Polyglutamine-expanded androgen receptor interferes with TFEB to elicit autophagy defects in SBMA.

Macroautophagy (hereafter autophagy) is a key pathway in neurodegeneration. Despite protective actions, autophagy may contribute to neuron demise when dysregulated. Here we consider X-linked spinal and bulbar muscular atrophy (SBMA), a repeat disorder caused by polyglutamine-expanded androgen receptor (polyQ-AR). We found that polyQ-AR reduced long-term protein turnover and impaired autophagic flux in motor neuron-like cells. Ultrastructural analysis of SBMA mice revealed a block in autophagy pathway progression. We examined the transcriptional regulation of autophagy and observed a functionally significant physical interaction between transcription factor EB (TFEB) and AR. Normal AR promoted, but polyQ-AR interfered with, TFEB transactivation. To evaluate physiological relevance, we reprogrammed patient fibroblasts to induced pluripotent stem cells and then to neuronal precursor cells (NPCs). We compared multiple SBMA NPC lines and documented the metabolic and autophagic flux defects that could be rescued by TFEB. Our results indicate that polyQ-AR diminishes TFEB function to impair autophagy and promote SBMA pathogenesis

Kank Is an EB1 Interacting Protein that Localises to Muscle-Tendon Attachment Sites in Drosophila

Little is known about how microtubules are regulated in different cell types during development. EB1 plays a central role in the regulation of microtubule plus ends. It directly binds to microtubule plus ends and recruits proteins which regulate microtubule dynamics and behaviour. We report the identification of Kank, the sole Drosophila orthologue of human Kank proteins, as an EB1 interactor that predominantly localises to embryonic attachment sites between muscle and tendon cells. Human Kank1 was identified as a tumour suppressor and has documented roles in actin regulation and cell polarity in cultured mammalian cells. We found that Drosophila Kank binds EB1 directly and this interaction is essential for Kank localisation to microtubule plus ends in cultured cells. Kank protein is expressed throughout fly development and increases during embryogenesis. In late embryos, it accumulates to sites of attachment between muscle and epidermal cells. A kank deletion mutant was generated. We found that the mutant is viable and fertile without noticeable defects. Further analysis showed that Kank is dispensable for muscle function in larvae. This is in sharp contrast to C. elegans in which the Kank orthologue VAB-19 is required for development by stabilising attachment structures between muscle and epidermal cells

Clinical trials of CAR-T cells in China

Abstract Novel immunotherapeutic agents targeting tumor-site microenvironment are revolutionizing cancer therapy. Chimeric antigen receptor (CAR)-engineered T cells are widely studied for cancer immunotherapy. CD19-specific CAR-T cells, tisagenlecleucel, have been recently approved for clinical application. Ongoing clinical trials are testing CAR designs directed at novel targets involved in hematological and solid malignancies. In addition to trials of single-target CAR-T cells, simultaneous and sequential CAR-T cells are being studied for clinical applications. Multi-target CAR-engineered T cells are also entering clinical trials. T cell receptor-engineered CAR-T and universal CAR-T cells represent new frontiers in CAR-T cell development. In this study, we analyzed the characteristics of CAR constructs and registered clinical trials of CAR-T cells in China and provided a quick glimpse of the landscape of CAR-T studies in China

Identification of factors that function in Drosophila salivary gland cell death during development using proteomics

Proteasome inhibitors induce cell death and are used in cancer therapy, but little is known about the relationship between proteasome impairment and cell death under normal physiological conditions. Here, we investigate the relationship between proteasome function and larval salivary gland cell death during development in Drosophila. Drosophila larval salivary gland cells undergo synchronized programmed cell death requiring both caspases and autophagy (Atg) genes during development. Here, we show that ubiquitin proteasome system (UPS) function is reduced during normal salivary gland cell death, and that ectopic proteasome impairment in salivary gland cells leads to early DNA fragmentation and salivary gland condensation in vivo. Shotgun proteomic analyses of purified dying salivary glands identified the UPS as the top category of proteins enriched, suggesting a possible compensatory induction of these factors to maintain proteolysis during cell death. We compared the proteome following ectopic proteasome impairment to the proteome during developmental cell death in salivary gland cells. Proteins that were enriched in both populations of cells were screened for their function in salivary gland degradation using RNAi knockdown. We identified several factors, including trol, a novel gene CG11880, and the cop9 signalsome component cop9 signalsome 6, as required for Drosophila larval salivary gland degradation

ENGAGE- 501: phase II study of entinostat (SNDX-275) in relapsed and refractory Hodgkin lymphoma

