bluuebunny/crossref_metadata_2025_split huggingface dataset:
Opposite Effects of Notch-1 and Notch-2 on Mesothelioma Cell Survival under Hypoxia Are Exerted through the Akt Pathway
Authors: Graziani Irene , Eliasz Sandra , De Marco Melissa A. , Chen Yuanbin , Pass Harvey I. , De May Richard M. , Strack Peter R. , Miele Lucio , Bocchetta Maurizio 
Published: December 2008

Abstract
Malignant mesothelioma (MM) is a cancer of the lining of the lungs, heart, and intestine and is known to respond poorly to chemotherapy. Here we show that malignant mesothelial cells have an elevated Notch signaling pathway compared with normal human mesothelial cells. We studied the role of Notch in MM under normoxic and hypoxic conditions, the latter condition best recapitulating the MM microenvironment. Genetic and chemical modulation of the Notch pathway indicated that MM cells are dependent on Notch signaling. More specifically, this signaling was Notch-1 dependent as the result of its negative transcriptional regulation on phosphatase and tensin homologue (PTEN), which led to activation of the prosurvival phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling pathway. Our study also provides evidence that whereas Notch-1 is elevated in the malignant setting, Notch-2 is diminished. This differential expression of the two Notch isoforms benefits cancer cell survival because reexpression of Notch-2 was toxic to MM cells. The mechanism of Notch-2 toxicity to MM cells countered that of Notch-1, as it was the result of positive transcriptional regulation of PTEN and inhibition of the PI3K/Akt/mTOR signaling pathway. These results provide new insight into the role of Notch in MM and suggest that Notch pathway inhibitors may be useful in the treatment of this deadly disease. [Cancer Res 2008;68(23):9678–85]
Degradation of BRCA2 in Alkyltransferase-Mediated DNA Repair and Its Clinical Implications
Authors: Philip Subha , Swaminathan Srividya , Kuznetsov Sergey G. , Kanugula Sreenivas , Biswas Kajal , Chang Suhwan , Loktionova Natalia A. , Haines Diana C. , Kaldis Philipp , Pegg Anthony E. , Sharan Shyam K. 
Published: December 2008

Abstract
Germ-line mutations in BRCA2 have been linked to early-onset familial breast cancer. BRCA2 is known to play a key role in repairing double-strand breaks. Here, we describe the involvement of BRCA2 in O6-alkylguanine DNA alkyltransferase (AGT)–mediated repair of O6-methylguanine adducts. We show that BRCA2 physically associates and undergoes repair-mediated degradation with AGT. In contrast, BRCA2 with a 29-amino-acid deletion in an evolutionarily conserved domain does not bind to alkylated AGT; the two proteins are not degraded; and mouse embryonic fibroblasts are specifically sensitive to alkylating agents that result in O6-methylguanine adducts. We show that O6-benzylguanine (O6BG), a nontoxic inhibitor of AGT, can also induce BRCA2 degradation. BRCA2 is a viable target for cancer therapy because BRCA2-deficient cells are hypersensitive to chemotherapeutic DNA-damaging agents. We show a marked effect of O6BG pretreatment on cell sensitivity to cisplatin. We also show the efficacy of this approach on a wide range of human tumor cell lines, which suggests that chemosensitization of tumors by targeted degradation of BRCA2 may be an important consideration when devising cancer therapeutics. [Cancer Res 2008;68(23):9973–81]
A Range of Cancers Is Associated with the rs6983267 Marker on Chromosome 8
Authors: Wokołorczyk Dominika , Gliniewicz Bartłomiej , Sikorski Andrzej , Złowocka Elżbieta , Masojć Bartłomiej , Dębniak Tadeusz , Matyjasik Joanna , Mierzejewski Marek , Mędrek Krzysztof , Oszutowska Dorota , Suchy Janina , Gronwald Jacek , Teodorczyk Urszula , Huzarski Tomasz , Byrski Tomasz , Jakubowska Anna , Górski Bohdan , van de Wetering Thierry , Walczak Swietłana , Narod Steven A. , Lubiński Jan , Cybulski Cezary 
Published: December 2008

