bioRxiv Science⌕ Search

bioRxiv · 10.64898/2026.10.22.761200

ANO6 Scaffolds ER Mitochondria Contacts to Govern Spatial Lipid Compartmentalization and Ferroptosis Evasion in Chemoresistant Breast Cancer

Abstract

Background: Metabolic glycerophospholipid remodeling promotes tumor persistence under neoadjuvant chemotherapy in breast cancer; however, how resistant cells evade lipotoxicity from accumulating peroxidizable lipids presents an intriguing metabolic conundrum. The underlying organelle-level spatial mechanisms remain poorly defined. Methods: Integrated multi-omic profiling of paired pre- and post-NAC clinical specimens was performed. Engineered ANO6 models (wild-type, knockout, and conformational mutants) were characterized using subcellular lipidomics of purified mitochondria-associated ER membranes (MAMs), electron microscopy, in situ proximity ligation assays, and preclinical xenograft models. Results: Chemoresistant lesions exhibited marked ANO6 upregulation and polyunsaturated phospholipid (PUFA-PL) accumulation without enhanced apoptosis. Beyond its canonical role as a plasma membrane scramblase, ANO6 operates as an organelle contact scaffold at MAMs, leveraging its conformational activation to coordinate inter-organellar tethering. ANO6 directly recruits vimentin (VIM) and VAPB to assemble a VIM-ANO6-VAPB-PTPIP51 tethering platform, structurally bridging intermediate filaments to organelle contact sites. This complex tightens ER-mitochondria coupling, establishing a specialized structural platform that routes and sequesters peroxidizable lipids into protective cytoplasmic lipid droplets, thereby shielding functional membrane bilayers from ferroptotic peroxidation. Functional dissection revealed that the active scaffolding conformation (I612A) sustains MAMs integrity and lipid packaging, whereas scaffold deficiency (D703R) compromises contact architecture. Pharmacologically perturbing this platform with niclosamide destabilized lipid sequestration, selectively resensitizing chemoresistant cells to synthetic lethal ferroptosis in vitro and in vivo. Conclusions: ANO6-mediated contact scaffolding governs spatial lipid compartmentalization, establishing the ANO6-MAMs structural axis as a potential target to exploit lipid metabolic vulnerabilities in refractory breast cancer.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Yang, Q., Yan, J., Zhao, P., Tang, Q., Zheng, K., Zhao, J., Zhou, Z.. 2026-10-23. ANO6 Scaffolds ER Mitochondria Contacts to Govern Spatial Lipid Compartmentalization and Ferroptosis Evasion in Chemoresistant Breast Cancer. https://doi.org/10.64898/2026.10.22.761200

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

C19 trityl and silyl andrographolide analogs exhibit in vitro anticancer activity in murine cancer models

Andrographolide, a labdane diterpenoid isolated from A. paniculata has been investigated for activity in a broad panel of biological contexts, including its anti-inflammatory, antiviral, and anticancer properties. Previously, A-ring analogs of andrographolide bearing silyl and trityl ethers at C19 have demonstrated improved in vitro anticancer activity in human cancer cell lines, with putative activity through the Wnt1/{beta}-catenin signaling axis. In order to investigate the activity of this series of C19 andrographolide analogs, alongside a cyclic A-ring acetonide analog, as anticancer agents in murine cancer cell models, we evaluated antiproliferative activity of these compounds in B16F10 melanoma, CT26 colorectal adenocarcinoma, Neuro2a neuroblastoma, and 4T1 mammary ductal carcinoma cell lines, and found that most compounds exhibited potent micromolar level anticancer activity. Among these, all trityl ethers exhibited nearly indistinguishable IC50 values of 4-20 M, and generally exhibited greater potency compared to C19 silyl ether analogs. This anticancer activity was further validated through apoptosis flow cytometry, wherein we concluded that our compounds induced apoptosis to a greater extent than the parent compound, andrographolide. Further, we examine the role of modulation of canonical Wnt1/{beta}-catenin signaling in a series of co-delivery assays with CHIR-99021, a selective GSK-3{beta} kinase inhibitor, and MSAB, a selective {beta}-catenin degrader. Finally, we demonstrate that a selection of silyl ether analogs of andrographolide elicit cell cycle arrest by flow cytometry in a manner that is decoupled to in vitro potency trends. Altogether, we report the first in vitro evaluation of trityl and silyl ether analogs of andrographolide within murine adherent cancer cells.

cancer biology↗

Aneuploidy profiling among different types of brain metastases reveals a colon cancer-specific chromosomal signature

Brain metastasis is a significant cause of patient morbidity and mortality. There is increasing evidence that genomic instability features such as aneuploidy are associated with metastases to the brain and other organs. We analyzed the genomic instability of brain metastases among different cancer types. This included brain metastases from non-small cell lung, breast, melanoma and colorectal cancer. Our study identified a significantly higher degree of genomic instability in colorectal brain metastases compared to the other types of brain metastases. Nex, we examined the brain metastases for the types of aneuploidy events, namely chromosomal arm imbalances that involved gains or losses. Colorectal cancer brain metastases had specific chromosomal arm imbalance profiles that included gains of 13q and 20q which were significantly more frequent compared to the other cancer types. We examined other colorectal cancer metastatic sites in the lung, liver, lymph nodes and the primary colon. Examining colorectal cancer metastases more closely, aneuploidy gains across either arms for chromosomes 7 and 16 were also higher among brain metastases compared to liver, lung and lymph node metastases. Overall, this study shows that colorectal cancer brain metastasis has specific aneuploidy profiles different than other cancer types as well as being different among other metastatic organ sites.

cancer biology↗

Identification of TM4SF1 as a novel tumor-associated antigen in biliary tract cancers targetable by CAR-T cell therapy

Background & Aims: Biliary tract cancers (BTCs) are a rare set of genetically heterogenous and aggressive malignancies associated with delayed presentation and poor prognosis. Thus, there is an unmet clinical need for the development of novel therapeutic strategies. Identification of uniquely expressed cell-surface, tumor-associated antigens (TAAs) holds promise in epithelial tumors more generally, as they can serve as ligands for a variety of therapeutics, including CAR-T cell therapy. However, TAA identification in BTCs has been limited by expression in normal liver tissue. Here, we aim to characterize the cell-surface protein transmembrane 4 L six family member 1 (TM4SF1) as a potential BTC TAA targetable by CAR-T therapy. Methods: TM4SF1 expression in BTC relative to normal hepatic/biliary tissue was characterized at the mRNA level by analyzing TCGA datasets and at the protein level by immunohistochemistry of archival primary BTC tissue. Anti-TM4SF1 CAR-T cells were evaluated through in vitro coculture assays against human-derived BTC cell lines and in a cell line-derived xenograft (CDX) model. Results: We find TM4SF1 is significantly upregulated in BTC relative to normal hepatic/biliary tissue and across BTC anatomical subtypes at the mRNA and protein level. To validate TM4SF1 as a targetable TAA in BTC, we show anti-TM4SF1 CAR-T cells demonstrate robust growth inhibition of BTC cell lines in vitro and significant anti-tumor activity against a CDX in vivo. Conclusions: Together, our data provides support for TM4SF1 as a promising TAA in BTCs that can be used for the rational development of targeted therapeutic modalities, including CAR-T cells, in a patient population with significant unmet need.

cancer biology↗