Deposition, remodeling, and signaling of the extracellular matrix facilitate tumor growth and metastasis. Here, we demonstrated that an enzyme, collagen prolyl 4-hydroxylase, alpha polypeptide I (P4HA1), which is involved in collagen synthesis and deposition, had elevated expression in colorectal cancers (CRCs) as compared to normal colonic tissues. The expression of P4HA1 in CRCs was independent of patient's age, race/ethnicity, gender, pathologic stage and grade, tumor location, and microsatellite instability (MSI) and p53 status. By modulating P4HA1 with shRNA, there was a reduction in malignant phenotypes of CRCs, including cell proliferation, colony formation, invasion, migration, and tumor growth, in mice regardless of their p53 and MSI status. Immunoblot analysis of excised xenograft tumors developed from cells with silenced PH4HA1 showed low levels of proliferating cell nuclear antigen. Further, in CRC mouse models, silencing of P4HA1 in HT29 cells resulted in less metastasis to liver and bone. P4HA1 expression was regulated by miR-124, and inhibition of cell growth was noted for CRC cells treated with miR-124. Furthermore, low levels of the transcriptional repressor EZH2 reduced P4HA1 expression in CRC cells. Inhibition of P4HA1 with the small molecule inhibitor diethyl-pythiDC decreased AGO2 and MMP1, which are P4HA1 target molecules, and reduced the malignant phenotypes of CRC cells. Treatment of CRC patient-derived xenografts that exhibit high expression of P4HA1 with diethyl-pythiDC resulted in tumor regression. Thus, the present study shows that P4HA1 contributes to CRC progression and metastasis and that targeting of P4HA1 with diethyl-pythiDC could be an effective therapeutic strategy for aggressive CRCs.

细胞外基质的沉积、重塑和信号传导促进肿瘤生长和转移。在这里，我们证明了与正常结肠组织相比，参与胶原蛋白合成和沉积的酶，胶原蛋白脯氨酰 4-羟化酶，α 多肽 I (P4HA1) 在结直肠癌 (CRC) 中的表达升高。P4HA1 在 CRC 中的表达与患者的年龄、种族/民族、性别、病理分期和分级、肿瘤位置、微卫星不稳定性 (MSI) 和 p53 状态无关。通过用 shRNA 调节 P4HA1，无论小鼠的 p53 和 MSI 状态如何，CRC 的恶性表型都减少了，包括细胞增殖、集落形成、侵袭、迁移和肿瘤生长。从具有沉默 PH4HA1 的细胞发展而来的切除异种移植肿瘤的免疫印迹分析显示低水平的增殖细胞核抗原。此外，在 CRC 小鼠模型中，HT29 细胞中 P4HA1 的沉默导致较少的肝脏和骨骼转移。P4HA1 表达受 miR-124 调节，并且对用 miR-124 处理的 CRC 细胞观察到细胞生长抑制。此外，低水平的转录抑制因子 EZH2 降低了 CRC 细胞中 P4HA1 的表达。用小分子抑制剂二乙基-pythiDC 抑制 P4HA1 可降低作为 P4HA1 靶分子的 AGO2 和 MMP1，并降低 CRC 细胞的恶性表型。用二乙基-pythiDC 治疗表现出 P4HA1 高表达的 CRC 患者来源的异种移植物导致肿瘤消退。因此，