Differences in response of myosin isozyme transition of ordinary and specialized myocardium to overload

To investigate the response of myosin isozyme transition in specialized myocardium to cardiac overload, we examined immunohistochemically the distribution of myosin isozymes in sinus node cells of overloaded canine atria, using the monoclonal antibodies CMA19 and HMC14, which are specific for atrial myosin heavy chain (alpha-HC) and ventricular myosin heavy chain (beta-HC), respectively. Overloading in canine right atria was induced by artificial tricuspid valve regurgitation and pulmonary stenosis. Right atrial mean pressure rose to 15-20 mm Hg (n = 4) 2 months after surgery. In the working myocardium, cardiac overload caused redistribution of myosin isozymes, alpha-HC to beta-HC. Compared with the normal right atria, fewer myocytes were labeled with CMA19, but more were labeled with HMC14. However, the reactivity of sinus node cells with CMA19 and HMC14 was not changed between normal and overloaded right atria, indicating no redistribution of myosin heavy chain isozymes, alpha-HC to beta-HC. These results suggest that isozymes in myosin heavy chains in the specialized myocardium are protected from overload effects by their firm cytoskeletal framework or other mechanisms.     

Anti-tumor effect of inhibition of IL-6 signaling in mucoepidermoid carcinoma

Mucoepidermoid carcinoma (MEC) is the most frequent malignant salivary gland cancer. Response to chemoradiotherapy is modest, and therefore radical surgery remains the standard-of-care. Emerging evidence suggests that Interleukin (IL)-6 signaling correlates with the survival of cancer stem cells and resistance to therapy. Here, we investigated whether inhibition of IL-6 receptor (IL-6R) signaling with tocilizumab (humanized anti-human IL-6R antibody) sensitizes MEC to chemotherapy using human mucoepidermoid carcinoma cell lines (UM-HMC) and correspondent xenograft models. In vitro, we observed that tocilizumab inhibited STAT3 phosphorylation but had no measurable effect in MEC cell viability (UM-HMC-1,-3A,-3B). In contrast, the anti-tumor effect of single agent tocilizumab on MEC xenografts was comparable to paclitaxel or cisplatin. Combination of tocilizumab with cisplatin or paclitaxel enhanced the inhibitory effect of chemotherapy on xenograft growth (P < 0.05), time to failure (P < 0.01), decreased vascular endothelial growth factor (VEGF) expression and tumor microvessel density (P < 0.05) without added systemic toxicities. Notably, tocilizumab decreased the fraction of MEC cancer stem cells (ALDH^highCD44^high) in vitro, and prevented paclitaxel-induced increase in the fraction of cancer stem cells in vivo (P < 0.05). Collectively, these findings demonstrate that tocilizumab enhances the anti-tumor effect of conventional chemotherapy in preclinical models of mucoepidermoid carcinoma, and suggest that patients might benefit from combination therapy with an inhibitor of IL-6R signaling and chemotherapeutic agent such as paclitaxel.     

Intravesical administration of exogenous microRNA-145 as a therapy for mouse orthotopic human bladder cancer xenograft

We previously reported that the level of microRNA (miR)-145 is attenuated in human bladder cancer cells. In this current study, we investigated whether intravesical administration of miR-145 could be a potential therapeutic strategy for controlling bladder cancer by using an orthotopic human bladder cancer xenograft model. Following transfection of 253J B-V cells with miR-145, the effects of the ectopic expression of miR-145 were examined by performing MTT, Western blotting analysis, Hoechst33342 staining, and wound healing assay in vitro. Also, a mouse orthotopic human bladder cancer model was established by inoculating 253J B-V cells into the bladder wall of mice. The anti-cancer effects of intravesical injections of miR-145 into these mice were then assessed. Transfection of 253J B-V cells with miR-145 induced apoptosis and suppression of cell migration in vitro. Western blotting showed that the levels of c-Myc, socs7, FSCN1, E-cadherin, β-catenin, and catenin δ-1 were decreased and that the PI3K/Akt and Erk1/2 signaling pathways were increased in compensatory fashion. In vivo, mice treated with miR-145 showed 76% inhibition of tumor growth, with a significant prolongation of animal survival (p = 0.0183 vs. control). Western blotting showed that both apoptosis and cell motility-related genes were significantly decreased as seen in vitro. Furthermore, PI3k/Akt and Erk1/2 signaling pathways, which were activated in a compensatory manner in vitro, were decreased in vivo. Intravesical administration of exogenous miR-145 was thus concluded to be a valid therapy for bladder cancer in this human bladder cancer xenograft model.     

