CXCL12 G801A polymorphism and breast cancer risk: a meta-analysis

Association of the SNPs in CCL2 and CXCL12 genes with the susceptibility to breast cancer: a case-control study in China

Background

Chemokines are well-known for playing an essential role in the development of cancer. However, the association between SNPs in the CCL2 and CXCL12 genes and the susceptibility to breast cancer remains unclear.

Methods

A case-control study was conducted in southeast China, including 1855 breast cancer patients and 1838 cancer-free controls. The association between single nucleotide polymorphisms (SNPs) in the CCL2 and CXCL12 genes and the susceptibility to breast cancer was investigated using logistic regression models. The association between plasma CCL2 and CXCL12 with breast cancer was further examined in 72 patients and 75 controls.

Results

The CXCL12 SNP rs3740085 was associated with breast cancer in the additive model (OR=1.15, 95%CI=1.01-1.32), particularly in postmenopausal women. The association between rs1024611 in CCL2 and breast cancer was only found in women with a BMI of ≥24kg/m2. SNPs in the CCL2 gene were mainly associated with PR-positive breast cancer, whereas rs1144471 in CXCL12 was associated with ER-negative (OR=0.43, 95% CI=0.23-0.84), PR-negative (OR=0.38, 95% CI=0.19-0.74), and HER-2-positive (OR=1.27, 95% CI=1.03-1.56) breast cancer. The interaction between rs1801157 and rs3740085 in CXCL12 SNPs was statistically significant, and rs3740085 was also associated with breast cancer survival. Additionally, we found a strong association between plasma CXCL12 and breast cancer.

Conclusion

CCL2 and CXCL12 SNPs are associated with breast cancer susceptibility in overweight and postmenopausal women, and the effect varies according to subtypes. The interaction of SNPs within CXCL12 gene and the association with breast cancer survival further suggest potential targets for improved risk assessment and treatment strategies.

Associations of CXCL12 polymorphisms with clinicopathological features in breast cancer: a case-control study

BACKGROUND

Previous studies suggested that CXCL12 was involved in the development, metastasis, and invasion of breast cancer, and genetic variants were associated with the diagnosis and prognosis of patients with breast cancer. The present study was aimed to assess the relationships between CXCL12 polymorphisms (rs1801157, rs2297630, and rs2839693) and susceptibility and clinicopathological features of breast cancer.

METHODS

A case-control study was conducted in 434 breast cancer patients and 450 health controls. Student t-test and chi-square test were used to analyze the differences of age distribution and genotype frequencies between the two groups. Correlations between polymorphisms and clinical parameters were also assessed by chi-square test. The potential effects of the three polymorphisms on CXCL12 were investigated by the public database.

RESULTS

A statistical association was found between CXCL12 rs1801157 polymorphism and breast cancer risk, possibility of metastasis, and estrogen receptor status. Patients with rs2839693 C/T or C/T-T/T genotypes were more likely to be progesterone receptor-negative. However, no associations of rs2297630 polymorphism with breast cancer risk or any clinicopathological characteristics were observed. In addition, rs2297630 affected the splicing quantitative trait loci of CXCL12 in the subcutaneous fat, rs2839693 polymorphism affected the splicing quantitative trait loci of CXCL12 in the human breast mammary tissues.

CONCLUSIONS

Those results indicated that CXCL12 polymorphisms might be potential diagnostic indicators, and more investigation is needed in the future.

Stromal cell derived factor-1, CXCR4 and CXCR7 gene transcripts in pterygia

PURPOSE

Pterygium is a pathologic process with angiogenic and tumor cell like characteristics. Chemokine and chemokine receptors may contribute to the formation and growth of pterygia. The aim of this study was to assess the expression of stromal cell derived factor (SDF)-1, as an angiogenic chemokine, and its receptors, CXCR4 and CXCR7, gene transcripts in pterygia.

METHODS

RNA was extracted from tissue samples of 33 patients with primary pterygium and 35 volunteers with conjunctiva as the control group. Then the mRNA expression of SDF-1, CXCR4, and CXCR7 was assessed through quantitative Real Time PCR method using appropriate primers.

RESULTS

SDF-1 and both receptors transcripts had significantly higher expression in pterygia samples compared to the control group (P < 0.05). The ratio of CXCR7 transcript expression to CXCR4 was 26.4 in patients while it was 11 in controls.

CONCLUSION

As SDF-1 and its receptors, CXCR4 and CXCR7, were up-regulated in pterygia, SDF-1/CXCR4/CXCR7 axis may contribute to pterygium formation which can be possibly restrained by down-regulating this signaling pathway.

