A phase II study of temsirolimus and liposomal doxorubicin for patients with recurrent and refractory bone and soft tissue sarcomas

Background Relapsed and refractory sarcomas continue to have poor survival rates. The cancer stem cell (CSC) theory provides a tractable explanation for the observation that recurrences occur despite dramatic responses to upfront chemotherapy. Preclinical studies demonstrated that inhibition of the mechanistic target of rapamycin (mTOR) sensitizes the CSC population to chemotherapy. Methods Here we present the results of the Phase II portion of a Phase I/II clinical trial that aimed to overcome the chemoresistance of sarcoma CSC by combining the mTOR inhibitor temsirolimus (20 mg/m2 weekly) with the chemotherapeutic agent liposomal doxorubicin (30 mg/m2 monthly). Results Fifteen patients with relapsed/refractory sarcoma were evaluable at this recommended Phase 2 dose level. The median progression free survival was 315 days (range 27–799). Response rate, defined as stable disease or better for 60 days, was 53%. Nine of the patients had been previously treated with doxorubicin. Therapy was well tolerated. In a small number of patients, pre- and post- treatment tumor biopsies were available for assessment of ALDH expression as a marker of CSCs and showed a correlation between response and decreased ALDH expression. We also found a correlation between biopsy-proven inhibition of mTOR and response. Conclusions Our study adds to the literature supporting the addition of mTOR inhibition to chemotherapy agents for the treatment of sarcomas, and proposes that a mechanism by which mTOR inhibition enhances the efficacy of chemotherapy may be through sensitizing the chemoresistant CSC population. Further study, ideally with pre- and post-therapy assessment of ALDH expression in tumor cells, is warranted. Trial registration The trial was registered on clinicaltrials.gov (NCT00949325) on 30 July 2009. http://www.editorialmanager.com/csrj/default.asp

Braveheart, a Long Noncoding RNA Required for Cardiovascular Lineage Commitment

Long noncoding RNAs (lncRNAs) are often expressed in a development-specific manner, yet little is known about their roles in lineage commitment. Here, we identified Braveheart (Bvht), a heart-associated lncRNA in mouse. Using multiple embryonic stem cell (ESC) differentiation strategies, we show that Bvht is required for progression of nascent mesoderm toward a cardiac fate. We find that Bvht is necessary for activation of a core cardiovascular gene network and functions upstream of mesoderm posterior 1 (MesP1), a master regulator of a common multipotent cardiovascular progenitor. We also show that Bvht interacts with SUZ12, a component of polycomb-repressive complex 2 (PRC2), during cardiomyocyte differentiation, suggesting that Bvht mediates epigenetic regulation of cardiac commitment. Finally, we demonstrate a role for Bvht in maintaining cardiac fate in neonatal cardiomyocytes. Together, our work provides evidence for a long noncoding RNA with critical roles in the establishment of the cardiovascular lineage during mammalian development.Damon Runyon Cancer Research Foundation (DRG 2032-09)Damon Runyon Cancer Research Foundation (DFS 04-12)European Molecular Biology Organization (Long-term Fellowship)National Heart, Lung, and Blood Institute. Bench to Bassinet Program (U01HL098179)National Heart, Lung, and Blood Institute. Bench to Bassinet Program (U01HL098188)Smith Family FoundationPew Charitable Trusts. Program in the Biomedical Science

A pragmatic approach to managing antiretroviral therapy-experienced patients diagnosed with HIV-associated cryptococcal meningitis: impact of antiretroviral therapy adherence and duration

Cryptococcal meningitis accounts for 15% of all HIV-related deaths [1]. The overall number of cryptococcal meningitis cases has remained relatively stable in many low-to-middle income countries (LMICs) despite increasing roll-out of antiretroviral therapy (ART). Increasing numbers of patients are at risk of developing cryptococcal meningitis following ART failure or discontinuation, offsetting declines in those presenting for the first time with advanced HIV [2–4]. Over half of patients diagnosed with cryptococcal meningitis in recent studies in sub-Saharan Africa are ART-experienced (i.e. currently receiving or previously received ART) [5,6]. Although there is robust evidence from prospective randomized trials that ART initiation should be delayed until 4–6 weeks after starting antifungal therapy in ART-naïve cryptococcal meningitis patients [7,8], the approach to ART management among ART-experienced cryptococcal meningitis patients lacks adequate evidence, with a paucity of published data

H2A.Z Acidic Patch Couples Chromatin Dynamics to Regulation of Gene Expression Programs during ESC Differentiation

