bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from miR-148b Functions as a Tumor Suppressor in Pancreatic Cancer by Targeting AMPKα1
Authors: Zhao Gang , Zhang Jun-Gang , Liu Yang , Qin Qi , Wang Bo , Tian Kui , Liu Lin , Li Xiang , Niu Yi , Deng Shi-Chang , Wang Chun-You
Published: April 2023

Abstract
miRNAs are small noncoding RNAs that participate in a variety of biologic processes, and dysregulation of miRNA is always associated with cancer development and progression. Aberrant expression of miR-148b has been found in some types of cancer, but its expression and potential biologic role in pancreatic cancer are still largely unknown. In this study, our data showed that miR-148b was significantly downregulated in 48 pairs of human pancreatic cancer tissues and five cell lines. Furthermore, the deregulated miR-148b was correlated with increased tumor size, late tumor–node–metastasis stage, lymphatic invasion, distant metastasis, and worse prognosis in pancreatic cancer. Functional studies indicated overexpression of miR-148b dramatically suppressed the growth of cancer cells, attributable to induction of apoptosis and cell-cycle arrest at S-phase. Meanwhile, miR-148b remarkably inhibited invasion and enhanced chemosensitivity of pancreatic cancer cells. Moreover, ectopic expression of miR-148b was able to inhibit tumorigenicity in nude mice. Further studies revealed that AMPKα1 might be the direct target gene of miR-148b, and overexpressed AMPKα1 inversely correlated with miR-148b in pancreatic cancer. Silencing of AMPKα1 with RNA interference inhibited the growth of pancreatic cancer cells in vitro and in vivo and also induced apoptosis, cell-cycle arrest, and inhibited invasion of cancer cells, which is consistent with the effects of miR-148b overexpression. In conclusion, miR-148b can inhibit cell proliferation, invasion, and enhance chemosensitivity of pancreatic cancer by targeting AMPKα1. Our present results implicate the potential effects of miR-148b on prognosis and treatment of pancreatic cancer. Mol Cancer Ther; 12(1); 83–93. ©2012 AACR.
Data from SKLB1206, a Novel Orally Available Multikinase Inhibitor Targeting EGFR Activating and T790M Mutants, ErbB2, ErbB4, and VEGFR2, Displays Potent Antitumor Activity Both In Vitro and In Vivo
Authors: Pan Youli , Xu Yong , Feng Shan , Luo Shidong , Zheng Renlin , Yang Jiao , Wang Lijiao , Zhong Lei , Yang Han-Yu , Wang Bing-Lin , Yu Yang , Liu Jingjing , Cao Zhixing , Wang Xiaoyan , Ji Pan , Wang Zerong , Chen Xin , Zhang Shuang , Wei Yu-Quan , Yang Sheng-Yong
Published: April 2023

Abstract
Anti-epidermal growth factor receptor (EGFR) treatment has been successfully applied in clinical cancer therapy. However, the clinical efficacy of first-generation reversible EGFR inhibitors, such as gefitinib and erlotinib, is limited by the development of drug-resistant mutations, including the gatekeeper T790M mutation and upregulation of alternative signaling pathways. Second-generation irreversible EGFR inhibitors that were designed to overcome the drug resistance due to the T790M mutation have thus far had limited success. Here, we report a novel reversible EGFR inhibitor, SKLB1206, which has potent activity against EGFR with gefitinib-sensitive and -resistant (T790M) mutations. In addition, SKLB1206 has also considerable inhibition potency against some other related oncokinases, including ErbB2, ErbB4, and VEGF receptor 2 (VEGFR2). SKLB1206 exhibited highly antiproliferative activity against a range of EGFR-mutant cell lines, including gefitinib-sensitive and -resistant cell lines, and EGFR or ErbB2-overexpressing cell lines. SKLB1206 also showed a potent antiangiogenesis effect in vitro, in a zebrafish embryonic angiogenesis assay, and in an alginate-encapsulate tumor cell assay. In vivo, oral administration of SKLB1206 showed complete tumor regression in gefitinib-sensitive HCC827 and PC-9 xenograft models and showed a considerable antitumor effect on the gefitinib-resistant H1975 model as well as other EGFR/ErbB2-overexpressing or -dependent tumor models including A431, LoVo, and N87 established in athymic mice. SKLB1206 also showed a very good oral bioavailability (50.1%). Collectively, these preclinical evaluations may support clinical development of SKLB1206 for cancers with EGFR-activating/resistance mutations or EGFR/ErbB2 overexpressed. Mol Cancer Ther; 11(4); 952–62. ©2012 AACR.
Data from Spongian Diterpenoids Inhibit Androgen Receptor Activity
Authors: Yang Yu Chi , Meimetis Labros G. , Tien Amy H. , Mawji Nasrin R. , Carr Gavin , Wang Jun , Andersen Raymond J. , Sadar Marianne D.
Published: April 2023

Abstract
Androgen receptor is a ligand-activated transcription factor and a validated drug target for all stages of prostate cancer. Antiandrogens compete with physiologic ligands for androgen receptor ligand-binding domain (LBD). High-throughput screening of a marine natural product library for small molecules that inhibit androgen receptor transcriptional activity yielded the furanoditerpenoid spongia-13(16),-14-dien-19-oic acid, designated terpene 1 (T1). Characterization of T1 and the structurally related semisynthetic analogues (T2 and T3) revealed that these diterpenoids have antiandrogen properties that include inhibition of both androgen-dependent proliferation and androgen receptor transcriptional activity by a mechanism that involved competing with androgen for androgen receptor LBD and blocking essential N/C interactions required for androgen-induced androgen receptor transcriptional activity. Structure–activity relationship analyses revealed some chemical features of T1 that are associated with activity and yielded T3 as the most potent analogue. In vivo, T3 significantly reduced the weight of seminal vesicles, which are an androgen-dependent tissue, thereby confirming the on-target activity of T3. The ability to create analogues of diterpenoids that have varying antiandrogen activity represents a novel class of chemical compounds for the analysis of androgen receptor ligand-binding properties and therapeutic development. Mol Cancer Ther; 12(5); 621–31. ©2013 AACR.
Data from Small-Molecule Inhibitors of USP1 Target ID1 Degradation in Leukemic Cells
Authors: Mistry Helena , Hsieh Grace , Buhrlage Sara J. , Huang Min , Park Eunmi , Cuny Gregory D. , Galinsky Ilene , Stone Richard M. , Gray Nathanael S. , D'Andrea Alan D. , Parmar Kalindi
Published: April 2023

