated with microsatellite instability (MSI) results from loss of the mismatch repair system (MMR) activity. MSI is detected in 15% of all CRCs, and such tumors have a better prognosis and different chemotherapeutic outcome patterns, including high clinical benefit from immune checkpoint therapy or relative resistance to 5-FU as compared to microsatellite stable (MSS) tumors. The epidermal growth factor receptor (EGFR) signaling pathway plays an essential role in carcinogenesis of CRCs and is known to be overexpressed in MSI CRCs while highly mutated in Lung cancer. We analyzed the mutation frequency of deregulated pathways including EGFR and its downstream genes KRAS and BRAF in CRCs. We found a significantly elevated EGFR mutation frequency in CRC MSI-H subtype (45.5% vs. 6.5% in MSS CRCs, p<0.0000001). Although KRAS and NRAS are mutated with high frequency in both MSI-H and MSS groups, BRAF corresponding to RTK-RAS pathways is more altered in MSI-H than MSS CRCs (32.67% vs 13.10%; p=0.001), consistent with the known association between MSI-H CRCs and BRAF mutations. We hypothesized that there might be a mutation pattern in EGFR in CRC subtypes that provide a rationale for EGFR-targeted therapy for a subtype of CRC. Of 1104 profiled CRCs in the COSMIC v73 database, somatic EGFR mutations were mapped for 101 MSI-High versus 916 MSS CRCs. EGFR mutations mapped on the protein structure revealed that mutations are mainly targeting tyrosine kinase (TK) domain while the extracellular domain remained mostly wild-type with potential for targeting by anti-EGFR monoclonal antibodies. It is known that downstream genes such as KRAS as well as expression levels of EGFR ligands can affect the sensitivity of CRCs to anti-EGFR therapy. We didn’t detect any difference in mRNA expression level between MSI-H and MSS group but our analysis is indicative of the presence of G12D mutations in a high proportion of KRAS-mutated MSS CRCs, therefore resistance to anti-EGFR antibodies such as cetuximab would be expected. However, EGFR tyrosine kinase inhibitors such as erlotinib and gefitinib could be considered for further testing in patients with MSI-H tumors that have a lower frequency of G12D KRAS mutations and may have mutant EGFR.

Citation Format: Safoora Deihimi, Michael Slifker, Eric A. Ross, Wafik S. El-Deiry. High EGFR somatic mutation frequency targeting the TK domain in colorectal cancer patients with microsatellite instability (MSI) [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 1412. doi:10.1158/1538-7445.AM2017-1412
Abstract 1416: Development of small molecule inhibitors for cancer therapy by targeting RPA and XPA nucleotide excision repair proteins
Authors: Gavande Navnath S. , VanderVere-Carozza Pamela S. , Vernon Tyler L. , Pawelczak Katherine , Turchi John J.
Published: July 2017

Targeting DNA repair and the DNA damage response for cancer therapy has recently gained increasing attention with inhibitors of the PARP enzyme showing a therapeutic efficacy in various cancers. Solid tumors of the lung, pancreas, breast, and ovary represent a continuing clinical challenge in treatment and together account for over 250,000 deaths in the US alone, representing over 40% of all cancer deaths. There are limited therapeutic options for these patients, and targeted and combination therapies remain necessary for treating these aggressive cancers. The opportunity exists to exploit recent scientific advances in our knowledge of the underlying biology behind these cancers to create novel targeted therapeutics to dramatically enhance patient response to therapy and ultimately survival. To this end, we have developed a series of novel small chemical molecules that disrupt critical protein-DNA interactions in the nucleotide excision repair (NER) pathways. It is well understood that various cancer treatments like cisplatin, etoposide and ionizing radiation impart their chemotherapeutic effect by the formation of direct DNA damage which block DNA replication and transcription culminating in apoptosis. It is also well established that repair of this DNA damage by nucleotide excision repair (NER) or homologous recombination repair (HRR) reduces the effectiveness of chemo- or radio- therapy. Replication protein A (RPA) and Xeroderma Pigmentosum Group A (XPA) plays a crucial role in the NER pathway and makes them a novel drug target to develop novel cancer therapy. We anticipate both direct mechanisms of action on the repair pathways and synthetic lethal interactions can be exploited for therapeutic benefit. The series of novel small molecule inhibitors that we have developed targeting RPA and XPA proteins independently exhibit single-agent anti-cancer activity in cancer cell lines, and potentiate cellular sensitivity to chemotherapeutic agent. Data demonstrate that these novel inhibitors do not interact with DNA but directly bind the corresponding NER proteins. Our data demonstrate that this class of inhibitors can be further developed as an anti-cancer therapeutic with considerable potential to be used in conjunction with radiation therapy and other cancer therapies that induce DNA damage.

This works was supported by NIH grants R01-CA180710 and R41-CA162648 and the Tom and Julie Wood Family Foundation.

