Genetic susceptibility to prostate cancer in Taiwan: A genome-wide association study.

We conducted the first genome-wide association study (GWAS) of prostate cancer (PCa) in Taiwan with 1844 cases and 80,709 controls. Thirteen independent single-nucleotide polymorphisms (SNPs) reached genome-wide significance (p < 5 × 10-8 ). Among these, three were distinct from previously identified loci: rs76072851 in CORO2B gene (15q23), odds ratio (OR) = 1.54, 95% confidence interval (CI), 1.36-1.76, p = 5.30 × 10-11 ; rs7837051, near two long noncoding RNA (lncRNA) genes, PRNCR1 and PCAT2 (8q24.21), OR = 1.41 (95% CI, 1.31-1.51), p = 8.77 × 10-21 ; and rs56339048, near an lncRNA gene, CASC8 (8q24.21), OR = 1.25 (95% CI, 1.16-1.35), p = 2.14 × 10-8 . We refined the lead SNPs for two previously identified SNPs in Taiwanese: rs13255059 (near CASC8), p = 9.02 × 10-43 , and rs1456315 (inside PRNCR1), p = 4.33 × 10-42 . We confirmed 35 out of 49 GWAS-identified East Asian PCa susceptibility SNPs. In addition, we identified two SNPs more specific to Taiwanese than East Asians: rs34295433 in LAMC1 (1q25.3) and rs6853490 in PDLIM5 (4q22.3). A weighted genetic risk score (GRS) was developed using the 40 validated SNPs and the area under the receiver-operating characteristic curve for the GRS to predict PCa was 0.67 (95% CI, 0.63-0.71). These identified SNPs provide valuable insights into the molecular mechanisms of prostate carcinogenesis in Taiwan and underscore the significant role of genetic susceptibility in regional differences in PCa incidence.

A Genome-Wide Association Study Identified Novel Genetic Susceptibility Loci for Oral Cancer in Taiwan.

Taiwan has the highest incidence rate of oral cancer in the world. Although oral cancer is mostly an environmentally induced cancer, genetic factors also play an important role in its etiology. Genome-wide association studies (GWAS) have identified nine susceptibility regions for oral cancers in populations of European descent. In this study, we performed the first GWAS of oral cancer in Taiwan with 1529 cases and 44,572 controls. We confirmed two previously reported loci on the 6p21.33 (HLA-B) and 6p21.32 (HLA-DQ gene cluster) loci, highlighting the importance of the human leukocyte antigen and, hence, the immunologic mechanisms in oral carcinogenesis. The TERT-CLMPT1L locus on 5p15.33, the 4q23 ADH1B locus, and the LAMC3 locus on 9q34.12 were also consistent in the Taiwanese. We found two new independent loci on 6p21.32, rs401775 in SKIV2L gene and rs9267798 in TNXB gene. We also found two suggestive novel Taiwanese-specific loci near the TPRS1 gene on 8q23.3 and in the TMED3 gene on 15q25.1. This study identified both common and unique oral cancer susceptibility loci in the Taiwanese as compared to populations of European descent and shed significant light on the etiology of oral cancer in Taiwan.

Impact of Mir196a-2 Genotypes on Colorectal Cancer Risk in Taiwan.

We aimed to investigate the association between genotypes for mir146a and mir196a-2 and the risk of developing colorectal cancer (CRC). We used polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to determine the mir146a rs2910164 and mir196a-2 rs11614913 genotypes in 362 CRC patients and 362 controls. We also assessed the interactions between these genotypes and age, gender, smoking, alcohol consumption, and BMI status on CRC risk. Additionally, the serum expression level of mir196a-2 was quantified using quantitative reverse transcription-PCR. Our findings demonstrated that among the controls, the proportions of TT, CT, and CC genotypes of mir196a-2 rs11614913 were 32.3%, 48.1%, and 19.6%, respectively. As for the cases, the proportions were 24.6%, 45.0%, and 30.4%, respectively. Logistic regression analysis revealed that the CC genotype carriers had a 2.04-fold increased risk (95% confidence interval [CI] = 1.36-3.06, p = 0.0008). Furthermore, carriers of the CT + CC genotypes also exhibited a significant association with CRC risk (odds ratio [OR] = 1.46, 95% CI = 1.06-2.03, p = 0.0261). Moreover, carriers of the CC genotype had significantly higher serum levels of mir196a-2 compared to those with the TT genotype (p < 0.0001), indicating a genotype-phenotype correlation. No association was found regarding mir146a rs2910164. In conclusion, mir196a-2 rs2910164 genotypes, along with their associated expression, can serve as predictive markers for CRC risk.

