細胞激素Interleukin-6與趨化激素CXCL1在口腔鱗狀上皮細胞癌惡化及放射線抗性之角色

Interleukin-6 and CXCL1 in oral squamous cell carcinoma progression and radioresistance

魏鈴穎(Ling-Ying Wei)

指導教授 ： 賈景山 ； 李正?

國立臺灣大學/醫學院/臨床牙醫學研究所/博士(2019年)

https://doi.org/10.6342/NTU201900273

摘要

口腔鱗狀上皮細胞癌的腫瘤微環境是由細胞激素、趨化激素及免疫反應等交 織而成的發炎環境，發炎不僅調控癌症進程，亦影響了臨床的治療效果。本文第一 部分將探討腫瘤介質(tumoral mediators)在腫瘤細胞的生長與放射線抗性之調節 機制，第二部分則探討腫瘤相關纖維母細胞(cancer associated fibroblasts)在腫瘤 微環境中受到發炎訊號刺激後的反應，及其反向對腫瘤細胞侵犯及遷移能力的影響。
在第一部分，免疫組織化學染色及癌症基因體圖譜計畫(The Cancer Genome Atlas)資料庫分析發現當組織高量表現 interleukin-6(IL-6)時，口腔癌患者有較 差的放射治療反應及預後。細胞實驗及動物實驗顯示 IL-6 可以促進腫瘤細胞的生 長，且 IL-6 可以抑制放射線引起之細胞凋亡，其機制是透過 ERK1/2 訊息傳導路 徑減少雙股 DNA 斷裂。在動物模型中，當腫瘤的 STAT3 被抑制且同時給予 IL-6 刺激時，其對放射線的治療效果最差，顯示在放射線抗性的調節機制中，ERK1/2 訊息路徑之角色較 STAT3 來得重要。在第二部分，我們發現 CXCL1 高量表現在 腫瘤相關纖維母細胞中，且其在腫瘤中的表現高時病患之存活率較差。此外，我們 發現 IL-1β 的表現與 CXCL1 有正相關，當腫瘤相關纖維母細胞受到 IL-1β 刺激或 與腫瘤細胞株共同培養時，CXCL1 會透過 NF-κB 訊息路徑大量表現。相對地當腫 瘤細胞受到 CXCL1 刺激或以腫瘤相關纖維母細胞之培養液刺激時，會增加腫瘤細 胞侵犯及遷徙的能力，其機制是透過增加 MMP1 之表現，表示在腫瘤相關纖維母 細胞與腫瘤細胞之間存在一個相互影響之關係。
根據研究發現，我們了解細胞激素與趨化激素如 IL-6 與 CXCL1 在口腔癌腫 瘤微環境中扮演了一個重要的角色。IL-6 可以透過 STAT3 相關及不相關的路徑來 調控腫瘤的生長與放射線抗性，並且是一個獨立於癌症分期、可以作為預測預後的 重要因子。未來可以期待，針對阻斷 IL-6/ERK 路徑的藥物為口腔癌疾病的控制與克服放射線抗性帶來輔助的效果。此外，腫瘤微環境中的 IL-1β 可以教育或活化腫瘤相關纖維母細胞，其產生之 CXCL1 可以進一步使腫瘤細胞侵犯及遷徙的能力增 加，兩者間相互關係調控了腫瘤的進程與惡化。總地來說，腫瘤細胞與基質細胞之 間透過發炎介質產生交互作用，在腫瘤生物學中影響甚鉅。

關鍵字

口腔鱗狀上皮細胞癌 ； 放射線抗性 ； 腫瘤相關纖維母細胞 ； 介白質-1β ； 介白質-6 ； 趨化激素 CXCL1 ； 基質金屬蛋白-1 ； 腫瘤侵犯 ； 存活率

並列摘要

Oral squamous cell carcinoma (OSCC) induces an inflammatory microenvironment comprised of cytokines, chemokines, and immune responses that may not only modulate cancer progression but also affect the therapeutic effects. The molecular mechanisms that how tumoral mediators regulate tumor growth and radioresistance and how cancer associated fibroblasts (CAFs) respond to inflammatory signals to influence cancer cell migration and invasion were investigated.
In the tumoral mediators part, immunostaining and TCGA data-based analysis indicated that high interleukin-6 (IL-6) expression in Situ were associated with a clinically unfavorable prognosis and radioresistance of patients with OSCC. Genetically and pharmalogically increased IL-6 induced cell proliferation in vitro and accelerated tumor growth in in vivo models. Experiments of radiation response demonstrated that IL-6 inhibited radiation-induced cell death by reducing DNA damage through ERK1/2- dependent signaling. In xenograft model, the worst tumor growth inhibition of irradiation was found in the IL-6 supplemented STAT3-knockdown group. In other words, blockade of ERK1/2 but not STAT3 pathway led to a substantial increase in apoptosis of OSCC cells. In the stromal interaction part, analysis of the TCGA dataset revealed that CXCL1 is associated with poor survival, and highly expressed in CAFs. In addition to CXCL1, IL-1β and CXCR2 are also highly expressed in OSCC and IL-1β mRNA levels positively correlate with CXCL1 expression. Furthermore, CAFs co-cultured with a poorly differentiated OSCC cell line SAS, or stimulated with IL-1β exhibit increased CXCL1 secretion in an NF-κB-dependent manner. Treatment of SAS cells with CAF-conditioned medium or CXCL1 increased their invasion and migration capabilities, indicating a reciprocal activation between CAFs and cancer cells. Moreover, CXCL-1 upregulated matrix metalloprotease-1 (MMP-1) expression and activity in CAFs.
These findings demonstrate that the cytokines and chemokines, like IL-6 and CXCL1, play an important role in OSCC microenvironment. IL-6 promotes oral cancer cell growth and radioresistance in both STAT3-dependent and -independent manners and is a stage-independent predictor of poor prognosis. The possibility of targeting IL-6/ERK axis for a therapeutic strategy to suppress OSCC progression and overcome radioresistance could also be expected. Also, the induction of IL-1β following CXCL1 stimulation of CAFs mediates cancer cell migration and invasion, and there is a reciprocal dependency between CAFs and cancer cells. Taken together, crosstalk between cancer and stromal cells through the inflammatory mediators is known to be significantly involved in various aspects of tumor biology.

並列關鍵字

oral squamous cell carcinoma ； radioresistance ； cancer-associated fibroblasts ； IL-1β ； IL-6 ； CXCL1 ； matrix metalloproteinase 1 ； neoplasm invasiveness ； survival rate

參考文獻

[1] Bray F, Ferlay J, Soerjomataram I, Siegel RL, Torre LA, Jemal A. Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2018;68:394-424.

[2] Sturgis EM, Cinciripini PM. Trends in head and neck cancer incidence in relation to smoking prevalence: an emerging epidemic of human papillomavirus-associated cancers? Cancer. 2007;110:1429-35.

[3] Hsu WL, Chien YC, Chiang CJ, Yang HI, Lou PJ, Wang CP, et al. Lifetime risk of distinct upper aerodigestive tract cancers and consumption of alcohol, betel and cigarette. Int J Cancer. 2014;135:1480-6.

[4] Warnakulasuriya S. Global epidemiology of oral and oropharyngeal cancer. Oral Oncol. 2009;45:309-16.

[5] Thomson PJ, Hamadah O. Cancerisation within the oral cavity: the use of 'field mapping biopsies' in clinical management. Oral Oncol. 2007;43:20-6.