Medical resource usage for COVID-19 evaluated using the National Database of Health Insurance Claims and Specific Health Checkups of Japan.

PURPOSE: The coronavirus disease 2019 (COVID-19) pandemic exhibited several different waves threatening global health care. During this pandemic, medical resources were depleted. However, the kind of medical resources provided to each wave was not clarified. This study aimed to examine the characteristics of medical care provision at COVID-19 peaks in preparation for the next pandemic. METHODS: Using medical insurance claim records in Japan, we examined the presence or absence of COVID-19 infection and the use of medical resources for all patients monthly by age group. RESULTS: The wave around August 2021 with the Delta strain had the strongest impact on the working population in terms of hospital admission and respiratory support. For healthcare providers, this peak had the highest frequency of severely ill patients. In the subsequent wave, although the number of patients with COVID-19 remained high, they were predominantly older adults, with relatively fewer patients receiving intensive care. CONCLUSIONS: In future pandemics, we should refer to the wave around August 2021 as a situation of medical resource shortage resulting from the COVID-19 pandemic.

Barriers and Facilitators to the Implementation of an Electronic Patient-Reported Outcome System at Cancer Hospitals in Japan.

Background and objective Implementing electronic patient-reported outcomes (ePROs) in oncology practice has shown substantial clinical benefits. However, it can be challenging in routine practice, warranting strategies to adapt to different clinical contexts. In light of this, this study aimed to describe the implementation process of the ePRO system and elucidate the provider-level implementation barriers and facilitators to a novel ePRO system at cancer hospitals in Japan. Methods We implemented an ePRO system linked to electronic medical records at three cancer hospitals. Fifteen patients with solid cancers at the outpatient oncology unit were asked to regularly complete the Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE™) questionnaire and European Organization for Research and Treatment Core Quality of Life questionnaire (EORTC QLQ C30) by using the smartphone app between October 2021 and June 2022. Thirteen healthcare professionals were interviewed to identify implementation barriers and facilitators to the ePRO system by using the Consolidated Framework for Implementation Research framework. Results The healthcare professionals identified a lack of clinical resources and a culture and system that emphasizes treatment over care as the main barriers; however, the accumulation of successful cases, the leadership of managers, and the growing needs of patients can serve as facilitators to the implementation. Conclusions Our experience implementing an ePRO system in a few Japanese oncology practices revealed comprehensive barriers and facilitators. Further efforts are warranted to develop more successful implementation strategies.

Colorectal cancer harboring EGFR kinase domain duplication response to EGFR tyrosine kinase inhibitors.

Epidermal growth factor receptor kinase domain duplication (EGFR-KDD) is a rare, recurrent oncogenic variant that constitutively activates EGFR in non-small-cell lung cancer. Herein, we report the case of a 70-year-old man with resectable colorectal adenocarcinoma who underwent surgery followed by adjuvant therapy. He relapsed with multiple liver metastases and received standard chemotherapy until his disease became refractory. Comprehensive genomic profiling of his postoperative colorectal cancer tissue revealed EGFR-KDD. He was treated with an EGFR tyrosine kinase inhibitor (TKI), afatinib and achieved a partial response (- 55%) after 8 weeks; however, he developed massive malignant ascites after 13 weeks. Osimertinib, another EGFR-TKI, controlled his tumors for 9 months. Patient-derived cancer organoids from his malignant ascites confirmed sensitivity to EGFR-TKIs. The findings suggest that EGFR-TKIs can be a potential treatment option for this molecular subgroup.

A novel SREBF1::NACC1 gene fusion in an unclassifiable intracranial tumour.

