Clinical Significance of Multi-Cancer Genome Profiling: Data from a Single Hospital in Japan

BACKGROUND/AIM

Multi-cancer genome profiling (multi-CGP) testing intends to predict the therapeutic efficacy of anticancer medication treatments for eligible patients as part of "precision cancer care." The number of cases in which a new treatment was applied based on multi-CGP testing has been reported to be between 10% and 20% for all patients in Japan. This study aimed to determine the significance of multi-CGP testing in Japan by analyzing clinical data from multi-CGP testing in various solid cancers at our Hospital.

PATIENTS AND METHODS

A total of 230 patients examined by one of three tests for multi-CGP including NCC Oncopanel, FoundationOne CDx, and FoundationOne Liquid were retrospectively enrolled. Adequate treatment for each patient was discussed at the expert panel meeting according to the results from the genome profiling tests.

RESULTS

The most frequent cancer types enrolled in this study were pancreas cancer, bowel cancer, and biliary cancer. Of the 230 cases, 106 (46%) were druggable cases, and 21 (9.1%) were administered medication. Partial response (PR) effect was found in 7 (33.3%) of the 21 cases, of which 3 were biliary cancer and 3 had a BRCA2 mutation. Of all the 21 cases, 7 (33.3%) had the maximum treatment benefit of PR. Three cases of biliary tumors were found in the 7 PR cases within the 21 cases.

CONCLUSION

Of 230 patients, 21 were administered medication following multi-CGP testing data, especially frequent in biliary tumor patients. Multi-CGP testing might be particularly beneficial to patients with biliary tumors in Japan.

Improved Measurements of Muonic Helium Ground-State Hyperfine Structure at a Near-Zero Magnetic Field

Muonic helium atom hyperfine structure (HFS) measurements are a sensitive tool to test the three-body atomic system and bound-state quantum electrodynamics theory, and determine fundamental constants of the negative muon magnetic moment and mass. The world's most intense pulsed negative muon beam at the Muon Science Facility of the Japan Proton Accelerator Research Complex allows improvement of previous measurements and testing further CPT invariance by comparing the magnetic moments and masses of positive and negative muons (second-generation leptons). We report new ground-state HFS measurements of muonic helium-4 atoms at a near-zero magnetic field, performed for the first time using a small admixture of CH_{4} as an electron donor to form neutral muonic helium atoms efficiently. Our analysis gives Δν=4464.980(20)  MHz (4.5 ppm), which is more precise than both previous measurements at weak and high fields. The muonium ground-state HFS was also measured under the same conditions to investigate the isotopic effect on the frequency shift due to the gas density dependence in He with CH_{4} admixture and compared with previous studies. Muonium and muonic helium can be regarded as light and heavy hydrogen isotopes with an isotopic mass ratio of 36. No isotopic effect was observed within the current experimental precision.

Establishment of a gastric cancer cell line with high microsatellite instability, OCUM-13, derived from Borrmann type-2 primary tumor

Gastric cancer (GC) with microsatellite instability (MSI) has been reported to be sensitive to immunotherapy, however some of GC cases with MSI remain resistant to immunotherapy. Cancer cell lines showing MSI might be useful for the analysis of mechanisms of immunotherapy, while only a few GC cell lines with MSI are available so far. In this study, we established a unique GC cell line with MSI, OCUM-13, from a primary GC with abundant tumor-infiltrating lymphocytes. MSI assay indicated that OCUM-13 cells as well as the primary tumor showed a band shift in more than 3 of 5 microsatellite loci, suggesting that OCUM-13 did have high MSI. The subcutaneous inoculation of OCUM-13 cells into mice performed tumor formation. Insulin-like growth factor 1 receptor inhibitor decreased the growth of OCUM-13 cells. The newly established cell line with MSI, OCUM-13, might be useful for the analysis of cancer therapy for GC with MSI.

Hyaluronan driven by epithelial aPKC deficiency remodels the microenvironment and creates a vulnerability in mesenchymal colorectal cancer

Mesenchymal colorectal cancer (mCRC) is microsatellite stable (MSS), highly desmoplastic, with CD8+ T cells excluded to the stromal periphery, resistant to immunotherapy, and driven by low levels of the atypical protein kinase Cs (aPKCs) in the intestinal epithelium. We show here that a salient feature of these tumors is the accumulation of hyaluronan (HA) which, along with reduced aPKC levels, predicts poor survival. HA promotes epithelial heterogeneity and the emergence of a tumor fetal metaplastic cell (TFMC) population endowed with invasive cancer features through a network of interactions with activated fibroblasts. TFMCs are sensitive to HA deposition, and their metaplastic markers have prognostic value. We demonstrate that in vivo HA degradation with a clinical dose of hyaluronidase impairs mCRC tumorigenesis and liver metastasis and enables immune checkpoint blockade therapy by promoting the recruitment of B and CD8+ T cells, including a proportion with resident memory features, and by blocking immunosuppression.

Study of the N=32 and N=34 Shell Gap for Ti and V by the First High-Precision Multireflection Time-of-Flight Mass Measurements at BigRIPS-SLOWRI

The atomic masses of ^{55}Sc, ^{56,58}Ti, and ^{56-59}V have been determined using the high-precision multireflection time-of-flight technique. The radioisotopes have been produced at RIKEN's Radioactive Isotope Beam Factory (RIBF) and delivered to the novel designed gas cell and multireflection system, which has been recently commissioned downstream of the ZeroDegree spectrometer following the BigRIPS separator. For ^{56,58}Ti and ^{56-59}V, the mass uncertainties have been reduced down to the order of 10 keV, shedding new light on the N=34 shell effect in Ti and V isotopes by the first high-precision mass measurements of the critical species ^{58}Ti and ^{59}V. With the new precision achieved, we reveal the nonexistence of the N=34 empirical two-neutron shell gaps for Ti and V, and the enhanced energy gap above the occupied νp_{3/2} orbit is identified as a feature unique to Ca. We perform new Monte Carlo shell model calculations including the νd_{5/2} and νg_{9/2} orbits and compare the results with conventional shell model calculations, which exclude the νg_{9/2} and the νd_{5/2} orbits. The comparison indicates that the shell gap reduction in Ti is related to a partial occupation of the higher orbitals for the outer two valence neutrons at N=34.

β-Delayed One and Two Neutron Emission Probabilities Southeast of ^{132}Sn and the Odd-Even Systematics in r-Process Nuclide Abundances

The β-delayed one- and two-neutron emission probabilities (P_{1n} and P_{2n}) of 20 neutron-rich nuclei with N≥82 have been measured at the RIBF facility of the RIKEN Nishina Center. P_{1n} of ^{130,131}Ag, ^{133,134}Cd, ^{135,136}In, and ^{138,139}Sn were determined for the first time, and stringent upper limits were placed on P_{2n} for nearly all cases. β-delayed two-neutron emission (β2n) was unambiguously identified in ^{133}Cd and ^{135,136}In, and their P_{2n} were measured. Weak β2n was also detected from ^{137,138}Sn. Our results highlight the effect of the N=82 and Z=50 shell closures on β-delayed neutron emission probability and provide stringent benchmarks for newly developed macroscopic-microscopic and self-consistent global models with the inclusion of a statistical treatment of neutron and γ emission. The impact of our measurements on r-process nucleosynthesis was studied in a neutron star merger scenario. Our P_{1n} and P_{2n} have a direct impact on the odd-even staggering of the final abundance, improving the agreement between calculated and observed Solar System abundances. The odd isotope fraction of Ba in r-process-enhanced (r-II) stars is also better reproduced using our new data.

CXCR2 signaling might have a tumor-suppressive role in patients with cholangiocarcinoma

BACKGROUND

We reported that chemokine C-X-C motif receptor 2 (CXCR2) signaling appears to play an important role in the pathogenic signaling of gastric cancer (GC), and although CXCR2 may have a role in other solid cancers, the significance of CXCR2 in cholangiocarcinoma (CCA) has not been evaluated. Herein, we determined the clinicopathologic significance of CXCL1-CXCR2 signaling in CCA.

MATERIALS AND METHODS

Two human CCA cell lines, OCUG-1 and HuCCT1, were used. CXCR2 expression was examined by western blotting. We investigated the effects of CXCL1 on the proliferation (by MTT assay) and migration activity (by a wound-healing assay) of each cell line. Our immunohistochemical study of the cases of 178 CCA patients examined the expression levels of CXCR2 and CXCL1, and we analyzed the relationship between these expression levels and the patients' clinicopathologic features.

RESULTS

CXCR2 was expressed on both CCA cell lines. CXCL1 significantly inhibited both the proliferative activity and migratory activity of both cell lines. CXCL1 and CXCR2 were immunohistochemically expressed in 73% and 18% of the CCA cases, respectively. The CXCL1-positive group was significantly associated with negative lymph node metastasis (p = 0.043). The CXCR2-positive group showed significantly better survival (p = 0.042, Kaplan-Meier). A multivariate logistic regression analysis revealed that CXCR2 expression (p = 0.031) and lymph node metastasis (p = 0.004) were significantly correlated with the CCA patients' overall survival.

CONCLUSION

CXCR2 signaling might exert a tumor-suppressive effect on CCA cells. CXCR2 might be a useful independent prognostic marker for CCA patients after surgical resection.

