Background:

The death rate (the number of deaths per 100 000 people per year) of colorectal cancer (CRC) has been dropping since 1980 due to increased screening, lifestyle-related risk factors, and improved treatment options; however, CRC is the third leading cause of cancer-related deaths in men and women in the United States. Therefore, successful therapy for CRC is an unmet clinical need. This study aimed to investigate the impacts of andrographolide (AGP) and melatonin (MLT) on CRC and the underlying mechanism.

Methods:

To investigate AGP and MLT anticancer effects, a series of metastatic colon cancer cell lines (T84, Colo 205, HT-29, and DLD-1) were selected. In addition, a metastatic patient-derived organoid model (PDOD) was used to monitor the anticancer effects of AGP and MLT. A series of bioassays including 3D organoid cell culture, MTT, colony formation, western blotting, immunofluorescence, and quantitative polymerase chain reaction (qPCR) were performed.

Results:

The dual therapy significantly promotes CRC cell death, as compared with the normal cells. It also limits CRC colony formation and disrupts the PDOD membrane integrity along with decreased Ki-67 expression. A significantly higher cleaved caspase-3 and the endoplasmic reticulum (ER) stress proteins, IRE-1 and ATF-6 expression, by 48 hours were found. This combinatorial treatment increased reactive oxygen species (ROS) levels. Apoptosis signaling molecules BAX, XBP-1, and CHOP were significantly increased as determined by qPCR.

Conclusions:

These findings indicated that AGP and MLT associated ER stress-mediated apoptotic metastatic colorectal cancer (mCRC) cell death through the IRE-1/XBP-1/CHOP signaling pathway. This novel combination could be a potential therapeutic strategy for mCRC cells.

中文翻译：

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穿心莲内酯和褪黑激素联合药物治疗对转移性结肠癌细胞和类器官的影响

背景：

自 1980 年以来，由于筛查的增加、生活方式相关的危险因素和治疗方案的改进，结直肠癌 (CRC) 的死亡率（每年每 10 万人中的死亡人数）一直在​​下降；然而，CRC 是美国男性和女性癌症相关死亡的第三大原因。因此，CRC的成功治疗是未满足的临床需求。本研究旨在探讨穿心莲内酯 (AGP) 和褪黑激素 (MLT) 对 CRC 的影响及其潜在机制。

方法：

为了研究 AGP 和 MLT 的抗癌作用，选择了一系列转移性结肠癌细胞系（T84、Colo 205、HT-29 和 DLD-1）。此外，转移性患者衍生的类器官模型（PDOD）用于监测 AGP 和 MLT 的抗癌作用。进行了一系列生物测定，包括 3D 类器官细胞培养、MTT、集落形成、蛋白质印迹、免疫荧光和定量聚合酶链反应 (qPCR)。

结果：

与正常细胞相比，双重疗法显着促进CRC细胞死亡。它还限制 CRC 集落形成并破坏 PDOD 膜完整性以及降低 Ki-67 表达。发现到 48 小时，裂解的 caspase-3 和内质网 (ER) 应激蛋白 IRE-1 和 ATF-6 表达显着升高。这种组合处理增加了活性氧（ROS）水平。通过 qPCR 测定，细胞凋亡信号分子 BAX、XBP-1 和 CHOP 显着增加。

结论：

这些发现表明，AGP 和 MLT 通过 IRE-1/XBP-1/CHOP 信号通路与 ER 应激介导的凋亡性转移性结直肠癌 (mCRC) 细胞死亡相关。这种新的组合可能是 mCRC 细胞的潜在治疗策略。