Chang Nan-Shan, Schultz Lori, Hsu Li-Jin, Lewis Jennifer, Su Meng, Sze Chun-I
Guthrie Research Institute, Laboratory of Molecular Immunology, 1 Guthrie Square, Sayre, PA 18840, USA.
Oncogene. 2005 Jan 20;24(4):714-23. doi: 10.1038/sj.onc.1208124.
Human WWOX gene encodes a proapoptotic WW domain-containing oxidoreductase WOX1 (also named WWOX, FOR2 or WWOXv1). Apoptotic and stress stimuli activate WOX1 via Tyr33 phosphorylation and nuclear translocation. WOX1 possesses a tetrad NSYK motif in the C-terminal short-chain alcohol dehydrogenase/reductase (SDR) domain, which may bind estrogen and androgen. Here, we determined that 17beta-estradiol (E(2)) activated WOX1, p53 and ERK in COS7 fibroblasts, primary lung epithelial cells, and androgen receptor (AR)-negative prostate DU145 cells, but not in estrogen receptor (ER)-positive breast MCF7 cells. Androgen also activated WOX1 in the AR-negative DU145 cells. These observations suggest that sex hormone-mediated Tyr33 phosphorylation and nuclear translocation of WOX1 is independent of ER and AR. Stress stimuli increase physical binding of p53 with WOX1 in vivo. We determined here that E(2) increased the formation of p53/WOX1 complex and their nuclear translocation in COS7 cells; however, nuclear translocation of this complex could not occur in MCF7 cells. By immunohistochemistry, we determined that progression of prostate from normal to hyperplasia, cancerous and metastatic stages positively correlate with upregulation and activation of WOX1 and WOX2 (FOR1/WWOXv2). In contrast, breast cancer development to a premetastatic state is associated with upregulation and Tyr33 phosphorylation of cytosolic WOX1 and WOX2, followed by significant downregulation or absent expression during metastasis. These Tyr33-phosphorylated proteins are mostly located in the mitochondria without translocating to the nuclei, which is comparable to those findings in cultured breast cancer cells. Together, sex steroid hormone-induced activation of WOX1 and WOX2 is independent of ER and AR, and this activation positively correlates with cancerous progression of prostate and breast to a premetastatic state.
人类WWOX基因编码一种促凋亡的含WW结构域的氧化还原酶WOX1（也称为WWOX、FOR2或WWOXv1）。凋亡和应激刺激通过酪氨酸33磷酸化和核转位激活WOX1。WOX1在C端短链醇脱氢酶/还原酶（SDR）结构域中具有一个四联体NSYK基序，该基序可能结合雌激素和雄激素。在此，我们确定17β-雌二醇（E₂）可激活COS7成纤维细胞、原代肺上皮细胞和雄激素受体（AR）阴性的前列腺DU145细胞中的WOX1、p53和ERK，但在雌激素受体（ER）阳性的乳腺MCF7细胞中则不然。雄激素也可激活AR阴性的DU145细胞中的WOX1。这些观察结果表明，性激素介导的WOX1酪氨酸33磷酸化和核转位独立于ER和AR。应激刺激会增加体内p53与WOX1的物理结合。我们在此确定，E₂可增加COS7细胞中p53/WOX1复合物的形成及其核转位；然而，该复合物在MCF7细胞中无法发生核转位。通过免疫组织化学，我们确定前列腺从正常到增生、癌变和转移阶段的进展与WOX1和WOX2（FOR1/WWOXv2）的上调和激活呈正相关。相反，乳腺癌发展到转移前状态与胞质WOX1和WOX₂的上调和酪氨酸33磷酸化相关，随后在转移过程中显著下调或无表达。这些酪氨酸33磷酸化蛋白大多位于线粒体中，而不转位至细胞核，这与培养的乳腺癌细胞中的发现相似。总之，性甾体激素诱导的WOX1和WOX2激活独立于ER和AR，且这种激活与前列腺癌和乳腺癌发展到转移前状态呈正相关。
