CN-122012706-A - Application of DHODH-CHK alpha-TRIM 28 in screening medicines for inhibiting proliferation or growth of colorectal cancer cells

Abstract

The invention belongs to the technical field of biological medicines, and provides an application of DHODH-CHKalpha-TRIM 28 in screening medicines for inhibiting proliferation or growth of colorectal cancer cells. The prognosis of a colorectal cancer patient with high co-expression of DHODH and CHK alpha is poor, and the dual-targeting inhibition of DHODH and CHK alpha can synergistically inhibit proliferation or growth of colorectal cancer cells. DHODH inhibits TRIM 28-mediated ubiquitination of chkα at the K244 site and its subsequent proteasome degradation process by competitively binding to the F242/N243 domain of chkα, sterically hindering TRIM28 from accessing the K244 residue on chkα. DHODH-mediated increases in chkα stability drive oncogenic phosphatidylcholine accumulation, promoting colorectal cancer cell proliferation and tumor growth. The combination of leflunomide and MN58b dual targeting DHODH and chkα synergistically inhibits colorectal cancer growth. The DHODH-CHKα -TRIM28 axis is disclosed as a key metabolic susceptibility pathway.

Inventors

• YANG JIAN
• ZHAO ZHENXIANG
• ZHANG YANBIN
• MA MINGFENG
• DONG XIAOQING
• HUANG SIJIA
• YANG XIAOLONG
• Ren Xueke

Assignees

• 山西医科大学
• 吕梁市疾病预防控制中心
• 吕梁市第一人民医院(山西医科大学附属吕梁医院、山西医科大学第十一临床医学院)

Dates

Publication Date

20260512

Application Date

20260108

Claims (3)

1. The application of the DHODH-CHK alpha-TRIM 28 in screening medicaments for inhibiting proliferation or growth of colorectal cancer cells is characterized in that the DHODH and choline kinase alpha, namely CHK alpha, are co-expressed in colorectal cancer and are related to poor prognosis of patients, and the dual-targeting inhibition of the DHODH and the CHK alpha synergistically inhibit proliferation or growth of colorectal cancer cells.
2. 2. The method of claim 1, wherein the targeted inhibition of DHODH is direct binding between DHODH and CHK alpha, thereby releasing the competitive inhibition of the interaction of TRIM28 and CHK alpha by DHODH, enhancing the binding of TRIM28 to CHK alpha, promoting ubiquitination of CHK alpha at K244 site and subsequent proteasome degradation thereof, and finally reducing the stability and expression level of CHK alpha protein.
3. 3. The method of claim 1, wherein the agent targeted to inhibit DHODH is leflunomide and the agent targeted to inhibit CHK alpha is MN58b.

Description

Application of DHODH-CHK alpha-TRIM 28 in screening medicines for inhibiting proliferation or growth of colorectal cancer cells Technical Field The invention belongs to the technical field of biological medicines, and particularly relates to application of DHODH-CHK alpha-TRIM 28 in screening medicines for inhibiting proliferation or growth of colorectal cancer cells. Background The increasing global burden of colorectal cancer, especially the continuously rising incidence in young people, with 200 tens of thousands of cases in 2022, 15% in years, has highlighted the urgent need for a therapeutic strategy based on mechanism cognition [1,2]. Although early colorectal cancer can achieve about 80% five-year survival by surgical excision and multimodal treatment, metastatic cases remain largely incurable due to acquired resistance and tumor heterogeneity [3-6]. This therapeutic dilemma requires us to understand more deeply the oncogenic driving factors, especially those that govern the metabolic plasticity of cancer [7-10]. Targeting metabolic dependence has become a strategic paradigm for colorectal cancer treatment [11-13]. Among them, dihydroorotate dehydrogenase (DHODH) exhibits unique duality as mitochondrial flavoprotein which catalyzes the fourth step of pyrimidine de novo synthesis (dihydrouracil. Fwdarw. Orotate conversion) and drives nucleotide biosynthesis essential for tumor proliferation [14]. In addition to this classical function, DHODH also plays a non-enzymatic role in redox homeostasis (scavenging mitochondrial ROS) and stabilization of Wnt/β -catenin signaling pathway by β -catenin deubiquitination [15-17]. This pleiotropic property makes DHODH a metabolic core hub linking anabolism with pro-survival signaling pathways. Clinically, DHODH inhibitors (buconazole, leflunomide) exhibit a dual effect that, while effective in blocking pyrimidine synthesis in preclinical models, their single drug efficacy is limited by compensatory salvage pathways (28% response rate in phase II trials) and dose-limiting cytotoxicity [18-20]. Recent evidence suggests that these limitations stem from an underappreciated mechanism-the "part-time" function of DHODH, which may activate the bypass survival pathway, thus counteracting inhibition of its enzymatic activity. This finding shows the necessity of a paradigm shift that strategically targeting its interacting group with its single inhibition of DHODH might be able to circumvent drug resistance while destroying the oncogenic network. Current studies severely ignore DHODH's protein interactions and their ability to utilize lipid metabolic pathways. Disclosure of Invention The invention provides application of DHODH-CHK alpha-TRIM 28 in screening medicines for inhibiting proliferation or growth of colorectal cancer cells in order to solve the problem of how to coordinate phosphatidylcholine reprogramming through posttranslational regulation in the prior art. The invention is realized by the following technical scheme that the application of DHODH-CHKalpha-TRIM 28 in screening of medicines for inhibiting proliferation or growth of colorectal cancer cells is realized, the dihydroorotate dehydrogenase (DHODH) and choline kinase alpha (CHKalpha) show high co-expression in colorectal cancer and are obviously related to poor prognosis of patients, and the dual-targeting inhibition of DHODH and CHKalpha can synergistically inhibit proliferation or growth of colorectal cancer cells. Further, the targeted inhibition of DHODH refers to inhibition of direct interaction of DHODH protein with chkα. Specifically, DHODH competitively blocks recognition and binding of the adjacent K244 residue on chkα by E3 ubiquitin ligase TRIM28 by binding to the F242/N243 domain of chkα, thereby inhibiting TRIM 28-mediated chkα ubiquitination-proteasome degradation pathway. Inhibition of DHODH releases the competitive barrier, restores ubiquitination degradation of chkα by TRIM28, and ultimately reduces protein expression levels of chkα. The medicine for targeted inhibition of DHODH is leflunomide, and the medicine for targeted inhibition of CHK alpha is MN58b. Experiments prove that DHODH can competitively bind to F242/N243 domain of CHK alpha, and the binding prevents E3 ubiquitin ligase TRIM28 from approaching adjacent K244 residues on the CHK alpha spatially, so that the TRIM 28-mediated polyubiquitination and subsequent proteasome degradation of the CHK alpha at the K244 site are inhibited. DHODH mediated increases in chkα stability, driving accumulation of oncogenic phosphatidylcholine, which in turn promotes colorectal cancer cell proliferation and tumor growth. Clinical sample analysis showed that high co-expression of DHODH and chkα was closely related to poor prognosis in patients. The invention further discloses that TRIM28 is a key E3 ubiquitin ligase that regulates chkα protein homeostasis in colorectal cancer cells, wherein K244 is a key site for TRIM 28-mediated chkα ubiquitinatio