bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4202: Deciphering the effects of GNA13 mutations in B-cell lymphomas
Authors: O'Hayre Morgan L. , Kufareva Irina , Vaqué Jose P. , Piris Miguel A. , Gutkind J. Silvio
Published: May 2015

G-proteins and their cognate G-protein coupled receptors (GPCRs) are critical signal transduction molecules that regulate cell survival, proliferation, motility and differentiation. The aberrant expression or function of these molecules has been linked to growth, progression and metastasis of various cancers. Recent genome-wide sequencing efforts have unveiled numerous previously uncharacterized mutations in G-proteins and GPCRs, which could have significant implications to cancer initiation and progression. Of interest, recent analyses have demonstrated that there are frequent mutations in GNA13 in Burkitt's lymphoma and Diffuse Large B cell lymphomas (DLBCL) that are highly statistically significant over background cancer gene mutation rate, and occur in ∼10-13% of patients with these lymphomas. Mutations in the downstream target of G13, RhoA, are also present in several Burkitt's lymphoma tumors, highlighting that mutations in this G13-RhoA pathway may be key to the oncogenic potential of these B cell lymphomas. Although G13 activity has previously been linked cellular transformation and metastatic potential of epithelial cancers, our data suggests that the mutations in GNA13 in these B cell lymphomas are mostly inhibitory in nature. Thus, we have functionally characterized several mutations in GNA13 and RHOA found in Burkitt's lymphoma and DLBCL.

Citation Format: Morgan L. O'Hayre, Irina Kufareva, Jose P. Vaqué, Miguel A. Piris, J. Silvio Gutkind. Deciphering the effects of GNA13 mutations in B-cell lymphomas. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4202. doi:10.1158/1538-7445.AM2014-4202
Abstract 421: Differences of DNA methylation patterns according to histologic subtypes of early gastric carcinomas
Authors: Mia-Jan Khalilullah , Ryu Hoon , Lee Mi-Ra , Ji Sun-Young , Cho Mee-Yon
Published: May 2015

Background: The DNA methylation change is known to play a crucial role in early gastric carcinogenesis. However, its association with the histologic subtypes of EGCs has not been fully elucidated. In this study, we aim to know whether the subtypes of early gastric carcinomas (EGCs) are related to the differences of DNA methylation or not using genome wide methylation assay. Materials and Method: The comprehensive methylation analysis was performed by Illumina Infinium methylation assay (IIMA, 450K BeadChip kit) covering 450,000 sites on 12 tumors and 12 matched non-tumor mucosa from 12 patients with EGC. Hisytologically, the EGCs were devided into intestinal type (group A, n=6) and non-intestinal type (group B, diffuse=4 and mixed=2). The CpG sites in 450K microarray chip are classified into CpG islands, shores (2kb), shelves (2kb∼4kb) and open sea (>4kb) by CpG content and neighborhood context. According to the functional genomic distribution they are classified into promoter, body, 3′UTR and intergenic. To determine DMRs, average β-values were computed with β-values in signal intensity of over 3000. The Δβ-value was a result substracted average β-value of one from the other. When Δβ is over 0.2 or below -0.2, it was considered to be meaningful and refered to differentially methylated regions (DMRs) . Results: There were 484 DMRs in group A tumor and 208 DMRs in group B. The pattern of DMRs were different between two groups. In group A tumor, most of DMRs (97.73%) were hypermethylated and 75.26% were in CpG island. On the other hand, the group B tumors showed that 63.94% of DMRs were hypermethylated and only less than half of them (48.87%) were in CpG island. In terms of functional genomic distribution of DMRs, promoter (38.66%) was the most common site in group A while body (54.14%) was in group B. On Hierarchical clustering analysis, the clear grouping was made by 208 DMRs in three cases, two of them being mixed-type, by both correlation and Euclidean methods. However, no distinct grouping was found with DMRs in group A. Hierarchical clustering analysis of non-tumor mucosa showed a distinct separation between group A and B. Conclusions: DNA methylation pattern was distinctively different between the histologic subtype of EGCs. In the intestinal type of EGCs, the DNA methylation seems to be started in non-tumor mucosa.

Citation Format: Khalilullah Mia-Jan, Hoon Ryu, Mi-Ra Lee, Sun-Young Ji, Mee-Yon Cho. Differences of DNA methylation patterns according to histologic subtypes of early gastric carcinomas. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 421. doi:10.1158/1538-7445.AM2014-421
Abstract 4210: CPAP contributes to HBx-mediated NF-κB activation in hepatocellular carcinoma
Authors: Hung Liang-Yi
Published: May 2015

Hepatocellular carcinoma (HCC) is a type of tumor that results from chronic inflammation triggered by hepatotropic viruses or other toxic chemicals. Constitutive activation of nuclear factor (NF)-κB is an important event involved in chronic inflammation of the liver. The HBV X protein (HBx) is shown to activate NF-κB by inducing phosphorylation of IκBα and decreasing IκBα stability. Centrosomal protein P4.1-associated protein (CPAP), which plays important roles in centrosomal functions, is previously identified as the transcriptional co-activator of NF-κB. Herein, we demonstrate that CPAP can directly interact with HBx to enhance HBx-mediated NF-κB activation. Knockdown expression of CPAP abolishes this effect, indicating that CPAP is required for HBx-mediated NF-κB activation. In addition, HBx cooperates with cyclic adenosine monophosphate response element-binding protein (CREB) to increase the expression of CPAP by up-regulating its promoter activity. Furthermore, overexpression of CPAP enhances the protein stability of HBx. These results suggest that a positive feedback regulation exists between CPAP and HBx. The stable expression of CPAP in HCC cell lines increases cell proliferation. In addition, the co-expression of CPAP and HBx more greatly enhances the cell proliferation ability than either CPAP or HBx alone. Taken together, our study indicates that CPAP can cooperate with HBx and is important for HBx-induced NF-κB activation.

