bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract C251: Dianotecan: A novel water-soluble CPT prodrug as a potential anticancer agent with less susceptility to multidrug resistance than irinotecan.
Authors: Zhou Wenqiang , Fu Li-Wu
Published: August 2014

Camptothecin (CPT) and its derivatives are topoisomerase I inhibitors. Among these, irinotecan and topotecan have shown significant clinical activity against a broad range of malignancies. Irinotecan is approved for use in the treatment of advanced colorectal cancer, as first-line therapy in combination with 5-FU or as a salvage agent after failure of 5-fluorouracil-based chemotherapy. However, recent studies have revealed that SN-38 (the active metabolite of irinotecan) is the substrate of BCRP (ABCG2), an ATP-binding cassette (ABC) transport protein which confers multidrug resistance and is also characterized as the marker of stem and progenitor cells. In tumor cell lines over-expressing BCRP, selective BCRP efflux of SN-38 leads to decrease in cellular drug accumulation, resulting in drug resistance phenotype. Here we report discovery of a novel water-soluble CPT prodrug (dianotecan) which can be efficiently metabolized to CPT in vivo after i.v. Injection. In the tumor xenograft studies, dianotecan has been established as a potent inhibitor against a number of human solid tumors including HT-29, S1, NCI-446, MCF-7. Significantly, dianotecan has demonstrated anti-tumor efficacy far superior to irinotecan in the xenograft studies using the BCRP-overexpressing S1-M1-80 cell line. These findings suggest dianotecan, as a potential anticancer agent, is less susceptible to multidrug resistance than irinotecan. The preclinical data of dianotecan will be discussed in the poster.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C251.

Citation Format: Wenqiang Zhou, Li-Wu Fu. Dianotecan: A novel water-soluble CPT prodrug as a potential anticancer agent with less susceptility to multidrug resistance than irinotecan. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C251.
Abstract C266: Evaluation of Src as a therapeutic target in biliary tract cancer.
Authors: Oh Do-Youn , Nam Ah-Rong , Kim Tae Yong , Han Sae-Won , Song Sang-Hyun , Im Seock-Ah , Kim Tae-You , Bang Yung-Jue
Published: August 2014

Background: In biliary tract cancer (BTC), no molecular therapeutic target has been validated so far. Therefore, cytotoxic chemotherapy is the mainstay of treatment of advanced BTC and the prognosis is poor and there is a huge unmet medical need. Src is a nonreceptor tyrosine kinase involved in the crosstalk and mediation of many signaling pathways that promote cell proliferation, invasion and angiogenesis. Elevation of Src activity has been reported in many types of cancers including BTC. The purpose of this study is to evaluate of Src as a therapeutic target in BTC and to elaborate the therapeutic potential of bosutinib, an orally active small molecule c-Src/abl kinase inhibitor.

Methods: Eight human biliary tract cancer cell lines (SNU-245, 308, 478, 869, 1079, 1196, HuCCT1, TFK1) were used. MTT assay, colony formation assay and 3D culture were done for determining growth inhibitory effect of bosutinib, alone or in combination with chemotherapeutic agents (gemcitabine, cisplatin). Cell cycle analysis was done by FACS Calibur flow cytometer. Matrigel invasion assay and wound healing assay were done. The methods described by Chou and Talalay were used to determine whether a synergistic effect existed between drug combination. Tumor xenograft model was made and used for in vivo test of bosutinib/gemcitabine.

Results: Bosutinib inhibited the growth of BTC cells, especially SNU308, SNU478 and HuCCT1 (IC50 0.6-0.8 µmol/L). Bosutinib induced G1 arrest and decreased pSrc, pFAK, pAKT and pERK in these cells. Inhibition of pSrc was accompanied with increase of pSTAT3 in SNU308. Bosutinib inhibited the cell migration and invasion. Interestingly, bosutinib showed synergistic antiproliferative effects with gemcitabine. In the xenograft model of SNU478, bosutinib decreased tumor growth compared to control and bosutinib in combination of gemcitabine showed the synergistic antitumor effect.

Conclusion: These preclinical evaluations support that Src could be a potential therapeutic target in biliary tract cancer.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C266.

Citation Format: Do-Youn Oh, Ah-Rong Nam, Tae Yong Kim, Sae-Won Han, Sang-Hyun Song, Seock-Ah Im, Tae-You Kim, Yung-Jue Bang. Evaluation of Src as a therapeutic target in biliary tract cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C266.
Abstract C269: Targeting casein kinase 1 delta and epsilon (CK1δ/ϵ) in breast cancer therapeutics.
Authors: Rosenberg Laura H. , Chen Weimin , Nakanishi Shima , Bibian Mathieu , Cameron Michael D. , Cleveland John L. , Roush William R. , Duckett Derek R.
Published: August 2014

