Genetic polymorphisms in the osteopontin promoter increases the risk of distance metastasis and death in Chinese patients with gastric cancer

Decoding SPP1 regulation: Genetic and nongenetic insights into its role in disease progression

Secreted phosphoprotein 1 (SPP1), also known as osteopontin, is a multifunctional glycoprotein that plays a critical role in various physiological processes, including cell adhesion, chemotaxis, immune regulation, and tissue remodeling. Originally identified as a key component of the bone matrix, SPP1 is now recognized for its broad involvement in numerous tissues and significant impact on both normal physiology and disease progression. Dysregulation of SPP1 has been strongly implicated in the pathogenesis and progression of several diseases, including cancer, cardiovascular diseases, autoimmune disorders, and chronic inflammatory conditions. The expression of SPP1 is tightly regulated by genetic and nongenetic mechanisms. Genetic alterations, such as single-nucleotide polymorphisms, insertions and deletions, and structural variations within the SPP1 gene, have been associated with increased susceptibility to various diseases, influencing disease severity and outcomes. Additionally, nongenetic regulations, including DNA methylation, histone modifications, and long noncoding RNAs, play crucial roles in modulating SPP1 expression in response to environmental and cellular signals. This review provides a comprehensive overview of the genetic and nongenetic regulatory mechanisms governing SPP1 and examines their implications in disease pathogenesis. By integrating recent findings, this review highlights the complex interplay between genetic predispositions and nongenetic regulations in determining SPP1 activity and offers new insights into its role as a potential biomarker and therapeutic target. Understanding these regulatory pathways is essential for the development of targeted interventions for diseases in which SPP1 plays a pivotal role.

Common Variants in Osteopontin and CD44 Genes as Predictors of Treatment Outcome in Radiotherapy and Chemoradiotherapy for Non-Small Cell Lung Cancer

Osteopontin (OPN)-CD44 signaling plays an important role in promoting tumor progression and metastasis. In cancer, OPN and CD44 overexpression is a marker of aggressive disease and poor prognosis, and correlates with therapy resistance. In this study, we aimed to evaluate the association of single nucleotide polymorphisms (SNPs) in the OPN and CD44 genes with clinical outcomes in 307 non-small cell lung cancer (NSCLC) patients treated with radiotherapy or chemoradiotherapy. The potential impact of the variants on plasma OPN levels was also investigated. Multivariate analysis showed that OPN rs11730582 CC carriers had a significantly increased risk of death (p = 0.029), while the CD44 rs187116 A allele correlated with a reduced risk of locoregional recurrence (p = 0.016) in the curative treatment subset. The rs11730582/rs187116 combination was associated with an elevated risk of metastasis in these patients (p = 0.016). Furthermore, the OPN rs1126772 G variant alone (p = 0.018) and in combination with rs11730582 CC (p = 7 × 10-5) was associated with poor overall survival (OS) in the squamous cell carcinoma subgroup. The rs11730582 CC, rs187116 GG, and rs1126772 G, as well as their respective combinations, were independent risk factors for unfavorable treatment outcomes. The impact of rs11730582-rs1126772 haplotypes on OS was also observed. These data suggest that OPN and CD44 germline variants may predict treatment effects in NSCLC.

Thrombin Cleavage of Osteopontin and the Host Anti-Tumor Immune Response

Osteopontin (OPN) is a multi-functional protein that is involved in various cellular processes such as cell adhesion, migration, and signaling. There is a single conserved thrombin cleavage site in OPN that, when cleaved, yields two fragments with different properties from full-length OPN. In cancer, OPN has tumor-promoting activity and plays a role in tumor growth and metastasis. High levels of OPN expression in cancer cells and tumor tissue are found in various types of cancer, including breast, lung, prostate, ovarian, colorectal, and pancreatic cancer, and are associated with poor prognosis and decreased survival rates. OPN promotes tumor progression and invasion by stimulating cell proliferation and angiogenesis and also facilitates the metastasis of cancer cells to other parts of the body by promoting cell adhesion and migration. Furthermore, OPN contributes to immune evasion by inhibiting the activity of immune cells. Thrombin cleavage of OPN initiates OPN's tumor-promoting activity, and thrombin cleavage fragments of OPN down-regulate the host immune anti-tumor response.

Genetic Modifiers of Duchenne Muscular Dystrophy in Chinese Patients

Background: Duchenne muscular dystrophy (DMD) is a fatal, X-linked recessive muscle disorder characterized by heterogeneous progression and severity. We aimed to study the effects of single nucleotide polymorphisms (SNPs) in SPP1 and LTBP4 on DMD progression in Chinese patients.

