Michiyo Saimura

Intraperitoneal injection of adenovirus-mediated NK4 gene suppresses peritoneal dissemination of pancreatic cancer cell line AsPC-1 in nude mice

NK4, composed of the N-terminal hairpin and subsequent four-kringle domains of hepatocyte growth factor (HGF), acts not only as a competitive antagonist for HGF but also as a potent angiogenesis inhibitor. This study was designed to assess a therapeutic potential of adenovirus-mediated NK4 gene transfer for disseminated pancreatic cancer cells in the peritoneal lavage of nude mice. We constructed a recombinant adenovirus NK4 (Ad-NK4), which encodes a secretable form of human NK4. In vitro migration of AsPC-1 (human pancreatic cancer cell line) was stimulated by HGF, and it was completely inhibited by Ad-NK4 transfection. Weekly intraperitoneal injections of Ad-NK4 could suppress the development of tumor nodules in a nude mouse peritoneal dissemination model. NK4 expression was detected in the disseminated nodules, liver, pancreas, spleen, and mesenterium. Immunohistochemical study of the disseminated tumors showed a remarkable decrease in microvessel density and an increase in number of apoptotic tumor cells in the Ad-NK4–treated mice. Survival of the Ad-NK4–treated mice was significantly improved. This study indicates that the intraperitoneal transduction of adenovirus-mediated NK4 gene may be a useful therapeutic modality to prevent the development of peritoneal dissemination of pancreatic cancer.

Co-cultivation of pancreatic cancer cells with orthotopic tumor- derived fibroblasts: fibroblasts stimulate tumor cell invasion via HGF secretion whereas cancer cells exert a minor regulative effect on fibroblasts HGF production

The intensive stromal reaction is one of characteristics of pancreatic exocrine carcinoma. The mutual interaction between pancreatic cancer cells and orthotopic tumor-derived fibroblasts have not been clarified yet. In this study, we sought to elucidate the mechanism underlying the tumor-stromal interaction with an in vitro coculture experimental system. Considerable strong c-Met expression was detected in seven out ten lines of human pancreatic carcinoma cells, as determined by Western blotting. For hepatocyte growth factor (HGF)-production, however, none or only trace amounts of HGF could be detected in those ten cell lines. Of the two lots of tumor-derived fibroblasts obtained from two pancreatic cancer patients, the fibroblasts capable to produce HGF could initiate an apparent invasion-stimulating response in strong c-Met-expressed Suit-2 and Panc-1 cells but not in faint expressed Mia PaCa-2 and BxPC-3 cells. A specialized HGF antagonist, NK4 would effectively inhibit the fibroblast-mediated invasive growth, thus proving the key role of the paracrine-fashioned HGF/c-Met pathway in the tumor-stromal interaction. On the other hand, the regulative action of cancer cells on HGF expression of fibroblasts was also investigated using direct or indirect coculture systems. For the fibroblasts that originally did not produce HGF, cancer cells failed to show any HGF-inductive effect. For the HGF-producing fibroblasts, despite of somewhat upregulation or downregulation in fibroblast HGF expression, the feedback regulation by studied pancreatic cancer cells in both coculture modes were relatively limited. This in vitro study sketched out the interaction between cancerous and stromal compartments with an emphasis on HGF/c-Met signal pathway, thus possibly helping to unveil the more complicated mutual modulation in vivo between pancreatic cancer and host mesenchymal tissues.

Suppression of metastasis of human pancreatic cancer to the liver by transportal injection of recombinant adenoviral NK4 in nude mice

NK4, a 4‐kringle fragment of hepatocyte growth factor (HGF), is an HGF antagonist that also acts as an angiogenesis inhibitor. NK4 strongly inhibits the infiltration, metastasis, and tumor growth of pancreatic cancer. The aim of our study was to evaluate the antitumor effect of adenovirus‐mediated NK4 gene transfer to the liver on hepatic metastasis of pancreatic cancer in vivo. We constructed recombinant adenoviral NK4 (Ad‐NK4), which encodes a secreted form of human NK4. Intrasplenic injection of Ad‐NK4 induced high and relatively maintained expression of NK4 protein in the liver and suppressed the number and growth of metastatic foci in the liver in a nude mouse model. Microscopically, central necrosis was found even in small metastatic foci in Ad‐NK4 treated mice. Immunohistochemical analysis of metastatic tumors showed a remarkable decrease in microvessel density and an increase in the number of apoptotic tumor cells after treatment with Ad‐NK4. These results indicate that intraportal injection of Ad‐NK4 may be a useful therapeutic modality for the clinical control of hepatic metastasis in pancreatic cancer.

Peritumoral injection of adenovirus vector expressing NK4 combined with gemcitabine treatment suppresses growth and metastasis of human pancreatic cancer cells implanted orthotopically in nude mice and prolongs survival

NK4 or adenovirus vector expressing NK4 (Ad-NK4) can act bifunctionally as a hepatocyte growth factor antagonist and angiogenesis inhibitor and has potential value in cancer therapy. The aim of this study was to evaluate the therapeutic efficacy of Ad-NK4 in combination with gemcitabine (GEM) against pancreatic cancer. In vitro study showed a strong antiproliferative effect of GEM and a potent anti-invasive effect of Ad-NK4 against pancreatic cancer cells. In in vivo experiments, SUIT-2 human pancreatic cancer cells were implanted into the pancreas of nude mice. Mice were treated with Ad-NK4 by injection into the peritumoral region of the pancreas on day 5 after implantation followed by weekly i.p. injections of GEM. On day 28 after implantation, pancreatic tumor volume was significantly smaller than that in mice treated with Ad-LacZ, Ad-NK4 alone, or GEM alone. Furthermore, combination therapy completely suppressed peritoneal dissemination and liver metastases, leading to significantly increased survival. Histologic and immunohistochemical assays of primary tumors indicated that combination therapy prohibited both cell proliferation and angiogenesis, resulting in high levels of apoptosis. These results suggest that peritumoral injection of Ad-NK4 plus GEM is a potent combination therapy for pancreatic cancer.

