HLA Class I Analysis Provides Insight Into the Genetic and Epigenetic Background of Immune Evasion in Colorectal Cancer With High Microsatellite Instability

BACKGROUND & AIMS

A detailed understanding of antitumor immunity is essential for optimal cancer immune therapy. Although defective mutations in the B2M and HLA-ABC genes, which encode molecules essential for antigen presentation, have been reported in several studies, the effects of these defects on tumor immunity have not been quantitatively evaluated.

METHODS

Mutations in HLA-ABC genes were analyzed in 114 microsatellite instability-high colorectal cancers using a long-read sequencer. The data were further analyzed in combination with whole-exome sequencing, transcriptome sequencing, DNA methylation array, and immunohistochemistry data.

RESULTS

We detected 101 truncating mutations in 57 tumors (50%) and loss of 61 alleles in 21 tumors (18%). Based on the integrated analysis that enabled the immunologic subclassification of microsatellite instability-high colorectal cancers, we identified a subtype of tumors in which lymphocyte infiltration was reduced, partly due to reduced expression of HLA-ABC genes in the absence of apparent genetic alterations. Survival time of patients with such tumors was shorter than in patients with other tumor types. Paradoxically, tumor mutation burden was highest in the subtype, suggesting that the immunogenic effect of accumulating mutations was counterbalanced by mutations that weakened immunoreactivity. Various genetic and epigenetic alterations, including frameshift mutations in RFX5 and promoter methylation of PSMB8 and HLA-A, converged on reduced expression of HLA-ABC genes.

CONCLUSIONS

Our detailed immunogenomic analysis provides information that will facilitate the improvement and development of cancer immunotherapy.

Erratum: Evolution of π^{0} Suppression in Au+Au Collisions from sqrt[s_{NN}]=39 to 200 GeV [Phys. Rev. Lett. 109, 152301 (2012)]

This corrects the article DOI: 10.1103/PhysRevLett.109.152301.

Adsorptive Granulocyte and Monocyte Apheresis Is Effective in Ulcerative Colitis Patients Both with and without Concomitant Prednisolone

Background

The number of ulcerative colitis (UC) patients is increasing in Japan and other countries. Selective depletion of myeloid lineage leucocytes by adsorptive granulocyte and monocyte apheresis (GMA) with an Adacolumn (JIMRO, Takasaki, Japan) was introduced as a nonpharmacologic treatment strategy in UC patients in 2000. GMA has been reported to be effective in clinical trials; however, the effect of concomitant prednisolone (PSL) on GMA needs to be clarified.

Methods

Thirty-nine patients with active UC were treated with GMA at our institute between June 2009 and September 2018. All patients received GMA therapy once or twice a week with the Adacolumn. Conventional medication was to be continued during the whole GMA treatment course. The clinical response was retrospectively evaluated.

Results

According to the partial Mayo score, remission was 33.3%, significant efficacy 25.6%, effective 25.6%, and no response 15.4%. The average partial Mayo score was 6.2 ± 1.4 at entry and significantly declined to 1.8 ± 1.8 after GMA sessions (p < 0.0001). The average number of bowel movements was 9.5 ± 5.6 at entry and significantly declined to 3.0 ± 2.8 after GMA sessions (p < 0.0001). In a comparison between the group treated with concomitant PSL and the group without PSL, the change in partial Mayo score or the number of bowel movements from entry to after GMA sessions was not significantly different. Among 24 patients treated by GMA with concomitant PSL, 75% (18/24) became steroid free.

Conclusions

The effect of GMA with concomitant PSL and that of GMA without PSL were not different, and GMA was effective irrespective of PSL administration. The present study showed that GMA had efficacy and led many UC patients treated by PSL to be steroid free with no safety concern in the real world, although there is the possibility of recruitment bias due to the retrospective nature of the study.

Angiotensin I-converting enzyme inhibitors/angiotensin II receptor blockers may reduce tumor recurrence in left-sided and early colorectal cancers

BACKGROUND

Angiotensin signaling is suggested to be involved in tumorigenesis, tumor proliferation, and metastases. In colorectal cancer (CRC), it was demonstrated that angiotensin I-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) may reduce the risk of CRC; however, their impact on tumor recurrence remains unknown. Therefore, in this study, we evaluated the impact of ACEIs/ARBs on tumor recurrence in CRC patients.

PATIENTS AND METHODS

We retrospectively investigated the clinicopathological data of 461 stage I-III CRC patients. We divided the patients into those who took an ACEI and/or ARB (the ACEI/ARB+ group) and those who did not (the ACEI/ARB- group), and we compared the two groups' recurrence-free survival (RFS) using a Kaplan-Meier curve analysis and log rank test. We also examined the impact of AGTR1 expression on tumor recurrence, using two public CRC datasets.

RESULTS

The Kaplan-Meier curves showed a trend toward improved RFS in the ACEI/ARB+ group versus the ACEI/ARB- group (p = 0.063). Subgroup analyses demonstrated that the RFS was significantly better in the ACEI/ARB+ group versus the ACEI/ARB- group in the patients with left-sided CRC (p = 0.030) and those with stage I CRC (p = 0.009). Consistent with these findings, the AGTR1 expression was higher in the left-sided versus right-sided colon (p = 0.048). High AGTR1 expression levels were associated with poor RFS in the GSE39582 dataset's stage I-III CRC patients (p < 0.001), and this finding was also validated in the GSE17536 dataset (p = 0.023).

CONCLUSION

ACEI/ARB treatment may reduce tumor recurrence in left-sided CRC and early-stage CRC.

Plasma exosome-encapsulated microRNA-21 and microRNA-92a are promising biomarkers for the prediction of peritoneal recurrence in patients with gastric cancer

In patients with gastric cancer (GC), peritoneal recurrence is a common risk and associated with poor prognosis. A novel biomarker for the prediction of high-risk peritoneal recurrence in patients with GC is desirable. The present study investigated the effectiveness of exosome-encapsulated microRNAs (ex-miRNAs) as minimally invasive biomarkers in patients with GC that received curative surgery. Recurrence-specific ex-miRNAs were selected following comparison of miRNA microarray data from patients with TNM stage II GC with peritoneal recurrence (n=3) and without peritoneal recurrence following curative surgery (n=3), and three healthy volunteers. In this analysis, exosome-encapsulated miRNA-21 (ex-miR-21) and exosomal miR-92a (ex-miR-92a) exhibited the greatest alterations in expression patterns. Using plasma exosome samples collected from another 129 patients with stage II and III GC, the present study investigated the potential value of ex-miR-21 and ex-miR-92a as biomarkers. Ex-miRNA levels were measured using TaqMan miRNA assays. Ex-miR-21 levels were significantly higher and ex-miR-92a levels were significantly lower in samples from patients with GC compared with healthy controls. The overall survival (OS) and peritoneal recurrence-free survival (PRFS) were poorer in stage II and III patients with high ex-miR-21 levels than in patients with low miR-21 levels. OS and PRFS of stage II and III patients with low ex-miR92a levels were significantly worse than those with high ex-miR92a levels. Cox multivariate analyses indicated that ex-miR-21 and ex-miR-92a were independent prognostic factors for OS and PRFS in stage II and III GC. A negative correlation was detected between expression levels of miR-21 and programmed cell death protein 4 mRNA, and miR-92a and prostaglandin E receptor 4 mRNA. Therefore, ex-miR-21 and ex-miR-92a may function as effective and minimally invasive biomarkers for the prediction of peritoneal recurrence and the prognosis of patients with stage II/III GC.

