bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from The Heat Shock Protein 90 Inhibitor IPI-504 Induces KIT Degradation, Tumor Shrinkage, and Cell Proliferation Arrest in Xenograft Models of Gastrointestinal Stromal Tumors
Authors: Floris Giuseppe , Debiec-Rychter Maria , Wozniak Agnieszka , Stefan Cristiana , Normant Emmanuel , Faa Gavino , Machiels Kathleen , Vanleeuw Ulla , Sciot Raf , Schöffski Patrick
Published: March 2024

Abstract
The activity of the receptor tyrosine kinase KIT is crucial for gastrointestinal stromal tumor (GIST) growth and survival. Imatinib and sunitinib are very effective in advanced GIST, but have no curative potential. The observation that heat shock protein 90 (HSP90) inhibition results in KIT degradation prompted us to assess the efficacy of the HSP90 inhibitor retaspimycin hydrochloride (IPI-504) alone or in combination with imatinib or sunitinib in two GIST xenografts with distinctive KIT mutations. Nude mice were grafted with human GIST carrying KIT exon 13 (GIST-882; n = 59) or exon 11 (GIST-PSW; n = 44) mutations and dosed with imatinib (50 mg/kg twice daily), sunitinib (40 mg/kg once daily), IPI-504 (100 mg/kg 3 times per week), IPI-504 + imatinib, or IPI-504 + sunitinib. We evaluated tumor volume, proliferation and apoptosis, KIT expression and activation, as well as adverse events during treatment. Treatment with IPI-504 alone resulted in tumor regression, proliferation arrest, and induction of tumor necrosis. We documented downregulation of KIT and its signaling cascade in IPI-504–treated animals. Treatment effects were enhanced by combining IPI-504 with imatinib or sunitinib. On histologic examination, liver damage was frequently observed in animals exposed to combination treatments. In conclusion, IPI-504 shows consistent antitumor activity and induces KIT downregulation in GIST, as a single agent, and is more potent in combination with imatinib or sunitinib. The sequence of drug administration in the combination arms warrants further studies. Mol Cancer Ther; 10(10); 1897–908. ©2011 AACR.
Data from Dependence on the MUC1-C Oncoprotein in Non–Small Cell Lung Cancer Cells
Authors: Raina Deepak , Kosugi Michio , Ahmad Rehan , Panchamoorthy Govind , Rajabi Hasan , Alam Maroof , Shimamura Takeshi , Shapiro Geoffrey I. , Supko Jeffrey , Kharbanda Surender , Kufe Donald
Published: March 2024

Abstract
Non–small cell lung cancer (NSCLC) cells are often associated with constitutive activation of the phosphoinositide 3-kinase (PI3K) → Akt → mTOR pathway. The mucin 1 (MUC1) heterodimeric glycoprotein is aberrantly overexpressed in NSCLC cells and induces gene signatures that are associated with poor survival of NSCLC patients. The present results show that the MUC1 C-terminal subunit (MUC1-C) cytoplasmic domain associates with PI3K p85 in NSCLC cells. We show that inhibition of MUC1-C with cell-penetrating peptides blocks this interaction with PI3K p85 and suppresses constitutive phosphorylation of Akt and its downstream effector, mTOR. In concert with these results, treatment of NSCLC cells with the MUC1-C peptide inhibitor GO-203 was associated with downregulation of PI3K → Akt signaling and inhibition of growth. GO-203 treatment was also associated with increases in reactive oxygen species (ROS) and induction of necrosis by a ROS-dependent mechanism. Moreover, GO-203 treatment of H1975 (EGFR L858R/T790M) and A549 (K-Ras G12S) xenografts growing in nude mice resulted in tumor regressions. These findings indicate that NSCLC cells are dependent on MUC1-C both for activation of the PI3K → Akt pathway and for survival. Mol Cancer Ther; 10(5); 806–16. ©2011 AACR.
Data from MEK/ERK Inhibitor U0126 Increases the Radiosensitivity of Rhabdomyosarcoma Cells In vitro and In vivo by Downregulating Growth and DNA Repair Signals
Authors: Marampon Francesco , Gravina Giovanni Luca , Di Rocco Agnese , Bonfili Pierluigi , Di Staso Mario , Fardella Caterina , Polidoro Lorella , Ciccarelli Carmela , Festuccia Claudio , Popov Vladimir M. , Pestell Richard G. , Tombolini Vincenzo , Zani Bianca Maria
Published: March 2024

Abstract
Multimodal treatment has improved the outcome of many solid tumors, and in some cases the use of radiosensitizers has significantly contributed to this gain. Activation of the extracellular signaling kinase pathway (MEK/ERK) generally results in stimulation of cell growth and confers a survival advantage playing the major role in human cancer. The potential involvement of this pathway in cellular radiosensitivity remains unclear. We previously reported that the disruption of c-Myc through MEK/ERK inhibition blocks the expression of the transformed phenotype; affects in vitro and in vivo growth and angiogenic signaling; and induces myogenic differentiation in the embryonal rhabdomyosarcoma (ERMS) cell lines (RD). This study was designed to examine whether the ERK pathway affects intrinsic radiosensitivity of rhabdomyosarcoma cancer cells. Exponentially growing human ERMS, RD, xenograft-derived RD-M1, and TE671 cell lines were used. The specific MEK/ERK inhibitor, U0126, reduced the clonogenic potential of the three cell lines, and was affected by radiation. U0126 inhibited phospho-active ERK1/2 and reduced DNA protein kinase catalytic subunit (DNA-PKcs) suggesting that ERKs and DNA-PKcs cooperate in radioprotection of rhabdomyosarcoma cells. The TE671 cell line xenotransplanted in mice showed a reduction in tumor mass and increase in the time of tumor progression with U0126 treatment associated with reduced DNA-PKcs, an effect enhanced by radiotherapy. Thus, our results show that MEK/ERK inhibition enhances radiosensitivity of rhabdomyosarcoma cells suggesting a rational approach in combination with radiotherapy. Mol Cancer Ther; 10(1); 159–68. ©2011 AACR.
Data from Peloruside- and Laulimalide-Resistant Human Ovarian Carcinoma Cells Have βI-Tubulin Mutations and Altered Expression of βII- and βIII-Tubulin Isotypes
Authors: Kanakkanthara Arun , Wilmes Anja , O'Brate Aurora , Escuin Daniel , Chan Ariane , Gjyrezi Ada , Crawford Janet , Rawson Pisana , Kivell Bronwyn , Northcote Peter T. , Hamel Ernest , Giannakakou Paraskevi , Miller John H.
Published: March 2024

