Apocrine carcinoma-and-malignant myoepithelioma in a dog: a case of simultaneous malignant progression of both luminal epithelium and myoepithelium

A 9-y-old male Boxer dog developed a mandibular skin tumor, which histologically had a locally invasive growth pattern composed of bilayered structures of inner eosinophilic cuboidal tumor cells and outer clear polygonal tumor cells with cytoplasm containing glycogen granules. Both cell populations gradually changed from low-grade morphologic features to highly anaplastic ones. Immunohistochemically, the eosinophilic tumor cells were positive for cytokeratin 8, a useful marker for luminal epithelial cells. In contrast, the clear tumor cells expressed several myoepithelial markers, including α-smooth muscle actin, p63, and cytokeratin 14. Based on these histologic and immunohistochemical characteristics, we diagnosed this apocrine sweat gland tumor as a carcinoma-and-malignant myoepithelioma with high-grade transformation of both luminal and myoepithelial cells. Our case may be a helpful reference for the histogenesis of carcinoma-and-malignant myoepithelioma, in which both the luminal epithelial and myoepithelial components are malignant.

Infective endocarditis with systemic bacterial embolism caused by Staphylococcus aureus in a free-ranging Amami rabbit (Pentalagus furnessi)

The Amami rabbit (Pentalagus furnessi) is found only on the two islands of Amami-Ōshima and Tokunoshima in southwest Japan. It has a primitive appearance and ecology, is an evolutionarily valuable animal and has been assigned to the International Union for Conservation of Nature Red List of Threatened Species. We describe a case with mild purulent wounds on the distal digital skin of both forelimbs and multiple nodular lesions in various organs, including the heart and kidney. Microscopically, the heart lesions were characterized by disruption of the mitral valve and multifocal myocardial necrosis and abscesses due to infection with gram-positive cocci. Similar bacterial infarctions were also found in other organs, including the kidneys. The bacteria were identified as Staphylococcus aureus by immunohistochemical and molecular biological examinations. This first report of infective endocarditis and systemic infarctions caused by S. aureus in an Amami rabbit indicates the importance of monitoring purulent injuries, even if mild, to prevent secondary infections in this species.

Histological, immunohistochemical and ultrastructural features of polyglucosan bodies in uterine smooth muscle of pet rabbits (Oryctolaguscuniculus)

We document the frequency and morphological and immunohistochemical features of inclusion bodies in uterine smooth muscle cells in 56 (76%) of 74 investigated pet rabbits (Oryctolagus cuniculus). Inclusion bodies began to appear at the age of 2 years and their frequency increased with age (P = 0.047, r = 0.33). They ranged from 5 to 20 μm in diameter, were slightly basophilic to amphophilic with well-delimited oval bodies in haematoxylin and eosin-stained tissue sections and formed in the cytoplasm of the uterine smooth muscle cells with displacement of the cell nuclei. The inclusion bodies were positive with periodic acid-Schiff, Best's carmine, Lugol's iodine and Grocott's methenamine silver methods. They were immunoreactive to a monoclonal antibody raised against human polyglucosan and negative with monoclonal antibodies for several intermediate filament proteins. Electron microscopy revealed that they were non-membranous structures composed of electron-dense amorphous material. The morphological, histochemical, immunohistochemical and ultrastructural features of the inclusion bodies in the rabbi uteri were similar to those of human polyglucosan bodies (PGBs). PGBs appear to occur at a high frequency in the uterus of rabbits, which are known to be susceptible to uterine diseases.

Multiple cystic sphere formation from PK-8 cells in three-dimensional culture

Three-dimensional (3D) culture of cancer cells mimics the in vivo environment. Recently, we reported that pancreatic ductal adenocarcinoma (PDAC) cell lines with epithelial and mesenchymal features formed differently shaped spheres in 3D culture. However, only PK-8 cells, the epithelial PDAC cell line with the highest E-cadherin expression among the eight PDAC cell lines, formed multiple cystic spheres in 3D culture. Optical coherence tomography revealed interconnected cysts inside the spheres. A weak inter-cellular adhesion, individual cell degeneration, necrosis, and secretory granules in the cytoplasm were observed in the PK-8 spheres using electron microscopy. The expression of MUC1, MUC5AC, and amylase was increased in PK-8 cells in the 3D culture compared with that in 2D culture. These findings suggest that highly E-cadherin-expressing epithelial PK-8 cells form multiple cystic spheres, which may be promoted by enhanced mucin and amylase synthesis in 3D culture.

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PK-8 cells highly express E-cadherin in multiple cystic spheres in 3D culture.

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The cysts within the PK-8 spheres are interconnected.

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Individual cell degeneration and necrosis was observed in PK-8 spheres.

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MUC1, MUC5, and amylase levels increased in PK-8 spheres.

Three new species of Eimeria (Apicomplexa: Eimeriidae) from the Amami rabbit, Pentalagus furnessi (Mammalia: Leporidae)

The Amami rabbit, Pentalagus furnessi (Mammalia: Lagomorpha: Leporidae), is a relict and endangered species endemic to the Amami-Oshima and Tokunoshima Islands, located in southwestern Japan. Here, we described three new species of Eimeria (Apicomplexa: Eimeriidae) parasites detected from fecal samples of wild Amami rabbits. Eimeria furnessi n. sp., recorded in 21 (58.3%) samples, has ellipsoidal oocysts with two walls and micropyle, 26.0 × 16.6 μm, and elongate-ovoidal sporocysts, 13.1 × 6.3 μm, with Stieda body. Eimeria hilleri n. sp., recorded in 9 (25.0%) samples, has ellipsoidal oocysts with two walls and micropyle, 34.7 × 21.4 μm, and elongate-fusiform to elongate-ovoidal sporocysts, 15.7 × 8.3 μm, with Stieda and substieda bodies. Eimeria sagentae n. sp., recorded in 13 (36.1%) samples, has ellipsoidal oocysts with two walls and micropyle, 20.9 × 14.5 μm, and elongate-ovoidal sporocysts, 10.4 × 5.0 μm, with Stieda body. The three new species can be distinguished by the size and color of their oocysts. Further studies related to the pathogenicity of these parasites can improve the breeding and propagation procedures of the Amami rabbit.

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Amami rabbit, Pentalagus furnessi, only can be found on two small islands in Japan.

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Eimeria spp. detected in fecal samples underwent morphological studies.

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New species were defined as Eimeria furnessi, E. hilleri, and E. sagentae.

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The three new species can be distinguished by their oocysts size and color.

Abstract 2449: FGFR4 inhibitor BLU9931 induces cellular senescence in pancreatic ductal adenocarcinoma cell lines promoting sensitivity to senolytic therapy

Purpose: Fibroblast growth factor receptor 4 (FGFR4), one of the four tyrosine kinase receptors for FGFs, is involved in various cellular processes. Activation of the FGF19/FGFR4 signaling is strongly associated with cancer development and progression. BLU9931 is an irreversible and highly selective small-molecule inhibitor of FGFR4. In this study, we aimed to elucidate the role of FGF19/FGFR4 signaling using BLU9931 in human PDAC.

