The Applications of Nanopore Sequencing Technology in Pathogenic Microorganism Detection.

Infectious diseases are major threats to human health and lead to a serious public health burden. The emergence of new pathogens and the mutation of known pathogens challenge our ability to diagnose and control infectious diseases. Nanopore sequencing technology exhibited versatile applications in pathogenic microorganism detection due to its flexible data throughput. This review article introduced the applications of nanopore sequencing in clinical microbiology and infectious diseases management, including the monitoring of emerging infectious diseases outbreak, identification of pathogen drug resistance, and disease-related microbial communities characterization.

Prospective and longitudinal evaluations of telomere length of circulating DNA as a risk predictor of hepatocellular carcinoma in HBV patients.

Prospective and longitudinal epidemiological evidence is needed to assess the association between telomere length and risk of hepatocellular carcinoma (HCC). In 323 cancer-free Korean-American HBV patients with 1-year exclusion window (followed for >1 year and did not develop HCC within 1 year), we measured the relative telomere length (RTL) in baseline serum DNAs and conducted extensive prospective and longitudinal analyses to assess RTL-HCC relationship. We found that long baseline RTL conferred an increased HCC risk compared to short RTL [hazard ratio (HR) = 4.93, P = 0.0005). The association remained prominent when the analysis was restricted to patients with a more stringent 5-year exclusion window (HR = 7.51, P = 0.012), indicating that the association was unlikely due to including undetected HCC patients in the cohort, thus minimizing the reverse-causation limitation in most retrospective studies. Adding baseline RTL to demographic variables increased the discrimination accuracy of the time-dependent receiver operating characteristic analysis from 0.769 to 0.868 (P = 1.0 × 10-5). In a nested longitudinal subcohort of 16 matched cases-control pairs, using a mixed effects model, we observed a trend of increased RTL in cases and decreased RTL in controls along 5 years of follow-up, with a significant interaction of case/control status with time (P for interaction=0.002) and confirmed the association between long RTL and HCC risk [odds ratio [OR] = 3.63, P = 0.016]. In summary, serum DNA RTL may be a novel non-invasive prospective marker of HBV-related HCC. Independent studies are necessary to validate and generalize this finding in diverse populations and assess the clinical applicability of RTL in HCC prediction.

Genetic variations in genes of metabolic enzymes predict postoperational prognosis of patients with colorectal cancer.

BACKGROUND: Genetic alterations in tricarboxylic acid (TCA) cycle metabolic enzymes were recently linked to various cancers. However, the associations of single nucleotide polymorphisms (SNPs) in genes of these enzymes have not been well studied. METHODS: We genotyped 16 SNPs from 7 genes encoding TCA cycle metabolic enzymes in 697 colorectal carcinoma (CRC) patients receiving surgical resection and analyzed their associations with clinical outcomes by multivariate Cox proportional hazard model. Then, the significant results were validated in another cohort of 256 CRC patients. RESULTS: We identified 4 SNPs in 2 genes had significant associations with CRC death risk and 5 SNPs in 3 genes had significant associations with CRC recurrence risk. Similar significant results were confirmed for rs4131826 in SDHC gene, rs544184 in SDHD gene and rs12071124 in FH gene in a validation cohort. Further analysis indicated that unfavorable genotypes exhibited a significant cumulative effect on overall and recurrence-free survival in a dose-dependent manner. Moreover, survival tree analysis indicated that SNP rs4131826 in SDHC gene and SNP rs12071124 in FH gene were the primary factors contributing to the different overall survival time and recurrence-free survival time of CRC patients, respectively. Immunohistochemical analysis further validated the effect of rs4131826 and rs544184 on expression of SDHC and SDHD in tissue samples. CONCLUSIONS: Our study suggests that SNPs in TCA cycle metabolic enzymes might be significantly associated with clinical outcomes in Chinese population diagnosed with CRC. Further functional and validated studies are warranted to expend our results to clinical utility.

