bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from CDK-4 Inhibitor P276 Sensitizes Pancreatic Cancer Cells to Gemcitabine-Induced Apoptosis
Authors: Subramaniam Dharmalingam , Periyasamy Giridharan , Ponnurangam Sivapriya , Chakrabarti Debarshi , Sugumar Aravind , Padigaru Muralidhara , Weir Scott J. , Balakrishnan Arun , Sharma Somesh , Anant Shrikant
Published: March 2024

Abstract
Despite advances in molecular pathogenesis, pancreatic cancer remains a major unsolved health problem. It is a rapidly invasive, metastatic tumor that is resistant to standard therapies. The phosphatidylinositol-3-kinase/Akt and mTOR signaling pathways are frequently dysregulated in pancreatic cancer. Gemcitabine is the mainstay treatment for metastatic pancreatic cancer. P276 is a novel CDK inhibitor that induces G2/M arrest and inhibits tumor growth in vivo models. Here, we determined that P276 sensitizes pancreatic cancer cells to gemcitabine-induced apoptosis, a mechanism-mediated through inhibition of Akt-mTOR signaling. In vitro, the combination of P276 and gemcitabine resulted in a dose- and time-dependent inhibition of proliferation and colony formation of pancreatic cancer cells but not with normal pancreatic ductal cells. This combination also induced apoptosis, as seen by activated caspase-3 and increased Bax/Bcl2 ratio. Gene profiling studies showed that this combination downregulated Akt-mTOR signaling pathway, which was confirmed by Western blot analyses. There was also a downregulation of VEGF and interleukin-8 expression suggesting effects on angiogenesis pathway. In vivo, intraperitoneal administration of the P276-Gem combination significantly suppressed the growth of pancreatic cancer tumor xenografts. There was a reduction in CD31-positive blood vessels and reduced VEGF expression, again suggesting an effect on angiogenesis. Taken together, these data suggest that P276-Gem combination is a novel potent therapeutic agent that can target the Akt-mTOR signaling pathway to inhibit both tumor growth and angiogenesis. Mol Cancer Ther; 11(7); 1598–608. ©2012 AACR.
Data from Dacomitinib (PF-00299804), an Irreversible Pan-HER Inhibitor, Inhibits Proliferation of HER2-Amplified Breast Cancer Cell Lines Resistant to Trastuzumab and Lapatinib
Authors: Kalous Ondrej , Conklin Dylan , Desai Amrita J. , O'Brien Neil A. , Ginther Charles , Anderson Lee , Cohen David J. , Britten Carolyn D. , Taylor Ian , Christensen James G. , Slamon Dennis J. , Finn Richard S.
Published: March 2024

Abstract
The human EGF (HER) family of receptors has been pursued as therapeutic targets in breast cancer and other malignancies. Trastuzumab and lapatinib are standard treatments for HER2-amplified breast cancer, but a significant number of patients do not respond or develop resistance to these drugs. Here we evaluate the in vitro activity of dacomitinib (PF-00299804), an irreversible small molecule pan-HER inhibitor, in a large panel of human breast cancer cell lines with variable expression of the HER family receptors and ligands, and with variable sensitivity to trastuzumab and lapatinib. Forty-seven human breast cancer and immortalized breast epithelial lines representing the known molecular subgroups of breast cancer were treated with dacomitinib to determine IC50 values. HER2-amplified lines were far more likely to respond to dacomitinib than nonamplified lines (RR, 3.39; P < 0.0001). Furthermore, HER2 mRNA and protein expression were quantitatively associated with response. Dacomitinib reduced the phosphorylation of HER2, EGFR, HER4, AKT, and ERK in the majority of sensitive lines. Dacomitinib exerted its antiproliferative effect through a combined G0–G1 arrest and an induction of apoptosis. Dacomitinib inhibited growth in several HER2-amplified lines with de novo and acquired resistance to trastuzumab. Dacomitinib maintained a high activity in lines with acquired resistance to lapatinib. This study identifies HER2-amplified breast cancer lines as most sensitive to the antiproliferative effect of dacomitinib and provides a strong rationale for its clinical testing in HER2-amplified breast cancers resistant to trastuzumab and lapatinib. Mol Cancer Ther; 11(9); 1978–87. ©2012 AACR.
Data from Attenuation of Argininosuccinate Lyase Inhibits Cancer Growth via Cyclin A2 and Nitric Oxide
Authors: Huang Hau-Lun , Hsu Hui-Ping , Shieh Shu-Chu , Chang Yung-Sheng , Chen Wei-Ching , Cho Chien-Yu , Teng Chiao-Fang , Su Ih-Jen , Hung Wen-Chun , Lai Ming-Derg
Published: March 2024

Abstract
Arginine biosynthesis and nitric oxide (NO) production are important for cancer homeostasis. Degradation of arginine may be used to inhibit liver tumors with low argininosuccinate synthetase (ASS) expression. In this report, we investigated an alternative therapeutic approach by targeting argininosuccinate lyase (ASL). ASL is transcriptionally induced by endoplasmic reticulum stress and is overexpressed in some human liver tumors. Knockdown of ASL expression by short hairpin RNA (shRNA) in three liver cancer cell lines, ML-1, HuH-7, and HepG2, decreased colony formation in vitro and tumor growth in vivo. Furthermore, lentiviral infection of ASL shRNA inhibited tumor growth in a therapeutic animal tumor model. Analysis of ASL shRNA on the cell-cycle progression revealed a G2–M delay. Among cell-cycle regulatory molecules, cyclin A2 expression was reduced. Reintroduction of exogenous cyclin A2 restored the cell growth in ASL-knockdown cells. Autophagy was observed in the cells treated with ASL shRNA, as shown by an increase in LC3-II levels and autophagosome formation. The total cellular arginine level was not altered significantly. Inhibition of autophagy further attenuated cell growth, suggesting that autophagy induced by ASL shRNA plays a feedback prosurvival function. Knockdown of ASL reduced NO content, and addition of NO donor partially recovered the growth inhibition by ASL shRNA. In summary, downregulation of ASL attenuated tumor growth and the inhibition was mainly mediated by a decrease of cyclin A2 and NO. Mol Cancer Ther; 12(11); 2505–16. ©2013 AACR.
Data from miRNA-100 Inhibits Human Bladder Urothelial Carcinogenesis by Directly Targeting mTOR
Authors: Xu Chuanliang , Zeng Qinsong , Xu Weidong , Jiao Li , Chen Yanqiong , Zhang Zhensheng , Wu Chengyao , Jin Taile , Pan Anyin , Wei Rongchao , Yang Bo , Sun Yinghao
Published: March 2024