Abstract
Inhibitor of DNA binding 1 (ID1) transcription factor is essential for the proliferation and progression of many cancer types, including leukemia. However, the ID1 protein has not yet been therapeutically targeted in leukemia. ID1 is normally polyubiquitinated and degraded by the proteasome. Recently, it has been shown that USP1, a ubiquitin-specific protease, deubiquitinates ID1 and rescues it from proteasome degradation. Inhibition of USP1 therefore offers a new avenue to target ID1 in cancer. Here, using a ubiquitin-rhodamine–based high-throughput screening, we identified small-molecule inhibitors of USP1 and investigated their therapeutic potential for leukemia. These inhibitors blocked the deubiquitinating enzyme activity of USP1 in vitro in a dose-dependent manner with an IC50 in the high nanomolar range. USP1 inhibitors promoted the degradation of ID1 and, concurrently, inhibited the growth of leukemic cell lines in a dose-dependent manner. A known USP1 inhibitor, pimozide, also promoted ID1 degradation and inhibited growth of leukemic cells. In addition, the growth of primary acute myelogenous leukemia (AML) patient-derived leukemic cells was inhibited by a USP1 inhibitor. Collectively, these results indicate that the novel small-molecule inhibitors of USP1 promote ID1 degradation and are cytotoxic to leukemic cells. The identification of USP1 inhibitors therefore opens up a new approach for leukemia therapy. Mol Cancer Ther; 12(12); 2651–62. ©2013 AACR.
Data from MEDI0639: A Novel Therapeutic Antibody Targeting Dll4 Modulates Endothelial Cell Function and Angiogenesis In Vivo
Authors: Jenkins David W. , Ross Sarah , Veldman-Jones Margaret , Foltz Ian N. , Clavette Brandon C. , Manchulenko Kathy , Eberlein Cath , Kendrew Jane , Petteruti Philip , Cho Song , Damschroder Melissa , Peng Li , Baker Dawn , Smith Neil R. , Weir Hazel M. , Blakey David C. , Bedian Vahe , Barry Simon T.
Published: April 2023

Abstract
The Notch signaling pathway has been implicated in cell fate determination and differentiation in many tissues. Accumulating evidence points toward a pivotal role in blood vessel formation, and the importance of the Delta-like ligand (Dll) 4-Notch1 ligand–receptor interaction has been shown in both physiological and tumor angiogenesis. Disruption of this interaction leads to a reduction in tumor growth as a result of an increase in nonfunctional vasculature leading to poor perfusion of the tumor. MEDI0639 is an investigational human therapeutic antibody that targets Dll4 to inhibit the interaction between Dll4 and Notch1. The antibody cross-reacts to cynomolgus monkey but not mouse species orthologues. In vitro MEDI0639 inhibits the binding of Notch1 to Dll4, interacting via a novel epitope that has not been previously described. Binding to this epitope translates into MEDI0639 reversing Notch1-mediated suppression of human umbilical vein endothelial cell growth in vitro. MEDI0639 administration resulted in stimulation of tubule formation in a three-dimensional (3D) endothelial cell outgrowth assay, a phenotype driven by disruption of the Dll4-Notch signaling axis. In contrast, in a two-dimensional endothelial cell–fibroblast coculture model, MEDI0639 is a potent inhibitor of tubule formation. In vivo, MEDI0639 shows activity in a human endothelial cell angiogenesis assay promoting human vessel formation and reducing the number of vessels with smooth muscle actin-positive mural cells coverage. Collectively, the data show that MEDI0639 is a potent modulator of Dll4-Notch signaling pathway. Mol Cancer Ther; 11(8); 1650–60. ©2012 AACR.
Data from MK-2206, a Novel Allosteric Inhibitor of Akt, Synergizes with Gefitinib against Malignant Glioma via Modulating Both Autophagy and Apoptosis
Authors: Cheng Yan , Zhang Yi , Zhang Li , Ren Xingcong , Huber-Keener Kathryn J. , Liu Xiaoyuan , Zhou Lei , Liao Jason , Keihack Heike , Yan Li , Rubin Eric , Yang Jin-Ming
Published: April 2023

Abstract
Gefitinib, a small molecule inhibitor of the epidermal growth factor receptor tyrosine kinase, has been shown to induce autophagy as well as apoptosis in tumor cells. Yet, how to use autophagy and apoptosis to improve therapeutic efficacy of this drug against cancer remains to be explored. We reported here that MK-2206, a potent allosteric Akt inhibitor currently in phase I trials in patients with solid tumors, could reinforce the cytocidal effect of gefitinib against glioma. We found that cotreatment with gefitinib and MK-2206 increased the cytotoxicity of this growth factor receptor inhibitor in the glioma cells, and the CompuSyn synergism/antagonism analysis showed that MK-2206 acted synergistically with gefitinib. The benefit of the combinatorial treatment was also shown in an intracranial glioma mouse model. In the presence of MK-2206, there was a significant increase in apoptosis in glioma cells treated with gefitinib. MK-2206 also augmented the autophagy-inducing effect of gefitinib, as evidenced by increased levels of the autophagy marker, LC3-II. Inhibition of autophagy by silencing of the key autophagy gene, beclin 1 or 3-MA, further increased the cytotoxicity of this combinatorial treatment, suggesting that autophagy induced by these agents plays a cytoprotective role. Notably, at 48 hours following the combinatorial treatment, the level of LC3-II began to decrease but Bim was significantly elevated, suggesting a switch from autophagy to apoptosis. On the basis of the synergistic effect of MK-2206 on gefitinib observed in this study, the combination of these two drugs may be utilized as a new therapeutic regimen for malignant glioma. Mol Cancer Ther; 11(1); 154–64. ©2011 AACR.
Data from PARP1 Is Overexpressed in Nasopharyngeal Carcinoma and Its Inhibition Enhances Radiotherapy
Authors: Chow Jeremy P.H. , Man Wing Yu , Mao Mao , Chen Han , Cheung Florence , Nicholls John , Tsao Sai Wah , Li Lung Maria , Poon Randy Y.C.
Published: April 2023

