bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Pathway Analysis of Glioblastoma Tissue after Preoperative Treatment with the EGFR Tyrosine Kinase Inhibitor Gefitinib—A Phase II Trial
Authors: Hegi Monika E. , Diserens Annie-Claire , Bady Pierre , Kamoshima Yuta , Kouwenhoven Mathilde C. M. , Delorenzi Mauro , Lambiv Wanyu L. , Hamou Marie-France , Matter Matthias S. , Koch Arend , Heppner Frank L. , Yonekawa Yasuhiro , Merlo Adrian , Frei Karl , Mariani Luigi , Hofer Silvia
Published: April 2023

Abstract
Amplification of the epidermal growth factor receptor (EGFR) gene is one of the most common oncogenic alterations in glioblastoma (45%) making it a prime target for therapy. However, small molecule inhibitors of the EGFR tyrosine kinase showed disappointing efficacy in clinical trials for glioblastoma. Here we aimed at investigating the molecular effects of the tyrosine kinase inhibitor gefitinib on the EGFR signaling pathway in human glioblastoma. Twenty-two patients selected for reoperation of recurrent glioblastoma were treated within a phase II trial for 5 days with 500 mg gefitinib before surgery followed by postoperative gefitinib until recurrence. Resected glioblastoma tissues exhibited high concentrations of gefitinib (median, 4.1 μg/g), 20 times higher than respective plasma. EGFR-pathway activity was evaluated with phosphorylation-specific assays. The EGFR was efficiently dephosphorylated in treated patients as compared to a control cohort of 12 patients. However, no significant effect on 12 pathway constituents was detected. In contrast, in vitro treatment of a glioblastoma cell line, BS-153, with endogenous EGFRwt amplification and EGFRvIII expression resulted not only in dephosphorylation of the EGFR, but also of key regulators in the pathway such as AKT. Treating established xenografts of the same cell line as an in vivo model showed dephosphorylation of the EGFR without affecting downstream signal transductors, similar to the human glioblastoma. Taken together, gefitinib reaches high concentrations in the tumor tissue and efficiently dephosphorylates its target. However, regulation of downstream signal transducers in the EGFR pathway seems to be dominated by regulatory circuits independent of EGFR phosphorylation. Mol Cancer Ther; 10(6); 1102–12. ©2011 AACR.
Data from Histone Deacetylase Cytoplasmic Trapping by a Novel Fluorescent HDAC Inhibitor
Authors: Kong Yali , Jung Mira , Wang Kan , Grindrod Scott , Velena Alfredo , Lee Sung A. , Dakshanamurthy Sivanesan , Yang Yonghong , Miessau Matthew , Zheng Chaoyi , Dritschilo Anatoly , Brown Milton L.
Published: April 2023

Abstract
Inhibitors of histone deacetylases (HDAC) are an important emerging class of drugs for the treatment of cancers. HDAC inhibitors are currently under evaluation in clinical trials as single agents and as sensitizers in combinations with chemotherapies and radiation therapy. Although these drugs have important effects on cancer cell growth and functions, the mechanisms underlying HDAC inhibitor activities remain to be fully defined. By using rational drug design, compound 2, a fluorescent class II HDAC targeting inhibitor, was synthesized and observed to accumulate in the cytoplasmic compartments of treated cells, but not in the nuclei. Furthermore, immunostaining of inhibitor exposed cells for HDAC4 showed accumulation of this enzyme in the cytoplasmic compartment with concomitant increased acetylation of tubulin and nuclear histones. These observations support a mechanism by which nuclear histone acetylation is increased as a result of HDAC4 trapping and sequestration in the cytoplasm after binding to compound 2. The HDAC inhibitor offers potential as a novel theranostic agent, combining diagnostic and therapeutic properties in the same molecule. Mol Cancer Ther; 10(9); 1591–9. ©2011 AACR.
Data from Inhibition of Focal Adhesion Kinase by PF-562,271 Inhibits the Growth and Metastasis of Pancreatic Cancer Concomitant with Altering the Tumor Microenvironment
Authors: Stokes Jayme B. , Adair Sara J. , Slack-Davis Jill K. , Walters Dustin M. , Tilghman Robert W. , Hershey E. Dan , Lowrey Bryce , Thomas Keena S. , Bouton Amy H. , Hwang Rosa F. , Stelow Edward B. , Parsons J. Thomas , Bauer Todd W.
Published: April 2023

Abstract
Current therapies for pancreatic ductal adenocarcinoma (PDA) target individual tumor cells. Focal adhesion kinase (FAK) is activated in PDA, and levels are inversely associated with survival. We investigated the effects of PF-562,271 (a small-molecule inhibitor of FAK/PYK2) on (i) in vitro migration, invasion, and proliferation; (ii) tumor proliferation, invasion, and metastasis in a murine model; and (iii) stromal cell composition in the PDA microenvironment. Migration assays were conducted to assess tumor and stromal cell migration in response to cellular factors, collagen, and the effects of PF-562,271. An orthotopic murine model was used to assess the effects of PF-562,271 on tumor growth, invasion, and metastasis. Proliferation assays measured PF-562,271 effects on in vitro growth. Immunohistochemistry was used to examine the effects of FAK inhibition on the cellular composition of the tumor microenvironment. FAK and PYK2 were activated and expressed in patient-derived PDA tumors, stromal components, and human PDA cell lines. PF-562,271 blocked phosphorylation of FAK (phospho-FAK or Y397) in a dose-dependent manner. PF-562,271 inhibited migration of tumor cells, cancer-associated fibroblasts, and macrophages. Treatment of mice with PF-562,271 resulted in reduced tumor growth, invasion, and metastases. PF-562,271 had no effect on tumor necrosis, angiogenesis, or apoptosis, but it did decrease tumor cell proliferation and resulted in fewer tumor-associated macrophages and fibroblasts than control or gemcitabine. These data support a role for FAK in PDA and suggest that inhibitors of FAK may contribute to efficacious treatment of patients with PDA. Mol Cancer Ther; 10(11); 2135–45. ©2011 AACR.
Data from Development of Gene Expression–Based Score to Predict Sensitivity of Multiple Myeloma Cells to DNA Methylation Inhibitors
Authors: Moreaux Jérôme , Rème Thierry , Leonard Wim , Veyrune Jean-Luc , Requirand Guilhem , Goldschmidt Hartmut , Hose Dirk , Klein Bernard
Published: April 2023

