Association of cancer stem cell markers genetic variants with gallbladder cancer susceptibility, prognosis, and survival

Impact of ALDH1A1 and NQO1 gene polymorphisms on the response and toxicity of chemotherapy in Bangladeshi breast cancer patients

PURPOSE

Cyclophosphamide, Epirubicin/Doxorubicin, 5-fluorouracil (CEF or CAF) chemotherapy has long been a standard first-line treatment for breast cancer. The genetic variations of enzymes that are responsible for the metabolism of these drugs have been linked to altered treatment response and toxicity. Two drug-metabolizing enzymes ALDH1A1 and NQO1 are critically involved in the pathways of CEF/CAF metabolism. This study aimed to evaluate the effect of ALDH1A1 (rs13959) and NQO1 (rs1800566) polymorphisms on treatment response and toxicities caused by adjuvant (ACT) and neoadjuvant chemotherapy (NACT) where CEF/CAF combination was used to treat Bangladeshi breast cancer patients.

METHODS

A total of 330 patients were recruited from various hospitals, with 150 receiving neoadjuvant chemotherapy and 180 receiving adjuvant chemotherapy. To extract genomic DNA, a non-enzymatic simple salting out approach was adopted. The polymerase chain reaction-restriction fragment length polymorphism method was used to detect genetic polymorphisms. Unconditional logistic regression was used to derive odds ratios (ORs) with 95% confidence intervals (CIs) to study the association between genetic polymorphisms and clinical outcome and toxicity.

RESULTS

A statistically significant association was observed between ALDH1A1 (rs13959) polymorphism and treatment response (TT vs. CC: aOR = 6.40, p = 0.007; recessive model: aOR = 6.38, p = 0.002; allele model: p = 0.032). Patients with the genotypes TT and CT + TT of the NQO1 (rs1800566) polymorphism had a significantly higher risk of toxicities such as anemia (aOR = 0.34, p = 0.006 and aOR = 0.58, p = 0.021), neutropenia (aOR = 0.42, p = 0.044 and aOR = 0.57, p = 0.027), leukopenia (aOR = 0.33, p = 0.010 and aOR = 0.46, p = 0.005), and gastrointestinal toxicity (aOR = 0.30, p = 0.02 and aOR = 0.38, p = 0.006) when compared to the wild CC genotype, while patients with the genotype CT had a significant association with gastrointestinal toxicity (aOR = 0.42, p = 0.02) and leukopenia (aOR = 0.52, p = 0.010). The TT and CT + TT genotypes of rs13959 had a significantly higher risk of anemia (aOR = 2.00, p = 0.037 and aOR = 1.68, p = 0.029). There was no significant association between rs1800566 polymorphism and treatment response.

CONCLUSION

Polymorphisms in ALDH1A1 (rs13959) and NQO1 (rs1800566) may be useful in predicting the probability of treatment response and adverse effects from CEF or CAF-based chemotherapy in breast cancer patients.

Downregulated circRNA_CDKN1A promotes gallbladder cancer progression through activation of the NF-κB pathway

This study uncovered the potential clinical value and molecular driving mechanisms of circular RNAs (circRNAs) in gallbladder cancer (GBC). Differentially expressed circRNAs in GBC cells were screened by high-throughput sequencing. CircRNA_CDKN1A (circBase ID: hsa_circ_0076194) was knocked out in BGC-SD cells through transfection with sh-circRNA_CDKN1A. Then, proliferation was investigated via CCK8 and EdU assays, apoptosis via flow cytometry, migration via wound healing assays, and invasion via Transwell assays. Bioinformatics analysis of circRNA_CDKN1A-related signaling pathways was performed using MetScape and g:Profiler. Results showed that the knockdown of circRNA_CDKN1A enhanced the proliferation, migration, and invasion of GBC cells and inhibited apoptosis. In addition, knocking out circRNA_CDKN1A promoted GBC cell proliferation and enhanced the dry indices of the OCT4 protein and CD34 expression levels. The knockdown of circRNA_CDKN1A activated the epithelial-mesenchymal transition pathway. Bioinformatics analysis revealed that the biological role of circRNA_CDKN1A in GBC cells involved the NF-κB pathway. LY2409881, which is an NF-κB inhibitor, reversed the effects induced by the knockdown of circRNA_CDKN1A in GBC-SD cells. In summary, the knockdown of circRNA_CDKN1A promoted the progression of GBC by activating the NF-κB signaling pathway. For the first time, this study revealed the mechanism of circRNA_CDKN1A-mediated regulatory action in GBC and identified the newly discovered circRNA_CDKN1A-NF-κB signaling axis as a potentially important candidate for clinical therapy and prognostic diagnosis of GBC.