Effect of thymidylate synthase gene polymorphism on the response to chemotherapy and clinical outcome of non-small cell lung cancer patients.

Genetic polymorphisms of thymidylate synthase (TYMS) gene have been reported to be associated with development or prognosis of several cancers. However, the association between polymorphisms of TYMS gene and clinical outcomes of non-small cell lung cancer (NSCLC) patients are still unknown. In the present study, we investigated the associations between single nucleotide polymorphisms (SNPs) of TYMS gene and response to chemotherapy as well as clinical outcomes in NSCLC patients. Five SNPs in TYMS gene were genotyped using the Sequenom iPLEX genotyping system in a hospital-based cohort with 500 NSCLC patients, and their associations with NSCLC outcomes were evaluated by Cox proportional hazard regression analysis under three genetic models (additive, dominant, and recessive models). Our data showed that there was no significant association between individual SNP and overall survival of NSCLC patients. However, SNP rs2847153 was significantly associated with NSCLC recurrence under recessive model. We further identified a significant interaction between rs2847153 and chemotherapy in modifying clinical outcome of patients. Our data showed that individuals carrying GG/GA genotypes of rs2847153 had a significantly better response to chemotherapy when comparing to those carrying AA genotype. Conclusively, our data suggest that SNPs rs2847153 in TYMS gene may be a potential biomarker for predicting clinical outcome and personalized treatment in NSCLC patients.

Aspartate aminotransferase to platelet ratio index as a prospective predictor of hepatocellular carcinoma risk in patients with chronic hepatitis B virus infection.

BACKGROUND AND AIM: APRI (aspartate aminotransferase [AST] to platelet ratio index) is widely used to assess fibrosis and cirrhosis risk, especially in hepatitis C virus (HCV)-infected patients. Few studies have evaluated APRI and hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) risk. Prospective evidence is needed to assess whether APRI predicts HCC risk in HBV patients. METHOD: In a prospectively enrolled clinical cohort of 855 HBV patients with a 1-year exclusion window (followed for > 1 year and did not develop HCC within 1 year), the predictive value of APRI in HCC risk was evaluated by Cox proportional hazards model using univariate and multivariate analyses and longitudinal analysis. RESULTS: Higher APRI prospectively conferred a significantly increased risk of HCC in univariate analysis (quartile analysis, P trend = 2.9 × 10(-7) ). This effect remained highly significant after adjusting for common host characteristics but not cirrhosis (P trend = 7.1 × 10(-5) ), and attenuated when cirrhosis is adjusted (P trend = 0.021). The effect remained prominent when the analysis was restricted to patients with a more stringent 2-year exclusion window (P trend = 0.008 in quartile analysis adjusting all characteristics including cirrhosis), indicating that the association was unlikely due to including undetected HCC patients in the cohort, thus minimizing the reverse-causation limitation in most retrospective studies. Longitudinal comparison demonstrated a persistently higher APRI value in HBV patients who developed HCC during follow-up than those remaining cancer free. CONCLUSION: APRI might be a marker of HCC risk in HBV patients in cirrhosis-dependent and -independent manners. Further studies are warranted to validate this finding and test its clinical applicability in HCC prevention.

Circulating mitochondrial DNA content associated with the risk of liver cirrhosis: a nested case-control study.