Citation Format: Liang-Yi Hung. CPAP contributes to HBx-mediated NF-κB activation in hepatocellular carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4210. doi:10.1158/1538-7445.AM2014-4210
Abstract 4213: Evaluation of LMTK3 expression and tumor phenotype in estrogen-dependent colorectal cancer
Authors: Magturo Sybil , Giamas Georgios , Mallick Snay , Layton Austin , Stebbing Justin , Lenz Heinz-Josef , LaBonte Melissa J.
Published: May 2015

Background: Incompatible physiology between genders influences development and progression of colorectal cancer (CRC). It is postulated that improved survival of women with CRC may be due to exogenous estrogen exposure. A recent study used the age of 50 as a surrogate for menopause, evaluating survival in two age groups: women ≥50 and ≤50. It was observed that women ≤50 had a survival advantage that was contributed to protection by estrogen- a mechanism lost in menopause; with no significant difference found in men. Lemur tyrosine kinase 3 (LMTK3) was recently identified, that when in association with an estrogen receptor (ER) α modulator increased growth, progression, and altered resistance to endocrine therapy was observed in breast cancer. The ER family (ERα and ERβ) exerts contrasting actions of estrogen on different target tissues, where ERβ is the dominant receptor expressed in the gastrointestinal tract. The different ER distribution between breast and colon cancer led to the hypothesis that LMTK3 overexpression should stabilize ERβ and decrease tumorigenesis in CRC. Methods: CRC cell lines were characterized for LMTK3 mRNA (qRT-PCR) and protein expression (Western blot) in both transfected and non-transfected cell lines. Overexpression of LMTK3 was achieved utilizing pCMV6-XL4-LMTK3. Overexpressing LMTK3 CRC cells were evaluated for alterations to cell viability by MTT, colony formation (CFAs), invasion assays and chemosensitivity to 5-Fluororuacil, oxaliplatin, and tamoxifen. Results: CRC cell lines demonstrated a range of LMTK3, ERα and ERβ mRNA and protein expression. Caco-2, HCT116 and LoVo cells demonstrated estrogen sensitivity as evidenced by treatment with ER antagonist, tamoxifen. CFA demonstrated that the presence of estrogen plus overexpression of LMTK3 decreased cell viability by 27, 28 and 36% in Caco2, HCT116 and LoVo cells respectively, had limited impact on chemosensitivity, and decreased their ability to invade. Conclusion: This study demonstrates that estrogen mediated cell signaling and LMTK3 play an important role in decreasing CRC tumorigenesis. Further studies are underway to better understand estrogen and LMTK3's role in CRC.

Citation Format: Sybil Magturo, Georgios Giamas, Snay Mallick, Austin Layton, Justin Stebbing, Heinz-Josef Lenz, Melissa J. LaBonte. Evaluation of LMTK3 expression and tumor phenotype in estrogen-dependent colorectal cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4213. doi:10.1158/1538-7445.AM2014-4213
Abstract 4215: SPAG5 upregulation predicts poor prognosis of cervical cancer patients and alters the sensitivity of Taxol treatment via mTOR signaling pathway
Authors: Yuan Lin-Jing , Zhang Lan , Zhou Yun , Zheng Min
Published: May 2015

Our previous work found SPAG5 to be upregulated in pelvic lymphnode metastasis positive cervical cancer, the aim of the present study was to examine the role of SPAG5 in proliferation and tumorigenicity of cervical cancers, and its clinical significance in tumor progression. By detecting SPAG5 expression in cervical cancer patients and exploring cervical cancer cell function with SPAG5 downregulation in vitro, our results revealed that SPAG5 upregulated in tumor tissue compared with paired adjacent noncancerous tissues, and the upregulation of SPAG5 in tumor tissues also indicated poor disease free survival which was also an independent prognostic indicator of cervical cancer patients. In vitro study demonstrated that SPAG5 downregulation inhibited cell proliferation and growth significantly by G2/M arrest and apoptosis induction, and also hindered cell migration and invasion. Further study showed different sensitivity of cervical cells to different doses of Taxol treatment under SPAG5 downregulation, which is correlated with mTOR signaling pathway activity. In this study, we demonstrated that SPAG5 upregulation related to poor prognosis of cervical cancer patients, and SPAG5 was a regulator of mTOR activity during Taxol treatment in cervical cancer.

Note: This abstract was not presented at the meeting.

