Vendetti S, Cicconi R, Piselli P, Vismara D, Cassol M, Delpino A
Dept. of Biology, University of Tor Vergata, Rome, Italy.
J Exp Clin Cancer Res. 2000 Sep;19(3):329-34.
In human pancreatic carcinoma cells (HPC-4), a hyperthermic treatment at 43 degrees C for 30 min resulted in the vigorous induction of Hsp72, along with a less pronounced increase in the rate of synthesis of Hsp90, Hsp60 and Hsp 27. Biotinylation of surface-exposed proteins, followed by isolation of biotin-tagged proteins by affinity chromatography, demonstrated that both Hsp72 and Hsp60 are expressed on plasma membrane. Membrane expression of these two Hsps was confirmed by immunoprecipitation of surface biotinylated proteins with anti-Hsp72 and anti-Hsp60 specific antibodies. Cytotoxic assays showed that untreated HPC-4 cells are intrinsically resistant to NK-mediated lysis, while they were efficiently killed by LAK lymphocytes, as well as by exposure to TNFalpha. Following heat-treatment, cells became much more resistant to LAK-mediated lysis, while their sensitivity to NK-mediated lysis and to TNFalpha cytotoxicity remained unmodified.
在人胰腺癌细胞（HPC - 4）中，43摄氏度的热疗处理30分钟会强烈诱导Hsp72的产生，同时Hsp90、Hsp60和Hsp27的合成速率也有较不明显的增加。对表面暴露蛋白进行生物素化，然后通过亲和层析分离生物素标记的蛋白，结果表明Hsp72和Hsp60均在质膜上表达。用抗Hsp72和抗Hsp60特异性抗体对表面生物素化蛋白进行免疫沉淀，证实了这两种热休克蛋白的膜表达。细胞毒性试验表明，未处理的HPC - 4细胞对自然杀伤细胞（NK）介导的裂解具有内在抗性，而它们能被淋巴因子激活的杀伤细胞（LAK）以及暴露于肿瘤坏死因子α（TNFα）有效杀伤。热处理后，细胞对LAK介导的裂解更具抗性，而它们对NK介导的裂解和TNFα细胞毒性的敏感性保持不变。
