bluuebunny/crossref_metadata_2025 huggingface dataset:
Diet, Autophagy, and Cancer: A Review
Authors: Singletary Keith , Milner John
Published: July 2008

A host of dietary factors can influence various cellular processes and thereby potentially influence overall cancer risk and tumor behavior. In many cases, these factors suppress cancer by stimulating programmed cell death. However, death not only can follow the well-characterized type I apoptotic pathway but also can proceed by nonapoptotic modes such as type II (macroautophagy-related) and type III (necrosis) or combinations thereof. In contrast to apoptosis, the induction of macroautophagy may contribute to either the survival or death of cells in response to a stressor. This review highlights current knowledge and gaps in our understanding of the interactions among bioactive food constituents, autophagy, and cancer. Whereas a variety of food components including vitamin D, selenium, curcumin, resveratrol, and genistein have been shown to stimulate autophagy vacuolization, it is often difficult to determine if this is a protumorigenic or antitumorigenic response. Additional studies are needed to examine dose and duration of exposures and tissue specificity in response to bioactive food components in transgenic and knockout models to resolve the physiologic implications of early changes in the autophagy process. (Cancer Epidemiol Biomarkers Prev 2008;17(7):1596–610)
Testing a Multigene Signature of Prostate Cancer Death in the Swedish Watchful Waiting Cohort
Authors: Mucci Lorelei A. , Pawitan Yudi , Demichelis Francesca , Fall Katja , Stark Jennifer R. , Adami Hans-Olov , Andersson Swen-Olof , Andrén Ove , Eisenstein Anna , Holmberg Lars , Huang Wei , Kantoff Philip W. , Kim Robert , Perner Sven , Stampfer Meir J. , Johansson Jan-Erik , Rubin Mark A.
Published: July 2008

Although prostate cancer is a leading cause of cancer death, most men die with and not from their disease, underscoring the urgency to distinguish potentially lethal from indolent prostate cancer. We tested the prognostic value of a previously identified multigene signature of prostate cancer progression to predict cancer-specific death. The Örebro Watchful Waiting Cohort included 172 men with localized prostate cancer of whom 40 died of prostate cancer. We quantified protein expression of the markers in tumor tissue by immunohistochemistry and stratified the cohort by quintiles according to risk classification. We accounted for clinical variables (age, Gleason, nuclear grade, and tumor volume) using Cox regression and calculated receiver operator curves to compare discriminatory ability. The hazard ratio of prostate cancer death increased with increasing risk classification by the multigene model, with a 16-fold greater risk comparing highest-risk versus lowest-risk strata, and predicted outcome independent of clinical factors (P = 0.002). The best discrimination came from combining information from the multigene markers and clinical data, which perfectly classified the lowest-risk stratum where no one developed lethal disease; using the two lowest-risk groups as reference, the hazard ratio (95% confidence interval) was 11.3 (4.0-32.8) for the highest-risk group and difference in mortality at 15 years was 60% (50-70%). The combined model provided greater discriminatory ability (area under the curve = 0.78) than the clinical model alone (area under the curve = 0.71; P = 0.04). Molecular tumor markers can add to clinical variables to help distinguish lethal and indolent prostate cancer and hold promise to guide treatment decisions. (Cancer Epidemiol Biomarkers Prev 2008;17(7):1682–8)
No Reduction in C-Reactive Protein following a 12-Month Randomized Controlled Trial of Exercise in Men and Women
Authors: Campbell Kristin L. , Campbell Peter T. , Ulrich Cornelia M. , Wener Mark , Alfano Catherine M. , Foster-Schubert Karen , Rudolph Rebecca E. , Potter John D. , McTiernan Anne
Published: July 2008

Low-grade systemic inflammation is suggested to play a role in the development of several chronic diseases including cancer. Higher levels of physical activity and lower adiposity have been associated with reduced levels of markers of systemic inflammation, such as C-reactive protein (CRP); however, reductions in CRP have not been consistently observed in randomized controlled trials of exercise.

Purpose: To examine the effect of a 12-month aerobic exercise intervention on CRP levels in men and women.

Methods: One hundred two men and 100 women, sedentary and of ages 40 to 75 years, with mean body mass index (BMI) of 29.9 and 28.7 kg/m2, respectively, were randomly assigned to a 12-month moderate-to-vigorous aerobic exercise intervention (6 d/wk, 60 min/d, 60-85% maximum heart rate) or control group. Fasting blood samples were collected at baseline and at 12 months. CRP levels were measured by high-sensitivity latex-enhanced nephelometry.

Results: At baseline, CRP was 1.16 and 2.11 mg/L for men and women, respectively, and CRP was correlated with percent body fat (r = 0.48, P ≤0.001), BMI (r = 0.37, P ≤ 0.001), and aerobic fitness (r = −0.49, P ≤ 0.001). No intervention effects were observed for CRP in men or women, or when stratified by baseline BMI (<30 versus ≥30 kg/m2), baseline CRP (<3 versus ≥3 mg/L), or change in body weight, body composition, or aerobic fitness.