Methods: We genotyped LTBP4 haplotypes and the SPP1 promoter SNPs rs28357094, rs11730582, and rs17524488 in 326 patients registered in the neuromuscular database of The First Affiliated Hospital of Sun Yat-sen University. Kaplan-Meier curves and log-rank tests were used to estimate and compare median age at loss of ambulation, while Cox proportional hazard regression models were used as to analyze the effects of glucocorticoids treatments, DMD genotype, and SPP1/LTBP4 SNPs on loss of ambulation.

Results: The CC/CT genotype at rs11730582 was associated with a 1.33-year delay in ambulation loss (p = 0.006), with hazard ratio 0.63 (p = 0.008), in patients with truncated DMD genotype and undergoing steroid treatment. On the other hand, rs17524488 in SPP1 and the IAAM/IAAM haplotype in LTBP4 were not associated with time to ambulation loss.

Conclusions:SPP1 rs11730582 is a genetic modifier of the long-term effects of steroid treatment in Chinese DMD patients. Thus, any future clinical study in DMD should adjust for glucocorticoids use, DMD genotype, and SPP1 polymorphisms.

Osteopontin splice variants and polymorphisms in cancer progression and prognosis

Osteopontin (OPN) is an extracellular matrix protein that is overexpressed in various cancers and promotes oncogenic features including cell proliferation, survival, migration, and angiogenesis, among others. OPN can participate in the regulation of the tumor microenvironment, affecting both cancer and neighboring cells. Here, we review the roles of OPN splice variants (a, b, c) in cancer development, progression, and prognosis, and also discuss the identities of isoforms 4 and 5. We also discussed how single-nucleotide polymorphisms (SNPs) of the OPN gene are an additional factor influencing the level of OPN in individuals, modulating the risks of cancer development and outcome.

Association of Osteopontin Gene Polymorphisms with Colorectal Cancer

We investigated the association of the Osteopontin (OPN) (rs9138 and rs1126616) polymorphisms with colorectal cancer (CRC). One hundred CRC patients and 112 healthy individuals were subjected to OPN (rs9138 and rs1126616) genotyping and measurement of OPN protein plasma level. The C allele of OPN rs1126616 and the CC haplotype were significantly higher in CRC patient (p = 0.036, 0.003, respectively). In females, the C allele of OPN rs9318 (A/C) polymorphism was significantly associated with increased CRC risk (p = 0.036). The plasma OPN level >104.35 ng/mL was significantly associated with CRC. Our findings suggest a significant role played by OPN (rs9138 and rs1126616) in colorectal carcinogenesis.

Genetic variations in the osteopontin promoters T-443C and G-156GG increase carotid intima-media thickness

Carotid intima-media thickness (CIMT) is a clear predictor of atherosclerosis. The increase of CIMT is affected by mutations in the osteopontin (OPN) promoters. The purpose of this study was to examine genetic variations in OPN promoters T-443C and G-156GG, identified in Javanese children with ischemic stroke parents, and to investigate their relationship with the increase of CIMT. A case-control analytic study was performed on 20 case and 12 control samples. Case samples were Javanese children aged between 10 to 21 years with ischemic stroke parents. Control samples were children with healthy parents. Mutations of T-443C and G-156GG were determined by employing polymerase chain reaction. Results of sequencing were analyzed using CLC Main Workbench 6.0. CIMT was defined using ultrasound. Genetic variations of T-443C were identified in six samples. Likewise, genetic variations of G-156GG were identified in six samples. Genetic variations in the OPN promoters T-443C and G-156GG were not potential risk factors in an increase of CIMT (P=0.654 and P=0.654). This study proves that genetic variations could be identified at the points of T-443C and G-156GG in children with ischemic stroke parents. Although statistically insignificant, the tendency to increase CIMT occurs in children with genetic variations. Children with ischemic stroke parents have thicker CIMT than children of healthy parents.

Osteopontin, E-cadherin, and β-catenin expression as prognostic biomarkers in patients with radically resected gastric cancer

A correlation between osteopontin, E-cadherin, β-catenin, and cyclooxygenase 2 overexpression and poor clinicopathological features and prognosis has been previously suggested in gastric cancer. This translational study was aimed at assessing the correlation of these immunohistochemical biomarkers with outcome in patients with radically resected gastric cancer. We analyzed osteopontin, E-cadherin, β-catenin, and cyclooxygenase 2 expression by immunohistochemistry in 346 primary gastric tumor tissue samples from patients enrolled in the ITACA-S trial. This phase III study randomized patients with radically resected gastric cancer to receive adjuvant chemotherapy with either 5-fluorouracil and leucovorin or a sequential regimen of infusional 5-fluorouracil and leucovorin plus irinotecan followed by cisplatin and docetaxel. High expression of osteopontin was correlated with high histological grade, diffuse histotype, and peritoneal relapse, but not with TNM stage. Moreover, osteopontin overexpression was associated with higher risk of tumor recurrence and metastases, and was an independent prognostic factor for both relapse-free and overall survival of gastric cancer patients following adjuvant chemotherapy. Abnormal E-cadherin expression and abnormal β-catenin expression were correlated with more advanced disease stage, and as a consequence, with poor outcome. Our results suggest that osteopontin overexpression is a valuable independent predictor of tumor recurrence and survival in patients with radically resected gastric cancer.

