Wang Lin, Tang Cuiping, Cao Hong, Li Kuangfa, Pang Xueli, Zhong Liang, Dang Weiqi, Tang Hao, Huang Yunxiu, Wei Lan, Su Min, Chen Tingmei
a Department of Laboratory Medicine ; Key Laboratory of Diagnostic Medicine ; Ministry of Education ; Chongqing Medical University ; Chongqing , China.
Cancer Biol Ther. 2015;16(8):1220-30. doi: 10.1080/15384047.2015.1056409. Epub 2015 Jun 29.
Previous studies have revealed that leptin may be involved in epithelial-mesenchymal transition (EMT), a crucial initiator of cancer progression to facilitate metastatic cascade, increase tumor recurrence, and ultimately cause poor prognosis. However, the underlying mechanism remains unclear. The aim of our present study was to investigate the effect of leptin on EMT of breast cancer cells and the underlying mechanism.
Our data demonstrated that leptin significantly increased the phosphorylation of STAT3, Akt, and ERK1/2, elevated the expression of IL-8, and induced breast cancer cells to undergo EMT. The effect of leptin on IL-8 could visibly abolished by the inhibitor of PI3K LY294002. In addition, leptin-induced EMT of breast cancer cells was blocked by anti-IL-8 antibodies. Examination of the expression of ObR, leptin, IL-8 and EMT-related biomarkers in patient specimens demonstrated that malignant breast carcinoma with lymph node metastases (LNM), which represents poor prognosis, expressed higher levels of ObR, leptin, IL-8 than other types of breast cancer, and displayed more obvious EMT transversion. In vivo xenograft experiment revealed that leptin signally promoted tumor growth and metastasis and increased the expressions of IL-8 and EMT-related biomarkers.
Our results support that leptin-induced EMT in breast cancer cells requires IL-8 activation via the PI3K/Akt signal pathway.
先前的研究表明,瘦素可能参与上皮-间质转化(EMT),这是癌症进展的关键启动因素,可促进转移级联反应、增加肿瘤复发并最终导致预后不良。然而,其潜在机制仍不清楚。我们当前研究的目的是探讨瘦素对乳腺癌细胞EMT的影响及其潜在机制。
我们的数据表明,瘦素显著增加STAT3、Akt和ERK1/2的磷酸化,提高IL-8的表达,并诱导乳腺癌细胞发生EMT。PI3K抑制剂LY294002可明显消除瘦素对IL-8的影响。此外,抗IL-8抗体可阻断瘦素诱导的乳腺癌细胞EMT。对患者标本中ObR、瘦素、IL-8和EMT相关生物标志物表达的检测表明,伴有淋巴结转移(LNM)的恶性乳腺癌代表预后不良,其ObR、瘦素、IL-8的表达水平高于其他类型的乳腺癌,且显示出更明显的EMT转变。体内异种移植实验表明,瘦素显著促进肿瘤生长和转移,并增加IL-8和EMT相关生物标志物的表达。
我们的结果支持瘦素诱导的乳腺癌细胞EMT需要通过PI3K/Akt信号通路激活IL-8。