bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 894: Melanoma fights cisplatin with NO: S-nitrosation as a mechanism supporting drug-resistance.
Authors: Godoy Luiz C. , Anderson Chase C.T. , Chowdhury Rajdeep , Trudel Laura J. , Wogan Gerald N.
Published: August 2014

Melanoma patients experience inferior survival after bio-chemotherapy when their tumors contain numerous cells expressing the inducible isoform of NO synthase (iNOS), and elevated levels of nitrotyrosine, a product derived from nitric oxide (NO). Although several lines of evidence suggest that NO promotes tumor growth and increases resistance to chemotherapy, it is unclear how it shapes these outcomes. Here we demonstrate that modulation of NO-mediated S-nitrosation of cellular proteins is strongly associated with the pattern of response to the anti-cancer agent cisplatin in human melanoma cells in vitro. Cells were shown to express iNOS constitutively, and to generate sustained nanomolar levels of NO intracellularly. Inhibition of NO synthesis or scavenging of NO enhanced cisplatin-induced apoptotic cell death. Additionally, pharmacologic agents disrupting S-nitrosation markedly increased cisplatin toxicity, whereas treatments favoring stabilization of S-nitrosothiols decreased its cytotoxic potency. Activity of the pro-apoptotic enzyme caspase-3 was higher in cells treated with a combination of cisplatin and chemicals that decreased NO/S-nitrisothiols, whereas lower activity resulted from cisplatin combined with stabilization of S-nitrisothiols. Constitutive protein S-nitrosation in cells was detected by analysis with biotin switch and reduction/chemiluminescence techniques. Moreover, intracellular NO concentration increased significantly in cells that survived cisplatin treatment, resulting in augmented S-nitrosation of caspase-3 and prolyl-hydroxylase-2 (PHD2), the enzyme responsible for targeting the pro-survival transcription factor HIF-1α for proteasomal degradation. Because activities of these enzymes are inhibited by S-nitrosation, our data thus indicate that modulation of intrinsic intracellular NO levels substantially affects cisplatin toxicity in melanoma cells. The underlying mechanisms may thus represent potential targets for adjuvant strategies to improve the efficacy of chemotherapy.

Citation Format: Luiz C. Godoy, Chase C.T. Anderson, Rajdeep Chowdhury, Laura J. Trudel, Gerald N. Wogan. Melanoma fights cisplatin with NO: S-nitrosation as a mechanism supporting drug-resistance. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 894. doi:10.1158/1538-7445.AM2013-894
Abstract 910: Synergistic combinations of targeted therapy and chemotherapy for neuroendocrine cancer.
Authors: Dinnen Richard D. , Mao Yuehua , Petrylak Daniel P. , Fine Robert L.
Published: August 2014

We previously developed and reported a novel laboratory-derived chemotherapeutic regimen of capecitabine and temozolomide (TMZ) (CapTem). The CapTem regimen is highly active, well-tolerated with minor toxicities and may prolong survival and palliate symptoms in patients with well differentiated neuroendocrine tumors (NET).

Further studies with CapTem in our laboratory indicated that sunitinib, a tyrosine kinase inhibitor (TKI), was highly synergistic with 5-Fluorouracil (5-FU) in killing BON (NET) cells. (Capecitabine is enzymatically converted to 5-FU in the tumor). Synergy was observed at a low concentration of 1.0 μM 5-FU and 1 nM sunitinib. Addition of 100 nM sunitinib resulted in a 4.5 fold increase in cell death (14.2 vs 64.5%). In addition, if sunitinib was combined with the CapTem regimen, (5-FU followed by TMZ), a synergistic response was observed with both 5-FU and TMZ over a range of concentrations, giving a maximal cell death of 74.4%. This contrasts with the cell death obtained with 5-FU, TMZ and sunitinib alone, resulting in 9.0, 6.8 and 10.2% annexin V+ cells, respectively.

Sorafinib, a TKI closely related to sunitinib, not only did not synergize with 5-FU or TMZ, it inhibited cell death observed with sunitinib and 5-FU/ TMZ. In addition, K-252a, a potent inhibitor of tyrosine kinases, reduced the cell death induced by 5-FU/sunitinib suggesting a tyrosine kinase was involved. Considering the IC-50 of sunitinib for PDGF β is 75 nM, whereas for sorafinib it is 1129 nM, a difference of 15 fold, we hypothsized that the PDGF-β pathway might be involved. Addition of the PDGF-ββ form resulted in an enhancement of 5-FU/TMZ (CapTem) cell death. However, there was no effect on sunitinib-induced cell death, suggesting that the PDGF-β pathway may be involved but to an unknown extent in the cell death pathway induced by CapTem.

Exposure of BON cells to TMZ and 5-FU may mimic the in vivo exposure to these drugs in patients and the resulting cell line resistance may be similar to resistance in tumors. Preliminary studies with four resistant BON cell lines: TMZ-Resistant, 5-FU-Resistant, TMZ+5FU-Resistant, (concurrent exposure to TMZ and 5-FU) and TMZ -> 5FU-Resistant, (sequential exposure to 5FU and TMZ) found that cells resistant to CapTem still retain sensitivity to sunitinib. This suggests that addition of sunitinib can overcome CapTem resistance in BON cells.

