Insights into the cavitation morphology of rubber reinforced with a nano-filler

Notwithstanding the various uses of rubber, the fracture mechanism of filler-reinforced rubber remains unclear. This study used four-dimensional computed tomography (4D-CT) involving monochromatic synchrotron X-rays to examine the cavitation within silica-reinforced rubber quantitatively and systematically. The results suggested a threshold value of silica content for the cavitation morphology. Macroscopic fractures, such as those developed by void formation, occurred below the threshold value of silica content. Above this threshold, the density of rubber decreased but macroscopic voids rarely occurred. The lower-density rubber area in the high-silica-content rubber was reversible at the effective pixel size for 4D-CT. These results suggest that the growth of the damage points to macrosized voids could be stopped by the formation of a network of rigid polymer layers. This study allows the elucidation of the reinforcing mechanism and the cavitation morphology of filler-reinforced rubber.

ADAR1 is a promising risk stratification biomarker of remnant liver recurrence after hepatic metastasectomy for colorectal cancer

Adenosine-to-inosine RNA editing is a process mediated by adenosine deaminases that act on the RNA (ADAR) gene family. It has been discovered recently as an epigenetic modification dysregulated in human cancers. However, the clinical significance of RNA editing in patients with liver metastasis from colorectal cancer (CRC) remains unclear. The current study aimed to systematically and comprehensively investigate the significance of adenosine deaminase acting on RNA 1 (ADAR1) expression status in 83 liver metastatic tissue samples collected from 36 patients with CRC. The ADAR1 expression level was significantly elevated in liver metastatic tissue samples obtained from patients with right-sided, synchronous, or RAS mutant-type CRC. ADAR1-high liver metastasis was significantly correlated with remnant liver recurrence after hepatic metastasectomy. A high ADAR1 expression was a predictive factor of remnant liver recurrence (area under the curve = 0.72). Results showed that the ADAR1 expression level could be a clinically relevant predictive indicator of remnant liver recurrence. Patients with liver metastases who have a high ADAR1 expression requires adjuvant chemotherapy after hepatic metastasectomy.

The Relationship between Psychological Distress and Physical Frailty in Japanese Community-Dwelling Older Adults: A Cross-Sectional Study

BACKGROUND

Older adults' mental health and physical frailty have been a frequent research focus, but few studies have investigated the relationship between them.

OBJECTIVES

To investigate the association between mental health and physical frailty in community-dwelling older Japanese people.

DESIGN

Cross-sectional study from the Itoshima Frail Study.

SETTING

Itoshima City, Fukuoka, Japan.

PARTICIPANTS

A total of 919 community-dwelling older individuals aged 65-75 years.

MEASUREMENTS

Physical frailty was measured based on five criteria proposed by the Fried scale, and the subjects were classified into three groups: robust, pre-frailty, and frailty. Psychological distress was used to assess the subjects' mental health, with the Kessler 6-Item Psychological Distress Scale (K6) score; the subjects were divided into three groups based on their K6 score: 0-1, 2-4, and ≥5. Psychological distress was defined by K6 score ≥5. Ordinal logistic regression was used to estimate the odds ratios (OR) and 95% confidence intervals (CIs) between the psychological distress and physical frailty status.

RESULTS

Psychological distress was identified in 190 subjects (20.7%). Forty-six subjects (5.0%) presented with physical frailty, and 24 subjects (2.6%) had both psychological distress and physical frailty. With the increase in the K6 score, more subjects had pre-frailty and physical frailty (p<0.001). Significant positive associations were observed between psychological distress and the risks of pre-frailty (OR 2.94, 95%CI: 1.95-4.43) and frailty (OR 10.71, 95%CI: 4.68-24.51), even in a multivariable-adjusted analysis. In a subgroup analysis of components of frailty, one-point increment in K6 score was associated with higher odds of shrinking and fatigue.

CONCLUSION

A severe psychological distress was associated with increased risks of physical frailty and the frailty sub-items of shrinking and fatigue in community-dwelling older Japanese adults.

RNA editing is a valuable biomarker for predicting carcinogenesis in ulcerative colitis

BACKGROUND AND AIMS

Ulcerative colitis (UC) can develop colitis-associated colorectal neoplasm (CAN). Adenine-to-inosine RNA editing, which is regulated by adenosine deaminase acting on RNA (ADAR), induces the posttranscriptional modification of critical oncogenes, including antizyme inhibitor 1 (AZIN1), leading to colorectal carcinogenesis. Therefore, we hypothesized that ADAR1 might be involved in the development of CAN in UC.

METHODS

We systematically analyzed a cohort of 139 UC cases (40 acute phase, 73 remission phase, 26 CAN). The degree of inflammation was evaluated using the Mayo endoscopic score (MES).

RESULTS

The type 1 IFN-related inflammation pathway was upregulated in the rectum of active UC, rectum of UC-CAN, and tumor site of UC-CAN patients. ADAR1 expression was upregulated in the entire colon of CAN cases, while it was down-regulated in non-CAN MES0 cases. ADAR1 expression in the rectum predicted the development of CAN better than p53 or β-catenin, with an area under the curve of 0.93. The high expression of ADAR1 and high AZIN1 RNA editing in UC was triggered by type 1 IFN stimulation from UC-specific microbiomes, such as Fusobacterium in vitro analyses. The induction of AZIN1 RNA editing by ADAR1, whose expression is promoted by Fusobacterium, may induce carcinogenesis in UC.

CONCLUSIONS

The risk of CAN can be evaluated by assessing ADAR1 expression in the rectum of MES0 UC patients, freeing UC patients from unnecessary colonoscopy and reducing their physical burden. RNA editing may be involved in UC carcinogenesis, and may be used to facilitate the prevention and treatment of CAN in UC.

Microscopic observation of the effects of elongation on the polymer chain dynamics of crosslinked polybutadiene using quasi-elastic γ-ray scattering

A synchrotron-radiation-based quasi-elastic γ-ray scattering system has been developed that uses time-domain interferometry to observe microscopic polymer dynamics under uniaxial deformation. The stress-producing mechanism of crosslinked polybutadiene has been studied from a microscopic viewpoint. It was found that the mean relaxation time ⟨τ⟩ of the microscopic polymer motion observed over a relatively high temperature (T) range (i.e. T^-1 < 0.0045 K^-1) increased with elongation on both the intra- and intermolecular scales. Following an extensive strain dependence study, it was found that the strain dependences of both the intra- and intermolecular ⟨τ⟩ changed with the stress dependence. It was therefore suggested that ⟨τ⟩ increased due to the constraint of the local polymer chain motion caused by elongation. The local molecular dynamics of polymer chains under uniaxial deformation could be evaluated at intra- and intermolecular scales separately for the first time using our method.

RNA editing facilitates the enhanced production of neoantigens during the simultaneous administration of oxaliplatin and radiotherapy in colorectal cancer

Most cases of colorectal cancers (CRCs) are microsatellite stable (MSS), which frequently demonstrate lower response rates to immune checkpoint inhibitors (ICIs). RNA editing produces neoantigens by altering amino acid sequences. In this study, RNA editing was induced artificially by chemoradiation therapy (CRT) to generate neoantigens in MSS CRCs. Altogether, 543 CRC specimens were systematically analyzed, and the expression pattern of ADAR1 was investigated. In vitro and in vivo experiments were also performed. The RNA editing enzyme ADAR1 was upregulated in microsatellite instability-high CRCs, leading to their high affinity for ICIs. Although ADAR1 expression was low in MSS CRC, CRT including oxaliplatin (OX) treatment upregulated RNA editing levels by inducing ADAR1. Immunohistochemistry analyses showed the upregulation of ADAR1 in patients with CRC treated with CAPOX (capecitabine + OX) radiation therapy relative to ADAR1 expression in patients with CRC treated only by surgery (p < 0.001). Compared with other regimens, CRT with OX effectively induced RNA editing in MSS CRC cell lines (HT29 and Caco2, p < 0.001) via the induction of type 1 interferon-triggered ADAR1 expression. CRT with OX promoted the RNA editing of cyclin I, a neoantigen candidate. Neoantigens can be artificially induced by RNA editing via an OX-CRT regimen. CRT can promote proteomic diversity via RNA editing.

