Abstract
Tuberous sclerosis complex (TSC) and lymphangioleiomyomatosis (LAM) lack well-defined cellular origins, limiting treatment options. In this report, scRNA-seq of Tsc2+/– mouse renal cystadenomas revealed an 80-fold increase in a tumor cell subpopulation with neural crest features, expressing known cranial neural crest genes as SRY box transcription factor 9 (Sox9), transcription factor activator protein (Tfap2a), and candidate neurocristopathy markers, osteopontin (Spp1), lipocalin-2 (Lcn2), clusterin (Clu), and cytokeratin 18 (Krt18). These signatures were validated in mouse tumors and LAM patient lesions and serum, identifying a tumor phenotype distinct from traditional VEGFD detection. Pathway analysis indicated activation of WNT/SHH signaling, nephric duct formation, and protumorigenic signals, with transcription factor 7 (Tcf7) and ephrin-A ligands as key upstream regulators. Spp1 KO in cranial neural crest cells (CNCCs) significantly reduced proliferation (28%–33%), migration (54%–76%), and invasion (29%–64%) without affecting viability, while Tsc2 KO increased viability 3- to 6-fold with minimal effect on chemotaxis. Elevated serum levels of SPP1 and KRT18 in 1 subset of patients with LAM, decreased LCN2 in nearly all cases, and distinct increases in VEGFD in a separate subset suggest complementary roles for these biomarkers. Overall, findings support a neurocristopathic model of tumor development in TSC and LAM and identify potential biomarkers and therapeutic targets beyond mTOR inhibition.
Authors
Uchenna J. Unachukwu, Enio B. Garcia, Nooralam Rai, Jeanine M. D’Armiento
Figure 8
Evidence of neurocristopathy in LAM pulmonary neoplasms (KRT18 and SOX9).
