Association of fatty-acid synthase polymorphisms and expression with outcomes after radical prostatectomy.

BACKGROUND: Fatty-acid synthase (FASN), selectively overexpressed in prostate cancer (PCa) cells, has been described as linked to the aggressiveness of PCa. Constitutional genetic variation of the FASN gene and the expression levels of FASN protein in cancer cells could thus be expected to predict outcome after radical prostatectomy (RP). This study evaluates the associations of malignant tissue status, neoadjuvant androgen deprivation therapy (NADT) and single-nucleotide polymorphisms (SNPs) of FASN with FASN protein expression in prostate tissue. The study then examines the associations of FASN SNPs and gene expression with three measures of post-prostatectomy outcome. METHODS: Seven tagging FASN SNPs were genotyped in 659 European American men who underwent RP at Roswell Park Cancer Institute between 1993 and 2005. FASN protein expression was assessed using immunohistochemistry. The patients were followed for an average of 6.9 years (range: 0.1-20.6 years). Outcome was assessed using three end points: biochemical failure, treatment failure and development of distant metastatic PCa. Cox proportional hazards analyses were used to evaluate the associations of the tagging SNPs and FASN expression with these end points. Bivariate associations with outcomes were considered; the associations also were controlled for known aggressiveness indicators. RESULTS: Overall, no SNPs were associated with any known aggressiveness indicators. FASN staining intensity was stronger in malignant than in benign tissue, and NADT was associated with decreased FASN staining in both benign and malignant tissue. The relationships of FASN SNPs and staining intensity with outcome were less clear. One SNP, rs4246444, showed a weak association with outcome. FASN staining intensity also showed a weak and seemingly contradictory relationship with outcome. CONCLUSIONS: Additional study with longer follow-up and populations that include more metastatic patients is warranted.

Actin filament length tunes elasticity of flexibly cross-linked actin networks.

Networks of the cytoskeletal biopolymer actin cross-linked by the compliant protein filamin form soft gels that stiffen dramatically under shear stress. We demonstrate that the elasticity of these networks shows a strong dependence on the mean length of the actin polymers, unlike networks with small, rigid cross-links. This behavior is in agreement with a model of rigid filaments connected by multiple flexible linkers.

ICE SLURRY APPLICATIONS.

The role of secondary refrigerants is expected to grow as the focus on the reduction of greenhouse gas emissions increases. The effectiveness of secondary refrigerants can be improved when phase changing media are introduced in place of single phase media. Operating at temperatures below the freezing point of water, ice slurry facilitates several efficiency improvements such as reductions in pumping energy consumption as well as lowering the required temperature difference in heat exchangers due to the beneficial thermo-physical properties of ice slurry. Research has shown that ice slurry can be engineered to have ideal ice particle characteristics so that it can be easily stored in tanks without agglomeration and then be extractable for pumping at very high ice fraction without plugging. In addition ice slurry can be used in many direct contact food and medical protective cooling applications. This paper provides an overview of the latest developments in ice slurry technology.

Interaction of prenatal exposure to cigarettes and MAOA genotype in pathways to youth antisocial behavior.

Genetic susceptibility to antisocial behavior may increase fetal sensitivity to prenatal exposure to cigarette smoke. Testing putative gene x exposure mechanisms requires precise measurement of exposure and outcomes. We tested whether a functional polymorphism in the gene encoding the enzyme monoamine oxidase A (MAOA) interacts with exposure to predict pathways to adolescent antisocial behavior. We assessed both clinical and information-processing outcomes. One hundred seventy-six adolescents and their mothers participated in a follow-up of a pregnancy cohort with well-characterized exposure. A sex-specific pattern of gene x exposure interaction was detected. Exposed boys with the low-activity MAOA 5' uVNTR (untranslated region variable number of tandem repeats) genotype were at increased risk for conduct disorder (CD) symptoms. In contrast, exposed girls with the high-activity MAOA uVNTR genotype were at increased risk for both CD symptoms and hostile attribution bias on a face-processing task. There was no evidence of a gene-environment correlation (rGE). Findings suggest that the MAOA uVNTR genotype, prenatal exposure to cigarettes and sex interact to predict antisocial behavior and related information-processing patterns. Future research to replicate and extend these findings should focus on elucidating how gene x exposure interactions may shape behavior through associated changes in brain function.