Abstract
Multiple myeloma is a plasma cell cancer with poor survival, characterized by the clonal expansion of multiple myeloma cells (MMC), primarily in the bone marrow. Novel compounds are currently tested in this disease, but partial or minor patients' responses are observed for most compounds used as a single agent. The design of predictors for drug efficacy could be most useful to better understand basic mechanisms targeted by these drugs and design clinical trials. In the current study, we report the building of a DNA methylation score (DM score) predicting the efficacy of decitabine, an inhibitor of DNA methyltransferase (DNMT), targeting methylation-regulated gene expression. DM score was built by identifying 47 genes regulated by decitabine in human myeloma cell lines and the expression of which in primary MMCs of previously untreated patients is predictive for overall survival. A high DM score predicts patients' poor survival, and, of major interest, high sensitivity of primary MMCs or human myeloma cell lines to decitabine in vitro. Thus, DM score could be useful to design novel treatments with DMNT inhibitor in multiple myeloma and has highlighted 47 genes, the gene products of which could be important for multiple myeloma disease development. Mol Cancer Ther; 11(12); 2685–92. ©2012 AACR.
Data from 3,5-Bis(2,4-Difluorobenzylidene)-4-piperidone, a Novel Compound That Affects Pancreatic Cancer Growth and Angiogenesis
Authors: Subramaniam Dharmalingam , Nicholes Nathan D. , Dhar Animesh , Umar Shahid , Awasthi Vibhudutta , Welch Danny R. , Jensen Roy A. , Anant Shrikant
Published: April 2023

Abstract
Dysregulated Notch signaling plays an important role in the progression of cancer. Notch signaling affects tumor growth and angiogenesis through the actions of its ligand Jagged-1. In this study, we developed a novel compound 3,5-bis(2,4-difluorobenzylidene)-4-piperidone (DiFiD) and determined that it inhibits cancer cell growth and its effects on Notch signaling. Intraperitoneal administration of DiFiD significantly suppressed growth of pancreatic cancer tumor xenografts. There was a reduction in CD31-positive blood vessels, suggesting that there was an effect on angiogenesis. In vitro, DiFiD inhibited the proliferation of various human and mouse pancreatic cancer cells while increasing activated caspase-3. Cell-cycle analyses showed that DiFiD induced G2–M arrest and decreased the expression of cell-cycle–related proteins cyclin A1 and D1 while upregulating cyclin-dependent kinase inhibitor p21WAF1. We next determined the mechanism of action. DiFiD reduced Notch-1 activation, resulting in reduced expression of its downstream target protein Hes-1. We further determined that the reduced Notch-1 activation was due to reduction in the ligand Jagged-1 and two critical components of the γ-secretase enzyme complex presenilin-1 and nicastrin. Ectopic expression of the Notch intracellular domain rescued the cells from DiFiD-mediated growth suppression. DiFiD-treated tumor xenografts also showed reduced levels of Jagged-1 and the γ-secretase complex proteins presenilin-1 and nicastrin. Taken together, these data suggest that DiFiD is a novel potent therapeutic agent that can target different aspects of the Notch signaling pathway to inhibit both tumor growth and angiogenesis. Mol Cancer Ther; 10(11); 2146–56. ©2011 AACR.
Data from Targeted Nanogels: A Versatile Platform for Drug Delivery to Tumors
Authors: Murphy Eric A. , Majeti Bharat K. , Mukthavaram Rajesh , Acevedo Lisette M. , Barnes Leo A. , Cheresh David A.
Published: April 2023

Abstract
Although nanoparticle-based drug delivery formulations can improve the effectiveness and safety of certain anticancer drugs, many drugs, due to their chemical composition, are unsuitable for nanoparticle loading. Here, we describe a targeted nanogel drug delivery platform that can (i) encapsulate a wide range of drug chemotypes, including biological, small molecule, and cytotoxic agents; (ii) display targeting ligands and polymeric coatings on the surface; (iii) enhance drug retention within the nanogel core after photo-cross-linking; and (iv) retain therapeutic activity after lyophilization allowing for long-term storage. For therapeutic studies, we used integrin αvβ3–targeted lipid-coated nanogels with cross-linked human serum albumin in the core for carrying therapeutic cargoes. These particles exhibited potent activity in tumor cell viability assays with drugs of distinct chemotype, including paclitaxel, docetaxel, bortezomib, 17-AAG, sorafenib, sunitinib, bosutinib, and dasatinib. Treatment of orthotopic breast and pancreas tumors in mice with taxane-loaded nanogels produced a 15-fold improvement in antitumor activity relative to Abraxane by blocking both primary tumor growth and spontaneous metastasis. With a modifiable surface and core, the lipid-coated nanogel represents a platform technology that can be easily adapted for specific drug delivery applications to treat a wide range of malignant diseases. Mol Cancer Ther; 10(6); 972–82. ©2011 AACR.
Data from Honokiol in Combination with Radiation Targets Notch Signaling to Inhibit Colon Cancer Stem Cells
Authors: Ponnurangam Sivapriya , Mammen Joshua M.V. , Ramalingam Satish , He Zhiyun , Zhang Youcheng , Umar Shahid , Subramaniam Dharmalingam , Anant Shrikant
Published: April 2023

