E2F-1 Transcription Factor Immunoexpression is Inversely Associated with Tumor Growth in Colon Adenocarcinomas

• Published in: Anticancer research Vol. 24; no. 5A; pp. 3041 - 3047
• Main Authors: BRAMIS, John, ZACHARATOS, Panayotis, GORGOULIS, Vassilis G, PAPACONSTANTINOU, Ioannis, KOTSINAS, Athanassios, SIGALA, Frangisca, KORKOLIS, Dimitrios P, NIKITEAS, Nikolaos, PAZAITI, Anastasia, KITTAS, Christos, BASTOUNIS, Elias
• Format: Journal Article
• Language: English
• Published: Attiki International Institute of Anticancer Research 01.09.2004
• Subjects: Adenocarcinoma - immunology; Adenocarcinoma - metabolism; Adenocarcinoma - pathology; Biological and medical sciences; Cell Cycle Proteins - biosynthesis; Cell Cycle Proteins - immunology; Cell Growth Processes - physiology; Colonic Neoplasms - immunology; Colonic Neoplasms - metabolism; Colonic Neoplasms - pathology; DNA-Binding Proteins - biosynthesis; DNA-Binding Proteins - immunology; E2F Transcription Factors; E2F1 Transcription Factor; Gastroenterology. Liver. Pancreas. Abdomen; Humans; Immunohistochemistry; Medical sciences; Neoplasm Staging; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Transcription Factors - biosynthesis; Transcription Factors - immunology; Tumors; Adenocarcinoma; proliferation; Digestive system; Transcription factor E2F1; Malignant tumor; Colonic disease; Cancerology; Colon cancer; Tumor growth; Digestive diseases; Intestinal disease; E2F-1; Apoptosis
• ISSN: 0250-7005; 1791-7530

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.