Cancer-related gene mutations and intratumoral genetic heterogeneity in human epidermal growth factor receptor 2 heterogeneous gastric cancer.

Human epidermal growth factor receptor 2 (HER2) protein overexpression is associated with HER2 gene amplification, a critical driver oncogenetic change in gastric cancer. HER2 heterogeneity in advanced gastric cancer is associated with a poor prognosis and affects the clinical efficacy of trastuzumab. However, the mechanisms of HER2 heterogeneity are not fully understood. Here, we examined whether HER2 heterogeneous gastric cancer exhibited intratumoral genetic heterogeneity in other cancer-related genes. Two cases of advanced gastric cancer with HER2 heterogeneity were selected, and samples of HER2-positive and HER2-negative areas in each case were analyzed using a cancer-associated multiple gene panel. In both cases, TP53 mutations were observed in both HER2-positive and HER2-negative areas, whereas many of the potential driver and passenger mutations differed between HER2-positive and HER2-negative areas. Overall, our findings demonstrated that HER2 heterogeneous gastric cancer exhibited intratumoral genetic heterogeneity in other cancer-related genes and that the molecular mechanisms could differ between HER2-positive and -negative areas.

Antifibrotic Agent Pirfenidone Suppresses Proliferation of Human Pancreatic Cancer Cells by Inducing G0/G1 Cell Cycle Arrest.

BACKGROUND: Pirfenidone (PFD), which is an antifibrotic agent used for treatment of idiopathic pulmonary fibrosis, induces G0/G1 cell cycle arrest in fibroblasts. We hypothesized that PFD-induced G0/G1 cell cycle arrest might be achieved in other types of cells, including cancer cells. Here we investigated the effects of PFD on the proliferation of pancreatic cancer cells (PCCs) in vitro. METHOD: Human skin fibroblasts ASF-4-1 cells and human prostate stromal cells (PrSC) were used as fibroblasts. PANC-1, MIA PaCa-2, and BxPC-3 cells were used as human PCCs. Cell cycle and apoptosis were analyzed using flow cytometer. RESULTS: First, we confirmed that PFD suppressed cell proliferation of ASF-4-1 cells and PrSC and induced G0/G1 cell cycle arrest. Under these experimental conditions, PFD also suppressed cell proliferation and induced G0/G1 cell cycle arrest in all PCCs. In PFD-treated PCCs, expression of p21 was increased but that of CDK2 was not clearly decreased. Of note, PFD did not induce significant apoptosis among PCCs. CONCLUSIONS: These results demonstrated that the antifibrotic agent PFD might have antiproliferative effects on PCCs by inducing G0/G1 cell cycle arrest. This suggests that PFD may target not only fibroblasts but also PCCs in the tumor microenvironment of pancreatic cancer.

Extracellular vesicles from pancreatic ductal adenocarcinoma endoscopic ultrasound-fine needle aspiration samples contain a protein barcode.

BACKGROUND: The survival rate of pancreatic ductal adenocarcinoma (PDAC) is very poor because early detection is difficult. Extracellular vesicles (EVs) are released from cells associating with the cellular condition and circulated in the blood. We aimed to identify EV proteins from endoscopic ultrasound-fine needle aspiration (EUS-FNA) biopsy samples in order to develop novel biomarkers for PDAC. METHODS: Extracellular vesicles were isolated from EUS-FNA samples of 40 PDAC patients and six autoimmune pancreatitis (AIP) patients to be used as a control. EV proteins were identified using nanoLC-MS/MS. RESULTS: Intact EVs approximately 200 nm in diameter were detected from EUS-FNA samples. We identified 2059 or 1032 EV proteins in PDAC or AIP, respectively, and 1071 EV proteins were detected only in PDAC. One hundred and fifty-three EV proteins were significantly different between PDAC and AIP: 64 proteins were down-regulated in PDAC whereas 89 EV proteins were up-regulated in PDAC including mucins, keratins, Ras-related proteins, and olfactomedin-4, which proteins have been reported to be elevated in PDAC tissue/blood, or cultured pancreatic cancer cell lines. Notably, in the 89 up-regulated PDAC EV proteins we identified novel proteins including ADP-ribosylation factor 3, CD55, pyruvate kinase, and lipopolysaccharide-induced tumor necrosis factor. Out of 89 proteins, a total of 13 proteins including Ras-related proteins were significantly elevated in PDAC stages II-IV compared to PDAC stage I, including Ras-related proteins, moesin, and CD55. CONCLUSIONS: The EV proteins obtained from EUS-FNA samples contain a PDAC-specific protein barcode. The EV proteins identified from EUS-FNA samples include promising biomarkers for the diagnosis and clinical staging of PDAC.

