p53 mutation without allelic loss and absence of mdm-2 amplification in a transplantable hamster pancreatic ductal adenocarcinoma and derived cell lines but not primary ductal adenocarcinomas in hamsters

An investigation of p53 gene mutation by single-stranded conformation polymorphism analysis of polymerase chain reaction products followed by direct sequencing and of murine double minute 2 (mdm-2) gene amplification by Southern blot analysis was performed, using a series of hamster pancreatic duct adenocarcinomas: 18 primary adenocarcinomas induced by N-nitrosobis(2-oxopropyl)amine, a transplantable adenocarcinoma (HPD), and three cell lines derived from HPD (HPD1NR, HPD2NR, and HPD3NR). A mutation in the p53 gene was detected at codon 197, resulting in an amino acid change from leucine to phenylalanine, in both HPD and the three cell lines but in none of the 18 primary adenocarcinomas. In the three HPD cell lines, which were confirmed to contain only cancer cells, a normal p53 gene allele was retained. Immunohistochemical investigation of p53 expression using polyclonal antibody Ab-7 revealed positive nuclear staining in the HPD and two back-transplanted tumors derived from HPD1NR and HPD2NR but not in the 18 primary adenocarcinomas. mdm-2 gene amplification was not detected in 18 primary adenocarcinomas or any of the tumor cell lines. The results suggest that a p53 gene mutation without allelic loss, together with overexpression of p53 protein, may be a genetic alteration involved in the progression stage of multistep pancreatic carcinogenesis in hamsters and that mdm-2 gene amplification is not important for this process. © 1995 Wiley-Liss, Inc.     

Randomized study with mitomycin C + 5-fluorouracil + cytosine arabinoside (MFC) + 5-fluorouracil,MFC + tegafur and uracil (UFT), and MF + UFT in advanced gastric cancer: Interinstitutional differences in a multicenter study in Japan

In a phase III randomized trial of adjuvant chemotherapy for gastric cancer, interinstitutional differences were analyzed. A trial of three regimens: mitomycin C, 5-fluorouracil(5-FU) and CA (MFC) + continuous oral 5-FU (Group C); MFC + continuous oral UFT(tegafur and uracil) (Group B); and MF + UFT (Group C) after operation was conducted in 466 patients with gastric cancer (stage II and III) at four hospitals in Japan (CIH, CAD, ACC and NCC). Patients were stratified by the institution, stage, and tumor size (8 cm ><). The 5-year survival rates were in the order of Group A (79.0%) > B (70.0%) > C (61.0%) (P = 0.1228) in total, A (95.0%) > B (80.0%) > C (58.0%) (P < 0.05) at CAD (82 patients), A > C> B at CIH (215), C> A > B at ACC (95), and B > A > C at NCC (78). The survival rate of patients with S2(serosal exposure), 8 cm < and NO-1 cancer was higher at CIH than at the other institutions. The interinstitutional differences in patient characteristics and surgical technique were more powerful than the differences among the three groups. © 1995 Wiley-Liss, Inc.     

Advantage of gene gun-mediated over intramuscular inoculation of plasmid DNA vaccine in reproducible induction of specific immune responses

Utilizing a plasmid DNA encoding a single cytotoxic T lymphocyte (CTL) epitope and that encoding ovalbumin (OVA), we compared the reproducibility in the induction of immune responses by gene gun and intramuscular immunization. As compared to intramuscular inoculation, gene gun DNA immunization appeared to bring about highly reproducible and reliable results in the induction of specific CTL and IFN-gamma production to the CTL epitope and production of anti-OVA IgG. The results obtained by intramuscular inoculation vary significantly. Our data shown here strongly suggest that gene gun immunization of skin is a much more reliable method for DNA vaccination to induce effective immune responses in an animal model.     

Clinical Usefulness of Determining the Rate of Thermal Clearance within Heated Tumors

