bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3735: Monitoring the level of the universal nucleotide AMP in diverse enzymatic reactions using bioluminescent homogenous assay platform
Authors: Goueli Said A. , Hsiao Kevin , Zegzouti Hicham , Mondal Subhanjan
Published: May 2015

Adenine nucleotides are major determinants of the energy status of the cell and thus any modulation of their cellular concentration has significant consequences to cellular metabolism, cellular growth and cell death. Many biochemical reactions that generate AMP as a reaction product are pivotal players in a variety of signaling pathways and thus are considered validated drug targets. These include enzymes involved in protein ubiquitination (Ubiquitin ligases), protein synthesis (aminoacyl tRNA synthetases), second messenger signaling (cAMP-phosphodiesterases), and DNA synthesis and repair (prokaryotic and eukaryotic DNA ligases). Therefore, an assay that monitors the activity of these enzymes is desirable in the search for selective modulators and the development of novel therapeutics. As AMP is a common product of these enzymatic reactions, the development of an assay that monitors AMP in a homogenous and sensitive fashion will have significant impact in these diverse areas of research. In addition, enzyme reactions that generate products which can be converted to AMP can be also monitored using this assay. We demonstrate the utility of this assay platform in monitoring the activity of cAMP-PDE, aminoacyl tRNA synthetases, ubiquitin ligases, DNA ligases. Furthermore, enzyme reactions such as methyltransferases that produce product (SAH) which can be converted to AMP can be monitored using this assay platform

Citation Format: Said A. Goueli, Kevin Hsiao, Hicham Zegzouti, Subhanjan Mondal. Monitoring the level of the universal nucleotide AMP in diverse enzymatic reactions using bioluminescent homogenous assay platform. [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 3735. doi:10.1158/1538-7445.AM2014-3735
Abstract 3742: Detection of EGFR, HER2, HER3 and HER4 homodimerization and heterodimerization using EFC-based cellular assays
Authors: Lamerdin Jane , Saharia Abhishek , Lin-Jones Jennifer , Nguyen Mimi , Fabionar Hyna , Gunturi Sangeetha , Srivastava Abha , Wehrman Tom
Published: May 2015

Ligand-induced receptor dimerization is the first functional step in receptor signaling, representing the most proximal, functional read-out for receptor activation. Here we present a novel application of the Enzyme Fragment Complementation system to monitor receptor-receptor interactions at the surface of intact cells, applicable to diverse receptor types such as RTKs, Interleukin receptors, BMP receptors and cytokine receptors, amongst others. For the purpose of this poster, we will focus on the HER family of receptors. It is well understood that the HER family proteins can dimerize with the other members of its family leading to a complicated oncogenic signaling cascade. Surprisingly, existing cellular assays have been unable to faithfully monitor these interactions proximally in a drug discovery setting. We present EFC-based cellular assays that monitor EGFR homodimerization, EGFR-ErbB2 and ErbB2-ErbB3 heterodimerization events at the receptor. The high signal to noise ratio, serum tolerance and reproducibility make these assays ideal for a diverse range of applications for the identification and development of therapeutic small molecules and biologics, including screening, functional characterization, QC lot release assays and neutralizing antibody studies.

Citation Format: Jane Lamerdin, Abhishek Saharia, Jennifer Lin-Jones, Mimi Nguyen, Hyna Fabionar, Sangeetha Gunturi, Abha Srivastava, Tom Wehrman. Detection of EGFR, HER2, HER3 and HER4 homodimerization and heterodimerization using EFC-based cellular assays. [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 3742. doi:10.1158/1538-7445.AM2014-3742
Abstract 3750: Targeting PD-L1 sensitizes head and neck squamous cell carcinoma to cisplatin
Authors: Qiao Peter , Lajud Shayanne A. , Nagda Danish A. , Tanaka Nobuaki , Civantos Alyssa , O'Malley Bert W. , Li Daqing
Published: May 2015

Platinum-based chemotherapy agents such as Cisplatin (CDDP) are commonly used as first-line treatment for several types of human cancers including ovarian, lung, testicular, and head and neck squamous cell carcinomas (HNSCC). Unfortunately, CDDP monotherapy is often ineffective due to inherent or acquired tumor resistance to therapy, also known as chemoresistance. This contributes to a need for the administration of larger, more toxic doses, as well as failure of chemotherapy and tumor recurrence. Despite the clinical significance of chemoresistance, the mechanisms driving this phenomenon are not completely understood.

Programmed cell death ligand 1 (PD-L1), a membrane-bound glycoprotein responsible for modulating the immunological response through the induction of T-Cell anergy and apoptosis, has been shown to be overexpressed in many cancers, including HNSCC. While PD-L1 overexpression has been directly related to the immunoevasion of cancer cells allowing for tumor progression, recent reports suggest that PD-L1 also plays an important role in the tumor response to doxorubicin-based chemotherapy independent of its immune function. The present study investigates the role of PD-L1 in response to CDDP in HNSCC.

In vitro experiments were performed using four well-characterized human HNSCC cell lines. Quantitative polymerase chain reaction (qPCR) and western blot were conducted to determine the baseline and post-CDDP-treatment PD-L1 gene expression. The results demonstrated that PD-L1 mRNA transcription and protein expression are upregulated in response to CDDP, suggesting that PD-L1 is involved in the chemoresponse. Conversely, knockdown of PD-L1 using siRNA resulted in chemosensitization of HNSCC cells to CDDP. Together, these findings implicate PD-L1 in the CDDP-chemoresponse in HNSCC.

