Division of Oncology and Molecular Biology, Cancer Research Institute, Kanazawa University, Kanazawa, Ishikawa, Japan.
Oncogene. 2011 Feb 10;30(6):737-50. doi: 10.1038/onc.2010.448. Epub 2010 Oct 4.
The reversion-inducing cysteine-rich protein with Kazal motifs (RECK) gene had been isolated as an antagonist to RAS signaling; however, the mechanism of its action is not clear. In this study, the effect of loss of RECK function was assessed in various ways and cell systems. Successive cell cultivation of mouse embryonic fibroblasts (MEFs) according to 3T3 protocol revealed that the germline knockout of RECK confers accelerated cell proliferation and early escape from cellular senescence associated with downregulation of p19(Arf), Trp53 and p21(Cdkn1a). In contrast, short hairpin RNA-mediated depletion of RECK induced irreversible growth arrest along with several features of the Arf, Trp53 and Cdkn1a-dependent cellular senescence. Within 2 days of RECK depletion, we observed a transient increase in protein kinase B (AKT) and extracellular signal-regulated kinase (ERK) phosphorylation associated with an upregulated expression of cyclin D1, p19(Arf), Trp53, p21(Cdkn1a) and Sprouty 2. On further cultivation, RAS, AKT and ERK activities were then downregulated to a level lower than control, indicating that RECK depletion leads to a negative feedback to RAS signaling and subsequent cellular senescence. In addition, we observed that epidermal growth factor receptor (EGFR) activity was transiently upregulated by RECK depletion in MEFs, and continuously downregulated by RECK overexpression in colon cancer cells. These findings indicate that RECK is a novel modulator of EGFR signaling.
富含半胱氨酸的 Kazal 基序的反转诱导蛋白（RECK）基因已被分离为 RAS 信号的拮抗剂；然而，其作用机制尚不清楚。在这项研究中，通过各种方法和细胞系统评估了 RECK 功能丧失的影响。按照 3T3 方案对小鼠胚胎成纤维细胞（MEFs）进行连续细胞培养，结果表明 RECK 的种系敲除赋予了细胞增殖的加速和与 p19(Arf)、Trp53 和 p21(Cdkn1a)下调相关的早期逃离细胞衰老。相比之下，短发夹 RNA 介导的 RECK 耗竭诱导不可逆的生长停滞，同时伴有 Arf、Trp53 和 Cdkn1a 依赖性细胞衰老的多种特征。在 RECK 耗竭后 2 天内，我们观察到蛋白激酶 B（AKT）和细胞外信号调节激酶（ERK）磷酸化的短暂增加，伴随着细胞周期蛋白 D1、p19(Arf)、Trp53、p21(Cdkn1a)和 Sprouty 2 的上调表达。进一步培养后，RAS、AKT 和 ERK 活性被下调至低于对照的水平，表明 RECK 耗竭导致对 RAS 信号和随后的细胞衰老的负反馈。此外，我们观察到 RECK 耗竭可使 MEFs 中的表皮生长因子受体（EGFR）活性短暂上调，并通过 RECK 在结肠癌细胞中的过表达持续下调。这些发现表明 RECK 是 EGFR 信号的一种新型调节剂。
