bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from The Vitamin E Analogue α-TEA Stimulates Tumor Autophagy and Enhances Antigen Cross-Presentation
Authors: Li Yuhuan , Hahn Tobias , Garrison Kendra , Cui Zhi-Hua , Thorburn Andrew , Thorburn Jacqueline , Hu Hong-Ming , Akporiaye Emmanuel T.
Published: March 2023

Abstract
The semisynthetic vitamin E derivative alpha-tocopheryloxyacetic acid (α-TEA) induces tumor cell apoptosis and may offer a simple adjuvant supplement for cancer therapy if its mechanisms can be better understood. Here we report that α-TEA also triggers tumor cell autophagy and that it improves cross-presentation of tumor antigens to the immune system. α-TEA stimulated both apoptosis and autophagy in murine mammary and lung cancer cells and inhibition of caspase-dependent apoptosis enhanced α-TEA–induced autophagy. Cell exposure to α-TEA generated double-membrane–bound vesicles indicative of autophagosomes, which efficiently cross-primed antigen-specific CD8+ T cells. Notably, vaccination with dendritic cells pulsed with α-TEA–generated autophagosomes reduced lung metastases and increased the survival of tumor-bearing mice. Taken together, our findings suggest that both autophagy and apoptosis signaling programs are activated during α-TEA–induced tumor cell killing. We suggest that the ability of α-TEA to stimulate autophagy and enhance cross-priming of CD8+ T cells might be exploited as an adjuvant strategy to improve stimulation of antitumor immune responses. Cancer Res; 72(14); 3535–45. ©2012 AACR.
Data from FRMD4A Upregulation in Human Squamous Cell Carcinoma Promotes Tumor Growth and Metastasis and Is Associated with Poor Prognosis
Authors: Goldie Stephen J. , Mulder Klaas W. , Tan David Wei-Min , Lyons Scott K. , Sims Andrew H. , Watt Fiona M.
Published: March 2023

Abstract
New therapeutic strategies are needed to improve treatment of head and neck squamous cell carcinoma (HNSCC), an aggressive tumor with poor survival rates. FRMD4A is a human epidermal stem cell marker implicated previously in epithelial polarity that is upregulated in SCC cells. Here, we report that FRMD4A upregulation occurs in primary human HNSCCs where high expression levels correlate with increased risks of relapse. FRMD4A silencing decreased growth and metastasis of human SCC xenografts in skin and tongue, reduced SCC proliferation and intercellular adhesion, and stimulated caspase-3 activity and expression of terminal differentiation markers. Notably, FRMD4A attenuation caused nuclear accumulation of YAP, suggesting a potential role for FRMD4A in Hippo signaling. Treatment with the HSP90 inhibitor 17-DMAG or ligation of CD44 with hyaluronan caused nuclear depletion of FRMD4A, nuclear accumulation of YAP and reduced SCC growth and metastasis. Together, our findings suggest FRMD4A as a novel candidate therapeutic target in HNSCC based on the key role in metastatic growth we have identified. Cancer Res; 72(13); 3424–36. ©2012 AACR.
Data from Intracellular ATP Levels Are a Pivotal Determinant of Chemoresistance in Colon Cancer Cells
Authors: Zhou Yunfei , Tozzi Federico , Chen Jinyu , Fan Fan , Xia Ling , Wang Jinrong , Gao Guang , Zhang Aijun , Xia Xuefeng , Brasher Heather , Widger William , Ellis Lee M. , Weihua Zhang
Published: March 2023

Abstract
Altered metabolism in cancer cells is suspected to contribute to chemoresistance, but the precise mechanisms are unclear. Here, we show that intracellular ATP levels are a core determinant in the development of acquired cross-drug resistance of human colon cancer cells that harbor different genetic backgrounds. Drug-resistant cells were characterized by defective mitochondrial ATP production, elevated aerobic glycolysis, higher absolute levels of intracellular ATP, and enhanced HIF-1α–mediated signaling. Interestingly, direct delivery of ATP into cross-chemoresistant cells destabilized HIF-1α and inhibited glycolysis. Thus, drug-resistant cells exhibit a greater “ATP debt” defined as the extra amount of ATP needed to maintain homeostasis of survival pathways under genotoxic stress. Direct delivery of ATP was sufficient to render drug-sensitive cells drug resistant. Conversely, depleting ATP by cell treatment with an inhibitor of glycolysis, 3-bromopyruvate, was sufficient to sensitize cells cross-resistant to multiple chemotherapeutic drugs. In revealing that intracellular ATP levels are a core determinant of chemoresistance in colon cancer cells, our findings may offer a foundation for new improvements to colon cancer treatment. Cancer Res; 72(1); 304–14. ©2011 AACR.
Data from Distinct Patterns of Dysregulated Expression of Enzymes Involved in Androgen Synthesis and Metabolism in Metastatic Prostate Cancer Tumors
Authors: Mitsiades Nicholas , Sung Clifford C. , Schultz Nikolaus , Danila Daniel C. , He Bin , Eedunuri Vijay Kumar , Fleisher Martin , Sander Chris , Sawyers Charles L. , Scher Howard I.
Published: March 2023

