わが国における外国クルーズ船社誘致策の展開と国際クルーズマーケットの変化

外国クルーズ船社に対するわが国地方自治体によるマーケティング分野の政策・活動と、外国クルーズ船社の寄港の状況とその傾向を考察した。地方自治体は、商談会への参加をはじめとする多様なチャネルを活用した観光地・イベントの情報提供、モデルツアーの提案など、マーケティング活動を積極的に展開してきた。主要な外国クルーズ船社が就航し、中型船のカジュアルクルーズ、中型船のプレミアムクルーズを中心に寄港回数を増加させてきた。また、プレミアムクルーズならびにラグジュアリークルーズにおいては、その寄港回数が特定の地方・地域に偏っていないことから、マーケティング活動が特に有効に機能している可能性がある。This study examines the development of policies to attract foreign cruise liners in Japan, focusing on marketing related policies and activities. This study also examines the trends of such liners’ port calls and draws policy implication. Municipal governments in Japan have been actively developing and implementing marketing activities such as providing information on tourist attractions and events using various channels including participation in business meetings. The number of port calls has increased greatly, in casual-class cruise operated by medium-sized vessels and premium-class cruise by medium-sized vessels in particular. Premium-class and luxury-class cruises are not concentrated in specific regions, implying the effectiveness of marketing activities in such classes.遠藤伸明: 東京海洋大学学術研究院流通情報工学部門Nobuaki ENDO: Department of Logistics and Information Engineering, Tokyo University of Marine Science and Technology (TUMSAT)小川雅史: 京都大学経営管理大学院Masashi OGAWA: Graduate School of Management, Kyoto Universit

Synthesis-enabled understanding of the mechanism of action of amphotericin B and the development of increased therapeutic derivatives

The polyene macrolide amphotericin B (AmB) remains a critically vital antifungal as the last line of defense against a wide range of life-threatening fungal pathogen. Despite its clinical usage for over half a century, AmB has evaded the development of clinically relevant microbial resistance. AmB has been shown to form ion channels similar to that of their protein counterparts, which has led to the proposal that AmB kills yeast cells via membrane permeabilization. The capacity for ion channel formation and cytotoxicity of AmB are thought to be dependent upon membranous sterol, but the role of sterols in this mechanism and whether membrane permeabilizaton and biological activity are even linked has remained unclear. Thus, the complete understanding of the mechanism of action of AmB would enable the development of new antifungals with an improved therapeutic index, as well as guide the pursuit of new antimicrobials that evade resistance. To elucidate the operative mechanism, we pursued a systematic functional group deletion strategy where derivatives of AmB are synthesized lacking a single protic functional group to understand its role in AmB’s activity. The C35 hydroxyl group of AmB has been proposed to be critical for ion channel formation and so we accessed the derivative lacking the C35 hydroxyl via an iterative cross-coupling (ICC) strategy. The resulting derivative maintained the capacity to bind membranous ergosterol, but could no longer cause membrane permeabilization. Despite the lack of channel activity, this derivative still demonstrated potent fungicidal activity. Deletion of the mycosamine sugar yielded a derivative that could no longer bind ergosterol and was completely inactive against yeast. Collectively, these results led us to conclude that the primary mechanism by which AmB kills yeast is the binding of the ergosterol and that channel formation is a complementary mechanism that marginally increases AmB's potency. This finding suggests that toxicity to humans is likely due to the binding of the major mammalian sterol: cholesterol. Given the importance of the mycosamine appendage on the binding of sterol, we pursued an atomistic understanding of this interaction. The axial C2' hydroxyl group of AmB has been proposed to be critical in binding both sterols. Surprisingly, derivatives lacking or epimerizing the C2' hydroxyl maintained the capacity to bind ergosterol but could no longer bind cholesterol. Consistent with sterol binding being the operative mechanism for toxicity, both derivatives exhibited potent antifungal activity but no toxicity in human cells and mice. However, synthetic access to both derivatives limited their further pursuit. We hypothesized that the sterol selectivity resulted from a ligand-selective allosteric modification and proposed that a similar effect could be achieved by derivatization of the accessible C41 carboxylate. Similar to the C2' modified analogues, the new AmB ureas also demonstrated a preferential binding for ergosterol over cholesterol. This corresponded with their potent activity against a wide range of fungal pathogens as well as their substantial decrease in toxicity to human cells and mice. Despite their decreased toxicity, the AmB ureas maintained the ability to evade resistance similar to that of the parent compound

Metastatic recurrence in a pancreatic cancer patient derived orthotopic xenograft (PDOX) nude mouse model is inhibited by neoadjuvant chemotherapy in combination with fluorescence-guided surgery with an anti-CA 19-9-conjugated fluorophore.

