bluuebunny/crossref_metadata_2025 huggingface dataset:
Prognostic Value of Akt-1 in Human Prostate Cancer: A Computerized Quantitative Assessment with Quantum Dot Technology
Authors: Li Rile , Dai Hong , Wheeler Thomas M. , Sayeeduddin Mohammad , Scardino Peter T. , Frolov Anna , Ayala Gustavo E.
Published: May 2009

Background: Akt/protein kinase B signaling pathway has been implicated in tumorigenesis and progression. Previous studies showed the predictive potential of p-Akt-1, but total Akt-1 could provide more reliable information. We used image deconvolution, nanotechnology (quantum dots), and image analysis to improve Akt-1 quantification.

Design: This tissue microarray study included 840 radical prostatectomy cases. Slides were incubated with primary antibody against nonphosphorylated Akt-1 (Akt-1) followed by biotinylated secondary antibody and then by Qdot655 streptavidin conjugate. Slides were imaged under fluorescence microscopy and spectral deconvolution (Nuance) and quantified using plug-in image analysis software. Average intensity of Akt-1 signal was measured and subject to statistical analysis. Multivariate analysis (Cox regression) was applied to assess the prognostic value of Akt-1 for biochemical recurrence and prostate cancer-specific death. Akt-1 expression was also examined for correlations with Ki-67 index and apoptotic index in our database.

Result: Akt-1 was inversely correlated with apoptotic index (ρ = −0.203; P = 0.004) but not with Ki-67 index. The correlation between Akt and p-Akt is significant but weak (P = 0.0496; R2 = 0.118). On multivariate analysis Akt-1 was independently predictive of biochemical recurrence [hazard ratio, 2.863 (95% confidence interval, 1.127-7.271); P = 0.0270]. Akt-1 level is also predictive of prostate cancer-specific death (P = 0.0376).

Conclusion: High levels of Akt-1, assessed by quantum dots, deconvolution imaging, and image analysis, are associated with a higher risk of biochemical recurrence and prostate cancer-specific death.
A Phase I Study of the P-Glycoprotein Antagonist Tariquidar in Combination with Vinorelbine
Authors: Abraham Jame , Edgerly Maureen , Wilson Richard , Chen Clara , Rutt Ann , Bakke Susan , Robey Rob , Dwyer Andrew , Goldspiel Barry , Balis Frank , Van Tellingen Olaf , Bates Susan E. , Fojo Tito
Published: May 2009

Purpose: P-glycoprotein (Pgp) antagonists have had unpredictable pharmacokinetic interactions requiring reductions of chemotherapy. We report a phase I study using tariquidar (XR9576), a potent Pgp antagonist, in combination with vinorelbine.

Experimental Design: Patients first received tariquidar alone to assess effects on the accumulation of 99mTc-sestamibi in tumor and normal organs and rhodamine efflux from CD56+ mononuclear cells. In the first cycle, vinorelbine pharmacokinetics was monitored after the day 1 and 8 doses without or with tariquidar. In subsequent cycles, vinorelbine was administered with tariquidar. Tariquidar pharmacokinetics was studied alone and with vinorelbine.

Results: Twenty-six patients were enrolled. Vinorelbine 20 mg/m2 on day 1 and 8 was identified as the maximum tolerated dose (neutropenia). Nonhematologic grade 3/4 toxicities in 77 cycles included the following: abdominal pain (4 cycles), anorexia (2), constipation (2), fatigue (3), myalgia (2), pain (4) and dehydration, depression, diarrhea, ileus, nausea, and vomiting, (all once). A 150-mg dose of tariquidar: (1) reduced liver 99mTc-sestamibi clearance consistent with inhibition of liver Pgp; (2) increased 99mTc-sestamibi retention in a majority of tumor masses visible by 99mTc-sestamibi; and (3) blocked Pgp-mediated rhodamine efflux from CD56+ cells over the 48 hours examined. Tariquidar had no effects on vinorelbine pharmacokinetics. Vinorelbine had no effect on tariquidar pharmacokinetics. One patient with breast cancer had a minor response, and one with renal carcinoma had a partial remission.

Conclusions: Tariquidar is a potent Pgp antagonist, without significant side effects and much less pharmacokinetic interaction than previous Pgp antagonists. Tariquidar offers the potential to increase drug exposure in drug-resistant cancers.
Mitogen-Activated Protein Kinase Phosphatase-1 in Human Breast Cancer Independently Predicts Prognosis and Is Repressed by Doxorubicin
Authors: Rojo Federico , González-Navarrete Irene , Bragado Rafael , Dalmases Alba , Menéndez Silvia , Cortes-Sempere Maria , Suárez Cristina , Oliva Cristina , Servitja Sonia , Rodriguez-Fanjul Vanesa , Sánchez-Pérez Isabel , Campas Clara , Corominas Josep Maria , Tusquets Ignasi , Bellosillo Beatriz , Serrano Sergi , Perona Rosario , Rovira Ana , Albanell Joan
Published: May 2009

Purpose: Mitogen-activated protein kinase (MAPK) phosphatase-1 (MKP-1) dephosphorylates mitogen-activated protein kinase [extracellular signal-regulated kinase (ERK), c-Jun NH2-terminal kinase (JNK), and p38], mediates breast cancer chemoresistance, and is repressible by doxorubicin in breast cancer cells. We aimed to characterize doxorubicin effects on MKP-1 and phospho-MAPKs in human breast cancers and to further study the clinical relevance of MKP-1 expression in this disease.

Experimental Design: Doxorubicin effects on MKP-1, phospho-ERK1/2 (p-ERK1/2), phospho-JNK (p-JNK), and phospho-p38 were assayed in a panel of human breast cancer cells by Western blot and in human breast cancer were assayed ex vivo by immunohistochemistry (n = 50). MKP-1 expression was also assayed in a range of normal to malignant breast lesions (n = 30) and in a series of patients (n = 96) with breast cancer and clinical follow-up.

