Collagen XVII is expressed in the cancer cells of PDAC tumors and is associated with poor survival. A, Analysis of COL17A1 expression in cancer vs. normal tissues adapted from Oncomine. The numbers in the graphic indicate the number of datasets, grouped by cancer type, showing statistically significant changes in COL17A1 gene expression between cancer and normal tissues. Significance was defined using the following thresholds: P value ≤ 0.05, fold change ≥2, and inclusion in the top 10% of gene expression rankings. Upregulated gene expression is indicated by red cells, and downregulated gene expression is indicated by blue cells. Cell color intensity reflects the best gene rank percentile across all analyses included in the cell. B,COL17A1 expression of laser capture microdissected (LCM) separated matched cancer and stroma from tumors of patients with PDAC. Each bar represents the ratio of COL17A1 expression in a patient sample in cancer compared with the stroma (E/S, epithelial/stroma). C, Uniform Manifold Approximation and Projection for Dimension Reduction visualization of single cells from normal pancreas, pancreatitis, and PDAC samples. D,COL17A1 expression (purple) in each cell type in the global Uniform Manifold Approximation and Projection for Dimension Reduction. E, Bubble plot demonstrating the expression of transmembrane collagens across cell types. The intensity of the color is proportional to the average expression of the gene within a cluster, and the bubble size is proportional to the number of cells expressing the marker. F, IHC staining of collagen XVII on skin and acinar cells, ducts, and islets in the normal pancreas. Scale bars, 50 μm. G, IHC staining of collagen XVII on PDAC tissue. Representative images show negative, weak, moderate, and strong collagen XVII expression. Scale bars, 100 and 25 µm (inset). H,H-score distribution of collagen XVII expression in 46 treatment-naïve patients with PDAC. I, Kaplan–Meier survival analysis of treatment-naïve patients with PDAC for collagen XVII high (H-score >130; n = 24) vs. low (H-score n = 22) expressing PDAC tumors (n = 46, log-rank test, P = 0.02). J, Kaplan–Meier survival analysis of patients with PDAC for COL17A1 high (FPKM >43.77; n = 64) vs. low (FPKM ≤43.77; n = 112) expressing PDAC tumors (n = 176, log-rank test, P
Hank et al. (Tue,) studied this question.