Association of OPN rs11730582 polymorphism with cancer risk: a meta-analysis

Purpose

Several molecular epidemiological studies have investigated the association between OPN rs11730582 C>T polymorphism and cancer risk, but the results are inconsistent. Hence, a meta-analysis was conducted to determine the association of this polymorphism with cancer risk.

Materials and methods

The related articles were searched in PubMed, Embase, and Chinese National Knowledge Infrastructure databases. Pooled odds ratios and 95% confidence intervals were calculated to evaluate the strength of the associations. A random-effects model or fixed-effects model was employed depending on the heterogeneity.

Results

A total of ten case-control studies involving 2,749 cancer cases and 3,398 controls were included in the meta-analysis. In overall analysis, OPN rs11730582 C.T polymorphism was not associated with cancer risk. In a stratified analysis by cancer type, no significant association was found between OPN rs11730582 C>T polymorphism and the risk of glioma, gastric cancer, and other cancers.

Conclusion

This meta-analysis suggests that OPN rs11730582 C.T polymorphism is not associated with cancer susceptibility.

Association between promoter polymorphisms of OPN gene and cancer risk: a meta-analysis

Background

Results of the association between polymorphisms of osteopontin (OPN) gene promoter region and risk of cancer were inconclusive. The aim of this meta-analysis was to elucidate whether OPN promoter polymorphisms were associated with cancer risk.

Methods

Electronic databases including PubMed, Web of Science, and Chinese National Knowledge Infrastructure were systematically searched. Odd ratios (ORs) and their 95% confidential interval (CI) were used to assess the strength of association between OPN promoter polymorphisms and cancer risks.

Results

Nine studies were finally included in this meta-analysis. For OPN rs17524488 polymorphism, carriers of GG or -/G genotype were significantly associated with increased cancer risk compared with wild-type -/- carriers, respectively (GG vs -/-: OR =1.40, 95% CI =1.03–1.91, P=0.033; -/G vs -/-: OR =1.22, 95% CI =1.07–1.40, P=0.002). Additionally, G allele was significantly associated with increased cancer risk compared with (-) allele (OR =1.21, 95% CI =1.04–1.40, P=0.016). However, no significant association was observed of OPN rs11730582 polymorphism and cancer risk (CC vs TT: OR =0.98, 95% CI =0.49–1.97, P=0.964; CT vs TT: OR =0.88, 95% CI =0.54–1.43, P=0.610).

Conclusion

Carriers of GG or -/G genotype of OPN promoter rs17524488 (-156-/G) polymorphism might be associated with increased risk of cancer compared with wild-type -/- carriers, respectively. However, no significant association was observed between OPN promoter rs11730582 (-443C/T) polymorphism and risk of cancer.

Intracellular Osteopontin Induced by CagA-positive Helicobacter pylori Promotes Beta-catenin Accumulation and Interleukin-8 Secretion in Gastric Epithelial cells

BACKGROUND

Osteopontin, an important immune modulator and oncogenic promoter, is upregulated in H. pylori-infected gastric mucosa. However, the underlying mechanisms and biological significance are poorly understood. We investigated whether osteopontin was upregulated in gastric epithelial cells by H. pylori and the virulence factors involved. Moreover, cellular component changes caused by osteopontin were also investigated.

MATERIALS AND METHODS

The gastric epithelial cell line MKN45 was cocultured with wild-type and mutant H. pylori to analyze osteopontin expression. Beta-catenin levels in cell lysate and interleukin-8 levels in supernatant were analyzed. The difference in osteopontin expression levels in both gastric epithelium and plasma was compared between H. pylori-infected patients and uninfected controls.

RESULTS

H. pylori induced intracellular, but not secretory, osteopontin expression in MKN45 cells. Accordingly, osteopontin expression intensity in gastric epithelium was higher in H. pylori-infected patients than in controls, but osteopontin levels in plasma were similar between both patient groups. H. pylori virulence factor CagA delivered via the type IV secretion system was essential for intracellular osteopontin upregulation. H. pylori induced β-catenin accumulation and interleukin-8 secretion, whereas osteopontin knockdown completely abrogated these effects, in MKN45 cells. TLR2 antagonist abolished iOPN expression induced by H. pylori gastritis strain, but not by H. pylori cancer strain.