Experimental procedures: The expression of FGFR4 in eight human PDAC cell lines were examined using real-time PCR, immunoblotting, and FACS analysis. The effects of BLU9931 on FGFR4-positive PDAC cells were examined using growth assay, cell cycle assay, immunoblotting of downstream targets of FGF19/FGFR4 signaling, real-time PCR analysis of stemness markers, and sphere forming assays. Motility was evaluated using migration and invasion assays. Matrix metalloproteinase activity was evaluated using gelatin zymography. Induction of senescence was evaluated using senescence-associated β-galactosidase activity and real-time PCR analysis of senescence-associated, phenotype-related secretory genes. The synergistic effects of senolytic drugs on BLU9931-treated cells were evaluated using ATP assay. Expression and clinicopathological features of FGFR4 in PDAC patients were examined using immunohistochemical analysis of tissue microarrays.

Results: In human PDAC cases, FGFR4 expression was positively correlated with larger primary tumors and more advanced disease stage. Among the eight PDAC cell lines, FGFR4 was expressed at the highest level in PK-1 cell line, in which the single-nucleotide polymorphism G388R in FGFR4 was detected. Inhibition of signal transduction through the ERK, AKT, and STAT3 pathways by BLU9931 reduced proliferation of FGF19/FGFR4 signaling-activated PDAC cells. In contrast, BLU9931 did not alter stemness features, including stemness marker expression, anticancer drug resistance, and sphere-forming ability of PK-1 cells. However, BLU9931 inhibited cell invasion, in part, by downregulating membrane-type matrix metalloproteinase-1 (MT1-MMP) expression in FGF19/FGFR4 signaling-activated PDAC cells. Furthermore, downregulation of SIRT1 and SIRT6 by BLU9931 contributed to senescence induction, priming these cells for quercetin-induced death, a process termed senolysis.

Conclusions: We demonstrated that inhibition of signal transduction pathways through the ERK, AKT, and STAT3 pathways by BLU9931 inhibited PDAC cell proliferation and invasion, in part by downregulating MT1-MMP expression in autocrine/paracrine FGF19/FGFR4 signaling-positive PDAC cells. Furthermore, downregulation of SIRT1 and SIRT6 by BLU9931 may have contributed to senolysis in these cells. Thus, we propose that BLU9931 may be a promising drug for the treatment of FGFR4-positive PDAC.

Citation Format: Norihiko Sasaki, Fujiya Gomi, Hisashi Yoshimura, Masami Yamamoto, Yoko Matsuda, Masaki Michishita, Hitoshi Hatakeyama, Yoichi Kawano, Yoko Itakura, Masashi Toyoda, Murray Korc, Toshiyuki Ishiwata. FGFR4 inhibitor BLU9931 induces cellular senescence in pancreatic ductal adenocarcinoma cell lines promoting sensitivity to senolytic therapy [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 2449.

POS0532 AveRAGE PREDNISOLONE DOSE OF ONLY 1 MG PER DAY WAS RISK FACTOR FOR CLINICAL FRACTURES IN PATIENTS WITH RHEUMATOID ARTHRITIS - NINE-YEAR FINDINGS OF THE TOMORROW STUDY

Background:

Previous cohort studies showed that the use of prednisolone (PSL) was a risk factor for clinical fractures in patients with rheumatoid arthritis (RA). However, there are few reports on relationship between PSL dose and clinical fractures.

Objectives:

The present study aimed to determine the effect of PSL dose on the incidence of clinical fractures in the RA patients treated with PSL.

Methods:

We evaluated anthropoetric parameters, bone mineral density (BMD), disease activity score 28-erythrocyte sedimentation rate (DAS28-ESR), RA medication (methotrexate (MTX) dose, use of biologic disease modified anti-rheumatic-drugs (bDMARDs), and PSL dose) and the incidence of clinical fractures during nine years in RA patients who participant the TOMORROW study (UMIN000003876), which is a 10-years prospective cohort study. Data on clinical fracture was self-reported on the questionnaires. In this analysis, the data of RA patients treated with PSL at least once during nine-year period were evaluated. We analyzed the average dose of PSL until the incidence of the clinical fractures. The risk factor for clinical fractures were analyzed by using Cox proportional hazard model with adjustment for age, sex, body mass index (BMI), and smoking history.

Results:

We analyzed the data of 67 RA patients treated with PSL. Among them, median age was 61.8 year, 56 patients (83.6%) were female, 47 patients (70.1%) were never smoker and median disease duration was 12.1 year. The number of patients treated with PSL at baseline was 48 (69.1%). During 9 years, 23 clinical fractures were observed in 67 patients, and the incidence of clinical fracture was 0.046/person-year. In 19 patients, who were not treated with PSL at baseline but treated with PSL at least once during 9 years, 5 clinical fractures were observed. In 67 RA patients, Cox proportional hazard analysis revealed that baseline disease activities, BMD at thoracic vertebrae and medication were not significant risk factors for clinical fractures. However, average PSL dose of more than only 1 mg/day was a significant risk factor for the incidence of clinical fracture (hazard ratio (HR): 2.80; p=0.03) (Table 1).

Table 1.

Adjusted hazard ratio for clinical fractures in patients with rheumatoid arthritis treated with PSL.

* Adjusted Hazard ratio95% Confidence intervalP valueCRP (mg/dL)1.290.88-1.910.19RF (IU/mL)0.990.99-1.000.07ACPA (U/mL)0.990.98-1.000.18DAS28-ESR0.990.71-1.390.97BMD at thoracic vertebrae (mg/cm2)0.020.00-1.000.05bDMARDs use0.550.23-1.320.18Bisphosphonate use2.330.95-5.710.07average dose of MTX (mg/week)1.020.92-1.120.74average score of DAS28-ESR1.150.76-1.750.52average dose of PSL more than 1mg/day2.81.09-7.240.03

*Hazard ratio was adjusted for age, sex, body mass index (BMI), and smoking history. RF, Rheumatoid factor; ACPA, Anti-cyclic citrullinated peptide antibody; DAS28-ESR, disease activity score 28-erythrocyte sedimentation rate; BMD, Bone mineral density; bDMARDs, biologic disease modified anti-rheumatic-drugs; MTX, methotrexate; PSL, prednisolone.

Conclusion:

In RA patients treated with PSL, average PSL dose of only 1mg/day significantly increased the risk for the incidence of clinical fractures. Even for established RA patients, continuous use or initiation of low PSL dose was apparently significant risk factor for clinical fractures.

