Abiraterone acetate exerts a cytotoxic effect in human prostate cancer cell lines.

To study the capability of the CYP17A1 inhibitor abiraterone acetate (AER) to antagonize the androgen receptor (AR) activation in human prostate cancer (PCa) cell lines. T877A-AR-LNCaP, WT-AR-VCaP, AR-negative DU145, and PC3 PCa cell lines were used by MTT and cell count to study the ability of AER and enzalutamide (ENZ) to modify cell viability. The role of ARs in LNCaP was demonstrated through a gene-silencing experiment. The mechanism of AER cytotoxicity in LNCaP cells was studied, as well as the ability of AER to modulate AR gene expression. The in silico docking approach was applied to study the interaction of AER and ENZ with T877A-AR. Through high-performance liquid chromatography, the production of the AER main metabolite Δ4A was studied. AER bound AR in an almost identical manner to that of dihydrotestosterone (DHT). The higher binding energy for AER in T877A-AR could explain the major cytotoxic effect observed in LNCaP cells. The capability of LNCaP cells to synthesize Δ4A could mediate, at least in part, this effect. AER cytotoxicity in LNCaP cells was mainly due to the activation of apoptosis. Further, AER induced modification of AR target gene expression, suggesting a direct effect on AR activity. AER-induced cytotoxicity on PCa cell lines seemed to be mediated by binding with AR. The higher affinity of AER for T877A-AR may suggest a potential role of AER in the management of CRPC carrying this mutation; however, T877A-AR expressing CRPC patients developed AER resistance, probably due to the increase of progesterone.

[Recurrent Kidney Stones in a patient with Malabsorption Syndrome].

Enteric hyperoxaluria is one of the most frequent complications of bariatric surgery. In this setting the prevalence of kidney stones is increased. Currently the treatment of enteric hyperoxaluria is based not only on the reduction of urinary oxalate but even controlling other lithogenic risk factors, like urinary volume and urinary citrate levels. This case report suggests a possible benefit using magnesium citrate in addition to calcium supplementation, in the treatment of hyperoxaluria caused by enteric malabsorption.

Amiloride Is Effective in the Management of Abiraterone-Induced Mineralocorticoid Excess Syndrome without Interfering with Its Antineoplastic Activity.

BACKGROUND: The administration of abiraterone acetate (abiraterone) leads to an adrenocorticotropic hormone (ACTH)-driven increase in mineralocorticoid hormones, requiring glucocorticoid supplementation that may stimulate the growth of prostate cancer (PCa). Amiloride is a drug that selectively reduces the aldosterone-sensitive Na+/K+ exchange and could be effective in the management of mineralocorticoid excess syndrome (MCES). METHODS: The efficacy of amiloride + hydrochlorothiazide (HCT) in the clinical management of abiraterone-induced MCES was assessed in 5 consecutive patients with castration-resistant PCa (CRPC). Then, using the in vitro experimental model of PCa cell lines, the possible effects of drugs usually used in the clinical management of CRPC patients on PCa cell viability were investigated. RESULTS: Amiloride/HCT led to a complete disappearance of all clinical and biochemical signs of abiraterone-induced MCES in the 5 treated patients. The in vitro study showed that abiraterone treatment significantly decreased cell viability of both androgen receptor (AR)-expressing VCaP (vertebral-cancer of the prostate) and LNCaP (lymph node carcinoma of the prostate) cells, with no effect on AR-negative PC-3 cells. Prednisolone, spironolactone, and eplerenone increased LNCaP cell viability, while amiloride reduced it. The non-steroid aldosterone antagonist PF-03882845 did not modify PCa cell viability. CONCLUSIONS: The combination of amiloride/HCT was effective in the management of abiraterone-induced MCES. Amiloride did not negatively interfere with the abiraterone inhibition of PCa cell viability in vitro.

Antisecretive and Antitumor Activity of Abiraterone Acetate in Human Adrenocortical Cancer: A Preclinical Study.