In conclusion, we propose a role for PD-L1 that is distinct from the classic immunoevasion pathway. Our findings demonstrate that disruption of this protein leads to increased sensitivity of HNSCC cells to CDDP, suggesting a potential combination therapeutic strategy for patients with CDDP-resistant HNSCC.

Citation Format: Peter Qiao, Shayanne A. Lajud, Danish A. Nagda, Nobuaki Tanaka, Alyssa Civantos, Bert W. O'Malley, Daqing Li. Targeting PD-L1 sensitizes head and neck squamous cell carcinoma to cisplatin. [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 3750. doi:10.1158/1538-7445.AM2014-3750
Abstract 3753: Copper-chelator exerts synergistic interaction with platinum drugs through modulating copper transporters in oxaliplatin-resistant human gastric cancer cell
Authors: Chen Szu-Jung , Chang Jang-Yang , Kuo Ching-Chuan , Pan Hsin-Yi
Published: May 2015

Although platinum-based chemotherapy drugs including cisplatin, carboplatin, and oxaliplatin are commonly used in the treatment of human solid tumor, patients ultimately develop drug-resistance and result in treatment failure. Combination copper-chelator with platinum drugs has been reported to successfully treat a subset of cisplatin- resistant ovarian cancer patients. However, the underlying mechanisms of action remain unknown. We have previously established an oxaliplatin-resistant subclone from human gastric adenocarcinoma TSGH cells, S3. The mechanisms responsible for oxaliplatin resistance of S3 cells included down-regulation of hCtr1 and over-expression of ATP7A. In contrast to displaying additive to antagonistic interaction with platinum drugs in parental, TSGH cells, our studies showed that copper-chelator, D-penicillamine, exerts synergistic interaction with platinum drugs through increasing platinum- DNA adduct formations in S3 cells. D-penicillamine promotes copper uptake transporter hCtr1 expression via activation of transcription factor Sp1. In addition, Sp1 overexpression promotes p53 translocation from nucleus to cytosol and binds to ubiquitin, and finally causes p53 degradation, which further suppressed the expression of copper efflux transporter, ATP7A. Combination of D-penicillamine and oxaliplatin significantly inhibited S3 cell growth in animal model. Immunohistochemical analysis showed that up-regulation of hCtr1 and down-regulation of ATP7A were found in both D-penicillamine- and D-penicillamine/ Oxalipatin- treated S3 tumors, which were consistence to in vitro results. In conclusion, our results showed that D-penicillamine increases hCtr1 expression through regulating Sp1 level. Notably, D-penicillamine could down-regulate ATP7A expression through regulation of p53. Our finding demonstrated a new treatment strategy for cancer patient resistant to oxaliplatin treatment with low expression of hCtr1 and overexpression of ATP7A in tumor tissues. (This work was partially supported by the following grants: Department of Health, Taiwan DOH99-TD-C-111-004, National Health Research Institutes CA-101-PP-22, National Research Program for Biopharmaceuticals 100CAP015-5 and National Science Council 102-2325-B-400 -007)

Citation Format: Szu-Jung Chen, Jang-Yang Chang, Ching-Chuan Kuo, Hsin-Yi Pan. Copper-chelator exerts synergistic interaction with platinum drugs through modulating copper transporters in oxaliplatin-resistant human gastric cancer cell. [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 3753. doi:10.1158/1538-7445.AM2014-3753
Abstract 376: P-cadherin overexpression is associated with poor prognosis in pancreatic carcinoma and is regulated by its promoter hypomethylation
Authors: Sakamoto Keita , Imai Katsunori , Nakagawa Shigeki , Nitta Hidetoshi , Hayashi Hiromitsu , Chikamoto Akira , Ishiko Takatoshi , Beppu Toru , BaBa Hideo
Published: May 2015

[Background] P-cadherin belongs to the family of classic cadherin, and accumulating evidences shows hat P-cadherin is strongly associated with carcinogenesis and confers alignant phenotype of various cancers. Pancreatic cancer has a poor prognosis, with an overall 5-year survival rate of only 5%. Despite advances in therapy recently, its survival rate still remains poor. This study aimed to analyze P-cadherin expression and its prognostic value in pancreatic carcinoma and to validate the P-cadherin gene (CDH3) promoter methylation status as the mechanism of this gene regulation.

[Methods] Seventy-three patients diagnosed with pancreatic cancer were enrolled in this study. P-cadherin expression was examined by immunohistochemistry, and correlated with various clinicopathological features and prognosis. Furthermore, P-cadherin expression and its promoter methylation status were analyzed in pancreatic cancer cell lines.

[Results] In pancreatic tissues, 50.7% (37/73) of cases shows a high expression of P-cadherin by immunohistochemical analysis, and high expression of P-cadherin was significantly correlated with gender, posterior tissue invasion and other organs invasion. In multivariate analyses, P-cadherin expression was the independent prognostic factors for disease-free survival (relative risk:2.68, p=0.005). P-cadherin expression was found to be related to its promoter methylation status in pancreatic cancer cell lines. Furthermore, when P-cadherin was down-regulated by specific siRNA, cell migration and invasion were significantly reduced.

[Conclusion] These results suggested that expression of P-cadherin is a useful prognostic marker and seems to be important in the malignant behavior in pancreatic cancer. We are now conducting experiments to validate the CDH3 methylation status in the cancerous tissues and their adjacent normal counterpart, and investigating the biological role of P-cadherin in pancreatic cancer.

Note: This abstract was not presented at the meeting.