Abstract
Nasopharyngeal carcinoma is a rare but highly invasive cancer. As options of agents for effective combination chemoradiotherapy for advanced nasopharyngeal carcinoma are limited, novel therapeutic approaches are desperately needed. The ubiquitin ligase CHFR is known to target PARP1 for degradation and is epigenetically inactivated in nasopharyngeal carcinoma. We present evidence that PARP1 protein is indeed overexpressed in nasopharyngeal carcinoma cells in comparison with immortalized normal nasopharyngeal epithelial cells. Tissue microarray analysis also indicated that PARP1 protein is significantly elevated in primary nasopharyngeal carcinoma tissues, with strong correlation with all stages of nasopharyngeal carcinoma development. We found that the PARP inhibitor AZD2281 (olaparib) increased DNA damage, cell-cycle arrest, and apoptosis in nasopharyngeal carcinoma cells challenged with ionizing radiation or temozolomide. Isobologram analysis confirmed that the cytotoxicity triggered by AZD2281 and DNA-damaging agents was synergistic. Finally, AZD2281 also enhanced the tumor-inhibitory effects of ionizing radiation in animal xenograft models. These observations implicate that PARP1 overexpression is an early event in nasopharyngeal carcinoma development and provide a molecular basis of using PARP inhibitors to potentiate treatment of nasopharyngeal carcinoma with radio- and chemotherapy. Mol Cancer Ther; 12(11); 2517–28. ©2013 AACR.
Data from Niclosamide Overcomes Acquired Resistance to Erlotinib through Suppression of STAT3 in Non–Small Cell Lung Cancer
Authors: Li Rui , Hu Zhongliang , Sun Shi-Yong , Chen Zhuo G. , Owonikoko Taofeek K. , Sica Gabriel L. , Ramalingam Suresh S. , Curran Walter J. , Khuri Fadlo R. , Deng Xingming
Published: April 2023

Abstract
The emergence of resistance to EGF receptor (EGFR) inhibitor therapy is a major clinical problem for patients with non–small cell lung cancer (NSCLC). The mechanisms underlying tumor resistance to inhibitors of the kinase activity of EGFR are not fully understood. Here, we found that inhibition of EGFR by erlotinib induces STAT3 phosphorylation at Tyr705 in association with increased Bcl2/Bcl-XL at both mRNA and protein levels in various human lung cancer cells. PTPMeg2 is a physiologic STAT3 phosphatase that can directly dephosphorylate STAT3 at the Tyr705 site. Intriguingly, treatment of cells with erlotinib results in downregulation of PTPMeg2 without activation of STAT3 kinases [i.e., Janus-activated kinase (JAK2) or c-Src], suggesting that erlotinib-enhanced phosphorylation of STAT3 may occur, at least in part, from suppression of PTPMeg2 expression. Because elevated levels of phosphorylated STAT3 (pSTAT3), Bcl2, and Bcl-XL were observed in erlotinib-resistant lung cancer (HCC827/ER) cells as compared with erlotinib-sensitive parental HCC827 cells, we postulate that the erlotinib-activated STAT3/Bcl2/Bcl-XL survival pathway may contribute to acquired resistance to erlotinib. Both blockage of Tyr705 phosphorylation of STAT3 by niclosamide and depletion of STAT3 by RNA interference in HCC827/ER cells reverse erlotinib resistance. Niclosamide in combination with erlotinib potently represses erlotinib-resistant lung cancer xenografts in association with increased apoptosis in tumor tissues, suggesting that niclosamide can restore sensitivity to erlotinib. These findings uncover a novel mechanism of erlotinib resistance and provide a novel approach to overcome resistance by blocking the STAT3/Bcl2/Bcl-XL survival signaling pathway in human lung cancer. Mol Cancer Ther; 12(10); 2200–12. ©2013 AACR.
Data from Targeted Degradation of KRAS by an Engineered Ubiquitin Ligase Suppresses Pancreatic Cancer Cell Growth In Vitro and In Vivo
Authors: Ma Yihui , Gu Yumei , Zhang Qiang , Han Yongqing , Yu Shuangni , Lu Zhaohui , Chen Jie
Published: April 2023

Abstract
KRAS is an attractive pancreatic ductal adenocarcinoma (PDAC) therapeutic target. E3 ligase is thought to be the component of the ubiquitin conjugation system that is directly responsible for substrate recognition. In this study, an engineered E3 ubiquitin ligase (RC-U) was generated to target the KRAS oncoprotein for ubiquitination and degradation. The engineered E3 ubiquitin ligases (RC-U) were constructed (pRC-U and lentivirus-expressing RC-U). After transfecting the pRC-U plasmid into human pancreatic cancer cells, KRAS expression levels were determined. KRAS expression was also evaluated in cells transfected with pRC-U and treated with MG-132 or cycloheximide. Interactions between RC-U and KRAS as well as whether RC-U could ubiquitinate KRAS were investigated. Extracellular signal–regulated kinase 1/2 (ERK1/2) and phosphorylated ERK 1/2 (pERK1/2) levels were examined in pancreatic cancer cells transfected with pRC-U. The effects of RC-U on pancreatic cancer cell growth were assessed. RC-U decreased KRAS protein levels. After pRC-U transfection, KRAS stability was increased in the presence of MG-132. HEK 293T cells were transfected with a mutant KRAS construct together with pRC-U and incubated with cycloheximide to inhibit new protein synthesis. The exogenous mutant KRAS oncoprotein was degraded more quickly. RC-U can bind KRAS and KRAS can be ubiquitinated by RC-U. pERK1/2 protein levels were decreased. RC-U resulted in reduced cell proliferation in vitro and in vivo. KRAS destruction by RC-U occurred through a ubiquitin-dependent, proteasome-mediated degradation pathway. RC-U inhibited pancreatic cancer cell growth in vitro and in vivo. Mol Cancer Ther; 12(3); 286–94. ©2012 AACR.
Data from Evidence for the Ubiquitin Protease UBP43 as an Antineoplastic Target
Authors: Guo Yongli , Chinyengetere Fadzai , Dolinko Andrey V. , Lopez-Aguiar Alexandra , Lu Yun , Galimberti Fabrizio , Ma Tian , Feng Qing , Sekula David , Freemantle Sarah J. , Andrew Angeline S. , Memoli Vincent , Dmitrovsky Ethan
Published: April 2023