Between June 1987 and June 1988, 28 patients (28 tumors) withliver, retroperitoneal, intrapelvic, or superficial tumors weretreated with hyperthermia combined with radiotherapy and/orchemotherapy. Hyperthermia was administered once or twice aweek for 30-60 min per session, up to a total of 2–11sessions, with an 8-MHz RF capacitive heating device. Bloodflow in the tumors was evaluated from the rate of thermal clearance(TCR) using the bio-heat transfer equation. The TCR was measuredin the middle of the first heating session and at the end ofthe last heating session by turning off the output power ofthe heating device. For 9 patients, contrast-enhanced CT scanswere taken and CT numbers at the centers of tumors were measuredbefore and after the entire course of hyperthermia. Changesin TCR were closely related to average tumor center temperature,changes in CT number, and tumor response. When smaller and moresuperficial tumors were treated by hyperthermia combined withradiotherapy and/or chemotherapy that consisted of many heatingsessions and during which a high average tumor center temperaturewas achieved, a better tumor response was obtained. The betterthe tumor response, the higher the local control rate became.The cause-specific survival rate of patients who achieved goodtumor responses was higher than that of patients who showedpoor tumor responses. Changes in TCR and CT number in heatedtumors were useful and important indicators of tumor responseto hyperthermia.     

Comparison of in vivo Efficacy of Hypoxic Cytotoxin Tirapazamine and Hypoxic Cell Radiosensitizer KU-2285 in Combination with Single and Fractionated Irradiation

Development of strategies to eradicate radioresistant hypoxic cells would be of great benefit for clinical radiotherapy. In the present study, the in vivo effects of a promising hypoxic cytotoxin, tirapazamine (3-amino-1,2,4-benzotriazine 1,4-di-N-oxide), were examined in comparison with those of KU-2285, one of the best hypoxic cell radiosensitizers, in combination with both single and fractionated irradiation. The tumor response was assessed by the standard in vivo-in vitro clonogenic assay using SCCVII tumors in C3H mice and EMT-6/KU tumors in Balb/c mice with different characteristics of tumor hypoxia. With single-dose irradiation (18 Gy), both tirapazamine and KU-2285 showed significant enhancement of cell killing in a dose-dependent manner, but tirapazamine was more effective for SCCVII tumors with acutely hypoxic cells, while KU-2285 was more effective for EMT-6/KU tumors predominantly with chronically hypoxic cells. In fractionated irradiation regimens (4 fractions of 5 Gy at 12 h intervals), tirapazamine showed more marked combined effects at 10 and 20 mg/kg than KU2285 at 100–200 mg/kg in both SCCVII and EMT-6/KU tumors. We concluded that the effectiveness of KU-2285 and tirapazamine was correlated with the nature of tumor hypoxia with single-dose irradiation, whereas tirapazamine appeared more potent than KU-2285 with fractionated irradiation. These findings suggest the potential usefulness of tirapazamine in clinical fractionated radiotherapy.     

A phase I and II clinical trial of a newly developed ultrasound hyperthermia system with an improved planar transducer

: The clinical usefulness of a newly developed ultrasound hyperthermia system was evaluated.

: The hyperthermia system uses a modified planer transducer operated at frequencies of 0.5, 1.0, and 1.5 MHz. The transducer has a nonvibrating part at the center to reduce the central hot spot. Frequency sweeping technique is also used to eliminate the annular hot spot around the center. Thirty-eight tumors in 29 patients were examined in this study. In 35 tumors, hyperthermia was given in conjunction with irradiation and/or chemotherapy, and in the remaining 3 tumors, hyperthermia alone was given. In all, a total of 153 hyperthermia sessions were performed.

: The number of hyperthermia sessions per tumor ranged from 1 to 7 (mean, 4.0 ± 1.3). The number of intratumor thermometr points per session ranged from 1 to 8 (mean, 4.3 ± 1.5). The average intratumor temperature for tumors with a maximum depth of <3 cm, 3–6 cm, and >6 cm was 42.1 ± 1.2, 41.7 ± 1.4, and 39.9 ± 2.0°C, respectively. The percentage of monitored intratumor points with temperature exceeding 42°C was 56 ± 31%, 43 ± 34%, and 21 ± 24%, respectively. Of the 30 evaluable tumors treated with combined irradiation, 12 showed complete response, 14 partial response, and 4 no change. Observed complications included pain at the treatment site in 13 of the 153 treatment sessions and vesicle formation in 3 of the 38 treatment sites. No serious complication was seen.

: These results indicate that the newly developed ultrasound hyperthermia system is clinically useful for the treatment of localized superficial and subsurface tumors with a maximum tumor depth of no more than 6 cm.     