[Genomic Analysis and Immunotherapy by Liquid Biopsy]

This year, the genetic testing for cancer genome medicine approved in Japan, and the clinical basis for this medical area is developed. Focus will likely fall not only on genetic analysis in tissues, but also on genomic analysis by liquid biopsy using patient body fluids such as blood, saliva and urine. The advantages of liquid biopsy are the fact that it is minimally invasive and the possibility of broadening the diagnosis and selection of therapeutic agents, even in cases in which it is difficult to collect tumor tissues. Liquid biopsies of cancer patients will enable, circulating tumor cell(CTC), cell free DNA(cfDNA), circulating tumor cell DNA(ctDNA), exosomes and microRNA(miRNA). The potential usefulness of liquid biopsy for cancer diagnosis, recurrence prediction and monitoring of treatment effect has been mentioned in various manuscripts. In immunotherapy, liquid genetic biomarkers for predicting the therapeutic effect of immune checkpoint inhibitors are under development worldwide. Although issues such as standardization of the measurement methods and the samples used remain, early diagnosis of cancer by liquid biopsy may become a reality in the near future.

Plasma exosomal microRNA-125b as a monitoring biomarker of resistance to mFOLFOX6-based chemotherapy in advanced and recurrent colorectal cancer patients

Liquid biomarkers for the early detection of resistance to chemotherapy are important for improving prognosis. This study investigated the usefulness of plasma exosomal microRNA-125b (ex-miRNA-125b) for the early detection of resistance to modified fluorouracil, leucovorin and oxaliplatin (mFOLFOX6)-based first-line chemotherapy in patients with advanced or recurrent (advanced/recurrent) colorectal cancer (CRC). First, ex-miRNAs associated with resistance to mFOLFOX6-based chemotherapy were profiled via miRNA microarray analysis. In this analysis, ex-miR-125b exhibited the greatest upregulation in patients with progressive disease (PD) compared with the findings for patients with stable disease (SD) and healthy controls. Next, another 55 patients with advanced/recurrent CRC who received mFOLFOX6-based first-line chemotherapy underwent a validation study of ex-miR-125b. Blood samples were collected before and during treatment until tumor progression. Ex-miRNA levels were measured via TaqMan microRNA assays. Patients with CRC had significantly higher ex-miR-125b levels than healthy controls. In patients with partial responses, ex-miR-125b levels at the Response Evaluation Criteria in Solid Tumors (RECIST) judgment point were significantly lower than those measured before treatment. In patients with SD, ex-miR-125b levels did not differ before and during treatment. In patients with PD, ex-miR-125b levels at the RECIST judgment point were significantly higher than those measured before treatment. These changes in ex-miR-125b levels were significantly different between groups even 1 month after the initiation of chemotherapy. Progression-free survival (PFS) was significantly worse in patients with high baseline ex-miR-125b levels than in those with low levels. In the Cox analysis, baseline ex-miR-125b levels and KRAS mutation were indicated to be independent prognostic factors for PFS. The present results suggest that plasma ex-miR-125b levels may be useful for the early detection of resistance to mFOLFOX6-based first-line chemotherapy. Furthermore, ex-miR-125b before chemotherapy is a predictive biomarker for PFS in patients with advanced/recurrent CRC.

G12V and G12C mutations in the gene KRAS are associated with a poorer prognosis in primary colorectal cancer

PURPOSE

The increased incidence of colorectal cancer (CRC) has necessitated the development of novel prognostic and predictive factors from which new diagnostic tests could evolve. Evidence suggests the KRAS gene represents such a factor; its mutations are considered to be early indicators of CRC progression. This study assessed the prognostic impact of specific known KRAS codon 12/13 mutations on survival in patients with CRC.

METHODS

Formalin-fixed paraffin-embedded tissue blocks or sections from primary were obtained from patients registered between 2014 and 2016 for genomic DNA extraction. KRAS gene was analyzed by direct sequencing or Luminex assay. The primary endpoint was the frequency of KRAS gene mutations and the secondary endpoints were differences in KRAS mutation rates by various stratification factors. Univariate and multivariate analyses were performed to investigate relationships between KRAS mutation rates and patient background factors.

RESULTS

Sequencing of 200 CRC primary tumor samples demonstrated 74 (37.5%) with KRAS mutations in codons 12 (77%; 57/74) and 13 (23%; 17/74), all of which were TNM stages I-III. Tumors with KRAS mutations were more frequently located in the right side of the colon. Multivariate analysis indicated that G12V or G12C mutations were associated with poor prognosis [hazard ratio (HR) = 3.77, 95% confidence interval (CI), 1.54-8.39 and HR = 6.57; 95% CI, 1.90-17.7, respectively] in terms of recurrence-free survival.

CONCLUSION

KRAS codon 12G-to-V or G-to-C mutations are independent prognostic factors in patients with stage I-III CRC.

Beam Energy and Centrality Dependence of Direct-Photon Emission from Ultrarelativistic Heavy-Ion Collisions

The PHENIX collaboration presents first measurements of low-momentum (0.4<p_{T}<3  GeV/c) direct-photon yields from Au+Au collisions at sqrt[s_{NN}]=39 and 62.4 GeV. For both beam energies the direct-photon yields are substantially enhanced with respect to expectations from prompt processes, similar to the yields observed in Au+Au collisions at sqrt[s_{NN}]=200. Analyzing the photon yield as a function of the experimental observable dN_{ch}/dη reveals that the low-momentum (>1  GeV/c) direct-photon yield dN_{γ}^{dir}/dη is a smooth function of dN_{ch}/dη and can be well described as proportional to (dN_{ch}/dη)^{α} with α≈1.25. This scaling behavior holds for a wide range of beam energies at the Relativistic Heavy Ion Collider and the Large Hadron Collider, for centrality selected samples, as well as for different A+A collision systems. At a given beam energy, the scaling also holds for high p_{T} (>5  GeV/c), but when results from different collision energies are compared, an additional sqrt[s_{NN}]-dependent multiplicative factor is needed to describe the integrated-direct-photon yield.

Differential regulation of CpG island methylation within divergent and unidirectional promoters in colorectal cancer

The silencing of tumor suppressor genes by promoter CpG island (CGI) methylation is an important cause of oncogenesis. Silencing of MLH1 and BRCA1, two examples of oncogenic events, results from promoter CGI methylation. Interestingly, both MLH1 and BRCA1 have a divergent promoter, from which another gene on the opposite strand is also transcribed. Although studies have shown that divergent transcription is an important factor in transcriptional regulation, little is known about its implication in aberrant promoter methylation in cancer. In this study, we analyzed the methylation status of CGI in divergent promoters using a recently enriched transcriptome database. We measured the extent of CGI methylation in 119 colorectal cancer (CRC) clinical samples (65 microsatellite instability high [MSI‐H] CRC with CGI methylator phenotype, 28 MSI‐H CRC without CGI methylator phenotype and 26 microsatellite stable CRC) and 21 normal colorectal tissues using Infinium MethylationEPIC BeadChip. We found that CGI within divergent promoters are less frequently methylated than CGI within unidirectional promoters in normal cells. In the genome of CRC cells, CGI within unidirectional promoters are more vulnerable to aberrant methylation than CGI within divergent promoters. In addition, we identified three DNA sequence motifs that correlate with methylated CGI. We also showed that methylated CGI are associated with genes whose expression is low in normal cells. Thus, we here provide fundamental observations regarding the methylation of divergent promoters that are essential for the understanding of carcinogenesis and development of cancer prevention strategies.

New precise measurements of muonium hyperfine structure at J-PARC MUSE

High precision measurements of the ground state hyperfine structure (HFS) of muonium is a stringent tool for testing bound-state quantum electrodynamics (QED) theory, determining fundamental constants of the muon magnetic moment and mass, and searches for new physics. Muonium is the most suitable system to test QED because both theoretical and experimental values can be precisely determined. Previous measurements were performed decades ago at LAMPF with uncertainties mostly dominated by statistical errors. At the J-PARC Muon Science Facility (MUSE), the MuSEUM collaboration is planning complementary measurements of muonium HFS both at zero and high magnetic field. The new high-intensity muon beam that will soon be available at H-Line will provide an opportunity to improve the precision of these measurements by one order of magnitude. An overview of the different aspects of these new muonium HFS measurements, the current status of the preparation for high-field measurements, and the latest results at zero field are presented.