Disclosure of Interests:

Hitoshi Yoshimura: None declared, Tatsuya Koike Grant/research support from: Takeda Pharmaceutical, Mitsubishi Tanabe Pharma Corporation, Chugai Pharmaceutical, Eisai, Abbott Japan, Teijin Pharma, Banyu Pharmaceutical and Ono Pharmaceutical, Kenji Mamoto: None declared, Yuko Sugioka: None declared, Tadashi Okano: None declared, Masahiro Tada: None declared, Kentaro Inui Grant/research support from: Janssen Pharmaceutical K.K. and Astellas Pharma Inc, Hiroaki Nakamura: None declared

Involvement of Nestin in the Progression of Canine Mammary Carcinoma

Nestin, a class VI intermediate filament protein, is known to be expressed in various types of human neoplasms, including breast cancer, and is associated with their progression. However, its expression and role in canine mammary tumors remain unknown. We analyzed nestin expression in canine mammary tumors using in situ hybridization and immunohistochemistry. We also investigated its role in a canine mammary carcinoma cell line using RNA interference. Nestin expression was not observed in luminal epithelial cells of any of the 62 cases of benign mammary lesions examined, although myoepithelial cells showed its expression in most cases. In 16/50 (32%) primary mammary carcinomas and 6/15 (40%) metastases of mammary carcinomas, cytoplasmic nestin expression was detected in luminal epithelial cells. In luminal cells of primary mammary carcinomas, its expression was positively related to several pathological parameters that indicate high-grade malignancy, including histological grading (P < .01), vascular/lymphatic invasion (P < .01), Ki-67 index (P < .01), and metastasis (P < .05). Immunohistochemistry revealed that nestin expression was related to vimentin expression in mammary carcinomas (P < .01). This relationship was confirmed using reverse transcription-quantitative polymerase chain reaction using 9 cell lines derived from canine mammary carcinoma (P < .01). Finally, nestin knockdown in canine mammary carcinoma cells using small interfering RNA inhibited cell proliferation and migration based on WST-8, Boyden chamber, and cell-tracking assays. These findings suggest that nestin may at least partially mediate these behaviors of canine mammary carcinoma cells.

Genomic characterisation of bovine papillomavirus types 1 and 2 identified in equine sarcoids in Japan

BACKGROUND

Bovine papillomavirus types 1 and 2 (BPV1/2) infection in horses has been associated with the development of equine sarcoids. Previous findings revealed the presence of sarcoid-associated BPV sequence variants that have been proposed as a key factor of cross-species infection in horses. To verify this hypothesis, sarcoid-associated BPV variants should be identified regardless of geographic location.

OBJECTIVES

Sequence analyses of BPV1/2 derived from both horses and cattle were conducted to clarify the sarcoid-associated sequence variants. The aim of this study was to clarify the correlation between BPV phylogeny and the geographic origin/host species.

STUDY DESIGN

Cross-sectional study.

METHODS

Conventional PCR to detect BPV1/2 was performed with genomic DNA extracted from equine sarcoid (n = 10) and bovine papilloma (n = 10) samples collected in Japan. Direct sequencing results were compared between equine and bovine (equine/bovine)-derived BPV to identify sarcoid-associated variants of two early regions (E2, E5), one late region (L1) and the long control region (LCR). Phylogenetic and phylogeny-trait correlation were analysed using Bayesian Markov chain Monte Carlo (MCMC) method and Bayesian tip-association significance testing (BaTS).

RESULTS

Seven BPV1 and three BPV2 were identified from equine sarcoids using PCR and direct sequencing. Sequence analysis of equine/bovine-derived samples showed no sarcoid-associated variants in four regions (E2, E5, L1 and LCR) of either BPV1 or BPV2. The phylogenetic tree of BPV1 E2, L1 and LCR tended to cluster within its geographic origins. BaTS analysis demonstrated that BPV1 sequence variability may be due to the geographic origin rather than host species difference.

MAIN LIMITATIONS

There was a limitation in sample numbers.

CONCLUSIONS

This study supports the geographic-specific hypothesis of sequence variability, suggesting that BPV1 is shared between local equids and bovids. However, more extensively collected sequences worldwide and functional evaluations are needed to verify the geographic-specific sequence variability of BPV1/2 between equine- and bovine-derived sequence.

FGFR4 Inhibitor BLU9931 Attenuates Pancreatic Cancer Cell Proliferation and Invasion While Inducing Senescence: Evidence for Senolytic Therapy Potential in Pancreatic Cancer

Simple Summary

Pancreatic ductal adenocarcinoma (PDAC) is a deadly malignancy that is projected to become the leading cause of cancer death by 2050. Fibroblast growth factor receptor 4 (FGFR4) is a transmembrane receptor that is overexpressed in half of PDACs. We determined that its expression in PDAC positively correlated with larger tumor size and more advanced tumor stage, and that BLU9931, a selective FGFR4 inhibitor, reduced PDAC cell proliferation and invasion while promoting their senescence. Quercetin, a senolytic drug, induced cell death in BLU9931-treated cells. We propose that targeting FGFR4 in combination with senolysis could provide a novel therapeutic strategy in patients whose PDAC expresses high FGFR4 levels.

Abstract

Fibroblast growth factor receptor 4 (FGFR4), one of four tyrosine kinase receptors for FGFs, is involved in diverse cellular processes. Activation of FGF19/FGFR4 signaling is closely associated with cancer development and progression. In this study, we examined the expression and roles of FGF19/FGFR4 signaling in human pancreatic ductal adenocarcinoma (PDAC). In human PDAC cases, FGFR4 expression positively correlated with larger primary tumors and more advanced stages. Among eight PDAC cell lines, FGFR4 was expressed at the highest levels in PK-1 cells, in which single-nucleotide polymorphism G388R in FGFR4 was detected. For inhibition of autocrine/paracrine FGF19/FGFR4 signaling, we used BLU9931, a highly selective FGFR4 inhibitor. Inhibition of signal transduction through ERK, AKT, and STAT3 pathways by BLU9931 reduced proliferation in FGF19/FGFR4 signaling-activated PDAC cells. By contrast, BLU9931 did not alter stemness features, including stemness marker expression, anticancer drug resistance, and sphere-forming ability. However, BLU9931 inhibited cell invasion, in part, by downregulating membrane-type matrix metalloproteinase-1 in FGF19/FGFR4 signaling-activated PDAC cells. Furthermore, downregulation of SIRT1 and SIRT6 by BLU9931 contributed to senescence induction, priming these cells for quercetin-induced death, a process termed senolysis. Thus, we propose that BLU9931 is a promising therapeutic agent in FGFR4-positive PDAC, especially when combined with senolysis (195/200).

Primary Lymphangiosarcoma of the Urinary Bladder in a Dog

Abdominal ultrasonographical and computed tomography examinations of a 12-year-old neutered female toy poodle revealed a protruding mass, approximately 2 cm in diameter, at the apex of the bladder. The mass was firm and haemorrhagic with a homogeneously brownish-yellow cut surface. Microscopically, it was unencapsulated and located in the muscle layer with invasion of the extra-muscular layer. It was composed of spindloid to oval neoplastic cells that formed irregular clefts and diffuse sheets that dissected bundles of collagen. Immunohistochemically, the neoplastic cells were positive for vimentin and lymphatic vessel endothelial hyaluronan receptor 1 antigens, but negative for cytokeratin AE1/AE3, factor VIII-related antigen, CD31, CD34, Prox-1, S100, desmin, α-smooth muscle actin and MyoD1. Negative immunolabelling for laminin antigen supported the absence of evidence of a basal lamina on ultrastructural examination. Based on these findings, this tumour was identified as a lymphangiosarcoma. To the best of our knowledge, this case is the first report of lymphangiosarcoma arising from the bladder in a dog.

Alien parasitic infections in the endangered Ryukyu long-furred rat (Diplothrix legata) on Amami-Oshima Island, Japan

There is limited knowledge about parasites of the endangered Ryukyu long-furred rat, Diplothrix legata (Murinae, Rodentia) endemic to Okinawa, Tokunoshima, and Amami-Oshima Islands in Japan. In the present study, postmortem histopathological examination of an individual found on Amami-Oshima Island revealed a mixed helminth infection of Calodium hepaticum, Hydatigera taeniaeformis, and Angiostrongylus cantonensis. These helminths are considered non-native to Amami-Oshima Island and are maintained by invasive mammals, such as non-native rats and outdoor cats. This observation presents a new host record for C. hepaticum and H. taeniaeformis and the first record of A. cantonensis in Ryukyu long-furred rat on Amami-Oshima Island.

