bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Similar Nucleotide Excision Repair Capacity in Melanocytes and Melanoma Cells
Authors: Gaddameedhi Shobhan , Kemp Michael G. , Reardon Joyce T. , Shields Janiel M. , Smith-Roe Stephanie L. , Kaufmann William K. , Sancar Aziz
Published: March 2023

Abstract
Sunlight UV exposure produces DNA photoproducts in skin that are repaired solely by nucleotide excision repair in humans. A significant fraction of melanomas are thought to result from UV-induced DNA damage that escapes repair; however, little evidence is available about the functional capacity of normal human melanocytes, malignant melanoma cells, and metastatic melanoma cells to repair UV-induced photoproducts in DNA. In this study, we measured nucleotide excision repair in both normal melanocytes and a panel of melanoma cell lines. Our results show that in 11 of 12 melanoma cell lines tested, UV photoproduct repair occurred as efficiently as in primary melanocytes. Importantly, repair capacity was not affected by mutation in the N-RAS or B-RAF oncogenes, nor was a difference observed between a highly metastatic melanoma cell line (A375SM) or its parental line (A375P). Lastly, we found that although p53 status contributed to photoproduct removal efficiency, its role did not seem to be mediated by enhanced expression or activity of DNA binding protein DDB2. We concluded that melanoma cells retain capacity for nucleotide excision repair, the loss of which probably does not commonly contribute to melanoma progression. Cancer Res; 70(12); 4922–30. ©2010 AACR.
Data from Downregulation of Gadd45β Expression by Hepatitis C Virus Leads to Defective Cell Cycle Arrest
Authors: Higgs Martin R. , Lerat Hervé , Pawlotsky Jean-Michel
Published: March 2023

Abstract
Members of the Gadd45 family play central roles in the cellular response to genotoxic stress and have been implicated in several human cancers, including hepatocellular carcinomas. Chronic infection by hepatitis C virus (HCV) is a major risk factor for the onset and development of primary hepatocellular tumors, although the underlying mechanisms are unclear. Here, we show a novel link between diminished Gadd45β expression and HCV infection. Inhibited Gadd45β expression was observed in both nontumoral and tumoral tissues from infected individuals, and in cell lines harboring a HCV replicon and the infectious HCV strain JFH1. Decreased Gadd45β expression was confirmed in vivo in a transgenic murine model expressing the entire HCV open reading frame. Mechanistically, hypermethylation of the Gadd45β promoter in the presence of HCV is responsible for this defect. Diminished Gadd45β expression leads to aberrant cell cycle arrest and diminished DNA excision repair. Together, these results provide a novel insight into the mechanisms involved in HCV-associated hepatocellular carcinomas, showing that reduced Gadd45β expression may play a contributory role to this process, and providing evidence that HCV may interfere with epigenetic gene expression by altering promoter methylation. Cancer Res; 70(12); 4901–11. ©2010 AACR.
Data from Tpl2 Is a Key Mediator of Arsenite-Induced Signal Transduction
Authors: Lee Kyung Mi , Lee Ki Won , Bode Ann M. , Lee Hyong Joo , Dong Zigang
Published: March 2023

Abstract
Arsenite is a well-known human carcinogen that especially targets skin. The tumor progression locus 2 (Tpl2) gene encodes a serine/threonine protein kinase that is overexpressed in various cancer cells. However, the relevance of Tpl2 in arsenite-induced carcinogenesis and the underlying mechanisms remain to be explored. We show that arsenite increased Tpl2 kinase activity and its phosphorylation in mouse epidermal JB6 P+ cells in a dose- and time-dependent manner. Exposure to arsenite resulted in a marked induction of cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2), important mediators of inflammation and tumor promotion. Treatment with a Tpl2 kinase inhibitor or Tpl2 short hairpin RNA suppressed COX-2 expression and PGE2 production induced by arsenite treatment, suggesting that Tpl2 is critical in arsenite-induced carcinogenesis. We also found that arsenite-induced phosphorylation of extracellular signal-regulated kinases (ERK) or c-Jun NH2-terminal kinases (JNK) was markedly suppressed by Tpl2 kinase inhibitor or Tpl2 short hairpin RNA. Inhibition of arsenite-induced ERK or JNK signaling using a pharmacologic inhibitor of ERK or JNK substantially blocked COX-2 expression. Furthermore, inhibition of Tpl2 reduced the arsenite-induced promoter activity of NF-κB and activator protein-1 (AP-1), indicating that NF-κB and AP-1 are downstream transducers of arsenite-triggered Tpl2. Our results show that Tpl2 plays a key role in arsenite-induced COX-2 expression and PGE2 production and further elucidate the role of Tpl2 in arsenite signals that activate ERK/JNK and NF-κB/AP-1 in JB6 P+ cells. [Cancer Res 2009;69(20):8043–9]
Data from Dvl2 Promotes Intestinal Length and Neoplasia in the ApcMin Mouse Model for Colorectal Cancer
Authors: Metcalfe Ciara , Ibrahim Ashraf E.K. , Graeb Michael , de la Roche Marc , Schwarz-Romond Thomas , Fiedler Marc , Winton Douglas J. , Corfield Anthony , Bienz Mariann
Published: March 2023

