Genetic assessment of IPMN for predicting concomitant pancreatic ductal adenocarcinoma.

OBJECTIVE: Krüppel-like transcription factor 4(KLF4) mutations are more frequently observed in low-grade lesions than in high-grade lesions of intraductal papillary mucinous neoplasms (IPMN) of the pancreas. However, the role of KLF4 mutations in IPMNs with concomitant pancreatic ductal adenocarcinoma (PDAC) remains unclear. This study clarified the rate and effect of KLF4 mutations in IPMN with concomitant PDAC. METHODS: DNA was extracted from 65 formalin-fixed and paraffin-embedded samples from 52 patients including 13 IPMN with concomitant PDAC and 39 IPMN alone. A comprehensive screening was performed using next-generation sequencing (NGS) for the 5 IPMNs with concomitant PDAC and 5 IPMNs alone, followed by targeted sequencing for KLF4, GNAS, and KRAS mutations. RESULTS: In NGS screening, KRAS mutations were observed in all samples except for one, GNAS mutation in two IPMNs with concomitant PDAC, and a KLF4 mutation in one IPMN with concomitant PDAC. Targeted sequence detected KLF4 mutations in 11 of the 52 IPMNs. Concomitant PDAC developed only in the non-intestinal, non-invasive, and branch duct IPMN cases, and KLF4 mutations were more frequent in this IPMN type than in the other type (36% vs. 10%, p = 0.04). For this IPMN type with KLF4 mutation, PDAC-prediction sensitivity, specificity, and accuracy were 63%, 82%, and 79%, respectively. CONCLUSION: For selected IPMNs with non-intestinal, non-invasive, and branch duct, genetic assessment might be a helpful tool for predicting the possible development of concomitant PDAC, although a prospective validation study using a larger study population is needed.

Detection of retinal dysfunction induced by HCN channel inhibitors using multistep light stimulus and long-duration light stimulus ERG in rats.

Ivabradine, a hyperpolarization-activated cyclic nucleotide-gated (HCN) channel inhibitor, has been reported to induce photosensitivity-related visual disturbances such as phosphene in humans. Ivabradine-induced visual disturbances are caused by inhibition of HCN channels in the retina, and the mechanisms have been verified using HCN channel knockout mice and electroretinography (ERG). However, in rats, classical ERG using single flash light stimulus with standard analyses of waveform amplitude and latency has not revealed abnormal retinal function after administration of ivabradine. To verify whether retinal dysfunction after ivabradine administration was detectable in rats, we performed ERG using multistep flash light stimulation at the time when plasma concentration of ivabradine was high. Furthermore, the mechanism of the change in the waveform that appeared after the b-wave was investigated. Ivabradine and cilobradine, a selective HCN channel inhibitor, were administered subcutaneously to rats at 4-40 mg/kg as a single dose, and flash or long-duration ERG recordings at each light stimulus luminance were conducted 1.5 h after administration. Plasma and retinal concentrations of both compounds were measured immediately after the ERG recordings. In the flash ERG, prolongation of a- and/or b-wave latencies were detected at each light stimulus, and dose-dependent waveform changes after the b-wave were recorded at the specific light stimulus luminance for both compounds. These ERG changes increased in response to increasing plasma and retinal concentrations for both ivabradine and cilobradine. In the long-duration light stimulus ERG, a change in the waveform of the b-wave trough and attenuation of the c-wave were recorded, suggesting that the feedback control in the photoreceptor cells may be inhibited. This study revealed that the retinal dysfunction by HCN channel inhibitors in rats can be detected by multistep light stimulus ERG. Additionally, we identified that the inhibition of feedback current and the sustained responses in the photoreceptor cells cause the retinal dysfunction of HCN channel inhibitors in rats.

Oncogenic Targets Regulated by Tumor-Suppressive miR-30c-1-3p and miR-30c-2-3p: TRIP13 Facilitates Cancer Cell Aggressiveness in Breast Cancer.

