Fig. 8: Knockdown of NAP1L1 inhibits tumour growth and promotes the expression of the apoptotic protein cleaved caspase 9 in HCC.

A Immunohistochemical staining was performed to detect the expression of NAP1L1, BIRC2 and cleaved caspase 9 in xenograft tumour tissues from nude mice (×100 visual field, scale bar = 100 μm; ×400, scale bar = 50 μm). B NAP1L1 is highly expressed in HCC cells and tissues, and upregulated NAP1L1 directly inhibits the expression of apoptotic proteins, such as Bax and Cyt-c, thereby inducing the apoptotic escape of HCC cells. In addition, NAP1L1 plays a pro-tumorigenic role by inhibiting the expression of the E3 ubiquitin ligase UBR4, thereby reducing the ubiquitin-mediated degradation of BIRC2 and inhibiting the activation of the caspase pathway.