Role of microRNA-363 during tumor progression and invasion

Recent progresses in diagnostic and therapeutic methods have significantly improved prognosis in cancer patients. However, cancer is still considered as one of the main causes of human deaths in the world. Late diagnosis in advanced tumor stages can reduce the effectiveness of treatment methods and increase mortality rate of cancer patients. Therefore, investigating the molecular mechanisms of tumor progression can help to introduce the early diagnostic markers in these patients. MicroRNA (miRNAs) has an important role in regulation of pathophysiological cellular processes. Due to their high stability in body fluids, they are always used as the non-invasive markers in cancer patients. Since, miR-363 deregulation has been reported in a wide range of cancers, we discussed the role of miR-363 during tumor progression and metastasis. It has been reported that miR-363 has mainly a tumor suppressor function through the regulation of transcription factors, apoptosis, cell cycle, and structural proteins. MiR-363 also affected the tumor progression via regulation of various signaling pathways such as WNT, MAPK, TGF-β, NOTCH, and PI3K/AKT. Therefore, miR-363 can be introduced as a probable therapeutic target as well as a non-invasive diagnostic marker in cancer patients.

Single nucleotide polymorphisms within NFKBIA are associated with nasopharyngeal carcinoma susceptibility in Chinese Han population

Genes involved in latent membrane protein 1 (LMP1) signaling pathways have been suggested to play an important role in nasopharyngeal carcinogenesis. We investigated potentially functional genetic variants associated with the risk of nasopharyngeal carcinoma (NPC) in genes involved in the LMP1 signaling pathway. Altogether, 73 single nucleotide polymorphisms (SNPs) with MAF ≥ 10% were located within the regions of interest of the four genes TRAF3, NFKBIA, CHUK and MAP2K4. From these, 10 SNPs were selected for genotyping based on LD (r² ≥ 0.80) in a hospital-based case-control study of 332 NPC cases and 585 healthy controls from the Chinese Han population. Minor allele carriers of the promoter SNP rs2233409 in NFKBIA, had an increased risk of NPC (AA vs GG: OR 7.14, 95%CI, 1.08-34.18, P = 0.04, dominant model). Based on the results, we concluded that rs2233409 polymorphism in NFKBIA may be moderately associated with the risk of NPC. Further studies with larger independent samples and functional analysis are needed to verify our results.

Long noncoding RNA HNF1A-AS1 regulates proliferation and apoptosis of glioma through activation of the JNK signaling pathway via miR-363-3p/MAP2K4

Long noncoding RNAs (lncRNAs) have been proven to exert important functions in the various biological processes of human cancers. It has been reported that lncRNA HNF1 homeobox A antisense RNA 1 (HNF1A-AS1) was abnormally expressed and played a role in the initiation and development of various human cancers. In this study, we confirmed that the expression level of HNF1A-AS1 was increased in glioma tissues and cells. Knockdown of HNF1A-AS1 inhibited cell proliferation and promoted cell apoptosis in glioma. Then, we disclosed the downregulation of miR-363-3p in glioma tissues and cell lines. The interaction between HNF1A-AS1 and miR-363-3p was identified in glioma cells. Furthermore, an inverse correlation between HNF1A-AS1 and miR-363-3p was observed in glioma tissues. Afterwards, we recognized that MAP2K4 was a direct target of miR-363-3p. The expression of MAP2K4 was negatively correlated with miR-363-3p while positively related to HNF1A-AS1 in glioma tissues. We also found the regulatory effect of HNF1A-AS1 on the MAP2K4-dependent JNK signaling pathway. All findings indicated that HNF1A-AS1 induces the upregulation of MAP2K4 to activate the JNK signaling pathway to promote glioma cell growth by acting as a miR-363-3p sponge.

Overexpressed microRNA-136 works as a cancer suppressor in gallbladder cancer through suppression of JNK signaling pathway via inhibition of MAP2K4

In recent studies, microRNAs (miRs) have been widely explored as important regulators in tumor suppression. miR-136 has been suggested to participate in tumor inhibition through control of vital cellular processes, such as angiogenesis, proliferation, and apoptosis. This study aimed to evaluate the effects of overexpressed miR-136 by transferring mimics in gallbladder cancer (GBC) and to assess the functional role of miR-136 in GBC cell behaviors with the involvement of the mitogen-activated protein kinase kinase 4 (MAP2K4)-dependent JNK signaling pathway. Differentially expressed miRs associated with GBC were screened using microarray expression profiles, which identified that miR-136 expression was decreased in GBC. Furthermore, MAP2K4 was validated as a target gene of miR-136. To uncover functional relevance regarding miR-136 and MAP2K4 in GBC, cultured GBC cell lines were prepared to transfect with mimic, inhibitor, siRNA, or vectors. At the same time, the transfected GBC cells were inoculated into nude mice to validate findings in vivo. The obtained results demonstrated that overexpressed miR-136 inhibited angiogenesis and cell proliferation and promoted apoptosis in GBC cell lines in vitro, accompanied by impeded cellular tumorigenicity in nude mice via the suppression of MAP2K4. Moreover, the overexpression of MAP2K4 and the activation of the JNK signaling pathway reversed the inhibitory effects of miR-136 on the angiogenesis and tumorigenicity of GBC cells. Together, our results indicated that overexpressed miR-136 attenuates angiogenesis and enhances cell apoptosis in GBC via the JNK signaling pathway by downregulating the expression of MAP2K4.NEW & NOTEWORTHY This study is based on previous studies suggesting the tumor-suppressive role of microRNA (miR)-136 in various cancers. We aim to clarify whether miR-136 could function as a tumor suppressor in gallbladder cancer (GBC) and an underlying mechanism. In vitro and in vivo assays delineated that the tumor-suppressive role of miR-136 in GBC is achieved through inactivation of the JNK signaling pathway by downregulation of MAP2K4.

Evaluation of the association between the -1304T>G polymorphism in the promoter of the MKK4 gene and the risk of colorectal cancer: a PRISMA-compliant meta-analysis

Background

Colorectal cancer (CRC) is one of the most common cancers in China. Mitogen-activated protein kinase kinase 4 (MKK4) regulates tumorigenesis as a component of the MKK4 pathway. A number of studies have suggested a correlation between the MKK4 -1304T>G polymorphism and the risk of CRC. However, the results are still controversial. Therefore, we conducted a meta-analysis to obtain a more accurate assessment of the association between the MKK4 -1304T>G polymorphism and the risk of CRC.

Methods

Systematic literature searches were performed using PubMed, Embase, Cochrane Library, and CNKI. Four trials, including 1,255 cancer cases and 1,181 controls, were recruited in our study to assess the relationship of the MKK4 -1304T>G polymorphism with the risk of CRC.

