bluuebunny/crossref_metadata_2025 huggingface dataset:
Supplementary Figures from In Vitro and In Vivo Activity of AMG 337, a Potent and Selective MET Kinase Inhibitor, in MET-Dependent Cancer Models
Authors: Hughes Paul E. , Rex Karen , Caenepeel Sean , Yang Yajing , Zhang Yihong , Broome Martin A. , Kha Hue T. , Burgess Teresa L. , Amore Benny , Kaplan-Lefko Paula J. , Moriguchi Jodi , Werner Jonathan , Damore Michael A. , Baker Daniel , Choquette Deborah M. , Harmange Jean-Christophe , Radinsky Robert , Kendall Richard , Dussault Isabelle , Coxon Angela
Published: April 2023

Figure S1. Kinase interaction map for AMG 337; Figure S2. In a large unbiased cancer cell line viability screen only MET-amplified cell lines were sensitive to treatment with an analogue of AMG 337 (Compound 5); Figure S3: AMG 337 inhibits the phosphorylation of MET and but not its downstream effectors in MET-amplified, KRAS mutant NSCLC cell line NCI-H1573; Figure S4. Cell lines harboring MET FISH scores >3 exhibited sensitivity to AMG 337. MET FISH analysis was performed on a subset of cancer cell lines exhibiting elevated MET gene copy number; Figure S5. Selective inhibition of MET exhibits partial effects on the viability of U-87 MG glioblastoma cells harboring an HGF/MET autocrine loop; Figure S6. Increases in MET gene number correlate with high levels of total MET protein; Figure S7. AMG 337 inhibits Gab-1 phosphorylation in a concentration dependent manner in the TPR-MET mouse tumor model.
Figure S4 from In Vivo Antitumoral Efficacy of PhAc-ALGP-Doxorubicin, an Enzyme-Activated Doxorubicin Prodrug, in Patient-Derived Soft Tissue Sarcoma Xenograft Models
Authors: Cornillie Jasmien , Wozniak Agnieszka , Pokreisz Peter , Casazza Andrea , Vreys Lise , Wellens Jasmien , Vanleeuw Ulla , Gebreyohannes Yemarshet K. , Debiec-Rychter Maria , Sciot Raf , Hompes Daphne , Schöffski Patrick
Published: April 2023

Evolution of body weight (A), number of white blood cells (B), red blood cells (C) and platelets (D) in UZLX-STS3 and UZLX-STS5 DDLPS xenografts and in UZLX-STS7 SynSa xenograft. All data points are shown as mean {plus minus} SD.
Supplementary Data from Combination Immunotherapy with Cytotoxic T-Lymphocyte–Associated Antigen-4 and Programmed Death Protein-1 Inhibitors Prevents Postoperative Breast Tumor Recurrence and Metastasis
Authors: Sun Ting , Zhang Wenjia , Li Yuan , Jin Zhengyu , Du Yang , Tian Jie , Xue Huadan
Published: April 2023

Supplementary Figure1 to 4
Supplementary Figure 5 from A Novel Bispecific Antibody with PD-L1–assisted OX40 Activation for Cancer Treatment
Authors: Kuang Zhihui , Pu Pu , Wu Min , Wu Zhihai , Wang Li , Li Yiming , Zhang Shaofei , Jing Hua , Wu Weiwei , Chen Bingliang , Liu Junjian
Published: April 2023

Individual tumor growth curves
Supplementary Figure 3 from A Novel Bispecific Antibody with PD-L1–assisted OX40 Activation for Cancer Treatment
Authors: Kuang Zhihui , Pu Pu , Wu Min , Wu Zhihai , Wang Li , Li Yiming , Zhang Shaofei , Jing Hua , Wu Weiwei , Chen Bingliang , Liu Junjian
Published: April 2023

Cell bridging
Fig. S7 from Nf1-Mutant Tumors Undergo Transcriptome and Kinome Remodeling after Inhibition of either mTOR or MEK
Authors: Pucciarelli Daniela , Angus Steven P. , Huang Benjamin , Zhang Chi , Nakaoka Hiroki J. , Krishnamurthi Ganesh , Bandyopadhyay Sourav , Clapp D. Wade , Shannon Kevin , Johnson Gary L. , Nakamura Jean L.
Published: April 2023

Supplementary Figure 7
Fig. S6 from Nf1-Mutant Tumors Undergo Transcriptome and Kinome Remodeling after Inhibition of either mTOR or MEK
Authors: Pucciarelli Daniela , Angus Steven P. , Huang Benjamin , Zhang Chi , Nakaoka Hiroki J. , Krishnamurthi Ganesh , Bandyopadhyay Sourav , Clapp D. Wade , Shannon Kevin , Johnson Gary L. , Nakamura Jean L.
Published: April 2023

Supplementary Figure 6
Supplementary Data TS2 from Microparticle Encapsulation of a Prostate-targeted Biologic for the Treatment of Liver Metastases in a Preclinical Model of Castration-resistant Prostate Cancer
Authors: Rogers Oliver C. , Antony Lizamma , Levy Oren , Joshi Nitin , Simons Brian W. , Dalrymple Susan L. , Rosen D. Marc , Pickering Andrew , Lan Haoyue , Kuang Heidi , Ranganath Sudhir H. , Zheng Lei , Karp Jeffrey M. , Howard S. Peter , Denmeade Samuel R. , Isaacs John T. , Brennen W. Nathaniel
Published: April 2023

Tbl S2
Video A from Preclinical Development of MGC018, a Duocarmycin-based Antibody–drug Conjugate Targeting B7-H3 for Solid Cancer
Authors: Scribner Juniper A. , Brown Jennifer G. , Son Thomas , Chiechi Michael , Li Pam , Sharma Sharad , Li Hua , De Costa Anushka , Li Ying , Chen Yan , Easton Ann , Yee-Toy Nicholas C. , Chen Francine Z. , Gorlatov Sergey , Barat Bhaswati , Huang Ling , Wolff Christina R. , Hooley Jeff , Hotaling Tim E. , Gaynutdinov Timur , Ciccarone Valentina , Tamura James , Koenig Scott , Moore Paul A. , Bonvini Ezio , Loo Deryk
Published: April 2023

5000 Hs700T parental cells only without treatment
Supplementary Data from Aurora B Kinase Promotes CHIP-Dependent Degradation of HIF1α in Prostate Cancer Cells
Authors: Biswas Kuntal , Sarkar Sukumar , Said Neveen , Brautigan David L. , Larner James M.
Published: April 2023

supplementary data
Supplemental Figure 1 from Rac Signaling Drives Clear Cell Renal Carcinoma Tumor Growth by Priming the Tumor Microenvironment for an Angiogenic Switch
Authors: Goka Erik T. , Chaturvedi Pallavi , Lopez Dayrelis T. Mesa , Lippman Marc E.
Published: April 2023

