[Effect of antibacterial peptide hCAP18/LL-37 on ovarian cancer microenvironment and the regulatory mechanism of its expression].
Lu. Qian Q; Quan. Wenqiang W; Wu. Junlu J; Zhang. Xian X; Ma. Wei W; Pang. Li L; Li. Dong D
Key Findings
- Macrophage‑cancer cell co‑culture dramatically increases ovarian cancer cell invasion and LL‑37 levels in macrophages.
- Neutralizing LL‑37 with an antibody cuts the macrophage‑driven invasion back down.
- Versican V1 from cancer cells drives LL‑37 production in macrophages; knocking down versican reduces both LL‑37 and invasion.
Practical Outcomes
- If you’re considering LL‑37 supplements or ways to boost this peptide for immune health, be aware it might unintentionally support cancer cell spread in certain contexts. Until more safety data are available, it’s prudent to avoid chronic high‑dose LL‑37 exposure, especially if you have a history or risk of cancer.
Summary
The study shows that a natural immune peptide called LL‑37, which is released by immune cells called macrophages, can actually help ovarian cancer cells spread. When cancer cells and macrophages are grown together, the macrophages make more LL‑37 and the cancer cells become more invasive. Blocking LL‑37 or stopping a cancer‑cell protein called versican V1 reduces this invasion.
Abstract
To investigate the effect of antibacterial peptide hCAP18/LL-37 on ovarian cancer microenvironment and the regulatory mechanism of its expression. We assessed the effect of macrophage-promoted ovarian cancer cells invasion using BioCoat Matrigel invasion chamber. The expressions of hCAP18/LL-37 and versican V1 were determined by real-time PCR and Western blot analysis. SKOV3 cells were transfected with shRNA plasmid to abrogate the expression of versican V1, and then the expression of hCAP18/LL-37 in macrophages and the invasiveness of SKOV3 cells were assayed. The Matrigel invasion assay showed that after co-culture with macrophages for 4 days, the number of penetrated SKOV3 cells was 112.8±17.1/per high power field, significantly higher than that in the SKOV3 cells cultured alone (8.2±1.9/per high power field) (P<0.05). Addition of hCAP/LL-37 neutralizing antibody into the co-cultured macrophage-SKOV3 cells markedly inhibited the macrophage-promoted SKOV3 cells invasion. The penetrated SKOV3 cells was 22.2±5.6/per high power field, significantly lower than the 100.6±25.2/per high power field in the control macrophage- SKOV3 co-cultured cells (P<0.05). The expressions of hCAP18/LL-37 mRNA and protein in macrophages were remarkably enhanced upon co-culture with SKOV3 cells, but not changed in SKOV3 cells cultured alone. The expression and secretion of versican V1 in the ovarian cancer cells were also significantly increased after co-cultured with macrophages. Knockdown of versican V1 in SKOV3 cells by small interfering RNA significantly reduced the expression of hCAP18/LL-37 mRNA and protein in the macrophages, as well as decreased the invasiveness of SKOV3 cells (P<0.05). In the cancer microenvironment, the macrophage-secreted hCAP18/LL-37 promote the invasiveness of ovarian cancer cells, and the hCAP18/LL-37 expression is regulated by versican V1 protein released by ovarian cancer cells.
Study Information
pubmed
2015