Lipocalin-2 negatively regulates epithelial-mesenchymal transition through matrix metalloprotease-2 downregulation in gastric cancer

BACKGROUND

Although the role of Lipocalin-2 (LCN2) in cancer development has been focused on recent studies, the molecular mechanisms and clinical relevance of LCN2 in gastric cancer (GC) still remain unclear.

METHODS

Transcriptome analysis of GC samples from public human data was performed according to Lauren's classification and molecular classification. In vitro, Western blotting, RT-PCR, wound healing assay and invasion assay were performed to reveal the function and mechanisms of LCN2 in cell proliferation, migration and invasion using LCN2 knockdown cells. Gene set enrichment analysis (GSEA) of GC samples from public human data was analyzed according to LCN2 expression. The clinical significance of LCN2 expression was investigated in GC patients from public data and our hospital.

RESULTS

LCN2 was downregulated in diffuse-type GC, as well as in Epithelial-Mesenchymal Transition (EMT) type GC. LCN2 downregulation significantly promoted proliferation, invasion and migration of GC cells. The molecular mechanisms of LCN2 downregulation contribute to Matrix Metalloproteinases-2 (MMP2) stimulation which enhances EMT signaling in GC cells. GSEA revealed that LCN2 downregulation in human samples was involved in EMT signaling. Low LCN2 protein and mRNA levels were significantly associated with poor prognosis in patients with GC. LCN2 mRNA level was an independent prognostic factor for overall survival in GC patients.

CONCLUSIONS

LCN2 has a critical role in EMT signaling via MMP2 activity during GC progression. Thus, LCN2 might be a promising therapeutic target to revert EMT signaling in GC patients with poor outcomes.

Dipeptidyl Peptidase-4 from Cancer-associated Fibroblasts Stimulates the Proliferation of Scirrhous-type Gastric Cancer Cells

BACKGROUND/AIM

Cancer-associated fibroblasts (CAFs) may promote the malignancy of human scirrhous gastric cancer (SGC) cells. We conducted the present study to identify novel growth factors from CAFs.

MATERIALS AND METHODS

OCUM-12 and 2 CAF cell lines were used. The proliferation of cancer cells was determined by the number of cancer cells or the MTT assay. The growth factor(s) were purified and characterized by the gel filtration chromatography and protein array.

RESULTS

The molecular weight of the growth-stimulating factor was estimated to be approximately 66-669 kDa. Protein array of conditioned medium (CM) from CAFs indicated that dipeptidyl peptidase-4 (DPP-4) was one of the growth factors. The addition of CM increased the phosphorylation of C-X-C chemokine receptor 4 (CXCR4). The DPP-4 inhibitor significantly inhibited the growth-stimulating activity of CM.

CONCLUSION

DPP-4 from CAFs might be one of the growth-stimulating factors for SGC through CXCR4.

EMMPRIN in extracellular vesicles from peritoneal mesothelial cells stimulates the invasion activity of diffuse-type gastric cancer cells

Peritoneal metastasis of gastric cancer (GC) results in extremely poor prognoses. The peritoneal cavity is covered by a monolayer of peritoneal mesothelial cells (PMCs). Interactions between GC cells and PMCs might play a pivotal role in peritoneal metastasis. Extracellular vesicles (EVs) correlate with intercellular communication. Although intercellular communication between cancer cells and PMCs might be associated with the peritoneal metastatic process, the role of EVs from PMCs remains unclear. We investigated the effects of EVs from PMCs on GC cells. Three GC cell lines (OCUM-12, NUGC-3, and MKN74) and four mesothelial cell lines were used. The effects of EVs derived from the PMCs on the invasion and migration of GC cells were evaluated by Matrigel invasion assay. Factors contained in the PMC EVs were analyzed; extra-cellular matrix metalloproteinase inducer (EMMPRIN) was detected in the EVs. The effects of an EMMPRIN inhibitor on the invasion-stimulating activity of EVs were examined. The EMMPRIN expressions of 110 GCs were evaluated by immunohistochemistry. PMC EVs significantly promoted the invasion of diffuse-type GC cells, i.e., OCUM-12 and NUGC-3 cells. EMMPRIN in the EVs stimulated the invasion of OCUM-12 and NUGC-3 cells. The invasion-stimulating activity of PMC EVs was inhibited by the EMMPRIN inhibitor. A high EMMPRIN expression in PMCs was significantly associated with worse cancer-specific survival and peritoneal-recurrence-free survival. EMMPRIN in EVs from PMCs might stimulate the malignant progression of diffuse-type GC. EMMPRIN might be a useful prognostic marker of recurrence in GC patients.

The clinicopathologic significance of Tks5 expression of peritoneal mesothelial cells in gastric cancer patients

Background

Gastric cancer (GC) patients frequently develop peritoneal metastasis. Recently, it has been reported that peritoneal mesothelial cells (PMCs) activated by GC cells acquire a migratory capacity and promote GC cell invasion. The invasiveness of PMCs reportedly depends on the activity of Tks5, an adaptor protein required for invadopodia formation. However, the relationship between clinicopathologic features and Tks5 expression in PMCs has been poorly documented. In this study, we evaluated the clinicopathologic significance of the Tks5 expression of PMCs in GC patients.

Materials and methods

A total of 110 GC patients who underwent gastrectomy were enrolled in this study. Tks5 expressions in PMCs from the greater omentum, lesser omentum and retroperitoneum were evaluated by immunohistochemistry. We analyzed the correlation between Tks5 expressions in PMCs and the patients’ clinicopathologic features.

Results

Tks5 expression was found in 71 (64.5%) of the 110 patients, while 39 (35.5%) were Tks5-negative. Tks5 positivity was significantly (p = 0.038) associated with a greater tumor depth (i.e., T3/4 compared with T1/T2). Peritoneal recurrence was found in 12 of 98 cases within 3 years of surgery. The 3-year peritoneal recurrence-free survival (PRFS) rate in Tks5-positive cases was significantly poorer than that in Tks5-negative cases (80.1% vs 97.4%, p = 0.024). Multivariate analysis revealed that Tks5 positivity and lymph node metastasis were independent factors for PRFS.

Conclusion

Tks5 is frequently expressed in PMCs in advanced-stage gastric cancer. Tks5 might be a useful predictor for peritoneal recurrence in GC patients.

Abstract 258: Identification of characteristic genes of scirrhous-type gastric cancer cells by RNAseq

Introduction: Scirrhous gastric cancer shows an extremely poor prognosis with rapid growth and infiltration activity. One of the reasons for poor prognosis is a lack of the identification of driver gene for scirrhous gastric cancer. FGFR2 (fibroblast growth factor receptor 2), E-cadherin, TGFβR (transforming growth factor β receptor), CD44/IGFIR (insulin-like growth factor I receptor), have been reported as candidates of driver for scirrhous-type of gastric cancer, however useful molecular-targeted therapeutic agents against these driver molecules have not yet been clinically approved. In this study, we identified the characteristic genes of scirrhous-type gastric cancer by RNA-seq of gastric cancer cell lines.

Methods: RNA-seq was performed using 6 scirrhous gastric cancer cell lines (OCUM1, OCUM2MLN, OCUM8, OCUM12, OCUM13, OCUM14) using a next-generation sequencer (ION S5 system, Thermo Fisher Scientific). Furthermore, RNA-seq public data of 4 strains of scirrhous gastric cancer cell lines (KATO3, NUGC4, SNU601, SNU668) and 10 strains of non-scirrhous gastric cancer cell lines (MKN7, MKN45, MKN74, HS746T, SNU1, SNU16, SNU638, AZ521, HGC27, TMK1) on the Sequence Read Archive were added, and the genes expressed in scirrhous gastric cancer were compared and examined. The analysis tools used were kallisto and sleuth. We set p-value < 0.05 and log2 (fold change) > 2 as the cut-offs to screen out differentially expressed genes (DEGs). Pathway enrichment and protein-protein interaction (PPI) network analysis were performed based on metascape databases. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was also performed for the genes.

Results: A total of 234 DEGs were identified from this analysis. A gene co-expression network was constructed containing 8 DEGs. The genes were mainly associated with response to chemokine, and cytokine-mediated signaling pathway. Several critical genes were disclosed, such as C-C motif chemokine ligand 20 (CCL20) and C-X-C subfamiliy. Genes highly expressed in scirrhous gastric cancer cell lines were CCL20 (10.6-fold change, p=9.89×10-4) and C-X-C Motif Chemokine Ligand 3 (CXCL3, 19.5-fold change, p=1.67×10-5). The mean of abundances across samples (=log(counts+0.5)), which represent the average expression levels of all samples, were CCL20 and CXCL3, 4.04 and 4.53, respectively. KEGG pathway enrichment analysis showed that viral protein interaction with cytokine and cytokine receptor, Cytokine-cytokine receptor interaction and IL-17 signaling pathway were significantly over-represented.

Conclusion: CCL20 and CXCL3 might be characteristic genes for scirrhous-type of gastric cancer.

Citation Format: Tomohiro Sera, Masakazu Yashiro, Gen Tsujio, Yurie Yamamoto, Atsushi Sugimoto, Shuhei Kushiyama, Sadaaki Nishimura, Masaichi Ohira. Identification of characteristic genes of scirrhous-type gastric cancer cells by RNAseq [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 258.