CONCLUSIONS

H. pylori is dependent on CagA translocation via the type IV secretion system to induce intracellular osteopontin expression in gastric epithelial cells. Upregulated intracellular osteopontin may promote gastric carcinogenesis via increased β-catenin accumulation and interleukin-8 secretion.

Association of osteopontin polymorphism with cancer risk: a meta-analysis

To investigate the association of osteopontin gene -443 C>T, -156 G>GG, and -1748 A>G polymorphisms with cancer risk. The Medline, PubMed, PUBMED, EMBASE and Web of Science databases were searched. Meta-analyses were conducted using RevMan 5.2 software. After searching and evaluating the included papers, total 10 documents involved in -443 C>T, 8 papers involved in four articles involved in -156 G>GG and -1748 A>G were included into this meta analysis. There were no significant differences in genotype osteopontin -443 C>T distribution between cancer cases and control (OR=0.98, 95% CI=0.68-1.40, P=0.90; OR=0.90, 95% CI=0.60-1.35, P=0.62; OR=0.98, 95% CI=0.59-1.64, P=0.94; OR=0.87, 95% CI=0.60-1.25, P=0.44, respectively). Meanwhile, no association between osteopontin -1748 A>G polymorphism and tumors under all genetic models. (OR=0.73, 95% CI=0.54-1.00, P=0.05; OR=0.95, 95% CI=0.82-1.10, P=0.48; OR=1.31, 95% CI=0.95-1.81, P=0.10; OR=0.90, 95% CI=0.77-1.06, P=0.20, respectively). However, osteopontin -156 G>GG polymorphism is only partly related to the tumor risk. (GGGG+GGG vs GG model, OR=1.21, 95% CI=1.01-1.46, P=0.04; GGG vs GG model: OR=1.19, 95% CI=1.05-1.35, P=0.008, respectively) osteopontin gene polymorphisms, -443 C>T and -1748 A>G was not associated with cancer risk, but partly associated to tumor risk for -156 G>GG gene polymorphism.

OPN gene polymorphisms, rs17524488 GG/G, rs11730582 T/C, and rs9138 C/A, and cancer risk in a Chinese population

Previous studies have investigated the association between osteopontin (OPN) gene polymorphisms, rs17524488 (-156 GG/G), rs11730582 (-443 T/C), and rs9138 (C/A) and cancer risk in the Chinese population. However, the results are controversial and indefinite. We therefore carried out a meta-analysis to derive a more precise estimation of these associations. The PubMed database was systematically searched to identify potentially eligible reports. Crude odds ratios (OR) and 95% confidence intervals (CI) were used to assess the strength of associations between 3 OPN gene polymorphisms and cancer risk in a Chinese population. A total of 10 articles involving 2,391 cases and 3,007 controls were evaluated. The pooled OR indicated that OPN rs17524488 (-156 GG/G) polymorphism was significantly associated with cancer risk in Chinese population. In a stratified analysis by source of control, significant associations were also observed among rs17524488 (-156 GG/G) and rs11730582 (-443 T/C) polymorphisms and cancer. In addition, a stronger association was observed between rs9138 (C/A) polymorphism and cancer risk. In conclusion, this meta-analysis suggests that OPN rs17524488 (-156 GG/G), rs11730582 (-443 T/C), and rs9138 (C/A) polymorphisms may be associated with cancer susceptibility in the Chinese population. Nevertheless, further investigation on a larger population covering different ethnicities are warranted.

Associations between the Genetic Polymorphisms of Osteopontin Promoter and Susceptibility to Cancer in Chinese Population: A Meta-Analysis

Background and Aim

Several studies have been conducted to examine the associations between osteopontin (OPN) promoter gene SPP1 polymorphisms with human cancers in Chinese population, but the results remain inconsistent. The aim of this meta-analysis is to clarify the associations between SPP1 polymorphisms and cancer susceptibility.

Methods

All eligible case-control studies published up to March 2015 were identified by searching PubMed, Web of Science, Embase, and Cochrane Library without language restrictions. Pooled odds ratio (OR) and 95% confidence interval (95% CI) were calculated using fixed- or random-effect model.

