The Expression Of Promyelocytic Leukemia Zinc Finger (PLZF)and The Relationship Between PLZF And Clinicopathologic Parameters And Apoptosis In Coiorectal Cancer

ObjectiveTo investigate promyelocytic leukemia zinc-finger (PLZF) was expressed in colorectal cancer and to identify the clinical significance of its expression and the relationship between PLZF and clinicopathologic factors and apoptosis in colorectal cancer.Method1、115cases in colorectal cancer were seleted randomly from the patients which were operated in our hospital in Qingdao2、The mRNA levels of PLZF in tumor tissues and its matched normal tissues from115cases in primary colorectal cancer were detected by real time-polymerase chain reaction (RT-PCR), and the relationship between the PLZF expression of colorectal cancer and clinicopathologic parameters and were analysed, respectively.3、The protein expression of PLZF in tumor tissues and its matched normal tissues from115cases with primary colorectal cancer were detected by immunohistochemistry, and the relationship between the PLZF expression of colorectal cancer and clinicopathologic parameters were analysed.4、Apoptosis index (AI) in tumor tissues and its matched normal tissues from115cases with primary colorectal cancer were detected by TUNEL(TdT-mediated dUTP-biotin nick end labeling).ResultThe PLZF mRNA were detected both in colorectal cancer and normal colorectal tissues by RT-PCR and their levels were0.068±0.023and0.137±0.082, respectively. The mRNA expression of PLZF in colorectal cancer were significantly lower than those in normal colorectal tissues (t=4.174, P<0.01), and its mRNA levels have dereased by65.3%(χ2=1180, P<0.01).The expression of PLZF protein were detected in both normal tissues and adenocarcinoma. The protein expression of PLZF in colorectal cancer were lower than those in normal colorectal tissues (P<0.05), The PLZF expression was significantly correlated with depth of invasion, lymph node metastasis, Dukes stage, and degree of adenocarcinoma differentiation. Moreover, its protein expression was also significantly correlated with histological type(all P<0.05), but not with age, gender, gross type (P>0.05).Of all115samples in colorectal cancer,the mRNA levels of PLZF was associated with the levels of its protein; AI of colorectal cancer tissues with downregulated PLZF expression was significantly lower than that of cancer tissues with normal PLZF expression.ConclusionAs a potential transcription inhibitor and cell differentiation related factor, PLZF may be involed in tumorigenesis and progression in colorectal carcinoma. Its downregulation was related to clinical Dukes stages of patients, rectal wall infiltration depth, lymph node metastasis and tumor differentiation; The number of apoptotic cells were significantly reduced in colorectal cancer tissue with PLZF downregulated which suggested the effect on promoting tumor cell apoptosis by PLZF.These findingswill provid important theoretical basis for the molecular mechanisms in occurrence and development of colorectal carcinoma and clinical diagnosis and treatment.