Hepatic neuroendocrine carcinoma with metastases to the lymph nodes in a sika deer (Cervus nippon yakushimae)

A 26-year and 6-month-old male sika deer that was kept at the Showa Park, Tokyo, Japan, collapsed and died of severe disease wasting and severe tabefaction. Grossly, numerous masses, 0.3–1.0 cm diameter, were dispersed throughout the liver. The multiple masses were composed of tumor cells, which had hypochromatic nuclei and abundant faintly eosinophilic cytoplasm, arranged in nests of various sizes. Immunohistochemically, tumor cells were positive for cytokeratin, chromogranin A, synaptophysin and gastrin. Ultrastructurally, the cytoplasm of the tumor cells contained abundant membrane-bound electron-dense granules. A metastatic lesion was observed in the renal, hepatic and pancreatic lymph nodes. On the basis of these findings, this tumor was diagnosed as a neuroendocrine carcinoma with metastases to the lymph nodes.

Diffuse Pulmonary Meningotheliomatosis with Sarcomatous Transformation in a Shiba Dog

A 2-year-old neutered female Shiba dog exhibited laboured breathing for 1 month. Computed tomography of the thoracic cavity revealed multiple nodules (2-5 mm diameter) in the lungs. Grossly, the lungs were firm and normal in shape. The nodules were grey-white in colour. Microscopically, the nodules were non-encapsulated and exhibited an irregular shape. They were composed of polygonal or spindle cells with indistinct cell borders arranged in sheets. The cells had large, round, hyperchromatic nuclei and abundant pale eosinophilic cytoplasm with no atypia. Intrapulmonary arterial emboli and infiltration into the bronchioles were observed. Immunohistochemically, the cells were positive for vimentin and negative for cytokeratin, glial fibrillary acidic protein and α-smooth muscle actin. Ultrastructurally, the cells displayed cytoplasmic processes, desmosomes and intermediate filaments. These findings led to a diagnosis of diffuse pulmonary meningotheliomatosis with sarcomatous transformation. To the best of our knowledge, this is the first report of diffuse pulmonary meningotheliomatosis in a dog.

Abstract 3568: Metastasis-promoting role of H19 long non-coding RNA in pancreatic cancer cells

The H19 long non-coding RNA is highly expressed and carries out various functions in different types of cancers. Recently, we reported that H19 contributes to the metastasis of pancreatic ductal adenocarcinoma (PDAC) cells and its inhibition reduces metastasis in vivo. However, the molecular mechanisms underlying the metastasis-promoting role of H19 in PDAC cells remain unclear. With a focus on cancer stem cells (CSCs), we elucidated the mechanisms by which H19 regulates PDAC metastasis through the overexpression and knockdown of H19 in PDAC cells. To determine whether H19 is expressed heterogeneously or homogeneously in human PDAC cells, we examined its expression in PANC-1 cells using a highly sensitive in situ hybridization technique. Under 2D-culture conditions, PANC-1 cells showed heterogeneous H19 expression and the presence of small populations of H19-expressing cells. In contrast, numerous H19-expressing PANC-1 cells were detected in 3D-cultured spheres. These results suggest that H19 is expressed in CSC-like cells among PANC-1 cells. To investigate the involvement of H19 in the development of CSC characteristics, we examined self-renewal ability, anti-cancer drug resistance, and CSC-marker expression. Sphere formation of PDAC cells depended on H19expression. However, other CSC characteristics of the cells, including CSC-marker expression and anticancer-drug resistance were unaffected by H19 levels. In addition to its role in the development of CSC characteristics, we investigated the involvement of H19 in stromal invasion, which is a key step in the metastatic cascade. Although the invasion ability of PDAC cells was dependent on H19 expression, metalloproteinase activity, a key mediator of invasion, was independent of H19 expression. During the process of invasion, a critical event is the adhesion of cancer cells to the extracellular matrix. Therefore, we investigated whether H19 contributes to this cell-to-matrix adhesion step. We found that H19 promoted cell adhesion by regulating the expression of integrins and CD24. Notably, the increased adhesion of H19-overexpressing cells was blocked by an anti-β1-integrin antibody, which resulted in the inhibition of sphere formation and invasion. Taken together, H19 plays critical roles in CSC self-renewal and cell adhesion of PDAC cells that lead to invasion and metastasis. Our findings suggest that H19 represents a novel therapeutic target for the metastasis of pancreatic cancer.

Citation Format: Norihiko Sasaki, Masashi Toyoda, Hisashi Yoshimura, Yoko Matsuda, Tomio Arai, Yoko Itakura, Fujiya Gomi, Junko Aida, Toshiyuki Ishiwata. Metastasis-promoting role of H19 long non-coding RNA in pancreatic cancer cells [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 3568.

Toxoplasma gondii infection in Amami spiny rat on Amami-Oshima Island, Japan

The Amami spiny rat (Tokudaia osimensis) is an endangered rodent species that is endemic to the forests of Amami-Oshima Island, Kagoshima, Japan. In July 2018, a deceased adult male Amami spiny rat was found on the Yuwandake Mountain Trail on the south-central coast of Amami-Oshima Island. Histopathological observations revealed protozoan infections in the liver, lungs, and heart. Nested or semi-nested PCRs targeting the B1, SAG3, GRA6, and ROP18 genes successfully detected the genomic DNA of Toxoplasma gondii in the formalin-fixed and paraffin-embedded specimen. Sequence analyses of the SAG3, GRA6, and ROP18 genes suggested that the strain detected in the study specimen was related to the type II strain of T. gondii. This is the first confirmed case of T. gondii infection in an Amami spiny rat.

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A deceased Amami spiny rat was diagnosed with disseminated toxoplasmosis.

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We present the first case report of T. gondii infection in the Amami spiny rat.

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Feral cat populations require control to avoid the spread of T. gondii infection.

Malignant rhabdoid tumor of the musk gland and systemic T-cell lymphoma in a masked palm civet (Paguma larvata)

A 21-year-old male masked palm civet died after 2 months of continuous abdominal distention and poor appetite. Grossly, both musk glands were markedly swelled. Microscopically, round, polygonal and spindle neoplastic cells proliferated diffusely in the right musk gland and a metastatic focus was observed in the lung. The neoplastic cells had abundant cytoplasm with faintly eosinophilic inclusions that ultrastructurally corresponded to whorl aggregates of intermediate filaments. Immunohistochemically, these cells were positive for vimentin, cytokeratins and glial fibrillary acidic protein and negative for desmin. Based on these findings, the tumor was diagnosed as malignant rhabdoid tumor. Papillary adenoma was seen in the opposite musk gland. T-cell lymphoma of the lymph nodes, small intestine and liver was considered as the cause of death.