Results

A total of 11 case-control studies were included; of those, there were eleven studies (3130 cases and 3828 controls) for -443T>C polymorphism, ten studies (3019 cases and 3615 controls) for -156G>GG polymorphism, eight studies (2258 cases and 2846 controls) for -66T>G polymorphism. Overall, no evidence indicated that the -443 T>C polymorphism was associated with cancer risk (OR = 0.93, 95%CI 0.62–1.38 for dominant model, OR = 1.06, 95%CI 0.73–1.55 for recessive model, OR = 0.88, 95%CI 0.62–1.26 for CT vs TT model, OR = 1.03, 95%CI 0.61–1.73 for CC vs TT model). While, a significantly increase risk was found for -156 G>GG polymorphism (OR = 1.22, 95%CI 1.10–1.35 for dominant model, OR = 1.25, 95%CI 1.10–1.41 for recessive model, OR = 1.18, 95%CI 1.06–1.32 for GGG vs GG model, OR = 1.35, 95%CI 1.09–1.68 for GGGG vs GG model). For -66T>G polymorphism, we found a decrease risk of cancer (OR = 0.84, 95% CI 0.71–0.98 for dominant model), but this result changed (OR = 0.93, 95% CI 0.77–1.12 for dominant model) when we excluded a study.

Conclusion

This meta-analysis suggests that in Chinese population the -156G>GG polymorphism of SPP1 might be a risk factor for human cancers, while -443T>C mutation is not associated with cancer risk. For -66T>G polymorphism, it may be a protective factor for human cancers.

Association of SPP1 promoter variants with hip osteoarthritis susceptibility in Chinese population

Three genetic variants in the promoter of SPP1 (secreted phosphoprotein 1) gene have been reported to affect transcriptional activity of SPP1, thus conferring an increased risk for some diseases. To testify if these variants are associated with risk of hip osteoarthritis (OA) as well, we performed a case-control study including 389 hip OA patients and 315 healthy controls. Genotypes of SPP1 were determined by DNA sequencing, and differential expressions of SPP1 in relation with genotypes were evaluated by RT-PCR and ELISA. The results showed that rs17524488 (delG>insG) increased the risk of hip OA, with the adjusted OR 1.48 (95% CI 1.18-1.85, P<0.01) for risk allele insG, 1.90 (95% CI 1.35-2.66, P<0.01) for delG/insG and 2.04 (95% CI 1.20-3.49, P<0.01) for insG/insG respectively. However, as for rs11730582 (T>C), the adjusted ORs were 1.18 (95% CI 0.94-1.49, P=0.148) for allele C, 1.26 (95% CI 0.90-1.75, P=0.158) for TC, and 1.31 (95% CI 0.77-2.24, P=0.293) for CC, indicating no association of rs11730582 with hip OA risk. The variant rs28357094 was not observed in the tested subjects. Furthermore, the delG/insG and insG/insG genotypes of rs17524488 both correlated with higher levels of SPP1 expression in articular cartilage (P<0.01 for all comparisons) as well as in in synovial fluid (P<0.01 for all comparisons) compared with delG/delG, while rs11730582 had no effect on the SPP1 expression (P>0.05 for all comparisons). These results collectively indicate that the genetic variant rs17524488 in SPP1 promoter confers high risk for hip OA in a Chinese population, possibly through enhancing SPP1 expression.

The NFKB1 polymorphism (rs4648068) is associated with the cell proliferation and motility in gastric cancer

BACKGROUND

We have demonstrated previously that NFKB1 single nucleotide polymorphism (SNP) rs4648068 GG homozygote was associated with the increased risk of gastric cancer in Chinese Han population. In this study, we constructed the recombinant plasmid pGL3-AA, pGL3-GG, pGL3-AA-NFKB and pGL3-GG-NFKB to investigate the function of rs4648068 by cell biology experiments.

METHODS

Quantitative real-time PCR was used to detect NFKB1 SNP rs4648068 genotype in the patients with gastric cancer. Anti-NF-κB1 p50 polyclonal antibodies were used for immunohistochemical analysis of the tissue specimens. The subsection of NFKB1 containing the promoter site and adjacent three consecutive exons were obtained by PCR technique and subcloned into the vector pGL3-Basic. Dual-Luciferase reporter assay was used to detect the transcriptional activity of the constructed promoter. Effects of transcription factor NFKB1 on C/EBPβ expression were determined by chromatin immunoprecipitation and Western analysis. Furthermore, proliferation and invasion ability of the transduced cell were also measured and compared.

RESULTS

Intensive staining for p50 expression was observed in the tissues of GG genotype patients, compared with those of GA group and AA genotype patients. The transcriptional activity of rs4648068 (A > G) by dual-Luciferase reporter assay suggested that the luciferase activity of homozygote group (pGL3-GG) was greater than that of the control (pGL3-AA), especially at the stimulation of LPS. We found that the luciferase activity was also influenced by pGL3-GG levels. The effects of NFKB1 rs4648068 were enhanced by rs4648065 on the transduced cells. The interaction between NFKB1 promoter nucleotide sequence and C/EBPβ was regulated by the functional SNP rs4648068 in SGC-7901 cells. Our data indicated that the transduction of pGL3 expression plasmid pGL3-GG-NFKB improved the proliferation and motility of gastric cancer cells. Correspondingly, the homozygote GG of SNP rs4648068 strengthened the transcriptional activity of NFKB1 and influenced the cell biological activity.

