14-3-3zeta in ErbB2 Mediated Mammary Carcinogenesis

描述（由申请人提供）：ErbB2常见于高级别人DCIS(50-60%)，在80-85%的非侵袭性、癌前、喜剧型DCIS肿瘤中发现ErbB2基因扩增。有趣的是，ErbB2在25-30%的浸润性乳腺癌中过度表达。目前尚不清楚一些ErbB2过表达的DCIS如何发展为浸润性导管癌（invasive ductal carcinoma， IDC）。ErbB2在MCF10A乳腺上皮细胞中的急性激活在模拟乳腺中腺泡形成的体内条件的三维（3D）培养中生长的B2 MECs导致了多腺泡结构的产生，这些结构缺乏侵袭性，与DCIS具有相同的结构特性。因此，激活的ErbB2诱导MEC的早期转化，但不足以诱导侵袭行为。据推测，mec需要额外的遗传/分子事件或更高水平的ErbB2才能获得侵袭性。然而，激活ErbB2诱导MECs早期转化的机制以及其获得侵袭性特性的相关事件尚不清楚。有趣的是，我们发现14-3-3 -3zeta是一种参与许多重要细胞过程的蛋白，在大约30%的乳腺癌患者DCIS病变中与ErbB2高水平共表达，并与侵袭性和转移性疾病的复发有关。逆转录病毒感染增加10A细胞14-3-3 -3zeta表达。B2 mec在三维培养中导致侵袭性多腺泡结构，而在载体对照中则没有侵袭性。另一方面，阻断14-3-3 -3zeta在10A区的表达。通过siRNA抑制B2细胞向多腺泡结构的发育，通过14-3-3zeta干扰突变体阻断14-3-3 -3zeta功能，抑制erbb2介导的NIH3T3细胞转化。因此，我们假设14-3-3 -3zeta参与erbb2介导的乳腺癌发生，14-3-3 -3zeta的高表达在erbb2激活的mec中具有侵袭性，可能促进erbb2过表达的DCIS向IDC的发展。在本提案中，我们将研究14-3-3 -3zeta在ErbB2激活的mec转化和获得侵袭性中的作用和机制（目的1和2），并确认14-3-3 -3zeta在ErbB2过表达的DCIS向患者IDC进展中的作用（目的3）。这些综合方法将确定14 -3-3zetain erbb2介导的乳腺癌发生和侵袭的作用，并最终在erbb2过表达的DCIS向IDC的进展中发挥作用。该研究将为ErbB2和14-3-3 -3zeta高表达肿瘤患者的早期干预、诊断和治疗带来新的见解。

DESCRIPTION (provided by applicant): ErbB2 is frequently detected in high-grade human DCIS (50-60%) and ErbB2 gene amplification has been found in 80-85% of the non-invasive, premalignant, comedo-type DCIS tumors. Intriguingly, ErbB2 is overexpressed in 25-30% of invasive breast cancers. It is not clear how some of the ErbB2 overexpressing DCIS develop into invasive ductal carcinoma (IDC). Acute activation of ErbB2 in MCF10A mammary epithelial cells (10A.B2 MECs) grown in a three dimensional (3D) culture that simulates in vivo conditions of acini formation in the mammary gland has led to the generation of multi-acinar structures lacking invasive properties that share structural properties associated with DCIS. Thus, activated ErbB2 induces the early transformation of MEC but is not sufficient to induce invasive behavior. It was postulated that additional genetic/molecular events or much higher levels of ErbB2 are needed for MECs to acquire invasive properties. However, the mechanisms by which activated ErbB2 induces early transformation of MECs and the events involved in their acquisition of invasive properties are not clear. Interestingly, we found that 14-3-3zeta, a protein that participates in many important cellular processes, is co-expressed at high levels with ErbB2 in approximately 30% of DCIS lesions of breast cancer patients and is associated with recurrence of invasive and metastatic diseases. Increasing 14-3-3zeta expression by retroviral infection in the 10A.B2 MECs led to invasive multi-acinar structures in 3D culture in contrast to the lack of invasion in the vector controls. On the other hand, blocking 14-3-3zeta expression in the 10A.B2 cells by siRNA inhibited their development into multi-acinar structures and blocking 14-3-3zeta function with a 14 -3-3zeta interfering mutant led to the inhibition of ErbB2-mediated transformation in NIH3T3 cells. Therefore, we hypothesize that 14-3-3zeta contributes to ErbB2-mediated mammary carcinogenesis and 14-3-3zeta high expression confers invasive potential in ErbB2-activated MECs that may facilitate the progression of ErbB2-overexpressing DCIS to IDC. In this proposal, we will investigate the role and the mechanisms of 14-3-3zeta in the transformation and acquisition of invasiveness of ErbB2 activated MECs (Aims 1 and 2) and confirm the role of 14-3-3zeta in the progression of ErbB2-overexpressing DCIS to IDC in patients (Aim 3). These comprehensive approaches will define the role of 14 -3-3zetain ErbB2-mediated mammary carcinogenesis and invasion, and ultimately in the progression of ErbB2-overexpressing DCIS to IDC. The study will bring new insights into early intervention, diagnosis, and treatment that may benefit the high-risk group of patients with ErbB2 and 14-3-3zeta overexpressing tumors.