Trypsin inhibitors derived from plants have various pharmacological activities and promising clinical applications. In our previous study, a Bowman–Birk-type major trypsin inhibitor from foxtail millet bran (FMB-BBTI) was extracted with antiatherosclerotic activity. Currently, we found that FMB-BBTI possesses a prominent anticolorectal cancer (anti-CRC) activity. Further, a recombinant FMB-BBTI (rFMB-BBTI) was successfully expressed in a soluble manner in host strain Escherichia coli. BL21 (DE3) was induced by isopropyl-β-d-thiogalactoside (0.1 mM) at 37 °C for 3.5 h by the pET28a vector system. Fortunately, a purity greater than 93% of rFMB-BBTI with anti-CRC activity was purified by nickel-nitrilotriacetic acid affinity chromatography. Subsequently, we found that rFMB-BBTI displays a strikingly anti-CRC effect, characterized by the inhibition of cell proliferation and clone formation ability, cell cycle arrest at the G₂/M phase, and induction of cell apoptosis. It is interesting that the rFMB-BBTI treatment had no obvious effect on normal colorectal cells in the same concentration range. Importantly, the anti-CRC activity of rFMB-BBTI was further confirmed in the xenografted nude mice model. Taken together, our study highlights the anti-CRC activity of rFMB-BBTI in vitro and in vivo, uncovering the clinical potential of rFMB-BBTI as a targeted agent for CRC in the future.

中文翻译：

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谷子麸皮重组Bowman-Birk胰蛋白酶抑制剂的表达、纯化及其体内外抗结直肠癌作用

植物来源的胰蛋白酶抑制剂具有多种药理活性，具有广阔的临床应用前景。在我们之前的研究中，从谷子麸中提取了一种具有抗动脉粥样硬化活性的鲍曼-伯克型主要胰蛋白酶抑制剂（FMB-BBTI）。目前，我们发现FMB-BBTI具有显着的抗结直肠癌（抗CRC）活性。此外，重组FMB-BBTI(rFMB-BBTI)在宿主菌株大肠杆菌中以可溶方式成功表达。 BL21 (DE3)由 pET28a 载体系统在 37°C 下用异丙基-β - d-硫代半乳糖苷 (0.1 mM)诱导3.5 小时。幸运的是，通过镍-次氮基三乙酸亲和层析纯化了纯度大于93%的具有抗CRC活性的rFMB-BBTI。随后，我们发现rFMB-BBTI表现出显着的抗CRC作用，其特征是抑制细胞增殖和克隆形成能力、细胞周期停滞在G ₂ /M期并诱导细胞凋亡。有趣的是，在相同浓度范围内，rFMB-BBTI处理对正常结直肠细胞没有明显影响。重要的是，rFMB-BBTI的抗CRC活性在异种移植裸鼠模型中得到进一步证实。总而言之，我们的研究强调了 rFMB-BBTI 在体外和体内的抗 CRC 活性，揭示了 rFMB-BBTI 作为未来 CRC 靶向药物的临床潜力。