Fusion Kinases Identified by Genomic Analyses of Sporadic Microsatellite Instability-High Colorectal Cancers

PURPOSE

Colorectal cancers with microsatellite instability-high (MSI-H) status, due to mismatch repair deficiency, are associated with poor patient outcomes after relapse. We aimed to identify novel therapeutic targets for them.

EXPERIMENTAL DESIGN

We performed MSI analyses of over 2,800 surgically resected colorectal tumors obtained from consecutive patients treated in Japan from 1998 through June 2016. Whole-exome sequencing, transcriptome sequencing, and methylation analyses were performed on 149 of 162 tumors showing MSI in BAT25 and BAT26 loci. We analyzed patient survival times using Bonferroni-adjusted log-rank tests.

RESULTS

Sporadic MSI-H colorectal cancers with promoter methylation of MLH1 (called MM) had a clinicopathological profile that was distinct from that of colorectal cancers of patients with germline mutations (Lynch syndrome, LS-associated) or somatic, Lynch-like mutations in mismatch repair genes. MM tumors had more insertions and deletions and more recurrent mutations in BRAF and RNF43 than LS-associated or Lynch-like MSI-H tumors. Eleven fusion kinases were exclusively detected in MM MSI-H colorectal cancers lacking oncogenic KRAS/BRAF missense mutations and were associated with worse post-relapse prognosis. We developed a simple method to identify MM tumors and applied it to a validation cohort of 28 MSI-H colorectal cancers, identifying 16 MM tumors and 2 fusion kinases.

CONCLUSIONS

We discovered that fusion kinases are frequently observed among sporadic MM MSI-H colorectal cancers. The new method to identify MM tumors enables us to straightforwardly group MSI-H patients into candidates of LS or fusion kinase carriers.

Abstract 3394: Actionable fusion kinases in microsatellite instability-high colorectal cancers

Colorectal cancer (CRC) patients who are microsatellite instability-high (MSI-H) due to mismatch repair (MMR) deficiency have poor prognosis after relapse by consensus molecular subtyping. In response to reports of some MSI-H CRC resistance to immune checkpoint blockade and immune-related adverse events, we sought to identify a new therapeutic target. MSI testing was done on ~2,800 resected colorectal tumors; next-generation sequencing was done on 149 MSI-H tumors showing MSI in both BAT25 and BAT26 loci. MSI-H CRCs are conventionally divided into hereditary and sporadic categories; in this study whole-exome sequencing, transcriptome sequencing, and methylation array revealed that sporadic MSI-H CRCs are further classifiable into somatic MMR gene mutation (Lynch-like) or MLH1 promoter methylated (MM) types. Methylation of other MMR genes (MSH2/MSH6/PMS2) was not detected. The mutational properties of sporadic MSI-H CRCs harboring somatic MMR gene mutations more closely resembled those of Lynch syndrome-associated MSI-H CRCs than those of MM CRCs, which were more likely to develop in the right-sided colon and harbor more insertions/deletions, more recurrent mutations of BRAF/RNF43, and fewer recurrent mutations of KRAS/APC than Lynch syndrome-associated/Lynch-like CRCs (P &lt; 0.001, Fisher's exact test). Loss of heterozygosity of the locus encompassing TGFBR2, MLH1, and CTNNB1 was specific to Lynch syndrome-associated/Lynch-like MSI-H CRCs; this loss appears to be instrumental in the inactivation of TGFBR2/MLH1. Pathway-level analyses of MSI-H CRCs identified DNA damage-sensing and histone H3 methylation-associated pathways as well as Wnt signaling and RAS/RAF/mitogen-activated protein kinase pathways. One mutational signature, Mutational Signature A, accounted for a median percentage 2.3 times larger of mutations in tumors with mutated PMS2 than in tumors with intact PMS2 (P = 1.5 × 10-5, Mann-Whitney U test). Although it is believed that fusion kinases are found in less than 1% of all CRCs, clinically actionable fusion kinases were detected in 11/19 (58%) MM MSI-H CRCs lacking KRAS/BRAF oncogenes. A 3T3 transformation assay confirmed the tumorigenicity of identified fusion kinases; small-molecule inhibitors that suppress the activity of the kinases identified in fusion products significantly attenuated malignant transformation of 3T3 cells in a concentration-dependent manner. Patients with MSI-H CRCs harboring fusion kinases had worse post-relapse prognoses than did patients with MSI-H CRCs harboring KRAS oncogenes. These findings promise to advance MSI-H CRC precision medicine.

Citation Format: Kazuhito Sato, Masahito Kawazu, Yoko Yamamoto, Toshihide Ueno, Shinya Kojima, Genta Nagae, Manabu Soda, Takafumi Oga, Shinji Kohsaka, Eirin Sai, Yoshihiro Yamashita, Shoichi Hazama, Hisae Iinuma, Hiroyuki Aburatani, Hiroyuki Mano. Actionable fusion kinases in microsatellite instability-high colorectal cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3394.

Exosome‑encapsulated microRNA‑23b as a minimally invasive liquid biomarker for the prediction of recurrence and prognosis of gastric cancer patients in each tumor stage

Recently, exosome‑encapsulated microRNAs (miRNAs) have been attracting attention as stable and minimally invasive biomarkers in cancer patients. The aim of the present study was to clarify the value of plasma exosomal microRNA‑23b (miR‑23b) as a diagnostic and prognostic biomarker in gastric cancer (GC) patients at each tumor stage. We first selected recurrence specific exosomal miRNA by miRNA microarray from 6 GC patients (stage I) with or without recurrence, and 3 healthy volunteers. In this analysis, miR‑23b demonstrated the most significant change. Subsequently, we validated the usefulness of miR‑23b as a biomarker using the plasma exosome samples collected from 232 GC patients and 20 healthy volunteers. miR‑23b levels were evaluated by Taqman microRNA assays. Exosomal miR‑23b levels of GC patients were significantly lower than those of the healthy controls. A significant association was revealed between the plasma exosomal miR‑23b levels and the expression of miR‑23b in primary tumor tissues. Concerning the pathological condition, miR‑23b demonstrated a significant association with tumor size, depth of invasion, liver metastasis and TNM stage. The overall survival (OS) rates of low‑miR‑23b patients were significantly worse than those of high‑miR‑23b patients at stage I, II, III and IV. The disease‑free survival (DFS) rates of low exosomal miR‑23b patients were significantly worse than those of high‑miR‑23b patients at stage I, II and III. Cox multivariate analysis indicated that exosomal miR‑23b was an independent prognostic factor for OS and DFS at each tumor stage. Our results revealed that exosomal miR‑23b has potential as minimally invasive predictive biomarker for the recurrence and prognosis of GC in patients at all stages.

Exosome-encapsulated microRNA-223-3p as a minimally invasive biomarker for the early detection of invasive breast cancer

Patients diagnosed preoperatively with ductal carcinoma in situ (DCIS) breast cancer have the potential to develop invasive ductal carcinoma (IDC). The present study investigated the usefulness of exosome-encapsulated microRNA-223-3p (miR-223-3p) as a biomarker for detecting IDC in patients initially diagnosed with DCIS by biopsy. The potential association between miR-223-3p and clinicopathological characteristics was examined in patients with breast cancer. Exosomes of 185 patients with breast cancer were separated from plasma by ultracentrifugation. Initially a microRNA (miRNA) microarray was examined to reveal the invasion specific miRNAs using exosomes collected from 6 patients with breast cancer, including 3 DCIS patients, 3 IDC patients and 3 healthy controls. In the miR microarray analysis the miR-223-3p levels of IDC patients demonstrated the highest fold-change compared with those in the DCIS patients and healthy controls. The potential of miR-223-3p for cell proliferation and cell invasion were examined in vitro using MCF7 cells transfected with the miR-223-3p gene. MCF7 cells transfected with the miR-223-3p gene significantly promoted cell proliferation and cell invasive ability (P<0.05). The plasma exosomal miR-223-3p levels of the other 179 patients with breast cancer and 20 healthy controls were measured using TaqMan miR assays. The exosomal miR-223-3p levels of the patients with breast cancer were significantly increased compared with the healthy controls (P<0.01). A statistically significant association was observed between the exosomal miR-223-3p levels and histological type, pT stage, pN stage, pathological stage, lymphatic invasion and nuclear grade (P<0.05). The exosomal miR-223-3p levels of IDC patients (stage I) and upstaged IDC patients (stage I) were significantly higher compared with the DCIS patients (P<0.05). These results suggest that exosomal miR-223-3p may be a useful preoperative biomarker to identify the invasive lesions of DCIS patients diagnosed by biopsy. In addition, plasma exosome-encapsulated miR-223-3p level was significantly associated with the malignancy of breast cancer.