Abstract
Androgen receptor (AR) signaling persists in castration-resistant prostate carcinomas (CRPC), because of several mechanisms that include increased AR expression and intratumoral androgen metabolism. We investigated the mechanisms underlying aberrant expression of transcripts involved in androgen metabolism in CRPC. We compared gene expression profiles and DNA copy number alteration (CNA) data from 29 normal prostate tissue samples, 127 primary prostate carcinomas (PCa), and 19 metastatic PCas. Steroidogenic enzyme transcripts were evaluated by quantitative reverse transcriptase PCR in PCa cell lines and circulating tumor cells (CTC) from CRPC patients. Metastatic PCas expressed higher transcript levels for AR and several steroidogenic enzymes, including SRD5A1, SRD5A3, and AKR1C3, whereas expression of SRD5A2, CYP3A4, CYP3A5, and CYP3A7 was decreased. This aberrant expression was rarely associated with CNAs. Instead, our data suggest distinct patterns of coordinated aberrant enzyme expression. Inhibition of AR activity by itself stimulated AKR1C3 expression. The aberrant expression of the steroidogenic enzyme transcripts was detected in CTCs from CRPC patients. In conclusion, our findings identify substantial interpatient heterogeneity and distinct patterns of dysregulated expression of enzymes involved in intratumoral androgen metabolism in PCa. These steroidogenic enzymes represent targets for complete suppression of systemic and intratumoral androgen levels, an objective that is supported by the clinical efficacy of the CYP17 inhibitor abiraterone. A comprehensive AR axis–targeting approach via simultaneous, frontline enzymatic blockade, and/or transcriptional repression of several steroidogenic enzymes, in combination with GnRH analogs and potent antiandrogens, would represent a powerful future strategy for PCa management. Cancer Res; 72(23); 6142–52. ©2012 AACR.
Data from Cross-talk between HER2 and MED1 Regulates Tamoxifen Resistance of Human Breast Cancer Cells
Authors: Cui Jiajun , Germer Katherine , Wu Tianying , Wang Jiang , Luo Jia , Wang Shao-chun , Wang Qianben , Zhang Xiaoting
Published: March 2023

Abstract
Despite the fact that most breast cancer patients have estrogen receptor (ER) α-positive tumors, up to 50% of the patients are or soon develop resistance to endocrine therapy. It is recognized that HER2 activation is one of the major mechanisms contributing to endocrine resistance. In this study, we report that the ER coactivator MED1 is a novel cross-talk point for the HER2 and ERα pathways. Tissue microarray analysis of human breast cancers revealed that MED1 expression positively correlates most strongly with HER2 status of the tumors. MED1 was highly phosphorylated, in a HER2-dependent manner, at the site known to be critical for its activation. Importantly, RNAi-mediated attenuation of MED1 sensitized HER2-overexpressing cells to tamoxifen treatment. MED1 and its phosphorylated form, but not the corepressors N-CoR and SMRT, were recruited to the ERα target gene promoter by tamoxifen in HER2-overexpressing cells. Significantly, MED1 attenuation or mutation of MED1 phosphorylation sites was sufficient to restore the promoter recruitment of N-CoR and SMRT. Notably, we found that MED1 is required for the expression of not only traditional E2-ERα target genes but also the newly described EGF-ERα target genes. Our results additionally indicated that MED1 is recruited to the HER2 gene and required for its expression. Taken together, these findings support a key role for MED1 in HER2-mediated tamoxifen resistance and suggest its potential usage as a therapeutic target to simultaneously block both ERα and HER2 pathways for the treatment of this type of endocrine resistant breast cancer. Cancer Res; 72(21); 5625–34. ©2012 AACR.
Data from Concomitant Targeting of Tumor Cells and Induction of T-cell Response Synergizes to Effectively Inhibit Trastuzumab-Resistant Breast Cancer
Authors: Wang Qingfei , Li Shau-Hsuan , Wang Hai , Xiao Yi , Sahin Ozgur , Brady Samuel W. , Li Ping , Ge Hailiang , Jaffee Elizabeth M. , Muller William J. , Hortobagyi Gabriel N. , Yu Dihua
Published: March 2023

Abstract
Trastuzumab is an iconic rationally designed targeted therapy for HER2-positive breast cancers. However, the low response rate and development of resistance call for novel approaches for the treatment of patients. Here, we report that concurrent targeting of tumor cells and activation of T cells in the tumor microenvironment results in a synergistic inhibitory effect on tumor growth and overcomes resistance in two distinct PTEN loss–mediated trastuzumab-resistant mammary tumor mouse models. In vivo combination treatment with HER2/Neu antibody and Akt inhibitor triciribine effectively inhibited tumor growth in both models via inhibiting PI3K/AKT and mitogen-activated protein kinase signaling accompanied by increased T-cell infiltration in the tumor microenvironment. We showed that both CD8+ and CD4+ T cells were essential to the optimal antitumor effect of this combination treatment in an IFN-γ–dependent manner. Importantly, the antitumor activities of HER2/Neu antibody and triciribine combination treatment were further improved when coinhibitory receptor cytotoxic T-lymphocyte–associated antigen 4 was blocked to enhance the T-cell response. Our data indicate that multitargeted combinatorial therapies targeting tumor cells and concomitantly enhancing T-cell response in the tumor microenvironment could cooperate to exert maximal therapeutic activity, suggesting a promising clinical strategy for treating trastuzumab-resistant breast cancers and other advanced malignancies. Cancer Res; 72(17); 4417–28. ©2012 AACR.
Data from Defining NOTCH3 Target Genes in Ovarian Cancer
Authors: Chen Xu , Thiaville Michelle M. , Chen Li , Stoeck Alexander , Xuan Jianhua , Gao Min , Shih Ie-Ming , Wang Tian-Li
Published: March 2023

Abstract
NOTCH3 gene amplification plays an important role in the progression of many ovarian and breast cancers, but the targets of NOTCH3 signaling are unclear. Here, we report the use of an integrated systems biology approach to identify direct target genes for NOTCH3. Transcriptome analysis showed that suppression of NOTCH signaling in ovarian and breast cancer cells led to downregulation of genes in pathways involved in cell-cycle regulation and nucleotide metabolism. Chromatin immunoprecipitation (ChIP)-on-chip analysis defined promoter target sequences, including a new CSL binding motif (N1) in addition to the canonical CSL binding motif, that were occupied by the NOTCH3/CSL transcription complex. Integration of transcriptome and ChIP-on-chip data showed that the ChIP target genes overlapped significantly with the NOTCH-regulated transcriptome in ovarian cancer cells. From the set of genes identified, we showed that the mitotic apparatus organizing protein DLGAP5 (HURP/DLG7) was a critical target. Both the N1 motif and the canonical CSL binding motif were essential to activate DLGAP5 transcription. DLGAP5 silencing in cancer cells suppressed tumorigenicity and inhibited cellular proliferation by arresting the cell cycle at the G2–M phase. In contrast, enforced expression of DLGAP5 partially counteracted the growth inhibitory effects of a pharmacologic or RNA interference–mediated NOTCH inhibition in cancer cells. Our findings define direct target genes of NOTCH3 and highlight the role of DLGAP5 in mediating the function of NOTCH3. Cancer Res; 72(9); 2294–303. ©2012 AACR.
Data from p38 MAPK in Myeloma Cells Regulates Osteoclast and Osteoblast Activity and Induces Bone Destruction
Authors: He Jin , Liu Zhiqiang , Zheng Yuhuan , Qian Jianfei , Li Haiyan , Lu Yong , Xu Jingda , Hong Bangxing , Zhang Mingjun , Lin Pei , Cai Zhen , Orlowski Robert Z. , Kwak Larry W. , Yi Qing , Yang Jing
Published: March 2023