Conclusion: A 12-month moderate-to-vigorous aerobic exercise intervention did not affect CRP levels in previously sedentary men or women with average-risk CRP values at baseline. (Cancer Epidemiol Biomarkers Prev 2008;17(7):1714–8)
Ethnicity and Risk for Colorectal Cancers Showing Somatic BRAF V600E Mutation or CpG Island Methylator Phenotype
Authors: English Dallas R. , Young Joanne P. , Simpson Julie A. , Jenkins Mark A. , Southey Melissa C. , Walsh Michael D. , Buchanan Daniel D. , Barker Melissa A. , Haydon Andrew M. , Royce Simon G. , Roberts Aedan , Parry Susan , Hopper John L. , Jass Jeremy J. , Giles Graham G.
Published: July 2008

Colorectal cancers arising from serrated polyps are characterized by the CpG island methylator phenotype (CIMP) and somatic mutation (V600E) in the BRAF proto-oncogene. Few epidemiologic studies have investigated risk factors for these tumors. We conducted a cohort study of 41,328 residents of Melbourne, Australia that included 9,939 participants of southern European origin and 31,389 of Anglo-Celtic origin. Colorectal adenocarcinomas were identified from population-based cancer registries. BRAF V600E mutation in tumors was determined using a PCR-based allelic discrimination method. Tumors were classified as CIMP positive when at least three of five markers (RUNX3, CACNA1G, SOCS1, NEUROG1, and IGF2) were methylated according to MethyLight analysis. Hazard ratios (HR) and 95% confidence intervals (95% CI) were estimated by Cox regression with adjustment for risk factors for colorectal cancer. During follow-up, 718 participants were diagnosed with colorectal cancer. CIMP assays were done for 579 and BRAF V600E mutation testing for 582. After adjustment for other risk factors, when compared with people of Anglo-Celtic origin, those of southern European origin had lower incidence of colorectal cancer that had CIMP (HR, 0.32; 95% CI, 0.16-0.67) or BRAF mutations (HR, 0.30; 95% CI, 0.16-0.58) but similar incidence of colorectal cancer without CIMP (HR, 0.86; 95% CI, 0.70-1.05) or BRAF (HR, 0.90; 95% CI, 0.74-1.11). People of southern European origin had lower risk of colorectal cancers with CIMP and BRAF mutation than people of Anglo-Celtic origin, which may in part be due to genetic factors that are less common in people of southern European origin. (Cancer Epidemiol Biomarkers Prev 2008;17(7):1774–80)
GSTM1 and GSTT1 Gene Deletions and the Risk for Nasopharyngeal Carcinoma in Han Chinese
Authors: Guo Xiuchan , O'Brien Stephen J. , Zeng Yi , Nelson George W. , Winkler Cheryl A.
Published: July 2008

Southern China is a major nasopharyngeal carcinoma–endemic region. Environmental factors and genetic susceptibility contribute to nasopharyngeal carcinoma development in this area. Polymorphic deletions of GSTM1 and GSTT1 genes involved in the detoxification of potentially carcinogenic agents may be a risk factor for nasopharyngeal carcinoma. To investigate the roles of genetic variations of GSTM1 and GSTT1 in nasopharyngeal carcinoma susceptibility in the Chinese population, we conducted a case-control study of 350 nasopharyngeal carcinoma cases and 622 controls. GSTM1 and GSTT1 deletion variants were genotyped by multiplex PCR assays. Logistic regression analysis was used to estimate odds ratios and 95% confidence intervals (95% CI). No significant association was observed for either GSTM1- or GSTT1-null genotype independently in the contribution to nasopharyngeal carcinoma risk. To explore possible joint effects of the GSTM1- and GSTT1-null polymorphisms with each other and with other risk factors for nasopharyngeal carcinoma, we examined the association between each combined genotype and the risk for nasopharyngeal carcinoma stratified by gender and EBV replication status. We found that individuals who carried GSTM1/GSTT1–double null genotype had a higher risk for nasopharyngeal carcinoma in the male population (odds ratio, 1.76; 95% confidence interval, 1.04-2.97; P = 0.03); however, this was not significant after correction for multiple comparisons. No statistical difference was found between cases and controls in females and the subpopulation positive for immunoglobulin A antibodies to EBV capsid antigen for combined genotypes. Our results suggest that the GSTM1/GSTT1–double null genotype may be a risk factor for nasopharyngeal carcinoma among males in southern China, but this result warrants confirmation in other studies. (Cancer Epidemiol Biomarkers Prev 2008;17(7):1760–3)
Polymorphisms in Genes Involved in Sex Hormone Metabolism, Estrogen Plus Progestin Hormone Therapy Use, and Risk of Postmenopausal Breast Cancer
Authors: Diergaarde Brenda , Potter John D. , Jupe Eldon R. , Manjeshwar Sharmila , Shimasaki Craig D. , Pugh Thomas W. , DeFreese Daniele C. , Gramling Bobby A. , Evans Ilonka , White Emily
Published: July 2008

Hormone therapy, estrogen plus progestin (E+P) particularly, is associated with increased risk of breast cancer. Functionally relevant polymorphisms in genes involved in sex hormone metabolism may alter exposure to exogenous sex hormones and affect risk of postmenopausal breast cancer. We evaluated associations of common polymorphisms in genes involved in estrogen and/or progesterone metabolism, E+P use, and their interactions with breast cancer risk in a case-control study of postmenopausal women (324 cases; 651 controls) nested within the VITAL cohort. None of the polymorphisms studied was, by itself, statistically significantly associated with breast cancer risk. E+P use was significantly associated with increased breast cancer risk (≥10 years versus never; odds ratio, 1.9; 95% confidence interval, 1.3-2.8; Ptrend = 0.0002). Statistically significant interactions between CYP1A1 Ile462Val (Pinteraction = 0.04), CYP1A1 MspI (Pinteraction = 0.003), CYP1B1 Val432Leu (Pinteraction = 0.007), CYP1B1 Asn453Ser (Pinteraction = 0.04) and PGR Val660Leu (Pinteraction = 0.01), and E+P use were observed. The increased risk of breast cancer associated with E+P use was greater among women with at least one rare allele of the CYP1A1 Ile462Val, CYP1A1 MspI, CYP1B1 Asn453Ser, and PGR Val660Leu polymorphisms than among women homozygous for the common allele of these polymorphisms. Risk of breast cancer increased little with increasing years of E+P use among women with at least one CYP1B1 Val432 allele; a large increase in risk was seen among women homozygous for CYP1B1 Leu432. Our results support the hypothesis that specific polymorphisms in genes involved in sex hormone metabolism may modify the effect of E+P use on breast cancer risk. (Cancer Epidemiol Biomarkers Prev 2008;17(7):1751–9)
Limits of Detection of Chemopreventive Efficacy: Karyometry of Skin Biopsies
Authors: Bartels Peter H. , Yozwiak Michael L. , Bartels Hubert G. , Liu Yun , Hess Lisa M. , Alberts David S.
Published: July 2008

