Genetic contributions to female gout and hyperuricaemia using genome-wide association study and polygenic risk score analyses.

OBJECTIVES: To identify genetic variants and polygenic risk score (PRS) relating to female gout and asymptomatic hyperuricaemia (AH) in a genome-wide association study (GWAS). METHODS: Gout, AH and normouricemia controls were included from Taiwan biobank and China Medical University Hospital. All participants were divided into discovery and replication cohorts for GWAS. PRS was estimated according to whether the variant exhibited a protective effect on the phenotypes or not. Each cohort was separated into two groups by the age of 50 years old. RESULTS: A total of 59 472 females were enrolled, and gout and AH occupied 1.60% and 19.59%, respectively. Six variants located in genes SLC2A9, C5orf22, CNTNAP2 and GLRX5 were significantly predictors of female gout in those aged ≥50. For those aged <50 years old, only the variant rs147750368 (SPANXN1) on chromosome X was found. Most variants located in genes SLC2A9, ZNF518B, PKD2 and ABCG2 were found to be significantly related to AH in both age groups. The PRS could explain ∼0.59% to 0.89% of variance of gout in variants with protective effects, which showed 6.2 times of mean PRS in the risk variants, but only 1.2 times in the AH phenotype. Moreover, the PRS also revealed a dose-response trend between AH rates and quartile scores. CONCLUSION: The variants in gene SLC2A9 are the major genetic factors for females associated with gout in those aged ≥50. PRS can provide a more robust prediction of the gout/AH under a homogeneous selection of variants that show effects on the traits.

Dysregulation of Immune Cell Subpopulations in Atypical Hemolytic Uremic Syndrome.

Atypical hemolytic uremic syndrome (aHUS) is a rare, life-threatening thrombotic microangiopathy. Definitive biomarkers for disease diagnosis and activity remain elusive, making the exploration of molecular markers paramount. We conducted single-cell sequencing on peripheral blood mononuclear cells from 13 aHUS patients, 3 unaffected family members of aHUS patients, and 4 healthy controls. We identified 32 distinct subpopulations encompassing 5 B-cell types, 16 T- and natural killer (NK) cell types, 7 monocyte types, and 4 other cell types. Notably, we observed a significant increase in intermediate monocytes in unstable aHUS patients. Subclustering analysis revealed seven elevated expression genes, including NEAT1, MT-ATP6, MT-CYB, VIM, ACTG1, RPL13, and KLRB1, in unstable aHUS patients, and four heightened expression genes, including RPS27, RPS4X, RPL23, and GZMH genes, in stable aHUS patients. Additionally, an increase in the expression of mitochondria-related genes suggested a potential influence of cell metabolism on the clinical progression of the disease. Pseudotime trajectory analysis revealed a unique immune cell differentiation pattern, while cell-cell interaction profiling highlighted distinctive signaling pathways among patients, family members, and controls. This single-cell sequencing study is the first to confirm immune cell dysregulation in aHUS pathogenesis, offering valuable insights into molecular mechanisms and potential new diagnostic and disease activity markers.

Identification of 13 Novel Loci in a Genome-Wide Association Study on Taiwanese with Hepatocellular Carcinoma.

Liver cancer is caused by complex interactions among genetic factors, viral infection, alcohol abuse, and metabolic diseases. We conducted a genome-wide association study and polygenic risk score (PRS) model in Taiwan, employing a nonspecific etiology approach, to identify genetic risk factors for hepatocellular carcinoma (HCC). Our analysis of 2836 HCC cases and 134,549 controls revealed 13 novel associated loci such as the FAM66C gene, noncoding genes, liver-fibrosis-related genes, metabolism-related genes, and HCC-related pathway genes. We incorporated the results from the UK Biobank and Japanese database into our study for meta-analysis to validate our findings. We also identified specific subtypes of the major histocompatibility complex that influence both viral infection and HCC progression. Using this data, we developed a PRS to predict HCC risk in the general population, patients with HCC, and HCC-affected families. The PRS demonstrated higher risk scores in families with multiple HCCs and other cancer cases. This study presents a novel approach to HCC risk analysis, identifies seven new genes associated with HCC development, and introduces a reproducible PRS model for risk assessment.

