Abstract 309: AHNAK nucleoprotein 2 tune oxidative stress and resistance to chemotherapy in triple negative breast cancer

Abstract

Abstract Background: Resistance to chemotherapy is a major reason for the poorerprognosis in patients with triple negative breast cancer (TNBC). Growing evidence suggests that oxidative stress induced by reactive oxygen species (ROS) is an important factor in both tumourprogression and responses to chemotherapies, however, many signalling pathways and key molecular underlying the regulation of cancer cells to the ROS metabolism remains unclear. Aim: (i) To investigate the mechanistic role of AHNAK nucleoprotein 2 (AHNAK2) in TNBC and its links with breast cancer mortality, particularly caused by chemotherapeutic resistance; and (ii) to test a hypothesis that AHNAK2 facilitates the abnormal activation of ROSscavenging system, result in the resistance to chemotherapy in TNBC. Methods: The expression level of AHNAK2 was determined by immunohistochemical staining and analysed the mRNA expression profiles from The Cancer Genome Atlas of triple negative breast tumors. Roles of AHNAK2 in cancer cell growth, metastasis, chemotherapeutic resistanceand activation of oxygen scavenging systemwere determined by molecular and cell biology methods. A jetPEI nanocarrier was used as the vehicle for anti-AHNAK2 siRNAs in mouse models of cancer therapeutics. Results: AHNAK2 is a novel triple negative breast cancer target, which is overexpressed in TNBC tissues and significantly associated with clinical pathology of chemotherapeutic resistance and poor prognosis of tumour patients. Mechanistically, AHNAK2 antagonizes the ROS accumulation induced by epirubicinvia activating JAK-STAT signaling pathway and transportingphosphorylated STAT1 & STAT4 to the nucleus to promote the expression of SOD2, a key gene in ROS metabolism.And epirubicin enhanced AHNAK2 expression by induced the accumulation of ROS,which hence the Sp1-driven transcription of AHNAK2,result inde novo resistance. Furthermore, AHNAK2-specific siRNAs encapsulated by jetPEI nanocarriers prominently inhibit tumor growth and epirubicin-induced resistance in vivo. Conclusions: AHNAK2 plays a key role in resistance to chemotherapyby regulating the oxidative stressand ROS metabolism,representing a future biomarker and therapeutic target of TNBC. Citation Format: Na Hao. AHNAK nucleoprotein 2 tune oxidative stress and resistance to chemotherapy in triple negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 309.