Supplemental Figure 1. Rac1 is a driver of ccRCC. (A) Rac1 mRNA expression in normal kidney and ccRCC patients from Jones Renal Cohort. (B) Rac1 DNA copy number analysis of normal blood, normal kidney, and kidney tumors from the KIRC TCGA dataset. (C) Rac isoform expression analysis in normal kidney and kidney tumors from the TCGA KIRC dataset. (D) PREX1, VAV1, TIAM1, and TRIO mRNA expression in normal kidney and kidney tumors from the TCGA KIRC dataset. (E) Rac1 mRNA expression by clinical stage from the TCGA KIRC dataset. (F) Boyden chamber cellular migration assay of 786-O transfected with siNSC or siRac1 oligonucleotides. (G) Cellular proliferation assay of 786-O transfected with siNSC or siRac1 oligonucleotides.
Figure S2 from Reprogramming of Nucleotide Metabolism Mediates Synergy between Epigenetic Therapy and MAP Kinase Inhibition
Authors: Shorstova Tatiana , Su Jie , Zhao Tiejun , Dahabieh Michael , Leibovitch Matthew , De Sa Tavares Russo Mariana , Avizonis Daina , Rajkumar Shivshankari , Watson Ian R. , del Rincón Sonia V. , Miller Wilson H. , Foulkes William D. , Witcher Michael
Published: April 2023

Response of ovarian cancer cells to combination treatments of BETi with inhibitors of RTK-dependent signaling
Supplementary Figure S2 from A Novel Sulforaphane-Regulated Gene Network in Suppression of Breast Cancer–Induced Osteolytic Bone Resorption
Authors: Pore Subrata K. , Hahm Eun-Ryeong , Kim Su-Hyeong , Singh Krishna B. , Nyiranshuti Lea , Latoche Joseph D. , Anderson Carolyn J. , Adamik Juraj , Galson Deborah L. , Weiss Kurt R. , Watters Rebecca J. , Lee Boeun , Kumta Prashant N. , Singh Shivendra V.
Published: April 2023

Sulforaphane (SFN) treatment downregulated expression of Runt-related transcription factor 2 (RUNX2) in SK-BR-3 cell line.
Supplementary Data from Depatuxizumab Mafodotin (ABT-414)-induced Glioblastoma Cell Death Requires EGFR Overexpression, but not EGFRY1068 Phosphorylation
Authors: von Achenbach Caroline , Silginer Manuela , Blot Vincent , Weiss William A. , Weller Michael
Published: April 2023

Supplementary Figures
Supplementary Figure from Local Treatment of a Pediatric Osteosarcoma Model with a 4-1BBL Armed Oncolytic Adenovirus Results in an Antitumor Effect and Leads to Immune Memory
Authors: Martinez-Velez Naiara , Laspidea Virginia , Zalacain Marta , Labiano Sara , García-Moure Marc , Puigdelloses Montse , Marrodan Lucía , Gonzalez-Huarriz Marisol , Herrador Guillermo , de la Nava Daniel , Ausejo-Mauleon Iker , Fueyo Juan , Gomez-Manzano Candelaria , Patiño-García Ana , Alonso Marta M.
Published: April 2023

Supplementary Figure from Local Treatment of a Pediatric Osteosarcoma Model with a 4-1BBL Armed Oncolytic Adenovirus Results in an Antitumor Effect and Leads to Immune Memory
Supplementary Data from Targeting CD73 with AB680 (Quemliclustat), a Novel and Potent Small-Molecule CD73 Inhibitor, Restores Immune Functionality and Facilitates Antitumor Immunity
Authors: Piovesan Dana , Tan Joanne B.L. , Becker Annette , Banuelos Jesus , Narasappa Nell , DiRenzo Daniel , Zhang Kristen , Chen Ada , Ginn Elaine , Udyavar Akshata R. , Yin Fangfang , Paprcka Susan L. , Purandare Bhamini , Park Timothy W. , Kimura Nikki , Kalisiak Jaroslaw , Young Stephen W. , Powers Jay P. , Schindler Uli , Sivick Kelsey E. , Walters Matthew J.
Published: April 2023

Supplementary Data from Targeting CD73 with AB680 (Quemliclustat), a Novel and Potent Small-Molecule CD73 Inhibitor, Restores Immune Functionality and Facilitates Antitumor Immunity
Table S2 from Glypican-1 Is a Novel Target for Stroma and Tumor Cell Dual-Targeting Antibody–Drug Conjugates in Pancreatic Cancer
Authors: Tsujii Shigehiro , Serada Satoshi , Fujimoto Minoru , Uemura Sunao , Namikawa Tsutomu , Nomura Taisei , Murakami Ichiro , Hanazaki Kazuhiro , Naka Tetsuji
Published: April 2023

Supplementary Table S2
Supplementary Figure from Dual G9A/EZH2 Inhibition Stimulates Antitumor Immune Response in Ovarian High-Grade Serous Carcinoma
Authors: Spiliopoulou Pavlina , Spear Sarah , Mirza Hasan , Garner Ian , McGarry Lynn , Grundland-Freile Fabio , Cheng Zhao , Ennis Darren P. , Iyer Nayana , McNamara Sophie , Natoli Marina , Mason Susan , Blyth Karen , Adams Peter D. , Roxburgh Patricia , Fuchter Matthew J. , Brown Bob , McNeish Iain A.
Published: April 2023

Supplementary Figure from Dual G9A/EZH2 Inhibition Stimulates Antitumor Immune Response in Ovarian High-Grade Serous Carcinoma
Supplementary Data from Anti-LYPD1/CD3 T-Cell-Dependent Bispecific Antibody for the Treatment of Ovarian Cancer
Authors: Lo Amy A. , Johnston Jennifer , Li Ji , Mandikian Danielle , Hristopoulos Maria , Clark Robyn , Nickles Dorothee , Liang Wei-Ching , Hötzel Kathy , Dunlap Debra , Pham Thinh , Cai Hao , Ovacik Meric , Bravo-Perez Daniel , Mai Elaine , Slaga Dionysos , Ellerman Diego , Ziai James , Totpal Klara , Lee Genee , Boswell C. Andrew , Payandeh Jian , Wu Yan , Junttila Teemu T.
Published: April 2023