Abstract 3125: Analysis of intratumoral protein and gene expression heterogeneity in gastric cancer with a clustering analysis

Background/Aim: Intratumoral heterogeneity has been reported in various cancer types and may cause cancer metastasis and chemotherapy treatment resistance, including resistance to molecular targeted therapy. In gastric cancer, the intratumoral heterogeneity of cancer-associated molecules, such as HER2, has been reported and relates to the acquisition of chemotherapy resistance. To reveal whether intratumoral heterogeneity is related to cancer etiology, such as the mechanism of metastasis, and the development of new treatment strategies, such as combination therapy, we investigated intratumoral heterogeneity of gastric cancer with operative specimen and Cancer Genome Atlas (TGCA) data.

Methods: The study included 503 patients who underwent gastrectomy and immunohistochemical staining for gastric cancer between 2001 and 2006 and TGCA data. We conducted clustering analysis based on protein and gene expression data for FGFR2IIIb (FGFR2), HER2(ERBB2), CXCR2(CXCR2), CXCR4(CXCR4), cMet(MET), TGFβ1(TGFB1), IGF1R(IGF1R), and p-smad2(SMAD2), and we analyzed the relation of FGFR2IIIb (FGFR2) and HER2(ERBB2) expression with the expression of other proteins and genes. Additionally, we investigated clinicopathological feature correlations.

Result/Discussion: We divided gastric cancer specimens into nine clusters by immunohistochemical staining and 11 clusters using TCGA data. According to immunohistochemical staining, the high HER2 and FGFR2IIIb expression groups formed a cluster with high expression of various proteins. Analysis of stage 3-4 samples revealed more high protein expression clusters than the analysis of stage1-2, and this suggests that cancer acquires heterogeneity with cancer progression. In the TGCA data of stage 3-4, high FGFR2 and MET and high ERBB2 and SMAD2 or IGF1R expression formed clusters, which is consistent with the clustering analysis that was performed with immunohistochemical staining results.

Conclusion: Our findings suggest that the existence of a combination of intratumoral heterogeneity and clusters may change with cancer progression.

Citation Format: Gen Tsujio, Masakazu Yashiro, Yurie Yamamoto, Tomohiro Sera, Atsushi Sugimoto, Shuhei Kushiyama, Sadaaki Nishimura, Mami Yoshi, Tasuro Tamura, Takahiro Toyokawa, Hiroaki Tanaka, Shigeru Lee, Kazuya Muguruma, Masaichi Ohira. Analysis of intratumoral protein and gene expression heterogeneity in gastric cancer with a clustering analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3125.

Abstract 2895: Extracellular vesicles derived from mesothelial cells promotes the migration and invasion of gastric cancer cells

Background: Peritoneal dissemination is one of common causes of poor prognosis of patients with gastric cancer (GC). The mechanism of peritoneal metastasis has not been fully elucidated. Recent studies have reported that extracellular vesicles (EVs) play an important role for the intercellular communication in GC microenvironment. The peritoneal dissemination possesses some intercellular communication steps between cancer cells and hostile cells including peritoneal mesothelial cells (PMCs), however, the effect of EVs derived from PMCs on GC cells has not been validated. In the present study, to clarify the intercellular communication we evaluated the effect of EVs from PMCs on the proliferation, migration and invasion of GC cells.

Materials and Methods: Four GC cell lines (OCUM12, NUGC3, MKN45, MKN74) and 4 PMCs cell lines were used. PMCs cell lines were primary cultured from ascites of gastric cancer patients. The EVs derived from PMCs were isolated from conditioned medium of PMCs by ultracentrifugation. The EVs derived from PMCs were confirmed by the transmission electron microscope (TEM) using uranyl acetate and the western blotting using EV markers such as CD9, CD63, and CD81. The EVs derived from PMCs were fluorescently labelled using PKH26 and the uptakes of EVs were viewed under a fluorescence microscope. The effect of EVs from PMCs on the proliferation, migration and invasion of GC cells was evaluated by MTT assay, wound healing assay and Matrigel invasion assay respectively.

Results: The EVs derived from PMCs showed typical morphology of EVs by TEM, and were positive for EV markers such as CD9, CD63, and CD81 in western blotting. The EVs derived from PMCs significantly suppressed the proliferation of GC cells. On the other hand, the EVs derived from PMCs significantly promoted the migration of OCUM12 and NUGC3 cells, but not MKN45 and MKN74 cells. Furthermore, The EVs derived from PMCs significantly promoted the invasion of OCUM12 and NUGC3 cells. PKH26 labelled EVs derived from PMCs were found in cytoplasm of OCUM12 and NUGC3 cells.

Conclusion: The EVs derived from PMCs significantly promoted the migration and invasion of GC cells. The EVs derived from PMCs might be one of factors which associate with the intercellular communication steps in peritoneal dissemination possesses in GC.

Citation Format: Atsushi Sugimoto, Masakazu Yashiro, Tomohisa Okuno, Yuichiro Miki, Gen Tsujio, Yurie Yamamoto, Tomohiro Sera, Shuhei Kushiyama, Sadaaki Nishimura, Kenji Kuroda, Shingo Togano, Masaichi Ohira. Extracellular vesicles derived from mesothelial cells promotes the migration and invasion of gastric cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2895.

Abstract 2677: Clinicopathologic significance of CXCR2-CXCL1 signaling in cholangiocarcinoma

Background: Cancer progression has been recognized as not only the proliferation of tumor cells but also an interaction between cancer cells and the surrounding stroma in the tumor microenvironment. Among the tumor stromal cells, cancer-associated fibroblasts (CAF) have been reported to be closely associated with tumor development in various solid carcinomas. We previously reported that chemokine (C-X-C motif) receptor 2 (CXCR2) signaling might play an important role for the pathogenic construction of CAF in the gastric cancer (GC) microenvironment, suggesting that GC cells might alter their adjacent stroma to form a permissive environment for tumor progression, and also we reported that chemokine (C-X-C motif) ligand 1 (CXCL1) from cells stimulated the recruitment of bone marrow cells into GC microenvironment via CXCR2 signaling, resulting in the malignant progression of GC. Following these findings, we reported that among the CXCR2 ligands, CXCL1 might play an important role in the malignant progression of GC via CXCR2 signaling. And then, some studies suggest that CXCR2-CXCL1 plays an important role in not only GC but also other solid cancer. However, there is no report about the clinicopathological significance of CXCR2-CXCL1 signal in cholangiocarcinoma. Then, we examined the clinicopathological significance of CXCR2-CXCL1 signal in cholangiocarcinoma in this study.

Patients and Method: We retrospectively analyzed the total cases of 168 patients with cholangiocarcinoma. The expressions of CXCR2 and CXCL1 were investigated by immunohistochemistry, and we then analyzed the correlation between the clinicopathological features of 168 patients and the CXCR2 and CXCL1 expression level.

Results: The CXCR2 and CXCL1 positive expression wad as follows: CXCR2 was 18.5% (31/168), CXCL1 was 72.8% (126/173), both CXCR2 and CXCL1 was 17.9% (30/168). Metastasis negative was correlated with CXCL1 expression. Low depth invasion was correlated with CXCR2 expression. The prognoses of the both CXCR2 and CXCL1 positive patients were significantly better than those of CXCR2 and/or CXCL1 negative patients (p<0.023, log rank).

Conclusion:CXCLR2 and CXCL1 expression might be a better prognostic factor of patients with cholangiocarcinoma, and CXCR2-CXCL1 signaling might play an important role for tumor-suppressing effects of cholangiocarcinoma.

Citation Format: Yurie Yamamoto, Gen Tsujio, Tomohiro Sera, Atsushi Sugimoto, Syuhei Kushiyama, Sadaaki Nishimura, Kenji Kuroda, Ryota Tanaka, Kenjiro Kimura, Ryousuke Amano, Masaichi Ohira, Masakazu Yashiro. Clinicopathologic significance of CXCR2-CXCL1 signaling in cholangiocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2677.

Serine threonine kinase 11/liver kinase B1 mutation in sporadic scirrhous-type gastric cancer cells

Scirrhous-type gastric carcinoma (SGC), which is characterized by the rapid proliferation of cancer cells accompanied by extensive fibrosis, shows extremely poor survival. A reason for the poor prognosis of SGC is that the driver gene responsible for SGC has not been identified. To identify the characteristic driver gene of SGC, we examined the genomic landscape of six human SGC cell lines of OCUM-1, OCUM-2M, OCUM-8, OCUM-9, OCUM-12 and OCUM-14, using multiplex gene panel testing by next-generation sequencing. In this study, the non-synonymous mutations of serine threonine kinase 11/liver kinase B1 (STK11/LKB1) gene were detected in OCUM-12, OCUM-2M and OCUM-14 among the six SGC cell lines. Capillary sequencing analysis confirmed the non-sense or missense mutation of STK11/LKB1 in the three cell lines. Western blot analysis showed that LKB1 expression was decreased in OCUM-12 cells and OCUM-14 cells harboring STK11/LKB1 mutation. The mammalian target of rapamycin (mTOR) inhibitor significantly inhibited the proliferation of OCUM-12 and OCUM-14 cells. The correlations between STK11/LKB1 expression and clinicopathologic features of gastric cancer were examined using 708 primary gastric carcinomas by immunochemical study. The low STK11/LKB1 expression group was significantly associated with SGC, high invasion depth and frequent nodal involvement, in compared with the high STK11/LKB1 expression group. Collectively, our study demonstrated that STK11/LKB1 mutation might be responsible for the progression of SGC, and suggested that mTOR signaling by STK11/LKB1 mutation might be one of therapeutic targets for patients with SGC.