Abstract
New pharmacologic targets are needed for lung cancer. One candidate pathway to target is composed of the E1-like ubiquitin-activating enzyme (UBE1L) that associates with interferon-stimulated gene 15 (ISG15), which complexes with and destabilizes cyclin D1. Ubiquitin protease 43 (UBP43/USP18) removes ISG15 from conjugated proteins. This study reports that gain of UBP43 stabilized cyclin D1, but not other D-type cyclins or cyclin E. This depended on UBP43 enzymatic activity; an enzymatically inactive UBP43 did not affect cyclin D1 stability. As expected, small interfering RNAs that reduced UBP43 expression also decreased cyclin D1 levels and increased apoptosis in a panel of lung cancer cell lines. Forced cyclin D1 expression rescued UBP43 apoptotic effects, which highlighted the importance of cyclin D1 in conferring this. Short hairpin RNA-mediated reduction of UBP43 significantly increased apoptosis and reduced murine lung cancer growth in vitro and in vivo after transplantation of these cells into syngeneic mice. These cells also exhibited increased response to all-trans-retinoic acid, interferon, or cisplatin treatments. Notably, gain of UBP43 expression antagonized these effects. Normal-malignant human lung tissue arrays were examined independently for UBP43, cyclin D1, and cyclin E immunohistochemical expression. UBP43 was significantly (P < 0.01) increased in the malignant versus normal lung. A direct relationship was found between UBP43 and cyclin D1 (but not cyclin E) expression. Differential UBP43 expression was independently detected in a normal-malignant tissue array with diverse human cancers. Taken together, these findings uncovered UBP43 as a previously unrecognized antineoplastic target. Mol Cancer Ther; 11(9); 1968–77. ©2012 AACR.
Data from Microtubule Dynamics Control Tail Retraction in Migrating Vascular Endothelial Cells
Authors: Ganguly Anutosh , Yang Hailing , Zhang Hong , Cabral Fernando , Patel Kamala D.
Published: April 2023

Abstract
Drugs that target microtubules are potent inhibitors of angiogenesis, but their mechanism of action is not well understood. To explore this, we treated human umbilical vein endothelial cells with paclitaxel, vinblastine, and colchicine and measured the effects on microtubule dynamics and cell motility. In general, lower drug concentrations suppressed microtubule dynamics and inhibited cell migration whereas higher concentrations were needed to inhibit cell division; however, surprisingly, large drug-dependent differences were seen in the relative concentrations needed to inhibit these two processes. Suppression of microtubule dynamics did not significantly affect excursions of lamellipodia away from the nucleus or prevent cells from elongating; but, it did inhibit retraction of the trailing edges that are normally enriched in dynamic microtubules, thereby limiting cell locomotion. Complete removal of microtubules with a high vinblastine concentration caused a loss of polarity that resulted in roundish, rather than elongated, cells, rapid but nondirectional membrane activity, and little cell movement. The results are consistent with a model in which more static microtubules stabilize the leading edge of migrating cells, whereas more dynamic microtubules locate to the rear where they can remodel and allow tail retraction. Suppressing microtubule dynamics interferes with tail retraction, but removal of microtubules destroys the asymmetry needed for cell elongation and directional motility. The prediction that suppressing microtubule dynamics might be sufficient to prevent angiogenesis was supported by showing that low concentrations of paclitaxel could prevent the formation of capillary-like structures in an in vitro tube formation assay. Mol Cancer Ther; 12(12); 2837–46. ©2013 AACR.
Data from Subtype-Specific MEK-PI3 Kinase Feedback as a Therapeutic Target in Pancreatic Adenocarcinoma
Authors: Mirzoeva Olga K. , Collisson Eric A. , Schaefer Peter M. , Hann Byron , Hom Yun K. , Ko Andrew H. , Korn W. Michael
Published: April 2023

Abstract
Mutations in the KRAS oncogene are dominant features in pancreatic ductal adenocarcinoma (PDA). Because KRAS itself is considered “undruggable,” targeting pathways downstream of KRAS are being explored as a rational therapeutic strategy. We investigated the consequences of MAP–ERK kinase (MEK) inhibition in a large PDA cell line panel. Inhibition of MEK activated phosphoinositide 3-kinase in an EGF receptor (EGFR)-dependent fashion and combinations of MEK and EGFR inhibitors synergistically induced apoptosis. This combinatorial effect was observed in the epithelial but not mesenchymal subtype of PDA. RNA expression analysis revealed predictors of susceptibility to the combination, including E-cadherin, HER3, and the miR200-family of microRNAs, whereas expression of the transcription factor ZEB1 was associated with resistance to the drug combination. Knockdown of HER3 in epithelial-type and ZEB1 in mesenchymal-type PDA cell lines resulted in sensitization to the combination of MEK and EGFR inhibitors. Thus, our findings suggest a new, subtype-specific, and personalized therapeutic strategy for pancreatic cancer. Mol Cancer Ther; 12(10); 2213–25. ©2013 AACR.
Data from Activation of IL-6R/JAK1/STAT3 Signaling Induces De Novo Resistance to Irreversible EGFR Inhibitors in Non–Small Cell Lung Cancer with T790M Resistance Mutation
Authors: Kim Sun Mi , Kwon Oh-Joon , Hong Yun Kyoung , Kim Joo Hang , Solca Flavio , Ha Sang-Jun , Soo Ross A. , Christensen James G. , Lee Ji Hyun , Cho Byoung Chul
Published: April 2023

