Parthenolide Sensitizes Human Colorectal Cancer Cells to Tumor Necrosis Factor-related Apoptosis-inducing Ligand through Mitochondrial and Caspase Dependent Pathway

BACKGROUND/AIMS: Combination therapy utilizing tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) in conjunction with other anticancer agents, is a promising strategy to overcome TRAIL resistance in malignant cells. Recently, parthenolide (PT) has proved to be a promising anticancer agent, and several studies have explored its use in combination therapy. Here, we investigated the molecular mechanisms by which PT sensitizes colorectal cancer (CRC) cells to TRAIL-induced apoptosis. METHODS: HT-29 cells (TRAIL-resistant) were treated with PT and/or TRAIL for 24 hours. The inhibitory effect on proliferation was detected using the 3-(4, 5-dimethylthiazol-2yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Annexin V staining, cell cycle analysis, and Hoechst 33258 staining were used to assess apoptotic cell death. Activation of an apoptotic pathway was confirmed by Western blot. RESULTS: Treatment with TRAIL alone inhibited the proliferation of HCT 116 cells in a dose-dependent manner, whereas proliferation was not affected in HT-29 cells. Combination PT and TRAIL treatment significantly inhibited cell growth and induced apoptosis of HT-29 cells. We observed that the synergistic effect was associated with misregulation of B-cell lymphoma 2 (Bcl-2) family members, release of cytochrome C to the cytosol, activation of caspases, and increased levels of p53. CONCLUSION: Combination therapy using PT and TRAIL might offer an effetive strategy to overcome TRAIL resistance in certain CRC cells.

Continuous Long-Term Entecavir Therapy in Naive Chronic Hepatitis B Patients Showing Partial Virologic Response

BACKGROUND/AIMS: We investigated the efficacy of continuous long-term entecavir 0.5 mg treatment in naive chronic hepatitis B patients showing a partial virologic response (PVR). METHODS: A total of 227 patients were included. PVR was defined as a more than 1 log10 IU/mL decline in detectable serum hepatitis B virus (HBV) DNA by polymerase chain reaction (PCR; > or =20 IU/mL) at week 48. A complete virologic response (CVR) was defined as undetectable serum HBV DNA by PCR (<20 IU/mL) at week 48. RESULTS: At week 48, the rate of the PVR was 64/227 (28.2%). Among patients with PVR, the cumulative rates of virologic response (serum HBV DNA <20 IU/mL) at weeks 96 and 144 were 45.2% and 73.8%, respectively. The cumulative rates of genotypic resistance were not significantly different between patients with a PVR and patients with a CVR (p=0.057). However, the cumulative rates of virologic breakthrough were higher in patients with PVR than in patients with CVR (4% vs 0% and 11.2% vs 0% at weeks 96 and 144, respectively; p<0.001). CONCLUSIONS: Long-term continuous entecavir 0.5 mg treatment in patients with a PVR resulted in an additional virologic response without a significant increase in genotypic resistance. However, the rate of virologic breakthrough was higher in the partial responders.

A Case of Minoxidil Induced Pericardial Effusion

We saw a case of minoxidil induced pericardial effusion in a 36 years old female who developed generalized edema, weakness and hypertrichosis after taking minoxidil for 1 year. Her chest PA showed globular shaped cardiac enlargement and pulmonary congestion. Echocardiography of the heart showed moderate amount of pericardial effusion. 10 days later after cessation of the drug administration and conservative managements, her chest PA showed marked improvement of heart size and pulmonary congestion. 20 days later her blood pressure became normal with the continued use of other antihypertensive drugs.