Abstract
Several genome-wide searches for common cancers have lead to the identification of a small number of loci that harbor low-risk cancer susceptibility markers. One marker, rs6983267 on chromosome 8q24, has been linked to both colon and prostate cancer, and is therefore a good candidate for a multicancer susceptibility marker. To determine the range of cancer sites associated with rs6983267, we genotyped 7,665 cases of cancer, representing 11 common cancer sites, and 1,910 controls. A significant odds ratio (OR) was observed for prostate cancer for carriers of genotype GG [OR, 1.77; 95% confidence interval (CI), 1.47–2.13]. The homozygote OR was higher for tumors with Gleason score 8 to 10 (OR, 1.94; 95% CI, 1.18–3.20) than for tumors with Gleason score 7 and below (OR, 1.65; 95% CI, 1.31–2.08). Significantly elevated (homozygote) ORs were observed for 4 other cancer sites, including colon (OR, 1.36; 95% CI, 1.08–1.72), kidney (OR, 1.52; 95% CI, 1.12–2.05), thyroid (OR, 1.37; 95% CI, 1.02–1.82), and larynx (OR, 1.39; 95% CI, 1.02–1.90). Information was available on family histories of cancer for eight sites. For six of the eight sites (prostate, breast, bladder, larynx, lung, and kidney), the homozygote ORs were higher for cases with a positive family history (at least one first-degree with any cancer) than for cases with unaffected first-degree relatives. Our results suggest that the range of cancers associated with the rs6983267 marker might be larger than previously thought. [Cancer Res 2008;68(23):9982–6]
Bidirectional Crosstalk between Leptin and Insulin-like Growth Factor-I Signaling Promotes Invasion and Migration of Breast Cancer Cells via Transactivation of Epidermal Growth Factor Receptor
Authors: Saxena Neeraj K. , Taliaferro-Smith LaTonia , Knight Brandi B. , Merlin Didier , Anania Frank A. , O'Regan Ruth M. , Sharma Dipali 
Published: December 2008

Abstract
Obesity is an independent risk factor for breast cancer, and obese breast cancer patients exhibit a higher risk for larger tumor burden and increased metastasis. Obesity, as associated with metabolic syndrome, results in an increase in circulating insulin-like growth factor (IGF), which acts as a mitogen. In addition, higher plasma level of adipocytokine leptin is associated with obesity. In the present study, we show that cotreatment with leptin and IGF-I significantly increases proliferation as well as invasion and migration of breast cancer cells. We found a novel bidirectional crosstalk between leptin and IGF-I signaling; IGF-I induced phosphorylation of leptin receptor (Ob-Rb) and leptin induced phosphorylation of IGF-I receptor (IGF-IR), whereas cotreatment induced synergistic phosphorylation and association of Ob-Rb and IGF-IR along with activation of downstream effectors, Akt and extracellular signal–regulated kinase. Leptin increased phosphorylation of IGF signaling molecules insulin-receptor substrate (IRS)-1 and IRS-2. Interestingly, we found that leptin and IGF-I cotreatment synergistically transactivated epidermal growth factor receptor (EGFR), depending on the proteolytic release of EGFR ligands, as the broad-spectrum matrix metalloproteinase inhibitor GM6001 could inhibit this effect. Using clinically relevant EGFR inhibitors, erlotinib and lapatinib, we found that inhibition of EGFR activation effectively inhibited leptin- and IGF-I–induced invasion and migration of breast cancer cells. Taken together, these data suggest a novel bidirectional crosstalk between leptin and IGF-I signaling that transactivates EGFR and promotes the metastatic properties as well as invasion and migration of breast cancer cells. Our findings indicate the possibility of using EGFR inhibitors erlotinib and lapatinib to counter the procancerous effects of leptin and IGF-I in breast cancers. [Cancer Res 2008;68(23):9712–22]
Anti–Glypican 3 Antibody as a Potential Antitumor Agent for Human Liver Cancer
Authors: Ishiguro Takahiro , Sugimoto Masamichi , Kinoshita Yasuko , Miyazaki Yoko , Nakano Kiyotaka , Tsunoda Hiroyuki , Sugo Izumi , Ohizumi Iwao , Aburatani Hiroyuki , Hamakubo Takao , Kodama Tatsuhiko , Tsuchiya Masayuki , Yamada-Okabe Hisafumi 
Published: December 2008