BACKGROUND AND AIMS: Accumulating evidence has indicated that variations of mitochondrial DNA (mtDNA) content may affect the susceptibility to hepatocellular carcinoma (HCC). However, no study has been conducted to evaluate the association of circulating mtDNA content and the risk of liver cirrhosis, a leading cause of HCC. METHODS: We conducted a nested case-control study including 136 cirrhotic hepatitis B virus (HBV) cases and 136 frequency-matched non-cirrhotic HBV controls. We determined mtDNA content in serum DNA using quantitative real-time PCR and analyzed its association with cirrhosis risk. RESULTS: We found that cirrhotic HBV patients had significantly lower levels of mtDNA content than non-cirrhotic HBV controls (P = 0.0184). Compared to patients with high mtDNA content, those with low mtDNA content had a 2.25-fold increased risk of cirrhosis [odds ratio (OR) 2.25, 95 % confidence interval (CI) 1.26-4.02]. This association exhibited a significant dose relationship as evidenced in both tertile and quartile analyses (P for trend = 0.0018 and 0.0008, respectively). Stratified analyses showed that the association was prominent in younger patients (P = 0.0122), males (P = 0.0069), never smokers (P = 0.0063), never drinkers (P = 0.0078), patients with a family history of HBV infection (P = 0.0062), and patients with low values of aspartate aminotransferase to platelet ratio index (APRI), a commonly used noninvasive marker for cirrhosis (P = 0.0109). Moreover, a joint effect was observed between low mtDNA content and high APRI values on cirrhosis risk (OR 24.07, 95 % CI 6.72-86.24). CONCLUSIONS: Low circulating mtDNA content may confer an increased cirrhosis risk in HBV patients. Further prospective studies are warranted to validate these findings and explore the clinical significance.

Polymorphisms of EpCAM gene and prognosis for non-small-cell lung cancer in Han Chinese.

The epithelial cell adhesion molecule (EpCAM) is overexpressed in a wide variety of human cancers and is associated with patient prognosis, including those with lung cancer. However, the association of single nucleotide polymorphisms (SNPs) in the EpCAM gene with the prognosis for non-small-cell lung cancer (NSCLC) patients has never been investigated. We evaluated the association between two SNPs, rs1126497 and rs1421, in the EpCAM gene and clinical outcomes in a Chinese cohort of 506 NSCLC patients. The SNPs were genotyped using the Sequenom iPLEX genotyping system. Multivariate Cox proportional hazards model and Kaplan-Meier curves were used to assess the association of EpCAM gene genotypes with the prognosis of NSCLC. We found that the non-synonymous SNP rs1126497 was significantly associated with survival. Compared with the CC genotype, the CT+TT genotype was a risk factor for both death (hazard ratio, 1.40; 95% confidence interval [CI], 1.02-1.94; P = 0.040) and recurrence (hazard ratio, 1.34; 95% CI, 1.02-1.77; P = 0.039). However, the SNP rs1421 did not show any significant effect on patient prognosis. Instead, the AG+GG genotype in rs1421 was significantly associated with early T stages (T1/T2) when compared with the AA genotype (odds ratio for late stage = 0.65; 95% CI, 0.44-0.96, P = 0.029). Further stratified analysis showed notable modulating effects of clinical characteristics on the associations between variant genotypes of rs1126497 and NSCLC outcomes. In conclusion, our study indicated that the non-synonymous SNP rs1126497 may be a potential prognostic marker for NSCLC patients.

Functional polymorphisms in the NPAS2 gene are associated with overall survival in transcatheter arterial chemoembolization-treated hepatocellular carcinoma patients.

The functional abnormality of circadian regulation genes is involved in the development and progression of hepatocellular carcinoma (HCC). However, the association between functional single nucleotide polymorphisms (SNPs) in circadian gene NPAS2 and the overall survival of HCC patients treated with transcatheter arterial chemoembolization (TACE) has never been investigated. Six functional SNPs in the NPAS2 gene were genotyped using the Sequenom iPLEX genotyping system in a cohort of 448 unresectable Chinese patients with HCC treated with TACE. Multivariate Cox proportional hazards model and Kaplan-Meier curves were used for the prognosis analysis. We found that two SNPs, rs1053096 and rs2305160, in the NPAS2 gene showed significant associations with overall death risk in HCC patients in the recessive model (hazard ratio [HR] = 1.48; 95% confidence interval [CI], 1.13-1.94; P = 0.004) and in the dominant model (HR = 1.63; 95% CI, 1.29-2.07; P < 0.001), respectively. Moreover, we observed a cumulative effect of these two SNPs on HCC overall survival, indicating a significant trend of increasing death risk with increasing number of unfavorable genotypes (P for trend < 0.001). Compared with the patients without any unfavorable genotypes, the HRs for patients with one and two unfavorable genotypes were 1.41 (95% CI, 1.10-1.82; P = 0.007) and 2.09 (95% CI, 1.46-2.97, P < 0.001), respectively. The haplotype and diplotype analyses further characterized the association between NPAS2 genotype and survival of HCC patients. Our results for the first time suggest that NPAS2 gene polymorphisms may serve as an independent prognostic marker for HCC patients treated with TACE.