Results: MKP-1 was expressed at low levels in normal breast and in usual ductal hyperplasia and at high levels in in situ carcinoma. MKP-1 was overexpressed in ∼50% of infiltrating breast carcinomas. Similar to what was observed in breast cancer cell lines, ex vivo exposure of breast tumors to doxorubicin down-regulated MKP-1, and up-regulated p-ERK1/2 and p-JNK, in the majority of cases. However, in a proportion of tumors overexpressing MKP-1, doxorubicin did not significantly affect MKP-1 or phospho-MAPKs. With regard to patient outcome, MKP-1 overexpression was an adverse prognostic factor for relapse both by univariate (P < 0.001) and multivariate analysis (P = 0.002).

Conclusions: MKP-1 is overexpressed during the malignant transformation of the breast and independently predicts poor prognosis. Furthermore, MKP-1 is repressed by doxorubicin in many human breast cancers.
Selective Killing of Hypoxia-Inducible Factor-1–Active Cells Improves Survival in a Mouse Model of Invasive and Metastatic Pancreatic Cancer
Authors: Kizaka-Kondoh Shinae , Itasaka Satoshi , Zeng Lihua , Tanaka Shotaro , Zhao Tao , Takahashi Yumi , Shibuya Keiko , Hirota Kiichi , Semenza Gregg L. , Hiraoka Masahiro
Published: May 2009

Purpose: Pancreatic cancer is characterized by intratumoral hypoxia, early and aggressive local invasion, and metastatic potential. Hypoxia-inducible factor-1 (HIF-1) is the major transcriptional activator of hypoxia-responsive genes and intratumoral hypoxia is associated with increased risk of metastasis. However, the behavior of the cells having HIF-1 activity during the malignant progression in pancreatic cancer has not been tested.

Experimental Design: We orthotopically transplanted pancreatic cancer cells stably transfected with a HIF-1–dependent luciferase reporter gene and monitored HIF-1 activity in vivo in control and POP33-treated mice. POP33 is a novel prodrug, which has potential to increase caspase-3 activity and induce apoptosis in HIF-1–active/hypoxic cells.

Results: In vivo optical imaging showed that HIF-1 activity proceeded along with local invasion, the peritoneal dissemination, and the liver metastasis. HIF-1–active hypoxic cells were selectively eradicated by POP33. Moreover, selective killing of HIF-1–active hypoxic cells significantly suppressed malignant progression, resulting in a significant improvement in survival rate.

Conclusions: These results show that HIF-1–active cells constitute a large proportion of invading and metastatic cells and suggest that eradication of these cells may improve the outcome in advanced pancreatic cancer, a condition for which no effective therapy currently exists.
PCI-24781 Induces Caspase and Reactive Oxygen Species–Dependent Apoptosis Through NF-κB Mechanisms and Is Synergistic with Bortezomib in Lymphoma Cells
Authors: Bhalla Savita , Balasubramanian Sriram , David Kevin , Sirisawad Mint , Buggy Joseph , Mauro Lauren , Prachand Sheila , Miller Richard , Gordon Leo I. , Evens Andrew M.
Published: May 2009

Purpose: We investigated the cytotoxicity and mechanisms of cell death of the broad-spectrum histone deacetylase (HDAC) inhibitor PCI-24781, alone and combined with bortezomib in Hodgkin lymphoma and non-Hodgkin lymphoma cell lines and primary lymphoproliferative (CLL/SLL) cells.

Experimental Design: Apoptosis, mitochondrial membrane potential, cell cycle analysis, and reactive oxygen species (ROS) were measured by flow cytometry, whereas caspase activation was determined by Western blot. Nuclear factor κB (NF-κB)-related mRNAs were quantified by reverse transcription-PCR, NF-κB–related proteins by Western blotting, and NF-κB DNA-binding activity by electromobility shift assay. Finally, gene expression profiling was analyzed.

Results: PCI-24781 induced concentration-dependent apoptosis that was associated with prominent G0/G1 arrest, decreased S-phase, increased p21 protein, and increased ROS in Hodgkin lymphoma and non-Hodgkin lymphoma cell lines. Dose-dependent apoptosis with PCI-24781 was also seen among primary CLL/SLL cells. PCI-24781–induced apoptosis was shown to be ROS- and caspase-dependent. Combined PCI-24781/bortezomib treatment resulted in strong synergistic apoptosis in all non-Hodgkin lymphoma lines (combination indices, 0.19-0.6) and was additive in Hodgkin lymphoma and primary CLL/SLL cells. Further, PCI-24781/bortezomib resulted in increased caspase cleavage, mitochondrial depolarization, and histone acetylation compared with either agent alone. Gene expression profiling showed that PCI-24781 alone significantly down-regulated several antioxidant genes, proteasome components, and NF-κB pathway genes, effects that were enhanced further with bortezomib. Reverse transcription-PCR confirmed down-regulation of NF-κB1 (p105), c-Myc, and IκB-kinase subunits, where NF-κB DNA binding activity was decreased.

Conclusion: We show that PCI-24781 results in increased ROS and NF-κB inhibition, leading to caspase-dependent apoptosis. We also show that bortezomib is synergistic with PCI-24781. This combination or PCI-24781 alone has potential therapeutic value in lymphoma.
Chromosomal Instability and Copy Number Alterations in Barrett's Esophagus and Esophageal Adenocarcinoma
Authors: Paulson Thomas G. , Maley Carlo C. , Li Xiaohong , Li Hongzhe , Sanchez Carissa A. , Chao Dennis L. , Odze Robert D. , Vaughan Thomas L. , Blount Patricia L. , Reid Brian J.
Published: May 2009

Purpose: Chromosomal instability, as assessed by many techniques, including DNA content aneuploidy, loss of heterozygosity, and comparative genomic hybridization, has consistently been reported to be common in cancer and rare in normal tissues. Recently, a panel of chromosome instability biomarkers, including loss of heterozygosity and DNA content, has been reported to identify patients at high and low risk of progression from Barrett's esophagus (BE) to esophageal adenocarcinoma (EA), but required multiple platforms for implementation. Although chromosomal instability involving amplifications and deletions of chromosome regions have been observed in nearly all cancers, copy number alterations (CNA) in premalignant tissues have not been well characterized or evaluated in cohort studies as biomarkers of cancer risk.

