Strength of CAR signaling determines T cell versus ILC differentiation from pluripotent stem cells.

Generation of chimeric antigen receptor (CAR) T cells from pluripotent stem cells (PSCs) will enable advances in cancer immunotherapy. Understanding how CARs affect T cell differentiation from PSCs is important for this effort. The recently described artificial thymic organoid (ATO) system supports in vitro differentiation of PSCs to T cells. Unexpectedly, PSCs transduced with a CD19-targeted CAR resulted in diversion of T cell differentiation to the innate lymphoid cell 2 (ILC2) lineage in ATOs. T cells and ILC2s are closely related lymphoid lineages with shared developmental and transcriptional programs. Mechanistically, we show that antigen-independent CAR signaling during lymphoid development enriched for ILC2-primed precursors at the expense of T cell precursors. We applied this understanding to modulate CAR signaling strength through expression level, structure, and presentation of cognate antigen to demonstrate that the T cell-versus-ILC lineage decision can be rationally controlled in either direction, providing a framework for achieving CAR-T cell development from PSCs.

Brain Metastases from Endometrial Cancer: Clinical Characteristics, Outcomes, and Review of the Literature.

BACKGROUND: Brain metastases from endometrial cancer are rare and poorly described. We aimed to estimate the proportion of brain metastases at our institution that arose from endometrial cancer, and to detail clinicopathologic features and survival outcomes. METHODS: We retrospectively identified and reviewed the charts of 30 patients with brain metastases from endometrial cancer seen at Stanford Hospital from 2008 to 2018. RESULTS: Among all patients with brain metastases, the proportion arising from endometrial cancer was 0.84%. The median age at diagnosis was 62 years (range, 39-79 years), and the median overall survival from brain metastasis diagnosis was 6.8 months (range, 1.0-58.2 months). Most patients harbored endometrioid histology (53.3%), and some had concurrent metastases to lung (50.0%), bone (36.7%), and liver (20.0%). The median time from endometrial cancer diagnosis to brain metastasis development was 20.8 months (range, 1.4 months to 11.2 years), and the median number of brain metastases was 2 (range, 1-20). Patients with non-endometrioid histologies had more brain metastases than those with endometrioid histology (6.21 vs. 2.44, P = 0.029). There was no difference in overall survival by histology. CONCLUSIONS: We describe the largest cohort to date of patients with brain metastases originating from endometrial cancer. These patients represent a small fraction of all patients with brain metastases and have poor prognoses. These data enable providers caring for patients with brain metastases from endometrial cancer to appropriately counsel their patients.

Quality of Life of Postoperative Photon versus Proton Radiation Therapy for Oropharynx Cancer.

PURPOSE: Quality of life (QOL) for patients with oropharyngeal squamous cell cancer is negatively affected by conventional radiation (RT) owing to radiation exposure to normal tissues. Proton therapy, via pencil beam scanning (PBS), can better spare many of these tissues, and may thereby improve QOL. PATIENTS AND METHODS: Patient-reported outcomes were prospectively collected from patients treated from April 2013 to April 2015. Patients were treated with PBS or intensity-modulated radiation therapy (IMRT) via volumetric arc therapy after transoral robotic surgery. Validated QOL questionnaires were collected before RT, and 3, 6, and 12 months post RT. RESULTS: Sixty-four patients were treated with adjuvant RT after transoral robotic surgery, 33 (52%) with volumetric arc therapy, and 31 (48%) with PBS. Both groups were similar in terms of age, site, stage, and dose delivered. Patients receiving PBS had significantly less dose to many normal structures than those receiving IMRT. These dosimetric advantages with PBS were reflected in higher scores in head and neck specific, as well as general, QOL measures. Most notable was significantly less xerostomia with PBS, on multiple patient-reported outcomes at multiple timepoints (6 and 12 months). CONCLUSION: Pencil beam scanning, when compared to IMRT, confers a significant dosimetric advantage to many normal organs at risk, with a corresponding benefit in multiple patient-reported QOL parameters in patients receiving adjuvant RT for oropharyngeal squamous cell cancer.

Trim58 degrades Dynein and regulates terminal erythropoiesis.

TRIM58 is an E3 ubiquitin ligase superfamily member implicated by genome-wide association studies to regulate human erythrocyte traits. Here, we show that Trim58 expression is induced during late erythropoiesis and that its depletion by small hairpin RNAs (shRNAs) inhibits the maturation of late-stage nucleated erythroblasts to anucleate reticulocytes. Imaging flow cytometry studies demonstrate that Trim58 regulates polarization and/or extrusion of erythroblast nuclei. In vitro, Trim58 directly binds and ubiquitinates the intermediate chain of the microtubule motor dynein. In cells, Trim58 stimulates proteasome-dependent degradation of the dynein holoprotein complex. During erythropoiesis, Trim58 expression, dynein loss, and enucleation occur concomitantly, and all are inhibited by Trim58 shRNAs. Dynein regulates nuclear positioning and microtubule organization, both of which undergo dramatic changes during erythroblast enucleation. Thus, we propose that Trim58 promotes this process by eliminating dynein. Our findings identify an erythroid-specific regulator of enucleation and elucidate a previously unrecognized mechanism for controlling dynein activity.