Concomitant neoplasms in the skin and stomach unveil the role of type IV collagen and E-cadherin in mucin core protein 5AC expression in vivo

Mucin core protein (MUC) 5AC is a gel-forming glycoprotein that is expressed in different types of tumour cells. MUC5AC expression in cultured cells is regulated through the extracellular matrix and through remodelling by other membranous proteins such as type IV collagen (COL4) and E-cadherin. However, it has not been elucidated whether COL4 and E-cadherin affect MUC5AC expression in tumours in vivo. Here, by analysing a single individual with concomitant neoplasms in the skin [extramammary Paget disease (EMPD)] and the stomach (gastric cancer), we show that MUC5AC expression is reduced in COL4 and membranous E-cadherin-expressing EMPD specimens whereas MUC5AC is not abolished in gastric cancer with COL4 negativity and E-cadherin cytoplasmic localization. As the EMPD and gastric cancer specimens were derived from a single patient, each specimen had the same genetic background. These in vivo results support previous in vitro studies which showed that COL4 and E-cadherin downregulated MUC5AC expression. Our study suggests that concomitant neoplasms in different organs of the same individual can serve as a strong tool for uncovering functional diversity in tumour markers in distinct cancer cells.

Positron emission tomography-computed tomography can be useful in the early detection of metastases in primary mucinous carcinoma of the skin on the head and neck

Primary mucinous carcinoma of the skin (PMCS) is a rare cutaneous malignant neoplasm; its regional node metastasis is also rare. Currently, positron emission tomography-computed tomography (PET-CT) is known to be a useful tool to search for early metastatic lesions in various carcinomas. However, PET-CT is not always specific for head and neck lesions because of physiological uptake in the brain, palatine tonsil, salivary gland, thyroid etc. Herein we present two cases of head and neck PMCS in which metastasis was diagnosed accurately by PET-CT. In these cases, nodal uptake of fluorodeoxy-d-glucose (FDG) histopathologically proved PMCS metastasis, verifying the utility of PET-CT in detail. A surgeon was involved in the verification to compare the histopathological manifestations with the imaging results. Histopathologically, two of 13 nodes were positive in case 1, and one of 41 nodes was positive in case 2. These positive nodes were completely in accordance with the FDG uptake findings with no false negative findings. In treating PMCS on head and neck lesions, PET-CT may be useful in the preoperative assessment when planning the extent of resection.

Age-related alteration of expression and function of TLRs and NK activity in oral candidiasis

OBJECTIVE

Roles of aging or immune responses mediated by Toll-like receptors and natural killer cell in the onset or progression of human candidiasis remain unclear. This study was designed to elucidate the roles using peripheral blood mononuclear cells from healthy donors and patients with oral candidiasis.

SUBJECTS AND METHODS

Subjects tested were healthy volunteers and patients who visited Dental Clinical Division of Hokkaido University Hospital. The patients with oral candidiasis included 39 individuals (25-89 years of age) with major complaints on pain in oral mucosa and/or dysgeusia. Healthy volunteers include students (25-35 years of age) and teaching staffs (50-65 years of age) of Hokkaido University Graduate School of Dental Medicine.

RESULTS

Functions of Toll-like receptors 2 and 4 were downregulated significantly and the natural killer activity was slightly, but not significantly downregulated in aged healthy volunteers compared with healthy young volunteers. Functions of Toll-like receptors 2 and 4 and the natural killer activity were significantly downregulated in patients with oral candidiasis compared with healthy volunteers.

CONCLUSION

Downregulation of functions of Toll-like receptors 2 and 4 as well as natural killer activity is suggested to be associated with the onset or progression of oral candidiasis in human.

MMP13 can be a useful differentiating marker between squamous cell carcinoma and benign hyperkeratotic lesions in recessive dystrophic epidermolysis bullosa

Recessive dystrophic epidermolysis bullosa (RDEB) is a severe hereditary mechanobullous disease resulting from mutations in the COL7A1 gene, coding for type VII collagen. Patients with RDEB tend to develop squamous cell carcinomas (SCCs) at sites of chronic ulceration or scarring on the whole body. Distinguishing SCC from benign hyperkeratotic lesions is often difficult, not only clinically but also histologically in patients with RDEB. We investigated several matrix metallopeptidase (MMP) subtypes by comparing the DNA amplification microarray findings between evident SCCs and benign hyperkeratotic lesions in the same patient with RDEB. We report that MMP13 was found to be strongly positive in SCCs but negative in benign hyperkeratotic lesions. We found that there is an evident difference in the transitional area between SCCs and benign hyperkeratotic lesions. We propose that MMP13 may be a useful differentiating marker between SCC and benign hyperkeratotic lesions in RDEB.

Nitrogen digestion and urea recycling in Hokkaido native horses fed hay-based diets

Nitrogen (N) digestion and urea-N metabolism in Hokkaido native horses fed roughage-based diets containing different types and levels of protein sources were studied. Horses (173 ± 4.8 kg) fitted with an ileum cannula were fed four diets consisting of 100% timothy hay (TH), 88% TH and 12% soybean meal (SBM), 79% TH and 21% SBM, and 51% TH and 49% alfalfa hay at 2.2% of body weight. Dietary protein content varied from 5% to 15% of dry matter. Apparent N digestibilities in the pre-cecum and total tract for the TH diet were lower than those for other diets. However, the proportion of post-ileum N digestion to N intake was not affected by the diets. Urea-N production was linearly related to N intake, but gut urea-N entry was not affected by the diets. The proportion of gut urea-N entry to urea-N production tended to be higher for the TH diet (57%) than the two SBM diets (39%). Anabolic use of urea-N entering the gut was not affected by the diets (20-36% of gut urea-N entry). These results indicate that urea-N recycling provides additional N sources for microbial fermentation in the hindgut of Hokkaido native horses fed low-quality roughages.