Abstract
miRNAs are involved in cancer development and progression, acting as tumor suppressors or oncogenes. In this study, miRNA profiling was conducted on 10 paired bladder cancer tissues using 20 GeneChip miRNA Array, and 10 differentially expressed miRNAs were identified in bladder cancer and adjacent noncancerous tissues of any disease stage/grade. After being validated on expanded cohort of 67 paired bladder cancer tissues and 10 human bladder cancer cell lines by quantitative real-time PCR (qRT-PCR), it was found that miR-100 was downregulated most significantly in cancer tissues. Ectopic restoration of miR-100 expression in bladder cancer cells suppressed cell proliferation and motility, induced cell-cycle arrest in vitro, and inhibited tumorigenesis in vivo both in subcutaneous and in intravesical passage. Bioinformatic analysis showed that the mTOR gene was a direct target of miR-100. siRNA-mediated mTOR knockdown phenocopied the effect of miR-100 in bladder cancer cell lines. In addition, the cancerous metastatic nude mouse model established on the basis of primary bladder cancer cell lines suggested that miR-100/mTOR regulated cell motility and was associated with tumor metastasis. Both mTOR and p70S6K (downstream messenger) presented higher expression levels in distant metastatic foci such as in liver and kidney metastases than in primary tumor. Taken together, miR-100 may act as a tumor suppressor in bladder cancer, and reintroduction of this mature miRNA into tumor tissue may prove to be a therapeutic strategy by reducing the expression of target genes. Mol Cancer Ther; 12(2); 207–19. ©2012 AACR.
Data from Preclinical Analysis of the γ-Secretase Inhibitor PF-03084014 in Combination with Glucocorticoids in T-cell Acute Lymphoblastic Leukemia
Authors: Samon Jeremy B. , Castillo-Martin Mireia , Hadler Michael , Ambesi-Impiobato Alberto , Paietta Elisabeth , Racevskis Janis , Wiernik Peter H. , Rowe Jacob M. , Jakubczak John , Randolph Sophia , Cordon-Cardo Carlos , Ferrando Adolfo A.
Published: March 2024

Abstract
T-cell acute lymphoblastic leukemias (T-ALL) and lymphomas are aggressive hematologic cancers frequently associated with activating mutations in NOTCH1. Early studies identified NOTCH1 as an attractive therapeutic target for the treatment of T-ALL through the use of γ-secretase inhibitors (GSI). Here, we characterized the interaction between PF-03084014, a clinically relevant GSI, and dexamethasone in preclinical models of glucocorticoid-resistant T-ALL. Combination treatment of the GSI PF-03084014 with glucocorticoids induced a synergistic antileukemic effect in human T-ALL cell lines and primary human T-ALL patient samples. Mechanistically PF-03084014 plus glucocorticoid treatment induced increased transcriptional upregulation of the glucocorticoid receptor and glucocorticoid target genes. Treatment with PF-03084014 and glucocorticoids in combination was highly efficacious in vivo, with enhanced reduction of tumor burden in a xenograft model of T-ALL. Finally, glucocorticoid treatment effectively reversed PF-03084014–induced gastrointestinal toxicity via inhibition of goblet cell metaplasia. These results warrant the analysis of PF-03084014 and glucocorticoids in combination for the treatment of glucocorticoid-resistant T-ALL. Mol Cancer Ther; 11(7); 1565–75. ©2012 AACR.
Data from Immunotherapy for Hepatoma Using a Dual-Function Vector with Both Immunostimulatory and Pim-3–Silencing Effects
Authors: Guo Qie , Lan Peixiang , Yu Xin , Han Qiuju , Zhang Jian , Tian Zhigang , Zhang Cai
Published: March 2024

Abstract
Tumorigenesis is an immortalization process in which the growth of normal cells is uncontrolled and programmed cell death is suppressed. Molecular biologic and immunologic studies have revealed that the aberrant expression of some proto-oncogenes boosts proliferation and inhibits apoptosis, which is vital for tumor development. The hypofunction of the host immune system also drives the development and metastasis of malignant tumors. Pim-3, a member of the Pim family, is aberrantly expressed in several cancers. Data suggest that Pim-3 inhibits apoptosis by phosphorylating the proapoptotic BH3-only protein Bad. Here, we constructed a dual-function small hairpin RNA (shRNA) vector containing an shRNA targeting Pim-3 and a TLR7-stimulating ssRNA. Stimulation with this bi-functional vector in vitro promoted significant apoptosis of Hepa1-6 cells by regulating the expression of apoptosis-related proteins and induced secretion of type I IFNs. Most importantly, this bi-functional vector more effectively inhibited subcutaneous Hepa1-6 cell growth than did single shRNA and ssRNA treatment in vivo. Natural killer (NK), CD4+ T, and CD8+ T cells and macrophages were required for effective tumor suppression, and CD4+ T cells were shown to play a helper role in the activation of NK cells, possibly by regulating the secretion of Th1 or Th2 cytokines. This ssRNA–shRNA bi-functional vector may represent a promising approach for tumor therapy. Mol Cancer Ther; 13(6); 1503–13. ©2014 AACR.
Data from Drug Repurposing for Gastrointestinal Stromal Tumor
Authors: Pessetto Ziyan Y. , Weir Scott J. , Sethi Geetika , Broward Melinda A. , Godwin Andrew K.
Published: March 2024

