Detection of K-ras gene mutation by liquid biopsy in patients with pancreatic cancer

BACKGROUND

Cell-free circulating tumor DNA (ctDNA) in serum has been considered to be a useful candidate for noninvasive cancer diagnosis. The current study was designed to estimate the clinical usefulness of genetic analysis for ctDNA by digital polymerase chain reaction in patients with pancreatic cancer.

METHODS

The authors compared K-ras mutations detected in endoscopic ultrasound-guided fine-needle aspiration biopsy tissue DNA and in ctDNA from 75 patients with pancreatic cancer. K-ras mutations in the serum of 66 independent, consecutive patients with pancreatic cancer were also analyzed and the authors compared the results with survival rates.

RESULTS

The frequencies of the mutations in tissue samples at G12V, G12D, and G12R in codon 12 were 28 of 75 samples (37.3%), 22 of 75 samples (29.3%), and 6 of 75 samples (8.0%), respectively. Conversely, the rates of the mutations in ctDNA were 26 of 75 samples (34.6%), 29 of 75 samples (38.6%), and 4 of 75 samples (5.3%), respectively. Overall, the K-ras mutation rates in tissue and ctDNA were 74.7% and 62.6%, respectively, and the concordance rate between them was 58 of 75 samples (77.3%). Survival did not appear to differ by the presence of K-ras mutations in tissue DNA, but the survival of patients with K-ras mutations in ctDNA was significantly shorter than that of patients without mutations in both a development set (P = .006) and an independent validation set (P = .002). The difference was especially evident in cases with a G12V mutation.

CONCLUSIONS

Analysis of ctDNA is a new useful procedure for detecting mutations in patients with pancreatic cancer. This noninvasive method may have great potential as a new strategy for the diagnosis of pancreatic cancer as well as for predicting survival.

Droplet digital PCR measurement of HER2 in patients with gastric cancer

BACKGROUND

Although there are some new criteria for human epidermal growth factor receptor 2 (HER2) expression with immunohistochemistry/fluorescence in situ hybridisation (IHC/FISH) in gastric cancer, the method is still ambiguous and is somewhat dependent on the subjective qualities of the evaluator.

METHODS

We used droplet digital polymerase chain reaction (ddPCR) to evaluate HER2 amplification in formalin-fixed and paraffin-embedded (FFPE) samples and cell-free serum circulating tumour DNA (ctDNA) in 25 patients with gastric cancer.

RESULTS

The concordance rate of HER2 amplification examined in FFPE samples with ddPCR and IHC/FISH was 92% (23 out of 25). The concordance rate of FFPE with ctDNA was not high (62.5%); however, patients who were HER2-positive by ctDNA had significantly shorter survival compared with HER2-negative patients.

CONCLUSIONS

Our results demonstrated that this ddPCR method was as effective as IHC/FISH and therefore might become a standard method for analysing not only FFPE but also ctDNA.

Clair DK, Avadhani NG, Diehl JA, Nakagawa H. Mitochondrial SOD2 regulates epithelial-mesenchymal transition and cell populations defined by differential CD44 expression

Epithelial-mesenchymal transition (EMT) promotes cancer cell invasion, metastasis and treatment failure. EMT may be activated in cancer cells by reactive oxygen species (ROS). EMT may promote conversion of a subset of cancer cells from a CD44(low)-CD24(high) (CD44L) epithelial phenotype to a CD44(high)-CD24(-/low) (CD44H) mesenchymal phenotype, the latter associated with increased malignant properties of cancer cells. ROS are required for cells undergoing EMT, although excessive ROS may induce cell death or senescence; however, little is known as to how cellular antioxidant capabilities may be regulated during EMT. Mitochondrial superoxide dismutase 2 (SOD2) is frequently overexpressed in oral and esophageal cancers. Here, we investigate mechanisms of SOD2 transcriptional regulation in EMT, as well as the functional role of this antioxidant in EMT. Using well-characterized genetically engineered oral and esophageal human epithelial cell lines coupled with RNA interference and flow cytometric approaches, we find that transforming growth factor (TGF)-β stimulates EMT, resulting in conversion of CD44L to CD44H cells, the latter of which display SOD2 upregulation. SOD2 induction in transformed keratinocytes was concurrent with suppression of TGF-β-mediated induction of both ROS and senescence. SOD2 gene expression appeared to be transcriptionally regulated by NF-κB and ZEB2, but not ZEB1. Moreover, SOD2-mediated antioxidant activity may restrict conversion of CD44L cells to CD44H cells at the early stages of EMT. These data provide novel mechanistic insights into the dynamic expression of SOD2 during EMT. In addition, we delineate a functional role for SOD2 in EMT via the influence of this antioxidant upon distinct CD44L and CD44H subsets of cancer cells that have been implicated in oral and esophageal tumor biology.