Abstract
p38 mitogen-activated protein kinase (MAPK), which is constitutively activated in human myeloma, has been implicated in bone destruction by this cancer, but the processes it recruits are obscure. In this study, we show that p38 activity in myeloma inhibits osteoblast differentiation and bone formation, but also enhances osteoclast maturation and bone resorption. p38 regulated the expression and secretion of the Wnt pathway antagonist DKK-1 and the monocyte chemoattractant MCP-1. Attenuating p38, DKK-1, or MCP-1 were each sufficient to reduce bone lesions in vivo. Although it is well known that DKK-1 inhibits osteoblast differentiation, we found that together with MCP-1, it could also promote osteoclast differentiation and bone resorption. The latter effects were mediated by enhancing expression of RANK in osteoclast progenitor cells and by upregulating secretion of its ligand RANKL from stromal cells and mature osteoblasts. In summary, our study defined the mechanisms by which p38 signaling in myeloma cells regulates osteoblastogenesis, osteoclastogenesis, and bone destruction. Our findings, which may have implications for bone invasion by other cancers where p38 is elevated, strongly suggests that targeting p38 for inhibition may offer an effective therapeutic approach to treat osteolytic bone lesions in patients with myeloma. Cancer Res; 72(24); 6393–402. ©2012 AACR.
Data from Truncated DNMT3B Isoform DNMT3B7 Suppresses Growth, Induces Differentiation, and Alters DNA Methylation in Human Neuroblastoma
Authors: Ostler Kelly R. , Yang Qiwei , Looney Timothy J. , Zhang Li , Vasanthakumar Aparna , Tian Yufeng , Kocherginsky Masha , Raimondi Stacey L. , DeMaio Jessica G. , Salwen Helen R. , Gu Song , Chlenski Alexandre , Naranjo Arlene , Gill Amy , Peddinti Radhika , Lahn Bruce T. , Cohn Susan L. , Godley Lucy A.
Published: March 2023

Abstract
Epigenetic changes in pediatric neuroblastoma may contribute to the aggressive pathophysiology of this disease, but little is known about the basis for such changes. In this study, we examined a role for the DNA methyltransferase DNMT3B, in particular, the truncated isoform DNMT3B7, which is generated frequently in cancer. To investigate if aberrant DNMT3B transcripts alter DNA methylation, gene expression, and phenotypic character in neuroblastoma, we measured DNMT3B expression in primary tumors. Higher levels of DNMT3B7 were detected in differentiated ganglioneuroblastomas compared to undifferentiated neuroblastomas, suggesting that expression of DNMT3B7 may induce a less aggressive clinical phenotype. To test this hypothesis, we investigated the effects of enforced DNMT3B7 expression in neuroblastoma cells, finding a significant inhibition of cell proliferation in vitro and angiogenesis and tumor growth in vivo. DNMT3B7-positive cells had higher levels of total genomic methylation and a dramatic decrease in expression of the FOS and JUN family members that comprise AP1 transcription factors. Consistent with an established antagonistic relationship between AP1 expression and retinoic acid receptor activity, increased differentiation was seen in the DNMT3B7-expressing neuroblastoma cells following treatment with all-trans retinoic acid (ATRA) compared to controls. Our results indicate that DNMT3B7 modifies the epigenome in neuroblastoma cells to induce changes in gene expression, inhibit tumor growth, and increase sensitivity to ATRA. Cancer Res; 72(18); 4714–23. ©2012 AACR.
Data from RKI-1447 Is a Potent Inhibitor of the Rho-Associated ROCK Kinases with Anti-Invasive and Antitumor Activities in Breast Cancer
Authors: Patel Ronil A. , Forinash Kara D. , Pireddu Roberta , Sun Ying , Sun Nan , Martin Mathew P. , Schönbrunn Ernst , Lawrence Nicholas J. , Sebti Saïd M.
Published: March 2023

Abstract
The Rho-associated kinases ROCK1 and ROCK2 are critical for cancer cell migration and invasion, suggesting they may be useful therapeutic targets. In this study, we describe the discovery and development of RKI-1447, a potent small molecule inhibitor of ROCK1 and ROCK2. Crystal structures of the RKI-1447/ROCK1 complex revealed that RKI-1447 is a Type I kinase inhibitor that binds the ATP binding site through interactions with the hinge region and the DFG motif. RKI-1447 suppressed phosphorylation of the ROCK substrates MLC-2 and MYPT-1 in human cancer cells, but had no effect on the phosphorylation levels of the AKT, MEK, and S6 kinase at concentrations as high as 10 μmol/L. RKI-1447 was also highly selective at inhibiting ROCK-mediated cytoskeleton re-organization (actin stress fiber formation) following LPA stimulation, but does not affect PAK-meditated lamellipodia and filopodia formation following PDGF and Bradykinin stimulation, respectively. RKI-1447 inhibited migration, invasion and anchorage-independent tumor growth of breast cancer cells. In contrast, RKI-1313, a much weaker analog in vitro, had little effect on the phosphorylation levels of ROCK substrates, migration, invasion or anchorage-independent growth. Finally, RKI-1447 was highly effective at inhibiting the outgrowth of mammary tumors in a transgenic mouse model. In summary, our findings establish RKI-1447 as a potent and selective ROCK inhibitor with significant anti-invasive and antitumor activities and offer a preclinical proof-of-concept that justify further examination of RKI-1447 suitability as a potential clinical candidate. Cancer Res; 72(19); 5025–34. ©2012 AACR.
Data from Src Family Kinases as Novel Therapeutic Targets to Treat Breast Cancer Brain Metastases
Authors: Zhang Siyuan , Huang Wen-Chien , Zhang Lin , Zhang Chenyu , Lowery Frank J. , Ding Zhaoxi , Guo Hua , Wang Hai , Huang Suyun , Sahin Aysegul A. , Aldape Kenneth D. , Steeg Patricia S. , Yu Dihua
Published: March 2023