Development and application of a tender X-ray ptychographic coherent diffraction imaging system on BL27SU at SPring-8

Ptychographic coherent diffraction imaging (CDI) allows the visualization of both the structure and chemical state of materials on the nanoscale, and has been developed for use in the soft and hard X-ray regions. In this study, a ptychographic CDI system with pinhole or Fresnel zone-plate optics for use in the tender X-ray region (2-5 keV) was developed on beamline BL27SU at SPring-8, in which high-precision pinholes optimized for the tender energy range were used to obtain diffraction intensity patterns with a low background, and a temperature stabilization system was developed to reduce the drift of the sample position. A ptychography measurement of a 200 nm thick tantalum test chart was performed at an incident X-ray energy of 2.500 keV, and the phase image of the test chart was successfully reconstructed with approximately 50 nm resolution. As an application to practical materials, a sulfur polymer material was measured in the range of 2.465 to 2.500 keV including the sulfur K absorption edge, and the phase and absorption images were successfully reconstructed and the nanoscale absorption/phase spectra were derived from images at multiple energies. In 3 GeV synchrotron radiation facilities with a low-emittance storage ring, the use of the present system will allow the visualization on the nanoscale of the chemical states of various light elements that play important roles in materials science, biology and environmental science.

Immuno-hyperthermia effected by antibody-conjugated nanoparticles selectively targets and eradicates individual cancer cells

Hyperthermia has been used for cancer therapy for a long period of time, but has shown limited clinical efficacy. Induction-heating hyperthermia using the combination of magnetic nanoparticles (MNPs) and an alternating magnetic field (AMF), termed magnetic hyperthermia (MHT), has previously shown efficacy in an orthotopic mouse model of disseminated gastric cancer. In the present study, superparamagnetic iron oxide nanoparticles (SPIONs), a type of MNP, were conjugated with an anti-HER2 antibody, trastuzumab and termed anti-HER2-antibody-linked SPION nanoparticles (anti-HER2 SPIONs). Anti-HER2 SPIONs selectively targeted HER2-expressing cancer cells co-cultured along with normal fibroblasts and HER2-negative cancer cells and caused apoptosis only in the HER2-expressing individual cancer cells. The results of the present study show proof-of-concept of a novel hyperthermia technology, immuno-MHT for selective cancer therapy, that targets individual cancer cells.Abbreviations: AMF: alternating magnetic field; DDW: double distilled water; DMEM: Dulbecco's Modified Eagle's; Medium; f: frequency; FBS: fetal bovine serum; FITC: Fluorescein isothiocyanate; GFP: green fluorescent protein; H: amplitude; Hsp: heat shock protein; MHT: magnetic hyperthermia; MNPs: magnetic nanoparticles; PI: propidium iodide; RFP: red fluorescent protein; SPION: superparamagnetic iron oxide (Fe₃O₄) nanoparticle.

SMAD4 Germline Pathogenic Variant-Related Gastric Juvenile Polyposis with Adenocarcinoma Treated with Laparoscopic Total Gastrectomy: A Case Report

BACKGROUND Juvenile polyposis syndrome is an uncommon, autosomal-dominant hereditary disease that is distinguished by multiple polyps in the stomach or intestinal tract. It is associated with a high risk of malignancy. Pathogenic variants in SMAD4 or BMPR1A account for 40% of all cases. CASE REPORT A 49-year-old woman underwent esophagogastroduodenoscopy because of exacerbation of anemia. She had numerous erythematous polyps in most parts of her stomach. Based on biopsy findings, juvenile polyposis syndrome (JPS) was suspected morphologically, but there was no evidence of malignancy. Colonoscopy showed stemmed hyperplastic polyps and an adenoma; video capsule endoscopy revealed no lesions in the small intestine. After preoperative surveillance, laparoscopic total gastrectomy with D1 lymph node dissection was performed to prevent malignant transformation. The pathological diagnosis was juvenile polyp-like polyposis with adenocarcinoma. In addition, a germline pathogenic variant in the SMAD4 gene was detected with genetic testing. CONCLUSIONS JPS can be diagnosed with endoscopy and genetic testing. Further, appropriate surgical management may prevent cancer-related death in patients with this condition.

Hyperthermia generated by magnetic nanoparticles for effective treatment of disseminated peritoneal cancer in an orthotopic nude-mouse model

Magnetic hyperthermia (MHT), which combines magnetic nanoparticles (MNPs) with an alternating magnetic field (AMF), holds promise as a cancer therapy. There have been many studies about hyperthermia, most of which have been performed by direct injection of MNPs into tumor tissues. However, there have been no reports of treating peritoneal disseminated disease with MHT to date. In the present study, we treated peritoneal metastasis of gastric cancer with MHT using superparamagnetic iron oxide (Fe3O4) nanoparticle (SPION) coated with carboxydextran as an MNP, in an orthotopic mouse model mimicking early peritoneal disseminated disease of gastric cancer. SPIONs of an optimal size were intraperitoneally administered, and an AMF (390 kHz, 28 kAm-1) was applied for 10 minutes, four times every three days. Three weeks after the first MHT treatment, the peritoneal metastases were significantly inhibited compared with the AMF-alone group or the untreated-control group. The results of the present study show that MHT can be applied as a new treatment option for disseminated peritoneal gastric cancer.Abbreviations: AMF: alternating magnetic field; Cy1: cytology-positive; DMEM: Dulbecco's Modified Eagle's Medium; FBS: fetal bovine serum; H&E: hematoxylin and eosin; HIPEC: hyperthermic intraperitoneal chemotherapy; MEM: Minimum Essential Medium; MHT: magnetic hyperthermia; MNPs: magnetic nanoparticles; P0: macroscopic peritoneal dissemination; RFP: red fluorescent protein; SPION: superparamagnetic iron oxide (Fe3O4) nanoparticle.

Real-Time Fluorescence Image-Guided Oncolytic Virotherapy for Precise Cancer Treatment

Oncolytic virotherapy is one of the most promising, emerging cancer therapeutics. We generated three types of telomerase-specific replication-competent oncolytic adenovirus: OBP-301; a green fluorescent protein (GFP)-expressing adenovirus, OBP-401; and Killer-Red-armed OBP-301. These oncolytic adenoviruses are driven by the human telomerase reverse transcriptase (hTERT) promoter; therefore, they conditionally replicate preferentially in cancer cells. Fluorescence imaging enables visualization of invasion and metastasis in vivo at the subcellular level; including molecular dynamics of cancer cells, resulting in greater precision therapy. In the present review, we focused on fluorescence imaging applications to develop precision targeting for oncolytic virotherapy. Cell-cycle imaging with the fluorescence ubiquitination cell cycle indicator (FUCCI) demonstrated that combination therapy of an oncolytic adenovirus and a cytotoxic agent could precisely target quiescent, chemoresistant cancer stem cells (CSCs) based on decoying the cancer cells to cycle to S-phase by viral treatment, thereby rendering them chemosensitive. Non-invasive fluorescence imaging demonstrated that complete tumor resection with a precise margin, preservation of function, and prevention of distant metastasis, was achieved with fluorescence-guided surgery (FGS) with a GFP-reporter adenovirus. A combination of fluorescence imaging and laser ablation using a KillerRed-protein reporter adenovirus resulted in effective photodynamic cancer therapy (PDT). Thus, imaging technology and the designer oncolytic adenoviruses may have clinical potential for precise cancer targeting by indicating the optimal time for administering therapeutic agents; accurate surgical guidance for complete resection of tumors; and precise targeted cancer-specific photosensitization.

High-speed rotating device for X-ray tomography with 10 ms temporal resolution

The temporal resolution of X-ray tomography, using a synchrotron radiation X-ray source, has been improved to millisecond order in recent years. However, the sample must be rotated at a speed of more than a few thousand revolutions per minute, which makes it difficult to control the environment around the sample. In this study, a high-speed rotation device has been developed, comprising two synchronized coaxial motors movable along the direction of the axis, which can stretch or compress the rotating sample. Using this device, tomograms of breaking rubber were successfully obtained at a temporal resolution of 10 ms.

Visualization of epithelial-mesenchymal transition in an inflammatory microenvironment-colorectal cancer network

Epithelial-mesenchymal transition (EMT) is a biological process by which epithelial cells acquire mesenchymal characteristics. In malignant tumors, EMT is crucial for acquisition of a mesenchymal phenotype with invasive and metastatic properties, leading to tumor progression. An inflammatory microenvironment is thought to be responsible for the development and progression of colorectal cancer (CRC); however, the precise role of inflammatory microenvironments in EMT-related CRC progression remains unclear. Here, we show the spatiotemporal visualization of CRC cells undergoing EMT using a fluorescence-guided EMT imaging system in which the mesenchymal vimentin promoter drives red fluorescent protein (RFP) expression. An inflammatory microenvironment including TNF-α, IL-1β, and cytokine-secreting inflammatory macrophages induced RFP expression in association with the EMT phenotype in CRC cells. In vivo experiments further demonstrated the distribution of RFP-positive CRC cells in rectal and metastatic tumors. Our data suggest that the EMT imaging system described here is a powerful tool for monitoring EMT in inflammatory microenvironment-CRC networks.

