PDF(Pubmed)
Abstract：
BACKGROUND: The outcome of hepatocellular carcinoma (HCC) is limited by its complex molecular characteristics and changeable tumor microenvironment (TME). Here we focused on elucidating the functional consequences of Maternal embryonic leucine zipper kinase (MELK) in the tumorigenesis, progression and metastasis of HCC, and exploring the effect of MELK on immune cell regulation in the TME, meanwhile clarifying the corresponding signaling networks.
METHODS: Bioinformatic analysis was used to validate the prognostic value of MELK for HCC. Murine xenograft assays and HCC lung metastasis mouse model confirmed the role of MELK in tumorigenesis and metastasis in HCC. Luciferase assays, RNA sequencing, immunopurification-mass spectrometry (IP-MS) and coimmunoprecipitation (CoIP) were applied to explore the upstream regulators, downstream essential molecules and corresponding mechanisms of MELK in HCC.
RESULTS: We confirmed MELK to be a reliable prognostic factor of HCC and identified MELK as an effective candidate in facilitating the tumorigenesis, progression, and metastasis of HCC; the effects of MELK depended on the targeted regulation of the upstream factor miR-505-3p and interaction with STAT3, which induced STAT3 phosphorylation and increased the expression of its target gene CCL2 in HCC. In addition, we confirmed that tumor cell-intrinsic MELK inhibition is beneficial in stimulating M1 macrophage polarization, hindering M2 macrophage polarization and inducing CD8 + T-cell recruitment, which are dependent on the alteration of CCL2 expression. Importantly, MELK inhibition amplified RT-related immune effects, thereby synergizing with RT to exert substantial antitumor effects. OTS167, an inhibitor of MELK, was also proven to effectively impair the growth and progression of HCC and exert a superior antitumor effect in combination with radiotherapy (RT).
CONCLUSIONS: Altogether, our findings highlight the functional role of MELK as a promising target in molecular therapy and in the combination of RT therapy to improve antitumor effect for HCC.
METHODS: Bioinformatic analysis was used to validate the prognostic value of MELK for HCC. Murine xenograft assays and HCC lung metastasis mouse model confirmed the role of MELK in tumorigenesis and metastasis in HCC. Luciferase assays, RNA sequencing, immunopurification-mass spectrometry (IP-MS) and coimmunoprecipitation (CoIP) were applied to explore the upstream regulators, downstream essential molecules and corresponding mechanisms of MELK in HCC.
RESULTS: We confirmed MELK to be a reliable prognostic factor of HCC and identified MELK as an effective candidate in facilitating the tumorigenesis, progression, and metastasis of HCC; the effects of MELK depended on the targeted regulation of the upstream factor miR-505-3p and interaction with STAT3, which induced STAT3 phosphorylation and increased the expression of its target gene CCL2 in HCC. In addition, we confirmed that tumor cell-intrinsic MELK inhibition is beneficial in stimulating M1 macrophage polarization, hindering M2 macrophage polarization and inducing CD8 + T-cell recruitment, which are dependent on the alteration of CCL2 expression. Importantly, MELK inhibition amplified RT-related immune effects, thereby synergizing with RT to exert substantial antitumor effects. OTS167, an inhibitor of MELK, was also proven to effectively impair the growth and progression of HCC and exert a superior antitumor effect in combination with radiotherapy (RT).
CONCLUSIONS: Altogether, our findings highlight the functional role of MELK as a promising target in molecular therapy and in the combination of RT therapy to improve antitumor effect for HCC.
摘要：
背景：肝细胞癌（HCC）的预后受其复杂的分子特征和多变的肿瘤微环境（TME）的限制。在这里，我们专注于阐明母体胚胎亮氨酸拉链激酶（MELK）在肿瘤发生中的功能后果，肝癌的进展和转移，探讨MELK对TME中免疫细胞调控的影响,同时明确相应的信令网络。
方法：生物信息学分析用于验证MELK对HCC的预后价值。鼠异种移植试验和HCC肺转移小鼠模型证实了MELK在HCC肿瘤发生和转移中的作用。荧光素酶测定，RNA测序，免疫纯化-质谱(IP-MS)和免疫共沉淀(CoIP)用于探索上游调节因子,肝癌MELK的下游必需分子及相应机制。
结果：我们证实MELK是HCC的可靠预后因素，并确定MELK是促进肿瘤发生的有效候选者。programming,和HCC的转移；MELK的作用取决于上游因子miR-505-3p的靶向调节和与STAT3的相互作用，从而诱导STAT3磷酸化并增加其靶基因CCL2在HCC中的表达。此外,我们证实肿瘤细胞固有的MELK抑制有利于刺激M1巨噬细胞极化，阻碍M2巨噬细胞极化和诱导CD8+T细胞募集，依赖于CCL2表达的改变。重要的是,MELK抑制增强了RT相关的免疫效应，从而与RT协同发挥实质性的抗肿瘤作用。OTS167，一种MELK抑制剂，还被证明可以有效地损害HCC的生长和进展，并与放射疗法（RT）结合使用具有出色的抗肿瘤作用。
结论：总而言之，我们的研究结果强调了MELK作为分子治疗和联合RT治疗改善HCC抗肿瘤效果的一个有前景的靶点的功能作用.
方法：生物信息学分析用于验证MELK对HCC的预后价值。鼠异种移植试验和HCC肺转移小鼠模型证实了MELK在HCC肿瘤发生和转移中的作用。荧光素酶测定，RNA测序，免疫纯化-质谱(IP-MS)和免疫共沉淀(CoIP)用于探索上游调节因子,肝癌MELK的下游必需分子及相应机制。
结果：我们证实MELK是HCC的可靠预后因素，并确定MELK是促进肿瘤发生的有效候选者。programming,和HCC的转移；MELK的作用取决于上游因子miR-505-3p的靶向调节和与STAT3的相互作用，从而诱导STAT3磷酸化并增加其靶基因CCL2在HCC中的表达。此外,我们证实肿瘤细胞固有的MELK抑制有利于刺激M1巨噬细胞极化，阻碍M2巨噬细胞极化和诱导CD8+T细胞募集，依赖于CCL2表达的改变。重要的是,MELK抑制增强了RT相关的免疫效应，从而与RT协同发挥实质性的抗肿瘤作用。OTS167，一种MELK抑制剂，还被证明可以有效地损害HCC的生长和进展，并与放射疗法（RT）结合使用具有出色的抗肿瘤作用。
结论：总而言之，我们的研究结果强调了MELK作为分子治疗和联合RT治疗改善HCC抗肿瘤效果的一个有前景的靶点的功能作用.
