Integrin-mediated Regulation of TGFbeta Signaling and Tumorigenesis

描述（由申请人提供）：乳腺癌是一种异质性疾病，由至少5种主要肿瘤亚型组成，合并为美国女性癌症死亡的第二大原因。在个体乳腺癌亚型中，分类为三阴性乳腺癌（TNBC）的那些通过其侵袭性和转移性表型的呈现以及其在常规化疗治疗后快速复发的高倾向而在临床上是独特的。TNBC还值得注意的是它们不能表达激素受体（雌激素和孕酮）和ErbB 2/HER 2，ErbB 2/HER 2是一种使靶向化疗（例如，激素或HER 2导向的）无效，并导致TNBC患者的不良预后。尽管近年来我们对TNBC的分子特征和临床表现的理解有所增加，但科学和医学仍然缺乏对TNBC发展和进展的足够了解，以允许合成能够特异性靶向和缓解这种致命乳腺癌亚型的新型药物。转化生长因子-？(TGF-?)是乳腺肿瘤发生的有力抑制剂。有趣的是，晚期TNBC对TGF-？就好像这种细胞因子是肿瘤促进剂，导致获得转移性和干细胞表型。虽然TGF-？从肿瘤抑制因子到肿瘤促进因子在TNBC中的功能仍不完全清楚，我们的实验室最近定义了一种新的基于整合素的信号传导模块，其促进致癌性TGF-？TNBC中的信号传导。沿着这些线，我们发现赖氨酰氧化酶（LOX）的表达和活性，有助于致癌TGF-？信号传导部分由于机械转导的改变。基于这些和其他初步研究结果，我们假设整合素转换是TGF-β驱动的TNBC转移进展的基础。一个推论指出，开发新的化疗药物，以防止整合素转换和致癌的TGF-？信号传导将显著提高TNBC患者的总体存活率。这些假设将通过四个具体目标来解决。目的1将确定整合素和粘着斑复合物在机械转导引发“TGF-β Parkinson”过程中的作用。我们将操纵，积极和消极的，B1和B3整合素及其效应子的表达，以衡量他们的功能，在耦合机械转导的致癌活性的TGF-？无论是在体外还是在体内。同样，将评估机械转导和Smad 2/3信号传导在TNBC转移期间表观遗传学沉默E-钙粘蛋白表达的能力。目的2将确定LOX家族成员在介导致癌性TGF-β 1？TNBC中的信号传导。此外，将进行LOX家族成员的遗传和药理学失活，以评估其在驱动TGF-β刺激的TNBC转移中的功能。目的3将绘制与TNBC发展和转移进展相关的转录组和表观遗传事件。将确定通过随机乳晕周围细针抽吸分离的患者乳腺细胞中鉴定的表观遗传标记的存在，以评估它们作为 预测性TNBC生物标志物。最后，目标4将可视化TGF-？通过使用双重生物发光成像，在TNBC的转移进展期间的信号传导。同时，将采用基于CTL 1的MRI方法来监测肿瘤反应性基质的相应变化，并确定常规化疗如何影响这些转移事件。总的来说，这些研究将提供有关TGF-β，整合素和机械转导在促进TNBC的EMT、侵袭和转移中协同作用，更重要的是，在如何通过灭活TGF-β的致癌活性来控制这些致命过程中协同作用。此外，将我们的表观遗传生物标志物转化为临床诊断应用将使科学和医学能够显着提高TNBC患者的总体生存率。

DESCRIPTION (provided by applicant): Breast cancer is a heterogeneous disease comprised of at least 5 major tumor subtypes that coalesce as the second leading cause of cancer death in women in the United States. Amongst individual breast cancer subtypes, those classified as being triple-negative breast cancers (TNBCs) are clinically unique via their presentation of aggressive and metastatic phenotypes, and their high propensity to recur rapidly following conventional chemotherapy treatment. TNBCs are also noteworthy by their failure to express hormone receptors (estrogen and progesterone) and ErbB2/HER2, a phenotype that renders targeted chemotherapies (e.g., hormonal or HER2-directed) ineffective and contributes to the poor prognosis of TNBC patients. Although our understanding of the molecular features and clinical manifestations of TNBCs has increased in recent years, science and medicine still lack sufficient knowledge of TNBC development and progression to permit the synthesis of novel pharmaceuticals capable of specifically targeting and alleviating this lethal breast cancer subtype. Transforming growth factor-? (TGF-?) is a powerful suppressor of mammary tumorigenesis. Interestingly, late-stage TNBCs respond to TGF-? as if this cytokine were a tumor promoter, leading to the acquisition of metastatic and stem cell phenotypes. Although the molecular mechanisms underlying the conversion of TGF-? function from that of a tumor suppressor to a tumor promoter in TNBCs remains incompletely understood, our laboratory recently defined a novel integrin-based signaling module that facilitates oncogenic TGF-? signaling in TNBCs. Along these lines, we find the expression and activity of lysyl oxidase (LOX) to contribute to oncogenic TGF-? signaling in part due to alterations in mechanotransduction. Based on these and other preliminary findings, we hypothesize that integrin switching underlies metastatic progression of TNBCs driven TGF-?. A corollary states that developing novel chemotherapeutics to prevent integrin switching and oncogenic TGF-? signaling will significantly improve the overall survival rates of TNBC patients. These hypotheses will be addressed by four Specific Aims. Aim 1 will determine the role of integrins and focal adhesion complexes during initiation of the "TGF-B Paradox" by mechanotransduction. We will manipulate, both positively and negatively, the expression of B1 and B3 integrin and their effectors to gauge their function in coupling mechanotransduction to the oncogenic activities of TGF-? both in vitro and in vivo. Likewise, the ability of mechanotransduction and Smad2/3 signaling to epigenetically silence E-cadherin expression during TNBC metastasis will be assessed. Aim 2 will determine the role of LOX family members in mediating oncogenic TGF-? signaling in TNBCs. Additionally, genetic and pharmacological inactivation of LOX family members will be undertaken to assess their function in driving TNBC metastasis stimulated by TGF-B. Aim 3 will map the transcriptome and epigenetic events coupled to TNBC development and metastatic progression. The presence of identified epigenetic marks in patient breast cells isolated by random periareolar fine needle aspiration will be determined to assess their utility as predictive TNBC biomarkers. Lastly, Aim 4 will visualize TGF-? signaling during metastatic progression of TNBCs through the use of dual bioluminescent imaging. Simultaneous CTL1-based MRI approaches will be employed to monitor corresponding changes in tumor reactive stroma, as well as determine how conventional chemotherapies impact these metastatic events. Collectively, these studies will provide valuable information on how TGF-?, integrins, and mechanotransduction cooperate in promoting the EMT, invasion, and metastasis of TNBCs, and more importantly, on how to control these deadly processes by inactivating the oncogenic activities of TGF-?. Moreover, translating our epigenetic biomarkers to clinical diagnostic applications will enable science and medicine to significantly improve the overall survival of patients with TNBCs.