Study of twice-weekly injections of Teriparatide by comparing efficacy with once-weekly injections in osteoporosis patients: the TWICE study

A 48-week, multicenter, randomized, double-blind, double-dummy, active-controlled, non-inferiority trial (the TWICE study) conducted in Japanese primary osteoporosis patients with a high risk of fractures demonstrated that a 28.2-μg twice-weekly regimen of teriparatide can provide comparable efficacy to a 56.5-μg once-weekly regimen of teriparatide, while also improving safety.

INTRODUCTION

While a 56.5-μg once-weekly regimen of teriparatide has high efficacy for osteoporosis, treatment continuation rates are low, with one of the major causes being adverse drug reactions such as nausea or vomiting. The TWICE study was therefore conducted to investigate whether a twice-weekly regimen with 28.2-μg teriparatide can provide comparable efficacy to the 56.5-μg once-weekly regimen while improving safety.

METHODS

A 48-week, multicenter, randomized, double-blind, double-dummy, active-controlled, non-inferiority trial was conducted in Japan. Patients with primary osteoporosis aged ≥ 65 years at high risk of fractures (n = 553) were randomly allocated to the 28.2-μg twice-weekly group (n = 277) or the 56.5-μg once-weekly group (n = 276). The primary endpoint was the percentage change in lumbar spine (L2-L4) bone mineral density (BMD) at final follow-up.

RESULTS

The percentage changes in lumbar spine (L2-L4) BMD at final follow-up in the 28.2-μg twice-weekly and 56.5-μg once-weekly groups were 7.3% and 5.9%, respectively; the difference (95% confidence interval [CI]) in percentage change was 1.3% (0.400-2.283%). Since the lower limit of the 95% CI was above the pre-specified non-inferiority margin (- 1.6%), non-inferiority of the 28.2-μg twice-weekly group was demonstrated. Adverse drug reactions were significantly less frequent in the 28.2-μg twice-weekly group (39.7% vs 56.2%; p < 0.01); the incidence of major adverse drug reactions was lower, and the number of subjects who discontinued due to adverse drug reactions was less in the 28.2-μg twice-weekly group.

CONCLUSIONS

A 28.2-μg twice-weekly regimen of teriparatide can provide comparable efficacy to a 56.5-μg once-weekly regimen while improving safety.

CLINICAL TRIAL REGISTRATION

JapicCTI-163477 .

Abstract 4852: Boosting immunity against pancreatic cancer by OBP-702 (Pfifteloxin), telomerase-specific replicative adenovirus armed with wild-type p53 gene

Background: Pancreatic ductal adenocarcinoma (PDAC) is the most lethal disease with a 5-year survival rate of less than 10%. Although immune checkpoint blockade has recently emerged as a novel antitumor therapy, PDAC is less sensitive to immunotherapy due to small number of tumor-infiltrating T cells. Recently, oncolytic virotherapy has been shown to stimulate the immune system as an immunogenic antitumor therapy. Activation of p53 has been also known to enhance antitumor immunity. In this study, we investigated the potential of telomerases-specific p53-expressing oncolytic adenovirus (OBP-702, Pfifeteloxin) for inducing the immunogenic cell death in PDAC cells.

Methods: OBP-702 (Pfifteloxin) is a telomerase-specific oncolytic adenovirus, in which the human telomerase reverse transcriptase (hTERT) promoter drives the expression of the viral E1 gene for tumor-specific replication, that expresses the wild-type p53 by inserting the human p53 cDNA at the deleted E3. OBP-301 (Telomelysin) is an original telomerase-specific adenovirus lacking p53. OBP-502 is an RGD mutant fiber-containing OBP-301. We used 4 human PDAC cell lines (MIA PaCa-2, Capan-1, BxPC-3, Panc-1) and mouse PDAC cell line (Pan02). In vitro antitumor effect of these viruses was evaluated using a XTT assay. The molecular mechanism of virus-mediated cell death was investigated by western blot analysis. The virus-induced immunogenic cell death was assessed by analyzing the level of extracellular ATP and high-mobility group box protein B1 (HMGB1) using ELISA assay. The comparative in vivo antitumor efficacy was also investigated using a syngeneic Pan02 subcutaneous tumor model.

Results: Telomerase-specific oncolytic adenoviruses induced the antitumor effect in all PDAC cells in a dose-dependent manner. The antitumor effect of OBP-702 was superior to that of OBP-301 or OBP-502. OBP-301 and OBP-502 mainly induced autophagy, whereas OBP-702 induced autophagy and apoptosis at 72 h after infection. The concentration of extracellular ATP and HMGB1 was significantly increased in OBP-702-infected PDAC cells compared to OBP-301- or OBP-502-infected cells at 24 and 48 h after infection. In mice carrying subcutaneous Pan02 murine PDAC tumors, intratumoral injection of OBP-702 resulted in a significant inhibition of tumor growth. Moreover, the number of tumor-infiltrating CD8+ T cells was significantly increased in OBP-702-treated groups compared to mock-treated group.

Conclusion: Our data suggest that telomerases-specific p53-expressing oncolytic adenovirus OBP-702 (Pfifteloxin) induces profound immunogenic cell death to boost the immune responses in PDAC. Clinical trials with OBP-702 and immune checkpoint inhibitors for PDAC are warranted.

Citation Format: Hiroyuki Araki, Hiroshi Tazawa, Takuro Fushimi, Takeyoshi Nishiyama, Satotu Kikuchi, Shinji Kuroda, Ryuichi Yoshida, Hiroyuki Kishimoto, Masahiko Nishizaki, Yasuo Urata, Shunsuke Kagawa, Toshiyoshi Fujiwara. Boosting immunity against pancreatic cancer by OBP-702 (Pfifteloxin), telomerase-specific replicative adenovirus armed with wild-type p53 gene [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4852.

Abstract 4330: Activation of AZIN1 RNA editing facilitates and promotes invasive potential of cancer associated fibroblasts in colorectal cancer

Colorectal cancer (CRC) is a common malignancy worldwide and remains the second leading cause of cancer-related deaths in Western countries. Emerging evidence demonstrates that such lifestyle choices profoundly impact various epigenetic modifications, and lead to cancer.Adenosine-to-inosine (A-to-I) RNA editing is an epigenetic modification mediated by Adenosine Deaminases that act on the RNA (ADAR), and has recently been discovered to be dysregulated in human cancers. However, the clinical significance and the functional role of RNA editing in cancer-associated fibroblasts (CAFs) remains unclear. By systematically analyzing a large cohort of 627 CRC specimens, we investigated the expression pattern of ADAR1 and the its biological significance on the antizyme inhibitor 1(AZIN1)RNA editing levels, which is one of the most frequently edited genes in cancers. Both ADAR1 expression and AZIN1RNA editing levels were significantly elevated in CRC tissues vs. normal mucosa, and these findings correlated with the increased expression of mesenchymal markers, Vimentin (ρ=0.44) and Fibroblast activation protein (ρ=0.38). ADAR1 was specifically upregulated in consensus molecular subtype 4 (CMS4) CRCs, which have mesenchymal characteristics and associate with poor prognosis.Intriguingly, ADAR1 was overexpressed in both cancer cells and fibroblasts from cancerous lesions. We next assessed whether cancer cells can promote ADAR1 expression and enhance AZIN1RNA editing in fibroblasts. Fibroblasts were cultured in the conditioned medium (CM) derived from CRC cells. Fibroblasts cultured with such CM expressed ADAR1 at significantly higher levels when compared to controls. Likewise, the overexpression of ADAR1 was associated with corresponding increase in AZIN1RNA editing. Overexpression of edited AZIN1RNA enhanced invasiveness of fibroblasts relative to wild-type AZIN1(p=0.0079).Previously the oncogene, ODC, was identified as a downstream target of edited AZIN1. The overexpression of edited AZIN1RNA resulted in upregulation of ODC protein in fibroblasts, confirming that edited AZIN1RNA stabilizes ODC more effectively than its wild-type counterpart in fibroblasts. In the previous study, ODC was reported to be the promoter of invasive potential in fibroblasts. Our results suggest that edited AZIN1RNA may promote invasion of fibroblasts via accumulation of ODC.This study is the first to investigate the clinical significance of ADAR1 expression and the degree of AZIN1RNA editing in colorectal CAFs, along with the determination the functional role of AZIN1RNA editing in this malignancy. Taken together, our study suggests that overexpression of ADAR1 in cancer lesion promotes malignant potential in CRC. We present novel evidence that ADAR1 is overexpressed in fibroblasts and may facilitate invasive potential in cancerous lesions in CRC microenvironment.

Citation Format: Sho Takeda, Kunitoshi Shigeyasu, Yoshinaga Okugawa, Kazuhiro Yoshida, Yoshiko Mori, Shuya Yano, Kazuhiro Noma, Yuzo Umeda, Yoshitaka Kondo, Hiroyuki Kishimoto, Fuminori Teraishi, Hiroshi Tazawa, Shunsuke Kagawa, Ajay Goel, Toshiyoshi Fujiwara. Activation of AZIN1 RNA editing facilitates and promotes invasive potential of cancer associated fibroblasts in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4330.