Clinical application of liquid biopsy in cancer patients.

BACKGROUND: This study was to determine the prevalence and clinical significance of clonal hematopoiesis (CH)-related variants, and somatic and germline mutations in cancer patients and healthy individuals. METHODS: We performed next-generation sequencing of 275 cancer-related genes be-tween plasma and white blood cells in 92 cancer patients and 47 controls without cancer. Blood samples were recruited from May 2017 to July 2021, and blood cancer patients were excluded. For all statistical analysis in this study, p < 0.05 was considered statistically significant. RESULTS: Overall, 38.04% of patients and 46.81% of controls harbored at least one CH-related mutation in plasma cell-free DNA. Based on our results, older cancer patients exhibited a CH phenomenon more frequently than younger patients (p = 0.0024). A total of 39 somatic pathogenic (P)/likely pathogenic (LP) mutations were identified in 17 genes in 21 of 92 patients. We found that the presence of P/LP variants in cancer-related gene predicted shorter overall survival (OS) (p = 0.001). Multivariate analysis adjusted for CH-related mutations, germline mutations, and tumor stage, also indicated that somatic mutations correlated significantly with OS (p = 0.022). Moreover, the frequency of a germline P/LP variant was that of seven of 92 individuals in the cancer group and one of 42 individuals in the control group. CONCLUSIONS: We characterized the CH-related variants, and somatic and germline mutations in cancer patients and healthy individuals, and the results have important clinical significance.

APOE and KLF14 genetic variants are sex-specific for low high-density lipoprotein cholesterol identified by a genome-wide association study.

To demonstrate the loci that relate to high-density lipoprotein cholesterol (HDL-C) levels and genetic sex heterogeneity, we enrolled 41,526 participants aged between 30 and 70 years old from the Taiwan Biobank in a genome-wide association study. We applied the Manhattan plot to display the p-values estimated for the relationships between loci and low HDL-C. A total of 160 variants were significantly associated with low HDL-C. The genotype TT of rs1364422 located in the KLF14 gene has 1.30 (95% CI=1.20 - 1.42) times the risk for low-HDL compared to genotype CC in females (log(-p) =8.98). Moreover, the genes APOC1, APOE, PVRL2, and TOMM40 were associated significantly with low-HDL-C in males only. Excluding the variants with high linkage disequilibrium, we revealed the rs429358 located in APOE as the major genetic variant for lowering HDL-C, in which genotype CT has 1.24 (95% CI= 1.16 - 1.32) times the risk. In addition, we also examine 12 genes related to HDL-C in both sexes, including LPL, ABCA1, APOA5, BUD13, ZPR1, ALDH1A2, LIPC, CETP, HERPUD1, LIPG, ANGPTL8, and DOCK6. In conclusion, low-HDL-C is a genetic and sex-specific phenotype, and we discovered that the APOE and KLF14 are specific to low-HDL-C for men and women, respectively.

Mutation profile of non-small cell lung cancer revealed by next generation sequencing.

