Abstract
摘要:膀胱癌是最常見的泌尿癌。相較於膀胱根除手術,膀胱癌病人接受放射治療為基礎的治療,長期預後是比較差的。而且對於復發的膀胱或腎盂泌尿上皮癌,放射治療的效果是很不好的。然而從病人經驗中我們發現:放射治療在某些情況下是可能會促進膀胱癌惡化的。 我在上個年度的科技部計畫:”探討MMP-9在放射線誘發的膀胱癌細胞侵犯與轉移的角色:機轉與治療的意涵”,目前的結果顯示:次致死劑量的放射線可以促進膀胱癌細胞的侵犯和轉移。由於膀胱癌細胞以Matrigel和Gelatin塗層的Transwell侵犯實驗有類似的效果,意味著可與Gelatin結合的MMP-2和MMP-9可能在這個過程扮演重要角色。我們證明了MMP-9在細胞內的表現量和在細胞培養基的酵素活性都可以在放射線照射後增加,然而在MMP-9表現降低的膀胱癌細胞株就看不到放射線促進癌細胞侵犯的效果了。如此原來的假設”MMP-9與放射治療引發的膀胱癌侵犯和轉移有關”已得到初步證實。另一方面我們也發現afatinib,一個同時阻斷EGFR和HER2的酪胺酸激酶抑制劑,可以抑制放射線促進膀胱癌細胞侵犯的作用。本計畫的目的是澄清放射線對細胞間質中蛋白質的影響,同時找到有效可以增加放射治療效果的藥物。本計畫的目標:目標一:了解MMP-9在放射引發的膀胱癌侵犯和轉移中確切的機轉。我們將深入研究EGFR/HER2訊息傳導路徑為何可以抑制MMP-9中介的,放射治療引發的膀胱癌侵犯和轉移。初步的結果顯示:p-EGFR, pHER2和MMP9的表現會在膀胱癌細胞接受放射線照射後增加,而在EGFR/ HER2的雙重抑制(藥物或基因轉殖)後減少這樣的效果。我們的研究也顯示HER2可能藉由影響MAPK或NF-kB來改變MMP-9的表現。目標二:發現PD-1/PD-L1免疫治療可能在放射引發的膀胱癌侵犯和轉移扮演的治療角色。目前有高達五種的PD-1/PD-L1抑制劑被核可用來治療膀胱癌,其中錯配切除修復缺陷(mismatch repair deficient)的腫瘤效果特別好。我們將收集放射治療前的病人與老鼠手術與血液檢體。細胞間質蛋白(例如MMP-9),免疫檢查點(例如PD-L1)和錯配切除修復蛋白(MMR proteins)是分析的重點。這些結果將提供將來實驗室研究與臨床試驗的重要參考。
Abstract: Bladder cancer is the most common urinary tract cancer. The long-term prognosis of radiation- based therapy is inferior to radical cystectomy in bladder cancer patients. Furthermore, for recurrent urothelial carcinoma from bladder or renal pelvis, the effect of radiotherapy is poor. From patient experience we speculated that under certain conditions radiation can promote bladder cancer progression. In previous MOST grant “Exploring the role of MMP-9 in radiation-induced invasion and metastasis in bladder cancer cells: mechanism and therapeutic implications” we found that sublethal dose of irradiation promotes bladder cancer cell invasion. The results of Transwell invasion assay in Matrigel- or gelatin- coated wells were similar, meaning that gelatin-binding matrix metalloproteinases-2 (MMP-2) and matrix metalloproteinases-9 (MMP-9) might play an important role in this process. We demonstrated that MMP-9 intracellular protein expression and enzyme activity in culture media increased after irradiation in bladder cancer cells. Therefore, our hypothesis that MMP-9 is related to radiation-induced invasion and metastasis in bladder cancer cells is proved. On the other hand, we also found that afatinib, a tyrosine kinase inhibitor with EGFR and HER2 dual blockade effect, can inhibit radiation-promoted invasion. The objective of current study is to clarify the influence of radiotherapy on stroma protein and find useful drugs to enhance the effect of radiotherapy. In this project we have two aims:Aim 1: To understand the mechanism how MMP-9 mediates radiation-induced invasion and metastasis in bladder cancer cells. We will explore how EGFR/HER2 pathway can inhibit radiation-activated, MMP-9 mediation invasion and metastasis.The preliminary data showed that that expression of phospho-EGFR, phospho-HER2 and MMP-9 increased after irradiation in bladder cancer cell lines but was decreased after treatment with EGFR/HER2 dual inhibitor (drug or transfection). Our study also showed that HER2 may affect MMP-9 expression by MAPK or NF-kB pathways. Aim 2: To find the therapeutic potential of PD-1 checkpoint inhibitor in radiation-induced invasion and metastasis in bladder cancer cells. No as many as 5 different PD-1/PD-L1 inhibitors are approved to treat bladder cancer. For tumor with mismatch repair deficiency, they are more effective. We will collect patient as well as mouse tissue and blood sample before and after radiotherapy. The pathway analysis will focus on stroma protein (like MMP-9) , immune checkpoint (like PD-L1) and MMR proteins provide important clue for further bench work and clinical trial.
Keyword(s)
放射治療
膀胱癌
HER2
MMP-9
radiotherapy
bladder cancer