Supplementary Data
Figure S5 from Targeting the mTOR Pathway in Hurthle Cell Carcinoma Results in Potent Antitumor Activity
Authors: Dong Yiyu , Gong Yongxing , Kuo Fengshen , Makarov Vladimir , Reznik Ed , Nanjangud Gouri J. , Aras Omer , Zhao Huiyong , Qu Rui , Fagin James A. , Sherman Eric J. , Xu Bin , Ghossein Ronald , Chan Timothy A. , Ganly Ian
Published: April 2023

Combination treatment with rapamycin and lenvatinib in PDX model TC1m1. A, Combination treatment resulted in enhanced decrease in CD31 staining endothelial vessels compared to lenvatinib alone or rapamycin alone. B, The average IMVD values of CD31 in tumors from mice treated with different drugs were decreased to 44.5% (rapamycin), 60.6% (lenvatinib), and 16.9% (combination of rapamycin and lenvatinib), respectively, compared with that in vehicle control group.
Supplementary Tables from Taxanes Sensitize Prostate Cancer Cells to TRAIL-Induced Apoptotic Synergy via Endoplasmic Reticulum Stress
Authors: Grayson Korie A. , Hope Jacob M. , Wang Wenjun , Reinhart-King Cynthia A. , King Michael R.
Published: April 2023

Supplementary Tables
Supplementary Data 6 from Discovery of JNJ-63576253, a Next-Generation Androgen Receptor Antagonist Active Against Wild-Type and Clinically Relevant Ligand Binding Domain Mutations in Metastatic Castration-Resistant Prostate Cancer
Authors: Branch Jonathan R. , Bush Tammy L. , Pande Vineet , Connolly Peter J. , Zhang Zhuming , Hickson Ian , Ondrus Janine , Jaensch Steffen , Bischoff James R. , Habineza Georges , Van Hecke Geert , Meerpoel Lieven , Packman Kathryn , Parrett Christopher J. , Chong Yolanda T. , Gottardis Marco M. , Bignan Gilles
Published: April 2023

Kinase panel (KINOMEscan)
Data from Loss of the Malignant Phenotype of Human Neuroblastoma Cells by a Catalytically Inactive Dominant-Negative hTERT Mutant
Authors: Samy Mona , Gattolliat Charles-Henry , Pendino Frédéric , Hillion Josette , Nguyen Eric , Bombard Sophie , Douc-Rasy Sétha , Bénard Jean , Ségal-Bendirdjian Evelyne
Published: April 2023

Abstract
Telomerase, a ribonucleoprotein complex mainly composed of the reverse transcriptase catalytic subunit (human telomerase reverse transcriptase, hTERT) and the RNA component (hTR), is a key enzyme of cancer progression. That aggressive stage 4-neuroblastoma expressed high levels of telomerase activity, whereas favorable tumors had no or little telomerase expression and activity, prompted us to investigate the role of this enzyme in this tumor model of altered proliferation, neuronal differentiation, and apoptosis. A human MYCN-amplified neuroblastoma cell line (IGR-N-91) was engineered to stably express either the normal hTERT protein (WT-hTERT) or a catalytically inactive dominant-negative mutant of this protein (DN-hTERT). We showed that DN-hTERT expression inhibited the endogenous hTERT in the malignant neuroblasts without telomere shortening nor loss of in vitro proliferative capacity. Importantly, DN-hTERT expression induced major changes in cell morphology of neuroblasts that switched them from a neuronal to a substrate adherent phenotype, which was more prone to apoptosis and lost their tumorigenic properties in nude mice. These biologic effects arose from modifications in the expression of genes involved in both apoptosis and neuroblastoma biology. Taken together these results highlighted the functional relevance of noncanonical functions of hTERT in the determination of neuroblast cell fate. Therefore, our results envision new therapeutic strategies for metastatic neuroblastoma therapeutic management. Mol Cancer Ther; 11(11); 2384–93. ©2012 AACR.
Data from Neutralizing Monoclonal Antibody to Periostin Inhibits Ovarian Tumor Growth and Metastasis
Authors: Zhu Min , Saxton Romaine E. , Ramos Lillian , Chang David D. , Karlan Beth Y. , Gasson Judith C. , Slamon Dennis J.
Published: April 2023

Abstract
Periostin, an extracellular matrix protein, is reported to be overexpressed in a variety of human cancers and its functions seem to be linked to tumor metastasis. Our previous results show that engineered periostin overexpression promotes ovarian tumor growth and dissemination in vivo. In this study, we developed a neutra-lizing monoclonal antibody to periostin, named MZ-1, and investigated its effects on human ovarian tumor growth and metastasis. Our in vivo studies showed significant growth inhibition by MZ-1 on both subcutaneous and intraperitoneal (i.p.) tumors derived from the periostin-expressing ovarian cancer cell line A2780. In addition, MZ-1 treatment led to a reduction of the metastatic potential of these A2780 i.p. tumors. The in vivo antitumor effects of MZ-1 were linked to its specific inhibition of anchorage-independent growth and survival of periostin-expressing cells, as well as its neutralizing effects on periostin-induced cancer cell migration and invasion. The data suggest that blocking periostin expression may be a novel approach for treating the subset of invasive ovarian tumors that overexpress periostin protein. Mol Cancer Ther; 10(8); 1500–8. ©2011 AACR.
Data from Sorafenib-Mediated Targeting of the AAA+ ATPase p97/VCP Leads to Disruption of the Secretory Pathway, Endoplasmic Reticulum Stress, and Hepatocellular Cancer Cell Death
Authors: Yi Ping , Higa Arisa , Taouji Said , Bexiga Mariana G. , Marza Esther , Arma Daniela , Castain Claire , Le Bail Brigitte , Simpson Jeremy C. , Rosenbaum Jean , Balabaud Charles , Bioulac-Sage Paulette , Blanc Jean-Frédéric , Chevet Eric
Published: April 2023