A Case of Early-Stage Gallbladder Cancer, Positive for ALDH1A1, Which Arose from Adenomyomatosis of the Gallbladder

Adenomyomatosis (ADM) of the gallbladder is a condition characterized by the proliferation of Rokitansky–Aschoff sinus (RAS), in which the epithelium of the gallbladder extends into the muscular layer, causing a thickening of the gallbladder wall. Although ADM is generally considered not to be a precancerous lesion of gallbladder cancer, there are some reports of cases of gallbladder cancer from ADM. Therefore, the relationship between ADM and gallbladder cancer remains controversial. We herein report a case of early-stage gallbladder cancer, BilIN3 (high grade), arising from ADM that was positive for ALDH1A1, an important marker of stem cells and cancer stem cells.

MiR-552-3p promotes malignant progression of gallbladder carcinoma by reactivating the Akt/β-catenin signaling pathway due to inhibition of the tumor suppressor gene RGMA

Background

Gallbladder carcinoma (GBC) remains a highly lethal disease worldwide. MiR-552 family members promote the malignant progression of a variety of digestive system tumors, but the role of miR-552-3p in GBC has not been elucidated. miR-552-3p was predicted to target the 3'-untranslated region (3'UTR) of the mRNA for the tumor suppressor gene "repulsive guidance molecule BMP co-receptor a" (RGMA). The aim of the present study was to clarify the roles and mechanisms of miR-552-3p targeting RGMA in the malignant progression of GBC.

Methods

In vitro: expression of miR-552-3p was detected by real-time quantitative PCR (qRT-PCR) in tumor and non-tumor adjacent tissues (NATs). Lentivirus-miR-552-3p was employed to knockdown this miRNA in GBC cell lines. Stem cell-related transcription factors and markers were assessed by qRT-PCR. Cell Counting Kit-8 (CCK-8), sphere formation and transwell assays were used to determine the malignant phenotypes of GBC cells. Targeting the 3'UTR of RGMA by miR-552-3p was verified by integrated analysis including bioinformatics prediction, luciferase assays, measures of changes of gene expression and rescue experiments. In vivo: mouse models of subcutaneous tumors and lung metastases were established to observe the effect of miR-552-3p on tumorigenesis and organ metastasis, respectively.

Results

MiR-552-3p was abnormally highly expressed in GBC tissues and cancer stem cells. Interference with miR-552-3p in SGC-996 and GBC-SD cells significantly inhibited GBC stem cell expansion. Reciprocally, miR-552-3p promoted GBC cell proliferation, migration and invasion both in vitro and in vivo; hence, interference with this miRNA impeded the malignant progression of GBC. Furthermore, the important tumor suppressor gene RGMA was identified as a target of miR-552-3p. The effects of miR-552-3p on cell proliferation and metastasis were abrogated or enhanced by gain or loss of RGMA function, respectively. Mechanistically, miR-552-3p promoted GBC progression by reactivating the Akt/β-catenin pathway and epithelial-mesenchymal transformation (EMT). Clinically, miR-552-3p correlated with multi-malignant characteristics of GBC and acted as a prognostic marker for GBC outcome.

Conclusions

MiR-552-3p promotes the malignant progression of GBC by inhibiting the mRNA of the tumor suppressor gene RGMA, resulting in reactivation of the Akt/β-catenin signaling pathway.

