title: Expression of the murine double minute gene 2 oncoprotein in esophageal squamous cell carcinoma as a novel marker for lack of response to chemoradiotreatment.
abstract: The protein product of the murine double minute gene 2 (MDM2) negatively controls the work of the p53 protein and the retinoblastoma protein (pRB). Recent studies have found that MDM2 expression correlates with chemoresistance of tumor cells. In the present study, the correlation between MDM2 expression and chemoradioresistance was evaluated in patients with esophageal squamous cell carcinoma (ESCC). The immunoreactivities of p53, pRB, and MDM2 were evaluated in 148 surgically resected ESCC by using monoclonal antibodies. The disease-free survival of 107 surviving patients who underwent curative surgery was compared among groups with positive and negative expressions of p53, pRB, and MDM2. High immunoreactivities of p53, pRB, and MDM2 were detected in 47.3%, 64.2%, and 32.4% of cases, respectively. In 107 patients undergoing curative surgery, pRB losses and MDM2 overexpression were found to be poor prognostic factors by univariate analysis. In multivariate analysis, only MDM2 expression was determined to be a prognostic factor independent of the tumor stage. Moreover, we found that MDM2 expression correlates with short survival of patients undergoing postoperative adjuvant chemoradiotherapy. In patients without adjuvant therapy, however, the MDM2 status did not correlate with patient survival. The present results indicate that MDM2 expression may be not only a prognostic marker for patients with ESCC, but also a novel marker for predicting a lack of response to chemoradiotreatment.
authors.affiliation: Department of Surgery I, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago 683-8504, Japan.
authors.forename: Masahide
authors.initials: M
authors.lastname: Ikeguchi
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Ueda
authors.forename: Kenji
authors.initials: K
authors.lastname: Fukuda
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Shun-Ichi
authors.initials: S
authors.lastname: Tsujitani
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Kaibara
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000378:metabolism* / Q000532:radiotherapy / Q000601:surgery; D018572:Disease-Free Survival; D004938:Esophageal Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000532:radiotherapy / Q000601:surgery; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D009687:Nuclear Proteins; D011379:Prognosis; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051736:Proto-Oncogene Proteins c-mdm2; D016160:Retinoblastoma Protein / Q000378:metabolism; D012189:Retrospective Studies; D017211:Treatment Failure; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D016160:Retinoblastoma Protein; D016159:Tumor Suppressor Protein p53; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2