Abstract
The molecular mechanisms and cellular targets of sorafenib, a multikinase inhibitor used for the treatment of hepatocellular carcinoma (HCC), remain to be fully characterized. Recent studies have shown that sorafenib induces tumor cell death through the activation of endoplasmic reticulum stress signaling and/or autophagy in various cellular models. Using liver cancer–derived cell lines, we specifically show that the IRE1 and phosphorylated extracellular signal–regulated kinase arms of the unfolded protein response (UPR) become activated upon sorafenib treatment, whereas the ATF6 arm is inhibited. Our results also reveal that sorafenib treatment causes disruption to the secretory pathway, as witnessed by the fragmentation of the Golgi apparatus and the induction of autophagy. On the basis of these observations, we tested the relevance of the AAA+ ATPase p97/VCP as a potential functional target of sorafenib. Our results show that p97/VCP tyrosine phosphorylation is prevented upon sorafenib treatment, and that this can be correlated with enhanced membrane association. Moreover, we show that DBeQ, a recently discovered inhibitor of p97/VCP, enhances sorafenib-mediated toxicity in cultured cells. Our data show a novel mechanism for sorafenib-mediated cell death in HCC, which depends on the integrity of the secretory pathway; and we identify p97/VCP phosphorylation as a potential target for improved sorafenib treatment efficacy in patients. Mol Cancer Ther; 11(12); 2610–20. ©2012 AACR.
Data from CYP2S1 and CYP2W1 Mediate 2-(3,4-Dimethoxyphenyl)-5-Fluorobenzothiazole (GW-610, NSC 721648) Sensitivity in Breast and Colorectal Cancer Cells
Authors: Tan Boon Shing , Tiong Kai Hung , Muruhadas Ashwin , Randhawa Nirmal , Choo Heng Lungh , Bradshaw Tracey D. , Stevens Malcolm F.G. , Leong Chee-Onn
Published: April 2023

Abstract
Both 2-(4-amino-3-methylphenyl)-5-fluorobenzothiazole (5F-203; NSC 703786) and 2-(3,4-dimethoxyphenyl)-5-fluorobenzothiazole (GW-610; NSC 721648) are antitumor agents with novel mechanism(s). Previous studies have indicated that cytochrome (CYP) P450 1A1 is crucial for 5F-203 activity. In the present study, we investigated the functional role of 2 newly identified CYP P450 enzymes, CYP2S1 and CYP2W1, in mediating antitumor activity of benzothiazole compounds. We generated isogenic breast cancer (MDA-MB-468, MCF-7) and colorectal cancer (CRC; KM12 and HCC2998) cell lines depleted for CYP1A1, CYP2S1, or CYP2W1. The sensitivity of these cells to 5F-203 and GW-610 was then compared with vector control cells. 5F-203 exhibited potent activity against breast cancer cells, whereas GW-610 was effective against both breast and colorectal cancer cells. CYP1A1 was induced in both breast cancer and CRC cells, while CYP2S1 and CYP2W1 were selectively induced in breast cancer cells only following treatment with 5F-203 or GW-610. Depletion of CYP1A1 abrogated the sensitivity of breast cancer and CRC cells to 5F-203 and GW-610. Although depletion of CYP2S1 sensitized both breast cancer and CRC cells toward 5F-203 and GW-610, CYP2W1 knockdown caused marked resistance to GW-610 in CRC cells. Our results indicate that CYP-P450 isoforms, with the exception of CYP1A1, play an important role in mediating benzothiazole activity. CYP2S1 appears to be involved in deactivation of benzothiazoles, whereas CYP2W1 is important for bioactivation of GW-610 in CRC cells. Because CYP2W1 is highly expressed in colorectal tumors, GW-610 represents a promising agent for CRC therapy. Mol Cancer Ther; 10(10); 1982–92. ©2011 AACR.
Data from Epithelial–Mesenchymal Transition and Stem Cell Markers in Patients with HER2-Positive Metastatic Breast Cancer
Authors: Giordano Antonio , Gao Hui , Anfossi Simone , Cohen Evan , Mego Michal , Lee Bang-Ning , Tin Sanda , De Laurentiis Michele , Parker Charla A. , Alvarez Ricardo H. , Valero Vicente , Ueno Naoto T. , De Placido Sabino , Mani Sendurai A. , Esteva Francisco J. , Cristofanilli Massimo , Reuben James M.
Published: April 2023

Abstract
Currently, there is extensive information about circulating tumor cells (CTC) and their prognostic value; however, little is known about other characteristics of these cells. In this prospective study, we assessed the gene transcripts of epithelial-to-mesenchymal transition—inducing transcription factors (EMT-TF) and cancer stem cell (CSC) features in patients with HER2+ metastatic breast cancer (MBC). Epithelial cells were enriched from peripheral blood mononuclear cells (PBMC) using antibody-coated anti-CD326 antibody (CD326+) magnetic beads, and the residual CD326− PBMCs were further depleted of leukocytes using anti-CD45 antibody-coated magnetic beads (CD326−CD45−). RNA was extracted from all cell fractions, reverse transcribed to cDNA, and subjected to quantitative reverse transcription PCR to detect EMT-TFs (TWIST1, SNAIL1, ZEB1, and TG2) as a measure of CTCs undergoing EMT (EMT-CTCs). In addition, PBMCs were analyzed using multiparameter flow cytometry for ALDH activity and CSCs that express CD24, CD44, and CD133. Twenty-eight patients were included in this study. At least one EMT-TF mRNA was elevated in the CTCs of 88.2% of patients and in the CD326−CD45− cell fraction of 60.7% of patients. The CD326−CD45− fraction of patients with elevated SNAIL1 and ZEB1 transcripts also had a higher percentage of ALDH+/CD133+ cells in their blood than did patients with normal SNAIL1 and ZEB1 expression (P = 0.038). Our data indicate that patients with HER2+ MBCs have EMT-CTCs. Moreover, an enrichment of CSCs was found in CD326−CD45− cells. Additional studies are needed to determine whether EMT-CTCs and CSCs have prognostic value in patients with HER2+ MBCs treated with trastuzumab-based therapy. Mol Cancer Ther; 11(11); 2526–34. ©2012 AACR.
Data from ERK Inhibition Overcomes Acquired Resistance to MEK Inhibitors
Authors: Hatzivassiliou Georgia , Liu Bonnie , O'Brien Carol , Spoerke Jill M. , Hoeflich Klaus P. , Haverty Peter M. , Soriano Robert , Forrest William F. , Heldens Sherry , Chen Huifen , Toy Karen , Ha Connie , Zhou Wei , Song Kyung , Friedman Lori S. , Amler Lukas C. , Hampton Garret M. , Moffat John , Belvin Marcia , Lackner Mark R.
Published: April 2023

