Liu Qing-Hua, Shi Mei-Lin, Bai Jin, Zheng Jun-Nian
Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou, China E-mail :
Asian Pac J Cancer Prev. 2015;16(7):2719-24. doi: 10.7314/apjcp.2015.16.7.2719.
The aim of this study was to investigate the clinical significance of annexin a1 (ANXA1) and provide molecular evidence to support that decreased ANXA1 expression could enhance cancer migration and invasion in pancreatic ductal adenocarcinoma (PDAC).
Immunohistochemistry of a tissue microarray with 162 surgically resected PDAC specimens was performed to examine the expression of ANXA1. We also investigated the relationship between ANXA1 expression and clinicopathological factors and prognosis of PDAC patients. We further studied the role of ANXA1 in PDAC cell proliferation, migration and invasion by cell proliferation assay, migration assay and matrigel invasion assay with reduced ANXA1 expression by RNAi. Western blotting was used to detect matrix metalloproteinase-9 (MMP-9), and tissue inhibitor of metalloproteinase-1 (TIMP-1) expression. We also detected MMP-9 enzyme activity by gelatin zymography.
Decreased expression of ANXA1 was significantly associated with poor differentiation, lymph node metastasis and advanced TNM stage of PDAC patients (p<0.05). Moreover, decreased expression of ANXA1 was correlated with poor survival (p<0.05). Furthermore, we found that ANXA1 knockdown inhibited cell proliferation, induced G1 phase cell cycle arrest, increased PDAC cell migration and invasion capacity compared with controls. In addition, Western blotting showed that ANXA1 knockdown increased the MMP-9 protein level and decreased TIMP-1 expression. Gelatin zymography showed that MMP-9 enzyme activity was also elevated.
Negative ANXA1 expression is a most unfavorable prognostic factor for PDAC patients. ANXA1 knockdown inhibits cell proliferation by inducing G1 phase cell cycle arrest and increases migration and invasion of PDAC cells through up-regulating MMP-9 expression and activity, implying that ANXA1 may serve as a promising prognostic biomarker and therapeutic target for PDAC.
本研究旨在探讨膜联蛋白A1（ANXA1）的临床意义，并提供分子证据支持ANXA1表达降低可增强胰腺导管腺癌（PDAC）的癌症迁移和侵袭能力。
对162例手术切除的PDAC标本制作组织芯片，进行免疫组织化学检测以观察ANXA1的表达情况。我们还研究了ANXA1表达与PDAC患者临床病理因素及预后之间的关系。通过RNA干扰降低ANXA1表达，利用细胞增殖试验、迁移试验和基质胶侵袭试验进一步研究ANXA1在PDAC细胞增殖、迁移和侵袭中的作用。采用蛋白质免疫印迹法检测基质金属蛋白酶-9（MMP-9）和金属蛋白酶组织抑制剂-1（TIMP-1）的表达。我们还通过明胶酶谱法检测MMP-9酶活性。
ANXA1表达降低与PDAC患者的低分化、淋巴结转移及晚期TNM分期显著相关（p<0.05）。此外，ANXA1表达降低与较差的生存率相关（p<0.05）。此外，我们发现与对照组相比，敲低ANXA1可抑制细胞增殖，诱导G1期细胞周期阻滞，增加PDAC细胞的迁移和侵袭能力。另外，蛋白质免疫印迹显示敲低ANXA1可增加MMP-9蛋白水平并降低TIMP-1表达。明胶酶谱显示MMP-9酶活性也升高。
ANXA1阴性表达是PDAC患者最不利的预后因素。敲低ANXA1通过诱导G1期细胞周期阻滞抑制细胞增殖，并通过上调MMP-9表达和活性增加PDAC细胞的迁移和侵袭，这意味着ANXA1可能是一种有前景的PDAC预后生物标志物和治疗靶点。
