S-1投与ラットにおける味覚障害の想定される末梢メカニズム

BACKGROUND: Taste disorders are frequently observed in cancer patients undergoing chemotherapy and are serious adverse events which impair the quality of life (QoL) of the cancer patient. Nevertheless, taste disorder mechanisms in cancer patients undergoing chemotherapy have not yet been fully elucidated. The aim of this study was to reveal taste disorder-related peripheral mechanisms using the two-bottle preference test (TBPT) and histological examination of tongues by hematoxylin-eosin staining and immunohistochemistry with protein-gene product 9.5. METHODS: In the TBPT, one bottle was filled with the 0.01 mM quinine hydrochloride (quinine), as a bitter compound, and the other was filled with water. Doses of 50 and 100 mg kg-1 day-1 S-1 (tegafur/gimeracil/oteracil potassium) are lethal to Wistar rats. Therefore, doses ranging from 2-20 mg kg-1 day-1 were administered to the rats for 3 weeks. The S-1 dose of 2 mg kg-1 day-1 corresponds to the clinical dose administered to cancer patients. The part of the tongue containing the circumvallate papillae was excised the following TBPT. RESULTS: The rate of increase in terms of the average preference rate for the quinine vs. all intake (quinine plus water) was significant from the initial S-1 period to the final one, compared with that in control rats, suggesting the possibility of a worsening sensation for the bitter taste. In S-1 rats, the area of taste nerve fibers were significantly decreased and the rate of degeneration of intra-tongue ganglionic nerve cells was significantly increased. These changes were significantly correlated with the rate of increase in average preference rate of the quinine. CONCLUSION: Neuropathy of the gustatory nerve at the periphery may be involved in taste disorders induced by an anticancer drug.博士（医学）・乙1329号・平成26年3月17

Developmental genetic bases behind the independent origin of the tympanic membrane in mammals and diapsids

International audienceThe amniote middle ear is a classical example of the evolutionary novelty. Although paleontological evidence supports the view that mammals and diapsids (modern reptiles and birds) independently acquired the middle ear after divergence from their common ancestor, the developmental bases of these transformations remain unknown. Here we show that lower-to-upper jaw transformation induced by inactivation of the Endothelin1-Dlx5/6 cascade involving Goosecoid results in loss of the tympanic membrane in mouse, but causes duplication of the tympanic membrane in chicken. Detailed anatomical analysis indicates that the relative positions of the primary jaw joint and first pharyngeal pouch led to the coupling of tympanic membrane formation with the lower jaw in mammals, but with the upper jaw in diapsids. We propose that differences in connection and release by various pharyngeal skeletal elements resulted in structural diversity, leading to the acquisition of the tympanic membrane in two distinct manners during amniote evolution

Q fever in acute upper respiratory tract infection

We examined whether or not acute upper respiratory tract infection is associated with Q fever (Coxiella burnetii infection). The subjects consisted of 124 patients with acute upper respiratory tract infection. At initial medical consultation, the presence or absence of serum C. burnetii was examined by nested PCR method. Of the 124 patients, no patients (0 percent) were positive for C. burnetii in serum. These results suggested that the involvement of Q fever in acute upper respiratory tract infection is extremely low

[18F]fluoro-2-deoxyglucose-positron emission tomography を用いた進行口腔扁平上皮癌における術前化学放射線療法による治療効果判定の検討

BACKGROUND: [18F]fluoro-2-deoxyglucose-positron emission tomography (FDG-PET) is widely used to evaluate tumor metabolic activity. The aim of this study was to evaluate the usefulness of FDG-PET in assessing the histopathological response to preoperative concurrent chemoradiotherapy (CRT) in patients with oral squamous cell carcinoma (OSCC). METHODS: Forty-five patients with resectable advanced OSCC who had received preoperative CRT followed by tumor ablative surgery between January 2004 and December 2011 were included in the study. All patients underwent FDG-PET before and after preoperative CRT. The maximum standardized uptake value (SUVmax) before (pre-SUV) and after preoperative CRT (post-SUV) and the SUVmax reduction rate (ΔSUV %) were used to evaluate the response to preoperative CRT. Correlations among SUVmax, histopathological response, and expression of cancer antigen Ki-67 and hypoxia-inducible factor-1α (HIF-1α) were analyzed. RESULTS: Preoperative CRT significantly reduced intratumoral FDG uptake (P < 0.001). The pre-SUV and post-SUV were significantly lower in patients with a pathological complete response (pCR) than in those with a non-pCR (pre-SUV P = 0.037; post-SUV P = 0.001). ΔSUV % was higher in patients with pCR than in those with non-pCR (P = 0.029). The pre-SUV was significantly correlated with Ki-67 and HIF-1α expression in pretreatment biopsy specimens (Ki-67 P = 0.046, R = 0.292; HIF-1α P = 0.007, R = 0.385). The expression of both Ki-67 and HIF-1α was significantly lower in patients with pCR than in those with non-pCR (Ki-67 P < 0.001; HIF-1α P < 0.001). CONCLUSIONS: Low pre-SUV and post-SUV and high ΔSUV % may predict a good histopathological response to preoperative CRT. Ki-67 and HIF-1α expression in pretreatment biopsy specimens were predictors of histopathological response to preoperative CRT.博士（医学）・乙第1357号・平成27年3月16日© Springer International Publishing AG, Part of Springer Science+Business Media© Japan Society of Clinical Oncology 201