Abstract
The RAS/RAF/MEK pathway is activated in more than 30% of human cancers, most commonly via mutation in the K-ras oncogene and also via mutations in BRAF. Several allosteric mitogen-activated protein/extracellular signal–regulated kinase (MEK) inhibitors, aimed at treating tumors with RAS/RAF pathway alterations, are in clinical development. However, acquired resistance to these inhibitors has been documented both in preclinical and clinical samples. To identify strategies to overcome this resistance, we have derived three independent MEK inhibitor–resistant cell lines. Resistance to allosteric MEK inhibitors in these cell lines was consistently linked to acquired mutations in the allosteric binding pocket of MEK. In one cell line, concurrent amplification of mutant K-ras was observed in conjunction with MEK allosteric pocket mutations. Clonal analysis showed that both resistance mechanisms occur in the same cell and contribute to enhanced resistance. Importantly, in all cases the MEK-resistant cell lines retained their addiction to the mitogen-activated protein kinase (MAPK) pathway, as evidenced by their sensitivity to a selective inhibitor of the ERK1/2 kinases. These data suggest that tumors with acquired MEK inhibitor resistance remain dependent on the MAPK pathway and are therefore sensitive to inhibitors that act downstream of the mutated MEK target. Importantly, we show that dual inhibition of MEK and ERK by small molecule inhibitors was synergistic and acted to both inhibit the emergence of resistance, as well as to overcome acquired resistance to MEK inhibitors. Therefore, our data provide a rationale for cotargeting multiple nodes within the MAPK signaling cascade in K-ras mutant tumors to maximize therapeutic benefit for patients. Mol Cancer Ther; 11(5); 1143–54. ©2012 AACR.
Data from B7-H3 Silencing Increases Paclitaxel Sensitivity by Abrogating Jak2/Stat3 Phosphorylation
Authors: Liu Hao , Tekle Christina , Chen Yih-Wen , Kristian Alexandr , Zhao Yuhua , Zhou Ming , Liu Zixing , Ding Yan , Wang Bin , Mælandsmo Gunhild Mari , Nesland Jahn Marthin , Fodstad Oystein , Tan Ming
Published: April 2023

Abstract
In many types of cancer, the expression of the immunoregulatory protein B7-H3 has been associated with poor prognosis. Previously, we observed a link between B7-H3 and tumor cell migration and invasion, and in present study, we have investigated the role of B7-H3 in chemoresistance in breast cancer. We observed that silencing of B7-H3, via stable short hairpin RNA or transient short interfering RNA transfection, increased the sensitivity of multiple human breast cancer cell lines to paclitaxel as a result of enhanced drug-induced apoptosis. Overexpression of B7-H3 made the cancer cells more resistant to the drug. Next, we investigated the mechanisms behind B7-H3–mediated paclitaxel resistance and found that the level of Stat3 Tyr705 phosphorylation was decreased in B7-H3 knockdown cells along with the expression of its direct downstream targets Mcl-1 and survivin. The phosphorylation of Janus kinase 2 (Jak2), an upstream molecule of Stat3, was also significantly decreased. In contrast, reexpression of B7-H3 in B7-H3 knockdown and low B7-H3 expressing cells increased the phosphorylation of Jak2 and Stat3. In vivo animal experiments showed that B7-H3 knockdown tumors displayed a slower growth rate than the control xenografts. Importantly, paclitaxel treatment showed a strong antitumor activity in the mice with B7-H3 knockdown tumors, but only a marginal effect in the control group. Taken together, our data show that in breast cancer cells, B7-H3 induces paclitaxel resistance, at least partially by interfering with Jak2/Stat3 pathway. These results provide novel insight into the function of B7-H3 and encourage the design and testing of approaches targeting this protein and its partners. Mol Cancer Ther; 10(6); 960–71. ©2011 AACR.
Data from PF-04691502, a Potent and Selective Oral Inhibitor of PI3K and mTOR Kinases with Antitumor Activity
Authors: Yuan Jing , Mehta Pramod P. , Yin Min-Jean , Sun Shaoxian , Zou Aihua , Chen Jeffrey , Rafidi Kristina , Feng Zheng , Nickel Jeffrey , Engebretsen Jon , Hallin Jill , Blasina Alessandra , Zhang Eric , Nguyen Leslie , Sun Minghao , Vogt Peter K. , McHarg Aileen , Cheng Hengmiao , Christensen James G. , Kan Julie L.C. , Bagrodia Shubha
Published: April 2023

Abstract
Deregulation of the phosphoinositide 3-kinase (PI3K) signaling pathway such as by PTEN loss or PIK3CA mutation occurs frequently in human cancer and contributes to resistance to antitumor therapies. Inhibition of key signaling proteins in the pathway therefore represents a valuable targeting strategy for diverse cancers. PF-04691502 is an ATP-competitive PI3K/mTOR dual inhibitor, which potently inhibited recombinant class I PI3K and mTOR in biochemical assays and suppressed transformation of avian fibroblasts mediated by wild-type PI3K γ, δ, or mutant PI3Kα. In PIK3CA-mutant and PTEN-deleted cancer cell lines, PF-04691502 reduced phosphorylation of AKT T308 and AKT S473 (IC50 of 7.5–47 nmol/L and 3.8–20 nmol/L, respectively) and inhibited cell proliferation (IC50 of 179–313 nmol/L). PF-04691502 inhibited mTORC1 activity in cells as measured by PI3K-independent nutrient stimulated assay, with an IC50 of 32 nmol/L and inhibited the activation of PI3K and mTOR downstream effectors including AKT, FKHRL1, PRAS40, p70S6K, 4EBP1, and S6RP. Short-term exposure to PF-04691502 predominantly inhibited PI3K, whereas mTOR inhibition persisted for 24 to 48 hours. PF-04691502 induced cell cycle G1 arrest, concomitant with upregulation of p27 Kip1 and reduction of Rb. Antitumor activity was observed in U87 (PTEN null), SKOV3 (PIK3CA mutation), and gefitinib- and erlotinib-resistant non–small cell lung carcinoma xenografts. In summary, PF-04691502 is a potent dual PI3K/mTOR inhibitor with broad antitumor activity. PF-04691502 has entered phase I clinical trials. Mol Cancer Ther; 10(11); 2189–99. ©2011 AACR.
Data from ATM and p53 Regulate FOXM1 Expression via E2F in Breast Cancer Epirubicin Treatment and Resistance
Authors: Millour Julie , de Olano Natalia , Horimoto Yoshiya , Monteiro Lara J. , Langer Julia K. , Aligue Rosa , Hajji Nabil , Lam Eric W.-F.
Published: April 2023