Abstract
Cancer stem cells are implicated in resistance to ionizing radiation (IR) and chemotherapy. Honokiol, a biphenolic compound has been used in traditional Chinese medicine for treating various ailments. In this study, we determined the ability of honokiol to enhance the sensitivity of colon cancer stem cells to IR. The combination of honokiol and IR suppressed proliferation and colony formation while inducing apoptosis of colon cancer cells in culture. There were also reduced numbers and size of spheroids, which was coupled with reduced expression of cancer stem cell marker protein DCLK1. Flow cytometry studies confirmed that the honokiol–IR combination reduced the number of DCLK1+ cells. In addition, there were reduced levels of activated Notch-1, its ligand Jagged-1, and the downstream target gene Hes-1. Furthermore, expression of components of the Notch-1 activating γ-secretase complex, presenilin 1, nicastrin, Pen2, and APH-1 was also suppressed. On the other hand, the honokiol effects were mitigated when the Notch intracellular domain was expressed. To determine the effect of honokiol–IR combination on tumor growth in vivo, nude mice tumor xenografts were administered honokiol intraperitoneally and exposed to IR. The honokiol–IR combination significantly inhibited tumor xenograft growth. In addition, there were reduced levels of DCLK1 and the Notch signaling–related proteins in the xenograft tissues. Together, these data suggest that honokiol is a potent inhibitor of colon cancer growth that targets the stem cells by inhibiting the γ-secretase complex and the Notch signaling pathway. These studies warrant further clinical evaluation for the combination of honokiol and IR for treating colon cancers. Mol Cancer Ther; 11(4); 963–72. ©2012 AACR.
Data from Therapeutic Targeting the Loss of the Birt-Hogg-Dubé Suppressor Gene
Authors: Lu Xiaohong , Wei Wenbin , Fenton Janine , Nahorski Michael S. , Rabai Erzsebet , Reiman Anne , Seabra Laurence , Nagy Zsuzsanna , Latif Farida , Maher Eamonn R.
Published: April 2023

Abstract
Brit-Hogg-Dubé (BHD) syndrome, an autosomal dominant familial cancer, is associated with increased risk of kidney cancer. BHD syndrome is caused by loss-of-function mutations in the folliculin (FLCN) protein. To develop therapeutic approaches for renal cell carcinoma (RCC) in BHD syndrome, we adopted a strategy to identify tumor-selective growth inhibition in a RCC cell line with FLCN inactivation. The COMPARE algorithm was used to identify candidate anticancer drugs tested against the NCI-60 cell lines that showed preferential toxicity to low FLCN expressing cell lines. Fifteen compounds were selected and detailed growth inhibition (SRB) assays were done in paired BHD RCC cell lines (UOK257 derived from a patient with BHD). Selective sensitivity of FLCN-null over FLCN-wt UOK257 cells was observed in seven compounds. The most selective growth-inhibitory sensitivity was induced by mithramycin, which showed an approximately 10-fold difference in GI50 values between FLCN-null (64.2 ± 7.9 nmol/L, n = 3) and FLCN-wt UOK257 cells (634.3 ± 147.9 nmol/L, n = 4). Differential ability to induce caspase 3/7 activity by mithramycin was also detected in a dose-dependent manner. Clonogenic survival studies showed mithramycin to be approximately 10-fold more cytotoxic to FLCN-null than FLCN-wt UOK257 cells (200 nmol/L). Following mithramycin exposure, UOK257-FLCN-null cells were mainly arrested and blocked in S and G2-M phases of the cell cycle and low dose of rapamycin (1 nmol/L) potentiated mithramycin sensitivity (1.5-fold in G2-M population and 2-fold in G2-M period time, 2xGI50, 48 hours). These results provide a basis for further evaluation of mithramycin as a potential therapeutic drug for RCC associated with BHD. Mol Cancer Ther; 10(1); 80–9. ©2011 AACR.
Data from Inhibition of Dynamin by Dynole 34-2 Induces Cell Death following Cytokinesis Failure in Cancer Cells
Authors: Chircop Megan , Perera Swetha , Mariana Anna , Lau Hui , Ma Maggie P.C. , Gilbert Jayne , Jones Nigel C. , Gordon Christopher P. , Young Kelly A. , Morokoff Andrew , Sakoff Jennette , O'Brien Terence J. , McCluskey Adam , Robinson Phillip J.
Published: April 2023

Abstract
Inhibitors of mitotic proteins such as Aurora kinase and polo-like kinase have shown promise in preclinical or early clinical development for cancer treatment. We have reported that the MiTMAB class of dynamin small molecule inhibitors are new antimitotic agents with a novel mechanism of action, blocking cytokinesis. Here, we examined 5 of the most potent of a new series of dynamin GTPase inhibitors called dynoles. They all induced cytokinesis failure at the point of abscission, consistent with inhibition of dynamin while not affecting other cell cycle stages. All 5 dynoles inhibited cell proliferation (MTT and colony formation assays) in 11 cancer cell lines. The most potent GTPase inhibitor, dynole 34-2, also induced apoptosis, as revealed by cell blebbing, DNA fragmentation, and PARP cleavage. Cell death was induced specifically following cytokinesis failure, suggesting that dynole 34-2 selectively targets dividing cells. Dividing HeLa cells were more sensitive to the antiproliferative properties of all 5 dynoles compared with nondividing cells, and nontumorigenic fibroblasts were less sensitive to cell death induced by dynole 34-2. Thus, the dynoles are a second class of dynamin GTPase inhibitors, with dynole 34-2 as the lead compound, that are novel antimitotic compounds acting specifically at the abscission stage. Mol Cancer Ther; 10(9); 1553–62. ©2011 AACR.
Data from Linear Chain PEGylated Recombinant Bacillus Thiaminolyticus Thiaminase I Enzyme Has Growth Inhibitory Activity against Lymphoid Leukemia Cell Lines
Authors: Daily Abigail , Liu Shuqian , Bae Younsoo , Bhatnagar Saloni , Moscow Jeffrey A.
Published: April 2023