Berberine improved experimental chronic colitis by regulating interferon-γ- and IL-17A-producing lamina propria CD4+ T cells through AMPK activation

The herbal medicine berberine (BBR) has been recently shown to be an AMP-activated protein kinase (AMPK) productive activator with various properties that induce anti-inflammatory responses. We investigated the effects of BBR on the mechanisms of mucosal CD4+T cell activation in vitro and on the inflammatory responses in T cell transfer mouse models of inflammatory bowel disease (IBD). We examined the favorable effects of BBR in vitro, using lamina propria (LP) CD4+ T cells in T cell transfer IBD models in which SCID mice had been injected with CD4+CD45RBhigh T cells. BBR suppressed the frequency of IFN-γ- and Il-17A-producing LP CD4+ T cells. This effect was found to be regulated by AMPK activation possibly induced by oxidative phosphorylation inhibition. We then examined the effects of BBR on the same IBD models in vivo. BBR-fed mice showed AMPK activation in the LPCD4+ T cells and an improvement of colitis. Our study newly showed that the BBR-induced AMPK activation of mucosal CD4+ T cells resulted in an improvement of IBD and underscored the importance of AMPK activity in colonic inflammation.

Fibroblast growth factor-2-mediated FGFR/Erk signaling supports maintenance of cancer stem-like cells in esophageal squamous cell carcinoma

In esophageal squamous cell carcinoma (ESCC), a subset of cells defined by high expression of CD44 and low expression of CD24 has been reported to possess characteristics of cancer stem-like cells (CSCs). Novel therapies directly targeting CSCs have the potential to improve prognosis of ESCC patients. Although fibroblast growth factor-2 (FGF-2) expression correlates with recurrence and poor survival in ESCC patients, the role of FGF-2 in regulation of ESCC CSCs has yet to be elucidated. We report that FGF-2 is significantly upregulated in CSCs and significantly increases CSC content in ESCC cell lines by inducing epithelial-mesenchymal transition (EMT). Conversely, the FGFR inhibitor, AZD4547, sharply diminishes CSCs via induction of mesenchymal-epithelial transition. Further experiments revealed that MAPK/Erk kinase (Mek)/extracellular signal-regulated kinases (Erk) pathway is crucial for FGF-2-mediated CSC regulation. Pharmacological inhibition of FGF receptor (FGFR)-mediated signaling via AZD4547 did not affect CSCs in Ras mutated cells, implying that Mek/Erk pathway, downstream of FGFR signaling, might be an important regulator of CSCs. Indeed, the Mek inhibitor, trametinib, efficiently suppressed ESCC CSCs even in the context of Ras mutation. Consistent with these findings in vitro, xenotransplantation studies demonstrated that inhibition of FGF-2-mediated FGFR/Erk signaling significantly delayed tumor growth. Taken together, these findings indicate that FGF-2 is an essential factor regulating CSCs via Mek/Erk signaling in ESCC. Additionally, inhibition of FGFR and/or Mek signaling represents a potential novel therapeutic option for targeting CSCs in ESCC.

Cellular senescence checkpoint function determines differential Notch1-dependent oncogenic and tumor-suppressor activities

Notch activity regulates tumor biology in a context-dependent and complex manner. Notch may act as an oncogene or a tumor-suppressor gene even within the same tumor type. Recently, Notch signaling has been implicated in cellular senescence. Yet, it remains unclear as to how cellular senescence checkpoint functions may interact with Notch-mediated oncogenic and tumor-suppressor activities. Herein, we used genetically engineered human esophageal keratinocytes and esophageal squamous cell carcinoma cells to delineate the functional consequences of Notch activation and inhibition along with pharmacological intervention and RNA interference experiments. When expressed in a tetracycline-inducible manner, the ectopically expressed activated form of Notch1 (ICN1) displayed oncogene-like characteristics inducing cellular senescence corroborated by the induction of G0/G1 cell-cycle arrest, Rb dephosphorylation, flat and enlarged cell morphology and senescence-associated β-galactosidase activity. Notch-induced senescence involves canonical CSL/RBPJ-dependent transcriptional activity and the p16(INK4A)-Rb pathway. Loss of p16(INK4A) or the presence of human papilloma virus (HPV) E6/E7 oncogene products not only prevented ICN1 from inducing senescence but permitted ICN1 to facilitate anchorage-independent colony formation and xenograft tumor growth with increased cell proliferation and reduced squamous-cell differentiation. Moreover, Notch1 appears to mediate replicative senescence as well as transforming growth factor-β-induced cellular senescence in non-transformed cells and that HPV E6/E7 targets Notch1 for inactivation to prevent senescence, revealing a tumor-suppressor attribute of endogenous Notch1. In aggregate, cellular senescence checkpoint functions may influence dichotomous Notch activities in the neoplastic context.

