639-V

LB100 alone Induces DNA Damage and Apoptosis in BLCA Cells

Bladder carcinoma (BLCA) is a common urinary tract cancer with poor chemotherapy response. Protein phosphatase 2A (PP2A) regulates cellular processes like apoptosis and DNA-damage response. LB100, a PP2A inhibitor, enhances chemotherapy in various cancers, but its effects in BLCA are unknown. Gao's team tested LB100's cytotoxicity on 7 BLCA cell lines (T24, MGHU1, TCCSUP, 639 V, RT-4, RT112 and 97-1) using a viability assay and found it reduced cell viability dose-dependently (Fig. 1a). LB100 also induced γH2AX phosphorylation and Parp1 cleavage without changing PP2A expression (Fig. 1b). In a 639 V xenograft mouse model, LB100 significantly reduced tumor volumes without weight loss (Fig. 1c, d) and increased cleaved Parp1 and Caspase3 levels (Fig. 1e). These results indicate LB100 can induce DNA damage and apoptosis in BLCA cells both in vitro and in vivo.

RAB27A/B Expression is Upregulated in Bca Tissues and Cells

Bladder cancer (BCa) is a common malignancy of the urinary system. RAB27A and RAB27B have been linked to tumor development, yet their functions in BCa are unknown. Zhang et al. explored the function and mechanism of RAB27A and RAB27B in BCa. They determined the mRNA expression and protein levels of RAB27A/B in BCa cells (T24, 5637 and 639 V) and urothelial cells (SV-HUC-1) utilizing RT-qPCR and western blot analyses. RAB27A/B expression levels were significantly increased in BCa cells, particularly in T24 and 5637 cells (Fig. 2A). Then, they evaluated the expression of RAB27A/B in adjacent nontumor tissues (n = 45) and BCa tissues (n = 45). RAB27A/B also had relatively high expression in tumor tissues than in nontumor tissues (Fig. 2B).