Expression and Roles of S100A4 in Anaplastic Cells of Canine Mammary Carcinomas

S100A4 (metastasin), a member of the S100 protein family, was initially identified in metastatic cells and is well established as a marker of aggressive human cancer. However, expression and roles of S100A4 in canine mammary tumors have not been clarified. In this study, expression of S100A4 was examined immunohistochemically in normal, hyperplastic, and neoplastic mammary glands of dogs. In all normal and benign lesions, S100A4 was restricted to a few stromal fibroblasts and inflammatory cells. However, in 7 of 57 (12%) of the malignant tumors examined, cytoplasmic and nuclear expression of S100A4 was observed in epithelial tumor cells and stromal cells. Particularly, the frequency of S100A4-positive anaplastic carcinomas was high (4/8 cases, 50%). Next, we established a novel cell line, named NV-CML, from a S100A4-positive canine mammary carcinoma. The cultured NV-CML cells and the tumors that developed in the immunodeficient mice after subcutaneous injection of the cells maintained the immunophenotype of the original tumor, including S100A4 expression. Using this cell line, we examined the cellular functions of S100A4 using RNA interference. S100A4 expression level in NV-CML cells transfected with small interfering RNA (siRNA) targeting canine S100A4 (siS100A4) was reduced to about one-fifth of those with negative-control siRNA (siNeg). Cell proliferation in WST-8 assay and cell migration in Boyden chamber assay were significantly decreased in siS100A4-transfected cells compared with siNeg-transfected cells. These findings suggest that S100A4 may be related to progression of canine mammary carcinomas via its influence on cell growth and motility.

Pancreatic cancer stem cells: features and detection methods

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with a high incidence of distant metastasis and recurrence. Cancer stem cells (CSCs), which are pluripotent, self-renewable, and capable of forming tumors, contribute to PDAC initiation and metastasis and are responsible for resistance to chemotherapy and radiation. Three types of experimental methods are commonly used to identify CSCs: CSC-specific marker detection, a sphere-formation assay that reveals cell proliferation under non-adherent conditions, and detection of side-population (SP) cells that possess high intracellular-to-extracellular pump functions. Several CSC-specific markers have been reported in PDACs, including CD133, CD24, CD44, CXCR4, EpCAM, ABCG2, c-Met, ALDH-1, and nestin. There remains controversy regarding which markers are specific to PDAC CSCs and which are expressed alone or in combination in CSCs. Examining characteristics of isolated CSCs and discovering CSC-specific treatment options are important to improve the prognosis of PDAC cases. This review summarizes CSC-detection methods for PDAC, including CSC-marker detection, the sphere-formation assay, and detection of SP cells.

Reduced expression of the H19 long non-coding RNA inhibits pancreatic cancer metastasis

H19 is an oncofetal RNA expressed in the developing embryo as well as in bladder, breast, gastric, pancreatic, hepatocellular, and prostate cancers. Recent studies have shown that H19 enhances cancer invasion and metastasis; however, its roles in cancer remain controversial. In the current study, H19 exhibited the second largest increase (82.4-fold) and represented the only non-protein coding gene among 11 genes identified that were elevated over 10-fold in lung-metastasis-derived pancreatic cancer cells compared with their parental cells using a mouse metastatic model. Subsequently, we further clarified the roles of H19 in pancreatic cancer growth and metastasis using in vitro and in vivo techniques. In situ hybridization showed that H19 was detected in 23 of 139 invasive ductal carcinomas (17%), and that H19 expression positively correlated with higher histological grades (P < 0.0001). Overexpression of H19 in PANC-1 pancreatic cancer cells induced higher motilities, whereas H19 inhibition using shRNA and siRNA showed opposite results; however, cell growth rates were not impacted. Intravenous injection of H19 shRNA vector-transfected PANC-1 cells yielded marked inhibition of metastasis in the liver and lungs of immunodeficient mice. These findings suggest that H19 has important roles in pancreatic cancer metastasis, and that inhibition of H19 represents a novel candidate for pancreatic cancer therapy.

Expression and role of long non-coding RNA H19 in carcinogenesis

With the recent advent of whole genome and transcriptome sequencing technologies, long non-coding RNAs have been brought into the spotlight in molecular biology. H19 was one of the first reported long non-coding RNAs; its expression is high in embryonic organs and absent or greatly reduced in most adult tissues. Accumulating evidence suggests that H19 plays crucial roles in embryogenesis. However, its levels are increased in different cancers, including breast, hepato-gastrointestinal, urological, respiratory, and brain tumors. Although there have been several controversial reports as to whether H19 is oncogenic or tumor-suppressive, most studies have indicated that H19 is associated with growth, migration, invasion, and/or metastasis in many cancers; however, its reported functional mechanisms vary among cancer types. Furthermore, serum H19 levels in patients with certain cancers have been suggested to be useful for diagnosis and prognosis. Thus, H19 long non-coding RNA might be a candidate for development of promising therapeutic and diagnostic modalities for several cancers. The purpose of this review is to provide an inclusive report on the functional role of H19 in different cancers.

Cutaneous Angiolymphoid Hyperplasia in a Dog

A 5-year-old male miniature dachshund was presented with a dermal nodule on the left forelimb that increased to 5 mm in diameter over a 2-month period. Grossly, the nodule was firm, and both the external and cut surfaces were homogeneously pale pink in colour. Microscopically, the nodule was comprised of mainly plump endothelial cells and inflammatory cells; among the latter, lymphocytes were predominant, with few scattered plasma cells, mast cells and macrophages. Lymphoid follicles with germinal centres were often observed. Mitotic figures were not observed amongst the endothelial cells. Immunohistochemically, the endothelial cells were positive for vimentin, factor VIII-related antigen and CD31, and the surrounding cells were positive for smooth muscle actin. Lymphocytes expressed CD3 or BLA36. These findings led to a diagnosis of cutaneous angiolymphoid hyperplasia. To the best of our knowledge, this is the first report of a cutaneous proliferative disorder comprising an admixture of proliferating vascular endothelial cells and lymphocytic infiltration with follicle formation in a dog.

Disseminated histiocytic sarcoma with hemophagocytosis in a rabbit

A 7-year-old female domestic rabbit suffered from labored respiration, poor appetite, mild anemia and thrombocytopenia. Radioscopic examination revealed masses in multiple locations including the intrapleural cavity and spleen. Forty-three days after the first visit to a private veterinary clinic, the rabbit died of severe respiratory distress. Microscopically, all of the masses were composed of round to polygonal neoplastic cells with distinct cell borders that were arranged in a sheet pattern. Multinucleated giant neoplastic cells were often observed. Some neoplastic cells had phagocytozed one or more erythrocytes. Immunohistochemical staining revealed that the neoplastic cells expressed vimentin, CD204, Iba-1 and lysozyme, but not CD163. Based on the morphological and immunohistochemical findings, this case was diagnosed as disseminated histiocytic sarcoma with hemophagocytosis.