Abstract 4823: Elimination of invasive pancreatic cancer cells by p53-activating oncolytic virotherapy as novel precision medicine

Background: Pancreatic ductal adenocarcinoma (PDAC) is the most lethal disease due to early onset of local recurrence and distant metastasis. Invasive PDAC cells are the main causes of recurrence and metastasis after curative surgery. The precision medicine based on the genetic alterations in the KRAS, p53, CDKN2A, and SMAD4 genes has been recently expected as a promising strategy for the treatment of PDAC patients; however, therapeutic strategy for targeting these genetic alterations in PDAC has not been developed yet. To eliminate p53-inactivated malignant tumor cells, we have developed telomerase-specific replication-competent oncolytic adenovirus OBP-702 that expresses tumor suppressor p53. In this study, we investigated the in vitro and in vivo therapeutic potential of OBP-702 against PDAC cells.

Methods: Four human PDAC cell lines (Capan-1, MIA PaCa-2, BxPC-3, Panc-1) with different invasive property were used. The therapeutic effect of OBP-702 and p53-nonexpressing OBP-301 was assessed in the proliferation, migration and invasion abilities of PDAC cells. The underlying mechanism of virus-mediated therapeutic effect was analyzed on the modulation of p53 signaling and KRAS-MAPK signaling. Subcutaneous and orthotopic BxPC-3 xenograft tumor models were used to evaluate the virus-mediated antitumor efficacy.

Results: OBP-702 induced antitumor effect in association with autophagy and apoptosis more strongly compared to OBP-301 in PDAC cells through activation of p53 expression. OBP-702 inhibited the migration and invasion properties of PDAC cells more efficiently compared to OBP-301 through suppression of KRAS-ERK1/2 signaling, even when ERK signaling is enhanced by nerves and neurosecretory factors. Similar with OBP-702, treatment with ERK1/2 inhibitor or siRNA significantly reduced migration and invasion abilities. Moreover, OBP-702 significantly suppressed tumor growth in subcutaneous and orthotopic BxPC-3 xenograft tumor models.

Conclusions: Our results suggest that OBP-702 is a promising antitumor reagent to eliminate invasive PDAC cells through p53 activation and ERK suppression. Further clinical study is warranted to evaluate the safety and feasibility of OBP-702 as a novel precision medicine based on genetic alterations in KRAS and p53 genes.

Citation Format: Takuro Fushimi, Hiroshi Tazawa, Takeshi Koujima, Hiroyuki Araki, Takeyoshi Nishiyama, Satoru Kikuchi, Shinji Kuroda, Ryuichi Yoshida, Hiroyuki Kishimoto, Masahiko Nishizaki, Yasuo Urata, Shunsuke Kagawa, Toshiyoshi Fujiwara. Elimination of invasive pancreatic cancer cells by p53-activating oncolytic virotherapy as novel precision medicine [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4823.

Oxygen surface exchange properties and surface segregation behavior of nanostructured La0.6Sr0.4Co0.2Fe0.8O3-δ thin film cathodes

Cathode materials with highly reactive surfaces and long-term stability are required to achieve high-performance solid oxide fuel cells (SOFCs). In this study, a promising cathode material, La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF), was prepared as a nanostructured thin film using pulsed laser deposition (PLD) on gadolinia-doped ceria (GDC)-buffered YSZ single crystal substrates having (100) and (111) orientations. Characterization revealed intrinsic differences among the as-grown LSCF thin films in terms of dominant crystalline orientation and nanostructure depending on GDC preparation as well as the YSZ substrate orientation. Evaluation of the oxygen exchange properties using the isotope exchange depth profile method revealed that LSCF thin films grown on (111) GDC/YSZ exhibited higher values of the apparent surface exchange coefficient compared to LSCF thin films grown on (100) GDC/YSZ. However, when subjected to long-term annealing at high temperatures, the former exhibited a stronger tendency to surface segregation as compared to the latter. These behaviors are correlated with the intrinsic properties of LSCF thin films, including the nanostructure, the possible effects attributed to SrO activity, and the stability of perovskite surfaces which would drive surface segregation. These results have implications for tailoring the performance of cathode thin films by understanding the dependence of oxygen exchange properties and surface segregation on driving forces such as surface chemistry and nanostructure.

Physical Frailty and Risk of Needing Long-Term Care in Community-Dwelling Older Adults: a 6-Year Prospective Study in Japan

OBJECTIVE

To examine the association between physical frailty and risk of needing long-term care, and compare the predictive value and clinical usefulness of a simple frailty scale (FRAIL) with that of the original Cardiovascular Health Study (CHS) criteria.

DESIGN AND SETTING

A 6-year prospective cohort study of community-dwelling older adults in a west Japanese suburban town.

PARTICIPANTS

1,554 older adults aged 65 years and over who were initially free of long-term care needs at baseline.

MEASUREMENTS

Physical frailty was defined by the CHS criteria and the FRAIL scale. The onset of needing long-term care was ascertained using national records of certification of long-term care needs. Cox proportional hazard models were used to estimate the association between physical frailty and risk of needing long-term care. Decision curve analysis was performed to compare the clinical usefulness of the two physical frailty criteria.

RESULTS

During a median follow-up of 5.8 years, 244 were ascertained as needing long-term care. Baseline physical frailty was significantly associated with elevated risk of needing long-term care, with a multivariable-adjusted hazard ratio (HR) of 2.00 (95% confidence interval [CI], 1.32-3.02) for being frail and 1.50 (95% CI, 1.10-2.03) for being pre-frail as defined by the CHS criteria, compared with being robust (p for trend = 0.001). Similar results were found for physical frailty defined by the FRAIL scale, with a multivariable-adjusted HR (95% CIs) of 2.11 (1.25-3.56) for being frail and 1.73 (1.28-2.35) for being pre-frail vs. being robust (p for trend < 0.001). The two physical frailty criteria had similar net benefits in identifying individuals at high risk for needing long-term care.

CONCLUSIONS

Physical frailty is significantly associated with an increased risk of needing long-term care in community-dwelling older adults in Japan. Compared with the original CHS criteria, the simple FRAIL scale has comparable predictive value and clinical usefulness for identifying individuals at risk for needing long-term care.

Activation of AZIN1 RNA editing is a novel mechanism that promotes invasive potential of cancer-associated fibroblasts in colorectal cancer

Adenosine-to-inosine (A-to-I) RNA editing is a recently described epigenetic modification, which is believed to constitute a key oncogenic mechanism in human cancers. However, its functional role in cancer-associated fibroblasts (CAFs) within the tumor microenvironment (TME) and its clinical significance remains unclear. Herein, we systematically analyzed a large cohort of 627 colorectal cancer (CRC) specimens, and investigated the expression pattern of ADAR1 and its biological significance on the antizyme inhibitor 1 (AZIN1) RNA editing levels. Both ADAR1 expression and AZIN1 RNA editing levels were significantly elevated in CRC tissues vs. normal mucosa, and these findings correlated with the increased expression of mesenchymal markers, Vimentin (ρ = 0.44) and Fibroblast activation protein (ρ = 0.38). Intriguingly, ADAR1 expression was specifically upregulated in both cancer cells and fibroblasts from cancerous lesions. Conditioned medium from cancer cells led to induction of ADAR1 expression and activation of AZIN1 RNA editing in fibroblasts (p < 0.05). Additionally, edited AZIN1 enhanced the invasive potential of fibroblasts. In conclusion, we provide novel evidence that hyper-editing of AZIN1 enhances the invasive potential of CAFs within the TME in colon and is an important predictor of tumor invasiveness in CRC.

Long-term oral bisphosphonates delay healing after tooth extraction: a single institutional prospective study

Tooth extraction in patients receiving bisphosphonates is thought to be a risk factor for osteonecrosis of the jaw (ONJ); however, ONJ did not develop, even when tooth extraction was performed with continued oral bisphosphonate therapy. A drug holiday from bisphosphonates before tooth extraction may not be necessary.

INTRODUCTION

It is controversial whether bisphosphonate withdrawal is necessary prior to invasive procedures such as tooth extraction in order to prevent bisphosphonate-related osteonecrosis of the jaw (BRONJ). This study aimed to evaluate the clinical safety of continuing oral bisphosphonate therapy in patients undergoing tooth extraction.

METHODS

We prospectively enrolled 132 patients (20 men, 112 women) who were receiving oral bisphosphonates for the prevention or treatment of osteoporosis and required tooth extraction. All patients were managed using an identical protocol, which included preoperative antibiotic prophylaxis and did not necessarily require complete wound closure. The patients were classified into groups according to the duration of bisphosphonate administration: < 2 years (n = 51), 2-5 years (n = 41), 5-10 years (n = 28), and > 10 years (n = 12). The groups were compared regarding the time taken for the extraction socket to heal, and the occurrence of BRONJ. Follow-up duration was at least 3 months.

