Anticancer Research, 2014, 34(9):4685-92.

Genistein potentiates the antitumor effect of 5-fluorouracil by inducing apoptosis and autophagy in human pancreatic cancer cells

Rei Suzuki, Ya'an Kang, Xinqun Li, et al

Department of Gastroenterology, Hepatology and Nutrition, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA

BACKGROUND:

Although 5-fluorouracil (5-FU)-based combination chemotherapy (i.e. FOLFIRINOX) has demonstrated effectiveness against pancreatic cancer, novel therapeutic strategies must be developed to increase the therapeutic window of these cytotoxic agents. Genistein is a soy-derived isoflavone with pleiotropic biological effects that can enhance the antitumor effect of chemotherapeutic agents.

MATERIALS AND METHODS:

To understand how genistein potentiates the antitumor effects of 5-FU, we examined apoptosis and autophagy in MIA PaCa-2 human pancreatic cancer cells and their derived xenografts. Apoptosis was evaluated using DNA fragmentation assays, and western blots of poly(ADP ribose)polymerase and caspase-3. Meanwhile, autophagy was evaluated using western blots of microtubule-associated protein light chain 3 (LC3)-I/II, fluorescent microscopy observation of green fluorescent protein-LC3B puncta formation, and acidic vesicular organelle formation using acridine orange staining. Tumors from animal treatment studies were examined for apoptosis and autophagy using the TdT-mediated dUTP nick-end labeling assay and immunohistochemical staining of LC3B, respectively.

RESULTS:

We observed that genistein increased 5-FU-induced cell death through increased apoptosis, as well as autophagy. The increased autophagy was accompanied by decreased B-cell lymphoma 2 (Bcl2) and increased beclin-1 protein levels. Animal treatment studies supported these observations. The combination of 5-FU and genistein significantly reduced final xenograft tumor volume when compared to 5-FU-alone by inducing apoptosis as well as autophagy.

CONCLUSION:

Genistein can potentiate the antitumor effect of 5-FU by inducing apoptotic as well as autophagic cell death. These results demonstrate the potential of genistein as an adjuvant therapeutic agent against pancreatic cancer.

希腊《抗肿瘤研究》，2014年9月

在人体胰腺癌细胞中金雀异黄素通过诱导细胞凋亡及自我吞噬来增强5-氟尿嘧啶的抗肿瘤作用

铃木丽，康亚安，李新群，等

美国得克萨斯州得克萨斯大学安德森癌症中心肝脏和营养部消化内科和肿瘤外科

背景︰

虽然基于 5-氟尿嘧啶 (5-FU)的联合化疗法 (例如奥沙利铂三药联合化疗) 已经证明了对抗胰腺癌的有效性，但是必须开发新的治疗方法来增加这些细胞毒性药物的治疗窗口。金雀异黄素是一种来源于大豆的异黄酮，具有可以提高化疗药物抗肿瘤作用的多重生物学效应。

材料和方法︰

为了了解金雀异黄素如何增强 5-氟尿嘧啶的抗肿瘤作用，在 MIA PaCa-2 人体胰腺癌细胞及其异种移植瘤中我们检查了细胞凋亡和细胞自噬的情况。使用 DNA 碎片分析法和聚合酶与半胱氨酸蛋白酶-3 的免疫印迹法对细胞凋亡进行了测试。同时，使用微管相关蛋白轻链 3 (LC3)-I / II的免疫印迹法测试细胞自噬情况，用荧光显微镜观察绿色荧光蛋白 LC3B 以及用吖啶橙染色法测试酸性囊状细胞器的形成。使用 TdT 介导的原位缺口末端标记法和LC3B的免疫组化染色法分别测试动物治疗研究中的肿瘤的细胞凋亡和细胞自噬。

结果︰

我们观察到金雀异黄素通过增加细胞凋亡和细胞自噬促进了5-氟尿嘧啶对细胞死亡的诱导。增加的细胞自噬伴随着B 细胞淋巴瘤 2 (Bcl2)的减少和 beclin-1 蛋白水平的升高。动物治疗研究支持这些发现。与5-氟尿嘧啶单独通过诱导细胞凋亡以及细胞自噬相比，5-氟尿嘧啶和金雀异黄素的联合明显减少了最终异种移植瘤的体积。

结论︰

金雀异黄素可以通过诱导细胞凋亡以及自噬性细胞死亡增强 5-氟尿嘧啶的抗肿瘤作用。这些结果表明金雀异黄素作为辅助药物治疗胰腺癌的潜力。