Surfactant-Assisted Synthesis of Pt Nanocubes Using Poly(N-isopropylacrylamide) Nanogels

Poly(N-isopropylacrylamide) (PNIPAM) nanogels were prepared by emulsion polymerization using sodium dodecyl sulfate (SDS) and employed as a capping agent in platinum nanoparticle (Pt NP) synthesis by liquid-phase reduction with hydrogen gas. When the PNIPAM nanogels were used without removing SDS, that is, a slight amount of SDS was included in the reaction solution, Pt nanocubes (NCs) were predominantly produced (>80%). The proportion of the resultant Pt NCs was much higher than that obtained using the PNIPAM linear polymer (∼60%). To clarify the effects of the three-dimensional polymer network and SDS, we synthesized Pt NPs using the PNIPAM nanogel without SDS (SDS-free PNIPAM nanogel) and found that Pt NCs are rarely formed, and most NPs obtained have an irregular shape. When only SDS was used as a capping agent, NCs were hardly obtained, but other polyhedral NPs were formed. Furthermore, the use of SDS together with the PNIPAM polymer led to the decrease in the proportion of the Pt NCs compared with that obtained using only the linear polymer. These results indicate that the enhancement of the Pt NC proportion using the PNIPAM nanogel with SDS is attributable to not only the three-dimensional polymer network of the PNIPAM nanogel but also the assist of SDS as a capping agent.

Swelling and mechanical properties of thermoresponsive/hydrophilic conetworks with crosslinked domain structures prepared from various triblock precursors

Thermoresponsive conetworks with crosslinked domain structures were designed by the crosslinking of triblock polymers for responsive gel functioning without external water.

Design of monoalcohol - Copolymer system for high quality silver nanowires

Research to improve the dimensional properties of silver nanowires (Ag NWs) for transparent conductive film (TCF) applications are being carried out intensively. However, the protocol for the designed synthesis of high-quality Ag NWs is yet to be developed due to the inadequacy of knowledge on the role of parameters. Here, we attempt to elucidate the role played by the parameters and propose a monoalcohol-copolymer based system for the designed synthesis of Ag NWs superior in quality to the one synthesized using conventional ethylene glycol (EG)-polyvinylpyrrolidone (PVP) system. The key findings of the study are as follows: (1) the solubility of Ag source and the partially formed AgCl particles in monoalcohols was found to play an important role not only in the reduction to metallic Ag but also on the uniaxial growth, (2) the adsorption of capping agents on Ag NWs was carried through O and N atoms in the base molecule and their binding energies indicated that the strength is the key parameter to obtain Ag NWs with high aspect ratio, (3) the properties of nanowire could be enhanced through copolymerization of VP and base molecules that have O- and N-based ligands, and (4) the influence of copolymerization on the physical and chemical properties of the surface active agent has been theoretically and experimentally verified. Consequently, we succeeded in the development of a new technique to synthesize high yield of Ag NWs with improved aspect ratio than EG-PVP system by using benzyl alcohol as reducing solvent and N-vinylpyrrolidone/N,N-diethylaminoethyl metacrylate copolymer as a capping agent. The optical transmittance and electrical resistivity of TCFs prepared using the Ag NWs with an average diameter of 43 nm, and an average length of 13 μm were 98.6% and R: 49.1 Ω/□, respectively.

Effect of Monomer Sequence along Network Chains on Thermoresponsive Properties of Polymer Gels

The effect of monomer sequence along the network chain on the swelling behavior of polymer gels should be clarified for the advanced control of swelling properties of gel materials. To this end, we systematically investigated the swelling properties of poly(acrylamide derivative) gels with the same composition but different monomer sequence by utilizing two gel synthetic methods: copolymerization giving a random network and co-crosslinking giving a blocky network. Both of the copolymerization and the co-crosslinking gels were prepared from the combination of two of the three following monomers: hydrophilic N,N-dimethylacrylamide (DMAAm), hydrophobic N-n-butylacrylamide (NBAAm), and thermoresponsive N-isopropylacrylamide (NIPAAm) with various monomer compositions. The swelling measurement of the obtained gels showed totally different behaviors between the copolymerization and the co-crosslinking gels, even with the same monomer composition. The copolymerization gels had the average property from the two monomers, depending on monomer composition, because random monomer distribution changed the affinity of each network chain to water. On the other hand, the co-crosslinking gels behaved as if two components independently contributed to the swelling properties, probably due to the domain structure derived from two kinds of prepolymers.

