CXCL12 G801A polymorphism is associated with an increased risk of benign salivary gland tumors in the Chinese population

Potential Role of CXCR4 Targeting in the Context of Radiotherapy and Immunotherapy of Cancer

Cancer immunotherapy has been established as standard of care in different tumor entities. After the first reports on synergistic effects with radiotherapy and the induction of abscopal effects-tumor shrinkage outside the irradiated volume attributed to immunological effects of radiotherapy-several treatment combinations have been evaluated. Different immunotherapy strategies (e.g., immune checkpoint inhibition, vaccination, cytokine based therapies) have been combined with local tumor irradiation in preclinical models. Clinical trials are ongoing in different cancer entities with a broad range of immunotherapeutics and radiation schedules. SDF-1 (CXCL12)/CXCR4 signaling has been described to play a major role in tumor biology, especially in hypoxia adaptation, metastasis and migration. Local tumor irradiation is a known inducer of SDF-1 expression and release. CXCR4 also plays a major role in immunological processes. CXCR4 antagonists have been approved for the use of hematopoietic stem cell mobilization from the bone marrow. In addition, several groups reported an influence of the SDF-1/CXCR4 axis on intratumoral immune cell subsets and anti-tumor immune response. The aim of this review is to merge the knowledge on the role of SDF-1/CXCR4 in tumor biology, radiotherapy and immunotherapy of cancer and in combinatorial approaches.

Establishment and characterization of a carcinoma-associated fibroblast cell line derived from a human salivary gland adenoid cystic carcinoma

Salivary gland adenoid cystic carcinoma (SACC) is one of the most common malignancies in the oral and maxillofacial region. Carcinoma-associated fibroblast (CAF) is an important component in the tumor microenvironment and participates in SACC progression. In this study, we established a CAF cell line derived from a human SACC and named it CAF-SA. It was identified that CAF-SA expressed typical CAF biomarkers. Then, we studied the cellular communications between CAF-SA, tumor cells and endothelial cells. It was found that CAF-SA promoted the migration, invasion, and proliferation of SACC tumor cells in vitro. In addition, tube formation by endothelial cells was enhanced by CAF-SA. In vivo experiment showed that SACC cells formed larger xenografts in nude mice when they were transplanted with CAF-SA. Overall, we demonstrated that CAF-SA exhibited the most important defining feature of CAF by promoting cancer progression.

Relationship between rs1801157 polymorphism in stromal cell-derived factor gene and systemic lupus erythematosus risk

Objective

Present meta-analysis was performed to investigate the role of stromal cell-derived factor (SDF-1) gene rs1801157 polymorphism in systemic lupus erythematosus (SLE).

Results

Five publications with 1,087 cases and 1,181 controls were incorporated in this meta-analysis. Overall, a marginal association between SDF-1 rs1801157 polymorphism and reduced SLE risk was found under GA vs. GG model (OR = 0.84, 95% CI = 0.70–1.00). A similar result was also observed in Asian subgroup under the same comparison after stratification analysis by ethnicity (OR = 0.79, 95% CI = 0.63–1.00).

Materials and Methods

All included studies were retrieved from PubMed, EMBASE, Google Scholar Web and Chinese National Knowledge Infrastructure (CNKI). Odds ratios (ORs) with 95% confidence intervals (95% CIs) were calculated to appraise the strength of association between SDF-1 rs1801157 polymorphism and SLE risk. The stratification analysis was also performed according to ethnicity. In addition, heterogeneity was examined with Q test, and sensitivity analysis was used to test the stability of final results. Begg’s funnel plot and Egger’s test were adopted to evaluate publication bias.

Conclusions

SDF-1 rs1801157 polymorphism may not influence the risk of SLE. However, more studies with larger sample sizes involving different populations are needed to further explore this issue.