Objective: This study was designed to establish estimates of the smallest effects due to chemopreventive intervention detectable by karyometry in skin biopsies.

Methods: Estimates of the smallest change of statistical significance and estimates of the power of the test were derived for several key features descriptive of the distribution of nuclear chromatin. Results from triplicate biopsies from the same case were used to provide estimates of the within-case, biopsy-to-biopsy variance.

Results: Generally, a change in feature value due to chemopreventive intervention can be statistically secured when it amounts to 5% to 10%. In clinical trials where matched baseline and end of study biopsies from the same cases are available, paired comparison ANOVA can detect a 2% change on samples of 25 cases. Establishing efficacy in individual cases requires a change in feature values on the order of 10% to 15%.

Conclusions: Karyometry provides a sensitive, quantitative method for the assessment of efficacy of chemoprevention. The effects of within-case, biopsy-to-biopsy variance need to be considered only in the evaluation of individual cases and are on the order of 5% in skin biopsies. (Cancer Epidemiol Biomarkers Prev 2008;17(7):1689–95)
Genetic Polymorphisms of CYP2E1 and Risk of Colorectal Adenomas in the Self Defense Forces Health Study
Authors: Morita Makiko , Tabata Shinji , Tajima Osamu , Yin Guang , Abe Hiroshi , Kono Suminori
Published: July 2008

CYP2E1 is an enzyme involved in the metabolism of N-nitrosamines and other carcinogenic substances. Functional RsaI and 96-bp insertion polymorphisms in 5′-flanking region have drawn interest in relation to the risk of colorectal cancer. We investigated the relation of these genetic polymorphisms and colorectal adenoma, a well-established precursor lesion of colorectal cancer. Subjects were 455 cases of colorectal adenomas and 1,052 controls of normal colonoscopy among men receiving a preretirement health examination in the Self Defense Forces. Genotypes were determined by either PCR-RFLP or PCR method. Statistical adjustment was made for smoking, alcohol use, body mass index, physical activity, and others. Individuals with RsaI c2 allele showed a decreased risk of proximal colon adenomas; adjusted odds ratios (95% confidence interval) of proximal and distal adenomas for the c1/c2 or c2/c2 genotype versus c1/c1 was 0.61 (0.41-0.88) and 0.95 (0.71-1.27), respectively. CYP2E1 96-bp insertion allele was associated with an increased risk of large (≥ 5 mm) adenomas; adjusted odds ratios (95% confidence interval) of large and small adenomas for having at least one insertion allele were 1.41 (1.03-1.94) and 0.94 (0.71-1.25), respectively. A suggestive effect modification was noted for alcohol consumption on the association between RsaI polymorphism and proximal adenomas (Pinteraction = 0.09) as well as on the association between 96-bp insertion and large adenomas (Pinteraction = 0.05). These findings indicate that variation in activity and inducibility of CYP2E1 contribute to the development of colorectal carcinogenesis. (Cancer Epidemiol Biomarkers Prev 2008;17(7):1800–7)
Differential Effect of Doxorubicin and Zoledronic Acid on Intraosseous versus Extraosseous Breast Tumor GrowthIn vivo
Authors: Ottewell Penelope D. , Deux Blandine , Mönkkönen Hannu , Cross Simon , Coleman Robert E. , Clezardin Philippe , Holen Ingunn
Published: July 2008

Purpose: Breast cancer patients with bone metastases are commonly treated with chemotherapeutic agents such as doxorubicin and zoledronic acid to control their bone disease. Sequential administration of doxorubicin followed by zoledronic acid has been shown to increase tumor cell apoptosis in vitro. We have therefore investigated the antitumor effects of clinically relevant doses of these drugs in a mouse model of breast cancer bone metastasis.

Experimental Design: MDA-MB-231/BO2 cells were injected via the tail vein into athymic mice. Tumor-induced osteolytic lesions were detected in all animals following X-ray analysis 18 days after tumor cell inoculation (day 18). Mice were administered saline, 100 μg/kg zoledronic acid, 2 mg/kg doxorubicin, doxorubicin and zoledronic acid simultaneously, or doxorubicin followed 24 h later by zoledronic acid. Doxorubicin-treated animals received a second injection on day 25. Tumor growth in the marrow cavity and on the outside surface of the bone was measured as well as tumor cell apoptosis and proliferation. The effects of treatments on bone were evaluated following X-ray and μCT analysis.

Results: Sequential treatment with doxorubicin followed by zoledronic acid caused decreased intraosseous tumor burden, which was accompanied by increased levels of tumor cell apoptosis and decreased levels of proliferation, whereas extraosseous parts of the same tumors were unaffected. Administration of zoledronic acid, alone or in combination with doxorubicin, resulted in significantly smaller tumor-induced osteolytic lesions compared with control or doxorubicin-treated animals.

