bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 341: Breast cancer cell adhesion and degradome interact to drive metastasis
Authors: Rizwan Asif , Cheng Menglin , Bhujwalla Zaver M. , Krishnamachary Balaji , Jiang Lu , Glunde Kristine
Published: August 2015

Although primary breast tumors are detected early in most cases, it is inevitable that many patients remain at risk for future recurrence and death due to micrometastases. We investigated the metastatic process with a focus on matrix metalloproteases (MMPs) within the degradome and on integrins and E-cadherin within the adhesome. We have performed comparative studies with a set of non-metastatic (BT-474, T47D, MCF7) versus metastatic (MDA-MB-231, SUM149, SUM159) human breast cancer cell lines and xenografts. Experiments were performed to measure growth rate, migration, invasion, and colony formation. Immunoblotting and immunohistochemistry revealed a higher expression of MMPs and heterophilic cell adhesion molecules integrin β1 and lower expression of homophilic cell adhesion molecule E-cadherin in the metastatic tumor cells and xenografts. Using zymography and activatable fluorescent probes for noninvasive imaging of MMPs, we demonstrated that metastatic breast cancer cells and tumors displayed an elevated degradome activity as compared to non-metastatic cells and tumors. Cell adhesion and cell aggregation assays showed an increased heterophilic and decreased homophilic adhesion in the metastatic models. Inhibiting MMPs reduced the expression of integrin β1, and stimulating integrin β1 resulted in higher MMP activities in metastatic cells. Re-expression of E-cadherin in metastatic cells led to a reduced expression of active integrin β1. Finally, circulating breast cancer cells and cells from lung metastatic nodules generated from metastatic tdTomato-fluorescing breast cancer cells displayed a reduced expression of active integrin β1 and less epithelial-mesenchymal-transition (EMT) marker protein S100A4. Our results indicate that proteolytic ECM remodeling by MMPs and cell adhesion by integrin β1 and E-cadherin are interdependent processes that control transformation from benign to invasive carcinoma and are critical for metastasis.

Citation Format: Asif Rizwan, Menglin Cheng, Zaver M. Bhujwalla, Balaji Krishnamachary, Lu Jiang, Kristine Glunde. Breast cancer cell adhesion and degradome interact to drive metastasis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 341. doi:10.1158/1538-7445.AM2015-341
Abstract 3416: IHC assessment of PBRM1 loss in colon and lung carcinomas
Authors: Li Aihua , Gao Yongfu , Zhang Yuekai , Pan Hongyang , Chan Jackie K. , Yang Ximing J. , Chen Taiying
Published: August 2015

PBRM1 (also known as BAF 180) is a chromatin remodeling polybromodomain protein recently identified as the second most frequently mutated gene in renal cell carcinoma (RCC). Loss of PBRM1 protein expression is most frequently observed in clear cell RCC and correlated with tumor progression. Approximately 40-50% of patients with RCC have mutations in PBRM1, and loss of PBRM1 was also reported in 28% of melanocytic neoplasms. However, loss of PBRM1 has not been studied in other tumors using patient tissues. The purpose of this study was to assess the protein expression of PBRM1 in a wide-ranging collection of normal and tumor tissues. Here we report our findings of PBRM1 loss in colon and lung carcinomas using a newly developed rabbit monoclonal antibody (RabMAb), Clone EP342. The antibody was generated by immunization of rabbits with PBRM1 recombinant protein. Sera collected from immunized rabbits were screened by ELISA, WB and IHC. After fusion, antibody from final hybridoma cell line was characterized using ELISA and Western blot (WB). A 180 KDa PBRM1 protein was detected by WB in A431 and MCF7 cell lysates. The antibody was further characterized by extensive IHC testing using formalin-fixed and paraffin-embedded (FFPE) human normal and tumor tissue microarray (TMA). IHC analysis on human tissue microarray (TMA) comprising seventeen types of normal tissues showed that PBRM1 antibody stained positively in the nuclei of all normal cells except cardiac muscle cells. In tumor TMAs comprising of fifteen types of tumors (2-4 cases for each type), negative staining was observed in carcinomas of the lung and colon, as well as clear cell RCC. Further analysis of specific types of tumor TMAs showed that PBRM1 was lost in 5 out of 30 colon carcinomas (17%), 8 out of 35 (14%) lung carcinomas, and 8 out of 1844%) clear cell RCC. In summary, the RabMAb PBRM1 antibody, clone EP342 specifically labels normal cells and most tumor cells. It is a useful tool in identifying cancers with loss of PBRM1 expression on FFPE tissues. The rate of PBRM1 loss in clear cell RCC (44%) detected by this clone is consistent with literature reported. Our study showed that PBRM1 protein was lost in colon and lung carcinomas, but less frequent than that of clear cell RCC. Further studies on colon and lung carcinomas are needed to clarify the role of PBRM1 in tumor progression in these tumors.

