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Biomedical subjects

Wen Tan

Publications and source records attributed to Wen Tan.

At least 19 recordsLinked to original sources

HDGF induces inflammatory cancer-associated fibroblast formation through ENO1-mediated glycolytic reprogramming in esophageal squamous-cell carcinoma.

Inflammatory cancer-associated fibroblasts (iCAFs) are a highly plastic stromal population that critically shape tumor progression, immunosuppression, and therapeutic response in esophageal squamous-cell carcinoma (ESCC). Epithelial-intrinsic programs are increasingly recognized as key determinants of fibroblast reprogramming within the tumor microenvironment, yet the underlying mechanisms remain incompletely understood. Here, we identified hepatoma-derived growth factor (HDGF) as a pivotal epithelial-intrinsic regulator that drives iCAF formation in ESCC. Mechanistically, nuclear HDGF functioned as a transcriptional activator by directly binding the ENO1 promoter, thereby upregulating the expression of the glycolytic enzyme enolase 1, enhancing aerobic glycolysis, and promoting lactate secretion from tumor cells. Tumor-derived lactate was subsequently taken up by CAFs and induced histone H4 lysine 12 lactylation (H4K12la), which epigenetically activated NF-κB signaling and promoted iCAF formation. Functionally, HDGF-induced iCAFs promoted tumor progression through activation of the IL-6/JAK1/STAT3 axis and established an immunosuppressive microenvironment characterized by increased recruitment of regulatory T cells and reduced infiltration of CD8+ T cells, thereby facilitating immune evasion. Therapeutically, blockade of ENO1 effectively disrupted the glycolysis-lactylation cascade, markedly suppressing tumor growth and iCAF formation in vivo. Moreover, ENO1 inhibition reprogrammed the immunosuppressive tumor microenvironment and significantly enhanced the efficacy of anti-PD-1 therapy. Collectively, our findings reveal an HDGF/ENO1/H4K12la/iCAF axis that links tumor metabolic reprogramming, stromal inflammatory activation, and immunosuppression in ESCC, identifying this axis as a promising therapeutic target for overcoming immunotherapy resistance.

Phosphopyruvate Hydratase↗

Functional polymorphisms in FAS and FASL contribute to increased apoptosis of tumor infiltration lymphocytes and risk of breast cancer.

The FAS-FASL system plays crucial role in counterattack of cancer cell against immune system. This study examined the effects of FAS (-1377G/A and -670A/G) and FASL (-844T/C and 7896G/C) polymorphisms on breast cancer risk and apoptosis of T lymphocytes. The effect on breast cancer risk was determined by case-control analysis of 840 patients and 840 controls. The effects on T-lymphocyte apoptosis were determined by activation-induced cell death (AICD) of T cells ex vivo and by analyzing apoptotic tumor-infiltrating lymphocytes (TILs) in breast cancer tissue. We found moderately increased risk associated with FAS -1377AG [odds ratio (OR), 1.29; 95% confidence interval (CI), 1.05-1.59] and -1377AA (OR, 1.36; 95% CI, 1.01-1.82) genotypes compared with the -1377GG genotype and decreased risk associated with FASL -844CT (OR, 0.76; 95% CI, 0.62-0.94) and -844TT (OR, 0.66; 95% CI, 0.43-1.00) genotypes compared with the -844CC genotype. T lymphocytes with the FASL -844CC genotype had heightened FASL expression that is associated with increased AICD of the T cells stimulated by MCF-7 cells or phytohemagglutinin compared with the FASL -844TT genotype (10.38 +/- 4.09% and 24.29 +/- 1.50% versus 6.03 +/- 0.41% and 17.96 +/- 3.66%; P < 0.05 and 0.001). Breast cancer patients with the FASL -844CC genotype had higher apoptotic TILs in their cancer tissues than those with the FASL -844TT genotype (33.7 +/- 1.2% versus 19.1 +/- 2.0%; P = 0.007). These findings indicate that functional polymorphisms in FAS and FASL contribute to increased apoptosis of tumor infiltration lymphocytes and risk of breast cancer.

Adult↗

Associations of functional polymorphisms in cyclooxygenase-2 and platelet 12-lipoxygenase with risk of occurrence and advanced disease status of colorectal cancer.

