Proteome analysis of preserved formalin-fixed and paraffin-embedded specimens to explore the pathogenesis of infantile hypertrophic pyloric stenosis.

Purpose: This study aimed to explore the mechanisms underlying the development of infantile hypertrophic pyloric stenosis (IHPS) using formalin-fixed paraffin-embedded (FFPE) samples.

Methods: Among 306 patients with IHPS diagnosed at our hospital since 1982, 4 cases (male: female = 3:1, age = 2 ± 1 months) had pyloric muscle samples preserved as FFPE. A control group of three cases (male: female; 1:2, age = 70 ± 96 months) was also included. Proteomic analysis was performed on FFPE samples; statistical analysis was based on p values (< 0.05). Functional analysis was performed by Gene Ontology (GO) enrichment analysis.

Results: Proteomic analysis detected 8,704 host-derived proteins. Principal component analysis revealed distinct clustering between the IHPS and control groups. Proteins more abundant in the IHPS group included SERPINE1, HTRA1, SACS, CPXM2, and BMP1, whereas proteins more abundant in the control group included CDH19, MRC1, PCDH1, ACE, and ITGA6. GO enrichment analysis showed that proteins related to the extracellular matrix were more prevalent in the IHPS group, whereas proteins associated with RNA splicing were less frequent.

Conclusion: Proteomic analysis of FFPE samples may provide a new avenue for elucidating the pathophysiology of IHPS. Future collaborative studies should increase the sample size, allowing for a more detailed understanding of the underlying mechanisms.