Abstract
Despite significant treatment advances over the past decade, metastatic gastrointestinal stromal tumor (GIST) remains largely incurable. Rare diseases, such as GIST, individually affect small groups of patients but collectively are estimated to affect 25 to 30 million people in the United States alone. Given the costs associated with the discovery, development, and registration of new drugs, orphan diseases such as GIST are often not pursued by mainstream pharmaceutical companies. As a result, “drug repurposing” or “repositioning,” has emerged as an alternative to the traditional drug development process. In this study, we screened 796 U.S. Food and Drug Administration (FDA)-approved drugs and found that two of these compounds, auranofin (Ridaura) and fludarabine phosphate, effectively and selectively inhibited the proliferation of GISTs, including imatinib-resistant cells. One of the most notable drug hits, auranofin, an oral, gold-containing agent approved by the FDA in 1985 for the treatment of rheumatoid arthritis, was found to inhibit thioredoxin reductase activity and induce reactive oxygen species (ROS) production, leading to dramatic inhibition of GIST cell growth and viability. Importantly, the anticancer activity associated with auranofin was independent of imatinib-resistant status, but was closely related to the endogenous and inducible levels of ROS. Coupled with the fact that auranofin has an established safety profile in patients, these findings suggest for the first time that auranofin may have clinical benefit for patients with GIST, particularly in those suffering from imatinib-resistant and recurrent forms of this disease. Mol Cancer Ther; 12(7); 1299–309. ©2013 AACR.
Data from Bisphosphonamidate Clodronate Prodrug Exhibits Selective Cytotoxic Activity against Melanoma Cell Lines
Authors: Webster Marie R. , Kamat Chandrashekhar , Connis Nick , Zhao Ming , Weeraratna Ashani T. , Rudek Michelle A. , Hann Christine L. , Freel Meyers Caren L.
Published: March 2024

Abstract
Bisphosphonates are used clinically to treat disorders of calcium metabolism and malignant bone disease and are known to inhibit cancer cell growth, adhesion, and invasion. However, clinical use of these agents for the treatment of extraskeletal disease is limited because of low cell permeability. We recently described a bisphosphonamidate prodrug strategy for efficient intracellular release of bisphosphonates, including clodronate (CLO), in non–small cell lung cancer cells. To evaluate anticancer activity of this prodrug class across many cancer cell types, the bisphosphonamidate clodronate prodrug (CLO prodrug) was screened against the NCI-60 cell line panel, and was found to exhibit selectivity toward melanoma cell lines. Here, we confirm efficient cellular uptake and intracellular activation of this prodrug class in melanoma cells. We further demonstrate inhibition of melanoma cell proliferation, induction of apoptosis, and an antitumor effect of CLO prodrug in a xenograft model. These data suggest a novel therapeutic application for the CLO prodrug and potential to selectively target melanoma cells. Mol Cancer Ther; 13(2); 297–306. ©2013 AACR.
Data from NEO212, Temozolomide Conjugated to Perillyl Alcohol, Is a Novel Drug for Effective Treatment of a Broad Range of Temozolomide-Resistant Gliomas
Authors: Cho Hee-Yeon , Wang Weijun , Jhaveri Niyati , Lee David Jungpa , Sharma Natasha , Dubeau Louis , Schönthal Axel H. , Hofman Florence M. , Chen Thomas C.
Published: March 2024

Abstract
Patients with glioblastoma multiforme (GBM), a malignant primary brain tumor, inevitably develop resistance to standard-of-care chemotherapy, temozolomide. This study explores the effects of the novel agent NEO212, a conjugate of temozolomide to perillyl alcohol, on temozolomide-resistant gliomas. NEO212 was tested for cytotoxic activity on three human temozolomide-resistant glioma cell lines, which were resistant to temozolomide based on overexpression of the base excision repair (BER) pathway, mismatch repair (MMR) deficiency, or overexpression of O6 methyl-guanine-DNA methyltransferase (MGMT). BER expression was evaluated by Western blotting and PARP activity. MMR deficiency was determined by Western blotting and microsatellite instability. MGMT overexpression was evaluated by Western blotting and O6-benzylguanine (O6BG) inhibition. For in vivo evaluation of NEO212, temozolomide-resistant glioma cells were implanted into immune-incompetent mice, and NEO212 was administered. NEO212, at equimolar concentrations of temozolomide, was more cytotoxic for temozolomide-resistant cells than temozolomide and not toxic to normal cells. NEO212-induced cell death in temozolomide-resistant glioma cells was independent of such mechanisms of resistance as high levels of MGMT, MMR deficiencies, or overexpression of BER proteins. NEO212 functions as a DNA alkylating agent, similar to temozolomide; however, this novel conjugate is unique for it may induce endoplasmic reticulum (ER) stress and inhibits autophagy. In vivo studies show that NEO212 reduces intracranial tumor growth and increases animal survival without significant toxicity. These results demonstrate that NEO212 is an effective drug against malignant gliomas that can be used for a broad range of newly diagnosed and temozolomide-resistant gliomas. Mol Cancer Ther; 13(8); 2004–17. ©2014 AACR.
Data from BCL-2 Hypermethylation Is a Potential Biomarker of Sensitivity to Antimitotic Chemotherapy in Endocrine-Resistant Breast Cancer
Authors: Stone Andrew , Cowley Mark J. , Valdes-Mora Fatima , McCloy Rachael A. , Sergio C. Marcelo , Gallego-Ortega David , Caldon C. Elizabeth , Ormandy Christopher J. , Biankin Andrew V. , Gee Julia M.W. , Nicholson Robert I. , Print Cristin G. , Clark Susan J. , Musgrove Elizabeth A.
Published: March 2024

