Long-Term Exposure and Safety of a Novel Topical Rapamycin Cream for the Treatment of Facial Angiofibromas in Tuberous Sclerosis Complex: Results From a Single-Center, Open-Label Trial.

Facial angiofibromas, composed of fibrous tissue and blood vessels appearing on the face, are closely associated with tuberous sclerosis complex. Historically, oral rapamycin, a mammalian target of the rapamycin inhibitor of cell proliferation, has been used to treat visceral tuberous sclerosis-related tumors; however, the side effect profile of this medicine generally precludes its use in patients lacking significant internal involvement. The authors developed a novel topical formulation of rapamycin cream to treat the facial angiofibroma without exposing patients to possible systemic side effects. We followed 11 patients in a long-term, open-label, prospective study to evaluate the safety and effectiveness of rapamycin cream when used chronically. All of the patients showed an improvement in the appearance of their facial angiofibroma which was maintained in long-term follow-up without safety concerns or systemic absorption. The novel rapamycin cream was tolerated well by all patients and represents a way to address the cutaneous manifestation of tuberous sclerosis complex.

A statin-regulated microRNA represses human c-Myc expression and function.

c-Myc dysregulation is one of the most common abnormalities found in human cancer. MicroRNAs (miRNAs) are functionally intertwined with the c-Myc network as multiple miRNAs are regulated by c-Myc, while others directly suppress c-Myc expression. In this work, we identified miR-33b as a primate-specific negative regulator of c-Myc. The human miR-33b gene is located at 17p11.2, a genomic locus frequently lost in medulloblastomas, of which a subset displays c-Myc overproduction. Through a small-scale screening with drugs approved by the US Food and Drug Administration (FDA), we found that lovastatin upregulated miR-33b expression, reduced cell proliferation and impaired c-Myc expression and function in miR-33b-positive medulloblastoma cells. In addition, a low dose of lovastatin treatment at a level comparable to approved human oral use reduced tumour growth in mice orthotopically xenografted with cells carrying miR-33b, but not with cells lacking miR-33b. This work presents a highly promising therapeutic option, using drug repurposing and a miRNA as a biomarker, against cancers that overexpress c-Myc.