Citation Format: Navnath S. Gavande, Pamela S. VanderVere-Carozza, Tyler L. Vernon, Katherine Pawelczak, John J. Turchi. Development of small molecule inhibitors for cancer therapy by targeting RPA and XPA nucleotide excision repair proteins [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 1416. doi:10.1158/1538-7445.AM2017-1416
Abstract 1423: Nedd8-activating enzyme inhibitor pevonedistat synergizes with cisplatin and carboplatin through interference with nucleotide excision repair and interstrand cross-link repair mechanisms in non-small cell lung cancer
Authors: Liu Xiaozhen , Bouck David , Garcia Khristofer , Blank Jonathan , Bernard Hugues , Berger Allison , Kuranda Mike , Koenig Erik , Lightcap Eric
Published: July 2017

Platins are one of the most widely used classes of chemotherapeutic drugs. Although used as part of first-line standard of care regimens for advanced non-small cell lung cancer (NSCLC), their effectiveness remains limited, with a 5-year survival rate of 18%. Therefore, combination therapy to overcome resistance and improve survival is needed. Pevonedistat (TAK-924/MLN4924) is an investigational first-in-class Nedd8-activating enzyme (NAE) inhibitor that blocks activation of the cullin family of E3 ubiquitin ligases by preventing cullin conjugation with Nedd8, a ubiquitin-like protein. In vitro, pevonedistat is synergistic with carboplatin in a cell viability assay in 6 out of 20 NSCLC cell lines either with or without paclitaxel. In vivo studies using patient-derived xenograft (PDX) models showed a combination effect in a carboplatin-insensitive but not carboplatin-sensitive model. To evaluate the mechanism of the synergy between pevonedistat and platinum, RNAi of 320 DNA-damage response genes was performed in 4 cell lines in vitro. Depletion of genes involved in TC-NER (transcription-coupled nucleotide excision repair) and ICR (interstrand crosslink repair) reduced the synergy between pevonedistat and platinum, with the contribution of each pathway varying by cell line. Since TC-NER and ICR are also involved in the repair of DNA damage by platins, the results suggest that delaying completion of platin induced DNA repair by pevonedistat results in enhanced cell death. Pevonedistat may impede TC-NER by inhibition of neddylation of the E3 ubiquitin ligase CUL4-RBX1-DDB1-ERCC8, thereby possibly providing a direct reversal of resistance to platins.

Citation Format: Xiaozhen Liu, David Bouck, Khristofer Garcia, Jonathan Blank, Hugues Bernard, Allison Berger, Mike Kuranda, Erik Koenig, Eric Lightcap. Nedd8-activating enzyme inhibitor pevonedistat synergizes with cisplatin and carboplatin through interference with nucleotide excision repair and interstrand cross-link repair mechanisms in non-small cell lung 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 1423. doi:10.1158/1538-7445.AM2017-1423
Abstract 1427: Investigating role of RECQ1 in response to gemcitabine treatment in triple negative breast cancer
Authors: Parvathaneni Swetha , Lu Xing , Sharma Sudha
Published: July 2017

The response of cancer cells to therapeutic drugs aimed at causing DNA damage is dependent on proteins that play roles in DNA repair. Single nucleotide polymorphism in RECQ1 (also known as RECQL or RECQL1), a DNA helicase involved in DNA damage and replication stress response, is reported to influence patient’s response to gemcitabine in pancreatic cancer leading to poor survival. Gemcitabine is also used as a chemotherapeutic against triple negative breast cancer; however resistance to gemcitabine is reported. The mechanism by which gemcitabine chemoresistance is obtained is poorly understood. Given the importance of RECQ1 in replication fork restart and it being categorized as a breast cancer susceptibility gene, we wish to investigate the role of RECQ1 in modulating cellular response to gemcitabine in triple negative breast cancer cells. To study RECQ1 functions, we developed isogenic pairs of RECQ1-proficient and RECQ1-deficient cells by CRISPR-Cas9-mediated targeted inactivation of RECQ1 in breast cancer cell lines as in vitro model system. RECQ1-knockout MDA-MB-231 cells displayed reduced cell growth and proliferation, and increased DNA damage as compared to the MDA-MB-231 cells expressing wild type RECQ1. As compared to RECQ1-proficient MDA-MB-231 cells, RECQ1-deficient cells were more sensitive to gemcitabine treatment, incurred significantly greater load of double strand breaks upon gemcitabine treatment, and displayed aberrant cell cycle progression following recovery from gemcitabine treatment. Our ongoing experiments are investigating the detailed mechanism of RECQ1’s role in response to gemcitabine and its implications in therapeutic response.

Funding: This work was funded by the NIGMS/NIH grant SC1GM093999 to Sudha Sharma. We also acknowledge support from the NIMHD/NIH award number G12MD007597 and NIA/NIH award number 1R25 AG047843-02. We thank Drs. Ritu Chaudhary, Xiaoling Li and Ashish Lal (NCI) for their help and support.