Conclusions: This is the first study to show that sequential treatment with clinically relevant doses of doxorubicin, followed 24 h later by zoledronic acid, reduces intraosseous but not extraosseous growth of BO2 breast tumors. Our results suggest that breast cancer patients with metastatic bone disease may benefit from sequential treatment using doxorubicin and zoledronic acid.
Transformation by Oncogenic Mutants and Ligand-Dependent Activation of FLT3 Wild-type Requires the Tyrosine Residues 589 and 591
Authors: Vempati Sridhar , Reindl Carola , Wolf Ulla , Kern Ruth , Petropoulos Konstantin , Naidu Vegi M. , Buske Christian , Hiddemann Wolfgang , Kohl Tobias M. , Spiekermann Karsten
Published: July 2008

Purpose: Mutations in the receptor tyrosine kinase FLT3 are found in up to 30% of acute myelogenous leukemia patients and are associated with an inferior prognosis. In this study, we characterized critical tyrosine residues responsible for the transforming potential of active FLT3-receptor mutants and ligand-dependent activation of FLT3-WT.

Experimental Design: We performed a detailed structure-function analysis of putative autophosphorylation tyrosine residues in the FLT3-D835Y tyrosine kinase domain (TKD) mutant. All tyrosine residues in the juxtamembrane domain (Y566, Y572, Y589, Y591, Y597, and Y599), interkinase domain (Y726 and Y768), and COOH-terminal domain (Y955 and Y969) of the FLT3-D835Y construct were successively mutated to phenylalanine and the transforming activity of these mutants was analyzed in interleukin-3-dependent Ba/F3 cells. Tyrosine residues critical for the transforming potential of FLT3-D835Y were also analyzed in FLT3 internal tandem duplication mutants (FLT3-ITD)and the FLT3 wild-type (FLT3-WT) receptor.

Result: The substitution of the tyrosine residues by phenylalanine in the juxtamembrane, interkinase, and COOH-terminal domains resulted in a complete loss of the transforming potential of FLT3-D835Y-expressing cells which can be attributed to a significant reduction of signal tranducer and activator of transcription 5 (STAT5) phosphorylation at the molecular level. Reintroduction of single tyrosine residues revealed the critical role of Y589 and Y591 in reconstituting interleukin-3-independent growth of FLT3-TKD-expressing cells. Combined mutation of Y589 and Y591 to phenylalanine also abrogated ligand-dependent proliferation of FLT3-WT and the transforming potential of FLT3-ITD-with a subsequent abrogation of STAT5 phosphorylation.

Conclusion: We identified two tyrosine residues, Y589 and Y591, in the juxtamembrane domain that are critical for the ligand-dependent activation of FLT3-WT and the transforming potential of oncogenic FLT3 mutants.
Function of JunB in Transient Amplifying Cell Senescence and Progression of Human Prostate Cancer
Authors: Konishi Noboru , Shimada Keiji , Nakamura Mitsutoshi , Ishida Eiwa , Ota Ichiro , Tanaka Nobumichi , Fujimoto Kiyohide
Published: July 2008

Purpose: Replicative senescence in cells acts as a barrier against excessive proliferation and carcinogenesis. Transient amplifying cells (TAC) are a subset of basal cell populations within the prostate from which cancers are thought to originate; therefore, we focused on prostate TAC to investigate the molecular mechanisms by which the TAC may be able to evade senescence.

Experimental Design: TAC clones were isolated from each zone within the whole prostate and analyzed in flow cytometry. Prostate cancer cells were transfected with junB small interfering RNA (siRNA) and examined by chorioallantoic membrane assay for cancer invasion. Immunohistochemical analysis was done in primary and metastatic prostate cancer specimens.

Results: TAC populations showed increased expression of p53, p21, p16, and pRb, resulting in senescence. TAC clones with reduced p16 expression successfully bypassed this phase. We further found close correlation between the levels of junB and p16 expression. Repeated transfection of junB siRNA in prostatic TAC allowed the cells to escape senescence presumably through inactivation of p16/pRb. The chorioallantoic membrane invasion assay showed much lower in invasive cancer cells with high expression of junB; conversely, silencing of junB by transfection with junB siRNA promoted invasion. We also found that metastatic prostate cancers, as well as cancers with high Gleason scores, showed significantly low junB immunopositivity.

Conclusions: JunB is an essential upstream regulator of p16 and contributes to maintain cell senescence that blocks malignant transformation of TAC. JunB thus apparently plays an important role in controlling prostate carcinogenesis and may be a new target for cancer prevention and therapy.
ABCB1 Genetic Variation Influences the Toxicity and Clinical Outcome of Patients with Androgen-Independent Prostate Cancer Treated with Docetaxel
Authors: Sissung Tristan M. , Baum Caitlin E. , Deeken John , Price Douglas K. , Aragon-Ching Jeanny , Steinberg Seth M. , Dahut William , Sparreboom Alex , Figg William D.
Published: July 2008

Purpose: Polymorphisms that are associated with ABCB1 expression and function may be linked to treatment efficacy and the development of neutropenia and neurotoxicity in patients with androgen-independent prostate cancer receiving docetaxel.

Experimental Design: Patients with androgen-independent prostate cancer treated with docetaxel alone (n = 23) or docetaxel and thalidomide (n = 50) were genotyped for the ABCB1 1236C>T, 2677 G>T/A, and 3435 C>T alleles by direct sequencing, and diplotypes were constructed using an EM algorithm. The data were then compared with duration to onset of peripheral neuropathy, neutropenia grade, and survival after docetaxel.

