由中藥草中分離能提升輻射治癌效果的輻射增敏劑(3-3)

譚世特
國立清華大
本計畫之目的在:由中藥草等天然物之萃取物中篩檢出能使生物細胞增加游離輻射敏感性者。這些成份有潛力被研發成能提升輻射治癌效用的輻射增敏劑(radiosensitizers)。

在此三年計畫前二年，我們已建立一套以微生物細胞為基礎的快速篩檢步驟。篩檢條件的考慮要點包括菌株種類，測試時的細胞生理狀態，藥物處理條件，及游離輻射照射劑量等。

到目前為止，我們已檢測出對測試細胞(Deinococcus radiodurans IR)有明顯的輻射增敏效應兩個的樣品（THKM8605與THKM75）；此成功初步證明所採用的篩檢步驟的有效性。

計畫第三年的工作項目與目的為：（一）測試THKM8605與THKM75對各類哺乳類細胞（包括癌細胞與正常細胞）的輻射增敏效應及毒性；（二）測試與THKM8605或THKM75構造相似的化合物（分別是THKM8605-1、 THKM8605-2與THKM75-1）的增敏效果，以推測與輻射增敏效應有關化學構造；（三）探討 THKM8605與THKM75對D. radiodurans IR的輻射增敏效應的機制，初步將測試該機制是否涉及細胞循環調控；（四）初步建立適用於輻射增敏劑評估的動物實驗系統。 

關鍵字：癌症治療、中藥輻射增敏劑、抗癌中藥

Screening the Chinese Medicine for Radiation Sensitizers in Radiotherapy for Human Cancers (3-3)

Shieh-Te Tan, Ph.D. 
Institute of Radiation Biology, National Tsing Hua University
The three-year project was designed to isolate natural compounds that can increase the radiosensitivity of living cells. These compounds would then be used as the starting materials for developing radiosensitizers applicable in the treatment of human cancers by radiotherapy.

In the past two years, we have established an applicable microbe-based screening procedure for radiosensitizers. This procedure has been largely optimized with respect to strain, physiological state of the cells, conditions for drug treatment and irradiation.

We have identified two samples (THKM8605 and THKM75) to be capable of sensitizing the test strain Deinococcus radiodurans IR to ionizing radiation induced killing; the success suggests the usefulness of the screening protocol. 

The purposes of the third year of the project are (1) to determine the toxicity and radiosensitization capacity of THKM8605 and THKM75 toward various mammalian cell lines, (2) to assay the radiosensitization effects
關鍵字：Cancer therapy, Chinese medicine as radiosensitizer, Anticancer Chinese medicine