Genetic variants in genes of tricarboxylic acid cycle key enzymes predict postsurgical overall survival of patients with hepatocellular carcinoma.

BACKGROUND: Metabolic reprogramming is a hallmark of cancer, including the alterations of activity and expression in tricarboxylic acid (TCA) cycle key enzymes. However, the significance of single nucleotide polymorphisms (SNPs) in genes encoding these key enzymes has not been investigated in hepatocellular carcinoma (HCC). METHODS: In this study, 17 SNPs in seven genes encoding three TCA cycle enzyme families (SDH, FH, and IDH) were genotyped in 492 HCC patients with surgical treatment and their association with overall survival (OS) was analyzed. RESULTS: Five SNPs in four genes were identified to be associated with OS in HCC patients. Among them, rs3935401 in the 3' untranslated region of SDHC exhibited the most significant association (P < 0.001). The unfavorable genotype of these five SNPs showed a significant accumulative effect on the prognosis of HCC patients, with a P for trend of <0.001. Furthermore, the haplotype group consisting of wild type in rs4131826 and variant in rs3935401 was significantly associated with increased risk of death in HCC patients. Survival tree analysis indicated that variant genotype of rs3935401 was the primary risk factor contributing to the prediction of OS in HCC patients. CONCLUSIONS: SNPs in TCA cycle key enzyme genes may serve as potential biomarkers to predict the OS in HCC patients.

AST to ALT ratio as a prospective risk predictor for liver cirrhosis in patients with chronic HBV infection.

BACKGROUND: Serum aspartate aminotransferase (AST) to alanine aminotransferase (ALT) ratio (AAR) is one of the most frequent indicators to discriminate fibrosis and cirrhosis. However, the results remained controversial. The aim of this study was to evaluate the predictive effect of AAR on hepatitis B virus (HBV)-related cirrhosis development. METHOD: A retrospective cohort study was conducted based on 1754 chronic HBV-infected patients. Clinical variables at their initial visit and follow-up data were collected. Cox proportional hazards model was constructed to evaluate the predictive value of AAR on cirrhosis risk, and its discrimination accuracy was determined by receiver operating characteristic (ROC). The time-dependent effect was assessed by a Fine and Gray competing risk model. RESULTS: Compared to patients with lower AAR, those with elevated AAR level had higher risk of cirrhosis development by adjusting for host characteristics (dichotomized analyses: hazard ratio = 2.77, P = 8.25 × 10 -4 ; tertile analyses: hazard ratio = 2.95, P = 1.61 × 10 -3 ), with an increasing risk trend ( Ptrend = 4.56 × 10 -4 ). The effect remained prominent when ALT or AST was abnormal, while no significant risk was observed when AST and ALT were simultaneously normal. Time-dependent effect analysis demonstrated a persistently higher risk, with the average hazard ratio equivalent to 1.92. AAR level could improve the discrimination efficacy of host variables with area under the curve increased from 0.684 to 0.711 ( P  =  0.039 ). CONCLUSION: Higher AAR was significantly associated with increased risk of HBV-related cirrhosis, and might be a potential predictor of cirrhosis development.