Results

Four studies met our inclusion criteria and were finally included in the analysis, involving 1,255 cancer patients and 1,181 controls. Our meta-analysis revealed that the MKK4 -1304T>G polymorphism could reduce the risk of CRC (G vs. T: OR, 0.60, 95% CI: 0.48-0.76, P<0.0001; GG vs. TT: OR, 0.43, 95% CI: 0.29-0.62, P<0.0001; GG vs. TT + TG: OR, 0.50, 95% CI: 0.34-0.72, P=0.0003; TG + GG vs. TT: OR, 0.62, 95% CI: 0.53-0.73, P<0.0001; and TG vs. TT + GG: OR, 0.70, 95% CI: 0.59-0.82, P<0.0001).

Conclusions

In conclusion, our meta-analysis showed that the MKK4 -1304T>G polymorphism was associated with the susceptibility to CRC. In the future, large and well-designed case-control studies are needed to validate our findings.

XPG rs873601 G>A contributes to uterine leiomyoma susceptibility in a Southern Chinese population

XPG gene contributes to DNA repair defects and genomic instability, which may lead to the initiation of uterine leiomyoma. We hypothesized that genetic variants of XPG gene may alter the carriers' susceptibility to leiomyoma. The association between five potential functional single nucleotide polymorphisms (SNPs), i.e. rs2094258 C>T, rs751402 C>T, rs2296147 T>C, rs1047768 T>C, rs873601 G>A, and uterine leiomyoma risk in Chinese, was investigated in this case-control study, which included 398 incident leiomyoma cases and 733 controls. We found that rs873601 was significantly associated with tumor risk in a recessive genetic model after being adjusting for age and menopause. When compared with rs873601 GG/GA genotypes, the AA genotype had an increased leiomyoma risk (adjusted OR = 1.59, 95% CI = 1.16-2.18, P=0.004; Bonferroni adjusted P=0.040). Furthermore, stratified analysis revealed that the association between the rs873601 AA genotype and leiomyoma risk was more evident among subjects younger than 40 years old (adjusted OR = 1.58, 95% CI = 1.06-2.35, P=0.023) and patients who had more than three myomas (adjusted OR = 2.05, 95% CI = 1.24-3.41, P=0.006). Yet, no significant association between the other four polymorphisms and leiomyoma risk was observed. To sum up, the present study reported on the association between XPG gene polymorphisms and myoma risk. The observed data indicated that SNP rs873601 G>A contributes to uterine leiomyoma susceptibility in a Southern Chinese population.

Functional Polymorphism in the MSI1 Gene Promoter Confers a Decreased Risk of Lung Cancer in Chinese by Reducing MSI1 Expression

Background:

Musashi1 (MSI1) is a characteristic stem cell marker that regulates the balance between cell self-renewal and differentiation. Evidence has identified MSI1 as a pivotal oncogenic regulator in diverse malignancies. However, little evidence uncovers the role of genetic variations of MSI1 gene in cancer etiology.

Objective:

The aim of this study was to investigate the association between genetic variants in the MSI1 gene and lung cancer risk.

Methods:

Based on a two-stage retrospective study with a total of 1559 patients with lung cancer and 1667 healthy controls, we evaluated the relevance between three putative functional SNPs in the MSI1 promoter (i.e., -2696T>C[rs7959801], -2297T>C[rs3742038] and -1081C>T[rs34570155]) and lung cancer risk.

Results:

We found that the SNP rs7959801T>C was significantly associated with lung cancer susceptibility. Compared to those with rs7959801TT wild-genotype, individuals with CT/CC variant genotypes exerted consistently beneficial roles in lung cancer risk in the discovery set (adjusted odd ratios [OR] = 0.67; 95% confidence interval [CI] = 0.57-0.80), and in the validation set (OR=0.69; 95%CI=0.54-0.88). Functional assays indicated that the allele transformation from T to C in rs7959801 of MSI1 gene arrestingly decreased its transcription activity in vitro. Furthermore, the expression levels of MSI1 were significantly lower in the patients with CT/CC variants than in those who were with TT genotype.

Conclusion:

Our findings suggested that the rs7959801T>C polymorphism in the MSI1 promoter conferred a decreased risk to lung cancer by reducing the expression of MSI1 and it may be a promising indicator for lung cancer predisposition.

Identification and analysis of an MKK4 homologue in response to the nucleus grafting operation and antigens in the pearl oyster, Pinctada fucata

The mitogen-activated protein kinase kinase 4 (MKK4) is a key component of the c-Jun N-terminal kinase (JNK) signaling pathway and regulates multiple cellular activities. However, little is known about the roles of this kinase in pearl oyster. In this study, we identified an MKK4 homologue in Pinctada fucata by using a transcriptome database. Sequence analysis and protein structure prediction showed that PfMKK4 is highly conserved to MKK4 from other vertebrate and invertebrate species. Phylogenetic analysis revealed that PfMKK4 has the closest relationship with that from Crassostrea gigas. QPCR was used to investigate expression profiles in different healthy adult tissues and developmental stages of P. fucata. We found that PfMKK4 was ubiquitously expressed in all tissues and developmental stages examined except for in D-shaped larvae. Gene expression analysis suggested that PfMKK4 is involved in the response to the nucleus insertion operation. Lipopolysaccharide (LPS) and polyinosinic:polycytidylic acid [poly(I:C)] stimulation in vivo reduced PfMKK4 mRNA expression at 6 h, 48 h and 48 h, 72 h, respectively. LPS and poly(I:C) induced PfMKK4 phosphorylation in a primary mantle cell culture. These results contribute to better understanding of the potential role played by PfMKK4 in protecting the pearl oyster from injury caused by grafting or disease.

BRMS1 Expression in Surgically Resected Lung Adenocarcinoma Predicts Future Metastases and Is Associated with a Poor Prognosis

INTRODUCTION

Expression of breast cancer metastasis suppressor 1 gene (BRMS1) is decreased in NSCLC cells and tumors. We hypothesized that intratumoral breast cancer metastasis suppressor 1 (BRMS1) expression is associated with lung adenocarcinoma (LUAD) histologic subtypes and overall survival (OS) and disease-free survival (DFS) in patients undergoing resection for early-stage LUAD.

METHODS

Patients (N = 1030) who underwent complete resection for LUAD with tissue available for histologic evaluation were identified. Tissue microarrays were constructed, and immunostaining was performed and scored for intensity of BRMS1 expression. OS and DFS were estimated (by the Kaplan-Meier method) and compared between groups (by the log-rank test), stratified by stage. Hazard ratios (HRs) for hazard of death and recurrence were estimated using univariable and multivariable Cox proportional hazards models. OS and DFS nomograms were created, and model performance was examined.