Abstract
Despite better control of early-stage disease and improved overall survival of patients with breast cancer, the incidence of life-threatening brain metastases continues to increase in some of these patients. Unfortunately, other than palliative treatments there is no effective therapy for this condition. In this study, we reveal a critical role for Src activation in promoting brain metastasis in a preclinical model of breast cancer and we show how Src-targeting combinatorial regimens can treat HER2+ brain metastases in this model. We found that Src was hyperactivated in brain-seeking breast cancer cells derived from human cell lines or from patients' brain metastases. Mechanistically, Src activation promoted tumor cell extravasation into the brain parenchyma via permeabilization of the blood–brain barrier. When combined with the EGFR/HER2 dual-targeting drug lapatinib, an Src-targeting combinatorial regimen prevented outgrowth of disseminated breast cancer cells through the induction of cell-cycle arrest. More importantly, this combinatorial regimen inhibited the outgrowth of established experimental brain metastases, prolonging the survival of metastases-bearing mice. Our results provide a rationale for clinical evaluation of Src-targeting regimens to treat patients with breast cancer suffering from brain metastasis. Cancer Res; 73(18); 5764–74. ©2013 AACR.
Data from Specific Recruitment of γδ Regulatory T Cells in Human Breast Cancer
Authors: Ye Jian , Ma Chunling , Wang Fang , Hsueh Eddy C. , Toth Karoly , Huang Yi , Mo Wei , Liu Shuai , Han Bing , Varvares Mark A. , Hoft Daniel F. , Peng Guangyong
Published: March 2023

Abstract
Understanding the role of different subtypes of tumor-infiltrating lymphocytes (TIL) in the immunosuppressive tumor microenvironment is essential for improving cancer treatment. Enriched γδ1 T-cell populations in TILs suppress T-cell responses and dendritic cell maturation in breast cancer, where their presence is correlated negatively with clinical outcomes. However, mechanism(s) that explain the increase in this class of regulatory T cells (γδ Treg) in patients with breast cancer have yet to be elucidated. In this study, we show that IP-10 secreted by breast cancer cells attracted γδ Tregs. Using neutralizing antibodies against chemokines secreted by breast cancer cells, we found that IP-10 was the only functional chemokine that causes γδ Tregs to migrate toward breast cancer cells. In a humanized NOD-scid IL-2Rγnull (NSG) mouse model, human breast cancer cells attracted γδ Tregs as revealed by a live cell imaging system. IP-10 neutralization in vivo inhibited migration and trafficking of γδ Tregs into breast tumor sites, enhancing tumor immunity mediated by tumor-specific T cells. Together, our studies show how γδ Tregs accumulate in breast tumors, providing a rationale for their immunologic targeting to relieve immunosuppression in the tumor microenvironment. Cancer Res; 73(20); 6137–48. ©2013 AACR.
Data from CDK1 Phosphorylation of YAP Promotes Mitotic Defects and Cell Motility and Is Essential for Neoplastic Transformation
Authors: Yang Shuping , Zhang Lin , Liu Miao , Chong Rong , Ding Shi-Jian , Chen Yuanhong , Dong Jixin
Published: March 2023

Abstract
The Yes-associated protein, YAP, is a downstream effector of the Hippo pathway of cell-cycle control that plays important roles in tumorigenesis. Hippo-mediated phosphorylation YAP, mainly at S127, inactivates YAP function. In this study, we define a mechanism for positive regulation of YAP activity that is critical for its oncogenic function. Specifically, we found that YAP is phosphorylated in vitro and in vivo by the cell-cycle kinase CDK1 at T119, S289, and S367 during the G2–M phase of the cell cycle. We also found that ectopic expression of a phosphomimetic YAP mutant (YAP3D, harboring T119D/S289D/S367D) was sufficient to induce mitotic defects in immortalized epithelial cells, including centrosome amplification, multipolar spindles, and chromosome missegregation. Finally, we documented that mitotic phosphorylation of YAP was sufficient to promote cell migration and invasion in a manner essential for neoplastic cell transformation. In support of our findings, CDK1 inhibitors largely suppressed cell motility mediated by activated YAP-S127A but not the phosphomimetic mutant YAP3D. Collectively, our results reveal a previously unrecognized mechanism for controlling the activity of YAP that is crucial for its oncogenic function mediated by mitotic dysregulation. Cancer Res; 73(22); 6722–33. ©2013 AACR.
Data from Tumor Suppressor Function of the Plasma Glutathione Peroxidase Gpx3 in Colitis-Associated Carcinoma
Authors: Barrett Caitlyn W. , Ning Wei , Chen Xi , Smith Jesse Joshua , Washington Mary K. , Hill Kristina E. , Coburn Lori A. , Peek Richard M. , Chaturvedi Rupesh , Wilson Keith T. , Burk Raymond F. , Williams Christopher S.
Published: March 2023