Cohesive and Anisotropic Vascular Endothelial Cell Motility Driving Angiogenic Morphogenesis

Vascular endothelial cells (ECs) in angiogenesis exhibit inhomogeneous collective migration called “cell mixing”, in which cells change their relative positions by overtaking each other. However, how such complex EC dynamics lead to the formation of highly ordered branching structures remains largely unknown. To uncover hidden laws of integration driving angiogenic morphogenesis, we analyzed EC behaviors in an in vitro angiogenic sprouting assay using mouse aortic explants in combination with mathematical modeling. Time-lapse imaging of sprouts extended from EC sheets around tissue explants showed directional cohesive EC movements with frequent U-turns, which often coupled with tip cell overtaking. Imaging of isolated branches deprived of basal cell sheets revealed a requirement of a constant supply of immigrating cells for ECs to branch forward. Anisotropic attractive forces between neighboring cells passing each other were likely to underlie these EC motility patterns, as evidenced by an experimentally validated mathematical model. These results suggest that cohesive movements with anisotropic cell-to-cell interactions characterize the EC motility, which may drive branch elongation depending on a constant cell supply. The present findings provide novel insights into a cell motility-based understanding of angiogenic morphogenesis

Acquired resistance mechanisms to afatinib in HER2-amplified gastric cancer cells

Cancer treatment, especially that for breast and lung cancer, has entered a new era and continues to evolve, with the development of genome analysis technology and the advent of molecular targeted drugs including tyrosine kinase inhibitors. Nevertheless, acquired drug resistance to molecular targeted drugs is unavoidable, creating a clinically challenging problem. We recently reported the antitumor effect of a pan-HER inhibitor, afatinib, against human epidermal growth factor receptor 2 (HER2)-amplified gastric cancer cells. The purpose of the present study was to identify the mechanisms of acquired afatinib resistance and to investigate the treatment strategies for HER2-amplified gastric cancer cells. Two afatinib-resistant gastric cancer cell lines were established from 2 HER2-amplified cell lines, N87 and SNU216. Subsequently, we investigated the molecular profiles of resistant cells. The activation of the HER2 pathway was downregulated in N87-derived resistant cells, whereas it was upregulated in SNU216-derived resistant cells. In the N87-derived cell line, both MET and AXL were activated, and combination treatment with afatinib and cabozantinib, a multikinase inhibitor that inhibits MET and AXL, suppressed the cell growth of cells with acquired resistance both in vitro and in vivo. In the SNU216-derived cell line, YES1, which is a member of the Src family, was remarkably activated, and dasatinib, a Src inhibitor, exerted a strong antitumor effect in these cells. In conclusion, we identified MET and AXL activation in addition to YES1 activation as novel mechanisms of afatinib resistance in HER2-driven gastric cancer. Our results also indicated that treatment strategies targeting individual mechanisms of resistance are key to overcoming such resistance

Host selection of hematophagous leeches (Haemadipsa japonica): Implications for iDNA studies

The development of an efficient and cost‐effective method for monitoring animal populations or biodiversity is urgently needed, and invertebrate‐derived DNA (iDNA) may offer a promising tool for assessing the diversity and other ecological information of vertebrates. We studied the host species of a hematophagous leech (Haemadipsa japonica) in Yakushima by genetic barcoding and compared the results with those for mammal composition revealed by camera trapping. We analyzed 119 samples using two sets of primers by Sanger sequencing and one set of primer by next generation sequencing. The proportion of the samples that were successfully sequenced and identified to at least one species was 11.8–24.3%, depending on the three different methods. In all of these three methods, most of the samples were identified as sika deer (18/20, 6/15 and 16/29) or human (2/20, 7/15 and 21/29). The nonhuman mammal host species composition was significantly different from that estimated by camera trapping. Sika deer was the main host, which may be related with their high abundance, large body size and terrestriality. Ten samples included DNA derived from multiple species of vertebrates. This may be due to the contamination of human DNA, but we also found DNA from deer, Japanese macaque and a frog in the same samples, suggesting the mixture of the two meals in the gut of the leech. Using H. japonica‐derived iDNA would not be suitable to make an inventory of species, but it may be useful to collect genetic information on the targeted species, due to their high host selectivity

The Hippo Signaling Pathway Components Lats and Yap Pattern Tead4 Activity to Distinguish Mouse Trophectoderm from Inner Cell Mass

Outside cells of the preimplantation mouse embryo form the trophectoderm (TE), a process requiring the transcription factor Tead4. Here, we show that transcriptionally active Tead4 can induce Cdx2 and other trophoblast genes in parallel in embryonic stem cells. In embryos, the Tead4 coactivator protein Yap localizes to nuclei of outside cells, and modulation of Tead4 or Yap activity leads to changes in Cdx2 expression. In inside cells, Yap is phosphorylated and cytoplasmic, and this involves the Hippo signaling pathway component Lats. We propose that active Tead4 promotes TE development in outside cells, whereas Tead4 activity is suppressed in inside cells by cell contact- and Lats-mediated inhibition of nuclear Yap localization. Thus, differential signaling between inside and outside cell populations leads to changes in cell fate specification during TE formation