Impact of SRY-Box Transcription Factor 11 Gene Polymorphisms on Oral Cancer Risk and Clinicopathologic Characteristics

Oral cancer is among the most common cancers worldwide and has become a major global health problem because of its relatively high morbidity and mortality rates. The sex-determining region on the Y-chromosome-related high-mobility-group box (SOX) transcription factor 11 (SOX11) plays a key role in human development and differentiation and is frequently increased in various human cancers. However, the clinical significance of SOX11 polymorphisms in oral cancer and their association with oral cancer risk are unclear. In this study, we included 1196 patients with oral cancer and 1200 controls. Real-time polymerase chain reaction was applied to analyze three SOX11 single-nucleotide polymorphisms (rs77996007, rs66465560, and rs68114586). Our results shown that SOX11 polymorphisms carriers with betel quid chewing were found to have an 8.38- to 9.23-fold risk to have oral cancer compared to SOX11 wild-type carriers without betel quid chewing. Furthermore, oral cancer patients who carried SOX11 rs77996007 “TC + CC” variants were significantly associated with large tumor size (AOR, 1.324; 95% CI, 1.047–1.674; p = 0.019). Moreover, a database analysis using the Cancer Genome Atlas suggested that SOX11 mRNA expression was high during the tumor development process. In conclusion, our results suggest that SOX11 rs77996007 is involved in oral cancer progression and clinical characteristics.

Long Non-Coding RNAs in Biliary Tract Cancer-An Up-to-Date Review

The term long non-coding RNA (lncRNA) describes non protein-coding transcripts with a length greater than 200 base pairs. The ongoing discovery, characterization and functional categorization of lncRNAs has led to a better understanding of the involvement of lncRNAs in diverse biological and pathological processes including cancer. Aberrant expression of specific lncRNA species was demonstrated in various cancer types and associated with unfavorable clinical characteristics. Recent studies suggest that lncRNAs are also involved in the development and progression of biliary tract cancer, a rare disease with high mortality and limited therapeutic options. In this review, we summarize current findings regarding the manifold roles of lncRNAs in biliary tract cancer and give an overview of the clinical and molecular consequences of aberrant lncRNA expression as well as of underlying regulatory functions of selected lncRNA species in the context of biliary tract cancer.

Differential sequences and single nucleotide polymorphism of exosomal SOX2 DNA in cancer

Glioblastoma multiforme (GBM) is the most common form of brain cancer, with an average life expectancy of fewer than two years post-diagnosis. We have previously reported that cancer cell originated exosomes, including GBM, have NANOG and NANOGP8 DNA associated with them. The exosomal NANOG DNA has certain differences as compared to its normal counterpart that are of immense importance as a potential cancer biomarker. NANOG has been demonstrated to play an essential role in the maintenance of embryonic stem cells, and its pseudogene, NANOGP8, is suggested to promote the cancer stem cell phenotype. Similarly, SOX2 is another stemness gene highly expressed in cancer stem cells with an intimate involvement in GBM progression and metastasis as well as promotion of tumorigenicity in Neuroblastoma (NB). Since exosomes are critical in intercellular communication with a role in dissipating hallmark biomolecules responsible for cancer, we conducted a detailed analysis of the association of the SOX2 gene with exosomes whose sequence modulations with further research and appropriate sample size can help to identify diagnostic markers for cancer. We have detected SOX2 DNA associated with exosomes and have identified some of the SNPs and nucleotide variations in the sequences from a GBM and SH-SY5Y sample. Although a further systematic investigation of exosomal DNA from GBM and NB patient's blood is needed, finding of SOX2 DNA in exosomes in the current study may have value in clinical research. SOX2 is known to be misregulated in cancer cells by changes in miRNA function, such as SNPs in the binding sites. Our finding of cancer-specific SNPs in exosomal SOX2 DNA sequence may reflect those changes in the cancer stem cells as well as cancer cells. A series of our study on embryonic stem cell gene analysis in exosomal DNA may lead to a minimally invasive exosome-based diagnosis, and give us a key in understanding the mechanisms of cancer formation, progression, and metastasis.