Swelling properties of thermoresponsive/hydrophilic co-networks with functional crosslinked domain structures

We focused on the monomer/crosslinker sequence in a gel network and designed novel thermoresponsive/hydrophilic amphiphilic co-networks with crosslinked domain structures.

Genetic changes in pT2 and pT3 prostate cancer detected by comparative genomic hybridization

Prostate-specific antigen (PSA) screening has led to a remarkable increase in prostate cancer cases undergoing operative therapy. Over half of patients with locally advanced cancer (>or=pT3) develop rising PSA levels (biochemical failure) within 10 years. It is very difficult to predict which patients will progress rapidly to advanced disease following biochemical failure (BF). Therefore, a more useful prognostic factor is needed to suggest the most appropriate therapies for each patient. To determine chromosomal aberrations, we examined 30 patients with stage pT2 or pT3 primary prostate adenocarcinomas and no metastases (pN0M0) by comparative genomic hybridization (CGH). Laser capture microdissection (LCM) was used to gather cancer cells from frozen prostate specimens. Common chromosomal alterations included losses on 2q23-24, 4q26-28, 6q14-22, 8p12-22 and 13q21-31, as well as gains on 1p32-36, 6p21 and 17q21-22. Losses at 8p12-22 and 13q21-31 were observed more frequently in pT3 than pT2 tumors (P<0.05 and P<0.01, respectively). Losses at 8p12-22 were more frequent in tumors with BF (P<0.05), and those at 13q12-21 were more frequent in tumors with Gleason score (GS) 7 or more than lower GS (P<0.05). These findings suggest that losses of 8p12-22 and 13q21-31 are important determinants of prostate cancer progression.

Evaluation of the basic properties of the BANGkit gel dosimeter

We evaluated the basic properties of a commercially available BANGkit gel dosimeter, which is a normoxic type of BANG gel. This gel-kit has the same composition as the BANG 3 gel, but is fully oxygenated. To exclude oxygen, oxygen scavenging ascorbic acid and copper sulfate as a catalyst are used. The properties that we examined are the effects of the concentrations of copper sulfate and ascorbic acid on the response, the reproducibility, the long-term stability, the temperature effect at irradiation and the dose-rate effect. In our results, the excellent linear fit of the R2-dose response in a dose range for clinical use and its reproducibility were observed. The precision of a linear fit was preserved for about 3 weeks. The temperature at irradiation showed a significant effect on the dose response. Although the dose-rate dependence in the high-dose range was observed, it was negligible for the clinical dose range up to 270 cGy. In conclusion, this gel dosimeter is thought to be utilizable in clinical practice, while we have to pay attention to the temperature during the entire measurement processes, and additionally there is room for improvement in the linearity and the dose-rate dependence in the high-dose range.

Purpuric adult T-cell leukaemia/lymphoma: expansion of unusual CD4/CD8 double-negative malignant T cells expressing CCR4 but bearing the cytotoxic molecule granzyme B

A 78-year-old Japanese woman with adult T-cell leukaemia/lymphoma (ATL) presented with an unusual purpuric and erythematous eruption on the face and trunk. Immunohistochemical and flow cytometric analyses showed that the tumour cells were CD4/CD8 double-negative, and expressed CCR4 T-helper (Th) 2 chemokine receptors. Despite these features, the cells aberrantly produced granzyme B, which is a cytotoxic molecule usually produced by CD8(+) cytotoxic T cells, natural killer cells, or occasionally by Th1 cells. In a purpuric lesion, extravasation of erythrocytes was associated with an infiltrate of these cytotoxic tumour cells. Our case suggests phenotypical and functional heterogeneity of tumour cells in ATL, which may be closely related to the clinical appearance of the skin eruption.

A practical preparation of methyl 2-methoxy-6-methylaminopyridine-3-carboxylate from 2,6-dichloro-3-trifluoromethylpyridine

An effective and practical synthetic route to methyl 2-methoxy-6-methylaminopyridine-3-carboxylate (7), the key intermediate of 5-bromo-2-methoxy-6-methylaminopyridine-3-carboxylic acid (1), from 2,6-dichloro-3-trifluoromethylpyridine (12) was undertaken. Process improvements were highlighted by regioselectivity of 12 with a nitrogen nucleophile and conversion of the 3-trifluoromethyl group into the methoxycarbonyl group. The reaction of 12 with N-benzylmethylamine provided the 6-(N-benzyl-N-methyl)aminopyridine 26a and the regioisomer 26b in >98:<2 ratio in a quantitative yield. Treatment of 2-methoxy-6-methylamino-3-trifluoropyridine (14a) with a large excess of sodium methoxide followed by acid hydrolysis gave the pyridine-3-carboxylic ester 7 in an excellent yield. The potential application of this reaction is also described.