Abstract
In this report, we investigated the role and regulation of forkhead box M1 (FOXM1) in breast cancer and epirubicin resistance. We generated epirubicin-resistant MCF-7 breast carcinoma (MCF-7-EPIR) cells and found FOXM1 protein levels to be higher in MCF-7-EPIR than in MCF-7 cells and that FOXM1 expression is downregulated by epirubicin in MCF-7 but not in MCF-7-EPIR cells. We also established that there is a loss of p53 function in MCF-7-EPIR cells and that epirubicin represses FOXM1 expression at transcription and gene promoter levels through activation of p53 and repression of E2F activity in MCF-7 cells. Using p53−/− mouse embryo fibroblasts, we showed that p53 is important for epirubicin sensitivity. Moreover, transient promoter transfection assays showed that epirubicin and its cellular effectors p53 and E2F1 modulate FOXM1 transcription through an E2F-binding site located within the proximal promoter region. Chromatin immunoprecipitation analysis also revealed that epirubicin treatment increases pRB (retinoblastoma protein) and decreases E2F1 recruitment to the FOXM1 promoter region containing the E2F site. We also found ataxia-telangiectasia mutated (ATM) protein and mRNA to be overexpressed in the resistant MCF-7-EPIR cells compared with MCF-7 cells and that epirubicin could activate ATM to promote E2F activity and FOXM1 expression. Furthermore, inhibition of ATM in U2OS cells with caffeine or depletion of ATM in MCF-7-EPIR with short interfering RNAs can resensitize these resistant cells to epirubicin, resulting in downregulation of E2F1 and FOXM1 expression and cell death. In summary, our data show that ATM and p53 coordinately regulate FOXM1 via E2F to modulate epirubicin response and resistance in breast cancer. Mol Cancer Ther; 10(6); 1046–58. ©2011 AACR.
Data from Hypoxia Induces Genomic DNA Demethylation through the Activation of HIF-1α and Transcriptional Upregulation of MAT2A in Hepatoma Cells
Authors: Liu Quanyan , Liu Li , Zhao Yuhong , Zhang Jin , Wang Dongfeng , Chen Jiwei , He Yueming , Wu Jianguo , Zhang Zhonglin , Liu Zhisu
Published: April 2023

Abstract
Hypoxia-inducible factor 1 (HIF-1) emerges as a crucial player in tumor progression. However, its role in hepatocellular carcinoma (HCC), especially its relation with global DNA methylation patterns in HCC under hypoxic tumor microenvironment is not completely understood. Methionine adenosyltransferase 2A (MAT2A) maintains the homeostasis of S-adenosylmethionine (SAM), a critical marker of genomic methylation status. In this study, we investigated the link between HIF-1α and MAT2A as a mechanism responsible for the change in genomic DNA methylation patterns in liver cancer under hypoxia conditions. Our results showed that hypoxia induces genomic DNA demethylation in CpG islands by reducing the steady-state SAM level both in vitro and in vivo. In addition, HIF-1α and MAT2A expression is correlated with tumor size and TNM stage of liver cancer tissues. We further showed that hypoxia-induced MAT2A expression is HIF-1α dependent and requires the recruitment of p300 and HDAC1. We also identified an authentic consensus HIF-1α binding site in MAT2A promoter by site-directed mutagenesis, electrophoretic mobility shift assay, and chromatin immunoprecipitation assay. Taken together, we show for the first time that hypoxia induces genomic DNA demethylation through the activation of HIF-1α and transcriptional upregulation of MAT2A in hepatoma cells. These findings provide new insights into our understanding of the molecular link between genomic DNA methylation and tumor hypoxia in HCC. Mol Cancer Ther; 10(6); 1113–23. ©2011 AACR.
Data from A Locked, Dimeric CXCL12 Variant Effectively Inhibits Pulmonary Metastasis of CXCR4-Expressing Melanoma Cells Due to Enhanced Serum Stability
Authors: Takekoshi Tomonori , Ziarek Joshua J. , Volkman Brian F. , Hwang Sam T.
Published: April 2023

Abstract
The CXC chemokine receptor-4 (CXCR4) plays a critical role in cancer by positively regulating cancer cell metastasis and survival. We previously showed that high concentrations of the CXCR4 ligand, wild-type CXCL12 (wtCXCL12), could inhibit colorectal cancer metastasis in vivo, and we have hypothesized that wtCXCL12 dimerizes at high concentration to become a potent antagonist of CXCR4. To address this hypothesis, we engineered a covalently locked, dimeric variant of CXCL12 (CXCL122). Herein, we show that CXCL122 can not only inhibit implantation of lung metastasis of CXCR4-B16-F10 melanoma cells more effectively than AMD3100, but that CXCL122 also blocks the growth of established pulmonary tumors. To identify a basis for the in vivo efficacy of CXCL122, we conducted Western blot analysis and ELISA analyses, which revealed that CXCL122 was stable for at least 12 hours in serum, whereas wtCXCL12 was quickly degraded. CXCL122 also maintained its antagonist properties in in vitro chemotaxis assays for up to 24 hours in serum, whereas wtCXCL12 was ineffective after 6 hours. Heat-inactivation of serum prolonged the stability and function of wtCXCL12 by more than 6 hours, suggesting enzymatic degradation as a possible mechanism for wtCXCL12 inactivation. In vitro analysis of amino-terminal cleavage by enzymes dipeptidylpeptidase IV (DPPIV/CD26) and matrix metalloproteinase-2 (MMP-2) resulted in 25-fold and 2-fold slower degradation rates, respectively, of CXCL122 compared with wtCXCL12. In summary, our results suggest CXCL122 possesses greater potential as an antimetastatic drug as compared with AMD3100 or wtCXCL12, potentially due to enhanced serum stability in the presence of N-terminal degrading enzymes. Mol Cancer Ther; 11(11); 2516–25. ©2012 AACR.
Data from Characterization of the Oncogenic Activity of the Novel TRIM59 Gene in Mouse Cancer Models
Authors: Valiyeva Fatma , Jiang Fei , Elmaadawi Ahmed , Moussa Madeleine , Yee Siu-Pok , Raptis Leda , Izawa Jonathan I. , Yang Burton B. , Greenberg Norman M. , Wang Fen , Xuan Jim W.
Published: April 2023

