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Medulloblastoma (MB), the most common malignant paediatric brain tumor, is currently treated using a combination of surgery, craniospinal radiotherapy and chemotherapy. Owing to MB stem cells (MBSCs), a subset of MB patients remains untreatable despite standard therapy. CD133 is used to identify MBSCs although its functional role in tumorigenesis has yet to be determined. In this work, we showed enrichment of CD133 in Group 3 MB is associated with increased rate of metastasis and poor clinical outcome. The signal transducers and activators of transcription-3 (STAT3) pathway are selectively activated in CD133 + MBSCs and promote tumorigenesis through regulation of c-MYC, a key genetic driver of Group 3 MB. We screened compound libraries for STAT3 inhibitors and treatment with the selected STAT3 inhibitors resulted in tumor size reduction in vivo . We propose that inhibition of STAT3 signaling in MBSCs may represent a potential therapeutic strategy to treat patients with recurrent MB.

Mutations in the BCR-ABL1 kinase domain are an established mechanism of tyrosine kinase inhibitor (TKI) resistance in Philadelphia chromosome-positive leukemia, but fail to explain many cases of clinical TKI failure. In contrast, it is largely unknown why some patients fail TKI therapy despite continued suppression of BCR-ABL1 kinase activity, a situation termed BCR-ABL1 kinase-independent TKI resistance. Here, we identified activation of signal transducer and activator of transcription 3 (STAT3) by extrinsic or intrinsic mechanisms as an essential feature of BCR-ABL1 kinase-independent TKI resistance. By combining synthetic chemistry, in vitro reporter assays, and molecular dynamics-guided rational inhibitor design and high-throughput screening, we discovered BP-5-087, a potent and selective STAT3 SH2 domain inhibitor that reduces STAT3 phosphorylation and nuclear transactivation. Computational simulations, fluorescence polarization assays and hydrogen–deuterium exchange assays establish direct engagement of STAT3 by BP-5-087 and provide a high-resolution view of the STAT3 SH2 domain/BP-5-087 interface. In primary cells from chronic myeloid leukemia (CML) patients with BCR-ABL1 kinase-independent TKI resistance, BP-5-087 (1.0 μ M ) restored TKI sensitivity to therapy-resistant CML progenitor cells, including leukemic stem cells. Our findings implicate STAT3 as a critical signaling node in BCR-ABL1 kinase-independent TKI resistance, and suggest that BP-5-087 has clinical utility for treating malignancies characterized by STAT3 activation.

Keywords: TKI resistance, BCR-ABL1-independent resistance, BCR-ABL1-dependent resistance, CML stem cell, STAT3, pSTAT3[sup.Y705], BP-5-087

Medulloblastoma (MB), the most common malignant paediatric brain tumor, is currently treated using a combination of surgery, craniospinal radiotherapy and chemotherapy. Owing to MB stem cells (MBSCs), a subset of MB patients remains untreatable despite standard therapy. CD133 is used to identify MBSCs although its functional role in tumorigenesis has yet to be determined. In this work, we showed enrichment of CD133 in Group 3 MB is associated with increased rate of metastasis and poor clinical outcome. The signal transducers and activators of transcription-3 (STAT3) pathway are selectively activated in CD133 super(+) MBSCs and promote tumorigenesis through regulation of c-MYC, a key genetic driver of Group 3 MB. We screened compound libraries for STAT3 inhibitors and treatment with the selected STAT3 inhibitors resulted in tumor size reduction in vivo. We propose that inhibition of STAT3 signaling in MBSCs may represent a potential therapeutic strategy to treat patients with recurrent MB.

Correction to: Leukemia (2015) 29, 586–597; doi: 10.1038/leu.2014.245 It has come to our attention that a production error made by the Journal resulted in duplication of the immunoblot image from Figure 2a into the analogous position in Figure 2b, replacing the correct image for that panel. The complete, correct version of Figure 2 as originally submitted by the authors appears below.

