Thymosin beta15 expression in tumor cell lines with varying metastatic potential.

We previously isolated thymosin beta15 from highly metastatic Dunning rat prostatic carcinoma cells. Immunohistochemical study of human prostate cancer specimens revealed a general correlation between Gleason grade and thymosin beta15 expression, with high-grade (more malignant) tumors showing increased staining compared to low-grade tumors. To determine whether thymosin beta15 may be differentially expressed in cancer cells with different metastatic potential other than in the prostatic carcinoma cells, we examined thymosin beta15 mRNA levels in tumor cell lines from different species. We also examined thymosin beta15 protein levels in human breast cancer samples. Thymosin beta15 was upregulated in the highly metastatic mouse lung and human breast cancer cell lines in comparison to the nonmetastatic counterparts. Immunohistochemical staining showed the evidence of upregulation of thymosin beta15 in malignant human breast carcinomas as compared to benign breast tumors. The expression of thymosin beta15 was correlated with the metastatic potential of the mouse lung carcinoma and human breast carcinoma cells in addition to the prostatic carcinomas. Thymosin beta15 may be a useful marker to predict metastatic potential of certain human cancers.

胸腺素β15在具有不同转移潜能的肿瘤细胞系中的表达。

我们以前从高转移性Dunning大鼠前列腺癌细胞中分离出胸腺素β15。人类前列腺癌标本的免疫组织化学研究揭示了Gleason分级和胸腺素β15表达之间的一般相关性，与低级肿瘤相比，高级(更恶性)肿瘤显示出染色增加。为了确定胸腺素β15是否可以在除前列腺癌细胞之外的具有不同转移潜能的癌细胞中差异表达，我们检测了来自不同物种的肿瘤细胞系中胸腺素β15 mRNA的水平。我们还检测了人类乳腺癌样本中胸腺素β15蛋白的水平。胸腺素β15在高转移小鼠肺癌和人乳腺癌细胞系中与非转移对应细胞相比上调。免疫组织化学染色显示了与良性乳腺肿瘤相比，胸腺素β15在恶性人乳腺癌中上调的证据。除前列腺癌外，胸腺素β15的表达与小鼠肺癌和人乳腺癌细胞的转移潜能相关。胸腺素β15可能是预测某些人类癌症转移潜能的有用标记。