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Influence of CCND1 G870A polymorphism on the risk of HBV-related HCC and cyclin D1 splicing variant expression in Chinese population.

Zeng Z, Tu J, Cheng J, Yao M, Wu Y, Huang X, Xie X, Zhang X, Lu F, Chen X - Tumour Biol. (2015)

Bottom Line: The expression of both cyclins D1a and D1b decreased in HCC tissues (p = 0.003, p = 0.005), while increased in adjacent nontumor tissues as compared with normal liver tissues (p = 0.045, p = 0.034).Collectively, our data suggest that G870A polymorphism has only very limited predictive value for HBV-related HCC.Both cyclins D1a and D1b could promote cell proliferation, which might contribute to the potential oncogenic role of cyclin D1 variants during the precancerous cirrhotic stage of hepatocarcinogenesis.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Infectious Disease Center, School of Basic Medical Science, Peking University Health Science Center, 38 Xueyuan Road, Beijing, 100191, China.

ABSTRACT
The G870A polymorphism in the exon 4/intron 4 boundary of CCND1 gene is thought to influence the generation of two mRNAs (cyclin D1a and cyclin D1b). The "A" allele codes for a truncated variant, cyclin D1b, which may have higher transforming activity. Herein, the tumor relevance of G870A polymorphism, the association between cyclin D1 variant expression and G870A genotype, and the oncogenic potential of cyclin D1 variants in HBV-related hepatocellular carcinoma (HCC) were examined. We found that there is no significant difference of G870A distribution among the HCC, chronic HBV (CHB) infection, cirrhotic CHB, and healthy control groups. Stratification analysis revealed that in younger patients (ages ≤ 50), cirrhotic CHB patients with AA genotype had an increased risk of developing HCC with odds ratio of 1.943 (95 % CI 1.022-3.694, p = 0.0411) as compared with AG/GG genotypes. The two variants were both transcripted from "A" and "G" alleles, and neither cyclin D1a nor D1b production was influenced by G870A genotype in HCC. The expression of both cyclins D1a and D1b decreased in HCC tissues (p = 0.003, p = 0.005), while increased in adjacent nontumor tissues as compared with normal liver tissues (p = 0.045, p = 0.034). Overexpression of cyclin D1a or D1b could promote the cell proliferation and cell-cycle progression in Huh-7 and LO2 cell lines. Collectively, our data suggest that G870A polymorphism has only very limited predictive value for HBV-related HCC. Both cyclins D1a and D1b could promote cell proliferation, which might contribute to the potential oncogenic role of cyclin D1 variants during the precancerous cirrhotic stage of hepatocarcinogenesis.

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The effect of G870A genotype on the expression of cyclin D1 variants in HCC tissues. The expression of cyclin D1 variants in 17 genotyped HCC tissues was detected by real-time PCR. The expression of cyclin D1a (a) or D1b (b) in HCC tissues with AA genotype (n = 9) was compared to GG genotype (n = 8). The housekeeping gene CTBP1 was used to normalize the expression levels of cyclin D1a and cyclin D1b. Each sample was tested in triplicate in two separate experiments
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Fig1: The effect of G870A genotype on the expression of cyclin D1 variants in HCC tissues. The expression of cyclin D1 variants in 17 genotyped HCC tissues was detected by real-time PCR. The expression of cyclin D1a (a) or D1b (b) in HCC tissues with AA genotype (n = 9) was compared to GG genotype (n = 8). The housekeeping gene CTBP1 was used to normalize the expression levels of cyclin D1a and cyclin D1b. Each sample was tested in triplicate in two separate experiments

Mentions: Previous studies have provided evidence that G870A polymorphism may influence the expression levels of cyclin D1a and D1b [17, 18]. To address the contribution of G870A genotype to the production of cyclin D1 isoforms in HCC, we used two independent approaches. Initially, we sequenced the G870A polymorphism in the HCC tissues and compared the expressions of cyclin D1a or cyclin D1b in AA and GG genotype tissues. The results showed that in both HCC tumor and nontumor tissues, the expression of cyclin D1a had no significant difference between AA and GG genotype tissues (p = 0.6730 and p = 0.8742, respectively; Fig. 1a). Similar results were obtained from cyclin D1b expression (p = 0.5054 and p = 0.2345, respectively; Fig. 1b). These results suggested that neither cyclin D1a nor D1b production was influenced by G870A genotype in HCC. To support this notion, we then examined the distribution of “A” or “G” alleles in cyclin D1a and cyclin D1b transcripts by clone sequencing analysis in human HCC cell lines Huh-1 and Huh-7, which were identified as AG heterozygous at the 870 locus by genotyping. For this experiment, the fragment of cyclin D1a or cyclin D1b containing 870 locus was amplified from the cDNA of Huh-1 and Huh-7 cell lines by PCR assay with the specific primers of each variant. After PCR amplification, the PCR products were cloned into TA vector and a total of 20 clones of each transcript were randomly picked up for sequencing. If A allele promoted cyclin D1b production, we predicted that the cyclin D1a transcript from AG heterozygous cells should contain more G allele and cyclin D1b transcript should contain more A allele. However, the clone sequencing analysis failed to detect the preference of A allele for cyclin D1b transcript since both cyclin D1a and cyclin D1b transcripts had more G alleles than A alleles in these AG heterozygous cells. Instead, in these two cells, the percentage of clones with G allele was higher than that with A allele in both cyclins D1a and D1b transcripts (Table 3). Taken together, these findings suggested that the two variants of cyclin D1 were both transcripted from A and G alleles, while G allele may have higher transcript efficiency than A allele in liver tissues.Fig. 1


Influence of CCND1 G870A polymorphism on the risk of HBV-related HCC and cyclin D1 splicing variant expression in Chinese population.