Association of CD44 gene rs187115 polymorphism with colorectal cancer risk and prognosis in Chinese Han population: a case-control study

The cell surface adhesion receptor CD44 reportedly affects the development and progression of cancers. Moreover, CD44 gene rs187115 polymorphism appears to be genetic determinant of cancer susceptibility. We investigated whether CD44 rs187115 polymorphism is associated with colorectal cancer (CRC) risk and prognosis. We enrolled 669 CRC cases and 826 controls in this three-center case-control study in a Chinese Han population. All individuals were genotyped by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Cross-over analysis, multivariate logistic regression, Kaplan-Meier method, and Cox regression analysis were used for analysis. In this study, CD44 rs187115 polymorphism was associated with increased risk for CRC. Stratified analyses revealed that CD44 rs187115 polymorphism was correlated with increased risk for CRC in females, drinkers, smokers, and those aged ≥ 60 years. In addition, rs187115 polymorphism was significantly associated with TNM III+IV stage, lymph node metastasis and tumor size in CRC patients. Combined effects of CD44 rs187115 polymorphism (GG/AG vs. AA) and environmental factors (smoking and drinking) further increased the risk of CRC. GG genotype carriers showed poorer overall survival than AA genotype carriers. Cox regression analysis showed that drinking, CD44 rs187115 polymorphism, and TNM stage were independent prognostic factors affecting CRC. These findings show that CD44 rs187115 polymorphism may be a potential biomarker predictive of CRC susceptibility and prognosis.

Long non-coding RNA DILC promotes the progression of gallbladder carcinoma

Increasing evidence has demonstrated that long non-coding RNAs (lncRNAs) contribute to tumorigenesis, progression and recurrence of various malignancies including Gallbladder carcinoma (GBC). Lnc-DILC is reported to be the tumor suppressor gene to play an important role in liver cancer stem cells (CSCs). However, the role of lnc-DILC in GBC remains to be elucidated. Herein, we show that lnc-DILC is upregulated in gallbladder CSCs and GBC patients' tissues. Knockdown of lnc-DILC attenuates the self-renewal, tumorigenicity, proliferation and metastasis of gallbladder CSCs. Mechanistically, lnc-DILC promotes gallbladder CSCs expansion via Wnt/β-catenin pathway. Special Wnt/β-catenin inhibitor FH535 diminishes the discrepancy of self-renewal, growth and metastasis between lnc-DILC interference GBC cells and their control cells. In conclusion, lnc-DILC drives gallbladder CSCs self-renewal, tumorigenicity, proliferation and metastasis by activating Wnt/β-catenin signaling, and may therefore prove to be a potential therapeutic target for GBC patients.

CD44 is overexpressed and correlated with tumor progression in gallbladder cancer

Background

Gallbladder cancer (GBC) is a highly lethal disease and the most common biliary tract malignant tumor with poor prognosis. Accumulating evidence indicates that cluster of differentiation 44 (CD44) is overexpressed in several malignancies and has a crucial role in the development of cancer. However, its expression and function in GBC are unclear. The aim of this study was to explore CD44 expression and its role in GBC.

Materials and methods

The expression of CD44 was measured by immunohistochemistry. Tissue microarray analysis was used to confirm the relationship between CD44 expression and clinical outcomes of GBC patients. EDU assay, colony formation assay, cell migration and invasion assay were performed to detect the functions of CD44 in GBC-SD and NOZ transfected with si-RNA.

Results

CD44 was overexpressed and associated with poor outcomes in GBC patients. The univariate and multivariate analyses confirmed that elevated CD44 was an independent prognostic factor for the OS of GBC patients. Silencing CD44 could suppress the GBC cell proliferation, migration and invasion in vitro, as well as attenuated cancer stem cell functions.

Conclusion

CD44 markedly correlated with aggressive tumor behaviors and contributed to the progression of GBC, which could represent a novel prognostic marker and potential therapeutic target for GBC patients.