BACKGROUND: Precision therapy for lung cancer requires comprehensive genomic analyses. Specific effects of targeted therapies have been reported in Asia populations, including Taiwanese, but genomic studies have rarely been performed in these populations. METHOD: We enrolled 72 patients with non-small cell lung cancer, of whom 61 had adenocarcinoma, 10 had squamous cell carcinoma, and 1 had combined adenocarcinoma and squamous cell carcinoma. Whole-exome or targeted gene sequencing was performed. To identify trunk mutations, we performed whole-exome sequencing in two tumor regions in four patients. RESULTS: Nineteen known driver mutations in EGFR, PIK3CA, KRAS, CTNNB1, and MET were identified in 34 of the 72 tumors evaluated (47.22%). A comparison with the Cancer Genome Atlas dataset showed that EGFR was mutated at a much higher frequency in our cohort than in Caucasians, whereas KRAS and TP53 mutations were found in only 5.56% and 25% of our Taiwanese patients, respectively. We also identified new mutations in ARID1A, ARID2, CDK12, CHEK2, GNAS, H3F3A, KDM6A, KMT2C, NOTCH1, RB1, RBM10, RUNX1, SETD2, SF3B1, SMARCA4, THRAP3, TP53, and ZMYM2. Moreover, all ClinVar pathogenic variants were trunk mutations present in two regions of a tumor. RNA sequencing revealed that the trunk or branch genes were expressed at similar levels among different tumor regions. CONCLUSIONS: We identified novel variants potentially associated with lung cancer tumorigenesis. The specific mutation pattern in Taiwanese patients with non-small cell lung cancer may influence targeted therapies.

Construction and Validation of a Prognostic Gene-Based Model for Overall Survival Prediction in Hepatocellular Carcinoma Using an Integrated Statistical and Bioinformatic Approach.

Hepatocellular carcinoma (HCC) is one of the most common lethal cancers worldwide and is often related to late diagnosis and poor survival outcome. More evidence is demonstrating that gene-based prognostic models can be used to predict high-risk HCC patients. Therefore, our study aimed to construct a novel prognostic model for predicting the prognosis of HCC patients. We used multivariate Cox regression model with three hybrid penalties approach including least absolute shrinkage and selection operator (Lasso), adaptive lasso and elastic net algorithms for informative prognostic-related genes selection. Then, the best subset regression was used to identify the best prognostic gene signature. The prognostic gene-based risk score was constructed using the Cox coefficient of the prognostic gene signature. The model was evaluated by Kaplan-Meier (KM) and receiver operating characteristic curve (ROC) analyses. A novel four-gene signature associated with prognosis was identified and the risk score was constructed based on the four-gene signature. The risk score efficiently distinguished the patients into a high-risk group with poor prognosis. The time-dependent ROC analysis revealed that the risk model had a good performance with an area under the curve (AUC) of 0.780, 0.732, 0.733 in 1-, 2- and 3-year prognosis prediction in The Cancer Genome Atlas (TCGA) dataset. Moreover, the risk score revealed a high diagnostic performance to classify HCC from normal samples. The prognosis and diagnosis prediction performances of risk scores were verified in external validation datasets. Functional enrichment analysis of the four-gene signature and its co-expressed genes involved in the metabolic and cell cycle pathways was constructed. Overall, we developed a novel-gene-based prognostic model to predict high-risk HCC patients and we hope that our findings can provide promising insight to explore the role of the four-gene signature in HCC patients and aid risk classification.

Chromosomal Microarray Analysis in Taiwanese Patients with Williams-Beuren Syndrome.

Williams-Beuren Syndrome (WBS; OMIM #194050) is a rare neurodevelopmental disorder that results from a deletion at 7q11.23 spanning 25-27 genes. We performed chromosomal microarray analysis (CMA) in 9 Taiwanese patients with WBS to confirm the diagnosis. These samples had already been examined by FISH and diagnosed as WBS. Pathogenic copy number variations (CNVs) were identified in all patients, including 24 genes (spanning from FKBP6 to GTF2I) with typical 7q11.23 microdeletion. A deletion in TRIM50 was common in Taiwanese patients with WBS (8/9). Furthermore, 1 patient had 2 additional gene deletions in NCF1 and GTF2IRD2. We also found 4 patients with duplications of 4p16.1, 16p13.11, 10q26.3, and 21q22.3. All 9 WBS patients exhibited distinctive facial dysmorphisms, including a wide mouth, thick prominent lips, short nose with anteverted nares, and periorbital puffiness. However, cardiac defects were not frequent in our patients (3/9). In conclusion, we detected CNVs associated with WBS in a Taiwanese population using CMA. Although CMA is expensive and labor-intensive, it is useful for identifying typical/atypical CNVs, delineating distal break points, and detecting other CNVs.