Abstract
Human glypican 3 (GPC3) is preferentially expressed in the tumor tissues of liver cancer patients. In this study, we obtained a monoclonal antibody (mAb) against the COOH-terminal part of GPC3, which induced antibody-dependent cellular cytotoxicity (ADCC). The mAb, designated GC33, exhibited marked tumor growth inhibition of s.c. transplanted Hep G2 and HuH-7 xenografts that expressed GPC3 but did not inhibit growth of the SK-HEP-1 that was negative for GPC3. GC33 was efficacious even in an orthotopic model; it markedly reduced the blood α-fetoprotein levels of mice intrahepatically transplanted with Hep G2 cells. Humanized GC33 (hGC33) was as efficacious as GC33 against the Hep G2 xenograft, but hGC33 lacking carbohydrate moieties caused neither ADCC nor tumor growth inhibition. Depletion of CD56+ cells from human peripheral blood mononuclear cells markedly abrogated the ADCC caused by hGC33. The results show that the antitumor activity of hGC33 is mainly attributable to ADCC, and in human, natural killer cell–mediated ADCC is one possible mechanism of the antitumor effects by GC33. hGC33 will provide a novel treatment option for liver cancer patients with GPC3-positive tumors. [Cancer Res 2008;68(23):9832–8]
Genetic Ancestry and Risk of Breast Cancer among U.S. Latinas
Authors: Fejerman Laura , John Esther M. , Huntsman Scott , Beckman Kenny , Choudhry Shweta , Perez-Stable Eliseo , Burchard Esteban González , Ziv Elad 
Published: December 2008

Abstract
U.S. Latinas have a lower incidence of breast cancer compared with non-Latina White women. This difference is partially explained by differences in the prevalence of known risk factors. Genetic factors may also contribute to this difference in incidence. Latinas are an admixed population with most of their genetic ancestry from Europeans and Indigenous Americans. We used genetic markers to estimate the ancestry of Latina breast cancer cases and controls and assessed the association with genetic ancestry, adjusting for reproductive and other risk factors. We typed a set of 106 ancestry informative markers in 440 Latina women with breast cancer and 597 Latina controls from the San Francisco Bay area and estimated genetic ancestry using a maximum likelihood method. Odds ratios (OR) and 95% confidence intervals (95% CI) for ancestry modeled as a continuous variable were estimated using logistic regression with known risk factors included as covariates. Higher European ancestry was associated with increased breast cancer risk. The OR for a 25% increase in European ancestry was 1.79 (95% CI, 1.28–2.79; P &lt; 0.001). When known risk factors and place of birth were adjusted for, the association with European ancestry was attenuated but remained statistically significant (OR, 1.39; 95% CI, 1.06–2.11; P = 0.013). Further work is needed to determine if the association is due to genetic differences between populations or possibly due to environmental factors not measured. [Cancer Res 2008;68(23):9723–8]
The ARF Tumor Suppressor Can Promote the Progression of Some Tumors
Authors: Humbey Olivier , Pimkina Julia , Zilfou Jack T. , Jarnik Michal , Dominguez-Brauer Carmen , Burgess Darren J. , Eischen Christine M. , Murphy Maureen E. 
Published: December 2008