Red Blood Cell-Shaped Microparticles with a Red Blood Cell Membrane Demonstrate Prolonged Circulation Time in Blood.

Prolonging the circulation time (CT) of microparticles (MPs) in the blood is key for a successful microparticle-based medicinal approach to serve as drug delivery systems (DDSs). Previously, we reported that MPs that mimic the shape of red blood cells (RBCs) avoid accumulation in the spleen and lungs. We now describe the effectiveness of mimicking not only the shape of RBCs but also their surface structure for the prolongation of CT. RBC-shaped MPs (RBC-MPs) were electrosprayed with cellulose and covered with a native RBC membrane (RBCM) collected from mouse blood. Seven hours after intravenous injection, approximately twice as many RBCM-covered RBC-MPs (RBC-MPs@RBCM) were present in the blood of mice compared to unmodified RBC-MPs. Twenty-four hours postinjection, the concentration of RBC-MPs@RBCM in the blood was 4 times higher. These findings suggest that an RBCM covering the MPs contributed to significant CT prolongation, which may positively impact their applications as DDSs.

Association of HER2 gene amplification and tumor progression in early gastric cancer.

Overexpression of human epidermal growth factor receptor 2 (HER2) protein in association with HER2 gene amplification is found in 7-34% of gastric cancers. In breast cancer, HER2 overexpression is a prognostic factor in advanced cases and is associated with tumor progression in ductal carcinoma in situ. However, the biological and clinical significance of HER2 status in early gastric cancer is unknown. Here, we aimed to examine the correlation between HER2 gene amplification and tumor progression in early gastric cancer. The HER2 status was evaluated in 149 lesions from 141 consecutive patients with early gastric cancer who underwent endoscopic resection by immunohistochemistry and dual color in situ hybridization. HER2 gene amplification was detected in 35 (23.5%) of 149 lesions, and of those, 26 cases (74.3%) showed intratumoral heterogeneity. HER2 gene amplification was found in noninvasive carcinoma, and there was a significant correlation between HER2 status and T factor (P = 0.0290). Our study demonstrated that HER2 gene amplification occurred during the early stages of gastric cancer and showed heterogeneity in several cases. HER2 gene amplification may be involved in tumor progression in early gastric cancer.

Acute brainstem compression by intratumoral hemorrhages in an intracranial hypoglossal schwannoma.

A 77-year-old female in the hospital was found tachycardic and hypothermic by a nurse, and the patient's respiration subsequently ceased. Forensic autopsy revealed an intracranial cystic tumor that would have compressed the brainstem. On microscopic examination, the tumor was diagnosed as an Antoni A schwannoma growth, and recent multiple intratumoral hemorrhages in the intracranial schwannoma were observed, suggesting the sudden enlargement of the intracranial schwannoma due to intratumoral hemorrhaging. Accordingly, we diagnosed the cause of death as brainstem compression induced by the intratumoral hemorrhaging in the intracranial schwannoma. Meanwhile, a rhinopharyngeal tumor was also detected by the autopsy, which was compatible with an antemortem diagnosis of a dumbbell-shaped hypoglossal schwannoma.

Molecular-biological analysis of acute lung injury (ALI) induced by heat exposure and/or intravenous administration of oleic acid.

The aim of this study was to molecular-biologically investigate the interaction between heat exposure and pulmonary fat embolization in regards to the development of acute lung injury (ALI). Ten-week-old Wistar male rats were divided into four groups: (1) oleic acid injected into caudal vein after heat exposure, (2) oleic acid injected without heat exposure, (3) soybean oil injected after heat exposure, and (4) soybean oil injected without heat exposure, and then mRNA expression of eight inflammatory mediators related to ALI/acute respiratory distress syndrome (ARDS) and heat shock protein 70 (Hsp70) in lung was determined 1h after the injection. mRNA expression of interleukin 1 beta (Il1b), tumor necrosis factor alpha (Tnfa), vascular endothelial growth factor A (Vegfa), transforming growth factor beta 1 (Tgfb1) and Hsp70 was significantly increased by heat exposure, while that of Il1b, interleukin 6 (Il6), Tnfa, macrophage inflammatory protein 2 (Mip2) and granulocyte macrophage-colony stimulating factor (Gm-csf) was significantly elevated by the injection of oleic acid. Moreover, the expressions of inflammatory cytokines and chemokines in lung almost paralleled their mRNA expressions. In particular, IL-1ß expression was synergistically elevated by heat exposure followed by injection of oleic acid. Additionally, IL-6 expression tended to increase under the same conditions as well. It is likely that heat exposure itself injures lung tissue within a short time, and that more than two conditions which induce ALI/ARDS interact with each other synergistically, exacerbating the development of ALI/ARDS.