Citation Format: Richard D. Dinnen, Yuehua Mao, Daniel P. Petrylak, Robert L. Fine. Synergistic combinations of targeted therapy and chemotherapy for neuroendocrine cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 910. doi:10.1158/1538-7445.AM2013-910
Abstract 916: Preclinical responses of the MEK inhibitor AZD6244 in a genetically modified mouse model of prostate cancer.
Authors: Uemura Hirotsugu , Kura Yurie , Ando Naomi , Fukushima Emiko , Hatanaka Yuji , Yamamoto Yutaka , Shimizu Nobutaka , Nozawa Masahiro , Yoshimura Kazuhiro , Yoshikawa Kazuhiro , Nishio Kazuto , De Velasco Marco A.
Published: August 2014

The mitogen-activated protein kinase (MAPK) pathway is involved in a broad range of cellular processes that include proliferation, survival, apoptosis, and cellular differentiation. MAPK has also been shown to increase the transcription of androgen-dependent (AR) genes, independently of androgens by phosphorylation of the AR or its cofactors. Thus, MAPK signal inhibition has the potential to be a therapeutic target for prostate cancer. To determine the clinical benefit of MAPK inhibition, we used the highly selective MEK inhibitor, AZD6244, in a prostate-specific PTEN-conditional knockout mouse model of prostate cancer. In this model, prostate tumors from mice exhibit increased levels of p-Erk1/2 expression that correlates with tumor progression. Acute pharmacodynamic responses, after a single dose of AZD6244, showed a strong inhibition of Erk1/2 phosphorylation that was maintained for at least 24 hours after drug administration. Levels of cellular proliferation decreased, and apoptosis was induced shortly after the administration of AZD6244. However, apoptosis was suppressed after 8 hours. To further characterize the responses to MAPK signal inhibition, we examined the activity of downstream molecules of the PI3K/Akt and JAK/STAT3 signaling pathways. While PI3K/Akt activity decreased mildly, activation of JAK/STAT3 was transiently but strongly increased. To determine tumor responses to chronic administration of AZD6244, Pten-mutant mice harboring prostate tumors were treated with AZD6244 for 4 a period of 4 weeks. 2-D morphometric analysis of tumor surface area showed a reduction of 10.9% (P =0.035) in treated mice. Furthermore, inhibition of p-Erk was maintained and tumor cell proliferation was reduced by 25.24% (P =0.005). The apoptotic index increased from 3.9% in controls to 7.2% (P=0.004) in mice receiving AZD6244. Our findings suggest that inhibition of MAPK signaling can contribute to decreased tumor progression and may represent a promising therapeutic alternative.

Citation Format: Hirotsugu Uemura, Yurie Kura, Naomi Ando, Emiko Fukushima, Yuji Hatanaka, Yutaka Yamamoto, Nobutaka Shimizu, Masahiro Nozawa, Kazuhiro Yoshimura, Kazuhiro Yoshikawa, Kazuto Nishio, Marco A. De Velasco. Preclinical responses of the MEK inhibitor AZD6244 in a genetically modified mouse model of prostate cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 916. doi:10.1158/1538-7445.AM2013-916
Abstract 921: Small-molecule inhibitor BMS-777607 induces breast cancer cell polyploidy with increased resistance to cytotoxic chemotherapy agents.
Authors: Sharma Sharad , Zeng Jun-Yin , Zhunag Chunmei , Zhang Ruiwen , Wang Ming-hai
Published: August 2014

The RON receptor tyrosine kinase is a therapeutic target for cancer treatment. Here we report therapeutic effect and phenotypic change of breast cancer cells in response to BMS-777607, a RON tyrosine kinase inhibitor. Treatment of breast cancer cells with BMS-777607 at therapeutic doses inhibited cancerous clonogenic growth but had only minimal effect on cell apoptosis. Significantly, BMS-777607 induced extensive polyploidy with multiple sets of chromosomes in cancer cells. This effect is independent of RON expression. Knockdown of RON in T-47D and ZR-75-1 cells by specific siRNA did not prevent polyploid formation. Immunofluorescent analysis of α-tubulin and γ-tubulin expression in polyploid cells revealed that BMS-777607 disrupts bi-polar spindle formation and causes multi-polar-like microtubule assembly. Also, both metaphase equatorial alignment and chromosomal segregation were absent in polyploid cells. These results suggest that cellular mitosis arrests at prophase/pro-metaphase and fails to undergo cytokinesis. By analyzing kinase-inhibitory profiles, aurora kinase B was identified as the target molecule inhibited by BMS-777607. In BMS-777607 treated cells, aurora kinase B was inhibited followed by protein degradation. Moreover, BMS-777607 inhibited Ser10 phosphorylation of histone H3, a substrate of aurora kinase B. Chemosensitivity analysis indicated the resistance of polyploid cells towards chemotherapeutics. Treatment with doxorubicin, bleomycin,cisplatin, methotrexate, and paclitaxel significantly increased cellular IC50 values. These findings highlight the theory that BMS-777607 acts as a multi-kinase inhibitor at therapeutic doses and is capable of inducing polyploidy by inhibiting aurora kinase B. Increased resistance of polyploid cells to cytotoxic chemotherapeutics could have a negative impact on targeted cancer therapy using BMS-777607.

