Koshi Fujikawa

Opposing effect of angiopoietin‐1 on VEGF‐mediated disruption of endothelial cell–cell interactions requires activation of PKCβ

Angiopoietin‐1 (Ang1) and vascular endothelial growth factor (VEGF) cooperate in migration and survival of endothelial cells by activation of phosphatidylinositol‐3 (PI‐3) kinase and mitogen activating protein (MAP) kinase pathways. However, Ang1 opposes the effect of VEGF on vascular permeability. We found that Ang1 also blocks VEGF‐mediated diffusion of fluoresin isothiocyanate (FITC)‐labeled albumin across an endothelial cell monolayer. VEGF‐mediated vascular permeability has been attributed, in part, to activation of phospholipase A2 and subsequent formation of platelet activating factor. However, Ang1 had no effect on VEGF‐induced activation of phospholipase A2 or the release of arachidonic acid. VEGF‐mediated permeability was associated with disruption of endothelial cell junctional complexes, dissociation of β‐catenin from VE‐cadherin, and accumulation of β‐catenin in the cytosol. In contrast, Ang1 enhanced the interaction of β‐catenin with VE‐cadherin and impaired VEGF‐mediated dissociation of this complex. Ang1 also blocked VEGF‐induced translocation of protein kinase C (PKC) and β2 to the membrane, but had no effect on activation of PKCα. In addition, staurosporine and a PKCβ inhibitor, LY379196, blocked VEGF‐mediated dissociation of β‐catenin from VE‐cadherin, diffusion of albumin across the endothelial cell monolayer, and translocation of PKCβ isoforms. These data indicate that VEGF‐mediated disruption of endothelial cell–cell interactions requires activation of PKCβ isoforms and that this pathway is blocked by Ang1. J. Cell. Physiol. 198: 53–61, 2004.

NERF2, a member of the Ets family of transcription factors, is increased in response to hypoxia and angiopoietin-1: A potential mechanism for Tie2 regulation during hypoxia

Vascular endothelial growth factor (VEGF) and angiopoietins regulate endothelial cell survival and migration and are essential for angiogenesis. Considerable progress has been made towards understanding hypoxia‐mediated regulation of VEGF and its receptors. In contrast, little is known about the regulation of angiopoietins and their receptors in hypoxic cells. Using RT–PCR, RNAase protection assay, and Western blotting, we found that Tie1 and Tie2 mRNA and protein levels increased in response to hypoxia in human umbilical vein endothelial cells. Previously, we have shown that NERF2, a member of Ets family of transcription factors that is specifically expressed in endothelial cells, binds to the promoter region of Tie2 and transactivates Tie2 expression. In this study, we show that expression of NERF2 was increased under hypoxia and that this increase temporally correlated with the increase in Tie2 expression. Hypoxia‐induced expression of NERF2 and Tie2 was blocked by angiopoietin‐2, a competitive inhibitor of angiopoietin‐1, and by recombinant soluble extracellular domain of Tie2 but not by VEGF‐neutralizing antibodies. In addition, angiopoietin‐1 directly induced expression of NERF2 in quiescent cells. These novel findings suggest that angiopoietin‐1 regulates expression of NERF2 and its own receptor in hypoxic cells. J. Cell. Biochem. 85: 505–515, 2002.

Kinetics of Internalization and Cytotoxicity of Transferrin‐Neocarzinostatin Conjugate in Human Leukemia Cell Line, K562

ABSTRACT Human serum transferrin was conjugated with an anticancer‐active polypeptide, neocarzinostatin, by using N‐succinimidy1‐3‐(2‐pyridyldithio)propionate. The conjugate consisted of 1.8 mol of neocarzinostatin per 1 mol of transferrin on average and retained cytotoxic activity against human tumor cells. This conjugate was capable of binding to the transferrin receptor of human myelogenous leukemia K562 cells and was internalized by endocytosis. The LD50 values of the conjugate and neocarzinostatin alone in the presence of excess native bovine transferrin were 0.20 μ/ml and 1.80 μ/ml, respectively, suggesting that the effect of the conjugate was greater than that of neocarzinostatin alone. A pulse‐chase experiment using 125I‐labeled conjugate revealed that 25% of the internalized conjugate was degraded in lysosomes and the rest was recycled back to the cell surface without degradation. About 75% of this conjugate recycled back to the cell surface in 18.3 min (3.4 min for receptor binding and 14.9 min for recycling to the cell surface through the acidosomes), while the rest was delivered from the cell surface to the lysosome in 19.6 min. This phenomenon was confirmed by chasing the radioactivity in subcellular fractions separated by Percoll density gradient centrifugation. Therefore, it was concluded that this conjugate is internalized specifically by transferrin receptors and is at least partly transferred to and accumulated in lysosomal compartments, resulting in the inhibition of cellular DNA synthesis.

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.

