Key Laboratory of Breast Cancer in Shanghai, Department of Breast Surgery, Fudan University Shanghai Cancer Center, 270 Dong-An Road, Build 7, Room 303, Shanghai, 200032, China.
Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China.
Breast Cancer Res Treat. 2021 Jun;187(2):349-362. doi: 10.1007/s10549-021-06213-8. Epub 2021 Apr 16.
Metastasis is the main cause of breast cancer mortality. Recent studies have proved that lipid metabolic reprogramming plays critical roles in breast cancer carcinogenesis and metastasis. We aim to identify critical lipid metabolism genes in breast cancer metastasis.
We designed and cloned a CRISPR pooled library containing lipid metabolic gene guide RNAs and performed a genetic screen in vivo. Transwell assay and animal experiments were used to evaluate cell metastatic ability in vitro or in vivo, respectively. We performed immunohistochemistry with breast cancer tissue microarray to study the clinical significance of NSDHL.
We identified a cholesterol metabolic enzyme, NSDHL, as a potential metastatic driver in triple-negative breast cancer. NSDHL was highly expressed in breast cancer tissues and predicted a poor prognosis. NSDHL knockdown significantly suppressed cell proliferation and migration. Mechanistically, NSDHL activated the TGFβ signaling pathway by inhibiting the endosomal degradation of TGFβR2. In addition, blocking the upstream metabolism of NSDHL with ketoconazole rescued cancer metastasis and TGFβR2 degradation. However, the inactivation of NSDHL (Y151X) did not rescue the migration ability and the TGFβR2 protein expression.
Taken together, our findings established that NSDHL serves as a metastatic driver, and its function depends on its enzyme activity in cholesterol biosynthesis and is mediated by the NSDHL-TGFβR2 signal pathway. Our study indicated that NSDHL and steroid biosynthesis may serve as new drug targets for patients with advanced breast cancer.
转移是乳腺癌死亡的主要原因。最近的研究已经证明，脂质代谢重编程在乳腺癌的发生和转移中起着关键作用。我们旨在确定乳腺癌转移中的关键脂质代谢基因。
我们设计并克隆了一个包含脂质代谢基因指导 RNA 的 CRISPR pooled 文库，并在体内进行了遗传筛选。使用 Transwell 测定和动物实验分别评估体外和体内细胞转移能力。我们使用乳腺癌组织微阵列进行免疫组织化学研究 NSDHL 的临床意义。
我们确定了胆固醇代谢酶 NSDHL 是三阴性乳腺癌中的潜在转移驱动因子。NSDHL 在乳腺癌组织中高表达，预示着预后不良。NSDHL 敲低显著抑制细胞增殖和迁移。在机制上，NSDHL 通过抑制 TGFβR2 的内体降解来激活 TGFβ 信号通路。此外，用酮康唑阻断 NSDHL 的上游代谢可挽救癌症转移和 TGFβR2 降解。然而，NSDHL（Y151X）的失活不能挽救迁移能力和 TGFβR2 蛋白表达。
综上所述，我们的研究结果表明 NSDHL 作为一种转移驱动因子，其功能取决于其在胆固醇生物合成中的酶活性，并通过 NSDHL-TGFβR2 信号通路介导。我们的研究表明，NSDHL 和类固醇生物合成可能成为晚期乳腺癌患者的新药物靶点。
