21P - DNAJC1 inhibit the ferroptosis of glioma cells through stabilizing GPX4 by competing with TRIM21

Background

Glioma is a malignant brain tumor, with high mortality and high morbidity, accounting for 80-85% of malignant tumors in the central nervous system. Infinite proliferation of tumor cells, as the aftermath of imbalanced status in programmed cell death, is a critical stage in tumorigenesis. During the past several years, there has been increased interest in ferroptosis, which contributes to tumor progression.

Methods

U251 cells, U87 cells, and primary glioma cells were used in this study. The ferroptosis of cells were evaluated by cell viability, MDA, PI stain, and GPX. Truncated plasmids of DNAJC1, GPX4, and TRIM21 were conducted to perform the co-IP assays, which explore the regulatory mechanisms between DNAJC1, GPX4, and TRIM21. And we further designed a polypeptide, GAP-14, which could break the DNAJC1 protection of GPX4 from degradation by TRIM21. Orthotopic implantation models were further used to study the therapeutic effect of GAP-14.

Results

We first found that DNAJC1 was a susceptibility gene of glioma in the CGGA database, which was overexpressed in glioma tissues and accompanied by poor prognosis. Then, we discovered that DNAJC1 could protect glioma development by averting tumor cell ferroptosis, and DNAJC1 averted the glioma cells from ferroptosis via GPX4. CHX and MG132 were used to perform the assays that displayed DNAJC1 repressing proteasomal degradation of GPX4, and functioned as an inhibitor of GPX4 ubiquitination by competing with TRIM21. Moreover, under the regulatory mechanism between DNAJC1, GPX4, and TRIM21, GAP-14 was synthesized which specifically targeted on DNAJC1 regulating GPX4 stability. Orthotopic models showed that GAP-14, combined with TMZ, could prolong the survival time of the mice, and decrease the proliferation of glioma in vivo.

Conclusions

In the study, we investigated if DNAJC1 was a susceptibility gene of glioma, averting ferroptosis of tumor cells. It has been considered that the process with DNAJC1 protecting ferroptosis, is a vulnerable target in glioma treatment. Here, we have explored the gatekeeper mechanism of DNAJC1 regulating tumor cell ferroptosis, and designed a short polypeptide, GAP-14, which specifically resists the DNAJC1 protected ferroptosis, with curbing glioma exacerbation.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Tangdu Hospital.

Funding

1. Grant no. 81772661, The National Natural Science Foundation of China, Recipient: LW. 2. Grant no. 2020JZ-30, Natural Science Basic Research Program of Shaanxi Province, Recipient: LW. 3. Grant no. 2021ZTXM007, National Natural Science Foundation of China Booster Project of Tangdu Hospital, Recipient: MC. 4. Grant no. 2021SHRC012, Social Talent Funding Scheme of Tangdu Hospital, Recipient: MC.

Disclosure

All authors have declared no conflicts of interest.