Citation Format: Aihua Li, Yongfu Gao, Yuekai Zhang, Hongyang Pan, Jackie K. Chan, Ximing J. Yang, Taiying Chen. IHC assessment of PBRM1 loss in colon and lung carcinomas. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3416. doi:10.1158/1538-7445.AM2015-3416
Abstract 3420: Expression and significance of proliferation markers phosphohistone H3, Ki-67/MIB-1, and survivin in gastrointestinal stromal tumors
Authors: Wang Ming , Grissmann Benedict , Marx Alexander , Weiss Cleo-Aron , Deligianni Maria , Belharazem Djeda , Cao Hui , Hohenberger Peter
Published: August 2015

Background: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Mitotic index (MI) is an essential risk factor for predicting recurrence of GIST. However, the inter-observer disagreement and the selection bias of the area for counting limit the reliability and reproducibility of risk-stratification based on traditional MI counting method. Phosphohistone H3 (PHH3), a novel mitosis-specific antibody, has been proven as a promising marker for facilitating MFs identification in several types of tumors. The purpose of present study is to explore the feasibility and reliability of PHH3-based mitosis counting methods in GISTs and to study the correlation between PHH3 and other two proliferation markers Ki67/MIB-1 and survivin.

Methods: 83 GIST formalin-fixed paraffin-embedded (FFPE) specimens were enrolled in this study. The mitotic count was assessed either on hematoxylin and eosin sections (H&E) or on PHH3 immuno-stained sections. The proliferation activity of tumors was also evaluated by immuno-staining of Ki67/MIB-1 and survivin. The interrelationship between these indices was analyzed statistically with Spearman rank coeffcients. Continuous variables not following the normal distribution were compared using Mann-Whitney U test between two groups or using Kruskal-Wallis H test among more than two groups. SPSS statistical software program, version 20.0 was used and all results were considered significant if p<0.05.

Results: PHH3-based mitosis counting showed better inter-rate reliability (ICC 0.909 vs 0.821, p< 0.03) and stronger correlation with risk grade and clinical outcome than H&E-based mitoses counting. Both the labeling indices (LI) of Ki67/MIB-1 and survivin (r = 0.737, p<0.0001) were strongly correlated to risk grade, clinical outcome, and PHH3-based mitoses count, which was also validated by immunofluorescence and immunocytochemical staining (r = 0.644, p<0.002).

Conclusion: PHH3 could significantly facilitate determining the mitotic rate in GIST evaluation with superior inter-rate reliability. PHH3, Ki67/MIB-1, and survivin are co-expressed in GIST and their expressions are strongly correlated. Combined use of these markers is a promising technique for evaluating the prognosis of GIST and tailoring the treatment.

Citation Format: Ming Wang, Benedict Grissmann, Alexander Marx, Cleo-Aron Weiss, Maria Deligianni, Djeda Belharazem, Hui Cao, Peter Hohenberger. Expression and significance of proliferation markers phosphohistone H3, Ki-67/MIB-1, and survivin in gastrointestinal stromal tumors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3420. doi:10.1158/1538-7445.AM2015-3420
Abstract 3432: Dietary modifications of rectal cancer survivors to improve bowel function symptoms
Authors: Krouse Robert S. , Wendel Christopher S. , Demark-Wahnefried Wendy , Bulkley Joanna E. , McMullen Carmit K. , Grant Marcia , Hornbrook Mark C. , Altschuler Andrea , Sun Virginia , Herrinton Lisa J.
Published: August 2015

Purpose: Rectal cancer (RC) survivors with and without permanent ostomy have similar bowel function challenges, and seek improvement of symptoms through dietary modifications. Identifying patient-reported dietary modifications among survivors with different surgical reconstructions can guide postoperative supportive care and improve health-related quality of life (HRQOL).

Methods: We mailed a survey to long-term (≥5 years post-diagnosis) RC survivors enrolled in Kaiser Permanente (Northern California and Northwest). It included a question eliciting foods that were helpful with bowel function and the bowel symptoms that were impacted. Food types were recoded into broader categories based on food families developed around nutrition and common usage patterns and frequencies of food types and symptoms addressed were compared by sex and surgery type (ostomy vs. anastomosis).

Results: Of the 577 RC survivors who responded to the survey, 201 (35%) responded to the question related to foods that helped bowel function. Food groups that most commonly were used were fruits other than prunes (16.3%) and vegetables (15.5%). Water was often used (9.2%). The only specific food that was commonly used was prunes (7.6%). Most foods cited were credited with helping prevent the constellation of symptoms and signs of constipation or bloating, followed by predictability. A few foods (e.g., bananas, bread, rice) were more likely to help with diarrhea. Helpful foods addressing constipation/bloating were more likely cited by women than men (55% vs. 44%, p = .007). Vegetables were more likely cited by anastomosis than ostomy subjects (18% vs. 11%, p = .03).

Conclusions: Multiple dietary alterations are attempted by RC survivors. It appears very individualized, although multiple strategies can be suggested to improve bowel function. Through this exploratory analysis, strategies can be developed and tested for RC survivors.