Probing the Symmetry Energy with the Spectral Pion Ratio

Many neutron star properties, such as the proton fraction, reflect the symmetry energy contributions to the equation of state that dominate when neutron and proton densities differ strongly. To constrain these contributions at suprasaturation densities, we measure the spectra of charged pions produced by colliding rare isotope tin (Sn) beams with isotopically enriched Sn targets. Using ratios of the charged pion spectra measured at high transverse momenta, we deduce the slope of the symmetry energy to be 42<L<117  MeV. This value is slightly lower but consistent with the L values deduced from a recent measurement of the neutron skin thickness of ^{208}Pb.

Asporin Expression on Stromal Cells and/or Cancer Cells Might Be A Useful Prognostic Marker in Patients with Diffuse-Type Gastric Cancer

BACKGROUND

Asporin (ASPN), a member of the proteoglycan family, has been shown to have a close correlation with cancer progression. It is not known whether ASPN is an oncogenic driver or a tumor suppressor in human gastric cancer. We sought herein to determine the relationship between ASPN expression and clinicopathological features of gastric cancer.

PATIENTS AND METHODS

A total of 296 gastric cancer patients (diffuse type, n = 144; intestinal type, n = 152) were enrolled. The ASPN expression level in each case was analyzed by immunohistochemistry.

RESULTS

ASPN was mainly found on stromal cells, especially on fibroblasts in tumor stroma, i.e., cancer-associated fibroblasts. The ASPN expression on either cancer cells or stromal cells was significantly high in macroscopic scirrhous-type tumors (p < 0.001) and histologically abundant stroma-type tumors (p < 0.001). Interestingly, a Kaplan-Meier survival curve of the 144 cases of diffuse-type gastric cancer revealed a significantly poorer prognosis in patients with ASPN-positive expression (p = 0.043; log rank) compared to those with ASPN-negative expression, but the prognoses were not significantly different in these subgroups of the 152 cases of intestinal-type gastric cancer. A multivariate analysis with respect to overall survival showed that ASPN expression on stromal cells and/or cancer cells was significantly correlated with overall survival in patients with diffuse-type gastric cancer (p = 0.041).

CONCLUSION

In gastric cancer, ASPN was expressed mainly on stromal cells and partially on cancer cells. ASPN expression on stromal cells and/or cancer cells might be a useful prognostic marker in patients with diffuse-type gastric cancer.

Clinicopathologic significance of TROP2 and phospho-TROP2 in gastric cancer

Trophoblast cell-surface antigen 2 (TROP2) is a transmembrane glycoprotein expressed in epithelial cells. Increased TROP2 expression has been reported to be associated with malignant progression in most carcinomas; however, TROP2 has a tumor-suppressive function in certain types of cancer. Since the function of TROP2 is controversial, the present study subsequently aimed to clarify the clinicopathologic significance of TROP2 and pTROP2 expression in human gastric cancer (GC). The cases of 704 patients with GC who underwent gastrectomy were retrospectively analyzed. The expression levels of TROP2 and pTROP2 in each tumor were evaluated by immunohistochemistry. The association between the clinicopathologic features of patients with GC and the levels of TROP2 and pTROP2 in their tumors was analyzed. Increased TROP2 and pTROP2 expression was identified in 330 (46.9%) and 306 (43.5%) of the 704 patients with GC, respectively. Increased TROP2 expression was associated with the histological intestinal type, high tumor invasion depth (T3/T4), lymph node metastasis, lymphatic invasion and venous invasion. By contrast, increased pTROP2 expression was associated with intestinal type, low tumor invasion depth (T1/2), no lymph node metastasis and no lymphatic invasion. Increased TROP2 expression was associated with poorer overall survival (OS) (P<0.01; log rank test), whereas increased pTROP2 expression was significantly associated with improved OS (P<0.01; log rank test). In conclusion, increased expression levels of TROP2, but not pTROP2, may be associated with the metastatic ability of GC, resulting in poor prognosis of patients with GC.

Clinical benefit for clinical sequencing using cancer panel testing

BACKGROUND

Clinical sequencing using a panel of genes has recently been applied worldwide for patients with refractory solid tumors, but the significance of clinical sequencing using gene panel testing remains uncertain. Here we sought to clarify the feasibility and utility of clinical sequencing in the treatment of refractory tumors at our hospital.

METHODS

A total of 39 patients with advanced solid tumors treated at our hospital between 2018 and 2020 were enrolled in the clinical sequencing. Among them, we identified 36 patients whose tissue samples were of suitable quality for clinical sequencing, and we analyzed the genomic profiles of these tumors.

RESULTS

Pathogenic alterations were detected in 28 (78%) of the 36 patients. The most common mutation was TP53 (55%), followed by KRAS (22%), and the highest frequency of gene amplification was ERBB2 (17%). Nine of the 36 patients were identified as candidates for novel molecular-targeted therapy based on their actionable gene alterations, but only one case ended up receiving novel targeted therapy following the genetic tests.

CONCLUSIONS

Our current results suggested that clinical sequencing might be useful for the detection of pathogenic alterations and the management of additional cancer treatment. However, molecular target based on actionable genomic alteration does not always bridge to subsequent therapy due to clinical deterioration, refusal for unapproved drug, and complexity of clinical trial access. Both improved optimal timing of clinical sequencing and a consensus about its off-label use might help patients receive greater benefit from clinical sequencing.

SDF1α/CXCR4 axis may be associated with the malignant progression of gastric cancer in the hypoxic tumor microenvironment

Stromal cell-derived factor 1α (SDF1α) and its receptor C-X-C chemokine receptor type 4 (CXCR4) have been reported to form an important chemokine signaling pathway. Our previous study reported that SDF1α from tumor stromal cells may stimulate the proliferation of gastric cancer (GC) cells through the CXCR4 axis in a hypoxic microenvironment. However, a limited number of studies have addressed the clinicopathological significance of the expression of SDF1α and CXCR4 in GC, particularly at hypoxic regions. Immunohistochemistry was used to investigate the expression levels of SDF1α, CXCR4 and the hypoxic marker carbonic anhydrase 9 (CA9) in 185 patients with stage II and III GC. The results demonstrated that CA9 was expressed on cancer and stromal cells in hypoxic lesions, CXCR4 was mainly expressed in cancer cells, and SDFα was mainly expressed in stromal cells. CXCR4 expression in cancer cells and SDFα expression in stromal cells were associated with the hypoxic regions with CA9 expression. The CA9 and CXCR4 expression in the cancer cells, and the SDF1α expression in the stromal cells (CA9/CXCR4/SDF1α) was significantly associated with macroscopic type 4 tumor (P=0.012) and the pattern of tumor infiltration into the surrounding tissue (P<0.001). The prognosis of the all CA9/CXCR4/SDF1α-positive patients was significantly poorer compared with that of patients with CA9-, CXCR4- or SDF1α-negative GC at Stage III (P=0.041). These results indicated that hypoxia may upregulate SDFα production in stromal cells and CXCR4 expression in cancer cells. The SDF1α/CXCR4 axis may serve an important role in the progression of GC.

A novel three-dimensional visualization system revealed an essential adaptive angiogenic response during the early phase of pulmonary hypertension

Background

Pulmonary hypertension (PH) is characterized by increased pulmonary vascular resistance and right heart failure with progressive narrowing or occlusion of the pulmonary artery. However, the assessment of vascular remodeling is mostly limited to averaged increases in wall thickening, and even the role of vascular endothelial growth factor (VEGF), remains incompletely understood; Although abundantly expressed VEGF is expected to elicit angio-obliteration and the knockout of hypoxia inducible factor (HIF) prevents PH in mice, VEGF inhibitor Sugen exacerbates hypoxia (Hx)-induced PH model, which is referred to as VEGF paradox.

Purpose

To analyze three-dimensional (3D) spatiotemporal changes of pulmonary microstructure and function, which reflect the disease activity and lead to resolve the paradox.

Methods and results

We developed a novel 3D visualization system of microstructural networks in whole mouse organ with single-cell resolution, using combined tissue clearing technique called CUBIC and multiphoton excitation microscope. The system enabled the simultaneous 3D evaluation of microvascular structure, invaded macrophages and fibrosis with effective penetration of several mm (whole organ). Three-dimensional observations of PH mice models including Hx, Sugen/Hx, and human-like Alk1+/− hereditary PH models, revealed that not only inward (negative) microvessel remodeling with stenosis, but also marked elongation of microvascular ECs, was evident except Sugen/Hx model at the early phase, which had not been detected by 2D histological sections. Comparable transcriptome analysis revealed that PGC1α, which regulates HIF-independent VEGF expression and angiogenesis, plays an important role in the characteristic response for mitochondrial and microvascular maintenance. PGC1α was up-regulated in the early phage in Hx and Alk1+/− PH models with microvascular angiogenetic change, whereas Sugen/Hx-model did not increase PGC1α expression and did not show microvascular remodeling. Furthermore pulmonary ECs-specific PGC1α-deficient mice exacerbated Hx-PH model with decreased VEGF expression and microvessel density, and administration of Baicalin, a flavonoid enhancing PGC1α expression, ameliorated Hx-PH model with increased VEGF expression.