Abstract
Overexpression of the antiapoptotic factor BCL-2 is a frequent feature of malignant disease and is commonly associated with poor prognosis and resistance to conventional chemotherapy. In breast cancer, however, high BCL-2 expression is associated with favorable prognosis, estrogen receptor (ER) positivity, and low tumor grade, whereas low expression is included in several molecular signatures associated with resistance to endocrine therapy. In the present study, we correlate BCL-2 expression and DNA methylation profiles in human breast cancer and in multiple cell models of acquired endocrine resistance to determine whether BCL-2 hypermethylation could provide a useful biomarker of response to cytotoxic therapy. In human disease, diminished expression of BCL-2 was associated with hypermethylation of the second exon, in a region that overlapped a CpG island and an ER-binding site. Hypermethylation of this region, which occurred in 10% of primary tumors, provided a stronger predictor of patient survival (P = 0.019) when compared with gene expression (n = 522). In multiple cell models of acquired endocrine resistance, BCL-2 expression was significantly reduced in parallel with increased DNA methylation of the exon 2 region. The reduction of BCL-2 expression in endocrine-resistant cells lowered their apoptotic threshold to antimitotic agents: nocodazole, paclitaxel, and the PLK1 inhibitor BI2536. This phenomenon could be reversed with ectopic expression of BCL-2, and rescued with the BCL-2 inhibitor ABT-737. Collectively, these data imply that BCL-2 hypermethylation provides a robust biomarker of response to current and next-generation cytotoxic agents in endocrine-resistant breast cancer, which may prove beneficial in directing therapeutic strategy for patients with nonresectable, metastatic disease. Mol Cancer Ther; 12(9); 1874–85. ©2013 AACR.
Data from Monensin Inhibits Canonical Wnt Signaling in Human Colorectal Cancer Cells and Suppresses Tumor Growth in Multiple Intestinal Neoplasia Mice
Authors: Tumova Lucie , Pombinho Antonio R. , Vojtechova Martina , Stancikova Jitka , Gradl Dietmar , Krausova Michaela , Sloncova Eva , Horazna Monika , Kriz Vitezslav , Machonova Olga , Jindrich Jindrich , Zdrahal Zbynek , Bartunek Petr , Korinek Vladimir
Published: March 2024

Abstract
The Wnt signaling pathway is required during embryonic development and for the maintenance of homeostasis in adult tissues. However, aberrant activation of the pathway is implicated in a number of human disorders, including cancer of the gastrointestinal tract, breast, liver, melanoma, and hematologic malignancies. In this study, we identified monensin, a polyether ionophore antibiotic, as a potent inhibitor of Wnt signaling. The inhibitory effect of monensin on the Wnt/β-catenin signaling cascade was observed in mammalian cells stimulated with Wnt ligands, glycogen synthase kinase-3 inhibitors, and in cells transfected with β-catenin expression constructs. Furthermore, monensin suppressed the Wnt-dependent tail fin regeneration in zebrafish and Wnt- or β-catenin–induced formation of secondary body axis in Xenopus embryos. In Wnt3a-activated HEK293 cells, monensin blocked the phoshorylation of Wnt coreceptor low-density lipoprotein receptor related protein 6 and promoted its degradation. In human colorectal carcinoma cells displaying deregulated Wnt signaling, monensin reduced the intracellular levels of β-catenin. The reduction attenuated the expression of Wnt signaling target genes such as cyclin D1 and SP5 and decreased the cell proliferation rate. In multiple intestinal neoplasia (Min) mice, daily administration of monensin suppressed progression of the intestinal tumors without any sign of toxicity on normal mucosa. Our data suggest monensin as a prospective anticancer drug for therapy of neoplasia with deregulated Wnt signaling. Mol Cancer Ther; 13(4); 812–22. ©2014 AACR.
Data from Inhibition of GSK-3 Induces Differentiation and Impaired Glucose Metabolism in Renal Cancer
Authors: Pal Krishnendu , Cao Ying , Gaisina Irina N. , Bhattacharya Santanu , Dutta Shamit K. , Wang Enfeng , Gunosewoyo Hendra , Kozikowski Alan P. , Billadeau Daniel D. , Mukhopadhyay Debabrata
Published: March 2024

Abstract
Glycogen synthase kinase-3 (GSK-3), a constitutively active serine/threonine kinase, is a key regulator of numerous cellular processes ranging from glycogen metabolism to cell-cycle regulation and proliferation. Consistent with its involvement in many pathways, it has also been implicated in the pathogenesis of various human diseases, including type II diabetes, Alzheimer disease, bipolar disorder, inflammation, and cancer. Consequently, it is recognized as an attractive target for the development of new drugs. In the present study, we investigated the effect of both pharmacologic and genetic inhibition of GSK-3 in two different renal cancer cell lines. We have shown potent antiproliferative activity of 9-ING-41, a maleimide-based GSK-3 inhibitor. The antiproliferative activity is most likely caused by G0–G1 and G2–M phase arrest as evident from cell-cycle analysis. We have established that inhibition of GSK-3 imparted a differentiated phenotype in renal cancer cells. We have also shown that GSK-3 inhibition induced autophagy, likely as a result of imbalanced energy homeostasis caused by impaired glucose metabolism. In addition, we have demonstrated the antitumor activity of 9-ING-41 in two different subcutaneous xenograft renal cell carcinoma tumor models. To our knowledge, this is the first report describing autophagy induction due to GSK-3 inhibition in renal cancer cells. Mol Cancer Ther; 13(2); 285–96. ©2013 AACR.
Data from Nonclinical Safety Evaluation of VX15/2503, a Humanized IgG4 Anti-SEMA4D Antibody
Authors: Leonard John E. , Fisher Terrence L. , Winter Laurie A. , Cornelius Chad A. , Reilly Christine , Smith Ernest S. , Zauderer Maurice
Published: March 2024