Abstract
APC mutations cause activation of Wnt/β-catenin signaling, which invariably leads to colorectal cancer. Similarly, overexpressed Dvl proteins are potent activators of β-catenin signaling. Screening a large tissue microarray of different staged colorectal tumors by immunohistochemistry, we found that Dvl2 has a strong tendency to be overexpressed in colorectal adenomas and carcinomas, in parallel to nuclear β-catenin and Axin2 (a universal transcriptional target of Wnt/β-catenin signaling). Furthermore, deletion of Dvl2 reduced the intestinal tumor numbers in a dose-dependent way in the ApcMin model for colorectal cancer. Interestingly, the small intestines of Dvl2 mutants are shortened, reflecting in part a reduction of their crypt diameter and cell size. Consistent with this, mammalian target of rapamycin (mTOR) signaling is highly active in normal intestinal crypts in which Wnt/β-catenin signaling is active, and activated mTOR signaling (as revealed by staining for phosphorylated 4E-BP1) serves as a diagnostic marker of ApcMin mutant adenomas. Inhibition of mTOR signaling in ApcMin mutant mice by RAD001 (everolimus) reduces their intestinal tumor load, similarly to Dvl2 deletion. mTOR signaling is also consistently active in human hyperplastic polyps and has a significant tendency for being active in adenomas and carcinomas. Our results implicate Dvl2 and mTOR in the progression of colorectal neoplasia and highlight their potential as therapeutic targets in colorectal cancer. Cancer Res; 70(16); 6629–38. ©2010 AACR.
Data from Vorinostat and Sorafenib Increase CD95 Activation in Gastrointestinal Tumor Cells through a Ca2+-De novo Ceramide-PP2A-Reactive Oxygen Species–Dependent Signaling Pathway
Authors: Park Margaret A. , Mitchell Clint , Zhang Guo , Yacoub Adly , Allegood Jeremy , Häussinger Dieter , Reinehr Roland , Larner Andrew , Spiegel Sarah , Fisher Paul B. , Voelkel-Johnson Christina , Ogretmen Besim , Grant Steven , Dent Paul
Published: March 2023

Abstract
The targeted therapeutics sorafenib and vorinostat interact in a synergistic fashion to kill carcinoma cells by activating CD95, and this drug combination is entering phase I evaluation. In this study, we determined how CD95 is activated by treatment with this drug combination. Low doses of sorafenib and vorinostat, but not the individual drugs, rapidly increased reactive oxygen species (ROS), Ca2+, and ceramide levels in gastrointestinal tumor cells. The production of ROS was reduced in Rho zero cells. Quenching ROS blocked drug-induced CD95 surface localization and apoptosis. ROS generation, CD95 activation, and cell killing was also blocked by quenching of induced Ca2+ levels or by inhibition of PP2A. Inhibition of acidic sphingomyelinase or de novo ceramide generation blocked the induction of ROS; however, combined inhibition of both acidic sphingomyelinase and de novo ceramide generation was required to block the induction of Ca2+. Quenching of ROS did not affect drug-induced ceramide/dihydro-ceramide levels, whereas quenching of Ca2+ reduced the ceramide increase. Sorafenib and vorinostat treatment radiosensitized liver and pancreatic cancer cells, an effect that was suppressed by quenching ROS or knockdown of LASS6. Further, sorafenib and vorinostat treatment suppressed the growth of pancreatic tumors in vivo. Our findings show that induction of cytosolic Ca2+ by sorafenib and vorinostat is a primary event that elevates dihydroceramide levels, each essential steps in ROS generation that promotes CD95 activation. Cancer Res; 70(15); 6313–24. ©2010 AACR.
Data from β1-Integrin Circumvents the Antiproliferative Effects of Trastuzumab in Human Epidermal Growth Factor Receptor-2–Positive Breast Cancer
Authors: Lesniak David , Xu Yaoxian , Deschenes Jean , Lai Raymond , Thoms John , Murray David , Gosh Sunita , Mackey John R. , Sabri Siham , Abdulkarim Bassam
Published: March 2023

Abstract
Resistance to trastuzumab, the monoclonal antibody targeting human epidermal growth factor receptor 2 (HER-2), is a major concern for HER-2–positive metastatic breast cancer (MBC) patients. To date, HER-2 status is the only available biomarker for selecting patients for trastuzumab-based therapy. β1-Integrin, an adhesion molecule involved in cell survival and drug resistance, shares common downstream signaling elements with HER-2, such as the phosphatidylinositol 3-kinase/Akt and extracellular signal-regulated kinase-1/2 (ERK1/2) pathways. The significance of β1-integrin expression in HER-2–positive breast cancer and its involvement in a patient's response to trastuzumab-based therapy are unknown. We show here that overexpression of β1-integrin is an independent negative prognostic factor for tumor progression of HER-2–positive MBC patients treated with trastuzumab-based chemotherapy. Enforced overexpression of β1-integrin, its small interfering RNA–induced knockdown or treatment with a β1-integrin–blocking antibody in HER-2–positive breast cancer cells, identified a strong inverse relationship between expression level of β1-integrin and in vitro sensitivity to trastuzumab. Notably, β1-integrin overexpression increased the phosphorylation of Akt-Ser473 and ERK1/2, thereby promoting survival and mitogenic signals to bypass the antiproliferative effects of trastuzumab. Our findings show that β1-integrin provides a novel independent prognostic biomarker of trastuzumab response in HER-2–positive MBC patients and suggest a new target to augment the antiproliferative effects of trastuzumab. [Cancer Res 2009;69(22):8620–8]
Data from Targeting the Fanconi Anemia/BRCA Pathway Circumvents Drug Resistance in Multiple Myeloma
Authors: Yarde Danielle N. , Oliveira Vasco , Mathews Linda , Wang Xingyu , Villagra Alejandro , Boulware David , Shain Kenneth H. , Hazlehurst Lori A. , Alsina Melissa , Chen Dung-Tsa , Beg Amer A. , Dalton William S.
Published: March 2023