Nonlinear elasticity of stiff biopolymers connected by flexible linkers.

Networks of the biopolymer actin, cross-linked by the compliant protein filamin, form soft gels. They can, however, withstand large shear stresses due to their pronounced nonlinear elastic behavior. The nonlinear elasticity can be controlled by varying the number of cross-links per actin filament. We propose and test a model of rigid filaments decorated by multiple flexible linkers that is in quantitative agreement with experiment. This allows us to estimate loads on individual cross-links, which we find to be less than 10 pN.

Filamin A is essential for active cell stiffening but not passive stiffening under external force.

The material properties of a cell determine how mechanical forces are transmitted through and sensed by that cell. Some types of cells stiffen passively under large external forces, but they can also alter their own stiffness in response to the local mechanical environment or biochemical cues. Here we show that the actin-binding protein filamin A is essential for the active stiffening of cells plated on collagen-coated substrates. This appears to be due to a diminished capability to build up large internal contractile stresses in the absence of filamin A. To show this, we compare the material properties and contractility of two human melanoma cell lines that differ in filamin A expression. The filamin A-deficient M2 cells are softer than the filamin A-replete A7 cells, and exert much smaller contractile stresses on the substratum, even though the M2 cells have similar levels of phosphorylated myosin II light chain and only somewhat diminished adhesion strength. In contrast to A7 cells, the stiffness and contractility of M2 cells are insensitive to either myosin-inhibiting drugs or the stiffness of the substratum. Surprisingly, however, filamin A is not required for passive stiffening under large external forces.

Visualizing the strain field in semiflexible polymer networks: strain fluctuations and nonlinear rheology of F-actin gels.

We image semiflexible polymer networks under shear at the micrometer scale. By tracking embedded probe particles, we determine the local strain field, and directly measure its uniformity, or degree of affineness, on scales of 2-100 microm. The degree of nonaffine strain depends upon the polymer length and cross-link density, consistent with theoretical predictions. We also find a direct correspondence between the uniformity of the microscale strain and the nonlinear elasticity of the networks in the bulk.

Comparative genomics analysis of human sequence variation in the UGT1A gene cluster.

Common polymorphisms within the human UGT1A gene locus are associated with irinotecan and tranilast toxicity. To uncover additional functional variation across this gene cluster, cross-species sequence comparisons were performed. Evolutionarily conserved segments (a total of 47.1 kb) were re-sequenced in 24 African-American, 24 European-American, and 24 Asian individuals, and 381 segregating sites (including 123 singletons) were identified. Highly conserved coding sites were less likely to be polymorphic than diverged sites (P<0.0001) but this pattern was not observed at non-coding sites (P=0.1025). Among coding variants, the distribution of those computationally predicted to affect function was skewed toward low frequencies. Some alleles occurred at similar frequencies in each population; others had wide disparities. Although strong linkage disequilibrium was detected among the hepatically expressed genes, the degree of linkage disequilibrium varied among populations. These results suggest that rare functional gene variants and inter-population variability must be considered in the interpretation of association studies between UGT1A and drug metabolism/toxicity phenotypes.

Phase II trial of oxaliplatin, leucovorin and fluorouracil in patients with advanced carcinoma of the esophagus.