Leucine-rich alpha-2 glycoprotein as a marker of mucosal healing in inflammatory bowel disease

Leucine-rich alpha-2 glycoprotein (LRG) may be a novel serum biomarker for patients with inflammatory bowel disease. The association of LRG with the endoscopic activity and predictability of mucosal healing (MH) was determined and compared with those of C-reactive protein (CRP) and fecal markers (fecal immunochemical test [FIT] and fecal calprotectin [Fcal]) in 166 ulcerative colitis (UC) and 56 Crohn's disease (CD) patients. In UC, LRG was correlated with the endoscopic activity and could predict MH, but the performance was not superior to that of fecal markers (areas under the curve [AUCs] for predicting MH: LRG: 0.61, CRP: 0.59, FIT: 0.75, and Fcal: 0.72). In CD, the performance of LRG was equivalent to that of CRP and Fcal (AUCs for predicting MH: LRG: 0.82, CRP: 0.82, FIT: 0.70, and Fcal: 0.88). LRG was able to discriminate patients with MH from those with endoscopic activity among UC and CD patients with normal CRP levels. LRG was associated with endoscopic activity and could predict MH in both UC and CD patients. It may be particularly useful in CD.

EGFR inhibitors prevent induction of cancer stem-like cells in esophageal squamous cell carcinoma by suppressing epithelial-mesenchymal transition

There exists a highly tumorigenic subset of esophageal squamous cell carcinoma (ESCC) cells defined by high expression of CD44. A novel therapy targeting these cancer stem-like cells (CSCs) is needed to improve prognosis of ESCC. CSCs of ESCC have a mesenchymal phenotype and epithelial-mesenchymal transition (EMT) is critical to enrich and maintain CSCs. EGFR, frequently overexpressed in ESCC, has pivotal roles in EMT induced by TGF-β in invasive fronts. Thus, EMT in invasive fronts of ESCC might be important for CSCs and EGFR could be a target of a novel therapy eliminating CSCs. However, effects of EGFR inhibitors on CSCs in ESCC have not been fully examined. EGFR inhibitors, erlotinib and cetuximab, significantly suppressed enrichment of CSCs via TGF-β1-mediated EMT. Importantly, EGFR inhibitors sharply suppressed ZEB1 that is essential for EMT in ESCC. Further, EGFR inhibitors activated Notch1 and Notch3, leading to squamous cell differentiation. EGFR inhibition may suppress expression of ZEB1 and induce differentiation, thereby blocking EMT-mediated enrichment of CSCs. In organotypic 3D culture, a form of human tissue engineering, tumor cells in invasive nests showed high expression of CD44. Erlotinib significantly blocked invasion into the matrix and CD44 high expressing CSCs were markedly suppressed by erlotinib in organotypic 3D culture. In conclusion, EMT is a critical process for generation of CSCs and the invasive front of ESCC, where EMT occurs, might form a CSC niche in ESCC. EGFR inhibitors could suppress EMT in invasive fronts and be one therapeutic option targeting against generation of CSCs in ESCC.

Liquid biopsy of bile for the molecular diagnosis of gallbladder cancer

INTRODUCTION

Tissue sampling of gallbladder cancer (GBCa) is challenging because of the anatomy of the gallbladder. The aim of this study is to investigate the possibility of diagnosing GBCa patients by performing a liquid biopsy of bile in addition to current diagnostic methods.

METHODS

Thirty patients with GBCa were enrolled in this study. Cytological examination was performed in all patients. Using next generation sequencing (NGS), DNA isolated from the bile and tumor tissue was analyzed for mutations in 49 oncogenes. We also compared these mutations with cytology results.

RESULTS

57.1% of DNA samples from tumor tissue were positive for a mutation. In these patients, 87.5% of the bile circulating tumor DNA (ctDNA) samples had the same mutation. The concordance rate between bile ctDNA and tissue DNA samples was 85.7%, and the mutation frequencies detected in ctDNA were approximately half of what was detected in tumor tissue DNA. On the other hand, the sensitivity of the cytological and bile ctDNA analyses was 45.8% and 58.3%, respectively. The concordance rate between cytology and bile ctDNA analyses was 87.5%.

CONCLUSIONS

Mutated tumor DNA could be detected in bile by NGS. Liquid biopsy of bile might help us to diagnose GBCa because of higher sensitivity and positive predict value compared to cytology with ERCP.

Heterogeneous distribution of Fusobacterium nucleatum in the progression of colorectal cancer

BACKGROUND AND AIM

Fusobacterium nucleatum (Fn) is involved in colorectal cancer (CRC) growth and is a biomarker for patient prognosis and management. However, the ecology of Fn in CRC and the distribution of intratumoral Fn are unknown.

METHODS

We evaluated Fn and the status of KRAS and BRAF in 200 colorectal neoplasms (118 adenomas and 82 cancers) and 149 matched adjacent normal mucosas. The differentiation status between "surface" and "deep" areas of cancer tissue and matched normal mucosa were analyzed in 46 surgical samples; the Ki-67 index was also evaluated in these samples.