Abstract
The Fanconi anemia/BRCA (FA/BRCA) DNA damage repair pathway plays a pivotal role in the cellular response to replicative stress induced by DNA alkylating agents and greatly influences drug response in cancer treatment. We recently reported that FA/BRCA genes are overexpressed and causative for drug resistance in human melphalan-resistant multiple myeloma cell lines. However, the transcriptional regulation of the FA/BRCA pathway is not understood. In this report, we describe for the first time a novel function of the NF-κB subunits, RelB/p50, as transcriptional activators of the FA/BRCA pathway. Specifically, our findings point to constitutive phosphorylation of IκB kinase α and subsequent alterations in FANCD2 expression and function as underlying events leading to melphalan resistance in repeatedly exposed multiple myeloma cells. Inhibiting NF-κB by small interfering RNA, blocking the IκB kinase complex with BMS-345541, or using the proteasome inhibitor bortezomib drastically reduced FA/BRCA gene expression and FANCD2 protein expression in myeloma cells, resulting in diminished DNA damage repair and enhanced melphalan sensitivity. Importantly, we also found that bortezomib decreases FA/BRCA gene expression in multiple myeloma patients. These results show for the first time that NF-κB transcriptionally regulates the FA/BRCA pathway and provide evidence for targeting Fanconi anemia–mediated DNA repair to enhance chemotherapeutic response and circumvent drug resistance in myeloma patients. [Cancer Res 2009;69(24):9367–75]
Data from Srcasm Inhibits Fyn-Induced Cutaneous Carcinogenesis with Modulation of Notch1 and p53
Authors: Zhao Liang , Li Weijie , Marshall Christine , Griffin Thomas , Hanson Matthew , Hick Ryan , Dentchev Tzvete , Williams Erik , Werth Adrienne , Miller Christopher , Bashir Hasan , Pear Warren , Seykora John T.
Published: March 2023

Abstract
Src family tyrosine kinases (SFK) regulate cell proliferation, and increased SFK activity is common in human carcinomas, including cutaneous squamous cell carcinomas (SCC) and its precursors. The elevated SFK activity in cutaneous SCCs was modeled using K14-Fyn Y528F transgenic mice, which spontaneously form punctate keratotic lesions, scaly plaques, and large tumors resembling actinic keratoses, SCC in situ, and SCCs, respectively. Lesional tissue showed increased levels of activated SFKs, PDK1, STAT3, and ERK1/2, whereas Notch1/NICD protein and transcript levels were decreased. p53 levels also were decreased in SCC in situ and SCCs. Increasing Srcasm levels using a K14-Fyn Y528F/K14-Srcasm double transgenic model markedly inhibited cutaneous neoplasia. In contrast, increased expression of a nonphosphorylatable Srcasm mutant maintained the neoplastic phenotype. Increasing Srcasm levels decreased levels of Fyn, activated SFKs, ERK1/2, PDK1, and phospho-STAT3, and increased Notch1/NICD and p53 levels. Analysis of human specimens revealed that levels of Fyn and activated SFKs were elevated in SCCs compared with adjacent nonlesional epidermis. In addition, Notch1 and Srcasm protein and transcript levels were decreased in human SCCs compared with nonlesional epidermis. Therefore, the SCCs produced by the Fyn Y528F mice resemble their human counterparts at the molecular level. K14-Fyn Y528F mice represent a robust model of cutaneous carcinogenesis that manifests precancerous lesions and SCCs resembling human disease. The Fyn/Srcasm signaling nexus modulates activity of STAT3, PDK1, ERK1/2, Notch1, and p53. Further study of Fyn and Srcasm should provide insights into the mechanisms regulating keratinocyte proliferation and skin carcinogenesis. [Cancer Res 2009;69(24):9439–47]
Data from Disruption of Transforming Growth Factor-β Signaling by Five Frequently Methylated Genes Leads to Head and Neck Squamous Cell Carcinoma Pathogenesis
Authors: Bennett Kristi L. , Romigh Todd , Eng Charis
Published: March 2023

Abstract
Head and neck squamous cell carcinoma (HNSCC) is an aggressive cancer with low survival rates in advanced stages. To facilitate timely diagnosis and improve outcome, early detection markers (e.g., DNA methylation) are crucial for timely cancer diagnosis. In a recent publication, an epigenome-wide screen revealed a set of genes that are commonly methylated and downregulated in head and neck cancers (SEPT9, SLC5A8, FUSSEL18, EBF3, and IRX1). Interestingly, these candidates are potentially involved in the transforming growth factor-β (TGF-β) signaling pathway, which is often disrupted in HNSCC. Therefore, we sought to determine coordinated epigenetic silencing of these candidate genes in HNSCC as potential key disruptors of TGF-β signaling, which could ultimately result in HNSCC progression. Through immunoprecipitation studies, all five of the investigated candidate genes were found to interact with components of the TGF-β pathway. Overexpression of SLC5A8, EBF3, and IRX1 resulted in decreased mitotic activity and increased apoptosis. In addition, EBF3 was found to increase p21 promoter activity, and SMAD2 significantly increased IRX1 promoter activity. These findings are significant because they reveal a set of genes that interact with components of the TGF-β pathway, and their silencing via methylation in HNSCC results in coordinated decrease in apoptosis, increased proliferation, and decreased differentiation. [Cancer Res 2009;69(24):9301–5]
Data from CD117 and Stro-1 Identify Osteosarcoma Tumor-Initiating Cells Associated with Metastasis and Drug Resistance
Authors: Adhikari Amit S. , Agarwal Neeraj , Wood Byron M. , Porretta Constance , Ruiz Bernardo , Pochampally Radhika R. , Iwakuma Tomoo
Published: March 2023

