Figure 2. Expression of genes in the cell cycle pathway and antigen presentation pathway among single cancer cells are coregulated.
(A and C) Gene pathway clusters from metagene analysis of single cells from PDX LC-PT-45 or from LC2/ad-R and LC2/ad cell lines. K-means clustering of metagenes on SOMs into 6 clusters and 8 clusters, respectively. A hypergeometric test was performed on each cluster of metagenes to determine enrichment of canonical pathways. (A) For PDX LC-PT-45, cluster A was enriched for cell cycle pathways, while cluster B was enriched for antigen presentation pathways. (C) For LC2/ad-R and LC2/ad cell lines, cluster G/H was enriched for cell cycle pathways, while cluster F was enriched for antigen presentation pathways. P values in the parentheses are FDR corrected. (B and D) Second-level clustering of SOMs for (B) 77 single cells from PDX LC-PT-45 or (D) 159 single cells from LC2/ad-R and LC2/ad cell lines. Each square is a unique SOM pattern with the heatmap indicating the gene expression level of metagenes. Cells with the same SOM are collapsed with only 1 representative SOM. SOMs are arranged by mapping all cells together into a 2-dimensional mosaic pattern based on metagene expression. Coexpression of cell cycle pathway and antigen presentation pathway further separates cells into 3 major groups: cell cycle pathway high (I), antigen presentation pathway high (II), and both pathways low (III).