Abstract
The secondary T790M mutation in epidermal growth factor receptor (EGFR) is the major mechanism of acquired resistance to EGFR tyrosine kinase inhibitors (TKI) in non–small cell lung cancer (NSCLC). Although irreversible EGFR TKIs, such as afatinib or dacomitinib, have been introduced to overcome the acquired resistance, they showed a limited efficacy in NSCLC with T790M. Herein, we identified the novel de novo resistance mechanism to irreversible EGFR TKIs in H1975 and PC9-GR cells, which are NSCLC cells with EGFR T790M. Afatinib activated interleukin-6 receptor (IL-6R)/JAK1/STAT3 signaling via autocrine IL-6 secretion in both cells. Inhibition of IL-6R/JAK1/STAT3 signaling pathway increased the sensitivity to afatinib. Cancer cells showed stronger STAT3 activation and enhanced resistance to afatinib in the presence of MRC5 lung fibroblasts. Blockade of IL-6R/JAK1 significantly increased the sensitivity to afatinib through inhibition of afatinib-induced STAT3 activation augmented by the interaction with fibroblasts, suggesting a critical role of paracrine IL-6R/JAK1/STAT3 loop between fibroblasts and cancer cells in the development of drug resistance. The enhancement of afatinib sensitivity by inhibition of IL-6R/JAK1/STAT3 signaling was confirmed in in vivo PC9-GR xenograft model. Similar to afatinib, de novo resistance to dacomitinib in H1975 and PC9-GR cells was also mediated by dacomitinib-induced JAK1/STAT3 activation. Taken together, these findings suggest that IL-6R/JAK1/STAT3 signaling can be a potential therapeutic target to enhance the efficacy of irreversible EGFR TKIs in patients with EGFR T790M. Mol Cancer Ther; 11(10); 2254–64. ©2012 AACR.
Data from microRNA-9 Targets Matrix Metalloproteinase 14 to Inhibit Invasion, Metastasis, and Angiogenesis of Neuroblastoma Cells
Authors: Zhang Huanyu , Qi Meng , Li Shiwang , Qi Teng , Mei Hong , Huang Kai , Zheng Liduan , Tong Qiangsong
Published: April 2023

Abstract
Matrix metalloproteinase (MMP)-14 is the only membrane-anchored MMP that plays a critical role in tumor metastasis and angiogenesis. However, the mechanisms underlying MMP-14 expression in tumors still remain largely unknown. In this study, MMP-14 immunostaining was identified in 29/42 neuroblastoma tissues, which was correlated with clinicopathologic features and shorter patients' survival. In subtotal 20 neuroblastoma cases, microRNA 9 (miR-9) was downregulated and inversely correlated with MMP-14 expression. Bioinformatics analysis revealed a putative miR-9–binding site in the 3′-untranslated region (3′-UTR) of MMP-14 mRNA. Overexpression or knockdown of miR-9 responsively altered both the mRNA and protein levels of MMP-14 and its downstream gene, vascular endothelial growth factor, in cultured neuroblastoma cell lines SH-SY5Y and SK-N-SH. In an MMP-14 3′-UTR luciferase reporter system, miR-9 downregulated the luciferase activity, and these effects were abolished by a mutation in the putative miR-9–binding site. Overexpression of miR-9 suppressed the invasion, metastasis, and angiogenesis of SH-SY5Y and SK-N-SH cells in vitro and in vivo. In addition, the effects of miR-9 on MMP-14 expression, adhesion, migration, invasion, and angiogenesis were rescued by overexpression of MMP-14 in these cells. Furthermore, anti-miR-9 inhibitor or knockdown of MMP-14 respectively increased or inhibited the migration, invasion, and angiogenesis of neuroblastoma cells. These data indicate that miR-9 suppresses MMP-14 expression via the binding site in the 3′-UTR, thus inhibiting the invasion, metastasis, and angiogenesis of neuroblastoma. Mol Cancer Ther; 11(7); 1454–66. ©2012 AACR.
Data from Adenosine A2A and Beta-2 Adrenergic Receptor Agonists: Novel Selective and Synergistic Multiple Myeloma Targets Discovered through Systematic Combination Screening
Authors: Rickles Richard J. , Tam Winnie F. , Giordano Thomas P. , Pierce Laura T. , Farwell Melissa , McMillin Douglas W. , Necheva Antoaneta , Crowe David , Chen Mei , Avery William , Kansra Vikram , Nawrocki Steffan T. , Carew Jennifer S. , Giles Francis J. , Mitsiades Constantine S. , Borisy Alexis A. , Anderson Kenneth C. , Lee Margaret S.
Published: April 2023

Abstract
The use of combination drug regimens has dramatically improved the clinical outcome for patients with multiple myeloma. However, to date, combination treatments have been limited to approved drugs and a small number of emerging agents. Using a systematic approach to identify synergistic drug combinations, combination high-throughput screening (cHTS) technology, adenosine A2A and β-2 adrenergic receptor (β2AR) agonists were shown to be highly synergistic, selective, and novel agents that enhance glucocorticoid activity in B-cell malignancies. Unexpectedly, A2A and β2AR agonists also synergize with melphalan, lenalidomide, bortezomib, and doxorubicin. An analysis of agonists, in combination with dexamethasone or melphalan in 83 cell lines, reveals substantial activity in multiple myeloma and diffuse large B-cell lymphoma cell lines. Combination effects are also observed with dexamethasone as well as bortezomib, using multiple myeloma patient samples and mouse multiple myeloma xenograft assays. Our results provide compelling evidence in support of development of A2A and β2AR agonists for use in multi-drug combination therapy for multiple myeloma. Furthermore, use of cHTS for the discovery and evaluation of new targets and combination therapies has the potential to improve cancer treatment paradigms and patient outcomes. Mol Cancer Ther; 11(7); 1432–42. ©2012 AACR.
Data from Antitumor Activity of a Duocarmycin Analogue Rationalized to Be Metabolically Activated by Cytochrome P450 1A1 in Human Transitional Cell Carcinoma of the Bladder
Authors: Sutherland Mark , Gill Jason H. , Loadman Paul M. , Laye Jonathan P. , Sheldrake Helen M. , Illingworth Nicola A. , Alandas Mohammed N. , Cooper Patricia A. , Searcey Mark , Pors Klaus , Shnyder Steve D. , Patterson Laurence H.
Published: April 2023