Citation Format: Swetha Parvathaneni, Xing Lu, Sudha Sharma. Investigating role of RECQ1 in response to gemcitabine treatment in triple negative breast 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 1427. doi:10.1158/1538-7445.AM2017-1427
Abstract 1436: Identification of novel tumor suppressor candidates in familial cholangiocarcinoma using sequencing-based Megabase-scale haplotypes from germline and cancer genomes
Authors: Greer Stephanie , Nadauld Lincoln , Lau Billy , Miotke Laura , Hopmans Erik , Wood Christina M. , Bell John M. , Jones David A. , Ji Hanlee P.
Published: July 2017

Cholangiocarcinoma (bile duct cancer) is a rare epithelial malignancy with an extremely poor prognosis characterized by a 5-year survival of less than 10%. While this tumor type can be amenable to specific combination chemotherapy regimens, it is typically diagnosed at an advanced stage and inevitably progresses towards distant metastasis. We identified a family with a predisposition to cholangiocarcinoma, having multiple affected family members, and sought to identify the underlying germline mutation(s).

We employed linked-read sequencing, a microfluidic technology where high-molecular weight DNA molecules (>20 kb) are partitioned into droplets and labeled with unique barcodes, enabling computational reconstruction of the original large molecules following traditional short-read sequencing, to identify entire megabase-scale regions of the genome that segregate with the disease. We applied this technology to an entire generation of a family predisposed to cholangiocarcinoma, including a mix of 8 affected and unaffected siblings. We additionally utilized each affected individual’s cancer genome to search for a common second hit that would serve as further confirmation. Our analysis yielded a small set of four candidate pathogenic variants. Functional validation of the candidate genes in a zebrafish model, using morpholino-based gene silencing, identified one candidate whose silencing led to a reproducible phenotype consistent with known aspects of the candidate gene’s function. The candidate variant occurs in a TGF family-interacting domain, and has not been extensively characterized in other cancers. Cross-validation with TCGA datasets showed the gene was altered in 5% of cholangiocarcinomas, all of which displayed homozygous deletions. This identification of a germline allele associated with familial cholangiocarcinoma represents a unique discovery with clinical implications for the described family and warrants further investigation in other patients who display features of an inherited cholagniocarcinoma. This finding also raises the possibility of TGF pathway targeting as a therapeutic strategy in select cholangiocarcinomas, and highlights the power of whole-genome phasing to discover novel inherited tumor suppressor variants.

Citation Format: Stephanie Greer, Lincoln Nadauld, Billy Lau, Laura Miotke, Erik Hopmans, Christina M. Wood, John M. Bell, David A. Jones, Hanlee P. Ji. Identification of novel tumor suppressor candidates in familial cholangiocarcinoma using sequencing-based Megabase-scale haplotypes from germline and cancer genomes [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 1436. doi:10.1158/1538-7445.AM2017-1436
Abstract 1447: Identification of an oncogenic germline KRAS truncating mutation in hereditary cancers
Authors: Goswami Moloy T. , Hovelson Daniel H. , Johnson Anna , Tomlins Scott A. , Wang Lucy , Zhulke Kimberly , Singh Bhavneet , Anand Sharath Kumar , Cani Andi , Liu Albert , Kamberov Steven , Wu Yi-Mi , Robinson Dan , Chinnaiyan Arul , Cooney Kathleen A.
Published: July 2017

Somatic strongly activating KRAS mutations play an oncogenic role across numerous human cancers, while less activating germline KRAS mutations are associated with developmental disorders. KRAS encodes two splice variant products—KRAS-4A and KRAS-4B—differing in their C-terminus through alternative fourth coding exons. Though KRAS-4A is homologous to the original transforming transcript identified in Kirsten rat sarcoma virus, its role in human cancer is less characterized compared to KRAS-4B. Here, through genetic analyses of three cohorts of patients with hereditary and/or aggressive cancers, we identified a rare KRAS-4A specific C-terminal truncating germline mutation (KRAS-4A C180X; rs373169526) in affected men of three families with hereditary prostate cancer and a patient with hereditary melanoma (minor allele frequency [MAF] of 0.0014 in these combined cancer cohorts assessed vs. 0.000056 in the ExAC population database, odds ratio 24.6 [95% confidence interval 5.1-103.5], two sided Fisher’s exact test p = 9.0E-5). The KRAS-4A C180X mutation truncates the C-terminus, removing the polybasic region and -CAAX motifs previously demonstrated to be necessary for Ras family member membrane association, MAP kinase signaling activation and transformation, suggesting a loss of function phenotype. However, in silico assessment of reported human variation demonstrates truncating germline variants only in KRAS-4A and not KRAS-4B, consistent with tolerance. Expression of KRAS-4A protein in NIH3T3 and MDCK leads to loss of exclusive membrane association and inhibits GTP loading, as expected, but paradoxically resulted in modest but significantly increased proliferation and soft agar colony growth compared to control or wildtype KRAS expressing cells. Pro-oncogenic phenotypes were not dependent on MAPK signaling, but showed sensitivity to AKT inhibition. In summary, we identified a germline truncating KRAS-4A mutation over-represented in hereditary cancers that defines a novel mechanism of KRAS activation not dependent on the C-terminal polybasic and -CAAX motifs.