Analysis of the expression of SDF-1 splicing variants in human colorectal cancer and normal mucosa tissues

C-X-C motif chemokine ligand 12 (CXCL12), also termed stromal cell-derived factor-1 (SDF-1) is a small protein 8-14 kDa in length that is expressed as six isoforms, consisting of SDF-1α, SDF-1β, SDF-1γ, SDF-1δ, SDF-1ε and SDF-1θ. All six isoforms are encoded by the single CXCL12 gene on chromosome 10. This gene regulates leukocyte trafficking and is variably expressed in a number of normal and cancer tissues. The potential role of the novel CXCL12 splice variants as components of the CXCR4 axis in cancer development is not fully understood. The present study aimed to analyze the expression profile of the various SDF-1 isoforms and SDF-1 polymorphisms, and the association with the clinicopathological features and overall survival of patients with colorectal cancer (CRC). SDF-1 polymorphism analysis was performed using restriction fragment length polymorphism (RFLP) analysis in 73 histologically confirmed human CRC tissue samples at various stages of disease. The expression pattern of the SDF-1 isoforms was analyzed by reverse transcription-polymerase chain reaction in 40 histologically confirmed human CRC tissue samples obtained at various stages of disease, as well as in matched adjacent normal mucosa samples. The presence of the CXCL12 gene polymorphism rs1801157 demonstrated an association with local progression of the primary tumor, as indicated by the T stage. The frequency of the GG genotype was slightly increased in patients with stage 3 and 4 tumors (78.0%) compared with the incidence of the GA/AA genotype (69.5%; P=0.067). The expression of SDF-1β was associated with the presence of metastases (P=0.0656) and the expression of SDF-1γ was significantly associated with tumor size (P=0.0423). The present study is the first to analyze the association between the expression profile of the chemokine CXCL12 splice variants in human CRC tissues and their clinical relevance. The present results reveal that the CXCL12 G801A polymorphism is a low-penetrance risk factor for the development of CRC, and was associated with the T stage. All six isoforms of SDF-1 were expressed in CRC tissues. The expression of SDF-1β was found to be associated with metastases and SDF-1γ appears to be a possible tumor marker for local tumor progression.

Genome-wide association study identifies common genetic variants associated with salivary gland carcinoma and its subtypes

BACKGROUND

Salivary gland carcinomas (SGCs) are a rare malignancy with unknown etiology. The objective of the current study was to identify genetic variants modifying the risk of SGC and its major subtypes: adenoid cystic carcinoma and mucoepidermoid carcinoma.

METHODS

The authors conducted a genome-wide association study in 309 well-defined SGC cases and 535 cancer-free controls. A single-nucleotide polymorphism (SNP)-level discovery study was performed in non-Hispanic white individuals followed by a replication study in Hispanic individuals. A logistic regression analysis was applied to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs). A meta-analysis of the results was conducted.

RESULTS

A genome-wide significant association with SGC in non-Hispanic white individuals was detected at coding SNPs in CHRNA2 (cholinergic receptor, nicotinic, alpha 2 [neuronal]) (OR, 8.55; 95% CI, 4.53-16.13 [P = 3.6 × 10(-11)]), OR4F15 (olfactory receptor, family 4, subfamily F, member 15) (OR, 5.26; 95% CI, 3.13-8.83 [P = 3.5 × 10(-10)]), ZNF343 (zinc finger protein 343) (OR, 3.28; 95% CI, 2.12-5.07 [P = 9.1 × 10(-8)]), and PARP4 (poly(ADP-ribose) polymerase family, member 4) (OR, 2.00; 95% CI, 1.54-2.59 [P = 1.7 × 10(-7)]). Meta-analysis of the non-Hispanic white and Hispanic cohorts identified another genome-wide significant SNP in ELL2 (meta-OR, 1.86; 95% CI, 1.48-2.34 [P = 1.3 × 10(-7)]). Risk alleles were largely enriched in mucoepidermoid carcinoma, in which the SNPs in CHRNA2, OR4F15, and ZNF343 had ORs of 15.71 (95% CI, 6.59-37.47 [P = 5.2 × 10(-10)]), 15.60 (95% CI, 6.50-37.41 [P = 7.5 × 10(-10)]), and 6.49 (95% CI, 3.36-12.52 [P = 2.5 × 10(-8)]), respectively. None of these SNPs retained a significant association with adenoid cystic carcinoma.

CONCLUSIONS

To the best of the authors' knowledge, the current study is the first to identify a panel of SNPs associated with the risk of SGC. Confirmation of these findings along with functional analysis of identified SNPs are needed.