The novel gene LRP15 is regulated by DNA methylation and confers increased efficiency of DNA repair of ultraviolet-induced DNA damage.

LRP15 is a novel gene cloned from lymphocytic cells, and its function is still unknown. Bioinformatic data showed that LRP15 might be regulated by DNA methylation and had an important role in DNA repair. In this study, we investigate whether the expression of LRP15 is regulated by DNA methylation, and whether overexpression of LRP15 increases efficiency of DNA repair of UV-induced DNA damage in HeLa cells.

Methylation pattern of LRP15 gene in leukemia.

Objective: To investigate the methylation status of LRP15 gene in acute leukemia (AL) patients and its role in the tumorigenesis.

Methods: The methylation of LRP15 promoter and first exon of bone marrow mononuclear cells in 73 patients with AL, 10 with chronic leukemia (CL), 9 with hematological benign diseases, and 20 healthy transplantation donors was analyzed by using methylation specific polymerase chain reaction. The methylation of LRP15 gene promoter and first exon in COS7, K562, and HL60 cell lines was also assayed.

[Analysis of LRP16 gene promoter activity].

The study was aimed to analyze the characteristics of LRP16 gene promoter and its activity in order to explore the possible regulation mechanism of LRP16 gene expression. A 2.6 kb genomic DNA sequence of LRP16 5'-end was obtained from NCBI by BLAST software.

[Analysis of the methylation in the promoter of LRP15 gene and its expression].

To study the methylation in the promoter of LRP15 gene and its relationship with gene expression and to explore the possible mechanism of regulating LRP15 gene methylation, the methylation in the promoter of LRP15 gene in K562 cell line was detected by MS-PCR. Then K562 was exposed to 5-aza-2'-deoxycytidine (CdR) and trichostatin (TSA), to determine whether the silencing of LRP15 gene by de novo methylation could be reversed. As a result, it was confirmed by MS-PCR that the promoter of LRP15 was hypermathylated in K562 cell line, and lost its transcription activity.

[The methylation pattern of LRP15 gene in acute leukemia].

Objective: To investigate the methylation status of LRP15 gene in acute leukemia (AL) and its role in tumorigenesis.

Methods: 73 cases of AL and 9 healthy subjects as well as COS7, K562 and HL60 cell lines were studied with methylation specific PCR (MSP).

Results: LRP15 was not detected in all the samples.

[Effect of inhibitors for demethylation and histone deacetylase on proliferation of cell line K562 and expression of tumor related genes].

In order to observe the effect of inhibitors for demethylation and histone deacetylase on the growth of leukemia cell line K562 and the expressin of tumor related genes, the K562 cells were treated with 5-aza-2' deoxycytidine (DAC) and trichostatin A (TSA) in co-culture; the growth curves were observed; the cell cycle was detected by flow cytometry (FCM); the gene expression pattern before and after drug treatment was measured with Atlas7742-1 microarray. The results showed that the combination treatment of DAC and TSA inhibited the proliferation of K562 cells, the growth of most cells were stopped in G(1)/S phases after drug treatment, the gene expression after treatment was more than before, and a few gene expression were down-regulated. In conclusion, combination treatment of DAC and TSA had an inhibitive effect on the leukemia cell line K562, combination of DAC and TSA with microarray could be used for screening candidate genes inhibiting leukemia cells.

[Analysis of LRP15 Gene Expression Pattern and Its Expression in Leukemia Cells].

To explore the possible function of LRP15 gene in carcinogenesis and its significance in the classification and prognosis of leukemia, the expression pattern of LRP15 in normal tissues, tumor tissues and cell lines was detected with SAGE and gene expression database provided by NCBI and NCI respectively. RT-PCR was used to detect the expression of LRP15 in leukemia patients. The results showed that LRP15 was expressed in different tissues and tumor cell lines, the positive rate of LRP15 in immature blood cells was higher than that of mature blood cells and the positive rate of M(1), M(2) and M(3) was higher than that of other AML subtypes (P < 0.

[Inhibitory effect of antisense human telomerase reverse transcriptase(hTERT) on telomerase activity of human pulmonary giant cell carcinoma cell line(PLA-801D)].

Background & Objective: Telomerase has been thought to play an important role in the carcinogenesis in recent years. Human telomerase reverse transcriptase (hTERT) is a limiting component for telomerase activity. This study was designed to explore the effect of transfection of the full-length cDNA of antisense hTERT on the malignant phenotype of human pulmonary giant cell carcinoma cell line (PLA-801D) and its potential role in the gene therapy for cancers.

[Cloning of the full length cDNA for a novel leukemia relapse-associated candidate gene LRP15].

To clone the full length cDNA of a novel leukemia relapse-associated candidate gene (LRP15), the human ESTs (Expression Sequence Tags) fragments obtained from electronic hybridization were assembled by a 1.8 kb DNA probe, which was only methylated in relapsed leukemia. Then the primers were designed for rapid amplification of cDNA end (RACE).