Abstract
Peloruside A and laulimalide are potent microtubule-stabilizing natural products with a mechanism of action similar to that of paclitaxel. However, the binding site of peloruside A and laulimalide on tubulin remains poorly understood. Drug resistance in anticancer treatment is a serious problem. We developed peloruside A- and laulimalide-resistant cell lines by selecting 1A9 human ovarian carcinoma cells that were able to grow in the presence of one of these agents. The 1A9-laulimalide resistant cells (L4) were 39-fold resistant to the selecting agent and 39-fold cross-resistant to peloruside A, whereas the 1A9-peloruside A resistant cells (R1) were 6-fold resistant to the selecting agent while they remained sensitive to laulimalide. Neither cell line showed resistance to paclitaxel or other drugs that bind to the taxoid site on β-tubulin nor was there resistance to microtubule-destabilizing drugs. The resistant cells exhibited impaired peloruside A/laulimalide-induced tubulin polymerization and impaired mitotic arrest. Tubulin mutations were found in the βI-tubulin isotype, R306H or R306C for L4 and A296T for R1 cells. This is the first cell-based evidence to support a β-tubulin–binding site for peloruside A and laulimalide. To determine whether the different resistance phenotypes of the cells were attributable to any other tubulin alterations, the β-tubulin isotype composition of the cells was examined. Increased expression of βII- and βIII-tubulin was observed in L4 cells only. These results provide insight into how alterations in tubulin lead to unique resistance profiles for two drugs, peloruside A and laulimalide, that have a similar mode of action. Mol Cancer Ther; 10(8); 1419–29. ©2011 AACR.
Data from Caspase-3–Dependent Mitotic Checkpoint Inactivation by the Small-Molecule Inducers of Mitotic Slippage SU6656 and Geraldol
Authors: Riffell Jenna L. , Jänicke Reiner U. , Roberge Michel
Published: March 2024

Abstract
Microtubule-targeting cancer drugs such as paclitaxel block cell-cycle progression at mitosis by prolonged activation of the mitotic checkpoint. Cells can spontaneously escape mitotic arrest and enter interphase without chromosome segregation by a process termed mitotic slippage that involves the degradation of cyclin B1 without mitotic checkpoint inactivation. Inducing mitotic slippage with chemicals causes cells to die after multiple rounds of DNA replication without cell division, which may enhance the antitumor activity of microtubule-targeting drugs. Here, we explore pathways leading to mitotic slippage by using SU6656 and geraldol, two recently identified chemical inducers of mitotic slippage. Mitotic slippage induced by SU6656 or geraldol was blocked by the proteasome inhibitor MG-132 and involved proteasome-dependent degradation of cyclin B1 and the mitotic checkpoint proteins budding uninhibited by benzimidazole related 1 (BubR1) and cell division cycle 20 (Cdc20) in T98G cells. Mitotic slippage and the degradation of BubR1 and Cdc20 were also inhibited by the caspase-3 and -7 inhibitor DEVD-CHO. MCF-7 cells lacking caspase-3 expression could not degrade BubR1 or undergo mitotic slippage in response to SU6656 or geraldol. Introduction of caspase-3 completely restored the ability of MCF-7 cells to degrade BubR1 and undergo mitotic slippage. However, lack of expression of caspase-3 did not affect cell death after exposure to paclitaxel, with or without mitotic slippage induction. The requirement for caspase-3 for chemically induced mitotic slippage reveals a new mechanism for mitotic exit and a link between mitosis and apoptosis that has implications for the outcome of cancer chemotherapy. Mol Cancer Ther; 10(5); 839–49. ©2011 AACR.
Data from Glutathione-Conjugate Transport by RLIP76 Is Required for Clathrin-Dependent Endocytosis and Chemical Carcinogenesis
Authors: Singhal Sharad S. , Wickramarachchi Dilki , Yadav Sushma , Singhal Jyotsana , Leake Kathryn , Vatsyayan Rit , Chaudhary Pankaj , Lelsani Poorna , Suzuki Sumihiro , Yang Shaohua , Awasthi Yogesh C. , Awasthi Sanjay
Published: March 2024

Abstract
Targeted depletion of the RALBP1-encoded 76-kDa splice variant, RLIP76, causes marked and sustained regression of human xenografts of lung, colon, prostate, and kidney cancers without toxicity in nude mouse models. We proposed that the remarkable efficacy and broad spectrum of RLIP76-targeted therapy is because its glutathione-conjugate (GS-E) transport activity is required for clathrin-dependent endocytosis (CDE), which regulates all ligand-receptor signaling, and that RLIP76 is required not only for survival of cancer cells but also for their very existence. We studied RLIP76 mutant proteins and the functional consequences of their expression into RLIP76−/− MEFs, identified key residues for GS-E binding in RLIP76, established the requirement of RLIP76-mediated GS-E transport for CDE, and showed a direct correlation between GS-E transport activities with CDE. Depletion of RLIP76 nearly completely blocked signaling downstream of EGF in a CDE-dependent manner and Wnt5a signaling in a CDE-independent manner. The seminal prediction of this hypothesis—RLIP76−/− mice will be deficient in chemical neoplasia—was confirmed. Benzo[a]pyrene, dimethylbenzanthracene, and phorbol esters are ineffective in causing neoplasia in RLIP76−/−. PMA-induced skin carcinogenesis in RLIP76+/+ mouse was suppressed completely by depletion of either PKCα or RLIP76 by siRNA or antisense and could be restored by topical application of RLIP76 protein in RLIP76−/− mouse skin. Likewise, chemical pulmonary carcinogenesis was absent in female and nearly absent in male RLIP76−/− mice. In RLIP76−/− mice, p53, p38, and JNK activation did not occur in response to either carcinogen. Our findings show a fundamental role of RLIP76 in chemical carcinogenesis. Mol Cancer Ther; 10(1); 16–28. ©2011 AACR.
Data from Selective Targeting of Interferon γ to Stromal Fibroblasts and Pericytes as a Novel Therapeutic Approach to Inhibit Angiogenesis and Tumor Growth
Authors: Bansal Ruchi , Tomar Tushar , Östman Arne , Poelstra Klaas , Prakash Jai
Published: March 2024