Aberrant arachidonic acid metabolism by cyclooxygenase (COX)-2 and 12-lipoxygenase (LOX) has implicated in carcinogenesis. Genetic polymorphisms in COX-2 and 12-LOX might therefore affect susceptibility to colorectal cancer (CRC). To examine this hypothesis, genotypes of COX-2 -1290A>G, -1195G>A, -765G>C and 12-LOX 261Arg>Gln polymorphisms were determined in 1000 CRC patients and 1300 controls. Increased risk of developing CRC was associated with the COX-2 -1195GA [adjusted odds ratio (OR) = 1.24, 95% confidence interval (CI) = 1.00-1.54] and -1195AA (adjusted OR = 1.77, 95% CI = 1.38-2.25) genotypes compared with the -1195GG genotype. Similarly, the increased risk for CRC was also associated with the COX-2 -765GC genotype (adjusted OR = 1.73, 95% CI = 1.23-2.43) compared with the -765GG genotype. Consistent with the results of genotype analyses, the ORs for the A_(1195)-C_(765)-containing haplotypes were significantly higher than those for the G_(1195)-G_(765)-containing haplotypes (P < 0.01). Furthermore, the -1195A allele was further associated with advanced CRC, with adjusted ORs of Dukes D CRC against Dukes A CRC being 2.43 (95% CI = 1.15-4.97) and 2.66 (95% CI = 1.23-5.74) for the -1195GA and -1195AA genotypes, respectively. The increased risk of CRC was also associated with the 12-LOX 261Gln/Gln genotype compared with the Arg/Arg genotype (adjusted OR = 1.38, 95% CI = 1.09-1.74). Together, these observations indicate that inherited polymorphisms in arachidonic acid-metabolizing enzymes may confer susceptibility to CRC.

Aged↗

Haplotypes in matrix metalloproteinase gene cluster on chromosome 11q22 contribute to the risk of lung cancer development and progression.

PURPOSE: Matrix metalloproteinases (MMP) play important roles in cancer development and single nucleotide polymorphisms (SNP) in some MMP genes were shown to confer susceptibility to certain cancers. This study examined the association between genotypes and haplotypes in the MMP1-MMP3-MMP12 gene cluster and risk of lung cancer development and metastasis. EXPERIMENTAL DESIGN: A two-stage investigation was conducted. First, 35 SNPs covering these genes were selected and validated in 190 patients and 190 controls. Twenty-two validated SNPs were then analyzed in an entire case-control panel consisting of 711 patients and 716 controls. Associations with the risk of lung cancer were estimated by logistic regression. RESULTS: The investigated MMP gene region could be partitioned into two major haplotype blocks. One common haplotype in the block composed of major part of MMP1 transcription region was significantly associated with increased risk for the development [odds ratio (OR), 1.35; 95% confidence interval (95% CI), 1.11-1.63; P = 0.01; permutated P = 0.134] and distant metastasis of lung cancer (ORs for stage IV versus stages I-III, 1.67; 95% CI, 1.12-2.50; P = 0.009; permutated P = 0.048) and the other showed a protective effect against metastasis (ORs for stage IV versus stages I-III, 0.22; 95% CI, 0.07-0.62; P = 0.001; permutated P = 0.011). Another common haplotype in the block across MMP3 was significantly associated with decreased risk for developing lung cancer (OR, 0.71; 95% CI, 0.59-0.86; P = 0.003; permutated P = 0.027). CONCLUSIONS: The observed multiple cancer-associated genetic variants suggested that the MMP1-MMP3-MMP12 gene cluster plays important roles in lung cancer development and progression.

Adult↗

Genetic polymorphisms in cell cycle regulatory genes MDM2 and TP53 are associated with susceptibility to lung cancer.