Experimental Design: We examined CNAs in 98 patients having either BE or EA using Bacterial Artificial Chromosome (BAC) array comparative genomic hybridization to characterize CNAs at different stages of progression ranging from early BE to advanced EA.

Results: CNAs were rare in early stages (less than high-grade dysplasia) but were progressively more frequent and larger in later stages (high-grade dysplasia and EA), including high-level amplifications. The number of CNAs correlated highly with DNA content aneuploidy. Patients whose biopsies contained CNAs involving >70 Mbp were at increased risk of progression to DNA content abnormalities or EA (hazards ratio, 4.9; 95% confidence interval, 1.6-14.8; P = 0.0047), and the risk increased as more of the genome was affected.

Conclusions: Genome-wide analysis of CNAs provides a common platform for the evaluation of chromosome instability for cancer risk assessment as well as for the identification of common regions of alteration that can be further studied for biomarker discovery.
Combining PCI-24781, a Novel Histone Deacetylase Inhibitor, with Chemotherapy for the Treatment of Soft Tissue Sarcoma
Authors: Lopez Gonzalo , Liu Juehui , Ren Wenhong , Wei Wei , Wang Suizhao , Lahat Guy , Zhu Quan-Sheng , Bornmann William G. , McConkey David J. , Pollock Raphael E. , Lev Dina C.
Published: May 2009

Purpose: Histone deactylase inhibitors (HDACi) are a promising new class of anticancer therapeutics; however, little is known about HDACi activity in soft tissue sarcoma (STS), a heterogeneous cohort of mesenchymal origin malignancies. Consequently, we investigated the novel HDACi PCI-24781, alone/in combination with conventional chemotherapy, to determine its potential anti-STS–related effects and the underlying mechanisms involved.

Experimental Design: Immunoblotting was used to evaluate the effects of PCI-24781 on histone and nonhistone protein acetylation and expression of potential downstream targets. Cell culture–based assays were utilized to assess the effects of PCI-24781 on STS cell growth, cell cycle progression, apoptosis, and chemosensitivity. Quantitative reverse transcription-PCR, chromatin immunoprecipitation, and reporter assays helped elucidate molecular mechanisms resulting in PCI-24781–induced Rad51 repression. The effect of PCI-24781, alone or with chemotherapy, on tumor and metastatic growth was tested in vivo using human STS xenograft models.

Results: PCI-24781 exhibited significant anti-STS proliferative activity in vitro, inducing S phase depletion, G2/M cell cycle arrest, and increasing apoptosis. Superior effects were seen when combined with chemotherapy. A PCI-24781–induced reduction in Rad51, a major mediator of DNA double-strand break homologous recombination repair, was shown and may be a mechanism underlying PCI-24781 chemosensitization. We showed that PCI-24781 transcriptionally represses Rad51 through an E2F binding-site on the Rad51 proximal promoter. Although single-agent PCI-24781 had modest effects on STS growth and metastasis, marked inhibition was observed when combined with chemotherapy.

Conclusions: In light of these findings, this novel molecular-based combination may be applicable to multiple STS histologic subtypes, and potentially merits rigorous evaluation in human STS clinical trials.
Nrf2 Enhances Cell Proliferation and Resistance to Anticancer Drugs in Human Lung Cancer
Authors: Homma Shinsuke , Ishii Yukio , Morishima Yuko , Yamadori Tadahiro , Matsuno Yosuke , Haraguchi Norihiro , Kikuchi Norihiro , Satoh Hiroaki , Sakamoto Tohru , Hizawa Nobuyuki , Itoh Ken , Yamamoto Masayuki
Published: May 2009

Purpose: NF-E2-related factor 2 (Nrf2), a key transcription regulator for antioxidant and detoxification enzymes, is abundantly expressed in cancer cells. In this study, therefore, the role of Nrf2 in cancer cell proliferation and resistance to anticancer drugs was investigated.

Experimental Design: We used three human lung cancer cell lines with different degrees of Nrf2 activation: Nrf2 was highly activated in A549 cells, slightly activated in NCI-H292 cells, and not activated in LC-AI cells under unstimulated conditions.

Result: A549 cells showed higher resistance to cisplatin compared with NCI-H292 and LC-AI cells. The resistance to cisplatin was significantly inhibited in A549 but not in NCI-H292 or LC-AI cells by knockdown of Nrf2 with its specific small interfering RNA (Nrf2-siRNA). The cell proliferation was also most prominently inhibited in A549 cells by treatment with Nrf2-siRNA. In A549 cells, the expression of self-defense genes, such as antioxidant enzymes, phase II detoxifying enzymes, and drug efflux pumps, was significantly reduced by Nrf2-siRNA concomitant with a reduction of the cellular glutathione level. The degree of DNA crosslink and apoptosis after treatment with cisplatin was significantly elevated in A549 cells by Nrf2-siRNA. Knockdown of Nrf2 arrested the cell cycle at G1 phase with a reduction of the phosphorylated form of retinoblastoma protein in A549 and NCI-H292 cells but not in LC-AI cells.

Conclusion: These results indicate that the Nrf2 system is essential for both cancer cell proliferation and resistance to anticancer drugs. Thus, Nrf2 might be a potential target to enhance the effect of anticancer drugs.
Phase I and Pharmacokinetic Study of Trabectedin as a 1- or 3-hour Infusion Weekly in Patients with Advanced Solid Malignancies
Authors: Forouzesh Bahram , Hidalgo Manuel , Chu Quincy , Mita Alain , Mita Monica , Schwartz Garry , Jimeno José , Gómez Javier , Alfaro Vicente , Lebedinsky Claudia , Zintl Patrik , Rowinsky Eric K.
Published: May 2009

Purpose: This study was designed to determine the safety, tolerability, and pharmacokinetics, and to seek preliminary evidence of anticancer activity of trabectedin, a novel marine-derived DNA minor grove binder, when administered as a 1-hour or 3-hour i.v. infusion for 3 consecutive weeks every 4 weeks in patients with advanced solid malignancies. The study also sought to determine the maximum tolerated dose (MTD) levels of trabectedin on these schedules, as well as to recommend doses for disease-directed studies.