Abstract
We identify cytochrome P450 1A1 (CYP1A1) as a target for tumor-selective drug development in bladder cancer and describe the characterization of ICT2700, designed to be metabolized from a prodrug to a potent cytotoxin selectively by CYP1A1. Elevated CYP1A1 expression was shown in human bladder cancer relative to normal human tissues. RT112 bladder cancer cells, endogenously expressing CYP1A1, were selectively chemosensitive to ICT2700, whereas EJ138 bladder cells that do not express CYP1A1 were significantly less responsive. Introduction of CYP1A1 into EJ138 cells resulted in 75-fold increased chemosensitivity to ICT2700 relative to wild-type EJ138. Negligible chemosensitivity was observed in ICT2700 in EJ138 cells expressing CYP1A2 or with exposure of EJ138 cells to CYP1B1- or CYP3A4-generated metabolites of ICT2700. Chemosensitivity to ICT2700 was also negated in EJ138-CYP1A1 cells by the CYP1 inhibitor α-naphthoflavone. Furthermore, ICT2700 did not induce expression of the AhR-regulated CYP1 family, indicating that constitutive CYP1A1 expression is sufficient for activation of ICT2700. Consistent with the selective activity by CYP1A1 was a time and concentration-dependent increase in γ-H2AX protein expression, indicative of DNA damage, associated with the activation of ICT2700 in RT112 but not EJ138 cells. In mice-bearing CYP1A1-positive and negative isogenic tumors, ICT2700 administration resulted in an antitumor response only in the CYP1A1-expressing tumor model. This antitumor response was associated with detection of the CYP1A1-activated metabolite in tumors but not in the liver. Our findings support the further development of ICT2700 as a tumor-selective treatment for human bladder cancers. Mol Cancer Ther; 12(1); 27–37. ©2012 AACR.
Data from Combination Drug Scheduling Defines a “Window of Opportunity” for Chemopotentiation of Gemcitabine by an Orally Bioavailable, Selective ChK1 Inhibitor, GNE-900
Authors: Blackwood Elizabeth , Epler Jennifer , Yen Ivana , Flagella Michael , O'Brien Tom , Evangelista Marie , Schmidt Stephen , Xiao Yang , Choi Jonathan , Kowanetz Kaska , Ramiscal Judi , Wong Kenton , Jakubiak Diana , Yee Sharon , Cain Gary , Gazzard Lewis , Williams Karen , Halladay Jason , Jackson Peter K. , Malek Shiva
Published: April 2023

Abstract
Checkpoint kinase 1 (ChK1) is a serine/threonine kinase that functions as a central mediator of the intra-S and G2–M cell-cycle checkpoints. Following DNA damage or replication stress, ChK1-mediated phosphorylation of downstream effectors delays cell-cycle progression so that the damaged genome can be repaired. As a therapeutic strategy, inhibition of ChK1 should potentiate the antitumor effect of chemotherapeutic agents by inactivating the postreplication checkpoint, causing premature entry into mitosis with damaged DNA resulting in mitotic catastrophe. Here, we describe the characterization of GNE-900, an ATP-competitive, selective, and orally bioavailable ChK1 inhibitor. In combination with chemotherapeutic agents, GNE-900 sustains ATR/ATM signaling, enhances DNA damage, and induces apoptotic cell death. The kinetics of checkpoint abrogation seems to be more rapid in p53-mutant cells, resulting in premature mitotic entry and/or accelerated cell death. Importantly, we show that GNE-900 has little single-agent activity in the absence of chemotherapy and does not grossly potentiate the cytotoxicity of gemcitabine in normal bone marrow cells. In vivo scheduling studies show that optimal administration of the ChK1 inhibitor requires a defined lag between gemcitabine and GNE-900 administration. On the refined combination treatment schedule, gemcitabine's antitumor activity against chemotolerant xenografts is significantly enhanced and dose-dependent exacerbation of DNA damage correlates with extent of tumor growth inhibition. In summary, we show that in vivo potentiation of gemcitabine activity is mechanism based, with optimal efficacy observed when S-phase arrest and release is followed by checkpoint abrogation with a ChK1 inhibitor. Mol Cancer Ther; 12(10); 1968–80. ©2013 AACR.
Data from Betulinic Acid Targets YY1 and ErbB2 through Cannabinoid Receptor-Dependent Disruption of MicroRNA-27a:ZBTB10 in Breast Cancer
Authors: Liu Xinyi , Jutooru Indira , Lei Ping , Kim KyoungHyun , Lee Syng-ook , Brents Lisa K. , Prather Paul L. , Safe Stephen
Published: April 2023

Abstract
Treatment of ErbB2-overexpressing BT474 and MDA-MB-453 breast cancer cells with 1 to 10 μmol/L betulinic acid inhibited cell growth, induced apoptosis, downregulated specificity protein (Sp) transcription factors Sp1, Sp3, and Sp4, and decreased expression of ErbB2. Individual or combined knockdown of Sp1, Sp3, Sp4 by RNA interference also decreased expression of ErbB2 and this response was because of repression of YY1, an Sp-regulated gene. Betulinic acid–dependent repression of Sp1, Sp3, Sp4, and Sp-regulated genes was due, in part, to induction of the Sp repressor ZBTB10 and downregulation of microRNA-27a (miR-27a), which constitutively inhibits ZBTB10 expression, and we show for the first time that the effects of betulinic acid on the miR-27a:ZBTB10-Sp transcription factor axis were cannabinoid 1 (CB1) and CB2 receptor–dependent, thus identifying a new cellular target for this anticancer agent. Mol Cancer Ther; 11(7); 1421–31. ©2012 AACR.
Data from Molecular and Cellular Effects of NEDD8-Activating Enzyme Inhibition in Myeloma
Authors: McMillin Douglas W. , Jacobs Hannah M. , Delmore Jake E. , Buon Leutz , Hunter Zachary R. , Monrose Val , Yu Jie , Smith Peter G. , Richardson Paul G. , Anderson Kenneth C. , Treon Steven P. , Kung Andrew L. , Mitsiades Constantine S.
Published: April 2023

