二十二碳六烯酸透過破壞脂筏上整合素 α6β4的分佈及整合素α6β4訊號路徑 抑制Hs578T三陰性乳癌細胞之移行及侵襲

Docosahexanoic acid suppresses cell migration and invasion through disruption of the integrin α6β4 distribution in lipid raft and integrin α6β4-mediated signaling in Hs578T triple-negative breast cancer cells

葉靜宜(Jing-Yi Yeh)

指導教授 ： 李健群

中山醫學大學/健康管理學院/營養學系碩士班/碩士(2014年)

https://doi.org/10.6834/CSMU.2014.00076

摘要

乳癌為全球女性最常見的惡性腫瘤，癌細胞轉移是導致乳癌患者死亡的主要原因，在諸多乳癌分型之中，又屬缺乏雌激素(estrogen)、黃體素(progesterone)及人類第二型表皮生長因子(HER2/neu)受體的三陰性乳癌治療最為棘手。許多研究指出，整合素a6β4 (integrin a6β4)的表現與惡性腫瘤的發展息息相關。已有研究指出整合素a6β4、基質金屬蛋白酶-9 (matrix metalloproteinases, MMP-9)、尿激酶型血纖維蛋白溶解酶原活化因子(urokinase plasminogen activator, uPA)及S100鈣結合蛋白A4 (S100A4)在促進乳癌轉移過程中扮演重要角色。先前文獻指出二十二碳六烯酸(docosahexaenoic acid, DHA)對於多種人類癌症具有抗癌效果，然而，其對三陰性乳癌細胞的抗轉移效果及機制尚不清楚。本研究以Hs578T三陰性乳癌細胞為實驗模式，探討DHA對於Hs578T細胞轉移之影響。結果顯示DHA顯著抑制細胞移行、侵襲能力以及向下調節integrin a6β4表現，且呈現濃度依賴關係，而且DHA藉由瓦解細胞膜lipid raft降低其中integrin β4的分佈和Src表現及磷酸化，DHA處理PI3K可負向調控Src及Akt (Ser473)磷酸化及其下游MMP-9、uPA、S100A4蛋白質表現；siRNA knockdown integrin β4亦可抑制MMP-9、uPA、S100A4蛋白質表現。綜合上述結果得知，DHA降低MMP-9, uPA及S100A4表現進而抑制Hs578T乳癌細胞移行、侵襲，部分因素可能與DHA負向調控integrin a6β4表現、減少integrin
β4分佈於lipid raft及抑制integrin a6β4下游Src及Akt訊號路徑的活化。

關鍵字

二十二碳六烯酸 ； 整合素a6β4 ； S100鈣結合蛋白A4 ； 尿激酶型血纖 維蛋白溶解酶原活化因子 ； 基質金屬蛋白酶Hs578T三陰性乳癌細胞

並列摘要

Breast cancer is the commonly diagnosed cancer among women all over the world. Metastasis is leading cause of death from breast cancer. There are many subtypes of breast cancer, especially triple-negative breast cancer (TNBC), defined as the absence of staining for estrogen receptor (ER), progesterone receptor (PR), and HER2/neu receptor is most difficult to be cured. Several studies showed that integrin a6β4 also plays a pivotal role in advanced carcinoma progression. It has been reported that integrin a6β4, matrix metalloproteinase-9 (MMP-9), urokinase plasminogen activator (uPA), and S100A4 play a pivotal role in breast cancer metastasis. Previous studies showed that docosahexaenoic acid (DHA) exhibited an anti-cancer effect in various human carcinoma cells, but the effect of DHA on metastasis of TNBC is not fully clarified. We studied the anti-metastasis potential of DHA in Hs578T TNBC cells. We found that DHA significantly inhibited cell migration, invasion and dramatically down-regulated integrin a6β4 expression in a dose-dependent manner. Furthermore, DHA suppressed the integrin a6β4 distribution as well as Src expression and phosphorylation by disrupting the lipid rafts.DHA down-regulated Src, Akt (Ser473) phosphorylation as well as MMP-9, uPA and S100A4 expression. Knockdown of integrin β4 by integrin β4 siRNA led to decreased MMP-9, uPA and S100A4 protein level. These results suggest that DHA inhibits a6β4-mediated MMP-9, uPA and S100A4 expression as well as cell migration and invasion at least in part via down-regulating integrin a6β4 expression and decreasing the distribution of integrin β4 in lipid raft as well as the activation of
integrin a6β4-mediated Src and Akt signaling pathways.

並列關鍵字

docosahexaenoic acid ； integrin a6β4 ； S100A4 ； urokinase plasminogen activator ； matrix metalloproteinase-9 ； Hs578T triple-negative breast cancer cell

參考文獻

行政院衛生署國民健康局(2014)：中華民國100年癌症登記報告。臺北：行政院衛生署國民健康局　編印。

Sehgal G, Hua J, Bernhard EJ, Sehgal I, Thompson TC, Muschel RJ. Requirement for matrix metalloproteinase-9 (gelatinase B) expression in metastasis by murine prostate carcinoma. Am J Pathol (1998)；152：591–596.

Alonso A, Fernandez-Jarne E, Serrano-Martinez M, Martinez-Gonzalez MA. Fish and shellfish consumption in relation to death from myocardial infarction among men in Shanghai, China. Am J Epidemiol (2001)；157：809–816.

Daviglus ML, Stamler J, Orencia AJ, Dyer AR, Liu K, Greenland P, Walsh MK, Morris D, Shekelle RB. Fish consumption and the 30-year risk of fatal myocardial infarction. N Engl J Med (1997)；336：1046–1053

Barros FF, Powe DG, Ellis IO, Green AR. Understanding the HER family in breast cancer: interaction with ligands, dimerization and treatments. Histopathology (2010)；56：560–572.