Citation Format: Moloy T. Goswami, Daniel H. Hovelson, Anna Johnson, Scott A. Tomlins, Lucy Wang, Kimberly Zhulke, Bhavneet Singh, Sharath Kumar Anand, Andi Cani, Albert Liu, Steven Kamberov, Yi-Mi Wu, Dan Robinson, Arul Chinnaiyan, Kathleen A. Cooney. Identification of an oncogenic germline KRAS truncating mutation in hereditary 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 1447. doi:10.1158/1538-7445.AM2017-1447
Abstract 1455: Vitamin D receptor (VDR) gene polymorphisms among Sudanese females with breast cancer attending Radio and Isotope Center of Khartoum
Authors: Yousif Sara O. , Ismail Amar M. , Mohamed Abdelrahim O. , Mohamed Abdelrahim O.
Published: July 2017

Background: Vitamin D Receptor (VDR) gene polymorphisms has been reported to

be associated with different cancers, including breast cancer. geographical and

environmental factors have an impact on vitamin D (VD) metabolism. This study

aims to evaluate VDR-gene polymorphisms (Fok1, Bsm1, Taq1, Apa1) and its

association with breast cancer risk among Sudanese females.

Materials and Methods: this is a case control study done in the Radio and Isotope

Center in Khartoum, Sudan. Hundred thirty seven patients and 69 healthy controls

were enrolled after informed consent. Blood genomic DNA was extracted using

quinidine chloroform method, and single nucleotide polymorphisms (SNPs) Fok1

(T/C) [rs2228570], Bsm1 (G/A) [rs1544410], Taq1 (C/T) [rs731236] and Apa1 (C/A)

[(rs7975232] in VDR-gene were detected by PCR and restriction fragment length

polymorphism (PCR-RFLP) analysis.

Results: VDR-SNPs rs731236 correlated significantly with low risk of breast cancer

(OR=0.5, p= 0.002). There was no significant association observed with rs1544410

and rs7975232. Although our study did not show an overall statistically significant

association of VDR-SNPs rs2228570 with the risk of breast cancer, we found a 1.3

fold increased risk of breast cancer (OR= 1.3) among females with FF genotype when

compared with ff genotype, suggesting that females homozygous for F allele, might be

at more risk than females carrying homozygous f allele.

Conclusions: These results suggested that, VDR-SNPs rs2228570 may be related to

higher risk of breast cancer and VDR-SNPs rs731236 associated with lower risk of

breast cancer in Sudanese females.

Key words: Breast Cancer, VDR, Polymorphisms, SNPs

Citation Format: Sara O. Yousif, Amar M. Ismail, Abdelrahim O. Mohamed, Abdelrahim O. Mohamed. Vitamin D receptor (VDR) gene polymorphisms among Sudanese females with breast cancer attending Radio and Isotope Center of Khartoum [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 1455. doi:10.1158/1538-7445.AM2017-1455
Abstract 1460: miRNome analyses reveal that activity of CAF expressed podoplanin in tumor microenvironment is modulated by exosome miRNAs involved in the PTEN-PI3K-AKT-mTOR signaling
Authors: Tejchman Anna , Mennesson Eric , Fixe Isabelle , Foucher Alexandra , Perera Simon , Artigas Laura , Mas Jose Manuel , Grillon Catherine , Ugorski Maciej , Normand Nadia , Kieda Claudine
Published: July 2017

In breast cancer, cancer associated fibroblasts (CAF) express podoplanin but little is known about its mechanism of expression and modulation. This might be crucial for cancer cell movements and for the ability to escape from the tumor site. Podoplanin showed anti-adhesive activity towards tumor and immune cells. A key control of tumor microenvironment is exerted by microRNAs on gene expression. Therefore miRNAs profiling was performed with 3D-Gene microarray technology on a breast CAF model, on cell lysates and on secreted exosomes, in hypoxia versus normoxia culture conditions.

Systems biology enrichment analyses were carried out through bioinformatics using mathematical models that simulate in silico the behaviour of human physiology. Targets linked to the set of differential miRNAs, both up-regulated and down-regulated, have been analyzed with various methods including a hypergeometric distribution method. Processes linked to hypoxia, glycosylation, angiogenesis, extracellular matrix and pathways associated with PI3K-AKT, mTOR, P53 and chemokines signaling were studied.

We showed that podoplanin expression strongly affected miRNAs involved in these processes. Hypoxia increased expression of miR-210, miR-21 and miR-29b in cells over-expressing podoplanin. miR-21 is an oncogenic regulator in most cancer cells through its downstream target proteins among which stands the tumor suppressor PTEN, a candidate to alleviate hypoxia in tumors, regulating tumor angiogenesis and modulating tumor hypoxia. miR-29b is a tumor suppressor, it also correlates with PTEN repression.

We highlighted miRNA regulation of podoplanin expression through downregulation of upstream genes for tumor suppressor PTEN. The combination of miRNome analysis and systems biology bioinformatics uncovered potential miRNAs involved in the regulation of podoplanin activity in CAF. Such data analysis may be applied to protein and mRNA biomarkers and extended to other pathology pathways.

