Wu Trang-Tiau, Hsieh Yi-Hsien, Hsieh Yih-Shou, Liu Jer-Yuh
Department of Surgery, School of Medicine, College of Medicine, Chung Shan Medical University, Taichung 402, Taiwan.
J Cell Biochem. 2008 Jan 1;103(1):9-20. doi: 10.1002/jcb.21378.
Protein kinase C (PKC) superfamily play key regulatory roles on the development of cancer. However, the exact role of these enzymes in human hepatocellular carcinoma (HCC) has not been well established. Using the RT-PCR and Western blotting to analyze the levels of PKC isoforms mRNA and protein in the five different differentiated hepatoma cell lines, we found that PKC alpha was highly expressed in the poor-differentiated HCC cell lines (SK-Hep-1 and HA22T/VGH) as compared with that in the well-differentiated HCC cell lines (PLC/PRF/5, Hep3B, and HepG2). When treated with PKC alpha antisense oligonucleotides (ODN), both HA22T/VGH and SK-Hep-1 cells lines showed the reduction of PKC alpha expression, as well as a deceleration in the growth rate and in the level of cyclin D1, but the increase in the levels of p53 and p21(WAF1/CIP1). Moreover, the reduction of PKC alpha expression also inhibited the migratory and invasive potential of both HA22T/VGH and SK-Hep-1 cells lines, and revealed a down-regulation of several migration/invasion-related genes (MMP-1, u-PA, u-PAR, and FAK). These phenomenon were also confirmed by DNA-based small interfering RNA (siRNA) PKC alpha and PKC alpha/beta specific inhibitor Go6976. Thus, the results indicated that PKC alpha may be associated with regulation of cell proliferation/migration/invasion in human poorly differentiated HCC cells, suggesting a role for the PKC alpha in the malignant progression of human HCC.
蛋白激酶C（PKC）超家族在癌症发展过程中发挥着关键的调节作用。然而，这些酶在人类肝细胞癌（HCC）中的确切作用尚未完全明确。通过逆转录聚合酶链反应（RT-PCR）和蛋白质印迹法分析五种不同分化程度的肝癌细胞系中PKC亚型的mRNA和蛋白质水平，我们发现与高分化肝癌细胞系（PLC/PRF/5、Hep3B和HepG2）相比，PKCα在低分化肝癌细胞系（SK-Hep-1和HA22T/VGH）中高表达。用PKCα反义寡核苷酸（ODN）处理时，HA22T/VGH和SK-Hep-1细胞系中PKCα表达均降低，细胞生长速率和细胞周期蛋白D1水平减慢，但p53和p21（WAF1/CIP1）水平升高。此外，PKCα表达的降低还抑制了HA22T/VGH和SK-Hep-1细胞系的迁移和侵袭能力，并导致几种迁移/侵袭相关基因（MMP-1、u-PA、u-PAR和FAK）表达下调。基于DNA的小干扰RNA（siRNA）PKCα和PKCα/β特异性抑制剂Go6976也证实了这些现象。因此，结果表明PKCα可能与人类低分化肝癌细胞的细胞增殖/迁移/侵袭调节有关，提示PKCα在人类肝癌的恶性进展中发挥作用。
