G(1) and G(2) cell-cycle arrest following microtubule depolymerization in human breast cancer cells

Microtubule-depolymerizing agents are widely used to synchronize cells, screen for mitotic checkpoint defects, and treat cancer. The present study evaluated the effects of these agents on normal and malignant human breast cell lines. After treatment with 1 microM nocodazole, seven of ten breast cancer lines (type A cells) arrested in mitosis, whereas the other three (type B cells) did not. Similar effects were observed with 100 nM vincristine or colchicine. Among five normal mammary epithelial isolates, four exhibited type A behavior and one exhibited type B behavior. Further experiments revealed that the type B cells exhibited a biphasic dose-response curve, with mitotic arrest at low drug concentrations (100 nM nocodazole or 6 nM vincristine) that failed to depolymerize microtubules and a p53-independent p21(waf1/cip1)-associated G(1) and G(2) arrest at higher concentrations (1 microM nocodazole or 100 nM vincristine) that depolymerized microtubules. Collectively, these observations provide evidence for coupling of premitotic cell-cycle progression to microtubule integrity in some breast cancer cell lines (representing a possible "microtubule integrity checkpoint") and suggest a potential explanation for the recently reported failure of some cancer cell lines to undergo nocodazole-induced mitotic arrest despite intact mitotic checkpoint proteins.     

Multiple Tissue Biomarkers Independently and Additively Predict Prostate Cancer Pathology Outcomes

BackgroundDistinguishing indolent from aggressive prostate cancer remains a key challenge for decision making regarding prostate cancer management. A growing number of biomarkers are now available to help address this need, but these have rarely been examined together in the same patients to determine their potentially additive value.ObjectiveTo determine whether two previously validated plasma markers (transforming growth factor β1 [TGFβ1] and interleukin-6 soluble receptor [IL6-SR]) and two validated tissue scores (the Genomic Evaluators of Metastatic Prostate Cancer [GEMCaP] and cell cycle progression [CCP] scores) can improve on clinical parameters in predicting adverse pathology after prostatectomy, and how much they vary within tumors with heterogeneous Gleason grade.Design, setting, and participantsA case-control study was conducted among men with low-risk cancers defined by biopsy grade group (GG) 1, prostate-specific antigen (PSA) ≤10 ng/mL, and clinical stage ≤ T2 who underwent immediate prostatectomy. We collected paraffin-fixed prostatectomy tissue and presurgical plasma samples from 381 cases from the University of California, San Francisco, and 260 cases from the University of Washington.Outcome measurements and statistical analysisPathologic outcomes were minor upgrading/upstaging (GG 2 or pT3a) or major upgrading/upstaging (GG ≥ 3 or ≥ pT3b), and multinomial regression was performed to determine putative markers’ ability to predict these outcomes, controlling for PSA, percent of positive biopsy cores, age, and clinical site. For upgraded tumors, a secondary analysis of the GEMCaP and CCP scores from the higher-grade tumor was also performed to evaluate for heterogeneity.Results and limitationsOverall, 357 men had no upgrading/upstaging event at prostatectomy, 236 had a minor event, and 67 had a major event. Neither TGFβ1 nor IL6-SR was statistically significantly associated with any upgrading/upstaging. On the contrary, both the CCP and the GEMCaP score obtained from Gleason pattern 3 tissue were directly associated with minor and major upgrading/upstaging on univariate analysis. The two scores correlated with each other, but weakly. On multinomial analysis including both scores in the model, the CCP score predicted minor upgrading/upstaging (odds ratio [OR] 1.62, 95% confidence interval [CI] 1.05–2.49) and major upgrading/upstaging (OR 2.26, 95% CI 1.05–4.90), p = 0.04), and the GEMCaP score also predicted minor upgrading/upstaging (OR 1.05, 95% CI 1.03–1.08) and major upgrading/upstaging (OR 1.07, 95% CI 1.04–1.11), p < 0.01). The other clinical parameters were not significant in this model. Among upgraded tumors including both Gleason patterns 3 and 4, both the GEMCaP and the CCP score tended to be higher from the higher-grade tumor. The main limitation was the use of virtual biopsies from prostatectomy tissue as surrogates for prostate biopsies.ConclusionsBiomarker signatures based on analyses of both DNA and RNA significantly and independently predict adverse pathology among men with clinically low-risk prostate cancer undergoing prostatectomy.Patient summaryValidated biomarker scores derived from both prostate cancer DNA and prostate cancer RNA can add independent information to help predict outcomes after prostatectomy.     

Enhancing the efficacy of a weak allogeneic melanoma vaccine by viral fusogenic membrane glycoprotein-mediated tumor cell-tumor cell fusion

We have investigated how to make K1735 cells, a poor allogeneic melanoma vaccine, more effective for protection against B16 in vivo. To promote antigen release in an immunologically effective manner, tumor cells were transfected with a viral fusogenic membrane glycoprotein (vesicular stomatitis virus G glycoprotein), which kills cells through the formation, and degeneration, of large multinucleated syncytia. Vaccines consisting of a 1:1 mix of fusing allogeneic and autologous cells led to dramatic increases in survival of mice in both prophylactic and therapy models, dependent upon T cells, the mechanism of tumor-tumor cell fusion, and the nature of the fusion partner. Syncytia activate macrophages and fusogenic membrane glycoprotein-mediated cell killing very efficiently promotes cross-priming of immature dendritic cells with a model tumor antigen. Our data suggest that the unique manner in which syncytia develop and die provides a highly effective pathway for tumor antigen release and presentation to the immune system and offers a novel mechanism by which cancer cell vaccines may be prepared for clinical use.     

Comparison of Fundus Autofluorescence with Photopic and Scotopic Fine Matrix Mapping in Patients with Retinitis Pigmentosa: 4- to 8-Year Follow-up

Purpose. To assess the significance and evolution of parafoveal rings of high-density fundus autofluorescence (AF) in 12 patients with retinitis pigmentosa (RP). Methods. Twelve patients with autosomal recessive RP or Usher syndrome type 2 were ascertained who had a parafoveal ring of high-density AF and a visual acuity of 20/30 or better at baseline. Photopic and scotopic fine matrix mapping (FMM) were performed to test sensitivity across the macula. AF imaging and FMM were repeated after 4 to 8 years and optical coherence tomography (OCT) performed. Results. The size of the AF ring reduced over time and disappeared in one subject. Photopic thresholds were normal over the fovea; thresholds were elevated by 0.6 log units over the ring and by 1.2 log units external to the ring at baseline and differed by less than 0.1 log unit at follow-up. Mild photopic losses close to the internal edge of the ring were detected at baseline or follow-up in all. Mean scotopic thresholds over parafoveal areas within the ring were markedly elevated in 8 of 10 at baseline and were severely elevated in 9 of 11 at follow-up. The eccentricity of the inner edge of the AF ring corresponded closely with the lateral extent of the inner segment ellipsoid band in the OCT image. Conclusions. Ring constriction was largely coincident with progressive centripetal photopic threshold elevation led by worsening of rod photoreceptor function. The rate of constriction differed across patients, and a ring may reach a critical minimum before disappearing, at which stage central visual loss occurs. The structural and functional changes associated with rings of increased autofluorescence confirm that they provide an objective index of macular involvement and may aid the management of RP patients and the monitoring of future treatment efficacy.     

Progressive decline of T and B cell numbers and function in a patient with CDC42 deficiency

Immunologic Research - Single allele mutations in the Cell Division Control protein 42 homolog (CDC42) gene were recently shown to cause Takenouchi-Kosaki syndrome with diverse manifestations....