Increased transglutaminase 2 and GLUT-1 expression in breast tumors not susceptible to chemoprevention with antioxidants.
OBJECTIVE
Expression of GLUT-1 and transglutaminase 2 is increased in aggressive breast cancer, whereas claudin-1, which is expressed in normal tissues, is absent in such tumors. This experimental study was undertaken to establish the aggressiveness and prognosis of DMBA-induced mammary tumors in female Wistar rats based on the assessment of these markers.


METHODS
The rats were divided into two groups, a control group (n = 70) and a chemoprevention group (n = 70). Breast tumors were induced in both groups by administration of 7,12-dimethylbenz[a] anthracene (DMBA). The chemoprevention group also received alpha-tocopherol and a solution of micronutrients containing ascorbic acid and selenium. Neoplastic lesions of both groups were randomly selected for immunohistochemical assessment of the expression of GLUT-1, transglutaminase 2 and claudin-1.


RESULTS
A higher proportion of mammary tumors expressed GLUT-1 and transglutaminase 2 in the chemoprevention group. Claudin-1 expression was absent in all tumors of both groups.


CONCLUSIONS
These results are suggestive of increased aggressiveness of tumors not susceptible to chemoprevention by the agents used in this study.
Martins
Filipe C
FC
Gynecology Department, University Hospital of Coimbra, Coimbra, Portugal. filipecorreiamartins@gmail.com
Teixeira
Filipa
F
Reis
Ines
I
Geraldes
Nuno
N
Cabrita
A M Silvério
AM
Dias
Margarida F
MF
D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D016588:Anticarcinogenic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000139:chemically induced / Q000201:enzymology* / Q000517:prevention & control*; D002273:Carcinogens; D005260:Female; D019204:GTP-Binding Proteins / Q000187:drug effects*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D051272:Glucose Transporter Type 1 / Q000187:drug effects*; D007150:Immunohistochemistry; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D018036:Selenium Compounds / Q000494:pharmacology; D011503:Transglutaminases / Q000187:drug effects*; D017211:Treatment Failure; D024502:alpha-Tocopherol / Q000494:pharmacology
D016588:Anticarcinogenic Agents; D000975:Antioxidants; D014408:Biomarkers, Tumor; D002273:Carcinogens; D051272:Glucose Transporter Type 1; D018036:Selenium Compounds; C000717609:Tgm2 protein, rat; D015127:9,10-Dimethyl-1,2-benzanthracene; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases; D019204:GTP-Binding Proteins; D024502:alpha-Tocopherol; D001205:Ascorbic Acid