Citation Format: Keita Sakamoto, Katsunori Imai, Shigeki Nakagawa, Hidetoshi Nitta, Hiromitsu Hayashi, Akira Chikamoto, Takatoshi Ishiko, Toru Beppu, Hideo BaBa. P-cadherin overexpression is associated with poor prognosis in pancreatic carcinoma and is regulated by its promoter hypomethylation. [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 376. doi:10.1158/1538-7445.AM2014-376
Abstract 3760: Role of epithelial to mesenchymal transition in response to cisplatin in patient-derived ovarian carcinomas
Authors: Ricci Francesca , Guffanti Federica , Maddalena Fratelli , Perego Patrizia , Fruscio Robert , Baldo Romina , Magni Sonia , Broggini Massimo , Damia Giovanna
Published: May 2015

Epithelial ovarian cancer has the highest mortality rate in the western world among gynecological malignancies. Approximately 70% of patients achieve complete remission after first-line cisplatin (DDP)-based therapy, but almost all patients relapse with resistant disease. Understanding the mechanisms at the basis of the resistance to therapy is of pivotal importance and xenografts models are instrumental to address this topic.

We have recently been able to stabilize a panel of ovarian cancer xenografts that represent human tumors of origin both at the histological and molecular level.

Seven xenografts were characterized for their sensitivity to DDP given once a week for 3 weeks at the dose of 5 mg/kg. A second DDP cycle was given to the regrowing tumors, mimicking clinical conditions. Xenografts were classified as “Responder” (R) or “Non-Responder” (NR) on the basis of their DDP-response. Interestingly, almost all xenografts were less sensitive to the second cycle of DDP. In an attempt to study the role of genes involved in Epithelial-Mesenchymal Transition (EMT), we evaluated by RT-PCR (by the Qiagen RT2 ProfilerTM PCR Array System) in untreated and DDP-treated R and NR xenografts the expression level of 86 EMT genes.

By these analysis we wanted to investigate if some EMT genes could be predictive for DDP response, and if DDP treatment could itself induced EMT genes responsible for the observed DDP resistance. 12 genes (KRT14, BMP1, JAG1, PPPDE2, TFPI2, MSN, ITGA5, ITGAV, KRT7, FGFBP1, AHNAK and ESR1) were found to be more expressed in “NR” then “R” xenografts, and few were validated (i.e. AHNAK, JAG1). To address the second point, the fold change of gene expression was considered in DDP-treated versus control samples. 8 genes (ZEB2, TGFB1, WNT5B, MST1R, COL3A1, FN1,PLEK2, FGFBP1) involved in EMT activation were found to be upregulated by the DDP treatment, and are currently under validation.

These studies would suggest a predictive role of upregulation of specific EMT genes in response to DDP treatment, and possibly in the development of its resistance. The validation of these genes in patients whose clinical response to a DDP based therapy is known, will help in defining predictive markers to tailor DDP therapy in ovarian cancer patients.

Citation Format: Francesca Ricci, Federica Guffanti, Fratelli Maddalena, Patrizia Perego, Robert Fruscio, Romina Baldo, Sonia Magni, Massimo Broggini, Giovanna Damia. Role of epithelial to mesenchymal transition in response to cisplatin in patient-derived ovarian 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 3760. doi:10.1158/1538-7445.AM2014-3760
Abstract 3764: Antibody therapy against granulin-epithelin precursor sensitizes liver cancer to chemotherapy
Authors: Wong Nicholas , Cheung Phyllis , Yip Chi Wai , Chan Kui Fat , Ng Irene , Fan Sheung Tat , Cheung Siu Tim
Published: May 2015

The novel growth factor granulin-epithelin precursor (GEP, also named progranulin, acrogranin, or PC-derived growth factor) has shown to be upregulated in breast, ovary, prostate, liver and various human cancers. Our group has shown that GEP associated with chemo-resistance, recurrence and cancer stem cell properties in liver cancer [Gastroenterology 2011 and PLoS One 2011]. In the current study, we demonstrated that, both in vivo and in vitro, liver cancer cells that survived after chemotherapeutic agents demonstrated up-regulation of hepatic cancer stem cell marker CD133/GEP/ABCB5, and enhanced cancer stem cell properties, including colony formation and spheroid formation abilities. Importantly, combination of GEP antibody therapy and chemotherapy reversed the phenotypes induced by chemotherapy alone in the liver cancer cells and also the chemo-resistant subpopulations. Notably, combination of GEP antibody and cisplatin resulted in the eradication of all established intrahepatic human xenografts. This preclinical study demonstrated that combination treatment has the potential to be effective therapeutic regimen for GEP positive cancers.

Citation Format: Nicholas Wong, Phyllis Cheung, Chi Wai Yip, Kui Fat Chan, Irene Ng, Sheung Tat Fan, Siu Tim Cheung. Antibody therapy against granulin-epithelin precursor sensitizes liver cancer to chemotherapy. [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 3764. doi:10.1158/1538-7445.AM2014-3764
Abstract 3776: Identification of gene regulatory networks mediating melanoma cell resistance to temozolomide
Authors: Zhang Tongwu , Xu Mai , Chow Donald , Sereduk Chris , Trent Jeffrey M. , Yin Hongwei , Brown Kevin M.
Published: May 2015

