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BACKGROUND: In a phase III trial in patients with advanced, well-differentiated, progressive pancreatic neuroendocrine tumors, sunitinib 37.5 mg/day improved investigator-assessed progression-free survival (PFS) versus placebo (11.4 vs. 5.5 months; HR, 0.42; P < 0.001). Here, we present PFS using retrospective blinded independent central review (BICR) and final median overall survival (OS), including an assessment highlighting the impact of patient crossover from placebo to sunitinib.PATIENTS AND METHODS: In this randomized, double-blind, placebo-controlled study, cross-sectional imaging from patients was evaluated retrospectively by blinded third-party radiologists using a 2-reader, 2-time-point lock, followed by a sequential locked-read, batch-mode paradigm. OS was summarized using the Kaplan-Meier method and Cox proportional hazards model. Crossover-adjusted OS effect was derived using rank-preserving structural failure time (RPSFT) analyses.RESULTS: Of 171 randomized patients (sunitinib, n = 86; placebo, n = 85), 160 (94%) had complete scan sets/time points. By BICR, median (95% confidence interval [CI]) PFS was 12.6 (11.1-20.6) months for sunitinib and 5.8 (3.8-7.2) months for placebo (HR, 0.32; 95% CI 0.18-0.55; P = 0.000015). Five years after study closure, median (95%CI) OS was 38.6 (25.6-56.4) months for sunitinib and 29.1 (16.4-36.8) months for placebo (HR, 0.73; 95% CI 0.50-1.06; P = 0.094), with 69% of placebo patients having crossed over to sunitinib. RPSFT analysis confirmed an OS benefit for sunitinib.CONCLUSIONS: BICR confirmed the doubling of PFS with sunitinib compared with placebo. Although the observed median OS improved by nearly 10 months, the effect estimate did not reach statistical significance, potentially due to crossover from placebo to sunitinib.TRIAL REGISTRATION NUMBER: NCT00428597.

The effect of anandamide on human osteoblasts is unclear. This study examined the effect of anandamide on viability, apoptosis, mitogen-activated protein kinases (MAPKs) and Ca2+ levels in MG63 osteosarcoma cells. Anandamide at 50-200 microM decreased cell viability via apoptosis as demonstrated by propidium iodide staining and activation of caspase-3. Immunoblotting suggested that anandamide induced expression of ERK, JNK and p38 MAPK. Anandamide-induced cell death and apoptosis were reversed by SB203580, but not by PD98059 and SP600125, suggesting that anandamide's action was via p38 MAPK, but not via ERK and JNK. Anandamide at 1-100 microM induced [Ca2+]i increases. Removal of extracellular Ca2+ decreased the anandamide response, indicating that anandamide induced Ca2+ influx and Ca2+ release. Chelation of intracellular Ca2+ with BAPTA reversed anandamide-induced cell death and p38 MAPK phosphorylation. Collectively, in MG63 cells, anandamide induced [Ca2+]i increases which evoked p38 MAPK phosphorylation. This p38 MAPK phosphorylation subsequently activated caspase-3 leading to apoptosis.

The effect of the carcinogen safrole on intracellular Ca2+ movement has not been explored in osteoblast-like cells. This study examined whether safrole could alter Ca2+ handling and viability in MG63 human osteosarcoma cells. Cytosolic free Ca2+ levels ([Ca2+]i) in populations of cells were measured using fura-2 as a fluorescent Ca2+ probe. Safrole at concentrations above 130 microM increased [Ca2+]i in a concentration-dependent manner with an EC50 value of 450 microM. The Ca2+ signal was reduced by 30% by removing extracellular Ca2+. Addition of Ca2+ after safrole had depleted intracellular Ca2+ induced Ca2+ influx, suggesting that safrole caused Ca2+ entry. In Ca2+-free medium, after pretreatment with 650 microM safrole, 1 microM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor) failed to release more Ca2+; and pretreatment with thapsigargin inhibited most of the safrole-induced [Ca2+]i increases. Inhibition of phospholipase C with U73122 did not affect safrole-induced Ca2+ release; whereas activation of protein kinase C with phorbol ester enhanced safrole-induced [Ca2+]i increase. Trypan exclusion assays revealed that incubation with 65 microM safrole for 30 min did not kill cells, but incubation with 650 microM safrole for 10-30 min nearly killed all cells. Flow cytometry demonstrated that safrole evoked apoptosis in a concentration-dependent manner. Safrole-induced cytotoxicity was not reversed by chelation of Ca2+ with BAPTA. Collectively, the data suggest that in MG63 cells, safrole induced a [Ca2+]i increase by causing Ca2+ release mainly from the endoplasmic reticulum in a phospholipase C-independent manner. The safrole response involved Ca2+ influx and is modulated by protein kinase C. Furthermore, safrole can cause apoptosis in a Ca2+-independent manner.