Abstract
New approaches to block the function of tumor stromal cells such as cancer-associated fibroblasts and pericytes is an emerging field in cancer therapeutics as these cells play a crucial role in promoting angiogenesis and tumor growth via paracrine signals. Because of immunomodulatory and other antitumor activities, IFNγ, a pleiotropic cytokine, has been used as an anticancer agent in clinical trials. Unfortunately only modest beneficial effects, but severe side effects, were seen. In this study, we delivered IFNγ to stromal fibroblasts and pericytes, considering its direct antifibrotic activity, using our platelet-derived growth factor-beta receptor (PDGFβR)-binding carrier (pPB-HSA), as these cells abundantly express PDGFβR. We chemically conjugated IFNγ to pPB-HSA using a heterobifunctional PEG linker. In vitro in NIH3T3 fibroblasts, pPB-HSA-IFNγ conjugate activated IFNγ-signaling (pSTAT1α) and inhibited their activation and migration. Furthermore, pPB-HSA-IFNγ inhibited fibroblasts-induced tube formation of H5V endothelial cells. In vivo in B16 tumor-bearing mice, pPB-HSA-IFNγ rapidly accumulated in tumor stroma and pericytes and significantly inhibited the tumor growth while untargeted IFNγ and pPB-HSA carrier were ineffective. These antitumor effects of pPB-HSA-IFNγ were attributed to the inhibition of tumor vascularization, as shown with α-SMA and CD-31 staining. Moreover, pPB-HSA-IFNγ induced MHC-II expression specifically in tumors compared with untargeted IFNγ, indicating the specificity of this approach. This study thus shows the impact of drug targeting to tumor stromal cells in cancer therapy as well as provides new opportunities to use cytokines for therapeutic application. Mol Cancer Ther; 11(11); 2419–28. ©2012 AACR.
Data from Spliceosome-Mediated RNA Trans-Splicing Facilitates Targeted Delivery of Suicide Genes to Cancer Cells
Authors: Gruber Christina , Gratz Iris K. , Murauer Eva M. , Mayr Elisabeth , Koller Ulrich , Bruckner-Tuderman Leena , Meneguzzi Guerrino , Hintner Helmut , Bauer Johann W.
Published: March 2024

Abstract
Patients suffering from recessive dystrophic epidermolysis bullosa (RDEB), a hereditary blistering disease of epithelia, show susceptibility to develop highly aggressive squamous cell carcinoma (SCC). Tumors metastasize early and are associated with mortality in the 30th–40th years of life in this patient group. So far, no adequate therapy is available for RDEB SCC. An approach is suicide gene therapy, in which a cell death-inducing agent is introduced to cancer cells. However, lack of specificity has constrained clinical application of this modality. Therefore, we used spliceosome-mediated RNA trans-splicing technology, capable of replacing a tumor-specific transcript with one encoding a cell death-inducing peptide/toxin, to provide tumor-restricted expression. We designed 3′ pre–trans-splicing molecules (PTM) and evaluated their efficiency to trans-splice an RDEB SCC-associated target gene, the matrix metalloproteinase-9 (MMP9), in a fluorescence-based test system. A highly efficient PTM was further adapted to insert the toxin streptolysin O (SLO) of Streptococcus pyogenes into the MMP9 gene. Transfection of RDEB SCC cells with the SLO-PTM resulted in cell death and induction of toxin function restricted to RDEB SCC cells. Thus, RNA trans-splicing is a suicide gene therapy approach with increased specificity to treat highly malignant SCC tumors. Mol Cancer Ther; 10(2); 233–41. ©2011 AACR.
Data from The Clinically Active PARP Inhibitor AG014699 Ameliorates Cardiotoxicity but Does Not Enhance the Efficacy of Doxorubicin, despite Improving Tumor Perfusion and Radiation Response in Mice
Authors: Ali Majid , Kamjoo Marzieh , Thomas Huw D. , Kyle Suzanne , Pavlovska Ivanda , Babur Muhammed , Telfer Brian A. , Curtin Nicola J. , Williams Kaye J.
Published: March 2024

Abstract
AG014699 was the first inhibitor of the DNA repair enzyme PARP-1 to enter clinical trial in cancer patients. In addition to enhancing the cytotoxic effect of DNA-damaging chemotherapies, we have previously shown that AG014699 is vasoactive, thereby having the potential to improve drug biodistribution. The effectiveness of the clinical agent doxorubicin is confounded both by poor tumor penetration and cardiotoxicity elicited via PARP hyperactivation. In this study, we analyzed the impact of AG014699 on doxorubicin tolerance and response in breast (MDA-MB-231) and colorectal (SW620, LoVo) tumor models in vitro and in vivo. As anticipated, AG014699 did not potentiate the response to doxorubicin in vitro. In vivo, AG014699 did not influence the pharmacokinetics of doxorubicin; however, it did ameliorate cardiotoxicity. Both toxicity and extent of amelioration were more pronounced in male than in female mice. AG014699 improved vessel perfusion in both MDA-MB-231 and SW620 tumors; however, this neither led to improved tumor-accumulation of doxorubicin nor enhanced therapeutic response. In contrast, when combined with radiotherapy, AG014699 significantly enhanced response both in vitro and in vivo. Real-time assessment of tumor vessel function and companion histologic studies indicate that doxorubicin causes a profound antivascular effect that counters the positive effect of AG014699 on perfusion. These data indicate that although AG014699 can enhance response to some chemotherapeutic drugs via improved delivery, this does not apply to doxorubicin. PARP inhibitors may still be of use to counter doxorubicin toxicity, and if the gender effect translates from rodents to humans, this would have greater effect in males. Mol Cancer Ther; 10(12); 2320–9. ©2011 AACR.
Data from Small-Molecule Inhibitor BMS-777607 Induces Breast Cancer Cell Polyploidy with Increased Resistance to Cytotoxic Chemotherapy Agents
Authors: Sharma Sharad , Zeng Jun-Ying , Zhuang Chun-Mei , Zhou Yong-Qing , Yao Hang-Ping , Hu Xing , Zhang Ruiwen , Wang Ming-Hai
Published: March 2024