Protective Effects of Jujubosides on 6-OHDA-Induced Neurotoxicity in SH-SY5Y and SK-N-SH Cells.

6-hydroxydopamine (6-OHDA) is used to induce oxidative damage in neuronal cells, which can serve as an experimental model of Parkinson's disease (PD). Jujuboside A and B confer free radical scavenging effects but have never been examined for their neuroprotective effects, especially in PD; therefore, in this study, we aimed to investigate the feasibility of jujubosides as protectors of neurons against 6-OHDA and the underlying mechanisms. 6-OHDA-induced neurotoxicity in the human neuronal cell lines SH-SY5Y and SK-N-SH, was used to evaluate the protective effects of jujubosides. These findings indicated that jujuboside A and B were both capable of rescuing the 6-OHDA-induced loss of cell viability, activation of apoptosis, elevation of reactive oxygen species, and downregulation of the expression levels of superoxide dismutase, catalase, and glutathione peroxidase. In addition, jujuboside A and B can reverse a 6-OHDA-elevated Bax/Bcl-2 ratio, downregulate phosphorylated PI3K and AKT, and activate caspase-3, -7, and -9. These findings showed that jujubosides were capable of protecting both SH-SY5Y and SK-N-SH neuronal cells from 6-OHDA-induced toxicity via the rebalancing of the redox system, together with the resetting of the PI3K/AKT apoptotic signaling cascade. In conclusion, jujuboside may be a potential drug for PD prevention.

High circulating insulin-like growth factor-1 reduces the risk of renal cell carcinoma: a Mendelian randomization study.

Insulin and insulin-like growth factors play important roles in carcinogenesis. Circulating insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-binding protein-3 (IGFBP-3) have been linked to cancer susceptibility. The associations of circulating IGF-1 and IGFBP-3 with the risk of renal cell carcinoma (RCC) are inconsistent. Recent large genome-wide association studies have identified 413 single nucleotide polymorphisms (SNPs) associated with IGF-1 and 4 SNPs associated with IGFBP-3. In this large case-control study consisting of 2069 RCC patients and 2052 healthy controls of European ancestry, we used a two-sample Mendelian randomization (MR) approach to investigate the associations of genetically predicted circulating IGF-1 and IGFBP-3 with RCC risk. We used an individual level data-based genetic risk score (GRS) and a summary statistics-based inverse-variance weighting (IVW) method in MR analyses. We found that genetically predicted IGF-1 was significantly associated with RCC risk in both the GRS analysis [odds ratio (OR) = 0.43 per SD increase, 95% confidence interval (CI), 0.34-0.53] and the IVW analysis (OR = 0.46 per SD increase, 95% CI, 0.37-0.57). Dichotomized at the median GRS value of IGF-1 in controls, individuals with high GRS had a 45% reduced RCC risk (OR = 0.55, 95% CI, 0.48-0.62) compared with those with low GRS. Genetically predicted circulating IGFBP-3 was not associated with RCC risk. This is the largest RCC study of circulating IGF-1 and IGFBP-3 to date and our data suggest a strong inverse relationship between circulating IGF-1 level and RCC risk.

Associations of genetically predicted circulating insulin-like growth factor-1 and insulin-like growth factor binding protein-3 with bladder cancer risk.

Insulin-like growth factors (IGF) play important roles in carcinogenesis. The associations of circulating IGF-1 and insulin-like growth factor-binding protein-3 (IGFBP-3) with the risks of bladder cancer remain unclear. In this large case control study of 2011 bladder cancer cases and 2369 heathy controls, we assessed the associations of circulating IGF-1 and IGFBP-3 with bladder cancer risks using a Mendelian randomization approach, which uses genetic variants as instruments to study causal relationship between risk factors and diseases. We first constructed a weighted genetic risk score (GRS) predictive of circulating IGF-1 and IGFBP-3 using 413 genome-wide association study-identified single nucleotide polymorphisms (SNPs) associated with IGF-1 and four SNPs with IGFBP-3, respectively. We found that higher GRS for IGF-1 was associated with a significantly reduced bladder cancer risk (odds ratio [OR] = 0.66 per SD increase, 95% confidence interval [CI], 0.54-0.82, p < 0.001). We then used a summary statistics-based MR method, inverse-variance weighting (IVW), and found a similar risk estimate (OR = 0.67 per SD increase, 95% CI = 0.54-0.83, p < 0.001). When we categorized individuals into high and low IGF-1 groups using the median GRS value in the controls, the high GRS group had a 21% reduced bladder cancer risk (OR = 0.79, 95% CI = 0.70-0.89) compared to the low GRS group. Genetically predicted circulating IGFBP-3 was not associated with bladder cancer risk. In conclusion, our data demonstrated for the first time a strong inverse relationship between circulating IGF-1 level and bladder cancer risk.

