Intracellular Trafficking and Maturation of Herpes Simplex Virus Type 1 gB and Virus Egress Require Functional Biogenesis of Multivesicular Bodies▿

The biogenesis of multivesicular bodies (MVBs) is topologically equivalent to virion budding. Hence, a number of viruses exploit the MVB pathway to build their envelope and exit from the cell. By expression of dominant negative forms of Vps4 and Vps24, two components of the MVB pathway, we observed an impairment in infectious herpes simplex virus (HSV) assembly/egress, in agreement with a recent report showing the involvement in HSV envelopment of Vps4, the MVB-specific ATPase (C. M. Crump, C. Yates, and T. Minson, J. Virol. 81:7380-7387). Furthermore, HSV infection resulted in morphological changes to MVBs. Glycoprotein B (gB), one of the most highly conserved glycoproteins across the Herpesviridae family, was sorted to MVB membranes. In cells expressing the dominant negative form of Vps4, the site of intracellular gB accumulation was altered; part of gB accumulated as an endoglycosidase H-sensitive immature form at a calreticulin-positive compartment, indicating that gB traffic was dependent on a functional MVB pathway. gB was ubiquitinated in both infected and transfected cells. Ubiquitination was in part dependent on ubiquitin lysine 63, a signal for cargo sorting to MVBs. Partial deletion of the gB cytoplasmic tail resulted in a dramatic reduction of ubiquitination, as well as of progeny virus assembly and release to the extracellular compartment. Thus, HSV envelopment/egress and gB intracellular trafficking are dependent on functional MVB biogenesis. Our data support the view that the sorting of gB to MVB membranes may represent a critical step in HSV envelopment and egress and that modified MVB membranes constitute a platform for HSV cytoplasmic envelopment or that MVB components are recruited to the site(s) of envelopment

PSA Flare With Abiraterone in Patients With Metastatic Castration-Resistant Prostate Cancer

BACKGROUND: The aim of this study was to assess early serum prostate-specific antigen (PSA) changes in patients treated with abiraterone and to correlate those changes with clinical outcome. PATIENTS AND METHODS: We retrospectively evaluated 103 patients with castrate-resistant prostate cancer (CRPC) treated with compassionate use of abiraterone in Romagna, Italy. In these patients, serum PSA levels were monitored every 4 weeks, and a time course of serum PSA levels was obtained. The PSA flare phenomenon was evaluated. The log-rank test was applied to compare survival between groups of patients according to early PSA level changes. RESULTS: Of 103 patients, 43 (41.7%) had an immediate PSA response, whereas 9 (8.7%) had an initial PSA flare. Of the 9 patients with PSA flare, 5 attained a subsequent PSA response. The temporary PSA flare exceeded baseline values by a median of 19.7% (range, 5%-62.9%). The median PFS of the 9 patients in the PSA-flare group was higher compared with patients without the PSA flare (10.5 vs. 6.4 months; P = .0999) but was similar to the subgroup of patients with immediate PSA response (10.5 vs. 10.7 months; P = .7019). In the multivariate analysis, only the PSA response remained as a predictor of progression-free survival (PFS) (P < .0001) and overall survival (OS) (P = .0003), respectively. CONCLUSION: PSA flare occurs not infrequently in patients with CRPC who respond to abiraterone. Patients should be informed of this possible PSA flare phenomenon

Clinical outcomes of castration-resistant prostate cancer treatments administered as third or fourth line following failure of docetaxel and other second-line treatment: results of an Italian multicentre study

Background: The availability of new agents (NAs) active in patients with metastatic castration-resistant prostate cancer (mCRPC) progressing after docetaxel treatment (abiraterone acetate, cabazitaxel, and enzalutamide) has led to the possibility of using them sequentially to obtain a cumulative survival benefit. Objective: To provide clinical outcome data relating to a large cohort of mCRPC patients who received a third-line NA after the failure of docetaxel and another NA. Design, setting, and participants: We retrospectively reviewed the clinical records of patients who had received at least two successive NAs after the failure of docetaxel. Outcome measurements and statistical analysis: The independent prognostic value of a series of pretreatment covariates on the primary outcome measure of overall survival was assessed using Cox regression analysis. Results and limitations: Weassessed260patientswhoreceivedonethird-lineNAbetween January 2012 and December 2013, including 38 who received a further NA as fourth-line therapy. The median progression-free and overall survival from the start of third-line therapy was, respectively, 4 mo and 11 mo, with no significant differences between the NAs. Performance status, and haemoglobin and alkaline phosphatase levels were the only independent prognostic factors. The limitations of the study are mainly due its retrospective nature and the small number of patients treatedwith some of the sequences. Conclusions: We were unable to demonstrate a difference in the clinical outcomes of third-line NAs regardless of previous NA therapy. Patient summary: It is debated which sequence of treatments to adopt after docetaxel. Our data do not support the superiority of any of the three new agents in third-line treatment, regardless of the previously administered new agent