Weidong Ji

The Polymorphism and Haplotypes of PIN1 Gene are Associated with the Risk of Lung Cancer in Southern and Eastern Chinese Populations

Peptidyl‐prolyl cis/trans isomerase (PPIase), PIN1, has been found to be a critical catalyst that involves in multiple oncogenic signaling pathways. Recently, several putative functional polymorphisms of the PIN1 gene have been identified to be associated with cancer risk. In this study, we tested the hypothesis that two common polymorphisms, c.‐842G>C (rs2233678) and c.‐667C>T (rs2233679), in the PIN1 promoter are associated with risk of lung cancer. In two independent case‐control studies of 1,559 lung cancer cases and 1,679 controls conducted in Southern and Eastern Chinese population, we found that compared with the most common c.‐842GG genotype, the carriers of c.‐842C variant genotypes (GC + CC) had a decreased risk of lung cancer (odds ratio [OR] = 0.63, 95% confidence interval [CI] = 0.51–0.78, p = 1.13 × 10−5). Although no association was observed between the c.‐667C>T polymorphism and cancer risk, we found that the haplotype “C‐C” had a greater protective effect (OR = 0.39, 95% CI = 0.23–0.67, p = 5.03 × 10−4). The stratification analysis showed that the protective role of c.‐842C variants was more pronounced in current smokers (p = 4.45 × 10−5), especially in male smokers (p = 6.71 × 10−6) and in those who smoked more than 20 pack‐years (p = 2.30 × 10−5) and the c.‐842C variant genotypes interacted with smoking status (Pinteraction = 0.019) or pack‐years smoked (Pinteraction = 0.008) on reducing cancer risk. Further functional assay revealed that the c.‐842C variant allele had a lower transcription activity in luciferase assay and a lower DNA‐binding ability with nuclear proteins, and low transcription activity in western blot assay. In conclusions, our data suggest that functional c.‐842C variants and haplotype “C‐C” in the PIN1 promoter contribute to decreased risk of lung cancer by diminishing the promoter activity, which may be susceptibility biomarkers for lung cancer. Hum Mutat 32:1299–1308, 2011. ©2011 Wiley Periodicals, Inc.

A Functional Copy-Number Variation in MAPKAPK2 Predicts Risk and Prognosis of Lung Cancer

Mitogen-activated protein kinase-activated protein kinase 2 (MAPKAPK2) may promote cancer development and progression by inducing tumorigenesis and drug resistance. To assess whether the copy-number variation g.CNV-30450 located in the MAPKAPK2 promoter has any effect on lung cancer risk or prognosis, we investigated the association between g.CNV-30450 and cancer risk in three independent case-control studies of 2,332 individuals with lung cancer and 2,457 controls and the effects of g.CNV-30450 on cancer prognosis in 1,137 individuals with lung cancer with survival data in southern and eastern Chinese populations. We found that those subjects who had four copies of g.CNV-30450 had an increased cancer risk (odds ratio = 1.94, 95% confidence interval [CI] = 1.61-2.35) and a worse prognosis for individuals with lung cancer (with a median survival time of only 9 months) (hazard ratio = 1.47, 95% CI = 1.22-1.78) compared with those with two or three copies (with a median survival time of 14 months). Meanwhile, four copies of g.CNV-30450 significantly increased MAPKAPK2 expression, both in vitro and in vivo, compared with two or three copies. Our study establishes a robust association between the functional g.CNV-30450 in MAPKAPK2 and risk as well as prognosis of lung cancer, and it presents this functional copy-number variation as a potential biomarker for susceptibility to and prognosis for lung cancer.

A functional variant (-1304T > G) in the MKK4 promoter contributes to a decreased risk of lung cancer by increasing the promoter activity.

