Transcriptomic single cell

Abstract
Background&Aims: Gemcitabine combined with albumin-paclitaxel (AG) is an important treatment for pancreatic ductal adenocarcinoma (PDAC). However, the response to the chemotherapy is relatively poor, with rapid development of resistance. The aim of this study was to explore the mechanism of resistance to AG, and to develop strategies that can sensitize AG regimen.
Methods: Bioinformatic analysis and scRNA-seq were used to screen out the candidates mediating AG resistance. Organoid, PDX, and GEMM were utilized. Chromatin-Immunoprecipitation (Ch-IP), double luciferase assay, Co-immunoprecipitation (Co-IP), and far-western blotting analysis were performed to investigate the mechanism. The AVL9 inhibitors were identified by protein structure analysis and molecular docking analysis and their efficacy was verified in PDX, PDOX, and KPC models.
Results: AVL9 was identified as the key target for AG resistance in PDAC through multi-strategy screening, and its tumor-promoting effects were verified in our clinical cohorts. Meanwhile, AVL9 was proved to increase therapeutic resistance of PDAC to AG in vitro and in vivo. Mechanically, AVL9 was driven by anoxic and lactate-enriching acidic microenvironment and acted as a "scaffold" to promote the binding of IκBα to SKP1, resulting in increased ubiquitination degradation of IκBα, and further promoting the nuclear translocation of P65. Potential AVL9-targeting inhibitor, Edotecarin, was proved to reverse AG chemoresistance through in vitro and in vivo experiments.
Conclusion: AVL9 expression is driven by hypoxic microenvironment in PDAC. The physical interaction of AVL9, IκBα and SKP1 provides a novel molecular mechanism for the abnormal activation of NF-κB pathway. Therefore, AVL9-targeting drug Edotecarin could be a promising therapeutic strategy to sensitizing PDAC to AG.