Post-diagnosis hemoglobin change associates with overall survival of multiple malignancies - results from a 14-year hospital-based cohort of lung, breast, colorectal, and liver cancers.

BACKGROUND: Anemia refers to low hemoglobin (Hb) level and is a risk factor of cancer patient survival. The National Comprehensive Cancer Network recently suggested that post-diagnosis Hb change, regardless of baseline Hb level, indicates the potential presence of anemia. However, there is no epidemiological study evaluating whether Hb change has direct prognostic values for cancer patients at the population level. METHODS: We identified 6675 patients with a diagnosis of primary lung, breast, colorectal, or liver cancer who visited the Kimmel Cancer Center at the Thomas Jefferson University from 1998 to 2011. All patients had at least two Hb measurements within the first six months after diagnosis. We analyzed the main, dose-dependent, and time-dependent effects of Hb changes on patient survival. RESULTS: Compared to patients with a low Hb change (|∆Hb|≤2.6), those having a |∆Hb|>2.6 exhibited a significantly shorter survival (hazard ratio=1.40, 95% confidence interval 1.31-1.50, P=4.5 × 10(-22), Plog rank=1.6 × 10(-39)). This association remained significant across the four cancer types. Bootstrap resampling validated these findings 100% of the time with P<0.01 in all patients and in patients of individual cancers. The association exhibited an apparent U-shape dose-dependent pattern. Time-dependent modeling demonstrated that the effect of Hb change on the survival of the overall patient population persisted for approximately 4.5 years after diagnosis. CONCLUSION: Post-diagnosis Hb change associates with the survival of multiple cancers and may have clinical values in tailoring anti-anemia treatments. Because Hb level is frequently measured during cancer treatment, Hb changes may be a potentially important variable in building cancer prognosis models.

Potentially functional genetic variants in KDR gene as prognostic markers in patients with resected colorectal cancer.

Angiogenesis plays a key role in the development and treatment response of various tumors. The signaling transductions mediated by the binding of vascular endothelial growth factor (VEGF) to its receptor KDR (kinase insert domain receptor) is the most important pathway in tumor angiogenesis. Single nucleotide polymorphisms (SNPs) in VEGF have been extensively implicated in the etiology and treatment outcome of colorectal cancer (CRC). However, no study has been reported evaluating the role of KDR SNPs in CRC prognosis. We herein assessed the association between four potentially functional KDR SNPs and tumor recurrence in a Chinese population with 408 surgically resected CRC patients. The most significant SNP was for rs10013228 located in the KDR gene promoter. Compared with the homozygous wild-type genotype, the variant-containing genotypes of this SNP were significantly associated with a reduced recurrence risk with a hazard ratio (HR) of 0.53 (95% confidence interval [CI] 0.30-0.95, P = 0.032). Moreover, a borderline significant association was noted for another promoter SNP, rs2071559, with an HR of 0.67 (95% CI 0.42-1.07, P = 0.092). In stratified analysis, the associations of both SNPs were more prominent in patients receiving chemotherapy (HR = 0.47, 95% CI 0.23-0.94, P = 0.033 for rs10013228 and HR = 0.55, 95% CI 0.32-0.95, P = 0.032 for rs2071559). Further analysis revealed a protective effect on patient recurrence by chemotherapy (HR = 0.56, 95% CI 0.32-1.01, P = 0.046), which was more evident in patients with the variant-containing genotypes of each of the two SNPs (HR = 0.09, 95% CI 0.02-0.55, P = 0.009 for rs10013228 and HR = 0.39, 95% CI 0.18-0.86, P = 0.020 for rs2071559). Collectively, our findings suggest SNPs in the KDR gene modulate CRC recurrence, especially in those receiving chemotherapy.

Telomere length in circulating serum DNA as a novel non-invasive biomarker for cirrhosis: a nested case-control analysis.