Melanoma is the most dangerous type of skin cancer and the leading cause of death from skin cancer. While there are multiple promising new immunotherapeutic and targeted approaches for treating melanoma, not all patients are eligible for these therapies and most of those that are ultimately relapse, highlighting a critical need for improved chemotherapeutics. Temozolomide (TMZ) is an orally administered DNA-alkylating agent used in the treatment of advanced cancers including melanoma. TMZ has shown some advantage in the clinic in terms of preventing central nervous system relapse and patient quality of life. In order to find novel vulnerabilities that may be exploited to sensitize melanoma cells to TMZ, we utilized mRNA expression and TMZ-sensitivity profiling in a panel of 18 melanoma cell lines to develop a classifier of TMZ-sensitivity using the support vector machine (SVM) method. We subsequently applied this classifier to predict the TMZ-sensitivity in 47 independent melanoma cell lines. TMZ sensitivity profiling in smaller set of 22 of these lines resulted in a prediction accuracy of approximately 80%. We analyzed the genes differentiating TMZ-sensitive and -resistant melanoma cells using both microarray data in 40 cell lines, and more recently RNA-sequencing from the original 18 cell line training set. We found no correlation between TMZ sensitivity and expression of the DNA repair gene (MGMT), base excision repair gene (PARP1, PARG, etc.), and DNA mismatch repair gene (MLH1, MSH2, etc.). Instead, analysis using the Ingenuity IPA pathway analysis tool found that upregulation of MITF and a large set of MITF target genes, as well as downregulation TGFB1 and TGFB1 targets were strongly associated with TMZ resistance in melanoma cell line (p = 2.82E-67 and p = 1.17E-52, respectively in the microarray analysis; similar results observed in RNA sequencing data). E-cadherin (CDH1), which is know to play a key role in invasion and transition from radial to vertical growth in melanoma, was found to be one of the genes most significantly correlated with TMZ resistance. Finally, we also analyzed exome-sequencing data from these cell lines (n=55) and found that TMZ-sensitivity did not significantly correlate with the presence or absence of mutations to genes commonly mutated in melanoma. In conclusion, our gene expression data suggest that TMZ resistance in melanoma cells in vitro is likely mediated by large gene regulatory networks governed by MITF and TGFB1.

Citation Format: Tongwu Zhang, Mai Xu, Donald Chow, Chris Sereduk, Jeffrey M. Trent, Hongwei Yin, Kevin M. Brown. Identification of gene regulatory networks mediating melanoma cell resistance to temozolomide. [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 3776. doi:10.1158/1538-7445.AM2014-3776
Abstract 379: TARBP1, a member of the SPOUT methyltransferase family, is involved in human carcinogenesis
Authors: Nakakido Makoto , Nakamura Yusuke , Hamamoto Ryuji
Published: May 2015

It has recently been recognized that protein methylation plays a critical role in many biological processes, and its deregulation has been observed in various kinds of diseases, including cancer. To date, a number of protein methyltransferases have already been reported to be associated with human carcinogenesis. Although many protein methyltransferases belong to the SET-domain containing protein family or the protein arginine methyltransferase (PRMT) family, a series of other methyltransferase families have also been discovered by bioinformatics-based approaches. On the contrary, physiological functions of these methyltransferases, especially, the significance in human disease like cancer, still remains unknown. In this study, we demonstrated that expression levels of TARBP1 (TAR RNA-Binding Protein 1), a member of the SPOUT methyltransferase family, are significantly up-regulated in many types of cancer tissues compared to corresponding non-tumor tissues. In addition, knockdown of TARBP1 resulted in the suppression of cancer cell growth, indicating that TARBP1 seems to regulate the proliferation of cancer cells. Since expression levels of TARBP1 in normal tissues are significantly low, TARBP1 may be a good new target for anti-cancer therapy.

Citation Format: Makoto Nakakido, Yusuke Nakamura, Ryuji Hamamoto. TARBP1, a member of the SPOUT methyltransferase family, is involved in human carcinogenesis. [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 379. doi:10.1158/1538-7445.AM2014-379
Abstract 3797: Efficacy and pharmacokinetics of gold nanorods coupled with laser-induced photoplasmonic therapy in solid tumor bearing mice
Authors: Al-Abd Ahmed M. , Shabaka Ali A. , El-Shabrawy Osama A. , Yassin Nemat A. , Mahmoud Sawsan S. , El-Shenawy Siham M. , Al-Ashqar Emad , Eisa Wael H. , Farag Niveen M. , El-Shaer Marwa A. , Salah Nabila , El-Sayed Mostafa A.
Published: May 2015

Gold nanorods (GNR) are characterized by absorbing near IR beams and emitting heat which is called photoplasmonic response. Yet, the efficacy of nanoparticles is limited due to intratumoral tissue distribution reasons. In addition, distribution of GNRs to normal tissue might result in non specific toxicity. In the current study, we assessed the intratumoral and tissue distribution of PEGylated GNRs as well as its antitumor efficacy (coupled with laser photoplasmonic sessions) when given intravenously or intratumoral to solid tumor bearing mice. PEGylated GNRs with a longitudinal size of less than 100 nm were prepared with aspect ratio of 4.6 and showed strong surface plasmon absorption at wave length 800 nm. Pharmacokinetics of GNR after single I.V. administration (0.1 mg/kg) showed very short systemic circulating time (less than 3 h). On the other hand, tissue distribution of I.V. GNR (0.1 mg/kg) to normal animals showed preferential deposition in spleen tissue. Repeated administration of I.V. GNR resulted in preferential accumulation in both liver and spleen tissues. In addition, I.V. administration of GNR to Ehrlich carcinoma tumor bearing mice resulted in similar tissue distribution; tumor accumulation and anti-tumor effect compared to intratumoral administration. In conclusion, the concentration of GNR achieved within tumors microregions after I.V. administration was comparable to I.T. administration and sufficient to elicit tumoral growth arrest when coupled with laser-aided photoplasmonic treatment.