Abstract
Cancer cells acquire abnormalities in energy metabolism, collectively known as the Warburg effect, affecting substrate availability of thiamine-dependent enzymes. To investigate a strategy to exploit abnormal cancer-associated metabolism related to thiamine, we tested the cytotoxicity of native Bacillus thiaminolyticus thiaminase I enzyme, which digests thiamine, in the NCI60 cell line drug cytotoxicity screening program and found that leukemia cell lines were among the most sensitive to thiaminase I. We obtained additional lymphoid leukemia cell lines and confirmed that native thiaminase I and linear chain PEGylated thiaminase I enzyme (LCPTE) have cytotoxic activity in these cell lines. In addition, the IC50 of 3 of the 5 leukemia cell lines (Reh, RS4, and Jurkat) were at least 1,000-fold more sensitive than Molt-4 cells, which in turn, were among the most sensitive in the NCI60 panel. The 3 LCPTE-sensitive leukemia cell lines were also sensitive to removal of thiamine from the medium, thus suggesting the mechanism of action of LCPTE involves extracellular thiamine starvation. Surprisingly, rapamycin showed a protective effect against LCPTE toxicity in the 3 LCPTE-sensitive cell lines but not in the other 2 cell lines, suggesting involvement of an mTOR-dependent pathway. Immunoblot analysis of the LCPTE-sensitive cell lines after LCPTE exposure revealed changes in mTOR pathway phosphorylation. Nude mice bearing RS4 leukemia xenografts showed both tumor growth delay and prolonged survival after a single dose of LCPTE. Therefore, disruption of thiamine-dependent metabolism may be a novel therapeutic approach to target altered energy metabolism in leukemia and other cancers. Mol Cancer Ther; 10(9); 1563–70. ©2011 AACR.
Data from A Robust High-Content Imaging Approach for Probing the Mechanism of Action and Phenotypic Outcomes of Cell-Cycle Modulators
Authors: Sutherland Jeffrey J. , Low Jonathan , Blosser Wayne , Dowless Michele , Engler Thomas A. , Stancato Louis F.
Published: April 2023

Abstract
High-content screening is increasingly used to elucidate changes in cellular biology arising from treatment with small molecules and biological probes. We describe a cell classifier for automated analysis of multiparametric data from immunofluorescence microscopy and characterize the phenotypes of 41 cell-cycle modulators, including several protein kinase inhibitors in preclinical and clinical development. This method produces a consistent assessment of treatment-induced phenotypes across experiments done by different biologists and highlights the prevalence of nonuniform and concentration-dependent cellular response to treatment. Contrasting cell phenotypes from high-content screening to kinase selectivity profiles from cell-free assays highlights the limited utility of enzyme potency ratios in understanding the mechanism of action for cell-cycle kinase inhibitors. Our cell-level approach for assessing phenotypic outcomes is reliable, reproducible and capable of supporting medium throughput analyses of a wide range of cellular perturbations. Mol Cancer Ther; 10(2); 242–54. ©2011 AACR.
Data from Inhibition of TGF-β Enhances the In Vivo Antitumor Efficacy of EGF Receptor–Targeted Therapy
Authors: Bedi Atul , Chang Xiaofei , Noonan Kimberly , Pham Vui , Bedi Rishi , Fertig Elana J. , Considine Michael , Califano Joseph A. , Borrello Ivan , Chung Christine H. , Sidransky David , Ravi Rajani
Published: April 2023

Abstract
EGF receptor (EGFR)–targeted monoclonal antibodies (mAb), such as cetuximab, execute their antitumor effect in vivo via blockade of receptor–ligand interactions and engagement of Fcγ receptors on immune effector cells that trigger antibody-dependent cell-mediated cytotoxicity (ADCC). We show that tumors counteract the in vivo antitumor activity of anti-EGFR mAbs by increasing tumor cell-autonomous expression of TGF-β. We show that TGF-β suppresses the expression of key molecular effectors of immune cell–mediated cytotoxicity, including Apo2L/TRAIL, CD95L/FasL, granzyme B, and IFN-γ. In addition to exerting an extrinsic inhibition of the cytotoxic function of immune effectors, TGF-β–mediated activation of AKT provides an intrinsic EGFR-independent survival signal that protects tumor cells from immune cell–mediated apoptosis. Treatment of mice-bearing xenografts of human head and neck squamous cell carcinoma with cetuximab resulted in emergence of resistant tumor cells that expressed relatively higher levels of TGF-β compared with untreated tumor-bearing mice. Although treatment with cetuximab alone forced the natural selection of TGF-β–overexpressing tumor cells in nonregressing tumors, combinatorial treatment with cetuximab and a TGF-β–blocking antibody prevented the emergence of such resistant tumor cells and induced complete tumor regression. Therefore, elevated levels of TGF-β in the tumor microenvironment enable tumor cells to evade ADCC and resist the antitumor activity of cetuximab in vivo. Our results show that TGF-β is a key molecular determinant of the de novo and acquired resistance of cancers to EGFR-targeted mAbs, and provide a rationale for combinatorial targeting of TGF-β to improve anti-EGFR–specific antibody therapy of EGFR-expressing cancers. Mol Cancer Ther; 11(11); 2429–39. ©2012 AACR.
Data from Hsp90 Inhibitor–Mediated Disruption of Chaperone Association of ATR with Hsp90 Sensitizes Cancer Cells to DNA Damage
Authors: Ha Kyungsoo , Fiskus Warren , Rao Rekha , Balusu Ramesh , Venkannagari Sreedhar , Nalabothula Narasimha Rao , Bhalla Kapil N.
Published: April 2023