Abstract
The RON receptor tyrosine kinase is a therapeutic target for cancer treatment. Here, we report therapeutic effect and phenotypic change of breast cancer cells in response to BMS-777607, a RON tyrosine kinase inhibitor. Treatment of breast cancer cells with BMS-777607 at therapeutic doses inhibited cancerous clonogenic growth but had only minimal effect on cell apoptosis. Significantly, BMS-777607 induced extensive polyploidy with multiple sets of chromosomes in cancer cells. This effect is independent of RON expression. Knockdown of RON in T-47D and ZR-75-1 cells by specific siRNA did not prevent polyploid formation. Immunofluorescent analysis of α-tubulin and γ-tubulin expression in polyploid cells revealed that BMS-777607 disrupts bipolar spindle formation and causes multipolar-like microtubule assembly. Also, both metaphase equatorial alignment and chromosomal segregation were absent in polyploid cells. These results suggest that cellular mitosis arrests at prophase/pro-metaphase and fails to undergo cytokinesis. By analyzing kinase-inhibitory profiles, aurora kinase B was identified as the target molecule inhibited by BMS-777607. In BMS-777607–treated cells, aurora kinase B was inhibited followed by protein degradation. Moreover, BMS-777607 inhibited Ser10 phosphorylation of histone H3, a substrate of aurora kinase B. Chemosensitivity analysis indicated the resistance of polyploid cells toward chemotherapeutics. Treatment with doxorubicin, bleomycin, methotrexate, and paclitaxel significantly increased cellular IC50 values. These findings highlight the theory that BMS-777607 acts as a multikinase inhibitor at therapeutic doses and is capable of inducing polyploidy by inhibiting aurora kinase B. Increased resistance of polyploid cells to cytotoxic chemotherapeutics could have a negative impact on targeted cancer therapy using BMS-777607. Mol Cancer Ther; 12(5); 725–36. ©2013 AACR.
Data from Antitumor Activity of Triolimus: A Novel Multidrug-Loaded Micelle Containing Paclitaxel, Rapamycin, and 17-AAG
Authors: Hasenstein Jason R. , Shin Ho-Chul , Kasmerchak Kelsey , Buehler Darya , Kwon Glen S. , Kozak Kevin R.
Published: March 2024

Abstract
Triolimus is a first-in-class, multidrug-loaded micelle containing paclitaxel, rapamycin, and 17-AAG. In this study, we examine the antitumor mechanisms of action, efficacy, and toxicity of Triolimus in vitro and in vivo. In vitro cytotoxicity testing of Triolimus was conducted using two aggressive adenocarcinomas including the lung cancer cell line, A549, and breast cancer cell line, MDA-MB-231. The three-drug combination of paclitaxel, rapamycin, and 17-AAG displayed potent cytotoxic synergy in both A549 and MDA-MB-231 cell lines. Mechanistically, the drug combination inhibited both the Ras/Raf/mitogen-activated protein kinase and PI3K/Akt/mTOR pathways. Triolimus was advanced into tumor xenograft models for assessment of efficacy, toxicity, and mechanisms of action. In vivo, a three-infusion schedule of Triolimus inhibited A549 and MDA-MB-231 tumor growth far more potently than paclitaxel-containing micelles and effected tumor cures in MDA-MB-231 tumor-bearing animals. Tumor growth delays resulted from a doubling in tumor cell apoptosis and a 50% reduction in tumor cell proliferation compared with paclitaxel-containing micelles. Enhanced antitumor efficacy was achieved without clinically significant increases in acute toxicity. Thus, Triolimus displays potent synergistic activity in vitro and antitumor activity in vivo with comparable toxicity to paclitaxel. These observations provide strong support for further development of Triolimus and an important proof of concept for safe, effective nanoparticle-based delivery of three complementary anticancer agents. Mol Cancer Ther; 11(10); 2233–42. ©2012 AACR.
Data from Evaluation of the Antitumor Effects and Mechanisms of PF00299804, a Pan-HER Inhibitor, Alone or in Combination with Chemotherapy or Targeted Agents in Gastric Cancer
Authors: Nam Hyun-Jin , Ching Keith A. , Kan Julie , Kim Hwang-Phill , Han Sae-Won , Im Seock-Ah , Kim Tae-You , Christensen James G. , Oh Do-Youn , Bang Yung-Jue
Published: March 2024

Abstract
Recently, HER2-directed treatment, such as trastuzumab, has shown clinical benefit in HER2-amplified gastric cancer. On the basis of recent studies about epidermal growth factor receptor (EGFR) or HER2-targeting agents (including gefitinib, lapatinib, and trastuzumab) in gastric cancer, the potent effects of pan-HER inhibitors targeting the HER family are anticipated. In this study, we evaluated the activity and mechanisms of PF00299804, an irreversible pan-HER inhibitor, in gastric cancer in vitro and in vivo models. PF00299804 showed significant growth-inhibitory effects in HER2-amplified gastric cancer cells (SNU216, N87), and it had lower 50% inhibitory concentration values compared with other EGFR tyrosine kinase inhibitors, including gefitinib, lapatinib, BIBW-2992, and CI-1033. PF00299804 induced apoptosis and G1 arrest and inhibited phosphorylation of receptors in the HER family and downstream signaling pathways including STAT3, AKT, and extracellular signal–regulated kinases (ERK) in HER2-amplified gastric cancer cells. PF00299804 also blocked EGFR/HER2, HER2/HER3, and HER3/HER4 heterodimer formation as well as the association of HER3 with p85α in SNU216 cells. The combination of PF00299804 with clinically relevant chemotherapeutic agents or molecular-targeted agents including trastuzumab (an anti-HER2 monoclonal antibody), CP751871 (an IGF1R inhibitor), PD0325901 (an ERK1/2 inhibitor), and PF04691502 (a PI3K/mTOR inhibitor) produced synergistic effects. These findings indicate that PF00299804 can be used as a targeted therapy for the treatment of HER2-amplified gastric cancer through inhibition of HER family heterodimer formation and may augment antitumor efficacy of chemotherapeutic and/or molecular-targeted agents. Mol Cancer Ther; 11(2); 439–51. ©2011 AACR.
Data from Inhibition of Wee1 Sensitizes Cancer Cells to Antimetabolite Chemotherapeutics In Vitro and In Vivo, Independent of p53 Functionality
Authors: Van Linden Annemie A. , Baturin Dmitry , Ford James B. , Fosmire Susan P. , Gardner Lori , Korch Christopher , Reigan Philip , Porter Christopher C.
Published: March 2024