Citation Format: Lin-Jing Yuan, Lan Zhang, Yun Zhou, Min Zheng. SPAG5 upregulation predicts poor prognosis of cervical cancer patients and alters the sensitivity of Taxol treatment via mTOR signaling pathway. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4215. doi:10.1158/1538-7445.AM2014-4215
Abstract 4218: Combined effect of COX2 genotype, ER status, body constitution, and treatment on risk of early events in breast cancer patients
Authors: Markkula Andrea , Simonsson Maria , Ingvar Christian , Rose Carsten , Jernström Helena
Published: May 2015

Aim: The aim of the present study was to investigate the impact of the COX2 rs5277 polymorphism on early events and treatment response in relation to tumor ER-status and to determine whether any effect is modified by body constitution.

Background: The synonymous COX2 rs5277 polymorphism (306G>C, V102V) has been directly linked to several cancers associated with inflammation. Breast cancer patients with tumors expressing COX-2 have a shorter disease-free survival. It is currently unclear whether the rs5277 genotype is correlated with tumor COX-2 expression. Tumor COX-2 expression may have contrasting effects on breast cancer tumors depending on the tumor's estrogen receptor (ER) status. It has been associated with increased estrogen levels in ER-positive tumors and Akt-pathway activation in ER-negative tumors.

Methods: The present study is based on data collected from 634 patients initiating treatment between October 2002 and October 2008. Risk of early events was assessed for 570 rs5277-genotyped patients. Body measurements and questionnaires were obtained at the pre-operative visit. Clinical data, patient-, and tumor-characteristics were obtained from questionnaires, patients' charts, population registries, and pathology reports.

Results: Among all patients, 70.1% were GG-carriers, 27.5% were GC-carriers, and 2.4% were CC-carriers. Median follow-up was 5.1 years. Median age was 59.6 years (range 25-99 years). No association was seen between the G/G genotype and risk of early events in patients with ER-positive tumors, but this genotype conferred an over 4-fold increased risk in patients with ER-negative tumors (Pinteraction=0.015). G/G-carriers with a larger breast volume who had received chemotherapy had a 9-fold risk of early events irrespective of ER-status. C-allele carriers with ER-positive tumors who had a larger breast volume and had received endocrine-therapy had a 2-fold increased risk of early events.

Conclusion: COX2 genotype, body constitution, and ER-status had a combined effect on the risk of early events and treatment response. The high risk for early events in certain subgroups of patients suggests that COX2 genotype in combination with body measurements may provide a tool for identifying patients in need of more personalized treatment.

Citation Format: Andrea Markkula, Maria Simonsson, Christian Ingvar, Carsten Rose, Helena Jernström. Combined effect of COX2 genotype, ER status, body constitution, and treatment on risk of early events in breast cancer patients. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4218. doi:10.1158/1538-7445.AM2014-4218
Abstract 4219: miR-34a, miR-93 and miR-200c - novel molecular regulators of osteosarcoma dormancy
Authors: Tiram Galia , Ferber Shiran , Ofek Paula , Shomron Noam , Udagawa Taturo , Aviel-Ronen Sarit , Barshack Iris , Satchi-Fainaro Ronit
Published: May 2015

There is an increasing interest in elucidating the mechanisms of the earlier stages in tumor progression, the point at which a dormant tumor acquires the ability to grow and metastasize. Although the tumor dormancy phenomenon has important implications for early detection and treatment of cancer, its biology and genetic characteristics are poorly understood. MicroRNAs (miRs), small non-coding RNA molecules which regulate gene expression at the post-transcriptional level, are emerging as key regulators in physiological and pathological processes, including tumorigenesis. We hypothesized that specific miRs may also play a key role in the regulation of tumor dormancy and the “angiogenic switch”. We therefore established a pair of cell lines that generate dormant avascular or fast-growing angiogenic osteosarcomas in SCID mice (Saos-2-D and Saos-2-E respectively). Although these cells share similar growth rate in vitro, when inoculated into mice, Saos-2-E cells generate vascularized and palpable tumors within one month, while Saos-2-D cells remain avascular and non-palpable for a year.

Following our hypothesis, miR arrays of Saos-2-D and Saos-2-E cells were performed. Several miRs that were differentially-expressed in the dormant versus fast-growing-tumor-generating cells were selected for further evaluation. Out of those miRs, miR-34a, miR-93 and miR-200c, when administered complexed with a polymeric nanocarrier, reverted several tumor cell lines forming fast-growing tumors to a dormant non-angiogenic phenotype, both in vitro and in vivo. We therefore propose that these three miRs play a role in the switch from dormancy to progressive disease in human osteosarcoma tumors. Uncovering new molecular targets involved in the tumor dormancy phenomenon could provide important tools for novel dormancy-directed tumor therapy strategies.

Citation Format: Galia Tiram, Shiran Ferber, Paula Ofek, Noam Shomron, Taturo Udagawa, Sarit Aviel-Ronen, Iris Barshack, Ronit Satchi-Fainaro. miR-34a, miR-93 and miR-200c - novel molecular regulators of osteosarcoma dormancy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4219. doi:10.1158/1538-7445.AM2014-4219
Abstract 4220: A cell-penetrating nucleolytic lupus autoantibody damages DNA and is toxic to BRCA2-deficient cancer cells
Authors: Noble Philip W. , Young Melissa R. , Weisbart Richard H. , Hansen James E.
Published: May 2015

Identification of therapeutic agents that are more toxic to malignant cells than normal cells is a key goal in cancer research. Many tumor cells harbor genetic defects that distinguish them from normal cells, and some of these defects have the potential to be exploited in the development of targeted therapies for cancer. Cancer cells with defects in DNA repair are highly susceptible to DNA-damaging agents, but delivery of therapeutic agents into cell nuclei can be challenging. A subset of lupus autoantibodies is associated with nucleolytic activity, and some of these antibodies are capable of nuclear penetration. We hypothesized that such antibodies might be capable of damaging DNA in cell nuclei and therefore have potential as therapeutic agents targeted towards DNA repair-deficient malignancies, such as tumors that are BRCA2-deficient. To test this hypothesis we screened a panel of cell-penetrating lupus autoantibodies for nucleolytic activity, and we identified 5C6 as an antibody of interest. 5C6 catalyzes degradation of single and double-stranded DNA in vitro and induces phospho-H2AX formation in BRCA2-deficient cells. When tested on a matched pair of BRCA2-proficient and deficient cancer cells, 5C6 selectively suppressed the growth of and was significantly more toxic to the BRCA2-deficient cells. These findings demonstrate the potential utility of 5C6 in targeted therapy for DNA repair-deficient malignancies and strengthen the rationale for studies of additional lupus autoantibodies in order to identify the best candidates for development as therapeutic agents. In addition, the toxicity of 5C6 for BRCA2-deficient cells provides further support for the hypothesis that some lupus autoantibodies contribute to the unusual cancer risk profile associated with systemic lupus erythematosus.

Citation Format: Philip W. Noble, Melissa R. Young, Richard H. Weisbart, James E. Hansen. A cell-penetrating nucleolytic lupus autoantibody damages DNA and is toxic to BRCA2-deficient cancer cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4220. doi:10.1158/1538-7445.AM2014-4220
Abstract 4222: Targeting PI3K and mTOR with BEZ235, a dual inhibitor, is efficacious in trastuzumab refractory and HER2+/PIK3CA-mutated breast cancer models
Authors: Williams Casey , Sun Yuliang , Carlson Jennifer , Leyland-Jones Brian , Dey Nandini , De Pradip
Published: May 2015

Background: PI3K pathway activation is a common event in HER2+ breast cancer (BC) either through inactivation of the tumor suppressor gene, PTEN, or activation of PIK3CA. This PIK3CA mutation leads to an oncogenic activity of the PI3K pathway and contributes to therapeutic resistance to trastuzumab (T). The PI3K pathway inhibitor is therefore an attractive drug for HER2+ BC, especially in T-resistant and PIK3CA mutated conditions. Methodology: Here we have studied the in vitro and in vivo effects of BEZ235 in HER2+/T-sensitive (BT474), HER2+/T-resistant (BT474HerR) and HER2+/PIK3CA (HCC1954) mutated models. We assessed in vitro anti-proliferative and activation status of the PI3K-AKT-mTOR signaling pathway following BEZ235 treatment in HER2+ BC cell lines. We next evaluated the impact of BEZ235 on tumor growth and angiogenesis using xenograft models. Results: 1) BEZ235 inhibited downstream activation of the PI3K signaling pathway effectors, p-AKT (Ser473, The308), p-P70S6K, p-S6RP and p-4EBP1, 2) the anti-proliferative activity of BEZ235 was observed by 3D-ON-TOP clonogenic assay, 3) consistent with anti-proliferative effects of BEZ235, the proportion of cells in the G1 phase of the cell cycle increased in all three cell lines with a concomitant decrease in the S phase of their treatment with BEZ235, 4) the initiation of apoptotic activity (annexin V) of BEZ235 was significantly superior to that of RAD001, an allosteric inhibitor of mTOR, and 5) in the HER2+/T-sensitive, HER2+/T-resistant and HER2+/PIK3CA mutated BC xenograft models, BEZ235 inhibited PI3K signaling and had potent anti-tumor activity. Along with its anti-tumor effect, BEZ235 effectively decreased tumor angiogenesis (tumor micro-vessel density via CD31 staining). These inhibitions were more pronounced when BEZ235 was combined with T. Conclusions: BEZ235 inhibits the PI3K-AKT-mTOR signaling pathway and results in anti-proliferative and anti-tumor activity in HER2+ breast cancer cells with both wild type and mutated PIK3CA.

Citation Format: Casey Williams, Yuliang Sun, Jennifer Carlson, Brian Leyland-Jones, Nandini Dey, Pradip De. Targeting PI3K and mTOR with BEZ235, a dual inhibitor, is efficacious in trastuzumab refractory and HER2+/PIK3CA-mutated breast cancer models. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4222. doi:10.1158/1538-7445.AM2014-4222
Abstract 4231: Enhanced antitumor efficacy of T-DM1 in combination with pertuzumab in HER2-positive breast cancer models
Authors: Sun Yuliang , Dey Nandini , Carlson Jennifer , Brammer Melissa , De Pradip , Leyland-Jones Brian
Published: May 2015

Background: The HER2 oncogene is amplified in approximately 20-25% of human breast cancers and is a well established therapeutic target. HER2-targeted therapy by trastuzumab (T) has become increasingly important for treating HER2+ breast cancers, and following the EMILIA trial, T-DM1 is expected to serve as a suitable alternative to trastuzumab. Pertuzumab (P), a HER2 targeted monoclonal antibody that prevents HER2 dimerization, showed progression-free survival when used with trastuzumab and docetaxel on HER2+ metastatic breast cancer (CLEOPATRA trial). In this preclinical study, we investigated the effect of combining T-DM1 and P on xenografted HER2+ breast tumors.