Abstract
The NEDD8-activating enzyme is upstream of the 20S proteasome in the ubiquitin/proteasome pathway and catalyzes the first step in the neddylation pathway. NEDD8 modification of cullins is required for ubiquitination of cullin-ring ligases that regulate degradation of a distinct subset of proteins. The more targeted impact of NEDD8-activating enzyme on protein degradation prompted us to study MLN4924, an investigational NEDD8-activating enzyme inhibitor, in preclinical multiple myeloma models. In vitro treatment with MLN4924 led to dose-dependent decrease of viability (EC50 = 25–150 nmol/L) in a panel of human multiple myeloma cell lines. MLN4924 was similarly active against a bortezomib-resistant ANBL-6 subline and its bortezomib-sensitive parental cells. MLN4924 had submicromolar activity (EC50 values <500 nmol/L) against primary CD138+ multiple myeloma patient cells and exhibited at least additive effect when combined with dexamethasone, doxorubicin, and bortezomib against MM.1S cells. The bortezomib-induced compensatory upregulation of transcripts for ubiquitin/proteasome was not observed with MLN4924 treatment, suggesting distinct functional roles of NEDD8-activating enzyme versus 20S proteasome. MLN4924 was well tolerated at doses up to 60 mg/kg 2× daily and significantly reduced tumor burden in both a subcutaneous and an orthotopic mouse model of multiple myeloma. These studies provide the framework for the clinical investigation of MLN4924 in multiple myeloma. Mol Cancer Ther; 11(4); 942–51. ©2012 AACR.
Data from Inhibiting Aurora Kinases Reduces Tumor Growth and Suppresses Tumor Recurrence after Chemotherapy in Patient-Derived Triple-Negative Breast Cancer Xenografts
Authors: Romanelli Angela , Clark Anderson , Assayag Franck , Chateau-Joubert Sophie , Poupon Marie-France , Servely Jean-Luc , Fontaine Jean-Jacques , Liu Xiaohong , Spooner Edward , Goodstal Samantha , de Cremoux Patricia , Bièche Ivan , Decaudin Didier , Marangoni Elisabetta
Published: April 2023

Abstract
Triple-negative breast cancers (TNBC) have an aggressive phenotype with a relatively high rate of recurrence and poor overall survival. To date, there is no approved targeted therapy for TNBCs. Aurora kinases act as regulators of mammalian cell division. They are important for cell-cycle progression and are frequently overexpressed or mutated in human tumors, including breast cancer. In this study, we investigated the therapeutic potential of targeting Aurora kinases in preclinical models of human breast cancers using a pan-inhibitor of Aurora kinases, AS703569. In vitro, AS703569 was tested in 15 human breast cancer cell lines. TNBC cell lines were more sensitive to AS703569 than were other types of breast cancer cells. Inhibition of proliferation was associated with cell-cycle arrest, aneuploidy, and apoptosis. In vivo, AS703569 administered alone significantly inhibited tumor growth in seven of 11 patient-derived breast cancer xenografts. Treatment with AS703569 was associated with a decrease of phospho-histone H3 expression. Finally, AS703569 combined to doxorubicin–cyclophosphamide significantly inhibited in vivo tumor recurrence, suggesting that Aurora kinase inhibitors could be used both in monotherapy and in combination settings. In conclusion, these data indicate that targeting Aurora kinases could represent a new effective approach for TNBC treatment. Mol Cancer Ther; 11(12); 2693–703. ©2012 AACR.
Data from Polymorphic CAG Repeat and Protein Expression of Androgen Receptor Gene in Colorectal Cancer
Authors: Huang Rui , Wang Guiyu , Song Yanni , Wang Feng , Zhu Bing , Tang Qingchao , Liu Zheng , Chen Yinggang , Zhang Qian , Muhammad Shan , Wang Xishan
Published: April 2023

Abstract
Although somatic alterations in CAG repeats in the androgen receptor (AR) gene have been suggested to predispose to colorectal cancer, less is known about AR in colorectal cancer carcinogenesis. Because of lack of relevant analysis on CAG repeat length and AR expression in colorectal cancer, we aimed to investigate the prognostic value of polymorphic CAG and protein expression of the AR gene in patients with colorectal cancer. A case–control study was carried out on 550 patients with colorectal cancer and 540 healthy controls to investigate whether polymorphic CAG within the AR gene is linked to increased risk for colorectal cancer. Polymorphic CAG and AR expression were analyzed to clarify their relationship with clinicopathologic and prognostic factors in patients with colorectal cancer. The study showed that the AR gene in patients with colorectal cancer had a longer CAG repeat sequence than those in the control group, as well as increased risk for colorectal cancer among females (P = 0.013), males (P = 0.002), and total colorectal cancer population (P < 0.001), respectively. AR expression exhibited a significant difference in long CAG repeat sequence among males (P < 0.001), females (P < 0.001), and total colorectal cancer study population (P < 0.001). Both long CAG repeat sequence and negative AR expression were associated with a short 5-year overall survival (OS) rate in colorectal cancer. Long CAG repeat sequences and the absence of AR expression were closely related to the development of colorectal cancer. Both long CAG and decreased AR expression were correlated with the poor 5-year OS in patients with colorectal cancer. Mol Cancer Ther; 14(4); 1066–74. ©2015 AACR.
Data from Apoptotic Circulating Tumor Cells in Early and Metastatic Breast Cancer Patients
Authors: Kallergi Galatea , Konstantinidis Georgios , Markomanolaki Harris , Papadaki Maria A. , Mavroudis Dimitris , Stournaras Christos , Georgoulias Vassilis , Agelaki Sofia
Published: April 2023