Results: For patients receiving docetaxel alone, individuals carrying a diplotype consisting of the 1236C-2677G-3435C linked alleles had improved overall survival after treatment (P = 0.0017). Additionally, patients treated with docetaxel and thalidomide carrying a diplotype consisting of the 2677T-3435T haplotype had a shorter median survival (P = 0.045). After adjusting for a particular set of polymorphisms and diplotype groupings, a hazard ratio of 10.87 was found for patients carrying the 2677GG genotype versus patients carrying other genotypes (P = 0.0048) in the docetaxel and thalidomide cohort. Among both treatment arms together, individuals carrying the 2677GG genotype also had a significantly longer time to neuropathy (P = 0.035). Finally, there was a strong trend toward patients carrying the 2677TT-3435TT diplotype having higher grades of neutropenia (P = 0.053).

Conclusion: The data suggest that docetaxel-induced neuropathy, neutropenia grade, and overall survival could be linked to ABCB1 allelic variants with ensuing negative implications for docetaxel treatment in patients carrying ABCB1 variant genotypes.
Histone Deacetylase Inhibitor Panobinostat Induces Clinical Responses with Associated Alterations in Gene Expression Profiles in Cutaneous T-Cell Lymphoma
Authors: Ellis Leigh , Pan Yan , Smyth Gordon K. , George Daniel J. , McCormack Chris , Williams-Truax Roxanne , Mita Monica , Beck Joachim , Burris Howard , Ryan Gail , Atadja Peter , Butterfoss Dale , Dugan Margaret , Culver Kenneth , Johnstone Ricky W. , Prince H. Miles
Published: July 2008

Purpose: Histone deacetylase inhibitors can alter gene expression and mediate diverse antitumor activities. Herein, we report the safety and activity of the histone deacetylase inhibitor panobinostat (LBH589) in cutaneous T-cell lymphoma (CTCL) and identify genes commonly regulated by panobinostat.

Experimental Design: Panobinostat was administered orally to patients with CTCL on Monday, Wednesday, and Friday of each week on a 28-day cycle. A dose of 30 mg was considered excessively toxic, and subsequent patients were treated at the expanded maximum tolerated dose of 20 mg. Biopsies from six patients taken 0, 4, 8, and 24 h after administration were subjected to microarray gene expression profiling and real-time quantitative PCR of selected genes.

Results: Patients attained a complete response (n = 2), attained a partial response (n = 4), achieved stable disease with ongoing improvement (n = 1), and progressed on treatment (n = 2). Microarray data showed distinct gene expression response profiles over time following panobinostat treatment, with the majority of genes being repressed. Twenty-three genes were commonly regulated by panobinostat in all patients tested.

Conclusions: Panobinostat is well tolerated and induces clinical responses in CTCL patients. Microarray analyses of tumor samples indicate that panobinostat induces rapid changes in gene expression, and surprisingly more genes are repressed than are activated. A unique set of genes that can mediate biological responses such as apoptosis, immune regulation, and angiogenesis were commonly regulated in response to panobinostat. These genes are potential molecular biomarkers for panobinostat activity and are strong candidates for the future assessment of their functional role(s) in mediating the antitumor responses of panobinostat.
Lenalidomide Enhances Natural Killer Cell and Monocyte-Mediated Antibody-Dependent Cellular Cytotoxicity of Rituximab-Treated CD20+ Tumor Cells
Authors: Wu Lei , Adams Mary , Carter Troy , Chen Roger , Muller George , Stirling David , Schafer Peter , Bartlett J. Blake
Published: July 2008

Purpose: Lenalidomide has significant activity in myelodysplastic syndromes, multiple myeloma, and non-Hodgkin's lymphoma (NHL). In previous studies, natural killer (NK) cell expansion by lenalidomide was shown to enhance the cytotoxic effect of rituximab. This study assessed the ability of lenalidomide to enhance antibody-dependent cellular cytotoxicity (ADCC) in rituximab-treated NHL cell lines and primary tumor cells from patients with B-cell chronic lymphocytic leukemia (B-CLL) in vitro.

Experimental Design: An in vitro ADCC system was used to assess the ability of lenalidomide to enhance human NK cell and monocyte function in response to rituximab.

Results: Lenalidomide directly enhanced IFN-γ production via Fc-γ receptor-mediated signaling in response to IgG. It was also a potent enhancer of NK cell-mediated and monocyte-mediated tumor cell ADCC for a variety of rituximab-treated NHL cell lines in vitro, an effect that was dependent on the presence of antibody and either interleukin-2 or interleukin-12. Lenalidomide also enhanced the ability of NK cells to kill primary tumor cells derived from three patients with B-CLL who have been treated previously with fludarabine plus cyclophosphamide. Enhanced NK cell ADCC was associated with enhanced granzyme B and Fas ligand expression and could be inhibited by a granzyme B inhibitor and partially inhibited by antibody to FasL. Enhanced NK cell Fc-γ receptor signaling is associated with enhanced phosphorylated extracellular signal-related kinase levels leading to enhanced effector function.

Conclusions: These findings suggest that lenalidomide has the potential to enhance the rituximab-induced killing of NHL cell lines and primary B-cell chronic lymphocytic leukemia cells via a NK cell-mediated and monocyte-mediated ADCC mechanism in vitro, providing a strong rationale for the combination of lenalidomide with IgG1 antibodies to target tumor-specific antigens in patients with cancer.
KML001 Cytotoxic Activity Is Associated with Its Binding to Telomeric Sequences and Telomere Erosion in Prostate Cancer Cells
Authors: Phatak Pornima , Dai Fangping , Butler Melody , Nandakumar M.P. , Gutierrez Peter L. , Edelman Martin J. , Hendriks Hans , Burger Angelika M.
Published: July 2008

Purpose: KML001 (sodium metaarsenite) is an orally bioavailable arsenic compound that has entered phase I/II clinical trials in prostate cancer. In this study, we elucidated the mode of action of KML001 and investigated its effects on telomerase and telomeres.