Abstract
Inhibition of Wee1 is emerging as a novel therapeutic strategy for cancer, and some data suggest that cells with dysfunctional p53 are more sensitive to Wee1 inhibition combined with conventional chemotherapy than those with functional p53. We and others found that Wee1 inhibition sensitizes leukemia cells to cytarabine. Thus, we sought to determine whether chemosensitization by Wee1 inhibition is dependent on p53 dysfunction and whether combining Wee1 inhibition is tolerable and effective in vivo. Synergistic inhibition of proliferation with a Wee1 inhibitor in clinical development, MK1775, and cytarabine was observed in all acute myelogenous leukemia (AML) cell lines tested, regardless of p53 functionality. Mechanistic studies indicate that inhibition of Wee1 abrogates the S-phase checkpoint and augments apoptosis induced by cytarabine. In AML and lung cancer cell lines, genetic disruption of p53 did not alter the cells' enhanced sensitivity to antimetabolites with Wee1 inhibition. Finally, mice with AML were treated with cytarabine and/or MK1775. The combination of MK1775 and cytarabine was well tolerated in mice and enhanced the antileukemia effects of cytarabine, including survival. Thus, inhibition of Wee1 sensitizes hematologic and solid tumor cell lines to antimetabolite chemotherapeutics, whether p53 is functional or not, suggesting that the use of p53 mutation as a predictive biomarker for response to Wee1 inhibition may be restricted to certain cancers and/or chemotherapeutics. These data provide preclinical justification for testing MK1775 and cytarabine in patients with leukemia. Mol Cancer Ther; 12(12); 2675–84. ©2013 AACR.
Data from Glycolysis Inhibition Sensitizes Non–Small Cell Lung Cancer with T790M Mutation to Irreversible EGFR Inhibitors via Translational Suppression of Mcl-1 by AMPK Activation
Authors: Kim Sun Mi , Yun Mi Ran , Hong Yun Kyoung , Solca Flavio , Kim Joo-Hang , Kim Hyun-Jung , Cho Byoung Chul
Published: March 2024

Abstract
The secondary EGF receptor (EGFR) T790M is the most common mechanism of resistance to reversible EGFR-tyrosine kinase inhibitors (TKI) in patients with non–small cell lung cancer (NSCLC) with activating EGFR mutations. Although afatinib (BIBW2992), a second-generation irreversible EGFR-TKI, was expected to overcome the acquired resistance, it showed limited efficacy in a recent phase III clinical study. In this study, we found that the inhibition of glycolysis using 2-deoxy-d-glucose (2DG) improves the efficacy of afatinib in H1975 and PC9-GR NSCLC cells with EGFR T790M. Treatment with the combination of 2DG and afatinib induced intracellular ATP depletion in both H1975 and PC9-GR cells, resulting in activation of AMP-activated protein kinase (AMPK). AMPK activation played a central role in the cytotoxicity of the combined treatment with 2DG and afatinib through the inhibition of mTOR. The alteration of the AMPK/mTOR signaling pathway by the inhibition of glucose metabolism induced specific downregulation of Mcl-1, a member of the antiapoptotic Bcl-2 family, through translational control. The enhancement of afatinib sensitivity by 2DG was confirmed in the in vivo PC9-GR xenograft model. In conclusion, this study examined whether the inhibition of glucose metabolism using 2DG enhances sensitivity to afatinib in NSCLC cells with EGFR T790M through the regulation of the AMPK/mTOR/Mcl-1 signaling pathway. These data suggest that the combined use of an inhibitor of glucose metabolism and afatinib is a potential therapeutic strategy for the treatment of patients with acquired resistance to reversible EGFR-TKIs due to secondary EGFR T790M. Mol Cancer Ther; 12(10); 2145–56. ©2013 AACR.
Data from Peptidomimetic Src/Pretubulin Inhibitor KX-01 Alone and in Combination with Paclitaxel Suppresses Growth, Metastasis in Human ER/PR/HER2-Negative Tumor Xenografts
Authors: Anbalagan Muralidharan , Ali Alaa , Jones Ryan K. , Marsden Carolyn G. , Sheng Mei , Carrier Latonya , Bu Yahao , Hangauer David , Rowan Brian G.
Published: March 2024