Abstract
The detection of circulating tumor cells (CTC) in breast cancer is strongly associated with disease relapse. Since it is unclear whether all CTCs are capable of generating metastasis, we investigated their apoptotic and proliferative status in 56 CTC-positive (29 early and 27 metastatic) patients with breast cancer. Double-staining immunofluorescence experiments were carried out in peripheral blood mononuclear cells (PBMC) cytospins, using the pancytokeratin A45-B/B3 antibody and either M30 (apoptotic marker) or Ki67 (proliferation marker) antibodies. Apoptosis was also evaluated using a polycaspase detection kit. Patients with metastatic disease had significantly lower numbers of apoptotic CTCs compared with patients with early breast cancer (polycaspase kit: 8.1% vs. 47.4% of the total CTC number; P = 0.0001; M30-antibody: 32.1% vs. 76.63%; P = 0.002). The median percentage of apoptotic CTCs per patient was also lower in patients with advanced compared with those with early disease (polycaspase kit: 0% vs. 53.6%; M30-antibody: 15% vs. 80%). Ki67-positive CTCs were identified in 51.7% and 44% of patients with early and metastatic disease, respectively. Adjuvant chemotherapy reduced both the number of CTCs per patient and the number of proliferating CTCs (63.9% vs. 30%). In conclusion, apoptotic CTCs could be detected in patients with breast cancer irrespective of their clinical status, though the incidence of detection is higher in early compared with metastatic patients. The detection of CTCs that survive despite adjuvant therapy implies that CTC elimination should be attempted using agents targeting their distinctive molecular characteristics. Mol Cancer Ther; 12(9); 1886–95. ©2013 AACR.
Data from Endothelial Cells Enhance Prostate Cancer Metastasis via IL-6→Androgen Receptor→TGF-β→MMP-9 Signals
Authors: Wang Xiaohai , Lee Soo Ok , Xia Shujie , Jiang Qi , Luo Jie , Li Lei , Yeh Shuyuan , Chang Chawnshang
Published: April 2023

Abstract
Although the potential roles of endothelial cells in the microvascules of prostate cancer during angiogenesis have been documented, their direct impacts on the prostate cancer metastasis remain unclear. We found that the CD31-positive and CD34-positive endothelial cells are increased in prostate cancer compared with the normal tissues and that these endothelial cells were decreased upon castration, gradually recovered with time, and increased after prostate cancer progressed into the castration-resistant stage, suggesting a potential linkage of these endothelial cells with androgen deprivation therapy. The in vitro invasion assays showed that the coculture of endothelial cells with prostate cancer cells significantly enhanced the invasion ability of the prostate cancer cells. Mechanism dissection found that coculture of prostate cancer cells with endothelial cells led to increased interleukin (IL)-6 secretion from endothelial cells, which may result in downregulation of androgen receptor (AR) signaling in prostate cancer cells and then the activation of TGF-β/matrix metalloproteinase-9 (MMP-9) signaling. The consequences of the IL-6→AR→TGFβ→MMP-9 signaling pathway might then trigger the increased invasion of prostate cancer cells. Blocking the IL-6→AR→TGFβ→MMP-9 signaling pathway either by IL-6 antibody, AR-siRNA, or TGF-β1 inhibitor all interrupted the ability of endothelial cells to influence prostate cancer invasion. These results, for the first time, revealed the important roles of endothelial cells within the prostate cancer microenvironment to promote the prostate cancer metastasis and provide new potential targets of IL-6→AR→TGFβ→MMP-9 signals to battle the prostate cancer metastasis. Mol Cancer Ther; 12(6); 1026–37. ©2013 AACR.
Data from Dinaciclib (SCH727965) Inhibits the Unfolded Protein Response through a CDK1- and 5-Dependent Mechanism
Authors: Nguyen Tri K. , Grant Steven
Published: April 2023

Abstract
Evidence implicating dysregulation of the IRE1/XBP-1s arm of the unfolded protein response (UPR) in cancer pathogenesis (e.g., multiple myeloma) has prompted the development of IRE1 RNase inhibitors. Here, effects of cyclin-dependent kinase (CDK) inhibitor SCH727965 (dinaciclib) on the IRE1 arm of the UPR were examined in human leukemia and myeloma cells. Exposure of cells to extremely low (e.g., nmol/L) concentrations of SCH727965, a potent inhibitor of CDKs 1/2/5/9, diminished XBP-1s and Grp78 induction by the endoplasmic reticulum (ER) stress-inducers thapsigargin and tunicamycin, while sharply inducing cell death. SCH727965, in contrast to IRE1 RNase inhibitors, inhibited the UPR in association with attenuation of XBP-1s nuclear localization and accumulation rather than transcription, translation, or XBP-1 splicing. Notably, in human leukemia cells, CDK1 and 5 short hairpin RNA (shRNA) knockdown diminished Grp78 and XBP-1s upregulation while increasing thapsigargin lethality, arguing for a functional role for CDK1/5 in activation of the cytoprotective IRE1/XBP-1s arm of the UPR. In contrast, CDK9 or 2 inhibitors or shRNA knockdown failed to downregulate XBP-1s or Grp78. Furthermore, IRE1, XBP-1, or Grp78 knockdown significantly increased thapsigargin lethality, as observed with CDK1/5 inhibition/knockdown. Finally, SCH727965 diminished myeloma cell growth in vivo in association with XBP-1s downregulation. Together, these findings demonstrate that SCH727965 acts at extremely low concentrations to attenuate XBP-1s nuclear accumulation and Grp78 upregulation in response to ER stress inducers. They also highlight a link between specific components of the cell-cycle regulatory apparatus (e.g., CDK1/5) and the cytoprotective IRE1/XBP-1s/Grp78 arm of the UPR that may be exploited therapeutically in UPR-driven malignancies. Mol Cancer Ther; 13(3); 662–74. ©2013 AACR.