Abstract
The humanized IgG4 monoclonal antibody VX15/2503 bound with 1 to 5 nmol/L affinity to purified recombinant semaphorin 4D (SEMA4D; CD100) produced using murine, rat, cynomolgus macaque, and human sequences. The affinity for native SEMA4D expressed on macaque T lymphocytes was approximately 0.6 nmol/L. Tissues from rats and cynomolgus macaques demonstrated specific staining only with resident lymphocytes. Single-dose and one-month toxicology/PK studies used VX15/2503 dose levels of 0 to 100 mg/kg. No toxicity was observed with either species in these studies, thus the no observed adverse effect level (NOAEL) was 100 mg/kg. Cmax, exposure, and half-life values were similar for both rats and macaques. The NOAEL in a primate maximum feasible dose study was 200 mg/kg. Saturation of T-cell–associated SEMA4D occurred following administration of single doses of 0.1 mg/kg and above; five weekly injections of VX15/2503 at a dose level of 100 mg/kg produced saturation lasting for more than 120 and 130 days, respectively, for rats and primates. Macaques administered five weekly doses of VX15/2503 showed dose-dependent reductions of 2- to 3-fold in T-cell SEMA4D (cSEMA4D) expression levels compared with controls. Reduced cSEMA4D expression levels continued until serum antibody concentrations were 2 to 5 μg/mL, and thereafter normal cSEMA4D levels were restored. On the basis of these data, a phase I clinical study of the safety and tolerability of VX15/2503 was conducted, enrolling adult patients with advanced solid tumor diseases; a single-dose, dose escalation, phase I safety study was also initiated with subjects with multiple sclerosis. Mol Cancer Ther; 14(4); 964–72. ©2015 AACR.
Data from Anetumab Ravtansine: A Novel Mesothelin-Targeting Antibody–Drug Conjugate Cures Tumors with Heterogeneous Target Expression Favored by Bystander Effect
Authors: Golfier Sven , Kopitz Charlotte , Kahnert Antje , Heisler Iring , Schatz Christoph A. , Stelte-Ludwig Beatrix , Mayer-Bartschmid Anke , Unterschemmann Kerstin , Bruder Sandra , Linden Lars , Harrenga Axel , Hauff Peter , Scholle Frank-Detlef , Müller-Tiemann Beate , Kreft Bertolt , Ziegelbauer Karl
Published: March 2024

Abstract
Mesothelin is a tumor differentiation antigen frequently overexpressed in tumors such as mesothelioma, ovarian, pancreatic, and lung adenocarcinomas while showing limited expression in nonmalignant tissues. Mesothelin is therefore an attractive target for cancer therapy using antibody–drug conjugates (ADC). This study describes the detailed characterization of anetumab ravtansine, here referred to as BAY 94-9343, a novel ADC consisting of a human anti-mesothelin antibody conjugated to the maytansinoid tubulin inhibitor DM4 via a disulfide-containing linker. Binding properties of the anti-mesothelin antibody were analyzed using surface plasmon resonance, immunohistochemistry, flow cytometry, and fluorescence microscopy. Effects of BAY 94-9343 on cell proliferation were first studied in vitro and subsequently in vivo using subcutaneous, orthotopic, and patient-derived xenograft tumor models. The antibody binds to human mesothelin with high affinity and selectivity, thereby inducing efficient antigen internalization. In vitro, BAY 94-9343 demonstrated potent and selective cytotoxicity of mesothelin-expressing cells with an IC50 of 0.72 nmol/L, without affecting mesothelin-negative or nonproliferating cells. In vivo, BAY 94-9343 localized specifically to mesothelin-positive tumors and inhibited tumor growth in both subcutaneous and orthotopic xenograft models. In addition, BAY 94-9343 was able to induce a bystander effect on neighboring mesothelin-negative tumor cells. Antitumor efficacy of BAY 94-9343 correlated with the amount of mesothelin expressed and was generally superior to that of standard-of-care regimen resulting in complete tumor eradication in most of the models. BAY 94-9343 is a selective and highly potent ADC, and our data support its development for the treatment of patients with mesothelin-expressing tumors. Mol Cancer Ther; 13(6); 1537–48. ©2014 AACR.
Data from Combining Hedgehog Signaling Inhibition with Focal Irradiation on Reduction of Pancreatic Cancer Metastasis
Authors: Gu Dongsheng , Liu Hailan , Su Gloria H. , Zhang Xiaoli , Chin-Sinex Helen , Hanenberg Helmut , Mendonca Marc S. , Shannon Harlan E. , Chiorean E. Gabriela , Xie Jingwu
Published: March 2024

Abstract
Pancreatic cancer often presents in advanced stages and is unresponsive to conventional treatments. Thus, the need to develop novel treatment strategies for pancreatic cancer has never been greater. Here, we report that combination of focal irradiation with hedgehog (Hh) signaling inhibition exerts better than additive effects on reducing metastases. In an orthotopic model, we found that focal irradiation alone effectively reduced primary tumor growth but did not significantly affect metastasis. We hypothesized that cancer stem cells (CSC) of pancreatic cancer are responsible for the residual tumors following irradiation, which may be regulated by Hh signaling. To test our hypothesis, we showed that tumor metastasis in our model was accompanied by increased expression of CSC cell surface markers as well as Hh target genes. We generated tumor spheres from orthotopic pancreatic and metastatic tumors, which have elevated levels of CSC markers relative to the parental cells and elevated expression of Hh target genes. Irradiation of tumor spheres further elevated CSC cell surface markers and increased Hh target gene expression. Combination of Hh signaling inhibition with radiation had more than additive effects on tumor sphere regeneration in vitro. This phenotype was observed in two independent cell lines. In our orthotopic animal model, focal radiation plus Hh inhibition had more than additive effects on reducing lymph node metastasis. We identified several potential molecules in mediating Hh signaling effects. Taken together, our data provide a rationale for combined use of Hh inhibition with irradiation for clinical treatment of patients with pancreatic cancer. Mol Cancer Ther; 12(6); 1038–48. ©2013 AACR.
Data from Trifluridine Induces p53-Dependent Sustained G2 Phase Arrest with Its Massive Misincorporation into DNA and Few DNA Strand Breaks
Authors: Matsuoka Kazuaki , Iimori Makoto , Niimi Shinichiro , Tsukihara Hiroshi , Watanabe Sugiko , Kiyonari Shinichi , Kiniwa Mamoru , Ando Koji , Tokunaga Eriko , Saeki Hiroshi , Oki Eiji , Maehara Yoshihiko , Kitao Hiroyuki
Published: March 2024

