Gamma-amino-butyric acid immunoreactivity in intramucosal colonic tumors.
OBJECTIVE
The level of gamma-amino-butyric acid (GABA) is reported to be increased in colon cancer. Moreover, data suggests that GABA plays a role in the proliferation or maturation of some types of cells. We examined the expression of GABA in intramucosal colonic tumors to clarify the relation between GABA and the degree of atypia.


METHODS
Paraffin sections were prepared from 56 protruded-type colonic neoplasms, which were classified as intramucosal adenocarcinoma (AC), adenoma with severe atypia (ASA), or adenoma with mild to moderate atypia (AMA). Expression of GABA was investigated immunohistochemically, and GABA immunoreactivity was compared to the staining patterns of carcinoembryonic antigen (CEA) and cancer-associated antigen (CA19-9) which were classified into three categories.


RESULTS
Intense GABA immunoreactivity was observed in 73.7%, 54.6%, 13.3%, and 5.4% of AC, ASA, AMA, and normal mucosa specimens, respectively. Kendall's correlation coefficient between GABA immunoreactivity and the degree of atypia was 0.447. Strong, positive CEA staining (pattern 3) was observed in 57.9%, 36.3%, and 13.3% of AC, ASA, and AMA specimens, respectively. Strong, positive CA19-9 staining was observed: 26.3%, 9.1% and 0%, respectively. In AC and ASA, the proportion of glands with strong GABA immunoreactivity was greater than the proportion of glands that were strongly positive for CA19-9.


CONCLUSIONS
GABA may be useful as a tumor marker in combination with other tumor markers such as CEA and CA19-9.
Maemura
Kentaro
K
Department of Anatomy, Osaka Medical College, 2-7 Daigaku-machi, Takatsuki, Osaka 569-8686, Japan.
Yamauchi
Hiroaki
H
Hayasaki
Hana
H
Kanbara
Kiyoto
K
Tamayama
Takumi
T
Hirata
Ichiro
I
Watanabe
Masahito
M
D000230:Adenocarcinoma / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism*; D000236:Adenoma / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism*; D003110:Colonic Neoplasms / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism*; D012720:Severity of Illness Index; D005680:gamma-Aminobutyric Acid / Q000032:analysis / Q000096:biosynthesis*
D005680:gamma-Aminobutyric Acid