Genetic landscape of gallbladder cancer: Global overview

Gallbladder cancer (GBC) is a rare malignancy of biliary tract cancer (BTC), characterized by late presentation and poor prognosis. It exhibits wide geographical as well as ethnical variations. So, diverse epidemiology along with etiological factors have been discussed in the current article. Present review unravels the germ line polymorphisms contributing to GBC susceptibility through candidate gene approach and GWAS. GBC is enriched with multiple mutations consisting of both passenger and driver mutations. The identification of the hotspot driver mutations which are involved in the etiopathogenesis of this cancer is necessary, before targeted therapies could be implemented clinically. Thus, this review sheds lights on both traditional low throughput methods along with high throughput NGS used to determine somatic mutations in cancer. With the advent of GWAS and high throughput sequencing methods, it is possible to comprehend the mutational landscape of this enigmatic disease. This article is the first one to provide insights into the genetic heterogeneity of GBC along with somatic mutational data from Catalogue of Somatic Mutations in Cancer (COSMIC) database. In addition, management of tumor heterogeneity as a therapeutic challenge has been discussed. Future goals involve liquid biopsy based research for better clinical management of the disease. Therefore, research efforts involving discovery of non- invasive markers for early stage cancer detection along with novel therapies should be directed.

Common polymorphisms in CD44 gene and susceptibility to cancer: A systematic review and meta-analysis of 45 studies

CD44 is one of the commonly recognized stem cell markers, which plays a critical role in many cancer related cellular processes. Relationships between CD44 polymorphisms and cancer risk have been widely investigated previously, whereas results derived from these studies were inconclusive and controversial. We conducted present meta-analysis aiming to explore the association between CD44 polymorphisms and cancer risk. We calculated pooled odds ratios (ORs) corresponding with the 95% confidence intervals (CIs) to make the evaluation clear. Embase, Web of Science, PubMed and Cochrane Library databases were retrieved to identify all eligible publications. As a result, a total of 12 publications comprised 25,777 cases and 27,485 controls fulfilled the inclusion criteria. Nevertheless, the pooled analyses suggested that no significant association was uncovered between CD44 (rs10836347, rs11821102, rs13347, rs1425802, rs353639, rs713330 and rs187115) polymorphisms with overall cancer risk. Subsequently, we conducted subgroup analysis for rs13347 polymorphism based on source of control, and we identified a significantly increased cancer risk for the population-based (P-B) group restricted to a recessive model (TT vs. TC+CC: OR = 2.030, 95%CI: 1.163-3.545, PAdjust < 0.001). In conclusion, our meta-analysis demonstrates that CD44 polymorphisms may not represent risk factors for cancer. Future well-designed large-scale case-control studies are warranted to verify our findings.

Gallbladder cancer epidemiology, pathogenesis and molecular genetics: Recent update

Gallbladder cancer is a malignancy of biliary tract which is infrequent in developed countries but common in some specific geographical regions of developing countries. Late diagnosis and deprived prognosis are major problems for treatment of gallbladder carcinoma. The dramatic associations of this orphan cancer with various genetic and environmental factors are responsible for its poorly defined pathogenesis. An understanding to the relationship between epidemiology, molecular genetics and pathogenesis of gallbladder cancer can add new insights to its undetermined pathophysiology. Present review article provides a recent update regarding epidemiology, pathogenesis, and molecular genetics of gallbladder cancer. We systematically reviewed published literature on gallbladder cancer from online search engine PubMed (http://www.ncbi.nlm.nih.gov/pubmed). Various keywords used for retrieval of articles were Gallbladder, cancer Epidemiology, molecular genetics and bullion operators like AND, OR, NOT. Cross references were manually searched from various online search engines (http://www.ncbi.nlm.nih.gov/pubmed,https://scholar.google.co.in/, http://www.medline.com/home.jsp). Most of the articles published from 1982 to 2015 in peer reviewed journals have been included in this review.

Different Genotype of rs3130932 Single Nucleotide Polymorphism Between Gastric Cancer Patients and Normal Subjects

PURPOSE

Octamer binding transcription factor B gene (OCT4) is responsible for development and self-renewal maintenance of embryonic stem cells. The rs3130932 single nucleotide polymorphism (SNP) may play a role in tumor genesis. Because of high prevalence of gastric cancer in north of Iran, this study was investigated role of rs3130932 polymorphism and stomach cancer.