RESULTS

Intratumoral BRMS1 expression was high in 632 patients (61%) and low in 398 (39%). Low BRMS1 expression was associated with higher pathologic T stage (p = 0.001), larger tumor size (p ≤ 0.0001), greater lymphatic (p = 0.032) and vascular (p = 0.001) invasion, LUAD histologic subtype (p = 0.001), and intermediate and high architectural tumor grade (p = 0.003). Low BRMS1 expression was an independent predictor of worse OS (HR = 1.35, 95% confidence interval: 1.10-1.65, p = 0.004) and DFS (HR = 1.27, 95% confidence interval: 1.05-1.54, p = 0.012). OS and DFS nomograms showed excellent predictive performance based on discrimination and calibration.

CONCLUSIONS

Among patients with surgically resected LUAD, OS and DFS were significantly worse in cases with low intratumoral BRMS1 expression. Our findings suggest that BRMS1 is an independent biomarker with prognostic significance in surgically resected LUAD.

[Coexpression of MAP2K4 and vimentin proteins in human endometrial carcinoma and its clinicopathological significance]

OBJECTIVE

To analyze the expression of MAP2K4 and vimentin in human endometrial carcinoma (EC) and their association with the clinicopathological features and prognosis of the patients.

METHODS

MAP2K4 and vimentin expressions were detected immunohistochemically in paraffin-embedded tissue sections from 128 patients with EC, and the correlation of MAP2K4 and vimentin expressions with the clinicopathological factors of the patients was analyzed.

RESULTS

MAP2K4 and vimentin proteins were positively expressed in 49 (38.3%) and 83 (64.8%) of the patients, respectively. A positive expression of MAP2K4 was negatively correlated with FIGO stage of the tumor (P=0.010) and lymph node status (P=0.016); a positive expression of vimentin was positively correlated with FIGO stage of the tumor (P=0.025), histological grades (P=0.017), depth of myometrial invasion (P=0.044) and lymph node status (P=0.032). MAP2K4 was inversely associated with vimentin expression in EC(r=-0.598, P<0.001). Patients positive for MAP2K4 tended to have a higher overall survival rate (P=0.002), and those positive for vimentin tended to have a lower overall survival rate (P=0.007); patients positive for MAP2K4 but negative for vimentin had the longest survival time, while those negative for MAP2K4 and positive for vimentin had lowest survival rate (P=0.004).

CONCLUSION

Detection of MAP2K4 and vimentin might help in early diagnosis and prognostic evaluation of patients with EC.

Registered report: Diverse somatic mutation patterns and pathway alterations in human cancers

The Reproducibility Project: Cancer Biology seeks to address growing concerns about reproducibility in scientific research by conducting replications of selected experiments from a number of high-profile papers in the field of cancer biology. The papers, which were published between 2010 and 2012, were selected on the basis of citations and Altmetric scores (Errington et al., 2014). This Registered Report describes the proposed replication plan of key experiments from "Diverse somatic mutation patterns and pathway alterations in human cancers" by Kan and colleagues published in Nature in 2010 (Kan et al., 2010). The experiments to be replicated are those reported in Figures 3D-F and 4C-F. Kan and colleagues utilized mismatch repair detection (MRD) technology to identify somatic mutations in primary human tumor samples and identified a previously uncharacterized arginine 243 to histidine (R243H) mutation in the G-protein α subunit GNAO1 in breast carcinoma tissue. In Figures 3D-F, Kan and colleagues demonstrated that stable expression of mutant GNAO1(R243D) conferred a significant growth advantage in human mammary epithelial cells, confirming the oncogenic potential of this mutation. Similarly, expression of variants with somatic mutations in MAP2K4, a JNK pathway kinase (shown in Figures 4C-E) resulted in a significant increase in anchorage-independent growth. Interestingly, these mutants exhibited reduced kinase activity compared to wild type MAP2K4, indicating these mutations impose a dominant-negative influence to promote growth (Figure 4F). The Reproducibility Project: Cancer Biology is a collaboration between the Center for Open Science and Science Exchange and the results of the replications will be published in eLife.

Mitogen-Activated Protein Kinase Kinase 4 Gene Polymorphism and Cancer Risk

A number of epidemiological studies have assessed the association of -1304T > G polymorphism in the MKK4 gene and risk of cancer, but the results lack of statistical power due to the limited subjects used in these studies. This study was devised to identify the genetic effects of the -1304T > G polymorphism on cancer risk in a large meta-analysis.Eligible studies were identified by searching both Chinese and English databases. General as well as subgroup analyses were performed for 8 independent case-control publications with a total of 4623 cases and 5256 cancer-free controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to estimate the association.Overall, this meta-analysis showed that the association between the -1304T > G polymorphism and cancer risk was statistically significant (GG vs TT: OR = 0.63, 95% CI, 0.52-0.75; GG + TG vs TT: OR = 0.85, 95% CI, 0.79-0.91; GG vs TG + TT: OR = 0.67, 95% CI, 0.56-0.80; G vs T: OR = 0.82, 95% CI, 0.77-0.88; TG vs TT: OR = 0.86, 95% CI, 0.79-0.93).Our meta-analysis reveals that the presence of the -1304T > G polymorphism is likely to decrease risk of cancer. Future larger studies are necessary to validate the current finding.

Polymorphisms of NFκB1 and IκBα and Their Synergistic Effect on Nasopharyngeal Carcinoma Susceptibility

Nasopharyngeal carcinoma (NPC) is a multifactoral and polygenic disease with high prevalence in Southeast Asia and Southern China. Environmental factors and genetic susceptibility play important roles in NPC pathogenesis. In the present study, we tested the hypothesis that single nucleotide polymorphisms (SNPs) in nuclear factor-kappa B (NFκB) and its inhibitor (IκBα) conferred consistent risks for NPC. Four putatively functional SNPs (NFκB1: rs28362491del>ins ATTG; NFκB2: rs12769316G>A; IκBα: rs2233406C>T and rs696G>A) were analyzed to evaluate their associations with NPC risk in total 1590 NPC cases and 1979 cancer-free controls. We found that the rs28362491 insATTG variants (ins/del + ins/ins) in NFκB1 conferred an increased risk of NPC (odds ratio [OR] = 1.30, 95% confidence interval [CI] = 1.09–1.55, and P = 2.80 × 10⁻³) compared with the del/del homozygous genotype. The rs696AA variant in IκBα had an increased risk of NPC (OR = 1.41, 95% CI = 1.20–1.66, and P = 2.28 × 10⁻⁵) by decreasing IκBα expression due to the modulation of microRNA hsa-miR-449a. Furthermore, both adverse genotypes of NFκB/IκBα and their interaction also exerted an increased risk on NPC. Taken together, Our findings indicated that genetic variants in NFκB1 (rs28362491del>ins ATTG) and IκBα (rs696G>A) and their synergistic effect might contribute to NPC predisposition.