Zeng Z, Tu J, Cheng J, Yao M, Wu Y, Huang X, Xie X, Zhang X, Lu F, Chen X - Tumour Biol. (2015)

The effect of G870A genotype on the expression of cyclin D1 variants in HCC tissues. The expression of cyclin D1 variants in 17 genotyped HCC tissues was detected by real-time PCR. The expression of cyclin D1a (a) or D1b (b) in HCC tissues with AA genotype (n = 9) was compared to GG genotype (n = 8). The housekeeping gene CTBP1 was used to normalize the expression levels of cyclin D1a and cyclin D1b. Each sample was tested in triplicate in two separate experiments
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4644212&req=5

Fig1: The effect of G870A genotype on the expression of cyclin D1 variants in HCC tissues. The expression of cyclin D1 variants in 17 genotyped HCC tissues was detected by real-time PCR. The expression of cyclin D1a (a) or D1b (b) in HCC tissues with AA genotype (n = 9) was compared to GG genotype (n = 8). The housekeeping gene CTBP1 was used to normalize the expression levels of cyclin D1a and cyclin D1b. Each sample was tested in triplicate in two separate experiments
Mentions: Previous studies have provided evidence that G870A polymorphism may influence the expression levels of cyclin D1a and D1b [17, 18]. To address the contribution of G870A genotype to the production of cyclin D1 isoforms in HCC, we used two independent approaches. Initially, we sequenced the G870A polymorphism in the HCC tissues and compared the expressions of cyclin D1a or cyclin D1b in AA and GG genotype tissues. The results showed that in both HCC tumor and nontumor tissues, the expression of cyclin D1a had no significant difference between AA and GG genotype tissues (p = 0.6730 and p = 0.8742, respectively; Fig. 1a). Similar results were obtained from cyclin D1b expression (p = 0.5054 and p = 0.2345, respectively; Fig. 1b). These results suggested that neither cyclin D1a nor D1b production was influenced by G870A genotype in HCC. To support this notion, we then examined the distribution of “A” or “G” alleles in cyclin D1a and cyclin D1b transcripts by clone sequencing analysis in human HCC cell lines Huh-1 and Huh-7, which were identified as AG heterozygous at the 870 locus by genotyping. For this experiment, the fragment of cyclin D1a or cyclin D1b containing 870 locus was amplified from the cDNA of Huh-1 and Huh-7 cell lines by PCR assay with the specific primers of each variant. After PCR amplification, the PCR products were cloned into TA vector and a total of 20 clones of each transcript were randomly picked up for sequencing. If A allele promoted cyclin D1b production, we predicted that the cyclin D1a transcript from AG heterozygous cells should contain more G allele and cyclin D1b transcript should contain more A allele. However, the clone sequencing analysis failed to detect the preference of A allele for cyclin D1b transcript since both cyclin D1a and cyclin D1b transcripts had more G alleles than A alleles in these AG heterozygous cells. Instead, in these two cells, the percentage of clones with G allele was higher than that with A allele in both cyclins D1a and D1b transcripts (Table 3). Taken together, these findings suggested that the two variants of cyclin D1 were both transcripted from A and G alleles, while G allele may have higher transcript efficiency than A allele in liver tissues.Fig. 1

Bottom Line: The expression of both cyclins D1a and D1b decreased in HCC tissues (p = 0.003, p = 0.005), while increased in adjacent nontumor tissues as compared with normal liver tissues (p = 0.045, p = 0.034).Collectively, our data suggest that G870A polymorphism has only very limited predictive value for HBV-related HCC.Both cyclins D1a and D1b could promote cell proliferation, which might contribute to the potential oncogenic role of cyclin D1 variants during the precancerous cirrhotic stage of hepatocarcinogenesis.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Infectious Disease Center, School of Basic Medical Science, Peking University Health Science Center, 38 Xueyuan Road, Beijing, 100191, China.

ABSTRACT
The G870A polymorphism in the exon 4/intron 4 boundary of CCND1 gene is thought to influence the generation of two mRNAs (cyclin D1a and cyclin D1b). The "A" allele codes for a truncated variant, cyclin D1b, which may have higher transforming activity. Herein, the tumor relevance of G870A polymorphism, the association between cyclin D1 variant expression and G870A genotype, and the oncogenic potential of cyclin D1 variants in HBV-related hepatocellular carcinoma (HCC) were examined. We found that there is no significant difference of G870A distribution among the HCC, chronic HBV (CHB) infection, cirrhotic CHB, and healthy control groups. Stratification analysis revealed that in younger patients (ages ≤ 50), cirrhotic CHB patients with AA genotype had an increased risk of developing HCC with odds ratio of 1.943 (95 % CI 1.022-3.694, p = 0.0411) as compared with AG/GG genotypes. The two variants were both transcripted from "A" and "G" alleles, and neither cyclin D1a nor D1b production was influenced by G870A genotype in HCC. The expression of both cyclins D1a and D1b decreased in HCC tissues (p = 0.003, p = 0.005), while increased in adjacent nontumor tissues as compared with normal liver tissues (p = 0.045, p = 0.034). Overexpression of cyclin D1a or D1b could promote the cell proliferation and cell-cycle progression in Huh-7 and LO2 cell lines. Collectively, our data suggest that G870A polymorphism has only very limited predictive value for HBV-related HCC. Both cyclins D1a and D1b could promote cell proliferation, which might contribute to the potential oncogenic role of cyclin D1 variants during the precancerous cirrhotic stage of hepatocarcinogenesis.

Show MeSH
Related in: MedlinePlus