Cholinergic Receptor Nicotinic Beta 2 Subunit Promotes the Peritoneal Disseminating Metastasis of Colorectal Cancer

Peritoneal dissemination in colorectal cancer (CRC) is associated with poor prognosis due to limited efficacy of current therapeutic strategies. The cholinergic receptor nicotinic beta 2 subunit (CHRNB2), a component of the acetylcholine receptor, has been implicated in other malignancies, but its role in CRC remains unknown.

This study evaluated the expression and function of CHRNB2 in CRC. CHRNB2 mRNA levels were quantified by qRT-PCR in cell lines and clinical specimens. Functional assays were conducted using CRC cell lines with high CHRNB2 expression, in which CHRNB2 was knocked down by shRNA. Cell proliferation, migration, and invasion were assessed in vitro. In vivo effects were evaluated using subcutaneous and peritoneal xenograft models. The impact of CHRNB2 monoclonal antibody (mAb) treatment on CRC cell proliferation was also examined. Clinical correlations were assessed between CHRNB2 expression and clinicopathological features, including recurrence patterns.

CHRNB2 expression varied among CRC cell lines, with the highest levels observed in LOVO cells. CHRNB2 knockdown significantly inhibited proliferation, migration, and invasion in vitro and suppressed tumor growth in vivo. CHRNB2 mAb treatment reduced cell proliferation. Clinically, high CHRNB2 expression correlated with a significantly higher cumulative rate of peritoneal recurrence, but not with recurrence in the liver, lungs, or lymph nodes. Multivariate analysis identified high CHRNB2 expression and T4 tumor depth as independent predictors of peritoneal recurrence.

CHRNB2 promotes the malignant phenotype of CRC, particularly in peritoneal dissemination. These findings suggest that CHRNB2 may serve as a novel diagnostic biomarker and therapeutic target for CRC with peritoneal metastasis.