Male-Specific Long Noncoding RNA TTTY15 Inhibits Non-Small Cell Lung Cancer Proliferation and Metastasis via TBX4.

Gender affects cancer susceptibility. Currently, there are only a few studies on Y chromosome-linked long noncoding RNAs (lncRNAs), and the potential association between lncRNAs and cancers in males has not been fully elucidated. Here, we examined the expression of testis-specific transcript Y-linked 15 (TTTY15) in 37 males with non-small cell lung cancer (NSCLC), and performed circular chromosome conformation capture with next-generation sequencing to determine the genomic interaction regions of the TTTY15 gene. Our results showed that the expression levels of TTTY15 were lower in NSCLC tissues. Lower TTTY15 expression levels were associated with Tumor-Node-Metastasis (TNM) stage. A TTTY15 knockdown promoted malignant transformation of NSCLC cells. Based on the bioinformatics analysis of circular chromosome conformation capture data, we found that T-box transcription factor 4 (TBX4) may be a potential target gene of TTTY15. The RNA immunoprecipitation and chromatin immunoprecipitation results showed that TTTY15 may interact with DNA (cytosine-5)-methyltransferase 3A (DNMT3A), and the TTTY15 knockdown increased the binding of DNMT3A to the TBX4 promoter. We concluded that low TTTY15 expression correlates with worse prognosis among patients with NSCLC. TTTY15 promotes TBX4 expression via DNMT3A-mediated regulation. The identification of lncRNAs encoded by male-specific genes may help to identify potential targets for NSCLC therapy.

DNA-Sensing and Nuclease Gene Expressions as Markers for Colorectal Cancer Progression.

OBJECTIVE: Oncogene-driven stress-related DNA damage has been observed in lesions of colon cancer. Furthermore, DNA sensors and nucleases are stimulated during active DNA damage and replication. However, their changes and influences with respect to cancer remain largely unknown. METHODS: The gene expression levels of cGAS, IFI16, STING, TBK1, IFNB1, TREX1, SAMHD1, RNASEH2A, RNASEH2B, and RNASEH2C were examined in the paired colorectal cancer and adjacent normal part tissues of 53 patients. Their associations with the clinical stages of cancer were then analyzed. RESULTS: All cytosolic DNA-sensing and nuclease-related genes except cGAS, RNASEH2A, and RNASEH2B showed lower mRNA expressions in the colorectal tumor tissues. Moreover, cGAS upregulation was found to be associated with early-stage colorectal cancers, while higher expressions of RNASEH2B, RNASEH2C, and SAMHD1 correlated with metastasis. RNASEH2C knockdown in a colon cancer cell line impaired cell migration, and analysis of the cancer RNA-seq data from The Cancer Genome Atlas (TCGA) database revealed a negative correlation between RNASEH2C expression and E-cadherin levels. CONCLUSIONS: In contrast to DNA-sensing events in viral infections or autoimmunity, cGAS-STING-IFNB signaling is disrupted in colorectal cancer. The expression levels of cGAS, RNASEH2B, RNASEH2C, and SAMHD1 could be prognostic markers of colorectal cancer.

Analysing the mutational status of adenomatous polyposis coli (APC) gene in breast cancer.

BACKGROUND: Breast cancer is a heterogeneous disorder for which the underlying genetic basis remains unclear. We developed a method for identifying adenomatous polyposis coli (APC) mutations and we evaluated the possible association between APC genetic variants and breast cancer susceptibility. METHODS: Genomic DNA was extracted from tumor and matched peripheral blood samples collected from 89 breast cancer patients and from peripheral blood samples collected from 50 controls. All samples were tested for mutations in exons 1-14 and the mutation cluster region of exon 15 by HRM analysis. All mutations were confirmed by direct DNA sequencing. RESULTS: We identified a new single nucleotide polymorphism (SNP), c.465A>G (K155K), in exon 4 and seven known SNPs: c.573T>C (Y191Y) in exon 5, c.1005A>G (L335L) in exon 9, c.1458T>C (Y486Y) and c.1488A>T (T496T) in exon 11, c.1635G>A (A545A) in exon 13, and c.4479G>A (T1493T) and c.5465T>A (V1822D) in exon 15. The following alterations were found in 2, 1, 2, and 1 patients, respectively: c.465A>G, c.573T>C, c.1005A>G, and c.1488A>T. There was no observed association between breast cancer risk and any of these APC SNPs. CONCLUSIONS: APC mutations occur at a low frequency in Taiwanese breast cancer cases. HRM analysis is a powerful method for the detection of APC mutations in breast.