Citation Format: Sharad Sharma, Jun-Yin Zeng, Chunmei Zhunag, Ruiwen Zhang, Ming-hai Wang. Small-molecule inhibitor BMS-777607 induces breast cancer cell polyploidy with increased resistance to cytotoxic chemotherapy agents. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 921. doi:10.1158/1538-7445.AM2013-921
Abstract 929: Caboxylic acid esters as inhibitors of the MEK1/2 and MEK5 signaling cascades.
Authors: Cavanaugh Jane E. , Monlish Darlene A. , Chakrabarty Suravi , Qin Si , Flaherty Patrick T.
Published: August 2014

The purpose of the current study is to examine how structural variation on methyl anthranilates can differentially affect specific branches of the MAPK signaling cascade. The specific goal is to correlate the role of MEK1/2 versus MEK5 in breast cancer proliferation and migration modeled by the profile of pERK isoforms in treated BT-474 (ER+/PR+/HER2high) and MDA-MB-231 (ER−/PR−/HER2low) human breast cancer cell lines. The MAPK signaling pathway is a complex interconnected signaling cascade activated by extracellular stimuli, including growth factors, cytokines, and mechanical and chemical stressors, to elicit appropriate cellular responses including cell survival, proliferation, differentiation, and apoptotic cell death. The interconnected nature of these pathways permits a single external stimulus to be interpreted in the context of the immediate metabolic demands of the cell. The singularly specific and parallel event is phosphorylation of ERK by its corresponding activating kinase or MEK. In the course of examining small molecules with the design goal of developing selective inhibitors of the MEK5 isoform, we identified a simple substituted methyl anthranilate derivative that unexpectedly and specifically inhibited ERK1/2 activation but had little effect on ERK5 activation. We subsequently explored structural variations and prepared structure assisted new compounds from this initial find. In the BT-474 and MDA-MB-231 cell lines, western blot analysis was performed to determine the expression and activation of ERK1/2 and ERK5 following treatment with the novel MEK-specific inhibitors. An MTT assay was used to assess changes in cell proliferation following kinase inhibition, while scratch and invasion assays were performed to assess the effect of the carboxylic acid esters on cell migration and invasion in these cell lines. The data obtained from these studies indicate methyl anthranilate derivatives warrant further investigation as potential inhibitors of tumor proliferation and migration in breast cancer.

Citation Format: Jane E. Cavanaugh, Darlene A. Monlish, Suravi Chakrabarty, Si Qin, Patrick T. Flaherty. Caboxylic acid esters as inhibitors of the MEK1/2 and MEK5 signaling cascades. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 929. doi:10.1158/1538-7445.AM2013-929
Abstract 933: Modeling acquired resistance to EGFR-directed therapies in mouse models of lung cancer.
Authors: Pirazzoli Valentina , de Stanchina Elisa , Xia Jungfeng , Zhao Zhongming , Pao William , Politi Katerina A.
Published: August 2014

Seventy percent of patients with Epidermal Growth Factor Receptor (EGFR) mutant lung cancer respond to treatment with the tyrosine kinase inhibitors (TKIs) erlotinib or gefitinib. Despite this high response rate, patients almost inevitably develop resistance to these drugs on average within a year of starting drug treatment. Acquired resistance to EGFR TKIs is most commonly due to the emergence of a secondary mutation (T790M) in EGFR (in 50% of cases), amplification of the genes encoding the ERBB2 and MET receptor tyrosine kinases in 12 and 5% of cases, respectively, and phenotypic transformation of the adenocarcinomas to small cell lung cancer (5% of cases). Previously, in an effort to develop strategies to overcome T790M-mediated resistance, we generated tetracycline-inducible transgenic mice that express the EGFRL858R+T790M in the lung epithelium. Upon administration of doxycycline these mice develop lung adenocarcinomas that are resistant to TKIs. However, the combination of the irreversible TKI afatinib and the EGFR antibody cetuximab showed dramatic responses in these transgenic mice. These preclinical studies led to a clinical trial of these agents, which has showing a promising 30% response rate in patients with EGFR mutant tumors resistant to TKIs. However, tumors also acquire resistance to this drug combination and the mechanisms of resistance to afatinib+cetuximab are currently unknown. We set out to identify these mechanisms using xenograft and transgenic mouse models of EGFR mutant lung cancer. Transgenic mice with EGFRL858R+T790M-induced tumors were treated with afatinib+cetuximab using an intermittent dosing strategy that we had previously used to generate erlotinib-resistant tumors in mice with EGFRL858R and EGFRDEL-induced tumors. 75% of mice develop afatinib+cetuximab resistant tumors after three month-long rounds of treatment. The same treatment strategy applied to xenografts harboring subcutaneous tumors induced by EGFRDEL+T790M gave rise to resistant tumors in 20% of cases. Analysis of the afatinib+cetuximab resistant tumors performed to date has not revealed additional mutations in the EGFR transgene, the ERBB2 kinase domain or KRAS. Additional sequencing studies and examination of signaling pathway alterations in the resistant tumors are ongoing. Uncovering mechanisms of resistance to this drug combination will allow the development of strategies to treat tumors that acquire resistance to EGFR-directed therapies.

