The prognosis for metastatic sarcoma in children remains bleak. Cellular immunotherapy with chimeric antigen receptor T cells (CAR-T) can be a suitable approach for these hard-to-treat cancers. ...However, a paucity of relevant tumor-associated antigens exists in sarcoma, limiting their therapeutic potential. We describe the creation of a novel CAR-T against the surface protein endoglin (ENG, CD105), a TGF-β co-receptor, expresed on sarcomas. We identified ENG as a significant target of endogenous immune reactivity in an exceptional responder with metastatic sarcoma, after co-administration of HER2 CAR-T and lymphodepletion chemotherapy in our clinical study NCT00902044. We aim to target the broad expression of ENG on cancer cells, neovascular endothelial cells and cancer-associated fibroblasts in sarcomas using endoglin-directed CAR-T (ENG CAR-T).
To target ENG, we engineered iterations of second-generation CAR molecules combining the anti-ENG mAb c-SN6j, the intracellular signaling domain (ICD) derived from the CD28-, 41BB- or OX40-molecules and the CD3-ζ activating domain. Retroviral transduction was used to express the ENG CAR molecules on primary human T cells. The functional assessments for the ENG CAR-T included cytokine release, T-cell proliferation, impedance-based cytotoxicity, 3D spheroid disruption and anti-tumor efficacy in murine orthotopic xenograft models of sarcoma.
Co-culture of ENG CAR-T with sarcoma cell lines revealed the best outcomes with CD28-ICD-mediated signaling, displaying enhanced release of IFN-γ and IL-2, increased proliferation and robust cytotoxic responses in vitro. ENG CAR-T efficiently disrupted the formation of 3D spheroids in sarcoma lines, both independently and when co-cultured with fibroblast lines. In intratibial orthotopic models of osteosarcoma and Ewing sarcoma, as well as an intramuscular model of rhabdomyosarcoma, ENG-CART exhibited potent anti-tumor activity, extending survival rates in mice and delaying metastasis. In conclusion, the results suggest that the novel ENG CAR-T demonstrates anti-tumor activity in experimental models of advanced sarcomas
The RAS family of proto-oncogenes are among the most commonly mutated genes in human cancers and predict poor clinical outcome. Several mechanisms underlying oncogenic RAS transformation are well ...documented, including constitutive signaling through the RAF-MEK-ERK proproliferative pathway as well as the PI3K-AKT prosurvival pathway. Notably, control of redox balance has also been proposed to contribute to RAS transformation. However, how homeostasis between reactive oxygen species (ROS) and antioxidants, which have opposing effects in the cell, ultimately influence RAS-mediated transformation and tumor progression is still a matter of debate and the mechanisms involved have not been fully elucidated. Here, we show that oncogenic KRAS protects fibroblasts from oxidative stress by enhancing intracellular GSH levels. Using a whole transcriptome approach,we discovered that this is attributable to transcriptional up-regulation of xCT, the gene encoding the cystine/glutamate antiporter. This is in line with the function of xCT, which mediates the uptake of cystine, a precursor for GSH biosynthesis. Moreover, our results reveal that the ETS-1 transcription factor downstream of the RAS-RAF-MEK-ERK signaling cascade directly transactivates the xCT promoter in synergy with the ATF4 endoplasmic reticulum stress-associated transcription factor. Strikingly, xCT was found to be essential for oncogenic KRAS-mediated transformation in vitro and in vivo bymitigating oxidative stress, as knockdown of xCT strongly impaired growth of tumor xenografts established from KRAS-transformed cells. Overall, this study uncovers a mechanism by which oncogenic RAS preserves intracellular redox balance and identifies an unexpected role for xCT in supporting RAS-induced transformation and tumorigenicity.
Atypical teratoid/rhabdoid tumors (ATRTs) typically arise in the central nervous system (CNS) of children under 3 years of age. Despite intensive multimodal therapy (surgery, chemotherapy and, if age ...permits, radiotherapy), median survival is 17 months
. We show that ATRTs robustly express B7-H3/CD276 that does not result from the inactivating mutations in SMARCB1 (refs.
), which drive oncogenesis in ATRT, but requires residual SWItch/Sucrose Non-Fermentable (SWI/SNF) activity mediated by BRG1/SMARCA4. Consistent with the embryonic origin of ATRT
, B7-H3 is highly expressed on the prenatal, but not postnatal, brain. B7-H3.BB.z-chimeric antigen receptor (CAR) T cells administered intracerebroventricularly or intratumorally mediate potent antitumor effects against cerebral ATRT xenografts in mice, with faster kinetics, greater potency and reduced systemic levels of inflammatory cytokines compared to CAR T cells administered intravenously. CAR T cells administered ICV also traffic from the CNS into the periphery; following clearance of ATRT xenografts, B7-H3.BB.z-CAR T cells administered intracerebroventricularly or intravenously mediate antigen-specific protection from tumor rechallenge, both in the brain and periphery. These results identify B7-H3 as a compelling therapeutic target for this largely incurable pediatric tumor and demonstrate important advantages of locoregional compared to systemic delivery of CAR T cells for the treatment of CNS malignancies.
Background
Traumatic brain injury (TBI) with isolated subarachnoid hemorrhage (iSAH) is a common finding in the emergency department. In many centers, a repeat CT scan is routinely performed 24 to72 ...h following the trauma to rule out further radiological progression. The aim of this study is to assess the clinical utility of the repeat CT scan in clinical practice.
Methods
We reviewed the medical charts of all patients who presented to our institution with mild TBI (mTBI) and isolated SAH between January 2015 and October 2017. CT scan at admission and control after 24 to 72 h were examined for each patient in order to detect any possible change. Neurological deterioration, antiplatelet/anticoagulant therapy, coagulopathy, SAH location, associated injuries, and length of stay in hospital were analyzed.
Results
Of the 649 TBI patients, 106 patients met the inclusion criteria. Fifty-four patients were females and 52 were males with a mean age of 68.2 years. Radiological iSAH progression was found in 2 of 106 (1.89) patients, and one of them was under antiplatelet therapy. No neurological deterioration was observed. Ten of 106 (9.4%) patients were under anticoagulation therapy, and 28 of 106 (26.4%) were under antiplatelet therapy.
Conclusion
ISAH in mTBI seems to be a radiological stable entity over 72 h with no neurological deterioration. The clinical utility of a repeat head CT in such patients is questionable, considering its radiation exposure and cost. Regardless of anticoagulation/antiplatelet therapy, neurologic observation and symptomatic treatment solely could be a reasonable alternative.
In this issue of Molecular Cell, Hofman et al.1 identify the translation of a non-canonical upstream open reading frame of the ASNSD1 gene into a microprotein that supports medulloblastoma growth.
In ...this issue of Molecular Cell, Hofman et al.1 identify the translation of a non-canonical upstream open reading frame of the ASNSD1 gene into a microprotein that supports medulloblastoma growth.
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