BACKGROUND: The aim of the study was to evaluate the efficacy and tolerability of the combination of oxaliplatin, fluorouracil and leucovorin in patients with advanced esophagus cancer. PATIENTS AND METHODS: Thirty-five patients with recurrent or metastatic esophageal adenocarcinoma or squamous cell carcinoma were enrolled. Up to one prior chemotherapy regimen was allowed. All patients had bi-dimensionally measurable disease. Patients received oxaliplatin 85 mg/m2 as a 2-h infusion on day 1. Leucovorin (500 mg/m2) followed by fluorouracil bolus (400 mg/m2) and 22-h continuous infusion fluorouracil (600 mg/m2) was administered on days 1 and 2. Granulocyte colony stimulating factor was not routinely administered unless the patient developed febrile neutropenia or prolonged neutropenia. Treatment was repeated every 14 days. RESULTS: Of the thirty-five patients enrolled, all were evaluated for toxicity and 34 were evaluated for response. The overall response rate was 40% (95% confidence interval, 24% to 57%) with complete and partial response rates of 3% and 37%, respectively. The median response duration was 4.6 months, and the median overall survival was 7.1 months. One-year survival was 31%. The major toxicity noted was cumulative neutropenia, with 29% developing grade 4 toxicity. There was one treatment-related death secondary to neutropenic sepsis. The most common non-hematologic toxicity encountered with this regimen was cumulative peripheral neuropathy, with 26% experiencing grade 2 or 3 toxicity. CONCLUSIONS: The combination of oxaliplatin, leucovorin, and fluorouracil shows significant anti-tumor activity and a favorable toxicity profile in patients with metastatic carcinoma of the esophagus.

Glioma expansion in collagen I matrices: analyzing collagen concentration-dependent growth and motility patterns.

We study the growth and invasion of glioblastoma multiforme (GBM) in three-dimensional collagen I matrices of varying collagen concentration. Phase-contrast microscopy studies of the entire GBM system show that invasiveness at early times is limited by available collagen fibers. At early times, high collagen concentration correlates with more effective invasion. Conversely, high collagen concentration correlates with inhibition in the growth of the central portion of GBM, the multicellular tumor spheroid. Analysis of confocal reflectance images of the collagen matrices quantifies how the collagen matrices differ as a function of concentration. Studying invasion on the length scale of individual invading cells with a combination of confocal and coherent anti-Stokes Raman scattering microscopy reveals that the invasive GBM cells rely heavily on cell-matrix interactions during invasion and remodeling.

Impact of disease burden at time of allogeneic stem cell transplantation in adults with acute myeloid leukemia and myelodysplastic syndromes.

The impact of disease burden on the outcome of patients with acute myeloid leukemia (AML) undergoing allogeneic stem cell transplantation (SCT) has not been well defined. Data from several retrospective series suggest that overt leukemia at the time of transplant increases the risk of relapse. We reviewed the outcomes of 68 consecutive adults with AML (n=60) or myelodysplastic syndromes (MDS) (n=8) who received an allogeneic SCT at the University of Chicago between May 1986 and October 2002 to confirm the importance of currently recognized risk factors for overall survival (OS) and progression-free survival (PFS). In addition, we wanted to determine whether quantification of residual disease by blast percentage or cytogenetic abnormalities at the time of SCT was correlated with outcome. AML subtypes based on the FAB classification were as follows: M0=9, M1=9, M2=16, M3=2, M4=16, M5=3, M6=5. Cytogenetic analysis was available from 52 patients. Using standard morphologic criteria, 34 patients were in complete remission (CR) and 34 had visible leukemia present. The majority of donors were HLA-identical siblings (n=55). In all, 56 patients received myeloablative conditioning regimens and 12 received a reduced-intensity, fludarabine-based conditioning regimen. OS and PFS times were 7.1 months (95% CI, 4.8-10.4) and 5.1 months (95% CI, 3.2-7.8), respectively. Median follow-up from SCT was 4.6 years (range, 0.6-17.0) for survivors. In multivariate analysis, the following factors were found to be associated with worse survival: (1) increased percentage of blasts in the bone marrow at the time of SCT, (2) presence of acute graft-versus-host disease, (3) mismatched donor, (4) Zubrod performance score of >/=2, and (5) age >/=45 years. We also found a trend towards improved outcome among patients in cytogenetic remission as compared to those who had residual cytogenetic abnormalities and those in overt relapse. These data support an association between pre-transplant disease burden and poor outcome after SCT.