Mycobacterium tuberculosis infection within Warthin's tumor: report of two cases

We report two patients with Warthin's tumor who were also infected with Mycobacterium tuberculosis. Case 1 was a 75-year-old woman with Warthin's tumor and multiple small epithelioid granulomas with caseous necrosis involving the submandibular gland. This patient died of tuberculous meningitis 4 months after biopsy. Case 2 was a 78-year-old man with a 10-year history of a parotid mass which had enlarged rapidly over 2 months. Surgical excision revealed Warthin's tumor and epithelioid granulomas involving the left parotid gland. DNA extracted from paraffin sections was amplified by nested polymerase chain reaction (PCR) with primer sets for the mycobacterial 65-KDa antigen gene. Restriction enzyme digestion of the PCR products could differentiate Mycobacterium tuberculosis from other mycobacteria in both cases. Although the histogenesis of lymphoid components of Warthin's tumor is controversial, the frequent prevalence of inflammation or necrosis and our present findings suggest these components have a similar behavior to regional lymph nodes.

Radiation therapy for superficial esophageal cancer: a comparison of radiotherapy methods

PURPOSE

A comparison of treatment outcomes in response to various methods of radiotherapy for superficial esophageal cancer (SEC) was carried out for a large series of patients.

METHODS AND MATERIALS

During the period from March 1987 to November 1998, 147 patients with superficial esophageal cancer received definitive radiation therapy at nine radiotherapy institutions in Japan. Fifty-five patients were treated with external radiation therapy alone, 69 with high-dose-rate intracavitary radiation therapy with or without external radiation therapy, and 23 with low-dose-rate intracavitary radiation therapy and external radiation therapy.

RESULTS

The 5-year survival rates for mucosal and submucosal cancer patients were 62% and 42%, respectively. The 5-year cause-specific survival rates for mucosal and submucosal cancer patients were 81% and 64%, respectively (p = 0.013). There was no statistically significant difference in the survival rates for either mucosal or submucosal cancer patients between treatment groups. Metastasis was observed only in submucosal cancer patients. Esophageal ulcers developed only in patients who received intracavitary radiation therapy, and were especially common in patients treated with a fraction size of 5 Gy or more.

CONCLUSIONS

The use of intracavitary radiation therapy does not influence the survival or local control rate of SEC. Optimal radiotherapy methods for SEC should be determined by a randomized clinical trial.

The role of epigenetic modifications in retinoic acid receptor beta2 gene expression in human prostate cancers

The retinoic acid receptor (RAR) beta gene is a putative tumor suppressor gene on chromosome 3p24, where a high incidence of loss of heterozygosity is detected in many types of tumors. Retinoic acid suppresses cancer cell growth through binding to RARs, especially RARbeta, indicating a critical role in mediating anticancer effects. Selective loss or down-regulation of RARbeta mRNA and protein has been reported in prostate cancers (PCas), although the mechanisms remain unclear. We investigated the role of epigenetic modification in RARbeta2 gene silencing. Aberrant methylation was detected in 11 of 14 (79%) primary PCas, 9 of 10 (90%) hormone-refractory PCas, and 2 of 4 (50%) PCa cell lines, but not in any normal prostate samples. Chromatin immunoprecipitation assay showed that all RARbeta2-negative cells (LNCaP, PC3, and DU145) were hypoacetylated at both histones H3 and H4. After exposure to 5-aza-2prime;-deoxycytidine treatment, Trichostatin A and all-trans retinoic acid induced partial demethylation, increased accumulation of acetylated histones, and markedly restored the expression of RARbeta2 in RARbeta2-negative cells. These data suggest that the RARbeta2 gene may be one of the frequently silenced genes by epigenetic modifications in PCa.

