Overexpression of c-Maf contributes to T-cell lymphoma in both mice and human

c-Maf translocation or overexpression has been observed in human multiple myeloma. Although c-maf might function as an oncogene in multiple myeloma, a role for this gene in other cancers has not been shown. In this study, we have found that mice transgenic for c-Maf whose expression was direct to the T-cell compartment developed T-cell lymphoma. Moreover, we showed that cyclin D2, integrin beta(7), and ARK5 were up-regulated in c-Maf transgenic lymphoma cells. Furthermore, 60% of human T-cell lymphomas (11 of 18 cases), classified as angioimmunoblastic T-cell lymphoma, were found to express c-Maf. These results suggest that c-Maf might cause a type of T-cell lymphoma in both mice and humans and that ARK5, in addition to cyclin D2 and integrin beta(7), might be downstream target genes of c-Maf leading to malignant transformation.     

Preoperative chemotherapy and radiation therapy for squamous cell carcinoma of the maxillary sinus

OBJECTIVE: This study was undertaken to assess the prognostic factors for the management of squamous cell carcinoma (SCC) of the maxillary sinus, who received preoperative chemotherapy and radiation therapy (RT). We also elucidated the appropriate sequence of chemotherapy. METHODS: A total of 124 patients (median age 62 years) with SCC of the maxillary sinus were analysed retrospectively. T3 or T4 disease was found in 93% of the patients. Thirty-nine patients received neoadjuvant chemotherapy (NA), 38 patients received concurrent chemoradiotherapy (CRT) and 47 patients received NA followed by CRT. The median dose of RT was 60 Gy. Maxillectomy was undertaken in 98 patients. RESULTS: The 5 year overall survival (OAS) and local control probability (LCP) were 56.6 and 73.7%, respectively. On univariate analysis, surgery (P < 0.0001) and T classification (P < 0.04) were significant prognostic factors for OAS and LCP. Histological grade and nodal status were also related to OAS. However, any chemotherapy sequence was not associated with the treatment outcome. On multivariate analysis, surgery (P < 0.0005) and T classification (P < 0.05) were identified as significant prognostic factors for LCP and OAS. CONCLUSIONS: This study suggests that both surgery and T stage are important prognostic factors for LCP and OAS in the management of SCC of the maxillary sinus. The appropriate sequence of chemotherapy remains to be elucidated in the future study.     

The usefulness of rabbits as an animal model for the neuropathological assessment of neurotoxicity following the administration of vincristine

Vincristine is an effective chemotherapeutic agent for a variety of human neoplasms, but has dose-limiting neurotoxicity. Since laboratory rodents have proven to be refractive in such neurotoxicological studies, we conducted a neuropathological and behavioral assessment in rabbits treated with vincristine at doses known to be both chemotherapeutically effective and neurotoxic in humans. Rabbits (Kbl: NZW) were given vincristine intravenously at doses of 0 (saline), 200, 250 or 300 microg/kg once a week for 6 weeks, 500 microg/kg once a week for 3 weeks, or a single 500 microg/kg administration. Detailed periodic neurologic examination revealed ataxia in a few animals. Pathologically, axonal injury progressing to fiber degeneration was observed in sensory tracts such as the posterior spinocerebellar tract and posterior funiculus, and in peripheral nerves after treatment with vincristine. These alterations were observed even after a single dose of 500 microg/kg. In the group given weekly doses of 500 microg/kg, neuronal chromatolysis was also found in the spinal cord. These results suggest the rabbit is responsive to vincristine neurotoxicity producing a predominantly sensory neuropathy and confirming earlier studies.     

Role of Ca(v) 2.3 (alpha1E ) Ca2+ channel in ischemic neuronal injury

We investigated the role of the Ca(v)2.3 (alpha1E) channel in ischemic neuronal injury using Ca(v)2.3 mutant mice. In focal ischemia model with a complete occlusion of the middle cerebral artery in vivo, infarct at 24 h was significantly larger in Ca(v)2.3 mutant mice compared with that in wild-type controls. In vitro Ca2+ imaging studies using hippocampal slices revealed that oxygen-glucose deprivation induced a [Ca2+]i increase in the hippocampal CA1 region more vigorously in Ca(v)2.3 mutant mice than in wild-type controls, and that tetrodotoxin or bicuculline application abolished the difference between the genotypes. These results suggest that the Ca(v)2.3 channel plays a protective role in ischemic neuronal injury by a mechanism in which GABAergic neuronal actions are involved.     

