3.2 Cell proliferation and immune response are conserved features for BrMs
The following four essential hallmarks of metastatic cells during invasion and brain metastasis have been previously proposed: (a) motility and invasion; (b) modulation of the microenvironment; (c) plasticity; and (d) colonization [24]. L.C, B.C, and C.C are the most common types of cancer that metastasize to the brain. Here, we performed unsupervised clustering and searched for robust clustering of distinct features of the proteome correlated with all BrMs to increase our understanding of the general mechanisms of BrMs. Hierarchical clustering identified 3 clusters across all samples, resulting in 79 proteins in cluster 1, 192 proteins in cluster 2, and 125 proteins in cluster 3 (Figure 3A and Table S2). Functional analysis of the three clusters revealed marked enrichment in cell proliferation for colonization and immune response to modulate the microenvironment (Figure 3B, Figure S2A and B). Importantly, the transcriptomic results of BrMs validate these functions [16].