bluuebunny/crossref_metadata_2025 huggingface dataset:
Transcription Inhibition of Heat Shock Proteins: A Strategy for Combination of 17-Allylamino-17-Demethoxygeldanamycin and Actinomycin D
Authors: Cervantes-Gomez Fabiola , Nimmanapalli Ramadevi , Gandhi Varsha
Published: April 2009

The heat shock protein (HSP) 90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG) is currently in clinical trials because of its unique mechanism of action and antitumor activity. However, 17-AAG triggers the transcription and elevation of antiapoptotic HSP90, HSP70, and HSP27, which lead to chemoresistance in tumor cells. We hypothesized that inhibiting HSP90, HSP70, and HSP27 transcription may enhance 17-AAG–induced cell death in multiple myeloma cell lines. Actinomycin D (Act D), a clinically used agent and transcription inhibitor, was combined with 17-AAG. The concentrations for 17-AAG and Act D were selected based on the target actions and plasma levels during therapy. Inducible and constitutive HSP27, HSP70, and HSP90 mRNA and protein levels were measured by real-time reverse transcription-PCR and immunoblot assays. Compared with no treatment, Act D alone decreased HSP mRNA levels in MM.1S and RPMI-8226 cell lines. Combining Act D with 17-AAG did not attenuate 17-AAG–mediated increases in transcript levels of inducible HSP70; however, constitutive HSP mRNA levels were decreased. In contrast to its effect on mRNA levels, Act D was able to abrogate 17-AAG–mediated increases in all HSP protein levels. The cytotoxicity of combined Act D and 17-AAG was assessed. Treatment with Act D alone caused <40% cell death, whereas the combination of 17-AAG and Act D resulted in an increase of cell death in both multiple myeloma cell lines. In conclusion, these results indicate that 17-AAG–mediated induction of HSP70 and HSP27 expression can be attenuated by Act D and therefore can potentially improve the clinical treatment of multiple myeloma. [Cancer Res 2009;69(9):3947–54]
Associations between α-Tocopherol, β-Carotene, and Retinol and Prostate Cancer Survival
Authors: Watters Joanne L. , Gail Mitchell H. , Weinstein Stephanie J. , Virtamo Jarmo , Albanes Demetrius
Published: April 2009

Previous studies suggest that carotenoids and tocopherols (vitamin E compounds) may be inversely associated with prostate cancer risk, yet little is known about how they affect prostate cancer progression and survival. We investigated whether serum α-tocopherol, β-carotene, and retinol concentrations, or the α-tocopherol and β-carotene trial supplementation, affected survival of men diagnosed with prostate cancer during the α-Tocopherol, β-Carotene Cancer Prevention Study, a randomized, double-blind, placebo-controlled primary prevention trial testing the effects of β-carotene and α-tocopherol supplements on cancer incidence in adult male smokers in southwestern Finland (n = 29,133). Prostate cancer survival was examined using the Kaplan-Meier method with deaths from other causes treated as censoring, and using Cox proportional hazards regression models with hazard ratios (HR) and 95% confidence intervals (CI) adjusted for family history of prostate cancer, age at randomization, benign prostatic hyperplasia, age and stage at diagnosis, height, body mass index, and serum cholesterol. As of April 2005, 1,891 men were diagnosed with prostate cancer and 395 died of their disease. Higher serum α-tocopherol at baseline was associated with improved prostate cancer survival (HR, 0.67; 95% CI, 0.45–1.00), especially among cases who had received the α-tocopherol intervention of the trial and who were in the highest quintile of α-tocopherol at baseline (HR, 0.51; 95% CI, 0.20–0.90) or at the 3-year follow-up measurement (HR, 0.26; 95% CI, 0.09–0.71). Serum β-carotene, serum retinol, and supplemental β-carotene had no apparent effects on survival. These findings suggest that higher α-tocopherol (and not β-carotene or retinol) status increases overall prostate cancer survival. Further investigations, possibly including randomized studies, are needed to confirm this observation. [Cancer Res 2009;69(9):3833–41]
Genetic Variation in B-Cell–Activating Factor Is Associated with an Increased Risk of Developing B-Cell Non–Hodgkin Lymphoma
Authors: Novak Anne J. , Slager Susan L. , Fredericksen Zachary S. , Wang Alice H. , Manske Michelle M. , Ziesmer Steven , Liebow Mark , Macon William R. , Dillon Stacey R. , Witzig Thomas E. , Cerhan James R. , Ansell Stephen M.
Published: April 2009

Elevated B-cell–activating factor (BAFF; TNFSF13B) levels have been found in patients with B-cell malignancies and autoimmune diseases, suggesting that it may play a pathogenic role. We previously found that a single nucleotide polymorphism (SNP) in the TNFSF13B promoter resulted in increased transcription, suggesting that genetic variation in TNFSF13B may influence its expression. We therefore wanted to determine if genetic variation in TNFSF13B is associated with high BAFF levels and non–Hogkin lymphoma (NHL) risk. We genotyped 9 tagSNPs within TNFSF13B in a clinic-based study of 441 NHL cases and 475 matched controls and evaluated the association of individual SNPs with risk of NHL; 3 tagSNPs were significant (P < 0.05). When categorized into low-, moderate-, and high-risk groups based on risk alleles, we found the permutation-corrected odds ratio for the trend to be 1.43 (P = 0.0019) for risk of B-cell NHL, 1.69 (P = 0.0093) for diffuse large B-cell lymphoma, 1.43 (P = 0.029) for follicular lymphoma, and 1.06 (P = 0.21) for chronic lymphocytic leukemia/small lymphocytic lymphoma. The mean serum BAFF level in those who carried the low-risk alleles was 2 ng/mL compared with 4.3 ng/mL in those with the high-risk alleles (P = 0.02). Taken together, our data suggest that genetic variation in the TNFSF13B gene is significantly associated with NHL risk and elevated serum BAFF levels. [Cancer Res 2009;69(10):4217–24]
TGF-β1 + EGF-Initiated Invasive Potential in Transformed Human Keratinocytes Is Coupled to a Plasmin/MMP-10/MMP-1–Dependent Collagen Remodeling Axis: Role for PAI-1
Authors: Wilkins-Port Cynthia E. , Ye Qunhui , Mazurkiewicz Joseph E. , Higgins Paul J.
Published: April 2009