A 39-year-old man had an intracranial tumour without infiltration into the surrounding cerebral tissue. The tumour recurred seven times in 11 years but maintained a well-demarcated character. Histopathological examination of the 4th surgical specimens showed nests of tumour cells surrounding small blood vessels. The tumour cells harboured amphophilic cytoplasm and small round nuclei with fine chromatin, and perinuclear haloes and clear borders were frequently observed, which was unclassifiable histology. By the Deutsches Krebsforschungszentrum methylation classifier, the tumour was not classified into any of the methylation classes. mRNA sequencing identified a novel SREBF1::NACC1 gene fusion. This intracranial tumour could be a novel tumour entity with NACC1 rearrangement showing characteristic histological and diagnostic imaging findings.

Prevalence of pathogenic germline variants in the circulating tumor DNA testing.

BACKGROUND: Somatic and germline variants are not distinguishable by circulating tumor DNA (ctDNA) testing without analyzing non-tumor samples. Although confirmatory germline testing is clinically relevant, the criteria for selecting presumed germline variants have not been established in ctDNA testing. In the present study, we aimed to evaluate the prevalence of pathogenic germline variants in clinical ctDNA testing through their variant allele fractions (VAFs). METHODS: A total of consecutive 106 patients with advanced solid tumors who underwent ctDNA testing (Guardant360®) between January 2018 and March 2020 were eligible for this study. To verify the origin of pathogenic variants reported in ctDNA testing, germline sequencing was performed using peripheral blood DNA samples archived in the Clinical Bioresource Center in Kyoto University Hospital (Kyoto, Japan) under clinical research settings. RESULTS: Among 223 pathogenic variants reported in ctDNA testing, the median VAF was 0.9% (0.02-81.8%), and 88 variants with ≥ 1% VAFs were analyzed in germline sequencing. Among 25 variants with ≥ 30% VAFs, seven were found in peripheral blood DNA (BRCA2: n = 6, JAK2: n = 1). In contrast, among the 63 variants with VAFs ranging from 1 to < 30%, only one variant was found in peripheral blood DNA (TP53: n = 1). Eventually, this variant with 15.6% VAF was defined to be an acquired variant, because its allelic distribution did not completely link to those of neighboring germline polymorphisms. CONCLUSION: Our current study demonstrated that VAFs values are helpful for selecting presumed germline variants in clinical ctDNA testing.

Germline sequencing for presumed germline pathogenic variants via tumor-only comprehensive genomic profiling.

BACKGROUND: The European Society for Medical Oncology Precision Medicine Working Group (ESMO-PMWG) published recommendations regarding confirmatory germline testing for presumed germline pathogenic variants (PGPVs) in tumor-only comprehensive genomic profiling (CGP). However, the clinical validity of these recommendations has not been investigated in a real-world practice. METHODS: Medical records of 180 consecutive patients who obtained the results of a tumor-only CGP (FoundationOne® CDx, Foundation Medicine, Inc, Cambridge, MA, USA) between October 2018 and March 2020, were retrospectively reviewed. After excluding patients with no reported variants in 45 actionable genes (n = 6), or no archived germline DNA samples (n = 31), 143 patients were investigated. The PGPVs were selected from the CGP report and germline sequencing were performed using DNA samples archived in Clinical Bioresource Center in Kyoto University Hospital (Kyoto, Japan). RESULTS: A total of 195 variants were classified as PGPV based on the conventional criteria. Germline sequencing disclosed that 12 variants (6.2%) were of germline origin. In contrast, after filtering these 195 variants through the ESMO-PMWG recommendation criteria for confirmatory germline testing, following seven PGPVs, BRCA2 (n = 2), BRIP1 (n = 1), BAP1 (n = 1), PMS2 (n = 1), MSH2 (n = 1), and SDHB (n = 1) remained and six variants (85.7%) were confirmed to be of germline origin. CONCLUSION: Our current data suggested that the application of ESMO-PMWG criteria is helpful in selecting PGPVs with a high likelihood of germline origin in a tumor-only CGP in daily clinical practice.

Inter-assay variability of next-generation sequencing-based gene panels.