Radiation therapy for T1,2 glottic carcinoma: impact of overall treatment time on local control

Purpose: Local control probabilities of T1,2 glottic laryngeal cancer were evaluated in relation to dose and fractionation of radiation therapy (RT). Materials and methods: Between 1975 and 1993, 96 T1N0M0 glottic cancers and 32 T2N0M0 glottic cancers were treated with definitive RT. Total RT dose was 60–66 Gy/2 Gy for most of the T1 and T2 tumors, although 10 T2 tumors were treated with hyperfractionation (72–74.4 Gy/1.2 Gy bid). Of the 128 patients, 90 T1 glottic tumors and 30 T2 glottic tumors were followed for >2 years after treatment. Multivariate analyses using the Cox proportional hazards model and a logistic regression analysis were performed to evaluate the significance of prognostic variables on local control. Results: The 5-year local control probability for T1 tumors was 85%, whereas that for T2 tumors was 71%. Multivariate analyses demonstrated that only overall treatment time (OTT) was a significant variable for local control. Total RT dose, normalized total doses at a fraction size of 2 Gy, and fraction size were not significant. Local control probability of T1 tumors with an OTT of 42–49 days was significantly higher than that of tumors with an OTT of >49 days (P < 0.02). Only a 1-week interruption of RT, due to holidays, significantly reduced the 5-year local control probability of T1 glottic tumors from 89 to 74% (P < 0.05). Conclusions: These results indicate that OTT is a significant prognostic factor for local control of T1 glottic tumors.     

Age-dependent prevalence of mutations at the GLC1A locus in primary open-angle glaucoma

PURPOSE: To screen a population with primary open-angle glaucoma for mutations in the gene that encodes the trabecular meshwork inducible glucocorticoid response protein (TIGR), also known as myocilin (MYOC). METHODS: Ophthalmologic information was collected for study subjects with primary open-angle glaucoma and their relatives. Mutation screening of 74 primary open-angle glaucoma probands was conducted by sequencing TIGR/MYOC coding sequence and splice sites. RESULTS: In 23 families we detected 13 nonsynonymous sequence changes, nine of which appear to be mutations likely to cause or contribute to primary open-angle glaucoma. Two mutations, Arg272Gly and Ile499Ser, and one nonsynonymous sequence variant, Asn57Asp, are novel. We found mutations in nine of 25 juvenile glaucoma probands (36%) and two of 49 adult-onset glaucoma probands (4%). Age classification of families rather than individual probands revealed mutations in three of nine families with strictly juvenile primary open-angle glaucoma (33%), and no mutations in 39 families with strictly adult-onset primary open-angle glaucoma (0%). In families with mixed-onset primary open-angle glaucoma containing both juvenile primary open-angle glaucoma and adult-onset primary open-angle glaucoma cases, we found mutations in eight of 26 families (31%). CONCLUSIONS: Our data suggest that Gly252Arg, Arg272Gly, Glu323Lys, Gln368STOP, Pro370Leu, Thr377Met, Val426Phe, Ile477Asn, and Ile499Ser are likely to play roles that cause or contribute to the etiology of autosomal dominant primary open-angle glaucoma. Our finding of more TIGR/MYOC mutations in families with mixed-onset primary open-angle glaucoma than in the families with strictly adult-onset primary open-angle glaucoma implies that the presence of relatives with juvenile primary open-angle glaucoma in a family could be used as a basis for identifying a subset of the population with adult-onset primary open-angle glaucoma with higher prevalence of TIGR/MYOC mutations. To address this issue, and to refine estimations of mutation prevalence in these age-defined subpopulations, prospective study of a larger population ascertained entirely through adult-onset primary open-angle glaucoma probands will be needed.     

Preservation of ovarian function and reproductive ability in patients with malignant ovarian tumors

In a study designed to determine the merit of preserving ovarian function and childbearing capability in women with unilateral malignant ovarian tumors, the results of radical surgery (n = 86) and conservative surgery (n = 106) were compared. The mean length of survival was slightly but not significantly shorter following conservative surgery. There were 15 recurrences (14%) and 11 deaths among the conservative surgery group. The incidence of metastasis to the preserved ovary was high. In the most cases restoration of normal menses was fairly rapid after initial treatment, but this appeared to depend on whether or not chemotherapy was given postoperatively, the specific agents used, and the duration of their administration. Hypergonadotropic hypogonadism was the most common finding among the anovulatory patients. Sixteen women experienced a total of 27 pregnancies and 18 normal infants were born. Abortion was induced when conception occurred during a course of chemotherapy. These findings are encouraging in terms of the feasibility of preserving childbearing capability in ovarian cancer patients. However, they also underscore the necessity for close, long-term follow-up, which will be improved as new technologies become available.