AUTHOR=Zhang Li , Zhou Shixia , Zhou Tiejun , Li Xiaoming , Tang Junling 

TITLE=Targeting the lncRNA DUXAP8/miR-29a/PIK3CA Network Restores Doxorubicin Chemosensitivity via PI3K-AKT-mTOR Signaling and Synergizes With Inotuzumab Ozogamicin in Chemotherapy-Resistant B-Cell Acute Lymphoblastic Leukemia

JOURNAL=Frontiers in Oncology

VOLUME=12

YEAR=2022

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2022.773601

DOI=10.3389/fonc.2022.773601

ISSN=2234-943X

ABSTRACT=<sec><title>Purpose</title><p>This study aimed to determine the expression profiles of long non-coding RNA (lncRNA), microRNA (miRNA), and mRNA in chemotherapy-resistant B-cell acute lymphoblastic leukemia (B-ALL).</p></sec><sec><title>Methods</title><p>LncRNA, miRNA, and mRNA profiles were assessed by RNA-seq in diagnostic bone marrow samples from 6 chemotherapy-resistant and 6 chemotherapy-sensitive B-ALL patients. The lncRNA DUXAP8/miR-29a/<italic>PIK3CA</italic> signaling network was identified as the most dysregulated in chemoresistant patient samples, and its effect on cellular phenotypes, PI3K-AKT-mTOR signaling, and chemosensitivity of doxorubicin (Dox)-resistant Nalm-6 (N6/ADR), and Dox-resistant 697 (697/ADR) cells were assessed. Furthermore, its synergy with inotuzumab ozogamicin treatment was investigated.</p></sec><sec><title>Results</title><p>1,338 lncRNAs, 75 miRNAs, and 1620 mRNAs were found to be dysregulated in chemotherapy-resistant B-ALL in comparison to chemotherapy-sensitive B-ALL patient samples. Through bioinformatics analyses and RT-qPCR validation, the lncRNA DUXAP8/miR-29a/<italic>PIK3CA</italic> network and PI3K-AKT-mTOR signaling were identified as significantly associated with B-ALL chemotherapy resistance. In N6/ADR and 697/ADR cells, LncRNA DUXAP8 overexpression and <italic>PIK3CA</italic> overexpression induced proliferation and inhibited apoptosis, and their respective knockdowns inhibited proliferation, facilitated apoptosis, and restored Dox chemosensitivity. MiR-29a was shown to affect the lncRNA DUXAP8/<italic>PIK3CA</italic> network, and luciferase reporter gene assay showed direct binding between lncRNA DUXAP8 and miR-29a, as well as between miR-29a and <italic>PIK3CA</italic>. Targeting lncRNA DUXAP8/miR-29a/<italic>PIK3CA</italic> network synergized with inotuzumab ozogamicin’s effect on N6/ADR and 697/ADR cells.</p></sec><sec><title>Conclusion</title><p>Targeting the lncRNA DUXAP8/miR-29a/<italic>PIK3CA</italic> network not only induced an apoptotic effect on Dox-resistant B-ALL and restored Dox chemosensitivity <italic>via</italic> PI3K-AKT-mTOR signaling but also showed synergism with inotuzumab ozogamicin treatment.</p></sec>