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Purpose This phase III study compared the efficacy and safety of bevacizumab combined with standard chemotherapy regimens versus chemotherapy alone as second-line treatment of patients with human epidermal growth factor receptor 2 (HER2) –negative metastatic breast cancer. Patients and Methods Patients were randomly assigned 2:1 to chemotherapy + bevacizumab or to chemotherapy + placebo. Before random assignment, investigators chose capecitabine, a taxane (paclitaxel, nab-paclitaxel, or docetaxel), gemcitabine, or vinorelbine. Dosing for bevacizumab or placebo was 15 mg/kg every 3 weeks or 10 mg/kg every 2 weeks, depending on chemotherapy regimen. The primary end point was progression-free survival (PFS). Secondary end points included overall survival, PFS by chemotherapy cohort, objective response rate (ORR), duration of objective response, 1-year survival rate, and safety. Results RIBBON-2 enrolled 684 patients (225, chemotherapy + placebo; 459, chemotherapy + bevacizumab). The combination of bevacizumab with chemotherapy demonstrated a statistically significant benefit. Median PFS increased from 5.1 to 7.2 months (stratified hazard ratio for PFS, 0.78; 95% CI, 0.64 to 0.93; P = .0072). The 10% improvement in ORR between the placebo- and bevacizumab-containing arms (39.5% v 29.6%; P = .0193), although not statistically significant, was consistent with previous trials. There was no statistically significant difference in overall survival. The most common grade ≥ 3 adverse events (AEs) related to bevacizumab treatment were hypertension (9.0%) and proteinuria (3.1%). There was an increased number of AEs leading to study discontinuation in the chemotherapy + bevacizumab arm compared with the chemotherapy + placebo arm (13.3% v 7.2%). Conclusion The combination of bevacizumab with commonly used chemotherapies improved PFS in the second-line treatment of patients with HER2-negative metastatic breast cancer, with a safety profile comparable with that in prior phase III studies.

BackgroundThe cerebrospinal fluid (CSF) biomarkers amyloid β (Aβ)‐42, total‐tau (T‐tau), and phosphorylated‐tau (P‐tau) demonstrate good diagnostic accuracy for Alzheimer's disease (AD). However, there are large variations in biomarker measurements between studies, and between and within laboratories. The Alzheimer's Association has initiated a global quality control program to estimate and monitor variability of measurements, quantify batch‐to‐batch assay variations, and identify sources of variability. In this article, we present the results from the first two rounds of the program.MethodsThe program is open for laboratories using commercially available kits for Aβ, T‐tau, or P‐tau. CSF samples (aliquots of pooled CSF) are sent for analysis several times a year from the Clinical Neurochemistry Laboratory at the Mölndal campus of the University of Gothenburg, Sweden. Each round consists of three quality control samples.ResultsForty laboratories participated. Twenty‐six used INNOTEST enzyme‐linked immunosorbent assay kits, 14 used Luminex xMAP with the INNO‐BIA AlzBio3 kit (both measure Aβ‐(1‐42), P‐tau(181P), and T‐tau), and 5 used Meso Scale Discovery with the Aβ triplex (AβN‐42, AβN‐40, and AβN‐38) or T‐tau kits. The total coefficients of variation between the laboratories were 13% to 36%. Five laboratories analyzed the samples six times on different occasions. Within‐laboratory precisions differed considerably between biomarkers within individual laboratories.ConclusionsMeasurements of CSF AD biomarkers show large between‐laboratory variability, likely caused by factors related to analytical procedures and the analytical kits. Standardization of laboratory procedures and efforts by kit vendors to increase kit performance might lower variability, and will likely increase the usefulness of CSF AD biomarkers.

The chromosomal translocation t (11;14)(q13;q32) leading to cyclin-D1 overexpression plays an essential role in the development of mantle cell lymphoma (MCL), an aggressive tumor that remains incurable with current treatment strategies. Cyclin-D1 has been postulated as an effective therapeutic target, but the evaluation of this target has been hampered by our incomplete understanding of its oncogenic functions and by the lack of valid MCL murine models. To address these issues, we generated a cyclin-D1–driven mouse model in which cyclin-D1 expression can be regulated externally. These mice developed cyclin-D1–expressing lymphomas capable of recapitulating features of human MCL. We found that cyclin-D1 inactivation was not sufficient to induce lymphoma regression in vivo; however, using a combination of in vitro and in vivo assays, we identified a novel prosurvival cyclin-D1 function in MCL cells. Specifically, we found that cyclin-D1, besides increasing cell proliferation through deregulation of the cell cycle at the G 1 –S transition, sequestrates the proapoptotic protein BAX in the cytoplasm, thereby favoring BCL2’s antiapoptotic function. Accordingly, cyclin-D1 inhibition sensitized the lymphoma cells to apoptosis through BAX release. Thus, genetic or pharmacologic targeting of cyclin-D1 combined with a proapoptotic BH3 mimetic synergistically killed the cyclin-D1–expressing murine lymphomas, human MCL cell lines, and primary lymphoma cells. Our study identifies a role of cyclin-D1 in deregulating apoptosis in MCL cells, and highlights the potential benefit of simultaneously targeting cyclin-D1 and survival pathways in patients with MCL. This effective combination therapy also might be exploited in other cyclin-D1–expressing tumors.