BACKGROUND: Tumor heterogeneity has been known to cause inter-assay discordance among next-generation sequencing (NGS) results. However, whether preclinical factors such as sample type, sample quality and analytical features of gene panel can affect the concordance between two different assays remains largely unexplored. METHODS: Replicate sets of DNA samples extracted from formalin-fixed paraffin-embedded tissues (FFPE) (n = 20) and fresh frozen (FF) tissues (n = 10) were herein analyzed using a tumor-only (TO) and paired tumor-normal (TN) gene panel in laboratories certified by the Clinical Laboratory Improvement Amendment. Reported variants from the TO and TN panels were then compared. Furthermore, additional FFPE samples were sequentially sliced from the same FFPE block and submitted to another TN panel assay. RESULTS: Substantial discordance (71.8%) was observed between the results of the two panels despite using identical DNA samples, with the discordance rate being significantly higher for FFPE samples (p < 0.05). Among the 99 variants reported only in the TO panel, 32.3% were consistent with germline variants, which were excluded in the TN panel, while 30.3% had an allele frequency of less than 5%, some of which were highly likely to be artificial calls. The comparison of two independent TN panel assay results from the same FFPE block also showed substantial discordance rate (55.3%). CONCLUSIONS: In the context of clinical settings, our comparative analysis revealed that inter-NGS assay discordance commonly occurred due to sample types and the different analytical features of each panel.

Precision cancer genome testing needs proficiency testing involving all stakeholders.

To implement precision oncology, analytical validity as well as clinical validity and utility are important. However, proficiency testing (PT) to assess validity has not yet been systematically performed in Japan. To investigate the quality of next-generation sequencing (NGS) platforms and cancer genome testing prevalent in laboratories, we performed pilot PT using patient samples. We prepared genomic DNA from the cancer tissue and peripheral blood of 5 cancer patients and distributed these to 15 laboratories. Most participating laboratories successfully identified the pathogenic variants, except for two closely located KRAS variants and 25 bp delins in EGFR. Conversely, the EGFR L858R variant was successfully identified, and the allele frequency was similar for all the laboratories. A high DNA integrity number led to excellent depth and reliable NGS results. By conducting this pilot study using patient samples, we were able to obtain a glimpse of the current status of cancer genome testing at participating laboratories. To enhance domestic cancer genome testing, it is important to conduct local PT and to involve the parties concerned as organizers and participants.

[From the Standpoint of a Core Center Hospital for Cancer Genome Medicine-Establishment of a Provision System for Wide-Area Precision Oncology].

In Japan, 2 comprehensive genome profiling(CGP)tests for cancer was covered by national health insurance in June 2019, and cancer genome medicine was introduced at a total of 225 hospitals designated by the Ministry of Health, Labor and Welfare as"core center hospitals for cancer genome medicine(12 hospitals)"," core hospitals for cancer genome medicine (33 hospitals)", and"collaborative hospitals for cancer genome medicine(180 hospitals)". On the other hand, the interpretation of the results of the cancer CGP test must be discussed by an expert panel conducted at the core center hospitals for cancer genome medicine or the core hospitals for cancer genome medicine, and the results must be explained to patients in order to be covered by insurance. In other words, these hospitals are required to review not only their own cases but also those of collaborating hospitals. In addition, core center hospitals for cancer genome medicine are required to share information and develop human resources with core hospitals and collaborative hospitals for cancer genome medicine. We herein describes the system for providing cancer genome medicine in our hospital as a core center hospital for cancer genome medicine.

Visceral fat obesity is the key risk factor for the development of reflux erosive esophagitis in 40-69-years subjects.