Accumulating evidence suggests that the miR-30 family act as critical players (tumor-suppressor or oncogenic) in a wide range of human cancers. Analysis of microRNA (miRNA) expression signatures and The Cancer Genome Atlas (TCGA) database revealed that that two passenger strand miRNAs, miR-30c-1-3p and miR-30c-2-3p, were downregulated in cancer tissues, and their low expression was closely associated with worse prognosis in patients with BrCa. Functional assays showed that miR-30c-1-3p and miR-30c-2-3p overexpression significantly inhibited cancer cell aggressiveness, suggesting these two miRNAs acted as tumor-suppressors in BrCa cells. Notably, involvement of passenger strands of miRNAs is a new concept of cancer research. Further analyses showed that seven genes (TRIP13, CCNB1, RAD51, PSPH, CENPN, KPNA2, and MXRA5) were putative targets of miR-30c-1-3p and miR-30c-2-3p in BrCa cells. Expression of seven genes were upregulated in BrCa tissues and predicted a worse prognosis of the patients. Among these genes, we focused on TRIP13 and investigated the functional significance of this gene in BrCa cells. Luciferase reporter assays showed that TRIP13 was directly regulated by these two miRNAs. TRIP13 knockdown using siRNA attenuated BrCa cell aggressiveness. Inactivation of TRIP13 using a specific inhibitor prevented the malignant transformation of BrCa cells. Exploring the molecular networks controlled by miRNAs, including passenger strands, will facilitate the identification of diagnostic markers and therapeutic target molecules in BrCa.

Coronin 1C, Regulated by Multiple microRNAs, Facilitates Cancer Cell Aggressiveness in Pancreatic Ductal Adenocarcinoma.

Coronin proteins are actin-related proteins containing WD repeat domains encoded by seven genes (CORO1A, CORO1B, CORO1C, CORO2A, CORO2B, CORO6, and CORO7) in the human genome. Analysis of large cohort data from The Cancer Genome Atlas revealed that expression of CORO1A, CORO1B, CORO1C, CORO2A, and CORO7 was significantly upregulated in pancreatic ductal adenocarcinoma (PDAC) tissues (p < 0.05). Moreover, high expression of CORO1C and CORO2A significantly predicted the 5 year survival rate of patients with PDAC (p = 0.0071 and p = 0.0389, respectively). In this study, we focused on CORO1C and investigated its functional significance and epigenetic regulation in PDAC cells. Knockdown assays using siRNAs targeting CORO1C were performed in PDAC cells. Aggressive cancer cell phenotypes, especially cancer cell migration and invasion, were inhibited by CORO1C knockdown. The involvement of microRNAs (miRNAs) is a molecular mechanism underlying the aberrant expression of cancer-related genes in cancer cells. Our in silico analysis revealed that five miRNAs (miR-26a-5p, miR-29c-3p, miR-130b-5p, miR-148a-5p, and miR-217) are putative candidate miRNAs regulating CORO1C expression in PDAC cells. Importantly, all five miRNAs exhibited tumor-suppressive functions and four miRNAs except miR-130b-5p negatively regulated CORO1C expression in PDAC cells. CORO1C and its downstream signaling molecules are potential therapeutic targets in PDAC.

Surgical Stress Evaluation of Left Lateral Sectionectomy Based on Skeletal Muscle Catabolism.

BACKGROUND: By examining skeletal muscle catabolism, we aimed to investigate whether laparoscopic left lateral sectionectomy (LLS) is less invasive compared with the open approach. METHODS: The psoas muscle index (PMI) was measured using computed tomography images before and after surgery. We assessed the relationship between the perioperative PMI reduction rate and the estimation of physiologic ability and surgical stress (E-PASS) score and then compared the PMI reduction rates associated with different approaches. RESULTS: Of the 31 patients, 13 and 18 underwent the open and laparoscopic approaches, respectively. A strong correlation was observed between the PMI reduction rates and surgical stress scores (SSS) ( r =0.561, P <0.01). The laparoscopic approach was associated with a significantly lower PMI reduction rate ( P <0.01) and SSS ( P <0.01) than the open approach. CONCLUSION: Laparoscopic LLS should be less invasive than the open approach from the perspective of not only perioperative outcomes but also skeletal muscle catabolism.

Successful conversion surgery for stage IV gastric cancer with liver metastases after second-line chemotherapy with ramucirumab and paclitaxel: a case report.

BACKGROUND: In recent years, conversion surgery after chemotherapy has been considered a promising strategy for improving the prognosis of patients with stage IV gastric cancer. However, there are few reports on conversion gastrectomy after second-line chemotherapy. Here, we report a case of long-term survival of a patient with liver metastases from gastric cancer who underwent conversion surgery after second-line chemotherapy with ramucirumab and paclitaxel. CASE PRESENTATION: A 77-year-old man complaining of weight loss was diagnosed with human epidermal growth factor receptor 2-positive gastric cancer with multiple liver metastases. Although the patient initially received trastuzumab-based chemotherapy, it was discontinued, because he experienced trastuzumab-induced infusion reactions. Thereafter, he was treated with six courses of S-1 plus cisplatin and six courses of ramucirumab plus paclitaxel as the first- and second-line regimens, respectively. The primary tumor and liver metastases remarkably shrank, and the reduction rate of the measurable metastatic liver lesions was 81.1%. According to the Response Evaluation Criteria in Solid Tumors, the patient responded partially. Therefore, he underwent total gastrectomy with D2 lymphadenectomy and partial hepatectomy of segments 3 and 4. Pathological examination revealed tumor invasion into the muscularis propria, a grade 1a histological response, and no lymph node metastases. No viable cancer cells were identified in the specimens resected from liver segments 3 and 4. Accordingly, the patient was pathologically diagnosed with stage IB (ypT2N0M0). Postoperatively, the patient received adjuvant chemotherapy with S-1 for 6 months, and he survived without recurrence for 42 months after conversion surgery. CONCLUSIONS: Conversion surgery might be clinically useful for improving survival in certain patients with gastric cancer, including those who previously received second-line chemotherapy.

