Fig 2: KLK6 expression and the association of KLK6 with clinical parameters. Volcano plot represents the gene expression between BLCA tissues (n = 414) and normal tissues (n = 19), and DEGs were filtrated using |Log2(fold change)| > 1 and Adj.p < 0.05 (a). The Venn diagram represents the number of genes between DEGs and the top100 prognostic factors (b). KLK6 expression was significantly up-regulated in BLCA tissues (n = 414) compared with normal tissues (n = 19) (c). The association of KLK6 gene expression with clinical parameters, including T stage (d), N stage (e), M stage (f), pathologic stage (g), and histologic stage (h). The promoter methylation level of KLK6 in BLCA was analyzed by UALCAN database (i). *p < 0.05, **p < 0.01, ***p < 0.001; ns: no significant.

Fig 3: GO, KEGG, and GSEA of KLK6-related genes in BLCA. GO, including BP (a) and MF (b) and KEGG (c) and GSEA (d), revealed that KLK6-related genes were enriched in multiple signaling pathways.

Fig 4: The mRNA levels of up-regulated or down-regulated genes in ESCC cell lines monocultured and co-cultured with TAM-like PBMo-derived macrophages by quantitative RT-PCR. (a–e) The mRNA levels of CYP1A1, DHRS3, ANXA10, KLK6 and CYP1B1 were up-regulated and (f, g) AMTN and IGFL1 were down-regulated in co-cultured TE-8 and TE-9 cells compared to the respective monocultured ESCC cell lines. GAPDH was used as a control. Data are mean ± SEM in triplicate. **P < 0.01, Student's t-test.

Fig 5: KLK6 related with Th2 cell enrichment in BLCA. The relationship between KLK6 and Th2 cell enrichment in BLCA was implemented using the TCGA database (a). Th2 cell enrichment was associated with upregulation of KLK6 expression in BLCA (b). We analyzed whether Th2 cell enrichment generated an unfavorable prognosis in patients with BLCA using Kaplan-Meier Plotter online tool (c). ***p < 0.001.