PBMC‑secreted Sgp130FcH Inhibits Colorectal Cancer Cells and Cholangiocarcinoma: Proof‑of‑Concept Evidence.

UNLABELLED: Introduction/

Objective

IL-6 is associated with carcinogenesis, tumor burden, and poor prognosis in multiple malignancies, including Colorectal Cancer (CRC) and Cholangiocarcinoma (CCA). This study aimed to establish and evaluate the in vitro anti-cancer effect of Peripheral Blood Mononuclear Cell (PBMC)-derived soluble gp130Fc (PBMC Sgp130FcH) on CRC and CCA.

METHODS

Freshly isolated PBMCs and HCT116 cells were transfected with plasmids encoding Sgp130FcH and hyper-IL-6 (HIL6), respectively. mRNA expression was semi-quantified by RT-qPCR with gene-specific primers. The concentration of Sgp130 in the culture supernatant was measured by ELISA. The anti-cancer effects of PBMC Sgp130FcH, including its effects on cell proliferation, migration, and colony formation, were assessed through direct co-culture with CRC (HCT116) and CCA (TFK1) cell lines.

RESULTS

Stable establishment of constitutively activated IL-6 trans-signaling (HCT116 HIL6) and Sgp130FcH-secreting PBMCs (PBMC Sgp130FcH) was achieved. HCT116 HIL6 cells exhibited significantly increased proliferation, migration, and colony formation compared with HCT116 WT (p < 0.05). PBMC Sgp130FcH expressed Sgp130FcH mRNA and secreted high concentrations of Sgp130 ten days after transfection. Compared with PBMC WT, PBMC Sgp130FcH significantly and persistently suppressed proliferation, migration, and colony formation of both CCA and CRC cells in a dose-dependent manner.

DISCUSSION: Sustained overexpression of IL-6 trans-signaling in CRC cells promoted a carcinogenic phenotype in vitro. Compared with PBMC WT, PBMC Sgp130FcH showed superior in vitro inhibition on both CRC and CCA cell lines, supporting the functional activity of PBMC-secreted Sgp130FcH as a negative regulator of IL-6 trans-signaling.

CONCLUSION

Our data demonstrate the inhibition of PBMC Sgp130FcH on CRC and CCA cells in vitro, providing preliminary proof-of-concept evidence. Further mechanistic studies and in vivo validation are warranted.