CR-1-31-B

Melanoma A375 (vemurafenib [VEM]-sensitive) and A375R (VEM-resistant) cells were exposed to eIF4Fi RocA at varying doses and durations in vitro...Combined CR-1-31-B, EZH2i, and AKT1i effectively overcame resistance to RocA and VEM resistance both in vitro and in vivo. The eIF4F complex inhibitor reactivates ERK1/2-EZH2 and AKT1 signaling pathways, resulting in resistance to both eIF4Fi and VEM. Combined administration of an eIF4Fi with EZH2 and AKT1 inhibitors effectively enhances sensitivity to both eIF4F complex and BRAF inhibitors.

Using the MOLM-14 human AML cell line to model therapy-resistant disease, we previously demonstrated the anti-leukemic effect of a potent and specific eIF4A inhibitor (eIF4Ai), CR-1-31-B, both in vitro and in vivo (Fooks et al, J Exp Clin Cancer Res 2022). This is of interest as several translation inhibitors are currently tested in phase 1/2 clinical trials in solid malignancies. # co-corresponding authors

In short, we establish the specific effect of mTOR-S6 on translation in cells lacking 4EBP1 and show that mTOR inhibition leads to feedback activation of translation via AKT-RSK1-eIF4E signals. Therefore, targeting translation downstream of mTOR presents a more efficient therapeutic strategy in pancreatic cancer.

We discovered that chemoresistant MOLM-14 cells rely on eIF4A-dependent cap translation for survival in vitro and in vivo. EIF4A drives an intrinsic metabolic program sustaining bioenergetic and redox homeostasis and regulates the expression of anti-apoptotic proteins. Overall, our work suggests that eIF4A-dependent cap translation contributes to adaptive processes involved in resistance to relevant therapeutic agents in AML.

We find that a synthetic silvestrol analogue (CR-1-31 B) has nanomolar activity across many cancer cell lines...Accordingly, loss of FN3K results in NRF2 hyper-glycation and inactivation and resensitizes cancer cells to eIF4A inhibition. Together, our findings implicate NRF2 in the translation of eIF4A-dependent mRNAs and point to FN3K inhibition as a new strategy to block NRF2 functions in cancer.

Taken together, the results of the present study show that CR‑31 treatment countered the resistance to TRAIL in GBC cells in vitro and in vivo. Therefore, eIF4A may serve as a novel therapeutic target and its combination with TRAIL‑CR‑31 as a therapy may serve as a novel strategy for GBC treatment.