Preparation of two types p53 recombinant adenovirus and quantitative exogenous expression of green fluorescence protein by flow cytometry / 中国肺癌杂志

<p><b>BACKGROUND AND OBJECTIVE</b>The p53 as a transcription factor in cell stress was activated to regulate cell cycle and programmed cell death to inhibit tumor growth. Usually, p53 is kept in non-activated state through various mechanisms, including the action of p53 C-terminal negative regulatory sequences. The purpose of the study is to prepare the two types p53 recombinant adenoviruses that carry full-length p53 as well as deletion of negative regulatory sequences at p53 C-terminus and to detect exogenous GFP expression in human lung cancer cell infected-virus by FCM scatter plot.</p><p><b>METHODS</b>Using pAdEasy-Track vector system the p53 recombinant plasmids was constructed and the homologous recombinants in E. coli was produced. The three kinds of recombinant adenovirus in L293 cells was generated, sequencing proved. Exogenous GFP expression in human lung cancer 801D cells infected-virus was detected by FCM scatter plot.</p><p><b>RESULTS</b>p53 recombinant adenoviruses named Ad-p53(wtp), Ad-p53(del) and Ad-(empty carrier) were produced. Results of sequences indicate that the Ad-p53(del) was deletion of 111 bases before stop codon TGA and of 3 untranslated region at p53, the Ad-p53(wtp) no loss of any p53 base, the Ad-(empty carrier) no p53 sequence. FCM scatter plot indicate the percentage of 801D cells expressed GFP with three kinds of viral infection was almost same and was increased with the virus density. 801D contains ratio of cells with different fluorescence intensity.</p><p><b>CONCLUSION</b>The preparation of recombinant adenovirus, Ad-p53(del), pA-p53(wtp) and Ad-(empty carrier). The cells expressed-GFP can be quantitatively detected by FCM scatter plot. It was provide that the reliability of the virus system and accurate method for selecting viruses density to infecting cells.</p>

Effects of p53 antisense RNA on malignant phenotype and sensitivity to cisplatin of human lung cancer cell line / 中国肺癌杂志

<p><b>BACKGROUND</b>To study the effects of extraneous p53 antisense RNA on malignant growth and sensitivity to cisplatin of human lung cancer cell line.</p><p><b>METHODS</b>801D cell line with p53 deletion and mutation at 248 codon was selected as a parent cell line. An 1.8 kb human p53 full length cDNA was inserted into a mammalian expression vector PEGFP to construct a p53 antisense RNA recombined plasmid PEGFP-p53(AS) and GFP gene at plasmid was a report gene to monitor extraneous gene expression. The extraneous gene was detected by PCR. The p53 mutation protein was examined by immunohitochemical stain of p53 monoclonal antibody. The inhibition growth efficacy of extraneous p53 in vitro was determined by clonogenic survival assay. Sensitivity of cells to cisplatin was examined with MTT assay. FCM analysis was performed to measure the effect of p53 antisense RNA on cell cycle.</p><p><b>RESULTS</b>Two cell lines, PEGFP-p53(AS)-801D and PEGFP-801D, were established after transfection of 801-D cells by lipofection and selection. Presence of extraneous p53 gene in PEGFP-p53(AS)-801D was proved by PCR and expression of extraneous p53 was estimated when green fluorescence in those cells was found out under the fluorescent microscopy. Mutated p53 protein in parent cell line 801D was positive and in PEGFP-p53(AS)-801D was negative with immunochemical stain. The inhibition rate of colony formation was 61% for PEGFP-p53(AS)-801D (P < 0.001). The sensitivity of PEGFP-p53(AS)-801D cells to cisplatin was increased. FCM analysis showed that the cell line was arrested at G1 phase.</p><p><b>CONCLUSIONS</b>p53 mutation at 248 code plays an important role on malignant growth and resistance to cisplatin of human lung cancer cell line 801D. Malignant growth of cells with p53 deletion and mutation at 248 codon can be inhibited by extraneous p53 antisense RNA, and simultaneously the sensitivity to cisplatin is also increased.</p>

Study on the effects of p53 deletion and mutation on malignant phenotype of human lung cancer cell line / 中国肺癌杂志

<p><b>BACKGROUND</b>To study the inhibition effects of both extraneous right sense and antisense p53 on malignant phenotype of human lung cancer cell line.</p><p><b>METHODS</b>The named 801D cell line with p53 deletion and mutation at 248 code was selected as a model in vitro. The recombined plasmid pEGFP-p53(RS) and pEGFP-p53(AS) were constructed. The extraneous gene was detected by PCR. The p53 mutation protein was examined by immunohistochemical stain of p53 antibody. The inhibition effect of extraneous p53 on tumor growth in vitro were determined by clonogenic survival assay. FCM analysis was carried out in cells. The inhibition effect on malignant growth of extraneous p53 in vivo was observed by heteroplastic transplant on nude mouse.</p><p><b>RESULTS</b>The transfected cell lines, pEGFP-p53(AS)-801D, pEGFP-p53(RS)-801D and pEGFP-801D were established. Presence of extraneous p53 and neo genes in pEGFP-p53(AS)-801D and pEGFP-p53(RS)-801D was proved by PCR and green fluorescence was found out in those cells under the microscope. Mutant protein in pEGFP-p53(AS)-801D was negative by immunohistochemical stain. The malignant growth of these transfected cell lines was inhibited comparing with parents in vivo and in vitro. Inhibition rate of colony formation was 62.0% for pEGFP-p53(AS)-801D and 80.8% for pEGFP-p53(RS)-801D. The tumorigenicity in nude mice was suppressed. Inhibition effects of extraneous right sense p53 on malignant growth of 801D was more distinct. FCM analysis showed that pEGFP-p53(AS)-801D cells were arrested at G1 phase.</p><p><b>CONCLUSIONS</b>The transfected cell lines with extraneous right sense and antisense p53 appear that malignant growth can be inhibited in vivo and in vitro.</p>