Experimental Design: We compared telomere length to KML001 cytotoxic activity in a panel of human solid tumor cell lines. Duration of exposure and concentrations of KML001 that affect telomerase and telomeres were evaluated in relation to established mechanisms of arsenite action such as reactive oxygen species–related DNA damage induction. Binding of KML001 to telomeres was assessed by matrix-assisted laser desorption/ionization mass spectrometry.

Results: We established a significant inverse correlation (r2 = 0.9) between telomere length and cytotoxicity. KML001 exhibited activity in tumor cells with short telomeres at concentrations that can be achieved in serum of patients. We found that telomerase is not directly inhibited by KML001. Instead, KML001 specifically binds to telomeric sequences at a ratio of one molecule per three TTAGGG repeats leading to translocation of the telomerase catalytic subunit into the cytoplasm. In prostate cancer cells with short telomeres, KML001 caused telomere-associated DNA damage signaling as shown by γ-H2AX induction and chromatin immunoprecipitation assays as well as a rapid telomere erosion shown by metaphase fluorescence in situ hybridization. These effects were not seen in a lung cancer cell line with long telomeres. Importantly, arsenification of telomeres preceded DNA lesions caused by reactive oxygen species production.

Conclusions: Sodium metaarsenite is a telomere targeting agent and should be explored for the treatment of tumors with short telomeres.
Local Administration of PF-3512676 CpG-B Instigates Tumor-Specific CD8+ T-Cell Reactivity in Melanoma Patients
Authors: Molenkamp Barbara G. , Sluijter Berbel J.R. , van Leeuwen Paul A.M. , Santegoets Saskia J.A.M. , Meijer Sybren , Wijnands Pepijn G.J.T.B. , Haanen John B.A.G. , van den Eertwegh Alfons J.M. , Scheper Rik J. , de Gruijl Tanja D.
Published: July 2008

Purpose: Impaired immune effector functions in the melanoma sentinel lymph node (SLN) may allow for early metastatic events. Local administration of PF-3512676 (formerly known as CpG 7909) has shown immunostimulatory effects of both dendritic cell and T-cell subsets in the melanoma SLN. Here, we set out to ascertain whether these PF-3512676-induced immunostimulatory effects translate into higher frequencies of melanoma-specific CD8+ T cells.

Experimental Design: Twenty-four stage I to III melanoma patients were randomized to preoperative local administration of either PF-3512676 or saline. CD8+ T cells from SLN and peripheral blood were tested for reactivity by IFN-γ ELISPOT assay against several HLA-A1/A2/A3-restricted epitopes derived from various melanoma-associated antigens (MAA) in 21 of 24 enrolled patients. Frequencies of natural killer (NK) cells and frequencies and maturation state of dendritic cell subsets in the SLN were determined by flow cytometry.

Results: Melanoma-specific CD8+ T-cell response rates against >1 MAA epitope in the SLN were 0 of 11 for the saline group versus 5 of 10 for the PF-3512676-administered group (P = 0.012). Of these 5 responding patients, 4 also had a measurable response to >1 MAA epitope in the blood. Increased frequencies in the SLN of both MAA-specific CD8+ T cells and NK cells correlated to CpG-induced plasmacytoid dendritic cell maturation.

Conclusions: These data show an increase in melanoma-specific CD8+ T-cell frequencies as well as an increased effector NK cell rate after a single dose of PF-3512676 and thus support the utility of local PF-3512676 administration as adjuvant treatment in early-stage melanoma to try and halt metastatic spread.
Comparison of Nomograms With Other Methods for Predicting Outcomes in Prostate Cancer: A Critical Analysis of the Literature
Authors: Shariat Shahrokh F. , Karakiewicz Pierre I. , Suardi Nazareno , Kattan Michael W.
Published: July 2008

Purpose: Accurate estimates of risk are essential for physicians if they are to recommend a specific management to patients with prostate cancer. Accurate risk estimates are also required for clinical trial design, to ensure homogeneous patient groups. Because there is more than one model available for prediction of most outcomes, model comparisons are necessary for selection of the best model. We describe the criteria based on which to judge predictive tools, describe the limitations of current predictive tools, and compare the different predictive methodologies that have been used in the prostate cancer literature.

Experimental Design: Using MEDLINE, a literature search was done on prostate cancer decision aids from January 1966 to July 2007.

Results: The decision aids consist of nomograms, risk groupings, artificial neural networks, probability tables, and classification and regression tree analyses. The following considerations need to be applied when the qualities of predictive models are assessed: predictive accuracy (internal or ideally external validation), calibration (i.e., performance according to risk level or in specific patient subgroups), generalizability (reproducibility and transportability), and level of complexity relative to established models, to assess whether the new model offers advantages relative to available alternatives. Studies comparing decision aids have shown that nomograms outperform the other methodologies.

Conclusions: Nomograms provide superior individualized disease-related risk estimations that facilitate management-related decisions. Of currently available prediction tools, the nomograms have the highest accuracy and the best discriminating characteristics for predicting outcomes in prostate cancer patients.
Paclitaxel Encapsulated in Cationic Liposomes Increases Tumor Microvessel Leakiness and Improves Therapeutic Efficacy in Combination with Cisplatin
Authors: Strieth Sebastian , Eichhorn Martin E. , Werner Alexander , Sauer Birgitta , Teifel Michael , Michaelis Uwe , Berghaus Alexander , Dellian Marc
Published: July 2008

Purpose: Paclitaxel encapsulated in cationic liposomes (EndoTAG-1) is a vascular targeting formulation for the treatment of solid tumors. It triggers intratumoral microthrombosis, causing significant inhibition of tumor perfusion and tumor growth associated with endothelial cell apoptosis. Here, we quantified the effects of repeated EndoTAG-1 therapy on tumor microvascular leakiness with respect to leukocyte-endothelial cell interactions, the targeting property of cationic liposomes, and the therapeutic combination with conventional cisplatin chemotherapy.