Neoadjuvant chemotherapy with docetaxel, nedaplatin, and fluorouracil for resectable esophageal cancer: A phase II study

Cisplatin plus 5‐fluorouracil is regarded as standard neoadjuvant chemotherapy for esophageal squamous cell carcinoma (ESCC) in Japan, but the prognosis remains poor. We have previously described how definitive chemoradiotherapy with docetaxel, nedaplatin, and 5‐fluorouracil (DNF) led to a very high response rate and promising survival times. We therefore undertook a phase II trial to evaluate the feasibility and efficacy of neoadjuvant DNF. The study included patients with clinical stage Ib‐III ESCC. Chemotherapy consisted of i.v. docetaxel (30 mg/m2) and nedaplatin (50 mg/m2) on days 1 and 8, and a continuous infusion of 5‐fluorouracil (400 mg/m2/day) on days 1‐5 and 8‐12, every 3 weeks. After three courses of chemotherapy, esophagectomy was carried out. The primary end‐point was the completion rate of the protocol treatment. Twenty‐eight patients were enrolled (cStage Ib/II/III, 2/3/23) and all received at least two cycles of chemotherapy. Twenty‐five patients underwent surgery, all of whom achieved an R0 resection, leading to a completion rate of 89.3%. The overall response rate was 87.0%. A pathological complete response was confirmed in eight (32.0%) cases. Grade 3/4 adverse events included leukopenia (32.1%), neutropenia (39.3%), febrile neutropenia (10.7%), thrombocytopenia (10.7%), and diarrhea (14.3%), but were manageable. Treatment‐related deaths and major surgical complications did not occur. Estimated 2‐year progression‐free and overall survival rates were 70.4% and 77.2%, respectively. Thus, DNF therapy was well tolerated and deemed feasible, with a strong tumor response in a neoadjuvant setting for ESCC. This trial is registered with the University Hospital Medical Information Network (UMIN ID: 000014305).

Skin Disorders and Primary Tumor Location as Prognostic Factors in Patients with Metastatic Colorectal Cancer Treated with Cetuximab and Chemotherapy

Background: Cetuximab-induced skin disorder is common in colorectal cancer (CRC), and is known to affect prolonged overall survival (OS). Patients with left-sided CRC survive longer than those with right-sided CRC, among those treated with combination cetuximab and chemotherapy. However, no study has evaluated patient prognosis in terms of OS and progression-free survival (PFS) in relation to both tumor location and skin disorder. This study aimed to determine the incidence of skin disorder according to tumor location and analyze the relationship of tumor location and skin disorder with OS. Methods: Patients with metastatic colorectal cancer (mCRC) treated with standard chemotherapy and cetuximab as first-line therapy were included. Differences in the incidence of skin disorders due to the location of the primary tumors were compared in the same patient. The OS and PFS in relation to the location of the primary tumors and presence or absence of skin disorder were also compared. Results: Total frequency of each skin disorder as rash acneiform, paronychia, and dry skin in patients with left- and right-sided mCRC was 70%, 70%, and 43% and 27%, 36%, and 27%, respectively. The median OS was 8.9 months for mCRC on the left-sided without skin disorder and 56.3 months for mCRC on the left-sided with skin disorder. In comparison, the median OS was 10.4 months for mCRC on the right-sided without skin disorder and 11.3 months for mCRC on the right-sided with skin disease (left-sided with skin disorder versus other three group; P<0.001). Conclusions: Primary tumor location and the presence of skin disorder are important factors in patients with mCRC who receive cetuximab. In particular, our results show the new fact that the left-sided and right-sided mCRC survival time were comparable if there is no skin disorder caused by cetuximab.

The prognostic factor and the optimal timing of conversion surgery in unresectable stage IV gastric cancer: A retrospective analysis.

78 Background: Conversion surgery could be an option for unresectable stage IV gastric cancer when distant metastasis (M1) is disappeared by chemotherapy. However, the indication and the optimal timing of conversion surgery in stage IV gastric cancer remain unclear, even if metastatic lesions disappear with chemotherapy. Guideline of National Comprehensive Cancer Network also shows no principle after down-staging. Methods: This retrospective study examined 34 gastric cancer patients who underwent curative conversion surgery at our institute between 2005 and 2014. Clinicopathologic characteristics and patient outcomes were analyzed, with particular focus on the potential to select patients who might benefit from surgical resection. Results: The number of M1 factors was one in 31 patients and two in 3, including metastases to non-regional lymph node in 21, peritoneum in 8, liver in 5, and lung in 3. The regimen of chemotherapy was Docetaxel/CDDP/S-1 in 23 patients, Docetaxel/CDDP/S-1+Trastuzmab in 6, S-1/CD...

Retrospective cohort study on the safety and efficacy of panitumumab for patients with metastatic colorectal cancer: The HGCSG1002 study—Analysis of adverse events.

554 Background: Panitumumab (Pmab) is a fully human monoclonal antibody specific to the epidermal growth factor receptor. It has been associated with very few infusion reactions, but has been point...

A novel treatment for early gastrointestinal carcinoma by ultrasonic endoscopic mucosal stripping.

PurposeThe aim of this study was to clarify the indications for a new endoscopic mucosal resection (EMR) technique that employs a cavitational ultrasonic surgical aspirator (CUSA). Endoscopic mucosal resection has proved an effective technique for treating early mucosal gastrointestinal cancer. However, resecting a lesion larger than 2 cm en bloc requires special devices and a long processing time; and it engenders the risk of bleeding, perforation, and other complications.MethodsWe investigated application of the CUSA for detaching the mucosa from the muscularis propria of extracted porcine stomachs and then clarified the specification of an endoscopic ultrasonic scalpel for endoscopic mucosal resection by investigating characteristics of two original, handmade prototype cavitational ultrasonic surgical aspirators.ResultsUse of a cavitational ultrasonic surgical aspirator should improve the ease and safety of detaching the mucosa. A small, high-power ultrasonic cylindrical vibrator should be developed to make possible a probe-type scalpel with a piezoelectric vibrator mounted in the tip of a catheter. An ultrasonic transmission-type scalpel could lead to the development of a new endoscopic mucosal resection device for clinical use.ConclusionsThe CUSA should enable us to develop a safer, simpler, time-saving scalpel for endoscopic mucosal resection, although some resolvable technical problems remain. The CUSA might enable us to diagnose carcinoma invasion into the submucosa in aspirated specimens and then aspirate out the entire invading submucosal carcinoma.