Citation Format: Ahmed M. Al-Abd, Ali A. Shabaka, Osama A. El-Shabrawy, Nemat A. Yassin, Sawsan S. Mahmoud, Siham M. El-Shenawy, Emad Al-Ashqar, Wael H. Eisa, Niveen M. Farag, Marwa A. El-Shaer, Nabila Salah, Mostafa A. El-Sayed. Efficacy and pharmacokinetics of gold nanorods coupled with laser-induced photoplasmonic therapy in solid tumor bearing mice. [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 3797. doi:10.1158/1538-7445.AM2014-3797
Abstract 3798: Shift of Cx43 isoform expression by PQ1 in SW480 human colorectal cancer cells
Authors: Bigelow Kristina M. , Nguyen Thu Annelise
Published: May 2015

Colorectal cancer is one of the most common cancers in men and women in the United States. On average, the risk of developing colorectal cancer is about 1 in 20 over an individuals' lifetime. Cancer cells exhibit many deficiencies in cell-to-cell communication, particularly gap junctional intercellular communication (GJIC). GJIC has been reported to diminish as cancer cells progress. Gap junctions are intercellular channels composed of connexin proteins, which mediate the direct passage of small molecules from one cell to the next. They are involved in the regulation of cell cycle, cell differentiation, and cell signaling. Previously, a class of substituted quinolines, known as PQs, demonstrated to increase GJIC in cancer cells and subsequently attenuated tumor growth. The goal of this study is to determine whether the mode of PQ1 is by directly regulating the connexin protein. The results show that the low expression of connexin 43 (Cx43) in SW480 human colorectal cancer cells remains constant in the presence of PQ1. However, PQ1 caused a change in isoform expression of Cx43 in which there was a shift of Cx43 expression from P0 to P1 and P2 isoforms. This suggests that the trafficking of Cx43 from the Golgi to the membrane occurs in the presence of PQ1. Furthermore, the results show that Cx43 interacts with PKCα in SW480 cells; however, PQ1 does not affect the interaction of Cx43 and PKCα, suggesting that the shift in Cx43 isoforms is not due to PKCα phosphorylation. These findings provide in part that the increase of GJIC by PQ1 is due to the shift in Cx43 from P0 to P1 and P2 isoforms in SW480 colorectal cancer cells.

Citation Format: Kristina M. Bigelow, Thu Annelise Nguyen. Shift of Cx43 isoform expression by PQ1 in SW480 human colorectal 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 3798. doi:10.1158/1538-7445.AM2014-3798
Abstract 3801: Small molecule inhibitor of Stat3 induces antitumor cell effects in vitro and antitumor effects in vivo against human glioma or breast cancer model
Authors: Yue Peibin , Lopez-Tapia Francisco , Tius Marcus , Turkson James
Published: May 2015

Aberrant activation of signal transducer and activator of transcription 3 (Stat3) is prevalent in many human cancers. Compelling evidence shows that constitutively-active Stat3 constitutes a point of convergence in oncogenic tyrosine kinase signaling, functioning as a master regulator of events crucial for tumorigenesis and malignant progression. We show herein that the small-molecule, SH5-07 abrogates constitutive activation of Stat3 and Stat3-dependent functions in human glioma and breast cancer cells. SH5-07 inhibits in vitro Stat3 DNA-binding activity with an IC50 value of 3.9 μM. Treatment of human glioma U251MG and breast cancer MDA-MB-231 cells that harbor aberrantly-active Stat3 with low micromolar SH5-07 blocks Stat3 phosphorylation, DNA-binding, and transcriptional activities in a time and dose-dependent manner. By contrast, SH5-07 shows little or no effect on the induction of pJAK2, pSrc, pErk1/2, and pShc in glioma and breast cancer cells. SH5-07 preferentially inhibited viability of human glioma and breast cancer cells that harbor aberrant Stat3 activity, with IC50 of 1.1-5.2 µM, compared to IC50 of 6.0-10.8 µM for cells that do not. Inhibition of aberrantly-active Stat3 by SH5-07 preferentially suppresses the anchorage-dependent and independent growth, induces apoptosis, and blocks migration and invasion in vitro of human glioma and breast cancer cells that harbor constitutively-active Stat3. Moreover, oral administration of SH5-07 inhibits the growth of human breast tumor xenografts in mice. Data together indicates SH5-07 is a promising small-molecule Stat3 inhibitor and a suitable drug candidate for clinical development.

Citation Format: Peibin Yue, Francisco Lopez-Tapia, Marcus Tius, James Turkson. Small molecule inhibitor of Stat3 induces antitumor cell effects in vitro and antitumor effects in vivo against human glioma or breast cancer model. [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 3801. doi:10.1158/1538-7445.AM2014-3801
Abstract 3803: Obatoclax analogue SC-2001 inhibits STAT3 phosphorylation by enhancing protein tyrosine phosphatase SHP-1 expression and induces apoptosis in human breast cancer cells
Authors: Liu Chun-Yu , Su Jung-Chen , Tseng Ling-Ming , Chu Pei-Yi , Tai Wei-Tien , Shiau Chung-Wai , Chen Kuen-Feng
Published: May 2015

Background: Interfering the oncogenic STAT3 signaling is considered as promising anti-cancer strategy. Previously, we have reported an obatoclax analogue, SC-2001, as a novel STAT3 inhibitor in hepatocellular carcinoma cells (Cancer Letter 2012). Here, we examined the efficacy and drug mechanism of SC-2001 in breast cancer cells.

Methods: Human breast cancer cell lines were used for in vitro studies. Cell viability was examined by MTT assay. Apoptosis was examined by both flow cytometry and western blot. Signal transduction pathways in cells were assessed by western blot. Small interference RNA was used to knockdown SHP-1. Quantitative RT-PCR was used for assessing gene transcription. In vivo efficacy of SC-2001 was tested in xenografted nude mice.