Citation Format: Anna Tejchman, Eric Mennesson, Isabelle Fixe, Alexandra Foucher, Simon Perera, Laura Artigas, Jose Manuel Mas, Catherine Grillon, Maciej Ugorski, Nadia Normand, Claudine Kieda. miRNome analyses reveal that activity of CAF expressed podoplanin in tumor microenvironment is modulated by exosome miRNAs involved in the PTEN-PI3K-AKT-mTOR signaling [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 1460. doi:10.1158/1538-7445.AM2017-1460
Abstract 1464: miR-6734 induces cell cycle arrest and apoptosis via up-regulation of p21 expression in colon cancer cells
Authors: Kang Jong Soon , Kang Moo Rim
Published: July 2017

Recently, microRNAs have been implicated in the regulation of gene expression in terms of both gene silencing and gene activation. Here, we investigated the effects of miR-6734, which has a sequence homology with a specific region of p21WAF1/CIP1 (p21) promoter, on cancer cell growth and the mechanisms involved in this effect. miR-6734 up-regulated p21 expression at both mRNA and protein levels and chromatin immunoprecipitation analysis using biotin-labeled miR-6734 confirmed the association of miR-6734 with p21 promoter. Moreover, miR-6734 inhibited cancer cell growth and induced cell cycle arrest and apoptosis in HCT-116 cells, which was abolished by knockdown of p21. The phosphorylation of Rb and the cleavage of caspase 3 and PARP were suppressed by miR-6734 transfection in HCT-116 cells and these effects were also reversed by p21 knockdown. In addition, miR-6734 transfection caused prolonged induction of p21 gene and modification of histones in p21 promoter, which are typical aspects of a phenomenon referred to as RNA activation (RNAa). Collectively, our results demonstrated that miR-6734 inhibits the growth of colon cancer cells by up-regulating p21 gene expression and subsequent induction of cell cycle arrest and apoptosis, suggesting its role as an important endogenous regulator of cancer cell proliferation and survival.

Citation Format: Jong Soon Kang, Moo Rim Kang. miR-6734 induces cell cycle arrest and apoptosis via up-regulation of p21 expression in colon cancer 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 1464. doi:10.1158/1538-7445.AM2017-1464
Abstract 1470: Fine-tuning the expression of heterogeneous network of genes involved in androgen signaling, aerobic glycolysis, apoptosis and epithelial-mesenchymal transition by microRNA-644a in prostate cancer potentiation of AR signaling therapy by miR-644a: Selective manipulation of the prostate cancer transcriptome by miR-644a
Authors: Ebron Jey Sabith , Singh Jagjit , Shankar Eswar , Weyman Crystal , Gupta Sanjay , Lindner Daniel J. , Shukla Girish C.
Published: July 2017

Intratumoral Prostate cancer (PCa) heterogeneity is characterized by multiple intrinsic mechanisms including Androgen signaling, aerobic glycolysis, aberrant transcriptional activation of c-Myc and dysregulation of miRNAs. The ability of prostate cancer cells to alter growth and metabolism in a manner distinct from benign cells is a major concern in the treatment of castration-resistant prostate cancer. Therefore, targeting the diverse oncogenesis promoting pathways involved in PCa progression and resistance at the posttranscriptional level using micro RNAs (miRNAs) offers a novel therapeutic option. Using a miRNA mimic screen, we identified a human-specific miRNA miR-644a, which modulates expression of a diverse set of oncogenic pathways in PCa including androgen signaling, AKT/IGF-1R signaling, c-myc mediated signaling and EMT pathways. We have also demonstrated a potent tumor suppressive function of miR-644a in mouse prostate cancer xenograft model. miR-644a also sensitizes the PCa tumors to current therapeutic options including AR antagonist Enzalutamide by regulating the key modulators in development of drug resistance. In conclusion, our study demonstrates that miR-644a is a novel tumor suppressor miRNA regulating key prostate carcinogenesis promoting pathways.

Citation Format: Jey Sabith Ebron, Jagjit Singh, Eswar Shankar, Crystal Weyman, Sanjay Gupta, Daniel J. Lindner, Girish C. Shukla. Fine-tuning the expression of heterogeneous network of genes involved in androgen signaling, aerobic glycolysis, apoptosis and epithelial-mesenchymal transition by microRNA-644a in prostate cancer potentiation of AR signaling therapy by miR-644a: Selective manipulation of the prostate cancer transcriptome by miR-644a [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 1470. doi:10.1158/1538-7445.AM2017-1470
Abstract 1473: miR-1207-3p regulates c-Myc in aggressive prostate cancer
Authors: Das Dibash K. , Ogunwobi Olorunseun O.
Published: July 2017