The phenotypic switching called epithelial-to-mesenchymal transition is frequently associated with epithelial tumor cell progression from a comparatively benign to an aggressive, invasive malignancy. Coincident with the emergence of such cellular plasticity is an altered response to transforming growth factor-β (TGF-β) as well as epidermal growth factor (EGF) receptor amplification. TGF-β in the tumor microenvironment promotes invasive traits largely through reprogramming gene expression, which paradoxically supports matrix-disruptive as well as stabilizing processes. ras-transformed HaCaT II-4 keratinocytes undergo phenotypic changes typical of epithelial-to-mesenchymal transition, acquire a collagenolytic phenotype, and effectively invade collagen type 1 gels as a consequence of TGF-β1 + EGF stimulation in a three-dimensional physiologically relevant model system that monitors collagen remodeling. Enhanced collagen degradation was coupled to a significant increase in matrix metalloproteinase (MMP)-10 expression and involved a proteolytic axis composed of plasmin, MMP-10, and MMP-1. Neutralization of any one component in this cascade inhibited collagen gel lysis. Similarly, addition of plasminogen activator inhibitor type 1 (SERPINE1) blocked collagen degradation as well as the conversion of both proMMP-10 and proMMP-1 to their catalytically active forms. This study therefore identifies an important mechanism in TGF-β1 + EGF-initiated collagen remodeling by transformed human keratinocytes and proposes a crucial upstream role for plasminogen activator inhibitor type 1–dependent regulation in this event. [Cancer Res 2009;69(9):4081–91]
IRF4: Immunity. Malignancy! Therapy?
Authors: Shaffer Arthur L. , Emre N.C. Tolga , Romesser Paul B. , Staudt Louis M.
Published: April 2009

IRF4, a member of the Interferon Regulatory Factor (IRF) family of transcription factors, is expressed in cells of the immune system, where it transduces signals from various receptors to activate or repress gene expression. IRF4 expression is a key regulator of several steps in lymphoid-, myeloid-, and dendritic-cell differentiation, including the differentiation of mature B cells into antibody-secreting plasma cells. IRF4 expression is also associated with many lymphoid malignancies, with recent evidence pointing to an essential role in multiple myeloma, a malignancy of plasma cells. Interference with IRF4 expression is lethal to multiple myeloma cells, irrespective of their genetic etiology, making IRF4 an “Achilles' heel” that may be exploited therapeutically.
LYRIC/AEG-1 Is Targeted to Different Subcellular Compartments by Ubiquitinylation and Intrinsic Nuclear Localization Signals
Authors: Thirkettle Hayley J. , Girling Joanne , Warren Anne Y. , Mills Ian G. , Sahadevan Kanagasabai , Leung Hing , Hamdy Freddie , Whitaker Hayley C. , Neal David E.
Published: April 2009

Purpose: LYRIC/AEG-1 has been reported to influence breast cancer survival and metastases, and its altered expression has been found in a number of cancers. The cellular function of LYRIC/AEG-1 has previously been related to its subcellular distribution in cell lines. LYRIC/AEG-1 contains three uncharacterized nuclear localization signals (NLS), which may regulate its distribution and, ultimately, function in cells.

Experimental Design: Immunohistochemistry of a human prostate tissue microarray composed of 179 prostate cancer and 24 benign samples was used to assess LYRIC/AEG-1 distribution. Green fluorescent protein-NLS fusion proteins and deletion constructs were used to show the ability of LYRIC/AEG-1 NLS to target green fluorescent protein from the cytoplasm to the nucleus. Immunoprecipitation and Western blotting were used to show posttranslational modification of LYRIC/AEG-1 NLS regions.

Results: Using a prostate tissue microarray, significant changes in the distribution of LYRIC/AEG-1 were observed in prostate cancer as an increased cytoplasmic distribution in tumors compared with benign tissue. These differences were most marked in high grade and aggressive prostate cancers and were associated with decreased survival. The COOH-terminal extended NLS-3 (amino acids 546-582) is the predominant regulator of nuclear localization, whereas extended NLS-1 (amino acids 78-130) regulates its nucleolar localization. Within the extended NLS-2 region (amino acids 415-486), LYRIC/AEG-1 can be modified by ubiquitin almost exclusively within the cytoplasm.

Conclusions: Changes in LYRIC/AEG-1 subcellular distribution can predict Gleason grade and survival. Two lysine-rich regions (NLS-1 and NLS-3) can target LYRIC/AEG-1 to subcellular compartments whereas NLS-2 is modified by ubiquitin in the cytoplasm.
Identification and Metastatic Potential of Tumor-Initiating Cells in Malignant Rhabdoid Tumor of the Kidney
Authors: Yanagisawa Satohiko , Kadouchi Ichiro , Yokomori Kinji , Hirose Masao , Hakozaki Michiyuki , Hojo Hiroshi , Maeda Kosaku , Kobayashi Eiji , Murakami Takashi
Published: April 2009

Purpose: Malignant rhabdoid tumor of the kidney (MRTK) is a rare and highly aggressive malignancy of infanthood. In an effort to delineate MRTK progression, we investigated the metastatic fate of some MRTK cells using xenotransplantation animal models and the tumor-initiating potential of CD133+ MRTK cells.

Experimental Design: We established two MRTK cell lines (JMU-RTK-1 and JMU-RTK-2) from patients with MRTK. We generated five luciferase-expressing MRTK cells for in vivo luminescent imaging and evaluated the metastatic fate in an orthotopic xenotransplantation model. Capacities of MRTK-initiating cells were examined in nonobese diabetic/severe combined immunodeficient mice after antibody-mediated magnetic bead sorting. Use of chemokine receptor CXCR4 expression as a metastatic marker was evaluated by flow cytometry and Western blotting.