Abstract
The glutathione peroxidases, a family of selenocysteine-containing redox enzymes, play pivotal roles in balancing the signaling, immunomodulatory, and deleterious effects of reactive oxygen species (ROS). The glutathione peroxidase GPX3 is the only extracellular member of this family, suggesting it may defend cells against ROS in the extracellular environment. Notably, GPX3 hypermethylation and underexpression occur commonly in prostate, gastric, cervical, thyroid, and colon cancers. We took a reverse genetics approach to investigate whether GPX3 would augment inflammatory colonic tumorigenesis, a process characterized by oxidative stress and inflammation, comparing Gpx3−/− mice in an established two-stage model of inflammatory colon carcinogenesis. Gpx3-deficient mice exhibited an increased tumor number, though not size, along with a higher degree of dysplasia. In addition, they exhibited increased inflammation with redistribution toward protumorigenic M2 macrophage subsets, increased proliferation, hyperactive WNT signaling, and increased DNA damage. To determine the impact of acute gene loss in an established colon cancer line, we silenced GPX3 in human Caco2 cells, resulting in increased ROS production, DNA damage and apoptosis in response to oxidative stress, combined with decreased contact-independent growth. Taken together, our results suggested an immunomodulatory role for GPX3 that limits the development of colitis-associated carcinoma. Cancer Res; 73(3); 1245–55. ©2012 AACR.
Data from Critical Role for the Receptor Tyrosine Kinase EPHB4 in Esophageal Cancers
Authors: Hasina Rifat , Mollberg Nathan , Kawada Ichiro , Mutreja Karun , Kanade Geetanjali , Yala Soheil , Surati Mosmi , Liu Ren , Li Xiuqing , Zhou Yue , Ferguson Benjamin D. , Nallasura Vidya , Cohen Kenneth S. , Hyjek Elizabeth , Mueller Jeffery , Kanteti Rajani , El Hashani Essam , Kane Dorothy , Shimada Yutaka , Lingen Mark W. , Husain Aliya N. , Posner Mitchell C. , Waxman Irving , Villaflor Victoria M. , Ferguson Mark K. , Varticovski Lyuba , Vokes Everett E. , Gill Parkash , Salgia Ravi
Published: March 2023

Abstract
Esophageal cancer incidence is increasing and has few treatment options. In studying receptor tyrosine kinases associated with esophageal cancers, we have identified EPHB4 to be robustly overexpressed in cell lines and primary tumor tissues. In total, 94 squamous cell carcinoma, 82 adenocarcinoma, 25 dysplasia, 13 Barrett esophagus, and 25 adjacent or unrelated normal esophageal tissues were evaluated by immunohistochemistry. EPHB4 expression was significantly higher in all the different histologic categories than in adjacent normal tissues. In 13 esophageal cancer cell lines, 3 of the 9 SCC cell lines and 2 of the 4 adenocarcinomas expressed very high levels of EPHB4. An increased gene copy number ranging from 4 to 20 copies was identified in a subset of the overexpressing patient samples and cell lines. We have developed a novel 4-nitroquinoline 1-oxide (4-NQO)-induced mouse model of esophageal cancer that recapitulates the EPHB4 expression in humans. A specific small-molecule inhibitor of EPHB4 decreased cell viability in a time- and dose-dependent manner in 3 of the 4 cell lines tested. The small-molecule inhibitor and an EPHB4 siRNA also decreased cell migration (12%–40% closure in treated vs. 60%–80% in untreated), with decreased phosphorylation of various tyrosyl-containing proteins, EphB4, and its downstream target p125FAK. Finally, in a xenograft tumor model, an EPHB4 inhibitor abrogated tumor growth by approximately 60% compared with untreated control. EphB4 is robustly expressed and potentially serves as a novel biomarker for targeted therapy in esophageal cancers. Cancer Res; 73(1); 184–94. ©2012 AACR.
Data from Loss of miR-204 Expression Enhances Glioma Migration and Stem Cell-like Phenotype
Authors: Ying Zhe , Li Yun , Wu Jueheng , Zhu Xun , Yang Yi , Tian Han , Li Wei , Hu Bo , Cheng Shi-Yuan , Li Mengfeng
Published: March 2023

Abstract
Phenotypic similarities have long been recognized between subpopulations of glioma and neural stem cells. Many of these similar properties, including the robust abilities to self-renew, migrate, and invade, are hallmarks of glioma cells that render them extremely aggressive. However, the molecular mechanisms underlying this character, particularly in glioma stem-like cells that drive this disease, remain poorly understood. Here, we report the results of a differential miRNA expression screen that compared glioma and neural stem cells, where we found that miR-204 was markedly downregulated in both types of cells. Mechanistic investigations revealed that miR-204 simultaneously suppressed self-renewal, stem cell-associated phenotype, and migration of glioma cells by targeting the stemness-governing transcriptional factor SOX4 and the migration-promoting receptor EphB2. Restoring miR-204 expression in glioma cells suppressed tumorigenesis and invasiveness in vivo and increased overall host survival. Further evaluation revealed that the miR-204 promoter was hypermethylated and that attenuating promoter methylation was sufficient to upregulate miR-204 in glioma cells. Together, our findings reveal miR-204 as a pivotal regulator of the development of stem cell-like phenotypes and cell motility in malignant glioma cells. Cancer Res; 73(2); 990–9. ©2012 AACR.
Data from Bispecific Antibody to ErbB2 Overcomes Trastuzumab Resistance through Comprehensive Blockade of ErbB2 Heterodimerization
Authors: Li Bohua , Meng Yanchun , Zheng Lei , Zhang Xunmin , Tong Qing , Tan Wenlong , Hu Shi , Li Hui , Chen Yang , Song Jinjing , Zhang Ge , Zhao Lei , Zhang Dapeng , Hou Sheng , Qian Weizhu , Guo Yajun
Published: March 2023

