McManaway M E, Marti G E, Tosato G, Liu A K, al-Nasser A A, Kiwanuka J, Magrath I T
Pediatric Branch, National Cancer Institute, NIH, Bethesda, MD 20892.
Pathobiology. 1993;61(3-4):164-72. doi: 10.1159/000163785.
We have explored the factors which influence tumorigenicity of Burkitt's lymphoma (BL) cell lines in athymic nude mice. Four cell lines, Namalwa, CA46, JD38, and ST486 revealed tumor incidence of 63.5, 69.0, 45.5 and 10.0%, respectively, in nude mice, but there was no correlation between tumor incidence and growth rate in vivo. Thus, growth rate and tumorigenicity are dependent upon different biochemical pathways. Evidence of tumor cell heterogeneity was demonstrated in the CA46 parent cell line. Five subclones derived from CA46 revealed varying degrees of tumor incidence (but very similar growth rates) that were consistently less than the parent CA46 line. Line 5, for example, produced 5.7-fold less tumors than the parent line. None of the BL cell lines or clones produced any metastatic lesions in liver, lung, brain, bone marrow or spleen in athymic nude mice. Northern blot analysis of c-myc mRNA levels in different BL cell lines revealed a possible relationship between percent tumor takes (but not growth rates) and the level of c-myc oncogene expression. However, no correlation was observed between c-myc mRNA levels and tumor incidence or growth rates among the CA46 clones. There was no correlation between the ability of the cell lines and the subclones to either secrete growth factors or to respond to growth factors secreted by Epstein-Barr virus-induced lymphoblastoid cells or lipopolysaccharide-activated monocytes, and their growth rates or percent tumor takes in mice. Comparison of tumor incidence and growth rates in irradiated and unirradiated mice showed that host factors influenced the growth of BL in nude mice.(ABSTRACT TRUNCATED AT 250 WORDS)
我们研究了影响伯基特淋巴瘤（BL）细胞系在无胸腺裸鼠体内致瘤性的因素。Namalwa、CA46、JD38和ST486这四种细胞系在裸鼠中的肿瘤发生率分别为63.5%、69.0%、45.5%和10.0%，但肿瘤发生率与体内生长速率之间并无相关性。因此，生长速率和致瘤性取决于不同的生化途径。在CA46亲本细胞系中证实了肿瘤细胞的异质性。从CA46衍生的五个亚克隆显示出不同程度的肿瘤发生率（但生长速率非常相似），且始终低于亲本CA46细胞系。例如，第5亚克隆产生的肿瘤比亲本细胞系少5.7倍。在无胸腺裸鼠中，没有一种BL细胞系或克隆在肝脏、肺、脑、骨髓或脾脏中产生任何转移性病变。对不同BL细胞系中c-myc mRNA水平的Northern印迹分析揭示了肿瘤发生率百分比（而非生长速率）与c-myc癌基因表达水平之间可能存在的关系。然而，在CA46克隆中未观察到c-myc mRNA水平与肿瘤发生率或生长速率之间的相关性。细胞系和亚克隆分泌生长因子或对爱泼斯坦-巴尔病毒诱导的淋巴母细胞或脂多糖激活的单核细胞分泌的生长因子作出反应的能力，与它们在小鼠中的生长速率或肿瘤发生率百分比之间没有相关性。比较照射和未照射小鼠的肿瘤发生率和生长速率表明，宿主因素影响了BL在裸鼠中的生长。（摘要截短于250字）