Results: SC-2001 inhibited cell growth and induced apoptosis in breast cancer cell lines (MDA-MB-468, MDA-MB-231, MDA-MB-453, MCF-7 and HCC 1937). SC-2001 downregulated the phosphorylation of STAT3 (Tyr 705) and subsequently inhibited its transcriptional activities in a dose-dependent manner. STAT3-regulated proteins, including Mcl-1, survivin and cyclin D1, were also repressed by SC-2001. Over-expression of STAT3 in MDA-MB-468 cells protected cells from SC-2001-induced apoptosis. Moreover, SC-2001 enhanced the expression of SHP-1, a negative regulator of STAT3, in a time-dependent manner. The enhanced SHP-1 expression, in conjunction with increased SHP-1 phosphatase activity, was mediated by upregulated transcription. Furthermore, co-immunoprecipitation experiment showed that SC-2001 upregulated SHP-1 expression through enhanced transcription by RFX-1 transcription factor. Importantly, SC-2001 showed efficacious antitumor activity and p-STAT3 downregulation in MDA-MB-468 xenograft tumors.

Conclusion: Our results suggest that SC-2001 induced apoptosis in breast cancer cells, and that this effect is mediated through RFX-1 upregulated SHP-1 expression and SHP-1-dependent STAT3 inactivation.

(Supported by Yen Tjing Ling Medical Foundation; NSC 101-2325-B-075-006, NSC-102-2325-B-075-006 and NSC 100-2325-B-010-007; and V100-D-005-4)

Citation Format: Chun-Yu Liu, Jung-Chen Su, Ling-Ming Tseng, Pei-Yi Chu, Wei-Tien Tai, Chung-Wai Shiau, Kuen-Feng Chen. Obatoclax analogue SC-2001 inhibits STAT3 phosphorylation by enhancing protein tyrosine phosphatase SHP-1 expression and induces apoptosis in human breast 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 3803. doi:10.1158/1538-7445.AM2014-3803
Abstract 3804: CPA-7, an inhibitor of STAT3, is a potent tumoricidal agent in peripheral tumor models and is impermeable to the CNS
Authors: Assi Hikmat , Paran Chris , Savakus Jon , Hoeschle James , Raptis Leda , Lowenstein Pedro R. , Castro Maria G.
Published: May 2015

Analogues of the prototypical cancer drug cisplatin number by the hundreds with variable effects on DNA and signal transduction. Of these compounds, CPA-7 has been shown to elicit potent tumoricidal activity by preferentially targeting STAT3 in transformed cells. In this study, we characterized the response of rodent and human glioma cells to STAT3 inhibition by CPA-7. In addition, we determined if CPA-7 administration is sufficient for the induction of tumor regression in intracranial and peripheral mouse tumor models. Cultured glioma cells treated with CPA-7 ceased to proliferate and underwent apoptosis. Induction of apoptosis was associated with reduction of phosphorylated STAT3 and downstream transcriptional products such as cyclin D, survivin, and Bcl-xl. Although CPA-7 inhibits STAT3 preferentially, we observed an inhibition of STAT1 at doses higher than 30uM. Furthermore, mice bearing GL26 flank tumors underwent complete tumor regression in response to CPA-7 administration. This potent therapeutic effect of CPA-7 could not be duplicated in mice bearing intracranial GL26 brain tumors as that group became moribund at the same time as vehicle treated mice. Western blot and immunohistochemistry analysis of tumors isolated from CPA-7 treated mice demonstrated a reduction of phosphorylated STAT3 in peripheral but not intracranial tumors. This data suggests that CPA-7 is impermeable to the brain as a consequence of its molecular structure. Permeability measurements of CPA-7 using the PAMPA assay support this notion. These observations were corroborated in the B16-f0 and B16-f10 mouse melanoma models. Inhibition of STAT3 has been shown to be an effective strategy at inducing tumor regression in multiple cancer types. Although the discovery of effective and specific inhibitors has been limited, we believe that CPA-7 is a compound with potential therapeutic activity for peripheral solid tumors and warrants further evaluation and pharmacological characterization.

Supported by NIH/NINDS

Citation Format: Hikmat Assi, Chris Paran, Jon Savakus, James Hoeschle, Leda Raptis, Pedro R. Lowenstein, Maria G. Castro. CPA-7, an inhibitor of STAT3, is a potent tumoricidal agent in peripheral tumor models and is impermeable to the CNS. [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 3804. doi:10.1158/1538-7445.AM2014-3804
Abstract 3805: Anticancer agent HJC0416 inhibits the growth of breast cancer xenografts via downregulating STAT3 signaling
Authors: Xiong Ailian , Chen Haijun , Yang Zhengduo , Cai Guoshuai , Wang Lili , Ding Chunyong , Xu Grace G. , Wild Christopher , Ye Na , Uray Ivan P. , Zhou Jia , Shen Qiang
Published: May 2015