Long noncoding RNA TUG1 is downregulated in non-small cell lung cancer and can regulate CELF1 on binding to PRC2.

BACKGROUND: Long noncoding RNAs (lncRNAs) play crucial roles in tumorigenesis, and lncRNA taurine-upregulated gene 1 (TUG1) has been proven to be associated with several human cancers. However, the mechanisms of TUG1-involved regulation remain largely unknown. METHODS: We examined the expressions of TUG1 in a cohort of 89 patients with non-small cell lung cancer (NSCLC) to determine the association between TUG1 expression and clinical parameters. We used circular chromosome conformation capture (4C) coupled with next-generation sequencing to explore the genome regions that interact with TUG1 and the TUG1-mediated regulation. RESULTS: TUG1 was significantly downregulated, and the TUG1 downregulation correlated with sex (p = 0.006), smoking status (p = 0.016), and tumor differentiation grade (p = 0.001). Knockdown of TUG1 significantly promoted the proliferation of NSCLC cells. According to the bioinformatic analysis result of TUG1 4C sequencing data, 83 candidate genes and their interaction regions were identified. Among these candidate genes, CUGBP and Elav-like family member 1 (CELF1) are potential targets of TUG1 in-trans regulation. To confirm the interaction between TUG1 and CELF1, relative expressions of CELF1 were examined in TUG1 knockdown H520 cells; results showed that CELF1 was significantly upregulated in TUG1 knockdown H520 cells. RNA immunoprecipitation was then performed to examine whether TUG1 RNA was bound to PRC2, a TUG1-involved regulation mechanism reported in previous studies. The results demonstrated that TUG1 RNA was bound to enhancer of zeste protein 2/embryonic ectoderm development (EZH2/EED), which is essential for PRC2. Finally, our designed ChIP assay revealed that the EZH2/EED was bound to the promotor region of CELF1 within 992 bp upstream of the transcript start site. CONCLUSION: TUG1 is downregulated in NSCLC. Using TUG1 4C sequencing and bioinformatic analysis, we found CELF1 to be a potential target of TUG1 RNA in in-trans regulation. Moreover, subsequent experiments showed that TUG1 RNA could bind to PRC2 in the promotor region of CELF1 and negatively regulate CELF1 expressions in H520 cells. Our results may facilitate developing new treatment modalities targeting TUG1/PRC2/CELF1 interactions in patients with NSCLC.

Genetic alterations in endometrial cancer by targeted next-generation sequencing.

Many genetic factors play important roles in the development of endometrial cancer. The aim of this study was to investigate genetic alterations in the Taiwanese population with endometrial cancer. DNA was extracted from 10 cases of fresh-frozen endometrial cancer tissue. The exomes of cancer-related genes were captured using the NimbleGen Comprehensive Cancer Panel (578 cancer-related genes) and sequenced using the Illumina Genomic Sequencing Platform. Our results revealed 120 variants in 99 genes, 21 of which were included in the Oncomine Cancer Research Panel used in the National Cancer Institute Match Trial. The 21 genes comprised 8 tumor suppressor candidates (ATM, MSH2, PIK3R1, PTCH1, PTEN, TET2, TP53, and TSC1) and 13 oncogene candidates (ALK, BCL9, CTNNB1, ERBB2, FGFR2, FLT3, HNF1A, KIT, MTOR, PDGFRA, PPP2R1A, PTPN11, and SF3B1). We identified a high frequency of mutations in PTEN (50%) and genes involved in the endometrial cancer-related molecular pathway, which involves the IL-7 signaling pathway (PIK3R1, n=1; AKT2, n=1; FOXO1, n=1). We report the mutational landscape of endometrial cancer in the Taiwanese population. We believe that this study will shed new light on fundamental aspects for understanding the molecular pathogenesis of endometrial cancer and may aid in the development of new targeted therapies.