Abstract
Emerging evidence indicates the presence of tumor-initiating cells (TIC) or cancer stem cells in osteosarcoma. However, no study has shown specific markers to identify osteosarcoma TICs with in vivo tumor formation ability. Additionally, there has been a lack of investigations gauging the contribution of osteosarcoma TICs to metastatic and drug-resistant properties. In this study, we have identified mouse and human osteosarcoma TICs using mesenchymal stem cell markers CD117 and Stro-1. These markers were preferentially expressed in spheres and doxorubicin-resistant cells. Both mouse and human cells expressing these markers were sorted and analyzed for their abilities of tumor formation with as few as 200 cells, self-renewability, multipotency, drug resistance, metastatic potential, and enrichment of a metastasis-associated marker (CXCR4) and a drug resistance marker (ABCG2). CD117+Stro-1+ cells efficiently formed serially transplantable tumors, whereas CD117−Stro-1− cells rarely initiated tumors. On orthotopic injections, CD117+Stro-1+ cell-derived tumors metastasized at a high frequency. Further, CD117+Stro-1+ cells showed high invasive and drug-resistant properties and were efficiently enriched for CXCR4 (20–90%) and ABCG2 (60–90%). These results suggest possible mechanisms for the high metastatic and drug-resistant properties of osteosarcoma TICs. In summary, CD117 and Stro-1 identify osteosarcoma TICs associated with the most lethal characteristics of the disease—metastasis and drug resistance—and these markers offer candidates for TIC-targeted drug delivery aimed at eradicating osteosarcoma. Cancer Res; 70(11); 4602–12. ©2010 AACR.
Data from A Cancer Detection Platform Which Measures Telomerase Activity from Live Circulating Tumor Cells Captured on a Microfilter
Authors: Xu Tong , Lu Bo , Tai Yu-Chong , Goldkorn Amir
Published: March 2023

Abstract
Circulating tumor cells (CTC) quantified in cancer patients' blood can predict disease outcome and response to therapy. However, the CTC analysis platforms commonly used cannot capture live CTCs and only apply to tumors of epithelial origin. To address these limitations, we have developed a novel cancer detection platform which measures telomerase activity from live CTCs captured on a parylene-C slot microfilter. Using a constant low-pressure delivery system, the new microfilter platform was capable of cell capture from 1 mL of whole blood in less than 5 minutes, achieving 90% capture efficiency, 90% cell viability, and 200-fold sample enrichment. Importantly, the captured cells retained normal morphology by scanning electron microscopy and could be readily manipulated, further analyzed, or expanded on- or off-filter. Telomerase activity—a well-recognized universal cancer marker—was reliably detected by quantitative PCR from as few as 25 cancer cells added into 7.5 mL of whole blood and captured on the microfilter. Moreover, significant telomerase activity elevation was also measured from patients' blood samples and from single cancer cells lifted off of the microfilter. Live CTC capture and analysis is fast and simple yet highly quantitative, versatile, and applicable to nearly all solid tumor types, making this a highly promising new strategy for cancer detection and characterization. Cancer Res; 70(16); 6420–6. ©2010 AACR.
Data from The Limitations of the G1-S Checkpoint
Authors: Deckbar Dorothee , Stiff Thomas , Koch Barbara , Reis Caroline , Löbrich Markus , Jeggo Penny A.
Published: March 2023

Abstract
It has been proposed that the G1-S checkpoint is the critical regulator of genomic stability, preventing the cell cycle progression of cells with a single DNA double-strand break. Using fluorescence-activated cell sorting analysis of asynchronous cells and microscopic analysis of asynchronous and synchronized cells, we show that full blockage of S-phase entry is only observed >4 hours after irradiation. The process is ataxia-telangiectasia mutated (ATM) dependent and Chk1/2 independent and can be activated throughout G1 phase. By monitoring S-phase entry of irradiated synchronized cells, we show that the duration of arrest is dose dependent, with S-phase entry recommencing after arrest with kinetics similar to that observed in unirradiated cells. Thus, G1-S checkpoint arrest is not always permanent. Following exposure to higher doses (≥2 Gy), G1-S arrest is inefficiently maintained, allowing progression of G1-phase cells into G2 with elevated γH2AX foci and chromosome breaks. At early times after irradiation (≤4 h), G1-S checkpoint arrest is not established but cells enter S phase at a reduced rate. This early slowing in S-phase entry is ATM and Chk2 dependent and detectable after 100 mGy, showing a novel and sensitive damage response. However, the time needed to establish G1-S checkpoint arrest provides a window when cells can progress to G2 and form chromosome breaks. Our findings detail the efficacy of the G1-S checkpoint and define two significant limitations: At early times after IR, the activated checkpoint fails to efficiently prevent S-phase entry, and at later times, the checkpoint is inefficiently maintained. Cancer Res; 70(11); 4412–21. ©2010 AACR.
Data from Synthetic Lethality through Combined Notch–Epidermal Growth Factor Receptor Pathway Inhibition in Basal-Like Breast Cancer
Authors: Dong Yiyu , Li Aimin , Wang Jianbo , Weber Jason D. , Michel Loren S.
Published: March 2023

Abstract
Basal-like breast cancers (BLBC) are highly aggressive, yet selective therapies targeting the specific oncoproteins driving these tumors have not been developed. These cancers frequently express epidermal growth factor receptor (EGFR), with resistance to its inhibition being well documented, albeit poorly understood. Notch pathway activation is also common in this breast cancer subtype and can be suppressed by γ-secretase inhibitors, which effectively block receptor cleavage and activation. Herein, we show that although inhibition of either EGFR or Notch signaling alone is insufficient to suppress basal-like breast tumor cell survival and proliferation, simultaneous inhibition uncovers a synthetic lethal relationship between these two oncogenic pathways. This lethality is due in part to significant decreases in AKT activation caused by combined EGFR and Notch inhibition. Expression of the activated form of Notch1 restores AKT activity and enables cells to overcome cell death after dual-pathway blockade. Combined pathway inhibition is also dramatically more effective at suppressing tumor growth in mice than blocking EGFR or Notch signaling alone. Thus, we show that Notch pathway activation contributes to resistance to EGFR inhibition, and provide a novel treatment strategy for BLBCs. Cancer Res; 70(13); 5465–74. ©2010 AACR.
Data from Tumor Antigen Epitopes Interpreted by the Immune System as Self or Abnormal-Self Differentially Affect Cancer Vaccine Responses
Authors: Ryan Sean O. , Turner Michael S. , Gariépy Jean , Finn Olivera J.
Published: March 2023