RESULTS

Fusobacterium nucleatum presence in the tumor increased according to pathological stage (5.9% [adenoma] to 81.8% [stage III/IV]), while Fn presence in normal mucosa also increased (7.6% [adenoma] to 40.9% [stage III/IV]). The detection rates of Fn on the tumor surface and in deep areas were 45.7% and 32.6%, while that of normal mucosa were 26.1% and 23.9%, respectively. Stage III/IV tumors showed high Fn surface area expression (66.7%). Fn intratumoral heterogeneity (34.8%) was higher than that of KRAS (4.3%; P < 0.001) and BRAF (2.2%; P < 0.001). The Ki-67 index in Fn-positive cases was higher than that in negative cases (93.9% vs 89.0%; P = 0.01).

CONCLUSIONS

Fusobacterium nucleatum was strongly present in CRC superficial areas at stage III/IV. The presence of Fn in the deep areas of adjacent normal mucosa also increased. The intratumoral heterogeneity of Fn is important in the use of Fn as a biomarker, as Fn is associated with CRC proliferative capacity.

Utility of serum DNA as a marker for KRAS mutations in pancreatic cancer tissue

BACKGROUND/OBJECTIVES

The detection of cancer-specific DNA in peripheral blood, known as a liquid biopsy, has been reported recently. Most such studies have used plasma as a sample; however, whether or not serum can be used as effectively is unclear. We attempted to clarify suitable samples for detecting KRAS mutations in circulating DNA in the blood of pancreatic cancer patients using droplet digital polymerase chain reaction (PCR).

METHODS

DNA was extracted from the tissue, plasma, and serum of 40 pancreatic cancer patients. The presence of KRAS mutations G12D, G12V, and G12R was analyzed by droplet digital PCR.

RESULTS

The amount of DNA isolated from the serum was much higher than that from plasma (1.0- to 42.0-fold). At least 1 KRAS mutation was observed in 93% of cancer tissues, whereas we detected the mutations in only 48% of the serum and plasma DNA samples. The G12D mutation was the most prevalent of the three mutations, followed by the G12V mutation. The presence of the G12D KRAS mutation in the plasma, serum, or tissue did not correlate to the overall survival; however, the prognosis of the patients with a KRAS mutation at G12V in the plasma or serum was significantly poorer than that of the patients without the mutation (P < 0.01).

CONCLUSIONS

Serum and plasma were found to be good materials for detecting cancer-specific DNA in the peripheral blood and the presence of KRAS mutations in blood-derived DNA may be used as a prognostic biomarker for patients with pancreatic cancer.

Risk factors for recurrence after transarterial chemoembolization for early-stage hepatocellular carcinoma

BACKGROUND

Radiofrequency ablation (RFA) is a standard therapy for the treatment of hepatocellular carcinoma (HCC) with 3 or fewer tumors of up to 3 cm (early-stage HCC); when RFA is unsuccessful or unfeasible, transcatheter arterial chemoembolization (TACE) has often been performed. However, little information about the outcome of TACE for early-stage HCC has been reported and it is hard to decide whether to perform additional treatment following TACE in these difficult conditions. The aim of this study was to determine the risk factors for local or intrahepatic distant recurrence after TACE in early-stage HCC.

METHODS

Among 1,560 newly diagnosed HCC patients who were admitted to Okayama University Hospital, 43 patients with early-stage HCC who received only TACE in at least one nodule were enrolled in this study. We analyzed the risk factors for local and distant recurrence by the Cox proportional hazard model.

RESULTS

The local recurrence rates and intrahepatic distant recurrence rates at 3 months, 6 months, and 1 year were 18.6, 33.4, and 61.8%, and 2.8, 2.8, and 34.3%, [corrected] respectively.Among 12 parameters examined as possible risk factors for recurrence, heterogeneous Lipiodol uptake (risk ratio 3.38; 95% confidence interval 1.14-10.60) and high serum des-gamma-carboxy prothrombin (DCP) (2.58; 1.03-7.14) were significantly correlated with local recurrence, and the presence of multiple tumors (10.64; 1.76-93.75) was significantly correlated with intrahepatic distant recurrence.

CONCLUSIONS

Heterogeneous Lipiodol uptake, high serum DCP, and multiple tumors are risk factors for recurrence in patients with early-stage HCC who have undergone palliative TACE.

Involvement of platelets in extrahepatic metastasis of hepatocellular carcinoma

AIM

Recently, a relationship between platelets and cancer metastasis has been reported. The aim of this study is to elucidate the risk factors for extrahepatic metastasis (EHM), with emphasis on association with platelets in patients, with hepatocellular carcinoma (HCC).

METHODS

We examined risk factors for EHM in 1613 consecutive, newly diagnosed HCC patients by logistic regression analysis (case-control study). We also examined the factors by Cox proportional hazard model in a retrospective cohort fashion in 803 patients who received non-curative treatment for HCC.