Abstract
Trifluridine (FTD) is a key component of the novel oral antitumor drug TAS-102, which consists of FTD and a thymidine phosphorylase inhibitor. Like 5-fluoro-2′-deoxyuridine (FdUrd), a deoxynucleoside form of 5-fluorouracil metabolite, FTD is sequentially phosphorylated and not only inhibits thymidylate synthase activity, but is also incorporated into DNA. Although TAS-102 was effective for the treatment of refractory metastatic colorectal cancer in clinical trials, the mechanism of FTD-induced cytotoxicity is not completely understood. Here, we show that FTD as well as FdUrd induce transient phosphorylation of Chk1 at Ser345, and that this is followed by accumulation of p53 and p21 proteins in p53-proficient human cancer cell lines. In particular, FTD induced p53-dependent sustained arrest at G2 phase, which was associated with a proteasome-dependent decrease in the Cyclin B1 protein level and the suppression of CCNB1 and CDK1 gene expression. In addition, a p53-dependent increase in p21 protein was associated with an FTD-induced decrease in Cyclin B1 protein. Although numerous ssDNA and dsDNA breaks were induced by FdUrd, few DNA strand breaks were detected in FTD-treated HCT-116 cells despite massive FTD misincorporation into genomic DNA, suggesting that the antiproliferative effect of FTD is not due to the induction of DNA strand breaks. These distinctive effects of FTD provide insights into the cellular mechanism underlying its antitumor effect and may explain the clinical efficacy of TAS-102. Mol Cancer Ther; 14(4); 1004–13. ©2015 AACR.
Data from Pharmacodynamic and Antineoplastic Activity of BI 836845, a Fully Human IGF Ligand-Neutralizing Antibody, and Mechanistic Rationale for Combination with Rapamycin
Authors: Friedbichler Katrin , Hofmann Marco H. , Kroez Monika , Ostermann Elinborg , Lamche Herbert R. , Koessl Christian , Borges Eric , Pollak Michael N. , Adolf Günther , Adam Paul J.
Published: March 2024

Abstract
Insulin-like growth factor (IGF) signaling is thought to play a role in the development and progression of multiple cancer types. To date, therapeutic strategies aimed at disrupting IGF signaling have largely focused on antibodies that target the IGF-I receptor (IGF-IR). Here, we describe the pharmacologic profile of BI 836845, a fully human monoclonal antibody that utilizes an alternative approach to IGF signaling inhibition by selectively neutralizing the bioactivity of IGF ligands. Biochemical analyses of BI 836845 demonstrated high affinity to human IGF-I and IGF-II, resulting in effective inhibition of IGF-induced activation of both IGF-IR and IR-A in vitro. Cross-reactivity to rodent IGFs has enabled rigorous assessment of the pharmacologic activity of BI 836845 in preclinical models. Pharmacodynamic studies in rats showed potent reduction of serum IGF bioactivity in the absence of metabolic adverse effects, leading to growth inhibition as evidenced by reduced body weight gain and tail length. Moreover, BI 836845 reduced the proliferation of human cell lines derived from different cancer types and enhanced the antitumor efficacy of rapamycin by blocking a rapamycin-induced increase in upstream signaling in vitro as well as in human tumor xenograft models in nude mice. Our data suggest that BI 836845 represents a potentially more effective and tolerable approach to the inhibition of IGF signaling compared with agents that target the IGF-I receptor directly, with potential for rational combinations with other targeted agents in clinical studies. Mol Cancer Ther; 13(2); 399–409. ©2013 AACR.
Data from Nedd8-Activating Enzyme Inhibitor MLN4924 Provides Synergy with Mitomycin C through Interactions with ATR, BRCA1/BRCA2, and Chromatin Dynamics Pathways
Authors: Garcia Khristofer , Blank Jonathan L. , Bouck David C. , Liu Xiaozhen J. , Sappal Darshan S. , Hather Greg , Cosmopoulos Katherine , Thomas Michael P. , Kuranda Mike , Pickard Michael D. , Liu Ray , Bandi Syamala , Smith Peter G. , Lightcap Eric S.
Published: March 2024

Abstract
MLN4924 is an investigational small-molecule inhibitor of the Nedd8-activating enzyme currently in phase I clinical trials. MLN4924 induces DNA damage via rereplication in most cell lines. This distinct mechanism of DNA damage may affect its ability to combine with standard-of-care agents and may affect the clinical development of MLN4924. As such, we studied its interaction with other DNA-damaging agents. Mitomycin C, cisplatin, cytarabine, UV radiation, SN-38, and gemcitabine demonstrated synergy in combination with MLN4924 in vitro. The combination of mitomycin C and MLN4924 was shown to be synergistic in a mouse xenograft model. Importantly, depletion of genes within the ataxia telangiectasia and Rad3 related (ATR) and BRCA1/BRCA2 pathways, chromatin modification, and transcription-coupled repair reduced the synergy between mitomycin C and MLN4924. In addition, comet assay demonstrated increased DNA strand breaks with the combination of MLN4924 and mitomycin C. Our data suggest that mitomycin C causes stalled replication forks, which when combined with rereplication induced by MLN4924 results in frequent replication fork collisions, leading to cell death. This study provides a straightforward approach to understand the mechanism of synergy, which may provide useful information for the clinical development of these combinations. Mol Cancer Ther; 13(6); 1625–35. ©2014 AACR.
Data from Biochemical Assays for the Discovery of TDP1 Inhibitors
Authors: Marchand Christophe , Huang Shar-yin N. , Dexheimer Thomas S. , Lea Wendy A. , Mott Bryan T. , Chergui Adel , Naumova Alena , Stephen Andrew G. , Rosenthal Andrew S. , Rai Ganesha , Murai Junko , Gao Rui , Maloney David J. , Jadhav Ajit , Jorgensen William L. , Simeonov Anton , Pommier Yves
Published: March 2024

