Nonsense Mutation at Codon 63 of the BRCA1 Gene in Japanese Breast Cancer Patients

The involvement of abnormalities of the BRCA1 gene in breast cancers in Japanese patients without any family history of this cancer was investigated by polymerase chain reaction-based single-strand conformation polymorphism analysis of the DNA sequences corresponding to the zinc finger domain (exons 2, 3 and 5) and the binding domain with Rad51 (exon 11) of the BRCA1 protein. An identical nonsense mutation at codon 63 (TTA to TAA) was found in 2 of 56 (3.5%) breast cancers from independent patients. The nucleotide change was also detected in the DNAs from non-cancerous tissues of both patients and therefore was a germline mutation. One of the patients was a member of a pedigree involving 3 ovarian cancer and 1 gastric cancer patients, while the other patient had no family history of malignancy. The same germline mutation at codon 63 was reported in four other independent Japanese pedigrees with frequent breast cancer, but not in such families in other countries. These observations suggest that the mutation commonly originated from a single Japanese ancestor. No other mutation of the BRCA1 gene was observed in the samples analyzed in this study. A low incidence of germline mutation and the absence of somatic mutation suggest that the aberration of the BRCA1 gene is involved only in a subset of Japanese breast cancers.     

Response of quiescent and total tumor cells in solid tumors to neutrons with various cadmium ratios

Purpose: Response of quiescent (Q) and total tumor cells in solid tumors to neutron irradiation with three different cadmium (Cd) ratios was examined. The role of Q cells in tumor control was also discussed.Methods and Materials: C3H/He mice bearing SCC VII tumors received continuous administration of 5-bromo-2′-deoxyuridine (BrdU) for 5 days using implanted mini-osmotic pumps to label all proliferating (P) cells. Thirty minutes after intraperitoneal injection of sodium borocaptate-¹⁰B (BSH), or 3 h after oral administration of dl-p-boronophenylalanine-¹⁰B (BPA), the tumors were irradiated with neutrons, or those without ¹⁰B-compounds were irradiated with gamma rays. This neutron irradiation was performed using neutrons with three different cadmium (Cd) ratios. The tumors were then excised, minced, and trypsinized. The tumor cell suspensions were incubated with cytochalasin-B (a cytokinesis-blocker), and the micronucleus (MN) frequency in cells without BrdU labeling (Q cells) was determined using immunofluorescence staining for BrdU. The MN frequency in total (P + Q) tumor cells was determined from tumors that were not pretreated with BrdU. The sensitivity to neutrons was evaluated in terms of the frequency of induced micronuclei in binuclear tumor cells (MN frequency).Results: Without ¹⁰B-compounds, the MN frequency in Q cells was lower than that in the total cell population. The sensitivity difference between total and Q cells was reduced by neutron irradiation. Relative biological effectiveness (RBE) of neutrons compared with gamma rays was larger in Q cells than in total cells, and the RBE values for low-Cd-ratio neutrons tended to be larger than those for high-Cd-ratio neutrons. With ¹⁰B-compounds, MN frequency for each cell population was increased, especially for total cells. This increase in MN frequency was marked when high-Cd-ratio neutrons were used. BPA increased the MN frequency for total tumor cells more than BSH. Nevertheless, the sensitivity of Q cells treated with BPA was lower than that in BSH-treated Q cells. This tendency was clearly observed in high-Cd-ratio neutrons.Conclusion: From the viewpoint of enhancing the Q-cell sensitivity, tumors should be irradiated with high-Cd-ratio neutrons after BSH administration. However, normal tissue reaction remains to be examined because of its low tumor-to-normal tissue and tumor-to-blood biodistribution ratios.     

Expression of apoptosis-related proteins in adenomyotic uteri treated with danazol and GnRH agonists.

The biologic properties of adenomyosis and the effects of therapeutic agents on adenomyosis were evaluated with immunohistochemistry, terminal deoxy-nucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) method, transmission electron microscopy, and analysis of genomic abnormality. In the adenomyotic endometrium, estrogen receptor (ER) expression was more intense than in the eutopic endometrium during the secretory phase, and bcl-2 was constantly expressed throughout the menstrual cycle. The expression of ER and bcl-2 was weaker in the adenomyotic endometrium treated with danazol than in that treated with gonadotro-pin-releasing hormone agonist (GnRHa), whereas bcl-2 phosphorylated on serine-87 was more intensely expressed in danazol-treated adenomyotic endometrium than in the GnRHa-treated one. The number of TUNEL-positive cells increased in the adenomyotic endometrium treated with danazol or GnRHa. Ultrastructurally, most of the adenomyotic endometrial cells treated with danazol underwent postapoptotic necrosis and formed a cluster of dead cells. In contrast, cells treated with GnRHa underwent typical apoptosis and were sparsely distributed in the adenomyotic endometrium. Analysis of several cancer-related genes showed no microsatellite instability or loss of heterozygosity in adenomyotic tissues. Therefore, we conclude that the occurrence of adenomyosis is correlated to bcl-2 expression regulated by estrogen and ER rather than genetic mutation.     