Usefulness of Plasma Exosomal MicroRNA-451a as a Noninvasive Biomarker for Early Prediction of Recurrence and Prognosis of Non-Small Cell Lung Cancer

OBJECTIVES

The aim of this study was to clarify the usefulness of plasma exosomal microRNA-451a (miR-451a) as a novel biomarker for the early prediction of recurrence and prognosis in non-small cell lung cancer (NSCLC) patients after curative resection.

METHODS

Before surgery, plasma samples were collected and exosomal microRNA (miRNA) levels were evaluated. We first profiled specific exosomal miRNAs related to recurrence in 6 NSCLC patients with stage IA cancer by miRNA microarray. We then validated the usefulness of selected miRNAs as biomarkers using the other 285 NSCLC patients.

RESULTS

Plasma exosomal miR-451a showed the highest upregulation in the NSCLC patients with recurrence in the miRNA microarray analysis. A significant positive correlation was demonstrated between exosomal miR-451a levels and NSCLC tissue miR-451a levels. Exosomal miR-451a showed a significant association with lymph node metastasis, vascular invasion, and stage. In stage I, II, or III patients, the overall survival (OS) and disease-free survival (DFS) rates among the high-exosomal-miR-451a patients were significantly worse than those among the low-exosomal-miR-451a patients. In Cox multivariate analysis, exosomal miR-451a showed significance for OS and DFS.

CONCLUSION

Plasma exosomal miR-451a might serve as a reliable biomarker for the prediction of recurrence and prognosis in NSCLC patients with stage I, II, or III cancer.

Usefulness of exosome-encapsulated microRNA-451a as a minimally invasive biomarker for prediction of recurrence and prognosis in pancreatic ductal adenocarcinoma

BACKGROUND

MicroRNAs (miRNAs) encapsulated in the exosomes of plasma is of interest as stable and minimally invasive biomarkers for recurrence and prognosis in cancer patients. The aim of this study was to clarify the predictive and prognostic value of plasma exosomal microRNA-451a (miR-451a) in patients with pancreatic ductal adenocarcinoma (PDAC).

METHODS

Microarray-based expression profiling of miRNAs derived from exosomes in the plasma of six PDAC patients with UICC stage II was employed to identify a biomarker to distinguish between patients with and without recurrence. For validation analysis, plasma exosome samples of other 50 PDAC patients were measured by TaqMan MicroRNA assays.

RESULTS

In the miRNA microarray analyses, miR-451a showed the highest upregulation in the stage II patients who showed recurrence after surgery. In the relationship to pathological factors, exosomal miR-451a showed a significant association with tumor size and stage. The overall survival (OS) and disease-free survival rates (DFS) of the high exosomal miR-451a patients were significantly worse than those of the low miR-451a patients. In Cox proportional hazards model analysis, exsomal miR-451a showed significance to OS and DFS.

CONCLUSIONS

Plasma exosomal miR-451a levels may be a useful minimally invasive biomarker for the prediction of recurrence and prognosis in PDAC patients.

Efficacy of a sheet combined with fibrin glue in repair of pleural defect at the early phase after lung surgery in a canine model

OBJECTIVE

Polyglycolic acid and oxidized regenerated cellulose have been widely used as a sealant for repairing pulmonary air leakage during respiratory surgery. However, fundamental research of these materials has not been sufficiently conducted. Therefore, we conducted studies to assess the pressure resistance ability of these materials using a canine visceral pleural defect model at the early phase.

METHOD

The 6-mm circular defect and the 12-mm square defect were created on the visceral pleura of anesthetized beagles. These defects were then repaired using one of four methods: method A using polyglycolic acid and fibrin glue; method B using oxidized regenerated cellulose and fibrin glue; method C using oxidized regenerated cellulose; method D using fibrin glue. Airway pressure was measured as bursting pressure when air leakage from the repaired areas occurred at 5 min, 3 h, and 24 h after repair.

RESULTS

For the 6-mm circle defect, method A showed higher bursting pressures than the other methods at 5 min and 3 h (p < 0.05); method B showed higher than methods C and D at 5 min and 3 h (p < 0.05). For the 12-mm square defect, method A showed higher bursting pressures than the other methods at all time points (p < 0.05). Moreover, method B showed higher than method C at 24 h (p < 0.05).

CONCLUSION

Visceral pleural repairs using polyglycolic acid combined with fibrin glue showed the highest bursting pressure. Oxidized regenerated cellulose combined with fibrin glue showed sufficiently high bursting pressure in repair of small 6-mm circular defects.

Impact of pregabalin on early phase post-thoracotomy pain compared with epidural analgesia

Background

The purpose of this randomized study was to compare the effects of pregabalin with epidural analgesia on early phase post-thoracotomy pain.

Methods

This study was conducted on 90 adult patients who underwent thoracotomy. Patients were randomly divided into two groups, an epidural analgesia group, where 45 patients received 0.2% ropivacaine hydrochloride and fentanyl through a thoracic epidural catheter, and a pregabalin group, where 45 patients received 75 mg pregabalin orally twice daily. Both groups were also administered orally with celecoxib along with each treatment. Numerical rating scale (NRS) and sleep interference rate (SIR) were evaluated on the first day, third day, and fifth day after surgery. Anesthetic induction time, operation time, recovery time, the use of additional analgesic drugs and adverse effects were also examined.

Results

NRS and SIR were significantly lower in the pregabalin group at all time points (P<0.05). The number of patients requiring additional analgesic drugs within 24 hours after surgery showed no difference between the two groups; however, the number was significantly decreased in the pregabalin group after post-operative day 1 (P<0.001). Adverse effects including pneumonia, dysuria, constipation and nausea were identified among many patients in the epidural analgesia group (P<0.05). Operation time and recovery time were the same for both groups, while the epidural analgesia group showed a significantly longer anesthetic induction time (P<0.001).

Conclusions

Pregabalin is considered to be a safe and effective treatment method which is an alternative to epidural analgesia for acute post-thoracotomy pain.

Clinical Significance of Area of Psoas Major Muscle on Computed Tomography after Gastrectomy in Gastric Cancer Patients

Background: The measurement of a single abdominal image on computed tomography (CT) can provide an estimate of the total body skeletal muscle. We evaluate the change of the area of the psoas major muscle (PMMA) in a CT which was performed routinely after gastrectomy in gastric cancer. Methods: A total of 119 gastric cancer patients who underwent gastrectomy were enrolled for the study. A CT image at the top of the iliac crest level was obtained at the following times: 3 postoperative months (POM), 6 POM, 1 postoperative year (POY), 2 POY, 3 POY, and 5 POY. We analyzed the change rate of PMMA after gastrectomy and before or after recurrence. Results: PMMA change after gastrectomy was approximately between -8 and -10% over the 5-year observation period. PMMA in the R2 (macroscopic residual tumor)/recurrence group was lower than that in the no recurrence group, and a significant difference was observed at 2 POY (-21.7 ± 3.6% vs. -7.9 ± 2.3%, p < 0.01). PMMA after freshly diagnosed recurrence had decreased significantly by 14.1 ± 1.8% (p < 0.01). Conclusions: Evaluation of PMMA change by CT after gastrectomy could assist in the diagnosis of the progression of cancer state in gastric cancer patients.