The Caesin Kinase 1 (CK1) family consists of 7 ubiquitously expressed serine/threonine kinases that play diverse roles in a number of cellular processes. Interestingly, CK1δ and ϵ are highly expressed in some cancer types where they have been shown to promote cell growth, survival, and tumorigenicity in vivo. For example, exogenous expression of kinase dead mutants of CK1δ block SV40 induced cell transformation as well as mammary carcinogenesis in xenograft models. Furthermore, the effect of CK1δ/ϵ shRNAs on breast cancer cell growth has been shown to correlate with high levels of nuclear β-catenin, a molecular phenotype known to be associated with the invasive TNBC subtype and poor clinical outcome. Therefore, we investigated whether inhibition of CK1 δ/ϵ could represent a viable strategy for the treatment of TNBC, for which there are currently no targeted therapies. Here we report the development of novel small molecule, ATP competitive inhibitors of CK1δ/ϵ, that are highly selective for CK1δ and ϵ and have low nanomolar biochemical and anti-breast cancer cell potency. In particular, our top leads (such as SR-3029) show selectivity toward cancer cells over non-tumorigenic cells and screening of the NCI-60 panel of tumor cell lines suggest potency against a number of additional malignancies, including GBM and melanoma. We show, using genetic tools, that SR-3029 is on-target and functions to promote apoptotic cell death in TNBC cells through negative regulation of β-catenin. Furthermore, SR-3029 is highly efficacious in vivo, promoting regression of human MDA-MB-231 tumors established in the mouse mammary fat pad. Our studies demonstrate pre-clinical proof of concept that targeting of CK1δ/ϵ is an effective anti-TNBC strategy.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C269.

Citation Format: Laura H. Rosenberg, Weimin Chen, Shima Nakanishi, Mathieu Bibian, Michael D. Cameron, John L. Cleveland, William R. Roush, Derek R. Duckett. Targeting casein kinase 1 delta and epsilon (CK1δ/ϵ) in breast cancer therapeutics. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C269.
Abstract C274: FGF receptor mutations and fusions are therapeutic targets for inhibition by AZD4547.
Authors: Denz Christopher R. , Guan Nin , Jacques Kelly , Kilgour Elaine , Jenkins Emma , Guichard Sylvie , Smith Paul
Published: August 2014

Aberrant fibroblast growth factor (FGF) signaling has been implicated in tumorgenesis and chemoresistance in a number of cancer types including lung, breast, gastric, endometrial as well as others. The small molecule FGF receptor (FGFR) kinase inhibitor, AZD4547, is currently in Phase I/II clinical development (gastric, squamous lung and breast cancer) to test the FGFR amplified tumor-driven hypothesis. Our aim was to identify and characterize additional genetic subtypes based on reported FGFR aberrations and determine the sensitivity to AZD4547. Eight mutations in FGFR2: G614V, W290C, H544Q, D238N, N211I, T786K, K659N, and N550K and 3 mutations in FGFR3: S249C, R248C, Y373C, plus the FGFR fusions FGFR3-TACC3 and FGFR1-TACC1 found in ∼3% of glioblastoma [Singh et al., Science 337, 1231 (2012)] were assessed for in vitro transformation of normal breast epithelial cells (MCF10A) in a 3D soft agar colony formation assay. Several FGFR mutations/fusions were able to drive in vitro transformation as well as increase downstream signaling (pFGFR, pFRS2) in MCF10A engineered lines. For most FGFR mutations AZD4547 inhibited colony formation and downstream signaling at concentrations comparable to the WT isoforms (10-<1nM). Although AZD4547 inhibited N550K, a shift in potency was observed (>100nM). Taken together, these findings characterized gain-of-function mutations in FGFR2, FGFR3, and FGFR-TACC fusions and demonstrated the antiproliferative activity of AZD4547 against key genetic sub-types of FGFR aberrant cancers.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C274.

Citation Format: Christopher R. Denz, Nin Guan, Kelly Jacques, Elaine Kilgour, Emma Jenkins, Sylvie Guichard, Paul Smith. FGF receptor mutations and fusions are therapeutic targets for inhibition by AZD4547. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C274.
Abstract C276: Ruxolitinib induces apoptotic cell death through the suppression of pJAK1 in human colon cancer cells.
Authors: An Ho Jung , Choi Eun Kyoung , Kim Jin-Sun , Hong Seung-Woo , Moon Jai-Hee , Shin Jae-Sik , Ha Seung-Hee , Kim Kyu-Pyo , Hong Yong Sang , Lee Jae-Lyun , Choi Eun Kyung , Lee Jung Shin , Jin Dong-Hoon , Kim Tae Won
Published: August 2014

Janus kinase (JAK) is one of the main upstream activators of signal transducers and activators of transcription (STAT) that are constitutively activated in various malignancies and are associated with cell growth, survival, and carcinogenesis. Here, we investigated to role of JAKs in colorectal cancer in order to develop effective therapeutic targets for ruxolitinib, which is the first JAK1/2 inhibitor to be approved by FDA. After examining the basal expression levels of phospho-JAK1 and phospho-JAK2, we measured the effects of ruxolitinib on the phosphorylation of JAK1/2 using western blot analysis. Cell viability was determined using the trypan blue exclusion assay. The cell death mechanism was identified by the activation of caspase 3 using western blot and annexin V staining. The basal levels of phospho-JAK1 and phospho-JAK2 were cancer cell type dependent. Colorectal cancer cell lines that phosphorylate both JAK1 and JAK2 include DLD-1 and RKO. Ruxolitinib inactivates both JAK1 and JAK2 in DLD-1 cells but inactivates only JAK1 in RKO cells. Cell death was proportional to the inactivation of JAK1 but not JAK2. Ruxolitinib causes caspase-dependent cell death, which is prevented by treatment with z-VAD. The inhibition of JAK1 phosphorylation seemed sufficient to allow ruxolitinib-mediated apoptosis. JAK1 is a key molecule that is involved in colon cancer cell survival and the inhibition of JAK1 by ruxolitinib results in caspase-dependent apoptosis in colorectal cancer cells. The use of selective JAK1 inhibitors could be an attractive therapy against colorectal cancer, but further clinical investigations are needed to test this possibility.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C276.

