Acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) remains a major challenge in the treatment of lung cancer. Cancer associated fibroblasts (CAFs) play a key role in promoting resistance to anti-cancer therapies. This study identified a subpopulation of CAFs characterized by the overexpression of collagen triple helix repeat-containing 1 (CTHRC1) through single-cell RNA sequencing of lung cancer patients undergoing EGFR-TKI treatment. These CTHRC1+ CAFs were enriched in drug-resistant tumors. Mechanistically, CTHRC1+ CAFs enhance the glycolytic activity of cancer cells by activating the TGF-β/Smad3 signaling pathway. Excess lactate produced in the process of glycolysis further upregulates CTHRC1 expression in CAFs through histone lactylation, creating a positive feedback loop that sustains EGFR-TKI resistance. The study also demonstrated that Gambogenic Acid, a natural compound, can disrupt this feedback loop, thereby improving the efficacy of EGFR-TKI therapy. Additionally, the presence of CTHRC1+ CAFs in tumor tissues could serve as a biomarker for predicting the response to EGFR-TKI therapy and patient prognosis. Overall, this study highlights the significant role of CAFs in EGFR-TKI resistance and suggests that targeting CTHRC1+ CAFs could be a promising strategy to overcome drug resistance in lung cancer.
© 2025. The Author(s).

This study demonstrates that adipose-derived stem cells from debrided skin (dsASCs) of burn patients can be isolated in sufficient quantities and differentiated into cytokeratin-expressing cells by treating them with all-trans retinoic acid (ATRA) and the peroxisome proliferator-activated receptor-α (PPARα) specific activator fenofibrate. Differentiation of dsASCs with ATRA and a combination of growth factors induced expression of simple epithelial markers (KRT7, KRT8, KRT18, and KRT19), along with low levels of stratified epithelial markers (KRT5, KRT10, KRT13, and KRT14). We have optimized a condition to induce dsASCs differentiation to epithelial cells by treatment with ATRA and fenofibrate alone. Real-time polymerase chain reaction analysis showed a significant increase in transcript levels (>75-fold) for basal (KRT5 and KRT14), suprabasal (KRT10), and cornified envelope markers (involucrin [IVL] and Loricrin [LOR]) with this treatment. Expression of the proteins encoded by these transcripts was confirmed by immunocytochemical analysis. Further, we show that dsASCs differentiated to a skin epithelial cell phenotype through activation of nuclear hormone receptors PPARα and RXRγ. Collectively this study shows that dsASCs can be differentiated to skin epithelial cells, without the requirement for exogenous growth factors. This differentiation protocol using dsASCs in combination with an appropriate biocompatible scaffold can be adapted to develop epithelial skin substitute for burn wound treatment.
© 2018 Wiley Periodicals, Inc.