Cellular Senescence Is Associated with Faster Progression of Focal Segmental Glomerulosclerosis.

BACKGROUND: A current, albeit unproven, hypothesis is that an acceleration of cellular senescence is involved in impaired renal repair and progression of glomerular diseases. Focal segmental glomerulosclerosis (FSGS) is a glomerular disease with a substantial risk for progression to ESRD. However, if and to what extent cell senescence predicts a negative outcome in FSGS is still unknown. METHODS: The hypothesis that cell senescence represents a proximate mechanism by which the kidney is damaged in FSGS (NOS phenotype) was investigated in 26 consecutive kidney biopsies from adult FSGS cases (eGFR 72 ± 4 mL/min, proteinuria 2.3 ± 0.6 g/day) who were incident for 2 years in a Northern Italian nephrology center and had a 6-year clinical follow-up. RESULTS: Cell senescence (p16INK4A, SA-ß-galactosidase [SA-ß-Gal]) was upregulated by ∼3- to 4-fold in both glomerular and tubular cells in kidney biopsies of FSGS as compared to age-matched controls (p < 0.05-0.01). Tubular SA-ß-Gal correlated with proteinuria and glomerulosclerosis, while only as a trend, tubular p16INK4A was directly associated with interstitial fibrosis. At univariate analysis, basal eGFR, proteinuria, and tubular expression of SA-ß-Gal and p16INK4A were significantly directly related to the annual loss of eGFR. No correlation was observed between glomerular p16INK4A and eGFR loss. However, at multivariate analysis, eGFR, proteinuria, and tubular p16INK4A, but not SA-ß-Gal, contributed significantly to the prediction of eGFR loss. CONCLUSIONS: The results indicate that an elevated cell senescence rate, expressed by an upregulation of p16INK4A in tubules at the time of initial biopsy, represents an independent predictor of progression to ESRD in adult patients with FSGS.

Vismodegib for the treatment of basal cell skin cancer.

PURPOSE: The pharmacology, clinical efficacy, adverse effects, cost, and place in therapy of vismodegib are reviewed. SUMMARY: Vismodegib, the first oral treatment for basal cell carcinoma (BCC), was recently approved for the treatment of patients with locally advanced or metastatic BCC whose cancer is refractory to standard treatments or who are not candidates for surgery or radiation. Vismodegib is a small molecule that potently inhibits signal transduction in the hedgehog signaling pathway, demonstrates nonlinear pharmacokinetics, and has a half-life of 13 days. Agents that increase gastrointestinal pH may reduce the solubility and bioavailability of vismodegib. It is effective in both locally advanced and metastatic BCCs, with response rates ranging from 30% to 60% in two clinical trials. Vismodegib is available as a 150-mg capsule, and the approved dosage is 150 mg orally once daily. The most common adverse effects of vismodegib include mild-to-moderate hair loss, muscle cramps, taste disturbance, and weight loss. The estimated cost of one month of treatment with vismodegib is $7500. CONCLUSION: Vismodegib was recently approved for the treatment of locally advanced or metastatic BCC that is refractory to standard treatments or if patients are not candidates for surgery or radiation. Vismodegib may have little effect on the treatment of BCC, given its high cost, the high cure rates achieved with standard therapies, and its unacceptable toxicity profile in patients with a non-life-threatening disease. However, vismodegib's novel mechanism of action, oral dosage form, preliminary efficacy, and tolerability compared with cytotoxic chemotherapy may make it an attractive candidate for the treatment of other cancers.