Immunoreaction at 43 kDa with anti-ubiquitin antibody in breast neoplasms.


Protein ubiquitination has been implicated in ATP-dependent protein turnover and normal cell proliferation. To investigate whether the ubiquitin-mediated system is functionally involved in the cancerous state, we examined changes in protein ubiquitination in 52 surgically resected primary breast tumors. Immunohistochemically, ubiquitin (Ub) was identified in the cytoplasm of cancer cells, which were stained more strongly than adjacent normal ductal epithelium. Corresponding immunoblot analysis of normal and neoplastic regions of human breast showed that the immunoreaction for Ub at about 43 kDa was increased in all of the tumors (100%), regardless of the clinical stage or histologic grade. This protein, which gave a single spot on two-dimensional gel electrophoresis, had partial amino acid sequences which were identical to those of actin family members. Our results suggest that ubiquitination of this 43-kDa protein may be involved in the carcinogenesis or biological characteristics of human breast neoplasms.

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@article{Iwaya1997ImmunoreactionA4, title={Immunoreaction at 43 kDa with anti-ubiquitin antibody in breast neoplasms.}, author={K Iwaya and Hideki Nishibori and T Osada and Yoshihiro Matsuno and Hitoshi Tsuda and Shin Sato and Hiroshi Kono and Takashi Fukutomi and M Suzuki and Chikao Torikata and Akihiro Iwamatsu and Setsuo Hirohashi}, journal={Japanese journal of cancer research : Gann}, year={1997}, volume={88 3}, pages={273-80} }