Results: MRTK cell lines showed distant organ metastasis. JMU-RTK-1, JMU-RTK-2, and G401 cells showed considerable aggressiveness compared with SWT-1 and SWT-2 cells (P < 0.05). Moreover, as few as 1,000 CD133+ MRTK cells initiated tumor development in nonobese diabetic/severe combined immunodeficient mice by 21 days (60-100%) in all examined cell lines, although the same number of CD133− MRTK cells could not form tumors (0%). Interestingly, the metastatic potential of the CD133+ population remained unaffected compared with a nonenriched population. The potential metastatic marker CXCR4 was expressed in CD133+ and CD133− MRTK cells, and CD133− cells seemed to play a cooperative role in terms of tumorigenicity and metastasis.

Conclusions: These results suggest that CD133+ cells may determine the metastatic fate of MRTK cells and that CD133− cells may play an auxiliary role in tumor progression and metastasis.
Protein Acetylation and Histone Deacetylase Expression Associated with Malignant Breast Cancer Progression
Authors: Suzuki Junko , Chen Yunn-Yi , Scott Gary K. , DeVries Sandy , Chin Koei , Benz Christopher C. , Waldman Frederic M. , Hwang E. Shelley
Published: April 2009

Purpose: Excess histone deacetylase (HDAC) activity can induce hypoacetylation of histone and nonhistone protein substrates, altering gene expression patterns and cell behavior potentially associated with malignant transformation. However, HDAC expression and protein acetylation have not been studied in the context of breast cancer progression.

Experimental Design: We assessed expression levels of acetylated histone H4 (ac-H4), ac-H4K12, ac-tubulin, HDAC1, HDAC2, and HDAC6 in 22 reduction mammoplasties and in 58 specimens with synchronous normal epithelium, ductal carcinoma in situ (DCIS), and invasive ductal carcinoma (IDC) components. Differences among groups were tested for significance using nonparametric tests.

Results: From normal epithelium to DCIS, there was a marked reduction in histone acetylation (P < 0.0001). Most cases showed similar levels of acetylation in DCIS and IDC, although some showed further reduction of ac-H4 and ac-H4K12 from DCIS to IDC. Expression of HDAC1, HDAC2, and HDAC6 was also significantly reduced but by a smaller magnitude. Greater reductions of H4 acetylation and HDAC1 levels were observed from normal to DCIS in estrogen receptor–negative compared with estrogen receptor–positive, and in high-grade compared with non–high-grade tumors.

Conclusion: Overall, there was a global pattern of hypoacetylation associated with progression from normal to DCIS to IDC. These findings suggest that the reversal of this hypoacetylation in DCIS and IDC could be an early measure of HDAC inhibitor activity.
BI 6727, A Polo-like Kinase Inhibitor with Improved Pharmacokinetic Profile and Broad Antitumor Activity
Authors: Rudolph Dorothea , Steegmaier Martin , Hoffmann Matthias , Grauert Matthias , Baum Anke , Quant Jens , Haslinger Christian , Garin-Chesa Pilar , Adolf Günther R.
Published: April 2009

Purpose: Antimitotic chemotherapy remains a cornerstone of multimodality treatment for locally advanced and metastatic cancers. To identify novel mitosis-specific agents with higher selectivity than approved tubulin-binding agents (taxanes, Vinca alkaloids), we have generated inhibitors of Polo-like kinase 1, a target that functions predominantly in mitosis.

Experimental Design: The first compound in this series, suitable for i.v. administration, has entered clinical development. To fully explore the potential of Polo-like kinase 1 inhibition in oncology, we have profiled additional compounds and now describe a novel clinical candidate.

Results: BI 6727 is a highly potent (enzyme IC50 = 0.87 nmol/L, EC50 = 11-37 nmol/L on a panel of cancer cell lines) and selective dihydropteridinone with distinct properties. First, BI 6727 has a pharmacokinetic profile favoring sustained exposure of tumor tissues with a high volume of distribution and a long terminal half-life in mice (Vss = 7.6 L/kg, t1/2 = 46 h) and rats (Vss = 22 L/kg, t1/2 = 54 h). Second, BI 6727 has physicochemical and pharmacokinetic properties that allow in vivo testing of i.v. as well as oral formulations, adding flexibility to dosing schedules. Finally, BI 6727 shows marked antitumor activity in multiple cancer models, including a model of taxane-resistant colorectal cancer. With oral and i.v. routes of administration, the total weekly dose of BI 6727 is most relevant for efficacy, supporting the use of a variety of well-tolerated dosing schedules.

Conclusion: These findings warrant further investigation of BI 6727 as a tailored antimitotic agent; clinical studies have been initiated.
Involvement of a Novel Chemokine Decoy Receptor CCX-CKR in Breast Cancer Growth, Metastasis and Patient Survival
Authors: Feng Lan-Yun , Ou Zhou-Luo , Wu Feng-Ying , Shen Zhen-Zhou , Shao Zhi-Ming
Published: April 2009

Purpose: The biological axes of chemokines and chemokine receptors, such as CXCR4/CXCL12, CCR7/CCL19 (CCL21), CCR9/CCL25, and CXCR5/CXCL13, are involved in cancer growth and metastasis. This study is aimed at the potential regulatory role of atypical chemokine binder CCX-CKR, as a scavenger of CCL19, CCL21, CCL25, and CXCL13, in human breast cancer.

Experimental Design: The role of CCX-CKR in human breast cancer was investigated in cell lines, animal models, and clinical samples.

Results: Overexpression of CCX-CKR inhibited cancer cell proliferation and invasion in vitro and attenuated xenograft tumor growth and lung metastasis in vivo. CCX-CKR can be regulated by cytokines such as interleukin-1β, tumor necrosis factor-α, and IFN-γ. Lack or low expression of CCX-CKR correlated with a poor survival rate in the breast cancer patients. A significant correlation between CCX-CKR and lymph node metastasis was observed in human breast cancer tissues. CCX-CKR status was an independent prognostic factor for disease-free survival in breast cancer patients.