Sorting mesoscopic objects with periodic potential landscapes: optical fractionation.

Viscously damped objects driven through a periodically modulated potential energy landscape can become kinetically locked in to commensurate directions through the landscape, and thus can be deflected away from the driving direction. We demonstrate that the threshold for an object to become kinetically locked in to an array can depend exceptionally strongly on its size. When implemented with an array of holographic optical tweezers, this process provides the basis for a continuous and continuously optimized sorting technique for mesoscopic objects called "optical fractionation."

A phase II study of oxaliplatin and paclitaxel in patients with advanced non-small-cell lung cancer.

PURPOSE: To evaluate the efficacy and toxicity of oxaliplatin and paclitaxel as first-line therapy for patients with advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: The treatment regimen was given as defined in a phase I investigation in patients with previously treated ovarian cancer. It consisted of paclitaxel 175 mg/m(2) (1-h infusion) and oxaliplatin 130 mg/m(2) (2-h infusion) given every 21 days. Eligible patients had stage IIIB (pleural effusion)/IV NSCLC, measurable disease, no prior chemotherapy, Eastern Cooperative Oncology Group performance status 0-2, and adequate hematological, renal and hepatic function. RESULTS: A total of 38 patients were enrolled with the following characteristics: 29% male (n = 11); 71% female (n = 27); median age 64.5 years (range 37-78); performance status of 0-1 84% (n = 32); stage IIIB 8% (n = 3); stage IV 92% (n = 35). One hundred and eighty-one cycles were administered, with a median of four per patient (range one to 12). The overall objective response rate for all 38 patients was 34.2% [95% confidence interval (CI) 19.6% to 51.4%]. This response rate includes 13 patients who met criteria for a partial response. No complete responses were observed. Median overall survival time was 9.2 months (95% CI 6-12.4) and median progression-free survival time was 4.3 months (95% CI 2.1-6.5). The 1- and 2-year overall survival rates were 37% and 21%, respectively. Hematological toxicity included six patients with grade 4 neutropenia. Non-hematological toxicity consisted mainly of grades 1 and 2 neurosensory toxicity. Laryngodysesthesia was observed in two patients following oxaliplatin infusion. No grade 4 non-hematological toxicities were encountered. CONCLUSION: This regimen is well tolerated, and demonstrates activity in patients with advanced NSCLC.

A phase II trial of the epothilone B analog, BMS-247550, in patients with previously treated advanced colorectal cancer.

BACKGROUND: The epothilone B analog, BMS-247550, is a non-taxane microtubulin-stabilizing agent with preclinical activity in taxane-resistant cell lines and phase I activity in colorectal cancer. We conducted a phase II study of single-agent BMS-247550 in advanced colorectal cancer patients who had disease progression following treatment with irinotecan-5-fluorouracil-leucovorin (IFL). PATIENTS AND METHODS: Patients were required to have histologically or cytologically confirmed advanced or metastatic colorectal cancer; progressed on or after chemotherapy with IFL; Eastern Cooperative Oncology Group performance status < or =1; peripheral neuropathy grade < or =1; and adequate laboratory parameters. BMS-247550 40 mg/m(2) was administered intravenously over 3 h every 3 weeks. Patients were evaluated for response every 6 weeks. RESULTS: Twenty-five patients were enrolled; all were evaluable for toxicity and 23 were evaluable for response. There were no complete or partial responses. Thirteen patients (56%) had stable disease after two cycles of therapy; five patients (20%) received six or more cycles. The median time to progression was 11 weeks; median overall survival was 36 weeks. There was considerable grade 3/4 hematological toxicity, including neutropenia (48%) and leukopenia (36%). Grade 3/4 non-hematological toxicities included grade 3 hypersensitivity reaction (12%) and peripheral neuropathy (20%). CONCLUSIONS: Single-agent BMS-247550 (40 mg/m(2)) administered every 21 days demonstrated no activity in advanced colorectal cancer. Peripheral neuropathy was treatment-limiting.