Citation Format: Valentina Pirazzoli, Elisa de Stanchina, Jungfeng Xia, Zhongming Zhao, William Pao, Katerina A. Politi. Modeling acquired resistance to EGFR-directed therapies in mouse models of lung cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 933. doi:10.1158/1538-7445.AM2013-933
Abstract 985: Design of a model for the development of cisplatin resistance in H526 human small cell lung cancer xenografts.
Authors: Caffrey Paula B. , Frenkel Gerald D.
Published: August 2014

Treatment of Small Cell Lung Cancer (SCLC) often fails due to the rapid development of resistance to chemotherapy drugs. Reversal of resistance has proven to be difficult to achieve; thus, we have suggested an alternative strategy - prevention of its development [Frenkel & Caffrey, Current Pharmaceutical Design, (2001) 7: 1595-1614]. In order to investigate this possibility we previously designed a model of the development of cisplatin resistance in ovarian cancer xenografts, which mimics the development of clinical resistance in ovarian cancer patients [Caffrey & Frenkel, Cancer Chemotherapy Pharmacology (2000) 46: 74-78]. We used this model to identify compounds which are able to prevent resistance; these are being further investigated in a Phase I clinical trial. We have now designed an analogous model of the development of resistance in SCLC xenografts. Mice were injected sc with H526 SCLCL cells. Those bearing visible tumors were injected i.p. with a single “pretreatment” dose of cisplatin ranging from 0.75 - 3.0 mg/kg. On the 3rd, 5th or 7th day after this pretreatment, mice were injected i.p. with a single “high” dose of cisplatin (3.0 mg/kg). This high dose decreased the growth rate of control (PBS pretreated) tumors by 40%. Tumors whose growth curve was decreased by less than 40% were considered resistant. Our results indicated that several potential models resulted in a low incidence of resistance. However, pretreatment with 1.5 mg/kg followed seven days later by high dose treatment of 3.0 mg/kg consistently resulted in the development of cisplatin-resistant tumors. This model can be used to screen a variety of agents for their ability to prevent the induction of platinum resistance in SCLC tumors. Supported by a grant from the PA State System of Higher Education.

Citation Format: Paula B. Caffrey, Gerald D. Frenkel. Design of a model for the development of cisplatin resistance in H526 human small cell lung cancer xenografts. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 985. doi:10.1158/1538-7445.AM2013-985
Abstract ADV04: Wisconsin Breast Cancer and the Environment Research Program.
Authors: Berry Mary Pat
Published: August 2014

The Breast Cancer and Environmental Research Program was established by the NIH to better understand if and how a women's risk of developing breast cancer, is increased by impacted environmental carcinogens during key periods of her development. These periods are referred to as “Windows of Susceptibility.” UW-Madison is one of the eleven project collaborators. The UW-Madison Principal Investigators are Michael Gould and Amy Trentham-Dietz. Dr. Gould is focusing on genetics of supectibilty and resistance to breast cancer during periods of mammary development. His work is focused on areas of the DNA that may be associated with breast cancer. Dr. Trentham-Dietz is looking at environmental exposures that may be associated with breast cancer risk. The joint role of genetics and environmental factors research utilizes data on over 7,000 Wisconsin women. Once the Gould lab identifies genes that confer resistance of susceptibility, the Trentham-Dietz lab will use human DNA to actively identify similar genes in women.

The Wisconsin project includes a particularly strong community partnership whose roles include giving input on the interests of women in the state. These community partners represent diverse organizations whose missions relate to breast cancer. The partners are: Wisconsin Cancer Council, the Breast Cancer Task Force of the WI Cancer Control Plan, Wisconsin Breast Cancer Coalition, Susan G. Komen- South Central Wisconsin Affiliate and the UW-Milwaukee Institute for Urban Health Partnerships. Together and with their distinct constituencies (health organizations, survivors, underserved populations, culturally diverse women, real women and advocates), these community partners do outreach for education relating to the program as well as for dissemination of the work being done at other sites as well as the UW-Madison.

Citation Format: Mary Pat Berry. Wisconsin Breast Cancer and the Environment Research Program. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr ADV04. doi:10.1158/1538-7445.AM2013-ADV04
Abstract ADV16: Working together to advance research, support patients and create hope.
Authors: Nelson Scott
Published: August 2014

The Pancreatic cancer Action Network (PanCan) is a nationwide network of people dedicated to working together to advance research, support patients and create hope for those affected by pancreatic cancer. Our comprehensive approach included: 1) funding research, 2) demanding more aggressive federal research funding, 3) providing patients and caregivers with reliable information to make informed decisions with their healthcare teams, and 4) helping individuals and communities work together to raise awareness and fund for pancreatic cancer. We have over 500 mostly volunteer team members working in 70 affiliate locations around the country. We have more than 4000,000 constituents. We support the development of a comprehensive pancreatic cancer research community. We recruit, develop and retain the most adept investigators. We provide resources and tools and foster collaborations to advance scientific progress.

Citation Format: Scott Nelson. Working together to advance research, support patients and create hope. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr ADV16. doi:10.1158/1538-7445.AM2013-ADV16
Abstract ADV23: Bridging the gap: An advocate's breast cancer journey.
Authors: Walker Desiree
Published: August 2014

The poster will prtray the various steps an advocate can take in the world of breast cancer. It will also define the journey through self-advocacy, local advocacy, patient advocacy and legislatie advocacy. These actions support bridging the gap trhough education and empowerment.