Abstract 3484: A long non-coding RNA, H19, as a novel therapeutic target for pancreatic cancer metastasis

Long non-coding RNAs (lncRNAs) comprise mRNA-like transcripts longer than 200 ribonucleotides and lack significant open reading frames. Recently, long non-coding RNAs have been reported to play important roles in epigenetic regulation, and acts on precursors or inhibitor of micro RNA. In our previous studies, we injected PANC-1, human pancreatic cancer cells into the spleens of NOG mice, and established a lung metastasis-derived cell line from lung metastatic nodules. Lung metastasis derived pancreatic cells had a high metastatic ability to liver and lungs compared with the parental cells (Matsuda et al., Am J Pathol, 2014). To examine the different gene expressions between the lung metastasis derived cells and parental cells, we performed a DNA microarray analysis. We found that 11 genes were expressed at greater than 10-fold levels in lung metastasis derived cancer cells compared to their parental cells. H19 showed an 82.4-fold increase in expression levels, and it was the second most increased and the only non-protein coding gene in the 11 genes. H19 is an imprinted lncRNA transcribed exclusively from the maternal allele and H19 gene produces a 2.3 kilo base pair long non-coding RNA. Two microRNAs, miR-675-3p and miR-675-5p are embedded in the exon1 of H19 and these miRNAs are reported to correlate with cell proliferation. H19 is an oncofetal RNA expressed in developing embryos and in tumors including bladder, breast, gastric, pancreatic, hepatocellular, and prostate cancers. Studies have shown that H19 enhances cancer invasion and metastasis; however, its role in cancer remains debatable. We examined the roles of H19 in pancreatic cancer growth and metastasis. Quantitative RT-PCR analysis using human pancreatic cancer tissues showed that H19 was more highly expressed in cancer tissues than the adjacent normal tissues in 11 of 18 cases. Branched DNA in situ hybridization analysis using tissue microarrays showed that H19 was detected in 17% (23/139) of invasive ductal carcinomas, and its expression positively correlated with higher histological tumor grades (P &lt; 0.0001). H19 was expressed in 9 pancreatic cancer cell lines at various levels. Overexpression of H19 in PANC-1 cells induced higher motilities, whereas H19 inhibition using shRNA and siRNA showed opposite results; however, cell growth rates were unaffected in vitro. Expression levels of miR-675-3p and miR-675-5p altered as similar to the H19 levels in both H19 increased PANC-1 cells and H19 decreased cells. Tail vein injection of H19 shRNA vector-transfected PANC-1 cells markedly inhibited metastasis in the liver and lungs of immunodeficient mice. These findings suggest that H19 plays an important role in pancreatic cancer metastasis and H19 is a novel therapeutic target for metastasis of pancreatic cancer.

Citation Format: Toshiyuki Ishiwata, Hisashi Yoshimura, Yoko Matsuda, Naoshi Ishikawa, Kaiyo Takubo, Tomio Arai, Junko Aida. A long non-coding RNA, H19, as a novel therapeutic target for pancreatic cancer metastasis [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 3484. doi:10.1158/1538-7445.AM2017-3484

Pancreatic neuroendocrine carcinoma with exocrine differentiation in a young cat

A 35-mo-old spayed female mixed-breed cat with continuous vomiting, emaciation, and abdominal distention for 2 wk was presented to a private veterinary clinic for evaluation. At 71 d after the initial visit, the cat died with anemia, jaundice, and hypoalbuminemia, and was subjected to autopsy. Grossly, numerous firm masses, 0.5-2.5 cm diameter, were randomly located in the left lobe of the pancreas. Histologic examination revealed that the pancreatic mass consisted of 2 tumor cell types: mostly small round cells with a minority of epithelial cells. The small cells were arranged in nests of various sizes, which were separated by thin fibrous stroma, and had small, round, hyperchromatic nuclei, scant cytoplasm containing argyrophilic granules, and often formed rosettes. The epithelial cells formed luminal structures. Metastases were observed in the liver, greater omentum, and pancreatic, gastric, pulmonary, and mediastinal lymph nodes. Immunohistochemical examination revealed that the small cells were positive for vimentin, neuron-specific enolase, chromogranin A, cytokeratin (CK) AE1/AE3, and trypsin, whereas the epithelial cells were positive for AE1/AE3, trypsin, CK19, and nestin. Ultrastructurally, the small cells contained abundant electron-dense granules, ~200 nm diameter, whereas the epithelial cells had apical microvilli and numerous zymogen granules, ~300 nm diameter. These findings indicated that the tumor was a pancreatic neuroendocrine carcinoma with exocrine differentiation and systemic metastases.

Nestin phosphorylation at threonines 315 and 1299 correlates with proliferation and metastasis of human pancreatic cancer

The neuroepithelial stem cell marker nestin is a cytoskeletal protein that regulates cell proliferation, invasion, and stemness in various tumors, including pancreatic tumors. In the present study, we examined the expression and roles of phosphorylated nestin in pancreatic cancer cells. Nestin phosphorylation at threonines 315 (Thr315) and 1299 (Thr1299) was observed during mitosis in human pancreatic cancer cells. Nestin phosphorylation was positively correlated with a cell proliferation marker, MIB-1 expression in human pancreatic cancer samples. Transfection of MIA PaCa-2 cells with nestin mutated at Thr315 and/or Thr1299 (to suppress phosphorylation) resulted in lower proliferation rates than those in control groups. Transfecting MIA PaCa-2 cells with wild-type nestin or with nestin mutated at Thr315 increased migration and invasion. In contrast, transfection with nestin mutated at both phosphorylation sites (Thr315 and Thr1299) did not enhance cell migration or invasion. In an intra-splenic xenograft experiment using MIA PaCa-2 cells, tumors expressing the nestin double mutant formed fewer liver metastases than tumors expressing wild-type nestin. Nestin phosphorylation at these two sites was decreased upon treatment with inhibitors for cyclin dependent kinases, AKT, and Aurora in PANC-1 cells, which express a high baseline level of phosphorylated nestin. These findings suggest that phosphorylation of nestin at Thr315 and/or Thr1299 affects cell proliferation, and inhibition of both phosphorylation sites suppresses invasion and metastasis of human pancreatic cancer. Inhibiting nestin phosphorylation at these two sites may represent a novel therapeutic strategy for pancreatic cancer.

Contribution of oral triamcinolone to treating proliferative and necrotising otitis externa in a 14-year-old Persian cat

Case summary

A 14-year-old female spayed cat was referred for recurrent otitis externa and unusual proliferative lesions in both ear canals. The affected pinnae and external ear canals were covered with large reddish-to-dark-brown verrucous and necrotic tissue. Friable material and exudates occluded both ear canals. Proliferative lesions developed in both ears 2–3 weeks before referral. The histopathological diagnosis from two biopsies obtained from the friable materials with endoscopic biopsy forceps was proliferative and necrotising otitis externa (PNOE). Treatment was initiated with once-daily application of a potent topical glucocorticoid (mometasone furoate) to both ears. Although the auricle and vertical ear canals responded well, no improvement was seen in the horizontal part of the ear canal after 9 weeks. Therefore, oral triamcinolone (0.9 mg/kg q24h) was added for 1 week, and was then tapered (q48h) for 3 weeks. Most lesions resolved, and after a further 2 weeks of prednisolone (2 mg/kg q48h) there was complete resolution. No recurrence was observed during a 2 year follow-up period.

Relevance and novel information

PNOE commonly occurs in kittens, but it can develop in older cats. To our knowledge, the PNOE in this case is the oldest age of onset reported. This condition is rare and was only described recently, and therapeutic options appear limited. According to previously published reports, steroid therapy is ineffective, and tacrolimus is the only treatment known to achieve resolution. However, oral and topical glucocorticoids were beneficial in this case.

