Secretory Patterns of Senescent Tumor Cells

描述（由申请方提供）：诱导细胞衰老是人肿瘤组织对化疗和放疗的显著反应。 虽然衰老细胞不分裂，但它们分泌许多与癌症和其他慢性疾病有关的生物活性蛋白。 这些蛋白质中的一些刺激而另一些抑制邻近肿瘤细胞的生长和存活。 细胞周期蛋白依赖性激酶抑制剂（CDKI）蛋白（如p21/Waf 1）的表达，这是经常在衰老细胞上调，增强肿瘤促进因子的生产。 不同类型的衰老正常细胞和肿瘤细胞被发现产生不同的促肿瘤或抑肿瘤旁分泌活性。 了解衰老细胞的癌症相关活动的光谱和决定因素应有助于开发生物标志物和策略，以管理肿瘤衰老对长期治疗结果的影响。 在第一个具体目标中，将用三种不同的抗癌剂处理HCT 116结肠癌和HT 1080纤维肉瘤细胞系。 存活细胞的衰老和增殖部分将通过流式分选分离。 将测定这些级分中由衰老细胞中在RNA水平诱导的基因编码的生物活性蛋白的产生和分泌。 在第二个具体目标中，将测试衰老肿瘤细胞的影响肿瘤细胞生长、存活、耐药性、侵袭或血管生成的旁分泌活性。 衰老细胞中增加的旁分泌活性将与能够赋予这种活性的蛋白质的分泌相关，并且将使用特异性抑制剂来测试这种蛋白质的作用。 第三个具体的目标是询问是否抑制CDKI激活的转录途径改变了衰老肿瘤细胞的分泌模式，有利于肿瘤抑制活性。 对于该分析，将比较HCT 116细胞的衰老群体及其衍生物（其中CDKI途径被抑制）之间的分泌蛋白和旁分泌活性。 第四个具体目标是研究通过在裸鼠中作为异种移植物生长并通过体内照射衰老的衰老HCT 116细胞产生生物活性蛋白。 此外，异种移植共植入试验将用于研究具有不同CDKI途径状态的衰老HCT 116细胞对体内肿瘤生长的影响。 该计划将有助于阐明肿瘤衰老对癌症治疗结果的不同影响及其对患者健康的长期影响。

DESCRIPTION (provided by applicant): Induction of cell senescence is a prominent response of human tumor tissues to chemotherapy and radiation. Although senescent cells do not divide, they secrete many bioactive proteins implicated in cancer and other chronic diseases. Some of these proteins stimulate while others inhibit the growth and survival of neighboring tumor cells. Expression of cyclin-dependent kinase inhibitor (CDKI) proteins (such as p21/Waf1), which are frequently upregulated in senescent cells, enhances the production of tumor-promoting factors. Different types of senescent normal and tumor cells were found to produce different tumor-promoting or tumor-inhibiting paracrine activities. Understanding the spectra and determinants of cancer-relevant activities of senescent cells should help in developing biomarkers and strategies for managing the impact of tumor senescence on the long-term treatment outcome. In the first specific aim, HCT116 colon carcinoma and HT1080 fibrosarcoma cell lines will be treated with three different anticancer agents. Senescent and proliferating fractions of surviving cells will be separated by flow sorting. These fractions will be assayed for the production and secretion of bioactive proteins encoded by genes that are induced at the RNA level in senescent cells. In the second specific aim, senescent tumor cells will be tested for paracrine activities that affect tumor cell growth, survival, drug resistance, invasion or angiogenesis. Paracrine activities increased in senescent cells will be correlated with the secretion of proteins capable of conferring such activities, and the role of such proteins will be tested using specific inhibitors. The third specific aim asks whether inhibition of the CDKI-activated transcriptional pathway alters the secretory patterns of senescent tumor cells in favor of tumor-suppressing activities. For this analysis, secreted proteins and paracrine activities will be compared between senescent populations of HCT116 cells and their derivatives where CDKI pathway is inhibited. The fourth specific aim investigates production of bioactive proteins by senescent HCT116 cells grown in nude mice as xenografts and rendered senescent by irradiation in vivo. In addition, xenograft coimplantation assays will be used to investigate the effects of senescent HCT116 cells with different CDKI pathway status on tumor growth in vivo. The proposed program should help in elucidating different effects of tumor senescence on the outcome of cancer treatment and on its long-term implications for the patient's health.