ABSTRACT
To investigate the proliferation and apoptosis of lung adenocarcinoma cells line HI299 by the lentiviral vector mediated RNA binding protein quaking-5 ( QKI-5). Methods GV358 ( up-regulation ) and GV248 ( down-regulation) vectors were used to construct the lentiviral QKI-5 up-regulation vector and down-regulation vector, respectively. The vectors were transfected into 293T cells for lentiviral packaging and viral titer were then determined. Gene sequencing was performed to screen the sequence of vectors. Then Real-time PCR was used to evaluate the expression of QKI-5 mRNA and the proliferation of H1299 cells was examined by colony forming assay after transfection. The apoptosis of HI299 cells was determined by the detection of the expression membrane protein V (annexin V ) and propyl iodide ingot (PI) by flow cytometry. Pro-apoptotic protein Caspae-3 and Caspase-8 were evaluated by Western blotting. Results QKI-5 up-regulation and down-regulation lentiviral vectors were constructed successfully. Compared with the controls, the expression of QKI-5 mRNA of HI299 cells was up-regulated, the cell colony formation was decreased, and the early apoptosis of HI299 cells was increased with the over-expression of Caspase-8 after transfected with up-regulated vector, whereas transfecting with QKI-5 down-regulated vector had opposite effect. Conclusion Lenviral vector mediated QKI-5 could inhibit proliferation and promote apoptosis of lung adenocarcinoma cells through Caspase-8.
ABSTRACT
Objective: To identify the relationship between the expression of protein tyrosine phosphatase non-receptor type 12 (PTPN12) and radiotherapy effect in non-small cell lung cancer (NSCLC) tissues and to determine whether PTPN12 deficiency can sensi-tize lung cancer cells to irradiation. Methods: From September 2013 to October 2014, 92 NSCLC patients undergoing radiotherapy with or without platinum-based combination chemotherapy were analyzed retrospectively. Before the treatment, PTPN12 expression was detected through immunohistochemistry. After the completion of radiotherapy, the patients' responses were assessed and radio-therapeutic efficacy analyzed. The human NSCLC cell line H1299 was infected with shPTPN12 knockdown, and colony survival assay was analyzed after irradiation. Chi-square test was used to examine the correlation between PTPN12 expression and clinicopathologi-cal characteristics. Univariate analyses and Logistic regression test were used to analyze the relationship between clinicopathological characteristics and radiotherapeutic response. Results: Patients with low PTPN12 expression were more sensitive to radiotherapy than those with high PTPN12 expression (80.0%vs. 57.1%, P=0.018). Multivariate analysis showed that PTPN12 expression was the on-ly independent predictor of radiotherapeutic response in NSCLC. The H1299-shPTPN12-knockdown cells were sensitive to irradiation. Conclusions:The results of the study indicated that downregulation of PTPN12 improved the radiosensitivity of NSCLC cells.
ABSTRACT
Background and purpose: Protein kinase P1k3 could increase the transcriptional activity of p53. However, the effect of P1k3 on the transcriptional activity of p73 is still unknown. Our study was to investigate the effect of P1k3 on the transcriptional activity of p73. Methods: Luciferase reporter assay, RT-PCR and colony formation assay were adopted to study the effect of P1k3 and kinase-deficient P1k3 (K52R) on the transcriptional activity of p73 in p53-deficient human lung carcinoma H1299 cells. Results: Luciferase reporter assay showed that p73 increased the luciferase activities induced by p21~(WAF1) and Bax promoters (P<0.05). After co-transfection with p73 and P1k3, the luciferase activities induced by p21~(WAF1) and Bax promotors were significantly decreased in a dose-dependent manner as compared with the group that transfected p73 only (P<0.05). However, kinase-deficient Plk3 (K52R) had no significant effect on the luciferase activities induced by p21~(WAF1) and Bax promoters (P>0.05). RT-PCR showed that p73 increased the mRNA expressions of p21~(WAF1) and BAX (P<0.05). P1k3 decreased the expressions of p21~(WAF1) and Bax induced by p73 (P<0.05). Kinase-deficient P1k3 (K52R) had no significant effect on the expressions of p21~(WAF1) and Bax induced by p73 (P>0.05). Colony formation assay revealed that p73 decreased the colony formation of H1299 cells (P<0.05). P1k3 decreased the inhibitory effect of p73 on the colony formation of H1299 cells (P<0.05). Kinase-deficient P1k3 (K52R) had no significant effect on the inhibitory effect of p73 on the colony formation of H1299 cells (P>0.05).Conclusion: P1k3 can inhibit the transcriptional activity of p73, where as kinase-deficient P1k3 has no effect on the transcriptional activity of p73.