Citation Format: Desiree Walker. Bridging the gap: An advocate's breast cancer journey. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr ADV23. doi:10.1158/1538-7445.AM2013-ADV23
Abstract LB-101: Targeting pancreatic cancer stroma with Palmatine, a novel compound from herbal supplement.
Authors: Chakravarthy Divya , Gong Jingjing , Hwang Rosa F. , Kumar Addanki Pratap
Published: August 2014

Pancreatic ductal adenocarcinoma is the fourth leading cause of cancer related deaths with 5-year survival rates less than 6%. Survival periods with gemcitabine in combination with various agents average over 6 months. Desmoplasia is a striking feature of pancreatic cancer. It is characterized by formation of dense stroma surrounding the tumor. This dense stroma serves as a therapeutic barrier for many chemotherapeutic drugs, in turn decreasing their efficacy. Pancreatic stellate cells (PSCs) have been reported to be involved in the observed desmoplastic reaction. Therefore targeting this stroma can be an alternate approach to pancreatic cancer. Previous studies from our laboratory showed that Nexrutine, a herbal supplement inhibits proliferation of multiple pancreatic cancer cells through modulation of Stat3/NFκB/Cox-2 signaling and reduced the number of animals developing fibrosis in vivo. To the best of our knowledge, the effect of Nexrutine or its active components on pancreatic stroma has not been studied. In this study we evaluated the effect of Nexrutine and Palmatine, an active component of Nexrutine, for its ability to target the stroma. Our studies show for the first time that Palmatine (i) inhibits proliferation of PSCs as well as the tumor cells; (ii) inhibits hedgehog signaling as evidenced by GLI expression and reporter activity; (iii) modulates expression and activity of downstream targets of GLI including Patched1, IKKB-ε and anti-apoptotic protein Survivin. Remarkably Palmatine treatment inhibits invasive ability of PSCs that is associated with reduced levels of COL1A1. Overall this is the first study reporting the ability of Palmatine to modulate Hh signaling and may have utility either alone or in conjunction with Gemcitabine for treatment of pancreatic ductal adenocarcinoma. Supported by NCCAM (AT 005513-01A1 and AT 007448l; APK).

Citation Format: Divya Chakravarthy, Jingjing Gong, Rosa F. Hwang, Addanki Pratap Kumar. Targeting pancreatic cancer stroma with Palmatine, a novel compound from herbal supplement. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-101. doi:10.1158/1538-7445.AM2013-LB-101
Abstract LB-107: Mitochondrial DNA mutations are diagnostic markers of renal oncocytomas.
Authors: Lang Martin , Vocke Cathy D. , Merino Maria J. , Schmidt Laura S. , Linehan Marston W.
Published: August 2014

Oncocytomas are mostly benign tumors of epithelial origin, characterized by dense accumulation of defective mitochondria. To date, no nuclear gene has been found to be responsible for these tumors, but a correlation of the oncocytic phenotype with the occurrence of disruptive mitochondrial DNA (mtDNA) mutations, mostly affecting genes encoding for proteins of Complex I of the respiratory chain (NADH dehydrogenase), has been shown in sporadic oncocytomas of different organs, including renal oncocytomas (RO).

Kidney cancer is made up of a number of tumors that present with a different histology and clinical course. They are caused by different genes, and therefore therapy needs to be adapted for each type of renal tumor. Imaging techniques are usually not sufficient to distinguish between benign and malignant forms of renal cell cancer (RCC). In addition, it is difficult to differentiate benign ROs from malignant forms of RCCs in samples from biopsies, because they share ultrastructural appearances, including abnormal mitochondria with altered cristae. Therefore, a reliable diagnostic tool would be invaluable to guide clinicians in the management of patients with RCC of unclear phenotype.

In our current work we tested whether mtDNA mutations can be used as diagnostic tools to distinguish between benign ROs and more aggressive forms of RCC. We sequenced the entire mtDNA in 36 samples that included sporadic, bilateral and multifocal as well as familial ROs and 30 non-oncocytic RCCs of different histologies. Moreover, the mitochondrial copy number was determined in all samples by real-time PCR. Furthermore, we sequenced the mtDNA from biopsies and compared it to the mtDNA sequence of the resected tumor.

We found a strong correlation between the presence of disruptive mtDNA mutations affecting complex I genes and the oncocytic phenotype in renal tumors. Additionally, oncocytomas showed significantly higher mtDNA copy number when compared to other RCCs. We also show that the mtDNA sequences from the biopsies correspond to the sequence of the tumor itself and are predictive of the phenotype. Hence, we propose that sequencing of the mitochondrial genome, supported by the analysis of the mtDNA copy number, may be used as a diagnostic tool to distinguish between benign and aggressive forms of RCCs to guide physicians in choosing the appropriate treatment for patients.