RESULTS

In the case-control study, multivariate analysis revealed that high platelet counts (odds ratio [OR] = 4.84; 95% confidence interval [CI] = 1.29-29.54; P = 0.01), high tumor number and the presence of macroscopic vascular invasion were significantly associated with EHM. In the cohort study, EHM was diagnosed in 71 patients during the study period (mean observation time = 23.3 months). On multivariate analysis, high tumor number, high des-γ-carboxyprothrombin (DCP) and Child-Pugh class A were significantly correlated with EHM, and the patients with high platelet counts tended to develop EHM (OR = 1.73; 95% CI = 0.99-3.14; P = 0.055).

CONCLUSION

HCC patients with high platelet counts, as well as large numbers of tumors, high serum DCP and Child-Pugh class A, are at risk for EHM.

Use of non-invasive serum glycan markers to distinguish non-alcoholic steatohepatitis from simple steatosis

BACKGROUND AND AIMS

Serum glycans have been reported to be promising diagnostic markers for many inflammatory diseases and cancers. The aims of this study were to investigate whole glycan expression in patients with non-alcoholic fatty liver diseases and to evaluate the potential use of glycan profiles as new clinical biomarkers to distinguish non-alcoholic steatohepatitis (NASH) from simple steatosis (SS).

METHODS

We collected sera from 42 histologically proven NASH and 15 SS patients prior to treatment. Serum glycan profiles were measured by comprehensive, quantitative, high-throughput glycome analysis, and diagnostic values of serum glycans for NASH prediction were examined.

RESULTS

Among the 41 serum glycans examined, the expression levels of 8 glycans in NASH were significantly higher than those of SS. Out of these eight glycans, three glycans (m/z 1955, 2032, and 2584) showed high areas under the receiver operating characteristic curve (0.833, 0.863, and 0.866, respectively) for distinguishing NASH from SS. In multivariate analyses with clinical parameters and serum glycans, these three glycans were significant predictive factors for distinguishing NASH from SS. The odds ratio of m/z 1955, 2032, and 2584 were 48.5, 6.46, and 11.8, respectively. These glycans also correlated significantly with lobular inflammation, ballooning, and fibrosis, but not with steatosis.

CONCLUSION

We clearly demonstrated whole-serum glycan profiles in NASH patients, and the feasibility of serum glycans (m/z 1955, 2032, and 2584) as new noninvasive biomarkers for distinguishing NASH from SS.

Prediction of the prognosis of advanced hepatocellular carcinoma by TERT promoter mutations in circulating tumor DNA

BACKGROUND ANDAIM

Human telomerase reverse transcriptase (TERT) promoter mutations were the most prevalent mutations in patients with hepatocellular carcinoma (HCC). We tried to detect the mutations with plasma circulating tumor DNA (ctDNA) in patients with advanced HCC and elucidated their clinical utility.

METHODS

Circulating tumor DNA in plasma was extracted from 130 patients with advanced HCC who were treated with systemic chemotherapy (n = 86) or transcatheter arterial chemoembolization (n = 44), and TERT promoter mutations were examined with digital droplet polymerase chain reaction. The correlations between these mutations and the clinical outcome of patients were analyzed.

RESULTS

Of the 130 patients examined, 71 patients (54.6%) were positive for TERT promoter mutations in ctDNA, of which 64 patients were -124bp G > A and 10 were -146bp G > A. The presence of TERT promoter mutations was correlated with large intrahepatic tumor size (P = 0.05) and high des-gamma carboxyprothrombin (P = 0.005). Overall survival of the patients with the mutations was significantly shorter than those without them (P < 0.001), and the patients with high (≥ 1%) fractional abundance of the mutant alleles showed shorter survival than those with low (< 1%) fractional abundance. Multivariate analysis revealed that TERT promoter mutation (hazard ratio [HR]: 1.94; 95% confidence interval [CI], 1.18-3.24; P < 0.01), systemic chemotherapy (HR: 2.38; 95% CI, 1.29-4.57; P < 0.01), and vascular invasion (HR: 2.16; 95% CI, 1.22-3.76; P < 0.01) were significant factors for poor overall survival.

CONCLUSIONS

TERT promoter mutations in ctDNA were associated with short survival and could be a valuable biomarker for predicting the prognosis of patients with advanced HCC.

Utility of liquid biopsy using urine in patients with pancreatic ductal adenocarcinoma

In recent years, liquid biopsy for blood and body fluid in cancer patients has attracted attention. However, there have been few reports of liquid biopsy focusing on urine of pancreatic ductal adenocarcinoma (PDAC). In 56 patients with PDAC, DNA was extracted from urine and plasma prior to treatment, and KRAS mutations were analyzed with droplet digital PCR to examine the mutation detection rate. Our study showed that KRAS mutations were found in 27 cases (48%) in urine and 27 cases (48%) in plasma. The detection rate of urine KRAS mutations varied by renal functions. The rates were 70% (14/20) and 36% (13/36) in the creatinine clearance rate (CCr) < 70 mL/min group and in the CCr ≥ 70 mL/min group, respectively (P = .024). Whereas, no influence of the CCr was observed in the detection rates of plasma KRAS mutations. The rates were 50% (10/20) and 47% (17/36) in cases with the CCr < 70 mL/min group and the CCr ≥ 70 mL/min group, respectively. Although the sample size was small, this study clearly indicated a new possibility of less invasive urine liquid biopsy in PDAC patients.