BACKGROUND: Visceral fat obesity can be defined quantitatively by abdominal computed tomography, however, the usefulness of measuring visceral fat area to assess the etiology of gastrointestinal reflux disease has not been fully elucidated. METHODS: A total of 433 healthy subjects aged 40-69 years (234 men, 199 women) were included in the study. The relationship between obesity-related factors (total fat area, visceral fat area, subcutaneous fat area, waist circumference, and body mass index) and the incidence of reflux erosive esophagitis was investigated. Lifestyle factors and stomach conditions relevant to the onset of erosive esophagitis were also analyzed. RESULTS: The prevalence of reflux erosive esophagitis was 27.2% (118/433; 106 men, 12 women). Visceral fat area was higher in subjects with erosive esophagitis than in those without (116.6 cm2 vs. 64.9 cm2, respectively). The incidence of erosive esophagitis was higher in subjects with visceral fat obesity (visceral fat area ≥ 100 cm2) than in those without (61.2% vs. 12.8%, respectively). Visceral fat obesity had the highest odds ratio (OR) among obesity-related factors. Multivariate analysis showed that visceral fat area was associated with the incidence of erosive esophagitis (OR = 2.18), indicating that it is an independent risk factor for erosive esophagitis. In addition, daily alcohol intake (OR = 1.54), gastric atrophy open type (OR = 0.29), and never-smoking history (OR = 0.49) were also independently associated with the development of erosive esophagitis. CONCLUSIONS: Visceral fat obesity is the key risk factor for the development of reflux erosive esophagitis in subjects aged 40-69 years.

Gene expression profiles of liver cancer cell lines reveal two hepatocyte-like and fibroblast-like clusters.

Cancer cell lines are widely used in basic research to study cancer development, growth, invasion, or metastasis. They are also used for the development and screening of anticancer drugs. However, there are no clear criteria for choosing the most suitable cell lines among the wide variety of cancer cell lines commercially available for research, and the choice is often based on previously published reports. Here, we investigated the characteristics of liver cancer cell lines by analyzing the gene expression data available in the Cancer Cell Line Encyclopedia. Unsupervised clustering analysis of 28 liver cancer cell lines yielded two main clusters. One cluster showed a gene expression pattern similar to that of hepatocytes, and the other showed a pattern similar to that of fibroblasts. Analysis of hepatocellular carcinoma gene expression profiles available in The Cancer Genome Atlas showed that the gene expression patterns in most hepatoma tissues were similar to those in the hepatocyte-like cluster. With respect to liver cancer research, our findings may be useful for selecting an appropriate cell line for a specific study objective. Furthermore, our approach of utilizing a public database for comparing the properties of cell lines could be an attractive cell line selection strategy that can be applied to other fields of research.

Comprehensive genomic profiling for patients with chemotherapy-naïve advanced cancer.

Comprehensive genomic profiling (CGP) testing by next-generation sequencing has been introduced into clinical practice as part of precision cancer medicine to select effective targeted therapies. However, whether CGP testing at the time of first-line chemotherapy could be clinically useful is not clear. We conducted this single-center, prospective, observational study to investigate the feasibility of CGP testing for chemotherapy-naïve patients with stage III/IV gastrointestinal cancer, rare cancer, and cancer of unknown primary, using the FoundationOne® companion diagnostic (F1CDx) assay. The primary outcome was the detection rate of at least one actionable/druggable cancer genomic alteration. Actionable/druggable cancer genomic alterations were determined by the F1CDx report. An institutional molecular tumor board determined the molecular-based recommended therapies. A total of 197 patients were enrolled from October 2018 to June 2019. CGP success rate was 76.6% (151 of 197 patients), and median turnaround time was 19 days (range: 10-329 days). Actionable and druggable cancer genomic alterations were reported in 145 (73.6%) and 124 (62.9%) patients, respectively. The highest detection rate of druggable genomic alterations in gastrointestinal cancers was 80% in colorectal cancer (48 of 60 patients). Molecular-based recommended therapies were determined in 46 patients (23.4%). CGP testing would be a useful tool for the identification of a potentially effective first-line chemotherapy.

Synthetic Lethality with Trifluridine/Tipiracil and Checkpoint Kinase 1 Inhibitor for Esophageal Squamous Cell Carcinoma.