The effect of miconazole, an anti-fungal drug, on cytoplasmic free Ca 2+ concentrations ([Ca 2+ ] i ) in human osteosarcoma cells (MG63) was explored by using the Ca 2+ -sensitive dye fura-2. Miconazole acted in a concentration-dependent manner with an EC 50 of 75 μM. The Ca 2+ signal comprised a gradual rise and a sustained elevation. Removal of extracellular Ca 2+ reduced 50% of the signal. In Ca 2+ -free medium, the [Ca 2+ ] i rise induced by 1 μM thapsigargin (an endoplasmic reticulum Ca 2+ pump inhibitor) was completely inhibited by pretreatment with 20 μM miconazole. Pretreatment with thapsigargin partly inhibited miconazole-induced Ca 2+ release. The miconazole-induced Ca 2+ release was not changed by inhibition of phospholipase C with 2 μM U73122. By using tetrazolium as a fluorescent probe, it was shown that 10–100 μM miconazole decreased cell proliferation rate in a concentration-dependent manner. Collectively, this study shows that miconazole induces [Ca 2+ ] i rises in human osteosarcoma cells via releasing Ca 2+ mainly from the endoplasmic reticulum in a manner independent of phospholipase C activity, and by causing Ca 2+ influx. Furthermore, miconazole may be cytotoxic to the cells at higher concentrations.

In human neuroblastoma IMR32 cells, the effect of the anti-depressant maprotiline on baseline intracellular Ca 2+ concentrations ([Ca 2+ ] i ) was explored by using the Ca 2+ -sensitive probe fura-2. Maprotiline at concentrations greater than 100 μM caused a rapid rise in [Ca 2+ ] i in a concentration-dependent manner (EC 50 = 200 μM). Maprotiline-induced [Ca 2+ ] i rise was reduced by 50% by removal of extracellular Ca 2+ . Maprotiline-induced [Ca 2+ ] i rises were inhibited by half by nifedipine, but was unaffected by verapamil or diiltiazem. In Ca 2+ -free medium, thapsigargin, an inhibitor of the endoplasmic reticulum Ca 2+ -ATPase, caused a monophasic [Ca 2+ ] i rise, after which the increasing effect of maprotiline on [Ca 2+ ] i was abolished. U73122, an inhibitor of phospholipase C, did not affect maprotiline-induced [Ca 2+ ] i rises. These findings suggest that in human neuroblastoma cells, maprotiline increases [Ca 2+ ] i by stimulating extracellular Ca 2+ influx and also by causing intracellular Ca 2+ release from the endoplasmic reticulum via a phospholiase C-independent manner.

Expression of the p16 gene from 30 malignant skin tumors has been surveyed by immunohistochemical assay. Gene point mutations were detected by DNA direct sequencing and the mRNA level of gene expression was measured by RT-PCR. A silent point mutation of the p16 gene was found in only one patient. However, loss of expression of the p16 gene was noticed in 23 of 29 samples (79.3%). Correlation between loss of expression of the p16 gene and metastasis is significant (p = 0.0036). These findings suggest that loss of expression of the p16 gene may play a critical role in tumor progression of malignant skin tumors.