Transcribed pseudogene ψPPM1K generates endogenous siRNA to suppress oncogenic cell growth in hepatocellular carcinoma.

Pseudogenes, especially those that are transcribed, may not be mere genomic fossils, but their biological significance remains unclear. Postulating that in the human genome, as in animal models, pseudogenes may function as gene regulators through generation of endo-siRNAs (esiRNAs), antisense RNAs or RNA decoys, we performed bioinformatic and subsequent experimental tests to explore esiRNA-mediated mechanisms of pseudogene involvement in oncogenesis. A genome-wide survey revealed a partial retrotranscript pseudogene ψPPM1K containing inverted repeats capable of folding into hairpin structures that can be processed into two esiRNAs; these esiRNAs potentially target many cellular genes, including NEK8. In 41 paired surgical specimens, we found significantly reduced expression of two predicted ψPPM1K-specific esiRNAs, and the cognate gene PPM1K, in hepatocellular carcinoma compared with matched non-tumour tissues, whereas the expression of target gene NEK8 was increased in tumours. Additionally, NEK8 and PPM1K were downregulated in stably transfected ψPPM1K-overexpressing cells, but not in cells transfected with an esiRNA1-deletion mutant of ψPPM1K. Furthermore, expression of NEK8 in ψPPM1K-transfected cells demonstrated that NEK8 can counteract the growth inhibitory effects of ψPPM1K. These findings indicate that a transcribed pseudogene can exert tumour-suppressor activity independent of its parental gene by generation of esiRNAs that regulate human cell growth.

Developing and Evaluating the HRM Technique for Identifying Cytochrome P450 2D6 Polymorphisms.

BACKGROUND: Cytochrome P450 2D6 is one of the important enzymes involved in the metabolism of many widely used drugs. Genetic polymorphisms of CYP2D6 can affect its activity. Therefore, an efficient method for identifying CYP2D6 polymorphisms is clinically important. METHODS: We developed a high-resolution melting (HRM) analysis to investigate CYP2D6 polymorphisms. Genomic DNA was extracted from peripheral blood samples from 71 healthy individuals. All nine exons of the CYP2D6 gene were sequenced before screening by HRM analysis. This method can detect the most genotypes (*1, *2, *4, *10, *14, *21 *39, and *41) of CYP2D6 in Chinese. RESULTS: All samples were successfully genotyped. The four most common mutant CYP2D6 alleles (*1, *2, *10, and *41) can be genotyped. The single nucleotides polymorphism (SNP) frequencies of 100C > T (rs1065852), 1039C > T (rs1081003), 1661G > C (rs1058164), 2663G > A (rs28371722), 2850C > T (rs16947), 2988G > A (rs28371725), 3181A > G, and 4180G > C (rs1135840) were 58%, 61%, 73%, 1%, 13%, 3%, 1%, 73%, respectively. We identified 100% of all heterozygotes without any errors. The two homozygous genotypes (1661G > C and 4180G > C) can be distinguished by mixing with a known genotype sample to generate an artificial heterozygote for HRM analysis. Therefore, all samples could be identified using our HRM method, and the results of HRM analysis are identical to those obtained by sequencing. Our method achieved 100% sensitivity, specificity, positive prediction value and negative prediction value. CONCLUSION: HRM analysis is a nongel resolution method that is faster and less expensive than direct sequencing. Our study shows that it is an efficient tool for typing CYP2D6 polymorphisms.