Circulating exosomal microRNA-203 is associated with metastasis possibly via inducing tumor-associated macrophages in colorectal cancer

A primary tumor can create a premetastatic niche in distant organs to facilitate the development of metastasis. The mechanism by which tumor cells communicate with host cells to develop premetastatic niches is unclear. We focused on the role of microRNA (miR) signaling in promoting metastasis. Here, we identified miR-203 as a signaling molecule between tumors and monocytes in metastatic colorectal cancer (CRC) patients. Notably, high expression of serum exosomal miR-203, a major form in circulation, was associated with distant metastasis and an independent poor prognostic factor, whereas low expression in tumor tissues was a poor prognostic factor in CRC patients. We also found that exosomes carrying miR-203 from CRC cells were incorporated into monocytes and miR-203 could promote the expression of M2 markers in vitro, suggesting miR-203 promoted the differentiation of monocytes to M2-tumor-associated macrophages (TAMs). In a xenograft mouse model, miR-203-transfected CRC cells developed more liver metastasis compared to control cells. In conclusion, serum exosomal miR-203 expression is a novel biomarker for predicting metastasis, possibly via promoting the differentiation of monocytes to M2-TAMs in CRC. Furthermore, we propose the concept of site-dependent functions for miR-203 in tumor progression.

Circulating exosomal microRNA-203 is associated with metastasis possibly via inducing tumor-associated macrophages in colorectal cancer

A primary tumor can create a premetastatic niche in distant organs to facilitate the development of metastasis. The mechanism by which tumor cells communicate with host cells to develop premetastatic niches is unclear. We focused on the role of microRNA (miR) signaling in promoting metastasis. Here, we identified miR-203 as a signaling molecule between tumors and monocytes in metastatic colorectal cancer (CRC) patients. Notably, high expression of serum exosomal miR-203, a major form in circulation, was associated with distant metastasis and an independent poor prognostic factor, whereas low expression in tumor tissues was a poor prognostic factor in CRC patients. We also found that exosomes carrying miR-203 from CRC cells were incorporated into monocytes and miR-203 could promote the expression of M2 markers in vitro, suggesting miR-203 promoted the differentiation of monocytes to M2-tumor-associated macrophages (TAMs). In a xenograft mouse model, miR-203-transfected CRC cells developed more liver metastasis compared to control cells. In conclusion, serum exosomal miR-203 expression is a novel biomarker for predicting metastasis, possibly via promoting the differentiation of monocytes to M2-TAMs in CRC. Furthermore, we propose the concept of site-dependent functions for miR-203 in tumor progression.

Does lung cancer surgery cause circulating tumor cells?-A multicenter, prospective study

BACKGROUND

Cancer relapse is caused by residual isolated tumor cells (ITCs) remaining in the body after surgery. It is speculated that surgical manipulation may cause circulating tumor cells (CTCs) which are the origin of ITCs in the body. The occurrence of CTCs in surgical patients with non-small cell lung cancer (NSCLC) has been shown in retrospective observation, but not prospectively, thus we conducted a multicenter prospective study regarding the occurrence of CTCs by surgical manipulation.

METHODS

Patients with T1b-2N0M0 lung cancer were studied. Blood samples were collected from the peripheral artery in the operating room at both pre- and post-lobectomy to extract CTCs by a size selection method. The CTCs detection rate, pathological findings, and background of each patient were studied.

RESULTS

The histological diagnosis of 29 patients were adenocarcinoma in 24 patients, squamous cell carcinoma in 3 patients, and other types in 2 patients. The number of pre-CTCs positive patients was 13 and the number of post CTCs positive patients was 17. Among the 16 patients who were pre-CTCs negative, 4 patients showed post CTCs positive, while all pre-CTCs positive patients remained post-CTCs positive.

CONCLUSIONS

The likelihood of CTC dislodgement by surgical manipulation is indicated based on the result that CTCs were detected after lung cancer surgery, where there were no cases of pre-CTCs positive and post CTCs negative.

Correction: Integrated Multiregional Analysis Proposing a New Model of Colorectal Cancer Evolution

[This corrects the article DOI: 10.1371/journal.pgen.1005778.].

Pericardial Conduit for Pulmonary Artery Reconstruction by Surgical Stapling

Pulmonary artery reconstruction in lung cancer surgery is an effective surgical method to avoid pneumonectomy that leads to longer survival times with few adverse effects. The pericardium is often used for the interposition of a prosthetic conduit. A pericardial conduit can be easily and precisely constructed by surgical stapling, which facilitates pulmonary artery reconstruction. In this report, the process and pitfalls of surgical stapling are described.

Circulating Exosomal MicroRNA-21 as a Biomarker in Each Tumor Stage of Colorectal Cancer

OBJECTIVE

We clarified the predictive and prognostic value of circulating plasma exosomal microRNA-21 (miR-21) in each TNM stage of colorectal cancer (CRC) patients.

METHODS

The microRNA (miRNA) profiles of the plasma exosomes, primary tumor tissues, and liver metastasis tissues from the same CRC patients were examined using a microarray. For validation analysis, the plasma exosome samples from 326 CRC patients were measured by TaqMan miRNA assays.

RESULTS

In the miRNA microarray analyses, miR-21 showed the highest upregulation in exosomes, primary tumor tissues, and liver metastasis tissues. Significant correlations were demonstrated between exosomal miR-21 and tissue miR-21 levels. As for the relationship to the pathological condition, exosomal miR-21 showed a significant association with liver metastasis and TNM stage. The overall survival (OS) rates and disease-free survival (DFS) rates in high-exosomal-miR-21 patients were significantly worse than those in low-miR-21 patients. Exosomal miR-21 levels were an independent prognostic factor for OS and DFS in CRC patients with TNM stage II or III, and for OS in patients with TNM stage IV.

CONCLUSION

Plasma exosomal miR-21 levels are a useful biomarker for the prediction of recurrence and poor prognosis in CRC patients with TNM stage II, III, or IV.

Exosomal microRNA in plasma as a non-invasive biomarker for the recurrence of non-small cell lung cancer

Predictive biomarkers for the recurrence of non-small cell lung cancer (NSCLC) in patients who have received curative resection are important for cancer treatment. The functional microRNAs (miRNAs/miRs) in the exosomes of plasma and serum samples are of interest as stable and non-invasive biomarkers for recurrence in cancer patients. The aim of the present study was to clarify the usefulness of plasma exosomal miRNAs as biomarkers for the prediction of recurrence in NSCLC following curative resection. First, microarray-based expression profiling of miRNAs derived from exosomes in the plasma of 6 patients was employed to identify a biomarker that distinguishes between patients with and without NSCLC recurrence. In the miRNA microarray analyses, the exosomal miR-21 and miR-4257 levels of the NSCLC patients showed marked upregulation in those individuals with recurrence compared with those without recurrence and healthy individuals. These two miRNAs were thus selected as recurrence-specific biomarkers and their potential was evaluated in a separate cohort of 195 NSCLC patients. In comparison to the levels in 30 healthy individuals, exosomal miR-21 and miR-4257 levels showed a significant increase in the NSCLC patients (P<0.01). When evaluating the clinicopathological significance of these miRNAs, exosomal miR-21 showed a significant association with tumor size and tumor-node-metastasis (TNM) stage (P<0.05). Exosomal miR-4257 showed a significant association with histological type, lymphatic invasion and TNM stage (P<0.05). The disease-free survival (DFS) rates of high exosomal miR-21 patients were significantly worse than those of low exosomal miR-21 patients (P<0.05), and the DFS rates of patients with high exosomal miR-4257 levels were significantly worse than those with low exosomal miR-4257 levels (P<0.01). In the Cox multivariate analysis, plasma exosomal miR-21 and miR-4257 expression showed a significance association with DFS (P<0.05). These results suggest that plasma exosomal miR-21 and mir-4257 expression has potential as a predictive biomarker for recurrence in NSCLC patients who have received curative resection.