Efficient syntheses of novel C2'-alkylated (+/-)-K252a analogues

Recent efforts in our laboratories have resulted in a synthetic approach toward C2'-alkylated K252a analogues via extension of a K252a cyclofuranosylation strategy. The bis-indole-N-glycosidic coupling of 6-N-(3,4-dimethoxybenzyl)-staurosporinone (21) with a number of highly functionalized carbohydrates has given access to previously unattainable, biologically relevant analogues.

Signal therapy for RAS-induced cancers in combination of AG 879 and PP1, specific inhibitors for ErbB2 and Src family kinases, that block PAK activation

BACKGROUND

Both EGF family ligands and ErbB family receptor kinases act upstream of RAS to induce mitogenesis of normal cells, such as NIH 3T3 fibroblasts. However, oncogenically mutated RAS, such as v-Ha-RAS is constitutively activated and therefore no longer requires these ligands or receptors for its activation. Nevertheless, it up-regulates the expression of these EGF family ligands. To understand the biologic significance of RAS-induced up-regulation of these ligands in both RAS-induced PAK activation and malignant transformation, we have conducted the following studies, based on the previous observations that (1) the N-terminal SH3 domain of PIX selectively binds a Pro-rich domain of 18 amino acids of PAKs, CDC42/Rac-dependent Ser/Thr kinase family, and (2) this specific interaction is essential for both PAK activation and membrane ruffling

RESULTS

Using four distinct, cell-permeable, and highly specific inhibitors, namely WR-PAK18, which blocks the PAK-PIX interaction; AG 1478, which inhibits ErbB1 kinase activity; and AG 825 or AG 879, which inhibits ErbB2 kinase activity, we demonstrate that (1) the PAK-PIX interaction is essential for v-Ha-RAS-induced malignant transformation; (2) v-Ha-RAS requires not only ErbB1 but also ErbB2, which are activated through two independent autocrine pathways to induce both the PIX/Rac/CDC42-dependent PAK activation and malignant transformation in vitro; and (3) a combination of AG 879 and the Src family kinase-specific inhibitor PP1 suppresses almost completely the growth of RAS-induced sarcomas in nude mice.

CONCLUSION

These findings not only change our conventional view on the role of these RAS-inducible ligands and ErbB family receptors (serving as RAS activators) but also suggest a new avenue for the treatment of RAS-associated cancers by a combination of inhibitors specific for ERbB, Src, or PAK family kinases.

Autocrine and paracrine Müllerian inhibiting substance hormone signaling in reproduction

Members of the transforming growth factor beta (TGFbeta) superfamily are polypeptide growth factors that exhibit diverse effects on normal cell growth, adhesion, mesenchymal-epithelial interactions, cell differentiation, and programmed cell death. This chapter will discuss the work of ourselves and others on one member of this large superfamily, Müllerian inhibiting substance (MIS, or anti-Müllerian hormone, AMH) and its role in reproductive tract development and the adult gonad. Using recombinant MIS protein, it is possible to begin unraveling the molecular mechanism of duct involution in the embryo. Our recent results suggest that MIS triggers cell death by altering mesenchymal-epithelial interactions. In addition to the developmental effects of MIS in secondary sexual differentiation, expression studies of the MIS ligand and the MIS type II receptor (MISIIR) suggest a potential regulatory role for MIS in adult germ cell maturation and gonadal function. Recent data from others suggest that MIS may act in a paracrine manner to block differentiation of interstitial cells of the adult gonad by repressing all or some steps of steroidogenesis. Our studies are highly suggestive of direct repression of steroidogenic enzyme gene expression by activation of the MIS signaling pathway. Thus, for the first time, an opportunity to define fully target genes and components of the MIS signaling pathway may be possible.

Radiotherapy combined with transcatheter arterial infusion of cisplatin versus oral fluoropyrimidine anticancer agent for locally advanced carcinoma of the uterine cervix: a prospective follow-up study

