Lung Cancer Research Today is a free monthly online journal that collates and summarizes the latest research about Lung Cancer, including details on symptoms, smoking, genetics, treatment, causes. | ||||||||
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Role of cdk4, p16INK4, and Rb expression in the prognosis of bronchioloalveolar carcinomas.Ghazizadeh M, Jin E, Shimizu H, Fujiwara M, Arai S, Ohaki Y, Takemura T, Kawanami O Department of Molecular Pathology, Institute of Gerontology, Nippon Medical School, Nakahara-ku, Kawasaki, Japan. ciem@nms.ac.jp BACKGROUND: The p16(INK4) protein has been identified as a potent inhibitor of cyclin-dependent kinase (cdk)4 by blocking cdk4-mediated phosphorylation of the tumor suppressor retinoblastoma (Rb) protein, thus allowing Rb-mediated growth suppression. OBJECTIVES: Loss of p16(INK4) has been associated with a poor cancer prognosis, but its potential significance in bronchioloalveolar carcinomas (BACs) has not been explored. METHODS: We examined immunohistochemical expression of p16(INK4), cdk4, and Rb proteins in 38 BACs and correlated their expression levels with known clinicopathological features of the disease. RESULTS: All BACs expressed cdk4, while 89 and 82% expressed p16(INK4) and Rb proteins, respectively. None of the clinicopathological factors correlated with p16(INK4), cdk4, or Rb expression separately. A low p16(INK4)/cdk4 ratio was significantly associated with a high disease stage (p = 0.04), and the ratio tended to be lower in mucinous than nonmucinous tumors. BACs with a low p16(INK4)/cdk4 ratio showed significantly higher Rb expression levels (p = 0.02). Univariable survival analyses showed a significantly lower 5-year survival probability in patients with a high stage (p = 0.002) or low p16(INK4)/cdk4 ratio (p = 0.01). CONCLUSIONS: The results suggest a role of the cdk4/p16(INK4) pathway in the prognosis of BACs. Further studies are warranted to clarify whether a low p16(INK4)/cdk4 ratio may identify tumors that are destined to behave unfavorably. Published 8 March 2005 in Respiration, 72(1): 68-73.
© 2004-2008 Lung Cancer Research Today. All Rights Reserved. |
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