Abstract
Src kinase is elevated in breast tumors that are ER/PR negative and do not overexpress HER2, but clinical trials with Src inhibitors have shown little activity. The present study evaluated preclinical efficacy of a novel peptidomimetic compound, KX-01 (KX2-391), that exhibits dual action as an Src and pretubulin inhibitor. KX-01 was evaluated as a single-agent and in combination with paclitaxel in MDA-MB-231, MDA-MB-157, and MDA-MB-468 human ER/PR/HER2-negative breast cancer cells. Treatments were evaluated by growth/apoptosis, isobologram analysis, migration/invasion assays, tumor xenograft volume, metastasis, and measurement of Src, focal adhesion kinase (FAK), microtubules, Ki67, and microvessel density. KX-01 inhibited cell growth in vitro and in combination with paclitaxel resulted in synergistic growth inhibition. KX-01 resulted in a dose-dependent inhibition of MDA-MB-231 and MDA-MB-157 tumor xenografts (1 and 5 mg/kg, twice daily). KX-01 inhibited activity of Src and downstream mediator FAK in tumors that was coincident with reduced proliferation and angiogenesis and increased apoptosis. KX01 also resulted in microtubule disruption in tumors. Combination of KX-01 with paclitaxel resulted in significant regression of MDA-MB-231 tumors and reduced metastasis to mouse lung and liver. KX-01 is a potently active Src/pretubulin inhibitor that inhibits breast tumor growth and metastasis. As ER/PR/HER2-negative patients are candidates for paclitaxel therapy, combination with KX-01 may potentiate antitumor efficacy in management of this aggressive breast cancer subtype. Mol Cancer Ther; 11(9); 1936–47. ©2012 AACR.
Data from NMS-P937, an Orally Available, Specific Small-Molecule Polo-like Kinase 1 Inhibitor with Antitumor Activity in Solid and Hematologic Malignancies
Authors: Valsasina Barbara , Beria Italo , Alli Cristina , Alzani Rachele , Avanzi Nilla , Ballinari Dario , Cappella Paolo , Caruso Michele , Casolaro Alessia , Ciavolella Antonella , Cucchi Ulisse , De Ponti Anna , Felder Eduard , Fiorentini Francesco , Galvani Arturo , Gianellini Laura M. , Giorgini Maria L. , Isacchi Antonella , Lansen Jaqueline , Pesenti Enrico , Rizzi Simona , Rocchetti Maurizio , Sola Francesco , Moll Jürgen
Published: March 2024

Abstract
Polo-like kinase 1 (PLK1) is a serine/threonine protein kinase considered to be the master player of cell-cycle regulation during mitosis. It is indeed involved in centrosome maturation, bipolar spindle formation, chromosome separation, and cytokinesis. PLK1 is overexpressed in a variety of human tumors and its overexpression often correlates with poor prognosis. Although five different PLKs are described in humans, depletion or inhibition of kinase activity of PLK1 is sufficient to induce cell-cycle arrest and apoptosis in cancer cell lines and in xenograft tumor models. NMS-P937 is a novel, orally available PLK1-specific inhibitor. The compound shows high potency in proliferation assays having low nanomolar activity on a large number of cell lines, both from solid and hematologic tumors. NMS-P937 potently causes a mitotic cell-cycle arrest followed by apoptosis in cancer cell lines and inhibits xenograft tumor growth with clear PLK1-related mechanism of action at well-tolerated doses in mice after oral administration. In addition, NMS-P937 shows potential for combination in clinical settings with approved cytotoxic drugs, causing tumor regression in HT29 human colon adenocarcinoma xenografts upon combination with irinotecan and prolonged survival of animals in a disseminated model of acute myelogenous leukemia in combination with cytarabine. NMS-P937, with its favorable pharmacologic parameters, good oral bioavailability in rodent and nonrodent species, and proven antitumor activity in different preclinical models using a variety of dosing regimens, potentially provides a high degree of flexibility in dosing schedules and warrants investigation in clinical settings. Mol Cancer Ther; 11(4); 1006–16. ©2012 AACR.
Data from Targeting the Inhibitor of Apoptosis Proteins as a Novel Therapeutic Strategy in Medulloblastoma
Authors: Keating Joanna , Tsoli Maria , Hallahan Andrew R. , Ingram Wendy J. , Haber Michelle , Ziegler David S.
Published: March 2024

Abstract
Medulloblastoma is the most common malignant brain tumor of childhood. Novel therapeutic strategies are urgently needed to overcome cytotoxic resistance. We hypothesized that antiapoptotic signals contribute to resistance and that treatment with proapoptotic agents could increase the efficacy of conventional therapies. A PCR array was used to assess the status of the apoptotic signaling pathway in medulloblastoma cells after treatment with cytotoxic chemotherapy. Treatment with cisplatin led to the upregulation of antiapoptotic signals, including inhibitor of apoptosis proteins (IAP), in medulloblastoma cells. We subsequently investigated the synergistic effect of a small-molecule IAP inhibitor, LBW242, in combination with cisplatin and/or radiotherapy in three human medulloblastoma cell lines and 5 short term primary patient medulloblastoma cultures. The addition of LBW242 to chemotherapy resulted in significantly increased antitumor activity with a similar effect observed in combination with radiotherapy. Measurement of caspase-8 and -9 activity indicated that the synergy resulted from induction of both the intrinsic and extrinsic apoptotic pathways. Apoptosis was confirmed by Annexin V staining and activation of caspases 3/7. Xenograft models were used to evaluate the mechanism of action and efficacy in vivo. The combination therapy significantly reduced the tumor burden in a medulloblastoma xenograft model and TUNEL analysis in a medulloblastoma orthograft confirmed in vivo induction of apoptosis. These findings support the strategy of targeting IAPs in combination with cytotoxic therapy as a novel treatment strategy for patients with medulloblastoma. Mol Cancer Ther; 11(12); 2654–63. ©2012 AACR.
Data from CEP-28122, a Highly Potent and Selective Orally Active Inhibitor of Anaplastic Lymphoma Kinase with Antitumor Activity in Experimental Models of Human Cancers
Authors: Cheng Mangeng , Quail Matthew R. , Gingrich Diane E. , Ott Gregory R. , Lu Lihui , Wan Weihua , Albom Mark S. , Angeles Thelma S. , Aimone Lisa D. , Cristofani Flavio , Machiorlatti Rodolfo , Abele Cristina , Ator Mark A. , Dorsey Bruce D. , Inghirami Giorgio , Ruggeri Bruce A.
Published: March 2024