Experimental Design: Using dorsal skinfold chamber preparations in Syrian Golden hamsters, in vivo fluorescence microscopy experiments were done after repeated EndoTAG-1 treatment of A-Mel-3 tumors. Controls received glucose, paclitaxel alone, or cationic liposomes devoid of paclitaxel. Extravasation of rhodamine-labeled albumin was measured to calculate microvessel permeability, and intratumoral leukocyte-endothelial cell interactions were quantified. Subcutaneous tumor growth was evaluated after combination therapy followed by histologic analysis.

Results: Microvascular permeability was significantly increased only after treatment with EndoTAG-1, whereas intratumoral leukocyte-endothelial cell interactions were not affected by any treatment. In separate skinfold chamber experiments, fluorescently labeled cationic liposomes kept their targeting property for tumor endothelial cells after repeated EndoTAG-1 treatment and no signs of extravasation were observed. Subcutaneous A-Mel-3 tumor growth was significantly inhibited by the combination of cisplatin and EndoTAG-1.

Conclusions: These data show that vascular targeting with EndoTAG-1 increases tumor microvessel leakiness probably due to vascular damage. This mechanism is not mediated by inflammatory leukocyte-endothelial cell interactions. Manipulating the blood-tumor barrier by repeated tumor microvessel targeting using EndoTAG-1 can effectively be combined with tumor cell–directed conventional cisplatin chemotherapy.
Targeted Therapies to Improve Tumor Immunotherapy
Authors: Begley Jonathan , Ribas Antoni
Published: July 2008

Durable tumor regression and potential cures of metastatic solid cancers can be achieved by a variety of cellular immunotherapy strategies, including cytokine therapy, dendritic cell–based vaccines, and immune-activating antibodies, when used in so-called immune-sensitive cancers such as melanoma and renal cell carcinoma. However, these immunotherapy strategies have very low tumor response rates, usually in the order of 5% to 10% of treated patients. We propose that the antitumor activity of adequately stimulated tumor antigen–specific T cells is limited by local factors within the tumor milieu and that pharmacologic modulation of this milieu may overcome tumor resistance to immunotherapy. By understanding the mechanisms of cancer cell immune escape, it may be possible to design rational combinatorial approaches of novel therapies able to target immunosuppressive or antiapoptotic molecules in an attempt to reverse resistance to immune system control. We term this mode of treatment “immunosensitization.” Ideal candidates for immunosensitizing drugs would be targeted drugs that block key oncogenic mechanisms in cancer cells resulting in a proapoptotic cancer cell milieu and at the same time do not negatively interfere with critical lymphocyte functions.
Genomic Differences Between Pure Ductal Carcinoma In Situ of the Breast and that Associated with Invasive Disease: a Calibrated aCGH Study
Authors: Iakovlev Vladimir V. , Arneson Nona C.R. , Wong Vietty , Wang Chunjie , Leung Stephanie , Iakovleva Gaiane , Warren Keisha , Pintilie Melania , Done Susan J.
Published: July 2008

Purpose: In the quest for new targets, genomes of ductal carcinoma in situ (DCIS) and infiltrating duct carcinoma (IDC) have been compared previously; however, genomic alterations associated with cancer progression were difficult to identify. We hypothesized that significant events can be detected by comparing lesions with a broader range of behavior: from pure DCIS to IDC associated with lymph node metastasis.

Experimental Design: Array comparative genomic hybridization, calibrated by self-self hybridization tests, was used to study 6 cases of pure DCIS and 17 cases of DCIS paired with IDC where 8 tumors had spread to the local lymph nodes.

Results: Pure DCIS exhibited a marginally higher degree of genomic complexity than DCIS and IDC components of invasive tumors. The latter two showed similarity between tumors and between components of the same tumor with several regions detected preferentially compared with pure DCIS. IDC associated with lymph node metastases showed similarity of genomic profiles as a group. Gain on 17q22-24.2 was associated with higher histologic grade, large IDC size, lymphatic/vascular invasion, and lymph node metastasis (P < 0.05).

Conclusions: Our findings suggest that DCIS and IDC are associated with specific genomic events. DCIS associated with IDC is genomically similar to the invasive component and therefore may represent either a clone with high invasive potential or invasive cancer spreading through the ducts. Specifically, gain on 17q22-24.2 is a candidate region for further testing as a predictor of invasion when detected in DCIS and predictor of nodal metastasis when detected in DCIS or IDC.
Molecular Characterization of the Pediatric Preclinical Testing Panel
Authors: Neale Geoffrey , Su Xiaoping , Morton Christopher L. , Phelps Doris , Gorlick Richard , Lock Richard B. , Reynolds C. Patrick , Maris John M. , Friedman Henry S. , Dome Jeffrey , Khoury Joseph , Triche Timothy J. , Seeger Robert C. , Gilbertson Richard , Khan Javed , Smith Malcolm A. , Houghton Peter J.
Published: July 2008

Purpose: Identifying novel therapeutic agents for the treatment of childhood cancers requires preclinical models that recapitulate the molecular characteristics of their respective clinical histotypes.