Citation Format: Ho Jung An, Eun Kyoung Choi, Jin-Sun Kim, Seung-Woo Hong, Jai-Hee Moon, Jae-Sik Shin, Seung-Hee Ha, Kyu-Pyo Kim, Yong Sang Hong, Jae-Lyun Lee, Eun Kyung Choi, Jung Shin Lee, Dong-Hoon Jin, Tae Won Kim. Ruxolitinib induces apoptotic cell death through the suppression of pJAK1 in human colon cancer cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C276.
Abstract C278: Topoisomerase 1 immunoassay provides proof of target engagement by the indenoisoquinoline class of topoisomerase 1 inhibitors in canine lymphomas.
Authors: Pfister Thomas D. , Ferry-Galow Katerine V. , Mohabbat Tariq , Kinders Robert J. , Khanna Chand , Mazcko Christina , Parchment Ralph E. , Pommier Yves , Tomaszewski Joseph E. , Doroshow James H.
Published: August 2014

Topoisomerase I (Top1) is the molecular target for a number of drugs used in cancer chemotherapy. Several third generation Top1 inhibitors are being evaluated, including the indenoisoquinolines (NSC 725776 and NSC743400) which are currently in clinical trials at the National Cancer Institute. We previously reported the development and validation of a quantitative ELISA to measure Top1 levels in cells and solid tissues [PloS ONE (2012) 7(12)]. We observed a large variation in baseline Top1 levels in xenografts and human patient biopsies using the published method. Baseline Top1 levels in needle biopsies for some patients were too low to allow for the reporting of a drug effect. We have modified our tissue processing procedures to improve assay sensitivity. We have also demonstrated the fitness of the assay in a clinical trial of the indenoisoquinolines for canine lymphoma as a stepping stone to human clinical trials. Baseline Top1 levels in canine lymphoma patients varied greatly, consistent with our previous findings in xenografts and a limited number of human tumor biopsies. These data suggest that it may not be possible to measure drug effect based on post-dose Top1 levels alone, but will require paired pre-dose and post-dose specimens from the same patient. Decreased Top1 levels following therapy (compared to pre-dose) were detected in tumors from a number of dogs, each treated with one of three indenoisoquinolines (NSC706744, NSC 725776 and NSC743400), demonstrating evidence of target engagement as predicted by in vitro and xenograft models. Measurement of baseline Top1 levels in this trial will be correlated with the degree of drug-related target reduction and evidence of drug efficacy in the dogs enrolled on this study. Funded by NCI Contract No. HHSN261200800001E.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C278.

Citation Format: Thomas D. Pfister, Katerine V. Ferry-Galow, Tariq Mohabbat, Robert J. Kinders, Chand Khanna, Christina Mazcko, Ralph E. Parchment, Yves Pommier, Joseph E. Tomaszewski, James H. Doroshow. Topoisomerase 1 immunoassay provides proof of target engagement by the indenoisoquinoline class of topoisomerase 1 inhibitors in canine lymphomas. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C278.
Abstract C279: Novel anthracenedione derivatives demonstrating several potential modes of actions.
Authors: Pumuye Paul P. , Medan Jelena E. , Sleebs Brad , Watson Keith , Evison Benny J. , Phillips Donald R. , Cutts Suzanne M.
Published: August 2014

DNA has been regarded as the primary target of numerous non-specific cytotoxic anticancer agents such as the nitrogen mustards and anthracycline antibiotics. The anthracyclines, most notably doxorubicin, proved to be highly potent and were thus incorporated into numerous chemotherapeutic regimens. However, their dose dependent redox activity that presumably contributes to their broad spectrum versatility is also associated with potentially lethal cardiotoxic adverse effects and thus, inspired the development of synthetic analogues including the anthracenediones. Like the anthracylines, their structural frame constitutes the DNA intercalating anthraquinone chromophore with functional amino groups stabilizing its insertion via hydrogen bonds and Van der Waal interactions. This interaction poisons the topoisomerase II cleavable complex which induces widespread DNA strand breaks culminating in the induction of apoptosis.

We have shown that the availability of the methyl donating molecule, formaldehyde, generates adduct formation via a covalent aminal linkage between the exocyclic N2 amino group of guanine residue at specific CpG dinucleotides and an amino group on the anthracenediones side chains. The formaldehyde mediated DNA adduct formation, achievable via simultaneous formaldehyde-releasing prodrug administration, increases cancer cell toxicity and potentially endows general cardioprotective activity. Such cardioprotection has been associated with formaldehyde-mediated doxorubicin-DNA adducts

We have synthesised a new series of anthracenediones that vary in their potential to induce covalent DNA adducts. We now show that the new anthracenediones including pixantrone (unlike the anthracyclines) also exhibits a preference for forming adducts with single stranded DNA and RNA, and these have similar characteristics to adducts that are formed with DNA.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C279.