The tumor suppressor TP53 pathway plays a crucial role in preventing carcinogenesis through its ability to impose cell cycle arrest and apoptosis following DNA damage and oncogene activation. MDM2 is a key negative regulator of the TP53 pathway and is overexpressed in many cancers as oncoprotein. We investigated the association between genetic variation in the promoter region of MDM2 (c.-5+309G>T, rs2279744:g.G>T) and the coding region of TP53 (c.215G>C, rs1042522:g.G>C, designated Arg72Pro) and the risk of developing lung cancer. The genotypes of 1,106 patients and 1,420 controls were determined by tetra-primer amplification refractory mutation system (ARMS)-PCR or PCR-based restriction fragment length polymorphism (RFLP). Associations with risk of lung cancer were estimated by logistic regression. We observed an increased lung cancer risk associated with the MDM2 GG (odds ratio [OR] = 1.83, 95% confidence interval [CI] = 1.45-2.32) and TG (OR = 1.33, 95% CI = 1.09-1.63) genotypes. An increased risk was also associated with the TP53 Pro/Pro genotype (OR = 1.47, 95% CI = 1.17-1.85, P = 0.003) compared to the Arg/Arg genotype. The gene-gene interaction of MDM2 and TP53 polymorphisms increased lung cancer risk in a supermultiplicative manner (OR for the presence of both MDM2 GG and TP53 Pro/Pro genotypes = 4.56, 95% CI = 2.76-7.54). Significant interactions were observed between these polymorphisms (respectively and jointly) and smoking (OR = 10.41, 95% CI = 5.26-20.58) for smokers with both the MDM2 GG and TP53 Pro/Pro genotypes. In conclusion, genetic polymorphisms in cell cycle regulatory genes MDM2 and TP53 contribute to the risk of developing lung cancer.

Aged↗

Adenosine diphosphate ribosyl transferase and x-ray repair cross-complementing 1 polymorphisms in gastric cardia cancer.

BACKGROUND & AIMS: Adenosine diphosphate ribosyl transferase (ADPRT) and x-ray repair cross-complementing 1 (XRCC1) are major DNA base excision repair proteins acting interactively in repair processes. This study examined the effects of ADPRT Val762Ala and XRCC1 Arg399Gln polymorphisms on ADPRT-XRCC1 interaction in vitro in cells and their contributions to gastric cardia adenocarcinoma (GCA) risk. METHODS: The ADPRT-XRCC1 interaction in cells transfected with ADPRT and XRCC1 variant complementary DNA (cDNA) constructs were examined by immunoprecipitation and immunoblotting analysis. Genotypes were analyzed in 500 patients and 1000 controls, and odds ratios (ORs) were estimated by logistic regression. RESULTS: Interactions between ADPRT-762Val and XRCC1-399Arg or XRCC1-399Gln were robust, but interactions between ADPRT-762Ala and either XRCC1-399Arg or XRCC1-399Gln were very weak. A case-control analysis showed ORs of 2.17 (95% CI, 1.55-3.04) and 1.61 (95% CI, 1.06-2.44) for GCA in the ADPRT Ala/Ala or XRCC1 Gln/Gln genotype carriers, respectively, compared with noncarriers. Gene-gene interaction of ADPRT and XRCC1 polymorphisms increased the OR of GCA in a multiplicative manner (OR for the presence of both ADPRT Ala/Ala and XRCC1 Gln/Gln genotypes, 6.43; 95% CI, 1.80-22.97). A supermultiplicative joint effect between the ADPRT polymorphism and smoking was observed. The ORs (95% CIs) of the Ala/Ala genotype for nonsmokers and smokers who smoked < or = 24 or > 24 pack-years were 1.44 (0.89-2.32), 2.00 (1.09-3.67), or 3.19 (1.59-6.42), respectively (Ptrend test = .008). CONCLUSIONS: The ADPRT and XRCC1 polymorphisms confer host susceptibility to GCA, which might result from reduced ADPRT-XRCC1 interaction and attenuated base excision repair capacity.

ADP Ribose Transferases↗

[Correlation of genetic polymorphisms in DNA repair genes ADPRT and XRCC1 to risk of gastric cancer].

BACKGROUND & OBJECTIVE: Adenosine diphosphate ribosyl transferase (ADPRT) and X-ray repair cross-complementing 1 (XRCC1) are 2 major DNA base excision repair (BER) proteins and act interactively in stimulating and executing BER processes. Polymorphisms of ADPRT 762Val-->Ala and XRCC1 399Arg-->Gln have been verified to associate with altered protein function and BER activity. This study was to examine the contribution of these 2 polymorphisms, alone or in combination, to the risk of developing gastric cancer. METHODS: A total of 236 patients with gastric cancer and 708 cancer-free controls were genotyped for the 2 polymorphisms by polymerase chain reaction-restrictive fragment length polymorphism (PCR-RFLP) method. Odds ratio (OR) and 95% confidence interval (CI) were calculated using unconditional logistic regression model to evaluate the impact of these 2 polymorphisms on the risk of developing gastric cancer. RESULTS: The subjects having the ADPRT Ala/Ala genotype had an OR of 2.07 (95% CI=1.33-3.21; P=0.001) compared with those having the Val/Val genotype. Gene-gene interaction of ADPRT and XRCC1 polymorphisms increased the risk of gastric cancer in a super-multiplicative manner, with an OR of 5.32 (95% CI=1.12-28.57) for the presence of both ADPRT 762Ala/Ala and XRCC1 399Gln/Gln genotypes, although the XRCC1 polymorphism itself was not associated with the risk of gastric cancer. CONCLUSION: The ADPRT 762Val-->Ala polymorphism plays an important role in the development of gastric cancer, and the XRCC1 399Arg-->Gln polymorphism may serve as a risk modifier.

