Department of Biotechnology, Rathinam College of Arts and Science, RathinamTechzone Campus, Eachanari, Coimbatore, 641 021, Tamil Nadu, India.
Institute of Advanced Virology, Thiruvananthapuram, 695014, Kerala, India.
Microb Pathog. 2023 Dec;185:106396. doi: 10.1016/j.micpath.2023.106396. Epub 2023 Oct 19.
Cancer is a major public burden and leading cause of death worldwide; furthermore, it is a significant barrier to increasing life expectancy in most countries of the world. Among various types of cancers, breast and lung cancers lead to significant mortality in both males and females annually. Bacteria-derived products have been explored for their use in cancer therapy. Although bacteria contain significant amounts of anticancer substances, attenuated bacteria may still pose a potential risk for infection owing to the variety of immunomodulatory molecules present in the parental bacteria; therefore, non-cellular bacterial extracellular vesicles (BEVs), which are naturally non-replicating, safer, and are considered to be potential anticancer agents, are preferred for cancer therapy. Gram-positive bacteria actively secrete cytoplasmic membrane vesicles that are spherical and vary between 10 and 400 nm in size. However, no studies have considered cytoplasmic membrane vesicles derived from Bacillus licheniformisin cancer treatment. In this study, we investigated the potential use of B. licheniformis extracellular nanovesicles (BENVs) as therapeutic agents to treat cancer. Purified BENVs from the culture supernatant of B. licheniformis using ultracentrifugation and ExoQuick were characterized using a series of analytical techniques. Human breast cancer cells (MDA-MB-231) and lung cancer cells (A549) were treated with different concentrations of purified BENVs, which inhibited the cell viability and proliferation, and increased cytotoxicity in a dose-dependent manner. To elucidate the mechanism underlying the anticancer activity of BENVs, the oxidative stress markers such as reactive oxygen species (ROS) and glutathione (GSH) levels were measured. The ROS levels were significantly higher in BENV-treated cells, whereas the GSH levels were markedly reduced. Cells treated with BENVs, doxorubicin (DOX), or a combination of BENVs and DOX showed significantly increased expression of p53, p21, caspase-9/3, and Bax, and concomitantly decreased expression of Bcl-2. The combination of BENVs and doxorubicin enhanced mitochondrial dysfunction, DNA damage, and apoptosis. To our knowledge, this is the first study to determine the anticancer properties of BENVs derived from industrially significant probacteria on breast and lung cancer cells.
癌症是全球主要的公共负担和主要死因；此外，它也是大多数国家提高预期寿命的重大障碍。在各种类型的癌症中，乳腺癌和肺癌每年在男性和女性中的死亡率都很高。人们一直在探索细菌衍生产品在癌症治疗中的应用。尽管细菌中含有大量抗癌物质，但由于亲代细菌中存在多种免疫调节分子，减毒细菌仍可能存在感染的潜在风险；因此，非细胞细菌细胞外囊泡（BEVs），由于其是非复制性的、更安全的，被认为是潜在的抗癌药物，因此更适合癌症治疗。革兰氏阳性菌积极分泌细胞质膜囊泡，其为球形，大小在 10 至 400nm 之间。然而，目前还没有研究考虑过来自地衣芽孢杆菌的细胞质膜囊泡在癌症治疗中的应用。在这项研究中，我们研究了地衣芽孢杆菌细胞外纳米囊泡（BENV）作为治疗剂治疗癌症的潜力。使用超速离心和 ExoQuick 从地衣芽孢杆菌的培养上清液中纯化 BENV，并使用一系列分析技术对其进行了表征。不同浓度的纯化 BENV 处理人乳腺癌细胞（MDA-MB-231）和肺癌细胞（A549），结果显示其以剂量依赖性方式抑制细胞活力和增殖，并增加细胞毒性。为了阐明 BENV 抗癌活性的机制，测量了氧化应激标志物，如活性氧（ROS）和谷胱甘肽（GSH）水平。BENV 处理的细胞中的 ROS 水平显著升高，而 GSH 水平明显降低。用 BENV、阿霉素（DOX）或 BENV 和 DOX 联合处理的细胞显示出 p53、p21、caspase-9/3 和 Bax 的表达显著增加，而 Bcl-2 的表达显著降低。BENV 和阿霉素的联合作用增强了线粒体功能障碍、DNA 损伤和细胞凋亡。据我们所知，这是第一项关于工业上重要的益生菌地衣芽孢杆菌来源的 BENV 对乳腺癌和肺癌细胞的抗癌特性的研究。
