The effect of hypoxia on potentiation of cyclooxygenase-2 expression
碩士 === 國立成功大學 === 生理學研究所 === 95 === Cyclooxygenase-2 (COX-2) is overexpressed in many pathological tissues such as cancerous and endometriotic cells, which often results in increased malignancy and poor prognosis. However, mechanisms responsible for overexpression of COX-2 in these tissues are larg...
| Main Authors: | , |
|---|---|
| Other Authors: | |
| Format: | Others |
| Language: | zh-TW |
| Published: |
2007
|
| Online Access: | http://ndltd.ncl.edu.tw/handle/62891257677241346294 |
| Summary: | 碩士 === 國立成功大學 === 生理學研究所 === 95 === Cyclooxygenase-2 (COX-2) is overexpressed in many pathological tissues such as cancerous and endometriotic cells, which often results in increased malignancy and poor prognosis. However, mechanisms responsible for overexpression of COX-2 in these tissues are largely unkown. Here we first took endometriosis as our model and hypothesized that overexpression of COX-2 in ectopic stromal cells is likely due to hypoxia-mediated modification of COX-2 gene leading to increased sensitivity to exogenous stimuli such as proinflammatory cytokines. To test this hypothesis, we cultured eutopic endometrial stromal cells under hypoxia and examined the responsiveness of COX-2. Hypoxia had different effects on COX-2 responsiveness among patients with half of the cases tested showing down-regulation. Hypoxia pretreatment in cervical cancer cell line (HeLa cells) enhanced COX-2 promoter activity but decreased the protein expression in response to IL-1刍. However, endometrial cancer cell line treated and pretreated with hypoxia increased COX-2 expression. These results indicated that hypoxia pretreatment had different effects on COX-2 responsiveness in different tissues. The mechanisms of differential regulation of hypoxia on COX-2 should be further investigated to reveal the biological significance.
|
|---|