Topical Rapamycin Targets Vascular Tumors via mTOR Pathway

A 2013 study published in Laboratory Investigation investigates the role of the mTOR signaling pathway—specifically the activation of p70 S6‑kinase—in both benign (infantile hemangioma) and malignant (angiosarcoma) vascular tumors. The researchers found that these tumors exhibit elevated levels of activated S6K and ribosomal protein S6. By using genetic knockdown, they demonstrated that reducing S6K levels suppressed tumor cell proliferation and migration. Furthermore, applying rapamycin topically—a well-known mTOR inhibitor—produced significant reductions in tumor growth both in lab and animal models, while minimizing systemic exposure. These findings suggest that localized mTOR inhibition may offer an effective and well-tolerated alternative therapy for cutaneous vascular lesions.
Learn more: Vascular tumors have increased p70 S6‑kinase activation and are inhibited by topical rapamycin