Citation Format: Paul P. Pumuye, Jelena E. Medan, Brad Sleebs, Keith Watson, Benny J. Evison, Donald R. Phillips, Suzanne M. Cutts. Novel anthracenedione derivatives demonstrating several potential modes of actions. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C279.
Abstract C281: The carcinogen cadmium promotes activation of lysine 63 (K63)-linked ubiquitin-dependent signaling by inhibiting selective autophagy and CYLD K63 deubiquitination.
Authors: Chargui Abderrahman , Belaid Amine , Imbert-Rezzonico Véronique , Samson Michel , Guigonis Jean-Marie , L'hoste Sebastien , Tauc Michel , Peyron Jean François , Poujeol Philippe , Hofman Paul , Mograbi Baharia
Published: August 2014

K63-linked ubiquitination– i.e. conjugation of a chain of ubiquitins (Ub) linked through lysine 63– has emerged as a key mechanism regulating signaling transduction pathways. Although critical, very little information is currently available about how subversion of K63 ubiquitination might contribute to inflammatory diseases and cancers. The present study provides the first evidence that cadmium (Cd), a widespread environmental carcinogen, is a powerful activator of K63 ubiquitination. Indeed, Cd induces accumulation of K63 polyubiquitinated proteins, independently of oxidative damage, activation of ubiquitin ligase or proteasome impairment. Rather, we demonstrate that Cd activates K63 ubiquitination by inhibiting both CYLD and autophagy, two tumor suppressors that selectively deubiquitinate and degrade K63-linked ubiquitinated proteins, respectively. As a result, we found that cadmium treatment induces sustained activation of NF-κB, a pathway critically dependent on K63 ubiquitination. Given the role of NF-κB in survival, proliferation, and inflammation, these findings provide a potential molecular link between cadmium exposure and the increased incidences of inflammatory diseases and cancers.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C281.

Citation Format: Abderrahman Chargui, Amine Belaid, Véronique Imbert-Rezzonico, Michel Samson, Jean-Marie Guigonis, Sebastien L'hoste, Michel Tauc, Jean François Peyron, Philippe Poujeol, Paul Hofman, Baharia Mograbi. The carcinogen cadmium promotes activation of lysine 63 (K63)-linked ubiquitin-dependent signaling by inhibiting selective autophagy and CYLD K63 deubiquitination. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C281.
Abstract C29: Characterization and identification of specific EGFR mutations in circulating tumor cells (CTCs) isolated from non-small cell lung cancer patients using an antibody independent method, ApoStream™: An update report.
Authors: Tran Hai T. , Melnikova Vladislava , Tsao Anne S. , Fossella Frank V. , Johnson Faye M. , Papadimitrakoupoulou Vali , Richardson Katherine , Lewis Marcia E. , Legendre Ben , Anderes Kenna L. , Davis Darren W. , Heymach John V.
Published: August 2014

Background: A variety of methods for capture of rare CTCs of epithelial origin are available; most employ antibodies to epithelial cell adhesion molecule (EpCAM) and cytokeratin (CK). Using a classic phenotypic definition, a CTC is nucleated, CK(+), CD45(-) cell. However, some CTCs may elude capture as they originate from primary tumor cells which have undergone epithelial-mesenchymal transition (EMT). We report here the use of ApoStream™, a novel dielectrophoresis field-flow-assisted, antibody-free method to isolate CTCs from blood.

Methods: Blood was collected from consented NSCLC patients and processed using ApoStream™. For CTC enumeration comparison, the CellSearch® FDA-approved kit was used. Isolated cells were evaluated with a multiplexed immunofluorescent assay and laser scanning cytometry was applied to identify multiple combinations of positive and/or negative staining for CK/CD45/DAPI and EpCAM. To determine specific EGFR mutations from captured CTCs, samples were analyzed using Improved and Complete Enrichment with CO-amplification at Lower Denaturation temperature (ICE COLD-PCR).

Results: Blood samples from 37 NSCLC patients and 8 healthy volunteers were processed and the results of the cell populations isolated using ApoStream™ are summarized in table. EGFR mutations [exon 19 deletion and exon 21 L858R] were determined and found to be concordant when compared to tumor tissue analysis by Sanger sequencing.

Conclusions: The ApoStream™ platform enriched EpCAM(+) and EpCAM(-) CTCs from the blood of NSCLC patients demonstrating utility in recovering cancer cells with multiple phenotypes. From recovered CTCs, detection of EGFR mutations was possible indicating the clinical relevance and potential utility of CTCs as an alternative to tissue biopsy. Additional sensitivity and complete mutation analysis will be presented. (a portion of this data was presented at 2013 ASCO Annual Meeting, Chicago, IL, USA)

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C29.