Abstract
Following DNA damage that results in stalled replication fork, activation of ATR-CHK1 signaling induces the DNA damage response (DDR) in transformed cells. In the present studies on human cervical and breast cancer cells, we determined the effects of hsp90 inhibition on the levels and accumulation of DNA damage/repair–associated proteins following exposure to γ-ionizing radiation (IR; 4 Gy). We show that hsp90 inhibition with 17-allylamino-demehoxygeldanamycin or the novel, nongeldanamycin analogue AUY922 (resorcinylic isoxazole amide; Novartis Pharma) dose-dependently reduced the levels of ATR and CHK1 without affecting ATM levels. AUY922-mediated depletion of ATR and CHK1 was associated with an increase in their polyubiquitylation and decreased binding to hsp90. Cotreatment with bortezomib partially restored AUY922-mediated depletion of ATR and CHK1 levels. Additionally, treatment with AUY922 reduced the accumulation of ATR, p53BP1, and CHK1 but not γ-H2AX to the sites of DNA damage. Following exposure to IR, AUY922 treatment abrogated IR-induced phospho (p)-ATR and p-CHK1 levels, but significantly enhanced γ-H2AX levels. AUY922 treatment also increased IR-induced accumulation of the cells in G2–M phase of the cell cycle, inhibited the repair of IR-induced DNA damage, and augmented IR-mediated loss of clonogenic survival. Short hairpin RNA–mediated depletion of ATR also inhibited IR-induced p-ATR and p-CHK1, but increased γ-H2AX levels, sensitizing cancer cells to IR-induced apoptosis and loss of clonogenic survival. These findings indicate that ATR is a bona fide hsp90 client protein and post-IR administration of AUY922, by inhibiting ATR-CHK1–mediated DDR, sensitizes cancer cells to IR. Mol Cancer Ther; 10(7); 1194–206. ©2011 AACR.
Data from An Integrated Chemical Biology Approach Identifies Specific Vulnerability of Ewing's Sarcoma to Combined Inhibition of Aurora Kinases A and B
Authors: Winter Georg E. , Rix Uwe , Lissat Andrej , Stukalov Alexey , Müllner Markus K. , Bennett Keiryn L. , Colinge Jacques , Nijman Sebastian M. , Kubicek Stefan , Kovar Heinrich , Kontny Udo , Superti-Furga Giulio
Published: April 2023

Abstract
Ewing's sarcoma is a pediatric cancer of the bone that is characterized by the expression of the chimeric transcription factor EWS-FLI1 that confers a highly malignant phenotype and results from the chromosomal translocation t(11;22)(q24;q12). Poor overall survival and pronounced long-term side effects associated with traditional chemotherapy necessitate the development of novel, targeted, therapeutic strategies. We therefore conducted a focused viability screen with 200 small molecule kinase inhibitors in 2 different Ewing's sarcoma cell lines. This resulted in the identification of several potential molecular intervention points. Most notably, tozasertib (VX-680, MK-0457) displayed unique nanomolar efficacy, which extended to other cell lines, but was specific for Ewing's sarcoma. Furthermore, tozasertib showed strong synergies with the chemotherapeutic drugs etoposide and doxorubicin, the current standard agents for Ewing's sarcoma. To identify the relevant targets underlying the specific vulnerability toward tozasertib, we determined its cellular target profile by chemical proteomics. We identified 20 known and unknown serine/threonine and tyrosine protein kinase targets. Additional target deconvolution and functional validation by RNAi showed simultaneous inhibition of Aurora kinases A and B to be responsible for the observed tozasertib sensitivity, thereby revealing a new mechanism for targeting Ewing's sarcoma. We further corroborated our cellular observations with xenograft mouse models. In summary, the multilayered chemical biology approach presented here identified a specific vulnerability of Ewing's sarcoma to concomitant inhibition of Aurora kinases A and B by tozasertib and danusertib, which has the potential to become a new therapeutic option. Mol Cancer Ther; 10(10); 1846–56. ©2011 AACR.
Data from Overexpression of Mitotic Centromere–Associated Kinesin Stimulates Microtubule Detachment and Confers Resistance to Paclitaxel
Authors: Ganguly Anutosh , Yang Hailing , Cabral Fernando
Published: April 2023

Abstract
Numerous studies have implicated mutations in tubulin or the overexpression of specific tubulin genes in resistance to microtubule-targeted drugs. Much less is known about the role of accessory proteins that modulate microtubule behavior in the genesis of drug resistance. Here, we examine mitotic centromere–associated kinesin (MCAK), a member of the kinesin family of microtubule motor proteins that has the ability to stimulate microtubule depolymerization, and show that overexpressing the protein confers resistance to paclitaxel and epothilone A, but increases sensitivity to colcemid. Cells transfected with FLAG-tagged MCAK cDNA using a tet-off–regulated expression system had a disrupted microtubule cytoskeleton and were able to survive a toxic concentration of paclitaxel in the absence, but not in the presence of tetracycline, showing that drug resistance was caused by ectopic MCAK production. Moreover, a population that was heterogeneous with respect to FLAG-MCAK expression became enriched with cells that produced the ectopic protein when it was placed under paclitaxel selection. Similar to previously isolated mutants with altered tubulin, paclitaxel resistant cells resulting from MCAK overexpression were found to have decreased microtubule polymer and a seven-fold increase in the frequency of microtubule detachment from centrosomes. These data are consistent with a model for paclitaxel resistance that is based on stability of the attachment of microtubules to their nucleating centers, and they implicate MCAK in the mechanism of microtubule detachment. Mol Cancer Ther; 10(6); 929–37. ©2011 AACR.
Data from Restitution of Tumor Suppressor MicroRNAs Using a Systemic Nanovector Inhibits Pancreatic Cancer Growth in Mice
Authors: Pramanik Dipankar , Campbell Nathaniel R. , Karikari Collins , Chivukula Raghu , Kent Oliver A. , Mendell Joshua T. , Maitra Anirban
Published: April 2023

