title: Expression of early growth response-1 in colorectal cancer and its relation to tumor cell proliferation and apoptosis.
abstract: Early growth response-1 (Egr-1) is implicated in the regulation of cell growth, proliferation, differentiation and apoptosis. Egr-1 is considered tobe either a tumor-suppressor or tumor-promoter, depending on the cell type and environment. The aim of the present study was to evaluate the expression of Egr-1 in colorectal cancer and its correlation with tumor cell proliferation, apoptosis and clinicopathological features. The expression of Egr-1 in colorectal cancer tissues was investigated by reverse transcription-polymerase chain reaction (RT-PCR), western blotting and immunohistochemistry. Apoptosis was detected by terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL), and cellular proliferative activity was evaluated by immunohistochemical staining with the Ki-67 antibody. Egr-1 expression was significantly elevated in colorectal cancer tissues, when compared to that in the paired normal mucosa at the mRNA and protein levels. In addition, Egr-1 expression was significantly increased in the metastatic lymph node tissues, when compared to that in the non‑metastatic lymph node tissues at the protein level. The mean Ki-67 labeling index (KI) and apoptotic index (AI) values for 158 tumors were 53.6±15.4 and 9.0±1.0, respectively. Higher KI values were significantly associated with distant metastasis. Lower AI values were significantly associated with lymph node metastasis. However, KI or AI values were not associated with patient survival. The mean KI value of Egr-1-positive tumors was significantly higher than that of Egr-1-negative tumors. However, there was no significant difference between Egr-1 expression and AI value. Positive expression of Egr-1 was significantly associated with age, lymphovascular invasion, lymph node and distant metastasis, tumor stage and poor survival. These results indicate that Egr-1 may be associated with colorectal cancer progression via tumor cell proliferation.
authors.affiliation: Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Dae-Seong
authors.initials: DS
authors.lastname: Myung
authors.affiliation: Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Young-Lan
authors.initials: YL
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Nuri
authors.initials: N
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Cho-Yun
authors.initials: CY
authors.lastname: Chung
authors.affiliation: Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Hyung-Chul
authors.initials: HC
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Jong-Sun
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Sung-Bum
authors.initials: SB
authors.lastname: Cho
authors.affiliation: Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Wan-Sik
authors.initials: WS
authors.lastname: Lee
authors.affiliation: Department of Pathology, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Jae-Hyuk
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Young-Eun
authors.initials: YE
authors.lastname: Joo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis / Q000235:genetics*; D002454:Cell Differentiation / Q000235:genetics; D049109:Cell Proliferation; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000401:mortality; D018450:Disease Progression; D051766:Early Growth Response Protein 1 / Q000096:biosynthesis / Q000235:genetics*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000235:genetics*; D013534:Survival; D014407:Tumor Cells, Cultured
chemical_list: C497325:EGR1 protein, human; D051766:Early Growth Response Protein 1