Citation Format: Hai T. Tran, Vladislava Melnikova, Anne S. Tsao, Frank V. Fossella, Faye M. Johnson, Vali Papadimitrakoupoulou, Katherine Richardson, Marcia E. Lewis, Ben Legendre, Kenna L. Anderes, Darren W. Davis, John V. Heymach. Characterization and identification of specific EGFR mutations in circulating tumor cells (CTCs) isolated from non-small cell lung cancer patients using an antibody independent method, ApoStream™: An update report. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C29.
Abstract C298: Conformational characterization of tumor suppressor protein Merlin and phosphomimetic Merlin(S518D) mutant in solution.
Authors: Ali Khajeh Jahan , Atchiba Moussoubaou , Bu Zimei
Published: August 2014

Merlin is a tumor suppressor protein that inhibits cell proliferation upon establishing cell-cell contacts. Because Merlin is homologous to the Ezrin-Radixin-Moesin (ERM) family of proteins, the structural model of ERM proteins cycling between closed/resting and open/active conformational states is employed to explain Merlin function. Nevertheless, using the ERM protein model has generated confusion about the mechanisms of Merlin tumor suppressor activity. Here, using contrast-matching small angle neutron scattering (SANS), we have determined the molecular shapes of Merlin and its phosphomimetic Merlin(S518D) mutant. In solution, both Merlin and Merlin(S518D) adopted a closed conformation that is capable of binding to the scaffolding protein NHERF1 with comparable binding affinities. However, in the presence of the phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), the wild-type Merlin shifts toward an open conformation whereas Merlin(S518D) remains locked in a closed conformation. Our data implied that although Merlin has similar molecular shape as ERM proteins, it has different protein-binding properties, and phosphorylation and PI(4,5)P2-binding modulate its conformational changes differently from ERM proteins.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C298.

Citation Format: Jahan Ali Khajeh, Moussoubaou Atchiba, Zimei Bu. Conformational characterization of tumor suppressor protein Merlin and phosphomimetic Merlin(S518D) mutant in solution. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C298.
Abstract C32: PTEN and p53 expression in endometrial cancer correlated with clinicopathological phenotype.
Authors: Kularatne Bihani , Capitanio Arrigo , Arora Rupali , Jones Philippa , Lopes Andre , Paterson Jennifer , Kristeleit Rebecca
Published: August 2014

p53 overexpression and loss of PTEN expression have been implicated in the pathogenesis of endometrial cancer. Our aim was to correlate expression levels of these proteins with clinicopathological parameters to characterise their utility as biomarkers.

Immunohistochemistry was done on 49 cases of formalin fixed paraffin embedded endometrial cancer tissue for p53 and 47 for PTEN expression. For p53 staining the Hue Saturation and Intensity mathematical model was used to evaluate different degrees of positivity of the immunohistochemical stain. The quick score was used for p53 and immunoreactive score for PTEN was done to score immunoreactivity. For PTEN, average percentage of positive cells and intensity was evaluated and the immunoreactive score was calculated. Both these scoring methods incorporated percentage of positive cells and staining intensity.

Univariate Cox regression analysis for cause specific survival showed a hazard ratio of 9.2 for p53 overexpression (P<0.05). High levels of P53 were significantly associated with histologic type, grade, LVI and recurrent disease. There was no significant association between PTEN expression and clinicopathological features but it was noted that the 8 patients who relapsed were PTEN negative. Cause specific survival could not be assessed for PTEN expression due to the lack of events in this group. PTEN and p53 (n=46) combined analysis failed to demonstrate a significant association on prognostic features in this group.

Overexpression of P53 has a negative effect on disease specific survival and was associated with poor prognostic features. We did not demonstrate a significant association with clinicopathological features assessed and PTEN expression. However of the 8 patients who relapsed all were PTEN negative and 7 were p53 positive. Dual assessment of p53 and PTEN warrants further investigation as a prognostic indicator.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C32.

Citation Format: Bihani Kularatne, Arrigo Capitanio, Rupali Arora, Philippa Jones, Andre Lopes, Jennifer Paterson, Rebecca Kristeleit. PTEN and p53 expression in endometrial cancer correlated with clinicopathological phenotype. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C32.
Abstract C42: Development and validation of an IHC-based detection method for studying indoleamine 2,3-dioxygenase 1 (IDO1) expression in human cancers.
Authors: Liu Xiangdong , Yang Gengjie , Margulis Alexander , Wynn Rich , Scherle Peggy , Newton Robert
Published: August 2014

Indoleamine 2,3-dioxygenase-1 (IDO1) mediates oxidative cleavage of tryptophan, an amino acid essential for cell proliferation and survival. The depletion of tryptophan and the generation of tryptophan metabolites have been demonstrated to be an important regulator of immune function. IDO1 is induced by interferons and TLR agonists and is expressed in a wide variety of human cancers as well as in the tumor-draining lymph nodes. High IDO1 expression is significantly associated with more rapid disease progression and poor prognosis in multiple cancer types. Numerous studies have shown that IDO1 negatively regulates immune functions via several potential cellular mechanisms, which in turn allows tumor escape from host immune surveillance. Therefore, inhibition of IDO1 may have therapeutic potential in cancer and IDO1 expression may serve as a selective marker of a responsive population. INCB024360, a novel IDO1-selective inhibitor, is currently being evaluated in clinical trials of cancer patients. To support the clinical development of INCB024360, we have developed and validated an immunohistochemistry (IHC)-based method using rabbit polyclonal antisera that specifically detects IDO1 protein expression. The method has been used to determine IDO1 expression in primary biopsies from patients studied in INCB024360 clinical trials. The method can be used to determine the prevalence of IDO1 expression in a variety of human cancers, identify histologic subtypes that might be associated with IDO1 expression and examine IDO1 coexpression with other immune modifying pathways.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C42.

