The Meanings of Galanin and Galanin Reseptors In Head and Neck Cancer

2007 Fiscal Year Final Research Report Summary

• Project/Area Number: 18591903
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Otorhinolaryngology
• Research Institution: Aichi Medical University (2007); Aichi Cancer Center Research Institute (2006)
• Principal Investigator: OGAWA Tetsuya Aichi Medical University, Medicine, Associate Professor (40334940)
• Project Period (FY): 2006 – 2007
• Keywords: Head and Neck Cancer / Gprotein coupled receptor / signal transduction / oncogene / tumor suppressor gene

Research Abstract

This research was done both in Aichi Cancer Center Hospital and Aichi Medical University because the head investigator changed his position. During 2006 to 2007, the expressions of Galanin receptor 1 and Galanin receptor 2 were examined using immunohistochemical technique. In 2006, samples were selected from those operated for tongue cancer at Aichi Cancer Center Hospital. On 2007, the samples of many other head and neck cancers were selected from patients operated at Aichi Medical University. (Results of 2006 research) Tongue cancer samples were used. The antibodies used were made by Gene Tex. The expression of Galanin receptor 1 was seen in normal tissue. However, in the tumor tissue, the expression of Galanin receptor 1 was rarely seen. For Galanin receptor 2, the expression was not seen in either normal or tumor tissue. (Results of 2007) The research was done in Aichi Medical University. The antibodies used were made by Alpha Diagnostic. In the normal tissue, both the expression of Galanin receptor 1 and 2 were seen. However, in the tumor tissue, the expression of Galanin receptor 1 was decreased. The expression Galanin receptor 2 was very strong. In addition, the parotid malignant tumor specimen was used and examined. The expressions of Galanin receptor 1 and 2 were confirmed in the parotid tissue for the first time. We focused on a mixed case sample of a less malignant lesion and a highly malignant lesion. In the less malignant lesion, the expression of Galanin receptor 1 was higher than that of Galanin receptor 2. On the other hand, in the highly malignant lesion, the expression of Galanin receptor 1 was lower than that of Galanin receptor 2.
(Discussion) We originally assumed that Galanin receptor 1 worked as a tumor suppressor gene and Galanin receptor 2 as an oncogene. This difference and distribution derive from the signal transduction differences from the different G-protein coupling. From the results of 2007 research, Galanin receptor 1 will be able to work as a tumor suppressor gene, and Galanin receptor 2 as an oncogene. It seems that a further examination is necessary in the future.