Citation Format: Robert S. Krouse, Christopher S. Wendel, Wendy Demark-Wahnefried, Joanna E. Bulkley, Carmit K. McMullen, Marcia Grant, Mark C. Hornbrook, Andrea Altschuler, Virginia Sun, Lisa J. Herrinton. Dietary modifications of rectal cancer survivors to improve bowel function symptoms. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3432. doi:10.1158/1538-7445.AM2015-3432
Abstract 3469: Measuring antitumor effect of c-Myc-Max heterodimerization inhibitor 100258-F4 on ovarian cancer cells using cellometer image cytometry
Authors: Chan Leo Li-Ying , Wang Jiandong , Ma Xiaoli , Song Fang , Zhang Weiyuan , Jones Hannah M. , Bae-Jump Victoria L. , Zhou Chunxiao
Published: August 2015

Epithelial ovarian carcinoma is the most lethal gynecological cancer due to its silent onset and recurrence with resistance to chemotherapy. Overexpression of oncogene c-Myc is one of the most frequently encountered events present in ovarian carcinoma. Disrupting the function of c-Myc and its downstream target genes is a promising strategy for cancer therapy. In this work, we aimed to evaluate the potential effects of small-molecule c-Myc inhibitor, 10058-F4, on ovarian cancer cells and the underlying mechanisms by which 10058-F4 exerts its actions. Using Cellometer image cytometry for cell cycle and Annexin V apoptosis assays, flow cytometry, MTT assay, and colony formation, we found that 10058-F4 significantly inhibited cell proliferation of both SKOV3 and Hey ovarian cancer cells in a dose dependent manner through induction of apoptosis and cell cycle G1 arrest. Treatment with 10058-F4 reduced cellular ATP production and ROS levels in SKOV3 and Hey cells. Consistently, primary cultures of ovarian cancer treated with 10058-F4 showed induction of caspase-3 activity and inhibition of cell proliferation in 15 of 18 cases. These novel findings suggest that targeting c-Myc-Max heterodimerization could be a potential therapeutic strategy for ovarian cancer.

Note: This abstract was not presented at the meeting.

Citation Format: Leo Li-Ying Chan, Jiandong Wang, Xiaoli Ma, Fang Song, Weiyuan Zhang, Hannah M. Jones, Victoria L. Bae-Jump, Chunxiao Zhou. Measuring antitumor effect of c-Myc-Max heterodimerization inhibitor 100258-F4 on ovarian cancer cells using cellometer image cytometry. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3469. doi:10.1158/1538-7445.AM2015-3469
Abstract 347: Mechanism of c-Met TKI resistance and role of epithelial mesenchymal transition in melanoma
Authors: Rajanna Supriya , Rastogi Ichwaku , Palani Sunil , Puri Neelu
Published: August 2015

Various tyrosine kinase inhibitors (TKI’s) are approved for the treatment of melanoma, but their efficacies are limited due to development of drug resistance. To analyze the resistance to c-Met inhibitors we used two melanoma cell lines: MU which has mutated BRAF (V600E +ve) and RU which has wild type BRAF. These cell lines were also made resistant to c-Met inhibitor, SU11274 by growing them in progressively increasing concentrations of drug.

In earlier studies we observed activation of Wnt pathway in both of the aforementioned cell lines indicating the role of active β-Catenin in transcription and hence cell proliferation. β-Catenin levels when localized and accumulated in the nucleus binds to TCF/LEF and activates transcription. The level of β-Catenin in the cytosol is regulated by the adherens junction proteins (E-Cadherin) along with the Wnt pathway. Increased levels of β-Catenin might be a possible result of loss of E-Cadherin which is related to epithelial mesenchymal transition. During epithelial mesenchymal transition (EMT) cells transition from epithelial (attached, non-migratory) to mesenchymal (unattached and migratory) cells which promotes metastasis.

We examined the role of EMT in the development of resistance in the c-Met TKI resistant melanoma cell lines. We quantified the β-Catenin activity using luciferase assay and observed a 5 fold upregulation in the SU11274 resistant MU cells when compared to MU parental cells in the presence of HGF. Additionally, we performed immunoblotting, where we observed modulation in EMT related proteins in MU and RU parental and resistant cells. E-Cadherin, ZO-1, Claudin-1 and Slug were found to be downregulated 1.5 - 2.7 fold, 1.5 - 2.0 fold, 2 - 9 fold and 1.5 - 2 fold respectively and N-Cadherin and β-Catenin were found to be upregulated 1.8 - 5.3 and 2.4 - 3.7 fold respectively in the SU11274 resistant MU cells in the presence and absence of HGF and SU11274 treatments. Similarily we observed upregulation of β-Catenin by 1.7 fold and downregulation of E-Cadherin and ZO-1 by 2 - 3.5 fold and 6 - 9 fold respectively in SU11274 resistant RU cells when compared to RU parental cells in the presence and absence of HGF and SU11274 treatments. Further studies are being carried to understand the role of EMT in the development of this acquired resistance.

These results may help in development of novel therapies for melanoma patients or may help in increasing the efficacy and beneficence from the currently available therapeutics.

Citation Format: Supriya Rajanna, Ichwaku Rastogi, Sunil Palani, Neelu Puri. Mechanism of c-Met TKI resistance and role of epithelial mesenchymal transition in melanoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 347. doi:10.1158/1538-7445.AM2015-347
Abstract 3470: Atypical protein kinase C inhibition in prostate cancer cells: A study of ICA-1 and ACPD
Authors: Apostolatos Andre H. , Apostolatos Christopher , Acevedo-Duncan Mildred
Published: August 2015

