[Inhibitory effect of p53 with deletion of c-terminal 356 - 393 amino acids on malignant phenotype of human lung cancer cell line].
OBJECTIVE
To study the effect of extraneous p53 gene with deletion of c-terminal 356 - 393 amino acids on inhibition of malignant phenotype of human lung cancer cell line.


METHODS
Recombinant plasmid pEGFP-p53 (del) with codon deletion of c-terminal 37 amino acids from 393 to 356 region and pEGFP-p53 (wild type) were constructed. The human lung cancer cell line 801D served as a receipt cell had p53 deletion and mutation at 248 codon. 801D cells, having been transfected by pEGFP-p53 (wild type), pEGFP-p53 (del) or pEGFP, were selected by G418. Growing transfected cells were cloned respectively by method of dilution. Presence of extraneous gene was detected by PCR, their expression in cells was examined by fluorescence microscopy. Cloning efficiency was in vitro tested to examine the cellular proliferating ability. The xenograft in nude mice was performed and xenograft tumors were weighed one month later. Expression of GFP in tumor and transplanted cellular mass were detected by blot slices.


RESULTS
pEGFP-p53 (del)-801D, pEGFP-p53-801D and pEGFP-801D were established. Extraneous p53 gene and expression of GFP were found in pEGFP-p53 (del)-801D and pEGFP-p53-801D. Inhibitory rate of colony was 99.6% for pEGFP-p53 (del)-801D and 81.0% for pEGFP-p53-801D. Inhibition of malignant proliferation of extraneous p53 (del) was higher than that of p53 (wild type) (P < 0.01). Even when inhibition of malignant proliferation extraneous pEGFP-p53 (del) was obvious, 0.2% colonies were formed, extraneous p53 and expression of GFP were observed. Animal test showed that tumor on the nude mice was positive (4/4, 4/4) in the control group (801D and pEGFP-801D), but negative (0/4, 0/4) in the experiment group [pEGFP-p53 (del) 801D and pEGFP-p53 (wild type) 801D]. Expression of GFP in the cells of cellular mass transplanted by pEGFP-p53 (del) 801D or pEGFP-p53 (wild type) 801D was observed.


CONCLUSIONS
In vitro inhibitory effect of extraneous p53 gene with deletion of C-terminal 356 - 393 amino acids on malignant growth of lung cancer cell with p53 mutation or deletion at 248 codon is marked. Inhibitory action of p53 on malignant proliferation of cancer cells is heterogeneous.
Wang
Hui
H
Laboratory of Cell-molecular Biology, Beijing Thoracic Tumor Research Institute, Beijing 101149, China.
Li
Jin-zhao
JZ
Lai
Bai-tang
BT
Yang
Xue-hui
XH
Zhang
Chun-yan
CY
Yue
Wen-tao
WT
Zhan
Xiu-ping
XP
D000818:Animals; D002453:Cell Cycle; D045744:Cell Line, Tumor; D016158:Genes, p53; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000473:pathology*; D051379:Mice; D009154:Mutation; D010641:Phenotype; D013329:Structure-Activity Relationship; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry* / Q000502:physiology*
D016159:Tumor Suppressor Protein p53