Abstract
Epitope selection is an important consideration in the design of cancer vaccines, but factors affecting selection are not fully understood. We compared the immune responses to peptides and glycopeptides from the common human tumor antigen MUC1, a mucin that is coated with O-linked carbohydrates in its variable number of tandem repeats (VNTR) region. MUC1 expressed on tumor cells is characteristically underglycosylated, creating peptide and glycopeptide neoepitopes that are recognized by the immune system. The response to VNTR peptides is weaker in MUC1-transgenic mice (MUC1-Tg mice) than in wild-type (WT) mice, whereas the response to VNTR glycopeptides is equally strong in the two strains. Thus, glycopeptides seem to be recognized as foreign, whereas peptides, although immunogenic, are perceived as self. To explore this further, we generated MUC1 peptide– and glycopeptide–specific T-cell receptor transgenic mice and studied the function of their CD4 T cells when adoptively transferred into MUC1-Tg or WT mice. Peptide-specific T-cell precursors were not centrally deleted in MUC1-Tg mice and did not acquire a T regulatory phenotype. However, their response to the cognate peptide was reduced in MUC1-Tg mice compared with WT mice. In contrast, glycopeptide-specific CD4 T cells responded equally well in the two hosts and, when simultaneously activated, also enhanced the peptide-specific T-cell responses. Our data show that the immune system differentially recognizes various epitopes of tumor-associated antigens either as self or as foreign, and this controls the strength of antitumor immunity. This represents an important consideration for designing safe and effective cancer vaccines. Cancer Res; 70(14); 5788–96. ©2010 AACR.
Data from Ectopic Runx2 Expression in Mammary Epithelial Cells Disrupts Formation of Normal Acini Structure: Implications for Breast Cancer Progression
Authors: Pratap Jitesh , Imbalzano Karen M. , Underwood Jean M. , Cohet Nathalie , Gokul Karthiga , Akech Jacqueline , van Wijnen Andre J. , Stein Janet L. , Imbalzano Anthony N. , Nickerson Jeffrey A. , Lian Jane B. , Stein Gary S.
Published: March 2023

Abstract
The transcription factor Runx2 is highly expressed in breast cancer cells compared with mammary epithelial cells and contributes to metastasis. Here we directly show that Runx2 expression promotes a tumor cell phenotype of mammary acini in three-dimensional culture. Human mammary epithelial cells (MCF-10A) form polarized, growth-arrested, acini-like structures with glandular architecture. The ectopic expression of Runx2 disrupts acini formation, and electron microscopic ultrastructural analysis revealed the absence of lumens. Characterization of the disrupted acini structures showed increased cell proliferation (Ki-67 positive cells), decreased apoptosis (Bcl-2 induction), and loss of basement membrane formation (absence of β4 integrin expression). In complementary experiments, inhibition of Runx2 function in metastatic MDA-MB-231 breast cancer cells by stable expression of either short hairpin RNA-Runx2 or a mutant Runx2 deficient in subnuclear targeting resulted in reversion of acini to more normal structures and reduced tumor growth in vivo. These novel findings provide direct mechanistic evidence for the biological activity of Runx2, dependent on its subnuclear localization, in promoting early events of breast cancer progression and suggest a molecular therapeutic target. [Cancer Res 2009;69(17):6807–14]
Data from Steroid Receptor Coactivator-3 Expression in Lung Cancer and Its Role in the Regulation of Cancer Cell Survival and Proliferation
Authors: Cai Di , Shames David S. , Raso Maria Gabriela , Xie Yang , Kim Young H. , Pollack Jonathan R. , Girard Luc , Sullivan James P. , Gao Boning , Peyton Michael , Nanjundan Meera , Byers Lauren , Heymach John , Mills Gordon , Gazdar Adi F. , Wistuba Ignacio , Kodadek Thomas , Minna John D.
Published: March 2023

Abstract
Steroid receptor coactivator-3 (SRC-3) is a histone acetyltransferase and nuclear hormone receptor coactivator, located on 20q12, which is amplified in several epithelial cancers and well studied in breast cancer. However, its possible role in lung cancer pathogenesis is unknown. We found SRC-3 to be overexpressed in 27% of non–small cell lung cancer (NSCLC) patients (n = 311) by immunohistochemistry, which correlated with poor disease-free (P = 0.0015) and overall (P = 0.0008) survival. Twenty-seven percent of NSCLCs exhibited SRC-3 gene amplification, and we found that lung cancer cell lines expressed higher levels of SRC-3 than did immortalized human bronchial epithelial cells (HBEC), which in turn expressed higher levels of SRC-3 than did cultured primary human HBECs. Small interfering RNA–mediated downregulation of SRC-3 in high-expressing, but not in low-expressing, lung cancer cells significantly inhibited tumor cell growth and induced apoptosis. Finally, we found that SRC-3 expression is inversely correlated with gefitinib sensitivity and that SRC-3 knockdown results in epidermal growth factor receptor tyrosine kinase inhibitor–resistant lung cancers becoming more sensitive to gefitinib. Taken together, these data suggest that SRC-3 may be an important oncogene and therapeutic target for lung cancer. Cancer Res; 70(16); 6477–85. ©2010 AACR.
Data from EWS/FLI and Its Downstream Target NR0B1 Interact Directly to Modulate Transcription and Oncogenesis in Ewing's Sarcoma
Authors: Kinsey Michelle , Smith Richard , Iyer Anita K. , McCabe Edward R.B. , Lessnick Stephen L.
Published: March 2023