Abstract
The anti-ErbB2 antibody trastuzumab has shown significant clinical benefits in metastatic breast cancer. However, resistance to trastuzumab is common. Heterodimerization between ErbB2 and other ErbBs may redundantly trigger cell proliferation signals and confer trastuzumab resistance. Here, we developed a bispecific anti-ErbB2 antibody using trastuzumab and pertuzumab, another ErbB2-specific humanized antibody that binds to a distinct epitope from trastuzumab. This bispecific antibody, denoted as TPL, retained the full binding activities of both parental antibodies and exhibited pharmacokinetic properties similar to those of a conventional immunoglobulin G molecule. Unexpectedly, TPL showed superior ErbB2 heterodimerization-blocking activity over the combination of both parental monoclonal antibodies, possibly through steric hindrance and/or inducing ErbB2 conformational change. Further data indicated that TPL potently abrogated ErbB2 signaling in trastuzumab-resistant breast cancer cell lines. In addition, we showed that TPL was far more effective than trastuzumab plus pertuzumab in inhibiting the growth of trastuzumab-resistant breast cancer cell lines, both in vitro and in vivo. Importantly, TPL treatment eradicated established trastuzumab-resistant tumors in tumor-bearing nude mice. Our results suggest that trastuzumab-resistant breast tumors remain dependent on ErbB2 signaling and that comprehensive blockade of ErbB2 heterodimerization may be an effective therapeutic avenue. The unique potential of TPL to overcome trastuzumab resistance warrants its consideration as a promising treatment in the clinic. Cancer Res; 73(21); 6471–83. ©2013 AACR.
Data from Autoantibody Signatures Involving Glycolysis and Splicesome Proteins Precede a Diagnosis of Breast Cancer among Postmenopausal Women
Authors: Ladd Jon J. , Chao Timothy , Johnson Melissa M. , Qiu Ji , Chin Alice , Israel Rebecca , Pitteri Sharon J. , Mao Jianning , Wu Mei , Amon Lynn M. , McIntosh Martin , Li Christopher , Prentice Ross , Disis Nora , Hanash Samir
Published: March 2023

Abstract
We assessed the autoantibody repertoire of a mouse model engineered to develop breast cancer and the repertoire of autoantibodies in human plasmas collected at a preclinical time point and at the time of clinical diagnosis of breast cancer. In seeking to identify common pathways, networks, and protein families associated with the humoral response, we elucidated the dynamic nature of tumor antigens and autoantibody interactions. Lysate proteins from an immortalized cell line from a MMTV-neu mouse model and from MCF7 human breast cancers were spotted onto nitrocellulose microarrays and hybridized with mouse and human plasma samples, respectively. Immunoglobulin-based plasma immunoreactivity against glycolysis and spliceosome proteins was a predominant feature observed both in tumor-bearing mice and in prediagnostic human samples. Interestingly, autoantibody reactivity was more pronounced further away than closer to diagnosis. We provide evidence for dynamic changes in autoantibody reactivity with tumor development and progression that may depend, in part, on the extent of antigen–antibody interactions. Cancer Res; 73(5); 1502–13. ©2012 AACR.
Data from Biallelic DICER1 Mutations in Sporadic Pleuropulmonary Blastoma
Authors: Seki Masafumi , Yoshida Kenichi , Shiraishi Yuichi , Shimamura Teppei , Sato Yusuke , Nishimura Riki , Okuno Yusuke , Chiba Kenichi , Tanaka Hiroko , Kato Keisuke , Kato Motohiro , Hanada Ryoji , Nomura Yuko , Park Myoung-Ja , Ishida Toshiaki , Oka Akira , Igarashi Takashi , Miyano Satoru , Hayashi Yasuhide , Ogawa Seishi , Takita Junko
Published: March 2023

Abstract
Pleuropulmonary blastoma (PPB) is a rare pediatric malignancy whose pathogens are poorly understood. Recent reports suggest that germline mutations in the microRNA-processing enzyme DICER1 may contribute to PPB development. To investigate the genetic basis of this cancer, we performed whole-exome sequencing or targeted deep sequencing of multiple cases of PPB. We found biallelic DICER1 mutations to be very common, more common than TP53 mutations also found in many tumors. Somatic ribonuclease III (RNase IIIb) domain mutations were identified in all evaluable cases, either in the presence or absence of nonsense/frameshift mutations. Most cases had mutated DICER1 alleles in the germline with or without an additional somatic mutation in the remaining allele, whereas other cases displayed somatic mutations exclusively where the RNase IIIb domain was invariably affected. Our results highlight the role of RNase IIIb domain mutations in DICER1 along with TP53 inactivation in PPB pathogenesis. Cancer Res; 74(10); 2742–9. ©2014 AACR.
Data from The Major Reverse Transcriptase–Incompetent Splice Variant of the Human Telomerase Protein Inhibits Telomerase Activity but Protects from Apoptosis
Authors: Listerman Imke , Sun Jie , Gazzaniga Francesca S. , Lukas Jason L. , Blackburn Elizabeth H.
Published: March 2023

Abstract
Human telomerase reverse transcriptase (hTERT; the catalytic protein subunit of telomerase) is subjected to numerous alternative splicing events, but the regulation and function of these splice variants is obscure. Full-length hTERT includes conserved domains that encode reverse transcriptase activity, RNA binding, and other functions. The major splice variant termed α+β− or β-deletion is highly expressed in stem and cancer cells, where it codes for a truncated protein lacking most of the reverse transcriptase domain but retaining the known RNA-binding motifs. In a breast cancer cell panel, we found that β-deletion was the hTERT transcript that was most highly expressed. Splicing of this transcript was controlled by the splice regulators SRSF11, HNRNPH2, and HNRNPL, and the β-deletion transcript variant was associated with polyribosomes in cells. When ectopically overexpressed, β-deletion protein competed for binding to telomerase RNA (hTR/TERC), thereby inhibiting endogenous telomerase activity. Overexpressed β-deletion protein localized to the nucleus and mitochondria and protected breast cancer cells from cisplatin-induced apoptosis. Our results reveal that a major hTERT splice variant can confer a growth advantage to cancer cells independent of telomere maintenance, suggesting that hTERT makes multiple contributions to cancer pathophysiology. Cancer Res; 73(9); 2817–28. ©2013 AACR.
Data from Dual Functions of the Homeoprotein DLX4 in Modulating Responsiveness of Tumor Cells to Topoisomerase II-Targeting Drugs
Authors: Trinh Bon Q. , Ko Song Yi , Barengo Nicolas , Lin Shiaw-Yih , Naora Honami
Published: March 2023

