Identification of key molecules promoting lepidic–filigree micropapillary–conventional/overt micropapillary progression in lung adenocarcinoma: A comprehensive gene expression analysis study using the spatial gene expression solution methodology

The micropapillary (mPAP) histological subtype is a high-grade element and a poor prognostic marker in lung adenocarcinoma (LUAD). This subtype develops through the lepidic–filigree mPAP–conventional/overt mPAP pathway. In the present study, we aimed to identify key molecules that promote this progression. To this end, we investigated gene expression profiles specific to lepidic, filigree mPAP (filigree), and conventional/overt mPAP (mPAP) elements in histological sections obtained from four different LUAD cases. We studied four cases of surgically resected lung adenocarcinoma (LUAD). Eight tissue FFPE sections (n = 2 each from the four LUAD samples) that included lepidic, filigree and mPAP elements were analyzed using Visium Spatial Gene Expression Profiling System. RNA transcriptome data were obtained from individual spots corresponding to each histological element. The mRNA levels in the lepidic, filigree, and mPAP components were then compared and analyzed.