Aggressive and metastatic prostate cancers are highly lethal tumors and are one of the leading causes of death among men. Certain prostate cancers are highly lethal tumors due to the emergence of therapy-resistant cancer cells. There is a gap in knowledge relating to which intracellular chemicals confer the emergence of therapy-resistant prostate cancer cells, which intracellular chemicals are responsible for prostate cancer survival and which chemicals regulate intracellular signaling pathways in prostate cancer. To address this critical problem, we investigated two drugs that act as inhibitors of atypical protein kinase C. The objective of this study was to test the effectiveness of ACPD [Diabetes. 63:2690-2701 (2014)] as an atypical PKC inhibitor and ICA-1 as an inhibitor of PKC-iota [The Inter. J. Biochem. & Cell Biol. 43:784-794(2011)]. DU-145 prostate carcinoma cells and non-malignant prostate RWPE-1 cells were each cultivated in separate flasks. They were treated with drugs of interest for three consecutive days. The cells were counted before and after the treatments and a statistical analysis was performed. The cells were lysed and levels of PKC-iota and PKC-zeta were measured by Western blotting and immunoprecipitation. Our preliminary results demonstrated that treatment of DU-145 showed a statistically significant decrease in cells that was proportional to the concentration in both drugs. Treatment of the RWPE-1 cells showed no statistically significant change in population. Western blotting showed that both drugs decreased PKC-iota. In conclusion ACPD is an effective inhibitor of PKC-iota and PKC-zeta and consequently significantly reduced the neogenesis of the prostate DU-145 carcinoma cells while having negligible effect on the non-malignant prostate RWPE-1 cells.

Citation Format: Andre H. Apostolatos, Christopher Apostolatos, Mildred Acevedo-Duncan. Atypical protein kinase C inhibition in prostate cancer cells: A study of ICA-1 and ACPD. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3470. doi:10.1158/1538-7445.AM2015-3470
Abstract 3480: Combinatorial apoptotic activity of capsaicin and camptothecin in human small cell lung cancer
Authors: Perry Haley E. , Brown Kathleen C. , Stevenson Cathryn D. , Rollyson William D. , Stover Cody A. , Dasgupta Piyali
Published: August 2015

Small cell lung cancer (SCLC) accounts for about 13% of all lung cancer cases and is the most aggressive form of lung cancer. Cisplatin and cisplatin-based combination therapies are the cornerstone of SCLC treatment. Platinum refractoriness is defined as disease which has persisted or progressed (grown) while receiving cisplatin chemotherapy. Patients with platinum resistant or refractory disease have very limited options, as the only standard chemotherapy with an FDA-approved drug, topotecan, has an objective response rate of approximately 3% and little or no survival benefit. Topotecan is a derivative of camptothecin. The objective of our study was to examine whether capsaicin could sensitize human SCLC cells to the apoptotic effects of camptothecin. We observed that the combination of capsaicin and camptothecin displays significantly higher apoptotic activity in human SCLC cell lines as compared to either agent alone. Chou-Talalay analysis showed that the interactions between capsaicin and camptothecin were synergistic. We also measured the effect of capsaicin-camptothecin combination on several Bcl-2 family proteins, namely Bcl-2, Bax, Bak, Bcl-XL, Mcl-1, etc. The results of our studies may be of importance in therapy of platinum-refractory SCLCs.

Citation Format: Haley E. Perry, Kathleen C. Brown, Cathryn D. Stevenson, William D. Rollyson, Cody A. Stover, Piyali Dasgupta. Combinatorial apoptotic activity of capsaicin and camptothecin in human small cell lung cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3480. doi:10.1158/1538-7445.AM2015-3480
Abstract 3481: Sigma-2 ligands sensitize triple negative breast cancer cells to PARP inhibitor treatment
Authors: Zeng Chenbo , Mankoff Julia , Mach Robert H.
Published: August 2015

Triple-negative breast cancer (TNBC) accounts for 15-25% of breast cancer cases. Effective targeted treatment for TNBC is lacking. Poly (ADP-ribose) polymerase (PARP) is a key enzyme involved in single-strand DNA break repair. PARP inhibitors have been used in combination with various chemotherapeutic agents in TNBC with limited success. The sigma-2 receptor is associated with cellular proliferation and quiescence and has been used as the target for imaging solid tumors by positron emission tomography. The sigma-2 receptor has been identified as progesterone receptor membrane component 1 (PGRMC1) protein complex. Recent work has suggested that the sigma-2 receptor may also be an effective therapeutic target. In this study we looked for potential synergy between PARP inhibitors and sigma-2 ligands using a triple negative breast cancer cell line, MDA-MB231.

We showed that the sigma-2 ligand, SW43, and a PGRMC1 ligand, AG205, induced cell toxicity and caspase 3 activation in a dose-dependent manner. The combination of SW43 and PARP inhibitor, Olaparib, resulted in additive cytotoxicity by cell viability assay and colony forming assay. Olaparib inhibited PARP activity in MDA-MB231 cell line, suggesting that the single-strand DNA break repair may be inhibited. SW43 and AG205 treatment decreased PGRMC1 and EGFR protein levels, suggesting that sigma-2/PGRMC1 ligands reduce growth factor signaling. In conclusion, SW43 and Olaparib induce cell death by separate signaling pathways. Sigma-2 ligands may selectively sensitize tumors to PARP inhibitor treatment in triple negative breast cancer patients.