Abstract
Mis-expression of microRNAs (miRNA) is widespread in human cancers, including in pancreatic cancer. Aberrations of miRNA include overexpression of oncogenic miRs (Onco-miRs) or downregulation of so-called tumor suppressor TSG-miRs. Restitution of TSG-miRs in cancer cells through systemic delivery is a promising avenue for pancreatic cancer therapy. We have synthesized a lipid-based nanoparticle for systemic delivery of miRNA expression vectors to cancer cells (nanovector). The plasmid DNA–complexed nanovector is approximately 100 nm in diameter and shows no apparent histopathologic or biochemical evidence of toxicity upon intravenous injection. Two miRNA candidates known to be downregulated in the majority of pancreatic cancers were selected for nanovector delivery: miR-34a, which is a component of the p53 transcriptional network and regulates cancer stem cell survival, and the miR-143/145 cluster, which together repress the expression of KRAS2 and its downstream effector Ras-responsive element binding protein-1 (RREB1). Systemic intravenous delivery with either miR-34a or miR-143/145 nanovectors inhibited the growth of MiaPaCa-2 subcutaneous xenografts (P < 0.01 for miR-34a; P < 0.05 for miR-143/145); the effects were even more pronounced in the orthotopic (intrapancreatic) setting (P < 0.0005 for either nanovector) when compared with vehicle or mock nanovector delivering an empty plasmid. Tumor growth inhibition was accompanied by increased apoptosis and decreased proliferation. The miRNA restitution was confirmed in treated xenografts by significant upregulation of the corresponding miRNA and significant decreases in specific miRNA targets (SIRT1, CD44 and aldehyde dehydrogenase for miR34a, and KRAS2 and RREB1 for miR-143/145). The nanovector is a platform with potential broad applicability in systemic miRNA delivery to cancer cells. Mol Cancer Ther; 10(8); 1470–80. ©2011 AACR.
Data from Synthetic Triterpenoid Cyano Enone of Methyl Boswellate Activates Intrinsic, Extrinsic, and Endoplasmic Reticulum Stress Cell Death Pathways in Tumor Cell Lines
Authors: Ravanan Palaniyandi , Sano Renata , Talwar Priti , Ogasawara Satoshi , Matsuzawa Shu-ichi , Cuddy Michael , Singh Sanjay K. , Rao G.S.R. Subba , Kondaiah Paturu , Reed John C.
Published: April 2023

Abstract
We explored the effect of a novel synthetic triterpenoid compound cyano enone of methyl boswellates (CEMB) on various prostate cancer and glioma cancer cell lines. CEMB displayed concentration-dependent cytotoxic activity with submicromolar lethal dose 50% (LD50) values in 10 of 10 tumor cell lines tested. CEMB-induced cytotoxicity is accompanied by activation of downstream effector caspases (caspases 3 and 7) and by upstream initiator caspases involved in both the extrinsic (caspase 8) and intrinsic (caspase 9) apoptotic pathways. By using short interfering RNAs (siRNA), we show evidence that knockdown of caspase 8, DR4, Apaf-1, and Bid impairs CEMB-induced cell death. Similar to other proapoptotic synthetic triterpenoid compounds, CEMB-induced apoptosis involved endoplasmic reticulum stress, as shown by partial rescue of tumor cells by siRNA-mediated knockdown of expression of genes involved in the unfolded protein response such as IRE1α, PERK, and ATF6. Altogether, our results suggest that CEMB stimulates several apoptotic pathways in cancer cells, suggesting that this compound should be evaluated further as a potential agent for cancer therapy. Mol Cancer Ther; 10(9); 1635–43. ©2011 AACR.
Data from Molecular and Cellular Pharmacology of the Novel Noncamptothecin Topoisomerase I Inhibitor Genz-644282
Authors: Sooryakumar Dhriti , Dexheimer Thomas S. , Teicher Beverly A. , Pommier Yves
Published: April 2023

