brequinar (DUP 785)

To overcome these limitations, we have engineered a calcium phosphate-mineralized ferroptosis inducer nanoplatform, termed Lf-PEG-CaP@iFSP1-Brequinar-Erastin-Fe3+-TA (LP-CaP@iBEFT), designed to augment ferroptosis by simultaneously targeting three key pathways: glutathione peroxidase 4 (GPX4), ferroptosis suppressor protein 1 (FSP1), and dihydroorotate dehydrogenase (DHODH). This approach effectively dismantles the "triple defense" mechanism that tumor cells employ to resist ferroptosis. In addition, this nanoplatform synergizes with anti-PD-L1 immune checkpoint blockade, enhancing the T cell-mediated destruction of tumor cells.

The combination of DHODH inhibition with Brequinar and BCL-XL degradation by DT2216, a proteolysis targeting chimera (PROTAC), significantly inhibits PDAC tumor growth. These data define mechanisms of adaptation to DHODHi and support combination therapy targeting BCL-XL in PDAC.

In addition, molecular docking studies show their stable binding modes in the brequinar-binding site of DHODH...Finally, they exhibit metabolic stability with half-lives varying from 57 to 216 min in rodent and human liver microsomes. Our study highlights that the new PYRUB-SO salts improve the water solubility of this new family of DHODH inhibitors while maintaining their biological activity.

In addition, molecular docking studies evidenced their potential to bind in the brequinar-binding site located on DHODH which was confirmed using the DHODH inhibition assay showing that PUB-SOs are potent DHODH inhibitors (half maximal inhibitory concentration (IC50) = 7.7-1000 nM)...Furthermore, SFOM-0046 induced apoptosis in MOLM-13 cells, which was confirmed by the increase of annexin V/propidium iodide (PI) and caspase 3/7 positive cells. In summary, our results highlight PUB-SOs as a novel family of DHODH inhibitors inducing both cell differentiation and apoptosis in AML cells, underscoring their potential as therapeutic agents for AML treatment.

We showed that MCF-7 and MDAMB-231 cells of the subtypes (ER+/PR+/HER2-) and (ER-/PR-/HER2-), respectively, were responsive to brequinar...Collectively, we have found that MDAMB-231 TNBC cell was the most affected by DHODH inhibition in terms of sensitivity, cell cycle arrest, induction of cell differentiation, production of ROS, and mitochondrial complexes disruption. In conclusion, these findings suggest that DHODH inhibitors can potentially become a valuable targeted therapy for TNBC subtype and further consolidates its therapeutic potential as part of the combinatorial therapy against this resilient breast cancer subtype.

Human stromal cell lines HS-5 and HS-27, as well as primary MSCs isolated from patient bone marrow, were superior in promoting AML differentiation compared to mouse cells in response to AICAr and brequinar, with the inhibitors not significantly affecting the stromal cells themselves. In conclusion, our study highlights the supportive role of human BM MSCs in enhancing the differentiation effects of pyrimidine synthesis inhibitors on AML cells, suggesting that AML treatment strategies focusing on differentiation rather than cell killing may be successful in clinical settings.

Here, we rationally designed a hollow iron-doped SiO2-based nanozyme (FeSHS) loaded with brequinar (BQR) and lificiguat (YC-1), named FeSHS/BQR/YC-1-PEG, for tumor ferroptosis activation...The elevation of levels of iron and PUFAs while simultaneously disrupting the GPX4/DHODH/FSP1 inhibitory pathways by our designed nanoplatform displayed high therapeutic efficacy both in vitro and in vivo. This work elucidates rationally designing smart nanoplatforms for ferroptosis activation and future tumor treatments.

In vivo studies demonstrated synergetic tumor growth inhibition in xenograft models with brequinar and venetoclax combination treatment. These results provide preliminary evidence for the rational combination of DHODH and BCL2 blockade in HGBCL with abnormal MYC and BCL2.

The negatively charged nanomedicine ensured good blood stability and high tumor accumulation, while the charge-reversal to positive in response to the acidic pH in the tumor microenvironment (TME) and lysosomes enhanced the uptake by tumor cells and lysosome escape, achieving accumulation in mitochondria. The subsequently released Na+ in mitochondria not only contributed to the formation of mitomiR-494 induced G-quadruplexes for AIE imaging diagnosis but also led to an osmolarity surge that was enhanced by brequinar to achieve effective ion-interference therapy.

Furthermore, the in vivo studies revealed that BQR@MLipo could remarkably accumulate into the bladder tumor and successfully initiate the infiltration of CD8 T cells into tumor microenvironment for enabling efficient CBI to inhibit bladder tumor growth. Therefore, BQR@MLipo may represent a clinically promising modality for enhancing CBI in bladder tumor.

Their poor prognosis is linked to the presence of glioblastoma stem cells (GSC), which support resistance to therapy, notably to temozolomide (TMZ)...Finally, we provide a mechanism whereby mitochondrial transfer from MSCs to GSCs contributes to GBM resistance to TMZ therapy, by demonstrating that inhibition of orotate production by Brequinar (BRQ) restores TMZ sensitivity in GSCs with acquired mitochondria...Mitochondria acquired from MSCs enhance the chemoresistance of GBMs. The discovery that they also generate metabolic vulnerability in GSCs paves the way for novel therapeutic approaches.