Citation Format: Martin Lang, Cathy D. Vocke, Maria J. Merino, Laura S. Schmidt, Marston W. Linehan. Mitochondrial DNA mutations are diagnostic markers of renal oncocytomas. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-107. doi:10.1158/1538-7445.AM2013-LB-107
Abstract LB-109: Identification of novel keratin fusion in squamous cell carcinomas.
Authors: Cheng Jack , Lai Ming-Tsung , Lee Shan-Chih , Chao Chun-Chin , Chen Chih-Mei , Ng Ka-Lok , Sheu Jim Jinn-Chyuan
Published: August 2014

Genetic instability is a hallmark during cancer development, such that gene fusions frequently occur when chromosomal translocation joins different genes. A variety of gene fusions have been identified in cancer, some of them are well known biomarkers for cancer diagnostic or chemotherapy targets. Our preliminary study uncovered novel gene fusions joining type I and II keratins in oral squamous cell carcinoma (OSCC) by pair-end RNA-seq transcriptome study. This finding was further validated by dual-color FISH and Sanger sequencing following nested PCR. Keratins form imtermediate filaments in a cell with equal-molar pairing of type I and II keratins, which maintain cell integrity under mechanical stresses and regulate adhesion and migration activity. Although keratins have been known as biomarkers in different types of squamous cell carcinoma (SCC), their functions in cancer development remain controversial. Interestingly, we detected the presence of keratin fusion in early-stage cancer specimens, suggesting the involvement of keratin fusion in carcinogenesis. Although sample size was limited, we found the presence of some keratin fusion variants exclusive to late-stage cancer specimens, which suggest the correlation of keratin fusion with cancer development. Besides OSCC, we also identified keratin fusion in esophageal, nasopharyngeal and cervical carcinoma in our preliminary study, which may suggest keratin fusion as a common driving mechanism among SCCs.

Citation Format: Jack Cheng, Ming-Tsung Lai, Shan-Chih Lee, Chun-Chin Chao, Chih-Mei Chen, Ka-Lok Ng, Jim Jinn-Chyuan Sheu. Identification of novel keratin fusion in squamous cell carcinomas. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-109. doi:10.1158/1538-7445.AM2013-LB-109
Abstract LB-119: Nucleolin promotes leukemogenesis through DNA hypermethylation.
Authors: Shen Na , Yan Fei , Pang Jiuxia , Liu shujun
Published: August 2014

Nucleolin (NCL), an abundant multifunctional phosphoprotein, is upregulated in numerous cancers. While NCL overexpression is implicated in tumor growth and angiogenesis, how NCL over-function contributes to tumorigenesis is poorly understood. Aberrant activity of DNA methyltransferase (DNMT) has been well documented in cancers and higher DNMT expression predicts worse prognosis, but how DNMT gene is regulated remains elusive. Given that NCL deregulation disrupts NFκB pathway, a DNMT1 gene transactivator, we speculated that NCL might promote cancer via DNA hypermethylation. To test this, initially we statistically analyzed 5 datasets from Gene Expression Omnibus. We found that NCL expression is elevated (n=121) and positively correlated with DNMT1/3a/3b in leukemia patients (n=242), indicative of their functional interaction in leukemogenesis. When Kasumi-1 and MV4-11 cells were transfected with NCL siRNA for 48 hours, by Western blot and PCR, we observed that NCL knockdown caused DNMT downregulation. Similar results were obtained when Kasumi-1 and MV4-11 cells were exposed to 1µM or 3µM of AS1411, a quadruplex DNA aptamer binding to NCL, for 48 hours. In contrast, ectopic expression of NCL in 293T cells upregulated DNMT, arguing for the positive role of NCL in DNMT transcription. Mechanistically, NCL-driven DNMT upregulation occurred via NFκB signaling, as NCL dysfunction (by siRNA and AS1411) dephosphorylated NFκBp65 (Ser536), and siRNA-mediated NFκB depletion abolished its phosphorylation leading to DNMT suppression. We then extracted genomic DNA from the above treated cells and subjected to Dotblot using 5mC antibody. We evidenced that NCL inactivation induced global DNA hypomethylation, whereas NCL overexpression resulted in DNA hypermethylation. Functionally, NCL inhibition by siRNA and AS1411 activated caspase-3 and caspase-8 and significantly abrogated leukemia cell clonogenic potential. Further, when MV4-11 cells were transfected with NCL siRNA, at 6 hours after transfection when the cells were not apoptotic, 2X106 cells were injected subcutaneously into nude mice for tumorigenesis (n=6). Compared to scramble control, we found that NCL knockdown dramatically decreased tumor volume and weight. H&E and IHC staining by Ki-67 or 5mC indicated the excessive reduction of tumor-forming rate and the significant decrease of DNA methylation. Thus, our collective findings highlight the interactive features between DNMT machinery and NCL oncogenic pathway providing a rationale for targeting NCL as a general approach to treat cancers unresponsive to current DNA methylation inhibitor therapy.

