Im Joo-Young, Kim Da-Mi, Park Hyunkyung, Kang Mi-Jung, Kim Da-Yoon, Chang Kwan Young, Kim Bo-Kyung, Won Misun
Personalized Genomic Medicine Research Center, KRIBB, Daejeon, 34141, Republic of Korea.
R&D Center, OneCureGEN Co., Ltd, Daejeon, 34141, Republic of Korea.
Biochim Biophys Acta Mol Cell Res. 2021 Jan;1868(1):118892. doi: 10.1016/j.bbamcr.2020.118892. Epub 2020 Oct 16.
We previously reported that vestigial-like 1 (VGLL1), a cofactor of transcriptional enhanced associate domain 4 (TEAD4), is transcriptionally regulated by PI3K and β-catenin signaling and is involved in gastric cancer malignancy. However, the precise mechanism underlying the regulation of VGLL1 activation remains unknown. Therefore, we aimed to investigate the molecular mechanism underlying the transforming growth factor-β (TGF-β)-mediated activation of VGLL1 and the VGLL1-TEAD4 interaction in gastric cancer cells. We showed that TGF-β enhanced VGLL1 phosphorylation and that this phosphorylated VGLL1 functioned as a transcription cofactor of TEAD4 in NUGC3 cells. TGF-β also increased the phosphorylation of ERK and ribosomal S6 kinase 2 (RSK2) in NUGC3 cells, thereby triggering the translocation of phosphorylated RSK2 to the nucleus. Site-directed mutagenesis and immunoprecipitation experiments revealed that RSK2 phosphorylated VGLL1 at S84 in the presence of TGF-β. Mutation of VGLL1 at S84 suppressed VGLL1-TEAD4 binding and the subsequent transcriptional activation of matrix metalloprotease 9 (MMP9). Moreover, VGLL1 peptide containing S84 suppressed the TGF-β-induced MMP9 expression and reduced the invasion and proliferation of gastric cancer cells, whereas VGLL1 peptide containing S84A did not. Furthermore, suppression of expression or activation of VGLL1 enhances the therapeutic effects of lapatinib. Collectively, these results indicate that VGLL1 phosphorylation via TGF-β/ERK/RSK2 signaling plays a crucial role in MMP9-mediated malignancy of gastric cancer. In addition, our study highlights the therapeutic potential of the peptide containing VGLL1 S84 for the treatment of gastric cancer.
我们之前报道过，转录增强关联结构域4（TEAD4）的辅助因子类 vestigial 蛋白1（VGLL1）受PI3K和β-连环蛋白信号通路的转录调控，并参与胃癌的恶性进展。然而，VGLL1激活调控的精确机制仍不清楚。因此，我们旨在研究转化生长因子-β（TGF-β）介导的胃癌细胞中VGLL1激活及VGLL1-TEAD4相互作用的分子机制。我们发现TGF-β增强了VGLL1的磷酸化，且这种磷酸化的VGLL1在NUGC3细胞中作为TEAD4的转录辅因子发挥作用。TGF-β还增加了NUGC3细胞中细胞外信号调节激酶（ERK）和核糖体S6激酶2（RSK2）的磷酸化，从而触发磷酸化的RSK2易位至细胞核。定点诱变和免疫沉淀实验表明，在TGF-β存在的情况下，RSK2使VGLL1的S84位点发生磷酸化。VGLL1的S84位点突变抑制了VGLL1-TEAD4结合以及随后基质金属蛋白酶9（MMP9）的转录激活。此外，含S84的VGLL1肽抑制了TGF-β诱导的MMP9表达，并降低了胃癌细胞的侵袭和增殖，而含S84A的VGLL1肽则没有此作用。此外，抑制VGLL1的表达或激活可增强拉帕替尼的治疗效果。总体而言，这些结果表明，通过TGF-β/ERK/RSK2信号通路对VGLL1进行磷酸化在MMP9介导的胃癌恶性进展中起关键作用。此外，我们的研究突出了含VGLL1 S84的肽在治疗胃癌方面的潜在治疗价值。