Polymorphism in mature microRNA-608 sequence is associated with an increased risk of nasopharyngeal carcinoma

Accumulative evidences indicated that microRNAs (miRNAs) can function as tumor suppressors and oncogenes, in which genetic variations are implicated in various cancer susceptibilities. However, it remains unclear whether single nucleotide polymorphisms (SNPs) in mature miRNA sequence alter nasopharyngeal carcinoma (NPC) susceptibility. In this study, we analyzed associations between eight SNPs in miRNA mature sequences (i.e., rs3746444T>C in hsa-mir-499, rs4919510C>G in hsa-mir-608, rs13299349G>A in hsa-mir-3152, rs12220909G>C in hsa-mir-4293, rs2168518G>A in hsa-mir-4513, rs8078913T>C in hsa-mir-4520a, rs11237828T>C in hsa-mir-5579, and rs9295535T>C in hsa-mir-5689) and NPC susceptibility in southern China with 906 NPC cases and 1072 cancer-free controls, and validated the significant findings in eastern China with 684 cases and 907 healthy controls. Functional assays were further performed to identify the biological effects of these polymorphisms. We found that rs4919510C>G polymorphism showed a consistent association with NPC risk in southern China (GC+GG versus CC genotype, odds ratio [OR]=1.36, 95% confidence interval [CI]=1.10-1.70) and eastern China (GC+GG versus CC: OR=1.37, 95% CI=1.08-1.74). After the two populations were merged, the ORs and 95% CI were 1.38 and 1.18 to 1.62, respectively. Moreover, the rs4919510C>G adverse genotypes significantly interacted with Epstein-Barr virus (EBV) infection on increasing NPC risk (P=0.001). The functional assay further showed that the CNE-2 cell lines that transfected with miR-608-rs4919510G allele expression vector exerted more colony number formations than cell lines that transfected with miR-608-rs4919510C allele expression vector (P=0.001). These data suggested that rs4919510C>G of miR-608 may be a susceptible biomarker of NPC in China.

The functional polymorphism of NBS1 p.Glu185Gln is associated with an increased risk of lung cancer in Chinese populations: case-control and a meta-analysis

NBS1 plays pivotal roles in maintaining genomic stability and cancer development. The exon variant rs1805794G>C (p.Glu185Gln) of NBS1 has been frequently studied in several association studies. However, the results were conflicting. Also, the function of this variant has never been well studied. In the current study, we performed a two centers case-control study and function assays to investigate the effect of the variant rs1805794G>C on lung cancer risk in Chinese, and a meta-analysis to summarize the data on the association between rs1805794G>C and cancer risk. We found that compared with the rs1805794GG genotype, the C genotypes (CG/CC) conferred a significantly increased risk of lung cancer in Chinese (OR=1.40, 95% CI=1.21-1.62) and interacted with medical ionizing radiation exposure on increasing cancer risk (Pinteraction=0.015). The lymphocyte cells from the C genotype individuals developed more chromatid breaks than those from the GG genotype carriers after the X-ray radiation (P=0.036). Moreover, the rs1805794C allele encoding p.185Gln attenuated NBS1's ability to repair DNA damage as the cell lines transfected with NBS1 cDNA expression vector carrying rs1805794C allele had significantly higher DNA breaks than those transfected with NBS1 cDNA expression vector carrying rs1805794G allele (P<0.05). The meta-analysis further confirmed the association between the variant rs1805794G>C and lung cancer risk, that compared with the GG genotype, the carriers of C genotypes had a 1.30-fold risk of cancer (95% CI=1.14-1.49, P=8.49×10(-5)). These findings suggest that the rs1805794G>C of NBS1 may be a functional genetic biomarker for lung cancer.

A functional polymorphism in the 3'-UTR of PXR interacts with smoking to increase lung cancer risk in southern and eastern Chinese smoker

Pregnane X receptor (PXR) is an important member of the nuclear receptor superfamily that copes with various endobiotic and xenobiotic stimuli, such as carcinogens by regulating an array of environmental response genes. Low PXR expression has been shown to promote tumor initiation and metastasis. The aim of the current study was to investigate whether the single nucleotide polymorphisms (SNPs) of PXR could alter lung cancer susceptibility in Chinese by affecting the function or expression of PXR. We genotyped three putatively functional SNPs of PXR (i.e., rs3814055C>T, rs3732360C>T, and rs3814058C>T) and analyzed their associations with lung cancer risk in a two-stage case-control study with a total of 1559 lung cancer cases and 1679 controls in the southern and eastern Chinese population. We found that in comparison to the rs3814058CC common genotype, the rs3814058T variants (TC/TT) which is located in the 3'-untranslated region (3'-UTR) of PXR conferred a consistently increased risk of lung cancer in both the southern Chinese (odd ratios (OR) = 1.24, 95% confidence interval (CI) = 1.03−1.49) and the eastern Chinese (OR = 1.33, 95% CI = 1.02−1.75). The variants also significantly interacted with smoking on increasing cancer risk (p = 0.023). Moreover, lung cancer tissues with the rs3814058T variants showed significantly lower PXR expression than those with rs3814058CC genotype in the smokers (p = 0.041). These results suggested that the rs3814058C>T polymorphism of PXR interacts with smoking on increasing lung cancer risk in Chinese smokers, which might be a functional genetic biomarker for lung cancer.

A Newfound association between MDC1 functional polymorphism and lung cancer risk in Chinese

Mediator of DNA damage checkpoint protein 1 (MDC1) plays an early and core role in Double-Strand Break Repair (DDR) and ataxia telangiectasia-mutated (ATM) mediated response to DNA double-strand breaks (DSBs), and thus involves the pathogenesis of several DNA damage-related diseases such as cancer. We hypothesized that the single nucleotide polymorphisms (SNPs) of MDC1 which have potencies on affecting MDC1 expression or function were associated with risk of lung cancer. In a two-stage case-control study, we tested the association between 5 putatively functional SNPs of MDC1 and lung cancer risk in a southern Chinese population, and validated the promising association in an eastern Chinese population. We found the SNP rs4713354A>C that is located in the 5′-untranslated region of MDC1 was significantly associated with lung cancer risk in both populations (P = 0.001), with an odds ratio as 1.33(95% confidence interval = 1.14–1.55) for the rs4713354C (CA+CC) genotypes compared to the rs4713354AA genotype. The correct sixth sentence is: The gene-based analysis rested with these SNPs suggested the MDC1 as a susceptible gene for lung cancer (P = 0.057) [corrected]. Moreover, by querying the gene expression database, we further found that the rs4713354C genotypes confer a significantly lower mRNA expression of MDC1 than the rs4713354AA genotype in 260 cases of lymphoblastoid cells (P = 0.002). Our data suggested that the SNP rs4713354A>C of MDC1 may be a functional genetic biomarker for susceptibility to lung cancer in Chinese.