The acquisition of schemata about location of urban facilities in public space

The purpose of this study is to investigate acquisition of schemata about location of urban facilities. Materials were photos of public space, in which one of three urban facilities (a mailbox, a public-telephone, and a coin--operated locker) were removed by photo-retouching software. The task was to choose the most suitable urban facility for each corrected-photo and to locate it at the most suitable position on the photo. Among three participant groups (primary school 3rd grade: n = 153, primary school 5th grade: n = 118, undergraduate: n = 250), undergraduates chose the most suitable urban facility, and their located position was more concentrated. The results suggest that participants acquire the schemata and use them for inference. Although even 3rd grade children have acquired the schema to some extent, the adults have more detailed schemata of urban facilities in public space.     

Immunohistochemical studies in canine prostatic hyperplasia--effect of antiandrogen

To investigated spontaneous benign prostatic hyperplasia (BPH) in dog the effect of a synthetic steroidal antiandrogen, chlormadinone acetate (CMA) was studied. Old male beagle dogs (5-8 years old) were divided into following experimental groups: group 1 consisted of BPH controls; group 2 received CMA 0.3mg/kg/day p.o., for 6 months. In group 1 animals, glandular hyperplasia of the prostate was clearly detected. The glandular epithelial cells showed uniformly intense immunostaining for nuclear androgen receptors (AR). AR was also localized in the nuclei of the fibro-muscular cells. Immunoreactivity of 5alpha-reductase type I was positive in most glandular epithelial cells. The staining was positive in the cytoplasm but not in the nuclei. No fibro-muscular cells were stained. In contrast, CMA produced marked atrophy of the glandular epithelium. The interacinar fibro-muscular stroma was prominent. Furthermore, immunostaining of nuclear AR of both epithelial and stroma cells was remarkably decreased. The intensity of staining for 5alpha-reductase type I in most glandular epithelial cells also decreased. Interestingly, some basal cells exhibited positive staining for 5alpha-reductase type I. These results indicate that the uptake of testosterone and/or its androgenic effect on the prostate may be suppressed by CMA. We further speculate that the basal cells produce sufficient dihydrotestosterone to maintain themselves even in the presence of low testosterone levels.     

Assay and disposition of carvedilol enantiomers in humans and monkeys: evidence of stereoselective presystemic metabolism

Carvedilol is a new beta-blocking agent with vasodilating activities, which is a racemic mixture of R(+)- and S(-)-enantiomers. Since the two enantiomers differ in pharmacological properties, it is necessary to individually measure their plasma concentrations in order to evaluate the pharmacological effects of racemic carvedilol after oral administration. In this study, a sensitive, stereospecific high-performance liquid chromatographic assay was used to determine the plasma concentration of each enantiomer. The assay involves the diastereomeric derivatization of racemic carvedilol with 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl isothiocyanate as a chiral reagent. After oral administration of racemic carvedilol to humans, the mean Cmax and AUC infinity values for R(+)-enantiomer were 2.6 and 2.8 times greater, respectively, than those for the more active S(-)-enantiomer. Similarly, in monkeys, the respective R:S enantiomer ratios for Cmax and AUC infinity were 1.5 and 1.2. The difference in AUCoral between these enantiomers is ascribed to the greater intrinsic clearance of S(-)-enantiomer than that of the R(+)-enantiomer in the liver, and to a lower plasma protein binding of the S(-)-enantiomer.     

Changes in proliferative potential, apoptosis and Bcl-2 protein expression in cytotrophoblasts and syncytiotrophoblast in human placenta over the course of pregnancy

In order to evaluate placental trophoblast proliferation and apoptosis during pregnancy, we investigated proliferating cell nuclear antigen (PCNA) expression, apoptosis and Bcl-2 protein expression in the human placenta using avidin/biotin immunoperoxidase method to examine PCNA and Bcl-2 protein expression, and TUNEL method to assess apoptosis. The appearance of apoptotic cells in very early term placental trophoblasts was also examined by transmission electron microscopy. PCNA was immunolocalized in the nuclei of cytotrophoblasts (C-cells). Determination of the mean percentage of PCNA-positive nuclei of C-cells revealed that PCNA expression in C-cells was highest in very early term (4th to 5th wk) placentas and significantly decreased with the advance of pregnancy. Bcl-2 protein was immunolocalized in the cytoplasm of syncytiotrophoblast (S-cell), being least abundant in very early term placentas, less abundant in early term and midterm placentas, and most abundant in term placentas. On the basis of TUNEL method, apoptosis was apparent in the nuclei of both C-cells and S-cell. The apoptosis positive rate of C-cell nuclei was highest in very early term 4th to 5th wk placentas, and significantly decreased in early term 7th to 9th wk and midterm placentas, but somewhat increased in term placentas compared to that in midterm placentas. On the other hand, apoptosis positive rate of S-cell nuclei was remarkably higher only in very early term 4th to 5th wk placentas compared to that in early term, midterm and term placentas. Transmission electron microscopy revealed the appearance of apoptotic nucleus in very early term placental trophoblasts. These results demonstrate for the first time that apoptosis in the human normal placenta predominates in both C-cells and S-cell in very early term 4th to 5th wk pregnancy and drastically diminished after 7th wk of pregnancy. An apparent increase in apoptosis in C-cells in term placentas compared to that in midterm placentas may reflect aging of the placenta or parturition-associated biological change. The abundant expression of Bcl-2 protein in S-cell in term placentas may be responsible for the diminished occurrence of apoptosis in S-cell in term placentas.     

