水通道蛋白3在表皮生长因子诱导的乳腺癌细胞迁移中的作用机制研究

目的研究水通道蛋白3（aquapofin3，AQm）与表皮生长因子（EGF）诱导的乳腺癌细胞迁移之间的关系，并对其可能的机制进行初步探索。方法采用Westernblot法检测4种乳腺癌细胞MDA—MB-231、T47D、MCF-7、ER—ZR-70中的AQP3与EGFR的表达情况，选取高表达的细胞株进行EGF诱导，观察细胞迁移（划痕愈合实验）及AQP3表达的变化。施加CuSO。（AQm抑制剂）后观察细胞迁移及AQP3表达的变化。为进一步证明EGF通过哪条通路来调节AQF3的表达，采用LY294002（P13K／AKT通路抑制剂）及U1026（MAPK／ERK1／2通路抑制剂）分别进行阻断，观察AQP3的表达变化。结果Western blot检测发现迁移性强的MDA—MB-231细胞具有EGFR和AQP3的高表达。针对此细胞用不同浓度的EGF进行诱导，发现AQ1Y3的反应性表达与伤口愈合程度呈现一致的趋势（r=0．885，P〈0．01），采用不同浓度的CuSO。对AQP3的表达进行抑制，MDA—MB-231细胞的伤口愈合程度明显下降（r=0．959，P〈0．01）。采用LY294002阻断P13K／AKT通路后，AQm表达下降，而U1026作用后AQP3表达无明显变化。结论在乳腺癌细胞中存在AQP3表达；在EGF诱导的乳腺癌细胞迁移中，AQP3的反应性表达起到重要的作用，而EGF可能通过P13K／AKT通路来调节AQP3的表达。

Critical role of aquaporin-3 in epidermal growth factor-induced migration in breast cancer cells

Objective To explore the relationship between aquaporin 3 （AQP3） expression and epidermal growth factor （EGF） induced cell migration in breast cancer cells. Methods AQP3 and EGF receptor（EGFR） expressions were tested by Western blot in four breast carcinoma cell lines MDA-MB-231, T47D, MCF-7 and ER-ZR-70. Cultured MDA-MB-231 cells were treated with hmnan EGF and subjected to cell migration assay （scratch test）. The expression or activation level of proteins was analyzed by Western blot. CuSQ（ AQP3 inhibitor） was applied to observe the cell migration and AQP3 expression. To further demonstrate the pathway by which EGF regulates AQP3 expression, LY294002 （PI3K/AKT pathway inhibitor） and U1026 （ MAPK/ERK1/2 pathway inhibitor） were used separately to observe the changes in AQIY3 expression. Results Western blot analysis found that MDA-MB-231 cells, which had a strong potential of migration, showed the high expression of EGFR and AQP3. After EGF at different concentrations was used to induce the migration, it was found that AQP3 reactive expression was colxelated with the degree of wound healing （r = O. 885, P〈0. 01 ）. After CuSQ at different concentrations was added to inhibit AQP3 expression, the degree of wound healing was decreased in MDA-MB -231 ceils significantly （r=0. 959, P〈0. 01 ）. The expression of AQP3 was reduced after LY294002 application, but presented no statistical difference after U1026 application. Conclusions AQP3 is expressed in breast cancer cells. AQP3 expression plays an important role in EGF-induced breast cancer cell migration and EGF could regulate AQP3 expression via PI3K/AKT pathway.