Citation Format: Na Shen, Fei Yan, Jiuxia Pang, shujun Liu. Nucleolin promotes leukemogenesis through DNA hypermethylation. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-119. doi:10.1158/1538-7445.AM2013-LB-119
Abstract LB-121: Tumor suppressor p53 is involved in a CHAMP-dependent spindle assembly checkpoint pathway.
Authors: Zhang Piyan , Ungewitter Erica , Appella Ettore , Scrable Heidi
Published: August 2014

A p53-dependent mouse spindle checkpoint has been reported since 1995. However the underlying mechanism is still unknown. Here, we found that p53 formed complexes with CHAMP and MAD2L2. Immunofluorescence analysis revealed that p53, CHAMP and MAD2L2 colocalized at spindle fibres from pro-metaphase to anaphase. CHAMP binds MAD2L2 and antagonizes its inhibition function on APC/C. We discovered that p53 enhanced the inhibition of MAD2L2 by CHAMP. P53 knock-down decreased M-phase index. Exogenous expression of p53 increased M-phase index and extended remarkable length of time in M phase. Notably, the regulation of p53 on M phase index was completely abrogated by either CHAMP or MAD2l2 knock-down, suggesting that the regulation of p53 on spindle assembly checkpoint pathway is dependent on CHAMP and MAD2L2. These results demonstrate that p53 participates in a mitotic checkpoint that ensures the maintenance of genetic fidelity during development.

Citation Format: Piyan Zhang, Erica Ungewitter, Ettore Appella, Heidi Scrable. Tumor suppressor p53 is involved in a CHAMP-dependent spindle assembly checkpoint pathway. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-121. doi:10.1158/1538-7445.AM2013-LB-121
Abstract LB-122: LY2835219, a selective inhibitor of CDK4 and CDK6, inhibits growth in preclinical models of human cancer.
Authors: Dempsey Jack A. , Chan Edward M. , Burke Teresa F. , Beckmann Richard P.
Published: August 2014

Cell growth is regulated by the activity of certain cyclin-dependent kinases (CDKs), including CDK4 and CDK6 (hereafter CDK4/6), which specifically regulate cell cycle progression through the G1 restriction point. These CDKs act with the D-type cyclins to phosphorylate and inactivate the retinoblastoma (Rb) tumor suppressor protein, which in turn enables cell cycle progression from G1 to S phase. LY2835219 is a selective inhibitor of CDK4/6 with IC50 of 2 and 10 nM for CDK4 and CDK6, respectively. The current study evaluates the activity of LY2835219 in preclinical models of human cancer including non-small cell lung cancer (NSCLC), melanoma, mantle cell lymphoma (MCL), and ovarian cancer. A secondary focus of this study is to identify potential predictive biomarkers for response to LY2835219 in NSCLC, melanoma, and other cancers. For NSCLC, increased sensitivity to LY2835219 is associated both in vitro and in vivo with KRAS mutations. For established melanoma cell lines, similar levels of in vitro sensitivity are observed in different genetic subtypes. Accordingly, LY2835219 shows single-agent activity in the A375 melanoma xenograft model with daily oral dosing at 45 or 90 mg/kg. For MCL, durable growth inhibition of subcutaneously implanted xenografts is achieved with daily oral dosing at 50mg/kg. Finally, in an intra-peritoneal model that recapitulates clinical features of human ovarian cancer, LY2835219 not only inhibits tumor growth but also increases survival. These studies suggest that LY2835219 may have potential therapeutic application in the treatment of human cancers with specific molecular alterations.

Citation Format: Jack A. Dempsey, Edward M. Chan, Teresa F. Burke, Richard P. Beckmann. LY2835219, a selective inhibitor of CDK4 and CDK6, inhibits growth in preclinical models of human cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-122. doi:10.1158/1538-7445.AM2013-LB-122
Abstract LB-165: Safety and pharmacokinetics of liposomal curcumin in healthy subjects:A randomized placebo-controlled double blind first-in human study.
Authors: Storka Angela , Wolzt Michael , Vcelar Brigitta , Bolger Gordon , Majeed Muhammed , Helson Lawrence
Published: August 2014

Purpose: Curcumin exerts anti-proliferative and pro-apoptotic effects against various tumors in vitro and in vivo, and it has been found to suppress carcinogenesis in various organs. A liposomal curcumin formulation was developed enabling intravenous application.

Methods: 50 healthy male or female subjects between 18 and 45 years were allocated to receive single ascending doses of liposomal curcumin as a continuous infusion over 120 min. Dose levels ranged from 10 to 400 mg/m2. Within each dose group one subject was randomized to receive placebo. A premedication of intravenous diphenhydramine and dexamethasone or diphenhydramine alone was administered to prevent hypersensitivity reactions. Pharmacokinetic assessments included plasma and urine levels of Curcumin and tetrahydrocurcumin (THC), the active metabolite of Curcumin and were analyzed by a validated LC/MS/MS method. Safety assessments included monitoring for adverse events, laboratory safety parameters with special focus on hemolysis, vital signs and ECG.

Results and Conclusions: Liposomal curcumin infusions were tolerated without clinical symptoms. At the maximum tolerated dose of 400 mg/m2 of liposomal curcumin, transient increases in erythrocyte mean cell volume, echinocyte formation, and increased plasma lactate were observed. Markers of hemolysis (HBDH, potassium, haptoglobin, LDH, erythrocytes, Hb) did not change significantly, however, a tendency of erythrocyte loss (-0.5 T/l) was observed.