Abstract
p14/p19ARF (ARF) is a tumor suppressor gene that is frequently mutated in human cancer. ARF has multiple tumor suppressor functions, some of which are mediated by signaling to p53. Surprisingly, a significant fraction of human tumors retain persistently high levels of ARF, suggesting that ARF may possess a prosurvival function. We show that ARF protein is markedly up-regulated in cells exposed to nutrient starvation. Cells with silenced ARF show reduced autophagy and reduced viability when placed under conditions of starvation. We show for the first time that ARF silencing can limit the progression of some tumors, such as lymphoma, but not others, such as E1A/Ras-induced tumors. Specifically, myc-driven lymphomas with mutant p53 tend to overexpress ARF; we show that silencing ARF in these tumors greatly impedes their progression. These data are the first to show that ARF can act in a p53-independent manner to promote the progression of some tumors. [Cancer Res 2008;68(23):9608–13]
Folate Targeting Enables Durable and Specific Antitumor Responses from a Therapeutically Null Tubulysin B Analogue
Authors: Leamon Christopher P. , Reddy Joseph A. , Vetzel Marilynn , Dorton Ryan , Westrick Elaine , Parker Nikki , Wang Yu , Vlahov Iontcho 
Published: December 2008

Abstract
The membrane-bound high-affinity folate receptor (FR) is highly expressed on a wide range of primary and metastatic human cancers, such as those originating in ovary, lung, breast, endometrium, kidney, and brain. Because folate-linked conjugates bind to and become internalized within FR-expressing cells (similar to that of free folic acid), we explored the possibility of using the folate ligand to target a potent, semisynthetic analogue of the microtubule inhibitor tubulysin B to FR-enriched tumors. When tested in vitro, a novel folate conjugate, herein referred to as EC0305, was found to specifically inhibit the growth of a panel of FR-positive cell lines (IC50 range, 1–10 nmol/L) in a dose-dependent manner, whereas cells lacking FR expression were unaffected. The potency of EC0305 was also confirmed against a human KB xenograft-nu/nu mouse cancer model. Here, a brief three times per week, 2-week regimen yielded remarkable antitumor activity (100% tumor-free animals) without causing significant weight loss or major organ tissue degeneration. In contrast, antitumor activity was completely abolished in EC0305-treated animals that were co-dosed with an excess of a nontoxic folate-containing analogue, thereby confirming that the antitumor effect of this agent was mediated by FRs. The advantage provided by folate conjugation was further proved by the untargeted free drug, which was found to be completely inactive at both tolerable and highly toxic dose levels. Collectively, these results show that this potent antiproliferative tubulysin compound can be specifically delivered to FR-positive tumors to provide substantial therapeutic benefit using well-tolerable dosing regimens. [Cancer Res 2008;68(23):9839–44]
Targeting the Stroma by T Cells to Limit Tumor Growth
Authors: Zhang Bin 
Published: December 2008

Abstract
Solid tumors may modulate their environment and keep stromal cells in an immunosuppressive and tumor-promoting state. Recent findings indicate that targeting not only cancer cells but also nonmalignant stromal cells by T cells is required for the eradication of established tumor. Interestingly, a single adoptive transfer of effector T cells that recognize tumor antigen-loaded stromal cells, but not the cancer cells themselves, causes long-term inhibition of tumor growth associated with T cell–mediated killing of stromal CD11b+/Gr1+ myeloid cells. Therefore, targeting tumor stroma by T cells points to an important alternative approach to the effective control of tumor growth, particularly in the absence of direct targeting of cancer cells. [Cancer Res 2008;68(23):9570–3]
Fetal Microchimerism and Cancer
Authors: Sawicki Janet A. 
Published: December 2008

