Breast cancer patients' clinical outcome measures are associated with Src kinase family member expression.
BACKGROUND
This study determined mRNA expression levels for Src kinase family (SFK) members in breast tissue specimens and assessed protein expression levels of prominent SFK members in invasive breast cancer to establish associations with clinical outcome. Ki67 was investigated to determine association between SFK members and proliferation.


METHODS
The mRNA expression levels were assessed for eight SFK members by quantitative real-time PCR. Immunohistochemistry was performed for c-Src, Lyn, Lck and Ki67.


RESULTS
mRNA expression was quantified in all tissue samples. SRC and LYN were the most highly expressed in malignant tissue. LCK was more highly expressed in oestrogen receptor (ER)-negative, compared with ER-positive tumours. High cytoplasmic Src kinase protein expression was significantly associated with decreased disease-specific survival. Lyn was not associated with survival at any cellular location. High membrane Lck expression was significantly associated with improved survival. Ki67 expression correlated with tumour grade and nuclear c-Src, but was not associated with survival.


CONCLUSIONS
All eight SFK members were expressed in different breast tissues. Src kinase was highest expressed in breast cancer and had a negative impact on disease-specific survival. Membrane expression of Lck was associated with improved clinical outcome. High expression of Src kinase correlated with high proliferation.
Elsberger
B
B
Western Infirmary Glasgow, Section of Surgery, Division of Cancer Sciences and Molecular Pathology, Faculty of Medicine, Level 2, McGregor Building, Dumbarton Road, Glasgow G11 6NT, UK.
Fullerton
R
R
Zino
S
S
Jordan
F
F
Mitchell
T J
TJ
Brunton
V G
VG
Mallon
E A
EA
Shiels
P G
PG
Edwards
J
J
D001943:Breast Neoplasms / Q000201:enzymology* / Q000473:pathology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019061:src-Family Kinases / Q000235:genetics*
D012333:RNA, Messenger; D019061:src-Family Kinases