Methodology: Growth inhibition, apoptosis, and antitumor efficacy were examined using the 3D-ON-TOP assay, annexinV staining and mouse xenografts respectively, in BT474 (T- sensitive), BT474HR (T-resistant) and HCC1954 (PIK3CA mutated) breast cancer cell lines.

Results: Treatment of HER2-overexpressing tumor cells (T-sensitive, T-resistant and PIK3CA mutant) in vitro with T-DM1 plus pertuzumab resulted in synergistic inhibition of cell proliferation (3D-ON-TOP and 2D clonogenic assays) and induction of apoptotic cell death (annexinV positive cells). The combination (T-DM1+P) also inhibited p-AKT (Ser473 and Thr308) in HER2-overexpressing cells. T-sensitive and T-resistant xenografts regressed completely after 6 weeks of therapy with T-DM1 plus P whereas either single agent inhibited tumor growth partially in both groups. Mice with HCC1954 (HER2+/PIK3CA mutated) xenograft treated with the same combination exhibited significant tumor growth inhibition when compared with vehicle treated mice after 6 weeks of treatment. Conclusions: Our in vitro and in vivo data clearly demonstrated that dual-targeting HER2 with a combination of T-DM1 plus P was highly efficacious both in HER2+/T-resistant and HER2+/PIK3CA mutated xenograft models.

Citation Format: Yuliang Sun, Nandini Dey, Jennifer Carlson, Melissa Brammer, Pradip De, Brian Leyland-Jones. Enhanced antitumor efficacy of T-DM1 in combination with pertuzumab in HER2-positive breast cancer models. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4231. doi:10.1158/1538-7445.AM2014-4231
Abstract 4237: Antitumor activity of 2-hydroxycinnamaldehyde against human colorectal cancer cells is mediated by the Wnt/β-catenin signaling pathway
Authors: Kim Won Kyung , Oh Jedo , Bae Song Yi , Song Jayoung , Shin Yoonho , Choi Tae Joon , Jeong Eun Ju , Park So Hyun , Jang Eun Jeong , Kang Ji In , Park Hyen Joo , Hong Ji-Young , Lee Min Ai , Chung Hwa-Jin , Lee Sang Kook
Published: May 2015

The antiproliferative and antitumor activities of 2-hydroxycinnamaldehyde (1), a phenylpropanoid isolated from the bark of Cinnamomum cassia , were investigated using human colorectal cancer cells. Compound 1 exhibited antiproliferative effects in HCT116 colon cancer cells, accompanied by modulation of the Wnt/β-catenin cell signaling pathway. This substance was found also to inhibit β-catenin/T-cell factor (TCF) transcriptional activity in HEK293 cells and HCT116 colon cancer cells. Further mechanistic investigations in human colon cancer cells with aberrantly activated Wnt/β-catenin signaling showed that 1 suppressed significantly the binding of β-catenin/TCF complexes to their specific genomic targets in the nucleus and led to the down-regulation of Wnt target genes such as c-myc and cyclin D1. In an in vivo xenograft model, the intraperitoneal administration of 1 (10 or 20 mg/kg body weight, three times/week) for four weeks suppressed tumor growth in athymic nude mice implanted with HCT116 colon cancer cells significantly, without any apparent toxicity. In an ex vivo biochemical analysis of the tumors, compound 1 was also found to suppress Wnt target genes associated with tumor growth including β-catenin, c-myc, cyclin D1, and survivin. The suppression of the Wnt/β-catenin signaling pathway is a plausible mechanism of action underlying the antiproliferative and antitumor activity of 1 in human colorectal cancer cells (Acknowledgements: This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean Government (MEST) No. 20120004939)

Citation Format: Won Kyung Kim, Jedo Oh, Song Yi Bae, Jayoung Song, Yoonho Shin, Tae Joon Choi, Eun Ju Jeong, So Hyun Park, Eun Jeong Jang, Ji In Kang, Hyen Joo Park, Ji-Young Hong, Min Ai Lee, Hwa-Jin Chung, Sang Kook Lee. Antitumor activity of 2-hydroxycinnamaldehyde against human colorectal cancer cells is mediated by the Wnt/β-catenin signaling pathway. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4237. doi:10.1158/1538-7445.AM2014-4237
Abstract 4243: EGFR inhibition causes growth delay and induces apoptosis in HPV-positive head and neck cancer
Authors: Law Alexandra D. Torres , Blitzer Grace C. , Smith Molly A. , Armstrong Eric A. , Kimple Randall J.
Published: May 2015

Purpose: Cetuximab, a monoclonal antibody inhibiting the epidermal growth factor receptor (EGFR), is approved for use in the treatment of head and neck cancer (HNC).  However, studies of cetuximab were performed with HPV-negative cells, clinical trials were performed without regard to HPV status, and current studies on HPV+ HNC treatment with cetuximab are contradicting. This study was performed to determine whether HPV+ HNC responds to cetuximab and to examine the mechanisms through which cetuximab affects HPV+ HNC. 