Experimental Design: A total of 32 and 31 patients were treated in sequential cohorts with trabectedin on the 1-hour schedule (doses ranging from 0.46 to 0.80 mg/m2) and on the 3-hour schedule (doses ranging from 0.30 to 0.65 mg/m2).

Results: Neutropenia, transient elevations in hepatic transaminases and creatine phosphokinase, and fatigue precluded dose escalation above 0.70 mg/m2 (1-hour schedule) and 0.65 mg/m2 (3-hour schedule), which were determined to be the MTD levels, respectively. The pharmacokinetics of trabectedin on both schedules were characterized by a high clearance rate, a long terminal half-life, and a large volume of distribution. A patient with soft tissue sarcoma had partial response, and several soft tissue sarcoma patients had prolonged (≥6 months) stable disease.

Conclusions: The MTD levels of trabectedin given weekly for 3 weeks every 4 weeks is 0.61 mg/m2 as a 1-hour infusion and 0.58 mg/m2 as a 3-hour infusion. The manageable toxicities at the MTDs, preliminary evidence of antitumor activity, pharmacokinetic profile, and the unique mechanistic aspects of trabectedin warrant further disease-directed evaluations on weekly schedules.
A Phase I Trial of Enzastaurin in Patients with Recurrent Gliomas
Authors: Kreisl Teri N. , Kim Lyndon , Moore Kraig , Duic Paul , Kotliarova Svetlana , Walling Jennifer , Musib Luna , Thornton Donald , Albert Paul S. , Fine Howard A.
Published: May 2009

Purpose: Enzastaurin is a selective inhibitor of protein kinase C β. Prior phase I studies did not show increased drug exposures with escalating once daily administration. Limits from gastrointestinal absorption may be overcome by twice daily dosing, potentially improving antitumor effects.

Experimental Design: We conducted a phase I dose escalation study in 26 patients with recurrent malignant glioma, stratified by use of enzyme-inducing antiepileptic drugs, to investigate whether divided twice daily dosing results in higher exposures compared with once daily dosing. Phosphorylated glycogen synthase 3 β was analyzed as a potential biomarker of enzastaurin activity.

Results: Enzastaurin was poorly tolerated at all dose levels evaluated (500, 800, and 1,000 mg total daily), with thrombocytopenia and prolonged QTc as dose-limiting toxicities. The average drug concentration of enzastaurin under steady-state conditions was doubled by twice daily dosing compared with daily dosing [1.990; 90% confidence interval (CI), 1.450-2.730]. Additionally, geometric mean ratios doubled with 800 versus 500 mg dosing for both daily (2.687; 90% CI, 1.232-5.860) and twice daily regimens (1.852; 90% CI, 0.799-4.292). Two patients achieved long-term benefit (over 150 weeks progression free).

Conclusions: Higher and more frequent dosing of enzastaurin resulted in improved drug exposure but with unacceptable toxicity at the doses tested. Phosphorylated glycogen synthase 3 β may be a useful biomarker of the biological activity of enzastaurin. Enzastaurin has activity in a subset of malignant glioma patients and warrants continued study in combination with other agents using a maximal once daily dose of 500 mg.
XIII International Charles Heidelberger Symposium and 50 Years of Fluoropyrimidines in Cancer Therapy Held on September 6 to 8, 2007 at New York University Cancer Institute, Smilow Conference Center
Authors: Muggia Franco M. , Peters Godefridus J. , Landolph Joseph R.
Published: May 2009

This conference opened with Franco Muggia, host and principal organizer, thanking Joseph Landolph, co-Chair of the International Scientific Organizing Committee and its members (Franco Muggia, co-Chair, Max Costa, Steven Burakoff, Howard Hochster, Eliezer Huberman, John Bertram, Peter Danenberg, and Richard Moran); the members of the Local Organizing Committee (Drs. Costa, Guttenplan, Geacintov, and Hochster); and the Charles and Patricia Heidelberger Foundation for Cancer Research for developing the scientific program and for working to help him create this special symposium honoring the late Charles Heidelberger, former president of the American Association for Cancer Research, member of the National Academy of Sciences, and extraordinary scientist in the fields of carcinogenesis and cancer chemotherapy. It was most appropriate to commemorate the 50th anniversary of the patent obtained by him for 5-fluorouracil (5FU), a drug that came to symbolize the promise chemotherapy of nonhematologic malignancies. After this compound was shown to be helpful in the treatment of colorectal and breast cancers, Dr. Heidelberger proceeded to develop other fluoropyrimidines and to inspire Ph.D. students and postdoctoral fellows to investigate their mechanisms of action and to develop assays applicable to clinical specimens (what we now refer to as translational science). Steven Burakoff, director of the NYU Cancer Institute (2000 to 2008), followed with welcoming remarks. Dr. Burakoff pointed to his personal fortuitous connection to the Symposium: The famous immunologist, Michael Heidelberger, Charles' father, who was known as the Father of Immunochemistry, trained Elvin Kabat while at Columbia, who trained Baruch Benacerraf, who moved from NYU to Harvard and subsequently became Burakoff's mentor. The renowned NYU Division of Immunology carries the name Michael Heidelberger because he spent more than 30 years in the Department of Pathology at the NYU School of Medicine after retiring from Columbia University. [Mol Cancer Ther 2009;8(5):992–9]
Genetic inhibition of telomerase results in sensitization and recovery of breast tumor cells
Authors: Poynter Kennon R. , Sachs Patrick C. , Bright A. Taylor , Breed Meghan S. , Nguyen Binh N. , Elmore Lynne W. , Holt Shawn E.
Published: May 2009