ADP Ribose Transferases↗

[Genetic polymorphisms in the promoter region of cyclooxygenase-2 and their association with risk of gastric cancer].

OBJECTIVE: To examine the genetic polymorphisms in the promoter region of cyclooxygenase-2 ( COX-2) and evaluate their association with the risk of gastric cancer. METHODS: Single-strand conformational polymorphism and DNA sequencing were used to screen the genetic variants of the COX-2 promoter region. Total 323 patients with gastric cancer and 646 frequency-matched controls were genotyped by polymerase chain reaction-restriction fragment length polymorphism method. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by logistic regression. Haplotype frequency was estimated using Haplo. stat software. RESULTS: Three single nucleotide polymorphisms, including - 1290A > G, -1195G > A, and -765G > C were identified in the promoter of COX- 2. Case-control analysis showed an increased risk of developing gastric cancer for the -1290AG (OR 1.64; 95% CI 1.03-2.61), -1195AA (OR 2.68; 95% CI 1.65-4.33), and -765CG (OR 2.66; 95% CI 1.53-4.64) genotype carriers, respectively, compared with noncarriers. A greater risk of developing gastric cancer was observed for the A(-1290) -A(-1195) -C(-765) haplotype compared with the A(-1290) -G(-1195) -G(-765) haplotypes (OR 11.80; 95% CI 2.43-57.25). CONCLUSION: Genetic polymorphisms in COX-2 promoter region may play a role in gastric carcinogenesis.

Adult↗

[Association between genetic polymorphism in STK15 and risk of colorectal cancer in a Chinese population].

OBJECTIVE: This case-control study was designed to detect the association between STK15 Phe31Ile polymorphism and colorectal cancer. METHODS: Genotypes were determined in 283 patients with colorectal cancer and 283 controls. The adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression model. RESULTS: The frequency of the STK15 Ile/Ile genotype was significantly higher in cancer cases than in controls (50.2% vs. 36.8%; P = 0.02). Subjects with the Ile/Ile genotype had an increased risk for the occurrence of colorectal cancer compared with those with the STK15 Phe/Phe genotype (adjusted OR, 1.92; 95% CI, 1.13 - 3.27). No significant association was observed between this STK15 polymorphism and risk of metastasis of the cancer. CONCLUSION: These findings suggest that STK15 Phe/Ile polymorphism may be a genetic susceptibility factor for colorectal cancer among Chinese.

Adult↗

[Association of the responsiveness of advanced non-small cell lung cancer to platinum-based chemotherapy with p53 and p73 polymorphisms].

OBJECTIVE: It has been proposed that genetic polymorphisms in apoptosis-related genes might be associated with sensitivity of cancer cells to platinum-based chemotherapy. This study examined the relationship between p53 and p73 genetic polymorphisms and the response to platinum-based chemotherapy in patients with advanced non-small cell lung cancer (NSCLC). METHODS: A total of 165 patients with advanced NSCLC treated with platinum-based chemotherapy were genotyped for the p53 codon 72 Pro-->Arg and p73 exon 2 G4C14-->A4T14 polymorphisms using PCR-RFLP and ARMS-PCR assays. Clinical response to the chemotherapy was obtained after 2 to 3 cycles. The adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using unconditional logistic regression model. All statistical tests were two-sided. RESULTS: The p53 Pro allele carriers had higher response rate than non-carriers (OR = 2.46; 95% CI = 1.11 - 5.45). A higher response rate was also observed for the p73 G4C14/A4T14 or A4T14/A4T14 genotype, compared with the G4C14/G4C14 genotype (OR = 2.22; 95% CI = 1.14 - 4.30). When these two polymorphisms were combined to be analyzed, it was found that the response rate in those carrying the wild-type genotypes at both genes was only 7.7%, whereas the response rates in patients carrying 1, 2, or more than 2 variant alleles of p53 and p73 were 34.8%, 42.2% and 40.7%, respectively. CONCLUSION: Those results suggest that p53 and p73 polymorphisms may be associated with clinical responsiveness to platinum-based chemotherapy in advanced NSCLC.

