Meng Yu-Qi, Feng Hai-Ming, Li Bin, Xie Yuan, Li Zheng, Li Zhen-Qing, Li Xuan
Department of Thoracic Surgery, The Second Hospital & Clinical Medical School, Lanzhou University, Lanzhou, China.
Gansu Province Key Laboratory of Environmental Oncology, Lanzhou, China.
J Gene Med. 2025 Mar;27(3):e70017. doi: 10.1002/jgm.70017.
The expression and functional role of pyrroline-5-carboxylate reductase 1 (PYCR1) in esophageal squamous cell carcinoma (ESCC) remain poorly understood. This study aimed to elucidate the role and underlying mechanisms of PYCR1 in ESCC.
We utilized an ESCC tissue microarray coupled with immunohistochemical staining to assess variability in PYCR1 protein expression among ESCC patients and evaluate its clinical relevance. PYCR1 was silenced in ESCC cell lines with short hairpin RNA (shRNA), followed by functional assays (colony formation, caspase 3/7 activity, methylthiazol tetrazolium, wound healing, and migration/invasion assays) to evaluate its role in ESCC progression. In vivo, mouse tumor xenograft models were used to examine PYCR1's impact on tumor growth. To identify downstream targets and pathways, we conducted coimmunoprecipitation, mass spectrometry, immunofluorescence, and proteomic analyses, validated by western blotting and rescue experiments.
Our findings demonstrated a consistent upregulation of PYCR1 in ESCC tissues. Both in vitro and in vivo studies revealed that PYCR1 suppression significantly inhibited ESCC progression, impacting key processes such as proliferation, apoptosis, migration, and invasion. Mechanistically, PYCR1 was shown to interact with EGFR, promoting ESCC progression and metastasis by activating the PI3K/AKT/mTOR signaling pathways, which are integral to the aggressive behavior of the disease. Rescue experiments further confirmed that EGFR overexpression effectively reversed the inhibitory effects of PYCR1 knockdown in ESCC cells.
This study highlights the critical role of PYCR1 in driving ESCC progression and metastasis, underscoring its potential as a promising therapeutic target for managing this malignancy.
脯氨酸 - 5 - 羧酸盐还原酶1（PYCR1）在食管鳞状细胞癌（ESCC）中的表达及功能作用仍知之甚少。本研究旨在阐明PYCR1在ESCC中的作用及潜在机制。
我们利用ESCC组织芯片结合免疫组化染色来评估ESCC患者中PYCR1蛋白表达的变异性，并评估其临床相关性。用短发夹RNA（shRNA）使ESCC细胞系中的PYCR1沉默，随后进行功能测定（集落形成、半胱天冬酶3/7活性、甲基噻唑四氮唑、伤口愈合以及迁移/侵袭测定）以评估其在ESCC进展中的作用。在体内，使用小鼠肿瘤异种移植模型来研究PYCR1对肿瘤生长的影响。为了鉴定下游靶点和途径，我们进行了免疫共沉淀、质谱分析、免疫荧光和蛋白质组学分析，并通过蛋白质印迹和挽救实验进行验证。
我们的研究结果表明ESCC组织中PYCR1持续上调。体外和体内研究均显示，抑制PYCR1可显著抑制ESCC进展，影响增殖、凋亡、迁移和侵袭等关键过程。机制上，PYCR1被证明与表皮生长因子受体（EGFR）相互作用，通过激活PI3K/AKT/mTOR信号通路促进ESCC进展和转移，而这些信号通路是该疾病侵袭性行为所必需的。挽救实验进一步证实，EGFR过表达可有效逆转ESCC细胞中PYCR1敲低的抑制作用。
本研究强调了PYCR1在驱动ESCC进展和转移中的关键作用，突显了其作为治疗这种恶性肿瘤的有前景治疗靶点的潜力。