At a dose of 120 mg/m2 intermittent echinocyte formation of some erythrocytes was evident. Curcumin and THC levels were established rapidly forming a plateau during infusion with Cmax for curcumin ranging between 42 ± 22 and 2359 ± 412 ng/mL for doses of 10 to 400mg/m2, respectively. Cmax for THC was 7.1 - 15.8-fold lower than Cmax of curcumin. Upon termination of infusion Curcumin and THC were rapidly cleared from plasma with a mean residence time of 0.62 hr for curcumin and 1.69 hr for THC. Urinary curcumin levels accounted for <0.12% of total systemic clearance.Conclusions: Relevant plasma levels of Curcumin were achieved by infusion of liposomal curcumin over 120 min. A continuous infusion (eg 24h) seems appropriate to achieve sustained exposure to curcumin. 120 mg liposomal curcumin/m2 is proposed as safe starting dose for phase I studies in patients with solid tumors.

Citation Format: Angela Storka, Michael Wolzt, Brigitta Vcelar, Gordon Bolger, Muhammed Majeed, Lawrence Helson. Safety and pharmacokinetics of liposomal curcumin in healthy subjects:A randomized placebo-controlled double blind first-in human study. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-165. doi:10.1158/1538-7445.AM2013-LB-165
Abstract LB-211: Targeting triple negative breast cancer by using non-oncologic drug targets.
Authors: Bernemann Christof , Huelsewig Carolin , von Wahlde Marie-Kristin , Kiesel Ludwig , Liedtke Cornelia
Published: August 2014

Background:

Triple negative breast cancer (TNBC) is defined by the lack of estrogen-receptor alpha (ERα) and pro-gesterone receptor (PGR) expression as well as absence of human epidermal growth factor receptor2 (HER2/neu) overexpression. This type of breast cancer is characterized by a poor prognosis and sig-nificantly reduced survival rate compared to other breast cancer subtypes. This is mostly due to the lack of targeted agents like endocrine or anti HER2 targets.

Gene expression analysis revealed that different molecular targets are overexpressed in triple nega-tive breast cancer compared to other breast cancer subtypes. Therefore, these drug targets hold great potential for newly personalized therapeutic approaches in TNBC as well as other cancer types.

Methods:

Based on a list previously published (Liedtke et al., Cancer Res 2009) we defined the enzyme ALOX5 (arachidonate 5-lipoxygenase) as being a prominent new potential drug target. By using a set of known inhibitors of ALOX5 we deeply analyzed the effect on triple negative breast cancer cells as well as other breast cancer subtypes.

Results:

We firstly could show, that expression of ALOX5 correlates with the subtype of triple negative breast cancer, by trend. Treatment with meclofenamic acid additionally, showed significant decrease of proliferative capacity in at least some triple negative breast cancer cell lines.

Conclusion:

We could show that - in case of ALOX5 - its expression correlates with the triple negative breast cancer subtype by trend. Therefore, an inhibition of this molecular target might provoke anti prolife-rative effects on triple negative breast cancer cells. Actually, treatment with meclofenamic acid - a drug already used for joint, arthritis, muscular pain - showed reduction of proliferation in triplen negative breast cancer cells. Whether this effect relies on inhibition of ALOX5 or its function has to be analyzed further.

Citation Format: Christof Bernemann, Carolin Huelsewig, Marie-Kristin von Wahlde, Ludwig Kiesel, Cornelia Liedtke. Targeting triple negative breast cancer by using non-oncologic drug targets. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-211. doi:10.1158/1538-7445.AM2013-LB-211
Abstract LB-216: Acquired lapatinib resistance in HER2-positive breast cancer cells is associated with up-regulation of mutant PI3K and/or secondary PI3K mutation.
Authors: Brady Samuel , Zhang Jian , Yu Dihua
Published: August 2014

Resistance to the HER2 kinase inhibitor lapatinib is a major challenge in the treatment of HER2-positive breast cancer. To model acquired lapatinib resistance we generated two drug-resistant cell lines by extended exposure to lapatinib. Both HER2-amplified parental cell lines (BT474 and UACC893) possesssed PI3K p110α activating mutations, and were lapatinib-sensitive. Both lapatinib-resistant (LapR) cell lines possessed 2- to 3-fold increased levels of the PI3K p110α subunit and increased levels of phosphorylated Akt during lapatinib treatment. p110α increase occurred through gene amplification in the BT474 LapR cells and post-transcriptional protein increase in the UACC893 LapR cells. One of the two cell lines (BT474 LapR) also acquired a hotspot strong activating mutation (E542K) in p110α, whereas the parental cells possessed only a weak activating mutation (K111N). Mutant PI3K (E542K or H1047R) was sufficient to promote lapatinib resistance. Moreover, knockdown of p110α, but not p110β, sensitized both LapR cell lines to lapatinib. PI3K inhibitors were also effective in overcoming drug resistance. To our knowledge, this is the first suggestion of this dose-dependent effect of mutant p110α in lapatinib resistance and the first identified instance of post-transcriptional up-regulation of mutant p110α in lapatinib resistance. These findings may explain why some HER2-positive, PI3K p110α-mutant breast cancers are lapatinib-sensitive while others are lapatinib-resistant (increased level of p110α). Our findings also reinforce those of others indicating that HER2-positive breast cancer patients with mutant PI3K should be co-treated with HER2-targeting and PI3K-targeting therapies in order to prevent or overcome drug resistance.

Citation Format: Samuel Brady, Jian Zhang, Dihua Yu. Acquired lapatinib resistance in HER2-positive breast cancer cells is associated with up-regulation of mutant PI3K and/or secondary PI3K mutation. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-216. doi:10.1158/1538-7445.AM2013-LB-216