Citation Format: Xiangdong Liu, Gengjie Yang, Alexander Margulis, Rich Wynn, Peggy Scherle, Robert Newton. Development and validation of an IHC-based detection method for studying indoleamine 2,3-dioxygenase 1 (IDO1) expression in human cancers. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C42.
Abstract C44: Targeting neuregulin1-ErbB3 signaling in wild-type BRAF/NRAS melanoma.
Authors: Capparelli Claudia , Gaborit Nadège , Yarden Yosef , Aplin Andrew
Published: August 2014

Melanoma is the deadliest form of skin cancer due to its highly metastatic nature and refractoriness to standard chemotherapies. At present, few therapy options exist for wild-type BRAF/NRAS (WT/WT) melanoma patients. We examined the role of the neuregulin (NRG1)-ErbB3 signaling pathway in WT/WT melanoma cells since it is emerging as an important player in melanocyte homeostasis and melanoma pathogenesis. NRG1 has been shown to promote melanoblast proliferation and survival. ErbB3 is elevated in malignant melanoma specimens and cell lines and its expression correlates with reduced patient survival. The purpose of this study was to determine the role of the NRG1-ErbB3 signaling pathway in WT/WT melanoma cells. We demonstrated that in a subgroup of WT/WT cell lines, expressing high level of ErbB3 and NRG1, neuregulin is able to activate ErbB3 in basal conditions. Knockdown of NRG1 in high NRG1-expressing cells led to reduction of cell viability. This effect was associated with a decrease in the phosphorylation of ErbB3 and ErbB2 receptors as well as downstream AKT and ERK1/2 signaling. All these effects were rescued by exogenous addition of NRG1. We obtained analogous effects targeting ErbB3 with either small interfering RNAs or with clinical grade ErbB3 monoclonal antibodies. In these WT/WT cell lines with high expression of NRG1, inhibition of ErbB2-ErbB3 dimerization with pertuzumab caused a decrease in AKT phosphorylation and cell growth, indicating that ErbB3 signaling is dependent on ErbB2. Synergistic effects on cell growth as well as on AKT and ERK1/2 signaling were observed targeting ErbB2 and ErbB3 combining both antibodies. Our study demonstrates that targeting ErbB3 and ErbB2 signaling in a cohort WT/WT melanoma cell lines leads to tumor growth reduction. We propose that NRG1 activation of ErbB3 signaling promotes progression in these tumors and that these findings may form the basis for the use of agents targeting the NRG1-ErbB3 axis as novel treatment strategies in a subset of malignant melanoma.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C44.

Citation Format: Claudia Capparelli, Nadège Gaborit, Yosef Yarden, Andrew Aplin. Targeting neuregulin1-ErbB3 signaling in wild-type BRAF/NRAS melanoma. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C44.
Abstract C53: Fractional response to small-molecule TKIs in single cancer cells: A combination rational to overcome adaptive drug resistance.
Authors: Honarnejad Saman
Published: August 2014

Targeted cancer therapies block the growth and spread of cancer cells by interfering with specific molecules that support tumor growth and progression. Despite the successful application of these drugs in clinical settings, patient-to-patient variability and acquired resistance are still the primary challenges facing development and use of such cancer therapies. Here, we describe a cell cycle dependent mechanism of drug sensitivity and the consequential fractional response in a library of small-molecules. In particular, using high-throughput single-cell imaging methods we show how perturbing specific biochemical nodes in a signaling pathway controlling cellular machinery for metabolism and growth leads to heterogeneity in abundance of response modulating protein complexes with known functional roles in cellular senescence and apoptosis. Furthermore, we provide evidence towards a feedback mechanism coordinating signaling state with cell cycle that leads to adaptive drug resistance and propose a combination therapy rational to overcome this resistance.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C53.

Citation Format: Saman Honarnejad. Fractional response to small-molecule TKIs in single cancer cells: A combination rational to overcome adaptive drug resistance. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C53.
Abstract C57: The biological evaluation of small molecule inducers of Nrf2 transcriptional activity that inhibit the Keap1-Nrf2 protein-protein interaction.
Authors: Fowkes Adrian , Schaap Marjolein , Bertrand Helene , Thiollier Clarisse , Kaatchi Hiroko , Wells Geoff
Published: August 2014

The transcription factor Nrf2 up-regulates a range of cytoprotective enzymes with antioxidant response elements in their promoter regions and thus can protect cells against oxidative damage. Nrf2 is negatively regulated by the ubiquitination facilitator protein Keap1 that facilitates degradation of Nrf2. A number of natural products, including the isothiocyanate sulforaphane up-regulate Nrf2 by interacting with Keap1 in a covalent manner to stall its activity. Inhibition of the protein-protein interaction (PPI) between Keap1 and Nrf2 with small molecules constitutes an alternative strategy for developing pharmacological tool compounds and potential anti-inflammatory and chemopreventive therapeutic agents. We have applied structure-based drug design methods, including in silico screening, to develop a series of new inhibitors of the Keap1-Nrf2 interaction that mimic Nrf2 peptide motifs that bind to the Keap1 Kelch domain. Initial screening demonstrated that a series of substituted diaryl heterocycles were capable of inhibiting the PPI in vitro and inducing the expression of Nrf2 dependent gene products. The early hit compound HB229 is not cytotoxic (IC50>250 µM), induced the expression of NAD(P)H oxidoreductase-1 (NQO1) and hemeoxygenase-1 (HO1) at low micromolar concentrations and increased the nuclear accumulation of Nrf2 in cell based assays using mouse Hepa1c1c7 hepatoma and human Hela and HEK293 cell lines. HB229 inhibited the PPI with an apparent IC50 of ∼7.1 µM in a fluorescence polarisation assay. Further biological evaluation of HB229, and a derivative of a recently described bis-sulphonamide Keap1-Nrf2 PPI inhibitor, revealed a consistent time and dose dependent Nrf2 induction. Additionally, both compounds appear to be capable of interacting with the aryl hydrocarbon receptor (AhR) pathway to some extent. For instance, both compounds induce nuclear accumulation of the AhR in cells, however this behaviour was not observed with the prototype irreversible Nrf2 inducer sulforaphane. The significance of these findings will be discussed.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C57.

