Mahacek M L, Beer D G, Frank T S, Ethier S P
Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor 48109-0582.
Breast Cancer Res Treat. 1993 Dec;28(3):267-76. doi: 10.1007/BF00666588.
We recently described culture conditions that allow proliferation of metastatic human breast cancer cells from biopsy specimens of certain patient samples. These conditions resulted in the development of an immortalized cell strain designated SUM-44PE. These same culture conditions were used to isolate a human breast cancer cell strain from a metastatic lymph node of a separate breast cancer patient. The SUM-16LN human breast cancer cells isolated from this specimen were cultured either in serum-free medium or serum-containing medium supplemented with insulin and hydrocortisone. Unlike the SUM-44PE cells that have proliferated in culture continuously for over two years, SUM-16LN cells proliferated in culture for approximately 200 days and underwent 15 to 20 population doublings before undergoing cell senescence. No cells of this strain proliferated beyond passage 8. SUM-16LN cells were keratin-19 positive and had an aneuploid karyotype. These cells overexpressed p53 protein and had an amplified epidermal growth factor (EGF) receptor gene that resulted in high level expression of tyrosine phosphorylated EGF receptor protein. Despite the presence of high levels of tyrosine phosphorylated EGF receptor in these cells, they proliferated in serum-free, EGF-free medium and did not secrete detectable levels of EGF-like mitogenic growth factor. In addition, these cells were potently growth inhibited by all concentrations of exogenous EGF tested and by the neutralizing EGF receptor antibody Mab 425. These results suggest that the high level of tyrosine phosphorylated EGF receptor present in these cells is the direct result of receptor overexpression and not the result of the presence of a stimulatory ligand. Thus, SUM-16LN represents a human breast cancer cell strain that exhibited genetic and cellular characteristics of advanced human breast cancer cells. Nevertheless, these cells exhibited a finite proliferative lifespan in culture, suggesting that cellular immortalization is not a phenotype expressed by all human breast cancer cells.
我们最近描述了一种培养条件，该条件可使来自某些患者样本活检标本的转移性人乳腺癌细胞增殖。这些条件导致了一种永生化细胞系的产生，命名为SUM-44PE。相同的培养条件被用于从另一位乳腺癌患者的转移性淋巴结中分离出一种人乳腺癌细胞系。从该标本中分离出的SUM-16LN人乳腺癌细胞在无血清培养基或添加了胰岛素和氢化可的松的含血清培养基中培养。与在培养中连续增殖超过两年的SUM-44PE细胞不同，SUM-16LN细胞在培养中增殖约200天，经历15至20次群体倍增后进入细胞衰老。该细胞系没有细胞在第8代后继续增殖。SUM-16LN细胞角蛋白-19呈阳性，具有非整倍体核型。这些细胞过度表达p53蛋白，并且具有扩增的表皮生长因子（EGF）受体基因，导致酪氨酸磷酸化的EGF受体蛋白高水平表达。尽管这些细胞中存在高水平的酪氨酸磷酸化EGF受体，但它们在无血清、无EGF的培养基中增殖，并且不分泌可检测水平的EGF样促有丝分裂生长因子。此外，所有测试浓度的外源性EGF以及中和性EGF受体抗体Mab 425均能有效抑制这些细胞的生长。这些结果表明，这些细胞中存在的高水平酪氨酸磷酸化EGF受体是受体过度表达的直接结果，而非存在刺激性配体的结果。因此，SUM-16LN代表了一种人乳腺癌细胞系，其表现出晚期人乳腺癌细胞的遗传和细胞特征。然而，这些细胞在培养中表现出有限的增殖寿命，这表明细胞永生化并非所有人类乳腺癌细胞都具有的表型。