Abstract
Most Ewing's sarcomas harbor chromosomal translocations that encode fusions between EWS and ETS family members. The most common fusion, EWS/FLI, consists of an EWSR1-derived strong transcriptional activation domain fused, in-frame, to the DNA-binding domain–containing portion of FLI1. EWS/FLI functions as an aberrant transcription factor to regulate genes that mediate the oncogenic phenotype of Ewing's sarcoma. One of these regulated genes, NR0B1, encodes a corepressor protein, and likely plays a transcriptional role in tumorigenesis. However, the genes that NR0B1 regulates and the transcription factors it interacts with in Ewing's sarcoma are largely unknown. We used transcriptional profiling and chromatin immunoprecipitation to identify genes that are regulated by NR0B1, and compared these data to similar data for EWS/FLI. Although the transcriptional profile overlapped as expected, we also found that the genome-wide localization of NR0B1 and EWS/FLI overlapped as well, suggesting that they regulate some genes coordinately. Further analysis revealed that NR0B1 and EWS/FLI physically interact. This protein-protein interaction is likely to be relevant for the development of Ewing's sarcoma because mutations in NR0B1 that disrupt the interaction have transcriptional consequences and also abrogate oncogenic transformation. Taken together, these data suggest that EWS/FLI and NR0B1 physically interact, coordinately modulate gene expression, and mediate the transformed phenotype of Ewing's sarcoma. [Cancer Res 2009;69(23):9047–55]
Data from Bcl9/Bcl9l Are Critical for Wnt-Mediated Regulation of Stem Cell Traits in Colon Epithelium and Adenocarcinomas
Authors: Deka Jürgen , Wiedemann Norbert , Anderle Pascale , Murphy-Seiler Fabienne , Bultinck Jennyfer , Eyckerman Sven , Stehle Jean-Christophe , André Sylvie , Vilain Nathalie , Zilian Olav , Robine Sylvie , Delorenzi Mauro , Basler Konrad , Aguet Michel
Published: March 2023

Abstract
Canonical Wnt signaling plays a critical role in stem cell maintenance in epithelial homeostasis and carcinogenesis. Here, we show that in the mouse this role is critically mediated by Bcl9/Bcl9l, the mammalian homologues of Legless, which in Drosophila is required for Armadillo/β-catenin signaling. Conditional ablation of Bcl9/Bcl9l in the intestinal epithelium, where the essential role of Wnt signaling in epithelial homeostasis and stem cell maintenance is well documented, resulted in decreased expression of intestinal stem cell markers and impaired regeneration of ulcerated colon epithelium. Adenocarcinomas with aberrant Wnt signaling arose with similar incidence in wild-type and mutant mice. However, transcriptional profiles were vastly different: Whereas wild-type tumors displayed characteristics of epithelial-mesenchymal transition (EMT) and stem cell–like properties, these properties were largely abrogated in mutant tumors. These findings reveal an essential role for Bcl9/Bcl9l in regulating a subset of Wnt target genes involved in controlling EMT and stem cell–related features and suggest that targeting the Bcl9/Bcl9l arm of Wnt signaling in Wnt-activated cancers might attenuate these traits, which are associated with tumor invasion, metastasis, and resistance to therapy. Cancer Res; 70(16); 6619–28. ©2010 AACR.
Data from Sodium Orthovanadate Inhibits p53-Mediated Apoptosis
Authors: Morita Akinori , Yamamoto Shinichi , Wang Bing , Tanaka Kaoru , Suzuki Norio , Aoki Shin , Ito Azusa , Nanao Tomohisa , Ohya Soichiro , Yoshino Minako , Zhu Jin , Enomoto Atsushi , Matsumoto Yoshihisa , Funatsu Osamu , Hosoi Yoshio , Ikekita Masahiko
Published: March 2023

Abstract
Sodium orthovanadate (vanadate) inhibits the DNA-binding activity of p53, but its precise effects on p53 function have not been examined. Here, we show that vanadate exerts a potent antiapoptotic activity through both transcription-dependent and transcription-independent mechanisms relative to other p53 inhibitors, including pifithrin (PFT) α. We compared the effects of vanadate to PFTα and PFTμ, an inhibitor of transcription-independent apoptosis by p53. Vanadate suppressed p53-associated apoptotic events at the mitochondria, including the loss of mitochondrial membrane potential, the conformational change of Bax and Bak, the mitochondrial translocation of p53, and the interaction of p53 with Bcl-2. Similarly, vanadate suppressed the apoptosis-inducing activity of a mitochondrially targeted temperature-sensitive p53 in stable transfectants of SaOS-2 cells. In radioprotection assays, which rely on p53, vanadate completely protected mice from a sublethal dose of 8 Gy and partially from a lethal dose of 12 Gy. Together, our findings indicated that vanadate effectively suppresses p53-mediated apoptosis by both transcription-dependent and transcription-independent pathways, and suggested that both pathways must be inhibited to completely block p53-mediated apoptosis. Cancer Res; 70(1); 257–65
Data from In vivo Dynamics and Distinct Functions of Hypoxia in Primary Tumor Growth and Organotropic Metastasis of Breast Cancer
Authors: Lu Xin , Yan Carol H. , Yuan Min , Wei Yong , Hu Guohong , Kang Yibin
Published: March 2023

Abstract
Tumor hypoxia is known to activate angiogenesis, anaerobic glycolysis, invasion, and metastasis. However, a comparative analysis of the potentially distinct functions of hypoxia in primary tumor growth and organ-specific metastasis has not been reported. Here, we show distinct hypoxia kinetics in tumors generated by the MDA-MB-231 breast cancer sublines with characteristically different primary tumor growth rates and organotropic metastasis potentials. Hypoxia-induced angiogenesis promotes both primary tumor growth and lung metastasis but is nonessential for bone metastasis. Microarray profiling revealed that hypoxia enhances the expression of a significant number of genes in the lung metastasis signature, but only activates a few bone metastasis genes, among which DUSP1 was functionally validated in this study. Despite the different mechanisms by which hypoxia promotes organ-specific metastasis, inhibition of HIF-1α with a dominant-negative form of HIF-1α or 2-methoxyestradiol reduced metastasis to both lung and bone. Consistent with the extensive functional overlap of hypoxia in promoting primary tumor growth and lung metastasis, a 45-gene hypoxia response signature efficiently stratifies breast cancer patients with low or high risks of lung metastasis, but not for bone metastasis. Our study shows distinct functions of hypoxia in regulating angiogenesis and metastasis in different organ microenvironments and establishes HIF-1α as a promising target for controlling organotropic metastasis of breast cancer. Cancer Res; 70(10); 3905–14. ©2010 AACR.
Data from Metastasis-Associated Protein 1 Short Form Stimulates Wnt1 Pathway in Mammary Epithelial and Cancer Cells
Authors: Kumar Rakesh , Balasenthil Seetharaman , Pakala Suresh B. , Rayala Suresh K. , Sahin Aysegul A. , Ohshiro Kazufumi
Published: March 2023