BACKGROUND & AIMS: Previous studies have indicated that telomere length is associated with altered risk of various tumours including hepatitis B virus (HBV)-related hepatocellular carcinoma. However, the association between telomere length and the risk of cirrhosis has not been reported. METHODS: In this nested case-control study, we used real-time quantitative PCR to determine the relative telomere length (RTL) in serum DNA samples from 100 HBV-related cirrhosis cases and 100 frequency-matched HBV controls, and evaluated the associations between RTL and cirrhosis risk by logistic regression analyses. RESULTS: We found that cirrhotic cases had a significantly longer RTL (median, 0.36; range, 0.08-1.87) than non-cirrhotic controls (median, 0.20; range, 0.05-1.11) (P < 0.0001). Compared with subjects with short RTL, those with long RTL had a significantly increased cirrhosis risk [odds ratio, 2.76, 95% confidence interval, 1.50-5.10; P = 0.001]. Quartile analysis further indicated a dose-response effect for this association. Compared with patients with the lowest quartile of RTL, the cirrhosis risk for those with the second, third and highest quartile of RTL was 2.68 (0.91-7.87, P = 0.073), 3.37 (1.32-10.54, P = 0.013) and 6.64 (2.41-18.32, P < 0.0001) respectively (P(trend) <0.0001). Moreover, the area under the receiver operating characteristic curve increased from 0.60 (epidemiological variables) to 0.72 (epidemiological variables plus RTL), with statistically significant difference assessed by bootstrap analysis. CONCLUSIONS: Our study presents the first epidemiological evidence that RTL in serum DNA could potentially be used as a simple, inexpensive and non-invasive marker of cirrhosis risk, a finding that warrants further investigations in independent retrospective and prospective populations.

The hepatocyte in the innate immunity.

The hepatocytes, as the main cells in the liver, exert liver functions by expressing innate immune receptors. The innate immune receptors include Toll-like receptors (TLRs), RIG-like receptors (retinoic acid inducible gene I-like receptors, RLRs) and NOD-like receptors (nucleotide binding oligomerization domain-like receptors, NLRs). The hepatocytes, recognize extracellular pathogen-associated molecular patterns (PAMPs) and intracellular damage-associated molecular patterns (DAMPs) through the above receptors. After the activation of the innate immune receptors, the hepatocytes produce cytokines, such as interferon (IFN), to protect the liver, through a series of signaling cascades.

Extrachromosomal circular DNA in cancer drug resistance and its potential clinical implications.

Chemotherapy is widely used to treat patients with cancer. However, resistance to chemotherapeutic drugs remains a major clinical concern. The mechanisms of cancer drug resistance are extremely complex and involve such factors such as genomic instability, DNA repair, and chromothripsis. A recently emerging area of interest is extrachromosomal circular DNA (eccDNA), which forms owing to genomic instability and chromothripsis. eccDNA exists widely in physiologically healthy individuals but also arises during tumorigenesis and/or treatment as a drug resistance mechanism. In this review, we summarize the recent progress in research regarding the role of eccDNA in the development of cancer drug resistance as well as the mechanisms thereof. Furthermore, we discuss the clinical applications of eccDNA and propose some novel strategies for characterizing drug-resistant biomarkers and developing potential targeted cancer therapies.

Increased Drp1 promotes autophagy and ESCC progression by mtDNA stress mediated cGAS-STING pathway.