RESULTS

A total of 274 teeth were removed. Long-term oral bisphosphonate therapy for > 5 years significantly delayed the healing of the extraction socket in comparison with administration for < 5 years; however, BRONJ did not develop in any group. There was no prolongation of wound healing due to systemic risk factors such as glucocorticoid administration and diabetes mellitus. There were no adverse skeletal events such as bone fracture.

CONCLUSIONS

Patients who underwent tooth extraction with continued oral bisphosphonate therapy showed delayed healing of the extraction socket as the cumulative administration period prolonged, but BRONJ did not develop.

A large-aperture high-sensitivity avalanche image intensifier panel

A large-aperture high-sensitivity image intensifier panel that consists of an avalanche photodiode array and a light-emitting diode array is presented. The device has 40% quantum efficiency, over 10⁴ optical gain, and 80-ns time resolution. The aperture size of the device is 20 cm, and with the current manufacturing process, it can be scaled to arbitrarily larger sizes. The device can intensify the light from a single particle scintillation emission to an eye-visible bright flash. The image resolution of the device is currently limited by the size of the avalanche photodiode that is 2 mm, although it can be scaled to smaller sizes in the near future. The image intensifier is operated at a small voltage, typically +57 V. The device can be applied to various applications, such as scintillation imaging, night vision cameras, and an image converter from non-visible light (such as infrared or ultraviolet) to visible light.

Integrated fluorescent cytology with nano-biologics in peritoneally disseminated gastric cancer

Gastric cancer patients positive for peritoneal cytology are at increased risk of tumor recurrence, but although a certain proportion of cytology‐positive patients relapse rapidly with aggressive progression, others survive longer with conventional chemotherapies. This heterogeneity makes it difficult to stratify patients for more intensive therapy and poses a substantial challenge for the implementation of precision medicine. We developed a new approach to identify biologically malignant subpopulations in cytology‐positive gastric cancer patients, using a green fluorescent protein (GFP)‐expressing attenuated adenovirus in which the telomerase promoter regulates viral replication (TelomeScan, OBP‐401). The fluorescence emitted from TelomeScan‐positive cells was successfully quantified using a multi‐mode microplate reader. We then analyzed clinical peritoneal washes obtained from 68 gastric cancer patients and found that patients positive for TelomeScan had a significantly worse prognosis. In 21 cytology‐positive patients, the median survival time of those who were TelomeScan positive (235 days) was significantly shorter than that for those who were TelomeScan negative (671 days; P = 0.0062). This fluorescent virus‐guided cytology detects biologically malignant cancer cells from the peritoneal washes of gastric cancer patients and may thus be useful for both therapy stratification and precision medicine approaches based on genetic profiling of disseminated cells.

Abstract 4807: Novel theranostic strategy against peritoneal metastasis of scirrhous gastric cancer: Combination with fluorescence oncolytic adenovirus and chemotherapy

Background: Scirrhous gastric cancer (SGC), which is characterized by poorly differentiated tumor cells that diffusely infiltrate the gastric wall, accounts for 10% of all gastric cancers, and often causes peritoneal metastasis. The prognosis of SGC patients is very poor, because no effective treatment to overcome peritoneal metastasis of SGC has been developed yet. In recent years, intraperitoneal (i.p.) administration of paclitaxel (PTX) has been focused against various cancers with peritoneal metastasis and has been also attempted to SGC, but regrettably its effect is not satisfactory. Therefore, a novel therapeutic strategy is required for the treatment of SGC with peritoneal metastasis.

Methods: We previously developed a telomerase-specific replication-competent adenovirus, OBP-401 (TelomeScan), which can replicate only within the tumor cells selectively and express green fluorescent protein (GFP). OBP-401 infection also induces tumor-specific cell death in monotherapy and combination therapy with chemotherapy. In this study, we assessed the in vitro and in vivo antitumor effects of combination therapy with OBP-401 and chemotherapeutic agent, paclitaxel (PTX), in human SGC cell lines (GCIY and KATO III) and SGC xenograft peritoneal metastasis model, respectively. The molecular mechanism underlying synergistic effect of the combination therapy was evaluated in aspects of cell death and replication efficiency of OBP-401.

Results: SGC cells were visualized as GFP-positive cells selectively by the infection of OBP-401, whereas normal fibroblast cells were not. OBP-401 synergistically suppressed the viability of human SGC cells in combination with PTX. OBP-401 monotherapy dose-dependently induced apoptosis and autophagy, although PTX monotherapy induced only apoptosis. The combination therapy induced autophagy at a lower concentration of OBP-401. In the time-lapse imaging of treatment, the combination therapy enhanced the replication efficiency of OBP-401 in tumor cells. Moreover, the combination therapy with i.p. administration of OBP-401 and PTX also significantly inhibited the tumor growth of peritoneal metastasis, as compared to monotherapy.

Conclusion: These results suggest that OBP-401 has a promising potential to detect peritoneal micrometastasis of SGC intraoperatively and the combination therapy with i.p. induction of OBP-401 and PTX would be a novel theranostic strategy for the treatment of SGC with peritoneal metastasis.

Citation Format: Wataru Ishikawa, Satoru Kikuchi, Hiroshi Tazawa, Toshiaki Ohara, Shinji Kuroda, Kazuhiro Noma, Hiroyuki Kishimoto, Masahiko Nishizaki, Yasuo Urata, Shunsuke Kagawa, Toshiyoshi Fujiwara. Novel theranostic strategy against peritoneal metastasis of scirrhous gastric cancer: Combination with fluorescence oncolytic adenovirus and chemotherapy [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 4807.

Abstract 1101: Visualization of epithelial-mesenchymal transition in inflammatory microenvironment-colorectal cancer network in vitro and in vivo

Background: Epithelial-mesenchymal transition (EMT) is a biologic process by which epithelial cancer cells acquire mesenchymal phenotype with malignant properties for invasion and metastasis, leading to poor prognosis. Inflammatory microenvironment has been shown to be responsible for the development and progression of colorectal cancer (CRC). However, the precise role of inflammatory microenvironment in the EMT-related tumor progression remains unclear because EMT network is regulated by complex crosstalk between tumor and normal cells. In this study, we developed a fluorescence-guided live-cell imaging system for the spatiotemporal visualization of EMT state, and assessed the in vitro and in vivo visualization of EMT state in human CRC cells under the inflammatory microenvironment.

Methods: We used two human CRC cell lines, HCT116 and RKO. The promoter of mesenchymal marker vimentin was used for inducing the EMT-dependent red fluorescence protein (RFP) expression in human CRC cells. The RFP expression was quantitatively analyzed to evaluate its association with EMT-related markers and malignant phenotype. Inflammatory cytokines, IL-1β (1 ng/ml) and TNF-α (20 ng/ml), or co-culture with inflammatory mouse macrophage cell line RAW264.7 stimulated by lipopolysaccharide (LPS) (200 ng/mL) were used as an inflammatory microenvironment. Biodistribution of EMT cells was analyzed using in vivo experiments with primary and metastatic CRC xenograft tumors.

Results: Inflammatory cytokines reversely induced the RFP expression in association with EMT-related malignant phenotype, such as morphologic change, EMT marker modulation, and invasion ability, in HCT116 and RKO cells. Co-culture with LPS-stimulated inflammatory macrophages also induced the RFP expression by secreting inflammatory cytokines. In vivo experiments revealed that EMT cells were detected within tumor tissues at colon, liver and peritoneum.

Conclusions: Our results suggest that inflammatory microenvironment has a great potential to induce EMT program in CRC cells. This fluorescence-guided EMT imaging system is a useful tool for monitoring the EMT state in the inflammation microenvironment-CRC network in vitro and in vivo.

Citation Format: Hiroshi Tazawa, Takeshi Ieda, Shuya Yano, Satoru Kikuchi, Shinji Kuroda, Toshiaki Ohara, Kazuhiro Noma, Hiroyuki Kishimoto, Masahiko Nishizaki, Shunsuke Kagawa, Takashi Saitou, Takeshi Imamura, Toshiyoshi Fujiwara. Visualization of epithelial-mesenchymal transition in inflammatory microenvironment-colorectal cancer network in vitro and in vivo [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 1101.

Abstract 5915: Overexpression of tumor suppressor p53 gene by oncolytic adenovirus boosts immune responses in human pancreatic ductal adenocarcinoma cells

Background: Pancreatic ductal adenocarcinoma (PDAC) is the worst prognosis disease with an overall 5-year survival rate of less than 5%. Although immune checkpoint therapy has been emerged as a novel antitumor therapy, PDAC is less sensitive to immunotherapy due to small number of infiltrating T cells. Recently, oncolytic virotherapy has been shown to promote intratumoral T cell infiltration as an immunogenic antitumor therapy. In the current study, we explored whether overexpression of the wild-type p53 tumor suppressor gene could synergize with oncolysis for induction of immunogenic cell death in human PDAC cells.