Abstract
Drug screening against novel targets is warranted to generate biochemical probes and new therapeutic drug leads. TDP1 and TDP2 are two DNA repair enzymes that have yet to be successfully targeted. TDP1 repairs topoisomerase I–, alkylation-, and chain terminator–induced DNA damage, whereas TDP2 repairs topoisomerase II–induced DNA damage. Here, we report the quantitative high-throughput screening (qHTS) of the NIH Molecular Libraries Small Molecule Repository using recombinant human TDP1. We also developed a secondary screening method using a multiple loading gel-based assay where recombinant TDP1 is replaced by whole cell extract (WCE) from genetically engineered DT40 cells. While developing this assay, we determined the importance of buffer conditions for testing TDP1, and most notably the possible interference of phosphate-based buffers. The high specificity of endogenous TDP1 in WCE allowed the evaluation of a large number of hits with up to 600 samples analyzed per gel via multiple loadings. The increased stringency of the WCE assay eliminated a large fraction of the initial hits collected from the qHTS. Finally, inclusion of a TDP2 counter-screening assay allowed the identification of two novel series of selective TDP1 inhibitors. Mol Cancer Ther; 13(8); 2116–26. ©2014 AACR.
Data from Antiproliferative Effects of Continued Mitogen-Activated Protein Kinase Pathway Inhibition following Acquired Resistance to BRAF and/or MEK Inhibition in Melanoma
Authors: Carlino Matteo S. , Gowrishankar Kavitha , Saunders Catherine A.B. , Pupo Gulietta M. , Snoyman Stephanie , Zhang Xu Dong , Saw Robyn , Becker Therese M. , Kefford Richard F. , Long Georgina V. , Rizos Helen
Published: March 2024

Abstract
Inhibitors of the mitogen-activated protein kinases (MAPK), BRAF, and MAP–ERK kinase (MEK) induce tumor regression in the majority of patients with BRAF-mutant metastatic melanoma. The clinical benefit of MAPK inhibitors is restricted by the development of acquired resistance with half of those who benefit having progressed by 6 to 7 months and long-term responders uncommon. There remains no agreed treatment strategy on disease progression in these patients. Without published evidence, fears of accelerated disease progression on inhibitor withdrawal have led to the continuation of drugs beyond formal disease progression. We now show that treatment with MAPK inhibitors beyond disease progression can provide significant clinical benefit, and the withdrawal of these inhibitors led to a marked increase in the rate of disease progression in two patients. We also show that MAPK inhibitors retain partial activity in acquired resistant melanoma by examining drug-resistant clones generated to dabrafenib, trametinib, or the combination of these drugs. All resistant sublines displayed a markedly slower rate of proliferation when exposed to MAPK inhibitors, and this coincided with a reduction in MAPK signaling, decrease in bromodeoxyuridine incorporation, and S-phase inhibition. This cytostatic effect was also associated with diminished levels of cyclin D1 and p-pRb. Two short-term melanoma cultures generated from resistant tumor biopsies also responded to MAPK inhibition, with comparable inhibitory changes in proliferation and MAPK signaling. These data provide a rationale for the continuation of BRAF and MEK inhibitors after disease progression and support the development of clinical trials to examine this strategy. Mol Cancer Ther; 12(7); 1332–42. ©2013 AACR.
Data from A Novel Inhibitor of c-Met and VEGF Receptor Tyrosine Kinases with a Broad Spectrum of In Vivo Antitumor Activities
Authors: Awazu Yoshiko , Nakamura Kazuhide , Mizutani Akio , Kakoi Yuichi , Iwata Hidehisa , Yamasaki Seiji , Miyamoto Naoki , Imamura Shinichi , Miki Hiroshi , Hori Akira
Published: March 2024

Abstract
The c-Met receptor tyrosine kinase and its ligand, hepatocyte growth factor (HGF), are dysregulated in a wide variety of human cancers and are linked with tumorigenesis and metastatic progression. VEGF also plays a key role in tumor angiogenesis and progression by stimulating the proangiogenic signaling of endothelial cells via activation of VEGF receptor tyrosine kinases (VEGFR). Therefore, inhibiting both HGF/c-Met and VEGF/VEGFR signaling may provide a novel therapeutic approach for treating patients with a broad spectrum of tumors. Toward this goal, we generated and characterized T-1840383, a small-molecule kinase inhibitor that targets both c-Met and VEGFRs. T-1840383 inhibited HGF-induced c-Met phosphorylation and VEGF-induced VEGFR-2 phosphorylation in cancer epithelial cells and vascular endothelial cells, respectively. It also inhibited constitutively activated c-Met phosphorylation in c-met–amplified cancer cells, leading to suppression of cell proliferation. In addition, T-1840383 potently blocked VEGF-dependent proliferation and capillary tube formation of endothelial cells. Following oral administration, T-1840383 showed potent antitumor efficacy in a wide variety of human tumor xenograft mouse models, along with reduction of c-Met phosphorylation levels and microvessel density within tumor xenografts. These results suggest that the efficacy of T-1840383 is produced by direct effects on tumor cell growth and by an antiangiogenic mechanism. Furthermore, T-1840383 showed profound antitumor activity in a gastric tumor peritoneal dissemination model. Collectively, our findings indicate the therapeutic potential of targeting both c-Met and VEGFRs simultaneously with a single small-molecule inhibitor for the treatment of human cancers. Mol Cancer Ther; 12(6); 913–24. ©2013 AACR.
Data from Characterization of LY2228820 Dimesylate, a Potent and Selective Inhibitor of p38 MAPK with Antitumor Activity
Authors: Campbell Robert M. , Anderson Bryan D. , Brooks Nathan A. , Brooks Harold B. , Chan Edward M. , De Dios Alfonso , Gilmour Raymond , Graff Jeremy R. , Jambrina Enrique , Mader Mary , McCann Denis , Na Songqing , Parsons Stephen H. , Pratt Susan E. , Shih Chuan , Stancato Louis F. , Starling James J. , Tate Courtney , Velasco Juan A. , Wang Yong , Ye Xiang S.
Published: March 2024