Esophageal squamous cell carcinoma (ESCC) is a disease characterized by a high mutation rate of the TP53 gene, which plays pivotal roles in the DNA damage response (DDR) and is regulated by checkpoint kinase (CHK) 2. CHK1 is another key DDR-related protein, and its selective inhibition is suggested to be particularly sensitive to TP53-mutated cancers, because a loss of both pathways (CHK1 and/or CHK2-p53) is lethal due to the serious impairment of DDR. Such a therapeutic strategy is termed synthetic lethality. Here, we propose a novel therapeutic strategy based on synthetic lethality combining trifluridine/tipiracil and prexasertib (CHK1 inhibitor) as a treatment for ESCC. Trifluridine is a key component of the antitumor drug combination with trifluridine/tipiracil (an inhibitor of trifluridine degradation), also known as TAS-102. In this study, we demonstrate that trifluridine increases CHK1 phosphorylation in ESCC cells combined with a reduction of the S-phase ratio as well as the induction of ssDNA damage. Because CHK1 phosphorylation is considered to be induced as DDR for trifluridine-mediated DNA damage, we examined the effects of CHK1 inhibition on trifluridine treatment. Consequently, CHK1 inhibition by short hairpin RNA or treatment with the CHK1 inhibitor, prexasertib, markedly enhanced trifluridine-mediated DNA damage, represented by an increase of γH2AX expression. Moreover, the combination of trifluridine/tipiracil and CHK1 inhibition significantly suppressed tumor growth of ESCC-derived xenograft tumors. Furthermore, the combination of trifluridine and prexasertib enhanced radiosensitivity both in vitro and in vivo Thus, the combination of trifluridine/tipiracil and a CHK1 inhibitor exhibits effective antitumor effects, suggesting a novel therapeutic strategy for ESCC.

Experimental model for the irradiation-mediated abscopal effect and factors influencing this effect.

Radiotherapy (RT) is the primary treatment for cancer. Ionizing radiation from RT induces tumor damage at the irradiated site, and, although clinically infrequent, may cause regression of tumors distant from the irradiated site-a phenomenon known as the abscopal effect. Recently, the abscopal effect has been related to prolongation of overall survival time in cancer patients, though the factors that influence the abscopal effect are not well understood. The aim of this study is to clarify the factors influencing on abscopal effect. Here, we established a mouse model in which we induced the abscopal effect. We injected MC38 (mouse colon adenocarcinoma) cells subcutaneously into C57BL/6 mice at two sites. Only one tumor was irradiated and the sizes of both tumors were measured over time. The non-irradiated-site tumor showed regression, demonstrating the abscopal effect. This effect was enhanced by an increase in the irradiated-tumor volume and by administration of anti-PD1 antibody. When the abscopal effect was induced by a combination of RT and anti-PD1 antibody, it was also influenced by radiation dose and irradiated-tumor volume. These phenomena were also verified in other cell line, B16F10 cells (mouse melanoma cells). These findings provide further evidence of the mechanism for, and factors that influence, the abscopal effect in RT.

Unexpected metastasis of intraductal papillary neoplasm of the bile duct without an invasive component to the brain and lungs: A case report.