We randomized patients with locally advanced cervical cancer to receive radiotherapy combined with transcatheter arterial infusion (TAI) of cisplatin or oral fluoropyrimidine anticancer agents, and compared the prognosis by a prospective follow-up study. Sixty patients were studied who completed their planned radiation therapy with chemotherapy at the Department of Obstetrics and Gynecology of Hiroshima University Hospital between January 1991 and December 1998. Patients were randomly assigned to receive (A) radiotherapy with TAI of 120 mg/body cisplatin twice a month at the interval of 4 weeks or (B) radiotherapy with 200 mg/day oral 5-FU or UFT every day. In both groups, radiotherapy is routinely 50 Gy of external beam irradiation to the whole pelvis and 18-20 Gy (point A dose) of intracavitary irradiation using a remote after loading system (RALS). Serious adverse reactions interfering with treatment did not appear in either group. The effective histologic response was 28/32 (87.5%) in group A and 25/28 (89.3%) in group B. The median follow-up period were 28.3 months and 25.4 months in group A and B, respectively. There was no significant difference in the overall survival and disease-free survival rates for all patients, clinical stage III and squamous cell carcinoma. We could not conclude that radiotherapy with TAI of cisplatin achieved superior therapeutic efficacy in locally advanced cervical cancer. To improve the therapeutic effects, it is important to establish a new cisplatin-containing chemoradiotherapy regimen.

Epigenetic regulation of androgen receptor gene expression in human prostate cancers

Epigenetic mechanisms including DNA methylation and histone deacetylation are thought to play important roles in gene transcriptional inactivation. Heterogenous expression of androgen receptor (AR), which appears to be related to variable responses to endocrine therapy in prostate cancer (PCa) may also be due to epigenetic factors. The methylation status of the 5' CpG island of the AR in 3 prostate cancer cell lines and 10 primary and 14 hormone-refractory PCa samples was determined using the bisulfite PCR methods. In DU145, CpG-rich regions of the AR were hypermethylated. By an immunohistochemical analysis, only one PCa sample had no AR expression, the others being heterogenous. Bisulfite sequencing and methylation-specific PCR analysis showed aberrant methylation of AR 5'-regulatory region in 20% of 10 primary and 28% of 14 hormone-refractory PCa samples. To clarify the effect of epigenetic regulation on AR expression, we treated three prostate cancer cell lines with a demethylating agent, 5-aza-2'-deoxycytidine (azaC), and a histone deacetylase inhibitor, Trichostatin A (TSA). In DU145, re-expression of AR mRNA was detected after treatment with azaC and/or TSA. Our results suggest that epigenetic regulations including CpG methylation and histone acetylation may play important roles in the regulation of the AR.

An efficient synthesis of 5-bromo-2-methoxy-6-methylaminopyridine-3carboxylic acid

An efficient synthesis of 5-bromo-2-methoxy-6-methylaminopyridine-3-carboxylic acid (1), a carboxylic acid moiety of a potent dopamine D2 and D3 and serotonin-3 (5-HT3) receptors antagonist, (R)-5-bromo-N-(1-ethyl-4-methylhexahydro-1 ,4-diazepin-6-yl)-2-methoxy-6-methylaminopyridine-3-carboxamide, is described. Reaction of methyl 2,6-difluoropyridine-3-carboxylate (12) with methylamine in EtOH at -25 degrees C gave a mixture of methyl 2-fluoro-6-methylaminopyridine-3-carboxylate (13) and the regioisomer 14 in a ratio of 57 : 43. On the other hand, reaction of 12 and methyl 2,6-dichloropyridine-3-carboxylate (16) with sodium methoxide in tetrahydrofuran (THF) and CH2Cl2 provided the 2-methoxypyridine-3-carboxylic esters 20 and 23, respectively, as main products. Similar reaction of 16 in N,N-dimethylformamide (DMF) and MeOH proved to be highly regioselective for the 6-position. A much greater regioselectivity for substitution at the 6-position (>97%) was observed when 16 was treated with 4-methylbenzenethiolate anion in DMF (quantitative yield). After methoxylation of methyl 2-chloro-6-(4-methylbenzenethio)pyridine-3-carboxylate (25b) and successive oxidation of the 6-benzenethio moiety, nucleophilic substitution of the sulfoxide derivative 28 with methylamine gave the 6-methylamino derivative 8. Finally, bromination of 8 and alkaline hydrolysis produced the desired product 1 in an overall yield of 67%.