BACKGROUND: Mitochondrial dynamics homeostasis is important for cell metabolism, growth, proliferation, and immune responses. The critical GTPase for mitochondrial fission, Drp1 is frequently upregulated in many cancers and is closely implicated in tumorigenesis. However, the mechanism underling Drp1 to influence tumor progression is largely unknown, especially in esophageal squamous cell carcinoma (ESCC). METHODS: Immunohistochemistry was used to examine Drp1 and LC3B expression in tissues of ESCC patients. Autophagic vesicles were investigated by transmission electron microscopy. Fluorescent LC3B puncta and mitochondrial nucleoid were observed by fluorescent and confocal microscopy. Mitochondrial function was evaluated by mitochondrial membrane potential, ROS and ATP levels. Xenograft tumor model was performed in BALB/c nude mice to analyze the role of Drp1 on ESCC progression. RESULTS: We found that Drp1 high expression is correlated with poor overall survival of ESCC patients. Drp1 overexpression promotes cell proliferation and xenograft ESCC tumor growth by triggering autophagy. Furthermore, we demonstrated that Drp1 overexpression disturbs mitochondrial function and subsequent induces mitochondrial DNA (mtDNA) released into the cytosol thereby inducing cytosolic mtDNA stress. Mechanistically, cytosolic mtDNA activates the cGAS-STING pathway and facilitates autophagy, which promotes ESCC cancer growth. Moreover, mtDNA digestion with DNase I and autophagy inhibition with chloroquine attenuates the cGAS-STING pathway activation and ESCC cancer growth. CONCLUSIONS: Our finding reveals that Drp1 overexpression induces mitochondrial dysfunction and cytosolic mtDNA stress, which subsequently activates the cGAS-STING pathway, triggers autophagy and promotes ESCC progression.

Zinc deficiency activates S100A8 inflammation in the absence of COX-2 and promotes murine oral-esophageal tumor progression.

Zinc (Zn)-deficiency (ZD) is implicated in the pathogenesis of human oral-esophageal cancers. Previously, we showed that in ZD mice genetic deletion of cyclooxygenase-2 (Cox-2) enhances N-nitrosomethylbenzylamine-induced forestomach carcinogenesis. By contrast, Cox-2 deletion offers protection in Zn-sufficient (ZS) mice. We hypothesize that ZD activates pathways insensitive to COX-2 inhibition, thereby promoting carcinogenesis. This hypothesis is tested in a Cox-2(-/-) mouse tongue cancer model that mimics pharmacologic blockade of COX-2 by firstly examining transcriptome profiles of forestomach mucosa from Cox-2(-/-) and wild-type mice on a ZD vs. ZS diet, and secondly investigating the roles of identified markers in mouse forestomach/tongue preneoplasia and carcinomas. In Cox-2(-/-) mice exposed to the tongue carcinogen 4-nitroquinoline 1-oxide, dietary ZD elicited tongue/esophagus/forestomach carcinomas that were prevented by ZS. The precancerous ZD:Cox-2(-/-) vs. ZS:Cox-2(-/-) forestomach had an inflammatory signature with upregulation of the proinflammation genes S100a8 and S100a9. Bioinformatics analysis revealed overrepresentation of inflammation processes comprising S100a8/a9 and an nuclear factor (NF)-κB network with connectivity to S100A8. Immunohistochemistry revealed co-overexpression of S100A8, its heterodimeric partner S100A9, the receptor for advanced glycation end-products (RAGE), NF-κB p65, and cyclin D1, in ZD:Cox-2(-/-) forestomach/tongue preneoplasia and carcinomas, evidence for the activation of a RAGE-S100A8/A9 inflammatory pathway. Accumulation of p53 in these carcinomas indicated activation of additional inflammatory pathways. Zn-replenishment in ZD:Cox-2(-/-) mice reversed the inflammation and inhibited carcinogenesis. Thus, ZD activates alternative inflammation-associated cancer pathways that fuel tumor progression and bypass the antitumor effect of Cox-2 ablation. These findings have important clinical implications, as combination cancer therapy that includes Zn may improve efficacy.

Cancer Biomarkers Discovery of Methylation Modification With Direct High-Throughput Nanopore Sequencing.

