Expression and localization of homeodomain proteins DLX4/HB9 in normal and malignant human breast tissues.
BACKGROUND
Alterations in the control of gene expression is a key event in neoplastic transformation. Investigating the expression of transcription factors such as homeodomain proteins may therefore allow better characterization of molecular mechanisms underlying the transformation process.


METHODS
Expression of homeodomain proteins DLX4 and HB9 was detected by RT-PCR and immunohistochemically in 24 breast tumors and their corresponding non-malignant tissue.


RESULTS
Although the percentage of nuclei expressing both DLX4 (p = 0.001) and HB9 (p = 0.0001) is increased in breast carcinoma, their intensity of nuclear staining is decreased compared to non-malignant nuclei. Furthermore HB9 nuclear immunoreactivity decreased progressively with increasing tumor grade (p = 0.001).


CONCLUSIONS
These data suggest that the reduction in malignant nuclear DLX4 immunoreactivity is an earlier event in breast carcinogenesis than the progressive loss of HB9 expression observed with increasing tumor grade. With further study and in conjunction with standard criterion of pathology, these findings may help to predict the malignant behaviour of some breast cancers.
Neufing
Petra J
PJ
Dame Roma Mitchell Cancer Research Laboratories, University of Adelaide, Hanson Institute, PO BOx 14, Rundle Mall, Adelaide S.A. 5000, Australia. petra.neufing@imvs.sa.gov.au
Kalionis
Bill
B
Horsfall
David J
DJ
Ricciardelli
Carmela
C
Stahl
Juergen
J
Vivekanandan
Suchindra
S
Raymond
Wendy
W
Tilley
Wayne D
WD
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D000818:Animals; D000912:Antibodies, Neoplasm / Q000096:biosynthesis / Q000276:immunology; D001940:Breast / Q000737:chemistry* / Q000378:metabolism; D001943:Breast Neoplasms / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D002277:Carcinoma / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000556:secondary; D002467:Cell Nucleus / Q000737:chemistry; D015342:DNA Probes; D018450:Disease Progression; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D018398:Homeodomain Proteins / Q000032:analysis* / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D006801:Humans; D007106:Immune Sera; D007124:Immunoenzyme Techniques; D008207:Lymphatic Metastasis; D008875:Middle Aged; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000032:analysis* / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D012334:RNA, Neoplasm / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012756:Sheep; D014157:Transcription Factors / Q000032:analysis* / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology
D000912:Antibodies, Neoplasm; C105304:DLX4 protein, human; D015342:DNA Probes; D018398:Homeodomain Proteins; D007106:Immune Sera; C490003:MNX1 protein, human; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D014157:Transcription Factors