Tassone Pierfrancesco, Di Martino Maria Teresa, Ventura Monica, Pietragalla Antonella, Cucinotto Iole, Calimeri Teresa, Bulotta Alessandra, Neri Paola, Caraglia Michele, Tagliaferri Pierosandro
Medical Oncology Unit, Magna Graecia University and Tommaso Campanella Cancer Center, Campus Salvatore Venuta, Catanzaro, Italy. oncologia@@unicz.it
Cancer Biol Ther. 2009 Apr;8(7):648-53. doi: 10.4161/cbt.8.7.7968. Epub 2009 Apr 28.
Previous reports suggested a central role of BRCA1 in DNA-damage repair mechanisms elicited by cell exposure to anti-tumor agents. Here we studied if BRCA1-defective HCC1937 or BRCA1-reconstituted HCC1937/(WT)BRCA1 human breast cancer xenografts (HBCXs) generated in SCID mice were differentially sensitive to cisplatin (CDDP) in vivo and we investigated potential molecular correlates of this effect.
CDDP induced almost complete growth inhibition of BRCA1-defective HBCXs, while BRCA1-reconstituted HBCXs were only partially inhibited. Cell cycle analysis showed a significant S- and G(2)/M blockade in BRCA1-defective as compared with parental BRCA1-reconstituted cells. Comparative gene expression profiling of HCC1937 and HCC1937/(WT)BRCA1 showed upregulation of RAD52 and XRCC4, whereas ERCC1 and RRM1 were downregulated. Pathway finder analysis of gene arrays data indicated perturbations of major proliferation and survival pathways suggesting that BRCA1 is mostly involved in G(2)/M but also in G(1)/S-phase checkpoints as well as in several important signaling pathways, including IGF, VEGF, estrogen receptor, PI3K/AKT and EGF.
HCC1937 or HCC1937/(WT)BRCA1 HBCXs were generated in SCID mice. Animals were then weekly treated with 5 mg/kg CDDP i.p. or with vehicle for 4 w. Tumor volume and mice survival were evaluated. Tumors were retrieved from animals 12 hours after the last treatment with CDDP or vehicle treatment and the cell suspension underwent cell cycle analysis. Differential gene expression and pathway modulation between HCC1937 and HCC1937/(WT)BRCA1 cells were also studied.
Our data suggest that BRCA1-defective in vivo HBCXs express a molecular scenario predictive of high sensitivity to platinum-derived compounds strongly supporting the rationale for prospective tailored clinical trials in hereditary breast cancer.
先前的报告表明，BRCA1在细胞暴露于抗肿瘤药物引发的DNA损伤修复机制中起核心作用。在此，我们研究了在SCID小鼠中生成的BRCA1缺陷型HCC1937或BRCA1重组型HCC1937/(WT)BRCA1人乳腺癌异种移植瘤（HBCXs）在体内对顺铂（CDDP）的敏感性是否存在差异，并研究了这种效应的潜在分子关联。
CDDP几乎完全抑制了BRCA1缺陷型HBCXs的生长，而BRCA1重组型HBCXs仅受到部分抑制。细胞周期分析显示，与亲本BRCA1重组细胞相比，BRCA1缺陷型细胞出现显著的S期和G(2)/M期阻滞。HCC1937和HCC1937/(WT)BRCA1的比较基因表达谱显示RAD52和XRCC4上调，而ERCC1和RRM1下调。基因阵列数据的通路查找分析表明主要增殖和存活通路受到干扰，提示BRCA1主要参与G(2)/M期，但也参与G(1)/S期检查点以及包括IGF、VEGF、雌激素受体、PI3K/AKT和EGF在内的几种重要信号通路。
在SCID小鼠中生成HCC1937或HCC1937/(WT)BRCA1 HBCXs。然后，动物每周腹腔注射5 mg/kg CDDP或溶剂，持续4周。评估肿瘤体积和小鼠存活率。在末次给予CDDP或溶剂处理12小时后从动物体内取出肿瘤，细胞悬液进行细胞周期分析。还研究了HCC1937和HCC1937/(WT)BRCA1细胞之间的差异基因表达和通路调节。
我们的数据表明，体内BRCA1缺陷型HBCXs呈现出对铂类化合物高度敏感的分子特征，这有力地支持了在遗传性乳腺癌中进行前瞻性个体化临床试验的理论依据。