Automatic switching valve system to minimize variation of liquid chromatography-tandem mass spectrometry-based chiral amino acid profiling.

Although d-amino acids are less prevalent in nature, they have been detected in mammals (including humans) and it is widely accepted that they might play important physiological roles. While an analytical method for chiral amino acid profiling is strongly required, it has not been well-established because of the difficulties associated with analysis. A high-sensitivity and high-throughput liquid chromatography-tandem mass spectrometry (LC-MS/MS) analytical method was recently reported by our group for chiral amino acids; however, it lacked sufficient repeatability for several d-amino acids. Thus, the aim of this research was to reduce the experimental variation of chiral amino acid analysis. By installing an automatic switching valve system in LC-MS/MS, it was possible to reduce the relative standard deviations of d-amino acid ratios (d/(d+l)) in rat urine obtained from three technical replicates. The results indicated that the automatic switching valve system was effective in minimizing the variation of d-amino acid ratios, and could be applied for profiling d-amino acids because of its high repeatability.

[A Case of Advanced Gastric Cancer Showing Pathological Complete Response after Neoadjuvant Chemotherapy with S-1 and Oxaliplatin].

A 57-year-old woman was admitted to our hospital for treatment of gastric cancer presenting as a type 2 tumor in the lower third of the stomach. According to pre-therapeutic imaging examinations and laparoscopy, she was diagnosed with advanced gastric cancer, cT4a(SE)N2M0, Stage Ⅲ. Therefore, neoadjuvant chemotherapy was planned, and she received the SOX regimen. After 3 courses of chemotherapy, post-therapeutic imaging examinations showed that the primary gastric tumor and metastatic lymph nodes had reduced in size. We performed distal gastrectomy with D2 lymphadenectomy. Final pathological examinations demonstrated that no viable tumor cells remained in the resected stomach and dissected lymph nodes (Grade 3). SOX may be useful as neoadjuvant chemotherapy to improve prognosis in patients with advanced gastric cancer. Herein, we report a case of advanced gastric cancer with pathological complete response after neoadjuvant chemotherapy with the SOX regimen.

Availability of multistep light stimulus method for evaluation of visual dysfunctions.

In the field of drug safety research, electroretinography (ERG) is commonly conducted according to the international standard method propounded by the International Society for Clinical Electrophysiology of Vision (ISCEV) in recent years. However, various ERG methods other than the ISCEV standard method are also utilized depending on the intended purpose of the evaluation. In this study, we investigated the availability of a multistep light stimulus method for evaluation of rod function in Long-Evans rats using sildenafil, which is known to inhibit phosphodiesterase 6 (PDE6) in phototransduction and induce visual dysfunctions in humans. Sildenafil was orally administered to female Long-Evans rats at doses of 15, 50, and 150 mg/kg, and ERG was recorded at 1.5 h after treatment. In addition to a - 2.0 log cd·s/m2 stimulus corresponding to dark-adapted 0.01 ERG in the ISCEV standard method, light stimulus intensities of -4.5, -4.0, -3.0, -1.0, 0.0, and +1.0 log cd·s/m2 were applied for multistep ERG recording. The amplitude and implicit time of the a-wave were decreased and prolonged, respectively, at doses of ≥50 mg/kg. The amplitude and implicit time of the b-wave were decreased and prolonged, respectively, at all doses. However, the b-wave at 15 mg/kg was only diminished or attenuated at ≤ - 3.0 log cd·s/m2, as weaker stimuli than dark-adapted 0.01 ERG in the ISCEV standard protocol. These findings suggest that sildenafil triggers visual dysfunctions through PDE6 inhibition, and indicate that the multistep light stimulus method is highly sensitive for detection of phototransduction abnormalities in retinal rod cells.

