Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.
Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA; University of Colorado Comprehensive Cancer Center, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.
Eur Urol. 2019 Feb;75(2):242-250. doi: 10.1016/j.eururo.2018.10.040. Epub 2018 Nov 7.
The response to first-line, platinum-based treatment of muscle-invasive bladder cancer has not improved in 3 decades.
To identify genes that influence cisplatin resistance in bladder cancer.
DESIGN, SETTING, AND PARTICIPANTS: We performed a whole-genome CRISPR screen in a bladder cancer cell line to identify genes that mediate resistance to cisplatin.
Targeted validation was performed in two bladder cancer cell lines. The top gene candidate was validated in a publicly available bladder cancer dataset.
From the CRISPR screen, we identified MSH2 as the most significantly enriched gene and mismatch repair as the most significantly enriched pathway that promoted resistance to cisplatin. Bladder cancer cells with knockdown of MSH2 showed a reduction in cisplatin-mediated apoptosis. MSH2 loss did not impact the sensitivity to other chemotherapies, including the cisplatin analog oxaliplatin. Bladder tumors with low MSH2 protein levels, quantified using reverse-phase protein array, showed poorer survival when treated with cisplatin- or carboplatin-based therapy; these results require future validation using immunohistochemistry. Additionally, results are retrospective from patients with primarily high-grade tumors; thus, validation in a controlled clinical trial is needed.
We generated in vitro evidence that bladder cancer cell lines depleted of MSH2 are more resistant to cisplatin. We additionally found an association between low MSH2 in bladder tumors and poorer patient survival when treated with platinum-based chemotherapy. If successfully validated prospectively, MSH2 protein level could assist in the selection of patients for chemotherapy.
We report the first evidence that MSH2 protein level may contribute to chemotherapy resistance observed in muscle-invasive bladder cancer. MSH2 has potential as a biomarker predictive of response to platinum-based therapy.
30 年来，肌肉浸润性膀胱癌一线铂类治疗的反应没有改善。
确定影响膀胱癌顺铂耐药的基因。
设计、设置和参与者：我们在膀胱癌细胞系中进行了全基因组 CRISPR 筛选，以确定介导顺铂耐药的基因。
在两种膀胱癌细胞系中进行了靶向验证。对一个公开的膀胱癌数据集进行了顶级基因候选物的验证。
从 CRISPR 筛选中，我们确定 MSH2 是最显著富集的基因，错配修复是最显著富集的促进顺铂耐药的途径。MSH2 敲低的膀胱癌细胞显示顺铂介导的细胞凋亡减少。MSH2 缺失不影响对其他化疗药物的敏感性，包括顺铂类似物奥沙利铂。使用反相蛋白阵列定量的 MSH2 蛋白水平低的膀胱癌肿瘤在接受顺铂或卡铂为基础的治疗时显示出较差的生存；这些结果需要使用免疫组织化学进行进一步验证。此外，结果是回顾性的，来自主要为高级别肿瘤的患者；因此，需要在对照临床试验中进行验证。
我们在体外产生了证据，表明 MSH2 耗尽的膀胱癌细胞系对顺铂的耐药性增加。我们还发现，膀胱癌中 MSH2 水平低与接受铂类化疗的患者生存较差之间存在关联。如果前瞻性地成功验证，MSH2 蛋白水平可能有助于选择接受化疗的患者。
我们报告了第一个证据，即 MSH2 蛋白水平可能导致肌肉浸润性膀胱癌中观察到的化疗耐药。MSH2 有可能成为预测对铂类治疗反应的生物标志物。