CCR2-64I polymorphism is associated with Non-Small Cell Lung Cancer in Tunisian patients

Single nucleotide polymorphism (SNPs) in genes coding for chemokines may be associated with some cancer. The purpose of this study was to investigate the impact of CCR2-64I and CXCL12-3'A SNPs on the susceptibility and the clinicopathological characteristics of NSCLC (Non-Small Cell Lung Cancer) in the Tunisian population. 170 NSCLC patients and 225 healthy controls screened by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis were enrolled. A significant association for the homozygous genotype CCR2 64I/64I with lung cancer risk was observed (P=0.004). An increased significant frequency of the -64I allele (P=0.0006) was noted in the patient's group. Clinical analysis indicated a positive association of the -64I allele among squamous cell lung carcinoma patients (P=0.003). The CCR2 mRNA extracted from peripheral blood mononuclear cells (PBMC) was found highly expressed in NSCLC patients compared to controls. The same higher levels were found in patients carrying the CCR2 64I/64I genotype. No significant association was retrieved with CXCL12-3'A polymorphism. In conclusion, our results revealed that the subjects with -64I allele of CCR2-64I gene polymorphism, expressed a significantly higher risk for NSCLC risk without influence on its pathological progression.

The G801A polymorphism in the CXCL12 gene and risk of breast carcinoma: evidence from a meta-analysis including 2,931 subjects

More and more evidence indicates that the G801A polymorphism in the CXCL12 gene might be associated with susceptibility to breast carcinoma in humans being. However, individually published results have been inconsistent. The purpose of this meta-analysis was to investigate the association between the G801A polymorphism in the CXCL12 gene and breast carcinoma risk. A complete search strategy was done by the electronic databases including PubMed and Chinese Biomedical Literature Database. A meta-analysis including seven individual studies was carried out in order to explore the association between the G801A polymorphism in the CXCL12 gene polymorphisms and breast carcinoma. The pooled odds ratios (ORs) and their corresponding 95% confidence intervals (95%CIs) between the G801A polymorphism in the CXCL12 gene and breast carcinoma risk were assessed by the random-effects model. A significant relationship between the G801A polymorphism in the CXCL12 gene and breast carcinoma was discovered in an allelic genetic model (OR: 1.214, 95%CI: 1.085- 1.358, p=0.001), a homozygote model (OR: 1.663, 95%CI: 1.240-2.232, p=0.001), a heterozygote model (OR: 1.392, 95%CI: 1.190-1.629, p=0.000), a recessive genetic model (OR: 1.407, 95%CI: 1.060-1.868, p=0.018) and a dominant genetic model (OR: 1.427, 95%CI: 1.228-1.659, p=0.000). On sub-group analysis based on ethnicity, significance was observed between the European group and the mixed group. A significant relationship was found between the G801A polymorphism in the CXCL12 gene and breast carcinoma risk. Individuals with the A allele of the G801A polymorphism in the CXCL12 gene are under a higher risk for breast carcinoma.

MMP-2 -1306C>T polymorphism in breast cancer: a case-control study in a South European population

This case control study aims to investigate the role of MMP-2 -1306C>T polymorphism as a potential risk factor and possible prognostic marker for breast cancer in a South European population. 113 consecutive incident cases of histologically confirmed ductal breast cancer and 124 healthy controls were recruited. MMP-2 -1306C>T polymorphism was genotyped; multivariate logistic regression as well as Cox regression analysis were performed. MMP-2 -1306C>T status was not associated with breast cancer risk either at the total sample or at the subanalyses on premenopausal and postmenopausal women. At the survival analysis, a trend towards a favorable association between MMP-2 -1306C>T allele and disease-free survival as well as overall survival was observed. Regarding subanalyses on ER-negative and ER-positive cases, the favorable association implicating MMP-2 -1306C>T allele was particularly evident among ER-positive cases; no significant associations emerged among ER-negative cases. MMP-2 -1306C>T polymorphism does not seem to be a risk factor for breast cancer in South European population; however, a trend towards a favorable association with survival has been observed.

HTERT MNS16A polymorphism in breast cancer: a case-control study

This case-control study aims to investigate the role of HTERT MNS16A polymorphism as a potential risk factors and/or a prognostic marker for breast cancer. 113 consecutive incident cases of histologically confirmed ductal breast cancer and 124 healthy controls were recruited. HTERT MNS16A polymorphism was genotyped (L: long allele, S: short allele); multivariate logistic regression was performed. No significant association was noted either at the overall analysis (OR = 1.57, 95 % CI 0.84-2.93 for heterozygous LS carriers; OR = 1.02, 95 % CI 0.54-1.95 for homozygous SS carriers) or at the subanalyses in premenopausal and postmenopausal women. With respect to survival analysis, HTERT MNS16A polymorphism was not associated with either disease-free survival or overall survival. HTERT MNS16A polymorphism does not seem to be a risk factor for breast cancer in the Caucasian Greek population. Further, larger studies from other countries and subjects seem to be needed as this novel polymorphism is being examined in depth.