CONCLUSION

The transcriptional activity of NFKB1 was associated with SNP rs4648068, and this functional SNP site has the important effects on cell proliferation and motility.

Genetic association of osteopontin (OPN) and its receptor CD44 genes with susceptibility to Chinese gastric cancer patients

PURPOSE

(1) To investigate associations between single nucleotide polymorphisms (SNPs) in osteopontin (OPN) and its receptor-cluster of differentiation 44 (CD44) genes and gastric cancer susceptibility. (2) To explore the correlation of OPN and CD44 expression of gastric cancer.

METHODS

We detected 26 SNPs of the genes in gastric cancer patients from the Chinese Han population by Sequenom technique and performed expression of OPN in combination with CD44 in 243 tissues samples of the cases by tissue microarray and immunohistochemistry (IHC).

RESULTS

We found that the minor alleles of OPN rs4754C>T and OPN rs9138C>A remained strongly associated with decreased gastric cancer risk (P = 1.53 × 10(-4), odds ratio (OR) 0.642, 95 % confidence interval (CI) 0.511-0.808 and P = 1.59 × 10(-4), OR 0.642, 95 %CI 0.510-0.809). OPN variant rs1126772A>G and CD44 variant rs353639A>C significantly contributed to elevated risk of gastric cancer (P = 0.042, OR 1.279, 95 % CI 1.008-1.622 and P = 0.047, OR 1.334, 95 % CI 1.003-1.772). Haplotypes of OPN and CD44 variants significantly influenced risk of gastric cancer. Clinical data indicated that rs4754 and rs9138 of OPN were significantly associated with smoking (P = 0.029, OR 0.343, 95 % CI 0.127-0.926 and P = 0.029, OR 0.343, 95 %CI 0.127-0.926) and OPN rs1126772 revealed associations with tumor-node-metastasis (TNM) stage (P = 0.025, OR 1.765, 95 % CI 1.073-2.905) and tumor differentiation (P = 0.031, OR 1.722, 95 % CI 1.049-2.825). OPN expression was observed in 133 of the 243 cases (54.7 %) by IHC and was correlated with serosa invasion (P = 0.013), TNM stage (P = 0.003) and lymph node metastasis (P = 0.002). CD44 expression was found in 92 of the 243 cases (37.9 %) and was associated with tumor size (P = 0.005) and lymph node metastasis (P = 0.023), respectively. The OPN expression displayed a positive association with CD44 (P = 0.01, r s = 0.164).

CONCLUSIONS

We found that the polymorphisms rs4754, rs9138 and rs1126772 of OPN gene and rs353639 of CD44 gene were significantly associated with gastric cancer. Our IHC data indicated that interaction of OPN and CD44 protein would promote progression and metastasis of gastric cancer.

Functional annotation of putative regulatory elements at cancer susceptibility Loci

Most cancer-associated genetic variants identified from genome-wide association studies (GWAS) do not obviously change protein structure, leading to the hypothesis that the associations are attributable to regulatory polymorphisms. Translating genetic associations into mechanistic insights can be facilitated by knowledge of the causal regulatory variant (or variants) responsible for the statistical signal. Experimental validation of candidate functional variants is onerous, making bioinformatic approaches necessary to prioritize candidates for laboratory analysis. Thus, a systematic approach for recognizing functional (and, therefore, likely causal) variants in noncoding regions is an important step toward interpreting cancer risk loci. This review provides a detailed introduction to current regulatory variant annotations, followed by an overview of how to leverage these resources to prioritize candidate functional polymorphisms in regulatory regions.

Interstitial calcinosis in renal papillae of genetically engineered mouse models: relation to Randall's plaques

