The Role of TIMPs in Cell Growth, Tumor Progression and Metastasis

主要活动/具体目标。我们正在进行的研究工作的主要目标 是深入了解MMP独立活动的机制， TIMP家族成员，特别是TIMP-2。我们已经确定了以下具体 目的：1）研究TIMPs在改变生长中的作用， 2）TIMP对肿瘤细胞体外侵袭能力的影响; 体内转移性肿瘤生长; 3）研究TIMPs对肿瘤细胞募集的影响， 免疫调节细胞（骨髓源性抑制细胞（MDSC））对原发性肿瘤的作用， 4）更好地理解细胞间 TIMP。在先前的实验中，我们观察到TIMP-2在肿瘤细胞中的强制表达 抑制原发性肿瘤生长。肿瘤生长的抑制伴随着 肿瘤微血管密度计数（CD 31+或CD 34+）统计学显著降低， 抗血管生成作用的测量，以及增加的肿瘤细胞凋亡（也可能是 由于抑制血管生成）。有点出乎意料的是，我们还观察到， 在TIMP-2表达肿瘤中，粘着斑激酶（FAK）显著降低， 在表达TIMP-2和Ala+TIMP-2的肿瘤细胞中，这两种肿瘤细胞都具有磷酸化（Y397）。我们的观察 FAK和/或AKT（蛋白激酶B，PKB）磷酸化在TIMP-2中减少， Ala+TIMP-2在肿瘤组织中的意义在于：1）FAK是AKT信号传导的上游， TIMP-2和Ala+TIMP-2表达减少 体外肿瘤细胞迁移。我们以前报道过， 在内皮细胞中，它参与控制eNOS活性。在我的实验室里， 在小鼠肿瘤模型中检测外源性TIMP-2的作用。我们正在研究 对肿瘤生长和转移的影响，目的是更好地了解 这些最新的发现表明TIMP-2可能与细胞凋亡有关。 对肿瘤和宿主细胞都有多种作用，这些作用联合收割机产生一种有效的 可以用于临床的抗肿瘤活性。

Major Activities/Specific Objectives. The principal goal of our ongoing research effort is to develop an in depth mechanistic understanding of the MMP-independent activities of members of the TIMP family, in particular TIMP-2. We have identified the following specific objectives to obtain our goals: 1) examine the role of TIMPs in altering the growth and invasive potential of cancer cells in vitro; 2) study to effects of TIMPs on primary and metastatic tumor growth in vivo; 3) study the influence of TIMPs on recruitment of immune-modulatory cells (myeloid-derived suppressor cells (MDSC)) to the primary tumor and metastatic niche4) develop a better understanding of the uptake and role of intercellular TIMP. In prior experiments with forced expression of TIMP-2 in tumor cells we have observed suppression of primary tumor growth. The suppression of tumor growth was accompanied by a statistically significant decrease in tumor microvascular density count (CD 31+ or CD34+), a measure of antiangiogenic effects, as well as by increased tumor cell apoptosis (also possibly due to inhibition of angiogenesis). Somewhat unexpectedly, we also observed a decrease in focal adhesion kinase (FAK) in TIMP-2 expressing tumors and a significant decrease in FAK phosphorylation (Y397) in both TIMP-2 and Ala+TIMP-2 expressing tumor cells. Our observation that both FAK and/or AKT (Protein Kinase B, PKB) phosphorylation is reduced in TIMP-2 and Ala+TIMP-2 tumor tissues is significant in that: 1) FAK is upstream of AKT signaling, and both are involved in regulation of cell migration; 2) TIMP-2 and Ala+TIMP-2 expression reduced tumor cell migration in vitro. We previously reported decreased FAK phosphorylation in endothelial cells where it is involved in control of eNOS activity. A major focus in my lab has been to examine the effects of exogenous TIMP-2 in murine tumor models. We are studying the effects on tumor growth and metastasis with the aim of developing a better understanding of the mechanisms that may affect these processes.These recent findings suggest that TIMP-2 has a variety of effects on both tumor and host cells that combine to produce a potent anti-tumor activity that could be exploited clinically.