HSP90, HSPA8, HIF-1 alpha and HSP70-2 polymorphisms in breast cancer: a case-control study

This case control study aims to investigate the role of HSP90 Gln488His (C > G), HSP70-2 P1/P2, HIF-1 alpha C1772T and HSPA8 intronic 1541-1542delGT polymorphisms as potential risk factors and/or prognostic markers for breast cancer. 113 consecutive incident cases of histologically confirmed ductal breast cancer and 124 healthy cases were recruited. The above mentioned polymorphisms were genotyped; multivariate logistic regression was performed. HSP90 GG (His/His) genotype was associated with elevated breast cancer risk. Similarly, the allele dose-response model pointed to increase in breast cancer risk per G allele. HSP70-2 P1/P2, HSPA8 intronic 1541-1542delGT and HIF-1 alpha polymorphisms were not associated with breast cancer risk, as evidenced by the dose-response allele models. The positive association between HSP90 G allele and breast cancer risk seemed to pertain to both premenopausal and postmenopausal women. With respect to survival analysis, none of the aforementioned polymorphisms was associated with either disease-free survival or overall survival. HSP90α Gln488His polymorphism seems to be a risk factor for breast cancer. On the other hand, our study did not point to excess risk conferred by HSPA8 1541-1542delGT, Hsp70-2 P1/P2 and HIF-1α C1772T.

The CXCL12 G801A polymorphism and cancer risk: evidence from 17 case-control studies

CXCL12 has been implicated in human carcinogenesis, but the association between the most-studied G801A polymorphism (rs1801157) and the risk of various cancers was reported with inconclusive results. The aim of this study was to assess the association between the CXCL12 G801A polymorphism and cancer risk. A meta-analysis of 17 studies with 3048 cancer patients and 4522 controls was conducted to evaluate the strength of the association using odds ratio (OR) with its 95% confidence interval (CI). The overall results showed that the variant genotypes were associated with a significantly increased risk of all cancer types (OR=1.38, 95%CI=1.18-1.61 for GA versus GG, and OR=1.36, 95%CI=1.17-1.59 for GA/AA versus GG). In the stratified analyses, there was a significantly increased risk for the studies of breast cancer (OR=1.64, 95% CI=1.16-2.33 for AA versus GG, OR=1.42, 95%CI=1.18-1.71 for GA versus GG, and OR=1.44, 95%CI=1.21-1.72 for GA/AA versus GG) and lung cancer (OR=2.86, 95% CI=1.75-4.69 for AA versus GG, OR=1.62, 95% CI=1.20-2.18 for GA vs. GG, OR=1.80, 95% CI=1.36-2.39 for GA/AA versus GG, and OR=2.24, 95%CI=1.41-3.57 for AA versus GA/GG), which remained for the studies of Asian populations and hospital-based control sources. Although some modest bias could not be eliminated, this meta-analysis indicates that the CXCL12 G801A polymorphism is a low-penetrance risk factor for cancer development.

Genetically determined inflammatory-response related cytokine and chemokine transcript profiles between mammary carcinoma resistant and susceptible rat strains

Multiple human breast and rat mammary carcinoma susceptibility (Mcs) alleles have been identified. Wistar Kyoto (WKY) rats are resistant to developing mammary carcinomas, while Wistar Furth (WF) females are susceptible. Gene transcripts at Mcs5a1, Mcs5a2, and Mcs5c are differentially expressed between resistant WKY and susceptible WF alleles in immune-system tissues. We hypothesized that immune-related gene transcript profiles are genetically determined in mammary carcinoma resistant and susceptible mammary glands. Low-density QPCR arrays were used to compare inflammation related genes between mammary carcinoma resistant WKY and susceptible WF females. Mammary gland gene transcript levels predicted to be different based on arrays were tested in independent samples. In total, 20 females per strain were exposed to 7,12-dimethylbenz(a)anthracene (DMBA) to induce mammary carcinogenesis. Twelve age-matched controls per strain without DMBA were included to determine main effects of DMBA-exposure. Significant (ANOVA P ≤ 0.01) effects of strain on mammary gland transcript level were observed for Cx3cl1, Il11ra, Il4, C3, Ccl20, Ccl11, Itgb2, Cxcl12, and Cxcr7. Significant effects of DMBA-exposure were observed for Cx3cl1, Il11ra, Cxcr4, Il4ra, and Il4. Strain and DMBA-exposure interaction effects were significant for Cx3cl1. Transcript levels of Cxcr7 relative to Cxcr4 were modified differently by DMBA in mammary carcinoma resistant and susceptible strains. In conclusion, several genetically-determined differences in cytokine, chemokine, and receptor gene transcript levels were identified between mammary carcinoma susceptible and resistant mammary glands, which may be indicative of cell populations and activities that suppress mammary carcinogenesis in resistant genotypes.