利用基因芯片法探索人前列腺癌细胞PC-3M在裸鼠体内淋巴道转移相关基因

Differential metastasis-related gene analysis of prostate cancer cells isolated from primary tumor and spontaneous metastases in nude mice with orthotopic injection of PC-3M cells by cDNA microarray

背静与目的:前列腺癌是欧美国家最常见的一种男性恶性肿瘤,近年来在我国该病也有明显上升趋势。目前认为肿瘤转移是由于一部分肿瘤细胞在肿瘤生长过程中发生基因水平的变化而改变性质变成“转移克隆的细胞”,这部分细胞能突破机体防御系统最终到达远处组织器官形成转移灶。本实验旨在探索人前列腺癌细胞PC-3M在裸鼠体内淋巴道转移的相关基因,为进一步研究前列腺癌淋巴道转移机制打下一定的基础。方法:将PC-3M细胞原位接种于裸鼠体内两个月后分别从原发灶和淋巴结转移灶分离肿瘤细胞,通过体外侵袭和粘附实验,比较两者体外侵袭和粘附能力的差异,并应用基因芯片技术,检测两细胞在转移相关基因丰度水平上的差异。结果:淋巴结转移灶分离的肿瘤细胞的体外侵袭及粘附能力显著高于原发灶内分离的肿瘤细胞,大约分别为后者的2.5倍和1.5倍;而且前者在一些转移相关基因丰度水平上明显高于后者,这些基因按其编码产物的属性和功能可划分为:①编码降解细胞外基质(ECM)的蛋白水解酶包括组织蛋白酶、基质金属蛋白酶;②编码转录因子家族成员;③编码参与肿瘤细胞异质性粘附的分子;④编码细胞表面受体。结论:原发灶内的前列腺癌细胞和淋巴结转移灶内的肿瘤细胞在侵袭和粘附能力上存在显著差异,经鉴定的差异表达分子可能在前列腺癌细胞由原发灶迁移到远处组织器官的转移过程中发挥重要作用。

Background and Purpose： Prostate cancer is one of the most common cancers and the second leading cause of cancer-related death in Europan and North American males, The incidence of prostate cancer has also been increasing during the past few decades in China, It is widely accepted that this heterogeneity, which results from the tumor progression driven largely by genomie instability（ genetic and/or epigenetic alterations） of tumor cells in primary tumor, endows specific populations of tumor cells with the unique character needed for invasion, migration, and metastasis colony formation in other organs and only these subpopulations possessing thost character can survive the potentially destructive journey from the primary tumor to the sites of metastases. The purpose of the present study was to explore the genes associated with invasion and metastasis of human prostate cancer cell line PC-3M in nude mice. Methods： After PC-3M cells were inoculated into orthotopic site （prostate） in a male nude mouse for two months, tumor cells were isolated from the primary tumor and lymph node metastasis, separately. Cell invasion and adhesion ability in vitro were first compared between two cells. Then metastasis-related genes differentially expressed between them were analyzed by utilizing cDNA microarray technique. Results： The in vitro cell invasion and adhesion potential of tumor cells from lymph node metastasis was significantly higher than those from primary tumor by 2.5 fold and 1.5 fold, respectively. Metastasis-related genes differentially expressed between those two sublines were identified, all of them were up-regulated in the tumor ceils from lymph node metastasis and could be categorilized： 1. genes encoding cellular matrix-degrading proteolytic enzyme including cathepsin and MMP. 2. genes encoding transcription factors. 3. genes related to heterotypic adhesion of tumor cells. 4. genes encoding cell surface receptors.Conclusions：There are significant differences in invasion and adhesion potential between cells from primary tumor and those from lymph node metastasis. Some differentially expressed molecules might be playing pivotal roles in promoting tumor cells to migrate from primary tumors to distant metastases, which may be helpful to elucidate the possible mechanism of metastasis in prostate cancer.