Abstract
A novel TRIM family member, TRIM59 gene was characterized to be upregulated in SV40 Tag oncogene–directed transgenic and knockout mouse prostate cancer models as a signaling pathway effector. We identified two phosphorylated forms of TRIM59 (p53 and p55) and characterized them using purified TRIM59 proteins from mouse prostate cancer models at different stages with wild-type mice and NIH3T3 cells as controls. p53/p55-TRIM59 proteins possibly represent Ser/Thr and Tyr phosphorylation modifications, respectively. Quantitative measurements by ELISA showed that the p-Ser/Thr TRIM59 correlated with tumorigenesis, whereas the p-Tyr-TRIM59 protein correlated with advanced cancer of the prostate (CaP). The function of TRIM59 was elucidated using short hairpin RNA (shRNA)-mediated knockdown of the gene in human CaP cells, which caused S-phase cell-cycle arrest and cell growth retardation. A hit-and-run effect of TRIM59 shRNA knockdown was observed 24 hours posttransfection. Differential cDNA microarrray analysis was conducted, which showed that the initial and rapid knockdown occurred early in the Ras signaling pathway. To confirm the proto-oncogenic function of TRIM59 in the Ras signaling pathway, we generated a transgenic mouse model using a prostate tissue–specific gene (PSP94) to direct the upregulation of the TRIM59 gene. Restricted TRIM59 gene upregulation in the prostate revealed the full potential for inducing tumorigenesis, similar to the expression of SV40 Tag, and coincided with the upregulation of genes specific to the Ras signaling pathway and bridging genes for SV40 Tag–mediated oncogenesis. The finding of a possible novel oncogene in animal models will implicate a novel strategy for diagnosis, prognosis, and therapy for cancer. Mol Cancer Ther; 10(7); 1229–40. ©2011 AACR.
Data from Low-Dose Fractionated Radiation Potentiates the Effects of Cisplatin Independent of the Hyper-Radiation Sensitivity in Human Lung Cancer Cells
Authors: Gupta Seema , Koru-Sengul Tulay , Arnold Susanne M. , Devi Gayathri R. , Mohiuddin Mohammed , Ahmed Mansoor M.
Published: April 2023

Abstract
In this study, the role of hyper-radiation sensitivity (HRS) in potentiating the effects of cisplatin by low-dose fractionated radiation (LDFRT) was evaluated in four human non–small cell lung cancer cell lines. Presence of HRS and cisplatin enhancement ratio (CER) by LDFRT/2 Gy was assessed using colony-forming and apoptotic assays. Cell-cycle disturbances were studied by flow cytometry. Expression of genes involved in apoptosis was assessed using real-time reverse transcriptase PCR arrays. H-157 cells showed a distinct HRS region, followed by UKY-29 and A549 cells, whereas it was absent in H460 cells, which when lack HRS showed maximum CER with LDFRT (4 × 0.5 Gy) both by clonogenic inhibition and by apoptosis compared with single fraction of 2 Gy whereas the most radioresistant A549 cells had the least CER, with no significant differences between LDFRT or 2 Gy. Interestingly, in H-157 cells, a more pronounced CER was observed with LDFRT when assessed by apoptosis but clonogenic inhibition-CER was higher with 2 Gy than with LDFRT. Excluding H-157 cells, the CER by LDFRT was inversely proportional to radioresistance [(determined by D0, the dose to reduce survival by 67% from any point on the linear portion of the survival curve or surviving fraction (SF) at 2 Gy (SF2)] of the cells. LDFRT alone or in combination with cisplatin induced larger number of proapoptotic genes than 2 Gy or cisplatin + 2 Gy in cells showing HRS when compared to H460 cells that lack HRS. These findings indicate that chemopotentiation by LDFRT is correlated more with the intrinsic radiation sensitivity of the non–small lung cancer cells than the HRS phenomenon whereas the mode of cell killing is both through apoptosis and clonogenic inhibition. Mol Cancer Ther; 10(2); 292–302. ©2011 AACR.
Data from Caspase-3–Dependent Mitotic Checkpoint Inactivation by the Small-Molecule Inducers of Mitotic Slippage SU6656 and Geraldol
Authors: Riffell Jenna L. , Jänicke Reiner U. , Roberge Michel
Published: April 2023

Abstract
Microtubule-targeting cancer drugs such as paclitaxel block cell-cycle progression at mitosis by prolonged activation of the mitotic checkpoint. Cells can spontaneously escape mitotic arrest and enter interphase without chromosome segregation by a process termed mitotic slippage that involves the degradation of cyclin B1 without mitotic checkpoint inactivation. Inducing mitotic slippage with chemicals causes cells to die after multiple rounds of DNA replication without cell division, which may enhance the antitumor activity of microtubule-targeting drugs. Here, we explore pathways leading to mitotic slippage by using SU6656 and geraldol, two recently identified chemical inducers of mitotic slippage. Mitotic slippage induced by SU6656 or geraldol was blocked by the proteasome inhibitor MG-132 and involved proteasome-dependent degradation of cyclin B1 and the mitotic checkpoint proteins budding uninhibited by benzimidazole related 1 (BubR1) and cell division cycle 20 (Cdc20) in T98G cells. Mitotic slippage and the degradation of BubR1 and Cdc20 were also inhibited by the caspase-3 and -7 inhibitor DEVD-CHO. MCF-7 cells lacking caspase-3 expression could not degrade BubR1 or undergo mitotic slippage in response to SU6656 or geraldol. Introduction of caspase-3 completely restored the ability of MCF-7 cells to degrade BubR1 and undergo mitotic slippage. However, lack of expression of caspase-3 did not affect cell death after exposure to paclitaxel, with or without mitotic slippage induction. The requirement for caspase-3 for chemically induced mitotic slippage reveals a new mechanism for mitotic exit and a link between mitosis and apoptosis that has implications for the outcome of cancer chemotherapy. Mol Cancer Ther; 10(5); 839–49. ©2011 AACR.
Data from Crizotinib Induces PUMA-Dependent Apoptosis in Colon Cancer Cells
Authors: Zheng Xingnan , He Kan , Zhang Lin , Yu Jian
Published: April 2023

Abstract
Oncogenic alterations in MET or anaplastic lymphoma kinase (ALK) have been identified in a variety of human cancers. Crizotinib (PF02341066) is a dual MET and ALK inhibitor and approved for the treatment of a subset of non–small cell lung carcinoma and in clinical development for other malignancies. Crizotinib can induce apoptosis in cancer cells, whereas the underlying mechanisms are not well understood. In this study, we found that crizotinib induces apoptosis in colon cancer cells through the BH3-only protein PUMA. In cells with wild-type p53, crizotinib induces rapid induction of PUMA and Bim accompanied by p53 stabilization and DNA damage response. The induction of PUMA and Bim is mediated largely by p53, and deficiency in PUMA or p53, but not Bim, blocks crizotinib-induced apoptosis. Interestingly, MET knockdown led to selective induction of PUMA, but not Bim or p53. Crizotinib also induced PUMA-dependent apoptosis in p53-deficient colon cancer cells and synergized with gefitinib or sorafenib to induce marked apoptosis via PUMA in colon cancer cells. Furthermore, PUMA deficiency suppressed apoptosis and therapeutic responses to crizotinib in xenograft models. These results establish a critical role of PUMA in mediating apoptotic responses of colon cancer cells to crizotinib and suggest that mechanisms of oncogenic addiction to MET/ALK-mediated survival may be cell type-specific. These findings have important implications for future clinical development of crizotinib. Mol Cancer Ther; 12(5); 777–86. ©2013 AACR.
Data from Stromal Platelet-Derived Growth Factor Receptor α (PDGFRα) Provides a Therapeutic Target Independent of Tumor Cell PDGFRα Expression in Lung Cancer Xenografts
Authors: Gerber David E. , Gupta Puja , Dellinger Michael T. , Toombs Jason E. , Peyton Michael , Duignan Inga , Malaby Jennifer , Bailey Timothy , Burns Colleen , Brekken Rolf A. , Loizos Nick
Published: April 2023

