The Expression And Clinical Significance Of PTEN And Its Pseudogene PTENP1 In The Gastric Cancer Tissues And Celllines

Objective1. Examine the m RNAs expressions of PTEN and PTENP1 in 36 pairs of gastric cancer tissue and para-carcinoma tissue, and analyze the correlations between the PTEN and PTENP1;2. Explore the correlations between the two m RNAs and some related clinical pathological factors;3. Construct plasmid and product lentivirus that could efficiently overexpress PTENP1 expression level in gastric cancer cell lines.Method1. 36 cases of gastric cancer tissue and adjacent non-tumorous tissues were collected in Tianjin Medical University Cancer Institute & Hospital from 2014 to2015. Demographic and clinicopathological data of these patients were collected.None of the patients received chemotherapy or radiotherapy before collecting samples.Meanwhile, all aspects of this study were approved from the Human Research Ethics Committee from Tianjin Medical University.(1)Analyze the clinical pathological data for all patients;(2) Realtime-PCR was performed to detect the expression level of PTEN and PTENP1 m RNA;(3) Western blot was performed to detect the expression level of PTEN and PTENP1 protein;(4)Evaluate the relationship between PTEN and PTENP1.(5)Evaluate the relationship between PTEN / PTENP1 and various clinicopathological factors and to explore its relationship with prognosis. Fisher's exact test and chi-square test were used to evaluate the association between PTEN /PTENP1 expression and clinicopathological parameters. P<0.05 was considered statistically significant. All statistical analyses were done using SPSS16.0 software program.2. MGC-803 and MKN-45 cell lines were infected by the lentivirus and selected by puromycin to built clones that stably overexpress PTENP1.Results1. m RNA and protein expression level of PTEN and PTENP1 in para-carcinoma tissue are significantly higher than that in gastric cancer tissue,P<0.001.2. There is a positive correlation between PTEN and PTENP1 m RNA expression in gastric carcnoma samples, rs=0.7889;P<0.05.3. There is no significant correlations between PTEN and PTENP1 with gender,age, family history of cancer, smoking, drinking, histologic classification,differentitation, distant metastasis and location of tumor(P>0.05); The expression level of PTEN and PTENP1 have significant correlations with size of tumor,Lymphatic invasion, depth of tumor invision and TNM stage(P<0.05). PTEN and PTENP1 expression in large tumor size group(long diameter?5cm) are significant lower than that in small tumor size group(long diameter<5cm), P=0.027, P=0.031;PTEN and PTENP1 expression in lymphatic invasion group are significant lower than that in no lymphatic invasion group, P=0.018, P=0.0032; PTEN and PTENP1 expression in deep invasion group are significant lower than that in shallow invasion group, P=0.008,P=0.001; PTEN and PTEN1 expression in ??? TNM stage group are significant higher than that in ??? TNM stage group, P=0.002,P=0.025.4. MGC-803 and MKN-45 cell lines were infected by lentivirus. Realtime-PCR confirmed that the expression level of PTENP1 is elevated. Overexpress of PTENP1 can up regulate PTEN expression.Conclusions1. There is a positive correlation between PTEN and PTENP1 expression in gastric cancer.2. The expression level of PTEN and PTENP1 in gastric carcinoma is significantly lower than that in para-carcinoma tissue. There is significant correlation between the expression level of PTEN and PTENP1 with tumor size, Lymphatic invasion, depth of tumor invasion and TNM stage. PTEN and PTEN1 maybe a new target for gastric cancer diagnosis and treatment.3. PTENP1 could up regulate PTEN expression level in MGC-803 and MKN-45 cell lines...