PI3K/AKT 訊息調控的細胞凋亡分子在人類癌細胞之放射線治療角色

放射治療是世界上癌症的主要治療方法之一。然而，在放射治療中癌細胞具有放射線抗性的問題仍然難以解決。本研究由放射毒裡學的角度，探討放射線對人類癌細胞毒殺效應的分子機制。第一部分:我們探討放射線治療過程miR-17-5p的效應，在活體的研究中，我們發現在：照射前用miR-17-5p AS ODN處理過的小鼠顯著增強p53蛋白表達並減少腫瘤生長。這些結果表明miR-17-5p調節放射治療下口腔癌OC3細胞中的凋亡相關蛋白;其p53蛋白表達則是透過miR-17-5p / PTEN訊息傳導路徑，強化OC3細胞的放射毒殺效應。第二部分:我們探討可以調節miR-17-5p分子的褐藻糖膠對乳癌細胞的效應。我們發現褐藻糖膠可以通過激活磷酸肌醇3-激酶PI3K/AKT路徑導致乳癌細胞的上皮 - 間質轉化被抑制。褐藻糖膠會通過調節miR-29c/ADAM12和miR-17-5p/PTEN訊息傳導路徑抑制乳癌細胞的進展。此外，miR-17-5p/PTEN antisense oligonucleotides (AS ODN) 反義寡核苷酸也使用於評估體外和體內放射增敏作用。第三部分：我們評估了上皮細胞生長因子接受體epidermal growth factor receptor (EGFR)抑制劑Erbitux和放射治療對PC-3前列腺癌細胞（雄激素非依賴性前列腺癌）的放射毒殺反應。通過使用凋亡蛋白陣列分析，我們發現數種凋亡相關蛋白(Catalase, cIAP-1, Clusterin, Fas, HIF-1α, HSP27, HSP60, HSP70, SMAC 以及Survivin)在放射治療和Erbitux組合中顯著下降。我們也發現了Erbitux會藉由抑制PI3K/Akt的活化，而抑制PI3K/Akt調控之抗細胞凋亡蛋白的表現。我們的系列研究結果顯示，癌細胞中PI3K/Akt訊息活化是癌細胞之放射線治療抗性的重要分子機制。利用天然成份褐藻糖膠阻斷放射線治療過程中的miR-17-5p/PTEN及臨床用藥Erbitux阻斷PI3K/AKT訊號傳遞，都可抑制其下游重要的抗細胞凋亡相關蛋白，而增強放射線對人類腫瘤細胞的毒殺作用。

關鍵字

PI3K / AKT訊號傳遞途徑；放射線治療；放射線抗性；凋亡

並列摘要

Radiotherapy is one of the main therapies for cancers in the world. However, radioresistance is still difficultly resolved in radiotherapy. To evaluate the primary pathway to enhance radiation effect in cancer treatment, we analyses some radioresistance cancers with radiotherapy. Initially we found the effects of fucoidan led to inhibition of epithelial-mesenchymal transition in breast cancer cells by an activation of phosphoinositide 3-kinase (PI3K)/Akt pathway. Fucoidan inhibit the progression of breast cancer cells through regulating the miR-29c/ADAM12 and miR-17-5p/PTEN axes. Furthermore, miR-17-5p AS ODN was used to evaluate the in vitro and in vivo radiosensitization effect. Our further study revealed that the enhancement of p53 expression significantly enhanced the radiation-induced G2/M arrest of the OC3 cells (betel nut chewing induced radioresistence buccal cancer cell line). In the in vivo study, treatment with miR-17-5p AS ODN before irradiation significantly enhanced p53 expression and reduced tumor growth. These results revealed that miR-17-5p regulates apoptosis-related proteins in irradiated OC3 cells; its effect on p53 protein expression contributes to the modulation of the radiosensitivity of the OC3 cells. Finally, we evaluated the effects of combining the EGFR inhibition and radiation on PC-3 prostate cancer cells (androgen-independent). By using a apaptosis protein array, we found that several apaptosis related protein (Catalase, cIAP-1, Clusterin, Fas, HIF-1α, HSP27, HSP60, HSP70, SMAC and Survivin) were significantly downregulated in radiation and ERBITUX combined group. Our results demonstrated that Erbitux enhanced apoptosis effects of radiation on PC-3 through down-regulation of PI3K/AKT Signaling. Taken together, modulation of PI3K/AKT signaling related apoptosis protein enhanced radio sensitivity of human cancer cells.

並列關鍵字

PI3K/AKT Signaling ； radiotherapy ； radioresistence ； apoptosis

參考文獻

1. Siegel R, Naishadham D and Jemal A. Cancer statistics, 2013. CA: a cancer journal for clinicians. 2013; 63(1):11-30.

2. Health Promotion Administration MoHaW. (2011). Taiwan Cancer Registry report, 2011 edition. (Health Promotion Administration, Ministry of Health and Welfare.

3. Liao CT, Wallace CG, Lee LY, Hsueh C, Lin CY, Fan KH, Wang HM, Ng SH, Lin CH, Tsao CK, Chen IH, Huang SF, Kang CJ and Yen TC. Clinical evidence of field cancerization in patients with oral cavity cancer in a betel quid chewing area. Oral oncology. 2014; 50(8):721-731.

4. Liao CT, Kang CJ, Chang JT, Wang HM, Ng SH, Hsueh C, Lee LY, Lin CH, Cheng AJ, Chen IH, Huang SF and Yen TC. Survival of second and multiple primary tumors in patients with oral cavity squamous cell carcinoma in the betel quid chewing area. Oral oncology. 2007; 43(8):811-819.

5. Chen YJ, Chang JT, Liao CT, Wang HM, Yen TC, Chiu CC, Lu YC, Li HF and Cheng AJ. Head and neck cancer in the betel quid chewing area: recent advances in molecular carcinogenesis. Cancer science. 2008; 99(8):1507-1514.

國際替代計量

PI3K/AKT 訊息調控的細胞凋亡分子在人類癌細胞之放射線治療角色

主題瀏覽