Abstract
Although Wnt1 downstream signaling components as well as cytoplasmic level of metastatic tumor antigen 1 short form (MTA1s) are elevated in human breast cancer, it remains unknown whether a regulatory cross-talk exists between these two pathways. Here, we provide evidence of a remarkable correlation between the levels of MTA1s and stimulation of the Wnt1 signaling components, leading to increased stabilization of β-catenin and stimulation of Wnt1 target genes in the murine mammary epithelial and human breast cancer cells. We found that MTA1s influences Wnt1 pathway through extracellular signal-regulated kinase (ERK) signaling as selective silencing of the endogenous MTA1s or ERK, or its target glycogen synthase kinase 3β resulted in a substantial decrease in β-catenin expression, leading to the inhibition of Wnt1 target genes. Furthermore, downregulation of β-catenin in cells with elevated MTA1s level was accompanied by a corresponding decrease in the expression of Wnt1 target genes, establishing a mechanistic role for the ERK/glycogen synthase kinase 3β/β-catenin pathway in the stimulation of the Wnt1 target genes by MTA1s in mammary epithelial cells. In addition, mammary glands from the virgin MTA1s transgenic mice mimicked the phenotypic changes found in the Wnt1 transgenic mice and exhibited an overall hyperactivation of the Wnt1 signaling pathway, leading to increased stabilization and nuclear accumulation of β-catenin. Mammary glands from the virgin MTA1s-TG mice revealed ductal hyperplasia and ductal carcinoma in situ, and low incidence of palpable tumors. These findings reveal a previously unrecognized role for MTA1s as an important modifier of the Wnt1 signaling in mammary epithelial and cancer cells. Cancer Res; 70(16); 6598–608. ©2010 AACR.
Data from KRAB Zinc Finger Protein ZNF382 Is a Proapoptotic Tumor Suppressor That Represses Multiple Oncogenes and Is Commonly Silenced in Multiple Carcinomas
Authors: Cheng Yingduan , Geng Hua , Cheng Suk Hang , Liang Pei , Bai Yan , Li Jisheng , Srivastava Gopesh , Ng Margaret H.L. , Fukagawa Tatsuo , Wu Xiushan , Chan Anthony T.C. , Tao Qian
Published: March 2023

Abstract
Zinc finger transcription factors are involved broadly in development and tumorigenesis. Here, we report that the little studied zinc finger transcription factor ZNF382 functions as a tumor suppressor in multiple carcinomas. Although broadly expressed in normal tissues, ZNF382 expression was attenuated in multiple carcinoma cell lines due to promoter CpG methylation. ZNF382 was also frequently methylated in multiple primary tumors (nasopharyngeal, esophageal, colon, gastric, and breast). Ectopic expression of ZNF382 in silenced tumor cells significantly inhibited their clonogenicity and proliferation and induced apoptosis. We further found that ZNF382 inhibited NF-κB and AP-1 signaling and downregulated the expression of multiple oncogenes including MYC, MITF, HMGA2, and CDK6, as well as the NF-κB upstream factors STAT3, STAT5B, ID1, and IKBKE, most likely through heterochromatin silencing. ZNF382 could suppress tumorigenesis through heterochromatin-mediated silencing, as ZNF382 was colocalized and interacted with heterochromatin protein HP1 and further changed the chromatin modifications of ZNF382 target oncogenes. Our data show that ZNF382 is a functional tumor suppressor frequently methylated in multiple carcinomas. Cancer Res; 70(16); 6516–26. ©2010 AACR.
Data from Optimized Peptide Vaccines Eliciting Extensive CD8 T-Cell Responses with Therapeutic Antitumor Effects
Authors: Cho Hyun-Il , Celis Esteban
Published: March 2023

Abstract
A major challenge for developing effective therapeutic vaccines against cancer is overcoming immunologic tolerance to tumor-associated antigens that are expressed on both malignant cells and normal tissues. Herein, we describe a novel vaccination approach, TriVax, that uses synthetic peptides representing CD8 T-cell epitopes, Toll-like receptor agonists that function as potent immunologic adjuvants and costimulatory anti-CD40 antibodies to generate large numbers of high-avidity antigen-reactive T cells capable of recognizing and killing tumor cells. Our results show that TriVax induced huge numbers of long-lasting antigen-specific CD8 T cells that displayed significant antitumor effects in vivo. The administration of a TriVax formulation containing a CD8 T-cell epitope derived from a melanosomal antigen (Trp2180-188) elicited antigen-specific CD8 T cells that induced systemic autoimmunity (vitiligo). More important, TriVax immunization was effective in eliciting potent protective antitumor immunity as well as remarkable therapeutic effects against established B16 melanoma. This therapeutic effect was mediated by CD8 T cells via perforin-mediated lysis and required the participation of type-I IFN but not IFNγ. These results suggest that similar strategies would be applicable for the design of effective vaccination for conducting clinical studies in cancer patients. [Cancer Res 2009;69(23):9012–9]
Data from Increased Expression of α6 Integrin in Endothelial Cells Unveils a Proangiogenic Role for Basement Membrane
Authors: Primo Luca , Seano Giorgio , Roca Cristina , Maione Federica , Gagliardi Paolo Armando , Sessa Roberto , Martinelli Marianna , Giraudo Enrico , di Blasio Laura , Bussolino Federico
Published: March 2023