Abstract
Anaplastic lymphoma kinase (ALK) is constitutively activated in a number of human cancer types due to chromosomal translocations, point mutations, and gene amplification and has emerged as an excellent molecular target for cancer therapy. Here we report the identification and preclinical characterization of CEP-28122, a highly potent and selective orally active ALK inhibitor. CEP-28122 is a potent inhibitor of recombinant ALK activity and cellular ALK tyrosine phosphorylation. It induced concentration-dependent growth inhibition/cytotoxicity of ALK-positive anaplastic large-cell lymphoma (ALCL), non-small cell lung cancer (NSCLC), and neuroblastoma cells, and displayed dose-dependent inhibition of ALK tyrosine phosphorylation in tumor xenografts in mice, with substantial target inhibition (>90%) for more than 12 hours following single oral dosing at 30 mg/kg. Dose-dependent antitumor activity was observed in ALK-positive ALCL, NSCLC, and neuroblastoma tumor xenografts in mice administered CEP-28122 orally, with complete/near complete tumor regressions observed following treatment at doses of 30 mg/kg twice daily or higher. Treatment of mice bearing Sup-M2 tumor xenografts for 4 weeks and primary human ALCL tumor grafts for 2 weeks at 55 or 100 mg/kg twice daily led to sustained tumor regression in all mice, with no tumor reemergence for more than 60 days postcessation of treatment. Conversely, CEP-28122 displayed marginal antitumor activity against ALK-negative human tumor xenografts under the same dosing regimens. Administration of CEP-28122 was well tolerated in mice and rats. In summary, CEP-28122 is a highly potent and selective orally active ALK inhibitor with a favorable pharmaceutical and pharmacokinetic profile and robust and selective pharmacologic efficacy against ALK-positive human cancer cells and tumor xenograft models in mice. Mol Cancer Ther; 11(3); 670–9. ©2011 AACR.
Data from 177Lu-EC0800 Combined with the Antifolate Pemetrexed: Preclinical Pilot Study of Folate Receptor Targeted Radionuclide Tumor Therapy
Authors: Reber Josefine , Haller Stephanie , Leamon Christopher P. , Müller Cristina
Published: March 2024

Abstract
Targeted radionuclide therapy has shown impressive results for the palliative treatment of several types of cancer diseases. The folate receptor has been identified as specifically associated with a variety of frequent tumor types. Therefore, it is an attractive target for the development of new radionuclide therapies using folate-based radioconjugates. Previously, we found that pemetrexed (PMX) has a favorable effect in reducing undesired renal uptake of radiofolates. Moreover, PMX also acts as a chemotherapeutic and radiosensitizing agent on tumors. Thus, the aim of our study was to investigate the combined application of PMX and the therapeutic radiofolate 177Lu-EC0800. Determination of the combination index (CI) revealed a synergistic inhibitory effect of 177Lu-EC0800 and PMX on the viability of folate receptor–positive cervical (KB) and ovarian (IGROV-1) cancer cells in vitro (CI < 0.8). In an in vivo study, tumor-bearing mice were treated with 177Lu-EC0800 (20 MBq) and a subtherapeutic (0.4 mg) or therapeutic amount (1.6 mg) of PMX. Application of 177Lu-EC0800 with PMXther resulted in a two- to four-fold enhanced tumor growth delay and a prolonged survival of KB and IGROV-1 tumor-bearing mice, as compared to the combination with PMXsubther or untreated control mice. PMXsubther protected the kidneys from undesired side effects of 177Lu-EC0800 (20 MBq) by reducing the absorbed radiation dose. Intact kidney function was shown by determination of plasma parameters and quantitative single-photon emission computed tomography using 99mTc-DMSA. Our results confirmed the anticipated dual role of PMX. Its unique features resulted in an improved antitumor effect of folate-based radionuclide therapy and prevented undesired radio-nephrotoxicity. Mol Cancer Ther; 12(11); 2436–45. ©2013 AACR.
Data from Pharmacogenomic Profiling and Pathway Analyses Identify MAPK-Dependent Migration as an Acute Response to SN38 in p53 Null and p53-Mutant Colorectal Cancer Cells
Authors: Allen Wendy L. , Turkington Richard C. , Stevenson Leanne , Carson Gail , Coyle Vicky M. , Hector Suzanne , Dunne Philip , Van Schaeybroeck Sandra , Longley Daniel B. , Johnston Patrick G.
Published: March 2024

Abstract
The topoisomerase I inhibitor irinotecan is used to treat advanced colorectal cancer and has been shown to have p53-independent anticancer activity. The aim of this study was to identify the p53-independent signaling mechanisms activated by irinotecan. Transcriptional profiling of isogenic HCT116 p53 wild-type and p53 null cells was carried out following treatment with the active metabolite of irinotecan, SN38. Unsupervised analysis methods showed that p53 status had a highly significant impact on gene expression changes in response to SN38. Pathway analysis indicated that pathways involved in cell motility [adherens junction, focal adhesion, mitogen-activated protein kinase (MAPK), and regulation of the actin cytoskeleton] were significantly activated in p53 null cells, but not p53 wild-type cells, following SN38 treatment. In functional assays, SN38 treatment increased the migratory potential of p53 null and p53-mutant colorectal cancer cell lines, but not p53 wild-type lines. Moreover, p53 null SN38-resistant cells were found to migrate at a faster rate than parental drug-sensitive p53 null cells, whereas p53 wild-type SN38-resistant cells failed to migrate. Notably, cotreatment with inhibitors of the MAPK pathway inhibited the increased migration observed following SN38 treatment in p53 null and p53-mutant cells. Thus, in the absence of wild-type p53, SN38 promotes migration of colorectal cancer cells, and inhibiting MAPK blocks this potentially prometastatic adaptive response to this anticancer drug. Mol Cancer Ther; 11(8); 1724–34. ©2012 AACR.
Data from Isolation of a Novel Thioflavin S–Derived Compound That Inhibits BAG-1–Mediated Protein Interactions and Targets BRAF Inhibitor–Resistant Cell Lines
Authors: Enthammer Marion , Papadakis Emmanouil S. , Salomé Gachet Maria , Deutsch Martin , Schwaiger Stefan , Koziel Katarzyna , Ashraf Muhammad Imtiaz , Khalid Sana , Wolber Gerhard , Packham Graham , Cutress Ramsey I. , Stuppner Hermann , Troppmair Jakob
Published: March 2024

