# Mechanistic insights into SLAMF8-mediated prostate cancer metastasis via the TLR4-NF-κB pathway

## TL;DR

This study shows that SLAMF8 promotes prostate cancer metastasis through the TLR4-NF-κB pathway and could be a target for immunotherapy.

## Contribution

The study reveals a novel mechanistic link between SLAMF8 overexpression and prostate cancer progression via the TLR4-NF-κB pathway.

## Key findings

- SLAMF8 is overexpressed in prostate cancer and correlates with poor survival and advanced tumor stages.
- SLAMF8 overexpression promotes tumor growth, reduces apoptosis, and increases invasion in prostate cancer cells.
- SLAMF8 enhances metastasis via the TLR4-NF-κB pathway and is associated with immune cell infiltration.

## Abstract

SLAMF8 functions as a cancer-promoting immune checkpoint and could be targeted for therapy in multiple cancer types. Its effect on the immune microenvironment and metastasis of prostate cancer (PCa) is not well understood.

We analyzed SLAMF8 distribution in PCa and normal tissues using TIMER and examined its role in drug sensitivity and immunotherapy for PCa. The prognostic value and clinical relevance of SLAMF8 in PCa were assessed using multiple datasets. GO, KEGG, and GSEA analyses identified dysregulated pathways in tumors with varying SLAMF8 levels. Tumor purity and immune cell infiltration, and their correlation with SLAMF8 overexpression, were analyzed and confirmed in PCa samples. Additionally, CCK-8, flow cytometry, and transwell assays evaluated the viability, apoptosis, and invasion capacity of SLAMF8-overexpressing PCa cells. Allograft models in C57BL/6 mice were used to study the effects of SLAMF8 overexpression on tumor growth and immune cell infiltration.

Compared to non-tumor tissues, SLAMF8 was overexpressed in PCa tumors. High SLAMF8 levels are linked to poor distant metastasis-free survival (DMFS), higher Gleason scores (GS), and advanced T stage. SLAMF8 expression in PCa tumors negatively correlates with tumor purity but positively correlates with the infiltration of B cells, T cells, dendritic cells, and macrophages. SLAMF8 overexpression in prostate cancer cells promoted cell growth, lowered apoptosis rates, and boosted invasion in vitro, alongside hastening tumor development in mice. This study demonstrates that SLAMF8 enhances PCa metastasis via the TLR4-NF-κB pathway. SLAMF8 is a potential predictor of distant metastasis and a promising target for PCa immunotherapy.

The online version contains supplementary material available at 10.1186/s12967-025-07234-3.