Mitochondrial DNA copy number in peripheral blood leukocytes is associated with biochemical recurrence in prostate cancer patients in African Americans.

Mitochondria play multiple important cellular functions. The purpose of this study was to evaluate whether leukocyte mitochondrial DNA copy number (mtDNAcn) is associated with aggressive prostate cancer (PCa) in African American (AA) men. We measured the mtDNAcn in peripheral blood leukocytes from 317 localized AA PCa patients and evaluated its associations with aggressive disease features at diagnosis and biochemical recurrence (BCR) after treatments. There was no significant difference in mtDNAcn among the clinical features at diagnosis, including age, prostate-specific antigen level, Gleason score and clinical stage under analysis of variance test. However, mtDNAcn was significantly associated with BCR in multivariate Cox analysis. Dichotomized into low and high mtDNAcn groups by the median value of mtDNAcn, patients with low mtDNAcn exhibited a significantly lower risk of BCR (hazard ratio = 0.32, 95% confidence interval: 0.13-0.79) compared to those with high mtDNAcn. There was a significant dose-response in tertile and quartile analyses (P for trend = 0.012 and 0.002, respectively). In Kaplan-Meier survival analyses, patients with higher mtDNAcn exhibited significantly shorter BCR-free survival time than those with lower mtDNAcn in dichotomous, tertile and quartile analyses, with long-rank P values of 0.017, 0.024 and 0.019, respectively. Our results showed for the first time that high leukocyte mtDNAcn was associated with worse prognosis in AA PCa patients.

Leukocyte telomere length is associated with aggressive prostate cancer in localized African American prostate cancer patients.

Telomeres play important roles in cancer initiation and progression. Leukocyte telomere length (LTL) has been associated with the risk and prognosis of several cancers, but its association with prostate cancer (PCa) prognosis in African Americans (AAs) has not been reported. In this study, we measured relative LTL from 317 AA PCa patients and assessed its associations with aggressive disease characteristics at diagnosis and biochemical recurrence (BCR) after radical prostatectomy and radiotherapy. LTL was shorter in patients with higher Gleason scores (GS) at diagnosis. Dichotomized into short and long LTL groups, patients with short LTL exhibited a 1.91-fold (95% confidence interval, CI, 1.14-3.20, P = 0.013) increased risk of being diagnosed with high-risk disease (GS =7 [4 + 3] and GS ≥8) than those with long LTL in multivariable logistic regression analysis. Moreover, shorter LTL was significantly associated with an increased risk of BCR (hazard ratio = 1.68, 95% CI, 1.18-11.44, P = 0.024) compared with longer LTL in localized patients receiving prostatectomy or radiotherapy in multivariable Cox analysis. Kaplan-Meier survival analysis showed patients with short LTL had significantly shorter BCR-free survival time than patients with long LTL (Log rank P = 0.011). In conclusion, our results showed for the first time that LTL was shorter in PCa patients with higher GS and short LTL was associated with worse prognosis in AA PCa patients receiving prostatectomy or radiotherapy.

Protective effects of valproic acid on 6-hydroxydopamine-induced neuroinjury.

