METHODS: We analyzed the data from public databsets to screen candidate genes and then focused on SOX4, a regulator of NE trans-differentiation. The expression changes of SOX4 and its relationship with tumor progression were validated in clinical tumor tissues. We evaluated malignant characteristics related to NEPC in prostate cancer cell lines with stable overexpression or knockdown of SOX4 in vitro. Tumor xenografts were analyzed after inoculating the relevant cell lines into nude mice. RNA-seq, ATAC-seq, non-targeted metabolomics analysis, as well as molecular and biochemical assays were carried out to determine the mechanism.
RESULTS: We screened public datasets and identified that expression of SOX4 was significantly elevated in NEPC. Overexpressing SOX4 in C4-2B cells increased cell proliferation and migration, upregulated the expression of NE marker genes, and inhibited AR expression. Consistently, inhibition of SOX4 expression in DU-145 and PC-3 cells reduced the above malignant phenotypes and repressed the expression of NE marker genes. For the in vivo assay, we found that knockdown of SOX4 inhibited tumor growth of subcutaneous xenografts in castrated nude mice which were concomitantly treated with enzalutamide (ENZ). Mechanically, we identified that one of the key enzymes in gluconeogenesis, PCK2, was a novel target of SOX4. The activation of carbohydrate metabolism reprogramming by SOX4 could promote NE trans-differentiation via the SOX4/PCK2 pathway.
CONCLUSIONS: Our findings reveal that SOX4 promotes NE trans-differentiation both in vitro and in vivo via directly enhancing PCK2 activity to activate carbohydrate metabolism reprogramming. The SOX4/PCK2 pathway and its downstream changes might be novel targets for blocking NE trans-differentiation.
方法:我们分析了来自公共数据集的数据以筛选候选基因,然后将重点放在SOX4上,SOX4是NE转分化的调节剂。在临床肿瘤组织中验证了SOX4的表达变化及其与肿瘤进展的关系。我们在体外评估了SOX4稳定过表达或敲低的前列腺癌细胞系中与NEPC相关的恶性特征。在将相关细胞系接种到裸小鼠中后分析肿瘤异种移植物。RNA-seq,ATAC-seq,非靶向代谢组学分析,进行了分子和生化测定以确定其机理。
结果:我们筛选了公共数据集,确定SOX4的表达在NEPC中显著升高。在C4-2B细胞中过表达SOX4可增加细胞增殖和迁移,上调NE标记基因的表达,并抑制AR表达。始终如一,抑制DU-145和PC-3细胞中SOX4的表达可减少上述恶性表型并抑制NE标记基因的表达。对于体内测定,我们发现SOX4的敲减抑制了去势裸鼠皮下移植瘤的肿瘤生长,这些裸鼠同时用恩杂鲁胺(ENZ)治疗。机械上,我们确定了糖异生的关键酶之一,PCK2是SOX4的新靶标。SOX4激活碳水化合物代谢重编程可通过SOX4/PCK2途径促进NE转分化。
结论:我们的发现表明,SOX4通过直接增强PCK2活性以激活碳水化合物代谢重编程,在体外和体内促进NE的转分化。SOX4/PCK2通路及其下游变化可能是阻断NE转分化的新靶点。