A function for the mitochondrial chaperonin Hsp60 in the structure and transmission of mitochondrial DNA nucleoids in Saccharomyces cerevisiae

The yeast mitochondrial chaperonin Hsp60 has previously been implicated in mitochondrial DNA (mtDNA) transactions: it is found in mtDNA nucleoids associated with single-stranded DNA; it binds preferentially to the template strand of active mtDNA ori sequences in vitro; and wild-type (ρ+) mtDNA is unstable in hsp60 temperature-sensitive (ts) mutants grown at the permissive temperature. Here we show that the mtDNA instability is caused by a defect in mtDNA transmission to daughter cells. Using high resolution, fluorescence deconvolution microscopy, we observe a striking alteration in the morphology of mtDNA nucleoids in ρ+ cells of an hsp60-ts mutant that suggests a defect in nucleoid division. We show that ρ− petite mtDNA consisting of active ori repeats is uniquely unstable in the hsp60-ts mutant. This instability of ori ρ− mtDNA requires transcription from the canonical promoter within the ori element. Our data suggest that the nucleoid dynamics underlying mtDNA transmission are regulated by the interaction between Hsp60 and mtDNA ori sequences

Three-arm, randomized, phase 2 study of carboplatin and paclitaxel in combination with cetuximab, cixutumumab, or both for advanced non-small cell lung cancer (NSCLC) patients who will not receive bevacizumab-based therapy: An Eastern Cooperative Oncology Group (ECOG) study (E4508)

BACKGROUND: Preclinical evidence supports the clinical investigation of inhibitors to the insulin-like growth factor receptor (IGFR) and the epidermal growth factor receptor (EGFR) either alone or in combination as treatment for patients with non-small cell lung cancer (NSCLC). METHODS: Patients with chemotherapy-naïve, advanced NSCLC who had an Eastern Cooperative Oncology Group performance status of 0 or 1 were eligible. Patients were randomized to receive carboplatin intravenously at an area under the plasma drug concentration-time curve of 6.0 plus paclitaxel 200 mg/m(2) intravenously on day 1 every 3 weeks combined with either intravenous cetuximab weekly (arm A), intravenous cixutumumab every 2 weeks (arm B), or both (arm C). Patients who had nonprogessing disease after 12 weeks of therapy were permitted to continue on maintenance antibody therapy until they developed progressive disease. The primary endpoint was progression-free survival (PFS). The study design required 180 eligible patients and had 88% power to detect a 60% increase in median PFS for either comparison (arm A vs arm C or arm B vs arm C) using the log-rank test. RESULTS: From September 2009 to December 2010, 140 patients were accrued. The study was closed to accrual early because of an excessive number of grade 5 events reported on arms A and C. Thirteen patients died during treatment (6 patients on arm A, 2 patients on arm B, and 5 patients on arm C), including 9 within approximately 1 month of starting therapy. The estimated median PFS for arms A, B, and C were similar at 3.4 months, 4.2 months, and 4 months, respectively. CONCLUSIONS: On the basis of the apparent lack of efficacy and excessive premature deaths, the current results do not support the continued investigation of carboplatin, paclitaxel, and cixutumumab either alone or in combination with cetuximab for patients with advanced NSCLC

Macrophage-Engineered Vesicles for Therapeutic Delivery and Bidirectional Reprogramming of Immune Cell Polarization

Macrophages, one of the most important phagocytic cells of the immune system, are highly plastic and are known to exhibit diverse roles under different pathological conditions. The ability to repolarize macrophages from pro-inflammatory (M1) to anti-inflammatory (M2) or vice versa offers a promising therapeutic approach for treating various diseases such as traumatic injury and cancer. Herein, it is demonstrated that macrophage-engineered vesicles (MEVs) generated by disruption of macrophage cellular membranes can be used as nanocarriers capable of reprogramming macrophages and microglia toward either pro- or anti-inflammatory phenotypes. MEVs can be produced at high yields and easily loaded with diagnostic molecules or chemotherapeutics and delivered to both macrophages and cancer cells in vitro and in vivo. Overall, MEVs show promise as potential delivery vehicles for both therapeutics and their ability to controllably modulate macrophage/microglia inflammatory phenotypes