Classical Hodgkin lymphoma treatment is evolving rapidly with high response rates from antibody-drug conjugates targeting CD30 and immune checkpoint antibodies. However, most patients do not achieve a complete response, therefore development of novel therapies is warranted to improve patient outcomes. In this phase II study, patients with relapsed or refractory Hodgkin lymphoma were treated with entinostat, an isoform selective histone deacetylase inhibitor. Forty-nine patients were enrolled: 33 patients on Schedule A (10 or 15 mg oral entinostat once every other week); 16 patients on Schedule B (15 mg oral entinostat once weekly in 3 of 4 weeks). Patients received a median of 3 prior treatments (range 1–10), with 80% of the patients receiving a prior stem cell transplant and 8% of patients receiving prior brentuximab vedotin. In the intention-to-treat analysis, the overall response rate was 12% while the disease control rate (complete response, partial response, and stable disease beyond 6 months) was 24%. Seven patients did not complete the first cycle due to progression of disease. Tumor reduction was observed in 24 of 38 (58%) evaluable patients. Median progression-free survival and overall survival was 5.5 and 25.1 months, respectively. The most frequent grade 3 or 4 adverse events were thrombocytopenia (63%), anemia (47%), neutropenia (41%), leukopenia (10%), hypokalemia (8%), and hypophosphatemia (6%). Twenty-five (51%) patients required dose reductions or delays. Pericarditis/pericardial effusion occurred in one patient after 12 cycles of therapy. Future studies are warranted to identify predictive biomarkers for treatment response and to develop mechanism-based combination strategies. (clinicaltrials.gov identifier: 00866333

Polyglutamine-expanded androgen receptor interferes with TFEB to elicit autophagy defects in SBMA.

Macroautophagy (hereafter autophagy) is a key pathway in neurodegeneration. Despite protective actions, autophagy may contribute to neuron demise when dysregulated. Here we consider X-linked spinal and bulbar muscular atrophy (SBMA), a repeat disorder caused by polyglutamine-expanded androgen receptor (polyQ-AR). We found that polyQ-AR reduced long-term protein turnover and impaired autophagic flux in motor neuron-like cells. Ultrastructural analysis of SBMA mice revealed a block in autophagy pathway progression. We examined the transcriptional regulation of autophagy and observed a functionally significant physical interaction between transcription factor EB (TFEB) and AR. Normal AR promoted, but polyQ-AR interfered with, TFEB transactivation. To evaluate physiological relevance, we reprogrammed patient fibroblasts to induced pluripotent stem cells and then to neuronal precursor cells (NPCs). We compared multiple SBMA NPC lines and documented the metabolic and autophagic flux defects that could be rescued by TFEB. Our results indicate that polyQ-AR diminishes TFEB function to impair autophagy and promote SBMA pathogenesis

ABCL-185 Mosunetuzumab with Polatuzumab Vedotin: Subgroup Analyses in Patients (pts) With Primary Refractory or Early Relapsed Large B-Cell Lymphoma (LBCL)

Mosunetuzumab with polatuzumab vedotin (mosun-pola; investigational off-label use) in the phase Ib/II study (NCT03671018), demonstrated durable responses and manageable safety in pts with relapsed/refractory, transplant-ineligible LBCL. Present results for primary refractory (refr) or early relapse (rel) subgroups from NCT03671018 after a median follow-up of 23.9 months. Pts with relapsed/refractory LBCL (diffuse LBCL not otherwise specified [NOS], high-grade B-cell lymphoma [HGBCL], transformed FL, and FL grade 3b) and who received ≥1 prior line of therapy (including an anti-CD20 antibody) were treated with mosun-pola. Refr defined as SD, PD, PR, or CR with relapse <3 months after 1L therapy. Rel defined as CR with relapse ≥3 and ≤12 months after 1L therapy. The primary endpoint was best ORR by IRC using Lugano 2014 response criteria. Key secondary endpoints included CR rate, duration of response (DOR), duration of CR (DOCR), PFS, OS, and safety. All patients provided informed consent. As of July 6, 2023, of the 98 pts in the overall population, 45 (46%) and 27 (28%) pts had refr or rel LBCL, respectively. At baseline, the median age in the refr and rel subgroups was 68 and 70 years, respectively; 23/45 pts (51%) and 6/27 pts (22%) were treated with 2L mosun-pola, respectively. The majority of refr/rel pts had DLBCL NOS (71%; 78%) or HGBCL (24%; 19%). In refr pts, the ORR (49%), CR (36%), and median PFS (8.1 [4.8-16.5] months) were generally consistent with the overall population (ORR: 59%; CR: 46%; PFS: 11.4 [6.2-18.7] months); although the sample size was limited, higher responses (ORR: 74%; CR: 59%) and PFS (12.7 [8.8-NE] months) were observed in rel pts. The safety profile was consistent with the overall population. Grade 3 CRS occurred in one pt in each subgroup. Treatment-related ICANS-like events occurred in 2/45 pts (4%; refr) and 3/27 pts (11%; rel). Mosun-pola demonstrated durable benefits in ORR and CR rates irrespective of a poor response to 1L treatment. Copyright: © 2024 American Society of Clinical Oncology, Inc. Reused with permission. This abstract was accepted and previously presented at the 2024 ASCO Annual Meeting. All rights reserved