Telomerase, a ribonucleoprotein enzyme minimally composed of an RNA template (human telomerase RNA) and a catalytically active protein subunit (human telomerase reverse transcriptase), synthesizes telomeric repeats onto chromosome ends and is obligatory for continuous tumor cell proliferation. Telomerase is an attractive anticancer therapeutic target because its activity is present in >90% of human cancers, including >95% of breast carcinomas. Traditional chemotherapies lack the ability to effectively control and cure breast cancer, in part because residual cells are often resistant to DNA-damaging modalities. Although numerous telomerase inhibition strategies cause cancer cells to undergo apoptosis or senescence, there is often a lag period between the beginning of the treatment regimen and a biological effect. Thus, our goal for these studies was to show that effectively blocking telomerase genetically together with standard chemotherapeutic agents, doxorubicin/Adriamycin or Taxol, would increase the sensitization and efficacy for triggering senescence and/or apoptosis in cultures of breast cancer cells while reducing toxicity. We find that blocking telomerase in breast tumor cells substantially increases the sensitization at lower doses of Adriamycin or Taxol and that the kinetics of senescence/apoptosis is more rapid at higher concentrations. Combined with telomerase inhibition, Taxol treatment induced both apoptosis (its typical cell fate) and senescence, both at high enough levels to suggest that these two cellular responses are not mutually exclusive. Genetic inhibition of telomerase is eventually reversed due to up-regulation of endogenous telomerase activity without a net change in telomere length, suggesting that telomerase inhibition itself, not necessarily short telomeres, is important for sensitization.[Mol Cancer Ther 2009;8(5):1319–27]
Radiosensitization of solid tumors by Z-VAD, a pan-caspase inhibitor
Authors: Moretti Luigi , Kim Kwang Woon , Jung Dae Kwang , Willey Christopher D. , Lu Bo
Published: May 2009

Despite recent advances in the management of breast and lung cancer, novel treatment strategies are still needed to further improve patient outcome. The targeting of cell death pathways has therefore been proposed to enhance therapeutic ratio in cancer. In this study, we examined the in vitro and in vivo effects of Z-VAD, a broad-spectrum caspase inhibitor, on breast and lung cancer in association with radiation. Using clonogenic assays, we observed that Z-VAD markedly radiosensitized breast and lung cancer cells, with a radiation dose enhancement ratio of 1.31 (P < 0.003). For both models, the enhanced tumor cytotoxicity was associated with induction of autophagy. Furthermore, we found that administration of Z-VAD with radiation in both breast and lung cancer xenograft produced a significant tumor growth delay compared with radiation alone and was well tolerated. Interestingly, Z-VAD also had dramatic antiangiogenic effect when combined with radiation both in vitro and in vivo and thus represents an attractive anticancer therapeutic strategy. In conclusion, this preclinical study supports the therapeutic potential of Z-VAD as a radiosensitizer in breast and lung cancer. This study also suggests caspase inhibition as a promising strategy to enhance the therapeutic ratio of radiation therapy in solid tumors. Therefore, clinical trials are needed to determine the potential of this combination therapy in cancer patients. [Mol Cancer Ther 2009;8(5):OF1–10]
Effective gene-viral therapy of leukemia by a new fiber chimeric oncolytic adenovirus expressing TRAIL: in vitro and in vivo evaluation
Authors: Jin Jie , Liu Hui , Yang Chunmei , Li Gongchu , Liu Xinyuan , Qian Qijun , Qian Wenbin
Published: May 2009

Conditionally replicating adenoviruses (CRAd) have been under extensive investigations as anticancer agents. Previously, we found that ZD55, an adenovirus serotype 5-based CRAd, infected and killed the leukemia cells expressing coxsackie adenovirus receptor (CAR). However, majority of leukemic cells lack CAR expression on their cell surface, resulting in resistance to CRAd infection. In this study, we showed that SG235, a novel fiber chimeric CRAd that has Ad35 tropism, permitted CAR-independent cell entry, and this in turn produced selective cytopathic effects in a variety of human leukemic cells in vitro and in vivo. Moreover, SG235 expressing exogenous tumor necrosis factor-related apoptosis-inducing ligand (SG235-TRAIL) effectively induced apoptosis of leukemic cells via the activation of extrinsic and intrinsic apoptotic pathway and elicited a superior antileukemia activity compared with SG235. In addition, normal hematopoietic progenitors were resistant to the inhibitory activity of SG235 and SG235-TRAIL. Our data suggest that these novel oncolytic agents may serve as useful tools for the treatment of leukemia. [Mol Cancer Ther 2009;8(5):1387–97]
The antitumor properties of a nontoxic, nitric oxide–modified version of saquinavir are independent of Akt
Authors: Maksimovic-Ivanic Danijela , Mijatovic Sanja , Miljkovic Djordje , Harhaji-Trajkovic Ljubica , Timotijevic Gordana , Mojic Marija , Dabideen Darrin , Cheng Kai Fan , McCubrey James A. , Mangano Katia , Al-Abed Yousef , Libra Massimo , Garotta Gianni , Stosic-Grujicic Stanislava , Nicoletti Ferdinando
Published: May 2009