Abstract
Topoisomerase II (TOP2)-targeting poisons such as anthracyclines and etoposide are commonly used for cancer chemotherapy and kill tumor cells by causing accumulation of DNA double-strand breaks (DSB). Several lines of evidence indicate that overexpression of TOP2A, the gene encoding topoisomerase IIα, increases sensitivity of tumor cells to TOP2 poisons, but it is not clear why some TOP2A-overexpressing (TOP2A-High) tumors respond poorly to these drugs. In this study, we identified that TOP2A expression is induced by DLX4, a homeoprotein that is overexpressed in breast and ovarian cancers. Analysis of breast cancer datasets revealed that TOP2A-high cases that also highly expressed DLX4 responded more poorly to anthracycline-based chemotherapy than TOP2A-high cases that expressed DLX4 at low levels. Overexpression of TOP2A alone in tumor cells increased the level of DSBs induced by TOP2 poisons. In contrast, DLX4 reduced the level of TOP2 poison-induced DSBs irrespective of its induction of TOP2A. DLX4 did not stimulate homologous recombination–mediated repair of DSBs. However, DLX4 interacted with Ku proteins, stimulated DNA-dependent protein kinase activity, and increased erroneous end-joining repair of DSBs. Whereas DLX4 did not reduce levels of TOP2 poison-induced DSBs in Ku-deficient cells, DLX4 stimulated DSB repair and reduced the level of TOP2 poison–induced DSBs when Ku was reconstituted in these cells. Our findings indicate that DLX4 induces TOP2A expression but reduces sensitivity of tumor cells to TOP2 poisons by stimulating Ku-dependent repair of DSBs. These opposing activities of DLX4 could explain why some TOP2A-overexpressing tumors are not highly sensitive to TOP2 poisons. Cancer Res; 73(2); 1000–10. ©2012 AACR.
Data from Caveolin-1–LRP6 Signaling Module Stimulates Aerobic Glycolysis in Prostate Cancer
Authors: Tahir Salahaldin A. , Yang Guang , Goltsov Alexei , Song Ki-Duk , Ren Chengzhen , Wang Jianxiang , Chang Wenjun , Thompson Timothy C.
Published: March 2023

Abstract
Caveolin 1 (Cav-1) is a plasma membrane–associated protein with the capacity to modulate signaling activities in a context-dependent fashion. Interactions between Cav-1 and low-density lipoprotein receptor–related protein 6 (LRP6) were reported to be important for the regulation of Wnt-β-catenin (β-cat) signaling. Cav-1 also interacts with insulin and IGF-I receptors (IGF-IR/IR) and can stimulate IR kinase activities. We found positive correlation between Cav-1 and LRP6 expression in both human primary prostate cancer and metastasis tissues and in PC-3 cells. Cav-1 stimulation of Wnt–β-cat signaling and c-Myc levels was positively associated with LRP6 expression in LNCaP, PC-3, and DU145 prostate cancer cells. Importantly, LRP6 and, to a lesser extent, Cav-1 were found to stimulate aerobic glycolysis. These activities were positively associated with the expression of HK2 and Glut3 and shown to be dependent on Akt signaling by both gene knockdown and chemical inhibition methods. We further showed that Cav-1 and LRP6 exert their effects on Akt and glycolytic activities by stimulating IGF-IR/IR signaling. Overall, our results show that Cav-1 interacts with LRP6 to generate an integrated signaling module that leads to the activation of IGF-IR/IR and results in stimulation of Akt–mTORC1 signaling and aerobic glycolysis in prostate cancer. Cancer Res; 73(6); 1900–11. ©2012 AACR.
Data from CUL3 and NRF2 Mutations Confer an NRF2 Activation Phenotype in a Sporadic Form of Papillary Renal Cell Carcinoma
Authors: Ooi Aikseng , Dykema Karl , Ansari Asif , Petillo David , Snider John , Kahnoski Richard , Anema John , Craig David , Carpten John , Teh Bin-Tean , Furge Kyle A.
Published: March 2023

Abstract
Sustained activation of the stress-regulated transcription factor NRF2 (NFE2L2) is a prominent feature of many types of cancer, implying that mutations driving NRF2 may be important to tumor progression. In hereditary type 2 papillary renal cell carcinoma (PRCC2, also known as hereditary leiomyomatosis and renal cell cancer), NRF2 activation is a direct consequence of the accumulation of intracellular fumarate, a result of fumarate hydratase (FH) inactivation, but it is not clear how NRF2 may be activated in sporadic forms of PRCC2. Here we show that somatic mutations in NRF2, CUL3, and SIRT1 are responsible for driving the NRF2 activation phenotype in sporadic PRCC2. Transcriptome sequencing revealed the expression pattern of mutant alleles of NRF2, CUL3, and SIRT1 and also confirmed NRF2 activation in clinical specimens. Our results show a convergence in somatic mutations in sporadic PRCC2 with FH mutation in hereditary PRCC2. Cancer Res; 73(7); 2044–51. ©2013 AACR.
Data from Monoclonal Antibody Targeting of the Cell Surface Molecule TM4SF5 Inhibits the Growth of Hepatocellular Carcinoma
Authors: Kwon Sanghoon , Choi Kyung-Chan , Kim Young-Eun , Ha Yang-Wha , Kim Dongbum , Park Byoung Kwon , Wu Guang , Kim Doo-Sik , Lee Younghee , Kwon Hyung-Joo
Published: March 2023

