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Biology subjects

Ahmadi, P.

Publications and source records attributed to Ahmadi, P..

2 recordsLinked to original sources

eIF4G2-dependent translation restrains pancreatic cancer progression

Pancreatic ductal adenocarcinoma (PDA) is among the most lethal cancers, driven by cellular plasticity that fuels therapeutic resistance and early dissemination. The contribution of translational control to this plasticity remains poorly understood. Through an in vivo CRISPR/Cas9 screen, we identify the non-canonical initiation factor eIF4G2 (DAP5/NAT1) as a translational checkpoint restraining PDA progression. Loss of eIF4G2 accelerated tumor growth, induced poorly differentiated, basal-like histology, and triggered widespread metastasis. Ribosome profiling revealed that eIF4G2 loss does not alter bulk protein synthesis but instead impairs translation of a selective regulon, including tumor suppressors such as PTEN and CREBBP. Functional studies confirmed that PTEN loss was sufficient to drive dedifferentiation but insufficient to promote metastasis, implicating the broader eIF4G2-dependent program, including translational control of transcriptional regulators like CREBBP, in limiting dissemination. Consistently, eIF4G2-deficient tumors exhibited transcriptomic enrichment of programs related to migration and wound healing. Computational inference from human PDA datasets revealed reduced eIF4G2 activity in metastases, aligning with basal-like features and predicting poorer survival. These results support a model in which eIF4G2 maintains epithelial identity and restrains metastatic potential, highlighting selective translation as a determinant of PDA subtype and clinical outcome.

cancer biology↗

An Iron-regulated Signalling Pathway Controls Adipose Browning and Cancer Cachexia

The browning and atrophy of white adipose tissue (WAT) are early events in cachexia, a lethal metabolic disorder affecting nearly half of cancer patients, including those with pancreatic ductal adenocarcinoma (PDA). Using patient-derived specimens and PDA mouse models, we identified perturbations in iron metabolism and proteinaceous methionine oxidation as key initiating events of adipose browning. In particular, the iron influxes that accompany WAT browning induce the activity of methionine sulfoxide reductase A (MSRA), an enzyme that reverses the oxidation of proteinaceous methionine residues. Mechanistically, iron coordination by the conserved iron-binding motifs (E203-xx-H206) of two MSRA polypeptides serves to multimerize, stabilize, and enzymatically activate MSRA. This in turns facilitates adipose browning by maintaining the reduced state of two methionines near the ATP-binding site of Protein Kinase A (PKA). Remarkably, in mouse models of PDA, MsrA deletion impairs WAT browning, significantly mitigates cachexia, and improves the overall survival of tumor-bearing animals. By establishing the iron-MSRA-PKA axis as a key nexus of cancer-associated cachexia, our study offers new perspectives for the treatment of this condition.

cancer biology↗