Methods: Four HPV+ cell lines were assessed for EGFR expression by immunoblot. Sensitivity to cetuximab was tested by examining cell proliferation and colony formation. Apoptosis was measured by caspase activation, flow cytometry for Annexin V, and immunoblot. Cell cycle was assessed by immunoblot and flow cytometry for propidium iodide stained cells.  HPV+ HNC subcutaneous flank cell line xenografts and patient-derived xenografts were placed in immunocompromised mice treated with cetuximab, tumor size was measured twice weekly.

Results: Cetuximab treatment resulted in significant delay in cell proliferation and significant decrease in colony formation. Cetuximab caused an increase in apoptosis in all methods measured. Also, as previously seen in HPV- cell lines, cetuximab resulted in a G1 cell cycle arrest. Using both cell line and patient-derived xenograft models of HPV+ HNCs, cetuximab resulted in significant tumor growth delay (median time to tumor quadrupling: 15 vs. 24 days, and 42 vs. 89 days, respectively).

Conclusions: Epidermal growth factor receptor inhibition by cetuximab is effective in slowing proliferation and inducing apoptosis in HPV+ HNC. The proposed mechanism of action appears to be similar to that shown in HPV- HNC. These results suggest that cetuximab may play a role in the management of patients with HPV+ HNC.

Citation Format: Alexandra D. Torres Law, Grace C. Blitzer, Molly A. Smith, Eric A. Armstrong, Randall J. Kimple. EGFR inhibition causes growth delay and induces apoptosis in HPV-positive head and neck cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4243. doi:10.1158/1538-7445.AM2014-4243
Abstract 4245: A comparative analysis of PI3K inhibitors in human tumor primary culture microspheroids
Authors: Nagourney Robert Alan , Bernard Paula J. , Francisco Federico , Evans Steven S.
Published: May 2015

Altered phosphoinosotide metabolism is a hallmark of many human malignances. The phosphoinsotide kinases (PI3K) of which there are several sub-classes, have been explored as targets for cancer therapy. Beyond the first generation pan-PI3K inhibitors Wortmannin & LY294002, new, clinically active agents with subclass specificity and/or dual inhibitory functions (PI3K & mTOR) have been developed, including BEZ235 (PI3K/mTOR), GDC0941(αβδ), BYL719(α) & Idelalisib (δ). To examine the activity of these agents we applied Ex Vivo Analysis of Programmed Cell Death (EVA/PCD) (Nagourney, R et al Anticancer Res., 2012)to human tumor microspheroids, isolated directly from surgical specimens. Lethal concentrations (LC50's) interpolated from 5-point dose response curves were compared for activity and for correlation by Pearson Moment. Results: Micro-molar activity favored BEZ > BYL > LY. Correlation coefficients reveal BYL vs. BEZ (N=15, R =0.69, P< 0.01); BYL vs. LY (N=7, R=0.74, P=0.1); BEZ vs. LY (N=61, R=0.52, P<0.001). A comparison of activity for hematologic (Heme) vs. Solid tumors (solid) for LY: Heme > Solid; BEZ: Solid > Heme; BYL: Heme > Solid with preliminary evidence for Idelalisib showing Heme > Solid.

Conclusions: The PI3K inhibitors are active in both Heme and Solid tumors, with relative concordance between agents, but some evidence of disease specificity. Additional comparisons with GDC 0941 and drug combination studies are being conducted to further characterize the clinical activity and combinatorial potential of this class of agents. EVA/PCD analyses, conducted in human tumor primary cultures, have the capacity to evaluate drug activity, synergy and sequence dependence offering clinically relevant insights into novel drug applications.

Citation Format: Robert Alan Nagourney, Paula J. Bernard, Federico Francisco, Steven S. Evans. A comparative analysis of PI3K inhibitors in human tumor primary culture microspheroids. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4245. doi:10.1158/1538-7445.AM2014-4245
Abstract 4246: Probing the inhibitor selectivity site of class II PI3KC2β
Authors: Sundaram Krithika , Jennings Ian , Arcaro Alexandre , Thompson Philip
Published: May 2015

Ever since their discovery in 1980's, phosphoinositide 3-kinases (PI3Ks) have played a vital role in many intracellular signaling pathways and PI3K inhibitors are prominent targets in drug discovery, especially in cancer. PI3Ks catalyse the phosphorylation of phosphatidylinositol at the 3′-position of the inositol ring and the resulting secondary by-products are implicated in various cellular activities such as cell survival, growth and proliferation. Although class I PI3K has been studied extensively, not much is known about members of class II PI3K. The class II PI3K has gained attention recently as they are believed to be up-regulated in certain types of cancers. The class II PI3Ks consists of three mammalian isoforms: PI3KC2α, PI3KC2β and PI3KC2γ however, as of yet there are no potent, selective inhibitors of class II PI3Ks.

We have generated a homology model of PI3KC2β and carried out molecular docking studies of known class I PI3K inhibitors that also show activity against PI3KC2β. Our docking results have revealed that while the overall binding poses are common for the two classes, there are non-conserved residues involved in interactions with these compounds that could be targeted for selectivity. To pursue a screening program based on these concepts, we have expressed and purified active PI3KC2β. Compounds from within our 400 compound PI3K inhibitor library are being screened as our first step to develop novel PI3KC2β-selective inhibitors. In conclusion, identified differences in the catalytic pocket of PI3KC2β, compared to other PI3Ks which may aid discovery of the first novel potent inhibitors of a class II PI3K.