Abstract
The persistence of fetal stem cells with multilineage potential in women who have been pregnant, a phenomenon known as fetal microchimerism, is emerging as a potential contributing factor in certain diseases, including cancer. For example, fetal microchimerism has been implicated in autoimmune disease, wound healing, and cancer. Studies of this phenomenon may provide a novel perspective on cancer in women, including in breast, ovarian, and lung cancers. [Cancer Res 2008;68(23):9567–9]
Targeting the Kinesin Spindle Protein: Basic Principles and Clinical Implications
Authors: Sarli Vasiliki , Giannis Athanassios 
Published: December 2008

Abstract
Kinesin spindle protein (KSP), a member of the kinesin superfamily of microtubule-based motors, plays a critical role in mitosis as it mediates centrosome separation and bipolar spindle assembly and maintenance. Inhibition of KSP function leads to cell cycle arrest at mitosis with the formation of monoastral microtubule arrays, and ultimately, to cell death. Several KSP inhibitors are currently being studied in clinical trials and provide new opportunities for the development of novel anticancer therapeutics alternative from the available microtubule targeting drugs.
Molecularly Targeted Radiosensitization of Human Prostate Cancer by Modulating Inhibitor of Apoptosis
Authors: Dai Yao , Liu Meilan , Tang Wenhua , DeSano Jeffrey , Burstein Ezra , Davis Mary , Pienta Kenneth , Lawrence Theodore , Xu Liang 
Published: December 2008

Abstract
Purpose: The inhibitor of apoptosis proteins (IAP) are overexpressed in hormone-refractory prostate cancer, rendering the cancer cells resistant to radiation. This study aims to investigate the radiosensitizing effect of small-molecule IAP inhibitor both in vitro and in vivo in androgen-independent prostate cancer and the possible mechanism of radiosensitization.
Experimental Design: Radiosensitization of SH-130 in human prostate cancer DU-145 cells was determined by clonogenic survival assay. Combination effect of SH-130 and ionizing radiation was evaluated by apoptosis assays. Pull-down and immunoprecipitation assays were employed to investigate the interaction between SH-130 and IAPs. DU-145 xenografts in nude mice were treated with SH-130, radiation, or combination, and tumor suppression effect was determined by caliper measurement or bioluminescence imaging. Nuclear factor-κB activation was detected by luciferase reporter assay and quantitative real-time PCR.
Results: SH-130 potently enhanced radiation-induced caspase activation and apoptosis in DU-145 cells. Both X-linked IAP and cIAP-1 can be pulled down by SH-130 but not by inactive SH-123. Moreover, SH-130 interrupted interaction between X-linked IAP/cIAP-1 and Smac. In a nude mouse xenograft model, SH-130 potently sensitized the DU-145 tumors to X-ray radiation without increasing systemic toxicity. The combination therapy suppressed tumor growth more significantly than either treatment alone, with over 80% of complete tumor regression. Furthermore, SH-130 partially blocked tumor necrosis factor-α- and radiation-induced nuclear factor-κB activation in DU-145 cells.
Conclusions: Our results show that small-molecule inhibitors of IAPs can overcome apoptosis resistance and radiosensitize human prostate cancer with high levels of IAPs. Molecular modulation of IAPs may improve the outcome of prostate cancer radiotherapy.
Akt-Dependent Proapoptotic Effects of Dietary Restriction on Late-Stage Management of a Phosphatase and Tensin Homologue/Tuberous Sclerosis Complex 2–Deficient Mouse Astrocytoma
Authors: Marsh Jeremy , Mukherjee Purna , Seyfried Thomas N. 
Published: December 2008

