E2F-1 transcription factor immunoexpression is inversely associated with tumor growth in colon adenocarcinomas.
E2F-1 is an intriguing transcription factor that accumulates the integrated signal of the G1-S transition regulators. Its role in cell fate, as depicted from in vivo models and a few studies on human tissues, is a matter of debate, since it confers a tissue-specific oncogenic or tumor suppressor behavior. In the present work, in an attempt to shed light on the role of E2F-1 in colon cancer, we examined E2F-1 expression in a series of 45 colon carcinomas and we further correlated it with tumor kinetics. E2F-1 expression and proliferation were evaluated by immunohistochemistry as the percentage of E2F-1 (E2F-1 index: EI) and Ki-67 (Proliferation index: PI)-positive cells, respectively; whereas apoptosis was estimated as the percentage of positive, by TUNEL assay, cells (Apoptotic index: AI). The relationship between E2F-1 expression and tumor kinetics was assessed by microscopical evaluation in semi-serial tissue sections and statistical analysis. Our results demonstrated that E2F-1 expression was inversely correlated with tumor growth (GI=PI/AI) (p=0.002). Specifically, the histological observations showed that E2F-1 was expressed in lesions with high apoptotic incidence and low proliferation. These results also supported the statistical findings showing that EI was inversely correlated with PI (p < 0.001) and positively associated with AI (p = 0.013). In conclusion, we suggest a tumor-suppressive behavior of E2F-1 in colon carcinomas.
Bramis
John
J
First Department and 4Second Department of Surgery, Laiko Hospital, Medical School of Athens, Athens, Greece.
Zacharatos
Panayotis
P
Papaconstantinou
Ioannis
I
Kotsinas
Athanassios
A
Sigala
Frangisca
F
Korkolis
Dimitrios P
DP
Nikiteas
Nikolaos
N
Pazaiti
Anastasia
A
Kittas
Christos
C
Bastounis
Elias
E
Gorgoulis
Vassilis G
VG
D000230:Adenocarcinoma / Q000276:immunology / Q000378:metabolism* / Q000473:pathology*; D018797:Cell Cycle Proteins / Q000096:biosynthesis* / Q000276:immunology; D048708:Cell Growth Processes / Q000502:physiology; D003110:Colonic Neoplasms / Q000276:immunology / Q000378:metabolism* / Q000473:pathology*; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000276:immunology; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; D006801:Humans; D007150:Immunohistochemistry; D009367:Neoplasm Staging; D014157:Transcription Factors / Q000096:biosynthesis* / Q000276:immunology
D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; C493753:E2F1 protein, human; D014157:Transcription Factors