C-erbB2, p27 and G1/S aberrations in human primary breast cancer

• Background: C-erbB2 is overexpressed in approximately one-fourth of human breast cancers. In spite of numerous reports suggesting a connection of c-erbB2 overexpression with cell cycle regulation through p27, D cyclins and c-myc. the relationship between c-erbB2 and proliferation through de-regulation of the pRb pathway in primaty breast cancer has not been fully clarified. Materials and Methods: For this purpose we compared the expression of c-erbB2 in a total of 10.5 primary breast tumours with a variety of cell cycle proteins and clinical parameters. Results: GerbB2 was strongly con-elated with down-regulation of p27 and overexpression of c-erbB2 was', as expected, associated with poor survival. However, there was no correlation with proliferation. There was, nevertheless, an association between c-erbB2 and proliferation in certain subtypes of breast cancer, as in oestrogen-receptor-positive e tumours, tumours with high cyclin D1 and in tumours with an overall linear pRb pathway, i.e. tumours with a preserved linearity between cyclin D1, pRb phosphorylation and proliferation. Conclusion: Our results suggest that c-erbB2 may have alternative functions in different subtypes of breast cancer, and further stress that c-erbB2, in addition to promoting proliferation, also functions through other mechanisms in breast cancer.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Cancer och onkologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Cancer and Oncology (hsv//eng)

Keyword

proliferation

pRb pathway

cyclins

p27

breast cancer

c-erbB2

Publication and Content Type

art (subject category)

ref (subject category)