Complete sequences of Schizosaccharomyces pombe subtelomeres reveal multiple patterns of genome variation.

Genome sequences have been determined for many model organisms; however, repetitive regions such as centromeres, telomeres, and subtelomeres have not yet been sequenced completely. Here, we report the complete sequences of subtelomeric homologous (SH) regions of the fission yeast Schizosaccharomyces pombe. We overcame technical difficulties to obtain subtelomeric repetitive sequences by constructing strains that possess single SH regions of a standard laboratory strain. In addition, some natural isolates of S. pombe were analyzed using previous sequencing data. Whole sequences of SH regions revealed that each SH region consists of two distinct parts with mosaics of multiple common segments or blocks showing high variation among subtelomeres and strains. Subtelomere regions show relatively high frequency of nucleotide variations among strains compared with the other chromosomal regions. Furthermore, we identified subtelomeric RecQ-type helicase genes, tlh3 and tlh4, which add to the already known tlh1 and tlh2, and found that the tlh1-4 genes show high sequence variation with missense mutations, insertions, and deletions but no severe effects on their RNA expression. Our results indicate that SH sequences are highly polymorphic and hot spots for genome variation. These features of subtelomeres may have contributed to genome diversity and, conversely, various diseases.

[Stability of Six Drugs in Total Parenteral Nutrition Solution].

Elneopa NF No. 1 and No. 2 infusions are total parenteral nutrition solutions packaged in four-chambered infusion bags. They have been used as home parenteral nutrition, with various drugs injected into the infusion bags, for treating patient symptoms. In this study, we investigated the stability of six drugs, including famotidine, scopolamine butylbromide, furosemide, bromhexine hydrochloride, betamethasone sodium phosphate, and metoclopramide hydrochloride in the infusion bags under dark conditions at 4℃ for 7 days. Additionally, we developed a high-performance liquid chromatography method to determine drug concentrations in the infusions. The concentrations of injected famotidine, scopolamine butylbromide, and betamethasone sodium phosphate remained unchanged when the four chambers of Elneopa NF No. 1 and No. 2 were opened and the infusions were mixed. Their respective concentrations in the upper and lower chambers also remained unchanged. The concentration of furosemide in the upper chamber of the No. 1 infusion bag decreased after 5 days, although no change was observed in the other chambers and the mixed infusions with the four chambers opened. The concentration of bromhexine hydrochloride slightly decreased in the upper chambers (approximately 3%) after the co-infusion but decreased significantly in the other chambers and the mixed infusions with the four chambers opened. The concentration of metoclopramide hydrochloride significantly decreased in the upper chambers after the co-infusion; however, no change in concentration was observed in the other chambers and the mixed infusion with the four chambers opened. The results of this study provide useful information on home-based parenteral nutrition.

Carcinoma in a solitary intraductal papilloma of the breast.

Herein is reported a rare case of carcinoma arising from papilloma of the breast. A 63-year-old postmenopausal woman noticed a nodule approximately 1 cm in diameter in her left breast. Ultrasonography indicated a mass with a solid pattern within an intracystic tumor measuring 1.5 x 1.5 x 1.4 cm in diameter located near the left nipple. On total image analysis malignancy could not be denied, therefore lumpectomy with resection of the surrounding tissue was performed. Histologically the tumor consisted of cancerous and papilloma components. The cancer cells had high-grade nuclear atypia, were irregular, and contained abundant eosinophilic cytoplasm with a thin vascular stalk. In contrast, the tumor cells had no atypia, and had a thick stroma in the papilloma components. Both lesions could be distinguished clearly from each other. In addition, a transition from papillary to cancerous elements in some areas was seen. An additional partial mastectomy was performed after the lumpectomy but no carcinoma foci were noted in the excised tissue. Possible occurrence of cancerous change in solitary intraductal papilloma of the breast was suspected.

[Evaluation of 5-fluorouracil-related genes in breast cancer to predict the effect of adjuvant therapy with CMF].