Genetic variant in the 3'-untranslated region of VEGFR1 gene influences chronic obstructive pulmonary disease and lung cancer development in Chinese population

Lung inflammation and epithelial to mesenchymal transition (EMT) are two pathogenic features for the two contextual diseases: chronic obstructive pulmonary disease (COPD) and lung cancer. VEGFR1 (or FLT1) plays a certain role in promoting tumour growth, inflammation and EMT. To simultaneously test the association between the single nucleotide polymorphisms (SNPs) in VEGFR1 and risk of COPD and lung cancer would reveal genetic mechanisms shared by these two diseases and joint aetiology. We conducted a two-population hospital-based case-control study. Three potential functional SNPs (rs664393, rs7326277 and rs9554314) were genotyped in southern Chinese and validated in eastern Chinese to explore their associations with COPD risk in 1511 COPD patients and 1677 normal lung function controls, and with lung cancer risk in 1559 lung cancer cases and 1679 cancer-free controls. We also detected the function of the promising SNP. Individuals carrying the rs7326277C (CT+CC) variant genotypes of VEGFR1 had a significant decrease in risk of both COPD (OR = 0.78; 95% CI = 0.68-0.90) and lung cancer (OR = 0.79; 95% CI = 0.64-0.98), compared with those carrying the rs7326277TT genotype. Functional assays further showed that the rs7326277C genotypes had lower transcriptional activity and caused decreased VEGFR expression, compared with the rs7326277TT genotype. However, no significant association was observed for the other two SNPs (rs664393 and rs9554314) and either COPD or lung cancer risk. Our data suggested that the rs7326277C variant of VEGFR1 could reduce both COPD and lung cancer risk by lowering VEGFR1 mRNA expression; the SNP might be a common susceptible locus for both COPD and lung cancer.

Copy number variation at 6q13 is associated with lung cancer risk in a Han Chinese population

Copy number variations (CNVs), a major source of human genetic polymorphism, have been suggested to have an important role in genetic susceptibility to common diseases such as cancer, immune diseases, and neurological disorders. Lung cancer is a multifactorial tumor closely associated with genetic background. Previous genome-wide association studies have identified single nucleotide polymorphisms (SNPs) that are associated with lung cancer susceptibility. This study examined the CNVR2966.1 at 6q13 and its association with lung cancer susceptibility. The CNVR2966.1 was found to be a 10,379 bp nucleotides deletion/insertion within the uniform boundaries chromosome 6: 74,648,791-74,659,169. The risk of lung cancer observed in 503 cases and 623 controls was significantly associated with copy number of CNVR2966.1, with the odds ratio (OR) being 1.38 [95% confidence interval (CI) = 1.05-1.79; P = .007] for one copy genotype compared with two copies genotype. These results suggest that CNVR2966.1 is associated with lung cancer risk.

Polymorphisms of CD44 gene and nasopharyngeal carcinoma susceptibility in a Chinese population

As members of adhesion molecule families, CD44 transmembrane glycoproteins have been originally thought to be essential for the formation of multicellular organisms and soon recognised to be able to initiate metastatic spread of tumour cells. To investigate the association between CD44 polymorphisms and nasopharyngeal carcinoma (NPC), we carried out a two-stage case-control study in 906 patients and 943 healthy controls in Eastern populations. Five single nucleotide polymorphisms of CD44 (rs10836347C>T, rs13347C>T, rs1425802A>G, rs11821102G>A and rs713330T>C) with proper frequency were selected from the HapMap database and genotyped with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Compared with the most common rs13347CC genotype, CT+TT genotypes significantly increased individuals' susceptibility to NPC (odds ratio = 2.58, 95% confidence interval = 2.13-3.13). Furthermore, our transient transfection focusing on reporter gene expression modulated by CD44 3'UTR demonstrated that the presence of an rs13347T allele led to greater transcriptional activity than the C allele. Similarly, more CD44 expression was shown in rs13347T carriers than C carriers in our western blotting results. All these findings suggest that CD44 rs13347C>T polymorphism may affect NPC development by improving CD44 expression.

A functional polymorphism in the promoter of ERK5 gene interacts with tobacco smoking to increase the risk of lung cancer in Chinese populations

Mitogen/extracellular signal-regulated kinase-5 (MEK5)/extracellular signal-regulated protein kinase-5 (ERK5) pathway plays a pro-oncogenic role in tumourigenesis by anticell apoptosis, promoting cell proliferation and differentiation in response to extracellular stimuli. As overexpressed MEK5/ERK5 is involved in the development of lung cancer, we hypothesised that the single nucleotide polymorphisms (SNPs) in MEK5 and ERK5 genes may influence gene expression and thus be associated with lung cancer risk. Five putative functional polymorphisms (rs3743353T>C, rs7172582C>T and rs2278076A>G of MEK5 and rs3866958G>T and rs2233083C>T of ERK5) were genotyped in two independent case-control studies with a total of 1559 lung cancer patients and 1679 controls in southern and eastern Chinese population. We found the rs3866958G>T of ERK5 was significantly associated with lung cancer risk, while other SNPs were not. Compared with the rs3866958TG/TT genotypes, the GG genotype conferred an increased risk of lung cancer (odds ratio = 1.30, 95% confidence interval = 1.12-1.51, P = 5.0×10(-4)), and this effect was more pronounced in smokers, accompanying with a significant interaction with smoking (P interaction = 0.013). The GG genotype also had significant higher mRNA levels of ERK5 in lung cancer tissues than TG/TT genotypes (P = 1.0×10(-4)); the luciferase reporter with the G allele showed significant higher transcription activities than the T allele, especially after the treatment with tobacco extract in vitro. Our data indicated that the functional polymorphism rs3866958G>T in ERK5 was associated with an increased lung cancer risk in smokers by virtue of the positive interaction with smoking on promoting the ERK5 expression, which might be a valuable indicator for predicting lung cancer risk in smokers.

Pathway analysis for genome-wide association study of lung cancer in Han Chinese population

Genome-wide association studies (GWAS) have identified a number of genetic variants associated with lung cancer risk. However, these loci explain only a small fraction of lung cancer hereditability and other variants with weak effect may be lost in the GWAS approach due to the stringent significance level after multiple comparison correction. In this study, in order to identify important pathways involving the lung carcinogenesis, we performed a two-stage pathway analysis in GWAS of lung cancer in Han Chinese using gene set enrichment analysis (GSEA) method. Predefined pathways by BioCarta and KEGG databases were systematically evaluated on Nanjing study (Discovery stage: 1,473 cases and 1,962 controls) and the suggestive pathways were further to be validated in Beijing study (Replication stage: 858 cases and 1,115 controls). We found that four pathways (achPathway, metPathway, At1rPathway and rac1Pathway) were consistently significant in both studies and the P values for combined dataset were 0.012, 0.010, 0.022 and 0.005 respectively. These results were stable after sensitivity analysis based on gene definition and gene overlaps between pathways. These findings may provide new insights into the etiology of lung cancer.