Cancer is a complex disease, driven by a combination of genetic and epigenetic alterations. DNA and RNA methylation modifications are the most common epigenetic events that play critical roles in cancer development and progression. Bisulfite converted sequencing is a widely used technique to detect base modifications in DNA methylation, but its main drawbacks lie in DNA degradation, lack of specificity, or short reads with low sequence diversity. The nanopore sequencing technology can directly detect base modifications in native DNA as well as RNA without harsh chemical treatment, compared to bisulfite sequencing. Furthermore, CRISPR/Cas9-targeted enrichment nanopore sequencing techniques are straightforward and cost-effective when targeting genomic regions are of interest. In this review, we mainly focus on DNA and RNA methylation modification detection in cancer with the current nanopore sequencing approaches. We also present the respective strengths, weaknesses of nanopore sequencing techniques, and their future translational applications in identification of epigenetic biomarkers for cancer detection and prognosis.

Circulating Cell-Free mtDNA Content as a Non-invasive Prognostic Biomarker in HCC Patients Receiving TACE and Traditional Chinese Medicine.

Hepatocellular carcinoma (HCC) accounts for 70-85% of liver cancer, and about 85% of HCC are hepatitis B virus-related (HBV-HCC) in China. Transarterial chemoembolization (TACE) combined with traditional Chinese medicine (TCM) has been reported as an effective treatment. Potential biomarkers to stratify patients who may benefit from this treatment are needed. In this study, we aimed to evaluate whether circulating cell-free mitochondrial DNA (ccf-mtDNA) content was associated with the outcome of HCC patients, especially of those who received the combination treatment of TACE and TCM. Univariate and multivariate Cox analyses were conducted to evaluate the association between ccf-mtDNA content and the overall survival of HBV-HCC patients. Kaplan-Meier analysis was used to compare the survival differences between patients with low and high ccf-mtDNA content. In a hospital-based cohort with 141 HBV-HCC patients, there was no statistically significant association between the ccf-mtDNA content and the overall survival of HBV-HCC patients in the univariate analysis, but a borderline significant association was found in the multivariate analyses. In a subcohort of 50 HBV-HCC patients who received TACE and TCM treatment, high ccfDNA content conferred an increased death risk with a hazard ratio of 4.01 (95% confidence interval: 1.25-12.84, p = 0.019) in the multivariate analysis. Kaplan-Meier survival analysis also showed that patients with high ccf-mtDNA content had unfavorable survival (log rank p = 0.097). Our findings suggest that ccf-mtDNA content is a potential non-invasive prognostic biomarker in HCC patients receiving TACE and TCM treatment.

Characterization of fragment sizes, copy number aberrations and 4-mer end motifs in cell-free DNA of hepatocellular carcinoma for enhanced liquid biopsy-based cancer detection.

Circulating cell-free DNA (cfDNA) fragmentomics, which encompasses the measurement of cfDNA length and short nucleotide motifs at the ends of cfDNA molecules, is an emerging field for cancer diagnosis. The utilization of cfDNA fragmentomics for the diagnosis of patients with hepatocellular carcinoma (HCC) caused by hepatitis B virus (HBV) is currently limited. In this study, we utilized whole-genome sequencing data of cfDNA in samples from patients with HCC (n = 197) and HBV (n = 187) to analyze the association of fragment size selection (< 150 bp) with tumor fraction (TF), copy number variation (CNV) alterations and the change in the proportion of 4-mer end motifs in HCC and HBV samples. Our analyses identified five typical CNV markers (i.e. loss in chr1p, chr4q and chr8p, and gain in chr1q and chr8q) in cfDNA with a cumulatively positive rate of ˜ 95% in HCC samples. Size selection (< 150 bp) significantly enhanced TF and CNV signals in HCC samples. Additionally, three 4-mer end motifs (CCCA, CCTG and CCAG) were identified as preferred end motifs in HCC samples. We identified 139 end motifs significantly associated with fragment size that showed similar patterns of associations between patients with HCC and HBV, suggesting that end motifs might be inherently coupled with fragment size by a ubiquitous mechanism. Here we conclude that CNV markers, fragment size selection and end-motif pattern in cfDNA have potential for effective detection of patients with HCC.