Antimalarial Drug Pyrimethamine Plays a Dual Role in Antitumor Proliferation and Metastasis through Targeting DHFR and TP

• Published in: Molecular cancer therapeutics Vol. 18; no. 3; pp. 541 - 555
• Main Authors: Liu, Huijuan, Qin, Yuan, Zhai, Denghui, Zhang, Qiang, Gu, Ju, Tang, Yuanhao, Yang, Jiahuan, Li, Kun, Yang, Lan, Chen, Shuang, Zhong, Weilong, Meng, Jing, Liu, Yanrong, Sun, Tao, Yang, Cheng
• Format: Journal Article
• Language: English
• Published: United States 01.03.2019
• Subjects: Antimalarials - chemistry; Antimalarials - pharmacology; Antineoplastic Agents - chemistry; Antineoplastic Agents - pharmacology; Cell Proliferation - drug effects; Humans; Lung Neoplasms - drug therapy; Lung Neoplasms - genetics; Lung Neoplasms - pathology; Methotrexate - chemistry; Methotrexate - pharmacology; Molecular Conformation; Neoplasm Metastasis; Protein Structure, Secondary; Pyrimethamine - chemistry; Pyrimethamine - pharmacology; Tetrahydrofolate Dehydrogenase - chemistry; Tetrahydrofolate Dehydrogenase - genetics; Thymidine Phosphorylase - antagonists & inhibitors; Thymidine Phosphorylase - chemistry; Thymidine Phosphorylase - genetics
• ISSN: 1535-7163; 1538-8514
• DOI: 10.1158/1535-7163.MCT-18-0936

Pyrimethamine (Pyr), an antimalarial drug that targeting plasmodium dihydrofolate reductase (pDHFR), has been proved to have antitumor activity. However, its direct target on cancer cells remains unclear. Methotrexate (MTX) is a widely used anticancer drug that blocks human dihydrofolate reductase (hDHFR). In this work, we examined the anticancer effects of Pyr and Our results showed that hDHFR and pDHFR have similar secondary and three-dimensional structures and that Pyr can inhibit the activity of hDHFR in lung cancer cells. Although Pyr and MTX can inhibit the proliferation of lung cancer cells by targeting DHFR, only Pyr can inhibit the epithelial-mesenchymal transition (EMT), metastasis and invasion of lung cancer cells. These results indicated that hDHFR is not the only target of Pyr. We further found that thymidine phosphorylase (TP), an enzyme that is closely associated with the EMT of cancer cells, is also a target protein of Pyr. The data retrieved from the Cancer Genome Atlas (TCGA) database revealed that TP overexpression is associated with poor prognosis of patients with lung cancer. In conclusion, Pyr plays a dual role in antitumor proliferation and metastasis by targeting DHFR and TP. Pyr may have potential clinical applications for the treatment of lung cancer.