Genetically engineered mouse models (GEMMs) have been highly instrumental in elucidating gene functions and molecular pathogenesis of human diseases, although their use in studying kidney stone formation or nephrolithiasis remains relatively limited. This review intends to provide an overview of several knockout mouse models that develop interstitial calcinosis in the renal papillae. Included herein are mice deficient for Tamm-Horsfall protein (THP; also named uromodulin), osteopontin (OPN), both THP and OPN, Na(+)-phosphate cotransporter Type II (Npt2a) and Na(+)/H(+) exchanger regulatory factor (NHERF-1). The baseline information of each protein is summarized, along with key morphological features of the interstitial calcium deposits in mice lacking these proteins. Attempts are made to correlate the papillary interstitial deposits found in GEMMs with Randall's plaques, the latter considered precursors of idiopathic calcium stones in patients. The pathophysiology that underlies the renal calcinosis in the knockout mice is also discussed wherever information is available. Not all the knockout models are allocated equal space because some are more extensively characterized than others. Despite the inroads already made, the exact physiological underpinning, origin, evolution and fate of the papillary interstitial calcinosis in the GEMMs remain incompletely defined. Greater investigative efforts are warranted to pin down the precise role of the papillary interstitial calcinosis in nephrolithiasis using the existing models. Additionally, more sophisticated, second-generation GEMMs that allow gene inactivation in a time-controlled manner and "compound mice" that bear several genetic alterations are urgently needed, in light of mounting evidence that nephrolithiasis is a multifactorial, multi-stage and polygenic disease.

Positive association between lymphotoxin-alpha variation rs909253 and cancer risk: a meta-analysis based on 36 case-control studies

Lymphotoxin-alpha (LTA) polymorphism rs909253 has been reported to be a risk factor for cancers, but some results are inconsistent. To establish a more conclusive association, we performed a meta-analysis of this variant with cancers. A systematic search was performed for informative case-control studies of rs909253 with cancers among literature databases, including PubMed, Web of Science, Embase, China National Knowledge Infrastructure (CNKI), and Wanfang Chinese Periodical Database. After a comprehensive filtration procedure, 36 publications involved with 35,677 participants were selected for the current meta-analysis. Stratified factors, such as cancer type, populations, and source of control, were used for a better interpretation of this variant. Minimal heterogeneity was shown in the current meta-analysis (I (2) = 0.0%, P = 0.48). Our results show a significant association of rs909253 and cancer risk (odds ratio (OR) = 1.12, P (z) < 0.001). In the subgroup analysis, significant association of rs909253 was found in adenocarcinoma (OR = 1.16, P (z) < 0.001) and hematological malignancy (OR = 1.10, P (z) < 0.001). Our meta-analyses established a significant association of rs909253 with cancer risk among multiple populations including North Americans, Asians, and Europeans.

Association of osteopontin polymorphisms with nasopharyngeal carcinoma risk

No previous study has reported the association of osteopontin polymorphisms with nasopharyngeal carcinoma (NPC) risk. We aimed to investigate the association in a Chinese population. Four variants of osteopontin, rs11730582, rs1126772, rs9138, and rs4754 polymorphisms, were assessed in a case-control study which consists of 108 NPC patients and 210 health controls, by using polymerase chain reaction--restriction fragment length polymorphism method. Serum osteopontin levels were measured by enzyme-linked immunosorbent assay. The serum osteopontin levels were significantly higher in NPC patients than those in controls (P<0.01). Carriers of CC and CT genotype of rs11730582 presented lower serum osteopontin levels than those of TT genotype carriers (P<0.05). Genotypes CT and CT+CC of rs11730582 were associated with the risk of NPC (CT:OR = 0.57, 95%CI = 0.34-0.94; CC+CT:OR = 0.54, 95%CI = 0.34-0.87). Haplotype analysis revealed that haplotype T-A-A-C of rs11730582, rs1126772, rs9138, and rs4754 was associated with NPC risk (OR = 0.49, 95%CI = 0.27-0.86). Stratification analysis showed that genotypes CT and CT+CC of rs11730582 were associated with tumor stage and lymph node metastasis (P<0.05). No associations were found between rs1126772, rs9138, and rs4754 polymorphisms and NPC risk (P>0.05). The variant rs11730582 of osteopontin is associated with NPC risk. It potentially serves as a genetic marker of NPC predisposition.

The polymorphisms of osteopontin gene and plasma osteopontin protein levels with susceptibility to colorectal carcinoma

Osteopontin (OPN) plays an important role in the development and progression of some tumors. The polymorphisms of OPN probably change its expression and contribute to interindividual differences of susceptibility to some cancers. The purpose of the present study was to explore the association of rs9138 (+1239; 3'UTR: 3'untranslated regions) and rs1126616 (+750; exon 7) polymorphisms located in the OPN gene with colorectal carcinoma (CRC) susceptibility and to investigate the correlation of the polymorphisms, plasma levels of the OPN protein, clinicopathologic parameters, tumor markers, and lipid. The genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism. The plasma levels, tumor markers, and lipid were measured by enzyme-linked immunosorbent assay. The results indicated that genotype AA and AC of rs9138 and CC and CT of rs1126616 were associated with increased risk of CRC. The allelic frequencies of rs9138A, rs1126616C, and the haplotype (A-C) were associated with increased risk of CRC. Although there was no significant difference of plasma levels in various genotypes, increased plasma protein expression in CRC patients compared with controls was found. Our results suggested that the rs9138 and rs1126616 of OPN were associated with CRC risk, and the OPN protein in plasma may be a potential tumor marker of CRC.