The correlations between mRNA expressions of 5-fluorouracil(5-FU)-related enzymes; thymidylate synthase(TS), dihydropyrimidine dehydrogenase(DPD), thymidine phosphorylase(TP), and orotate phosphoribosyltransferase (OPRT)in breast cancers, along with disease-free survival(DFS), were investigated in 35 patients treated with postoperative adjuvant chemotherapy using cyclophosphamide, methotrexate and 5-fluorouracil(CMF). The patients treated with CMF were divided into two groups, a lower group(L group)and a higher group(H group), according to the median value of the mRNA expression for each enzyme in 220 breast cancer specimens, which were resected between 1996 and 1998 in our institute. 5-year DFS was not significantly different between TS-L and H group(60% and 80%, p=0.38), DPD-L and H group(57.9% and 86.7%, p=0.088), and TP-L and H group(70% and 73.3%, p=0.89), respectively. 5-year DFS in the OPRT-H group(88.9%)was significantly better than that in the OPRT-L group(50%) (p=0.024). In the OPRT-H group, despite the fact that the proportion of patients with lymph node involvement in the CMF group was significantly higher than that in the postoperative adjuvant hormone therapy group, 5-year DFS was not significantly different between the two groups(p=0.10). Our results suggest that OPRT level was the significant predictive marker for DFS in the breast cancer patients treated with postoperative adjuvant chemotherapy using CMF.

Dihydropyrimidine dehydrogenase (DPD) expression is negatively regulated by certain microRNAs in human lung tissues.

Dihydropyrimidine dehydrogenase (DPD) is important to the antitumor effect of 5-fluorouracil (5-FU). DPD gene (DPYD) expression in tumors is correlated with sensitivity to 5-FU. Because the 5-FU accumulated in cancer cells is also rapidly converted into inactivated metabolites through catabolic pathways mediated by DPD, high DPD activity in cancer cells is an important determinant of the response to 5-FU. DPD activity is highly variable and reduced activity causes a high risk of 5-FU toxicity. Genetic variation in DPYD has been proposed as the main factor responsible for the variation in DPD activity. However, only a small proportion of the activity of DPD can be explained by DPYD mutations. In this study, we found that DPYD is a target of the following microRNAs (miRNA): miR-27a, miR-27b, miR-134, and miR-582-5p. In luciferase assays with HepG2 cells, the overexpression of these miRNAs was associated with significantly decreased reporter activity in a plasmid containing the 3'-UTR of DYPD mRNA. The level of DPD protein in MIAPaca-2 cells was also significantly decreased by the overexpression of these four miRNAs. The results suggest that miR-27a, miR-27b, miR-134, and miR-582-5p post-transcriptionally regulate DPD protein expression. The levels of miRNAs in normal lung tissue and lung tumors were compared; miR-27b and miR-134 levels were significantly lower in the tumors than normal tissue (3.64 ± 4.02 versus 9.75 ± 6.58 and 0.64 ± 0.75 versus 1.48 ± 1.39). DPD protein levels were significantly higher in the tumors. Thus, the decreased expression of miR-27b would be responsible for the high levels of DPD protein. This study is the first to show that miRNAs regulate the DPD protein, and provides new insight into 5-FU-based chemotherapy.

Primary micropapillary carcinoma of the colon: a case report and literature review.

We report a case of micropapillary carcinoma (MPC) of the transverse colon. A 56-year-old woman was admitted to our hospital with hematochezia. A lower gastrointestinal examination revealed an irregular ulcerative tumor of approximately 60 mm diameter with marginal elevation in the transverse colon. Abdominal computed tomography showed multiple swollen lymph nodes. A histological examination of the resected specimen revealed that cancer cells had invaded the subserosa. Microscopically, small papillary cells proliferated with lacuna spaces and the cribriform glandular configuration was observed. Immunohistochemically, the basal surface of the neoplastic cell clusters was diffusely positive for MUC1. No primary tumor was observed except for the colon. Therefore, this tumor was diagnosed as a primary MPC of the colon. Since a colorectal MPC was first reported in 2005, seven case reports and three pathological reviews have been presented in the English literature. MPC has an aggressive behavior with a high incidence of lymphovascular invasion and nodal metastases. We should take intensive chemotherapy for colorectal MPC into account, even if surgical resection is curative.