Citation Format: Adrian Fowkes, Marjolein Schaap, Helene Bertrand, Clarisse Thiollier, Hiroko Kaatchi, Geoff Wells. The biological evaluation of small molecule inducers of Nrf2 transcriptional activity that inhibit the Keap1-Nrf2 protein-protein interaction. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C57.
Abstract C59: Use of dietary antioxidant supplement during cancer therapy- pros and cons.
Authors: Ghosh Debjani , Dey Subrata , Saha Chabita
Published: August 2014

Black and green teas are rich in antioxidants and its flavonoids like thearubigins, epicatechins and catechins are known to have higher antioxidant efficacy than vitamin C. Despite significant research investigating the use of tea as dietary antioxidant supplement during conventional chemotherapy, no conclusion has been drawn regarding its mechanism of action and safety. In the present study chemopreventive effects of black tea extract (BTE) were evaluated on normal lymphocytes and compared with cancerous K562 cells. Chemotherapeutic drugs (Adriamycin and Daunomycin) act by generating oxidative stress and inducing apoptosis. The level of reactive oxygen species (ROS), apoptosis and gene expression in untreated and BTE treated cells were followed by different biochemical assays, flow cytometry and reverse transcription PCR. Results evidence that efficient scavenging of intracellular ROS by BTE resulting in reduced apoptotic cell population in normal lymphocytes. Gene expression of p53, bax, bcl2 and nrf2 show variation in untreated and BTE treated cells. Activity of endogenous antioxidant enzymes like SOD, GST and catalase is modified on tea treatment. Similar observations were recorded to a lower extent in K562 cells, suggesting BTE conferred protection to cancerous cells also. It can be summarized here that tea as a dietary supplement during chemotherapy shows interference in chemotherapeutic efficacy of the drugs in vitro. More in vitro, in vivo and clinical trials would shed light on the mechanism of action of the dietary antioxidant supplement during chemotherapy and its application.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C59.

Citation Format: Debjani Ghosh, Subrata Dey, Chabita Saha. Use of dietary antioxidant supplement during cancer therapy- pros and cons. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C59.
Abstract C6: Molecular and cellular signaling of PDGFB in cervical cancer cells.
Authors: Tudoran Oana M. , Soritau Olga , Balacescu Ovidiu , Balacescu Loredana , Lindberg Staffan , Berindan-Neagoe Ioana
Published: August 2014

Cervical cancer was reported to be the second most common female cancer worldwide, being the third cause of female cancer mortality annually. Romania ranks first among European countries in cervical cancer incidence and mortality raising the national awareness. Cervical cancer is one of the most aggressive gynecological diseases, mainly is due to rapid development of a functional tumor vascular network.

In solid tumors, PDGF signalling has been showed to participate in processes such as autocrine stimulation of tumor cell growth, recruitment of tumor stroma and stimulation of angiogenesis. PDGF signaling increases the interstitial fluid pressure, an important drawback in drug administration due to loss of active agents before they reach the tumors. Several studies have showed that targeting PDGF pathways have anti-angiogenic and anti-tumor effects, implying that inhibition of PDGF signaling may improve the efficacy of chemotherapies. However, these studies have been focused on effects on tumor vasculature and mural cells, and less on tumor cells. Moreover, the molecular mechanisms of PDGF signaling in tumor cells have yet to be investigated.

Here we report the molecular and cellular effects of PDGFb inhibition of in cervical tumor cells. We used the RNA interference pathway to trigger PDGFb silencing in two HPV16 positive cervical cancer cell lines (Hela, Caski). We investigated the changes in genes expression induced by PDGFb silencing by means of microarray analysis. Transcriptomic analysis revealed 579 genes to be differentially expressed upon PDGFb silencing. Among the top biological functions regulated by these genes are Cell Death and Survival, Cellular Growth and Proliferation, Cardiovascular System Development and Function, Cellular Movement, etc. Cellular investigations on proliferation, apoptosis, and invasion revealed that PDGFb silencing had no effects on cells ability to proliferate nor induced cell death, which suggest that alternative signaling mechanisms are activated to maintain the balance between cell proliferation and apoptosis. This is probably done throughout HPV16 signaling as some of the identified genes are known to be involved in viral infections. We did however observe that PDGFb silencing reduced the invasiveness of cervical cancer cells. Although preliminary, our results could explain the short-term success of antiangiogenic therapies.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C6.