Mutation Analysis of KCNQ1, KCNH2 and SCN5A Genes in Taiwanese Long QT Syndrome Patients.

Long QT syndrome (LQTS) is a genetic cardiac disease. Gene mutation affects the structure or function of ion channels that are associated with a high risk of sudden death. The goal of this study was to determine the frequency of KCNQ1, KCNH2, and SCN5A mutations in LQTS in a Taiwanese population. Genomic DNA was extracted from peripheral blood samples obtained from 5 patients with LQTS and the family members of 3 LQTS patients. High resolution melting (HRM) analysis and direct DNA sequencing were used to characterize the KCNQ1, KCNH2, and SCN5A genetic variations. HRM analysis was successfully optimized for 14 of the 16 exons of the KCNQ1, 5 of the 15 exons of the KCNH2, and 23 of the 27 exons of the SCN5A. HRM and direct DNA sequencing was applied to the cohort of 5 cases and some of their family. The genetic testing revealed two pathogenic mutations (p.T309I in KCNQ1 and p.R744fs in KCNH2) and all of the mutational frequencies in KCNQ1 and KCNH2 were 20%. In the two patients who carry the pathogenic mutation presenting with recurrent syncope due to ventricular fibrillation, an implantable cardioverter defibrillator was implanted. We also discovered 11 polymorphisms in KCNQ1, 3 in KCNH2, and 5 in SCN5A. Two-fifths of cases (40%) presented with one of the three major LQTS-causing gene mutations.

Detection of SF3B3 gene mutations in oral cancer by high resolution melting analysis.

BACKGROUND: There is a high prevalence of oral cancer in Taiwan, which is associated with betel quid chewing. Gene encoding splicing factors, especially splicing factor 3b subunit 1 (SF3B1), have been shown to be the most highly mutated in various hematological malignancies and have a great influence on clinical outcomes. However, few splicing targets have been identified for oral cancer. The aim of this study was to explore splicing factor 3b subunit 3 (SF3B3) gene mutations in oral cancer. METHODS: High resolution melting (HRM) analysis was used to characterize SF3B3 polymorphisms. Genomic DNA was extracted from 78 oral cancer tissues, and every exon from exon 2 to exon 26 of the SF3B3 gene was screened by HRM analysis. All results were confirmed by direct DNA sequencing over the range of codons of interest. RESULTS: Only one single nucleotide polymorphism with amino acid substitution was found to change from serine to asparagine at codon 811 (S811N) in exon 18 with an allele frequency of 1.3%. CONCLUSIONS: The molecular effects of drugs targeting the splicing factors in various cancers may offer a new perspective for the role in cancer progression and the development of novel antitumor therapy. HRM analysis with direct sequencing over the range of codons of interest is a fast, reliable, accurate, and cost-effective screening method to detect unknown gene mutations.

RAS, BRAF, and TP53 gene mutations in Taiwanese colorectal cancer patients.

BACKGROUND: Colorectal cancer (CRC) plays an important role in cancer mortality and morbidity. This study examined colorectal tissues for RAS, BRAF, and TP53 gene mutations to assess their value as indicators of outcomes of CRC therapy. MATERIAL AND METHODS: DNA was extracted from tissues taken from 165 patients with CRC. RAS gene mutations (exons 2 and 3) were detected by primer extension analysis. BRAF gene mutations (V600E) were detected by high resolution melting (HRM) analysis. TP53 gene mutations (exons 5-8) were detected by direct sequencing. RESULTS: RAS, BRAF, and TP53 mutations occurred in 36.97% (61/165), 4.24% (7/165), and 37.58% (62/165), respectively. The KRAS mutation is a predictor for poor 5-year survival (p = 0.05), and the co-presence of KRAS and TP53 mutations correlates with lymph node involvement (p = 0.029), tumor stage (p = 0.029), and poor survival (p = 0.021). Multivariate analysis adjusted for tumor size, histologic grade, lymph node metastasis, sex, and age also indicated that KRAS mutations correlate significantly with overall survival (p = 0.036). CONCLUSION: The KRAS mutation is not present in about one-third of CRC patients, and therefore other gene mutations need to be investigated to better understand the molecular mechanisms of CRC and its treatment.