Association between functional polymorphisms in genes involved in the MAPK signaling pathways and cutaneous melanoma risk

Genome-wide association studies (GWASs) have mainly focused on top significant single nucleotide polymorphisms (SNPs), most of which did not have clear biological functions but were just surrogates for unknown causal variants. Studying SNPs with modest association and putative functions in biologically plausible pathways has become one complementary approach to GWASs. To unravel the key roles of mitogen-activated protein kinase (MAPK) pathways in cutaneous melanoma (CM) risk, we re-evaluated the associations between 47 818 SNPs in 280 MAPK genes and CM risk using our published GWAS dataset with 1804 CM cases and 1026 controls. We initially found 105 SNPs with P ≤ 0.001, more than expected by chance, 26 of which were predicted to be putatively functional SNPs. The risk associations with 16 SNPs around DUSP14 (rs1051849) and a previous reported melanoma locus MAFF/PLA2G6 (proxy SNP rs4608623) were replicated in the GenoMEL dataset (P < 0.01) but failed in the Australian dataset. Meta-analysis showed that rs1051849 in the 3' untranslated regions of DUSP14 was associated with a reduced risk of melanoma (odds ratio = 0.89, 95% confidence interval: 0.82-0.96, P = 0.003, false discovery rate = 0.056). Further genotype-phenotype correlation analysis using the 90 HapMap lymphoblastoid cell lines from Caucasians showed significant correlations between two SNPs (rs1051849 and rs4608623) and messenger RNA expression levels of DUSP14 and MAFF (P = 0.025 and P = 0.010, respectively). Gene-based tests also revealed significant SNPs were over-represented in MAFF, PLA2G6, DUSP14 and other 16 genes. Our results suggest that functional SNPs in MAPK pathways may contribute to CM risk. Further studies are warranted to validate our findings.

Functional polymorphisms of CHRNA3 predict risks of chronic obstructive pulmonary disease and lung cancer in Chinese

Recently, several genome-wide association studies (GWAS) have identified many susceptible single nucleotide polymorphisms (SNPs) for chronic obstructive pulmonary disease (COPD) and lung cancer which are two closely related diseases. Among those SNPs, some of them are shared by both the diseases, reflecting there is possible genetic similarity between the diseases. Here we tested the hypothesis that whether those shared SNPs are common predictor for risks or prognosis of COPD and lung cancer. Two SNPs (rs6495309 and rs1051730) located in nicotinic acetylcholine receptor alpha 3 (CHRNA3) gene were genotyped in 1511 patients with COPD, 1559 lung cancer cases and 1677 controls in southern and eastern Chinese populations. We found that the rs6495309CC and rs6495309CT/CC variant genotypes were associated with increased risks of COPD (OR = 1.32, 95% C.I. = 1.14–1.54) and lung cancer (OR = 1.57; 95% CI = 1.31–1.87), respectively. The rs6495309CC genotype contributed to more rapid decline of annual Forced expiratory volume in one second (FEV1) in both COPD cases and controls (P<0.05), and it was associated with advanced stages of COPD (P = 0.033); the rs6495309CT/CC genotypes conferred a poor survival for lung cancer (HR = 1.41, 95%CI = 1.13–1.75). The luciferase assays further showed that nicotine and other tobacco chemicals had diverse effects on the luciferase activity of the rs6495309C or T alleles. However, none of these effects were found for another SNP, rs1051730G>A. The data show a statistical association and suggest biological plausibility that the rs6495309T>C polymorphism contributed to increased risks and poor prognosis of both COPD and lung cancer.

Association between chronic obstructive pulmonary disease and lung cancer: a case-control study in Southern Chinese and a meta-analysis

Background

Lung cancer and chronic obstructive pulmonary disease (COPD) share a common risk factor in cigarette smoking and a large portion of patients with lung cancer suffer from COPD synchronously. We therefore hypothesized that COPD is an independent risk factor for lung cancer. Our aim was to investigate the intrinsic linkage of COPD (or emphysema, chronic bronchitis and asthma) and lung cancer.

Methods

The present hospital-based case-control study included 1,069 patients with newly diagnosed lung cancer and 1,132 age frequency matched cancer-free controls. The odds ratios (ORs) for the associations between each previous pulmonary disease and lung cancer were estimated with logistic regression models, adjusting for age, sex, family history of cancer, BMI and pack year smoking. In meta-analysis, the pooled effects of previous pulmonary diseases were analyzed with random effects models; and stratification analyses were conducted on smoking status and ethnicity.

Results

In the case-control study, previous COPD was associated with the odds for increased risk of lung cancer (OR = 1.29, 95% confidence interval [CI] = 1.00∼1.68); so were emphysema (OR = 1.55, 95%CI = 1.03∼2.32) and chronic bronchitis (OR = 1.22, 95%CI = 0.99∼1.67); while asthma was associated with odds for decreased risk of lung cancer (OR = 0.29, 95%CI = 0.16∼0.53). These associations were more pronounced in smokers (P<.05 for all strata), but not in non-smokers. In meta-analysis, 35 studies (22,010 cases and 44,438 controls) were identified. COPD was significantly associated with the odds for increased risk of lung cancer (pooled OR = 2.76; 95% CI = 1.85–4.11), so were emphysema (OR = 3.02; 95% CI = 2.41–3.79) and chronic bronchitis (OR = 1.88; 95% CI = 1.49–2.36); and these associations were more pronounced in smokers than in non-smokers (P<.001 respectively). No significant association was observed for asthma.

Conclusion

Previous COPD could increase the risk of lung cancer, especially in smokers.

Role of the functional MKK4 promoter variant (-1304T>G) in a decreased risk of prostate cancer: case-control study and meta-analysis

PURPOSE

MKK4 has been suggested as a tumor suppressor. The functional variant (-1304T>G) in the MKK4 promoter has been implicated as a risk factor for many types of cancer. However, its role in prostate cancer (PCa) is unclear. To determine whether this SNP constitutes a risk factor for PCa susceptibility and to derive a more precise estimation of the associations between this SNP and cancer risk, we performed a case-control study and then a meta-analysis covering previous case-control studies.

METHODS

In this study, 222 male patients with PCa and 244 cancer-free controls were evaluated MKK4-1304T>G genotype. The transcriptional activity of MKK4 gene was measured by luciferase assay, and MKK4 serum expression was measured by ELISA.