Abstract
The integrin α6 subunit is part of the α6β1 and α6β4 integrin complexes, which are known to be receptors for laminins and to mediate several biological activities such as embryogenesis, organogenesis, and invasion of carcinoma cells. However, the precise role of α6 integrin in angiogenesis has not yet been addressed. We observed that both vascular endothelial growth factor-A and fibroblast growth factor-2 strongly upregulate α6 integrin in human endothelial cells. Moreover, α6 integrin was positively modulated in angiogenic vessels in pancreatic neuroendocrine carcinoma. In this transgenic mouse model of spontaneous tumorigenesis, α6 integrin expression increased in the angiogenic stage, while being expressed at low levels in normal and hyperplastic tissue. We studied the functional role of α6 integrin during angiogenesis by lentivirus-mediated gene silencing and blocking antibody. Cell migration and morphogenesis on basement membrane extracts, a laminin-rich matrix, was reduced in endothelial cells expressing low levels of α6 integrin. However, we did not observe any differences in collagen matrices. Similar results were obtained in the aortic ring angiogenesis assay. α6 integrin was required for vessel sprouting on basement membrane gels but not on collagen gels, as shown by stably silencing this integrin in the murine aorta. Finally, a neutralizing anti-α6 integrin antibody inhibited in vivo angiogenesis in chicken chorioallantoic membrane and transgenic tumor mouse model. In summary, we showed that the α6 integrin participated in vascular endothelial growth factor-A and fibroblast growth factor-2–driven angiogenesis in vitro and in vivo, suggesting that it might be an attractive target for therapeutic approaches in angiogenesis-dependent diseases such as tumor growth. Cancer Res; 70(14); 5759–69. ©2010 AACR.
Data from Synergistic Activity of Sorafenib and Sulforaphane Abolishes Pancreatic Cancer Stem Cell Characteristics
Authors: Rausch Vanessa , Liu Li , Kallifatidis Georgios , Baumann Bernd , Mattern Jürgen , Gladkich Jury , Wirth Thomas , Schemmer Peter , Büchler Markus W. , Zöller Margot , Salnikov Alexei V. , Herr Ingrid
Published: March 2023

Abstract
Recent evidence suggests that pancreatic cancer and other solid tumors contain a subset of tumorigenic cells capable of extensive self-renewal that contribute to metastasis and treatment resistance. Sorafenib (SO) is a promising new multikinase inhibitor for treatment of advanced kidney and liver cancers. We report here targeting of pancreatic cancer stem cells (CSC) by SO and the development of a strategy to enhance this effect. Although SO administration diminished clonogenicity, spheroid formation, aldehyde dehydrogenase 1 (ALDH1) activity, growth on immunodeficient mice, proliferation, and angiogenesis and induced apoptosis, we observed SO-induced activation of NF-κB associated with survival and regrowth of spheroids. For enhanced elimination of CSC characteristics by SO, we cotreated cells with sulforaphane (SF). This broccoli isothiocyanate was recently described to eliminate pancreatic CSCs by downregulation of NF-κB activity without inducing toxic side effects. On combination treatment, SF completely eradicated SO-induced NF-κB binding, which was associated with abrogated clonogenicity, spheroid formation, ALDH1 activity, migratory capacity, and induction of apoptosis. In vivo, combination therapy reduced the tumor size in a synergistic manner. This was due to induction of apoptosis, inhibition of proliferation and angiogenesis, and downregulation of SO-induced expression of proteins involved in epithelial-mesenchymal transition. Our data suggest that SF may be suited to increase targeting of CSCs by SO. Cancer Res; 70(12); 5004–13. ©2010 AACR.
Data from Construction and Characterization of a Bispecific Anti-CD20 Antibody with Potent Antitumor Activity against B-Cell Lymphoma
Authors: Li Bohua , Zhang Xunming , Shi Shu , Zhao Lei , Zhang Dapeng , Qian Weizhu , Zheng Lei , Gao Jie , Wang Hao , Guo Yajun
Published: March 2023

Abstract
To develop more effective anti-CD20 reagents for B-cell lymphoma, we designed and constructed a bispecific tetravalent anti-CD20 antibody, 11B8/2F2(ScFvHL)4-Fc, derived from two fully human monoclonal antibodies (mAb), 2F2 and 11B8. 2F2 is a type I CD20 mAb, which is potent in complement-dependent cytotoxicity (CDC) assays but poor at inducing apoptosis, whereas 11B8 is a type II CD20 mAb, which is effective in induction of apoptosis but ineffective in CDC. Our results showed that 11B8/2F2(ScFvHL)4-Fc possessed apoptosis-inducing activity markedly superior to that of 2F2, and even 11B8, 11B8 plus 2F2, and 2F2(ScFvHL)4-Fc, a 2F2-derived monospecific tetravalent antibody developed previously. Interestingly, 11B8/2F2(ScFvHL)4-Fc displayed a similar ability to mediate CDC as 2F2(ScFvHL)4-Fc, although two of its four antigen-binding arms originated from 11B8. To explore why 11B8/2F2(ScFvHL)4-Fc was so potent in both CDC and apoptotic activity, a bispecific divalent antibody composed of 2F2 and 11B8, denoted as 11B8/2F2-ScFvFc, was constructed and characterized. Our results partially explained the reason for the potent CDC and apoptosis-inducing activity of 11B8/2F2(ScFvHL)4-Fc. Further in vivo therapy studies showed that 11B8/2F2(ScFvHL)4-Fc had a significantly more potent antitumor activity compared with 2F2, 11B8, 2F2 plus 11B8, and 2F2(ScFvHL)4-Fc. These data suggest that 11B8/2F2(ScFvHL)4-Fc may serve as a potential therapeutic agent for B-cell lymphoma. Cancer Res; 70(15); 6293–302. ©2010 AACR.