METHODS

Blood samples were collected from 100 informed gastric cancer patients and 100 age and sex-matched healthy individuals, and were genotyped for the presence of rs3130932G allele by ssp PCR.

RESULTS

The mean age of participant (n = 200) was 67.83 ± 10.878 years. In genotyping and allelic analysis, TG genotype increased 66.147 times more likely to develop stomach cancer than the TT genotype, and disease risk increases 140.496 times more in GG genotype in comparison with TT genotype.

CONCLUSION

This study clearly emphasis on different genetic profile in this population and show that the rs3130932G allele and odds of gastric cancer are related to each other in northern of Iran.

Associations of five polymorphisms in the CD44 gene with cancer susceptibility in Asians

CD44 polymorphisms have been previously associated with cancer risk. However, the results between independent studies were inconsistent. Here, a meta-analysis was performed to systematically evaluate associations between CD44 polymorphisms and cancer susceptibility. A comprehensive literature search conducted in PubMed, Embase, and Web of Science databases through August 10, 2016 yielded 11 eligible publications consisting of 5,788 cancer patients and 5,852 controls. Overall, odds ratios (OR) calculated with 95% confidence intervals (CI) identified a significant association between CD44 polymorphism rs13347 and cancer susceptibility under all genetic models. Additionally, the minor allele of polymorphism rs11821102 was associated with a decreased susceptibility to cancer in allele contrast, dominant, and heterozygous models, while no significant association was identified for polymorphisms rs10836347, rs713330, or rs1425802. Subgroup analysis by ethnicity revealed rs13347 was significantly associated with cancer susceptibility for Chinese but not for Indians. Linkage disequilibrium (LD) between different polymorphisms varied across diverse ethnic populations. In conclusion, the results indicate that CD44 polymorphism rs13347 acts as a risk factor for cancer, especially in Chinese, while the minor allele of polymorphism rs11821102 may be associated with a decreased susceptibility to cancer. Nevertheless, further studies on a larger population covering different ethnicities are warranted.

Genetic Variation in CD166 Gene and Its Association with Bladder Cancer Risk in North Indian Population

Adhesion molecules play a key role in cancer progression and tumorigenesis. Genetic polymorphism of adhesion molecules may alter the normal functioning thereby leading to bladder cancer susceptibility. Hence we aimed to evaluate three SNPs of CD166 gene (CD166rs6437585 C/T, CD166rs10511244 C/T, and CD166rs1157 A/G) in bladder cancer patients and normal controls of North Indian population. A total of 270 healthy controls and 240 confirmed bladder cancer patients were recruited for this study. Three SNPs of CD166 gene viz. CD166rs6437585 C/T, CD166rs10511244 C/T, and CD166rs1157 A/G were selected for this study. CD166rs6437585 C/T and CD166rs10511244 C/T were genotyped by Taqman allelic discrimination assay and CD166rs1157 A/G was genotyped by PCR-RFLP. The statistical analysis was done using the SPSS software, version 16.0 (SPSS, Chicago, IL), and p < 0.05 was considered statistically significant. Haplotypic analysis was done by using SNP analyzer version 1.2A. CD166rs6437585 C/T and CD166rs10511244 C/T showed significant association with reduced risk in bladder cancer while CD166rs1157 A/G showed significant high risk along with association at genotypic and allelic levels. Haplotypic analysis showed 1.8-folds risk in CCG combination, whereas CTA and TCG showed significant association with reduced risk. Further stratification on the basis of smoking, tumor grade/stage and BGC therapy revealed no association of these three polymorphic sites of CD166. Our study suggests that CD166rs6437585 C/T and CD166rs10511244 C/T are predictive for the reduced risk of bladder cancer, whereas CD166rs1157 A/G had shown significant association with high risk of bladder cancer in North Indians. This somehow suggests that CD166rs1157 A/G can be used as a marker for risk prediction of bladder cancer.