Abstract
Purpose: Malignant astrocytomas exhibit constitutive Akt phosphorylation due to reduced phosphatase and tensin homologue (PTEN) tumor suppressor expression or to increased growth factor receptor tyrosine kinase activation. Many astrocytomas are also tuberous sclerosis complex 2 (TSC2) protein deficient and exhibit constitutive mammalian target of rapamycin (mTOR) activity. Astrocytomas harboring PTEN/Akt/TSC2 pathway mutations are dependent on glycolysis to satisfy their bioenergetic requirements. Therapies that disrupt energy homeostasis can potentially manage astrocytoma growth and progression. Although dietary restriction (DR) reduces glycolysis and manages early-stage astrocytoma growth, no prior studies have identified the mechanisms involved or determined if DR can also manage late-stage tumor growth.
Experimental Design: The effects of a late-onset intermittent DR feeding paradigm were examined in adult C57BL/6J mice bearing the syngeneic CT-2A malignant astrocytoma grown orthotopically or subcutaneously.
Results: In contrast to contralateral normal brain, CT-2A was PTEN/TSC2 protein deficient; exhibited constitutive Akt, mTOR, and BAD phosphorylation; and overexpressed insulin-like growth factor-I (IGF-I), IGF-I receptor, hypoxia-inducible transcription factor-1α (HIF-1α), type 1 glucose transporter protein (GLUT1), and pyruvate kinase. DR initiated 10 to 14 days after tumor implantation (late onset) reduced CT-2A growth, delayed malignant progression, and significantly extended survival. DR suppressed phosphorylation of Akt and BAD while reducing expression of IGF-I, HIF-1α, and GLUT1. DR also enhanced procaspase-9/procaspase-3 cleavage but had no effect mTOR phosphorylation.
Conclusions: Our findings indicate that IGF-I/Akt signaling is associated with the antiapoptotic and glycolytic phenotype of the CT-2A astrocytoma and that DR targets this pathway. Moreover, PTEN/TSC2 deficiency may impair adaptation to the DR-induced disruption of energy homeostasis, thus enhancing apoptosis. Our findings highlight the efficacy of late-onset DR in managing astrocytoma growth and suggest that DR may be an effective broad-spectrum inhibitor of Akt signaling in PTEN/TSC2–deficient astrocytomas.
A Phase II Trial of 17-Allylamino-17-Demethoxygeldanamycin in Patients with Hormone-Refractory Metastatic Prostate Cancer
Authors: Heath Elisabeth I. , Hillman David W. , Vaishampayan Ulka , Sheng Shijie , Sarkar Fazlul , Harper Felicity , Gaskins Melvin , Pitot Henry C. , Tan Winston , Ivy S. Percy , Pili Roberto , Carducci Michael A. , Erlichman Charles , Liu Glenn 
Published: December 2008

Abstract
Purpose: 17-Allylamino-17-demethoxygeldanamycin (17-AAG) is a benzoquinone ansamycin antibiotic with antiproliferative activity in several mouse xenograft models, including prostate cancer models. A two-stage phase II study was conducted to assess the activity and toxicity profile of 17-AAG administered to patients with metastatic, hormone-refractory prostate cancer.
Experimental Design: Patients with at least one prior systemic therapy and a rising prostate-specific antigen (PSA) were eligible. Patients received 17-AAG at a dose of 300 mg/m2 i.v. weekly for 3 of 4 weeks. The primary objective was to assess the PSA response. Secondary objectives were to determine overall survival, to assess toxicity, and to measure interleukin-6, interleukin-8, and maspin levels and quality of life.
Results: Fifteen eligible patients were enrolled. The median age was 68 years and the median PSA was 261 ng/mL. Patients received 17-AAG for a median number of two cycles. Severe adverse events included grade 3 fatigue (four patients), grade 3 lymphopenia (two patients), and grade 3 back pain (two patients). The median PSA progression-free survival was 1.8 months (95% confidence interval, 1.3-3.4 months). The 6-month overall survival was 71% (95% confidence interval, 52-100%).
Conclusions: 17-AAG did not show any activity with regard to PSA response. Due to insufficient PSA response, enrollment was stopped at the end of first stage per study design. The most significant severe toxicity was grade 3 fatigue. Further evaluation of 17-AAG at a dose of 300 mg/m2 i.v. weekly as a single agent in patients with metastatic, hormone-refractory prostate cancer who received at least one prior systemic therapy is not warranted.