Abstract
The cell surface transmembrane receptor TM4SF5 has been implicated in hepatocellular carcinoma (HCC), but its candidacy as a therapeutic target has not been evaluated. Building on findings that immunization with a peptide vaccine targeting human TM4SF5 can exert prophylactic and therapeutic effects in a murine model of HCC, we developed a monoclonal antibody to characterize expression of TM4SF5 in HCC and to target its function there as an anticancer strategy. We found that the antibody modulated cell signaling in HCC cells in vitro, reducing cell motility, modulating E-cadherin expression, altering p27kip1 localization, and increasing RhoA activity. Using a mouse xenograft model of human HCC, we documented the in vivo efficacy of the antibody, which suppressed tumor growth in either tumor prevention or treatment designs. Our work offers a preclinical proof of concept for TM4SF5 as a promising target for antibody therapeutics to treat HCC. Cancer Res; 74(14); 3844–56. ©2014 AACR.
Data from Downregulation of the Novel Tumor Suppressor DIRAS1 Predicts Poor Prognosis in Esophageal Squamous Cell Carcinoma
Authors: Zhu Ying-Hui , Fu Li , Chen Leilei , Qin Yan-Ru , Liu Haibo , Xie Fajun , Zeng Tingting , Dong Sui-Sui , Li Jiangchao , Li Yan , Dai Yongdong , Xie Dan , Guan Xin-Yuan
Published: March 2023

Abstract
Loss of chromosome 19p is one of the most frequent allelic imbalances in esophageal squamous cell carcinoma (ESCC), suggesting the existence of one or more tumor suppressor genes within this region. In this study, we investigated a role in ESCCs for a candidate tumor suppressor gene located at 19p13.3, the Ras-like small GTPase DIRAS1. Downregulation of DIRAS1 occurred in approximately 50% of primary ESCCs where it was associated significantly with advanced clinical stage, lymph node metastasis, and poor overall survival. LOH and promoter methylation analyses suggested that loss of DIRAS1 expression was mediated by epigenetic mechanisms. Functional studies established that ectopic re-expression of DIRAS1 in ESCC cells inhibited cell proliferation, clonogenicity, cell motility, and tumor formation. Mechanistic investigations suggested that DIRAS1 acted through extracellular signal–regulated kinase (ERK1/2; MAPK3/1) and p38 mitogen-activated protein kinase (MAPK; MAPK14) signaling to trigger BAD Ser112 dephosphorylation and matrix metalloproteinase (MMP)2/9 transcriptional inactivation to promote apoptosis and inhibit metastasis, respectively. Taken together, our results revealed that DIRAS1 has a pivotal function in ESCC pathogenesis, with possible use as a biomarker and intervention point for new therapeutic strategies. Cancer Res; 73(7); 2298–309. ©2013 AACR.
Data from Redox Modulation of Adjacent Thiols in VLA-4 by AS101 Converts Myeloid Leukemia Cells from a Drug-Resistant to Drug-Sensitive State
Authors: Layani-Bazar Adi , Skornick Itai , Berrebi Alain , Pauker Maor H. , Noy Elad , Silberman Alon , Albeck Michael , Longo Dan L. , Kalechman Yona , Sredni Benjamin
Published: March 2023

Abstract
Interaction between the integrin VLA-4 on acute myelogenous leukemia (AML) cells with stromal fibronectin is a decisive factor in chemotherapeutic resistance. In this study, we provide a rationale for a drug repositioning strategy to blunt integrin activation in AML cells and restore their sensitivity to chemotherapy. Specifically, we demonstrate that the nontoxic tellurium compound AS101, currently being evaluated in clinical trials, can abrogate the acquired resistance of AML. Mechanistic investigations revealed that AS101 caused redox inactivation of adjacent thiols in the exofacial domain of VLA-4 after its ligation to stromal fibronectin. This effect triggered cytoskeletal conformational changes that decreased PI3K/Akt/Bcl2 signaling, an obligatory step in chemosensitization by AS101. In a mouse xenograft of AML derived from patient leukemic cells with high VLA-4 expression and activity, we demonstrated that AS101 abrogated drug resistance and prolonged survival in mice receiving chemotherapy. Decreased integrin activity was confirmed on AML cells in vivo. The chemosensitizing activity of AS101 persisted in hosts with defective adaptive and innate immunity, consistent with evidence that integrin deactivation was not mediated by heightening immune attack. Our findings provide a mechanistic rationale to reposition the experimental clinical agent, AS101, to degrade VLA-4–mediated chemoresistance and improve clinical responses in patients with AML. Cancer Res; 74(11); 3092–103. ©2014 AACR.
Data from Inhibition of Protein Kinase CK2 Reduces Cyp24a1 Expression and Enhances 1,25-Dihydroxyvitamin D3 Antitumor Activity in Human Prostate Cancer Cells
Authors: Luo Wei , Yu Wei-Dong , Ma Yingyu , Chernov Mikhail , Trump Donald L. , Johnson Candace S.
Published: March 2023

Abstract
Vitamin D has broad range of physiological functions and antitumor effects. 24-Hydroxylase, encoded by the CYP24A1 gene, is the key enzyme for degrading many forms of vitamin D including the most active form, 1,25D3. Inhibition of CYP24A1 enhances 1,25D3 antitumor activity. To isolate regulators of CYP24A1 expression in prostate cancer cells, we established a stable prostate cancer cell line PC3 with CYP24A1 promoter driving luciferase expression to screen a small molecular library for compounds that inhibit CYP24A1 promoter activity. From this screening, we identified, 4,5,6,7-tetrabromobenzimidazole (TBBz), a protein kinase CK2 selective inhibitor as a disruptor of CYP24A1 promoter activity. We show that TBBz inhibits CYP24A1 promoter activity induced by 1,25D3 in prostate cancer cells. In addition, TBBz downregulates endogenous CYP24A1 mRNA level in TBBz-treated PC3 cells. Furthermore, siRNA-mediated CK2 knockdown reduces 1,25D3-induced CYP24A1 mRNA expression in PC3 cells. These results suggest that CK2 contributes to 1,25D3-mediated target gene expression. Finally, inhibition of CK2 by TBBz or CK2 siRNA significantly enhances 1,25D3-mediated antiproliferative effect in vitro and in vivo in a xenograft model. In summary, our findings reveal that protein kinase CK2 is involved in the regulation of CYP24A1 expression by 1,25D3 and CK2 inhibitor enhances 1,25D3-mediated antitumor effect. Cancer Res; 73(7); 2289–97. ©2013 AACR.