Citation Format: Chenbo Zeng, Julia Mankoff, Robert H. Mach. Sigma-2 ligands sensitize triple negative breast cancer cells to PARP inhibitor treatment. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3481. doi:10.1158/1538-7445.AM2015-3481
Abstract 3484: Synergism from combination of targeted therapy with tumor active phytochemicals in ovarian tumor models and changes in protein expression
Authors: Huq Fazlul
Published: August 2015

Introduction

Ovarian cancer is most lethal cause of gynecological types of cancer mainly because of acquired drug resistance and poor diagnosisis. In majority of cases it is detected at an advanced stage when it is likely to have spread beyond ovaries. Combination of platinum drugs with paclitaxel is the current mode of treatment. Although cancer cells respond well to the drug combination, relapse often occurs for which drugs fail to function. We have designed a number of novel platinums aimed to overcome platinum resistance in ovarian cancer. We also applied combinations of platinums and tumor active phytochemicals such as curcumin, EGCG, thymoquinone, resveratrol, ursolic acid and genistein to overcom drug resistance. This presentation will provide a brief overview of novel platinums designed in our lab with special emphasis on recent studies on combinations of platinum with phytochemicals and protein expression.

Methods

Activity of the compounds alone and in sequenced combination in ovarian cancer cell lines including A2780, A2780cisR and A2780ZD0473R were determined using MTT reduction assay. Drug uptake and drug-DNA binding were determined using developed protocols. Proteomic studies involving 2D gel electrophoresis and mass spectrometry were carried out to characterize key proteins associated with platinum resistance.

Results

Generally but not always sequenced combinations with 2 to 4 h time gap were found to be synergistic. The variation in combined drug action with the change in sequence of administration clearly indicates that the action of one drug has modulated that of the other. Proteomic studies have identified over thirty proteins believed to be associated with platinum resistance in ovarian cancer. They belong to six major groups including cytoskeletal proteins, molecular chaperone and stress related proteins, proteins involved in detoxification and drug resistance, proteins involved in metabolic processes and mRNA processing proteins. The proteins are restored to normalcy due to treatment with synergistic combinations.

Conclusion

If confirmed in vivo, the results of the study indicate that appropriate combinations of targeted therapy and tumor active phytochemicals may providing an effective and affordable means of overcoming drug resistance in ovarian cancer.

Citation Format: Fazlul Huq. Synergism from combination of targeted therapy with tumor active phytochemicals in ovarian tumor models and changes in protein expression. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3484. doi:10.1158/1538-7445.AM2015-3484
Abstract 3486: Synergistic effect of quinacrine in combination with decitabine for the treatment of acute myeloid leukemia cells in vitro: implication for treatment of AML in the elderly
Authors: Wang Wenge , Dicker David T. , Claxton David F. , Wang Hong-Gang , El-Deiry Wafik S.
Published: August 2015

Demethylating agents remain one of the few options for treatment of AML in the elderly; however, the response rate is limited. In searching for p53 pathway activating agents for cancer therapy, we found that quinacrine is a potent p53 stimulator and induces tumor cell death. Quinacrine also induces expression of Death Receptor 5 (DR5), reduces expression of anti-apoptotic Mcl-1, and suppresses NFkB activity in tumor cells. Because of its acceptable toxicity profile, history of use in humans, and relevance of the target pathways modulated by quinacrine we explored whether it may serve as a potent anti-leukemia drug as most leukemia cells carry a wild-type p53. We tested the cytotoxic effects of quinacrine on malignant hematopoietic cell lines derived from patients with myeloid leukemia, including HL-60, MOLM-13, and MV4-11. We found that quinacrine induces massive cell death in the cell lines tested, at concentrations from as less as 1 microM to 5 microM, 2-10 times lower than required to induce solid tumor cell death. Most interestingly, quinacrine facilitates cell death in decitabine pre-treated leukemia cells in a synergistic manner. Further mechanistic studies showed that quinacrine stabilizes p53, induces Mcl-1 degradation, and PARP cleavage in treated cells. Our work supports translational efforts to advance the use of quinacrine from the bench to the clinic and provides a preliminary rationale for its combination with decitabine for the treatment of AML.

Citation Format: Wenge Wang, David T. Dicker, David F. Claxton, Hong-Gang Wang, Wafik S. El-Deiry. Synergistic effect of quinacrine in combination with decitabine for the treatment of acute myeloid leukemia cells in vitro: implication for treatment of AML in the elderly. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3486. doi:10.1158/1538-7445.AM2015-3486
Abstract 3489: Novel translational pharmacology approaches on dose reduction and alternative scheduling for the combination of JAK inhibitor, ruxolitinib, PIM inhibitor, LGH447, and CDK4/6 inhibitor, LEE011 in a preclinical model of myeloproliferative neoplasia
Authors: Pinzon-Ortiz Maria , Rong Xianhui , Vanasse Gary , Cao Z. Alexander
Published: August 2015

