The Expression And Clinical Significance Of Autophagy-related Protein Beclin1 And P62 In Non-small Cell Lung Cancer

Background: With the change of our living environment, the incidence of various forms of tumor is increasing, lung cancer has become one of the highest incidence of malignant tumors. In our country, it ranks the first place among the male malignant tumors, and its incidence is rising year by year. Among all of the lung cancers, 80% is non-small cell lung cancer(NSCLC). In the clinical treatment, lung cancer can occasionally result in drug resistance for some chemotherapy drugs, automatically reduce the chemotherapy effect. O nly a small number of patients are suitable for using radiation therapy, and the efficacy of radiotherapy vary with each individual. The majority of patients are in the final stages of cancer at the time of diagnosis, losing the chance of surgical treatment. For advanced NSCLC patients, in spite of the treatments such as radiation as well as chemotherapy, these methods can only extend the median survival period 2-4 months, the prognosis remains poor. Early diagnosis is difficult and easy to distant metastasis factors make existing treatments(surgery, radiotherapy, chemotherapy) limited in clinical application. In addition to the need for early diagnosis, to find effective methods is also a problem we need to be addressed in NSCLC treatment.In the past few decades, the relationship between autophagy and tumor has always been the hot spot of the cancer research. Research shows that, there are autophagy activity abnormalities in tumor cells, the internal environment is affected when cells tend to malignant transformatio n, autophagy may be involved in cleaning up the damage or mutations of DNA during this period, result in inhibiting the development of precancerous cells, the role of autophagy is to inhibit the growth of tumor at this time. Tumor cells began to appear poor nutrition, lack of blood supply that is not conductive to the growth of tumor cells as the illness progress. At this point, the cancer cells use autophagy mechanism on the body resistance to poor nutrition and lack of oxygen, avoiding tumor cells death. Thus, it can be said that the role of autophagy is different at different times in cancer development. Autophagy is due to hunger, lack of oxygen, malnutrition or metabolic stress that causes the cell to cytoplasmic contents such as degradation of a self-digestion, known as Ⅱtype of programmed cell death. Autophagy plays an important role in cell self-renewal, tissues, organs development and growth.In the process of occurrence and development of non-small cell lung cancer, the change of microenvironment in cells, the occurrence of tumor angiogenesis, damaged cells to remove obstacles, are closely associated with autophagy. Beclin1 and P62 are two important autophagy-related proteins. Beclin1 is the key to the process of autophagy regulator, widely expressed in the human variety of normal tissues. A larger number of studies have demonstrated that Beclin1 is a tumor suppressor protein. While the important function of P62 is as the mechanism of autophagy and dispensing mechanism among autophagy substrates. In a variety of human tumors, researchers found the abnormal accumulation of P62, and high expression of P62 indicates poor prognosis. In addition, P62 can serve as a sign of tumor autophagy defects in some tumors. The role of Beclin1 and P62 in the development of non-small cell lung cancer has been urgent concern of many scholars, the relationship between the two proteins and patients, clinical pathological parameters has become a hot issue in clinical research. In this research, we explore the relation between the expression of Beclin1 as well as P62 and NSCLC by immunohistochemical method. The result may provide important clinical significance for NSCLC early diagnosis, treatment and prognosis.Objective:To investigate the expression and clinical significance of Beclin1 and P62 in non-small cell lung cancer.Method :60 cases of surgical resection of NSCLC specimens were selected, and the same period surgical resection of normal lung tissue of 20 cases were taken as control. The expression of Beclin1 as well as P62 were detected by immunohistochemical method respectively, analyzes the correlation of proteins expression with the clinical pathological parameters and the correlation of the them. Results:1.The expression of Beclin1 was detected in 36.7% NSCLC samples, significantly lower than it in normal lung group(80%)(P<0.05). Furthermore,Beclin1 expression in NSCLC was correlated with patients, TNM stage and lymph node metastasis(P<0.05), unrelated with gender, age, histological type and differentiation grade( P>0.05);2.The expression of P62 was detected in 51.7% NSCLC samples, significantly higher than it in normal lung group(15%)(P<0.05). P62 expression in NSCLC was correlated with patients, age and histological type(P<0.05). while had nothing to do with gender, differentiation grade, clinical stage or lymph node metastasis( P>0.05).3. The expression of Beclin1 and P62 in NSCLC is no correlation. Conclusion:Beclin1 is low expressed in NSCLC, while P62 is high expressed in NSCLC, the exception of autophagy and the occurrence of non-small cell lung cancer development may have a closely relationship.