The aim of this study is to determine the efficacy of neoadjuvant chemotherapy (NAC) with gemcitabine (GEM) in combination with fluorescence-guided surgery (FGS) on a pancreatic cancer patient derived orthotopic xenograft (PDOX) model. A PDOX model was established from a CA19-9-positive, CEA-negative tumor from a patient who had undergone a pancreaticoduodenectomy for pancreatic adenocarcinoma. Mice were randomized to 4 groups: bright light surgery (BLS) only; BLS+NAC; FGS only; and FGS+NAC. An anti-CA19-9 or anti-CEA antibody conjugated to DyLight 650 was administered intravenously via the tail vein of mice with the pancreatic cancer PDOX 24 hours before surgery. The PDOX was brightly labeled with fluorophore-conjugated anti-CA19-9, but not with a fluorophore-conjugated anti-CEA antibody. FGS was performed using the fluorophore-conjugated anti-CA19-9 antibody. FGS had no benefit over BLS to prevent metastatic recurrence. NAC in combination with BLS did not convey an advantage over BLS to prevent metastatic recurrence. However, FGS+NAC significantly reduced the metastatic recurrence frequency to one of 8 mice, compared to FGS only after which metastasis recurred in 6 out of 8 mice, and BLS+NAC with metastatic recurrence in 7 out of 8 mice (p = 0.041). Thus NAC in combination with FGS can reduce or even eliminate metastatic recurrence of pancreatic cancer sensitive to NAC. The present study further emphasizes the power of the PDOX model which enables metastasis to occur and thereby identify the efficacy of NAC in combination with FGS on metastatic recurrence

Efficacy of tumor-targeting Salmonella typhimurium A1-R in combination with anti-angiogenesis therapy on a pancreatic cancer patient-derived orthotopic xenograft (PDOX) and cell line mouse models.

The aim of the present study was to examine the efficacy of tumor-targeting Salmonella typhimurium A1-R treatment following anti-vascular endothelial growth factor (VEGF) therapy on VEGF-positive human pancreatic cancer. A pancreatic cancer patient-derived orthotopic xenograft (PDOX) that was VEGF-positive and an orthotopic VEGF-positive human pancreatic cancer cell line (MiaPaCa-2-GFP) as well as a VEGF-negative cell line (Panc-1) were tested. Nude mice with these tumors were treated with gemcitabine (GEM), bevacizumab (BEV), and S. typhimurium A1-R. BEV/GEM followed by S. typhimurium A1-R significantly reduced tumor weight compared to BEV/GEM treatment alone in the PDOX and MiaPaCa-2 models. Neither treatment was as effective in the VEGF-negative model as in the VEGF-positive models. These results demonstrate that S. typhimurium A1-R following anti-angiogenic therapy is effective on pancreatic cancer including the PDOX model, suggesting its clinical potential

The tumor-educated-macrophage increase of malignancy of human pancreatic cancer is prevented by zoledronic acid.