Signal transducers and activators of transcription (STATs) play important roles in regulating the expression of genes activated during tumorigenesis. Particularly, STAT3 has been shown to contribute significantly in breast carcinogenesis and is often overexpressed in primary breast tumors. Increased STAT3 transcriptional activity is correlated with ER-negative phenotype in breast cancer cell lines and in primary invasive ductal breast carcinomas. Therefore, STAT3 emerges as a promising target for breast cancer treatment and prevention. We have designed, synthesized and screened a series of novel STAT3 inhibitors utilizing fragment-based drug design strategy. A number of small molecules with novel scaffolds have been discovered with low-micromolar to nanomolar potency in inhibiting the proliferation of various human breast cancer and pancreatic cancer cells. The identified compound HJC0416 significantly suppresses STAT3 promoter activity and STAT3 phosphorylation, reduces total STAT3 protein expression, induces cell growth arrest and early apoptosis in triple-negative breast cancer cell line MDA-MB-231. HJC0416 also demonstrated a better efficacy in suppressing the growth of MDA-MB-231 breast xenograft tumors via intraperitoneal and oral administrative routes, with remarkably improved aqueous solubility and less toxicity than the lead compounds. We further demonstrated that p70S6K and MAPK pathways mediate the inhibitory effects from HJC0416 via downregulating RPS6, PDCD4 and EEF2K proteins. In conclusion, the new anticancer agent HJC0416 inhibits the growth of breast cancer xenografts via suppressing STAT3 expression and its phosphorylation.

Citation Format: Ailian Xiong, Haijun Chen, Zhengduo Yang, Guoshuai Cai, Lili Wang, Chunyong Ding, Grace G. Xu, Christopher Wild, Na Ye, Ivan P. Uray, Jia Zhou, Qiang Shen. Anticancer agent HJC0416 inhibits the growth of breast cancer xenografts via downregulating STAT3 signaling. [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 3805. doi:10.1158/1538-7445.AM2014-3805
Abstract 381: Characterizing the role of heterochromatin protein 1 gamma in normal intestinal homeostasis and tumorigenesis
Authors: Lio Ka Ian , Clarke Alan , Reed Karen
Published: May 2015

Background: Epigenetic modifications are being increasingly recognized to contribute to colorectal cancer formation. Heterochromatin Protein 1 gamma (HP1gamma) has an important role in carcinogenesis and tumorigenesis by regulating several mechanisms, such as heterochromatin formation, gene silencing and DNA replication and repair. The aim of this study was to characterize the role of HP1gamma in normal intestinal homeostasis, tumorigenesis and cancer progression.

Methods: The Cbx3 gene (encoding the HP1gamma protein) was conditionally deleted in the murine small intestinal epithelium under normal intestinal homeostasis and in the context of aberrant Wnt signaling using transgenic mouse models. Furthermore, the effect of CBX3 depletion on Wnt activation was investigated using an in vitro system.

Results: The level of Cbx3 was significantly up-regulated in small intestinal cancer tissues of mouse models, consistent with our preliminary observations that CBX3 was highly expressed in tumor samples of colorectal cancer patients compared to matched normal tissues. We found a dramatic increase in the lifespan of our colorectal cancer mouse model following the loss of Cbx3. Both in vivo and in vitro studies demonstrated that depletion of Cbx3 leads to decreased transcription of a subset of Wnt target genes and Wnt signaling activity, respectively. Furthermore, marked epigenetic alternations were observed in association patterns of HP1gamma and the heterochromatin markers (H3K9me2, H3K9me3 and H4K20me3) in wild-type and mouse model of colorectal cancer.

Conclusions: HP1gamma may play direct or indirect roles in regulating Wnt target gene expression by binding H3K9me3 or H4K20me3 and altering heterochromatin formation. These data provide stepping stones for further investigation of the mechanistic role of HP1gamma in normal intestinal homeostasis, tumor initiation and progression.

Citation Format: Ka Ian Lio, Alan Clarke, Karen Reed. Characterizing the role of heterochromatin protein 1 gamma in normal intestinal homeostasis and tumorigenesis. [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 381. doi:10.1158/1538-7445.AM2014-381
Abstract 3820: Expression of ST6Gal-1 in colorectal cancer and patient prognosis
Authors: Jadhav Trafina , Narang Saksham , Bae Jeehyun , Schultz Matthew , Eltoum Isam-Eldin , Bellis Susan , Bae Sejong , Manne Upender
Published: May 2015

Background: ST6Gal-1 sialyltransferase, a type II membrane protein that catalyzes the transfer of sialic acid to the N-glycans of certain receptors, is upregulated in several cancers, including colorectal cancers (CRCs), and its levels correlate with metastatic potential. Therefore, we investigated its prognostic value in CRCs.

Methodology: Formalin-fixed, paraffin-embedded CRC tissues from African Americans (Blacks) (n=50) and non-Hispanic Caucasians (Whites) (n=51) patients were evaluated for immunohistochemical (IHC) expression of ST6Gal-1. IHC expression was assessed using an anti-human ST6Gal-1 polyclonal antibody (R&D Systems) with antigen retrieval. The antibody-antigen complex was detected by the Immpact NovaRed system (Vector Labs). A semiquantitative immunostaining scoring system (ISS) on a scale of 0-4 was developed to assess the ST6Gal-1 expression, and a cutoff value (1.2 ISS) was determined by the bootstrap method. This value was used to classify tumors as low- or high-ST6Gal-I expressors. Previously, these tissues were evaluated for p53 nuclear accumulation (p53nac), an indicator of abnormal p53, by IHC. ST6Gal-1 expression levels were correlated with demographic and clinicopathologic features and with patient survival.

Results: Increased ST6Gal-1 expression was observed in all CRCs as compared to their corresponding normal tissues. The overall frequency of CRCs with increased ST6Gal-1 expression was 80%; it was more commonly found in Blacks (88%, 44 of 50) than in Whites (70%, 36 of 51) (X2 p=0.031). Also, increased expression was associated with p53nac, and ST6Gal-1 expression was higher in CRCs that exhibited p53nac (87%, 42 of 48) relative to CRCs without p53nac (70%, 35 of 50) (X2 p = 0.034). Moreover, patients with CRCs with high ST6Gal-1 had lower median survival (29.3 months) relative to those with low ST6Gal-1 expression (58.5 months).