Methods: OBP-702 is a tumor-specific replication-competent oncolytic adenovirus, in which the hTERT promoter drives the expression of the viral E1A and E1B genes for tumor-specific viral replication and the Egr-1 promoter induces wild-type p53 expression. We used 4 PDAC cell lines (MIA PaCa-2, Capan-1, BxPC-3, Panc-1). Molecular mechanisms of OBP-702-mediated cell death was investigated. Migration and invasion properties were assessed using transwell chamber assay. In addition, virus-induced immunogenic cell death was assessed by analyzing the level of extracellular ATP and high-mobility group box protein B1 (HMGB1). In vivo antitumor effect of OBP-702 was assessed using an orthotopic BxPC-3 xenograft tumor model.

Results: At 72 hours after virus infection, OBP-702 induced profound antitumor effect in all human PDAC cells. OBP-702 induced autophagy- and apoptosis-related cell deaths. In migration and invasion assays, MIA Paca-2 and Capan-1 cells were low-invasive type, and Panc-1 and BxPC-3 cells were high-invasive type. OBP-702 inhibited migration and invasion properties of high-invasive type PDAC cells At 24 and 48 hours after virus infection, the secretion of ATP was significantly higher in OBP-702-infected PDAC cells compared to p53-null virus-infected cells. Moreover, OBP-702 significantly induced the higher amount of extracellular HMGB1 in all PDAC cells. Finally, OBP-702 significantly suppressed tumor growth in an orthotopic BxPC-3 xenograft tumor model compared to p53-null virus.

Conclusions: Our data suggest that oncolytic adenovirus-mediated p53 overexpression induces more profound immunogenic cell death to boost the immune responses in PDAC. This additional immunological function of p53 is quite attractive and warrants clinical trials combined with immune checkpoint inhibitors.

Citation Format: Hiroyuki Araki, Hiroshi Tazawa, Takeshi Ieda, Takuro Fushimi, Shinji Kuroda, Ryuichi Yoshida, Hiroyuki Kishimoto, Masahiko Nishizaki, Yasuo Urata, Shunsuke Kagawa, Toshiyoshi Fujiwara. Overexpression of tumor suppressor p53 gene by oncolytic adenovirus boosts immune responses in human pancreatic ductal adenocarcinoma cells [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 5915.

Clinical outcomes of women with ovarian metastases of colorectal cancer treated with oophorectomy with respect to their somatic mutation profiles

We clarified the clinical prevalence of ovarian metastases from colorectal cancers (CRCs) in 296 female patients with CRC and evaluated clinical outcomes with relation to their mutational profiles, such as BRAF/KRAS mutation and microsatellite instability (MSI) status. The female CRCs were categorised into three subsets: CRCs with ovarian metastases [6.4% (n = 19), 5-year overall survival (OS) = 24.7%], CRCs with extra-ovarian metastases only [32.4% (n = 96), 5-year OS = 34.5%] and CRCs without any recurrence or metastasis [61.2% (n = 181), 5-year OS = 91.3%]. All patients with ovarian metastases underwent oophorectomy; of these, 9 who received preoperative chemotherapy had measurable metastases to extra-ovarian sites and the ovaries. Although 5 of 9 (56%) achieved partial response or complete response at extra-ovarian sites, no patient archived objective response at ovarian sites. Regarding the mutation profiles, in CRCs with extra-ovarian metastases only, the median survival time (MST) after initial treatments to progression to stage IV or recurrence was 13 [95% confidence interval (CI): 7–16 months] in BRAF-mutant and 34 months (95% CI: 22–58 months) in BRAF wild-type (P = 0.0033). Although ovarian metastases demonstrated poor response to systemic chemotherapy in CRCs with ovarian metastases, the MST after initial treatments to progression to stage IV or recurrence was 22 (95% CI: 21–25 months) in BRAF-mutant and 38 months (95% CI: 24–42 months) in BRAF wild-type (P = 0.0398). The outcomes of patients with ovarian metastases could be improved by oophorectomy regardless of their mutation profiles.

Fluorescence-guided surgery of a highly-metastatic variant of human triple-negative breast cancer targeted with a cancer-specific GFP adenovirus prevents recurrence

We have previously developed a genetically-engineered GFP-expressing telomerase-dependent adenovirus, OBP-401, which can selectively illuminate cancer cells. In the present report, we demonstrate that targeting a triple-negative high-invasive human breast cancer, orthotopically-growing in nude mice, with OBP-401 enables curative fluorescence-guided surgery (FGS). OBP-401 enabled complete resection and prevented local recurrence and greatly inhibited lymph-node metastasis due to the ability of the virus to selectively label and subsequently kill cancer cells. In contrast, residual breast cancer cells become more aggressive after bright (white)-light surgery (BLS). OBP-401-based FGS also improved the overall survival compared with conventional BLS. Thus, metastasis from a highly-aggressive triple-negative breast cancer can be prevented by FGS in a clinically-relevant mouse model.

Tumor-targeting adenovirus OBP-401 inhibits primary and metastatic tumor growth of triple-negative breast cancer in orthotopic nude-mouse models

Our laboratory previously developed a highly-invasive, triple-negative breast cancer (TNBC) variant using serial orthotopic implantation of the human MDA-MB-231 cell line in nude mice. The isolated variant was highly-invasive in the mammary gland and lymphatic channels and metastasized to lymph nodes in 10 of 12 mice compared to 2 of 12 of the parental cell line. In the present study, the tumor-selective telomerase dependent OBP-401 adenovirus was injected intratumorally (i.t.) (1 × 10⁸ PFU) when the high-metastatic MDA-MB-231 primary tumor expressing red fluorescent protein (MDA-MB-231-RFP) reached approximately 500 mm³ (diameter; 10 mm). The mock-infected orthotopic primary tumor grew rapidly. After i.t. OBP-401 injection, the growth of the orthotopic tumors was arrested. Six weeks after implantation, the fluorescent area and fluorescence intensity showed no increase from the beginning of treatment. OBP-401 was then injected into high-metastatic MDA-MB-231-RFP primary orthotopic tumor growing in mice which already had developed metastasis within lymphatic ducts. All 7 of 7 control mice subsequently developed lymph node metastasis. In contrast, none of 7 mice which received OBP-401 had lymph node metastasis. Seven of 7 control mice also had gross lung metastasis. In contrast, none of the 7 mice which received OBP-401 had gross lung metastasis. Confocal laser microscopy imaging demonstrated that all control mice had diffuse lung metastases. In contrast, all 7 mice which received OBP-401 only had a few metastatic cells in the lung. OBP-401 treatment significantly extended survival of the treated mice.

Physical Frailty Is Associated with Longitudinal Decline in Global Cognitive Function in Non-Demented Older Adults: A Prospective Study

OBJECTIVES

To assess the relationship between physical frailty and subsequent decline in global cognitive function in the non-demented elderly.

DESIGN AND SETTING

A prospective population-based study in a west Japanese suburban town, with two-year follow-up.

PARTICIPANTS

Community-dwellers aged 65 and older without placement in long-term care, and not having a history of dementia, Parkinson's disease and depression at baseline, who participated in the cohort of the Sasaguri Genkimon Study and underwent follow-up assessments two years later (N = 1,045).

MEASUREMENTS

Global cognitive function was assessed using the Montreal Cognitive Assessment (MoCA). Physical frailty was identified according to the following five components: weight loss, low grip strength, exhaustion, slow gait speed and low physical activities. Linear regression models were used to examine associations between baseline frailty status and the MoCA scores at follow-up. Logistic regression models were used to estimate the risk of cognitive decline (defined as at least two points decrease of MoCA score) according to baseline frailty status.

RESULTS

Seven hundred and eight non-demented older adults were included in the final analyses (mean age: 72.6 ± 5.5 years, male 40.3%); 5.8% were frail, and 40.8% were prefrail at baseline. One hundred and fifty nine (22.5%) participants experienced cognitive decline over two years. After adjustment for baseline MoCA scores and all confounders, being frail at baseline was significantly associated with a decline of 1.48 points (95% confidence interval [CI], -2.37 to -0.59) in MoCA scores, as compared with non-frailty. Frail persons were over two times more likely to experience cognitive decline (adjusted odds ratio 2.28; 95% CI, 1.02 to 5.08), compared to non-frail persons.

CONCLUSION

Physical frailty is associated with longitudinal decline in global cognitive function in the non-demented older adults over a period of two years. Physically frail older community-dwellers should be closely monitored for cognitive decline that can be sensitively captured by using the MoCA.

