GREB1 tissue expression is associated with organ-confined prostate cancer.
OBJECTIVE
By reason of its heterogeneous behavior, it is difficult to determine the prognosis of many prostate cancer cases. Patients with the same clinicopathologic conditions may present varying clinical findings and rates of progression. We determined the role of new genes as potential molecular markers for prostate cancer prognosis.


METHODS
We performed a microarray analysis of two pools of patients with prostate cancer divided according to their clinicopathologic characteristics. After that, we validated these results by testing the genes with most different expressions between the two pools using the quantitative real time polymerase chain reaction method. We analyzed gene expression in 33 patients with localized prostate cancer according to prostate specific antigen (PSA), pathologic stage, Gleason score, and biochemical recurrence. For statistical analysis we used the Mann-Whitney Test.


RESULTS
The microarray analysis revealed that 4,147 genes presented a different expression between the two pools. Among them, 3 genes, TMEFF2, GREB1, and TH1L, were at least 13-times overexpressed, and 1 gene, IGH3, which was at least 5 times under-expressed in pool 1 (good prognosis) compared with pool 2 (bad prognosis), were selected for analysis. After the validation tests, GREB1 was significantly more overexpressed among patients with stage T2 compared with T3 (P = 0.020). The expressions of other 3 genes did not present significant differences according to the clinicopathological variables.


CONCLUSIONS
Tissue expression of GREB1 is associated with organ-confined prostate cancer and may constitute a gene associated with a favorable prognosis.
Antunes
Alberto A
AA
Laboratory of Medical Investigation, LIM 55, Division of Urology, University of Sao Paulo Medical School, São Paulo, Brazil. antunesuro@uol.com.br
Leite
Kátia R
KR
Reis
Sabrina T
ST
Sousa-Canavez
Juliana M
JM
Camara-Lopes
Luiz H
LH
Dall'oglio
Marcos F
MF
Srougi
Miguel
M
D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics*; D020869:Gene Expression Profiling; D006801:Humans; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D009367:Neoplasm Staging; D020411:Oligonucleotide Array Sequence Analysis; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction
D014408:Biomarkers, Tumor; C416830:GREB1 protein, human; D009363:Neoplasm Proteins