Suppressor of cytokine signalling 2 (SOCS-2) expression in breast carcinoma.
OBJECTIVE
To investigate SOCS-2 (suppressor of cytokine signalling 2) protein expression in breast carcinoma samples in relation to biopathological parameters and survival.


METHODS
A polyclonal antibody against SOCS-2 was used to study 50 archival breast carcinoma samples, collected from 1993 to 1995. The presence of SOCS-2 protein was investigated in relation to clinical and biological parameters used in breast cancer pathology. Fluorescence in situ hybridisation (FISH) was used to study whether SOCS-2 expression was related to SOCS-2 gene copy number.


RESULTS
SOCS-2 protein was expressed in 34 of 50 breast carcinoma samples and was positively associated with low grade, low nuclear grade, and p27 protein. SOCS-2 expression was inversely related to Ki-67, cyclin A, retinoblastoma protein (pRb), and the epidermal growth factor receptor (EGFR). No relation with overall survival was demonstrated. SOCS-2 amplification was found in three samples. No relation between the number of FISH signals and SOCS-2 expression was found.


CONCLUSIONS
The significant correlation seen between SOCS-2 expression, grade, nuclear grade, p27, Ki-67, cyclin A, pRb, and EGFR labelling strongly supports the hypothesis that SOCS-2 loss might be related to cell proliferation and tumour growth in breast carcinoma. Gene copy number changes did not seem to play a role in SOCS-2 regulation and expression; other mechanisms might be involved and deserve further study.
Farabegoli
F
F
Department of Experimental Pathology, University of Bologna, Via San Giacomo, 14, 40126 Bologna, Italy. frbfl@alma.unibo.it
Ceccarelli
C
C
Santini
D
D
Taffurelli
M
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D018797:Cell Cycle Proteins / Q000378:metabolism; D049109:Cell Proliferation; D019925:Cyclin A / Q000378:metabolism; D050760:Cyclin-Dependent Kinase Inhibitor p27; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D019394:Ki-67 Antigen / Q000378:metabolism; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D016160:Retinoblastoma Protein / Q000378:metabolism; D050826:Suppressor of Cytokine Signaling Proteins; D015996:Survival Rate; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000378:metabolism
D014408:Biomarkers, Tumor; D018797:Cell Cycle Proteins; D019925:Cyclin A; D004268:DNA-Binding Proteins; D019394:Ki-67 Antigen; D009363:Neoplasm Proteins; D012097:Repressor Proteins; D016160:Retinoblastoma Protein; C106643:SOCS2 protein, human; D050826:Suppressor of Cytokine Signaling Proteins; D015534:Trans-Activators; D025521:Tumor Suppressor Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27; D066246:ErbB Receptors