Adult↗

[XRCC1 and XPD genetic polymorphisms predict clinical responses to platinum-based chemotherapy in advanced non-small cell lung cancer].

OBJECTIVE: DNA repair system plays an important role in tumor sensitivity to platinum-based chemotherapy. The purpose of this study was to examine the association between polymorphisms in XRCC1 and XPD, which are involved in DNA repair, and clinical responses to platinum-based chemotherapy in advanced non-small cell lung cancer (NSCLC). METHODS: XRCC1 Arg194Trp and XPD Lys751Gln were genotyped by PCR-RFLP method in 200 patients with advanced NSCLC who received platinum-based chemotherapy. Unconditional logistic regression model was used to analyze the association between genetic polymorphisms and clinical responses. RESULTS: The overall response rate (CR + PR) was 36.0%, including 1 CR, 72 PR, 94 SD and 34 PD. The XRCC1 194Trp allele carriers had higher response rate than the subjects with the Arg/Arg genotype (adjusted OR, 2.48; 95% CI, 1.36 - 4.51, P = 0.003). However, the XPD Lys751Gln polymorphism was not found to be associated with the platinum-based chemotherapy. These two genetic polymorphisms may have some interaction in the drug sensitivity, the P value for the trend was significant (P = 0.004). CONCLUSION: Those results suggest that the XRCC1 Arg194Trp and XPD Lys751Gln genetic polymorphisms may be associated with clinical responses to platinum-based chemotherapy in advanced non-small cell lung cancer.

Adult↗

[Association between genetic polymorphism in xeroderma pigmentosum G gene and risks of laryngeal and hypopharyngeal carcinomas].

OBJECTIVE: To study the association between polymorphism of DNA repair gene xeroderma pigmentosum G (XPG) Asp1104His and the risks of developing laryngeal and hypopharyngeal carcinomas. METHODS: Totally 175 patients with laryngeal or hypopharyngeal carcinoma and 525 cancer-free controls were genotyped for the polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The odds ratio (OR) and 95% confidence interval (CI) were calculated using unconditional logistic regression model. RESULTS: Compared with those having the Asp/Asp genotype, patients having the XPG 1104Asp/His genotype had a higher risk for laryngeal carcinoma (OR = 2.46, 95% CI = 1.15-5.24, P < 0.05), but not for hypopharyngeal carcinoma (OR = 1.36, 95% CI = 0.87-2.12, P > 0.05). In addition, the XPG 1104Asp/His genotype appeared to be associated with well differentiated squamous cell carcinoma in both larynx and hypopharynx (OR = 1.88, 95% CI = 1.05-3.40, P < 0.05 ). CONCLUSION: The XPG Asp1104His polymorphism may play a role in the development of laryngeal and hypopharyngeal carcinomas.

Case-Control Studies↗

Beta-2 adrenergic receptor gene (ADRB2) polymorphism and risk for lung adenocarcinoma: a case-control study in a Chinese population.

The incidence of lung adenocarcinoma (AC) has been increasing over recent decades. The tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is one of the most potent carcinogens and reproducibly induces a high incidence of lung AC in laboratory animals. In addition to its genotoxic effects, NNK has also epigenetic effects on lung cells by functioning as an agonist for beta adrenergic receptors and stimulating the signal pathways that lead to lung AC. Beta-2 adrenergic receptor (ADRB2) expressed on bronchial smooth muscle is a well-defined target for asthma treatment that has epidemiological implications in lung cancer development. And biochemical effect and pharmacogenetic relevance of regulatory and coding variants of ADRB2 have been well documented. Aiming to test whether the genetic variants of ADRB2 modify risk of lung AC, we compared the manifestation of three common single nucleotide polymorphisms (SNPs) of ADRB2 (G-1023A, G-654A, and A46G (Gly16Arg)) between 313 patients with lung AC and 321 controls. Overall association was not observed between risk and either individual of the three SNPs or their combined haplotypes. However, in the subgroup of young subjects < or =50 years old, significant association was observed for G-1023A (allele based OR, 1.82; 95% CI, 1.12-2.95), A46G (Gly16Arg) (allele based OR, 0.64; 95% CI, 0.40-1.03), and the haplotype A(-1023)A(46) (OR 2.62; 95% CI 1.30-5.27). Our results do not support a major independent role of ADRB2 polymorphisms in lung AC risk, suggesting that functional variants of other genes involved in the NNK epigenetic pathway of carcinogenesis should be investigated.