Citation Format: Krithika Sundaram, Ian Jennings, Alexandre Arcaro, Philip Thompson. Probing the inhibitor selectivity site of class II PI3KC2β. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4246. doi:10.1158/1538-7445.AM2014-4246
Abstract 4247: Characterization of the selective pan-RAF inhibitor TAK-632 with antitumor activity in BRAF inhibitor-resistant melanoma
Authors: Nakamura Akito , Arita Takeo , Tsuchiya Shuntarou , Donelan Jill , Chouitar Jouhara , Carideo Elizabeth , Galvin Katherine , Okaniwa Masanori , Ishikawa Tomoyasu , Yoshida Sei
Published: May 2015

Melanoma is one of the deadliest and most aggressive forms of skin cancer, arising from the malignant transformation of pigment-producing cells, melanocytes. The mitogen-activated protein kinase (MAPK) pathway is particularly important for the survival and proliferation of melanoma cells and somatic mutations in BRAF and NRAS are frequently observed in melanoma. Recently, it has been reported that the BRAF inhibitors vemurafenib and dabrafenib showed high response rates and improved overall survival in melanomas with BRAF-activating mutations. However, as BRAF inhibitors induce RAF paradoxical activation via RAF dimerization in BRAF wild-type cells, rapid emergence of acquired resistance and secondary skin tumors as well as presence of few effective treatment options for melanoma bearing wild-type BRAF (including NRAS mutant melanoma) are clinical concerns. In this preclinical study, we describe the biological characterization of TAK-632 as a potent and selective pan-RAF inhibitor that suppresses RAF activity in BRAF wild-type cells with minimal RAF paradoxical activation. We used both genetic and chemical approaches to investigate the dependence of NRAS-mutated melanoma and BRAF inhibitor-resistant BRAF mutant melanoma cells on RAF. Our analysis reveals that the MAPK pathway and proliferation of these cells is highly dependent on RAF. Such dependence was not observed in several RAS/RAF-wild type and KRAS-mutated cells. We also show that TAK-632 induces RAF dimerization but inhibits the kinase activity of the RAF dimer, probably because of its slow dissociation from RAF. Furthermore, we demonstrate that the combination of TAK-632 and various MAPK kinase (MEK) inhibitors exhibits synergistic anti-proliferative effects on these cells. Our findings indicate that TAK-632 has favorable characteristics in terms of suppressing the proliferation of NRAS mutant melanoma and BRAF inhibitor-resistant BRAF mutant melanoma cells.

Citation Format: Akito Nakamura, Takeo Arita, Shuntarou Tsuchiya, Jill Donelan, Jouhara Chouitar, Elizabeth Carideo, Katherine Galvin, Masanori Okaniwa, Tomoyasu Ishikawa, Sei Yoshida. Characterization of the selective pan-RAF inhibitor TAK-632 with antitumor activity in BRAF inhibitor-resistant melanoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4247. doi:10.1158/1538-7445.AM2014-4247
Abstract 4250: Nitric oxide synthase activity and its modulation in the treatment of colorectal cancer
Authors: Alam Asim , Rabender Chris , Wang Li , Gobalakrishnan Sundaresan , Zweit Jamal
Published: May 2015

The American Cancer Society estimates more than 141,000 new cases of and about 50,000 deaths from colorectal cancer every year. Treatment options include surgery, radiation therapy and targeted therapies such as anti-angiogenics. However, no therapies address the key driving factor of colorectal cancer: inflammation. It is well known that chronic inflammatory conditions such as Crohn's Disease, ulcerative colitis, diabetes, obesity and cigarette smoking all elevate the risk of developing colorectal cancer. One of the hallmarks of chronic inflammation is the elevated levels of reactive oxygen/nitrogen species (ROS/RNS). A primary source of these ROS/RNS is uncoupled Nitric Oxide Synthase. Under non-inflammatory conditions NOS generates Nitric Oxide. However, in an inflammatory environment, such as the oxidative tumor microenvironment, NOS's cofactor tetrahydrobiopterin (BH4) is oxidized to dihydrobiopterin (BH2). NOS bound to BH2 is said to be uncoupled and produces superoxide O2- and peroxyinitrite (ONOO-). Previous work in our and other's labs have shown that increased production of ROS/RNS leads to the activation of pro-inflammatory/proliferative molecules such as NFκB, Stat3, β-Catenin and Akt. NOS can be re-coupled by supplementing cells and animals with BH4 or its precursor Sepiapterin (SP). Herein Wwe have shownshow that by recoupling NOS with SP in HCT116, Caco-2 and HT29 cells, decreased tumor cell proliferation, increased β-Catenin degradation and decreased Akt activity. We have also seen increased tumor cell death measured via by in vitro clonogenic assays, as well decreased metabolic uptake in AOM/DSS induced colorectal cancer in vivo measured via by F18Deoxy-Glucose PET imaging. We believe by recoupling NOS both in vivo and in vitro we are modulatingion Wnt signaling via Akt and GSK-3β. Further studies are needed to elucidate the mechanism of decreased Akt activity and the downstream effectors of Wnt signaling which are affected by NOS recoupling. Lastly, we wish to combine radiation therapy with Sepiapterin SP to determine if the combination of these therapies can increase tumor cell deathincrease tumor control.