MRP1 mutated in the L0 region transports SN-38 but not leukotriene C4 or estradiol-17 (beta-D-glucuronate)

Multidrug resistance protein 1 (MRP1) is an ATP-binding cassette transporter that confers multidrug resistance on tumor cells. Much convincing evidence has accumulated that MRP1 transports most substances in a GSH-dependent manner. On the other hand, several reports have revealed that MRP1 can transport some substrates independently of GSH; however, the importance of GSH-independent transport activity is not well established and the mechanistic differences between GSH-dependent and -independent transport by MRP1 are unclear. We previously demonstrated that the amino acids W261 and K267 in the L0 region of MRP1 were important for leukotriene C4 (LTC4) transport activity of MRP1 and for GSH-dependent photolabeling of MRP1 with azidophenyl agosterol-A (azidoAG-A). In this paper, we further tested the effect of W222L, W223L and R230A mutations in MRP1, designated dmL0MRP1, on MRP1 transport activity. SN-38 is an active metabolic form of CPT-11 that is one of the most promising anti-cancer drugs. Membrane vesicles prepared from cells expressing dmL0MRP1 could transport SN-38, but not LTC4 or estradiol-17 (beta-D-glucuronate), and could not be photolabeled with azidoAG-A. These data suggested that SN-38 was transported by a different mechanism than that of GSH-dependent transport. Understanding the GSH-independent transport mechanism of MRP1, and identification of drugs that are transported by this mechanism, will be critical for combating MRP1-mediated drug resistance. We performed a pairwise comparison of compounds that are transported by MRP1 in a GSH-dependent or -independent manner. These data indicated that it may be possible to predict compounds that are transported by MRP1 in a GSH-independent manner.     

Effects of 3,5,3'-triiodothyronine on the invasive potential and the expression of integrins and matrix metalloproteinases in cultured early placental extravillous trophoblasts

It is well known that T(3) plays a crucial role in the maintenance of early pregnancy through the induction of endocrine function in villous trophoblasts. The effects of T(3) on extravillous trophoblast (EVT) function, however, remain to be elucidated. To investigate the possible role of T(3) in the regulation of EVT invasion to the decidua, we have examined whether T(3) affects EVT invasive potential and the expression of matrix metalloproteinase-2 (MMP-2), MMP-3, tissue inhibitor metalloproteinase-1, fetal fibronectin (FN), and integrin alpha(5)beta(1) in cultured early placental EVTs. Isolation and purification of trophoblasts differentiating into EVTs were performed by the enzymatic digestion of the anchoring chorionic villi, with the use of human FN-precoated culture dishes and FN-precoated Matrigel Transwells. The cells attached to the dishes were subcultured in DMEM supplemented with 10% fetal bovine serum for 48 h and were characterized by RT-PCR analysis after 24-h subculture and immunocytochemical analysis after 48-h subculture for specific EVT markers. Thereafter, the cultured cells were stepped down to a 4% fetal bovine serum condition and cultured in the presence or absence of T(3) (10(-8) m) for the subsequent 72 h. Matrigel invasion assay demonstrated that the treatment with T(3) significantly increased the number of cell projections of subsequent 24-, 48-, and 72-h cultured EVTs. RT-PCR analysis revealed that the treatment with T(3) increased the expression of MMP-2, MMP-3, fetal FN, and integrin alpha(5)beta(1) mRNA in subsequent 24-h cultured EVTs compared with those in control cultures. Immunocytochemical and Western immunoblot analyses revealed that treatment with T(3) increased the expression of MMP-2 and MMP-3 in subsequent 48-h cultured EVTs compared with those in control cultures. The present results suggest that T(3) (10(-8) m) may play a vital role in up-regulating the invasive potential of EVTs into the decidua.