CONTEXT: Patients with adrenocortical carcinoma (ACC) frequently suffer from cortisol excess, which portends a negative prognosis. Rapid control of cortisol hypersecretion and tumor growth are the main goals of ACC therapy. Abiraterone acetate (AA) is a potent inhibitor of 17alpha-hydroxylase/17,20-lyase, a key enzyme of adrenal steroidogenesis. OBJECTIVE: This study sought to investigate the therapeutic use of AA in preclinical models of ACC. DESIGN: AA antisecretive and antiproliferative effects were investigated in vitro using NCI-H295R and SW13 ACC cell lines and human primary ACC cell cultures, as well as in vivo using immunodeficient mice. METHODS: Steroid secretion, cell viability, and proliferation were analyzed in untreated and AA-treated ACC cells. The ability of AA to affect the Wnt/beta-catenin pathway in NCI-H295R cells was also analyzed. Progesterone receptor (PgR) gene was silenced by the RNA interference approach. The antitumor efficacy of AA was confirmed in vivo in NCI-H295R cells xenografted in immunodeficient mice. RESULTS: AA reduced the secretion of both cortisol and androgens, increased production of progesterone, and induced a concentration-dependent decrease of cell viability in the NCI-H295R cells and primary secreting ACC cultures. AA also reduced beta-catenin nuclear accumulation in NCI-H295R cells. AA administration to NCI-H295R-bearing mice enhanced progesterone levels and inhibited tumor growth. The cytotoxic effect of AA was prevented by either blocking PgR or by gene silencing. CONCLUSION: AA is able to inhibit hormone secretion and growth of ACC both in vitro and in vivo. It also reduces beta-catenin nuclear accumulation. The cytotoxic effect of AA seems to require PgR.

Cytokine removal under hemodiafiltration with endogenous reinfusion in acute kidney injury secondary to angioimmunoblastic T-cell lymphoma: a case report.

Angioimmunoblastic T-cell lymphoma shows a high release of cytokines. Different blood purification techniques are employed to control hypercytokinemia. Here we investigated the effects of intermittent supra-hemodiafiltration with endogenous reinfusion on cytokine removal in a patient presenting with acute kidney injury. After the first day of chemotherapy for angioimmunoblastic T-cell lymphoma, a 78-year-old male patient developed acute kidney injury and systemic inflammatory response syndrome due to massive release of inflammatory cytokines. Three sessions of supra-hemodiafiltration were performed. Blood samples for evaluation of renal function and inflammatory mediators were collected at the beginning and the end of each dialytic session. A marked improvement of clinical state and renal function was associated to a significant reduction of inflammatory markers. Our results suggest that renal replacement therapy with supra-hemodiafiltration may remove a wide spectrum of inflammatory mediators and uremic toxins involved in acute kidney injury and systemic inflammatory response syndrome.

[Treatment of electrolyte disorders by hemodialysis]. / La terapia emodialitica dei disordini elettrolitici.

Electrolyte disorders may constitute a life-threatening emergency. Sometimes they can be treated with medical therapy but there are cases where emergency dialysis will be necessary. An important role is played by the dialysate (including different concentrations of electrolytes), which removes uremic toxins and balances the electrolyte disorders in patients with end-stage renal disease. The choice of dialysate is also important for control of the patient's vital functions during the dialysis session and in the period between sessions. Sodium is strongly related to weight gain between dialysis sessions and its concentration causes fluid overload or, on the contrary, hypotension. The choice of the buffer takes into account any possible bicarbonate- or acetate-related systemic effects. Potassium is very important for heart contraction and its fast removal could be associated with cardiac arrhythmias. The role of magnesium is still controversial. Calcium is related to hemodynamic stability, mineral bone disease and also cardiac arrhythmias. A correctly balanced dialysate is important to prevent and reduce intradialytic and interdialytic complications. The dialysate should be tailored to the needs of the individual patient.