Expression and significance of miR-21 in multiple myeloma patients

The aim of the present study is to examine the expression level of peripheral mir-21 in multiple myeloma (MM) patients and to determine its clinical significance. MM patients (30), monoclonal gammopathy of undetermined significance (MGUS) patients (14), and normal controls (20) were recruited to determine the serum level of β2-MG, IgA and IgM, IgG, λ, κ, TP, ALB, Hb, LDH, and Ca(2+). Gene expression of mir-21 was quantified by SYBR green real-time fluorescent quantitative PCR. We found that the expression level of serum mir-21 in the MM group was significantly higher than the MGUS group and the NC group (P < 0.01). According to the ISS installment, the level of mir-21, lgG, κ, and ALB in the MM group in stage I differed from that in stages II and III. The level of IgA, β2-MG in stage III was higher as compared with stage I and II (P < 0.05 and P < 0.01).The levels of mir-21, κ, (κ+λ), IgG, (IgG + IgA + IgM), and β2-MG in MM patients were positively correlated with ALB (P < 0.01). Based on the results, miR-21 plays an important role as an oncogene. Mir-21 may be important in the occurrence, development, and disease prognosis of MM.

Lack of association between LIG4 gene polymorphisms and the risk of breast cancer: a HuGE review and meta-analysis

OBJECTIVE

Non-homologous end joining (NHEJ) is one of the pathways of repair of DNA double-strand breaks. A number of genes involved in NHEJ have been implicated as breast cancer susceptibility genes such as LIG4. However, some studies have generated conflicting results. The aim of this Human Genome Epidemiology (HuGE) review and meta-analysis was to investigate association between LIG4 gene polymorphisms in the NHEJ pathway and breast cancer risk.

METHODS

Studies focusing on the relationship between LIG4 gene polymorphisms and susceptibility to breast cancer were selected from the Pubmed, Cochrane library, Embase, Web of Science, Springerlink, CNKI and CBM databases. Data were extracted by two independent reviewers and the meta-analysis was performed with Review Manager Version 5.1.6 and STATA Version 12.0 software, calculating odds ratios (ORs) with 95% confidence intervals (95%CIs).

RESULTS

According to the inclusion criteria, we final included seven studies with a total of 10,321 breast cancer cases and 10,160 healthy controls in the meta-analysis. The results showed no association between LIG4 gene polymorphisms (rs1805386 T>C, rs1805389 C>T, rs1805388 C>T and rs2232641 A>G) and breast cancer risk, suggesting that the mutant situation of these SNPs neither increased nor decreased the risk for breast cancer. In the subgroup analysis by Hardy-Weinberg equilibrium (HWE) and ethnicity, we also found no associations between the variants of LIG4 gene and breast cancer risk among HWE, non-HWE, Caucasians, Asians and Africans.

CONCLUSION

This meta-analysis suggests that there is a lack of any association between LIG4 gene polymorphisms and the risk of breast cancer.

Genetic variants of CYP2D6 gene and cancer risk: a HuGE systematic review and meta-analysis

OBJECTIVE

Genetic polymorphisms in metabolic enzymes are associated with numerous cancers. A large number of single nucleotide polymorphisms (SNPs) in the CYP2D6 gene have been reported to associate with cancer susceptibility. However, the results are controversial. The aim of this Human Genome Epidemiology (HuGE) review and meta-analysis was to summarize the evidence for associations.

METHODS

Studies focusing on the relationship between CYP2D6 gene polymorphisms and susceptibility to cancer were selected from the Pubmed, Cochrane library, Embase, Web of Science, Springerlink, CNKI and CBM databases. Data were extracted by two independent reviewers and the meta-analysis was performed with Review Manager Version 5.1.6 and STATA Version 12.0 software. Odds ratios (ORs) with 95% confidence intervals (95%CIs) were calculated.

RESULTS

According to the inclusion criteria, forty-three studies with a total of 7,009 cancer cases and 9,646 healthy controls, were included in the meta-analysis. The results showed that there was a positive association between heterozygote (GC) of rs1135840 and cancer risk (OR=1.92, 95%CI: 1.14-3.21, P=0.01). In addition, we found that homozygote (CC) of rs1135840 might be a protective factor for cancer (OR=0.58, 95%CI: 0.34-0.97, P=0.04). Similarly, the G allele and G carrier (AG + GG) of rs16947 and heterozygote (A/del) of rs35742686 had negative associations with cancer risk (OR=0.69, 95%CI: 0.48-0.99, P=0.04; OR=0.60, 95%CI: 0.38-0.94, P=0.03; OR=0.50, 95%CI: 0.26-0.95, P=0.03; respectively).

