Liu Hui, Huang Jing, Wu Benquan, Zhou Yuqi, Zhu Jiaxin, Zhang Tiantuo
Department of Internal Medicine, Division of Pulmonary and Critical Care, The Third Affiliated Hospital of Sun Yat-sen University, No. 600, Tianhe Street, Guangzhou, 510630, China.
Med Oncol. 2008;25(4):419-30. doi: 10.1007/s12032-008-9057-z. Epub 2008 Mar 14.
Matrix metalloproteinase (MMP) family member MMP-7 (matrilysin) cleaves various cell-surface proteins to alter their effector functions in addition to a broad substrate specificity against extracellular matrix components. Matrilysin expression is closely associated with the advanced clinicopathological stages and unfavorable prognosis. The current study tried to describe the comprehensive impacts of matrilysin on proliferation, and focused on its influence on the susceptibility to FasL-induced apoptosis in A549 lung adenocarcinoma cell line. We also detected the expressions of apoptosis-relative genes to further clarify the underlying mechanisms.
The viability of A549 cells was determined by MTT and the apoptosis was assessed by Hoechst 33342 staining and Annexin V-FITC/PI apoptosis kit. The expressions of apoptosis-relative genes were evaluated by flow cytometry, ELISA, and real-time quantitative RT-PCR, respectively.
Overall, matrilysin exhibited the inhibition of cell growth in a dose- and time-dependent manner by arresting in G0/G1 phase of the cell cycle and inducing apoptosis on A549 cells. Although it directly promoted apoptosis at high concentrations, a certain range of matrilysin might protect tumor cells from FasL-mediated death. The underlying mechanism may be due to the imbalance in the susceptibility of surface membrane-bound Fas receptor and ligand to proteolysis activity of matrilysin.
Our data indicated matrilysin may be multiple, multifarious, and multifaceted functions contributing to early tumor growth. A therapeutic key might be to modulate activity and function of matrilysin under diverse pathological conditions, but not completely eliminate the expression or function.
基质金属蛋白酶（MMP）家族成员MMP-7（基质溶素）除了对细胞外基质成分具有广泛的底物特异性外，还能切割多种细胞表面蛋白以改变其效应功能。基质溶素的表达与临床病理晚期阶段及不良预后密切相关。本研究试图描述基质溶素对增殖的综合影响，并重点关注其对A549肺腺癌细胞系中FasL诱导凋亡敏感性的影响。我们还检测了凋亡相关基因的表达以进一步阐明潜在机制。
通过MTT法测定A549细胞的活力，通过Hoechst 33342染色和Annexin V-FITC/PI凋亡试剂盒评估细胞凋亡。分别通过流式细胞术、ELISA和实时定量RT-PCR评估凋亡相关基因的表达。
总体而言，基质溶素通过使细胞周期停滞在G0/G1期并诱导A549细胞凋亡，以剂量和时间依赖性方式抑制细胞生长。尽管在高浓度下它直接促进凋亡，但一定范围内的基质溶素可能保护肿瘤细胞免受FasL介导的死亡。潜在机制可能是由于表面膜结合的Fas受体和配体对基质溶素蛋白水解活性的敏感性失衡。
我们的数据表明基质溶素可能具有多种、多样且多方面的功能，有助于肿瘤早期生长。治疗的关键可能是在不同病理条件下调节基质溶素的活性和功能，而不是完全消除其表达或功能。