Asian People↗

The role of P53 and MDM2 polymorphisms in the risk of esophageal squamous cell carcinoma.

The tumor suppressor P53 pathway plays a crucial role in preventing carcinogenesis and genetic variations of this pathway may be associated with cancer susceptibility. We tested this hypothesis by examining the contribution of functional polymorphisms in P53 and MDM2 to risk of esophageal squamous cell carcinoma (ESCC). DNA from 758 ESCC patients and 1,420 controls were genotyped for P53 codon 72Arg>Pro and MDM2 309T>G polymorphisms. Odds ratios (OR) and 95% confidence intervals (CI) of ESCC were estimated by logistic regression. We observed an increased risk of ESCC associated with the P53 Pro/Pro (OR, 1.83; 95% CI, 1.43-2.35; P < 0.001) or MDM2 GG (OR, 1.49; 95% CI, 1.16-1.91; P = 0.002) genotype, compared with the P53 Arg/Arg or MDM2 TT genotype, respectively. Interaction between these P53 and MDM2 polymorphisms increased risk of ESCC in a multiplicative manner, with the OR being 3.10 (95% CI, 2.07-4.69) for subjects carrying both P53 Pro/Pro and MDM2 GG genotypes. Significant interactions were observed between these polymorphisms and smoking, with risk being the highest (OR, 5.29; 95% CI, 2.91-9.61) in smokers having both P53 Pro/Pro and MDM2 GG genotypes. The MDM2 GG genotype was also associated with risk of developing poorly differentiated and advanced ESCC compared with the GT or TT genotype (OR for high-grade and stages III-IV versus low-grade and stages I-II = 1.60; 95% CI, 1.00-2.64; P = 0.049). The P53 and MDM2 polymorphisms may be genetic determinants for the development of ESCC.

Adult↗

FASL -844C polymorphism is associated with increased activation-induced T cell death and risk of cervical cancer.

The FAS receptor-ligand system plays a key role in regulating apoptotic cell death, and corruption of this signaling pathway has been shown to participate in tumor-immune escape and carcinogenesis. We have recently demonstrated (Sun, T., X. Miao, X. Zhang, W. Tan, P. Xiong, and D. Lin. 2004. J. Natl. Cancer Inst. 96:1030-1036; Zhang, X., X. Miao, T. Sun, W. Tan, S. Qu, P. Xiong, Y. Zhou, and D. Lin. 2005. J. Med. Genet. 42:479-484) that functional polymorphisms in FAS and FAS ligand (FASL) are associated with susceptibility to lung cancer and esophageal cancer; however, the mechanisms underlying this association have not been elucidated. We show that the FAS -1377G, FAS -670A, and FASL -844T variants are expressed more highly on ex vivo-stimulated T cells than the FAS -1377A, FAS -670G, and FASL -844C variants. Moreover, activation-induced cell death (AICD) of T cells carrying the FASL -844C allele was increased. We also found a threefold increased risk of cervical cancer among subjects with the FASL -844CC genotype compared with those with the -844TT genotype in a case-control study in Chinese women. Together, these observations suggest that genetic polymorphisms in the FAS-FASL pathway confer host susceptibility to cervical cancers, which might be caused by immune escape of tumor cells because of enhanced AICD of tumor-specific T cells.

Adult↗

CYP2J2*7 single nucleotide polymorphism in a Chinese population.

