The Development of novel anticancer drugs for anaplastic thyroid carcinoma by collaboration of medicine and engineering

甲状腺未分化癌是一种发生于老年人的低分化癌。未分化癌患者预后差。因此，研究有效的治疗策略，抑制未分化癌的生长，延长患者的预后，已成为当务之急。我们重点研究了泛素-蛋白酶体系统。蛋白酶体是细胞内主要的蛋白酶，由14个分子量为21- 32 kD的同源亚基组成，组成约700 kDa的圆柱形结构。我们分析了蛋白酶体亚单位在甲状腺未分化癌中的表达，发现蛋白酶体亚单位C2和蛋白酶体激活剂g（PA 28 g）在其快速生长的癌细胞中高表达。PA 28 g定位于癌细胞核内，提示PA 28 g可能是调控癌细胞生长的良好候选物之一。蛋白酶体抑制剂如la 关于我们 ctacystin显著抑制甲状腺癌细胞系的DNA合成，表明内源性20 S蛋白酶体参与了癌细胞的生长。然后，我们使用大鼠功能性甲状腺细胞系FRTL 5细胞分析了PA 28 g的详细周转。有趣的是，TSH和胰岛素处理不仅上调PA 28-γ的表达，而且还将PA 28-γ从胞浆募集到细胞核。TSH和胰岛素的组合显示出最高的PA 28-γ的诱导以及FRTL 5的双DNA合成。因此，我们的研究结果表明，PA 28-γ是由甲状腺促甲状腺肿因子，TSH和胰岛素，在甲状腺细胞诱导，并可能有助于甲状腺细胞的生长，通过增强20 S蛋白酶体活性。总之，过表达的蛋白酶体组分如C2或PA 28-γ将是操纵蛋白酶体活性，从而干扰间变性癌细胞生长的良好候选基因。为了分离一个新的基因，我们使用了一种独特的策略，称为SEREX。我们使用来源于癌组织的表达文库，并通过自体患者血清测量1 × 106个斑块。毕竟，我们可以分离出两个阳性克隆。其中之一是WD重复蛋白1（WDR 1），它是肌动蛋白相互作用蛋白1的人类对应物。WDR 1在甲状腺未分化癌组织中高表达，表明WDR 1可能参与癌细胞增殖。WDR 1蛋白的降解途径是否依赖于泛素-蛋白酶体途径尚不清楚。但是，如果它是通过蛋白酶体依赖的方式降解，WDR 1将是一个很好的候选抗癌治疗。少

Anaplastic thyroid carcinoma is a poorly differentiated carcinoma found in elderly people. The patients with anaplastic carcinoma always suffer from poor prognosis. It is an urgent business to develop the effective strategy to suppress the growth of anaplastic carcinoma and prolong the prognosis of patients. We focused on the ubiquitin-proteasome sytem. Proteasome is a major intracellular proteinase found as a large protein complex composed of at least 14 distinct but homologous subunits with molecular masses of 21-32kD and they are assembled into an approximately 700kDa cylindcal structure. We analyzed the expression of proteasome subunits in anaplastic thyroid carcinoma and found that proteasome subunit C2 and proteasome activator g(PA28g) are highly expressed in its rapid-growing cancer cells. Interestinglly, PA28g is localized in nuclei of cancer cells, suggesting PA28g, could be one of the good candidate for manipulating the growth of cancer cells. Proteasome inhibitors such as la … More ctacystin significantly blocked the DNA synthesis of thyroid carcinoma cell line, indicating the intrinsic 20S proteasome is involved in cancer cell growth. We then analyzed the detailed turn-over of PA28g using rat functional thyroid cell line, FRTL5 cells. Interestingly, TSH and insulin treatment not only upregulate PA28-γ expression but also recruite PA28-γ from cytosol to nucleus. The combination of TSH and insulin showed highest inducibility of PA28-γ as well as dual DNA synthesis of FRTL5. Thus, our results indicate PA28-γ is induced by goitrogenic factors, TSH and insulin, in thyroid cell and potentially contribute to thyroid cell growth by potentiating 20S proteasome activity. Taken together, overexpressed proteasome component such as C2 or PA28-γ will be good candidates for manipulating proteasome activity, thereby interfering with anaplastic cancer cell growth.Simultaneously, we searched novel candidate genes for mapipulating the growth rate of anaplastic thyroid cancer. In order to isolate a novel gene, we used a unique strategy named SEREX. We used expression library derived from cancer tissue and surveyed 1X106 plaque by autologous patient sera. After all, we could isolate two positive clones. One of them was WD repeat protein 1(WDR1), which is the human counterpart of actin interacting protein 1. WDR1 is highly expressed in anaplastic thyroid cancer tissues, indicating that WDR1 could be involved in cancer cell proliferation. It still remains unclear that WDR1 protein is degraded by ubiquitin-proteasome dependent pathway. But, if it is degraded via proteasome-dependent fashion, WDR1 will be a good candidate for anti-cancer therapy. Less