Oxidative stress may play critically important roles in the etiology of Parkinson's disease (PD). 6-Hydroxydopamine (6-OHDA) is a physiological neurotoxin reported to induce oxidative-induced apoptosis of dopaminergic neurons in PD mice models. Valproic acid (VPA), a clinical mood stabilizer, is a HDAC inhibitor with neuroprotective capacities. In the study, we aim at examining the feasibility of VPA as a protector for dopaminergic neurons against damage from 6-OHDA, and the intracellular mechanisms. The 6-OHDA-induced neurotoxicity to the human dopaminergic cell line SH-SY5Y was applied for examining VPA protective effects. Pretreatment with VPA was able to improve cell viability and reduce 6-OHDA-induced reactive oxygen species. Furthermore, a significant suppression of apoptotic caspases including cleaved caspase-3, caspase-7, and caspase-9 was observed. The results also revealed VPA decreased the 6-OHDA-induced Bax/Bcl2 ratio, as measured at protein level. These novel findings indicate that VPA may be capable of protecting the SH-SY5Y dopaminergic neuronal cells from 6-OHDA-induced toxicity via the deceasing of apoptotic caspases (cleaved caspase-3, caspase-7, and caspase-9) and reducing of the Bax/Bcl2 ratio. Very possibly, VPA could serve as not only a mood stabilizer but also a potential antidote for PD prevention.

The role of genotype/phenotype at apurinic/apyrimidinic endonuclease Rs1130409 in renal cell carcinoma.

The DNA repair capacity plays a critical role in maintaining the genomic stability and gatekeeping for individual cancer risk. In this study, we aim at evaluation the role of the Asp148Glu (rs1130409) variant at apurinic/apyrimidinic endonuclease (APE) gene in renal cell carcinoma (RCC) risk and the contribution of different genotypes to its transcriptional mRNA levels. In the case-control study, 92 RCC patients and 580 cancer-free patients matched by age and gender were recruited. The apurinic/APE genotyping work was conducted with typical restriction fragment length polymorphism methodology after polymerase chain reaction. At the meanwhile, thirty renal tissue samples with variant genotypes were examined for their apurinic/APE mRNA and protein expressions by real-time quantitative reverse transcription method and Western blotting. The results showed that compared with the wild-type TT genotype, the people with TG and GG genotypes of apurinic/APE Asp148Glu had 0.88- and 1.09-fold risk of RCC, respectively. We have also examined the in vivo transcriptional (RNA) and translational (protein) levels with renal tissues of various apurinic/APE Asp148Glu genotypes, revealing that the apurinic/APE mRNA and protein were of similar levels among people of TT, TG, or GG genotypes. There was no joint gene-environment effect of apurinic/APE Asp148Glu genotype and smoking habit on RCC risk. The evidence indicated that apurinic/APE Asp148Glu genotypic variants did not alter its mRNA and protein expression among RCC patients. The genotype of apurinic/APE Asp148Glu may not serve as a proper predictive marker for RCC risk in Taiwan.

Validation of Enhancing Effects of Curcumin on Radiotherapy with F98/FGT Glioblastoma-Bearing Rat Model.

Glioblastoma, the most common and aggressive brain tumor with low survival rate, is difficult to be cured by neurosurgery or radiotherapy. Mounting evidence has reported the anti-inflammatory and anticancer effects of curcumin on several types of cancer in preclinical studies and clinical trials. To our knowledge, there is no platform or system that could be used to effectively and real-timely evaluate the therapeutic efficacy of curcumin for glioblastoma multiforme (GBM). In this study, we constructed a lentivirus vector with triple-reporter genes (Fluc/GFP/tk) and transduced into rat F98 glioblastoma cells to establish an orthotopic F98/FGT glioma-bearing rat model. In the model, the therapeutic efficacies for curcumin alone, radiation alone, and their combination were evaluated via noninvasive bioluminescent imaging and overall survival measurements. At the cell level, curcumin is capable of causing a G2/M cell cycle arrest and sensitizing the F98 cells to radiation. In animal model, curcumin synergistically enhances the effects of radiotherapy on suppressing the growth of both transplanted glioma cells and in situ brain tumors, and extending the overall survival periods longer than those of curcumin alone and radiation alone treatments. In conclusion, we have demonstrated that curcumin may serve as a novel radiosensitizer to combine with radiotherapy using the triple-reporter F98/FGT animal model for effective and simultaneous evaluation of therapeutic efficacy.

Methylation of global DNA repeat LINE-1 and subtelomeric DNA repeats D4Z4 in leukocytes is associated with biochemical recurrence in African American prostate cancer patients.