Conclusion: We showed for the first time that CCX-CKR is a negative regulator of growth and metastasis in breast cancer mainly by sequestration of homeostatic chemokines and subsequent inhibition of intratumoral neovascularity. This finding may lead to a new therapeutic strategy against breast cancer.
Antitumor Activity of GSK1904529A, a Small-molecule Inhibitor of the Insulin-like Growth Factor-I Receptor Tyrosine Kinase
Authors: Sabbatini Peter , Rowand Jason L. , Groy Arthur , Korenchuk Susan , Liu Qi , Atkins Charity , Dumble Melissa , Yang Jingsong , Anderson Kelly , Wilson Brian J. , Emmitte Kyle A. , Rabindran Sridhar K. , Kumar Rakesh
Published: April 2009

Purpose: Dysregulation of the insulin-like growth factor-I receptor (IGF-IR) signaling pathway has been implicated in the development of many types of tumors, including prostate, colon, breast, pancreatic, ovarian, and sarcomas. Agents that inhibit IGF-IR activity may be useful in treatment of patients with various cancers.

Experimental Design: Kinase assays were used to identify a selective small-molecule inhibitor of IGF-IR activity. The effects of this compound on IGF-IR signaling, cell proliferation, and the cell cycle were determined using a panel of cell lines. Antitumor activity was evaluated in human tumor xenografts growing in athymic mice. Inhibition of IGF-IR and the closely related insulin receptor (IR) was measured in vivo, and the effect on glucose metabolism was evaluated.

Results: GSK1904529A selectively inhibits IGF-IR and IR with IC50s of 27 and 25 nmol/L, respectively. GSK1904529A blocks receptor autophosphorylation and downstream signaling, leading to cell cycle arrest. It inhibits the proliferation of cell lines derived from solid and hematologic malignancies, with multiple myeloma and Ewing's sarcoma cell lines being most sensitive. Oral administration of GSK1904529A decreases the growth of human tumor xenografts in mice, consistent with a reduction of IGF-IR phosphorylation in tumors. Despite the potent inhibitory activity of GSK1904529A on IR in vitro and in vivo, minimal effects on blood glucose levels are observed in animals at doses that show significant antitumor activity.

Conclusion: GSK1904529A is a promising candidate for therapeutic use in IGF-IR–dependent tumors.
Helicobacter pylori Infection Induces Genetic Instability of Nuclear and Mitochondrial DNA in Gastric Cells
Authors: Machado Ana Manuel Dantas , Figueiredo Ceu , Touati Eliette , Máximo Valdemar , Sousa Sonia , Michel Valérie , Carneiro Fátima , Nielsen Finn Cilius , Seruca Raquel , Rasmussen Lene Juel
Published: April 2009

Purpose: Helicobacter pylori is a major cause of gastric carcinoma. To investigate a possible link between bacterial infection and genetic instability of the host genome, we examined the effect of H. pylori infection on known cellular repair pathways in vitro and in vivo. Moreover, various types of genetic instabilities in the nuclear and mitochondrial DNA (mtDNA) were examined.

Experimental Design: We observed the effects of H. pylori infection on a gastric cell line (AGS), on C57BL/6 mice, and on individuals with chronic gastritis. In AGS cells, the effect of H. pylori infection on base excision repair and mismatch repair (MMR) was analyzed by reverse transcription-PCR, Western blot, and activity assays. In mice, MMR expression was analyzed by reverse transcription-PCR and the CA repeat instabilities were examined by Mutation Detection Enhancement gel electrophoresis. Mutation spectra in AGS cells and chronic gastritis tissue were determined by PCR, single-stranded conformation polymorphism, and sequencing. H. pylori vacA and cagA genotyping was determined by multiplex PCR and reverse hybridization.

Results: Following H. pylori infection, the activity and expression of base excision repair and MMR are down-regulated both in vitro and in vivo. Moreover, H. pylori induces genomic instability in nuclear CA repeats in mice and in mtDNA of AGS cells and chronic gastritis tissue, and this effect in mtDNA is associated with bacterial virulence.

Conclusions: Our results suggest that H. pylori impairs central DNA repair mechanisms, inducing a transient mutator phenotype, rendering gastric epithelial cells vulnerable to the accumulation of genetic instability and thus contributing to gastric carcinogenesis in infected individuals.
Functionally Overlapping Roles of Abcg2 (Bcrp1) and Abcc2 (Mrp2) in the Elimination of Methotrexate and Its Main Toxic Metabolite 7-HydroxymethotrexateIn vivo
Authors: Vlaming Maria L.H. , Pala Zeliha , van Esch Anita , Wagenaar Els , de Waart Dirk R. , van de Wetering Koen , van der Kruijssen Cornelia M.M. , Oude Elferink Ronald P.J. , van Tellingen Olaf , Schinkel Alfred H.
Published: April 2009

Purpose: ABCC2 (MRP2) and ABCG2 (BCRP) transport various endogenous and exogenous compounds, including many anticancer drugs, into bile, feces, and urine. We investigated the possibly overlapping roles of Abcg2 and Abcc2 in the elimination of the anticancer drug methotrexate (MTX) and its toxic metabolite 7-hydroxymethotrexate (7OH-MTX).

Experimental Design: We generated and characterized Abcc2;Abcg2-/- mice, and used these to determine the overlapping roles of Abcc2 and Abcg2 in the elimination of MTX and 7OH-MTX after i.v. administration of 50 mg/kg MTX.