Conclusions

The 3D visualization system disclosed an unexpected change of angiogenic microvascular structure in the early phage of PH, which is regulated by EC PGC1α. Microvascular angiogenesis which is induced by up-regulation in PGC1α -VEGF pathway is a crucial factor for compensation of PH in the early phase, which provides a potential novel therapeutic target for PH.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): JSJP

Circulating tumor cells with FGFR2 expression might be useful to identify patients with existing FGFR2-overexpressing tumor

Fibroblast growth factor receptor (FGFR) is associated with proliferation, migration, and angiogenesis of carcinomas, and FGFR signaling inhibitors are considered a key drug for the treatment of solid tumors with FGFR overexpression. Amplification of FGFR2 is reportedly identified in 3%‐10% of gastric cancers (GCs). The aim of this study is to clarify whether the identification of the circulating tumor cells (CTCs) with FGFR2 overexpression is useful to detect patients with FGFR2‐overexpressing GC. One hundred GC patients who underwent gastrectomy were enrolled. A total volume of 8 mL of peripheral blood was collected from each patient just before gastrectomy, and mononuclear cells were enriched by Ficol density gradient centrifugation. These cells were immunostained with PI/CD45/EpCAM/FGFR2. The number of CTCs with FGFR2 expression in each sample was enumerated by FACScan. The FGFR2 expression level of the resected primary tumor was assessed by immunohistochemistry. The number of FGFR2‐positive CTCs in the GC patients' peripheral blood was significantly correlated with the FGFR2 expression level of the primary GC. The relapse‐free survival of the patients with FGFR2‐positive CTCs (≥5 cells/10 mL blood) was significantly poorer (P = .018, log‐rank) than that of the patients without FGFR2‐positive CTCs (<5 cell/10 mL blood). These findings suggested that the determination of FGFR2‐positive CTCs might help identify an existing tumor with FGFR2 overexpression.

Abstract 1217A: Serine threonine kinase 11/liver kinase B1 mutation in sporadic scirrhous-type gastric cancer cells

Background: Scirrhous-type gastric carcinoma (SGC), which is characterized by the rapid proliferation of cancer cells accompanied by extensive fibrosis, shows extremely poor survival. No driver gene responsible for the malignant potential of SGC has not been identified. Next-generation sequencing (NGS) technology has defined as the genomic landscape of various types of cancers, and has elucidated a number of novel driver mutations of gastric cancer. RHOA and CDH1 are characteristic mutations for SGC, but these mutations are not druggable. Novel molecular target therapy has been necessary for SGC based on its biological behavior.

Objective: We sought to identify the characteristic driver gene which is responsible for SGC.

Methods: DNA was isolated from six human SGC cell lines: OUCM-1, OCUM-2M, OCUM-8, OCUM-9, OCUM-12, and OCUM-14. The mutational status of 90 cancer-associated genes was examined by next-generation sequencing. The expression level of serine threonine kinase 11/liver kinase B1 (STK11/LKB1) in 708 gastric cancers was examined immunochemically, and the correlations between STK11/LKB1 expression and clinicopathologic features of gastric cancer were analyzed.

Results: The nonsynonymous mutations of STK11/LKB1 gene were found in three of the six SGC cell lines. Nonsense mutation of STK11/LKB1, which was associated with STK11/LKB1 loss (Y253*), was found in OCUM-12 cells, and missense mutation of STK11/LKB1 (F354L) was found in OCUM-2M cells and OCUM-14 cells. Rapamycin, an inhibitor of STK11/ AMP-activated protein kinase (AMPK)/mammalian target of rapamycin signaling (mTOR), showed inhibitory effects of SGC cells harboring STK11/LKB1 mutation. The low STK11/LKB1 expression group was significantly associated with SGC, high invasion depth, and nodal involvement, in compared to the high STK11/LKB1 expression group. The 5-year survival rate of patients with low STK11/LKB1 expression was significantly poorer compared to those with high STK11/LKB1 expression (p&lt;0.001). A conditional multivariate analysis showed that STK11/LKB1 expression status was an independent prognostic factor.

Conclusion: SGC cells frequently showed the nonsynonymous mutations of STK11/LKB1. STK11/LKB1 mutation might be responsible for the malignant potential of SGC. STK11/AMPK/mTOR signaling might be one of the therapeutic targets for patients with SGC.1

Citation Format: Sadaaki Nishimura, Masakazu Yashiro, Tomohiro Sera, Yurie Yamamoto, Atsushi Sugimoto, Shuhei Kushiyama, Shingo Togano, Kenji Kuroda, Tomohisa Okuno, Masaichi Ohira. Serine threonine kinase 11/liver kinase B1 mutation in sporadic scirrhous-type gastric cancer cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1217A.

Abstract 6193: The clinicopathologic significance of the CXCR2 ligands, CXCL1, CXCL2, CXCL3, CXCL5, CXCL6, CXCL7, and CXCL8 in gastric cancer

Background: Cancer progression has been recognized as not only the proliferation of tumor cells but also an interaction between cancer cells and the surrounding stroma in the tumor microenvironment. Among the tumor stromal cells, fibroblasts (especially cancer-associated fibroblasts) have been reported to be closely associated with tumor development in various solid carcinomas. We reported that chemokine (C-X-C motif) receptor 2 (CXCR2) signaling might play an important role in the pathogenic construction of tumor fibroblasts in the gastric tumor microenvironment, suggesting that gastric cancer cells might alter their adjacent stroma to form a permissive environment for tumor progression. Following those findings, we reported that chemokine (C-X-C motif) ligand 1 (CXCL1) from cells stimulated the recruitment of bone marrow cells into the gastric cancer (GC) microenvironment via chemokine (C-X-C motif) receptor 2 (CXCR2) signaling, resulting in the malignant progression of GC. The reported CXCR2 ligands are not only CXCL1 but also CXCL2, CXCL3, CXCL5, CXCL6, CXCL7, and CXCL8. However, there has been only a single in vitro study of significance of these CXCR2 ligands in GC. We thus examined the clinicopathological significance of these members of the CXCL family in GC.

Method: We retrospectively analyzed the cases of 590 GC patients. The expressions of CXCR2 ligands were investigated by immunohistochemistry, and we then analyzed the correlation between the clinicopathological features of the patients and the expressions of CXCR2 ligands.

Result: The expressions were as follows: CXCL1, 46.2% (257/557); CXCL2, 20.7% (122/590); CXCL3, 17.1% (101/589); CXCL5/CXCL6, 2.9% (17/589); CXCL7, 36.4% (215/590); and CXCL8 1.7% (10/585) of the cases. High invasion depth was correlated with CXCL1 expression. Lymph node metastasis was correlated with high expressions of CXCL1 and CXCL7. Lymphatic invasion and venous invasion were correlated with CXCL1 and CXCL7 expression. Peritoneal cytology positivity was correlated with high expressions of CXCL1 and CXCL7. The prognoses of the CXCL1-positive patients were significantly poorer than those of the CXCL1-negative patients (p&lt;0.001, log-rank).

Conclusion: Among the CXCR2 ligands, CXCL1 and CXCL7 were frequently expressed in GC cells. CXCL1 was closely associated with malignant potential of GC and was an independent prognostic factor. CXCL1 might play an important role in the malignant progression of GC via CXCL1/CXCR2 signaling.

Citation Format: Yurie Yamamoto, Kenji Kuroda, Tomohiro Sera, Atsushi Sugimoto, Syuhei Kushiyama, Sadaaki Nishimura, Shingo Togano, Tomohisa Okuno, Mami Yoshii, Tatsuro Tamura, Takahiro Toyokawa, Hiroaki Tanaka, Kazuya Muguruma, Masaichi Ohira, Masakazu Yashiro. The clinicopathologic significance of the CXCR2 ligands, CXCL1, CXCL2, CXCL3, CXCL5, CXCL6, CXCL7, and CXCL8 in gastric cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6193.

Abstract 6465: Clinicopathological features of TROP-2 and pTROP-2 in gastric cancer

Introduction: The human trophoblast cell-surface antigen TROP-2 is a cell surface glycoprotein receptor involved in tight junctions at the epithelial barrier. Although TROP-2 is reportedly overexpressed in various epithelial tumors and its expression correlates with aggressive tumor behavior, there is no report of the clinicopathological features of gastric cancer (GC) with TROP-2 and phosphorylated TROP-2 (pTROP-2) expression. We evaluated the clinicopathologic significance of TROP-2 and pTROP-2 expression in GC patients.

Materials and methods: We retrospectively analyzed the cases of 720 GC patients who underwent resection for GC. The expressions of TROP-2 and pTROP-2 in each tumor were evaluated by immunohistochemistry. We then divided the patients into the TROP-2 high group, TROP-2 low group, pTROP-2 high group, and pTROP-2 low group. The association between TROP-2 or pTROP-2 expression and clinicopathological variables were assessed by the chi-square test. Overall survival was analyzed by Kaplan-Meier method, and compared by log-rank test. The Cox proportional hazards model was used for multivariate analysis.