Citation Format: Oana M. Tudoran, Olga Soritau, Ovidiu Balacescu, Loredana Balacescu, Staffan Lindberg, Ioana Berindan-Neagoe. Molecular and cellular signaling of PDGFB in cervical cancer cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C6.
Abstract C76: FoxM1 inhibition sensitized BRCA-proficient triple-negative breast cancer to PARP inhibition.
Authors: Lee Jun Woo , Lee Kyung-Min , Han Wonshik
Published: August 2014

Breast cancer cells with mutations in breast cancer-associated 1 (BRCA1) or BRCA2 have defects in the homologous recombination (HR) DNA repair pathway and this confers sensitivity to inhibitors of poly (ADP) ribose polymerase (PARP). However, BRCA-deficient tumors represent only a small fraction of adult cancers, which might restrict the therapeutic utility of PARP inhibitor monotherapy. The transcription factor Forkhead box M1 (FoxM1) is a key regulator of cell proliferation and is overexpressed in many forms of primary cancers, leading to uncontrolled cell division and genomic instability. FoxM1 is implicated in genotoxic drug resistance but its role and mechanism of action remain unclear. Our results revealed that triple-negative breast cancer (TNBC) cell lines depleted in FoxM1 levels by small interfering RNA transfection display increase DNA damage, as evidence by activation of checkpoint kinase 2 (Chk2) and phosphorylation of histone H2AX. These results shows a role for FoxM1 in the transcriptional response during DNA damage/checkpoint signaling and we hypothesized that FoxM1 inhibition would result in HR impairment and subsequent sensitization to PARP inhibitor. We found that knockdown of FoxM1 led to sensitization to AZD2281, PARP inhibitor, in MDA-MB-231 (BRCA-wild-type) and MDA-MB-436 (BRCA-mutated) TNBC cells. Combined PARP and FoxM1 inhibition had a synergistic anti-proliferative effect on BRCA1-defective and BRCA-proficient TNBC cell lines in vitro. Furthermore, the combination treatment of AZD2281 and thiostrepton (FoxM1 inhibitor) increased DNA repair-related gene expression such as H2AX, chk1, chk2 and p53 and downregulated BRCA2 expression in TNBC cell lines. Here, we show that depletion or inhibition of FoxM1 compromises the ability of cells to repair DNA by HR and sensitization to PARP inhibition in TNBCs without BRCA mutations, providing a rationale to combine FoxM1 and PARP inhibitors. Therefore, this combination may be effective for treating both BRCA1-defective and BRCA-proficient TNBC.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C76.

Citation Format: Jun Woo Lee, Kyung-Min Lee, Wonshik Han. FoxM1 inhibition sensitized BRCA-proficient triple-negative breast cancer to PARP inhibition. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C76.
Abstract C77: A novel BRCA2 targeting antisense oligonucleotide sensitizes human tumor cells to chemotherapy and radiotherapy - the induction of ‘complementary lethality’ by targeting DNA repair.
Authors: Rytelewski Mateusz , Tong Jessica , Buensucesco Adrian , Maleki Vareki Saman , Ferguson Peter J. , Figueredo Rene , Vincent Mark , Shepherd Trevor , Deroo Bonnie J. , Koropatnick James D.
Published: August 2014

BRCA2 is a protein involved in homologous recombination repair of double-stranded DNA breaks in human cells. Inactivating mutations in BRCA2 predispose to early onset cancer of the breast, ovary and other tissues. However, patients with tumors that harbour BRCA2 mutations respond more favourably to cancer therapy. Therefore, inhibiting BRCA2 function in cancer cells capable of homologous recombination repair may sensitize otherwise resistant tumors to distinct types of anti-cancer treatment. We have reported that BRCA2 siRNA sensitizes human tumor cells to specific DNA-damaging agents (e.g., cisplatin), but not anti-folate drugs (e.g., pemetrexed), a phenomenon we termed ‘complementary lethality’. Based on these results, we developed and are testing a second generation antisense oligodeoxynucleotide (BR-1) that specifically targets BRCA2. BR-1 decreased BRCA2 mRNA and protein levels, and also inhibited BRCA2-mediated RAD51 repair focus formation. BR-1 potently sensitized human non-small cell lung cancer (A549) cells to cisplatin, melphalan, and carboplatin as evidenced by reduced overall proliferation. In addition, A549 cells exhibited reduced ability to form colonies after concomitant treatment with BR-1 and cisplatin, melphalan, or ionizing radiation. Furthermore, cisplatin-resistant, patient-derived head and neck squamous cancer cells (HN-5a) were rendered sensitive to cisplatin following BR-1 treatment, and the level of cisplatin sensitivity was comparable to that of the parent population. Interestingly, treatment with BR-1 and cisplatin significantly decreased cellular respiration compared to control oligonucleotide and cisplatin treatment, suggesting that downregulation of BRCA2 in the context of alkylating drug treatment alters cellular metabolism. However, this change in respiration occurred independently of mitochondrial integrity. BR-1 is currently being tested in vivo to determine its ability to downregulate BRCA2 in human xenografts and sensitize solid tumors to chemotherapy.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C77.

Citation Format: Mateusz Rytelewski, Jessica Tong, Adrian Buensucesco, Saman Maleki Vareki, Peter J. Ferguson, Rene Figueredo, Mark Vincent, Trevor Shepherd, Bonnie J. Deroo, James D. Koropatnick. A novel BRCA2 targeting antisense oligonucleotide sensitizes human tumor cells to chemotherapy and radiotherapy - the induction of ‘complementary lethality’ by targeting DNA repair. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C77.