Yano M, Naito Z, Tanaka S, Asano G
Department of Pathology, Nippon Medical School, Bunkyo-ku, Tokyo.
Jpn J Cancer Res. 1996 Sep;87(9):908-15. doi: 10.1111/j.1349-7006.1996.tb02119.x.
Heat shock proteins (hsps) are thought to play important roles in the cell cycle and various processes of carcinogenesis. Therefore, we evaluated the expression of hsps, mainly hsp90 and hsp70, in human breast cancer tissues. Hsp90alpha mRNA was expressed at much higher levels in the cancerous tissue than in the non-cancerous tissue. In addition, a close correlation between hsp90alpha mRNA expression and the proliferating-cell-nuclear-antigen labeling index (PCNA LI) was observed for the cancerous tissue. These findings suggest that increased expression of the hsp90alpha isoform may play a role in cell proliferation. On the other hand, hsp90beta mRNA expression was significantly higher in poorly differentiated carcinomas than in well differentiated carcinomas of the breast. The intracellular localization of hsp70 was consistent with that of ubiquitin. In specimens showing hsp70 in the nucleus, the PCNA LI was significantly high. Hsc73 mRNA, a member of the hsp70 family, was also expressed at higher levels in cancerous tissues associated with a high PCNA LI than in non-cancerous tissues. These results suggest that hsp90alpha may play a role in cancer cell proliferation and that hsp90beta may contribute to cell differentiation and structural constitution. In addition, hsp70, especially hsc73, is related to ubiquitin and seems to be a marker for cancer proliferation.
热休克蛋白（hsps）被认为在细胞周期和致癌作用的各种过程中发挥重要作用。因此，我们评估了热休克蛋白，主要是hsp90和hsp70在人乳腺癌组织中的表达情况。hsp90α mRNA在癌组织中的表达水平远高于非癌组织。此外，在癌组织中观察到hsp90α mRNA表达与增殖细胞核抗原标记指数（PCNA LI）之间存在密切相关性。这些发现表明，hsp90α异构体表达的增加可能在细胞增殖中起作用。另一方面，hsp90β mRNA在乳腺低分化癌中的表达明显高于高分化癌。hsp70的细胞内定位与泛素一致。在细胞核中显示有hsp70的标本中，PCNA LI显著较高。hsp70家族成员Hsc73 mRNA在与高PCNA LI相关的癌组织中的表达水平也高于非癌组织。这些结果表明，hsp90α可能在癌细胞增殖中起作用，而hsp90β可能有助于细胞分化和结构构成。此外，hsp70，尤其是Hsc73，与泛素相关，似乎是癌症增殖的一个标志物。