Application of the HIV protease inhibitor saquinavir (Saq) to cancer chemotherapy is limited by its numerous side effects. To overcome this toxicity, we modified the original compound by covalently attaching a nitric oxide (NO) group. We compared the efficacy of the parental and NO-modified drugs in vitro and in vivo. The novel compound saquinavir-NO (Saq-NO) significantly reduced the viability of a wide spectrum of human and rodent tumor cell lines at significantly lower concentration than the unmodified drug. In contrast to Saq, Saq-NO had no effect on the viability of primary cells and drastically reduced B16 melanoma growth in syngeneic C57BL/6 mice. In addition, at the equivalent of the 100% lethal dose of Saq, Saq-NO treatment caused no apparent signs of toxicity. Saq-NO blocked the proliferation of C6 and B16 cells, up-regulated p53 expression, and promoted the differentiation of these two cell types into oligodendrocytes or Schwann-like cells, respectively. Although it has been well documented that Saq decreases tumor cell viability by inhibiting Akt, the anticancer properties of Saq-NO were completely independent of the phosphatidylinositol 3-kinase/Akt signaling pathway. Moreover, Saq-NO transiently up-regulated Akt phosphorylation, delivering a protective signal that could be relevant for primary cell protection and the absence of drug toxicity in vivo. It was unlikely that released NO was independently responsible for these drug effects because Saq-NO treatment increased intracellular and secreted NO levels only slightly. Rather, the chemical modification seems to have produced a qualitatively new chemical entity, which may have a unique mode of action against cancer cells.[Mol Cancer Ther 2009;8(5):1169–78]
Anticancer peptide CIGB-300 binds to nucleophosmin/B23, impairs its CK2-mediated phosphorylation, and leads to apoptosis through its nucleolar disassembly activity
Authors: Perera Yasser , Farina Hernán G. , Gil Jeovanis , Rodriguez Arielis , Benavent Fernando , Castellanos Lila , Gómez Roberto E. , Acevedo Boris E. , Alonso Daniel F. , Perea Silvio E.
Published: May 2009

CIGB-300, formerly known as P15-tat, is a proapoptotic peptide with established antiproliferative activity in vitro and antitumoral activity in vivo. This hypothesis-driven peptide was initially selected for its ability to impair the in vitro CK2-mediated phosphorylation in one of its substrates through direct binding to the conserved acidic phosphoaceptor domain. However, the actual in vivo target(s) on human cancer cells among the hundreds of CK2 substrates as well as the subsequent events that lead to apoptosis on tumor cells remains to be determined. In this work, we identified the multifunctional oncoprotein nucleophosmin/B23 as a major target for CIGB-300. In vivo, the CIGB-300–B23 interaction was shown by pull-down experiments and confirmed by the early in situ colocalization of both molecules in the cell nucleolus. Moreover, CIGB-300 inhibits the CK2-mediated phosphorylation of B23 in a dose-dependent fashion both in vitro and in vivo as shown using the recombinant GST fusion protein and the metabolic labeling approach, respectively. Such phosphorylation impairment was correlated with the ability of CIGB-300 to induce nucleolar disassembly as documented by the use of established markers for nucleolar structure. Finally, we showed that such a sequence of events leads to the rapid and massive onset of apoptosis both at the molecular and cellular levels. Collectively, these findings provide important clues by which the CIGB-300 peptide exerts its proapoptotic effect on tumor cells and highlights the suitability of the B23/CK2 pathway for cancer-targeted therapy. [Mol Cancer Ther 2009;8(5):OF1–8]
In vivo antitumor effect of a novel inhibitor of protein geranylgeranyltransferase-I
Authors: Lu Jie , Chan Lai , Fiji Hannah D.G. , Dahl Russell , Kwon Ohyun , Tamanoi Fuyuhiko
Published: May 2009

Protein geranylgeranyltransferase-I (GGTase-I) catalyzes protein geranylgeranylation, which is critical for the function of proteins such as Rho, Rac, and Ral. We previously identified several small-molecule inhibitors of GGTase-I from an allenoate-derived compound library and showed that these compounds exhibit specific inhibition of GGTase-I resulting in the inhibition of proliferation associated with the induction of G1 cell cycle arrest of a variety of cancer cell lines. Because inhibition of GGTase-I is expected to suppress tumor growth, we investigated in vivo effects of one of these GGTase-I inhibitors (GGTI), P61A6, by using a human pancreatic cancer xenograft model in mice. The new compound GGTI P61A6 showed an excellent antitumor effect. I.p. administration of P61A6 significantly suppressed tumor growth of the PANC-1 xenograft. Even once per week administration of GGTI was enough to suppress tumor growth. Immunohistochemical examination indicated the inhibition of cell proliferation in the tumors by P61A6 treatment, but neither apoptosis nor antiangiogenesis was observed. Increased cytosolic localization of proteins such as Rap1 and RhoA in tumors was observed. In addition, the enzyme activity of GGTase-I in tumors was inhibited. Pharmacokinetic analysis showed that the plasma half-life of GGTI is ∼6 h, suggesting its prolonged effect. These data suggest that the novel GGTI compound P61A6 is an excellent chemotherapeutic drug candidate for human pancreatic cancer. They also provide evidence that protein GGTase-I may be a valid target for cancer therapy. [Mol Cancer Ther 2009;8(5)1218–26]
Amino acid containing thapsigargin analogues deplete androgen receptor protein via synthesis inhibition and induce the death of prostate cancer cells
Authors: Vander Griend Donald J. , Antony Lizamma , Dalrymple Susan L. , Xu Yi , Christensen S. Brogger , Denmeade Samuel R. , Isaacs John T.
Published: May 2009

