SMYD3 promotes implant metastasis of ovarian cancer via H3K4 trimethylation of integrin promoters
SMYD3 promotes implant metastasis of ovarian cancer via H3K4 trimethylation of integrin promoters
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DOI：
10.1002/ijc.32673
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发表时间：
2019-10-30
影响因子：
6.4
通讯作者：
Feng, Weiwei
中科院分区：
文献类型：
--
作者：
Lyu, Tianjiao;Jiang, Yahui;Feng, Weiwei
上皮性卵巢癌（EOC）的植入转移需要癌细胞从原发肿瘤脱离并在腹水中形成球状体，但这一过程的潜在机制尚未完全阐明。为了模拟这个过程，卵巢癌细胞在 3D 和 2D 培养物中生长。 Hey 和 OVCA433 球体表现出细胞增殖减少、粘附和侵袭增强。卵巢癌球体中 SMYD3 表达升高，与 H3K4 甲基化增加相关。通过瞬时 siRNA、稳定 shRNA 敲除和 SMYD3 抑制剂 BCI-121 来消除 SMYD3 均会减少球体侵袭和粘附。基因表达阵列显示整合素家族成员的下调。抑制测定证实球体的侵袭和粘附是由ITGB6和ITGAM介导的。 SMYD3缺陷细胞在强制过度表达SMYD3、ITGB6和ITGAM后重新获得了侵袭和粘附的能力。然而，在 ITGB6 和/或 ITGAM 缺陷的癌细胞中强制过度表达 SMYD3 并不能恢复这种生物学能力。与单层细胞相比，球状体中 ITGB6 和 ITGAM 启动子处的 SMYD3 和 H3K4me3 结合增加，而当 SMYD3 表达受到抑制时，结合减少，这与整合素的表达变化一致。 SMYD3 表达和整合素介导的粘附在腹膜内异种移植模型和 EOC 患者球体中也被激活。在体内，SMYD3敲低可抑制腹膜内异种移植模型和PDX模型中的肿瘤转移并减少腹水量。总的来说，我们的结果表明 SMYD3-H3K4me3-整合素通路在卵巢癌腹膜表面转移中发挥着至关重要的作用。
Detachment of cancer cells from the primary tumor and formation of spheroids in ascites is required for implantation metastasis in epithelial ovarian cancer (EOC), but the underlying mechanism of this process has not been thoroughly elucidated. To mimic this process, ovarian cancer cells were grown in 3D and 2D culture. Hey and OVCA433 spheroids exhibited decreased cell proliferation and enhanced adhesion and invasion. SMYD3 expression was elevated in ovarian carcinoma spheroids in association with increased H3K4 methylation. Depletion of SMYD3 by transient siRNA, stable shRNA knockdown and the SMYD3 inhibitor BCI-121 all decreased spheroid invasion and adhesion. Gene expression arrays revealed downregulation of integrin family members. Inhibition assays confirmed that invasion and adhesion of spheroids are mediated by ITGB6 and ITGAM. SMYD3-deficient cells regained the ability to invade and adhere after forced overexpression of SMYD3, ITGB6 and ITGAM. However, this biological ability was not restored by forced overexpression of SMYD3 in ITGB6- and/or ITGAM-deficient cancer cells. SMYD3 and H3K4me3 binding at the ITGB6 and ITGAM promoters was increased in spheroids compared to that in monolayer cells, and the binding was decreased when SMYD3 expression was inhibited, consistent with the expression changes in integrins. SMYD3 expression and integrin-mediated adhesion were also activated in an intraperitoneal xenograft model and in EOC patient spheroids. In vivo, SMYD3 knockdown inhibited tumor metastasis and reduced ascites volume in both the intraperitoneal xenograft model and a PDX model. Overall, our results suggest that the SMYD3-H3K4me3-integrin pathway plays a crucial role in ovarian cancer metastasis to the peritoneal surface.