Virtual scale function of gastrointestinal endoscopy for accurate polyp size estimation in real-time: a preliminary study

SIGNIFICANCE

Polyp size is important for selecting the surveillance interval or treatment policy. Nevertheless, it is challenging to accurately estimate the polyp size during endoscopy. An easy and cost-effective function to assist in polyp size estimation is required.

AIM

To propose a virtual scale function for endoscopy and evaluate its performance and expected accuracy.

APPROACH

An adaptive virtual scale behavior was demonstrated. The measurement error of the virtual scale along the distance between the tip of the endoscope and the object plane was evaluated using graph paper. The accuracy of polyp size estimation by an expert endoscopist was compared with the accuracy of the biopsy forceps method using phantom images.

RESULTS

The measurement errors of the virtual scale were   ≤  0.7  mm when the distance to the graph paper, which faced the tip of the endoscope, varied from 4 to 30 mm. The accuracy with the virtual scale was significantly higher than that obtained with biopsy forceps (5.3  ±  5.5  %   versus 11.9  ±  9.4  %  , P  <  0.001).

CONCLUSIONS

The virtual scale function, which operates in real-time without any additional device, can be used to estimate polyp sizes easily and accurately with endoscopy.

Prognotic impact of serum follistatin in patients with hepatocellular carcinoma

BACKGROUND AND AIM

Follistatin (FST) is a glycoprotein expressed in most organs, which interacts with activins or other members of the transforming growth factor beta family. Recently, several reports have shown that FST regulates a variety of processes during tumor progression. Here, serum FST in patients with liver diseases was measured, and its clinical utility as a biomarker was assessed.

METHODS

Serum was collected from 162 patients (91 hepatocellular carcinoma [HCC], 43 liver cirrhosis, and 28 chronic hepatitis) as well as from 16 healthy volunteers. FST was quantified by enzyme-linked immunosorbent assays, and levels were compared with clinical parameters including survival of the HCC patients.

RESULTS

Median serum FST levels in HCC, liver cirrhosis, chronic hepatitis, and healthy volunteers were 1168, 1606, 1324, and 1661 pg/mL, respectively, not significantly different. In HCC patients, higher serum FST was associated with greater age, hepatitis C virus antibody-negativity, large tumor size, g-glutamyl transpeptidase, des-gamma carboxyprothrombin and presence of portal vein tumor thrombus. Survival of HCC patients with high FST levels was significantly shorter than for those with low levels (P = 0.004). Multivariate analysis revealed that in addition to large tumor size and presence of portal vein thrombus, high FST levels were independently correlated with poor prognosis (hazard ratio = 2.41, 95% confidence interval = 1.16-5.00, P = 0.02).

CONCLUSIONS

Serum FST levels are significantly associated with HCC prognosis and could represent a predictive biomarker in this disease.

Alteration of N-glycan profiles in patients with chronic hepatitis and hepatocellular carcinoma

AIM

Most of the modification of N-glycosylation reported in cancers including hepatocellular carcinoma (HCC) were based on the examinations of a small number of patients or particular proteins. The aim of this study is to reveal changes in whole serum N-glycan profiles systematically during the process of hepatocarcinogenesis and to elucidate their clinical application.

METHODS

We analyzed sera from 105 patients with chronic hepatitis/liver cirrhosis (CH/LC) and age-/sex-matched healthy volunteers (HLT), as well as from 114 patients with HCC. Serum N-glycan profiles were measured comprehensively by a new, quantitative, high-throughput method and compared with clinical parameters.

RESULTS

The total amount of N-glycan expression was significantly higher in patients with CH/LC than in HLT; however, no differences were observed between CH/LC and HCC patients. In HCC patients, multi-antennary glycans with fucose residues, particularly m/z 3195, were increased compared with CH/LC patients. The expression of m/z 3195 was high, especially in patients with a high number of intrahepatic lesions (>3), large tumor size (>3 cm), macroscopic vascular invasion or metastasis. The ratio of pairs of glycans on the same path of the biosynthesis pathway (m/z 3195/1914) showed a higher area under the receiver-operator curve of 0.810 than any other single glycan to distinguish HCC from CH/LC.

CONCLUSION

We demonstrate the full spectrum of the alterations of serum N-glycans comprehensively in patients with liver disease, and elucidate the possible use of glycans as novel biomarkers of liver disease progression.

Clinical utility of serum fucosylated hemopexin in Japanese patients with hepatocellular carcinoma

AIM

  Hepatocellular carcinoma (HCC) is a common clinical problem all over the world. Fucosylated hemopexin (Fuc-Hpx) is a newly reported glycoprotein for the diagnosis of HCC, however, its clinical implications are unclear. The aim of this study was to elucidate the clinical utility of Fuc-Hpx in Japanese patients with HCC.