Abstract
In lung cancer, platelet-derived growth factor receptor α (PDGFRα) is expressed frequently by tumor-associated stromal cells and by cancer cells in a subset of tumors. We sought to determine the effect of targeting stromal PDGFRα in preclinical lung tumor xenograft models (human tumor, mouse stroma). Effects of anti-human (IMC-3G3) and anti-mouse (1E10) PDGFRα monoclonal antibodies (mAb) on proliferation and PDGFRα signaling were evaluated in lung cancer cell lines and mouse fibroblasts. Therapy studies were conducted using established PDGFRα-positive H1703 cells and PDGFRα-negative Calu-6, H1993, and A549 subcutaneous tumors in immunocompromised mice treated with vehicle, anti-PDGFRα mAbs, chemotherapy, or combination therapy. Tumors were analyzed for growth and levels of growth factors. IMC-3G3 inhibited PDGFRα activation and the growth of H1703 cells in vitro and tumor growth in vivo, but had no effect on PDGFRα-negative cell lines or mouse fibroblasts. 1E10 inhibited growth and PDGFRα activation of mouse fibroblasts, but had no effect on human cancer cell lines in vitro. In vivo, 1E10-targeted inhibition of murine PDGFRα reduced tumor growth as single-agent therapy in Calu-6 cells and enhanced the effect of chemotherapy in xenografts derived from A549 cells. We also identified that low expression cancer cell expression of VEGF-A and elevated expression of PDGF-AA were associated with response to stromal PDGFRα targeting. We conclude that stromal PDGFRα inhibition represents a means for enhancing control of lung cancer growth in some cases, independent of tumor cell PDGFRα expression. Mol Cancer Ther; 11(11); 2473–82. ©2012 AACR.
Data from Dibenzophenanthridines as Inhibitors of Glutaminase C and Cancer Cell Proliferation
Authors: Katt William P. , Ramachandran Sekar , Erickson Jon W. , Cerione Richard A.
Published: April 2023

Abstract
One hallmark of cancer cells is their adaptation to rely upon an altered metabolic scheme that includes changes in the glycolytic pathway, known as the Warburg effect, and elevated glutamine metabolism. Glutaminase, a mitochondrial enzyme, plays a key role in the metabolism of glutamine in cancer cells, and its inhibition could significantly impact malignant transformation. The small molecule 968, a dibenzophenanthridine, was recently shown to inhibit recombinantly expressed glutaminase C, to block the proliferation and anchorage-independent colony formation of human cancer cells in culture, and to inhibit tumor formation in mouse xenograft models. Here, we examine the structure–activity relationship that leads to 968-based inhibition of glutaminase and cancer cell proliferation, focusing upon a “hot-spot” ring previously identified as critical to 968 activity. We find that the hot-spot ring must be substituted with a large, nonplanar functionality (e.g., a t-butyl group) to bestow activity to the series, leading us to a model whereby the molecule binds glutaminase at a previously undescribed allosteric site. We conduct docking studies to locate potential 968-binding sites and proceed to test a specific set of docking solutions via site-directed mutagenesis. We verify the results from our initial assay of 968 and its analogues by cellular studies using MDA-MB-231 breast cancer cells. Mol Cancer Ther; 11(6); 1269–78. ©2012 AACR.
Data from Chemosensitization of Cancer Cells by KU-0060648, a Dual Inhibitor of DNA-PK and PI-3K
Authors: Munck Joanne M. , Batey Michael A. , Zhao Yan , Jenkins Helen , Richardson Caroline J. , Cano Celine , Tavecchio Michele , Barbeau Jody , Bardos Julia , Cornell Liam , Griffin Roger J. , Menear Keith , Slade Andrew , Thommes Pia , Martin Niall M.B. , Newell David R. , Smith Graeme C.M. , Curtin Nicola J.
Published: April 2023

Abstract
DNA double-strand breaks (DSB) are the most cytotoxic lesions induced by topoisomerase II poisons. Nonhomologous end joining (NHEJ) is a major pathway for DSB repair and requires DNA-dependent protein kinase (DNA-PK) activity. DNA-PK catalytic subunit (DNA-PKcs) is structurally similar to PI-3K, which promotes cell survival and proliferation and is upregulated in many cancers. KU-0060648 is a dual inhibitor of DNA-PK and PI-3K in vitro. KU-0060648 was investigated in a panel of human breast and colon cancer cells. The compound inhibited cellular DNA-PK autophosphorylation with IC50 values of 0.019 μmol/L (MCF7 cells) and 0.17 μmol/L (SW620 cells), and PI-3K–mediated AKT phosphorylation with IC50 values of 0.039 μmol/L (MCF7 cells) and more than 10 μmol/L (SW620 cells). Five-day exposure to 1 μmol/L KU-0060648 inhibited cell proliferation by more than 95% in MCF7 cells but only by 55% in SW620 cells. In clonogenic survival assays, KU-0060648 increased the cytotoxicity of etoposide and doxorubicin across the panel of DNA-PKcs–proficient cells, but not in DNA-PKcs–deficient cells, thus confirming that enhanced cytotoxicity was due to DNA-PK inhibition. In mice bearing SW620 and MCF7 xenografts, concentrations of KU-0060648 that were sufficient for in vitro growth inhibition and chemosensitization were maintained within the tumor for at least 4 hours at nontoxic doses. KU-0060648 alone delayed the growth of MCF7 xenografts and increased etoposide-induced tumor growth delay in both in SW620 and MCF7 xenografts by up to 4.5-fold, without exacerbating etoposide toxicity to unacceptable levels. The proof-of-principle in vitro and in vivo chemosensitization with KU-0060648 justifies further evaluation of dual DNA-PK and PI-3K inhibitors. Mol Cancer Ther; 11(8); 1789–98. ©2012 AACR.