Global DNA methylation may play important roles in cancer etiology and prognosis. The goal of this study is to investigate whether the methylation of long interspersed nucleotide elements (LINE-1) and subtelomeric DNA repeats D4Z4 in leukocyte DNA is associated with aggressive prostate cancer (PCa) in African Americans. We measured DNA methylation levels of LINE-1 and D4Z4 in 306 African American (AA) PCa patients using pyrosequencing and compared their methylation levels among clinical variables. We further applied multivariate Cox proportional hazards model and Kaplan-Meier survival function and log-rank tests to assess the association between DNA methylation and biochemical recurrence (BCR). Overall, there was no significant difference of the methylation levels of LINE-1 and D4Z4 among patients with different clinical and epidemiological characteristics. However, the methylation of LINE-1 and D4Z4 was associated with BCR. Patients with lower LINE-1 methylation and higher D4Z4 methylation exhibited markedly increased risks of BCR with adjusted hazard ratios of 3.34 (95% confidence interval, 1.32-8.45) and 4.12 (95% confidence interval, 1.32-12.86), respectively, and significantly shorter BCR-free survival times. Our results suggest that lower global DNA methylation and higher subtelomeric region methylation may predict worse prognosis in localized AA PCa patients.

Genetic variants in the nucleotide excision repair genes are associated with the risk of developing endometriosis.

Endometriosis is a major health issue among women of reproductive age. However, its etiology has not yet been completely understood. We investigated 10 single nucleotide polymorphisms from six novel nucleotide excision repair genes and the susceptibility to endometriosis. A total of 153 patients with endometriosis were recruited during 2000-2010 from central Taiwan. Pathological confirmation was necessary for all patients, and exclusion criteria included the presence of leiomyoma, adenomyosis, or cancer of the uterine, cervix, or ovary and a prescription of hormone therapy. Furthermore, a total of 636 age-matched individuals without endometriosis were recruited during the same time period from central Taiwan. The polymerase chain reaction coupled with restriction fragment length polymorphism methodology was applied for genotyping. The multivariate logistic regression analysis showed that subjects carrying the ERCC1 rs11615 TT (OR = 2.04, 95% CI = 1.36-3.41), ERCC2 rs1799793 AA (OR = 1.86, 95% CI = 1.14-3.11), and ERCC6 rs2228528 AA genotypes (OR = 1.79, 95% CI = 1.13-2.83) exhibited significantly increased risks of developing endometriosis compared with their counterparts carrying the wild-type genotypes. This study suggests that certain single nucleotide polymorphisms of nucleotide excision repair genes excision repair cross-complementation group 1 (ERCC1, ERCC2, and ERCC6) predispose women to the development of endometriosis.

The association of matrix metalloproteinas-2 promoter polymorphisms with lung cancer susceptibility in Taiwan.

Matrix metalloproteinases-2 (MMP2) has been reported to be overexpressed in various types of cancer. However, the contribution of various genotypes of MMP2 to lung cancer is controversial and not yet been examined in Taiwan. Therefore, in the current study, we investigated the association of MMP2 genotypes with lung cancer risk among Taiwanese. In this hospital-based, case-control study, 358 lung cancer patients and 716 age- and gender-matched healthy controls were recruited, and the genotypic distributions of MMP2-1306 and MMP2- 735 were determined. Then, their association with lung cancer was evaluated, and their interaction with personal smoking status was also examined via stratification analysis. The results showed that the percentages of variant CT and TT at MMP2-1306 were 17.3% and 1.7% among the lung cancer patients, respectively, much lower than those of 28.7% and 2.4%, respectively, among the healthy controls (P for trend = 0.0001). The allelic frequency distribution analysis showed that the variant T allele at MMP2-1306 conferred a statistically significantly lower lung cancer risk than the wild-type C allele (adjusted odds ratio = 0.54, 95% confidence interval = 0.41-0.72, P = 0.0001). There was an obvious effect of MMP2-1306 genotype on lung cancer risk among the subpopulations of ever smokers but not nonsmokers. As for the genotypes of MMP2-735, there was no such differential distribution in the aspects of genotypic or allelic frequencies, or combinative effects with smoking status. The genotypes of MMP2-1306 may act as a biomarker in determining personal susceptibility to lung cancer in Taiwan. The contribution of MMP2 genotypes alone and its joint effects with personal cigarette smoking habit on lung cancer susceptibility should be taken into consideration of the clinical practices for early detection and prediction of lung cancer in Taiwan.

Contribution of Inflammatory Cytokine Interleukin-18 Genotypes to Renal Cell Carcinoma.