Results: Compared with wild-type, the plasma areas under the curve (AUC) for MTX were 1.6-fold and 2.0-fold higher in Abcg2-/- and Abcc2-/- mice, respectively, and 3.3-fold increased in Abcc2;Abcg2-/- mice. The biliary excretion of MTX was 23-fold reduced in Abcc2;Abcg2-/- mice, and the MTX levels in the small intestine were dramatically decreased. Plasma levels of 7OH-MTX were not significantly altered in Abcg2-/- mice, but the areas under the curve were 6.2-fold and even 12.4-fold increased in Abcc2-/- and Abcc2;Abcg2-/- mice, respectively. This indicates that Abcc2 compensates for Abcg2 deficiency but that Abcg2 can only partly compensate for Abcc2 absence. Furthermore, 21-fold decreased biliary 7OH-MTX excretion in Abcc2;Abcg2-/- mice and substantial 7OH-MTX accumulation in the liver and kidney were seen. We additionally found that in the absence of Abcc2, Abcg2 mediated substantial urinary excretion of MTX and 7OH-MTX.

Conclusions: Abcc2 and Abcg2 together are major determinants of MTX and 7OH-MTX pharmacokinetics. Variations in ABCC2 and/or ABCG2 activity due to polymorphisms or coadministered inhibitors may therefore substantially affect the therapeutic efficacy and toxicity in patients treated with MTX.
A Phase I, Pharmacokinetic and Pharmacodynamic Study on Vorinostat in Combination with 5-Fluorouracil, Leucovorin, and Oxaliplatin in Patients with Refractory Colorectal Cancer
Authors: Fakih Marwan G. , Pendyala Lakshmi , Fetterly Gerald , Toth Karoli , Zwiebel James A. , Espinoza-Delgado Igor , Litwin Alan , Rustum Youcef M. , Ross Mary Ellen , Holleran Julianne L. , Egorin Merrill J.
Published: April 2009

Purpose: We conducted a phase I study to determine the maximum tolerated dose of vorinostat in combination with fixed doses of 5-fluorouracil (FU), leucovorin, and oxaliplatin (FOLFOX).

Experimental Design: Vorinostat was given orally twice daily for 1 week every 2 weeks. FOLFOX was given on days 4 and 5 of vorinostat. The vorinostat starting dose was 100 mg twice daily. Escalation occurred in cohorts of three to six patients. Pharmacokinetics of vorinostat, FU, and oxaliplatin were studied.

Results: Twenty-one patients were enrolled. Thrombocytopenia, neutropenia, gastrointestinal toxicities, and fatigue increased in frequency and severity at higher dose levels of vorinostat. Two of 4 evaluable patients at dose level 4 (vorinostat 400 mg orally twice daily) developed dose-limiting fatigue. One of 10 evaluable patients at dose level 3 (vorinostat 300 mg orally twice daily) had dose-limiting fatigue, anorexia, and dehydration. There were significant relationships between vorinostat dose and the area under the curve on days 1 and 5 (Pearson, < 0.001). The vorinostat area under the curve increased (P = 0.005) and clearance decreased (P = 0.003) on day 5 compared with day 1. The median Cmax of FU at each dose level increased significantly with increasing doses of vorinostat, suggesting a pharmacokinetic interaction between FU and vorinostat. Vorinostat-induced thymidylate synthase (TS) modulation was not consistent; only two of six patients had a decrease in intratumoral TS expression by reverse transcription-PCR.

Conclusions: The maximum tolerated dose of vorinostat in combination with FOLFOX is 300 mg orally twice daily × 1 week every 2 weeks. Alternative vorinostat dosing schedules may be needed for optimal down-regulation of TS expression.
Combining Simvastatin with the Farnesyltransferase Inhibitor Tipifarnib Results in an Enhanced Cytotoxic Effect in a Subset of Primary CD34+ Acute Myeloid Leukemia Samples
Authors: van der Weide Karen , de Jonge-Peeters Susan D.P.W.M. , Kuipers Folkert , de Vries Elisabeth G.E. , Vellenga Edo
Published: April 2009

Purpose: To show whether the inhibitory effects of the cholesterol synthesis inhibitor simvastatin on human CD34+ acute myeloid leukemia (AML) cells can be further promoted by combining it with the farnesyltransferase inhibitor tipifarnib.

Experimental Design: Normal CD34+, AML CD34+, and CD34− sorted subfractions, and AML cell lines (TF-1 and KG1A) were exposed to simvastatin and tipifarnib.

Results: Both simvastatin and tipifarnib showed a cytotoxic effect on AML cell lines, which was additive when used in combination. In primary sorted CD34+ AML cells, a heterogeneous response pattern was observed upon treatment with simvastatin when analyzing cell survival. A group of normal (n = 12) and abnormal (n = 10) responders were identified within the AML CD34+ subfraction when compared with normal CD34+ cells. This distinction was not observed within the AML CD34− cell fraction. When the CD34+ AML cells were exposed to simvastatin and tipifarnib, a significant enhanced inhibitory effect was shown exclusively in the normal AML responder group, whereas the AML CD34− cell fractions all showed an enhanced inhibitory effect. The observed heterogeneity in AML responsiveness could not be explained by differences in effects on cholesterol metabolism genes or extracellular signal-regulated kinase phosphorylation in response to simvastatin and tipifarnib treatment.

Conclusion: The results suggest that combined treatment with statins and farnesyltransferase inhibitors may be beneficial for a subset of AML patients that can be defined by studying the AML CD34+ fraction.
p53 Arg72Pro and MDM2 T309G Polymorphisms, Histology, and Esophageal Cancer Prognosis
Authors: Cescon David W. , Bradbury Penelope A. , Asomaning Kofi , Hopkins Jessica , Zhai Rihong , Zhou Wei , Wang Zhaoxi , Kulke Matthew , Su Li , Ma Clement , Xu Wei , Marshall Ariela L. , Heist Rebecca Suk , Wain John C. , Lynch Thomas J. , Christiani David C. , Liu Geoffrey
Published: April 2009

Purpose: This study aimed to evaluate the prognostic significance of two functional single nucleotide polymorphisms (SNP) in the p53 pathway (p53 Arg72Pro and MDM2 T309G) in patients with esophageal cancer, and to determine the importance of histologic subtype in the SNP-outcome relationships.