Polycystic kidney disease (PKD) is a genetic disorder characterized by growth of fluid-filled cysts predominately in kidney tubules and liver bile ducts. Currently, the clinical management of PKD is limited to cyst aspiration, surgical resection or organ transplantation. Based on an observation that PPAR γ agonists such as pioglitazone and rosiglitazone decrease mRNA levels of a Cl − transport protein, CFTR (cystic fibrosis transmembrane conductance regulator), and the Cl − secretory response to vasopressin in cultured renal cells, it is hypothesized that PPAR γ agonists will inhibit cyst growth. The current studies show that a 7- or 14-week pioglitazone feeding regimen inhibits renal and hepatic bile duct cyst growth in the PCK rat, a rodent model orthologous to human PKD. These studies provide proof of concept for the mechanism of action of the PPAR γ agonists and suggest that this class of drugs may be effective in controlling both renal and hepatic cyst growth and fibrosis in PKD.

A number of inherited disorders result in renal cyst development. The most common form, autosomal dominant polycystic kidney disease (ADPKD), is a disorder most often diagnosed in adults and caused by mutation in PKD1 or PKD2. The PKD1 protein, polycystin-1, is a large receptor-like protein, whereas polycystin-2 is a transient receptor potential channel. The polycystin complex localizes to primary cilia and may act as a mechanosensor essential for maintaining the differentiated state of epithelia lining tubules in the kidney and biliary tract. Elucidation of defective cellular processes has highlighted potential therapies, some of which are now being tested in clinical trials. ARPKD is the neonatal form of PKD and is associated with enlarged kidneys and biliary dysgenesis. The disease phenotype is highly variable, ranging from neonatal death to later presentation with minimal kidney disease. ARPKD is caused by mutation in PKHD1, and two truncating mutations are associated with neonatal lethality. The ARPKD protein, fibrocystin, is localized to cilia/basal body and complexes with polycystin-2. Rare, syndromic forms of PKD also include defects of the eye, central nervous system, digits, and/or neural tube and highlight the role of cilia and pathways such as Wnt and Hh in their pathogenesis.

ABSTRACT The human immunodeficiency virus type 1 (HIV-1) protein Vpr (viral protein R) arrests cells in the G 2 phase of the cell cycle, a process that requires activation of the ATR (ataxia-telangiectasia and Rad3-related) pathway. In this study we demonstrate that the expression of Vpr does not cause DNA double-strand breaks but rather induces ATR activation, as indicated by induction of Chk1 phosphorylation and the formation of γ-H2AX and 53BP1 nuclear foci. We define a C-terminal domain containing repeated H(F/S)RIG sequences required for Vpr-induced activation of ATR. Further investigation of the mechanism by which Vpr activates the ATR pathway reveals an increase in chromatin binding of replication protein A (RPA) upon Vpr expression. Immunostaining shows that RPA localizes to nuclear foci in Vpr-expressing cells. Furthermore, we demonstrate direct binding of Vpr to chromatin in vivo, whereas Vpr C-terminal domain mutants lose this chromatin-binding activity. These data support a mechanism whereby HIV-1 Vpr induces ATR activation by targeting the host cell DNA and probably interfering with normal DNA replication.

Cardiovascular complications are the leading cause of morbidity and mortality in autosomal dominant polycystic kidney disease. Pkd2 + /− vascular smooth muscle cells (VSMCs) have an abnormal phenotype and defective intracellular Ca 2+ ([Ca 2+ ] i ) regulation. We examined cAMP content in vascular smooth muscles from Pkd2 + /− mice because cAMP is elevated in cystic renal epithelial cells. We found cAMP concentration was significantly increased in Pkd2 + /− vessels compared with wild-type vessels. Furthermore, reducing the wild-type VSMC [Ca 2+ ] i by Verapamil or BAPTA-AM significantly increased cellular cAMP concentration (mainly by phosphodiesterase [PDE] inhibition), the rate of VSMC proliferation (determined by direct cell counting, 3 H-incorporation, FACS analysis of cells entering S phase, and quantitative Western PCNA and ERK1/2 analyses), and the rate of apoptosis (by Hoechst staining, FACS analysis of the Annexin-V positive cells, and quantitative Western Bax, cytochrome c , and activated caspase 9 and 3 analyses). The low [Ca 2+ ] i induced VSMC proliferation was independent of cAMP/B-Raf signaling, while that of apoptosis was promoted by cAMP. In summary, Pkd2 + /− VSMCs have elevated cAMP levels. This elevation can also be induced by reducing [Ca 2+ ] i in wild-type VSMCs. The [Ca 2+ ] i reduction and cAMP accumulation can cause an increase in both cellular proliferation and apoptosis, resembling Pkd mutant phenotype.