Birt-Hogg-Dube syndrome accompanied by pulmonary arteriovenous malformation

A 25-year-old male with Birt-Hogg-Dube (BHD) syndrome who developed hemothorax caused by ruptured of pulmonary arteriovenous malformation was reported. The patient was admitted to the hospital due to chest pain. A chest X-ray showed pleural fluid in his left lung, and a chest CT showed the presence of a tumor with enhanced contrast in the lower left lobe of approximately 5 cm in a diameter. Pleural fluid was collected by tap and indicated the presence of blood; therefore, hemothorax was suspected. Thoracoscopic surgery was performed to remove the mass for homostasis. Pathological findings indicated that the resected tumor-like lesion was an intrapulmonary hematoma, and aggregated vascular vessels of various diameters forming incomplete media elastic lamina was observed around the hematoma; therefore, it was diagnosed as pulmonary arteriovenous malformation. Family history of the patient indicated the presence of pneumothorax and malignant diseases, and the patient presented with papules and multiple pulmonary cysts. The genetic test revealed a deletion of exon 11 of the BHD gene; therefore, the patient was diagnosed with BHD syndrome. This report is the first to describe BHD syndrome accompanied by pulmonary arteriovenous malformation.

[Anti-PD-1 Antibody Drugs - Potential of Plasma PD-L1 Protein as a Biomarker]

The superior therapeutic effects of antibodies targeting immune checkpoints have been reported in the treatment of various cancers including non-small cell lung cancer(NSCLC)and malignant melanoma. However, the risk of reactivity against selfantigens and the high prices of these drugs are major concerns. Previously, PD-L1 protein expression and the number of infiltrating T cells in tumor tissues were investigated by immunohistochemical staining, as biomarkers for therapeutic anti-PD- 1 antibodies. However, further research into the clinical significance of PD-L1 expression in tumor tissues is still required. A promising and comprehensive gene mutation analysis of tumor tissues and T cell repertoire analysis has recently been undertaken. Liquid biopsy, which has the benefit of being minimally invasive, has also been investigated. We are currently, investigating the utility of plasma PD-L1 protein levels as a predictive biomarker of prognosis in NSCLC. Furthermore, it is important to explore useful biomarkers and develop reliable companion diagnostics for the individualized treatment with immune checkpoint drugs.

Integrated Multiregional Analysis Proposing a New Model of Colorectal Cancer Evolution

Understanding intratumor heterogeneity is clinically important because it could cause therapeutic failure by fostering evolutionary adaptation. To this end, we profiled the genome and epigenome in multiple regions within each of nine colorectal tumors. Extensive intertumor heterogeneity is observed, from which we inferred the evolutionary history of the tumors. First, clonally shared alterations appeared, in which C>T transitions at CpG site and CpG island hypermethylation were relatively enriched. Correlation between mutation counts and patients’ ages suggests that the early-acquired alterations resulted from aging. In the late phase, a parental clone was branched into numerous subclones. Known driver alterations were observed frequently in the early-acquired alterations, but rarely in the late-acquired alterations. Consistently, our computational simulation of the branching evolution suggests that extensive intratumor heterogeneity could be generated by neutral evolution. Collectively, we propose a new model of colorectal cancer evolution, which is useful for understanding and confronting this heterogeneous disease.

Cancer is heterogeneous disease; each tumor in different patients has different cancer genomes. Furthermore, another level of heterogeneity exists: even a single tumor harbors multiple genetically distinct subclones. This intratumor heterogeneity is presumably one of causes of therapeutic difficulty, and its understanding is clinically necessary. In this study, we investigated intratumor heterogeneity in colorectal cancer by analyzing sample obtained from geographically separated regions of 9 colorectal tumors. Our integrated data analyses combined with computational simulation strongly suggest that, after clonally shared alterations were accumulated by aging, numerous subclones were generated by neutral evolution. Importantly, this view can explain the robustness and evolvability of cancer: therapeutic action inducing an environmental change would convert some of the numerous neutral mutations to driver genes that confer therapeutic resistance. We believe that this study not only provides insights into colorectal cancer pathogenesis, but also constitutes a new basis for designing therapeutic strategies.

Measurements of Elliptic and Triangular Flow in High-Multiplicity 3He+Au Collisions at √(s(NN))=200 GeV

We present the first measurement of elliptic (v(2)) and triangular (v(3)) flow in high-multiplicity (3)He+Au collisions at √(s(NN))=200  GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in (3)He+Au and in p+p collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the (3)He+Au system. The collective behavior is quantified in terms of elliptic v(2) and triangular v(3) anisotropy coefficients measured with respect to their corresponding event planes. The v(2) values are comparable to those previously measured in d+Au collisions at the same nucleon-nucleon center-of-mass energy. Comparisons with various theoretical predictions are made, including to models where the hot spots created by the impact of the three (3)He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems.

Exosomal microRNA in serum is a novel biomarker of recurrence in human colorectal cancer

Background:

Functional microRNAs (miRNAs) in exosomes have been recognised as potential stable biomarkers in cancers. The aim of this study is to identify specific miRNAs in exosome as serum biomarkers for the early detection of recurrence in human colorectal cancer (CRC).

Methods:

Serum samples were sequentially obtained from six patients with and without recurrent CRC. The miRNAs were purified from exosomes, and miRNA microarray analysis was performed. The miRNA expression profiles and copy number aberrations were explored using microarray and array CGH analyses in 124 CRC tissues. Then, we validated exosomal miRNAs in 2 serum sample sets (90 and 209 CRC patients) by quantitative real-time RT–PCR.

Results:

Exosomal miR-17-92a cluster expression level in serum was correlated with the recurrence of CRC. Exosomal miR-19a expression levels in serum were significantly increased in patients with CRC as compared with healthy individuals with gene amplification. The CRC patients with high exosomal miR-19a expression showed poorer prognoses than the low expression group (P<0.001).

Conclusions:

Abundant expression of exosomal miR-19a in serum was identified as a prognostic biomarker for recurrence in CRC patients.

Measurement of Long-Range Angular Correlation and Quadrupole Anisotropy of Pions and (Anti)Protons in Central d+Au Collisions at sqrt[s_{NN}]=200 GeV

We present azimuthal angular correlations between charged hadrons and energy deposited in calorimeter towers in central d+Au and minimum bias p+p collisions at sqrt[s_{NN}]=200 GeV. The charged hadron is measured at midrapidity |η|<0.35, and the energy is measured at large rapidity (-3.7<η<-3.1, Au-going direction). An enhanced near-side angular correlation across |Δη|>2.75 is observed in d+Au collisions. Using the event plane method applied to the Au-going energy distribution, we extract the anisotropy strength v_{2} for inclusive charged hadrons at midrapidity up to p_{T}=4.5 GeV/c. We also present the measurement of v_{2} for identified π^{±} and (anti)protons in central d+Au collisions, and observe a mass-ordering pattern similar to that seen in heavy-ion collisions. These results are compared with viscous hydrodynamic calculations and measurements from p+Pb at sqrt[s_{NN}]=5.02 TeV. The magnitude of the mass ordering in d+Au is found to be smaller than that in p+Pb collisions, which may indicate smaller radial flow in lower energy d+Au collisions.

A case of invasive Langerhans cell histiocytosis localizing only in the lung and diagnosed as pneumothorax in an adolescent female

In infants, Langerhans cell histiocytosis (LCH) is associated with poor clinical outcomes as Langerhans cells invade and damage multiple organs, a presentation that is different from that in adults. Here, we present a case of a 15-year-old female who visited ourclinic complaining of right chest pain and dyspnea. She was diagnosed with right pneumothorax by chest X-ray. Chest computed tomography showed multiple cystic changes in the bilateral lung. Additionally, bullous lesions occupying the upper lobe and multiple white tiny nodules on the surface of the lung were observed by thoracoscopy. These nodules comprised proliferating atypical CD1a/S-100-positive cells invading the pulmonary parenchyma, leading to the diagnosis of LCH. Because of the extensive invasion into the pulmonary parenchyma, chemotherapy was administered. This case of LCH was unique in that the age of onset was atypical and the tumor cells occupied a single organ, despite their malignant behavior.

