Lymphangioleiomyomatosis (LAM) is a progressive lung disease with limited treatments, largely because of an incomplete understanding of its pathogenesis. Lymphatic endothelial cells (LECs) invade LAM cell clusters, which include human melanoma black-45–positive epithelioid cells and smooth muscle α-actin–expressing LAM-associated fibroblasts (LAMFs). Recent evidence shows that LAMFs resemble cancer-associated fibroblasts, with LAMF-LEC interactions contributing to disease progression. To explore these mechanisms, we used spatial transcriptomics on LAM lung tissues and identified a gene cluster enriched in kinase signaling pathways linked to myofibroblasts and coexpressed with LEC markers. Kinase arrays revealed elevated PDGFR and FGFR in LAMFs. Using a 3D coculture spheroid model of primary LAMFs and LECs, we observed increased invasion in LAMF-LEC spheroids compared with non-LAM fibroblasts. Treatment with sorafenib, a multikinase inhibitor, significantly reduced invasion, outperforming rapamycin. We also verified tuberous sclerosis complex 2–deficient renal angiomyolipoma (TSC2-null AML) cells as key VEGF-A secretors; VEGF-A was suppressed by sorafenib in both TSC2-null AML cells and LAMFs. These findings highlight VEGF-A and basic FGF as potential therapeutic targets and suggest multikinase inhibition as a promising strategy for LAM.
Sinem Koc-Gunel, Emily C. Liu, Lalit K. Gautam, Ben A. Calvert, Shubha Murthy, Noa C. Harriott, Janna C. Nawroth, Beiyun Zhou, Vera P. Krymskaya, Amy L. Ryan
Representative staining of LAM lung tissue highlighting distinct cell populations.