CONCLUSION

This meta-analysis suggests that CYP2D6 gene polymorphisms are involved in the pathogenesis of various cancers. The heterozygote (GC) of rs1135840 in CYP2D6 gene might increase the risk while the homozygote (CC) of rs1135840, G allele and G carrier (AG + GG) of rs16947 and heterozygote (A/del) of rs35742686 might be protective factors.

Association between XRCC5, 6 and 7 gene polymorphisms and the risk of breast cancer: a HuGE review and meta-analysis

OBJECTIVE

Non-homologous end joining (NHEJ) is a pathway for repairing DNA double-strand breaks. Recent publications indicated that XRCC5, XRCC6 and XRCC7 genes may participate in the pathogenesis of breast cancer. The aim of this Human Genome Epidemiology (HuGE) review and meta-analysis was to investigate associations between XRCC5, XRCC6 and XRCC7 genetic polymorphisms in the NHEJ pathway and breast cancer risk.

METHODS

Studies focusing on the relationship between genetic polymorphisms in XRCC5, XRCC6 and XRCC7 genes and susceptibility to breast cancer were selected from the Pubmed, Cochrane library, Embase, Web of Science, Springerlink, CNKI and CBM databases. Data were extracted by two independent reviewers. The meta-analysis was performed with Review Manager Version 5.1.6 and STATA Version 12.0 software. The odds ratio (OR) with 95% confidence interval (95%CI) was calculated based on the extracted data.

RESULTS

According to the inclusion criteria, we final included seven studies with a total of 2,864 breast cancer cases and 3,060 healthy controls. Meta-analysis results showed that rs3835 (G>A) and rs828907 (G>T) in XRCC5 gene, and rs132793 (G>A) in XRCC6 gene might increase the risk of breast cancer, while rs132788 G>T and rs6002421 (A>G) might be protective factors. However, there was no relationship between XRCC7 genetic polymorphisms and the risk of breast cancer.

CONCLUSION

This meta-analysis suggests that the rs3835 G>A and rs828907 G>T in XRCC5 gene, rs6002421 (A>G), rs132788 (G>T) and rs132793 (G>A) in XRCC6 gene might be risk factors for breast cancer, while the rs132788 (G>T) and rs6002421 (A>G) in XRCC6 gene might be protective.

Vascular endothelial growth factor gene polymorphisms and colorectal cancer risk: a meta-analysis

Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen involved in a number of pathologic processes, including angiogenesis, tumor growth and metastasis. Polymorphisms of the VEGF gene have been associated with susceptibility to colorectal cancer (CRC). However, the specific association still remains controversial. We made a meta-analysis of the association between VEGF gene polymorphisms and CRC risk. Only eight case-control studies were retrieved, with a total of 2337 CRC patients and 2032 healthy controls. Six VEGF gene polymorphisms were addressed in all studies included, +936C>T (rs3025039), -2578C>A (rs699947), -1154G>A (rs1570360), -634G>C (rs2010963), -460C>T (rs833061), and +405C>G (rs2010963). There was a significant association between -2578C>A polymorphism and susceptibility to CRC in the comparison of C allele carriers (CC + CA) versus AA (odds ratio = 0.77, 95% confidence interval = 0.62-0.96, P = 0.02). No association was found between +936C>T, -1154G>A, -634G>C, -460C>T, and +405C>G with susceptibility to CRC. We conclude that the C allele carrier (CC + CA) of VEGF -2578C>A polymorphism appears to be a protective factor for CRC.

Vascular endothelial growth factor +936C/T polymorphism and gastric cancer risk: A meta-analysis

The aim of this study was to determine whether the vascular endothelial growth factor (VEGF) +936C/T polymorphism confers susceptibility to gastric cancer (GC) by conducting a meta-analysis. Publications addressing the association between the VEGF +936C/T polymorphism and GC risk were selected from the Pubmed, Embase and CBM databases. Data were extracted from the studies by two independent reviewers. The meta-analysis was performed using RevMan 5.0.25 and STATA 9.2 software. From these data, the odds ratio (OR) with 95% confidence interval (CI) was calculated. Finally, 8 case-control studies were retrieved reporting a total of 2,131 gastrointestinal cancer patients and 2,670 controls. Meta-analysis results showed that there was no significant association between the VEGF +936C/T polymorphism and GC risk in all comparisons of the T allele vs. C allele (OR=1.08, 95% CI 0.90-1.30, P=0.42), CT+TT vs. CC (OR=1.08, 95% CI 0.87-1.34, P=0.49), TT vs. CC+CT (OR=1.14, 95% CI 0.85-1.53, P=0.37), TT vs. CC (OR=1.18, 95% CI 0.87-1.59, P=0.28) and TT vs. CT (OR=1.11, 95% CI 0.79-1.56, P=0.56). This meta-analysis confirms that there is a lack of association between the VEGF +936C/T polymorphism and GC risk.