Usefulness of computed tomography with air insufflation of the stomach prior to percutaneous endoscopic gastrostomy procedure.

We examined the results of computed tomography (CT) with and without air insufflation of the stomach prior to performing percutaneous endoscopic gastrostomy (PEG). We retrospectively analyzed 366 patients who underwent PEG. CT images obtained with and without air insufflation were examined for the presence or absence of contact between the gastric anterior wall and abdominal wall. PEG outcome based on CT findings was also examined. CT with and without air insufflation was performed in 272 and 94 patients, respectively. Contact between the gastric anterior wall and abdominal wall was shown in 254 (93.4%) with and 45 (47.9%) without air insufflation, all of whom underwent a successful PEG procedure. In patients without contact between the gastric anterior wall and abdominal wall, PEG was not successful in 3 of 49 (6.1%) examined by CT without and 6 of 18 (33.3%) examined with air insufflation (p = 0.004). Values for diagnostic accuracy for contact between the gastric anterior wall and abdominal wall shown by CT with and without air insufflation in successful PEG cases were 0.96 and 0.51, respectively. In conclusion, CT with air insufflation more often revealed contact between the gastric anterior wall and abdominal wall as compared to CT without air insufflation, which may help to predict PEG procedure success.

Long DNA passenger strand highly improves the activity of RNA/DNA hybrid siRNAs.

Small interfering RNAs (siRNAs) are potent tools in biomedical research, which can reduce the expression level of target proteins through RNAi pathway. They are composed of 19-25 bp double strand RNA (dsRNAs), therefore, stimulate dsRNAs dependent interferon responses in a non-specific manner. This problem has prevented siRNAs from being applied as new therapeautic agents. In the present paper, we tried to circumvent interferon responses using RNA/DNA hetero siRNAs (HsiRNAs) composed of RNA guide and DNA passenger strands. It was previously reported that siRNAs which were partially substituted with DNA had RNAi activity and that DNA substitution often caused the activity loss. In our results, HsiRNAs, in which the passenger strand of siRNAs were exchanged with DNA also showed much lower activity than that of parental siRNAs. Here, we found that attachment of 5' flanking sequence to DNA passenger strand improved the activity of HsiRNAs. Furthermore, the effective HsiRNAs induced much lower interferon responses than parental siRNAs. Thus, HsiRNAs with 5' flanking sequence are expected to be novel siRNA drug candidates.

Ulcerative colitis associated with isolated unilateral hypoglossal nerve palsy.

We herein describe a rare case of ulcerative colitis associated with unilateral hypoglossal nerve palsy. A 64-year-old woman developed severe active ulcerative colitis and was treated with prednisolone. The dose of oral prednisolone was reduced to 7.5 mg/day, following which the patient noticed slight dysphagia and a speech disturbance. She was diagnosed with unilateral hypoglossal nerve palsy, which was thought to be caused by mononeuritis. She was treated with intravenous methylprednisolone at a dose of 500 mg/day, which improved the neuropathy. When the neuropathy occurred, the patient was in a mildly active stage of ulcerative colitis. We concluded that the mononeuritis observed in the present case was likely an extraintestinal manifestation of ulcerative colitis.

Efficacy of peroral pancreatoscopy in the diagnosis of pancreatic diseases.

BACKGROUND: The aim of this study was to evaluate the usefulness of peroral pancreatoscopy in the diagnosis of pancreatic diseases. METHODS: Both 3.7-mm (thin) and 0.8-mm (ultra-thin) diameter fiberoptic pancreatoscopes were used in 115 cases (pancreatic cancer, 35; benign ductal stenosis, 20; intraductal papillary-mucinous tumor, 60). RESULTS: Observation rates for pancreatic cancer, benign ductal stenosis, and intraductal papillary-mucinous tumor were, respectively, 63%, 80%, and 95%. Tumor vessels and papillary tumor were observed when pancreatic cancer was smaller than 2 cm but not when the tumor was larger than 2 cm. Stenosis without significant mucosal changes was observed in 62% of cases of benign ductal stenosis. Coarse mucosa and friability were observed more frequently in association with pancreatic cancer than benign ductal stenosis. Granular mucosa or papillary tumor could be observed in 74% of cases of intraductal papillary-mucinous tumor. Papillary tumor was observed with increasing frequency in cases of intraductal papillary-mucinous tumor as the degree of malignancy increased. CONCLUSIONS: Peroral pancreatoscopy with an ultra-thin fiberscope is useful in the diagnosis of minute pancreatic lesions. Peroral pancreatoscopy with a thin fiberscope can provide a definitive diagnosis of intraductal papillary-mucinous tumor including the degree of malignancy.