Prostate cancer (PCa) is the most common non-skin cancer and the second leading cause of cancer-related death for men in the U.S. A major challenge is understanding the molecular mechanisms involved in the progression from the asymptomatic androgen-dependent PCa to the lethal castration resistant prostate cancer (CRPC). The chromosomal region 8q24 is associated with aggressive PCa and variants of this region have been identified to interact with the PVT1 non-coding gene in PCa. In previous work we demonstrated that microRNA-1207-3p (miR-1207-3p) has prognostic value in PCa, and directly binds to the 3’ UTR of Fibronectin type III domain containing 1 (FNDC1) to regulate a novel FNDC1/fibronectin (FN1)/androgen receptor (AR) pathway upregulated in metastatic PCa. miR-1207-3p is encoded at the PVT1 gene locus, which is located downstream of c-Myc on the 8q24 human chromosomal region. Studies have suggested amplification at the 8q24 human chromosomal region, which includes C-Myc, as a possible prognostic factor for CRPC. c-Myc is a well-established proto-oncogene that is commonly found to be amplified in up to 72% of CRPCs significant amplication of c-myc has been a consequence of antiandrogen treatment, and c-Myc is downstream of AR in some PCa. miRNAs have also been implicated in the regulation of c-Myc. Nevertheless, the mechanisms regulating c-Myc remain unclear in PCa. Using a panel of five PCa cell lines we discovered that c-Myc expression is higher in aggressive CRPC cell lines compared to non-aggressive CRPC and androgen-dependent prostate cancer cell lines. Furthermore, our data reveals that c-Myc expression is higher in the aggressive E006AA-hT PCa cell line when compared to the indolent E006AA PCa cell line. This suggests that c-Myc is associated with aggressive PCa. Moreover, overexpression of miR-1207-3p suppresses the expression of c-Myc in E006AA-hT PCa cells but not E006AA PCa cell line in which c-Myc is underexpressed compared to the normal prostate epithelial cell line, RWPE-1. Next, using a synthetic biotinylated miR-1207-3p duplex, we discovered that overexpression of miR-1207-3p more effictively inhibited migration, inhibited proliferation and increased apoptosis in the aggressive E006AA-hT PCa cell line with increased c-Myc expression when compared to the indolent E006AA PCa cell line with decreased c-Myc expression. These data demonstrate that the miR-1207-3p/FNDC1/FN1/AR pathway may regulate c-Myc in aggressive PCa.

Citation Format: Dibash K. Das, Olorunseun O. Ogunwobi. miR-1207-3p regulates c-Myc in aggressive 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 1473. doi:10.1158/1538-7445.AM2017-1473
Abstract 1480: Mir-182 is involved in sulindac anticancer activity in colon cancer
Authors: Zhao Hongyou , Yi Bin , Liang Zhipin , Ma Ruixia , Xi Yaguang
Published: July 2017

Nonsteroidal anti-inflammatory drugs (NSAIDs) display promising antineoplastic activity in many human solid tumors including colorectal cancer. Previous studies reported that sulindac sulfide (SS) can inhibit the growth of tumor cells through cyclooxygenase-2 (COX-2) dependent or independent pathways. Obviously, COX-2 independent pathway involves a low toxic property to support the clinical potential for using sulindac as a chemoprevention drug. However, the molecular mechanisms responsible for COX-2 independent pathway have not been completely elucidated. In this project, we employed two human colon cancer cell lines, referred to HCT116 and HT29. HCT116 cells are characterized for low COX-2 expression, while HT29 cells show relatively high COX-2 expression. We found that SS could unbiasedly inhibit the growth of HCT116 and HT29 cells by arresting cells in G1/G2 phases. CyclinG2 was found to be upregulated in response to SS treatment. FOXO3a has been reported to regulate CyclinG2 expression at the transcriptional level. Our results demonstrate that SS could also upregulate FOXO3a. By using the loss-of-function strategy, we found that SS could not efficiently upregulate CyclinG2 and lead to cell cycle arrest in cells with FOXO3a knockdown. In addition, we studied the mechanism that could be involved in SS regulation of FOXO3a. Our previous studies reported that a panel of miRNAs could be altered by SS treatment in both colon and breast cancer cells. In the downregulated miRNA list, we found that miR-182 could potentially target FOXO3a. By using luciferase assay, we validated the direct regulation of miR-182 on the expression of FOXO3a. When miR-182 was downregulated, SS could neither efficiently upregulate the expression of FOXO3a nor inhibit cell growth as it did in control cells. We gained highly consistent results in HT29 and HT29 cells with COX-2 knockdown. Therefore, our study demonstrates a pathway consisting of miR-182/ FOXO3a/ CyclinG2 as a novel mechanism responsible for SS anticancer activity in colon cancer, which may imply a COX-2 independent pathway.

Citation Format: Hongyou Zhao, Bin Yi, Zhipin Liang, Ruixia Ma, Yaguang Xi. Mir-182 is involved in sulindac anticancer activity in colon 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 1480. doi:10.1158/1538-7445.AM2017-1480
Abstract 1482: Triptolide inhibits the growth of osteosarcoma by regulating microRNA-181a via targeting PTEN gene in vivo and in vitro
Authors: Jiang Chunming , Fang Xiang , Wang Xuepeng , Li Maoqiang , Jiang Wu , Zhu Liulong , Bian Zhenyu
Published: July 2017

Objective: We aimed to study the effect of triptolide on OS and the related molecular mechanism.

