Panoply™ Human MPO Over-expressing Stable Cell Line

The progression of prostate cancer (PCa) is closely associated with metabolic reprogramming and immune microenvironment dysregulation, but the mechanisms by which lactate-associated genes (LAGs) function remain unclear. Here, researchers identified 17 differentially expressed LAGs and found that myeloperoxidase (MPO) is an independent prognostic marker for PCa. MPO was significantly downregulated in PCa tissues and PCa cell lines. MPO overexpression inhibited tumor proliferation in vitro and in vivo by suppressing PI3K/AKT pathway phosphorylation (p-PI3K/p-AKT) and reduced xenograft tumor volume. The MPO-overexpressing group exhibited increased natural killer (NK) cell infiltration and elevated immune checkpoint gene expression. Drug sensitivity prediction indicated that patients with high MPO expression were more sensitive to PI3K/AKT inhibitors (e.g., tesimolimus), but their TIDE scores suggested a potentially lower response to immunotherapy. Pan-cancer analysis confirmed low MPO expression levels across 20 cancer types, and MPO expression was significantly associated with the prognosis of various cancers, including colorectal cancer and glioblastoma. These findings suggest that MPO could serve as a novel target for combination therapies based on metabolic interventions.

To elucidate the functional role of MPO in PCa, researchers constructed MPO-overexpressing and MPO-knockdown PC-3 and DU145 cells (Figure 1A). As shown in Figures 1B-D, MPO overexpression significantly inhibited cell proliferation, while MPO silencing led to enhanced proliferation in both cell lines. To further evaluate the effect of MPO on in vivo tumor progression, researchers subcutaneously injected stable MPO-expressing PCa cells or MPO-knockdown PCa cells into the flanks of BALB/c nude mice. Tumor growth analysis showed that, compared with the control group, the xenografts with MPO overexpression were significantly smaller and lighter in color (Figure 1E-G). In summary, these results support the anti-cancer function of MPO by inhibiting cell proliferation in vitro and suppressing tumor development in vivo.

Figure 1. MPO inhibits the proliferation of PCa cells. (Zhou M, et al., 2025)