Eye Center & Key Laboratory of Cancer Prevention and Intervention, MOE, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310029, China.
Institute of Translational Medicine and The Cancer Institute of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310029, China.
Sci Adv. 2020 May 20;6(21):eaba5996. doi: 10.1126/sciadv.aba5996. eCollection 2020 May.
Microalgae, a naturally present unicellular microorganism, can undergo light photosynthesis and have been used in biofuels, nutrition, etc. Here, we report that engineered live microalgae can be delivered to hypoxic tumor regions to increase local oxygen levels and resensitize resistant cancer cells to both radio- and phototherapies. We demonstrate that the hypoxic environment in tumors is markedly improved by in situ-generated oxygen through microalgae-mediated photosynthesis, resulting in notably radiotherapeutic efficacy. Furthermore, the chlorophyll from microalgae produces reactive oxygen species during laser irradiation, further augmenting the photosensitizing effect and enhancing tumor cell apoptosis. Thus, the sequential combination of oxygen-generating algae system with radio- and phototherapies has the potential to create an innovative treatment strategy to improve the outcome of cancer management. Together, our findings demonstrate a novel approach that leverages the products of photosynthesis for treatment of tumors and provide proof-of-concept evidence for future development of algae-enhanced radio- and photodynamic therapy.
微藻是一种天然存在的单细胞微生物，能够进行光合作用，并已被用于生物燃料、营养等领域。在这里，我们报告说，经过工程改造的活体微藻可以被递送到缺氧的肿瘤区域，以增加局部氧气水平，并使耐药癌细胞对放射和光疗重新敏感。我们证明，通过微藻介导的光合作用原位产生的氧气可以显著改善肿瘤中的缺氧环境，从而显著提高放射治疗的疗效。此外，微藻中的叶绿素在激光照射下会产生活性氧，进一步增强光致敏作用，促进肿瘤细胞凋亡。因此，用产氧藻类系统与放射和光疗的序贯联合有可能创造一种创新的治疗策略，以改善癌症管理的结果。总之，我们的研究结果表明了一种利用光合作用产物治疗肿瘤的新方法，并为未来开发藻类增强的放射和光动力疗法提供了概念验证证据。