Experimental Design and Results: Here, we have applied Affymetrix HG-U133Plus2 profiling to an expanded panel of models in the Pediatric Preclinical Testing Program. Profiling led to exclusion of two tumor lines that were of mouse origin and five osteosarcoma lines that did not cluster with human or xenograft osteosarcoma samples. We compared expression profiles of the remaining 87 models with profiles from 112 clinical samples representing the same histologies and show that model tumors cluster with the appropriate clinical histotype, once “immunosurveillance” genes (contributed by infiltrating immune cells in clinical samples) are eliminated from the analysis. Analysis of copy number alterations using the Affymetrix 100K single nucleotide polymorphism GeneChip showed that the models have similar copy number alterations to their clinical counterparts. Several consistent copy number changes not reported previously were found (e.g., gain at 22q11.21 that was observed in 5 of 7 glioblastoma samples, loss at 16q22.3 that was observed in 5 of 9 Ewing's sarcoma and 4 of 12 rhabdomyosarcoma models, and amplification of 21q22.3 that was observed in 5 of 7 osteosarcoma models). We then asked whether changes in copy number were reflected by coordinate changes in gene expression. We identified 493 copy number–altered genes that are nonrandom and appear to identify histotype-specific programs of genetic alterations.

Conclusions: These data indicate that the preclinical models accurately recapitulate expression profiles and genetic alterations common to childhood cancer, supporting their value in drug development.
Irradiance-Dependent Photobleaching and Pain in δ-Aminolevulinic Acid-Photodynamic Therapy of Superficial Basal Cell Carcinomas
Authors: Cottrell William J. , Paquette Anne D. , Keymel Kenneth R. , Foster Thomas H. , Oseroff Allan R.
Published: July 2008

Purpose: In superficial basal cell carcinomas treated with photodynamic therapy with topical δ-aminolevulinic acid, we examined effects of light irradiance on photodynamic efficiency and pain. The rate of singlet-oxygen production depends on the product of irradiance and photosensitizer and oxygen concentrations. High irradiance and/or photosensitizer levels cause inefficient treatment from oxygen depletion in preclinical models.

Experimental Design: Self-sensitized photobleaching of protoporphyrin IX (PpIX) fluorescence was used as a surrogate metric for photodynamic dose. We developed instrumentation measuring fluorescence and reflectance from lesions and margins during treatment at 633 nm with various irradiances. When PpIX was 90% bleached, irradiance was increased to 150 mW/cm2 until 200 J/cm2 were delivered. Pain was monitored.

Results: In 33 superficial basal cell carcinomas in 26 patients, photobleaching efficiency decreased with increasing irradiance above 20 mW/cm2, consistent with oxygen depletion. Fluences bleaching PpIX fluorescence 80% (D80) were 5.7 ± 1.6, 4.5 ± 0.3, 7.5 ± 0.8, 7.4 ± 0.3, 12.4 ± 0.3, and 28.7 ± 7.1 J/cm2, respectively, at 10, 20, 40, 50, 60 and 150 mW/cm2. At 20-150 mW/cm2, D80 doses required 2.5-3.5 min; times for the total 200 J/cm2 were 22.2-25.3 min. No significant pain occurred up to 50 mW/cm2; pain was not significant when irradiance then increased. Clinical responses were comparable to continuous 150 mW/cm2 treatment.

Conclusions: Photodynamic therapy with topical δ-aminolevulinic acid using ∼40 mW/cm2 at 633 nm is photodynamically efficient with minimum pain. Once PpIX is largely photobleached, higher irradiances allow efficient, rapid delivery of additional light. Optimal fluence at a single low irradiance is yet to be determined.
Slug (SNAI2) Down-Regulation by RNA Interference Facilitates Apoptosis and Inhibits Invasive Growth in Neuroblastoma Preclinical Models
Authors: Vitali Roberta , Mancini Camillo , Cesi Vincenzo , Tanno Barbara , Mancuso Mariateresa , Bossi Gianluca , Zhang Ying , Martinez Robert V. , Calabretta Bruno , Dominici Carlo , Raschellà Giuseppe
Published: July 2008

Purpose: We assessed the relevance of Slug (SNAI2) for apoptosis resistance and invasion potential of neuroblastoma cells in vitro and in vivo.

Experimental Design: We evaluated the effect of imatinib mesylate on invasion and analyzed the genes modulated by imatinib mesylate treatment in neuroblastoma cells. Slug expression, inhibited by imatinib mesylate treatment, was knocked down in neuroblastoma cells by RNA interference, and the effects on invasion and apoptosis were evaluated in vitro. A pseudometastatic model of neuroblastoma in severe combined immunodeficient mice was used to assess the effects of Slug silencing alone or in combination with imatinib mesylate treatment on metastasis development.

Results: Microarray analysis revealed that several genes, including Slug, were down-regulated by imatinib mesylate. Slug expression was detectable in 8 of 10 human neuroblastoma cell lines. Two Slug-expressing cell lines were infected with a vector encoding a microRNA to Slug mRNA. Infected cells with reduced levels of Slug were tested for the expression of apoptosis-related genes (p53, Bax, and Bcl-2) identified previously as Slug targets. Bcl-2 was down-regulated in Slug-interfered cells. Slug down-regulation increased sensitivity to apoptosis induced by imatinib mesylate, etoposide, or doxorubicin. Invasion of Slug-silenced cells was reduced in vitro. Animals injected with Slug-silenced cells had fewer tumors than controls and the inhibition of tumor growth was even higher in animals treated with imatinib mesylate.

Conclusions: Slug down-regulation facilitates apoptosis induced by proapoptotic drugs in neuroblastoma cells and decreases their invasion capability in vitro and in vivo. Slug inhibition, possibly combined with imatinib mesylate, may represent a novel strategy for treatment of metastatic neuroblastoma.