The Unreliability of MTT Assay in the Cytotoxic Test of Primary Cultured Glioblastoma Cells

MTT assay is commonly used to assess the cellular cytotoxicity caused by anticancer drugs in glioblastomas. However, there have been some reports insisting that MTT assay exhibited non-specific intracellular reduction of tetrazolium which led to underestimated results of cytotoxicity. Here, we examine whether or not MTT assay can lead to incorrect information regarding alcohol-induced cytotoxicity on immortalized and primary glioblastoma cells. MTT assay was applied to assess the ethanol-induced cytotoxicity at various ethanol concentrations. The cellular cytotoxicity induced by different doses of ethanol was analyzed and compared through several cytotoxic assays. Ethanol-induced cytotoxicity observed through MTT assay on both cell types was shown to be ethanol dose-dependent below a 3% concentration. However, the cytotoxicity was shown to be markedly underestimated only in primary cells at a 5% concentration. RT-PCR and Western Blot showed increased expressions of pro-apoptotic proteins and decreased expressions of anti-apoptotic proteins in an ethanol dose-dependent manner in both cell types. Furthermore, we present a possible mechanism for the unreliable result of MTT assay. A high concentration of ethanol induces more severe membrane damage and increased intracellular concentration of NADH in primary cells which enhances the nonspecific reduction of tetrazolium salt. Together, our findings demonstrate that the cytotoxicity on primary cells could inaccurately be assessed when detected through MTT assay. Therefore, a careful interpretation is needed when one would analyze the cytotoxic results of MTT assay, and it is suggested that other assays must be accompanied to produce more reliable and accurate cytotoxic results on primary glioblastoma cells.

Progression of Peyronie's Disease during Tamoxifen Treatment / 대한남성과학회지

PURPOSE: Medical treatment of Peyronie's disease with tamoxifen has been initially proposed as acting upon the early phase of the disease. As recent reports show no significant benefit of tamoxifen, we review the long term results of tamoxifen treatment of Peyronie's disease. MATERIALS AND METHODS: Time to progression during tamoxifen treatment of patients showing acute disease and chronic disease was compared. The acute phase was identified by pain during erection. Progression was defined as enlargement of plaque size or appearance of calcification. RESULTS: The average treatment duration was 15.9+/-13.8 months (range: 3 to 48 months). The median time to progression was 7 months for acute patients and 20 months for chronic patients. Eighty percent of patients in the acute phase showed relief of pain; however, overall progression was 72.1% (78.0% for acute, 66.7% for chronic). Patient history, comorbidities, serum testosterone or initial plaque characteristics, and severity of curvature were not predictive of disease progression. CONCLUSIONS: Tamoxifen showed no significant benefit in slowing the progression of Peyronie's disease in the acute phase over the chronic phase. Peyronie's disease continued to progress, though at a dampened rate for patient's in the chronic phase.