Effects Of 9-CIS-Retinoic Acid On Transcription Of RAR_β In Lung Cancer Tissue And Study Of Clinical TNM Classification

Objective: To Observe the difference of basic transcriptional level of RARβ between lung cancer tissue and controlled lung tissue, to observe the effects of 9-cis-retinoic acid(9-cis-RA) on transcriptional changes of RARβ in lung cancer tissue and controlled lung tissue, and to evaluate the difference of transcriptional level of RARβ caused by clinical TNM classification so as to suggest the proper patient group to use 9-cis-retinoic acid as therapy means.Methods: Lung cancer and controlled lung tissue were cultured by tissue mass method while lung cancer cells were primarily cultured by cold digestion method to observe the cell livingness of the tissue which was cultured at the same time.Both the cells from lung cancer tissue and from controlled lung tissue are treated with 9-cis-RA for 24h. Extracting total RNA and the RARβ mRNA levels of tissue were detected by RT-PCR method.Statistics method is used to evaluate the difference of transcriptional level of RARβ caused by clinical TNM classification.Results: (1) The primarily-cultured lung cancer cells were observed in 72h and they were in a good growth and proliferation state, which indicated the cells livingness in the mass. (2) Compared with controlled lung tissue, lung cancer tissue had distinctly lower RARβ transcription level.After being treated with 9-cis-RA for 24h, transcription level increased distinctly in lung cancer tissue.(3) There are no statistical difference between RARβ transcriptional level of lung cancer tissue from patients with TNM I and TNM II .After being treated with 9-cis-RA for 24h, there is agreatly increase of RAR β transcriptional level in lung cancer tissue from patients of TNM I .While to those TNMII, the increase is mild .Conclusion: (1) There are discreasing expressions of RARβ in lung cancer tissue, which may be associated with lung carcinogenesis and development.(2)Lung cancer has a distinctly lower RARβ expression than controlled lung tissue and after treated with 9-cis-RA, RARβ expression was increased significantly, even reaching the transcriptional level in controlled lung tissue.(3) TNM I and TNM II can both reduce the transcriptional level of RARβ in controlled lung tissue and inhibit the effect of 9-cis-RA on raising the transcriptional level of RARβ in lung cancer tissue. (4) It can be suggested that 9-cis-RA should be primaryly applied on the patients of TNM I or early stage in clinical therapy of lung cancer.Significance: We studied the abnormal transcriptions of RARβ in lung cancer tissue and the effects of 9-cis-RA on transcriptional changes of RARβ, we evaluate the influence of clinical TNM classification on the transcriptional level of RARβ after being treated with 9-cis-RA, then provided the theoretical basis for clinical differentiational therapy of lung cancer and suggest the proper patients group which can gain the most efficient therapy effect while the same side effect caused by 9-cis-RA is concerned.