BACKGROUND: Despite an expanding number of studies on intraductal papillary neoplasm of the bile duct (IPNB), distant metastasis remains unexplained especially in cases of carcinoma in situ. In the present study, we report a rare and interesting case of IPNB without invasive components that later metastasized to lungs and brain. CASE SUMMARY: A 69-year-old male was referred to our hospital due to suspected cholangiocarcinoma. Laboratory tests on admission reported a mild elevation of alkaline phosphatase, γ-glutamyl transpeptidase, and total bilirubin in serum. Endoscopic retrograde cholangiography revealed a filling defect in the common bile duct (CBD) extending to the left hepatic duct. Peroral cholangioscopy delineated a tumor in the CBD that had a papillary pattern. Multidetector computed tomography and magnetic resonance cholangiopancreatography detected partial blockage ot interlude in the CBD leading to cholestasis without evidence of metastasis. Therefore, a diagnosis of IPNB cT1N0M0 was established. Left hepatectomy with bile duct reconstruction was performed. Pathological examination confirmed an intraepithelial neoplasia pattern without an invasive component and an R0 resection achievement. The patient was monitored carefully by regular examinations. However, at 32 mo after the operation, a 26 mm tumor in the lungs and a 12 mm lesion in the brain were detected following a suspicious elevated CA 19-9 level. Video-assisted thoracoscopic surgery of left upper lobectomy and stereotactic radiotherapy are indicated. In addition to histopathological results, a genomic profiling analysis using whole exome sequencing subsequently confirmed lung metastasis originating from bile duct cancer. CONCLUSION: This case highlights the important role of genomic profiling analysis using whole exome sequencing in identifying the origin of metastasis in patients with IPNB.

ALPlat criterion for the resection of hepatocellular carcinoma based on a predictive model of posthepatectomy liver failure.

BACKGROUND: The indocyanine green test is used widely to evaluate the risk of posthepatectomy liver failure for hepatocellular carcinoma. A more convenient and reliable scoring system is desired owing to limited accuracy and availability of the indocyanine green test. This study aimed to establish a new selection criterion for liver resection in HCC. METHODS: We reviewed retrospectively 876 patients undergoing a partial hepatectomy for hepatocellular carcinoma between 2007 and 2015 in 8 affiliated hospitals. Posthepatectomy liver failure grades B and C were regarded as posthepatectomy liver failure. We identified the risk factors for posthepatectomy liver failure and established a predictive model based on a formula for the probability of posthepatectomy liver failure. External validation was performed in an additional cohort of 250 patients. RESULTS: Posthepatectomy liver failure occurred in 92 patients (11%). The area under the receiver operating characteristic curve for the prediction of posthepatectomy liver failure was 0.646 for the platelet count, 0.641 for albumin, 0.623 for the percentage of liver remnant, and 0.607 for the plasma disappearance rate of indocyanine green. Logistic regression analysis provided a formula for the probability of posthepatectomy liver failure consisting of platelet count, albumin, and liver remnant. We defined platelet count + 90 × albumin as the ALPlat index and established an ALPlat-based criterion for operative resection that secured the same risk assumed by the indocyanine green-based criterion (Makuuchi's criterion). This criterion exhibited a greater sensitivity and specificity than the indocyanine green-based criterion in the validation cohort. CONCLUSION: The ALPlat criterion is a simple and useful method to assess liver function and to make therapeutic decisions in patients with hepatocellular carcinoma.

MicroRNA-9-5p-CDX2 Axis: A Useful Prognostic Biomarker for Patients with Stage II/III Colorectal Cancer.

A lack of caudal-type homeobox transcription factor 2 (CDX2) protein expression has been proposed as a prognostic biomarker for colorectal cancer (CRC). However, the relationship between CDX2 levels and the survival of patients with stage II/III CRC along with the relationship between microRNAs (miRs) and CDX2 expression are unclear. Tissue samples were collected from patients with stage II/III CRC surgically treated at Kyoto University Hospital. CDX2 expression was semi-quantitatively evaluated by immunohistochemistry (IHC). The prognostic impacts of CDX2 expression on overall survival (OS) and relapse-free survival (RFS) were evaluated by multivariable statistical analysis. The expression of miRs regulating CDX2 expression and their prognostic impacts were analyzed using The Cancer Genome Atlas Program for CRC (TCGA-CRC). Eleven of 174 CRC tissues lacked CDX2 expression. The five-year OS and RFS rates of patients with CDX2-negative CRC were significantly lower than those of CDX2-positive patients. Multivariate analysis of clinicopathological features revealed that CDX2-negative status is an independent marker of poor prognosis in stage II/III CRC. miR-9-5p was shown to regulate CDX2 expression. TCGA-CRC analysis showed that high miR-9-5p expression was significantly associated with poor patient prognosis in stage II/III CRC. In conclusion, CDX2, the post-transcriptional target of microRNA-9-5p, is a useful prognostic biomarker in patients with stage II/III CRC.

