sirolimus and Birt-Hogg-Dube-Syndrome

Birt-Hogg-Dubé syndrome is an autosomal dominantly inherited disease that predisposes patients to develop fibrofolliculoma, lung cysts and bilateral multifocal renal tumors, histologically hybrid oncocytic/chromophobe tumors, chromophobe renal cell carcinoma, oncocytoma, papillary renal cell carcinoma and clear cell renal cell carcinoma. The predominant forms of Birt-Hogg-Dubé syndrome-associated renal tumors, hybrid oncocytic/chromophobe tumors and chromophobe renal cell carcinoma are typically less aggressive, and a therapeutic principle for these tumors is a surgical removal with nephron-sparing. The timing of surgery is the most critical element for postoperative renal function, which is one of the important prognostic factors for Birt-Hogg-Dubé syndrome patients. The folliculin gene (FLCN) that is responsible for Birt-Hogg-Dubé syndrome was isolated as a novel tumor suppressor for kidney cancer. Recent studies using murine models for FLCN, a protein encoded by the FLCN gene, and its two binding partners, folliculin-interacting protein 1 (FNIP1) and folliculin-interacting protein 2 (FNIP2), have uncovered important roles for FLCN, FNIP1 and FNIP2 in cell metabolism, which include AMP-activated protein kinase-mediated energy sensing, Ppargc1a-driven mitochondrial oxidative phosphorylation and mTORC1-dependent cell proliferation. Birt-Hogg-Dubé syndrome is a hereditary hamartoma syndrome, which is triggered by metabolic alterations under a functional loss of FLCN/FNIP1/FNIP2 complex, a critical regulator of kidney cell proliferation rate; a mechanistic insight into the FLCN/FNIP1/FNIP2 pathway could provide us a basis for developing new therapeutics for kidney cancer.

Topics: Animals; Birt-Hogg-Dube Syndrome; Carrier Proteins; Gene Knockout Techniques; Humans; Kidney Neoplasms; Mechanistic Target of Rapamycin Complex 1; Mice; Multiprotein Complexes; Mutation; Neoplasms, Experimental; Nephrectomy; Proto-Oncogene Proteins; Rats; Sirolimus; TOR Serine-Threonine Kinases; Tumor Suppressor Proteins

Birt-Hogg-Dubé syndrome (BHD) is a rare autosomal dominant disorder characterised by the occurrence of benign, mostly facial, skin tumours called fibrofolliculomas, multiple lung cysts, spontaneous pneumothorax and an increased renal cancer risk. Current treatments for fibrofolliculomas have high rates of recurrence and carry a risk of complications. It would be desirable to have a treatment that could prevent fibrofolliculomas from growing. Animal models of BHD have previously shown deregulation of mammalian target of rapamycin (mTOR). Topical use of the mTOR inhibitor rapamycin is an effective treatment for the skin tumours (angiofibromas) in tuberous sclerosis complex, which is also characterised by mTOR deregulation. In this study we aimed to determine if topical rapamycin is also an effective treatment for fibrofolliculomas in BHD.. We performed a double blinded, randomised, facial left-right controlled trial of topical rapamycin 0.1% versus placebo in 19 BHD patients. Trial duration was 6 months. The primary outcome was cosmetic improvement as measured by doctors and patients. Changes in fibrofolliculoma number and size were also measured, as was occurrence of side effects.. No change in cosmetic status of fibrofolliculomas was reported in the majority of cases for the rapamycin treated (79% by doctors, 53% by patients) as well as the placebo treated facial sides (both 74%). No significant differences between rapamycin and placebo treated facial halves were observed (p = 1.000 for doctors opinion, p = 0.344 for patients opinion). No significant difference in fibrofolliculoma number or change in size of the fibrofolliculomas was seen after 6 months. Side effects occurred more often after rapamycin treatment (68% of patients) than after placebo (58% of patients; p = 0.625). A burning sensation, erythema, itching and dryness were most frequently reported.. This study provides no evidence that treatment of fibrofolliculomas with topical rapamycin in BHD results in cosmetic improvement.. ClinicalTrials.gov NCT00928798.

Topics: Administration, Topical; Adult; Aged; Antibiotics, Antineoplastic; Birt-Hogg-Dube Syndrome; Double-Blind Method; Female; Humans; Male; Middle Aged; Sirolimus; Skin; Skin Neoplasms; Treatment Outcome

Topics: Administration, Cutaneous; Aged; Biopsy; Birt-Hogg-Dube Syndrome; Combined Modality Therapy; Humans; Lasers; Low-Level Light Therapy; Male; Ointments; Proto-Oncogene Proteins; Signal Transduction; Sirolimus; Skin; TOR Serine-Threonine Kinases; Treatment Outcome; Tumor Suppressor Proteins

A 56-year-old man was referred to our clinic because of left lumbar pain and a left solitary renal tumor (9. 8 cm in diameter) and bilateral pulmonary metastases detected by computed tomographic scan. Pathologic diagnosis following open radical nephrectomy was papillary renal cell carcinoma, G2, pT2aN0M1. Subsequently, the patient was sequentially treated with interleukin-2 (3 months (mo), progressive disease (PD)), interferon-alpha (3 mo, PD), and oral S-1 as a clinical trial (28 mo, PD). Because of skin fibrofolliculomas, pulmonary cysts, and spontaneous pneumothorax history, Birt-Hogg-Dubé (BHD) syndrome was suspected during the treatment course, despite his having no family history of the disease. Subsequent genetic testing revealed a FLCN germline mutation (c. 1285dupC). He was started on molecular-targeting therapies sequentially, i.e., sorafenib (1 mo, PD), sunitinib (4 mo, PD), and everolimus (7 mo, PD). The patient died of progressive disease at 78 mo from the initial nephrectomy and 30 mo from the start of targeted agents. Loss of FLCN function has been shown to result in the upregulation of the PI3K/mTORC1 pathway in both in vitro experiments and in vivo FLCN knockout mice models. Despite its use as the sixth-line systematic treatment, the mTOR inhibitor everolimus exhibited a relatively long-term effect as compared with the previously used tyrosine kinase inhibitors and in contrast to the results in the RECORD-1 clinical trial. This finding may provide insight into the molecular mechanism of BHDassociated renal tumors.

Topics: Animals; Antineoplastic Agents; Birt-Hogg-Dube Syndrome; Carcinoma, Renal Cell; Everolimus; Humans; In Vitro Techniques; Indoles; Kidney Neoplasms; Male; Mice, Knockout; Middle Aged; Molecular Targeted Therapy; Neoplasm Metastasis; Niacinamide; Phenylurea Compounds; Pyrroles; Sirolimus; Sorafenib; Sunitinib