The NQO1*2/*2 polymorphism is associated with poor overall survival in patients following resection of stages II and IIIa non-small cell lung cancer

NAD(P)H:quinone oxidoreductase 1 (NQO1), is a cytosolic flavoenzyme that catalyzes the two-electron reduction of quinones into hydroquinones. A polymorphism (NQO1*2) alters enzymatic activity of NQO1 resulting in diminished NQO1 activity. Malignancies with NQO1*2 may be resistant to radiation and chemotherapy with resulting poorer survival. NQO1 allele was evaluated in subjects enrolled in ECOG 3590, a randomized comparison of radiation (RT) vs radiation and chemotherapy with cisplatin/etoposide (RCT) in patients with completely resected stages II and IIIa NSCLC. Overall survival was estimated using the Kaplan-Meier method and compared via the log-rank test. Cox models were used to assess the impact of covariates on outcomes. Among 152 patients with assessable samples, 24 (16%) had NQO1*2. Median follow-up was 139 months. The presence of NQO1*2/*2 was associated with decreased overall survival (OS) (median in the heterozygote/wild-type group 42.3 vs. 33.5 months in the variant group, p=0.04). In a multivariable Cox model, variant NQO1 (HR=1.58, p=0.05), age <60 (HR=0.67, p=0.04), PS 1 (HR=1.47, p=0.05), cardiovascular disease (HR=1.93, p=0.003) and alkaline phosphatase <100 mg/ml (HR=0.59, p=0.005) were all significant predictors of OS. NQO1*2/*2 may be an independent predictor of poor overall survival in individuals with resected stages II and IIIa NSCLC. Although the basis for the NQO1 association with decreased survival requires additional evaluation, NQO1 may represent a biomarker for guiding individualized therapy

A Phase I Dose Escalation and Expansion Study of Epidiolex (Cannabidiol) in Patients with Biochemically Recurrent Prostate Cancer

Purpose: Cannabinoids (CBD) have anti-tumor activity against prostate cancer (PCa). Preclinical studies have demonstrated a significant decrease in prostate specific antigen (PSA) protein expression and reduced tumor growth in xenografts of LNCaP and DU-145 cells in athymic mice when treated with CBD. Over-the-counter CBD products may vary in activity without clear standardization, and Epidiolex is a standardized FDA-approved oral CBD solution for treatment of certain types of seizures. We aimed to assess the safety and preliminary anti-tumor activity of Epidiolex in patients with biochemically recurrent (BCR) PCa. Experimental design: This was an open-label, single center, phase I dose escalation study followed by a dose expansion in BCR patients after primary definitive local therapy (prostatectomy +/− salvage radiotherapy or primary definitive radiotherapy). Eligible patients were screened for urine tetrahydrocannabinol prior to enrollment. The starting dose level of Epidiolex was 600 mg by mouth once daily and escalated to 800 mg daily with the use of a Bayesian optimal interval design. All patients were treated for 90 days followed by a 10-day taper. The primary endpoints were safety and tolerability. Changes in PSA, testosterone levels, and patient-reported health-related quality of life were studied as secondary endpoints. Results: Seven patients were enrolled into the dose escalation cohort. There were no dose-limiting toxicities at the first two dose levels (600 mg and 800 mg). An additional 14 patients were enrolled at the 800 mg dose level into the dose expansion cohort. The most common adverse events were 55% diarrhea (grade 1–2), 25% nausea (grade 1–2), and 20% fatigue (grade 1–2). The mean PSA at baseline was 2.9 ng/mL. At the 12-week landmark time-point, 16 out of 18 (88%) had stable biochemical disease, one (5%) had partial biochemical response with the greatest measurable decline being 41%, and one (5%) had PSA progression. No statistically significant changes were observed in patient-reported outcomes (PROs), but PROs changed in the direction of supporting the tolerability of Epidiolex (e.g., emotional functioning improved). Conclusion: Epidiolex at a dose of 800 mg daily appears to be safe and tolerable in patients with BCR prostate cancer supporting a safe dose for future studies