Oncocytic carcinoma of the salivary gland in a dog

A 3-y-old male miniature Dachshund was presented with an ~0.8 cm diameter mass in the right mandibular region. Fourteen months later, the mass was 5 × 4 × 3 cm. Grossly, the mass was encapsulated and was homogeneously gray-white on cut surface. Microscopically, the mass was composed of large, round to polygonal tumor cells that were arranged in solid nests and cords separated by a fibrovascular stroma. Tumor cells had large, round, hypochromatic nuclei containing large prominent nucleoli and abundant eosinophilic cytoplasm containing dark blue granules visible with phosphotungstic acid-hematoxylin stain. Metastasis was observed in the mandibular lymph node. Immunohistochemically, tumor cells were positive for CK AE1/AE3, low-molecular-weight CK (CAM5.2), E-cadherin, mitochondria ATPase beta subunit, and S100, but were negative for vimentin, carcinoembryonic antigen, p63, CK14, CD10, and chromogranin A. Ultrastructurally, tumor cells contained numerous mitochondria. Therefore, the tumor was diagnosed as an oncocytic carcinoma of the mandibular gland.

Polyglucosan Bodies in the Prostatic Stromal Smooth Muscles of Aged Dogs

Polyglucosan bodies (PGB) in the prostate of aged dogs without neurological signs were examined by light microscopy, histochemistry and immunohistochemistry. Prostatic PGB were round or oval and slightly basophilic. Most of the bodies were situated within the stromal smooth muscle cells. PGB were intensely positive for PAS, Best's carmine, Lugol's iodine and Grocott's methenamine silver method. Moreover, canine prostatic PGB were immunoreactive for monoclonal antibodies raised against human polyglucosan. The frequency of PGB in the smooth muscle cells was significantly correlated with the age of dogs. The occurrence of PGB in the canine prostate might be a non-specific finding related to ageing.

An Insight into the Characteristics of a Nucleation Catalyst in CFC-Free Rigid Foam Systems

The establishment of CFC-free polyurethane foam systems, aimed at total CFC elimination by the year 1995, is of paramount importance in the present day polyurethane foam technology. Especially in rigid foam systems, the attempts to apply a variety of alternative blowing agents such as HCFC-22, -141b, and -142b, HFC-134a and -356, and hydrocarbons such as n-pentane, isopentane and cyclopentane, as well as all-water blown systems, are being examined.

In all cases of alternative blown systems, however, there exist differences in foaming behavior as well as inferior foam properties compared to traditional CFC-11 blown systems. Especially in HCFC-141b and cyclopentane blown systems, which have gained the greatest interest among the above-mentioned options, the following three subjects are of major concern. The requirements involved in achieving the resolution of these problems are dependent not only on the development of major raw materials but also on the selection of suitable auxiliary intermediates such as catalysts and foam stabilizers. (1) Thermal Conductivity; HCFC-141b, cyclopentane and carbon dioxide, which is generated from the reaction of water and isocyanate, have high thermal conductivity compared to CFC-11, thereby causing inferior insulation performance of the foam. Fine cell technology is now being examined in order to improve the thermal conductivity. For the achievement of the fine cell structure, the selection of suitable amine catalyst systems is important, although the effect of foaming stabilizers has an especially large contribution. (2) Dimensional Stability; not only in all-water blown systems, but also in HCFC-141b and cyclopentane blown systems which use water in high concentration, dimensional stability becomes a large problem due to the diffusion of carbon dioxide gas from the foam cell. For the improvement of dimensional stability, there exists the option to increase the foam strength; moreover, it is important to improve the isotropy of cell structure by adjusting amine catalyst systems. (3) Foam density; since 141b and cyclopentane have relatively higher boiling points and less blowing efficiency, lowering the foam density becomes rather difficult. Moreover, lower foam density normally provides poor dimensional stability. It can be said that the catalytic activity ratio in blowing/gelling of amine catalysts play an important role for the lowering of foam density with improved dimensional stability.

It is very difficult to improve these three factors simultaneously. In this report, however, the improvements of these subjects are discussed from a standpoint of amine catalysts; also special newly developed nucleation catalyst systems are introduced for cyclopentane and HCFC-141b blown systems.

Abstract 1157: Single nucleotide polymorphisms in ARHGAP17 are associated with pancreatic intraepithelial neoplasia in 2401 autopsied elderly patients

Background: Aging, obesity, smoking, alcohol consumption, diabetes, and pancreatitis have been reported to be the risk factors for pancreatic cancer. There is much evidence showing that single nucleotide polymorphisms (SNPs), especially those in BCAR1, PDX1, ZNRF3, or TERT, influence one's predisposition to pancreatic cancers and survival. However, the association between SNP and pancreatic precancerous lesions is not yet clarified. In the present study, we clarified the clinicopathological features of precancerous lesions of the pancreas by examining autopsied elderly cases. Methods: We analyzed serial autopsy cases (men, 1326; women, 1075; mean age, 80.6) of pancreatic intraepithelial neoplasia (PanIN) and performed a comparative analysis based on the sex, age, and body mass index (BMI) of the patients. The SNPs were analyzed using HumanExome BeadChip. Results: The occurrence of PanIN increased with advanced age. Approximately, 60% of the elderly patients showed low-grade PanIN. The autopsy cases showed that the occurrence of low-grade PanIN was positively correlated with the female sex, advanced age, and increase in BMI. The SNPs of the ARHGAP17 gene, p.G782D (rs28365822) and rs1106576, were risk factors for PanIN (Table, P&lt;0.0001, *adjusted with age and gender). Discussion: A high incidence of low-grade PanIN in the elderly might be related to the increased risk of pancreatic cancer in the elderly. Further studies are needed to clarify the role of SNPs of ARHGAP17 in the carcinogenesis of pancreatic cancer. Association between SNPs in ARHGAP17 and pancreatic intraepithelial neoplasiasGenotypePanIN (-)PanIN (+)P valueunadjustedadjusted*rs28365822(%)Chi squareDominant-FisherLogistic regressionOdds ratio(95% confidence interval)CC1028(99.1)1192(96.7)&lt;0.00010.000040.00023.934.05TC9(0.9)41(3.3)(1.90-8.12)(1.94-8.47)TT0(0)0(0)GenotypePanIN (-)PanIN (+)P valueunadjustedadjusted*rs1106576(%)Chi squareDominant-FisherLogistic regressionOdds ratio(95% confidence interval)TT1027(99.1)1192(96.7)&lt;0.00010.000040.00023.934.05TC9(0.9)41(3.3)(1.90-8.12)(1.94-8.47)CC0(0)0(0)

Citation Format: Yoko Matsuda, Masashi Tanaka, Atsuko Seki, Keisuke Nonaka, Makoto Nishimura, Toshiyuki Ishiwata, Hisashi Yoshimura, Kaiyo Takubo, Tomio Arai. Single nucleotide polymorphisms in ARHGAP17 are associated with pancreatic intraepithelial neoplasia in 2401 autopsied elderly patients. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1157.