Association Between Preanalytical Factors and Tumor Mutational Burden Estimated by Next-Generation Sequencing-Based Multiplex Gene Panel Assay.

BACKGROUND: Tumor mutational burden (TMB) measured via next-generation sequencing (NGS)-based gene panel is a promising biomarker for response to immune checkpoint inhibitors (ICIs) in solid tumors. However, little is known about the preanalytical factors that can affect the TMB score. MATERIALS AND METHODS: Data of 199 patients with solid tumors who underwent multiplex NGS gene panel (OncoPrime), which was commercially provided by a Clinical Laboratory Improvement Amendments-licensed laboratory and covered 0.78 megabase (Mb) of capture size relevant to the TMB calculation, were reviewed. Associations between the TMB score and preanalytical factors, including sample DNA quality, sample type, sampling site, and storage period, were analyzed. Clinical outcomes of patients with a high TMB score (≥10 mutations per megabase) who received anti-programmed cell death protein 1 antibodies (n = 22) were also analyzed. RESULTS: Low DNA library concentration (<5 nM), formalin-fixed paraffin-embedded tissue (FFPE), and the prolonged sample storage period (range, 0.9-58.1 months) correlated with a higher TMB score. After excluding low DNA library samples from the analysis, FFPE samples, but not the sample storage period, exhibited a marked correlation with a high TMB score. Of 22 patients with a high TMB score, we observed the partial response in 2 patients (9.1%). CONCLUSION: Our results indicate that the TMB score estimated via NGS-based gene panel could be affected by the DNA library concentration and sample type. These factors could potentially increase the false-positive and/or artifactual variant calls. As each gene panel has its own pipeline for variant calling, it is unknown whether these factors have a significant effect in other platforms. IMPLICATIONS FOR PRACTICE: A high tumor mutational burden score, as estimated via next-generation sequencing-based gene panel testing, should be carefully interpreted as it could be affected by the DNA library concentration and sample type.

Nardilysin promotes hepatocellular carcinoma through activation of signal transducer and activator of transcription 3.

Nardilysin (NRDC) is a metalloendopeptidase of the M16 family. We previously showed that NRDC activates inflammatory cytokine signaling, including interleukin-6-signal transducer and activator of transcription 3 (STAT3) signaling. NRDC has been implicated in the promotion of breast, gastric and esophageal cancer, as well as the development of liver fibrosis. In this study, we investigated the role of NRDC in the promotion of hepatocellular carcinoma (HCC), both clinically and experimentally. We found that NRDC expression was upregulated threefold in HCC tissue compared to the adjacent non-tumor liver tissue, which was confirmed by immunohistochemistry and western blotting. We also found that high serum NRDC was associated with large tumor size (>3 cm, P = 0.016) and poor prognosis after hepatectomy (median survival time 32.0 vs 73.9 months, P = 0.003) in patients with hepatitis C (n = 120). Diethylnitrosamine-induced hepatocarcinogenesis was suppressed in heterozygous NRDC-deficient mice compared to their wild-type littermates. Gene silencing of NRDC with miRNA diminished the growth of Huh-7 and Hep3B spheroids in vitro. Notably, phosphorylation of STAT3 was decreased in NRDC-depleted Huh-7 spheroids compared to control spheroids. The effect of a STAT3 inhibitor (S3I-201) on the growth of Huh-7 spheroids was reduced in NRDC-depleted cells relative to controls. Our results show that NRDC is a promising prognostic marker for HCC in patients with hepatitis C, and that NRDC promotes tumor growth through activation of STAT3.