There are quantitative and/or qualitative mechanisms allowing androgen receptor (AR) growth signaling in androgen ablation refractory prostate cancer cells. Regardless of the mechanism, agents that deplete AR protein expression prevent such AR growth signaling. Thapsigargin (TG) is a highly cell-penetrant sequiterpene-lactone that once inside cells inhibits (IC50, ∼10 nmol/L) critically important housekeeping SERCA 2b calcium pumps in the endoplasmic reticulum. Using a series of five genetically diverse androgen ablation refractory human prostate cancer lines (LNCaP, LAPC-4, VCaP, MDA-PCa-2b, and CWR22Rv1), TG inhibition of SERCA pumps consistently results in depletion of the endoplasmic reticulum Ca+2 coupled with μmol/L elevation in the intracellular free Ca+2 initiating a molecular cascade that: (a) inhibits Cap-dependent AR protein synthesis resulting in 90% depletion of AR protein by 24 hours of TG exposure, (b) arrests the cells in G0, and (c) induces their apoptotic death. Unfortunately, due to its highly lipophilic nature, TG is not deliverable as a systemic agent without host toxicity. Therefore, TG analogues containing amino acids were developed, which retain ability to deplete AR protein and induce cell death and which can be covalently linked to peptide carriers producing water soluble prodrugs for systemic delivery. Specific amino acid sequences are used to restrict the liberation of cytotoxic amino acid containing TG analogues from the peptide prodrug by prostate-specific proteases, such as prostate-specific antigen and prostate-specific membrane antigen, or cancer-specific proteases, such as fibroblast activation protein, so that toxicity of these prodrugs is selectively targeted to metastatic sites of prostate cancer. Based on these results, these prodrugs are undergoing clinical development. [Mol Cancer Ther 2008;8(5):1340–9]
Changes in choline metabolism as potential biomarkers of phospholipase Cγ1 inhibition in human prostate cancer cells
Authors: Beloueche-Babari Mounia , Peak Joanna C. , Jackson L. Elizabeth , Tiet May-Yung , Leach Martin O. , Eccles Suzanne A.
Published: May 2009

Phosphoinositide-specific phospholipase Cγ1 (PLCγ1) is activated downstream of many receptor tyrosine kinases to promote cell motility. Inhibition of this protein is being explored as a therapeutic strategy for blocking cancer cell invasion and metastasis. The clinical development of such cytostatic therapies requires the implementation of pharmacodynamic biomarkers of target modulation. In this study, we use magnetic resonance spectroscopy to explore metabolic biomarkers of PLCγ1 down-regulation in PC3LN3 prostate cancer cells. We show that inhibition of PLCγ1 via an inducible short hairpin RNA system causes a reduction in phosphocholine levels by up to 50% relative to the control as detected by 1H and 31P magnetic resonance spectroscopy analyses. This correlated with a rounded-up morphology and reduced cell migration. Interestingly, the fall in phosphocholine levels was not recorded in cells with constitutive PLCγ1 knockdown where the rounded-up phenotype was no longer apparent. This study reveals alterations in metabolism that accompany the cellular effects of PLCγ1 knockdown and highlights phosphocholine as a potential pharmacodynamic biomarker for monitoring the action of inhibitors targeting PLCγ1 signaling.[Mol Cancer Ther 2009;8(5):1305–11]
MDA-7/IL-24–induced cell killing in malignant renal carcinoma cells occurs by a ceramide/CD95/PERK–dependent mechanism
Authors: Park Margaret A. , Walker Teneille , Martin Aditi Pandya , Allegood Jeremy , Vozhilla Nicollaq , Emdad Luni , Sarkar Devanand , Rahmani Mohammed , Graf Martin , Yacoub Adly , Koumenis Costas , Spiegel Sarah , Curiel David T. , Voelkel-Johnson Christina , Grant Steven , Fisher Paul B. , Dent Paul
Published: May 2009

Melanoma differentiation associated gene-7/interleukin-24 (mda-7/IL-24) is a novel cytokine displaying selective apoptosis-inducing activity in transformed cells without harming normal cells. The present studies focused on clarifying the mechanism(s) by which glutathione S-transferase (GST)-MDA-7 altered cell survival of human renal carcinoma cells in vitro. GST-MDA-7 caused plasma membrane clustering of CD95 and the association of CD95 with procaspase-8. GST-MDA-7 lethality was suppressed by inhibition of caspase-8 or by overexpression of short-form cellular FLICE inhibitory protein, but only weakly by inhibition of cathepsin proteases. GST-MDA-7–induced CD95 clustering (and apoptosis) was blocked by knockdown of acidic sphingomyelinase or, to a greater extent, ceramide synthase-6 expression. GST-MDA-7 killing was, in parallel, dependent on inactivation of extracellular signal–regulated kinase 1/2 and on CD95-induced p38 mitogen-activated protein kinase and c-jun NH2-terminal kinase-1/2 signaling. Knockdown of CD95 expression abolished GST-MDA-7–induced phosphorylation of protein kinase R–like endoplasmic reticulum kinase. GST-MDA-7 lethality was suppressed by knockout or expression of a dominant negative protein kinase R–like endoplasmic reticulum kinase that correlated with reduced c-jun NH2-terminal kinase-1/2 and p38 mitogen-activated protein kinase signaling and maintained extracellular signal–regulated kinase-1/2 phosphorylation. GST-MDA-7 caused vacuolization of LC3 through a mechanism that was largely CD95 dependent and whose formation was suppressed by knockdown of ATG5 expression. Knockdown of ATG5 suppressed GST-MDA-7 toxicity. Our data show that in kidney cancer cells GST-MDA-7 induces ceramide-dependent activation of CD95, which is causal in promoting an endoplasmic reticulum stress response that activates multiple proapoptotic pathways to decrease survival.[Mol Cancer Ther 2009;8(5):OF1–12]
Topoisomerase IIα-dependent and -independent apoptotic effects of dexrazoxane and doxorubicin
Authors: Yan Tiandong , Deng Shiwei , Metzger Annegret , Gödtel-Armbrust Ute , Porter Andrew C.G. , Wojnowski Leszek
Published: May 2009