The JAK-STAT pathway is an important signaling pathway downstream of multiple cytokine and growth factor receptors. It has been implicated in the pathogenesis of multiple human diseases. The genetic aberration of JAK2V617F and the associated activation of STAT in myeloproliferative neoplasia (MPN) is one example of the involvement of this pathway in human cancer. We have shown the combination benefits of combining ruxolitinib (Jak1, 2 inhibitor), with LGH447 (PIM inhibitor) and LEE011 (CDK4/6 inhibitor) in a Ba/F3-JAK2V617F-driven MPN model. This triple combination resulted in ∼99% reduction of total tumor burden and a ∼96% reduction of spleen weight. Furthermore, the triple combination of ruxolitinib, LGH447 and LEE011 reduced JAK2V617F allele burden by > 80%. To translate this combination from preclinical setting to the clinic, it is critical to evaluate dose to efficacy relationship for each agents and scheduling to efficacy correlation for this combination. Here, the preclinical doses for ruxolitinib, LGH447 and LEE011 were determined, based on their clinically achieved exposure. We then examined “intermittent dosing” of this combination in the same preclinical model. Our data suggest that the combination efficacy of ruxolitinib-LGH447-LEE011 is dependent on continuous administration of the agents. Finally, we examined the effect of dose reduction for each of the three agents on the combination efficacy in the Ba/F3-JAK2V617F-driven MPN model. By modifying the doses for ruxolitinib, LGH447 and LEE011 separately in the combination, our study reveals that the triple combination efficacy is most sensitive to LEE011 dose reduction, and it is least sensitive to LGH447 dose reduction. In summary, our studies aim to design novel preclinical approaches to inform and the design of clinical dose escalation in novel combination therapies.

Citation Format: Maria Pinzon-Ortiz, Xianhui Rong, Gary Vanasse, Z. Alexander Cao. Novel translational pharmacology approaches on dose reduction and alternative scheduling for the combination of JAK inhibitor, ruxolitinib, PIM inhibitor, LGH447, and CDK4/6 inhibitor, LEE011 in a preclinical model of myeloproliferative neoplasia. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3489. doi:10.1158/1538-7445.AM2015-3489
Abstract 350: HER3 mediates acquired resistance to HER2-targeted therapy in esophageal adenocarcinoma
Authors: Ebbing Eva A. , Medema Jan Paul , Meijer Sybren L. , Krishnadath Kausilia K. , van Berge Henegouwen Mark I. , Bijlsma Maarten F. , van Laarhoven Hanneke W. M.
Published: August 2015

Esophageal adenocarcinoma is an aggressive malignancy and its incidence is rapidly increasing. Despite multimodality treatment, patients face a poor 5-year survival of 15-25%, underscoring the urgency to improve treatment strategies. Receptor tyrosine kinases of the HER-family are involved in the development and progression of multiple epithelial tumors, and have consequently become widely used targets for the development of new anti-cancer therapies. Trastuzumab, an antibody against HER2, has shown potent growth inhibitory effects on HER2 overexpressing tumors, including gastro-esophageal cancer, however, resistance to this therapy is inevitable. Unfortunately, a paucity of data on cellular mechanisms of resistance to targeted therapeutic agents exist in esophageal adenocarcinoma. In order to study the effect of HER2 inhibition in vitro and in vivo, we established unique primary cultures of esophageal adenocarcinoma and patient-derived xenograft models. Using these novel tools, we demonstrate a conserved, hard-wired mechanism in which HER3 is upregulated upon trastuzumab-induced resistance in esophageal adenocarcinoma. Furthermore, blocking upregulated HER3 effectively resulted in a strong decrease in cell viability and induced cell death. Taken together, our data provide preclinical insight that strategies targeting HER3 in combination with trastuzumab could possibly prevent acquired resistance.

Citation Format: Eva A. Ebbing, Jan Paul Medema, Sybren L. Meijer, Kausilia K. Krishnadath, Mark I. van Berge Henegouwen, Maarten F. Bijlsma, Hanneke W. M. van Laarhoven. HER3 mediates acquired resistance to HER2-targeted therapy in esophageal adenocarcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 350. doi:10.1158/1538-7445.AM2015-350
Abstract 3515: RRx-001: A double action systemically non-toxic epigenetic agent for cancer therapy
Authors: Zhao Hongjuan , Ning Shoucheng , Scicinski Jan , Oronsky Bryan , Knox Susan , Peehl Donna M.
Published: August 2015

RRx-001 (also known as ABDNAZ, 1-bromoacetyl-3,3-dinitroazetidine) is a novel aerospace-derived compound that demonstrated anticancer activity in the absence of systemic toxicities in a recent phase I clinical trial and is now in phase II studies. With a highly energetic heterocyclic scaffold, RRx-001 generates reactive oxygen species (ROS) and nitric oxide (NO), modulates intracellular redox status, and triggers caspase-independent apoptosis in cancer cells. Here we showed that RRx-001 as a single chemical entity regulates at least two epigenetic processes, histone acetylation and DNA demethylation. Specifically, RRx-001 at its therapeutic concentrations (0.5-5 μM) significantly decreased global DNA methylation, i.e., 5-methylcytosine levels, in SCC VII tumor cells as determined by ELISA. Consistently, treatment of SCC VII cells with 0.5-5 μM RRx-001 significantly decreased Dnmt1 and Dnmt3a protein expression in a dose- and time-dependent manner as determined by Western blots. In addition, global methylation profiling using Illumina Infinium HumanMethylation450 BeadChip® identified differentially methylated genes in SCC VII cells treated with 0.5, 2, and 5 μM RRx-001 compared to control cells. Of 111 genes demethylated by RRx-001 identified using GenomeStudio software, methylation levels of 3 genes (FAM20C, STON1-GTF2A1L and TRIAP1) were decreased by at least 2-fold across all three concentrations of RRx-001. Validation of these changes by pyrosequencing is underway. Pathway enrichment analysis by IPA suggested that RRx-001 demethylated genes involved in hepatic fibrosis, G protein signaling, leucine degradation and remodeling of epithelial adherens junctions. Moreover, RRx-001 at 2 μM significantly increased global acetylated histone H3 and H4 levels in SCC VII cells after 24 hour treatment as determined by a fluorometric assay, suggesting that RRx-001 regulates global acetylation in cancer cells. Western blot analysis also showed significant increases in acetylated histone H3 and H4 levels in SCC VII cells in a dose and time-dependent manner after RRx-001 treatment. Taken together, our results demonstrated that, in contrast to the traditional “one drug one target” paradigm, RRx-001 has multi(epi)target features, which contribute to its anticancer activity.