Results: TROP-2 high group was found to be overexpressed in 330 (46.7%) tumor samples. Significantly higher expression of TROP-2 was significantly correlated with intestinal type, tumor invasion depth, lymph node metastasis, lymphatic invasion, and venous invasion. pTROP-2 high group was found to be overexpressed in 306 (43.4%) tumor samples. Significantly higher expression of pTROP-2 was correlated with intestinal type, low tumor invasion depth, no lymph node metastasis, and no lymphatic invasion. TROP2 overexpression was predictive for poor overall survival of patients with GC (p = 0.0002, log rank test), while multivariate analysis to overall survival revealed that TROP-2 overexpression was not an independent prognostic marker (p=0.06). In contrast, pTROP-2 overexpression was predictive for good overall survival of patients with GC (p = 0.004, log rank test).

Conclusion: TROP-2 might be associated with metastatic ability of gastric cancer cells, resulting poor prognosis of patients with GC.

Citation Format: Syuhei Kushiyama, Masakazu Yashiro, Sadaaki Nishimura, Shingo Togano, Kanji Kuroda, Atsushi Sugimoto, Tomohiro Sera, Yurie Yamamoto, Tomohisa Okuno, Yuichiro Miki, Hiroshi Nakada, Masaichi Ohira. Clinicopathological features of TROP-2 and pTROP-2 in gastric cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6465.

Sequential Nature of (p,3p) Two-Proton Knockout from Neutron-Rich Nuclei

Twenty-one two-proton knockout (p,3p) cross sections were measured from neutron-rich nuclei at ∼250  MeV/nucleon in inverse kinematics. The angular distribution of the three emitted protons was determined for the first time, demonstrating that the (p,3p) kinematics are consistent with two sequential proton-proton collisions within the projectile nucleus. Ratios of (p,3p) over (p,2p) inclusive cross sections follow the trend of other many-nucleon removal reactions, further reinforcing the sequential nature of (p,3p) in neutron-rich nuclei.

Metastable States of ^{92,94}Se: Identification of an Oblate K Isomer of ^{94}Se and the Ground-State Shape Transition between N=58 and 60

Here we present new information on the shape evolution of the very neutron-rich ^{92,94}Se nuclei from an isomer-decay spectroscopy experiment at the Radioactive Isotope Beam Factory at RIKEN. High-resolution germanium detectors were used to identify delayed γ rays emitted following the decay of their isomers. New transitions are reported extending the previously known level schemes. The isomeric levels are interpreted as originating from high-K quasineutron states with an oblate deformation of β∼0.25, with the high-K state in ^{94}Se being metastable and K hindered. Following this, ^{94}Se is the lowest-mass neutron-rich nucleus known to date with such a substantial K hindrance. Furthermore, it is the first observation of an oblate K isomer in a deformed nucleus. This opens up the possibility for a new region of K isomers at low Z and at oblate deformation, involving the same neutron orbitals as the prolate orbitals within the classic Z∼72 deformed hafnium region. From an interpretation of the level scheme guided by theoretical calculations, an oblate deformation is also suggested for the ^{94}Se_{60} ground-state band.

Fragmentation of Single-Particle Strength around the Doubly Magic Nucleus ^{132}Sn and the Position of the 0f_{5/2} Proton-Hole State in ^{131}In

Spectroscopic factors of neutron-hole and proton-hole states in ^{131}Sn and ^{131}In, respectively, were measured using one-nucleon removal reactions from doubly magic ^{132}Sn at relativistic energies. For ^{131}In, a 2910(50)-keV γ ray was observed for the first time and tentatively assigned to a decay from a 5/2^{-} state at 3275(50) keV to the known 1/2^{-} level at 365 keV. The spectroscopic factors determined for this new excited state and three other single-hole states provide first evidence for a strong fragmentation of single-hole strength in ^{131}Sn and ^{131}In. The experimental results are compared to theoretical calculations based on the relativistic particle-vibration coupling model and to experimental information for single-hole states in the stable doubly magic nucleus ^{208}Pb.

Microscopic distance from tumor invasion front to serosa might be a useful predictive factor for peritoneal recurrence after curative resection of T3-gastric cancer

Background

Peritoneal recurrence is one of the most frequent recurrent diseases in gastric cancer. Although the exposure of cancer cells to the serosal surface is considered a common risk factor for peritoneal recurrence, there are some cases of peritoneal recurrence without infiltration to the serosal surface even after curative surgery. This study sought to clarify the risk factors of peritoneal recurrence in the absence of invasion to the serosal surface.

Materials and methods

Ninety-six patients with gastric cancer who underwent curative surgery were enrolled. In all 96 cases, the depth of tumor invasion was subserosal (T3). The microscopic distance from the tumor invasion front to the serosa (DIFS) was measured using tissue slides by H&E staining and pan-cytokeratin staining. E-cadherin expression was evaluated by immunohistochemical staining.

Results

Among the 96 patients, 16 developed peritoneal recurrence after curative surgery. The DIFS of the tumors with peritoneal recurrence (156±220 μm) was significantly shorter (p = 0.011) than that without peritoneal recurrence (360±478 μm). Peritoneal recurrence was significantly correlated with DIFS ≤234 μm (p = 0.023), but not with E-cadherin expression. The prognosis of DIFS ≤234 μm was significantly poorer than that of DIFS >234 μm (log rank, p = 0.007). A multivariate analysis of the patients' five-year overall survival revealed that DIFS ≤234 μm and lymph node metastasis were significantly correlated with survival (p = 0.005, p = 0.032, respectively).

Conclusion

The measurement of the DIFS might be useful for the prediction of peritoneal recurrence in T3-gastric cancer patients after curative surgery.

Echocardiographic assessment of right heart size and function in dogs with pulmonary valve stenosis

INTRODUCTION/OBJECTIVES

We sought to determine the prevalence and clinical significance of right heart remodeling and right ventricular (RV) dysfunction in dogs with pulmonary valve stenosis (PS). We also sought to evaluate repeatability of several measurements of severity of PS, right heart size, and RV function in dogs with PS.

ANIMALS, MATERIALS AND METHODS

Several indices of right atrial (RA) size and RV size and function were prospectively evaluated in 48 dogs with PS. Regression analysis was used to determine if indices of right heart size and function were independently associated with maximum transpulmonary pressure gradient (max PG) and adverse clinical findings (exercise intolerance, syncope, or right heart failure). Eight dogs underwent a second echocardiogram performed by the same operator to assess repeatability of the echocardiographic indices, which was quantified by coefficient of variation (CV) and repeatability coefficient.

RESULTS

Increased RA size (81%), increased RV wall thickness (83%), and decreased tricuspid annular plane systolic excursion (TAPSE [81%]) were common. Right atrial size, end-diastolic RV area, and RV wall thickness were independently associated with max PG. Decreased TAPSE was independently associated with adverse clinical findings. All indices except RA area (18.6%) and RV systolic velocity (20.7%) had CVs <15%. Repeatability coefficients are available to help distinguish a true change versus measurement variability during serially obtained exams.

CONCLUSIONS

Right heart remodeling and RV dysfunction are common in dogs with PS and are associated with echocardiographic and clinical severity. Results support the quantitative assessment of right heart size and function in dogs with PS.

The clinicopathological significance of Thrombospondin-4 expression in the tumor microenvironment of gastric cancer

Introduction

Thrombospondin-4 [1] is an extracellular glycoprotein involved in wound healing and tissue remodeling. Although THBS4 is reportedly frequently expressed in solid tumors, there are few reports of the clinicopathological features of carcinomas with THBS4 expression. We evaluated the clinicopathologic significance of THBS4 expression in gastric carcinoma (GC).

Materials and methods

We retrospectively analyzed the cases of 584 GC patients. The expression of THBS4 in each tumor was evaluated by immunohistochemistry. We then divided the patients into the THBS4-high (n = 223, 38.2%) group and THBS4-low (n = 361, 61.8%) group. THBS4 expression in cancer-associated fibroblasts (CAFs), normal-associated fibroblasts (NFs) and gastric cancer cell lines was examined by western blotting.

Results

THBS4 is expressed on stromal cells with αSMA or Podoplanin expression in the GC microenvironment, but not expressed on cancer cells with cytokeratin expression. The western blot analysis results showed that CAFs (but not NFs and cancer cells) expressed THBS4. Compared to the THBS4-low expression status, the THBS4-high expression status was correlated with higher αSMA expression, higher invasion depth, lymph-node metastasis, lymphatic invasion, peritoneal cytology, peritoneal metastasis, larger tumor size, microscopic diffuse type, and the macroscopic diffuse infiltrating type. The THBS4-high group's 5-year overall survival rate was significantly poorer than that of the THBS4-low group. A multivariate analysis revealed that THBS4 expression was an independent prognostic factor.

Conclusion

THBS4 is expressed on CAFs in the gastric cancer microenvironment. THBS4 from CAFs is associated with the metastasis of cancer cells, and is a useful prognostic indicator for gastric cancer patients.