A case of recurrent cholangitis after bile duct injury during laparoscopic cholecystectomy: Value of scintigraphy with Tc-99m GSA and hepatobiliary scintigraphy for indication of lobectomy

A 39-year-old woman with acute cholecystitis and gallstones underwent laparoscopic cholecystectomy. She suffered from recurrent episodes of cholangitis due to injury of the major bile ducts during laparoscopic cholecystectomy. Hepatobiliary scintigraphy with Tc-99m Sn-N-pyridoxyl-5-methyltryptophan was performed. Although normal bile excretion was found from the left hepatic duct to the percutaneous transhepatic biliary drainage (PTBD) tube, excretion from the right hepatic lobe was prolonged. Scintigraphy with Tc-99m diethylenetriaminepentaacetic acid-galactosyl human serum albumin demonstrated atrophy of the right hepatic lobe and enlargement of the left hepatic lobe. Cholangiography via the PTBD tube revealed complete obstruction of the left hepatico-jejunal anastomosis and could not enhance the right intrahepatic bile duct. A right hepatic lobectomy was performed because of the atrophy, glissonitis and the absence of an appropriate bile duct for reconstruction. Postoperatively she was active and exhibited no evidence of recurrent cholangitis.     

Identification of transforming activity of free fatty acid receptor 2 by retroviral expression screening

Gallbladder cancer (GBC) is a highly fatal malignancy in humans. Genetic alterations in KRAS or TP53 as well as overexpression of ERBB2 have been shown to contribute to the development of certain types of GBC. However, many cases of GBC do not harbor such genetic changes, with other transforming events awaiting discovery. We here tried to identify novel cancer-promoting genes in GBC, with the use of a retroviral cDNA expression library. A retroviral cDNA expression library was constructed from a surgically resected clinical specimen of GBC, and was used to infect 3T3 fibroblasts in a focus formation assay. cDNA incorporated into the transformed foci was rescued by PCR. One such cDNA was found to encode free fatty acid receptor 2 (FFAR2), a G protein-coupled receptor for short-chain fatty acids. The oncogenic potential of FFAR2 was confirmed both in vitro with the focus formation assay and by evaluation of cell growth in soft agar as well as in vivo with a tumorigenicity assay in nude mice. The isolated FFAR2 cDNA had no sequence alterations, suggesting that upregulation of FFAR2 expression may contribute to malignant transformation. Indeed, all of quantitative RT-PCR, in situ hybridization, and immunohistochemical analyses showed that the amount of FFAR2 mRNA and its protein product was increased in digestive tract cancer specimens. Furthermore, short-chain fatty acids potentiated the mitogenic action of FFAR2 in 3T3 cells. Our data thus, for the first time, implicate FFAR2 in carcinogenesis of the digestive tract. ( Cancer Sci 2009)     

Study on the Fatigue Crack Initiation and Growth Behavior in Bismuth- and Lead-Based Free-Cutting Brasses

Several studies have been conducted on the fatigue behavior of copper and 7-3, and 6-4 brasses. However, there have been fewer studies on the fatigue behavior and fatigue crack growth (FCG) properties of free-cutting brass, primarily because emphasis has been placed on the development of lead-free free-cutting brass. In this study, fatigue experiments were performed in the atmosphere at room temperature using three types of free-cutting, two types of bismuth (Bi)-based (with different grain sizes), and lead (Pb)-based brasses. It was found that lead-free Bi-based free-cutting brass had approximately the same fatigue performance as that of Pb-based free-cutting brass. It was also clarified that the addition of Bi or Pb initiated fatigue cracks, and that the crack growth period occupied most of the fatigue life. Differences in the FCG behavior of the three free-cutting brasses were observed in the low ΔK range. The modified linear fracture mechanics parameter M was used to quantitatively analyze the fatigue life and FCG behavior (short surface cracks). A comparison between the calculated and experimental results showed that M was useful.     

Africane-type sesquiterpenoids from the Argentine liverwort Porella swartziana and their antibacterial activity

Seven africanes (1, 2a,b, 3-6), two of them new (1, 2a), three secoafricanes (7-9), one of them new (7), and two norsecoafricanes (10, 11a), one of them new (10), all of them swartzianin-type, have been isolated from an Argentine collection of the endemic liverwort Porella swartziana. The structures of the new compounds were established by extensive 1D and 2D NMR spectroscopic data. Absolute configurations of compounds 2a, 2b, and 10 were derived on the basis of CD spectra. The compounds were tested for activity against a variety of microbes, but none were found to exhibit significant antibacterial activity.