Experimental Design: A cohort of 371 patients with esophageal carcinoma enrolled in Boston, USA from 1999 to 2004 were genotyped for the p53 and MDM2 SNPs. Associations between genotypes and overall survival (OS; the primary outcome) and progression-free survival (PFS) were assessed using the Kaplan-Meier method. Cox proportional hazard models, adjusted for age, stage, performance status, and smoking were developed. Interaction analyses were done for histology (adenocarcinoma versus squamous cell carcinoma).

Results: At the median follow-up of 33 months, median survival (MS) and PFS were 29.1 and 15.7 months, respectively. p53 Pro/Pro was strongly associated with shorter survival in the entire cohort (MS of 11.8 versus 29.1 months, P < 0.0001; adjusted hazard ratio for death, 2.05; 95% confidence interval, 1.30-3.24; P = 0.002 for Pro/Pro versus Arg/Arg). MDM2 G/G was associated with markedly reduced survival in squamous cell carcinoma (MS of 10.3 versus 49.4 months; adjusted hazard ratio for death, 7.9; 95% confidence interval, 2.4-26.0; P = 0.0007 for G/G versus T/T) but not in adenocarcinoma (SNP-histology interaction P = 0.004).

Conclusions: In a large prospective cohort, p53 Arg72Pro Pro/Pro was associated with a 2-fold increased risk of death in all esophageal cancers, whereas MDM2 T309G G/G was associated with a 7-fold increased risk of death in squamous cell carcinoma.
The Breast Cancer Susceptibility Mutation PALB2 1592delT Is Associated with an Aggressive Tumor Phenotype
Authors: Heikkinen Tuomas , Kärkkäinen Hanni , Aaltonen Kirsimari , Milne Roger L. , Heikkilä Päivi , Aittomäki Kristiina , Blomqvist Carl , Nevanlinna Heli
Published: April 2009

Purpose: To determine the effect of the breast cancer susceptibility mutation PALB2 1592delT on tumor phenotype and patient survival.

Experimental Design: We defined the PALB2 mutation status in 947 familial and 1,274 sporadic breast cancer patients and 1,079 population controls, and compared tumor characteristics and survival in mutation carriers relative to other familial and sporadic cases and to 79 BRCA1 and 104 BRCA2 mutation carrier cases.

Results: The PALB2 1592delT mutation was found in 19 familial [2.0%; odds ratio, 11.03; 95% confidence interval (95% CI), 2.65-97.78; P < 0.0001] and eight sporadic patients (0.6%; odds ratio, 3.40; 95% CI, 0.68-32.95; P = 0.1207) compared with two (0.2%) control individuals. Tumors of the PALB2 mutation carriers presented triple negative (estrogen receptor negative/progesterone receptor negative/HER negative) phenotype more often (54.5%; P < 0.0001) than those of other familial (12.2%) or sporadic (9.4%) breast cancer patients. They were also more often of higher grade (P = 0.0027 and P = 0.0017, respectively) and had higher expression of Ki67 (P = 0.0004 and P = 0.0490, respectively). Carrying a PALB2 mutation was also associated with reduced survival, especially in familial cases (hazard ratio, 2.30; 95% CI, 1.01-5.24; P = 0.0466) and among familial patients with HER2-negative tumors (hazard ratio, 4.57; 95% CI, 1.96-10.64; P = 0.0004). Carrying a BRCA2 mutation was also found to be an independent predictor of poor survival at 10-year follow-up (P = 0.04).

Conclusions: The PALB2 1592delT mutation has a strong effect on familial breast cancer risk. The tumors rising in patients carrying this mutation manifest a phenotype associated with aggressive disease. Our results also suggest a significant impact of carrying a BRCA2 mutation on long-term breast cancer survival.
KIF5B-ALK, a Novel Fusion Oncokinase Identified by an Immunohistochemistry-based Diagnostic System for ALK-positive Lung Cancer
Authors: Takeuchi Kengo , Choi Young Lim , Togashi Yuki , Soda Manabu , Hatano Satoko , Inamura Kentaro , Takada Shuji , Ueno Toshihide , Yamashita Yoshihiro , Satoh Yukitoshi , Okumura Sakae , Nakagawa Ken , Ishikawa Yuichi , Mano Hiroyuki
Published: April 2009

Purpose: EML4-ALK is a transforming fusion tyrosine kinase, several isoforms of which have been identified in lung cancer. Immunohistochemical detection of EML4-ALK has proved difficult, however, likely as a result of low transcriptional activity conferred by the promoter-enhancer region of EML4. The sensitivity of EML4-ALK detection by immunohistochemistry should be increased adequately.

Experimental Design: We developed an intercalated antibody-enhanced polymer (iAEP) method that incorporates an intercalating antibody between the primary antibody to ALK and the dextran polymer-based detection reagents.

Results: Our iAEP method discriminated between tumors positive or negative for EML4-ALK in a test set of specimens. Four tumors were also found to be positive for ALK in an archive of lung adenocarcinoma (n = 130) and another 4 among fresh cases analyzed in a diagnostic laboratory. These 8 tumors were found to include 1 with EML4-ALK variant 1, 1 with variant 2, 3 with variant 3, and 2 with previously unidentified variants (designated variants 6 and 7). Inverse reverse transcription-PCR analysis revealed that the remaining tumor harbored a novel fusion in which intron 24 of KIF5B was ligated to intron 19 of ALK. Multiplex reverse transcription-PCR analysis of additional archival tumor specimens identified another case of lung adenocarcinoma positive for KIF5B-ALK.