Radiofrequency identification tag system improves the efficiency of closed vitrification for cryopreservation and thawing of bovine ovarian tissues

PURPOSE

A radiofrequency identification (RFID) tag system was designed to streamline cryopreservation and thawing procedures. This study evaluated the usefulness of the RFID tag system for improving the efficiency of cryopreserving/thawing bovine ovarian tissue by the closed vitrification protocol.

METHODS

Six participants carried out closed vitrification and thawing of bovine ovarian tissues procedures using either the conventional or the new RFID tag method, and the time required to perform each step of the respective methods was measured. After normality of data was confirmed by the Shapiro-Wilk test, the significance of differences was assessed by the unpaired t test.

RESULTS

When closed vitrification was performed, the time required for each step showed a significant difference between the two methods (t(4) = 2.938, p = 0.042, d = 2.40), and the total cryopreservation time was 11 min shorter using the RFID tag system. When thawing was performed, the time required for each step also showed a significant difference between the two methods (t(4) = 2.797, p = 0.049, d = 2.28), and the total thawing time was 2 min shorter using the RFID tag system.

CONCLUSION

The RFID tag system tested in this study seems to be suitable for managing biological samples stored in liquid nitrogen. Adoption of an RFID tag system by fertility centers may not only improve the efficiency of cryopreserving/thawing reproductive tissues but could also reduce human error.

The Anatomical Pattern of the Proximal Jejunal Vein as a Prognostic Factor in Patients With Pancreatic Head Cancer Treated With Preoperative Chemoradiation Therapy

BACKGROUND/AIM

The significance of the anatomical variations of proximal jejunal vein [the so-called 1st jejunal vein (J1v)] has been reported from a technical standpoint. The aim of this study was to retrospectively investigate the prognostic impact of the anatomical variations of J1v in the surgical treatment of resectable pancreatic cancer (PC).

PATIENTS AND METHODS

A total of 49 patients with resectable PC located in the uncinate process were included in this study. The J1v converging pattern was divided into 2 groups in terms of its relation to the SMA (i.e., the J1v status): i) group D: the J1v travels posterior to the SMA; ii) group V: the J1v travels anterior to the SMA. The associations between the J1v status and surgical outcome were assessed.

RESULTS

The 5-year survival rate after resection in group V (35%) was significantly lower than that in group D (70%) (p=0.029), and the J1v status of group V was the only independent negative prognostic factor (HR=5.49; 95% CI=1.69-19.3; p=0.005).

CONCLUSION

The J1v converging pattern is a significant prognostic variable in patients with PC located in the uncinate process: the J1v status of group V was significantly associated with impaired survival.

Feasibility of Identifying Patients at High Risk of Hereditary Gastric Cancer Based on Clinicopathological Variables

BACKGROUND/AIM

Multiplex gene panel tests using next-generation sequencing (NGS) are clinically available for gastric cancer (GC). The NGS tests can reveal unexpected pathogenic variants to be associated with hereditary diseases, i.e., secondary genetic findings. We investigated whether GC patients at high risk of having hereditary gastric cancer (HGC) can be identified by their clinicopathological variables before they undergo NGS cancer gene panel tests.

PATIENTS AND METHODS

The cases of 2,286 patients with GC treated at our hospital during the years 1999-2017 were retrospectively analyzed; of them, 143 patients were identified as being at high risk of having HGC (HR-HGC), and the remaining 2,143 patients were classified as having sporadic gastric cancer (SGC).

RESULTS

Compared to the SGC group, the HR-HGC status was significantly associated with younger age, female gender, macroscopic type IV and a histologically diffuse type. In a multivariate analysis, being young (i.e., ≤50 years old) was an independent risk factor for HR-HGC.

CONCLUSION

Female and young patients with diffuse-type GC are closely associated with a high risk of having HGC, and these factors might predict the detection of secondary genetic findings by NGS testing.

Abstract 5160: Extracellular vesicles from scirrhous gastric cancer cells induce premetastatic niche formation for peritoneal metastasis

Background: Human scirrhous gastric carcinoma (SGC) is also known as diffusely infiltrating carcinoma, type 4 on Borrmann’s criteria, and linitis plastica-type carcinoma. SGC is characterized by frequent peritoneal metastasis, high proliferation and infiltration activity with extensive fibrosis in the tumor stroma. We previously reported that a soluble factor(s) from SGC cells changed the peritoneum to pre-metastatic niche such as round shape of mesothelial cells and peritoneal fibrosis, which is a favorable environment for cancer cells to metastasize. Extracellular vesicles (EVs; Exosomes) might be one of soluble factor(s) which might change the peritoneal component to pre-metastatic niche. In this study, we investigated the effect of EVs from SGC cells on the pre-metastatic niche formation of the peritoneum.

Methods: Four SGC cell lines, OCUM-2M, OCUM-2MD3, OCUM-12, KATO-III, 2 non-SGC cell lines, MKN74, MKN45, and peritoneal mesothelial cells (PM cells) were used. The effect of EVs from gastric cancer cells on the peritoneum was examined in vitro and in vivo, as follows. PKH26-labeled EVs from OCUM-2MD3 cells were intravenously injected into nude mice for 3 weeks, then we examined the distribution of PKH26-labeled EVs by a fluorescence microscope. Next, we injected EVs intraperitoneally into nude mice, and investigated the morphology of peritoneum. Effect of EVs on the gene expression of PM cells was examined by RT-PCR. Clinical significance of EVs markers, CD9 and CD63, was evaluated by immunohistochemistry using 63 human gastric cancer specimens.

Results: PKH26-labeled EVs frequently distributed to peritoneum and the liver. The morphology of PM cells changed from round shape to spindle shape by EVs addiction in vitro and in vivo. mRNA expression level of ZEB and N-cadherin of PM cells was significantly increased following the addiction of EVs. The high expression of EVs

markers, CD9 and CD63, was significantly correlated with frequent peritoneal metastasis.

Conclusion: EVs from SGC cells might frequently distribute to mesothelial cells of peritoneum. EVs from SGC cells might play an important role for the formation of a pre-metastatic niche on peritoneum by the morphologic change of peritoneal mesothelial cells.

Citation Format: Tomohisa Okuno, Masakazu Yashiro, Shuhei Kushiyama, Sadaaki Nishimura, Shingo Togano, Kenji Kuroda, Tatsuro Tamura, Takahiro Toyokawa, Hiroaki Tanaka, Kazuya Muguruma, Kosei Hirakawa, Masaichi Ohira. Extracellular vesicles from scirrhous gastric cancer cells induce premetastatic niche formation for peritoneal metastasis [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 5160.

Abstract 3323: The feasibility for detecting hereditary genetic findings of familial gastric cancer

Background: Multiplex gene panel tests using next-generation sequencing has currently been clinically available for various cancer patients including gastric cancer in Japan. The original purpose of the Multiplex gene panel tests is to find actionable genetic alterations which might correlate with promising therapeutic antitumor drugs. Accordingly, secondary genetic findings as germline mutation which is associated with hereditary disease may also be detectable by the Multiplex gene panel tests. It has been reported that familial cancers represent around 5%–10% of all cancer patients. Gastric cancer is one of popular cancers in Japan. The prediction of patients with familial gastric cancer (FGC) before the multiplex gene panel tests might be important for the gene consultation for the patients and their family.

Objective: The aim of study is to clarify the characteristic clinico-pathologic features of FGC to predict the possibility of hereditary gastric cancer.

Patients and Methods: A total of 2301 gastric cancer patients who received gastrectomy at our department was enrolled in this study. We classified FGCs into 2 categories by modification of International Gastric Cancer Linkage Consortium (IGCLC) which excluded pathogenic types, as follows, group A: gastric cancer in an individual under the age of 40; group B: two gastric cancer cases in a family regardless of age. In contrast, the most gastric cancers were sporadic, which was classified as group C. The clinicopathological factors including E-cadherin and p53 expression by immunostaining, was retrospectively compared among 3 groups.

Results: One hundred and fifty-two cases (6.6%) of 2301 patients were classified as FGCs (group A: 71 cases; group B: 81 cases), whereas the remaining 2149 patients were classified as group C (93.4%). Female (43.4%) and diffuse-type gastric cancer (57.2%) was significantly (p&lt;0.001) more frequent in FGCs than that (30.5% and 42.5%) in group C. The significant difference (p&lt;0.05) of clinicopathological variables between group A (n=71) and B (n=81) was found in the rates of female (52.1% vs 35.8%), diffuse-type (83.1% vs 34.5%), and T4 status (38.0% vs 17.3%), respectively. There was also significant difference (p&lt;0.05) in the rates of female (52.1% vs 30.5%), diffuse-type (83.1% vs 42.5%) and Borrmann type 4 (15.5% vs 6.8%) between group A and C. No significant difference was found in clinicopathological variables between group B and C. No statistical correlation of E-cadherin loss between 3 groups. In this study, 2 cases were found in which p53 expression was positive for all cells.

Conclusion: Young age (&lt;40 years) and female patients with diffuse-type gastric cancer might have a high risk for FGC. It is necessary to take into consideration of hereditary gastric cancer when the multiplex gene panel test is performed for the young female gastric cancer patients with diffuse-type cancer.

Citation Format: Sadaaki Nishimura. The feasibility for detecting hereditary genetic findings of familial gastric 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 3323.