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 expression and thus cancer risk. In a case-control study of 1056 lung cancer cases and 1056 sex and age frequency-matched cancer-free controls, we genotyped two common polymorphisms in the MKK4 promoter region (-1304T>G and -1044A>T) with the Taqman assay, and we found that compared with the most common -1304TT genotype, carriers of -1304G variant genotypes had a decreased risk of lung cancer [odds ratio (OR) = 0.74; 95% confidence interval (CI) = 0.61-0.90 for TG, and OR = 0.62; 95% CI = 0.41-0.94 for GG] in an allele dose-response manner (adjusted P(trend) = 0.0005). Further stratification analysis showed that the protective role of the -1304G variant allele was more evident in low or normal body mass index (BMI) but restrained in the overweighters and that the -1304G variant genotypes interacted with BMI in reducing cancer risk (adjusted P(interaction) = 0.003). 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 protein 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 lung cancer. Our data suggest that the functional -1304G variant in the MKK4 promoter contributes to a decreased risk of lung cancer by increasing the promoter activity and that the G variant may be a marker for susceptibility to 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.

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.

Effects of a Functional Variant c.353T>C in Snai1 on Risk of Two Contextual Diseases. Chronic Obstructive Pulmonary Disease and Lung Cancer

RATIONALE Epithelial-mesenchymal transition (EMT) plays a key role in the development of chronic obstructive pulmonary disease (COPD) and lung cancer. OBJECTIVES There are five major EMT regulatory genes (Snai1, Slug, Zeb1, Zeb2, and Twist1) involved in EMT. We hypothesized that germline variants in these genes may influence the development of both diseases. METHODS Seven genetic variants were genotyped in two two-stage case-control studies with 2,072 lung cancer cases and 2,077 control subjects, and 1,791 patients with COPD and 1,940 control subjects to show their associations with development of both diseases. MEASUREMENTS AND MAIN RESULTS An exon variant c.353T>C(p.Val118Ala) of Snai1 harbored decreased risks of lung cancer (CT/CC vs. TT: odds ratio [OR], 0.76; 95% confidence interval [CI], 0.65-0.90) and COPD (CC vs. CT vs. TT: OR, 0.75; 95% CI, 0.63-0.89), and c.353T>C affected lung cancer risk indirectly through COPD (COPD accounted for 6.78% of effect that the variant had on lung cancer). Moreover, c.353T>C was correlated with lung cancer stages in smoking patients (P = 0.013), and those with the c.353C genotypes were less likely to have metastasis at diagnosis than those with the c.353TT genotype (OR, 0.60; 95% CI, 0.41-0.88). The c.353C allele encoding p.118Ala attenuated Snai1s ability to up-regulate mesenchymal biomarkers (i.e., fibronectin and vimentin) expression, and to promote EMT-like changes, including morphologic changes, cell migration, and invasion. However, these effects were not observed for the other variants. CONCLUSIONS The functional germline variant c.353T>C (p.Val118Ala) of Snai1 confers consistently decreased risks of lung cancer and COPD, and this variant affects lung cancer risk through a mediation effect of COPD.

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. Copyright

Tumor necrosis factor-α sensitizes breast cancer cells to natural products with proteasome-inhibitory activity leading to apoptosis.

The inflammatory microenvironment plays an important role in the process of tumor development. Tumor necrosis factor-α (TNF-α), a key pro-inflammatory cytokine, has a significant role in this process. Natural medicinal products such as Withaferin A (WA) and Celastrol (Cel) have shown anti-cancer and anti-inflammatory properties that can be attributed to multiple mechanisms including, but not limited to, apoptosis induction due to the inhibition of proteasomal activities. This study aimed to investigate the effects of TNF-α in combination with WA or Cel in vitro in MDA-MB-231 breast cancer cells. TNF-α, when combined with WA or Cel, activated caspase-3 and -9 and downregulated XIAP in a dose-dependent manner, leading to induction of apoptosis in MDA-MB-231 breast cancer cells. The combination also caused accumulation of the proteasomal target protein IκBα, resulting in inhibition of the nuclear translocation of nuclear factor-κB (NF-κB). Taken together, these results suggest that TNF-α could sensitize breast cancer cells MDA-MB-231 to WA and Cel, at least in part, through inhibiting the activation of NF-κB signaling, leading to XIAP inhibition with subsequent upregulation of caspase-3 and -9 activities. Thus, the anti-cancer activities of TNF-α are enhanced when combined with the natural proteasome inhibitors, WA or Cel.

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.