Citation Format: Hongjuan Zhao, Shoucheng Ning, Jan Scicinski, Bryan Oronsky, Susan Knox, Donna M. Peehl. RRx-001: A double action systemically non-toxic epigenetic agent for cancer therapy. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3515. doi:10.1158/1538-7445.AM2015-3515
Abstract 352: Up-regulation of CD44 in the development of metastasis, recurrence and drug resistance of ovarian cancer
Authors: Gao Yan , Foster Rosemary , Hornicek Francis J. , Amiji Mansoor M. , Duan Zhenfeng
Published: August 2015

Purpose: The clinical significance of Cluster of differentiation 44 (CD44) remains controversial in human ovarian cancer. The aim of this study is to evaluate the clinical significance of CD44 expression by using a unique tissue microarray, and then to determine the biological functions of CD44 in ovarian cancer.

Experimental Design: A unique ovarian cancer tissue microarray (TMA) was constructed with paired primary, metastatic, and recurrent tumor tissues from 26 individual patients. CD44 expression in TMA was assessed by immunohistochemistry. Western blotting and Immunofluorescence assay determined the expression of CD44 and/or P-glycoprotein (Pgp) in ovarian cancer cell lines and the tumor tissues of a paclitaxel treated ovarian cancer xenograft mouse model. MTT assay, wound healing assay, and matrigel invasion assay were utilized to assess the proliferation, drug sensitivity, and migration/invasion ability, respectively.

Results: Both the metastatic and recurrent ovarian cancer tissues expressed higher level of CD44 than the patient-matched primary tumor. A significant association has been shown between CD44 expression and both the disease free survival and overall survival. A strong increase of CD44 was found in the tumor recurrence of mouse model. Finally, when CD44 was knocked down, proliferation, migration/invasion activity, and spheroid formation were significantly suppressed, while drug sensitivity was enhanced.

Conclusions: Up-regulation of CD44 represents a crucial event in the development of metastasis, recurrence, and drug resistance to current treatments in ovarian cancer. Developing strategies to target CD44 may prevent metastasis, recurrence, and drug resistance in ovarian cancer.

Citation Format: Yan Gao, Rosemary Foster, Francis J. Hornicek, Mansoor M. Amiji, Zhenfeng Duan. Up-regulation of CD44 in the development of metastasis, recurrence and drug resistance of ovarian cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 352. doi:10.1158/1538-7445.AM2015-352
Abstract 3525: The BET inhibitor INCB054329 is efficacious as a single agent or in combination with targeted agents in colorectal cancer models
Authors: Liu Xuesong , Li Jun , He Xin , Stubbs Matthew , Favata Margaret , Wen Xiaoming , Chang Hong , Rumberger Beth R. , Li Yanlong , Maduskuie Thomas , Sparks Richard , Falahatpisheh Nikoo , Polam Padmaja , Combs Andrew P. , Huber Reid , Hollis Gregory , Scherle Peggy , Liu Phillip C.
Published: August 2015

The Bromodomain and extra-terminal (BET) family of proteins consists of BRD2, BRD3, BRD4 and BRDT. Each BET protein contains two bromodomains (BD1 and BD2) that recognize acetylated histones at enhancer and promoter regions of a select number of genes. BET proteins function as transcriptional regulators that are critical for the expression of oncogenes such as c-Myc; thus, BET proteins are important for cancer cell proliferation and survival. We have identified INCB054329, a potent and selective BET protein inhibitor that targets BD1 and BD2 of BRD2, BRD3 and BRD4. In this study, we characterized the pharmacology of INCB054329 in solid tumor cell lines. In a panel of colon cancer cell lines, more than 50% are sensitive to INCB054329 treatment with IC50 values below 500 nM in cell proliferation assays. INCB054329 down-regulated c-Myc expression, and induced cell cycle arrest and apoptosis in sensitive colon cancer cell lines. Moreover, INCB54329 was efficacious in the RKO colon cancer xenograft model. To understand whether BRD inhibition would synergize with other signaling pathway inhibitors and standard of care agents for colon cancer, we employed a high throughput combination screening strategy. Several combinations were active in a panel of colon cancer cell lines and demonstrated synergistic interactions based on combination index values. As an example, strong synergy was observed between INCB054329 and MEK inhibitors. The combination of INCB054329 and MEK inhibitors synergistically blocked expression of c-Myc protein and inhibited the MEK/ERK signaling pathway. Our data suggest the potential utilization of INCB054329 as a single agent or in combination with other targeted therapies for the treatment of colon cancer.

