Abstract A063: TLR4 nanoblocker inhibits ovarian cancer regardless of TNF-α sensitivity

Abstract Inflammation has a key role in all ovarian cancer (OC) stages: tumorigenesis, progression, and metastasis. TLR4 (Toll-like receptor 4) is a pathogen recognition receptor that initiates inflammatory response to exogenous PAMPs, e.g., LPS (TLR4 agonist), or endogenous DAMPs. High TLR4 expression is associated with poor prognosis in OC patients. TLR4 activates NF-κB, inducing growth factors, migratory drivers, and proinflammatory cytokines (e.g., TNF-α and IL-6) and chemokines (e.g., IL-8) that promote tumor progression and migration. IL-6 activates STAT3 signaling, which stimulates cancer proliferation and inhibits apoptosis. IL-8 is a chemokine that induces cancer migration. TNF-α has a dual role as an antitumor by inducing apoptosis and a protumor by inducing inflammation. In our lab, we have developed a telodendrimer (TD) nanoplatform with multiple negatively charged and hydrophobic moieties, which mimic LPS molecular patterns for receptor binding. A lead TD PEG5kSU8C174 exhibits potent immunomodulatory antagonism for LPS in TLR4 activation. TD inhibits TLR4 activation in HEK-TLR4 reporter cells and in human and mouse macrophages, evidenced by reduced TNF-α and IL-6 secretion in ELISA assay. Thus, we hypothesize that TLR4 nanoblocker TD may inhibit OC proliferation and metastasis. We have tested our TD in TNF-α resistant human OC cells, such as SKOV-3, ES-2, and mouse OC BR, in addition to TNF-α sensitive OC cells such as human OVCAR-3 and mouse ID-8. TD inhibited the phosphorylation of NF-κB in SKOV-3 and OVCAR-3 OC stimulated by LPS and directly inhibited STAT3 phosphorylation of SKOV-3 OC. LPS stimulated the viability of SKOV-3 and BR TNF-α resistant OC, which TD inhibited. However, LPS did not affect the viability of TNF-α sensitive cells. To study the effect of the inflammatory macrophage secretome on the viability of these OC cells, we prepared conditioned media of human and mouse macrophages treated with LPS. This conditioned media had an opposite effect on TNF-α resistant and sensitive cells, where it significantly increased the viability of TNF-α resistant OC. TD inhibited the autocrine secretion of IL-6 in TNF-α resistant SKOV-3, ES-2, and BR cells and the LPS-induced IL-6 secretion in OVCAR-3 and BR. Also, TD reduced IL-8 in human OC cell lines in a similar pattern. As a result, TD directly decreased the cell viability of SKOV-3 and ES-2 but not OVCAR-3, BR, and ID-8. However, TD directly impeded the migration of these OC cell lines in the scratch assay. To study the TD effect on tumor seeding of TNF-α resistant and sensitive OC, we used syngeneic mouse models where we injected LPS alone or with TD before OC cell inoculations (BR and ID8).TD inhibited tumor progression for both models. TD also reduced proinflammatory cytokines as TNF-α and IL-6, and protected against LPS hypothermia. In conclusion, a TLR4 nano blocker can inhibit the proliferation of TNF-α resistant OC and the migration of TNF-α sensitive OC in vitro, while in vivo TD can inhibit tumor progression of both. Citation Format: Hadil A. Gadelrab, Changying Shi, Dandan Guo, Rinki Agarwal, Sandra Orsulic, Juntao Luo. TLR4 nanoblocker inhibits ovarian cancer regardless of TNF-α sensitivity abstract. In: Proceedings of the AACR Immuno-Oncology Conference (AACR IO): Discovery and Innovation in Cancer Immunology: Revolutionizing Treatment through Immunotherapy; 2026 Feb 18-21; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Immunol Res 2026;14(2 Suppl):Abstract nr A063.