[Effects of low concentration of styrene monomer vapor on pregnancy]

To investigate the effects of exposure to styrene vapor on pregnancy, mice proved to be pregnant were exposed to 0, 2, 20 and 100 ppm styrene continuously for 24 hours during the period from day 0 to day 15 of gestation. A special small exposure chamber which can accurately maintain a constant low concentration of styrene vapor was made and used in the experiment. 1) In the 100 ppm group, hyperkinesis was presented in the chamber during the exposure period and inhibition of body weight gain was found (p < 0.01). No deaths occurred in any of the groups. 2) At necropsy of dams, no significant difference was found between the styrene exposed groups and the control group in any of the fertility indices, number of implantations, number of live fetuses, percentage of resorptions, or in the percentage of dead fetuses. The 100 ppm group showed lower fetal and placental weights (p < 0.01). 3) Gross necropsy of dams in the 100 ppm group showed significantly decreased adipose tissue. The liver, kidney and spleen weights were also low (p < 0.01). 4) When exposed to 100 ppm, which corresponds to 5 times the permissible concentration, i.e., 20 ppm, for 24 hours, non-pregnant dams showed no abnormality, while pregnant dams showed inhibition of body weight gain and significantly lower fetal and placental weights and maternal organ weights. Therefore, careful consideration should be given to exposure of women of childbearing age to styrene.

An anti-Ras cancer potential of PP1, an inhibitor specific for Src family kinases: in vitro and in vivo studies

BACKGROUND

We previously found that both PAK, a Rac/CDC42-activated Ser/Thr kinase, and its binding partner PIX are required for malignant transformation caused by oncogenic Ras mutants, such as v-Ha-Ras. Furthermore, oncogenic Ras requires an autocrine pathway to activate PAK. This pathway involves at least two distinct receptor kinases: EGF receptor (ErbB1) and ErbB2. Interestingly, both of these kinases are known to activate Src family kinases that phosphorylate CAT, another binding partner of PIX.

PURPOSE

The major aim of this study was to determine whether Src family kinases are required for both Ras-induced PAK activation and malignant transformation. For this purpose, we used PP1, an inhibitor specific for Src family kinases, which does not inhibit either EGF receptor or ErbB2.

METHODS AND RESULTS

We studied the effect of PP1 on the anchorage-dependent growth of normal and v-Ha-Ras transformed NIH 3T3 fibroblasts, PAK activation and anchorage-independent growth of Ras transformants, and development of Ras-induced sarcomas in nude mice. We found that PP1 (10 nM) strongly inhibits PAK activity in Ras transformants. PP1 at this concentration is known to inhibit c-Fyn kinase, but not c-Src kinase, and none of the three known Src family kinases (c-Src, c-Fyn, and c-Yes) expressed in fibroblasts is activated by v-Ha-Ras. Thus, it is most likely that the primary target of this drug is an as yet unidentified Ras-activated Tyr (Y) kinase or kinases, which we call "Ray." Although PP1 has no effect on their anchorage-dependent growth, it significantly inhibits their anchorage-independent growth in soft agar, as well as a rapid growth of Ras-induced sarcomas in mice.

CONCLUSION

Like EGF receptor and ErbB2, a member of Src family kinases (most likely a new Src-related kinase called "Ray") is essential for the Ras-induced activation of PAK and the malignant transformation both in vitro and in vivo. These findings suggest that PP1 and other inhibitors specific for Src family kinases are potentially useful for the treatment of Ras-associated cancers.

Treatment of ras-induced cancers by the F-actin-bundling drug MKT-077

A rhodacyanine dye called MKT-077 has shown a highly selective toxicity toward several distinct human malignant cell lines, including bladder carcinoma EJ, and has been subjected to clinical trials for cancer therapy. In the pancreatic carcinoma cell line CRL-1420, but not in normal African green monkey kidney cell line CV-1, it is selectively accumulated in mitochondria. However, both the specific oncogenes responsible for its selective toxicity toward cancer cells, and its target proteins in these cancer cells, still remain to be determined. This study was conducted using normal and ras-transformed NIH 3T3 fibroblasts to determine whether oncogenic ras mutants such as v-Ha-ras are responsible for the selective toxicity of MKT-077 and also to identify its targets, using its derivative called "compound 1" as a specific ligand. We have found that v-Ha-ras is responsible for the selective toxicity of MKT-077 in both in vitro and in vivo. Furthermore, we have identified and affinity purified at least two distinct proteins of 45 kD (p45) and 75 kD (p75), which bind MKT-077 in v-Ha-ras-transformed cells but not in parental normal cells. Microsequencing analysis has revealed that the p45 is a mixture of beta- and gamma-actin, whereas the p75 is HSC70, a constitutive member of the Hsp70 heat shock adenosine triphosphatase family, which inactivates the tumor suppressor p53. MKT-077 binds actin directly, bundles actin filaments by cross-linking, and blocks membrane ruffling. Like a few F-actin-bundling proteins such as HS1, alpha-actinin, and vinculin as well as F-actin cappers such as tensin and chaetoglobosin K (CK), the F-actin-bundling drug MKT-077 suppresses ras transformation by blocking membrane ruffling. These findings suggest that other selective F-actin-bundling/capping compounds are also potentially useful for the chemotherapy of ras-associated cancers.