RESULTS

As a whole, we found that compared to the most common -1304TT genotype, carriers of -1304G variant genotypes had a decreased risk of PCa (OR = 0.670; 95 % CI = 0.452-0.993, P = 0.046 for TG, and OR = 0.647; 95 % CI = 0.441-0.948, P = 0.025 for TG + GG). We found that carriers of the -1304G variant genotypes had greater transcriptional activity and serum expression of MKK4 than carriers of the -1304T allele. Our meta-analysis also suggested that the -1304G variant contributes to decreased risk of various cancers.

CONCLUSION

Our results suggest that the functional -1304G variant in the MKK4 promoter decreases the risk of PCa by increasing the promoter activity. In the future, prospective researches on patients from many parts of the world may validate our findings.

The polymorphisms and haplotypes of WWOX gene are associated with the risk of lung cancer in southern and eastern Chinese populations

The WW domain-containing oxidoreductase (WWOX) gene is an identified tumor suppressor gene, of which several single nucleotide polymorphisms have been reported to contribute to cancer susceptibility. We hypothesized that genetic variations in WWOX are associated with lung cancer risk. In two independent case-control studies conducted in southern and eastern Chinese, we genotyped five tagSNPs of WWOX gene (rs10220974C > T, rs3764340C > G, rs12918952G > A, rs383362G > T, and rs12828G > A) in 1,559 lung cancer cases and 1,679 controls. Logistic regression analysis showed that two tagSNPs (rs3764340C > G; rs383362G > T) were significantly associated with lung cancer risk in dominant model (rs3764340C > G, GC/GG vs. CC: adjust OR = 1.35, 95% CI = 1.11-1.65; rs383362G > T, TG + TT vs. GG: adjust OR = 1.33, 95% CI = 1.14-1.55). The haplotype analysis further shown that the haplotype "G-T" was associated with the highest increased risk of lung cancer (OR = 2.20; 95% CI = 1.43-3.37). After combined these two loci, the number of the risk genotypes was associated with increased cancer risk in a dose-response manner (Ptrend  = 3.16 × 10(-6) ). In addition, a gene-based association analysis by using VEGAS software suggested the WWOX as a susceptible gene for lung cancer (P = 0.009). However, for rs10220974C > T, rs12918952G > A, and rs12828G > A, no significant association was observed for lung cancer risk. Taken together, our data suggested that genetic variants in WWOX may be genetic biomarkers for susceptibility to lung cancer.

The association between -1304T>G polymorphism in the promoter of mitogen-activated protein kinase kinase 4 gene and the risk of cervical cancer in Chinese population

Mitogen-activated protein kinase kinase 4 (MKK4) is a critical mediator of stress-activated protein kinase signals that regulate apoptosis, inflammations, and tumorigenesis. Several polymorphisms have been identified in the MKK4 gene. We hypothesized that genetic variants in the MKK4 promoter may alter its functions and thus cancer risk. In the current, hospital-based case-control study of 471 cervical cancer cases and 600 sex and age frequency-matched cancer-free controls in an Eastern Chinese population, we genotyped two common polymorphisms in the MKK4 promoter region (-1304T>G, rs3826392 and -1044A>T, rs3809728)c and assessed their associations with the risk of cervical cancer. We found that compared with the most common -1304TT genotype, carriers of -1304G variant genotypes had a significantly decreased risk of cervical cancer [odds ratio (OR) = 0.71; 95% confidence interval (CI) = 0.53-0.92 for TG, and OR = 0.52; 95%CI = 0.30-0.91 for GG] in an allele dose-response manner (adjusted P(trend) = 0.004). Moreover, the luciferase assay showed that the G allele in the promoter significantly increased the transcription activity of the MKK4 gene in vitro and that the MKK4 mRNA expression levels of the G variant carriers was significantly higher in tumor tissues than those of the -1304TT genotype. However, no significant association was observed between the -1044A>T polymorphism and risk of cervical cancer. Our data suggest that the functional -1304G variant in the MKK4 promoter contributes to a decreased risk of cervical cancer by increasing the promoter activity and that the G variant may be a marker for susceptibility to cervical cancer.

Functional polymorphism in the EpCAM gene is associated with occurrence and advanced disease status of cervical cancer in Chinese population

The epithelial cell adhesion molecule (EpCAM) was originally identified as a tumor associated antigen, attributable to its high expression on rapidly proliferating tumors of epithelial origin. EpCAM plays vital roles in carcinogenesis, tumor progression and metastasis in most tumors. A non-synonymous polymorphism (rs1126497 C/T) was found in exon 3 of EpCAM, which cause a transition from 115 Met to 115 Thr. Another polymorphism (rs1421 A/G) in the 3'UTR causes loss of has-miR-1183 binding. We performed a multiple independent case-control analysis to assess the association between EpCAM genotypes and cervical cancer risk. Genotyping a total of 518 patients with cervical cancer and 723 control subjects in a Chinese population, we observed that the variant EpCAM genotypes (rs1126497 CT, and TT) were associated with substantially increased risk of cervical cancer. Compared with the rs1126497 CC genotype, CT genotype had a significantly increased risk of cervical cancer (Crude OR = 1.70; 95% CI = 1.33-2.20; adjusted OR = 1.72; 95% CI = 1.33-2.22), the TT carriers had a further increased risk of cervical cancer (Crude OR = 1.94; 95% CI = 1.01-3.72; adjusted OR = 1.96; 95%CI = 1.01-3.81), and there was a trend for an allele dose effect on risk of cervical cancer (P < 0.001). Moreover, the allele T increases the risk for invasive disease or metastatic disease, compared with C allele. However, there exists no significant difference in genotype frequencies of rs1421 A/G site between cases and controls (P = 0.798). These findings suggest that rs1126497 C/T polymorphism in EpCAM may be a genetic modifier for developing cervical cancer.

Exploring the function of the JNK (c-Jun N-terminal kinase) signalling pathway in physiological and pathological processes to design novel therapeutic strategies

JNK (c-Jun N-terminal kinase) is a member of the MAPK (mitogen-activated protein kinase) family that regulates a range of biological processes implicated in tumorigenesis and neurodegenerative disorders. For example, genetic studies have demonstrated that the removal of specific Jnk genes can reduce neuronal death associated with cerebral ischaemia. As such, targeting JNK signalling constitutes an obvious opportunity for therapeutic intervention. However, MAPK inhibitors can display toxic effects. Consequently, dual-specificity MKKs (MAPK kinases) may represent more attractive targets. In particular, evidence that blocking JNK activation by removing MKK4 offers an effective therapy to treat pathological conditions has started to emerge. MKK4 was the first JNK activator identified. The remaining level of JNK activity in cells lacking MKK4 expression led to the discovery of a second activator of JNK, named MKK7. Distinct phenotypic abnormalities associated with the targeted deletion of Mkk4 and Mkk7 in mice have revealed that MKK4 and MKK7 have non-redundant function in vivo. Further insights into the specific functions of the JNK activators in cancer cells and in neurons will be of critical importance to validate MKK4 and MKK7 as promising drug targets.