Spontaneous regression of multiple pulmonary recurrences of hepatocellular carcinoma after hepatectomy: report of a case

Spontaneous regression of hepatocellular carcinoma (HCC) is an extremely rare phenomenon. We herein report the case of a 73-year-old man who showed the spontaneous regression of multiple pulmonary recurrences of HCC that had occurred after hepatectomy. The patient was undergoing dialysis due to diabetic renal failure when ultrasonography revealed a liver tumor (diameter ~ 10 cm). A preoperative diagnosis of HCC with hepatic vein thrombosis was made. The liver function was well preserved and then the right hepatic vein area was resected. Two months after hepatectomy the α-fetoprotein level increased, and multiple lung nodules were observed on follow-up computed tomography. A diagnosis of multiple lung metastases was made, but no therapy was started because of the patient’s renal failure. Five months after hepatectomy the α-fetoprotein level normalized, and the metastases regressed completely. The patient is now doing well without any recurrence at 13 months after the surgery. The associated literature on spontaneous HCC regression is also reviewed.     

Recognition of other organ involvement might assist in the differential diagnosis of IgG4-associated sclerosing cholangitis without apparent pancreatic involvement: report of two cases

IgG4-associated sclerosing cholangitis (IAC) was recently defined as biliary involvement of IgG4-related systemic disease. It is frequently associated with autoimmune pancreatitis, characterized by pancreatic enlargement and irregular narrowing of the pancreatic duct. However, a few cases of IAC with no apparent pancreatic involvement have been described, the characteristics of which may mimic those of cholangiocarcinoma. We report two rare cases of IgG4-associated sclerosing cholangitis at the hepatic hilum, mimicking hilar cholangiocarcinoma. When trying to establish the diagnosis, we should consider other organs that could be involved, such as the pancreas, salivary glands, retroperitoneum, lymph nodes, and kidneys, as well as chronic inflammatory changes. By recognizing these lesions and measuring serum IgG4, IAC can be diagnosed correctly, thereby avoiding unnecessary major surgery for a condition that is treated effectively by steroid therapy.     

Glycolipid antigens for treating hepatic colorectal cancer metastases and their effect on the therapeutic efficacy of live attenuated Listeria monocytogenes

Previous work demonstrated that a subset of natural killer T cells in mice decreased the antitumor efficacy of live attenuated Listeria monocytogenes where the actin A and internalin B genes were genetically deleted (LMD) against murine hepatic colorectal cancer metastases. Therefore, we hypothesized that the use of specific glycolipids known to selectively stimulate natural killer T-cell subsets used alone or co-administered with LMD would increase survival. We found that early or multiple administrations of glycolipids after tumor challenge had a strong impact on survival with or without LMD. Solitary administration or treatment given later was less efficacious but still showed a strong trend toward enhancing the antitumor activity of LMD. These results underscore the potential of glycolipids in the treatment of hepatic metastases and encourage further investigations into the immunomodulation of natural killer T cells to enhance the antitumor activity of LMD.     

Molecular Identification of Chronic Bee Paralysis Virus Infection in Apis mellifera Colonies in Japan

Chronic bee paralysis virus (CBPV) infection causes chronic paralysis and loss of workers in honey bee colonies around the world. Although CBPV shows a worldwide distribution, it had not been molecularly detected in Japan. Our investigation of Apis mellifera and Apis cerana japonica colonies with RT-PCR has revealed CBPV infection in A. mellifera but not A. c. japonica colonies in Japan. The prevalence of CBPV is low compared with that of other viruses: deformed wing virus (DWV), black queen cell virus (BQCV), Israel acute paralysis virus (IAPV), and sac brood virus (SBV), previously reported in Japan. Because of its low prevalence (5.6%) in A. mellifera colonies, the incidence of colony losses by CBPV infection must be sporadic in Japan. The presence of the (-) strand RNA in dying workers suggests that CBPV infection and replication may contribute to their symptoms. Phylogenetic analysis demonstrates a geographic separation of Japanese isolates from European, Uruguayan, and mainland US isolates. The lack of major exchange of honey bees between Europe/mainland US and Japan for the recent 26 years (1985-2010) may have resulted in the geographic separation of Japanese CBPV isolates.     

Six-year survival following left hepatic trisectionectomy with simultaneous resection of the portal vein and right hepatic artery for advanced perihilar cholangiocarcinoma without lymph node metastases: report of a case

We report a case of survival for more than 6?years following left hepatic trisectionectomy and caudate lobectomy with simultaneous resection of the portal vein and right hepatic artery. The patient was a 65-year-old woman admitted to a local hospital with obstructive jaundice. The patient was diagnosed with perihilar cholangiocarcinoma and referred to our hospital. The tumor was located mainly in the left hilar region and occluded the left portal vein; furthermore, it involved the right portal vein and the right hepatic artery. The patient underwent left hepatic trisectionectomy and caudate lobectomy with simultaneous resection of the portal vein and right hepatic artery. The histological findings revealed that the tumor had invaded the portal vein and surrounded the right hepatic artery without any lymph node metastases. Microscopic curative (R0) resection was achieved. The patient is now healthy and still alive 6?years and 6?months after the surgery without any recurrence. Precise preoperative evaluation of the tumor and R0 resection by extended surgery contributed to a satisfactory outcome.