A preliminary outcome analysis of the Patterns of Care Study in Japan for esophageal cancer patients with special reference to age: non surgery group

BACKGROUND

The Patterns of Care Study (PCS) was imported to Japan from the United States in July 1996. A preliminary outcome analysis of the PCS for esophageal cancer patients in Japan was made with special reference to age, because the elderly population is rapidly increasing in Japan.

PATIENTS AND METHODS

From July 1996 to February 1998, external PCS audits were performed for 37 institutions nationwide and detailed information of 561 esophageal cancer patients treated during the period 1992-1994 was collected by using the fifth PCS data format developed in the United States. This format was provided courtesy of the American College of Radiology. For this study, patients who had not undergone surgery (n = 336) were selected. The patients were classified into three age groups: < 65 years old (n = 119), between 65 and 74 years (n = 93), and 75 years or older (n =123). Cox's proportional hazards model was used for the statistical analysis, with survival, acute/subacute complication and late complication of grade 3 or more based on RTOG criteria, as the endpoints.

RESULTS

Significant prognostic factors for the entire non-surgery group were Karnofsky Performance Status (KPS) (p = 0.0007), stage (p = 0.0001), and external irradiation dose (p = 0.0001). For the younger group, KPS (p = 0.0004), stage (p = 0.0197), and utilization of brachytherapy (p = 0.0010) were significant, while for the intermediate age group it was KPS (p = 0. 0027), history of pulmonary disease (p = 0.0339), stage (p = 0.0001), and external dose (p = 0.0001), and for the elderly group, stage (p = 0.0001) and external irradiation dose (p = 0.0224) were significant. Significant risk factors for complications for the entire group were stage (p = 0.0411), external dose (p = 0.0163), and stratification of institution (academic vs. nonacademic) (p = 0. 0114). Significant risk factors for the younger group were history of pulmonary disease (p = 0.0495) and external dose (p = 0.0037), and the other age groups showed no significant risk factors.

CONCLUSION

Age was not a significant prognostic or risk factor for esophageal cancer patients in the non-surgery group treated with radiation therapy. Therefore, radiation therapy represented an important treatment modality for the elderly as well as for the younger esophageal cancer patients. External dose was a treatment-related prognostic factor for the elderly as well as for the intermediate age group.

Expression of MAT1/PEA-15 mRNA isoforms during physiological and neoplastic changes in the mouse mammary gland

MAT1 is a novel transforming gene which was cloned from a mouse mammary tumor induced by N-methyl-N-nitrosourea in vitro in the presence of lithium as a mitogen. Later, it was found to be identical to the 3' untranslated region (UTR) of the 2.5 kb isoform of PEA-15 (phosphoprotein enriched in astrocytes-15 kDa). We re-cloned MAT1/PEA-15 cDNAs and showed 2.5, 2.0 and 1.8 kb isoforms and confirmed MAT1 localization as reported. The 2.0 and 1.8 kb isoforms were produced by alternative splicing and alternative polyadenylation at the 3' UTR, respectively. To analyze the role of MAT1/PEA-15, we examined the expression of MAT1/PEA-15 mRNA in normal mammary tissues and in mammary tumors. The mammary gland during pregnancy, lactation and weaning showed weak but stable expression. Compared with normal mammary gland, mammary tumors showed stronger expression. Aberrant expression of MAT1/PEA-15 isoforms was found in mouse mammary epithelial cell lines, FSK7 and TM6, which lost the 2.5/2.0 and 2.5 kb isoforms, respectively. In contrast to other oncogenes like c-myc, MAT1/PEA-15 mRNA was extremely stable after actinomycin D and cycloheximide treatments suggesting that other protein expression is prerequisite for degradation of MAT1/PEA-15 mRNA. It evoked the possibility of the 3' UTR of MAT1/PEA-15 (designated as MAT1-T) as a riboregulator in mammary tumorigenesis and necessity for further analysis of human breast cancers as well as mouse mammary tumors.