Coadministration of the iron chelator dexrazoxane reduces by 80% the incidence of heart failure in cancer patients treated with anthracyclines. The clinical application of dexrazoxane is limited, however, because its ability to inhibit topoisomerase IIα (TOP2A) is feared to adversely affect anthracycline chemotherapy, which involves TOP2A-mediated generation of DNA double-strand breaks (DSB). Here, we investigated the apoptotic effects of dexrazoxane and the anthracycline doxorubicin, alone and in combination, in a tumor cell line with conditionally regulated expression of TOP2A. Each drug caused apoptosis that was only partly dependent on TOP2A. Unexpectedly, dexrazoxane was found to cause TOP2A depletion, thereby reducing the doxorubicin-induced accumulation of DSB. Despite this latter effect, dexrazoxane showed no adverse effect on doxorubicin-induced apoptosis. This could be explained by the TOP2A-independent apoptotic effects of each drug: those of doxorubicin included TOP2A-independent DSB formation and depletion of intracellular glutathione, whereas those of dexrazoxane were caspase independent. In conclusion, both doxorubicin and dexrazoxane induce apoptosis via TOP2A-dependent and TOP2A-independent mechanisms, the latter compensating for the reduction in cell killing due to dexrazoxane-induced TOP2A depletion. These observations suggest an explanation for the absence of adverse dexrazoxane effects on clinical responses to doxorubicin. [Mol Cancer Ther 2009;8(5):1075–85]
Hazard Function and Secular Trends in the Risk of Recurrent Acute Myocardial Infarction
Authors: Gulliksson Mats , Wedel Hans , Köster Max , Svärdsudd Kurt
Published: May 2009

Background—

The incidence of a first acute myocardial infarction (AMI) has fallen considerably during the last decades. However, no previous studies have analyzed the underlying hazards function of experienceing a recurrent AMI, and none has analyzed the change of risk for a recurrent AMI over the last 3 decades.

Methods and Results—

The study was based on the Swedish national myocardial infarction register. The register contained more than 1 million AMI events. After exclusion of events occurring in subjects younger than 20 or older than 84 years and events with uncertain first AMI status, 775 901 events occurring between 1972 and 2001 remained for analysis. During the study period, the risk of a new event among survivors of a previous AMI decreased sharply during the first 2 years after the previous event, had its minimum after 5 years, and then increased slowly again. The risk for a recurrent AMI during the first year after a previous event was fairly stable over the years until the late 1970s and then decreased by 36% in women and 40% in men until the late 1990s, irrespective of age and AMI number, mirroring the incidence decrease over the years for primary events.

Conclusions—

The risk of a recurrent AMI event was highly dependent on time from the previous event, a novel finding which may affect risk scoring. There were strong secular trends toward diminishing risk for a recurrent AMI in recent years, even when other outcome affecting variables were taken into account.
Characteristics and Outcomes of America’s Lowest-Performing Hospitals
Authors: Popescu Ioana , Werner Rachel M. , Vaughan-Sarrazin Mary S. , Cram Peter
Published: May 2009

Background—

Studies suggest that most hospitals now have relatively high adherence with recommended acute myocardial infarction (AMI) process measures. Little is known about hospitals with consistently poor adherence with AMI process measures and whether these hospitals also have increased patient mortality.

Methods and Results—

We conducted a retrospective study of 2761 US hospitals reporting AMI process measures to the Center for Medicare and Medicaid Services Hospital Compare database during 2004 to 2006 that could be linked to 2005 Medicare Part A data. The main outcome measures were hospitals’ combined compliance with 5 AMI measures (aspirin and β-blocker on admission and discharge and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use at discharge for patients with left ventricular dysfunction) and risk-adjusted 30-day mortality for 2005. We stratified hospitals into those with low AMI adherence (ranked in the lowest decile for AMI adherence for 3 consecutive years [2004–2006, n=105]), high adherence (ranked in the top decile for 3 consecutive years [n=63]), and intermediate adherence (all others [n=2593]). Mean AMI performance varied significantly across low-, intermediate-, and high-performing hospitals (mean score, 68% versus 92% versus 99%,
P
<0.001). Low-performing hospitals were more likely than intermediate- and high-performing hospitals to be safety-net providers (19.2% versus 11.0% versus 6.4%;
P
=0.005). Low-performing hospitals had higher unadjusted 30-day mortality rates (23.6% versus 17.8% versus 14.9%;
P
<0.001). These differences persisted after adjustment for patient characteristics (16.3% versus 16.0% versus 15.7%;
P
=0.02).

Conclusion—

Consistently low-performing hospitals differ substantially from other US hospitals. Targeting quality improvement efforts toward these hospitals may offer an attractive opportunity for improving AMI outcomes.
The Effect of Environmental Design on Reducing Nursing Errors and Increasing Efficiency in Acute Care Settings
Authors: Chaudhury Habib , Mahmood Atiya , Valente Maria
Published: May 2009

Physical environment is an important component in the acute care setting that can affect nursing and medication accuracies, as any inadequacy in physical environment would contribute to staff fatigue, stress, and burnout and result in errors. The article discusses a study conducted involving an extensive review and analysis of the literature on this topic and focus groups with various categories of staff members at three hospitals. The review demonstrates that the following environmental variables can contribute to errors in acute care settings: noise levels, ergonomics/furniture/equipment, lighting, and design/layout. Focus groups address the role of the physical environment on medication ordering, storage, delivery, dispensation, preparation, administration, and possible design responses to reduce errors. Integrating the major issues identified and the key findings from the focus groups, four design-related principles are recommended: balance between patient accessibility and reduction of disruptions, automation, minimize staff fatigue, and promoting a culture of safety.
Examining Trends in Adolescent Environmental Attitudes, Beliefs, and Behaviors Across Three Decades
Authors: Wray-Lake Laura , Flanagan Constance A. , Osgood D. Wayne
Published: May 2009

Since the Environmental Movement began, adolescents’ views have been largely ignored in studies of public opinion. The article presents a descriptive analysis of trends in the environmental attitudes, beliefs, and behaviors of high school seniors from 1976 to 2005 using data from the Monitoring the Future study. Across a range of indicators, environmental concerns of adolescents show increases during the early 1990s and declines across the remainder of the three decades. Declining trends in reports of personal responsibility for the environment, conservation behaviors, and the belief that resources are scarce are particularly noteworthy. Across all years, findings reveal that youth tended to assign responsibility for the environment to the government and consumers rather than accepting personal responsibility. Recent declines in environmental concerns for this nationally representative sample of youth signal the need for a renewed focus on young people’s views and call for better environmental education and governmental leadership.