Cancer carrier screening in the general population using whole-genome sequencing.

BACKGROUND: Cancer is a major cause of death, and its early identification and intervention have potential for clinical actionability and benefits for human health. The studies using whole-genome sequencing (WGS) and large samples analysis of cancer-related genes have been rarely done. METHODS: We performed WGS to explore germline mutations in coding and non-coding areas of cancer-related genes and non-coding driver genes and regulatory areas. Structural variants (SVs) was also analyzed. We used several tools and a subgrouping method to analyze the variants in 1491 healthy participants. Moreover, 275 cancer-related genes sequencing was carried out in 125 cancer patients. RESULTS: The incidence of familial cancer in the Taiwanese general population is 8.79% (131/1491). Cancer carrier rate of cancer-related genes is about 7.04% (105/1491) for pathogenic/likely pathogenic variants (P/LP) on ClinVar database only, and 28.24% (421/1491) for P/LP and loss of function variants. The carrier frequencies of cancer-related genes P/LP on ClinVar database were as follows: 8.40% (11/131), 7.11% (28/394), and 6.83% (66/966) in FC, 1MC, and nMC, respectively. The SVs and non-coding driver gene variants are uncommon. There are 1.54% (23/1491) of actionable cancer genes in American College of Medical Genetics and Genomics (ACMG), and the germline mutation rate of 275 cancer-related genes is 7.2% (9/125) in cancer patients including 4.0% (5/125) of actionable cancer genes in ACMG. After analyzing the frequencies of P/LP variants on GJB2 and SLC25A13 genes, we suggest that these two genes may not be cancer-related genes and need be re-evaluated. CONCLUSIONS: WGS analysis can completely detect germline mutations in cancer carriers. This study use subgrouping approach for samples provides a strategy to study whether a gene or variant is a cancer-related gene or variant in the future studies.

Comprehensive Analysis and Drug Modulation of Human Endogenous Retrovirus in Hepatocellular Carcinomas.

BACKGROUND: Human endogenous retroviruses (HERVs) play an important role in the development of cancer and many diseases. Here, we comprehensively explored the impact of HERVs on hepatocellular carcinomas (HCCs). METHODS: We employed Telescope to identify HERVs and quantify their expression in the total RNA sequencing data obtained from 254 HCC samples, comprising 254 tumor tissues and 34 matched normal tissues. RESULTS: In total, 3357 locus-specific activations of HERVs were differentially expressed, and 180 were correlated with patient survival. Using these 180 HERVs for classification, we found four subgroups with survival correlation. Higher expression levels of the 180 HERVs were correlated with poorer survival, while age, AFP, some mutations, and copy and structural variants differed among subgroups. The differential expression of host genes in high expression of these 180 HERVs primarily involved the activation of pathways related to immunity and infection, lipid and atherosclerosis, MAPK and NF-kB signaling, and cytokine-cytokine receptor interactions. Conversely, there was a suppression of pathways associated with RNA processing, including nucleocytoplasmic transport, surveillance and ribosome biogenesis, and transcriptional misregulation in cancer pathways. Almost all genes involved in HERV activation restriction, KRAB zinc finger proteins, RNA nucleocytoplasmic transport, stemness, HLA and antigen processing and presentation, and immune checkpoints were overexpressed in cancerous tissues, and many over-expressed HERV-related nearby genes were correlated with high HERV activation and poor survival. Twenty-three immune and stromal cells showed higher expression in non-cancerous than cancerous tissues, and seven were correlated with HERV activation. Small-molecule modulation of alternative splicing (AS) altered the expression of survival-related HERVs and their activation-related genes, as well as nearby genes. CONCLUSION: Comprehensive and integrated approaches for evaluating HERV expression and their correlation with specific pathways have the potential to provide new companion diagnostics and therapeutic strategies for HCC.