BRAF V600E mutation is a predictive indicator of upfront chemotherapy for stage IV colorectal cancer

In stage IV colorectal cancer (CRC), initial resection of the primary tumor is considered to be an important strategy for improving disease outcome. However, there is no consensus on the timing as to when the surgical intervention of the primary tumor should occur. The present study hypothesizes that genetic profiles in CRC may indicate the appropriate treatment strategies for patients with stage IV CRC, and a cohort of 113 patients with stage IV CRC resected primary lesions at various periods were analyzed for the presence of mutations in the KRAS, exon 2, and BRAF genes, exon 15, and for the microsatellite instability status of the tumor. These data were additionally correlated with various clinicopathological features. Although BRAF-mutant was revealed to be an independent negative prognostic factor in stage IV CRC (HR, 8.42; 95% confidence interval, 2.72–26.02), BRAF-mutant samples exhibited better prognoses if they were treated with chemotherapy prior to tumor resection. Thus, the presence of BRAF mutations provides a compelling rationale for the establishment of intensive upfront chemotherapy to improve survival in stage IV CRC.

Quasielastic neutron scattering study of microscopic dynamics in polybutadiene reinforced with an unsaturated carboxylate

We studied the dynamics of zinc diacrylate (ZDA) reinforced polybutadiene rubber (BR) (ZDA/BR) using the quasielastic neutron scattering technique to determine the effect of concentration of ZDA on polymer dynamics. First, we evaluated the temperature dependence of mean square displacements (〈u²〉) for ZDA/BR with different ZDA volume fractions. 〈u²〉 increased with temperature below 170 K, and we observed no significant ZDA volume fraction dependence. However, it increased more steeply above 170 K, and the value of 〈u²〉 was smaller for the samples with increasing ZDA fraction. To elucidate the origin of the decrease in 〈u²〉 with increasing ZDA content, dynamic scattering laws (S(Q,ω)) were analyzed. An increase in the elastic component, an increase in the mean relaxation time, and a broadening of distribution of relaxation time were observed with the increasing volume fraction of ZDA. In addition, the ZDA volume fraction dependence of the elastic component roughly corresponded to that of elastic modulus, indicating that the elastic component is related to its mechanical strength. Referring to the previously reported static structure of the present ZDA/BR system, a model for the heterogeneous BR dynamics was proposed. This model assumes the coexistence of immobile, mobile, and interfacial constrained mobile regions. It was found to be appropriate for the explanation of the observed dynamics. We proposed that a network-like structure of the BR having a high crosslinking density around ZDA aggregates is mainly responsible for the high elastic modulus of ZDA/BR.

Structure and Mechanical Properties of Polybutadiene Thin Films Bound to Surface-Modified Carbon Interface

The structure and mechanical properties of polybutadiene (PB) films on bare and surface-modified carbon films were examined. There was an interfacial layer of PB near the carbon layer whose density was higher (lower) than that of the bulk material on the hydrophobic (hydrophilic) carbon surface. To glean information about the structure and mechanical properties of PB at the carbon interface, a residual layer (RL) adhering to the carbon surface, which was considered to be a model of "bound rubber layer", was obtained by rinsing the PB film with toluene. The density and thickness of the RLs were identical to those of the interfacial layer of the PB film. In accordance with the change in the density, normal stress of the RLs evaluated by atomic force microscopy was also dependent on the surface free energy: the RLs on the hydrophobic carbon were hard like glass, whereas those on the hydrophilic carbon were soft like rubber. Similarly, the wear test revealed that the RLs on the hydrophilic carbon could be peeled off by scratching under a certain stress, whereas the RLs on the hydrophobic carbons were resistant to scratching.

Therapeutic Cell-Cycle-Decoy Efficacy of a Telomerase-Dependent Adenovirus in an Orthotopic Model of Chemotherapy-Resistant Human Stomach Carcinomatosis Peritonitis Visualized With FUCCI Imaging

We have established an orthotopic nude-mouse model of gastric cancer carcinomatosis peritonitis, a recalcitrant disease in human patients. Human MKN45 poorly-differentiated human gastric cancer cells developed carcinomatosis peritonitis upon orthotopic transplantation in nude mice. The MKN45 cells expressed the fluorescent ubiquitination-based cell cycle indicator (FUCCI) that color codes the phases of the cell cycle. The intra-peritoneal tumors and ascites contained mostly quiescent G₁ /G_o cancer cells visualized as red by FUCCI imaging. Cisplatinum (CDDP) treatment did not reduce bloody ascites, and larger tumors formed in the peritoneal cavity after CDDP treatment in an early-stage carcinomatosis peritonitis orthotopic mouse model. Paclitaxel-treated mice had reduced ascites, but also had large tumor masses in the peritonium after treatment with cancer cells mostly in G₀ /G₁ , visualized by FUCCI red. In contrast, OBP-301 telomerase-dependent adenovirus-treated mice had no ascites and only small tumor nodules consisting of cancer cells mostly in S/G₂ phases in the early-stage carcinomatosis peritonitis model, visualized by FUCCI green. Furthermore, OBP-301 significantly reduced the size of tumors (P < 0.01) and ascites even in a late-stage carcinomatosis peritonitis model. These results suggest that quiescent peritoneally-disseminated gastric cancer cells are resistant to conventional chemotherapy, but OBP-301 significantly reduced the weight of the tumors and increased survival, suggesting clinical potential. J. Cell. Biochem. 118: 3635-3642, 2017. © 2016 Wiley Periodicals, Inc.

Comparison of outcomes between symptomatic and asymptomatic patients with colorectal cancer: a propensity score-matched analysis of surgical invasiveness, medical costs and oncological outcomes

Background and aims

Whether asymptomatic patients with colorectal cancer (CRC) who are treated in hospitals show better outcomes than symptomatic patients with CRC still remains unknown. The aim of this study was to evaluate differences in clinical benefits following treatment in asymptomatic and symptomatic patients with CRC.

Methods

This study was a retrospective cohort analysis with data obtained from records. A cohort of 145 asymptomatic and 123 symptomatic patients who underwent CRC surgery between January 2009 and December 2011 was enrolled. To reduce bias in comparing outcomes, propensity score (PS) analysis was used for matching of patients in the symptomatic and asymptomatic groups based on clinicopathological factors. Surgical invasiveness, medical costs and oncological outcomes were examined by unadjusted and PS-matched analysis.

Results

Tumours in the symptomatic group were more often diagnosed in advanced stages compared with tumours in the asymptomatic group. Therefore, fewer symptomatic group patients underwent minimally invasive surgery. Short-term outcomes, including amount of blood loss, duration of postoperative hospital stay and perioperative medical costs, were significantly better in the asymptomatic group. Although overall survival was significantly better in the asymptomatic group, there was no significant difference between the groups when the patients were adjusted on the basis of PS.

Conclusions

Though this study was limited by the retrospective nature and small sample size, favourable outcomes in asymptomatic patients were due to the higher proportion of patients in this group who were diagnosed with CRC in earlier stages, due to participation in CRC screening programmes.

Abstract 1103: Novel theranostic strategy against scirrhous gastric cancer; combination of chemotherapy and fluorescence oncolytic adenovirus

Background: Gastric cancer is one of the most common cancers worldwide, especially in Eastern Asia. Scirrhous gastric cancer (SGC), which is characterized by poorly differentiated tumor cells that diffusely infiltrate the gastric wall, accounts for 10% of all gastric cancers, and often causes peritoneal metastasis. Peritoneal carcinomatosis shows the worst prognosis among various metastatic patterns. Since it is difficult to detect peritoneal micrometastasis preoperatively or intraoperatively, SGC patients with peritoneal micrometastasis show the recurrence and refractory to conventional systemic chemotherapy after surgery. In recent year, intraperitoneal (i.p.) administration of paclitaxel (PTX) has been shown to have therapeutic effects against ovarian cancer with peritoneal metastasis. However, the effective treatment option to overcome peritoneal metastasis of SGC has not been developed yet, although i.p. administration of some chemotherapeutic agents has been attempted to SGC. Therefore, a novel therapeutic strategy is required for the treatment of peritoneal metastasis of SGC.

Methods: We previously developed a telomerase-dependent replication-selective adenovirus OBP-401 (TelomeScan), which can replicate within the tumor cells selectively and express green fluorescent protein (GFP). Moreover, OBP-401 infection also induces tumor-specific cell death in monotherapy or combination therapy with chemotherapy. In this study, we assessed synergistic effects in combination with novel theranostic agent OBP-401 and chemotherapeutic agent paclitaxel (PTX) using human SGC cell lines (GCIY and KATO III). In vitro experiment, SGC cells and normal human lung fibroblast (NHLF) cells were infected with OBP-401 at various doses. PTX was administrated after 48 hours of virus infection. Twenty-four hours after PTX administration, we evaluated the anti-tumor effect by XTT assay, and analyzed the synergistic effect by CalcuSyn Software.