Conclusions: These preliminary findings suggest that increased expression of ST6Gal-1 expression, found predominantly in Blacks patients and in CRCs with abnormal p53, is associated with poor patient survival.

Citation Format: Trafina Jadhav, Saksham Narang, Jeehyun Bae, Matthew Schultz, Isam-Eldin Eltoum, Susan Bellis, Sejong Bae, Upender Manne. Expression of ST6Gal-1 in colorectal cancer and patient prognosis. [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 3820. doi:10.1158/1538-7445.AM2014-3820
Abstract 3826: Breast cancer metastasis suppressor-1 promoter methylation in cell free DNA provides prognostic information in non-small cell lung cancer
Authors: Balkouranidou Ioanna , Chimonidou Maria , Milaki Georgia , Tsaroucha Emily , Kakolyris Stelios , Welch Danny , Georgoulias Vasilis , Lianidou Evi
Published: May 2015

Background: Breast-cancer metastasis suppressor 1 (BRMS1) gene encodes for a predominantly nuclear protein that differentially regulates the expression of multiple genes, leading to suppression of metastasis without blocking orthotopic tumor growth. The aim of the present study was to evaluate for the first time the prognostic significance of BRMS1 promoter methylation in cell free DNA (cfDNA) circulating in plasma of non-small cell lung cancer (NSCLC) patients. Towards this goal, we examined the methylation status of BRMS1 promoter in NSCLC tissues, matched adjacent non-cancerous tissues and corresponding cfDNA as well as in an independent cohort of patients with advanced NSCLC and healthy individuals.

Methods: BRMS1 promoter methylation was examined in 57 NSCLC tumors and adjacent non-cancerous tissues, in cfDNA isolated from 48 corresponding plasma samples, in cfDNA isolated from plasma of 74 patients with advanced NSCLC and 24 healthy individuals.

Results: BRMS1 promoter was highly methylated both in operable NSCLC primary tissues (59.6%) and corresponding cfDNA (47.9%) but not in cfDNA from healthy individuals ( 0%), while it was also highly methylated in cfDNA from advanced NSCLC patients (63.5%). In operable NSCLC, Kaplan-Meier estimates were significantly different in favor of patients with non-methylated BRMS1 promoter in cfDNA, concerning both DFI (p=0.048) and OS (p=0.007). In advanced NSCLC, OS was significantly different in favour of patients with non-methylated BRMS1 promoter in their cfDNA (p=0.003). Multivariate analysis confirmed that BRMS1 promoter methylation has a statistical significant influence both on operable NSCLC patients' DFI time and OS and on advanced NSCLC patients' PFS and OS.

Conclusions: BRMS1 promoter methylation in cfDNA isolated from plasma of NSCLC patients provides important prognostic information and merits to be further evaluated as a circulating tumor biomarker.

Citation Format: Ioanna Balkouranidou, Maria Chimonidou, Georgia Milaki, Emily Tsaroucha, Stelios Kakolyris, Danny Welch, Vasilis Georgoulias, Evi Lianidou. Breast cancer metastasis suppressor-1 promoter methylation in cell free DNA provides prognostic information in non-small cell lung 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 3826. doi:10.1158/1538-7445.AM2014-3826
Abstract 3827: Predictions for recurrence of non-muscle invasive bladder cancers by circulating miRNAs
Authors: Lin Shu-Hong , Lian Jie , Ye Yuanqing , Dinney Colin P. , Wu Xifeng
Published: May 2015

Background: Circulating microRNAs (miRNAs) have been extensively associated with disease conditions, and shown to be involved in tumorigenesis. In the current study, we aimed to identify miRNAs which are present specifically in the serum of non-muscle invasive bladder cancer (NMIBC) patients and correlate these miRNAs with clinical outcomes. Method: A pilot study was first conducted to profile the expression of 754 miRNAs using the Taqman® microRNA Array and identified 89 miRNAs that can be detected at high levels in more than 30% of samples. In this study, we applied a two-stage design with discovery phase of 280 cases followed by the validation phase of 276 cases using the Fluidigm BioMark™ System to assess whether these 89 miRNAs were associated with bladder cancer clinical outcomes. Results: Among 280 cases in the discovery phase, 134 recurrence events were observed. Further stratification by treatment showed that 147 patients received Bacillus Calmette-Guerin (BCG) treatment and 78 patients received transurethethral resection only (TUR). COX regression on dichotomized expression of miRNAs revealed that 2 and 6 miRNAs were associated with recurrence in the BCG group and the TUR group with p-values <0.05, respectively. The most significant observed association with recurrence had p-values of 0.008(BCG) and 0.005 (TUR). We constructed risk scores for recurrence using previous miRNAs identified by COX regression. Patients with high risk scores had significantly shorter recurrence-free survival in BCG group (p=0.006, mean survival time 9.04 and undefined for high risk and low risk scores) but not in TUR group possibly due to small sample size (p=0.114, mean survival time 4.60 and 14.04). We are in the progress of further verifying associations between candidate miRNAs and clinical outcomes in an additional 276 NIMBC samples. Conclusion: Our preliminary results demonstrate the potential of miRNAs as predictive markers for NMIBC recurrence.

Citation Format: Shu-Hong Lin, Jie Lian, Yuanqing Ye, Colin P. Dinney, Xifeng Wu. Predictions for recurrence of non-muscle invasive bladder cancers by circulating miRNAs. [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 3827. doi:10.1158/1538-7445.AM2014-3827