Abstract
Camptothecin derivatives are powerful anticancer drugs because of their ability to trap topoisomerase I (Top1)–DNA cleavage complexes. However, they exhibit clinical limitations due to the instability of their α-hydroxylactone six-membered E-ring structure. In addition, they exhibit bone marrow and intestinal toxicity, especially in adults, and are drug efflux substrates. Here, we report a novel Top1 inhibitor, Genz-644282. We show that Genz-644282 and its metabolites induce Top1 cleavage at similar, as well as unique genomic positions, compared with camptothecin. The compound also induces protein-linked DNA breaks and Top1–DNA cleavage complexes that persist longer after compound removal than camptothecin. Concentration-dependent and persistent γH2AX formation was readily observed in cells treated with Genz-644282, and was present in greater than 50% of the cell population following 24 hours compound exposure. The compound shows partial cross-resistance in cell lines resistant to camptothecin. These cell lines include the human prostate DU145RC0.1 and the leukemic CEM/C2 cells. Limited cross-resistance to Genz-644282 was also found in the Top1 knockdown colon cancer (HCT116) and breast cancer (MCF7) cell lines and in human adenocarcinoma cells (KB31/KBV1) that overexpress (P-glycoprotein, ABCB1), a member of the ATP-binding cassette family of cell surface transport proteins known to confer MDR. Together, our results provide the first molecular and cellular characterization of Genz-644282 and its clinically relevant metabolites. Mol Cancer Ther; 10(8); 1490–9. ©2011 AACR.
Data from Therapeutic Potential and Molecular Mechanism of a Novel, Potent, Nonpeptide, Smac Mimetic SM-164 in Combination with TRAIL for Cancer Treatment
Authors: Lu Jianfeng , McEachern Donna , Sun Haiying , Bai Longchuan , Peng Yuefeng , Qiu Su , Miller Rebecca , Liao Jinhui , Yi Han , Liu Meilan , Bellail Anita , Hao Chunhai , Sun Shi-Yong , Ting Adrian T. , Wang Shaomeng
Published: April 2023

Abstract
Smac mimetics are being developed as a new class of anticancer therapies. Because the single-agent activity of Smac mimetics is very limited, rational combinations represent a viable strategy for their clinical development. The combination of Smac mimetics with TNF-related apoptosis inducing ligand (TRAIL) may be particularly attractive because of the low toxicity of TRAIL to normal cells and the synergistic antitumor activity observed for the combination. In this study, we have investigated the combination synergy between TRAIL and a potent Smac mimetic, SM-164, in vitro and in vivo and the underlying molecular mechanism of action for the synergy. Our study shows that SM-164 is highly synergistic with TRAIL in vitro in both TRAIL-sensitive and TRAIL-resistant cancer cell lines of breast, prostate, and colon cancer. Furthermore, the combination of SM-164 with TRAIL induces rapid tumor regression in vivo in a breast cancer xenograft model in which either agent is ineffective. Our data show that X-linked IAP (XIAP) and cellular IAP 1 (cIAP1), but not cIAP2, work in concert to attenuate the activity of TRAIL; SM-164 strongly enhances TRAIL activity by concurrently targeting XIAP and cIAP1. Moreover, although RIP1 plays a minimal role in the activity of TRAIL as a single agent, it is required for the synergistic interaction between TRAIL and SM-164. This study provides a strong rationale to develop the combination of SM-164 and TRAIL as a new therapeutic strategy for the treatment of human cancer. Mol Cancer Ther; 10(5); 902–14. ©2011 AACR.
Data from Melanoma Prognosis: A REMARK-Based Systematic Review and Bioinformatic Analysis of Immunohistochemical and Gene Microarray Studies
Authors: Schramm Sarah-Jane , Mann Graham J.
Published: April 2023

Abstract
Despite intensive research efforts, within-stage survival rates for melanoma vary widely. Pursuit of molecular biomarkers with improved prognostic significance over clinicohistological measures has produced extensive literature. Reviews have synthesized these data, but none have systematically partitioned high-quality studies from the remainder across different molecular methods nor examined system properties of that output. Databases were searched for studies analyzing protein expression by immunohistochemistry (n = 617, extending the only systematic review to date by 102 studies) or for gene expression microarray studies (n = 45) in melanoma in relation to outcome. REMARK-derived criteria were applied to identify high-quality studies. Biomarkers and pathways were functionally assessed by using gene ontology software. Most manuscripts did not meet REMARK-based criteria, an ongoing trend that can impede translational research. Across REMARK-compliant literature, 41 proteins were significantly associated with outcome. Multimarker tests consistently emerged among the most promising potential biomarkers, indicating a need to continue assessing candidates in that composite setting. Twenty-one canonical pathways were populated by outcome-related proteins but not by those that failed to show such an association; we propose that this set of pathways warrants closer investigation to understand drivers of poor outcome in melanoma. Two-gene expression microarray studies met REMARK-based criteria reflecting a genuine paucity of literature in the area. The 254 outcome-related genes were examined for correspondences with the systematically identified protein signature. This analysis highlighted proliferating cell nuclear antigen and survivin as priorities for further examination as biomarkers in melanoma prognosis, and illustrated ongoing need to integrate alternative approaches to biomarker discovery in melanoma translational research. Mol Cancer Ther; 10(8); 1520–8. ©2011 AACR.
Data from Trabectedin and Its C Subunit Modified Analogue PM01183 Attenuate Nucleotide Excision Repair and Show Activity toward Platinum-Resistant Cells
Authors: Soares Daniele G. , Machado Miriana S. , Rocca Céline J. , Poindessous Virginie , Ouaret Djamila , Sarasin Alain , Galmarini Carlos M. , Henriques João A.P. , Escargueil Alexandre E. , Larsen Annette K.
Published: April 2023