Clinical significance of microRNA-21 as a biomarker in each Dukes' stage of colorectal cancer

The potential value of microRNAs (miRNAs) as prognostic biomarkers are of interest. It is known that microRNA-21 (miR-21) is implicated in the promotion, proliferation and progression of several types of human cancers. However, the prognostic significance of miR-21 in each tumor stage of colorectal cancer (CRC) remains elusive. The objective of this study was to clarify the prognostic value of miR-21 for CRC patients at each tumor stage. The expression levels of miR-21 in the tumor tissues and normal adjacent tumor tissues of 306 CRC patients were determined by TaqMan microRNA assays. In order to clarify the miRNA profile in CRC tissues, miRNA arrays were examined. In this analysis, miR-21, miR-224, miR-96, miR-31 and miR-155 showed marked upregulation, and miR-21 showed the highest level. Upon comparison of clinicopathological factors, miR-21 expression showed significant association with depth of invasion, lymphatic and venous invasion, liver metastasis and Dukes' stage. In the Kaplan-Meier survival curve analysis of all patients, overall survival (OS) and disease-free survival (DFS) rates of the patients with high miR-21 expression were significantly worse than these rates in patients with low miR-21 expression. In the Kaplan-Meier analysis of each tumor stage, the DFS of patients with high miR-21 expression was significantly worse than patients with low miR-21 levels in Dukes' stage A tumors. In Dukes' stage B and C, patients with high miR-21 expression showed a significantly worse OS and DFS than patients with low miR-21 expression. In Dukes' stage D, patients with high miR-21 expression showed a significantly worse OS than patients with low miR-21 expression. In the Cox multivariate analysis, it was shown that miR-21 expressions in CRC tissues is an independent prognostic factor in Dukes' stage B, C and D. In conclusion, miR-21 expression may be a valuable biomarker for prediction of poor prognosis in CRC patients with Dukes' stage B, C and D.

Cold-nuclear-matter effects on heavy-quark production at forward and backward rapidity in d + Au collisions at √sNN = 200 GeV

The PHENIX experiment has measured open heavy-flavor production via semileptonic decay over the transverse momentum range 1 < p(T) < 6  GeV/c at forward and backward rapidity (1.4 < |y| < 2.0) in d+Au and p + p collisions at √sNN = 200  GeV. In central d+Au collisions, relative to the yield in p + p collisions scaled by the number of binary nucleon-nucleon collisions, a suppression is observed at forward rapidity (in the d-going direction) and an enhancement at backward rapidity (in the Au-going direction). Predictions using nuclear-modified-parton-distribution functions, even with additional nuclear-p(T) broadening, cannot simultaneously reproduce the data at both rapidity ranges, which implies that these models are incomplete and suggests the possible importance of final-state interactions in the asymmetric d + Au collision system. These results can be used to probe cold-nuclear-matter effects, which may significantly affect heavy-quark production, in addition to helping constrain the magnitude of charmonia-breakup effects in nuclear matter.

Phase I clinical study of multiple epitope peptide vaccine combined with chemoradiation therapy in esophageal cancer patients

Background

Chemoradiation therapy (CRT) has been widely used for unresectable esophageal squamous cell carcinoma (ESCC) patients. However, many patients develop local recurrence after CRT. In this study, we hypothesized that the immunotherapy by peptide vaccine may be effective for the eradication of minimal residual cancer cells after CRT. This study was conducted as a phase I clinical trial of multiple-peptide vaccine therapy combined with CRT on patients with unresectable ESCC.

Patients and methods

HLA-A*2402 positive 11 unresectable chemo-naïve ESCC patients were treated by HLA-A*2402-restricted multi-peptide vaccine combined with CRT. The peptide vaccine included the 5 peptides as follows; TTK protein kinase (TTK), up-regulated lung cancer 10 (URLC10), insulin-like growth factor–II mRNA binding protein 3 (KOC1), vascular endothelial growth factor receptor 1 (VEGFR1) and 2 (VEGFR2). CRT consisted of radiotherapy (60 Gy) with concurrent cisplatin (40 mg/m²) and 5-fluorouracil (400 mg/m²). Peptide vaccines mixed with incomplete Freund’s adjuvant were injected subcutaneously once a week on at least 8 occasions combined with CRT.

Results

Vaccination with CRT therapy was well-tolerated, and no severe adverse effects were observed. In the case of grade 3 toxicities, leucopenia, neutropenia, anemia and thrombocutopenia occurred in 54.5%, 27.3%, 27.3% and 9.1% of patients, respectively. Grade 1 local skin reactions in the injection sites of vaccination were observed in 81.8% of patients. The expressions of HLA class I, URLC10, TTK, KOC1, VEGFR1 and VEGFR2 antigens were observed in the tumor tissues of all patients. All patients showed peptide-specific cytotoxic T lymphocytes responses in at least one of the 5 kinds of peptide antigens during the vaccination. Six cases of complete response (CR) and 5 cases of progressive disease (PD) were observed after the 8^th vaccination. The 4 CR patients who continued the peptide vaccination experienced long consistent CR for 2.0, 2.9 4.5 and 4.6 years.

Conclusions

A combination therapy of multi-peptide vaccine with CRT can successfully be performed with satisfactory levels of safety, and application of this combination therapy may be an effective treatment for patients with unresectable ESCC.

Trial registration

ClinicalTrial.gov, number NCT00632333.

Allelic imbalance at an 8q24 oncogenic SNP is involved in activating MYC in human colorectal cancer

BACKGROUND

The rs6983267 at 8q24.21 has been established as a significant cancer-related single nucleotide polymorphism (SNP). The risk allele showed similarity to the binding site of transcription factor TCF4/LEF1 that activates transcription of MYC. However, little is known about the role of this SNP in increasing MYC activity in colorectal cancers (CRCs).

METHODS

The genotypes of rs6983267 in peripheral blood and primary cancers, MYC activity and copy number (CN) alteration were examined in 107 CRCs. Next, we plotted the number of cancers cell lines exhibiting specific G/T genotypes in 746 cancer cell lines of the Sanger Institute database. Then we validated the relationship between the 8q24 SNP status and clinicopathologic parameters in 68 CRCs with loss of heterozygosity (LOH).

RESULTS

The MYC module activity was activated by either transcription in the risk allele (G) or by amplification in the non-risk allele (T). Then, we confirmed that the CN amplification dominantly occurred in the non-risk allele, whereas CN neutral LOH, which indicated uniparental disomy (UPD) was more frequently observed for the risk allele. Finally, we confirmed that risk allele dominant cases, either by amplification or by UPD, indicated a more malignant clinical phenotype than non-risk allele dominant cases.

CONCLUSIONS

The development of CRC requires MYC activation through retention of the risk allele, or amplification of the non-risk allele at the oncogenic SNP in the site of primary tumor.

Aberrant expression of plastin-3 via copy number gain induces the epithelial-mesenchymal transition in circulating colorectal cancer cells

PURPOSE

Plastin-3 (PLS3) is a novel marker for circulating tumor cells (CTCs) in colorectal cancer (CRC). We sought to investigate the mechanisms mediating the aberrant expression of PLS3, the role of PLS3 in the epithelial-mesenchymal transition (EMT), and its association with the acquisition of invasive and metastatic abilities in human CRC.

METHODS

The expression levels of PLS3 messenger RNA in the tumor drainage venous blood (TDB) were examined in 177 CRC cases, and the associations between PLS3 expression and Xq23 copy numbers were analyzed in 132 CRC samples. We then established a stable PLS3-expressing CRC cell line and assessed the role of PLS3 in the EMT.