Citation Format: Asim Alam, Chris Rabender, Li Wang, Sundaresan Gobalakrishnan, Jamal Zweit. Nitric oxide synthase activity and its modulation in the treatment of colorectal cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4250. doi:10.1158/1538-7445.AM2014-4250
Abstract 4259: The radiogenomic landscape of cancer
Authors: Abazeed Mohamed , Adams Drew , Tamayo Pablo , Meyerson Matthew , Hammerman Peter , Schreiber Stuart
Published: May 2015

Radiotherapy is the mainstay of treatment for many solid malignancies. Despite this, there have not been extensive systematic analyses of the correlation between therapeutic sensitivity and genomic parameters. To accelerate discovery of patient-matched radiotherapy, or precision radiotherapeutics, systematic approaches are needed to identify specific genetic features that confer radiotherapeutic resistance and target these features with small-molecule drugs. We have quantitatively measured the sensitivity of 533 genomically characterized cancer cell lines to radiation, uncovering novel and established genetic, lineage, chromosomal copy number, and gene-expression-based dependencies. We show that small molecules that target genetic alterations driving therapeutic resistance effect genotype selective radiosensitization, establishing a preclinical basis for personalized therapeutic regimens. This dataset is an important resource that can be used to develop novel therapeutic hypotheses and to accelerate discovery of drugs given concurrently with radiation matched to patients by their cancer genotype, thereby enhancing efficacy and limiting toxicity in the context of a new approach of precision radiotherapy.

Citation Format: Mohamed Abazeed, Drew Adams, Pablo Tamayo, Matthew Meyerson, Peter Hammerman, Stuart Schreiber. The radiogenomic landscape of cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4259. doi:10.1158/1538-7445.AM2014-4259
Abstract 4263: Identifying somatic mutation hotspots across protein family alignments
Authors: Imielinski Marcin , Du Charles , Meyerson Matthew
Published: May 2015

In cancer, somatic driver mutations often target “hotspots” of paralogous residues across evolutionarily related members of a single protein family. These hotspots usually confer a dominant oncogenic function, such as constitutive catalytic activity or binding. These hotspots generally represent the most “druggable” genetic alterations. Examples of protein families targeted in such a manner include the Ras and receptor Tyrosine Kinase family. Protein family hotspots are not directly assessed by standard computational approaches for statistically nominating genes under positive somatic selection, such as MutSig, InVex, or MuSic. These methods only assess single genes for statistical enrichment of total mutation burden or the presence of mutation hotspots. As a result, such approaches are only powered to detect protein family hotspots in cases where each (or at least one) protein family member is very frequently mutated (e.g. KRAS, NRAS, HRAS). They are not powered to detect hotspots in highly functionally redundant families, of which each member may be only mutated in <<1% of a tumor type. To directly identify such protein-family hotspots, we have developed a computational framework, MutPfam. This framework superimposes mutation data onto Pfam (http://pfam.sanger.ac.uk/) (protein family and subfamily multiple sequence alignments and identifies statistically significant hotspots. We demonstate our method on protein families involved in the catalysis of small-molecular catabolism using the TCGA Pan-Cancer dataset (https://tcga-data.nci.nih.gov/) comprising somatic mutation calls for 4608 whole-exome sequenced patients and 21 tumor types. As we demonstrate, our framework enables the de novo discovery of mutation hotspots across protein families. Though developed for somatic mutation analysis, this framework could also be applied to the analysis of inherited mutations. Computational issues meriting future investigation include (1) alternate definitions of protein alignments and sub-families (e.g. involving three dimensional structure, biophysical constraints) (2) improved statistical modeling of the local background mutation rate (incorporating local genomic covariates that mediate heterogeneity) (3) incorporation of variant functional impact scores for missense variants.

Citation Format: Marcin Imielinski, Charles Du, Matthew Meyerson. Identifying somatic mutation hotspots across protein family alignments. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4263. doi:10.1158/1538-7445.AM2014-4263
Abstract 4266: Moving beyond in vitro models and addressing the challenges of pooled RNAi screens in mouse xenografts
Authors: Tedesco Donato , Bonneau Kyle , Makhanov Mikhail , Deng Debbie , Diehl Paul , Sun Peiqing , Chenchik Alex
Published: May 2015

RNAi loss-of-function screening with pooled shRNA expression libraries has proven to be a useful tool to identify essential cancer genes and drug resistance mechanisms in numerous cell lines in vitro. The effects of knocking down large numbers of genes on cancer cell growth and viability can be measured simultaneously using this approach. Now there is considerable interest to adapt RNAi viability screens to ex vivo xenograft mouse models. However, small take rates, growth rate variance of cells, and differing cell microenvironments in these more complex tumor models impose significant challenges to this sort of assay. We have developed a novel approach based on the use of pooled shRNA libraries with clonal barcodes that enables proliferation measurements of clonal populations produced by the individual shRNA-expressing founder cells that produce the tumor. This RNAi clonal analysis provides a basis to separate, across large cell populations, the external parameters that strongly influence cell growth rates from shRNA-induced growth inhibition in these systems. We will present in vivo RNAi screening validation data for several cancer models.

Citation Format: Donato Tedesco, Kyle Bonneau, Mikhail Makhanov, Debbie Deng, Paul Diehl, Peiqing Sun, Alex Chenchik. Moving beyond in vitro models and addressing the challenges of pooled RNAi screens in mouse xenografts. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4266. doi:10.1158/1538-7445.AM2014-4266