Expression and prognostic relevance of Mcl-1 in breast cancer.
BACKGROUND
Bcl-2, an anti-apoptotic protein, is frequently associated with favourable prognosis in breast cancer. The potential role of mcl-1, another bcl-2 family member, in breast cancer has not yet been defined.


METHODS
This study examined the expression of mcl-1 and bcl-2 in 170 cases of invasive primary breast carcinoma, using reverse-transcriptase polymerase chain reaction and immunohistochemical analyses.


RESULTS
Expression of bcl-2 mRNA and protein were found to be favourably associated with outcome for patients, supporting a prognostic role for bcl-2 in breast cancer, whereas mcl-1 expression, at the mRNA or protein level, did not correlate with tumour size, grade, lymph node or ER status, age of patient at diagnosis, or disease outcome.


CONCLUSIONS
As these analyses of mcl-1 expression may have co-detected mcl-1(S/deltaTM) (a more recently identified, shorter variant, that may be pro-apoptotic) with the anti-apoptotic wild-type of mcl-1, it is possible that future studies may indicate some significant clinical correlations if the isoforms can be independently investigated.
O'Driscoll
L
L
National Institute for Cellular Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland. Lorraine.ODriscoll@dcu.ie
Cronin
D
D
Kennedy
S M
SM
Purcell
R
R
Linehan
R
R
Glynn
S
S
Larkin
A
A
Scanlon
K
K
McDermott
E W
EW
Hill
A D
AD
O'Higgins
N J
NJ
Parkinson
M
M
Clynes
M
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D009367:Neoplasm Staging; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics
D064549:Myeloid Cell Leukemia Sequence 1 Protein; D009363:Neoplasm Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger