Yutaka Okagawa

RNAi-mediated gene silencing of ST6GalNAc I suppresses the metastatic potential in gastric cancer cells

BackgroundST6GalNAc I is a sialyltransferase controlling the expression of sialyl-Tn antigen (STn), which is overexpressed in several epithelial cancers, including gastric cancer, and is highly correlated with cancer metastasis. However, the functional contribution of ST6GalNAc I to development or progression of gastric cancer remains unclear. In this study, we investigated the effects of suppression of ST6GalNAc I on gastric cancer in vitro and in vivo.MethodsGastric cancer cell lines were transfected with ST6GalNAc I siRNA and were examined by cell proliferation, migration, and invasion assays. We also evaluated the effect of ST6GalNAc I siRNA treatment in a peritoneal dissemination mouse model. The differences in mRNA levels of selected signaling molecules were analyzed by polymerase chain reaction (PCR) arrays associated with tumor metastasis in MKN45 cells. The signal transducer and activator of transcription 5b (STAT5b) signaling pathways that reportedly regulate the insulin-like growth factor-1 (IGF-1) were analyzed by Western blot.ResultsST6GalNAc I siRNA inhibited gastric cancer cell growth, migration, and invasion in vitro. Furthermore, intraperitoneal administration of ST6GalNAc I siRNA- liposome significantly inhibited peritoneal dissemination and prolonged the survival of xenograft model mice with peritoneal dissemination of gastric cancer. PCR array confirmed that suppression of ST6GalNAc I caused a significant reduction in expression of IGF-1 mRNA. Decreased IGF-1 expression in MKN45 cells treated with ST6GalNAc I siRNA was accompanied by reduced phosphorylation of STAT5b.ConclusionST6GalNAc I may regulate the gene expression of IGF-1 through STAT5b activation in gastric cancer cells and may be a potential target for treatment of metastasizing gastric cancer.

Clinical utility of capsule endoscopy with flexible spectral imaging color enhancement for diagnosis of small bowel lesions

Background and study aims: The clinical utility of computed virtual chromoendoscopy with flexible spectral imaging color enhancement (FICE) in capsule endoscopy (CE) remains controversial. To clarify the clinical utility of FICE-enhanced CE in evaluating small bowel lesions, we quantitatively assessed white light (WL), FICE, and blue mode (BM) images and examined the sensitivity of these 3 imaging modes of small-bowel lesions from patients who underwent CE. Methods: The CIELAB color difference (∆E) and visual analogue scales (VAS) were measured in 261 CE images (3 different lesion categories) using WL and FICE set 1, 2, and 3, and BM images, respectively. Three endoscopists reviewed CE videos with WL, 3 FICE mode settings, and BM, and compared the sensitivity and detectability for small intestinal diseases from 50 patients who underwent CE. Results: In the assessment of visibility in the 152 vascular lesion images, the ∆E and VAS of FICE set 1, 2, and BM images were significantly higher than that of WL images. In 88 erosion/ulceration images, the ∆E and VAS of FICE set 1 and 2 images were significantly higher than that of WL images. In 21 tumor images, there were no significant differences in ∆E among these modalities. When analyzed on a per-patient basis, FICE settings 1 and 2 had the highest sensitivity (100 %) and specificity (97.3 – 100 %) for vascular lesions. As for erosive/ulcerative lesions, FICE setting 2 had the highest sensitivity (100 %) and specificity (97.2 %). For tumors or polyps, WL had the highest sensitivity (90.9 %) and specificity (87.1 %). In per-lesion analysis, FICE settings 1 and 2 showed significantly superior detection ability over WL for vascular lesions. In the detection of erosive/ulcerative lesions, FICE setting 2 was significantly superior to WL. In tumor images, there was no significant improvement with any of the settings relative to WL images. Conclusions: FICE is most useful for improving CE image quality and detection in cases of angioectasia and erosion/ulceration of the small intestine.

Erratum to: Conversion therapy for inoperable advanced gastric cancer patients by docetaxel, cisplatin, and S-1 (DCS) chemotherapy: a multi-institutional retrospective study

Background Conversion therapy is an option for unresectable metastatic gastric cancer when distant metastases are controlled by chemotherapy; however, the feasibility and efficacy remain unclear. This study aimed to assess the feasibility and efficacy of conversion therapy in patients with initially unresectable gastric cancer treated with docetaxel, cisplatin, and S-1 (DCS) chemotherapy by evaluating clinical outcomes.

Activated p53 with Histone Deacetylase Inhibitor Enhances L-Fucose-Mediated Drug Delivery through Induction of Fucosyltransferase 8 Expression in Hepatocellular Carcinoma Cells.

Background The prognosis of advanced hepatocellular carcinoma (HCC) is dismal, underscoring the need for novel effective treatments. The α1,6-fucosyltransferase (fucosyltransferase 8, FUT8) has been reported to accelerate malignant potential in HCC. Our study aimed to investigate the regulation of FUT8 expression by p53 and develop a novel therapeutic strategy for targeting HCC cells using L-fucose-mediated drug delivery. Methods Binding sites for p53 were searched for within the FUT8 promoter region. FUT8 expression was assessed by immunoblotting. Chromatin immunoprecipitation (ChIP) assays were performed to analyze p53 binding to the FUT8 promoter. The delivery of Cy5.5-encapsulated L-fucose-liposomes (Fuc-Lip-Cy5.5) to a Lens Culinaris agglutinin-reactive fraction of α-fetoprotein (AFP-L3)-expressing HCC cells was analyzed by flow cytometry. The induction of FUT8 by histone deacetylase inhibitor (HDACi) -inducing acetylated -p53 was evaluated by immunoblotting. Flow cytometric analysis was performed to assess whether the activation of p53 by HDACi affected the uptake of Fuc-Lip-Cy5.5 by HCC cells. The cytotoxicity of an L-fucose-bound liposome carrying sorafenib (Fuc-Lip-sorafenib) with HDACi was assessed in vivo and in vitro. Results The knock down of p53 with siRNA led to decreased FUT8 expression. ChIP assays revealed p53 binds to the FUT8 promoter region. Flow cytometric analyses demonstrated the specific uptake of Fuc-Lip-Cy5.5 into AFP-L3-expressing HCC cells in a p53- and FUT8-dependent manner. HDACi upregulated the uptake of Fuc-Lip-Cy5.5 by HCC cells by increasing FUT8 via acetylated -p53. The addition of a HDACi increased apoptosis induced by Fuc-Lip-sorafenib in HCC cells. Conclusions Our findings reveal that FUT8 is a p53 target gene and suggest that p53 activated by HDACi induces Fuc-Lip-sorafenib uptake by HCC cells, highlighting this pathway as a promising therapeutic intervention for HCC.

A Phase 1/2 Study of Definitive Chemoradiation Therapy Using Docetaxel, Nedaplatin, and 5-Fluorouracil (DNF-R) for Esophageal Cancer.

PURPOSE Patient survival in esophageal cancer (EC) remains poor. The purpose of this study was to investigate a regimen of definitive chemoradiation therapy (CRT) that exerts good local control of EC. We performed a phase 1/2 study to assess the safety and efficacy of CRT with docetaxel, nedaplatin, and 5-fluorouracil (DNF-R). METHODS AND MATERIALS Eligible patients presented with stage IB to IV EC. Patients received 2 cycles of docetaxel (20, 30, or 40 mg/m(2)) and nedaplatin (50 mg/m(2)) on days 1 and 8 and a continuous infusion of 5-fluorouracil (400 mg/m(2)/day) on days 1 to 5 and 8 to 12, every 5 weeks, with concurrent radiation therapy (59.4 Gy/33 fractions). The recommended dose (RD) was determined using a 3 + 3 design. RESULTS In the phase 1 study, the dose-limiting toxicities were neutropenia and thrombocytopenia. The RD of docetaxel was determined to be 20 mg/m(2). In the phase 2 study, grade 3 to 4 acute toxicities included neutropenia (42.8%), febrile neutropenia (7.14%), thrombocytopenia (17.9%), and esophagitis (21.4%). Grade 3 to 4 late radiation toxicity included esophagostenosis (10.7%). The complete response rate was 82.1% (95% confidence interval: 67.9-96.3%). Both the median progression-free survival and overall survival were 41.2 months. CONCLUSIONS DNF-R showed good tolerability and strong antitumor activity, suggesting that it is a potentially effective therapeutic regimen for EC.

Relationship Between Increased Fucosylation and Metastatic Potential in Colorectal Cancer

BACKGROUND Fucose is utilized for the modification of different molecules involved in blood group determination, immunological reactions, and signal transduction pathways. We have recently reported that enhanced activity of the fucosyltransferase 3 and/or 6 promoted TGF-ß-mediated epithelial mesenchymal transition and was associated with increased metastatic potential of colorectal cancer (CRC), suggesting that fucose is required by CRC cells. With this in mind, we examined requirement of L-fucose in CRC cells and developed fucose-bound nanoparticles as vehicles for delivery of anticancer drugs specific to CRC. METHODS In this study, we first examined the expression of fucosylated proteins in 50 cases of CRC by immunochistochemical staining with biotinylated Aleuria aurantia lectin (AAL). Then we carried out an L-fucose uptake assay using three CRC cell lines. Finally, we developed fucose-bound nanoparticles as vehicles for the delivery of an anticancer drug, SN38, and examined tumor growth inhibition in mouse xenograft model (n = 6 mice per group). All statistical tests were two-sided. RESULTS We found a statistically significant relationship between vascular invasion, clinical stage, and intensity score of AAL staining (P≤ .02). L-fucose uptake assay revealed that L-fucose incorporation, as well as fucosylated protein release, was high in cells rich in fucosylated proteins. L-fucose-bound liposomes effectively delivered Cy5.5 into CRC cells. The excess of L-fucose decreased the efficiency of Cy5.5 uptake through L-fucose-bound liposomes, suggesting an L-fucose receptor dependency. Intravenously injected, L-fucose-bound liposomes carrying SN38 were successfully delivered to CRC cells, mediating efficient tumor growth inhibition (relative tumor growth ratio: no treatment group [NT], 8.29 ± 3.09; SN38-treated group [SN38], 3.53 ± 1.47; liposome-carrying, SN38-treated group [F0], 3.1 ± 1.39; L-fucose-bound, liposome-carrying, SN38-treated group [F50], 0.94 ± 0.89; F50 vs NT,P= .003; F50 vs SN38,P= .02, F50 vs F0,P= .04), as well as prolonging survival of mouse xenograft models (log-rank test,P< .001). CONCLUSIONS Thus, fucose-bound liposomes carrying anticancer drugs provide a new strategy for the treatment of CRC patients.

Targeting Notch-1 positive acute leukemia cells by novel fucose-bound liposomes carrying daunorubicin.

Complete remission by induction therapy in acute myelogenous leukemia (AML) can be achieved due to improvements in supportive and optimized therapy. However, more than 20% of patients will still need to undergo salvage therapy, and most will have a poor prognosis. Determining the specificity of drugs to leukemia cells is important since this will maximize the dose of chemotherapeutic agents that can be administered to AML patients. In turn, this would be expected to lead to reduced drug toxicity and its increased efficacy. We targeted Notch-1 positive AML cells utilizing fucose-bound liposomes, since activation of Notch-1 is required for O-fucosylation. Herein, we report that intravenously injected, L-fucose-bound liposomes containing daunorubicin can be successfully delivered to AML cells that express fucosylated antigens. This resulted in efficient tumor growth inhibition in tumor-bearing mice and decreased proliferation of AML patient-derived leukemia cells. Thus, biological targeting by fucose-bound liposomes that takes advantage of the intrinsic characteristics of AML cells could be a promising new strategy for Notch-1 positive-AML treatment.

[Therapy-related myelodysplastic syndrome as a late adverse event of definitive chemoradiotherapy for esophageal and oropharyngeal cancer].

The risks of myelodysplastic syndrome (MDS) and acute leukemia are increased in patients previously treated for other malignancies. Therapy-related MDS (t-MDS) occurs after exposure to certain cytotoxic agents or radiation used for cancer treatment. We report a case of t-MDS following curative chemoradiotherapy (CRT) for esophageal and oropharyngeal cancer. An 80-year-old male diagnosed with double cancers of the esophagus and oropharynx underwent definitive CRT and achieved a complete response. Six years later, he became anemic, and bone marrow examination showed 3.4% blast cells with fine chromatin structures and basophilic cytoplasm. Cytogenetic analysis indicated a complex karyotype that included chromosome 5 and 7 abnormalities. These findings were consistent with t-MDS. Subsequently, he developed acute myeloid leukemia and died 8 months later. This case indicates that long-term surveillance is needed to closely monitor the risk of t-MDS in patients treated with CRT.

Atypical presentation of a cushion sign-positive stomach gastrointestinal stromal tumor with cystic formation: A case report

Gastrointestinal stromal tumors (GIST) typically appear as solid masses, and cystic formation is uncommon. Most stomach GISTs with cystic formation progress outside the gastric wall and are frequently misdiagnosed as epigastric cystic tumors derived from pancreas or liver. An asymptomatic 72-year-old male underwent esophagogastroduodenoscopy, which revealed a submucosal tumor (SMT), approximately 50 mm in diameter, at the anterior wall of the gastric angle. The SMT was very soft with positive cushion sign. Endoscopic ultrasonography and contrast-enhanced computed tomography revealed that the SMT was a cystic tumor with solid component. Laparoscopic and endoscopic cooperative surgery were performed to remove the tumor. Histopathological analysis revealed that the tumor was a GIST with cystic formation. To the best of our knowledge, this the first documented case of a cushion sign-positive stomach GIST with cystic formation, which had mainly developed inside the stomach. This case suggests that we should keep in mind the possibility of cystic formation of GIST when the tumor has a solid component, even if it appears as a cushion sign-positive SMT.

Endoscopic submucosal dissection for early squamous cell carcinoma in the anal canal and Lugol chromoendoscopy for assessment of the lateral margin

A 66-year-old man underwent follow-up colonoscopy after colon polypectomy. The retroflexed view of the anal canal with white-light imaging revealed a whitish, slightly elevated lesion on the dentate line and an ill-defined flat lesion. A biopsy of the whitish elevation revealed squamous cell carcinoma (SCC), and endoscopic submucosal dissection (ESD) was planned. The lateral margin of the SCC was identified by spraying with Lugol’s iodine, and the tumor was resected en bloc with no complications. The pathological findings were SCC in situ with parakeratosis in the whitish elevation and high-grade intraepithelial neoplasia in the ill-defined flat lesion, which exhibited a wide iodine-unstained area by chromoendoscopy. Early SCC in the anal canal is a rare gastrointestinal cancer, and Lugol chromoendoscopy helped visualize the tumor margin for ESD.