Conclusions: The iAEP method should prove suitable for immunohistochemical screening of tumors positive for ALK or ALK fusion proteins among pathologic archives. Coupling of PCR-based detection to the iAEP method should further facilitate the rapid identification of novel ALK fusion genes such as KIF5B-ALK.
Regulation of Breast Cancer Metastasis by Atypical Chemokine Receptors
Authors: Cheng Xiaoyun , Hung Mien-Chie
Published: April 2009

The interaction between chemokines and their G-protein-coupled receptors plays an important role in promoting metastasis of different kinds of human cancers. However, the expression of an atypical chemokine receptor, CCX-CKR, which serves as a decoy receptor to attract chemokines, inhibits the growth and metastasis of breast cancer by sequestration of chemokines.
Thymidylate synthasegene variations: predictive and prognostic markers
Authors: Lurje Georg , Manegold Philipp C. , Ning Yan , Pohl Alexandra , Zhang Wu , Lenz Heinz-Josef
Published: April 2009

Since its introduction more than 50 years ago by Heidelberger et al., the fluoropyrimidine 5-fluorouracil (5-FU) has remained the mainstay of therapeutic regimens used in the treatment of colorectal cancer and other human malignancies, with single-agent response rates of 20% to 25% in advanced disease stage. Pharmacogenomics has emerged as a useful tool to address interindividual gene variations by analyzing the interplay of host and tumor genotype and drug efficacy and toxicity. Having a reliable panel of prognostic and predictive markers will be critical in selecting an individualized and tailored chemotherapy regimen based on the particular tumor and host genotype. Although conflicting results have been reported, higher thymidylate synthase (TS) protein and mRNA expression levels in tumors have generally been associated with poor clinical outcome in patients treated with 5-FU–based chemotherapy regimens. However, the cause of the variability in TS expression still remains not fully understood, although several germ-line polymorphisms seem to affect the expression of TS, some of which have been found to have an effect on prognosis and the probability of response to 5-FU–based chemotherapy. This review will provide an update on pharmacogenomic studies of TS that were aimed at elucidating their role as prognostic and predictive markers. [Mol Cancer Ther 2009;8(5):1000–7]
The indenoisoquinoline noncamptothecin topoisomerase I inhibitors: update and perspectives
Authors: Pommier Yves , Cushman Mark
Published: April 2009

Because camptothecins are effective against previously resistant tumors and are the only class of topoisomerase I (Top1) inhibitors approved for cancer treatment, we developed the indenoisoquinolines. Like camptothecins, the indenoisoquinolines selectively trap Top1-DNA cleavage complexes and have been cocrystallized with the Top1-DNA cleavage complexes. Indenoisoquinolines show antitumor activity in animal models. They have several advantages over the camptothecins: (a) They are synthetic and chemically stable. (b) The Top1 cleavage sites trapped by the indenoisoquinolines have different genomic locations, implying differential targeting of cancer cell genomes. (c) The Top1 cleavage complexes trapped by indenoisoquinolines are more stable, indicative of prolonged drug action. (d) They are seldom or not used as substrates for the multidrug resistance efflux pumps (ABCG2 and MDR-1). Among the >400 indenoisoquinolines synthesized and evaluated, three have been retained as leads for clinical development by the National Cancer Institute: NSC 706744, NSC 725776 (Indimitecan), and NSC 724998 (Indotecan). The trapping of Top1 cleavage complexes by indenoisoquinolines in cells results in the rapid and sustained phosphorylation of histone H2AX (γ-H2AX). We discuss the use of γ-H2AX as a pharmacodynamic biomarker for the clinical development of the indenoisoquinolines. [Mol Cancer Ther 2009;8(5):1008–14]
Decreased levels of UMP kinase as a mechanism of fluoropyrimidine resistance
Authors: Humeniuk Rita , Menon Lata G. , Mishra Prasun J. , Gorlick Richard , Sowers Rebecca , Rode Wojciech , Pizzorno Giuseppe , Cheng Yung-Chi , Kemeny Nancy , Bertino Joseph R. , Banerjee Debabrata
Published: April 2009

5-Fluorouracil (5-FU) continues to be widely used for treatment of gastrointestinal cancers. Because many tumors show primary or acquired resistance, it is important to understand the molecular basis underlying the mechanism of resistance to 5-FU. In addition to its effect on thymidylate synthase inhibition and DNA synthesis, 5-FU may also influence RNA metabolism. Our previous studies revealed that colorectal cancer cells resistant to bolus 5-FU (HCT-8/4hFU) showed significantly decreased incorporation of the drug into RNA. Resistance to bolus 5-FU was associated with lower expression of UMP kinase (UMPK), an enzyme that plays an important role in the activation of 5-FU to 5-FUTP and its incorporation into RNA. Activities of other 5-FU–metabolizing enzymes (e.g., thymidine kinase, uridine phosphorylase, thymidine phosphorylase, and orotate phosphoribosyltransferase) remained unchanged between sensitive and resistant cell lines. Herein, we show that UMPK down-regulation in 5-FU–sensitive cells (HCT-8/P) induces resistance to bolus 5-FU treatment. Moreover, HCT-8/4hFU cells are even more cross-resistant to treatment with 5-fluorouridine, consistent with the current understanding of 5-fluorouridine as a RNA-directed drug. Importantly, colorectal cancer hepatic metastases isolated from patients clinically resistant to weekly bolus 5-FU/leucovorin treatment exhibited decreased mRNA expression of UMPK but not thymidylate synthase or dihydropyrimidine dehydrogenase compared with tumor samples of patients not previously exposed to 5-FU. Our findings provide new insights into the mechanisms of acquired resistance to 5-FU in colorectal cancer and implicate UMPK as an important mechanism of clinical resistance to pulse 5-FU treatment in some patients.[Mol Cancer Ther 2009;8(4):OF1–8]
Dehydrocostuslactone disrupts signal transducers and activators of transcription 3 through up-regulation of suppressor of cytokine signaling in breast cancer cells
Authors: Kuo Po-Lin , Ni Wen-Chiu , Tsai Eing-Mei , Hsu Ya-Ling
Published: April 2009

