Verdict. ANO6 is a MAM scaffold that hides PUFA phospholipids in droplets so chemoresistant breast tumors survive ferroptosis. Break the VIM-ANO6-VAPB-PTPIP51 tether and the lipids become lethal.
Metal sites and redox
Ferroptosis is iron-dependent peroxidation of polyunsaturated phospholipids. This abstract names PUFA-PLs, membrane peroxidation, ferroptosis, and GPX4 inhibition with RSL3. It does not name labile Fe2+, a heme, or an iron-sulfur cluster. Do not assign [2Fe-2S] or [4Fe-4S] nuclearity. GPX4 is a selenocysteine peroxidase on the glutathione axis, not an Fe-S enzyme. The redox story the authors actually tell is spatial: peroxidizable lipids are moved out of membranes into droplets so the chain reaction never starts on the bilayer that matters.
What the authors report
Resistant lesions upregulate ANO6 and load PUFA phospholipids without turning on apoptosis. ANO6 leaves its textbook plasma-membrane scramblase job and sits at mitochondria-associated ER membranes. It recruits vimentin and VAPB, completing a VIM-ANO6-VAPB-PTPIP51 bridge from intermediate filaments to the contact site. That tightens ER-mitochondria coupling and feeds peroxidizable lipids into cytoplasmic droplets. I612A keeps the scaffold; D703R does not. Niclosamide opens the trap. With GPX4 blocked (RSL3), the freed lipids kill.
What was measured
Clinical multi-omics pre/post chemotherapy, MAM lipidomics, electron microscopy, proximity ligation, ANO6 alleles, xenografts, niclosamide, and ferroptosis resensitization.
Caveats
Abstract-level. Niclosamide is promiscuous. Iron is implied by ferroptosis, not measured. Scramblase-independence is claimed; the lipid route from MAM to droplet is not a named enzyme.
What to do with it
Treat ANO6-high residual disease as a contact-site ferroptosis problem. The chemical test is whether niclosamide (or a cleaner tether breaker) plus a GPX4 or PUFA-oxidation stress collapses the droplet shield in vivo.
Bibliographic record
| Field | Value |
|---|---|
| Title | ANO6 Scaffolds ER-Mitochondria Contacts to Govern Spatial Lipid Compartmentalization and Ferroptosis Evasion in Chemoresistant Breast Cancer |
| DOI | 10.64898/2026.10.22.761200 |
| Server | biorxiv |
| Posted | 2026-10-23 |
| Topics | ER-mitochondria contacts, ferroptosis, lipid peroxidation, MAMs, breast cancer, organelle architecture |
| Mitos score | 91/100 |
| Confidence | medium |
| HTML | https://www.biorxiv.org/content/10.64898/2026.10.22.761200 |
| https://www.biorxiv.org/content/10.64898/2026.10.22.761200.full.pdf |
Abstract-based editorial synthesis by Mitos. Not peer review.