The histone H2A variant H2A.Z is essential for embryonic development and for proper control of developmental gene expression programs in embryonic stem cells (ESCs). Divergent regions of amino acid sequence of H2A.Z likely determine its functional specialization compared to core histone H2A. For example, H2A.Z contains three divergent residues in the essential C-terminal acidic patch that reside on the surface of the histone octamer as an uninterrupted acidic patch domain; however, we know little about how these residues contribute to chromatin structure and function. Here, we show that the divergent amino acids Gly92, Asp97, and Ser98 in the H2A.Z C-terminal acidic patch (H2A.Z[superscript AP3]) are critical for lineage commitment during ESC differentiation. H2A.Z is enriched at most H3K4me3 promoters in ESCs including poised, bivalent promoters that harbor both activating and repressive marks, H3K4me3 and H3K27me3 respectively. We found that while H2A.Z[superscript AP3] interacted with its deposition complex and displayed a highly similar distribution pattern compared to wild-type H2A.Z, its enrichment levels were reduced at target promoters. Further analysis revealed that H2A.Z[superscript AP3] was less tightly associated with chromatin, suggesting that the mutant is more dynamic. Notably, bivalent genes in H2A.Z[superscript AP3] ESCs displayed significant changes in expression compared to active genes. Moreover, bivalent genes in H2A.Z[superscript AP3] ESCs gained H3.3, a variant associated with higher nucleosome turnover, compared to wild-type H2A.Z. We next performed single cell imaging to measure H2A.Z dynamics. We found that H2A.Z[superscript AP3] displayed higher mobility in chromatin compared to wild-type H2A.Z by fluorescent recovery after photobleaching (FRAP). Moreover, ESCs treated with the transcriptional inhibitor flavopiridol resulted in a decrease in the H2A.Z[superscript AP3] mobile fraction and an increase in its occupancy at target genes indicating that the mutant can be properly incorporated into chromatin. Collectively, our work suggests that the divergent residues in the H2A.Z acidic patch comprise a unique domain that couples control of chromatin dynamics to the regulation of developmental gene expression patterns during lineage commitment.Massachusetts Life Sciences Center (David H. Koch Institute for Integrative Cancer Research at MIT Core Grant P30-CA14051)National Science Foundation (U.S.). Emergent Behaviors of Integrated Cellular Systems (Grant CBET-0939511)MIT Faculty Start-up FundMassachusetts Institute of Technology. Computational and Systems Biology Initiative (Merck & Co. Postdoctoral Fellowship

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

Braveheart, a Long Noncoding RNA Required for Cardiovascular Lineage Commitment

Long noncoding RNAs (lncRNAs) are often expressed in a development-specific manner, yet little is known about their roles in lineage commitment. Here, we identified Braveheart (Bvht), a heart-associated lncRNA in mouse. Using multiple embryonic stem cell (ESC) differentiation strategies, we show that Bvht is required for progression of nascent mesoderm toward a cardiac fate. We find that Bvht is necessary for activation of a core cardiovascular gene network and functions upstream of mesoderm posterior 1 (MesP1), a master regulator of a common multipotent cardiovascular progenitor. We also show that Bvht interacts with SUZ12, a component of polycomb-repressive complex 2 (PRC2), during cardiomyocyte differentiation, suggesting that Bvht mediates epigenetic regulation of cardiac commitment. Finally, we demonstrate a role for Bvht in maintaining cardiac fate in neonatal cardiomyocytes. Together, our work provides evidence for a long noncoding RNA with critical roles in the establishment of the cardiovascular lineage during mammalian development.Stem Cell and Regenerative Biolog

Cost-effectiveness of single, high-dose, liposomal amphotericin regimen for HIV-associated cryptococcal meningitis in five countries in sub-Saharan Africa: an economic analysis of the AMBITION-cm trial

BackgroundHIV-associated cryptococcal meningitis is a leading cause of AIDS-related mortality. The AMBITION-cm trial showed that a regimen based on a single high dose of liposomal amphotericin B deoxycholate (AmBisome group) was non-inferior to the WHO-recommended treatment of seven daily doses of amphotericin B deoxycholate (control group) and was associated with fewer adverse events. We present a five-country cost-effectiveness analysis.MethodsThe AMBITION-cm trial enrolled patients with HIV-associated cryptococcal meningitis from eight hospitals in Botswana, Malawi, South Africa, Uganda, and Zimbabwe. Taking a health service perspective, we collected country-specific unit costs and individual resource-use data per participant over the 10-week trial period, calculating mean cost per participant by group, mean cost-difference between groups, and incremental cost-effectiveness ratio per life-year saved. Non-parametric bootstrapping and scenarios analyses were performed including hypothetical real-world resource use. The trial registration number is ISRCTN72509687, and the trial has been completed.FindingsThe AMBITION-cm trial enrolled 844 participants, and 814 were included in the intention-to-treat analysis (327 from Uganda, 225 from Malawi, 107 from South Africa, 84 from Botswana, and 71 from Zimbabwe) with 407 in each group, between Jan 31, 2018, and Feb 17, 2021. Using Malawi as a representative example, mean total costs per participant were US$1369 (95$1237 (1181-1293) in the control group. The incremental cost-effectiveness ratio was $128 (59-257) per life-year saved. Excluding study protocol-driven cost, using a real-world toxicity monitoring schedule, the cost per life-year saved reduced to$80 (15-275). Changes in the duration of the hospital stay and antifungal medication cost showed the greatest effect in sensitivity analyses. Results were similar across countries, with the cost per life-year saved in the real-world scenario ranging from $71 in Botswana to$121 in Uganda.InterpretationThe AmBisome regimen was cost-effective at a low incremental cost-effectiveness ratio. The regimen might be even less costly and potentially cost-saving in real-world implementation given the lower drug-related toxicity and the potential for shorter hospital stays.FundingEuropean Developing Countries Clinical Trials Partnership, Swedish International Development Cooperation Agency, Wellcome Trust and Medical Research Council, UKAID Joint Global Health Trials, and the National Institute for Health Research.TranslationsFor the Chichewa, Isixhosa, Luganda, Setswana and Shona translations of the abstract see Supplementary Materials section