Abstract 4577: Fibroblast growth factor receptor-4 (FGFR-4) as a novel therapeutic target for pancreatic cancer

The fibroblast growth factor receptor (FGFR) family plays crucial roles in development, tissue repair, and malignant tumors. FGFR-1, -2, and -3 each exist in two isoforms, IIIb and IIIc, due to alternative splicing of the extracellular domain, whereas FGFR-4 does not have these isoforms. FGFR-4 is reportedly over-expressed in various cancers such as breast, prostate, hepatocellular, ovarian, gastric, colorectal, and pancreatic cancers, wherein it contributes to tumor progression. Recent studies have shown that a decrease in FGFR-4 levels suppresses the aggressiveness of gastric, colorectal, and ovarian cancers. We found that pancreatic cancer cell lines expressed similar levels of the IIIb and IIIc isoforms of FGFR-1 to -3, but showed different FGFR-4 levels. These findings suggest that the cancer cells surviving after treatment with recently developed anti-FGFR drugs, which target FGFR-1 to -3, tend to express high levels of FGFR-4. Moreover, a single-nucleotide polymorphism (SNP) in exon 9 of the gene encoding FGFR-4 that results in the substitution of glycine with arginine at codon 388 (388 Gly/Arg) in the transmembrane domain is associated with poor outcomes of high-grade soft tissue sarcoma, prostate, lung, head and neck carcinoma, and advanced and treatment-resistant breast cancer. It has been reported that 40-50% of Caucasians carry at least one copy of the 388 Gly/Arg SNP of FGFR-4. In the present study, we examined the expression and roles of the 388 Gly/Arg SNP in pancreatic cancer and tried to clarify whether FGFR-4 may be a novel therapeutic target for cancer treatment. In human pancreatic tissues, FGFR-4 was weakly localized in the normal exocrine and endocrine pancreas, and was strongly expressed in 67 of 136 pancreatic ductal adenocarcinoma cases (49%). FGFR-4 expression positively correlated with larger primary tumors and more advanced stages of pancreatic cancer. FGFR-4 mRNA was expressed in 5 pancreatic cancer cell lines at various levels, and the mutation in codon 388 was detected in 3 of the cell lines, including PK-1 cells. A short hairpin RNA expression vector targeting FGFR-4 was stably transfected to these mutant-expressing PK-1 cells (388 Gly/Arg), which then showed lower growth rates and cell migration and invasion abilities compared to sham vector-transfected cells. DNA microarray analysis showed that decreased expression of FGFR-4 in PK-1 cells altered the expression levels of molecules related to cellular movement, cellular development, and cell-to-cell signaling and interactions. FGF-19—one of the major ligands for FGFR-4—was expressed in all 5 of the pancreatic cancer cell lines tested. These findings suggest that inhibition of the expression of FGFR-4 harboring the 388 Gly/Arg SNP may be a novel therapeutic strategy for pancreatic cancer, especially after treatment with the newly developed anti-FGFR-1 to -3-targeted drugs.

Citation Format: Toshiyuki Ishiwata, Hisashi Yoshimura, Yoko Matsuda, Shunji Ishiwata. Fibroblast growth factor receptor-4 (FGFR-4) as a novel therapeutic target for pancreatic cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4577.

Clinicopathological Features of 15 Occult and 178 Clinical Pancreatic Ductal Adenocarcinomas in 8339 Autopsied Elderly Patients

OBJECTIVE

The aim of the study was to investigate the clinicopathological features of pancreatic cancer at different stages using autopsy results.

METHODS

We retrospectively evaluated 8399 consecutive cases of autopsy performed between 1972 and 2013 at our geriatric hospital.

RESULTS

Macroscopic pancreatic lesions were detected in 6.13% of the cases. Primary and secondary pancreatic tumors were observed in 2.88% and 2.10% of the cases, respectively. Most primary tumors were invasive ductal adenocarcinomas (193 cases [2.31%]; mean patient age, 78.09 years) with a peak incidence at 50 to 59 years. Occult invasive ductal adenocarcinoma was discovered incidentally in 15 cases, with distant metastasis present in 26.67% of those. Microscopically, occult and advanced tumors exhibited similar characteristics such as hyalinized fibrous stroma, necrosis, invasion into vessels, peripancreatic fat tissues, and extrapancreatic nerve plexus. Mucin 1 and 2 immunohistochemical expression levels were also similar. Occult cancer incidence increased with age. Patients aged 85 years or older had shorter survival, a small tumor size, and a low incidence of lymph node metastasis. Approximately 8% of pancreatic invasive ductal adenocarcinomas progressed asymptomatically and were discovered incidentally at autopsy.

CONCLUSIONS

Pancreatic cancers in elderly patients tend to progress asymptomatically, but once symptoms develop, they are more often fatal than those in younger patients.

Systemic Administration of Small Interfering RNA Targeting Human Nestin Inhibits Pancreatic Cancer Cell Proliferation and Metastasis

OBJECTIVES

Nestin, a progenitor/stem cell marker, is expressed in human pancreatic cancer, where its expression correlates positively with invasiveness and metastasis. Here, we investigated the inhibition of nestin expression and the regulation of nestin expression.

METHODS

We analyzed the effects of small interfering RNA (siRNA) targeting nestin using pancreatic cancer cell lines.

RESULTS

Nestin siRNA inhibited the growth, migration, invasion, and sphere-forming ability of the pancreatic cancer cell lines. Pancreatic cancer cells cotreated with gemcitabine and nestin siRNA exhibited lower cell viability than cells treated with a control siRNA, gemcitabine alone, or nestin siRNA alone. Cells derived from the metastatic nodules of mice showed higher nestin expression than the parental cells, and nestin expression in pancreatic cancer cells was regulated by methylation of the nestin gene. In an orthotopic implantation model using mice, administration of nestin siRNA significantly decreased primary and metastatic tumor formation by human pancreatic cancer cells compared to tumor formation in control siRNA-treated mice.

CONCLUSIONS

Nestin plays a key role in pancreatic cancer cell metastasis and stemness and that administration of nestin siRNA may offer a novel therapeutic strategy for pancreatic cancer.

Mitotic index and multipolar mitosis in routine histologic sections as prognostic markers of pancreatic cancers: A clinicopathological study

OBJECTIVES

Pancreatic cancer is characterized by genomic complexity and chromosomal instability, and atypical mitotic figures are morphological features of this phenotype. In the present study, we determined the frequency and the clinicopathological and prognostic significance of mitotic figures in pancreatic cancers.

METHODS

We surveyed the mitotic figures of the normal ductal epithelium, acinar cells, pancreatic intraepithelial neoplasias, and pancreatic cancers on hematoxylin-and-eosin-stained tissue specimens (n = 121).

RESULTS

Pancreatic cancer cells showed significantly higher mitotic indices as compared with the ductal cells, acinar cells, and pancreatic intraepithelial neoplasias. Both normal and atypical mitosis were significantly elevated only in pancreatic cancers. In pancreatic cancers, approximately 30% of total mitosis was atypical including multipolar, lag-type, ring and asymmetrical mitosis, and anaphase bridges. The Kaplan-Meier curves in pancreatic cancers showed significant correlations between total mitosis and disease free survival. Furthermore, the cases with multipolar mitosis showed poorer prognosis than those without. Lymph node metastasis and multipolar mitosis were independent prognostic factors for overall survival of patients with pancreatic cancer. In addition, lymph node metastasis and total mitosis were independent factors for disease free survival.

CONCLUSION

These findings suggest that routinely obtained pathological specimens, even small biopsy or cytological specimens, can provide valuable information concerning the prognosis of pancreatic cancers.