Methods: The cell viability, apoptosis portion, tumor size, tumor weight and invasion of OS cells were determined. The relative level of miR-181 in OS tissues and the adjacent tissues was determined by qRT-PCR. The target gene of miR-181a was determined and verified by luciferase report assay. At last, OS cells were treated with triptolide and triptolide + miR-181a mimics to verify the relationship between triptolide and miRN-181a.

Results: Triptolide inhibited the cell viability, promoted the apoptosis, decreased the tumor size and weight, and reduced the invasion of OS cells. The level of miR-181a in OS cells decreased significantly after treating with triptolide, and the relative level of miR-181a in OS tissues was markedly higher than that in the adjacent tissues. PTEN was reported and verified the direct target gene of miR-181a. The overexpression of miR-181a decreased the inhibition of triptolide on OS proliferation and promotion on OS apoptosis.

Conclusion: Triptolide inhibited the proliferation of OS by regulating miR-181a via targeting PTEN gene in vivo and vitro.

Note: This abstract was not presented at the meeting.

Citation Format: Chunming Jiang, Xiang Fang, Xuepeng Wang, Maoqiang Li, Wu Jiang, Liulong Zhu, Zhenyu Bian. Triptolide inhibits the growth of osteosarcoma by regulating microRNA-181a via targeting PTEN gene in vivo and in vitro [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 1482. doi:10.1158/1538-7445.AM2017-1482
Abstract 1491: Mitochondrial dysfunction from defective Cytochrome oxidase complex induces tumorigenic phenotype
Authors: Srinivasan Satish , Guha Manti , Ruthel Gordon , Nakagawa Hiroshi , Avadhani Narayan
Published: July 2017

Mitochondrial defects that affect activity of the electron transport chain (ETC) complexes are associated with several diseases including cancer. Dysfunctional mitochondria resulting from mitochondrial DNA (mtDNA) alterations or exposure to xenobiotics have been shown to initiate retrograde signaling pathway characterized by disrupted membrane potential, elevated cytosolic calcium and activation of Calcineurin, a calcium dependent phosphatase. In some cell types these events form the basis for triggering transcriptional reprogramming that converts non tumorigenic cells to tumorigenic phenotype. Cytochrome oxidase (CcO) is the terminal enzyme of the ETC that catalyzes the transfer of electrons from reduced cytochrome C to oxygen. All the mutations of CcO subunits identified as prevalent in various cancers like prostrate, pancreatic, colon and ovarian cancers have been found in mtDNA encoded subunits. Effect of loss of nuclear subunits leading to reduced Cytochrome oxidase activity on tumor progression are not well studied. Nuclear subunits IVi1 and Vb of CcO are susceptible to various stress conditions like exposure to long term hypoxia, ischemia-reperfusion and treatment with ethanol resulting in selective degradation and loss of activity. Here we report the activation of retrograde signaling by loss of these subunits. Genetic silencing of the subunits IVi1 and Vb, and loss of activity resulted in metabolic shift to glycolysis and was accompanied by increased glucose utilization. Disruption of the CcO complex activated many of the hallmark factors of Ca2+/Calcineurin mediated retrograde signaling. Importantly, rescue of the CcO deficiency by overexpressing CcO subunits or by inhibitors of retrograde signaling pathway attenuated the phenotypic changes such as anchorage independent growth and increased invasive potential. Further, esophageal tumor sections from human patients revealed reduced CcO subunits IVi1 and Vb in the center of the tumor mass suggesting a pathological significance of these findings. Our results show that mitochondrial ETC defect initiates a retrograde signaling and induces genes with major roles in tumor development. (Supported by NIH grants CA-22762 and GM-34883)

Note: This abstract was not presented at the meeting.

Citation Format: Satish Srinivasan, Manti Guha, Gordon Ruthel, Hiroshi Nakagawa, Narayan Avadhani. Mitochondrial dysfunction from defective Cytochrome oxidase complex induces tumorigenic phenotype [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 1491. doi:10.1158/1538-7445.AM2017-1491
Abstract 1493: LonP1 is required for tumor maintenance and growth
Authors: Amidon Benjamin S. , Wu Dongyun , Bradley John , Ma Jingya , Tsu Christopher , Carideo-Cunniff Elizabeth , Kolev Vihren , Garnsey James , Shah Pooja , Koenig Erik , Liao Hua , Cullis Courtney
Published: July 2017

Proper mitochondrial function is critical for energy production and the cycling of metabolites required for tumor establishment and growth. LonP1 is an ATP-dependent serine protease that is critical for maintaining mitochondrial protein homeostasis by degrading misfolded and damaged proteins in the mitochondrial matrix. Knockdown of LonP1 has been shown to reduce tumorogenesis and is consistent with the model that requires properly functioning mitochondria for tumor establishment. It is unclear what the role of LonP1 is in tumor maintenance and growth from an established tumor, therefore the LonP1 gene was mutated and complemented by a doxycycline-inducible copy of LonP1. These complementation clones have the ability to establish tumors in vivo in the presence of doxycycline, however upon doxycycline withdrawal the tumors regress and show evidence of apoptosis. These xenograft lines permit unique insight into not only potential LonP1 substrates but also the direct and indirect effects from loss of mitochondrial matrix protein homeostasis. Comparison and contrast of these complemented cell lines in vitro and in vivo by expression and proteomic analysis will be discussed.