Citation Format: Xuesong Liu, Jun Li, Xin He, Matthew Stubbs, Margaret Favata, Xiaoming Wen, Hong Chang, Beth R. Rumberger, Yanlong Li, Thomas Maduskuie, Richard Sparks, Nikoo Falahatpisheh, Padmaja Polam, Andrew P. Combs, Reid Huber, Gregory Hollis, Peggy Scherle, Phillip C. Liu. The BET inhibitor INCB054329 is efficacious as a single agent or in combination with targeted agents in colorectal cancer models. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3525. doi:10.1158/1538-7445.AM2015-3525
Abstract 3529: BET bromodomain proteins regulate the canonical WNT signaling and drug resistance in colorectal cancer
Authors: Wang Lihong , Ma Yufang , Lee Ethan , Wang Jialiang
Published: August 2015

The canonical WNT signaling is aberrantly activated in the vast majority of colorectal cancer (CRC) and results in activation of beta-catenin and its downstream target MYC. These two oncogenic transcription factors play central roles in CRC pathogenesis, but are refractory to direct pharmacological interventions. The recurrent mutations of APC or β-catenin in CRC also limit the utilities of currently available WNT inhibitors that mostly target upstream regulators. The bromodomain and extra-terminal domain (BET) family epigenetic readers recently emerged as a key regulator of MYC expression. In the present study, we demonstrated that BET proteins regulated beta-catenin-mediated MYC expression in CRC. Inhibition of BET proteins repressed activities of both wild type and constitutively active β-catenin mutants. Pharmacological or genetic targeting of BET proteins broadly impaired proliferation and survival in CRC cells, including KRAS or BRAF-mutant lines. Furthermore, BET bromodomain inhibitors synergistically sensitized CRC cells to inhibitors of the MAPK pathway. The ability of BET inhibitors to augment the efficacy of the MAPK pathway inhibitors is potentially secondary to altered balance among pro-survival and pro-apoptotic regulators. Using KRAS- or BRAF-mutant CRC xenograft models, we showed that a combination of BET inhibitor and MEK inhibitor, but not either agent alone, induced significant tumor regression. Our findings suggest that BET-based epigenetic therapy can be utilized as an alternative approach to block the canonical WNT signaling in CRC and potentially other human cancers, in particular those carrying APC or beta-catenin mutations. Our results also identify a novel combination therapy for treating CRCs, including those refractory to currently available therapeutic options.

Citation Format: Lihong Wang, Yufang Ma, Ethan Lee, Jialiang Wang. BET bromodomain proteins regulate the canonical WNT signaling and drug resistance in colorectal cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3529. doi:10.1158/1538-7445.AM2015-3529
Abstract 3536: Targeting β-catenin with a Dicer-substrate siRNA (DsiRNA) in a sleeping beauty transposon-driven murine hepatoblastoma model
Authors: Abrams Marc T. , Tao Junyan , Ganesh Shanthi , Cyr Wendy , Ying Bo , Koser Martin , Arvan Rokhand , Chopda Girish , Dudek Hank , Lai Cheng , Wang Weimin , Brown Bob , Monga Satdarshan
Published: August 2015

Hepatoblastoma (HB), the commonest pediatric liver tumor is frequently associated with an N-terminal deletion in the CTNNB1 gene, which encodes stable β-catenin and promotes nuclear localization and transactivation activity. In 80% of patients, nuclear localization of β-catenin and Yes Associated Protein (YAP), a Hippo-related transactivator, is seen together. Further, stable hepatic co-expression of Δ90-CTNNB1 and active-YAP in mice causes rapid and aggressive HB. Dicer-substrate siRNAs (DsiRNAs) are potent RNA interference (RNAi) triggers that that are efficacious in preclinical tumor models of diverse origin, and are currently under clinical evaluation. To determine if CTNNB1-targeting DsiRNAs have potential as a therapy in HB, we encapsulated this oligonucleotide payload into lipid nanoparticles (LNPs), and systemically administered into mice bearing CTNNB1/YAP-induced HB. The LNP platform used, termed EnCore (because of its specific Envelope and Core lipid components), enables high encapsulation efficiency, long-term stability, and consistent analytical criteria. Downstream of LNP-mediated DsiRNA delivery, both qPCR and in situ hybridization were used to visualize changes in CTNNB1 expression in both tumor and normal liver. Robust and specific silencing of CTNNB1 mRNA was achieved in the tumors. The distribution of mRNA knockdown within each tumor nodule suggests efficient extravasation and internalization of the LNP and its payload into the tumor parenchyma, in contrast to previous reports of vascular-channel limited nanoparticle accumulation in tumors. Intriguingly, a “liver-centric” LNP formulation, which delivers cargo efficiently to a normal liver due to rapid hepatic extraction and apolipoprotein-mediated internalization, was inactive in the tumors. Further evaluation demonstrated efficacy of β-catenin targeting in this model. In conclusion, we report a highly relevant modality of RNAi delivery in a mouse model of hepatoblastoma to target a classically-undruggable oncogene.

Citation Format: Marc T. Abrams, Junyan Tao, Shanthi Ganesh, Wendy Cyr, Bo Ying, Martin Koser, Rokhand Arvan, Girish Chopda, Hank Dudek, Cheng Lai, Weimin Wang, Bob Brown, Satdarshan Monga. Targeting β-catenin with a Dicer-substrate siRNA (DsiRNA) in a sleeping beauty transposon-driven murine hepatoblastoma model. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3536. doi:10.1158/1538-7445.AM2015-3536