BACKGROUND: Human cytochrome P450 2J2 (CYP2J2) is the major arachidonic acid epoxygenase that plays important roles in the pathogenesis of a variety of diseases such as cardiovascular disorders and cancers, this P450 also plays a role in the metabolism of some antihistamine drugs. Variability of CYP2J2 gene is highly constrained except for at its proximal promoter a relatively common and functionally relevant single nucleotide polymorphism, namely CYP2J2*7, with allele frequency being 17%, 5.49%, 13%, and 4.23% in African, White, Asian, and Korean, respectively. Since this genetic variation differs strikingly between ethnic groups, we characterized the CYP2J2*7polymorphism in Chinese. METHODS: Polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) assays were used to genotype CYP2J2*7 in a sample of 384 healthy Chinese Han subjects. RESULTS: In this Chinese population, 20 (5.21%) heterozygotes and no homozygote for CYP2J2*7 allele were observed, and the allelic frequency was 2.60%. CONCLUSION: The CYP2J2*7 variant represents a relatively rare polymorphism in Chinese, with the allele frequency being comparable to that of Korean, but significantly lower than those of African and White groups. This data may be informative to design population-based association study of genetic predisposition to CYP2J2 related diseases and treatments.

Alleles↗

[Genetic polymorphisms of apoptosis-associated genes FAS and FASL and risk of colorectal cancer].

OBJECTIVE: The FAS and FASL system plays a key role in regulating apoptotic cell death and corruption of this signaling pathway has been shown to participate in tumorigenesis. We previously have shown that the FAS-1377G/A and FASL-844T/C polymorphisms are associated with esophageal cancer. This case-control study was to examine the contribution of the polymorphisms to susceptibility of colorectal cancer. METHODS: PCR-RFLP method was used to determine the genotypes of FAS-1377G/A and FASL-844T/C in 382 patients with colorectal cancer and 648 controls. The adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression model. RESULTS: The subjects with the AA genotype of FAS-1377G/A and CC genotype of FASL-844T/C had an increased risk for colorectal cancer compared with those with the FAS-1377GG genotype (adjusted OR, 1.65; 95% CI, 1.14-2.38) and FASL-844TT genotype (adjusted OR, 1.76; 95% CI, 1.37-2.28). Furthermore, the effect of FAS and FASL polymorphisms on risk of colorectal cancer displayed a significantly gene-gene interaction (likelihood ratio test, P = 0.002). CONCLUSION: These findings suggest that the FAS-1377G/A and FASL-844T/C polymorphisms may be genetic susceptibility factors for colorectal cancer among Chinese population.

Adult↗

DNA repair gene XPC genotypes/haplotypes and risk of lung cancer in a Chinese population.

DNA repair is central to normal cellular functions, and polymorphisms of DNA repair genes may cause variation in DNA repair capacity in the general population. Newly identified polymorphisms of xeroderma pigmentosum group C (XPC), one of the nucleotide excision repair genes, were shown to contribute to genetic susceptibility to cancer. In this study, we hypothesized that 2 exonic variants C499T and A939C and their haplotypes in XPC are associated with lung cancer risk. To test this hypothesis, we performed a case-control study of 320 histologically confirmed lung cancer patients and 322 age and sex frequency-matched cancer-free controls in a Chinese population. Multivariate logistic regression analyses revealed that the risks [adjusted odds ratios (ORs) and 95% confidence intervals (CIs)] associated with the XPC variant genotypes were 1.57 (95% CI = 1.13-2.19) for 499CT/TT and 1.21 (95% CI = 0.87-1.69) for 939AC/CC compared with the 499CC and 939AA wild-type homozygotes, respectively. Individuals with both putative risk genotypes (499CT/TT and 939AC/CC) had a greater risk of lung cancer (adjusted OR = 2.37; 95% CI = 1.33-4.21) compared with individuals with both wild-type genotypes (499CC and 939AA). When we performed the haplotype analysis and assumed the XPC 499T and 939C as risk alleles, the adjusted ORs increased as the number of variants in the haplotype genotypes increased (p(trend) < 0.001). In the stratified analysis, the greatest risk was found in smokers having the combined variant genotypes (adjusted OR = 7.36; 95% CI = 3.19-17.00) compared with nonsmokers having both wild-type genotypes and in smokers with 2 or 3 haplotype variants (adjusted OR = 7.27; 95% CI = 3.37-15.68) compared with nonsmokers having 0 haplotype variant. These findings indicate that XPC exonic variants may contribute to the risk of lung cancer in the Chinese population, and these variant genotypes may modulate the risk of lung cancer associated with smoking.

Alleles↗