Abstract
p38α mitogen-activated protein kinase (MAPK) is activated in cancer cells in response to environmental factors, oncogenic stress, radiation, and chemotherapy. p38α MAPK phosphorylates a number of substrates, including MAPKAP-K2 (MK2), and regulates the production of cytokines in the tumor microenvironment, such as TNF-α, interleukin-1β (IL-1β), IL-6, and CXCL8 (IL-8). p38α MAPK is highly expressed in human cancers and may play a role in tumor growth, invasion, metastasis, and drug resistance. LY2228820 dimesylate (hereafter LY2228820), a trisubstituted imidazole derivative, is a potent and selective, ATP-competitive inhibitor of the α- and β-isoforms of p38 MAPK in vitro (IC50 = 5.3 and 3.2 nmol/L, respectively). In cell-based assays, LY2228820 potently and selectively inhibited phosphorylation of MK2 (Thr334) in anisomycin-stimulated HeLa cells (at 9.8 nmol/L by Western blot analysis) and anisomycin-induced mouse RAW264.7 macrophages (IC50 = 35.3 nmol/L) with no changes in phosphorylation of p38α MAPK, JNK, ERK1/2, c-Jun, ATF2, or c-Myc ≤ 10 μmol/L. LY2228820 also reduced TNF-α secretion by lipopolysaccharide/IFN-γ–stimulated macrophages (IC50 = 6.3 nmol/L). In mice transplanted with B16-F10 melanoma, tumor phospho-MK2 (p-MK2) was inhibited by LY2228820 in a dose-dependent manner [threshold effective dose (TED)70 = 11.2 mg/kg]. Significant target inhibition (>40% reduction in p-MK2) was maintained for 4 to 8 hours following a single 10 mg/kg oral dose. LY2228820 produced significant tumor growth delay in multiple in vivo cancer models (melanoma, non–small cell lung cancer, ovarian, glioma, myeloma, breast). In summary, LY2228820 is a p38 MAPK inhibitor, which has been optimized for potency, selectivity, drug-like properties (such as oral bioavailability), and efficacy in animal models of human cancer. Mol Cancer Ther; 13(2); 364–74. ©2013 AACR.
Data from An Autocrine Loop between TGF-β1 and the Transcription Factor Brachyury Controls the Transition of Human Carcinoma Cells into a Mesenchymal Phenotype
Authors: Larocca Cecilia , Cohen Joseph R. , Fernando Romaine I. , Huang Bruce , Hamilton Duane H. , Palena Claudia
Published: March 2024

Abstract
The epithelial–mesenchymal transition (EMT) is a process associated with the metastasis of solid tumors as well as with the acquisition of resistance to standard anticancer modalities. A major initiator of EMT in carcinoma cells is TGF-β, which has been shown to induce the expression of several transcription factors ultimately responsible for initiating and maintaining the EMT program. We have previously identified Brachyury, a T-box transcription factor, as an inducer of mesenchymal features in human carcinoma cells. In this study, a potential link between Brachyury and TGF-β signaling has been investigated. The results show for the first time that Brachyury expression is enhanced during TGF-β1–induced EMT in various human cancer cell lines, and that a positive feedback loop is established between Brachyury and TGF-β1 in mesenchymal-like tumor cells. In this context, Brachyury overexpression is shown to promote upregulation of TGF-β1 at the mRNA and protein levels, an effect mediated by activation of the TGF-β1 promoter in the presence of high levels of Brachyury. Furthermore, inhibition of TGF-β1 signaling by a small-molecule inhibitor of TGF-β receptor type I decreases Brachyury expression, induces a mesenchymal-to-epithelial transition, and renders cancer cells more susceptible to chemotherapy. This study thus has implications for the future development of clinical trials using TGF-β inhibitors in combination with other anticancer agents. Mol Cancer Ther; 12(9); 1805–15. ©2013 AACR.
Data from Preclinical Pharmacological Evaluation of Letrozole as a Novel Treatment for Gliomas
Authors: Dave Nimita , Chow Lionel M.L. , Gudelsky Gary A. , LaSance Kathleen , Qi Xiaoyang , Desai Pankaj B.
Published: March 2024

Abstract
We present data that letrozole, an extensively used aromatase inhibitor in the treatment of estrogen receptor–positive breast tumors in postmenopausal women, may be potentially used in the treatment of glioblastomas. First, we measured the in vitro cytotoxicity of letrozole and aromatase (CYP19A1) expression and activity in human LN229, T98G, U373MG, U251MG, and U87MG, and rat C6 glioma cell lines. Estrogen receptor (ER)-positive MCF-7 and ER-negative MDA-MB-231 cells served as controls. Cytotoxicity was determined employing the MTT assay, and aromatase activity using an immunoassay that measures the conversion of testosterone to estrogen. Second, in vivo activity of letrozole was assessed in Sprague–Dawley rats orthotopically implanted with C6 gliomas. The changes in tumor volume with letrozole treatment (4 mg/kg/day) were assessed employing μPET/CT imaging, employing [18F]-fluorodeoxyglucose (F18-FDG) as the radiotracer. Brain tissues were collected for histologic evaluations. All glioma cell lines included here expressed CYP19A1 and letrozole exerted considerable cytotoxicity and decrease in aromatase activity against these cells (IC50, 0.1–3.5 μmol/L). Imaging analysis employing F18-FDG μPET/CT demonstrated a marked reduction of active tumor volume (>75%) after 8 days of letrozole treatment. Immunohistochemical analysis revealed marked reduction in aromatase expression in tumoral regions of the brain after letrozole treatment. Thus, employing multifaceted tools, we demonstrate that aromatase may be a novel target for the treatment of gliomas and that letrozole, an FDA-approved drug with an outstanding record of safety may be repurposed for the treatment of such primary brain tumors, which currently have few therapeutic options. Mol Cancer Ther; 14(4); 857–64. ©2015 AACR.