Mycoviruses generally contain dsRNA genomes but ssRNA and ssDNA examples are known. Mycovirus diversity is increasing, and here we describe a unique example that contains four dsRNA elements nominated Aspergillus fumigatus tetramycovirus-1 (AfuTmV-1). We show for the first time (to our knowledge) that both purified AfuTmV-1 and its dsRNA are infectious for protoplasts and that the virus genome is not conventionally encapsidated and has a unique organization. Separation of the genes encoding the RNA-dependent RNA polymerase enzyme responsible for copying the viral genome and an S -adenosyl methionine-dependent methyltransferase capping enzyme on different dsRNAs is also previously unreported for a mycovirus. AfuTmV-1 appears to be intermediate between dsRNA and positive-strand ssRNA viruses, as well as between encapsidated and capsidless RNA viruses. We report the discovery and characterization of a double-stranded RNA (dsRNA) mycovirus isolated from the human pathogenic fungus Aspergillus fumigatus , Aspergillus fumigatus tetramycovirus-1 (AfuTmV-1), which reveals several unique features not found previously in positive-strand RNA viruses, including the fact that it represents the first dsRNA (to our knowledge) that is not only infectious as a purified entity but also as a naked dsRNA. The AfuTmV-1 genome consists of four capped dsRNAs, the largest of which encodes an RNA-dependent RNA polymerase (RdRP) containing a unique GDNQ motif normally characteristic of negative-strand RNA viruses. The third largest dsRNA encodes an S -adenosyl methionine–dependent methyltransferase capping enzyme and the smallest dsRNA a P-A-S–rich protein that apparently coats but does not encapsidate the viral genome as visualized by atomic force microscopy. A combination of a capping enzyme with a picorna-like RdRP in the AfuTmV-1 genome is a striking case of chimerism and the first example (to our knowledge) of such a phenomenon. AfuTmV-1 appears to be intermediate between dsRNA and positive-strand ssRNA viruses, as well as between encapsidated and capsidless RNA viruses.

The study aimed to: (1) Identify distinct trajectories of change in depressive symptoms by mid-treatment during psychotherapy for late-life depression with executive dysfunction; (2) examine if nonresponse by mid-treatment predicted poor response at treatment end; and (3) identify baseline characteristics predicting an early nonresponse trajectory by mid-treatment. A sample of 221 adults 60 years and older with major depression and executive dysfunction were randomized to 12 weeks of either problem-solving therapy or supportive therapy. We used Latent Growth Mixture Models (LGMM) to detect subgroups with distinct trajectories of change in depression by mid-treatment (6th week). We conducted regression analyses with LGMM subgroups as predictors of response at treatment end. We used random forest machine learning algorithms to identify baseline predictors of LGMM trajectories. We found that ~77.5% of participants had a declining trajectory of depression in weeks 0–6, while the remaining 22.5% had a persisting depression trajectory, with no treatment differences. The LGMM trajectories predicted remission and response at treatment end. A random forests model with high prediction accuracy (80%) showed that the strongest modifiable predictors of the persisting depression trajectory were low perceived social support, followed by high neuroticism, low treatment expectancy, and low perception of the therapist as accepting. Our results suggest that modifiable risk factors of early nonresponse to psychotherapy can be identified at the outset of treatment and addressed with targeted personalized interventions. Therapists may focus on increasing meaningful social interactions, addressing concerns related to treatment benefits, and creating a positive working relationship.