METHODS

  The sera from 331 HCC patients, 45 with liver cirrhosis (LC), 85 with chronic hepatitis (CH) and 22 healthy people were examined for the expression of Fuc-Hpx; the level was compared with clinical parameters as well as hemopexin (Hpx) expression. The expressions of Fuc-Hpx in 12 HCC tissues and corresponding adjacent non-cancerous liver tissues were also examined.

RESULTS

  No correlation was observed between Hpx and Fuc-Hpx level. The median Fuc-Hpx levels in healthy people and CH, LC and HCC patients were 3.8, 3.7, 6.1 and 7.6 AU/mL, respectively (CH vs LC, P = 0.002; CH vs HCC, P < 0.001; LC vs HCC, P = 0.02). Multivariate analysis revealed that low albumin, low prothrombin time and the presence of HCC were significantly correlated with high Fuc-Hpx (P = 0.013, =0.001 and <0.001, respectively). Among the HCC patients, albumin was correlated with high Fuc-Hpx; however, none of the tumor factors, such as tumor size, tumor number and tumor stage, was correlated with Fuc-Hpx level. The expression of Fuc-Hpx in cancer tissue was not different from that in non-cancerous tissue.

CONCLUSION

  Fuc-Hpx is a valuable biomarker for HCC but it might be a marker for hypercarcinogenic liver rather than a marker for tumor-bearing liver.

Potential of alpha-fetoprotein as a prognostic marker after curative radiofrequency ablation of hepatocellular carcinoma

AIM

Recurrence of hepatocellular carcinoma (HCC) is observed frequently, even after curative treatments. The aim of this study is to elucidate the risk factors for recurrence of HCC after radiofrequency ablation (RFA), focusing on the carcinogenic potential of the liver assessed by α-fetoprotein (AFP).

METHODS

We enrolled 357 consecutive patients who underwent complete ablation by RFA for primary HCC (≤3 cm, ≤3 tumors) and analyzed the correlation between 17 critical parameters, including AFP and HCC recurrence.

RESULTS

Recurrence was observed in 236 patients during a mean observation period of 54.3 months. Multivariate analysis revealed that multiple tumors (risk ratio [RR] = 1.70, 95% confidence interval [CI] = 1.27-2.26, P < 0.001), high AFP (>10 ng/mL, RR = 1.45, 95% CI = 1.09-1.94, P < 0.001) and high des-γ-carboxyprothrombin (>40 mAU/mL, RR = 1.52, 95% CI = 1.13-2.02, P < 0.005) were significantly correlated with recurrence. AFP was selected as a significant factor even when the cut-off level was set lower (≤5 ng/mL). The risk of recurrence increased linearly according to the increase of the lowest AFP level after RFA and the adjusted ratios relative to AFP less than 5 ng/mL were 1.56, 2.14, 2.57 and 3.13 in AFP 5-10 ng/mL, 10-20 ng/mL, 20-50 ng/mL and over 50 ng/mL, respectively. In addition, the recurrence rate was predicted by the AFP level after RFA, regardless of the level before the treatment.

CONCLUSION

AFP less than 5 ng/mL after curative RFA was an important predictor of a better prognosis and was considered to indicate the low carcinogenic potential of the non-cancerous liver.

Metformin ameliorates chronic colitis in a mouse model by regulating interferon-γ-producing lamina propria CD4+ T cells through AMPK activation

Metformin, a commonly prescribed drug for type 2 diabetes mellitus, has been shown to activate AMP-activated protein kinase (AMPK). Notably, AMPK activation has recently been observed to be associated with anti-inflammatory responses. Metformin is also reported to elicit anti-inflammatory responses in CD4+ T cells, resulting in improvement in experimental chronic inflammatory diseases, such as systemic lupus erythematosus. To investigate the effect of metformin on inflammatory bowel disease (IBD), we developed a T cell-transfer model of chronic colitis in which SCID mice were injected with CD4+ CD45RBhigh T cells to induce colitis. We examined the effects of metformin via in vitro and in vivo experiments on lamina propria (LP) CD4+ T cells. We observed that metformin suppresses the frequency of interferon (IFN) -γ-producing LP CD4+ T cells in vitro, which were regulated by AMPK activation, a process possibly induced by the inhibition of oxidative phosphorylation. Furthermore, we examined the effects of metformin on an in vivo IBD model. Metformin-treated mice showed AMPK activation in LP CD4+ T cells and ameliorated colitis. Our study demonstrates that metformin-induced AMPK activation in mucosal CD4+ T cells contributes to the improvement of IBD by suppressing IFN-γ production. Moreover, our results indicate that AMPK may be a target molecule for the regulation of mucosal immunity and inflammation. Thus, AMPK-activating drugs such as metformin may be potential therapeutic agents for the treatment of IBD.

