Interactions between anti-EGFR therapies and cytotoxic chemotherapy in oesophageal squamous cell carcinoma: why clinical trials might have failed and how they could succeed

Harnessing the CD44-targeted delivery of self-assembled hyaluronan nanogel to reverse the antagonism between Cisplatin and Gefitinib in NSCLC cancer therapy

The combination of the standard platinum-based chemotherapy with EGFR-tyrosine kinase inhibitor Gefitinib (Gef) principally boosts the anticancer efficacy of advanced non-small cell lung cancer (NSCLC) through non-overlapping mechanisms of action, however the clinical trials of cisplatin (Cis) and Gef combination failed to show a therapeutic improvement likely due to compromised cellular influx of Cis with the Gef interference. To overcome the antagonism between Cis and Gef in anti-NSCLC therapy, here we demonstrated a self-targeted hyaluronan (HA) nanogel to facilitate the anticancer co-delivery by utilizing the HA's intrinsic targeting towards CD44, a receptor frequently overexpressed on lung cancer cells. The co-assembly between HA, Cis and Gef generated a HA/Cis/Gef nanogel of 177.8 nm, featuring a prolonged drug release. Unlike the Gef inhibited the Cis uptake, the HA/Cis/Gef nanogel efficiently facilitated the drug internalization through CD44-targeted delivery as verified by HA competition and CD44 knocking down in H1975 NSCLC model both in vitro and in vivo. Moreover, the HA/Cis/Gef nanogel significantly improved the anticancer efficacy and meanwhile diminished the side effects in reference to the combination of free Cis and Gef. This CD44-targeted HA/Cis/Gef nanogel provided a potent strategy to advance the platinum-based combination therapy towards optimized NSCLC therapy.

Recent advances in the potential role of RNA N4-acetylcytidine in cancer progression

N4-acetylcytidine (ac4C) is a highly conserved chemical modification widely found in eukaryotic and prokaryotic RNA, such as tRNA, rRNA, and mRNA. This modification is significantly associated with various human diseases, especially cancer, and its formation depends on the catalytic activity of N-acetyltransferase 10 (NAT10), the only known protein that produces ac4C. This review discusses the detection techniques and regulatory mechanisms of ac4C and summarizes ac4C correlation with tumor occurrence, development, prognosis, and drug therapy. It also comments on a new biomarker for early tumor diagnosis and prognosis prediction and a new target for tumor therapy. Video Abstract.

NAT10-mediated ac4C tRNA modification promotes EGFR mRNA translation and gefitinib resistance in cancer

Aberrant RNA modifications are frequently associated with cancers, while the underlying mechanisms and clinical significance remain poorly understood. Here, we find that the ac4C RNA acetyltransferase NAT10 is significantly upregulated in esophageal cancers (ESCAs) and associated with poor ESCA prognosis. In addition, using ESCA cell lines and mouse models, we confirm the critical functions of NAT10 in promoting ESCA tumorigenesis and progression in vitro and in vivo. Mechanistically, NAT10 depletion reduces the abundance of ac4C-modified tRNAs and decreases the translation efficiencies of mRNAs enriched for ac4C-modified tRNA-decoded codons. We further identify EGFR as a key downstream target that facilitates NAT10's oncogenic functions. In terms of clinical significance, we demonstrate that NAT10 depletion and gefitinib treatment synergistically inhibit ESCA progression in vitro and in vivo. Our data indicate the mechanisms underlying ESCA progression at the layer of mRNA translation control and provide molecular insights for the development of effective cancer therapeutic strategies.