Abstract
PM01183 is a novel marine-derived covalent DNA binder in clinical development. PM01183 is structurally similar to trabectedin (yondelis, ecteinascidin-743) except for the C subunit, and this modification is accompanied by different pharmacokinetics in cancer patients. We here characterize the interaction of PM01183 with the nucleotide excision repair (NER) pathway in comparison with trabectedin. Our results show for the first time that although neither PM01183 nor trabectedin is repaired by NER, both compounds are able to interfere with the NER machinery thereby attenuating the repair of specific NER substrates. We further show that the NER activity is increased in 3 of 4 cellular models with acquired resistance to cisplatin or oxaliplatin, confirming the involvement of NER in the resistance to platinum derivatives. Importantly, both PM01183 and trabectedin show unchanged or even enhanced activity toward all 4 cisplatin- and oxaliplatin-resistant cell lines. We finally show that combinations of PM01183 and cisplatin were mostly synergistic toward both parental and cisplatin-resistant ovarian carcinoma cells as indicated by Chou and Talalay analysis. These data show that the C subunit of trabectedin can be subjected to at least some structural modifications without loss of activity or NER interaction. While PM01183 and trabectedin appear functionally similar in cellular models, it is likely that the differences in pharmacokinetics may allow different dosing and scheduling of PM01183 in the clinic that could lead to novel and/or increased antitumor activity. Taken together, our results provide a mechanistic basis to support clinical trials of PM01183 alone or in combination with cisplatin. Mol Cancer Ther; 10(8); 1481–9. ©2011 AACR.
Data from Interactions of Tyrosine Kinase Inhibitors with Organic Cation Transporters and Multidrug and Toxic Compound Extrusion Proteins
Authors: Minematsu Tsuyoshi , Giacomini Kathleen M.
Published: April 2023

Abstract
The drug–drug interaction (DDI) potential of tyrosine kinase inhibitors (TKI) as interacting drugs via transporter inhibition has not been fully assessed. Here, we estimated the half maximal inhibitory concentration (IC50) values for 8 small-molecule TKIs (imatinib, dasatinib, nilotinib, gefitinib, erlotinib, sunitinib, lapatinib, and sorafenib) on [14C]metformin transport by human organic cation transporters (OCT), OCT1, OCT2, and OCT3, and multidrug and toxic compound extrusion (MATE) proteins, MATE1 and MATE2-K, using human embryonic kidney cells stably expressing these transporters. We then compared the estimated IC50 values to the maximum clinical concentrations of unbound TKIs in plasma (unbound Cmax,sys,p). Results showed that imatinib, nilotinib, gefitinib, and erlotinib exerted selectively potent inhibitory effects, with unbound Cmax,sys,p/IC50 values ≥0.1, on MATE1, OCT3, MATE2-K, and OCT1, respectively. In comparison to the common form of OCT1, the OCT1 polymorphism, M420del, was more sensitive to drug inhibition by erlotinib. Major metabolites of several TKIs showed IC50 values similar to those for unchanged TKIs. Taken together, these findings suggest the potential of clinical transporter-mediated DDIs between specific TKIs and OCTs and MATEs, which may affect the disposition, efficacy, and toxicity of metformin and other drugs that are substrates of these transporters. The study provides the basis for further clinical DDI studies with TKIs. Mol Cancer Ther; 10(3); 531–9. ©2011 AACR.
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: April 2023

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 Death Receptor Pathway Activation and Increase of ROS Production by the Triple Epigenetic Inhibitor UVI5008
Authors: Nebbioso Angela , Pereira Raquel , Khanwalkar Harshal , Matarese Filomena , García-Rodríguez José , Miceli Marco , Logie Colin , Kedinger Valerie , Ferrara Felicetto , Stunnenberg Hendrik G. , de Lera Angel R. , Gronemeyer Hinrich , Altucci Lucia
Published: April 2023

Abstract
Deregulation of the epigenome is recognized as cause of cancer and epigenetic factors are receiving major attention as therapeutic targets; yet, the molecular mode of action of existing epi-drugs is largely elusive. Here, we report on the decryption of the mechanism of action of UVI5008, a novel epigenetic modifier, that inhibits histone deacetylases, sirtuins, and DNA methyltransferases. UVI5008 highly efficiently induces cancer cell–selective death in a variety of models and exerts its activities in several human tumor xenografts and genetic mouse models of human breast cancer in vivo. Its anticancer activity involves independent activation of death receptors and reactive oxygen species production. Importantly, UVI5008 action is not critically dependent on p53, Bcl-2 modifying factor, and/or TNF-related apoptosis-inducing ligand as cell death is efficiently induced in cells mutated or deficient for these factors limiting the risk of drug resistance development and maximizing its application spectrum. The simultaneous modulation of multiple (epigenetic) targets promises to open new avenues with unanticipated potential against cancer. Mol Cancer Ther; 10(12); 2394–404. ©2011 AACR.
Data from Characterization of an Oxaliplatin Sensitivity Predictor in a Preclinical Murine Model of Colorectal Cancer
Authors: Kim Mickey K. , Osada Takuya , Barry William T. , Yang Xiao Yi , Freedman Jennifer A. , Tsamis Katherine A. , Datto Michael , Clary Bryan M. , Clay Timothy , Morse Michael A. , Febbo Philip G. , Lyerly H. Kim , Hsu David S.
Published: April 2023

Abstract
Despite advances in contemporary chemotherapeutic strategies, long-term survival still remains elusive for patients with metastatic colorectal cancer. A better understanding of the molecular markers of drug sensitivity to match therapy with patient is needed to improve clinical outcomes. In this study, we used in vitro drug sensitivity data from the NCI-60 cell lines together with their Affymetrix microarray data to develop a gene expression signature to predict sensitivity to oxaliplatin. To validate our oxaliplatin sensitivity signature, patient-derived colorectal cancer explants (PDCCE) were developed in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice from resected human colorectal tumors. Analysis of gene expression profiles found similarities between the PDCCEs and their parental human tumors, suggesting their utility to study drug sensitivity in vivo. The oxaliplatin sensitivity signature was then validated in vivo with response data from 14 PDCCEs treated with oxaliplatin and was found to have an accuracy of 92.9% (sensitivity = 87.5%; specificity = 100%). Our findings suggest that PDCCEs can be a novel source to study drug sensitivity in colorectal cancer. Furthermore, genomic-based analysis has the potential to be incorporated into future strategies to optimize individual therapy for patients with metastatic colorectal cancer. Mol Cancer Ther; 11(7); 1500–9. ©2012 AACR.