探討ITPKC透過鈣池調控鈣離子通道調控乳癌細胞生長之機制與藥物基因體學在新藥開發過程之法規與應用

Functional role of ITPKC gene in the pathogenesis of breast cancer and investigation of laws for pharmacogenomics applications

姚琬婷(Wan-Ting Yao)

指導教授 ： 張偉嶠

臺北醫學大學/藥學院/生技製藥企業經營管理產業碩士專班/碩士(2014年)

摘要

乳癌為全球女性發生率最高的癌症。在台灣，乳癌位居女性十大癌症發生率之首，其死亡率為排名第四。先前的研究指出STIM1和Orai1這兩種參與在鈣池調控鈣離子流入(Store-Operated Calcium Entry, SOCE)的分子對於乳癌細胞遷移和小鼠中癌症的轉移扮演非常重要的角色。近期的研究發現1,4,5-三磷酸肌醇激酶-C(Inositol 1,4,5-Trisphosphate 3-Kinase C, ITPKC)為SOCE之負調控子，並參與SOCE所誘導之NFAT訊息傳遞。為探討ITPKC是否經由抑制鈣池調控鈣離子流入而達到抑制乳癌轉移的作用，本研究透過細胞實驗將ITPKC大量表現於乳癌細胞株－MDA-MB-231中，並觀察乳癌細胞之遷移、侵襲與細胞鈣離子內流量。結果顯示ITPKC的過量表現會降低經由鈣池調控鈣離子通道(Store-Operated Calcium Channel, SOC)之鈣離子內流，進而抑制乳癌細胞的遷移與侵襲，且在早期乳癌組織中ITPKC有較高的表現情形。本研究亦納入384名台灣女性乳癌患者，並篩選出8個ITPKC的標籤單一核苷酸基因多型性，探討ITPKC基因多型性與乳癌轉移之相關性。結果顯示有4個ITPKC的單一核苷酸多型性(Single Nucleotide Polymorphism, SNP)－rs7257602、rs7251246、rs890934和rs2290692與腫瘤遠端轉移有顯著相關，其中當rs7251246為G/G基因型或攜帶G等位基因時，可看到乳癌之遠處轉移風險增加。此外rs11673492被發現在荷爾蒙受體陽性、Her-2陰性與三陽性受體的乳癌病患上，皆與無疾病存活期(Disease Free Survival, DFS)有顯著相關，且其為G/G基因型時會有較高的風險會導致復發或死亡。本研究顯示ITPKC基因為ㄧ保護性之角色，當ITPKC大量表現時，會抑制乳癌的生長與腫瘤的轉移，可能作為未來應用在臨床癌症診斷、治療與藥物開發上ㄧ具潛力的生物標記。
基因體生物標記為ㄧ重要臨床工具，有助於個人化醫療的發展。而隨著藥物基因體學研究的興起，藥物基因體生物標記已廣泛被加入藥物仿單的標示，並被納入藥物上市後的安全監測。藥物基因體學係指研究個體間的基因差異與藥物反應之相關性的ㄧ門學科，近年來為推動藥物開發以及法規科學，全球各法規管理局已發布關於藥物基因體學之準則。本研究主要針對歐美地區與我國對於藥物基因體學於新藥開發過程之法規與應用作ㄧ探討。

關鍵字

乳癌 ； 鈣池調控鈣離子通道 ； 1,4,5-三磷酸肌醇3激酶-C ； 藥物基因體學

並列摘要

Breast cancer is the most common cancer of women worldwide. In Taiwan, breast cancer is the fourth leading cause of death and its incidence is the highest among top ten cancer in women. Previous study reported that Orai1 and STIM1, which are involved in store-operated calcium entry (SOCE), play important roles in breast tumor cell migration in vitro and tumor metastasis in mice. Recent studies have indicated that 1, 4, 5-trisphosphate 3-kinase C (ITPKC) acting as a negative regulator of SOC participates in SOCE-mediated NFAT signaling pathway. To investigate whether ITPKC inhibits breast cancer metastasis via attenuation of SOCE, this study overexpressed ITPKC in a cell-based model using a breast cancer cell line – MDA-MB-231 cells and assessed the cancer migration, invasion and calcium influx. The results of the study showed that overexpression of ITPKC decreased the calcium influx through store-operated calcium channel (SOC) and inhibited the migration and invasion of breast cancer. In addition, the study also analyzed the genotypic distribution of eight genetic variations of ITPKC among 384 Taiwanese women patients with breast cancer to identify the association between ITPKC genetic polymorphisms and breast cancer development. The results revealed that four single nucleotide polymorphisms (SNPs), rs7257602, rs7251246, rs890934 and rs2290692, were correlated with metastasis of cancer and G/G genotype as well as G allele of rs7251246 significantly increased the risk of cancer metastasis. Additionally, rs11673492 was found to have significant correlation with disease free survival (DFS) in breast cancer patients being hormone receptor positive, Her-2 negative and triple-positive. Patients with G/G genotype of rs11673492 had higher risk to progress to recurrence or death. The study demonstrated the association of ITPKC polymorphisms and expression with breast cancer metastasis, suggesting ITPKC being a potential biomarker for diagnosis, treatment and drug development of cancer in the future.
Biomarker is an important clinical tool contributing to the development of personal medicine. With the rise of study in pharmacogenomics, many pharmacogenomic biomarkers have been included to drug labeling and pharmacovigilance. Pharmacogenomics is a subject aiming to identify the association between drug response and genetic difference among individuals. Many administrations worldwide have recently lunched rules regarding the pharmacogenomics in order to promote drug development and regulatory science. This study reviewed and discussed regulations of pharmacogenomics during the new drug development in United States, Europe and Taiwan

並列關鍵字

Breast cancer ； Store-operated calcium channel(SOC) ； 1, 4, 5-trisphosphate 3-kinase C(ITPKC) ； Pharmacogenomics

參考文獻

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