Background Existing treatments for depression are known to have only modest effects, are insufficiently targeted, and are inconsistently utilized, particularly in older adults. Indeed, older adults with impaired cognitive control networks tend to demonstrate poor response to a majority of existing depression interventions. Cognitive control interventions delivered using entertainment software have the potential to not only target the underlying cerebral dysfunction associated with depression, but to do so in a manner that is engaging and engenders adherence to treatment protocol. Methods In this proof‐of‐concept trial (Clinicaltrials.gov #: NCT02229188), individuals with late life depression (LLD) (22; 60+ years old) were randomized to either problem solving therapy (PST, n = 10) or a neurobiologically inspired digital platform designed to enhance cognitive control faculties (Project: EVO™, n = 12). Given the overlapping functional neuroanatomy of mood disturbances and executive dysfunction, we explored the impact of an intervention targeting cognitive control abilities, functional disability, and mood in older adults suffering from LLD, and how those outcomes compare to a therapeutic gold standard. Results EVO participants demonstrated similar improvements in mood and self‐reported function after 4 weeks of treatment to PST participants. The EVO participants also showed generalization to untrained measures of working memory and attention, as well as negativity bias, a finding not evident in the PST condition. Individuals assigned to EVO demonstrated 100% adherence. Conclusions This study provides preliminary findings that this therapeutic video game targeting cognitive control deficits may be an efficacious LLD intervention. Future research is needed to confirm these findings.

Cardiovascular disease (CVD) is the leading cause of death in women worldwide. The cardiovascular risk profile deteriorates after women enter menopause. By definition, women diagnosed with premature ovarian insufficiency (POI) experience menopause before 40 years of age, which may render these women even more susceptible to develop CVD later in life. However, prospective long-term follow up data of well phenotyped women with POI are scarce. In the current study we compare the CVD profile and risk of middle aged women previously diagnosed with POI, to a population based reference group matched for age and BMI. We compared 123 women (age 49.0 (± 4.3) years) and diagnosed with POI 8.1 (IQR: 6.8-9.6) years earlier, with 123 population controls (age 49.4 (± 3.9) years). All women underwent an extensive standardized cardiovascular screening. We assessed CVD risk factors including waist circumference, BMI, blood pressure, lipid profile, pulse wave velocity (PWV), and the prevalence of diabetes mellitus, metabolic syndrome (MetS) and carotid intima media thickness (cIMT), in both women with POI and controls. We calculated the 10-year CVD Framingham Risk Score (FRS) and the American Heart Association's suggested cardiovascular health score (CHS). Waist circumference (90.0 (IQR: 83.0-98.0) versus 80.7 (IQR: 75.1-86.8), p < 0.01), waist-to-hip ratio (0.90 (IQR: 0.85-0.93) versus 0.79 (IQR: 0.75-0.83), p < 0.01), systolic blood pressure (124 (IQR 112-135) versus 120 (IQR109-131), p < 0.04) and diastolic blood pressure (81 (IQR: 76-89) versus 78 (IQR: 71-86), p < 0.01), prevalence of hypertension (45 (37%) versus 21 (17%), p < 0.01) and MetS (19 (16%) versus 4 (3%), p < 0.01) were all significantly increased in women with POI compared to healthy controls. Other risk factors, however, such as lipids, glucose levels and prevalence of diabetes were similar comparing women with POI versus controls. The arterial stiffness assessed by PWV was also similar in both populations (8.1 (IQR: 7.1-9.4) versus 7.9 (IQR: 7.1-8.4), p = 0.21). In addition, cIMT was lower in women with POI compared to controls (550 μm (500-615) versus 684 μm (618-737), p < 0.01). The calculated 10-year CVD risk was 5.9% (IQR: 3.7-10.6) versus 6.0% (IQR: 3.9-9.0) (p = 0.31) and current CHS was 6.1 (1.9) versus 6.5 (1.6) (p = 0.07), respectively in POI versus controls. Middle age women with POI presented with more unfavorable cardiovascular risk factors (increased waist circumference and a higher prevalence of hypertension and MetS) compared to age and BMI matched population controls. In contrast, the current study reveals a lower cIMT and similar 10-year cardiovascular disease risk and cardiovascular health score. In summary, neither signs of premature atherosclerosis nor a worse cardiovascular disease risk or health score were observed among middle age women with POI compared to population controls. Longer-term follow-up studies of women of more advanced age are warranted to establish whether women with POI are truly at increased risk of developing CVD events later in life. ClinicalTrials.gov Identifier: NCT02616510.