This study investigates the anticancer effect of dehydrocostuslactone (DHE), a plant-derived sesquiterpene lactone, on human breast cancer cells. DHE inhibits cell proliferation by inducing cells to undergo cell cycle arrest and apoptosis. DHE suppresses the expression of cyclin D, cyclin A, cyclin-dependent kinase 2, and cdc25A and increases the amount of p53 and p21, resulting in G0/G1-S phase arrest in MCF-7 cells. In contrast, DHE caused S-G2/M arrest by increasing p21 expression and chk1 activation and inhibiting cyclin A, cyclin B, cdc25A, and cdc25C expression in MDA-MB-231 cells. DHE induces up-regulation of Bax and Bad, down-regulation of Bcl-2 and Bcl-XL, and nuclear relocation of the mitochondrial factors apoptosis-inducing factor and endonuclease G. We also found that DHE inhibits survival signaling through the Janus tyrosine kinase-signal transducer and activator of transcription-3 signaling by increasing the expression of suppressors of cytokine signaling (SOCS)-1 and SOCS-3. Reduction of SOCS-1 and SOCS-3 expression by small interfering RNA inhibits DHE-mediated signal transducer and activator of transcription-3 inhibition, p21 up-regulation, and cyclin-dependent kinase 2 blockade, supporting the hypothesis that DHE inhibits cell cycle progression and cell death through SOCS-1 and SOCS-3. Significantly, animal studies have revealed a 50% reduction in tumor volume after a 45-day treatment period. Taken together, this study provides new insights into the molecular mechanism of the DHE action that may contribute to the chemoprevention of breast cancer. [Mol Cancer Ther 2009;8(5):1328–39]
Two types of human malignant melanoma cell lines revealed by expression patterns of mitochondrial and survival-apoptosis genes: implications for malignant melanoma therapy
Authors: Su David M. , Zhang Qiuyang , Wang Xuexi , He Ping , Zhu Yuelin Jack , Zhao Jianxiong , Rennert Owen M. , Su Yan A.
Published: April 2009

Human malignant melanoma has poor prognosis because of resistance to apoptosis and therapy. We describe identification of the expression profile of 1,037 mitochondria-focused genes and 84 survival-apoptosis genes in 21 malignant melanoma cell lines and 3 normal melanocyte controls using recently developed hMitChip3 cDNA microarrays. Unsupervised hierarchical clustering analysis of 1,037 informative genes, and 84 survival-apoptosis genes, classified these malignant melanoma cell lines into type A (n = 12) and type B (n = 9). Three hundred fifty-five of 1,037 (34.2%) genes displayed significant (P ≤ 0.030; false discovery rate ≤ 3.68%) differences (±≥2.0-fold) in average expression, with 197 genes higher and 158 genes lower in type A than in type B. Of 84 genes with known survival-apoptosis functions, 38 (45.2%) displayed the significant (P < 0.001; false discovery rate < 0.15%) difference. Antiapoptotic (BCL2, BCL2A1, PPARD, and RAF1), antioxidant (MT3, PRDX5, PRDX3, GPX4, GLRX2, and GSR), and proapoptotic (BAD, BNIP1, APAF1, BNIP3L, CASP7, CYCS, CASP1, and VDAC1) genes expressed at higher levels in type A than in type B, whereas the different set of antiapoptotic (PSEN1, PPP2CA, API5, PPP2R1B, PPP2R1A, and FIS1), antioxidant (HSPD1, GSS, SOD1, ATOX1, and CAT), and proapoptotic (ENDOG, BAK1, CASP2, CASP4, PDCD5, HTRA2, SEPT4, TNFSF10, and PRODH) genes expressed at lower levels in type A than in type B. Microarray data were validated by quantitative reverse transcription-PCR. These results showed the presence of two types of malignant melanoma, each with a specific set of dysregulated survival-apoptosis genes, which may prove useful for development of new molecular targets for therapeutic intervention and novel diagnostic biomarkers for treatment and prognosis of malignant melanoma.[Mol Cancer Ther 2009;8(5):OF1–13]
Impact of Low-Frequency Hearing
Authors: Büchner A. , Schüssler M. , Battmer R.D. , Stöver T. , Lesinski-Schiedat A. , Lenarz T.
Published: April 2009

Today, cochlear implantation is the treatment of choice in the case of severe to profound hearing loss, but the speech perception abilities of many recipients in noisy conditions are still poor and the overall sound quality and ease of listening still require improvement. Residual low-frequency hearing has been associated with improved hearing performance in cochlear implant patients, especially in difficult listening environments (i.e. cocktail party effect). It seems that low-frequency information can enhance the segregation of competing voices, which leads to better speech understanding in noise. We investigated the effect of low-frequency hearing on speech perception performance in a group of subjects being implanted with the Nucleus Hybrid-L device. The Hybrid-L device is a modified Nucleus Freedom implant, which instead of the standard electrode carries a very delicate electrode array that allows preservation of residual hearing to a great extent. Sentence test results from 22 subjects are presented here. Additionally, for 8 subjects, the acoustically presented frequency range was limited to 300, 500 and 700 Hz, and speech perception tests with a single competing talker were conducted. The Hybrid-L study group achieved a speech reception threshold of 15.9 dB in the hearing aid alone condition, 10.8 dB in the cochlear implant alone condition, and 3.9 dB when using the combination of cochlear implant and hearing aid. Differences between the 3 conditions are statistically significant. Results from the additional experiment on the acoustically presented frequency range suggest that very limited residual hearing below 500 Hz is already sufficient to produce a significant improvement in speech perception performance in conjunction with a cochlear implant.
Results of Partial Deafness Cochlear Implantation Using Various Electrode Designs
Authors: Skarżyński Henryk , Lorens Artur , Piotrowska Anna , Podskarbi-Fayette Robert
Published: April 2009

Nineteen adults and 9 children who received a unilateral cochlear implant between 2002 and 2007 were included in the study. All subjects were preoperatively diagnosed with significant residual hearing in low frequencies, termed as ‘partial deafness’, and were implanted according to a 6-step round window surgical technique for partial deafness cochlear implantation. Hearing was preserved to a great extent in the partial deafness cochlear implantation (PDCI) group. After a short period following activation of the cochlear implant, highly significant improvement in the recognition of monosyllabic words was observed. With a developed round window surgical procedure and limited electrode insertion, hearing can be preserved in the majority of patients with partial deafness. PDCI is a feasible means of treating individuals who have good low-frequency hearing but severe to profound hearing loss in the mid to high frequencies.