Positive association between CD44 gene rs13347 C>T polymorphism and risk of cancer in Asians: a systemic review and meta-analysis

Background

Cluster of differentiation 44 (CD44) is an important surface marker of cancer stem cells in a variety of tumors. A number of previous studies have been conducted to investigate the association between CD44 gene rs13347 C>T polymorphism and cancer risk in humans; nevertheless, the results remain controversial. We therefore performed this meta-analysis to confirm the role of this polymorphism in susceptibility to human cancer.

Materials and methods

The studies published up to December 2015 were searched in PubMed, Web of Science, and China National Knowledge Infrastructure databases. Twelve eligible case–control studies were identified, involving a total of 6,982 cases and 7,430 controls. Pooled odds ratio (OR) and corresponding 95% confidence interval (CI) were calculated using a fixed or random-effect model to estimate the strength of the association.

Results

The results of the overall analyses indicated that CD44 gene rs13347 polymorphism was significantly associated with cancer risk in Asians (CT vs CC: OR =1.35, 95% CI =1.12–1.62; TT vs CC: OR =1.99, 95% CI =1.52–2.60; TT + CT vs CC: OR =1.41, 95% CI =1.16–1.71; and TT vs CC + CT: OR =1.74, 95% CI =1.41–2.14), especially in Chinese population (CT vs CC: OR =1.42, 95% CI =1.16–1.75; TT vs CC: OR =2.13, 95% CI =1.58–2.86; TT + CT vs CC: OR =1.50, 95% CI =1.21–1.87; and TT vs CC + CT: OR =1.80, 95% CI =1.43–2.26). In stratified analyses by cancer types, there was evidence for an association between this polymorphism and nasopharyngeal cancer and breast cancer, respectively.

Conclusion

The results of this meta-analysis suggest that the CD44 gene rs13347 C>T polymorphism is associated with elevated risk of human cancer in Asians, especially in Chinese population. Further well-designed studies on a larger population covering other ethnicities should be carried out to validate our results.

Association of Wnt signaling pathway genetic variants in gallbladder cancer susceptibility and survival

Gallbladder cancer (GBC) is the most common malignancy of the biliary tract with adverse prognosis and poor survival. Wnt signaling plays an important role in embryonic development and regeneration of tissues in all the species. Deregulation of expression and mutations in this pathway may lead to disease state such as cancer. In this study, we assessed the association of common germline variants of Wnt pathway genes (SFRP2, SFRP4, DKK2, DKK3, WISP3, APC, β-catenin, AXIN-2, GLI-1) to evaluate their contribution in predisposition to GBC and treatment outcomes. The study included 564 GBC patients and 250 controls. Out of 564, 200 patients were followed up for treatment response and survival. Tumor response (RECIST 1.1) was recorded in 116 patients undergoing non-adjuvant chemotherapy (NACT). Survival was assessed by Kaplan-Meier curve and Cox-proportional hazard regression. Single locus analysis showed significant association of SFRP4 rs1802073G > T [p value = 0.0001], DKK2 rs17037102C > T [p value = 0.0001], DKK3 rs3206824C > T [p value = 0.012], APC rs4595552 A/T [p value = 0.021], APC rs11954856G > T [p value = 0.047], AXIN-2 rs4791171C > T [p value = 0.001], β-catenin rs4135385A > G [p value = 0.031], and GLI-1 rs222826C > G [p value = 0.001] with increased risk of GBC. Gene-gene interaction using GMDR analysis predicted APC rs11954856 and AXIN2 rs4791171 as significant in conferring GBC susceptibility. Cox-proportional hazard model showed GLI-1 rs2228226 CG/GG and AXIN-2 rs4791171 TT genotype higher hazard ratio. In recursive partitioning, AXIN-2 rs4791171 TT genotype showed higher mortality and hazard. Most of studied genetic variants influence GBC susceptibility. APC rs11954856, GLI-1 rs2228226, and AXIN-2 rs4791171 were found to be associated with poor survival in advanced GBC patients.