Abstract 2742: Bone marrow-derived stromal cells in the tumor microenvironment might be associated with the progression of gastric cancer

Purpose: It has been reported that the interaction between cancer cells and cancer-associated fibroblasts (CAFs) is closely associated with the progression of various types of cancer. The aim of this study is to clarify the role of bone marrow-derived stromal cells (BM-SCs), which are supposed to be the origin of CAFs in the tumor microenvironment, on the development of gastric cancer.

Methods: The effect of human BM-SCs which frequently express CD271 on the proliferation and motility of six gastric cancer cell lines, OCUM-2M, OCUM-2MD3, OCUM-12, KATO-III, NUGC-3, and MKN-74, was examined. CD271 expression levels in BM-SCs were analyzed by flow cytometry. We also generated a gastric tumor model by orthotopic inoculation of OCUM-2MD3 cells in mice that had received transplantation of bone marrow from CAG-EGFP mice. The correlation between the clinicopathological features of 279 primary gastric carcinomas and CD271 expression in tumor stroma was examined by immunohistochemistry.

Results: Numerous BM-SCs infiltrated the gastric tumor microenvironment; CD271 expression was found approximately 25% of BM-SCs. Conditioned medium from BM-SCs significantly increased the proliferation of gastric cancer cell lines. Furthermore, conditioned medium from gastric cancer cells significantly increased the number of BM-SCs, while migration of OCUM-12 and NUGC-3 cells was significantly increased by conditioned medium from BM-SCs. CD271 expression in stromal cells was significantly associated with macroscopic type-4 cancers, diffuse-type tumors, and tumor invasion depth. The overall survival of patients (n=279) with CD271-positive stromal cells was significantly worse than that of patients with CD271-negative stromal cells. This is the first report of the significance of BM-SCs in gastric cancer progression.

Conclusions: BM-SCs were abundant in the tumor microenvironment of gastric cancer in vivo. In vitro study also indicated that the crosstalk between BM-SCs and gastric cancer cells might play an important role for the development of gastric cancer. CD271-positive tumor stromal cells might be a useful predictive prognostic factor for patients with gastric cancer. BM-SCs, therefore, might be one of therapeutic targets for cancer treatment.

Citation Format: Masakazu Yashiro, Hiroaki Kasashima, Syuhei Kushiyama, Sadaaki Nishimura, Kenji Kuroda, Shingo Togano, Tomohisa Okuno, Yuichiro Miki, Tatsunari Fukuoka, Hirohisa Nakamae, Masayuki Hino, Masaichi Ohira. Bone marrow-derived stromal cells in the tumor microenvironment might be associated with the progression of gastric 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 2742.

Improved Value for the Gamow-Teller Strength of the ^{100}Sn Beta Decay

A record number of ^{100}Sn nuclei was detected and new isotopic species toward the proton dripline were discovered at the RIKEN Nishina Center. Decay spectroscopy was performed with the high-efficiency detector arrays WAS3ABi and EURICA. Both the half-life and the β-decay end point energy of ^{100}Sn were measured more precisely than the literature values. The value and the uncertainty of the resulting strength for the pure 0^{+}→1^{+} Gamow-Teller decay was improved to B_{GT}=4.4_{-0.7}^{+0.9}. A discrimination between different model calculations was possible for the first time, and the level scheme of ^{100}In is investigated further.

Proton Shell Evolution below ^{132}Sn: First Measurement of Low-Lying β-Emitting Isomers in ^{123,125}Ag

The β-delayed γ-ray spectroscopy of neutron-rich ^{123,125}Ag isotopes is investigated at the Radioactive Isotope Beam Factory of RIKEN, and the long-predicted 1/2^{-} β-emitting isomers in ^{123,125}Ag are identified for the first time. With the new experimental results, the systematic trend of energy spacing between the lowest 9/2^{+} and 1/2^{-} levels is extended in Ag isotopes up to N=78, providing a clear signal for the reduction of the Z=40 subshell gap in Ag towards N=82. Shell-model calculations with the state-of-the-art V_{MU} plus M3Y spin-orbit interaction give a satisfactory description of the low-lying states in ^{123,125}Ag. The tensor force is found to play a crucial role in the evolution of the size of the Z=40 subshell gap. The observed inversion of the single-particle levels around ^{123}Ag can be well interpreted in terms of the monopole shift of the π1g_{9/2} orbitals mainly caused by the increasing occupation of ν1h_{11/2} orbitals.

Prominence of Pairing in Inclusive (p,2p) and (p,pn) Cross Sections from Neutron-Rich Nuclei

Fifty-five inclusive single nucleon-removal cross sections from medium mass neutron-rich nuclei impinging on a hydrogen target at ∼250  MeV/nucleon are measured at the RIKEN Radioactive Isotope Beam Factory. Systematically higher cross sections are found for proton removal from nuclei with an even number of protons as compared to odd-proton number projectiles for a given neutron separation energy. Neutron removal cross sections display no even-odd splitting, contrary to nuclear cascade model predictions. Both effects are understood through simple considerations of neutron separation energies and bound state level densities originating in pairing correlations in the daughter nuclei. These conclusions are supported by comparison with semimicroscopic model predictions, highlighting the enhanced role of low-lying level densities in nucleon-removal cross sections from loosely bound nuclei.

A Case of Feline T-cell Lymphoma with Tropism for Striated Muscle and Peripheral Nerve

An 11-year-old female American shorthair cat was presented with a 3-month history of hindlimb ataxia and knuckling of the left forelimb. Clinical abnormalities included weight loss, hyperaesthesia of the neck and back, cardiac murmur and systemic muscle atrophy. The cat died 10 days after the initial presentation and a necropsy examination was performed. Grossly, extensive pale lesions were seen in the wall of the left ventricle and the septum of the heart. There were no detectable masses in the heart, skeletal muscles or peripheral nerves. Histopathological examination revealed diffuse, extensive infiltration of atypical lymphoid cells in the heart; the cardiac muscles were markedly degenerate and atrophic and were replaced by the neoplastic cells. Neoplastic cells with similar morphology were seen in all specimens of the skeletal muscles and peripheral nerves. Clonality analysis of the paraffin wax-embedded heart tissue revealed a monoclonal rearrangement of the gene encoding the T-cell receptor γ chain. Based on these findings, the case was diagnosed as T-cell lymphoma with tropism for striated muscle and peripheral nerve.

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.

Pseudorapidity Dependence of Particle Production and Elliptic Flow in Asymmetric Nuclear Collisions of p+Al, p+Au, d+Au, and ^{3}He+Au at sqrt[s_{NN}]=200 GeV

Asymmetric nuclear collisions of p+Al, p+Au, d+Au, and ^{3}He+Au at sqrt[s_{NN}]=200  GeV provide an excellent laboratory for understanding particle production, as well as exploring interactions among these particles after their initial creation in the collision. We present measurements of charged hadron production dN_{ch}/dη in all such collision systems over a broad pseudorapidity range and as a function of collision multiplicity. A simple wounded quark model is remarkably successful at describing the full data set. We also measure the elliptic flow v_{2} over a similarly broad pseudorapidity range. These measurements provide key constraints on models of particle emission and their translation into flow.

Erratum: Persistence of the Z=28 Shell Gap Around ^{78}Ni: First Spectroscopy of ^{79}Cu [Phys. Rev. Lett. 119, 192501 (2017)]

This corrects the article DOI: 10.1103/PhysRevLett.119.192501.

Acute Inflammatory Syndrome Paradoxically Induced by De Novo Purine Inhibitors Synthesis Before Renal Transplantation: A Case Report and Review of the Literature

BACKGROUND

Mycophenolate mofetil (MMF) and mizoribine (MZR) are increasingly used as immunosuppressive agents for organ transplantation and chronic inflammation. We report a patient with rheumatoid arthritis who had an acute inflammatory syndrome triggered by preoperative immunosuppression therapy with both MMF and MZR.

CASE REPORT

A 41-year-old woman with IgA nephropathy was referred to our department for living donor renal transplantation. She had rheumatoid arthritis that was adequately treated with prednisolone 5 mg once a day and salazosulfapyridine 2000 mg once a day. MMF 1000 mg twice a day was started for desensitization therapy. Three days later, the patient developed arthritis in the joints of her left hand and elevated inflammatory markers. On day 7, MMF was switched to MZR 150 mg 3 times a day. However, the symptoms extended to both shoulders and the joints of the right foot; MZR was discontinued. The arthritis and inflammatory markers improved. Two months later, the patient was rechallenged with MMF followed by MZR, resulting in a similar clinical course as previously. Tacrolimus (TAC) 3 mg twice a day and everolimus (EVL) 0.5 mg twice a day were introduced as alternative immunosuppressant therapies. No arthritis occurred. ABO-compatible living donor renal transplantation was successfully performed. The patient received TAC, EVL, prednisolone, rituximab, and basiliximab, and her postoperative course was uneventful without arthritis or rejection. At 9 months postoperatively, the serum creatinine was 0.79 mg/dL.

CONCLUSIONS

Acute inflammatory syndrome is an extremely rare complication triggered by preoperative immunosuppression therapy. If antimetabolites cannot be used in immunologically high-risk patients, transplantation becomes very difficult. Clinicians should keep in mind this paradoxical reaction.