Expression And Significance Of P53 And PCNA In Gastrointestinal Stromal Tumors

PurposeGastrointestinal stromal tumor(GIST) is originated from the stromal tissue ofstomach and intestinal, including those called leiomyoma and leiomyosarcoma.Stromal tumor of stomach and intestinal take up about 80 persent of gastrointestinalstromal tumor. At present, immunohistochemical detection of CD₁₁₇ and CD₃₄ arenecessary for the diagnosis of GIST. However, there are great differencesoncobiology exist in clinically different GIST. Consequently, there comes a tendency,GIST is considered to be of potential dangerous degree,that is advocated rather thanthe former simple benign and malignant classification. Recently, clinical idea on themalignant classification standard of GIST is not unified. It also brings us challengeson how to use one or several indicators to judge accurtely the degreee of malignancyand prognosis. The occurrence of tumors are connected with genetic mutation anddamage, while the malignant degree of tumors is closely connected with the cellproliferation.. Therefore, to base our research of the biological features and themalignant transformation law on the ultimate resons for the occurance anddevelopment of tumors would be beneficial for new understanding of Gastrointestinalstromal tumor.This experiment based on the consideration above, through detecting theindicator of proliferating cell nuelear antigen(PCNA) and transforming andtumorigenesis potency catastrophe p53 gene in different malignant degreee GIST, todiscuss the expression of protein p53 and PCNA in gastrointestinal stromal tumor andthe relationship with the malignant transformation. Meanwhile, they will possibly bean important reference indicator to judge the malignant degreee of tumor clinically. Inaddition, the latest development of treating GIST is inclined to the combination of molecular organism targeted therapy(the application of Imatinib) and surgical therapy.Whether the expression levels of p53 and PCNA in GIST of different malignantdegreee could still provide a clinical guidance for medication juncture after surgery?This is what we are expecting.Methods1 Classification of the casesAll cases were made the diagnosis and classification of GIST again on the basis ofthe shapes under the light microscope, and combing the results ofimmunohistochemical staining (CD117 positive and/or CD34 positive).2 Preparation of the specimensSpecimens were fixed by 4% formaldehyde and paraffin embedded serialsection(4μm),and stained by HE and immunohistochemistry.The section ofimmunohistochemical staining were recover by microwave antigen,and carriedout DAB coloration by SP3 Judgement of immunohistochemical stain resultsBy using the tissuem sections of known breast cancer as positive control,andreplace the.one antigen with PBS as negtive control.The positive expressed levelof p53,PCNA was judged in 128 cases of GIST.4 Statistical analysisData are expressed as rate. Statistical interclass significance was analyzed by chisquare test.All data are processed by SPSS 11.5 software.Results1. In 128 cases of GIST, positive expressed level of p53 was 7.1% in the lowest mali-gnant group,and 45.0% in lower malignant group,and 72.6% in moderate malignantgroup and 93.8% in high malignant group.The positive expressed level increasedgradually with the raising of malignant degree.There was a significant difference(P＜0.05) as compared with each other in four groups.2. In 128 cases of GIST, positive expressed level of PCNA was 0% in lowest mali-gnant group,and 40.0% in lower malignant group,and 69.4% in moderate malignant group and 90.6% in high malignant group.The positive expressed level increasedgradually with the raising of malignant degree also.There was a significant difference(P＜0.05) as compared with each other.Conclusion1 These results showed that cell proliferation and apoptosis disequilibrium is alsoone of the important mechanisms in malignant transforming of GIST.2 The detection of p53,PCNA will conduce to the judgement of the malignantdegree of GIST.3 The expression levels of p53, PCNA in different malignant degree of GIST mightprovide the clinical guidance after surgical treatment.