Fig. 3

Molecular, signature, and biological characteristics of the negative group. a Heatmap with the normalized expression values of 24 TMM samples from RNA-seq data showing 3 distinct clusters in the negative group according to 53 selected significant genes. b Dot plot of GSEA preranked analysis showing the topmost significantly enriched functional gene clusters in the negative group compared with the telomerase and ALT groups. Cell cycle- and cell division-related gene sets were negatively enriched in the negative group. c TMM characteristics of primary GBM cell lines and differences in their growth rates. Nine primary GBM cell lines were classified into 3 different TMM groups, telomerase (n = 3), ALT (n = 1), and negative (n = 5), according to RTA% and CCA results. Among these nine cell lines, the 5 cell lines categorized as negative showed the slowest growth rates, and their doubling times were longer than those of the telomerase and ALT cell lines. d Terminal restriction fragment (TRF) analysis of 20 GBM samples classified into 4 groups: telomerase (n = 5), ALT (n = 6), both (n = 3), and negative (n = 6). The telomeres in the telomerase group were shorter than those in the other 3 groups. The telomere lengths of the ALT, both, and negative groups were similar