TPST1表达在CXCR4诱导的乳腺癌细胞侵袭中的作用研究

The Study of TPST1 Effects on CXCR4-induced Invasion of Breast Cancer Cells

C-X-C趋化因子受体4(CXCR4)是乳腺癌细胞运动的关键调节因子。CXCR4的功能性表达与乳腺癌的恶性进展密切相关。酪氨酸硫酸化转移酶1(tyrosylprotein sulfotransferase 1,TPST1)是CXCR4蛋白翻译后酪氨酸硫酸化修饰的一个关键酶。本研究将探索TPST1在CXCR4调节乳腺癌细胞侵袭过程中的作用机制。利用定量PCR,免疫组织化学和蛋白质免疫印迹等试验技术检测乳腺癌组织和细胞系中CXCR4和TPST1的mRNA和蛋白表达水平。RNA干扰,趋化试验和侵袭试验用于检测TPST1对于CXCR4诱导的乳腺癌细胞侵袭的影响。研究发现CXCR4蛋白在乳腺癌转移淋巴结组织中呈高表达(P=0. 0016)。CXCR4在乳腺癌转移淋巴结组织中的高表达与肿瘤浸润深度密切相关(P=0. 026)。TPST1与CXCR4蛋白表达在乳腺癌原发组织和配对转移淋巴结组织中均呈显著正相关(P=0. 009; P=0. 006)。TPST1在高度恶性乳腺癌MDA-MB-231细胞中呈高表达,在低度恶性乳腺癌MCF-7细胞中弱表达,而两者CXCR4表达基本相同。小RNA干扰降低TPST1的表达后,下调了乳腺癌MDA-MB-231细胞对于CXCR4配体即基质细胞衍生因子1α(stromal cell-derived factor 1 alpha,SDF-1α)的运动反应性,进而降低CXCR4诱导的MDA-MB-231细胞迁移和侵袭能力。综上,在CXCR4诱导的乳腺癌细胞侵袭过程中,TPST1表达对于CXCR4功能性活化至关重要,TPST1可能作为潜在的抗CXCR4药物治疗乳腺癌恶性进展的联合靶点。

C-X-C chemokine receptor type 4 （ CXCR4） is a key regulator of cell motility in breast cancer （ BrCa） .Growing evidence has shown that CXCR4 signaling pathway is associated with the malignant progression of BrCa. Thetyrosylproteinsulfotransferase 1 （TPST1） is an important enzyme for post-translational tyrosines sulfation of CXCR4. Thisstudy is to investigate the role of TPST1 in CXCR4-induced the invasion of BrCa cells. Using quantitative PCR,immunohistochemistry and western blot to test mRNA and protein expression of TPST1 and CXCR4 in BrCa tissues andcell lines. RNA interference, invasion assays and chemotaxis assays were used to evaluate the function of CXCR4through TPST1 signal pathway in invasion of BrCa cells. In this study, the results showed that the high expression ofCXCR4 protein was associated significantly with BrCa lymph nodes metastasis （ χ2test, P = 0. 0016 ） . There was asignificant correlation between high CXCR4 expression with BrCa tumor infiltrating depth in metastatic lymph nodes（ Pearson’ s chi-square test, P = 0. 026） . The expression of TPST1 and CXCR4 was positively correlated in BrCa primarytissues （Pearson’ s correlation, r = 0. 364, P = 0. 009） and metastatic lymph nodes（ Pearson’ s correlation, r = 0. 382,P = 0. 006 ） . TPST1 was strongly expressed in the highly malignant BrCa MDA-MB-231 cells compared to the lessmalignant BrCa MCF-7 cells, with the same in total CXCR4 protein levels in these two cells. Expression of TPST1 smallinterfering RNA（TPST1siRNA） decreased the cell motility response to stromal cell-derived factor 1 alpha （ SDF-1α） andreduced the invasiveness of MDA-MB-231 cells. In summary, TPST1 expression is necessary for CXCR4 functionactivation in the invasion of BrCa cells. TPST1 may be a potential anti-CXCR4 combined target to the treatment of breastcancer malignant progression.