The Study on the Effect and Mechanism of Crocinin Against Human Ewing Sarcoma

摘要

Ewing sarcoma is the second most common primary malignant bone tumor in pediatrics after osteosarcoma, which mainly occurs in children and adolescents aged 5-20 years and has a high degree of clinical malignancy, it is prone to occur metastasis of lung and bone, and the five years survival rate of children with metastatic spread is less than 30%. For the Ewing sarcoma with metastasis, the multimodal treatment based on chemotherapy is not ideal. Therefore, the search for mild, less toxic therapeutic drugs has become the focus of research. Crocin is the main active ingredient extracted from Crocus sativus and has significant inhibitory effect on many cancer cells. Therefore, this study observed the effect of crocin on human Ewing Sarcoma and its specific mechanism and provided molecular theoretical basis for clinical application. We cultured human Ewing sarcoma cells SK-ES-1 and RD-ES in vitro and treated them with 0, 2.5, 5, and 10 mmol/L crocin solution. And we used CCK-8 assay to detect cell viability, and adopted flow cytometry to detect cell apoptosis and cell cycle changes, used western-blot to detect the expression of apoptotic pathway-related proteins. At the same time, we also combined vincristine and crocin to treat the cells, to detect cell viability and apoptosis, and to observe whether there was synergistic effect. We established the xenografts model of Ewing's sarcoma in nude mice and observe the inhibitory effect of crocin and vincristine on xenografts. Crocin could not only inhibit the growth of human Ewing sarcoma cells SK-ES-1 and RD-ES in a dose-dependent manner, but also inhibit the growth of xenografts in nude mice and increase cell apoptosis and block cell cycle progression. The results of mechanism analysis showed that crocin and vincristine significantly increased the degradation of PARP and caspase-3, and increased the levels of anti-apoptotic proteins bcl-2, Bcl-xL and p21. And crocin could increase the effect of vincristine on proliferation inhibition and apoptosis increase of human Ewing sarcoma. Crocin could inhibit the growth of human Ewing sarcoma either alone or in combination with vincristine. This effect was mediated by increasing apoptosis-related pathways.

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