Low frequency of drug-resistant virus did not affect the therapeutic efficacy in daclatasvir plus asunaprevir therapy in patients with chronic HCV genotype-1 infection

BACKGROUND

The efficacy of a direct-acting antiviral agent (DAA) is compromised by the development of drug resistance. The associations between resistance-associated virus (RAV) and therapeutic outcomes have not been well-understood.

METHODS

A total of 30 patients with HCV genotype-1b were enrolled and treated for 24 weeks with asunaprevir (ASV) and daclatasvir (DCV). Viral sequences in non-structural (NS) regions 3 and 5A in serum and liver tissue before treatment were examined with direct sequencing, next-generation sequencing (NGS) and the PCR-invader method to evaluate the importance of drug-resistance in the prediction of the outcomes of ASV plus DCV therapy.

RESULTS

Of 30 patients (22 treatment-naive patients, 2 interferon-intolerant patients and 6 non-responders), 25 patients (83.3%) achieved sustained virological response (SVR) 24 weeks after the treatment. Viral breakthrough occurred in three treatment-naive patients and one non-responder. One treatment-naive patient experienced viral relapse. Among 25 patients without RAV, 24 obtained SVR, whereas 5 patients had RAV with a 1.3 to 88% frequency, resulting in various therapeutic outcomes. As for HCV compartments, similar RAVs were detected in serum and liver tissue for a patient obtaining SVR despite HCV NS5A Y93H and another developed viral breakthrough although no RAV was detected. Direct sequencing could not detect RAVs in low frequency (1.3 to 12%) for three of four patients.

CONCLUSIONS

Low frequency of RAVs might not affect the outcomes of ASV plus DCV therapy. Deep sequencing and PCR-invader methods can detect clinically significant RAVs for ASV plus DCV therapy.

Human Telomerase Reverse Transcriptase Gene Promoter Mutation in Serum of Patients with Hepatocellular Carcinoma

BACKGROUND

Mutations in the human telomerase reverse transcriptase (hTERT) gene promoter have been reported in hepatocellular carcinoma (HCC); however, analyses of these mutations in liquid biopsies have been technically difficult because of the high GC content of the regions of interest within this promoter. We evaluated the feasibility and prognostic value of hTERT promoter mutations identified in circulating cell-free DNA (cfDNA) from the serum of patients with HCC.

OBJECTIVE

A cohort of HCC patients (n = 36) who were curatively treated by surgical resection between June 2003 and September 2014 were enrolled in this study.

METHODS

The presence of hTERT promoter mutations in cfDNA from the patients' serum was analyzed via modified droplet digital polymerase chain reaction, and associations were sought between specific promoter mutations and patients' disease-free survival (DFS).

RESULTS

The G>A hTERT mutation at -124 bp was detected in the serum of 25 patients (69%). Although no marked differences were observed between the characteristics of the serum mutation-positive and serum mutation-negative patient groups, the DFS of patients with the mutation was significantly shorter than that of the serum mutation-negative patients (p = 0.02). Among 18 clinicopathologic and background liver factors examined, the presence of the -124 bp G>A mutation was an independent and significant predictor of patients' DFS (hazard ratio = 3.01, 95% confidence interval 1.11-10.5, p = 0.03) in multivariate analyses.

CONCLUSIONS

The -124 bp G>A hTERT promoter mutation was observed in the serum of 69% of HCC patients who underwent surgical resection and was an independent predictor of disease progression in HCC.

Clinical utility of a serum glycome analysis in patients with colorectal cancer

BACKGROUND AND AIM

Serum glycans are known to be good markers for the early diagnosis and prognostic prediction in many cancers. The aims of this study were to reveal the serum glycan changes comprehensively during the process of carcinogenesis from colorectal adenoma (CRA) to colorectal cancer (CRC) and to evaluate the usefulness of the glycan profiles as clinical markers for CRC.

METHODS

Serum samples were obtained from 80 histologically proven CRC and 36 CRA cases. The levels of glycans in the serum were examined with a comprehensive, quantitative, high-throughput unique glycome analysis, and their diagnostic and prognostic abilities were evaluated.

RESULTS

Among 34 stably detected glycans, nine were differentially expressed between CRC and CRA. Serum levels of hybrid type glycans were increased in patients with CRC compared with those with CRA (P < 0.001), and both hybrid-type and multi-antennary glycans were significantly increased in advanced cancer cases. The glycan, m/z 1914, showed the highest diagnostic value among the decreased glycans, whereas m/z 1708 showed the highest among the increased glycans. The glycan ratio m/z 1708/1914 showed a higher area under the receiver operating characteristic curve (0.889) than any other single glycan or conventional tumor marker, such as carcinoembryonic antigen (0.766, P = 0.040) and carbohydrate antigen 19-9 (0.615, P < 0.001). High m/z 1708/1914 was also correlated with an advanced cancer stage and short overall survival.

CONCLUSION

Serum glycans, especially the m/z 1708/1914 ratio, were useful for the diagnosis, staging, and prognosis prediction of CRC.