Pharmacogenomic synthetic lethal screens reveal hidden vulnerabilities and new therapeutic approaches for treatment of NF1-associated tumors.

Neurofibromatosis Type 1 (NF1) is a common cancer predisposition syndrome, caused by heterozygous loss of function mutations in the tumor suppressor gene . Individuals with NF1 develop benign tumors of the peripheral nervous system (neurofibromas), originating from the Schwann cell linage after somatic loss of the wild type allele, some of which progress further to malignant peripheral nerve sheath tumors (MPNST). There is only one FDA approved targeted therapy for symptomatic plexiform neurofibromas and none approved for MPNST.

Cryopreserved leukapheresis material can be transferred from controlled rate freezers to ultracold storage at warmer temperatures without affecting downstream CAR-T cell culture performance and in-vitro functionality.

Chimeric antigen receptor (CAR) T-cell therapies are increasingly adopted as a commercially available treatment for hematologic and solid tumor cancers. As CAR-T therapies reach more patients globally, the cryopreservation and banking of patients' leukapheresis materials is becoming imperative to accommodate intra/inter-national shipping logistical delays and provide greater manufacturing flexibility. This study aims to determine the optimal temperature range for transferring cryopreserved leukapheresis materials from two distinct types of controlled rate freezing systems, Liquid Nitrogen (LN2)-based and LN2-free Conduction Cooling-based, to the ultracold LN2 storage freezer (≤-135 °C), and its impact on CAR T-cell production and functionality.

Long-term outcomes and predictors of early response, late relapse, and survival for patients treated with bispecific LV20.19 CAR T-cells.

We previously reported results of a first-in-human trial of bispecific LV20.19 chimeric antigen receptor T-cell (CAR-T) therapy, demonstrating high response rates in patients with relapsed, refractory (R/R) B-cell malignancies. We now report two-year survival outcomes and predictors of early response, late relapse, and survival.

Bispecific targeting of CD20 and CD19 increases polyfunctionality of chimeric antigen receptor T-cell products in B-cell malignancies.

Background Aims: Selective immune pressure contributes to relapse due to target antigen downregulation in patients treated with anti-CD19 chimeric antigen receptor (CAR) T cells. Bispecific lentiviral anti-CD20/anti-CD19 (LV20.19) CAR T cells may prevent progression/relapse due to antigen escape.

P2RY14 cAMP signaling regulates Schwann cell precursor self-renewal, proliferation, and nerve tumor initiation in a mouse model of neurofibromatosis.

Neurofibromatosis type 1 (NF1) is characterized by nerve tumors called neurofibromas, in which Schwann cells (SCs) show deregulated RAS signaling. NF1 is also implicated in regulation of cAMP. We identified the G-protein-coupled receptor (GPCR) P2ry14 in human neurofibromas, neurofibroma-derived SC precursors (SCPs), mature SCs, and mouse SCPs.

WNT5A inhibition alters the malignant peripheral nerve sheath tumor microenvironment and enhances tumor growth.

Malignant peripheral nerve sheath tumors (MPNST) are aggressive soft-tissue sarcomas that cause significant mortality in adults with neurofibromatosis type 1. We compared gene expression of growth factors in normal human nerves to MPNST and normal human Schwann cells to MPNST cell lines. We identified WNT5A as the most significantly upregulated ligand-coding gene and verified its protein expression in MPNST cell lines and tumors.

Loss in a Model of Neurofibroma Demonstrates Stepwise Tumor Progression to Atypical Neurofibroma and MPNST.

Plexiform neurofibromas are benign nerve sheath Schwann cell tumors characterized by biallelic mutations in the neurofibromatosis type 1 (NF1) tumor suppressor gene. Atypical neurofibromas show additional frequent loss of CDKN2A/Ink4a/Arf and may be precursor lesions of aggressive malignant peripheral nerve sheath tumors (MPNST). Here we combined loss of Nf1 in developing Schwann cells with global Ink4a/Arf loss and identified paraspinal plexiform neurofibromas and atypical neurofibromas.

A molecular basis for neurofibroma-associated skeletal manifestations in NF1.

Purpose: Plexiform neurofibromas (pNF) develop in children with neurofibromatosis type 1 (NF1) and can be associated with several skeletal comorbidities. Preclinical mouse studies revealed Nf1 deficiency in osteoprogenitor cells disrupts, in a MEK-dependent manner, pyrophosphate (PPi) homeostasis and skeletal mineralization. The etiology of NF-associated skeletal manifestations remains unknown.

Polo-like kinase 1 as a therapeutic target for malignant peripheral nerve sheath tumors (MPNST) and schwannomas.

Neurofibromatosis type 1 (NF1) and Neurofibromatosis type 2 (NF2) are two dominantly inherited disorders that cause tumors in Schwann cells. NF1 patients have a high risk for malignant peripheral nerve sheath tumors (MPNST), which are often inoperable and do not respond well to current chemotherapies or radiation. NF2 patients have a high risk for schwannomas.

Targeted Inhibition of the Dual Specificity Phosphatases DUSP1 and DUSP6 Suppress MPNST Growth via JNK.

Purpose: In neurofibromatosis type 1 (NF1) and in highly aggressive malignant peripheral nerve sheath tumors (MPNSTs), constitutively active RAS-GTP and increased MAPK signaling are important in tumorigenesis. Dual specificity phosphatases (DUSPs) are negative regulators of MAPK signaling that dephosphorylate p38, JNK, and ERK in different settings. Although often acting as tumor suppressors, DUSPs may also act as oncogenes, helping tumor cells adapt to high levels of MAPK signaling.

Tonic ATP-mediated growth suppression in peripheral nerve glia requires arrestin-PP2 and is evaded in NF1.

Normal Schwann cells (SCs) are quiescent in adult nerves, when ATP is released from the nerve in an activity dependent manner. We find that suppressing nerve activity in adult nerves causes SC to enter the cell cycle. In vitro, ATP activates the SC G-protein coupled receptor (GPCR) P2Y2.

Aurora A kinase inhibition enhances oncolytic herpes virotherapy through cytotoxic synergy and innate cellular immune modulation.

Malignant peripheral nerve sheath tumor (MPNST) and neuroblastoma models respond to the investigational small molecule Aurora A kinase inhibitor, alisertib. We previously reported that MPNST and neuroblastomas are also susceptible to oncolytic herpes virus (oHSV) therapy. Herein, we show that combination of alisertib and HSV1716, a virus derived from HSV-1 and attenuated by deletion of RL1, exhibits significantly increased antitumor efficacy compared to either monotherapy.

CK2 blockade causes MPNST cell apoptosis and promotes degradation of β-catenin.

Malignant peripheral nerve sheath tumors (MPNSTs) are soft tissue sarcomas that are a major cause of mortality of Neurofibromatosis type 1 (NF1) patients. MPNST patients have few therapeutic options available and only complete surgical resection can be curative. MPNST formation and survival are dependent on activated β-catenin signaling.

An ShRNA Screen Identifies MEIS1 as a Driver of Malignant Peripheral Nerve Sheath Tumors.

Malignant peripheral nerve sheath tumors (MPNST) are rare soft tissue sarcomas that are a major source of mortality in neurofibromatosis type 1 (NF1) patients. To identify MPNST driver genes, we performed a lentiviral short hairpin (sh) RNA screen, targeting all 130 genes up-regulated in neurofibroma and MPNSTs versus normal human nerve Schwann cells. NF1 mutant cells show activation of RAS/MAPK signaling, so a counter-screen in RAS mutant carcinoma cells was performed to exclude common RAS-pathway driven genes.