A functional polymorphism at microRNA-629-binding site in the 3'-untranslated region of NBS1 gene confers an increased risk of lung cancer in Southern and Eastern Chinese population

The genetic variations in NBS1 gene have been reported to be associated with cancer risk. The polymorphisms in 3'-untranslated region (3'-UTR) of NBS1 might affect gene's function and thus contribute to cancer susceptibility. We hypothesized that these polymorphisms of NBS1 are associated with the lung cancer risk. In two independent case-control studies conducted in Southern and Eastern Chinese, we genotyped three tagSNPs (rs14448, rs13312986 and rs2735383) in Southern Chinese and then validated the discovered association in Eastern Chinese. No significant association was observed for rs13312986 and rs14448; we only found that the rs2735383CC genotype had a significantly increased risk of lung cancer under a recessive genetic model in the total 1559 cases versus 1679 controls (odds ratio = 1.40, 95% confidence interval = 1.18-1.66, P = 0.0001) when compared with GG or GC genotypes; the rs2735383CC genotype carriers had lower messenger RNA and protein expression levels in tumor tissues than those of other genotypes as quantitative polymerase chain reaction and western blot shown. Luciferase assay revealed that the rs2735383C allele had a lower transcription activity than G allele, and the hsa-miR-629 but not hsa-miR-499-5P had effect on modulation of NBS1 gene in vitro. We further observed that the X-ray radiation induced more chromatid breaks in lymphocyte cells from the carriers of rs2735383CC homozygote than those from the subjects with other genotypes (P = 0.0008). Our data suggested that the rs2735383G>C variation contributes to an increased risk of lung cancer by diminishing gene's expression through binding of microRNA-629 to the polymorphic site in the 3'-UTR of NBS1 gene.

A common genetic variant (97906C>A) of DAB2IP/AIP1 is associated with an increased risk and early onset of lung cancer in Chinese males

DOC-2/DAB2 interactive protein (DAB2IP) is a novel identified tumor suppressor gene that inhibits cell growth and facilitates cell apoptosis. One genetic variant in DAB2IP gene was reported to be associated with an increased risk of aggressive prostate cancer recently. Since DAB2IP involves in the development of lung cancer and low expression of DAB2IP are observed in lung cancer, we hypothesized that the variations in DAB2IP gene can increase the genetic susceptibility to lung cancer. In a case-control study of 1056 lung cancer cases and 1056 sex and age frequency-matched cancer-free controls, we investigated the association between two common polymorphisms in DAB2IP gene (-1420T>G, rs7042542; 97906C>A, rs1571801) and the risk of lung cancer. We found that compared with the 97906CC genotypes, carriers of variant genotypes (97906AC+AA) had a significant increased risk of lung cancer (adjusted odds ratio [OR] = 1.33, 95%CI = 1.04-1.70, P = 0.023) and the number of variant (risk) allele worked in a dose-response manner (P(trend) = 0.0158). Further stratification analysis showed that the risk association was more pronounced in subjects aged less than 60 years old, males, non-smokers, non-drinkers, overweight groups and in those with family cancer history in first or second-degree relatives, and the 97906A interacted with overweight on lung cancer risk. We further found the number of risk alleles (97906A allele) were negatively correlated with early diagnosis age of lung cancer in male patients (P = 0.003). However, no significant association was observed on the -1420T>G polymorphism. Our data suggested that the 97906A variant genotypes are associated with the increased risk and early onset of lung cancer, particularly in males.

A genome-wide association study identifies two new lung cancer susceptibility loci at 13q12.12 and 22q12.2 in Han Chinese

Lung cancer is the leading cause of cancer-related deaths worldwide. To identify genetic factors that modify the risk of lung cancer in individuals of Chinese ancestry, we performed a genome-wide association scan in 5,408 subjects (2,331 individuals with lung cancer (cases) and 3,077 controls) followed by a two-stage validation among 12,722 subjects (6,313 cases and 6,409 controls). The combined analyses identified six well-replicated SNPs with independent effects and significant lung cancer associations (P < 5.0 × 10(-8)) located in TP63 (rs4488809 at 3q28, P = 7.2 × 10(-26)), TERT-CLPTM1L (rs465498 and rs2736100 at 5p15.33, P = 1.2 × 10(-20) and P = 1.0 × 10(-27), respectively), MIPEP-TNFRSF19 (rs753955 at 13q12.12, P = 1.5 × 10(-12)) and MTMR3-HORMAD2-LIF (rs17728461 and rs36600 at 22q12.2, P = 1.1 × 10(-11) and P = 6.2 × 10(-13), respectively). Two of these loci (13q12.12 and 22q12.2) were newly identified in the Chinese population. These results suggest that genetic variants in 3q28, 5p15.33, 13q12.12 and 22q12.2 may contribute to the susceptibility of lung cancer in Han Chinese.

Functional variants of -1318T > G and -673C > T in c-Jun promoter region associated with increased colorectal cancer risk by elevating promoter activity

C-Jun plays important roles in the development of multiple cancers, but no well-designed association studies have been conducted to assess the roles of its genetic polymorphisms in cancer risk. In a cohort of 1016 pairs of colorectal cancer (CRC) patients and matched cancer-free controls, we investigated two genetic polymorphisms in the promoter regions of the c-Jun (rs4646999, -673C > T and rs2760501, -1318T > G) via the Taqman assay and evaluated the association between two polymorphisms and risk of CRC. We found that both the -1318G and -673C variant genotypes were associated with an increased risk of CRC [-1318TG: odds ratio (OR) = 1.26, 95% confidence interval (CI) = 1.04-1.54; -1318GG: OR = 1.63, 95% CI = 1.03-2.60; -673CT: OR = 1.60, 95% CI = 1.23-2.07; -673CC: OR = 1.80, 95% CI = 1.36-2.37]. Haplotype association analysis showed that compared with the carriers of -1318T-673T haplotype, carriers of the -1318T-673C, -1318G-673T, and -1318G-673C haplotypes all had a significantly increased risk of CRC (P < 0.05 for all). The combined genotypes incorporating both polymorphisms obtained a more significantly additive risk of CRC (one variant genotype: OR = 1.81, 95% CI = 1.30-2.51; two variant genotype: OR = 2.42, 95% CI = 1.70-3.44). Moreover, we found that the change of the -1318T to G allele interact with the -673T to C allele elevated the transcription activity of the c-Jun, and we confirmed the same trends by analyzing c-Jun protein expression in the CRC tissues from patients carrying different number of variant genotypes. This study suggests that -673C > T and -1318T > G genetic variants in c-Jun promoter regions contribute to an increased risk of CRC, possibly by elevating the transcription activity and protein expression levels that appeared to upregulate activity of c-Jun thus tumorigenesis.