Expression and localization of homeodomain proteins DLX4, HB9 and HB24 in malignant and benign human colorectal tissues.
BACKGROUND
The purpose of this study was to identify homeobox genes expressed in the human colon and to determine whether their expression levels were altered between matched non-malignant and malignant colon tissues.


METHODS
Homeobox genes expressed in colon tissue were identified by reverse transcription polymerase chain reaction (RT-PCR). Antibodies were raised to the homeodomain proteins DLX4, HB9 and HB24 and immunohistochemistry was performed on 3 moderately-differentiated tumors and their corresponding non-malignant colon tissue samples.


RESULTS
The RT-PCR screen identified expression of DLX4, HB9, HB24 and MSX2 in the normal colon. Immunoaffinity purified polyclonal antisera raised against DLX4, HB9 and HB24 detect specific immunoreactivity in glandular epithelial cells, stromal cells of the lamina propria but not in the submucosa. Nuclear epithelial immunoreactivity of all three antibodies decreased in moderately-differentiated tumors compared to the corresponding matched non-malignant mucosa. These data suggest that differential expression of HB9, HB24 and DLX4 may be associated with colorectal carcinogenesis.
Hollington
Paul
P
Dame Roma Mitchell Cancer Research Laboratories, University of Adelaide, Hanson Institute, IMVS, Adelaide, South Australia, Australia.
Neufing
Petra
P
Kalionis
Bill
B
Waring
Paul
P
Bentel
Jacky
J
Wattchow
David
D
Tilley
Wayne D
WD
D000328:Adult; D002454:Cell Differentiation / Q000502:physiology; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015870:Gene Expression; D018398:Homeodomain Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*
C105304:DLX4 protein, human; C084058:HLX protein, human; C489999:Hlx protein, mouse; D018398:Homeodomain Proteins; C490003:MNX1 protein, human; D014157:Transcription Factors