Abstract
Protein–protein interactions mediated through the C-terminal Bcl-2–associated athanogene (BAG) domain of BAG-1 are critical for cell survival and proliferation. Thioflavin S (NSC71948)—a mixture of compounds resulting from the methylation and sulfonation of primulin base—has been shown to dose-dependently inhibit the interaction between BAG-1 and Hsc70 in vitro. In human breast cancer cell lines, with high BAG-1 expression levels, Thioflavin S reduces the binding of BAG-1 to Hsc70, Hsp70, or CRAF and decreases proliferation and viability. Here, we report the development of a protocol for the purification and isolation of biologically active constituents of Thioflavin S and the characterization of the novel compound Thio-2. Thio-2 blocked the growth of several transformed cell lines, but had much weaker effects on untransformed cells. Thio-2 also inhibited the proliferation of melanoma cell lines that had become resistant to treatment with PLX4032, an inhibitor of mutant BRAF. In transformed cells, Thio-2 interfered with intracellular signaling at the level of RAF, but had no effect on the activation of AKT. Thio-2 decreased binding of BAG-1 to Hsc70 and to a lesser extent BRAF in vitro and in vivo, suggesting a possible mechanism of action. Given that tumors frequently develop resistance to kinase inhibitors during treatment, Thio-2 and related compounds may offer promising alternative strategies to currently available therapies. Mol Cancer Ther; 12(11); 2400–14. ©2013 AACR.
Data from Inhibition of HSP90 with AUY922 Induces Synergy in HER2-Amplified Trastuzumab-Resistant Breast and Gastric Cancer
Authors: Wainberg Zev A. , Anghel Adrian , Rogers Amy M. , Desai Amrita J. , Kalous Ondrej , Conklin Dylan , Ayala Raul , O'Brien Neil A. , Quadt Cornelia , Akimov Mikhail , Slamon Dennis J. , Finn Richard S.
Published: March 2024

Abstract
HSP90 enables the activation of many client proteins of which the most clinically validated is HER2. NVP-AUY922, a potent HSP90 inhibitor, is currently in phase II clinical trials. To explore its potential clinical use in HER2-amplified breast and gastric cancers, we evaluated the effect of AUY922 alone and in combination with trastuzumab in both trastuzumab-sensitive and -resistant models. A panel of 16 human gastric and 45 breast cancer cell lines, including 16 HER2-amplified (3 and 13, respectively) cells, was treated with AUY922 over various concentrations. In both breast and gastric cancer, we used cell lines and xenograft models with conditioned trastuzumab-resistance to investigate the efficacy of AUY922 alongside trastuzumab. Effects of this combination on downstream markers were analyzed via Western blot analysis. AUY922 exhibited potent antiproliferative activity in the low nanomolar range (<40 nmol/L) for 59 of 61 cell lines. In both histologies, HER2-amplified cells expressed greater sensitivity to AUY than HER2-negative cells. In conditioned trastuzumab-resistant models, AUY922 showed a synergistic effect with trastuzumab. In vitro, the combination induced greater decreases in HER2, a G2 cell-cycle arrest, and increased apoptosis. In a trastuzumab-resistant gastric cancer xenograft model, the combination of AUY922 and trastuzumab showed greater antitumor efficacy than either drug alone. These data suggest that AUY922 in combination with trastuzumab has unique efficacy in trastuzumab-resistant models. The combination of HSP90 inhibition and direct HER2 blockade represents a novel approach to the treatment of HER2-amplified cancers and clinical trials based on the above data are ongoing. Mol Cancer Ther; 12(4); 509–19. ©2013 AACR.
Data from Targeting Interleukin-4 Receptor α with Hybrid Peptide for Effective Cancer Therapy
Authors: Yang Liying , Horibe Tomohisa , Kohno Masayuki , Haramoto Mari , Ohara Koji , Puri Raj K. , Kawakami Koji
Published: March 2024

Abstract
Interleukin-4 receptor α (IL-4Rα) chain is highly expressed on the surface of various human solid tumors. We designed a novel hybrid peptide termed IL-4Rα–lytic peptide that targets the IL-4Rα chain. The IL-4Rα–lytic peptide contains a target moiety to bind to IL-4Rα and a cellular toxic lytic peptide that selectively kills cancer cells. The anticancer activity of the IL-4Rα–lytic peptide was evaluated in vitro and in vivo. It was found that the IL-4Rα–lytic peptide has cytotoxic activity in cancer cell lines expressing IL-4Rα, determined by quantitative real-time PCR. The IC50 ratios of the lytic peptide to the IL-4Rα–lytic peptide correlated well with the expression levels of IL-4Rα on cancer cells (r = 0.80). In addition, IL-4Rα–lytic peptide administered either intratumoraly or intravenously significantly inhibited tumor growth in xenograft model of human pancreatic cancer (BXPC-3) in mice. These results indicate that the IL-4Rα–lytic peptide generated in this study has a potent and selective anticancer potential against IL-4Rα–positive solid cancers. Mol Cancer Ther; 11(1); 235–43. ©2011 AACR.
Data from Selective Photodetection and Photodynamic Therapy for Prostate Cancer through Targeting of Proteolytic Activity
Authors: Zuluaga Maria-Fernanda , Sekkat Nawal , Gabriel Doris , van den Bergh Hubert , Lange Norbert
Published: March 2024

Abstract
Frequent side effects of radical treatment modalities and the availability of novel diagnostics have raised the interest in focal therapies for localized prostate cancer. To improve the selectivity and therapeutic efficacy of such therapies, we developed a minimally invasive procedure based on a novel polymeric photosensitizer prodrug sensitive to urokinase-type plasminogen activator (uPA). The compound is inactive in its prodrug form and accumulates passively at the tumor site by the enhanced permeability and retention effect. There, the prodrug is selectively converted to its photoactive form by uPA, which is overexpressed by prostate cancer cells. Irradiation of the activated photosensitizer exerts a tumor-selective phototoxic effect. The prodrug alone (8 μmol/L) showed no toxic effect on PC-3 cells, but upon irradiation the cell viability was reduced by 90%. In vivo, after systemic administration of the prodrug, PC-3 xenografts became selectively fluorescent. This is indicative of the prodrug accumulation in the tumor and selective local enzymatic activation. Qualitative analysis of the activated compound confirmed that the enzymatic cleavage occurred selectively in the tumor, with only trace amounts in the neighboring skin or muscle. Subsequent photodynamic therapy studies showed complete tumor eradication of animals treated with light (150 J/cm2 at 665 nm) 16 hours after the injection of the prodrug (7.5 mg/kg). These promising results evidence the excellent selectivity of our prodrug with the potential to be used for both imaging and therapy for localized prostate cancer. Mol Cancer Ther; 12(3); 306–13. ©2012 AACR.