A High-Throughput Screening Platform Identifies Novel Combination Treatments for Malignant Peripheral Nerve Sheath Tumors

Abstract

Malignant peripheral nerve sheath tumors (MPNSTs) are soft-tissue sarcomas that are the leading cause of mortality in Neurofibromatosis type 1 (NF1) patients. Single chemotherapeutic agents have shown response rates ranging from 18-44% in clinical trials, so there is still a high medical need to identify chemotherapeutic combination treatments that improve clinical prognosis and outcome. We screened a collection of compounds from the NCATS Mechanism Interrogation PlatE (MIPE) library in three MPNST cell lines, using cell viability and apoptosis assays. We then tested whether compounds that were active as single agents were synergistic when screened as pairwise combinations. Synergistic combinations in vitro were further evaluated in patient-derived orthotopic xenograft (orthoxenograft/PDOX) athymic models engrafted with primary MPNST matching with their paired primary-derived cell line where synergism was observed. The high-throughput screening identified 21 synergistic combinations, from which four exhibited potent synergies in a broad panel of MPNST cell lines. One of the combinations, MK-1775 with Doxorubicin, significantly reduced tumor growth in a sporadic PDOX model (MPNST-SP-01) (sevenfold) and in an NF1-PDOX model (MPNST-NF1-09) (fourfold) and presented greater effects in TP53 mutated MPNST cell lines. The other three combinations, all involving Panobinostat (combined with NVP-BGT226, Torin 2, or Carfilzomib), did not reduce the tumor volume in vivo at non-cytotoxic doses. Our results support the utility of our screening platform of in vitro and in vivo models to explore new therapeutic approaches for MPNSTs and identified that combination MK-1775 with Doxorubicin could be a good pharmacological option for the treatment of these tumors.

Expanding a precision medicine platform for malignant peripheral nerve sheath tumors: New patient‐derived orthotopic xenografts, cell lines and tumor entities

“…First, the thorough genomic and histologic characterization of tumors applied in a larger number of samples may facilitate a correct diagnostic of tumors currently labeled as MPNSTs in the clinics. Second, we should reinterpret results obtained with newly rediagnosed models previously considered MPNSTs, such as the STS-26T cell line (recently reclassified as probably being a melanoma [38]) and used by many different laboratories; or the SP-01 cell line (also MPNST-SP-01 in previous works) [32,34], used in our group. Our platform also includes cellular and mouse models from MPNSTs and confounded tumor entities.…”

“…The half‐maximal inhibitory concentration (IC 50 ) of JQ1, MLN8237 (Alisertib), and PD‐0325901 (Mirdametinib; Selleckchem, Houston, TX, USA) was calculated for each cell line, as we described previously [ 34 ]. Compounds (stock at 10 m m ) were added in three replicates and subsequently diluted fivefold from 100 μ m to 0.16 μ m .…”

“…The IC 50 was calculated using graphpad prism Version 6. For combination assays, the following previously described protocols were performed [ 34 ]. Combination Index (CI) values for the combinations were calculated using compusyn software, based on Chou‐Talalay calculations [ 53 ].…”

“…Over several years, our group has collected a total of 43 primary, relapsed, and metastatic tumors clinically diagnosed as MPNSTs from NF1 and sporadic patients and have generated PDOX models from most of them for precision medicine preclinical studies and the discovery of new therapeutic treatments [ 33 , 34 ]. In this work, we enlarge our preclinical platform by characterizing, at the molecular and histological level, six primary tumors diagnosed as MPNSTs by clinical pathology.…”

A Comprehensive Collection of Pain and Opioid Use Disorder Compounds for High-Throughput Screening and Artificial Intelligence-Driven Drug Discovery

“…Some libraries are aiming at approved therapeutics (for example, the NCATS Pharmaceutical Collection, NPC [11] ) or coverage of clinical space generally (such as the Broad Drug Re-purposing Hub [12]). Annotated libraries have also been designed around specific disease biology target space, as seen in the case of the NCATS MIPE library, which contains molecules with defined mechanisms of action associated with oncology indications [13].…”