We previously defined macrophages harvested from the peritoneal cavity of nude mice with subcutaneous human pancreatic tumors as "tumor-educated-macrophages" (Edu) and macrophages harvested from mice without tumors as "naïve-macrophages" (Naïve), and demonstrated that Edu-macrophages promoted tumor growth and metastasis. In this study, Edu- and Naïve-macrophages were compared for their ability to enhance pancreatic cancer malignancy at the cellular level in vitro and in vivo. The inhibitory efficacy of Zoledronic acid (ZA) on Edu-macrophage-enhanced metastasis was also determined. XPA1 human pancreatic cancer cells in Gelfoam co-cultured with Edu-macrophages proliferated to a greater extent compared to XPA1 cells cultured with Naïve-macrophages (P = 0.014). XPA1 cells exposed to conditioned medium harvested from Edu culture significantly increased proliferation (P = 0.016) and had more migration stimulation capability (P<0.001) compared to cultured cancer cells treated with the conditioned medium from Naïve. The mitotic index of the XPA1 cells, expressing GFP in the nucleus and RFP in the cytoplasm, significantly increased in vivo in the presence of Edu- compared to Naïve-macrophages (P = 0.001). Zoledronic acid (ZA) killed both Edu and Naïve in vitro. Edu promoted tumor growth and metastasis in an orthotopic mouse model of the XPA1 human pancreatic cancer cell line. ZA reduced primary tumor growth (P = 0.006) and prevented metastasis (P = 0.025) promoted by Edu-macrophages. These results indicate that ZA inhibits enhanced primary tumor growth and metastasis of human pancreatic cancer induced by Edu-macrophages

Establishment of a patient-derived orthotopic Xenograft (PDOX) model of HER-2-positive cervical cancer expressing the clinical metastatic pattern.

Squamous cell carcinoma of the cervix, highly prevalent in the developing world, is often metastatic and treatment resistant with no standard treatment protocol. Our laboratory pioneered the patient-derived orthotopic xenograft (PDOX) nude mouse model with the technique of surgical orthotopic implantation (SOI). Unlike subcutaneous transplant patient-derived xenograft (PDX) models, PDOX models metastasize. Most importantly, the metastasis pattern correlates to the patient. In the present report, we describe the development of a PDOX model of HER-2-positive cervical cancer. Metastasis after SOI in nude mice included peritoneal dissemination, liver metastasis, lung metastasis as well as lymph node metastasis reflecting the metastatic pattern in the donor patient. Metastasis was detected in 4 of 6 nude mice with primary tumors. Primary tumors and metastases in the nude mice had histological structures similar to the original tumor and were stained by an anti-HER-2 antibody in the same pattern as the patient's cancer. The metastatic pattern, histology and HER-2 tumor expression of the patient were thus preserved in the PDOX model. In contrast, subcutaneous transplantation of the patient's cervical tumors resulted in primary growth but not metastasis

Tumor-Targeting Salmonella typhimurium A1-R in Combination with Trastuzumab Eradicates HER-2-Positive Cervical Cancer Cells in Patient-Derived Mouse Models.

We have previously developed mouse models of HER-2-positive cervical cancer. Tumors in nude mice had histological structures similar to the original tumor and were stained by anti-HER-2 antibody in the same pattern as the patient's cancer. We have also previously developed tumor-targeting Salmonella typhimurium A1-R and have demonstrated its efficacy against patient-derived tumor mouse models, both alone and in combination. In the current study, we determined the efficacy of S. typhimurium A1-R in combination with trastuzumab on a patient-cancer nude-mouse model of HER-2 positive cervical cancer. Mice were randomized to 5 groups and treated as follows: (1) no treatment; (2) carboplatinum (30 mg/kg, ip, weekly, 5 weeks); (3) trastuzumab (20 mg/kg, ip, weekly, 5 weeks); (4) S. typhimurium A1-R (5 × 107 CFU/body, ip, weekly, 5 weeks); (5) S. typhimurium A1-R (5 × 107 CFU/body, ip, weekly, 5 weeks) + trastuzumab (20 mg/kg, ip, weekly, 5 weeks). All regimens had significant efficacy compared to the untreated mice. The relative tumor volume of S. typhimurium A1-R + trastuzumab-treated mice was smaller compared to trastuzumab alone (p = 0.007) and S. typhimurium A1-R alone (p = 0.039). No significant body weight loss was found compared to the no treatment group except for carboplatinum-treated mice (p = 0.021). Upon histological examination, viable tumor cells were not detected, and replaced by stromal cells in the tumors treated with S. typhimurium A1-R + trastuzumab. The results of the present study suggest that S. typhimurium A1-R and trastuzumab in combination are highly effective against HER-2-expressing cervical cancer