McKiernan E, O'Brien K, Grebenchtchikov N, Geurts-Moespot A, Sieuwerts A M, Martens J W M, Magdolen V, Evoy D, McDermott E, Crown J, Sweep F C G J, Duffy M J
Department of Pathology and Laboratory Medicine, St Vincent's University Hospital, Dublin, Ireland.
Br J Cancer. 2008 Nov 18;99(10):1644-50. doi: 10.1038/sj.bjc.6604728. Epub 2008 Oct 28.
The protein kinase C (PKC) family of genes encode serine/threonine kinases that regulate proliferation, apoptosis, cell survival and migration. Multiple isoforms of PKC have been described, one of which is PKCdelta. Currently, it is unclear whether PKCdelta is involved in promoting or inhibiting cancer formation/progression. The aim of this study was therefore to investigate the expression of PKCdelta in human breast cancer and relate its levels to multiple parameters of tumour progression. Protein kinase Cdelta expression at the mRNA level was measured using real-time PCR (n=208) and at protein level by both immunoblotting (n=94) and ELISA (n=98). Following immunoblotting, two proteins were identified, migrating with molecular masses of 78 and 160 kDa. The 78 kDa protein is likely to be the mature form of PKCdelta but the identity of the 160 kDa form is unknown. Levels of both these proteins correlated weakly but significantly with PKCdelta concentrations determined by ELISA (for the 78 kDa form, r=0.444, P<0.005, n=91 and for the 160 kDa form, r=0.237, P=0.023, n=91) and with PKCdelta mRNA levels (for the 78 kDa form, r=0.351, P=0.001, n=94 and for the 160 kDa form, r=0.216, P=0.037, n=94). Protein kinase Cdelta mRNA expression was significantly higher in oestrogen receptor (ER)-positive compared with ER-negative tumours (P=0.007, Mann-Whitney U-test). Increasing concentrations of PKCdelta mRNA were associated with reduced overall patient survival (P=0.004). Our results are consistent with a role for PKCdelta in breast cancer progression.
蛋白激酶C（PKC）基因家族编码丝氨酸/苏氨酸激酶，这些激酶可调节细胞增殖、凋亡、存活及迁移。PKC有多种亚型，其中之一是PKCδ。目前，尚不清楚PKCδ是促进还是抑制癌症形成/进展。因此，本研究旨在调查PKCδ在人乳腺癌中的表达，并将其水平与肿瘤进展的多个参数相关联。使用实时PCR（n = 208）在mRNA水平测量蛋白激酶Cδ的表达，并通过免疫印迹法（n = 94）和酶联免疫吸附测定（ELISA，n = 98）在蛋白水平进行测量。免疫印迹后，鉴定出两种蛋白，分子量分别为78 kDa和160 kDa。78 kDa的蛋白可能是PKCδ的成熟形式，但160 kDa形式的身份未知。这两种蛋白的水平与ELISA测定的PKCδ浓度（78 kDa形式，r = 0.444，P < 0.005，n = 91；160 kDa形式，r = 0.237，P = 0.023，n = 91）以及PKCδ mRNA水平（78 kDa形式，r = 0.351，P = 0.001，n = 94；160 kDa形式，r = 0.216，P = 0.037，n = 94）呈弱但显著的相关性。与雌激素受体（ER）阴性肿瘤相比，雌激素受体（ER）阳性肿瘤中蛋白激酶Cδ mRNA表达显著更高（P = 0.007，曼-惠特尼U检验）。PKCδ mRNA浓度增加与患者总体生存率降低相关（P = 0.004）。我们的结果与PKCδ在乳腺癌进展中发挥作用一致。