Results: SGC cells were visualized as GFP-positive cells selectively by the infection of OBP-401, whereas NHLF cells were not visualized with OBP-401. In both SGC cell lines, the suppression of cell viability dose-dependently by administration of OBP-401 or PTX alone was confirmed. OBP-401 synergistically suppressed the viability of SGC cells in combination with PTX as compared to monotherapy.

Conclusions: These results suggest that OBP-401 has a promising potential to detect peritoneal micrometastasis of SGC intraoperatively and combination of OBP-401 and PTX would be a novel theranostic strategy for the treatment of peritoneal metastasis of SGC.

Citation Format: Wataru Ishikawa, Satoru Kikuchi, Hiroshi Tazawa, Shinji Kuroda, Kazuhiro Noma, Hiroyuki Kishimoto, Takeshi Nagasaka, Masahiko Nishizaki, Shunsuke Kagawa, Toshiyoshi Fujiwara. Novel theranostic strategy against scirrhous gastric cancer; combination of chemotherapy and fluorescence oncolytic adenovirus [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1103. doi:10.1158/1538-7445.AM2017-1103

Training system for laparoscopy-assisted distal gastrectomy

PURPOSE

Laparoscopy-assisted distal gastrectomy (LADG) is likely to become a standard procedure for gastric cancer, which highlights the importance of establishing a training system in which even inexperienced surgeons can perform this procedure safely. This study assesses our training system for LADG based on short-term surgical outcomes.

METHODS

We evaluated retrospectively the short-term outcomes of 100 consecutive LADGs with curative D1/D1+ lymph node dissection. Our training system was assessed based on the learning curve of trainees, and factors related to achieving good-quality operations were analyzed statistically.

RESULTS

Overall, postoperative complications developed in 10 patients (10%), and included one case of anastomotic leakage (1%) and one case of pancreatic fistula (1%). The learning curve of the trainees plateaued after 10 operator cases in terms of operation time. The importance of the trainer's position was also confirmed by the result that the operation time was significantly longer when trainees with ≤10 operator cases performed LADG with a trainer as scopist vs. a trainer as the first assistant. Univariate and multivariate analyses revealed that >10 operator cases were the most important factor for achieving good-quality operations.

CONCLUSION

These results show that our current LADG procedure and training system are appropriate and effective.

Abstract 5809: Fluorescence-guided spatiotemporal dynamics of epithelial-mesenchymal transition under inflammatory microenvironment during colorectal cancer progression

Background: Epithelial-mesenchymal transition (EMT) is a biological process, by which epithelial cancer cells acquire mesenchymal phenotype with malignant properties for invasion and metastasis, leading to poor prognosis. Inflammatory microenvironment has been shown to be responsible for the development and progression of colorectal cancer. However, the role of inflammatory microenvironment in the EMT-related tumor progression remains unclear. To explore the relationship between inflammatory microenvironment and EMT, a live imaging system for EMT is a promising strategy on the in vitro and in vivo experiments. In this study, we developed a fluorescence-guided live cell imaging system for the assessment of spatiotemporal dynamics of EMT, and investigated the potential of inflammatory microenvironment for the induction of EMT phenotype in human colorectal cancer.

Methods: Two human colorectal cancer cell lines, HCT116 and RKO, were stably transfected with vimentin promoter-driven red fluorescence protein TurboFP635 expression vector. Both cell lines were treated with inflammatory cytokines, IL-1β (1 ng/ml) and TNF-α (20 ng/ml), or co-cultured with mouse macrophage cell line RAW264.7 in the presence of lipopolysaccharide (LPS) (200 ng/ml). The time-lapse live imaging was observed by confocal laser scanning microscope. Migration and invasion properties were examined by transwell chamber assays. The fluorescence intensity was measured by microplate reader and flow cytometric analysis. The expression of EMT-related markers was assessed by Western blot analysis and q-PCR. EMT-induced HCT116 and RKO cells were treated with anti-inflammatory agents, aspirin (1mM) and salicylic acid (1 mM), for the suppression of EMT.

Results: Inflammatory cytokines (IL-1β and TNF-α) induced red fluorescence intensity and morphological change like mesenchymal phenotype in HCT116 and RKO cells. Removal of inflammatory cytokines attenuated red fluorescence intensity and morphological change in both cells. Inflammatory cytokines also induced the migration and invasion properties in association with EMT-related markers. Moreover, co-culture with LPS-stimulated inflammatory macrophages also induced red fluorescence intensity and morphological change as well as inflammatory cytokines. Anti-inflammatory agents significantly suppressed the fluorescence-related EMT phenotype under inflammatory microenvironment.

Conclusions: These results suggest that inflammatory microenvironment has a great potential for the induction of EMT process during colorectal cancer progression. This unique fluorescence-guided EMT imaging system is useful method for the exploration of inflammation-mediated tumor progression.

Citation Format: Takeshi Ieda, Hiroshi Tazawa, Satoru Kikuchi, Shinji Kuroda, Toshiaki Ohara, Kazuhiro Noma, Hiroyuki Kishimoto, Takeshi Nagasaka, Masahiko Nishizaki, Shunsuke Kagawa, Takeshi Imamura, Toshiyoshi Fujiwara. Fluorescence-guided spatiotemporal dynamics of epithelial-mesenchymal transition under inflammatory microenvironment during colorectal cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5809. doi:10.1158/1538-7445.AM2017-5809

Abstract 3101: Hyperthermia at the single-cell level for disseminated cancer disease with immuno-magnetic nanoparticles

Hyperthermia using magnetic nanoparticles and alternating magnetic field is promising for cancer therapy. In most cases, the usefulness of this magnetic nanoparticle-based hyperthermia has been shown by applying magnetic nanoparticles to tumor tissue such as a subcutaneous tumor with direct injection technique; however, if the magnetic nanoparticles can be cancer cell-specifically delivered at the cellular level, the magnetic field hyperthermia would have the potential to treat various sorts of disseminated cancer diseases. The aim of this study is to prove this concept. Maghemite nanoparticles (MNPs) were conjugated with the anti-HER2 antibody (Tmab) for cancer targeting, and the Tmab-MNPs were applied to the co-culture flask containing both HER2-expressing breast cancer AU565 cells and normal fibroblast FEF3 cells. Thirty minutes later from the Tmab-MNPs administration, the medium was removed and the cells were washed to remove excess Tmab-MNPs. Prussian blue iron staining and immunostaining for Tmab showed co-localization of the maghemite nanoparticles and Tmab only on the cancer cells, which suggested that MNPs conjugation with Tmab was successful and that cancer specific delivery of MNPs at the cellular level was achieved in vitro. Moreover, application of alternating current magnetic field at 280 kHz for 1 hour caused apoptotic-like cell death only to cancer cells without any cell damage to normal fibroblast FEF3 cells. Intracellular hyperthermia using cancer-specific antibody-modified magnetic nanoparticles have the potential to be applied to the treatment of disseminated cancer diseases.

Citation Format: Tetsuya Kagawa, Hiroyuki Kishimoto, Toshiaki Ohara, Hiroshi Tazawa, Shunsuke Kagawa, Takeshi Nagasaka, Satoshi Nohara, Ichiro Kato, Adarsh Sandhu, Hiromichi Aono, Toshiyoshi Fujiwara. Hyperthermia at the single-cell level for disseminated cancer disease with immuno-magnetic nanoparticles [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3101. doi:10.1158/1538-7445.AM2017-3101

Cell-cycle-dependent drug-resistant quiescent cancer cells induce tumor angiogenesis after chemotherapy as visualized by real-time FUCCI imaging

We previously demonstrated that quiescent cancer cells in a tumor are resistant to conventional chemotherapy as visualized with a fluorescence ubiquitination cell cycle indicator (FUCCI). We also showed that proliferating cancer cells exist in a tumor only near nascent vessels or on the tumor surface as visualized with FUCCI and green fluorescent protein (GFP)-expressing tumor vessels. In the present study, we show the relationship between cell-cycle phase and chemotherapy-induced tumor angiogenesis using in vivo FUCCI real-time imaging of the cell cycle and nestin-driven GFP to detect nascent blood vessels. We observed that chemotherapy-treated tumors, consisting of mostly of quiescent cancer cells after treatment, had much more and deeper tumor vessels than untreated tumors. These newly-vascularized cancer cells regrew rapidly after chemotherapy. In contrast, formerly quiescent cancer cells decoyed to S/G2 phase by a telomerase-dependent adenovirus did not induce tumor angiogenesis. The present results further demonstrate the importance of the cancer-cell position in the cell cycle in order that chemotherapy be effective and not have the opposite effect of stimulating tumor angiogenesis and progression.