Efficacy and safety of eribulin as first- to third-line treatment in patients with advanced or metastatic breast cancer previously treated with anthracyclines and taxanes

OBJECTIVES Despite the survival benefit and acceptable tolerability of eribulin for advanced/metastatic breast cancer (MBC) patients pretreated with anthracyclines and taxanes, there is limited evidence of the clinical benefit of early eribulin use. We investigated the efficacy and safety of first- to third-line eribulin use in patients with MBC. MATERIALS AND METHODS In this phase II, open-label, single-arm study conducted at 14 sites in Kyushu, Japan, women with histologically confirmed human epidermal growth factor receptor 2-negative MBC were enrolled between December 1, 2011 and November 30, 2013 (Data cut-off: November 30, 2014). Objective response rate (ORR; primary endpoint), disease control rate (DCR), progression-free survival (PFS), duration of response (DOR), overall survival (OS), and safety were evaluated. RESULTS Of 53 recruited patients, 47 were enrolled. The ORR was 17.0% (95% confidence interval, 7.6-30.8), DCR was 66.0% (51.2-77.8), median PFS was 4.9 months (3.5-7.0), DOR was 6.6 months (1.9-14.3), and median OS was 17.4 months (10.1-not evaluable). The common grade 3/4 adverse events were neutropenia (25 patients; 53.2%), leucopenia (16 patients; 42.1%) and febrile neutropenia (4 patients; 8.5%). Toxicity did not increase during the long-term treatment. Subgroup analysis indicated that first-line treatment led to higher ORR and prolonged PFS and OS than second-/third-line treatment and that incidence of adverse events in patients of second-/third-line treatment was not higher than that in patients of first-line treatment. CONCLUSION Eribulin exhibited efficacy and manageable tolerability in Japanese women with pretreated MBC in first- to third-line use. (ID: UMIN000007121).

MULTISEPTATE GALLBLADDER : BILIARY MANOMETRY AND SCINTIGRAPHY

A 30-year-old man with multiseptate gallbladder, a very rare congenital anomaly, is presented. His presenting symptom was epigastric pain. A hypoplastic gallbladder with multiple septa was demonstrated by ultrasonography and endoscopic retrograde cholangiography. An injection of cerulein reproduced pain, and simultaneous biliary manometry and scintigraphy showed impairment of gallbladder filling and emptying. Laparoscopic cholecystectomy resulted in complete relief of the pain. Biliary manometry and scintigraphy are useful to determine the operative indication in a symptomatic patient with this entity.

Effect of serum depletion on centrosome overduplication and death of human pancreatic cancer cells after exposure to radiation

The tumor microenvironment is one of the key factors affecting the cellular response to radiation; however, the influence of serum concentration on tumor radiosensitivity remains poorly understood. We recently discovered that gamma-irradiation of tumor cells causes centrosome overduplication, which may lead to lethal nuclear fragmentation through the establishment of multipolar mitotic spindles. In the present study, we investigated the effect of serum depletion on radiation-induced cell death in relation to the centrosome dynamics in human pancreatic cancer cells. Exposure of Capan-1 cells to gamma-irradiation resulted in a time-dependent increase in cells containing multiple centrosomes in association with the appearance of mitotic cell death. Treatment of irradiated cells with serum depletion drastically accelerated centrosome overduplication and the formation of multipolar spindles, resulting in increased nuclear fragmentation and cell death. Cell cycle analysis of irradiated cultures revealed that the reduced serum level increased the population of cells arrested in the G2/M phase, which might be responsible for the abnormal centrosome accumulation. These findings suggest that serum concentration can influence radiation-induced cell killing through modulating cell cycle progression and possibly centrosome overduplication.

Endoscopy‐assisted breast‐conserving surgery for early breast cancer

Endoscopic surgery is reportedly associated with smaller scars and greater patient satisfaction. Herein we evaluate the early results of endoscopy‐assisted breast‐conserving surgery(E‐BCS).

Benign pseudotumorous lesion (fibroangiomyomatous hyperplasia with elastosis) in the gallbladder

We describe a rare case of a benign pseudotumorous lesion (fibroangiomyomatous hyperplasia with elastosis) in the gallbladder in a 44-year-old Japanese woman, and discuss the rarity of elastosis in the gallbladder. To our knowledge, this case may be the first report of a pseudotumorous lesion of the gallbladder with elastosis in Japan.

Secretory Carcinoma of the Breast in an Elderly Woman: Report of a Case

We herein report a case of secretory carcinoma of the breast in a 73-year-old woman. Secretory carcinoma is an extremely rare tumor and demonstrates distinctive pathologic characteristics. This tumor frequently occurs in either children or adolescents, and thus has been called juvenile carcinoma. We encountered this rare tumor in an elderly woman. Aspiration biopsy cytology was performed twice, but the cytological diagnosis was not carcinoma. Such pathologic characteristics as mild atypia, the absence of hyperchromasia, and a minimal degree of pleomorphism in the tumor cells can thus lead to a cytological misdiagnosis. An excisional biopsy was performed and secretory carcinoma was finally diagnosed. Consequently, a modified radical mastectomy (Kodamas method) was performed 7 days later. We describe this very rare tumors clinicopathologic characteristics.