RESULTS

In clinical CRC cases, high expression of PLS3 in CTCs of TDB as well as peripheral blood was established as an independent prognostic factor of overall survival (p < 0.001), and the copy number gain of Xq23, which is the locus of the PLS3 gene, was significantly related to PLS3 overexpression. PLS3 induced the EMT via transforming growth factor (TGF)-β signaling and resulted in the acquisition of invasive ability in CRC cells.

CONCLUSIONS

The aberrant expression of PLS3 was associated with copy number gain in CTCs from primary tumors and was involved in the regulation of the EMT, contributing to a poor prognosis in CRC patients.

Contrasting expression patterns of histone mRNA and microRNA 760 in patients with gastric cancer

PURPOSE

Recent studies revealed that both disseminated tumor cells and noncancerous cells contributed to cancer progression cooperatively in the bone marrow. Here, RNA-seq analysis of bone marrow from gastric cancer patients was performed to identify prognostic markers for gastric cancer.

EXPERIMENTAL DESIGN

Bone marrow samples from eight gastric cancer patients (stages I and IV: n = 4 each) were used for RNA-seq analysis. Results were validated through quantitative real-time PCR (qRT-PCR) analysis of HIST1H3D expression in 175 bone marrow, 92 peripheral blood, and 115 primary tumor samples from gastric cancer patients. miR-760 expression was assayed using qRT-PCR in 105 bone marrow and 96 primary tumor samples. Luciferase reporter assays were performed to confirm whether histone mRNAs were direct targets of miR-760. miR-760 expression was also evaluated in noncancerous cells from gastric cancer patients.

RESULTS

RNA-seq analysis of bone marrow samples from gastric cancer patients revealed higher expression of multiple histone mRNAs in stage IV patients. HIST1H3D expression in the bone marrow, peripheral blood, and primary tumor of stage IV patients was higher than that in stage I patients (P = 0.0284, 0.0243, and 0.0006, respectively). In contrast, miR-760 was downregulated in the bone marrow and primary tumor of stage IV patients compared with stage I patients (P = 0.0094 and 0.0018, respectively). Histone mRNA and miR-760 interacted directly. Furthermore, miR-760 was downregulated in noncancerous mucosa in stage IV gastric cancer patients.

CONCLUSION

Histone mRNA was upregulated, whereas miR-760 was downregulated in the bone marrow and primary tumor of advanced gastric cancer patients, suggesting that the histone mRNA/miR-760 axis had a crucial role in the development of gastric cancer.

Medium modification of jet fragmentation in Au+Au collisions at √[s(NN)]=200 GeV measured in direct photon-hadron correlations

The jet fragmentation function is measured with direct photon-hadron correlations in p+p and Au+Au collisions at √[s(NN)]=200 GeV. The p(T) of the photon is an excellent approximation to the initial p(T) of the jet and the ratio z(T)=p(T)(h)/p(T)(γ) is used as a proxy for the jet fragmentation function. A statistical subtraction is used to extract the direct photon-hadron yields in Au+Au collisions while a photon isolation cut is applied in p+p. I(AA), the ratio of hadron yield opposite the photon in Au+Au to that in p+p, indicates modification of the jet fragmentation function. Suppression, most likely due to energy loss in the medium, is seen at high z(T). The associated hadron yield at low z(T) is enhanced at large angles. Such a trend is expected from redistribution of the lost energy into increased production of low-momentum particles.

Plastin3 is a novel marker for circulating tumor cells undergoing the epithelial-mesenchymal transition and is associated with colorectal cancer prognosis

Circulating tumor cells (CTC) in blood have attracted attention both as potential seeds for metastasis and as biomarkers. However, most CTC detection systems might miss epithelial-mesenchymal transition (EMT)-induced metastatic cells because detection is based on epithelial markers. First, to discover novel markers capable of detecting CTCs in which EMT has not been repressed, microarray analysis of 132 colorectal cancers (CRC) from Japanese patients was conducted, and 2,969 genes were detected that were overexpressed relative to normal colon mucosa. From the detected genes, we selected those that were overexpressed CRC with distant metastasis. Then, we analyzed the CRC metastasis-specific genes (n = 22) to determine whether they were expressed in normal circulation. As a result, PLS3 was discovered as a CTC marker that was expressed in metastatic CRC cells but not in normal circulation. Using fluorescent immunocytochemistry, we validated that PLS3 was expressed in EMT-induced CTC in peripheral blood from patients with CRC with distant metastasis. PLS3-expressing cells were detected in the peripheral blood of approximately one-third of an independent set of 711 Japanese patients with CRC. Multivariate analysis showed that PLS3-positive CTC was independently associated with prognosis in the training set (n = 381) and the validation set [n = 330; HR = 2.17; 95% confidence interval (CI) = 1.38-3.40 and HR = 3.92; 95% CI = 2.27-6.85]. The association between PLS3-positive CTC and prognosis was particularly strong in patients with Dukes B (HR = 4.07; 95% CI = 1.50-11.57) and Dukes C (HR = 2.57; 95% CI = 1.42-4.63). PLS3 is a novel marker for metastatic CRC cells, and it possesses significant prognostic value.

[Usefulness of CTCs in tumor drainage vein blood as a biomarker for prognosis in colorectal cancer patients with Dukes' stage B and C]

We aimed to clarify the clinical significance of circulating tumor cells (CTCs) in the tumor drainage vein blood of colorectal cancer(CRC) patients with Dukes' stage B and C. This study included 111 patients with Dukes' stage B and 86 patients with Dukes' stage C. We selected multiple genetic markers, including the cancer-associated marker (CEA), epithelial markers(CK19 and CK20), and cancer stem-like cell marker(CD133), and the mRNA levels of these genes were detected by quantitative real-time reverse transcription-polymerase chain reaction assays. In Kaplan-Meier survival curve analysis, overall survival(OS) and disease-free survival(DFS) of Dukes' stage B and C patients who were positive for CEA, CK19, CK20, and/or CD133 (CEA/CK/CD133) were significantly worse than that in patients who were negative for these markers. By Cox progression analysis, it was demonstrated that CEA/CK/CD133 mRNA in tumor drainage vein blood was an independent prognostic factor for OS and DFS in these patients. These results suggest that CEA/CK/CD133 mRNA detection in tumor drainage vein blood is a useful tool for the determination of high-risk CRC patients with Dukes' stage B and C who are in need of postoperative adjuvant therapy.

Evolution of π(0) suppression in Au+Au collisions from √(s(NN))=39 to 200 GeV

Neutral-pion π(0) spectra were measured at midrapidity (|y|<0.35) in Au+Au collisions at √(s(NN))=39 and 62.4 GeV and compared with earlier measurements at 200 GeV in a transverse-momentum range of 1<p(T)<10 GeV/c. The high-p(T) tail is well described by a power law in all cases, and the powers decrease significantly with decreasing center-of-mass energy. The change of powers is very similar to that observed in the corresponding spectra for p+p collisions. The nuclear modification factors (R(AA)) show significant suppression, with a distinct energy, centrality, and p(T) dependence. Above p(T)=7 GeV/c, R(AA) is similar for √(s(NN))=62.4 and 200 GeV at all centralities. Perturbative-quantum-chromodynamics calculations that describe R(AA) well at 200 GeV fail to describe the 39 GeV data, raising the possibility that, for the same p(T) region, the relative importance of initial-state effects and soft processes increases at lower energies. The p(T) range where π(0) spectra in central Au+Au collisions have the same power as in p+p collisions is ≈5 and 7 GeV/c for √(s(NN))=200 and 62.4 GeV, respectively. For the √(s(NN))=39 GeV data, it is not clear whether such a region is reached, and the x(T) dependence of the x(T)-scaling power-law exponent is very different from that observed in the √(s(NN))=62 and 200 GeV data, providing further evidence that initial-state effects and soft processes mask the in-medium suppression of hard-scattered partons to higher p(T) as the collision energy decreases.