Osteopontin genetic variants are associated with overall survival in advanced non-small-cell lung cancer patients and bone metastasis

PURPOSE

Osteopontin (OPN) plays important roles in the modulation of apoptosis, angiogenesis, immune response, and tumor invasion. Elevated osteopontin expression has been reported in the lung cancer tissues compared to counterpart normal tissues. This study examined whether genetic variations in the osteopontin gene are associated with survival of lung cancer patients and occurrence rate of bone metastasis.

EXPERIMENTAL DESIGN

Three hundred and sixty patients with stages I to IV between 2003 and 2007 were recruited in this study and same number of healthy persons were used as control. Three promoter osteopontin polymorphisms, OPN-66 T/G, -156G/GG, and -443C/T variants were genotyped using DNA from blood lymphocytes. Chi-square test and a Fisher's exact test were used to analyze the genotype distribution among TNM stages and incidence of bone metastasis and lymph mode metastasis. Kaplan-Meier method and log-rank test were used to compare survival by different genotypes.

RESULTS

For the variant at nt -443 (CC), there was a significant difference between the number of patients with stage IV and those with all other stages of lung cancer (p < 0.01). Patients with -443 (CC) variant had significant higher incidence of bone metastasis development compared to other genotypes. For the variant at nt -443 (CT), there was a significant difference between the number of lung cancer patients with stage III + IV and those with stage I + II (P < 0.01). The survival rates for patients with the C/C genotype were significantly lower than for patients with the other two genotypes (C/T, T/T).

CONCLUSION

OSTEOPONTIN -443C/T polymorphism is a potential predictive marker of survival in lung cancer patients, it is correlated with bone metastasis significantly.

An osteopontin promoter polymorphism is associated with aggressiveness in breast cancer

Metastasis-related genes are deregulated in cancer by aberrant expression or splicing. Here, we analyzed polymorphic sites in the osteopontin promoter as potential contributors to aberrant expression in breast cancers. This study comprised 241 breast cancer specimens, for which DNA from normal surrounding tissue was available for 111, and 65 healthy breast samples. The polymorphic site in position -443 of the promoter was associated with tumor grade. As expected, there was no association between promoter single nucleotide polymorphisms (SNPs) and tumor stage or in situ carcinoma versus cancer, as stage and early transformation are determined by the sampling time more than by tumor genetics. In a subset of samples, osteopontin RNA expression levels had previously been obtained. The allelic distribution in positions -443 and -1748 was distinct between high and low expressors, confirming the importance of promoter SNPs. These two sites also form a haplotype. Osteopontin expression has been associated with breast cancer progression, regardless of the histological subtype of the cancer. Remarkably, the polymorphic site at -443, but not -1748 or -1776, showed differences between ER-positive and ER-negative breast cancers and between PR-positive and PR-negative breast cancers, but there was no association with HER2 status. In five cases, the genotype of the tumor was different from the genotype of the host, implying the possibility of somatic mutations in the osteopontin promoter that may affect expression. Our results corroborate that the osteopontin promoter SNPs -443 (rs11730582) and -1748 (rs2728127) are important for gene expression and breast cancer aggressiveness.

OPN gene polymorphisms influence the risk of knee OA and OPN levels in synovial fluid in a Chinese population

INTRODUCTION

A body of studies suggests the role of osteopontin (OPN) in onset and development of osteoarthritis (OA), however, the association between OPN polymorphisms and OA susceptibility as well as its clinical features has not been reported.

METHODS

A total of 750 patients with primary knee OA and 794 healthy volunteer were enrolled as controls. Both OA and control groups were interviewed to obtain demographic and clinical data. Three polymorphisms of OPN gene, namely, -156GG/G, -443C/T and -66T/G were determined. The levels of the full length and the thrombin-cleaved OPN in synovial fluid (SF) from OA subjects were measured.

RESULTS

We found the polymorphisms of the -443C/T and the -66/T/G were significantly associated with the OA risk and the radiographic severity. The -443TT and -66GG showed protective effect against developing OA and were associated with lower Kellgren-Lawrence grade. Besides, the polymorphisms of -443C/T and -66T/G significantly affected the thrombin-cleaved OPN levels in SF from OA subjects. Subjects with -443TT and -66GG genotypes had lower thrombin-cleaved OPN levels in SF. The thrombin-cleaved OPN levels in SF were positively correlated to the radiographic severity of OA.

CONCLUSIONS

Our findings suggest that certain OPN gene polymorphisms may be used as molecular markers for the susceptibility and severity of OA.