鞘氨醇激酶1在人骨肉瘤细胞中表达及靶向干预

Our previous studies have shown that that SphK1 is over-expressed in multiple human OS tissues, participating OS cell survival, proliferation and apoptosis resistance. Our preliminary studies have identified a novel SphK1 inhibitory microRNA: miR-103b. We showed that miR-103b was downregulated in multiple human OS tissues. Yet, over-expression of miR-103b in U2OS OS cells potently inhibited SphK1 expression as well as cell survival and proliferation. Meanwhile, we showed that itraconazole, a recently-characterized anti-cancer drug, inhibited SphK1 activity in OS cells, leading to significant anti-proliferative activity. In the current proposal, we will first exam the expression of SphK1 and miR-103b in human OS tissues and surrounding normal bone tissues, and explore their associations with patients’ clinical characteristics and outcomes. By using multiple biomedical methods, we are set to prove that low miR-103b expression is likely the reason of SphK1 overexpression in human OS tissues, and that miR-103b inhibits OS cells via downregulating SphK1. Further, we will exam the anti-OS ability of the potential novel SphK1 inhibitor itraconazole both in vivo and in vitro, and study the underlying mechanisms by focusing on SphK1. The results of this study will possibly be beneficial for the diagnosis and treatment of human OS.

前期研究证实鞘氨醇激酶1（SphK1）在人骨肉瘤（Osteosarcoma，OS）组织中高表达，并参与OS细胞存活、增殖和凋亡抵抗。预实验中，我们鉴定了一个新的SphK1抑制性miRNA：miR-103b，后者在人OS组织种表达显著降低；而在OS细胞中转染miR-103b则能显著下调SphK1，并抑制癌细胞存活、增殖。此外，我们还发现新型抗肿瘤药物伊曲康唑显著抑制SphK1活性及OS细胞存活、增殖。本课题中，我们将检测人OS组织中SphK1、miR-103b的表达水平，并分析两者与OS各临床指标的相关性。拟运用多种分子生物学方法，证实人OS组织中miR-103b下调可能是SphK1过表达的主要原因；miR-103b通过靶向下调SphK1而抑制OS细胞存活、增殖。最后体内、外系统观察潜在新型SphK1抑制剂伊曲康唑抗OS作用，解析抑制SphK1在其中的作用。为OS临床诊治的突破进行有益尝试。

前期研究证实鞘氨醇激酶1（SphK1）在人骨肉瘤（Osteosarcoma，OS）组织中高表达，并参与OS细胞存活、增殖和凋亡抵抗。我们鉴定了俩个新的SphK1靶向miRNA：miR-103b和miR-3677。它们在人OS组织种表达显著降低；人OS细胞中，SphK1特异性的miRNA（miR-103b和miR-3677）的异常下调导致其靶蛋白SphK1过度表达，后者介导OS细胞的恶性生物学行为，包括增殖、存活及凋亡抵抗等。而导入SphK1特异性的miRNA（miR-103b和miR-3677）或添加伊曲康唑则下调或抑制OS细胞内的SphK1，诱导OS细胞神经酰胺聚积，从而抑制OS细胞的存活和增殖，诱导癌细胞凋亡。上述研究证实了SphK1是OS关键促癌基因。研究结果为OS临床治疗学突破提供有益靶标，为下一步研究新型SphK1抑制剂伊曲康唑治疗OS提供理论和实验依据。