Interleukin-18 (IL-18) is a multi-functional immuno-mediator in the development and progression of many types of infectious and inflammatory diseases. In this study, we evaluated the contribution of IL-18 genotypes to renal cell carcinoma (RCC) in Taiwan via the genotyping of IL-18 -656 (A/C), -607 (A/C), and -137 (G/C). Moreover, we analyzed their interactions with smoking, alcohol drinking, hypertension, and diabetes status. The results showed an association of the AC and CC genotypes of IL-18 -607 with a significant decrease in the risk of RCC compared with the AA genotype (odds ratio (OR) = 0.44 and 0.35, 95% confidence interval (CI) = 0.27⁻0.72 and 0.18⁻0.66, p = 0.0008 and 0.0010, respectively). Furthermore, a significantly lower frequency of the C allele at -607 was observed in the RCC group (35.3% vs. 49.8%; OR = 0.53; 95% CI = 0.35⁻0.71, p = 0.0003). However, IL-18 -656 and -137 did not exhibit a likewise differential distribution of these genotypes between the control and case groups. Stratifying the population according to smoking, alcohol drinking, hypertension, and diabetes status revealed a different distribution of IL-18 -607 genotypes among non-smokers, non-drinkers, and patients without diabetes, but not among smokers, drinkers, or patients with diabetes. These findings suggest that IL-18 -607 genotypes may play a role in the etiology and progression of RCC in Taiwan and may serve as a useful biomarker for early detection.

Proteomics analysis of altered proteins in kidney of mice with aristolochic acid nephropathy using the fluorogenic derivatization-liquid chromatography-tandem mass spectrometry method.

Aristolochic acid (AA) causes interstitial renal fibrosis, called aristolochic acid nephropathy (AAN). There is no specific indicator for diagnosing AAN, so this study aimed to investigate the biomarkers for AAN using a proteomics method. The C3H/He female mice were given ad libitum AA-distilled water (0.5 mg/kg/day) and distilled water for 56 days in the AA and normal groups, respectively. The AA-induced proteins in the kidney were investigated using a proteomics study, including fluorogenic derivatization with 7-chloro-N-[2-(dimethylamino)ethyl]-2,1,3-benzoxadiazole-4-sulfonamide, followed by high-performance liquid chromatography analysis and liquid chromatography tandem mass spectrometry with a MASCOT database searching system. There were two altered proteins, thrombospondin type 1 (TSP1) and G protein-coupled receptor 87 (GPR87), in the kidney of AA-group mice on day 56. GPR87, a tumorigenesis-related protein, is reported for the first time in the current study. The renal interstitial fibrosis was certainly induced in the AA-group mice under histological examination. Based on the results of histological examination and the proteomics study, this model might be applied to AAN studies in the future. TSP1 might be a novel biomarker for AAN, and the further role of GPR87 leading to AA-induced tumorigenesis should be researched in future studies.

Dithiothreitol enhanced arsenic-trioxide-induced cell apoptosis in cultured oral cancer cells via mitochondrial dysfunction and endoplasmic reticulum stress.

Arsenic is naturally occurring toxic metalloid and drinking As2 O3 containing water are recognized to be related to increased risk of neurotoxicity, liver injury, blackfoot disease, hypertension, and cancer. On the contrary, As2 O3 has been an ancient drug used in traditional Chinese medicine with substantial anticancer activities, especially in the treatment of acute promyelocytic leukemia as well as chronic wound healing. However, the cytotoxicity and detail mechanisms of As2 O3 action in solid cancer cells, such as oral cancer cells, are largely unknown. In this study, we have primarily cultured four pairs of tumor and nontumor cells from the oral cancer patients and treated the cells with As2 O3 alone or combined with dithiothreitol (DTT). The results showed that 0.5 µM As2 O3 plus 20 µM DTT caused a significant cell death of oral cancer cells but not the nontumor cells. Also As2 O3 plus DTT upregulated Bax and Bak, downregulated Bcl-2 and p53, caused a loss of mitochondria membrane potential in oral cancer cells. On the other way, As2 O3 also triggered endoplasmic reticulum stress and increased the levels of glucose-regulated protein 78, calpain 1 and 2. Our results suggest that DTT could synergistically enhance the effects of As2 O3 on killing oral cancer cells while nontoxic to the nontumor cells. The combination is promising for clinical practice in oral cancer therapy and worth further investigations. © 2015 Wiley Periodicals, Inc. Environ Toxicol 32: 17-27, 2017.