Citation Format: Benjamin S. Amidon, Dongyun Wu, John Bradley, Jingya Ma, Christopher Tsu, Elizabeth Carideo-Cunniff, Vihren Kolev, James Garnsey, Pooja Shah, Erik Koenig, Hua Liao, Courtney Cullis. LonP1 is required for tumor maintenance and growth [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 1493. doi:10.1158/1538-7445.AM2017-1493
Abstract 1496: Connecting the metallome with metabolism in ovarian cancer
Authors: Shide Eric D. , Amable Lauren
Published: July 2017

Ovarian cancer has historically been diagnosed late stage and lacks effective biomarkers for detection and prognosis. The deregulation of metabolism and signaling cascades inherent of cancer may contribute to aberrant levels of metal within cells. Biological processes essential for cell proliferation require metals for enzyme cofactors, signaling molecules, and structural components. Metallomics is the study of the comprehensive, dynamic metal profile within cells. The goal of our study was to characterize the ovarian cancer metallome at the level of whole cell and mitochondria in comparison to non-cancer. Additionally, cellular metabolism was analyzed to connect the mitochondrial (mito-)metallome to mitochondrial function. Ten human ovarian cancer cell lines were used for experiments: A2780, CAOV3, A2780/CIS, A2780/CP70, ES2, OVCAR3, OVCAR5, SKOV3, TOV112, and TOV21. Three non-cancer human ovarian cell lines of epithelial and fibroblast origin served as controls. Inductively coupled mass spectrometry (ICP-MS) was used to evaluate the metallome by measuring the following metals: calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), molybdenum (Mo), phosphorous (P), sulfur (S), selenium (Se), and zinc (Zn). An XF24 Seahorse analyzer was used to measure cellular metabolism and mitochondrial function in the ovarian cancer and non-cancer cell lines. Our results demonstrated that there was a distinct metal profile at the level of the whole cell and mitochondria in ovarian cancer cells compared to non-cancer ovarian cells. The whole cell ovarian cancer metallome consisted of increased Mg, P, and Cu, and decreased Fe, Mn, and Se in comparison to non-cancer. The cancer mito-metallome consisted of increased Mg, P, Cu, Zn, Se, and Ca. Referencing established literature of the known metals that serve as cofactors for mitochondrial proteins, the relationship between the mito-metallome and functional metabolic pathways was established. Changes in cellular metabolism were reflected by changes in the mito-metallome. Our study was the first to evaluate an extensive panel of metals simultaneously in the mitochondria and bridge the unique metal signature of ovarian cancer to cell metabolism. Future proteomics studies will be used to further validate the connection of metals to cellular function. Metallomics and the ovarian cancer cell metallome provide further understanding of how cancer deregulates the metallome and how metallomics may provide an avenue for identifying new cancer biomarkers and allow for effective targeting of cancer with chemotherapy.

Citation Format: Eric D. Shide, Lauren Amable. Connecting the metallome with metabolism in ovarian 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 1496. doi:10.1158/1538-7445.AM2017-1496
Abstract 1504: Tumor-treating fields (TTFields) interfere with biological key properties of glioma cells in vitro
Authors: Silginer Manuela , Weller Michael , Stupp Roger , Roth Patrick
Published: July 2017

Tumor-treating fields (TTFields) are low amplitude alternating electric fields which are supposed to exert anti-tumor effects by targeting dividing tumor cells while sparing cells in the brain not undergoing cell division. Although this novel therapeutic approach has shown encouraging results in phase III trials in glioblastoma, its biological effects on tumor cells have only been poorly understood.

Here, we investigated the effects of TTFields on glioma cells in vitro using the inovitroTM system that allows the application of TTFields to cell cultures. Exposure to TTFields potently induce autophagy and necroptosis and interfere with the migration and invasion of long-term glioma cell lines, but also of glioma-initiating. The combination of TTFields with irradiation or temozolomide (TMZ) reduced viability and clonogenic survival in an additive or synergistic manner. Further studies suggest that the O6-methyl-guanine DNA methyltransferase (MGMT) status does not influence the efficacy of TTFields and TMZ-resistant glioma cells remain responsive to TTFields application, thus making TTFields particularly attractive for the majority of glioblastoma patients with tumors that are unlikely to benefit from TMZ treatment.

In summary, these findings demonstrate that the application of TTFields may interfere with various biological key properties of glioma cells and may allow for a more detailed clinical evaluation of TTFields beyond the clinical data available so far.

Citation Format: Manuela Silginer, Michael Weller, Roger Stupp, Patrick Roth. Tumor-treating fields (TTFields) interfere with biological key properties of glioma cells in vitro [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 1504. doi:10.1158/1538-7445.AM2017-1504