Egyptian Drug Authority, Giza, Egypt.
Biochemistry Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
J Biochem Mol Toxicol. 2023 May;37(5):e23324. doi: 10.1002/jbt.23324. Epub 2023 Feb 19.
Panitumumab is an approved monoclonal antibody for the treatment of colorectal cancer (CRC); however, mutations in EGFR signaling pathway resulted in poor response. Schisandrin-B (Sch-B) is a phytochemical that was suggested to protect against inflammation, oxidative stress, and cell proliferation. The present study aimed to investigate the potential effect of Sch-B on panitumumab-induced cytotoxicity in wild-type Caco-2, and mutant HCT-116 and HT-29 CRC cell lines, and the possible underlying mechanisms. CRC cell lines were treated with panitumumab, Sch-B, and their combination. The cytotoxic effect of drugs was determined by MTT assay. The apoptotic potential was assessed in-vitro by DNA fragmentation and caspase-3 activity. Additionally, autophagy was investigated via microscopic detection of autophagosomes and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) measurement of Beclin-1, Rubicon, LC3-II, and Bcl-2 expression. The drug pair enhanced panitumumab cytotoxicity in all CRC cell lines where IC50 of panitumumab was decreased in Caco-2 cell line. Apoptosis was induced through caspase-3 activation, DNA fragmentation, and Bcl-2 downregulation. Caco-2 cell line treated with panitumumab showed stained acidic vesicular organelles, contrariwise, all cell lines treated with Sch-B or the drug pair displayed green fluorescence indicating the lack of autophagosomes. qRT-PCR revealed the downregulation of LC3-II in all CRC cell lines, Rubicon in mutant cell lines, and Beclin-1 in HT-29 cell line only. Sch-B at 6.5 µM promoted panitumumab-induced apoptotic cell death, in-vitro, via caspase-3 activation and Bcl-2 downregulation, rather than autophagic cell death. This novel combination therapy against CRC, allows the reduction of panitumumab dose to guard against its adverse effects.
帕尼单抗是一种已获批用于治疗结直肠癌（CRC）的单克隆抗体；然而，EGFR 信号通路的突变导致其反应不佳。五味子丙素（Sch-B）是一种植物化学物质，据称可预防炎症、氧化应激和细胞增殖。本研究旨在探讨 Sch-B 对野生型 Caco-2 以及突变型 HCT-116 和 HT-29 CRC 细胞系中帕尼单抗诱导的细胞毒性的潜在影响，以及可能的潜在机制。用帕尼单抗、Sch-B 和它们的组合处理 CRC 细胞系。通过 MTT 测定法确定药物的细胞毒性作用。通过 DNA 片段化和 caspase-3 活性评估体外凋亡潜能。此外，通过自噬体的显微镜检测和 Beclin-1、Rubicon、LC3-II 和 Bcl-2 表达的定量逆转录聚合酶链反应（qRT-PCR）测量来研究自噬。药物组合增强了所有 CRC 细胞系中帕尼单抗的细胞毒性，其中 Caco-2 细胞系中帕尼单抗的 IC50 降低。通过 caspase-3 激活、DNA 片段化和 Bcl-2 下调诱导凋亡。用帕尼单抗处理的 Caco-2 细胞系显示染色的酸性囊泡细胞器，相反，用 Sch-B 或药物组合处理的所有细胞系均显示绿色荧光，表明缺乏自噬体。qRT-PCR 显示所有 CRC 细胞系中 LC3-II 下调，突变细胞系中 Rubicon 下调，仅 HT-29 细胞系中 Beclin-1 下调。6.5µM 的 Sch-B 在体外通过 caspase-3 激活和 Bcl-2 下调促进帕尼单抗诱导的细胞凋亡，而不是自噬性细胞死亡。这种针对 CRC 的新型联合治疗方法可以减少帕尼单抗的剂量，以防止其不良反应。