Inhibitory Effects of AVEMAR on Proliferation and Metastasis of Oral Cancer Cells.

Oral cancer is keeping its 4th rank on the death causing cancers among Taiwan males, and its metastatic and recurrent rates remain high and a life-threatening issue to the citizens. Fermented wheat germ extract (AVEMAR) is used in clinical cancer nutritional therapy in gastrointestinal cancers but not in oral cancer yet. In this study, the potential of AVEMAR to inhibit tumor proliferation and metastasis of oral cancer was first investigated. Antiproliferative activity of AVEMAR was determined in human oral squamous carcinoma SCC-4 cells by MTT methodology. Wound-healing migration, transwell invasion, and Western blotting assays were carried out to examine the in vitro antimetastatic effects and involved signaling molecules for AVEMAR in oral cancer cells. AVEMAR at 0.2-1.6 mg/ml significantly inhibited the cell viability with IC50 values of 1.19 and 0.98 mg/ml for 24-h and 48-h treatment. Furthermore, AVEMAR could induce cell apoptosis and inhibit the migration and invasion of metastatic SCC-4 cells at a similar dose range. Notably, AVEMAR suppressed the expression of matrix metalloproteinase (MMP)-2 and urokinase plasminogen activator (u-PA), but not MMP-1 or MMP-9, in SCC-4 cells. These results strongly support the antiproliferation and in vitro antimetastatic capacity of AVEMAR which may extend its contributions from cancer nutrition supplements to preventive agent for oral cancer.

The significant association of CCND1 genotypes with colorectal cancer in Taiwan.

Colorectal cancer, one million cases of diagnosis worldwide annually, is one of the most common malignant tumors and 20 % incidence caused by low penetrance susceptibility genes. Cyclin D1 (CCND1) regulating cell cycle transition may determine the susceptible individuals to genomic instability and carcinogenesis. The study aimed at examining the contribution of CCND1 genotypes to colorectal cancer risk in Taiwan. The genotypes of CCND1 A870G (rs9344) and G1722C (rs678653) were determined among 362 colorectal cancer patients and 362 age- and gender-matched cancer-free controls. Significant differences were observed between colorectal cancer and control groups in the distributions of genotypic (P = 9.71 × 10(-4)) and allelic (P = 0.0017) frequencies at CCND1 A870G. Additionally, individuals carried AG or GG genotype had 0.56- or 0.51-fold higher of odds ratios for developing colorectal cancer than the AA genotype (95 % confidence intervals = 0.40-0.78 and 0.32-0.81, respectively). Furthermore, G allele of CCND1 A870G performed a protective effects for nonsmokers and nonalcohol drinkers (P = 0.0012 and 0.0007, respectively) on colorectal cancer risk. These findings support the concept that the cell cycle regulation may play a role in colorectal cancer initiation and development and CCND1 A870G genotyping maybe a feasible technology for colorectal cancer early detection.

DNA double-strand break repair gene XRCC7 genotypes were associated with hepatocellular carcinoma risk in Taiwanese males and alcohol drinkers.

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide, the prevalence and mortality rates of which are very high in Taiwan. The study aimed at evaluating the contribution of XRCC7 G6721T, together with cigarette smoking and alcohol drinking lifestyles, to the risk of HCC. In this hospital-based case-control study, the association of XRCC7 single nucleotide polymorphism G6721T with HCC risk was examined by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) among 298 HCC patients and 889 age- and gender-matched healthy controls. The results showed that the percentages of TT, GT, and GG XRCC7 G6721T were 53.0, 41.3, and 5.7 % in the HCC patient group and 48.9, 43.1, and 8.0 % in the non-cancer control group, respectively. We have further stratified the populations by genders, cigarette smoking, and alcohol drinking status to investigate their combinative contributions with XRCC7 G6721T genotype to HCC risk. The results showed that the GG genotype of XRCC7 G6721T conducted a protective effect on HCC susceptibility which was obvious among males and drinkers, but not females, smokers, non-smokers, or non-drinkers (p = 0.0058, 0.0069, 0.1564, 0.2469, 0.9354, and 0.3416, respectively). Our results suggested that the GG and GT genotypes of X-ray repair cross-complementing group 7 (XRCC7) G6721T had no effect on HCC risk to the whole population, but had a protective effect on HCC risk among males and alcohol drinkers.