Publications by authors named "Dae Hwa Choi"

Background/aims: Although both VEGF and COX-2 are important factors influencing angiogenesis (and thus, carcinogenesis), the regulation of these factors in carcinogenesis remains poorly understood. The aim is to investigate the effects of tristetraprolin, an AU-rich element-binding protein on the expression of VEGF and COX-2 in human colon cancer cells.

Methodology: Expression of TTP, VEGF and COX-2 in the resected colorectal cancer surgical specimens were analyzed by immunohistochemistry.

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LATS2 is a tumor suppressor gene implicated in the control of cell growth and the cell cycle. Here, we investigated the post-transcriptional regulation of LATS2 expression by tristetraprolin (TTP). Our results show that the expression level of LATS2 is inversely correlated with TTP expression in human cancer cell lines.

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Tristetraprolin (TTP) is an AU-rich element-binding protein that regulates mRNA stability. Here, we report that TTP suppress the growth of human colon cancer cells both in vivo and in vitro by regulating of the expression of vascular endothelial growth factor (VEGF). TTP protein expression in human colonic tissues was markedly decreased in colonic adenocarcinoma compared with in normal mucosa and adenoma.

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Cisplatin is a chemotherapeutic agent that is widely used to treat cancers such as head and neck squamous cell carcinoma (HNSCC). Previously, we have reported that cisplatin induced an early caspase-dependent apoptosis (8 hr) in a HNSCC cell, HN4. In this study, we examined a late caspase-independent apoptosis as well as an early caspase-dependent apoptosis in cisplatin-treated HN4 cells.

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Heat shock protein (Hsp) in tumor cells has been proposed to enhance their resistance to chemotherapeutic agents. In the present study, we investigated the influence of Hsp expression on the irinotecan resistance of human colorectal cancer cells. Among eight Hsp genes tested in this study, we confirmed that the expression of Hsp27 correlated with irinotecan resistance in colorectal cancer cells.

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This study demonstrates a requirement for NF-kappaB activation in cis-diamminedichloroplatinum (cisplatin)-induced apoptosis in human head and neck squamous cell carcinoma (HNSCC) cell lines. This conclusion was supported by the following observations: cisplatin induced IkappaBalpha degradation and NF-kappaB-dependent transcriptional activation prior to cell death; pyrrolidine dithiocarbamate (PDTC), a chemical inhibitor of NF-kappaB activation, prevented apoptosis; lactacystin, an inhibitor of IkappaBalpha degradation, also prevented apoptosis; and finally, the expression of a super-repressor mutant IkappaBalpha blocked apoptosis. The expression of tumor necrosis factor alpha (TNFalpha) was promoted by cisplatin treatment and was suppressed by PDTC treatment.

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Schwannoma, which arises from the neural sheath of peripheral nerves, is the most common benign tumor in the retroperitoneum in adults. Complete excision is the treatment of choice for retroperitoneal schwannoma. During surgery, it seems to be unnecessary to identify the small peripheral nerve from which it develops.

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Cisplatin is a widely used chemotherapeutic agent in head and neck squamous cell carcinoma (HNSCC). Resistance to cisplatin is a common feature of HNSCC. To identify genes that may regulate cisplatin sensitivity, we carried out a cDNA microarray analysis of gene expression in cisplatin-sensitive and cisplatin-resistant HNSCC-derived cell lines.

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We report a case of predominantly cystic synovial sarcoma partly adherent to the hyoid bone in the submental area. The mass demonstrated posterior acoustic enhancement at sonography and a complex cystic mass with mural nodules and solid septa at CT.

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Heptaplatin is a recently developed platinum derivative. This agent has been reported to have a response rate of 17% as a single agent, and tolerable toxicity in the treatment of advanced gastric cancer. The aim of this study was to evaluate the efficacy and toxicity of a combination of 5-fluorouracil (5-FU) and heptaplatin in patients with advanced gastric cancer.

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