Biology subjects

Belzberg, A.

Publications and source records attributed to Belzberg, A..

3 recordsLinked to original sources

bioRxiv2024

Conditioned medium from painful schwannomatosis tumors increases pain behaviors in mice.

The majority of schwannomatosis (SWN) patients experience debilitating pain. Yet, it is not known why only some schwannomas cause pain or whether mutations in SWN-related genes, (SMARCB1 or LZTR1) differentially influence pain signaling pathways. Here, we established cell lines from SWN tumors resected from patients with varying degrees of pain and bearing mutations in different SWN-related mutations. Compared with conditioned medium (CM) collected from "nonpainful" SWN tumors, CM from "painful" SWN tumors contained elevated levels of specific inflammatory cytokines (IL-6, IL-8, VEGF), and was able to enhance sensory neuron responsiveness to noxious TRPV1 and TRPA1 agonists in vitro. In in vivo studies, injection of CM from painful SWN into the hind paws of healthy mice evoked both more acute pain behavior and greater enhancement of mechanical stimulus-evoked behavioral responses than did CM from nonpainful SWN. Furthermore, the behavioral effects of painful CM differed as a function of the SWN-related gene mutations identified in the tumors of origin. Painful SMARCB1 mutant CM, for example, sensitized mice to mechanical stimulation at low forces, compared to non-painful tumor CM and control media, but this effect waned over time. In contrast, CM from a painful tumor with no detectable mutation in either SMARCB1 or LZTR1 caused the greatest increase in responsiveness to low mechanical forces and this effect lasted for 2 days post-injection. These experiments establish a paradigm for examining the mechanisms by which painful SWN tumors bearing different mutations produce their sensory effects and will thus facilitate better understanding and, potentially, treatment of the pain endured by SWN patients.

neuroscience↗

bioRxiv2019

A clinically and genomically annotated nerve sheath tumor biospecimen repository.

Nerve sheath tumors occur as a heterogeneous group of neoplasms in patients with neurofibromatosis type 1 (NF1). The malignant form represents the most common cause of death in people with NF1, and even when benign, these tumors can result in significant disfigurement, neurologic dysfunction, and a range of profound symptoms. Lack of human tissue across the peripheral nerve tumors common in NF1 has been a major limitation in the development of new therapies. To address this unmet need, we have created an annotated collection of patient tumor samples, patient-derived cell lines, and patient-derived xenografts, and carried out high-throughput genomic and transcriptomic characterization to serve as a resource for further biologic and preclinical therapeutic studies. In this work, we release genomic and transcriptomic datasets comprised of 55 tumor samples derived from 23 individuals, complete with clinical annotation. All data are publicly available through the NF Data Portal and at http://synapse.org/jhubiobank.

cancer biology↗

bioRxiv2019

The Secretomes of Painful Versus Nonpainful Human Schwannomatosis Tumor Cells Differentially Influence Sensory Neuron Gene Expression and Sensitivity

Schwannomatosis is a multiple tumor syndrome in which patients develop benign tumors along peripheral nerves throughout the body. The first symptom with which schwannomatosis patients often present, prior to discovery of tumors, is pain. This pain can be debilitating and is often inadequately alleviated by pharmacological approaches. Schwannomatosis-associated pain can be localized to the area of a tumor, or widespread. Moreover, not all tumors are painful, and the occurrence of pain is often unrelated to tumor size or location. We speculate that some individual tumors, but not others, secrete factors that act on nearby nerves to augment nociception by producing neuronal sensitization or spontaneous neuronal firing. We created cell lines from human SWN tumors with varying degrees of pain. We have found that conditioned medium (CM) collected from painful SWN tumors, but not that from nonpainful SWN tumors, sensitized DRG neurons, causing increased sensitivity to depolarization by KCl, increased response to noxious TRPV1 and TRPA1 agonists and also upregulated the expression of pain-associated genes in DRG cultures. Multiple cytokines were also detected at higher levels in CM from painful tumors. Taken together our data demonstrate a differential ability of painful versus non-painful human schwannomatosis tumor cells to secrete factors that augment sensory neuron responsiveness, and thus identify a potential determinant of pain heterogeneity in schwannomatosis.

neuroscience↗