探討HMG-CoA synthase 2 (HMGCS2) 在乳癌中的致癌機制

Studies on the Oncogenic Mechanisms of HMG-CoA synthase 2 (HMGCS2) in Breast Cancer Development

張芳瑜(Fang-Yu Chang)

指導教授 ： 何元順

共同指導教授 ： 吳志雄(Chih-Hsiung Wu)

臺北醫學大學/醫學科技學院/醫學檢驗暨生物技術學系/碩士(2012年)

https://doi.org/10.6831/TMU.2012.00170

摘要

由於先前文獻利用DNA微陣列 (microarray analysis) 偵測與乳癌相關的基因，發現HMGCS2在乳癌腫瘤細胞中大量表現，而此研究並未進一步深入探討。本篇利用乳癌細胞株和乳癌臨床檢體探討HMGCS2在乳癌中的機轉與作用。首先，利用Real-time PCR偵測122名乳癌病人HMGCS2的表現，初步觀察到，在病人檢體中HMGCS2在乳癌組織的表現，大於正常組織25倍；並在年齡小於52歲 (中位數)、HER2過度表現、三重陰性 (Triple Negative) 的病人腫瘤組織，HMGCS2的表現量也高於正常組織，且都達到統計上的顯著差異。接著，我們再利用13株乳癌細胞株進行RT-PCR及Western Blot，發現的確HMGCS2在mRNA及蛋白上亦大量表現；並且發現EGF會透過調控HMGCS2 promoter而導致HMGCS2表現量上升。另外，由IP的實驗結果觀察到，在受到EGF刺激後，HMGCS2會與PPARα交互作用；進一步地利用核質分離實驗以及螢光免疫染色實驗發現，HMGCS2在處理EGF後，會從細胞質轉移到細胞核；ChIP證實HMGCS2可能為一個轉錄因子，調控HMGCS2或下游基因，同時HMGCS2也受到p300、SP1及c-jun調控。因此，本篇研究推論，HMGCS2可能為一個轉錄因子，並且受到EGF所調控。未來，我們將透過RNAi和Overexpression的方式，抑制或大量表現HMGCS2，驗證HMGCS2在乳癌之角色。

關鍵字

乳癌 ； HMGCS2

並列摘要

Due to the previous literature, finding breast cancer-related genes by DNA microarrays, detected HMGCS2 up-regulation in breast cancer tumor cells, but the mechanism did not further explored. In this paper, we investigated the mechanism and role of the HMGCS2 in breast cancer, by using breast cancer cell lines and breast cancer clinical specimens. First, the performance of Real-time PCR, detection HMGCS2 mRNA expression in 168 breast cancer patients, observed HMGCS2 in breast tumor tissues was higher than normal tissues for 25-fold, and the patients whom under 52 year-old, HER2 positive, Triple Negative, HMGCS2 is also higher in tumor tissues, compared to normal tissues, and all have statistically significant differences. Then, we detected HMGCS2 expression in 13 breast cancer cell lines by RT-PCR and Western Blot, and found that HMGCS2 was overexpression in breast cancer cell lines. In additional, EGF will regulation HMGCS2 promoter to cause HMGCS2 performance increased. Further, IP-experimental observed HMGCS2 interaction with PPARα, through by EGF stimulation, the nucleus-cytosol extraction experiments and immunofluorescence staining was found HMGCS2 will transfer from the cytoplasm to the nucleus. The ChIP confirmed the HMGCS2 may be a transcription factor, and receive the regulation by EGF, and also regulation by p300, SP1 and c-jun. Future, we will inhibit or overexpression HMGCS2 by RNAi and Overexpression experiment, to verify the HMGCS2 role in breast cancer.

並列關鍵字

Breast cancer ； HMGCS2

參考文獻

[1] T. Powles, R. Eeles, S. Ashley, D. Easton, J. Chang, M. Dowsett, A. Tidy, J. Viggers, and J. Davey, "Interim analysis of the incidence of breast cancer in the Royal Marsden Hospital tamoxifen randomised chemoprevention trial," The Lancet, vol. 352, pp. 98-101, 1998.

[2] E. A. a. R. B. Clarke, "Steroid receptors and cell cycle," Journal of Mammary Gland Biology and Neoplasia, 2004.

[3] P. Ascenzi, A. Bocedi, and M. Marino, "Structure-function relationship of estrogen receptor alpha and beta: impact on human health," Mol Aspects Med, vol. 27, pp. 299-402, Aug 2006.

[4] J. S. Lewis and V. C. Jordan, "Selective estrogen receptor modulators (SERMs): mechanisms of anticarcinogenesis and drug resistance," Mutat Res, vol. 591, pp. 247-63, Dec 11 2005.

[5] J. S. Carroll, O. W. Prall, E. A. Musgrove, and R. L. Sutherland, "A pure estrogen antagonist inhibits cyclin E-Cdk2 activity in MCF-7 breast cancer cells and induces accumulation of p130-E2F4 complexes characteristic of quiescence," J Biol Chem, vol. 275, pp. 38221-9, Dec 8 2000.