Gonadotropin-releasing hormone analogue conjugates with strong selective antitumor activity.
(1/1526)
Conjugation of gonadotropin-releasing hormone (GnRH) analogues GnRH-III, MI-1544, and MI-1892 through lysyl side chains and a tetrapeptide spacer, Gly-Phe-Leu-Gly (X) to a copolymer, poly(N-vinylpyrrolidone-co-maleic acid) (P) caused increased antiproliferative activity toward MCF-7 and MDA-MB-231 breast, PC3 and LNCaP prostate, and Ishikawa endometrial cancer cell lines in culture and against tumor development by xenografts of the breast cancer cells in immunodeficient mice. MCF-7 cells treated with P-X-1544 and P-X-1892 displayed characteristic signs of apoptosis, including vacuoles in the cytoplasm, rounding up, apoptotic bodies, bleb formation, and DNA fragmentation. Conjugates, but not free peptides, inhibited cdc25 phosphatase and caused accumulation of Ishikawa and PC3 cells in the G2/M phase of the cell cycle after 24 h at lower doses and in the G1 and G2 phases after 48 h. Since P-X-peptides appear to be internalized, the increased cytotoxicity of the conjugates is attributed to protection of peptides from proteolysis, enhanced interaction of the peptides with the GnRH receptors, and/or internalization of P-X-peptide receptor complexes so that P can exert toxic effects inside, possibly by inhibiting enzymes involved in the cell cycle. The additional specificity of P-X-peptides compared with free peptides for direct antiproliferative effects on the cancer cells but not for interactions in the pituitary indicates the therapeutic potential of the conjugates. (+info)
Hematopoietic stem cell tracking in vivo: a comparison of short-term and long-term repopulating cells.
(2/1526)
We have previously demonstrated that we could separate long-term repopulating stem cells from cells that provided radioprotection (short-term repopulating cells) on the basis of size and suggested that this might be due to the quiescent nature of long-term repopulating cells. To further define the activity of these populations, we used a dye (PKH26), which incorporates into the membrane of cells and is equally distributed to daughter cells when they divide. We developed an assay, which allowed us to retrieve PKH26(+) long-term and short-term repopulating cells in the hematopoietic tissues of the recipients posttransplant. We were able to recover the labeled cells and determine their cell cycle activity, as well as their ability to reconstitute secondary lethally irradiated hosts in limiting dilution. The results of our assay suggest that long-term repopulating cells are quiescent in the bone marrow (BM) 48 hours after transplant. We were able to detect only a few labeled cells in the peripheral blood posttransplant and even though cells homed to both the spleen and BM, more long-term repopulating cells homed to the marrow and only these cells, which homed to the marrow, were capable of reconstituting lethally irradiated secondary hosts long-term. (+info)
Mutant N-ras induces myeloproliferative disorders and apoptosis in bone marrow repopulated mice.
(3/1526)
Mutations that activate the N-ras oncogene are among the most frequently detected genetic alterations in human acute myeloid leukemias (AMLs), Philadelphia chromosome-negative myeloproliferative disorders (MPDs), and myelodysplastic syndromes (MDSs). However, because N-ras has not been shown to induce these disorders in an in vivo model, the role of N-ras in the evolution of myeloid leukemia is unclear. To investigate the potential of N-ras to induce myeloid leukemia, lethally irradiated mice were reconstituted with bone marrow (BM) cells infected with a retroviral vector carrying activated N-ras. Approximately 60% of these mice developed hematopoietic disorders, including severe MPDs resembling human chronic myelogenous leukemia (CML) or AML with differentiation (French-American-British [FAB] classification M2). Other reconstituted mice succumbed to hematopoietic defects that were pathologically similar to human MDSs. The latter disorders appeared to be due to a myeloid impairment that was demonstrated by enumeration of day-12 colony-forming units-spleen (CFU-S) and by in vitro colony assays. A high level of apoptosis associated with thymic atrophy and peripheral blood (PB) lymphopenia was also evident in N-ras reconstituted mice. Our results are consistent with a model in which antiproliferative effects are a primary consequence of N-ras mutations and secondary transforming events are necessary for the development of myeloid leukemia. This is the first report of an in vivo model for N-ras induced MPD and leukemia. (+info)
Radiation induced endothelial cell retraction in vitro: correlation with acute pulmonary edema.
(4/1526)
We determined the effects of low dose radiation (<200 cGy) on the cell-cell integrity of confluent monolayers of pulmonary microvascular endothelial cells (PMEC). We observed dose- and time-dependent reversible radiation induced injuries to PMEC monolayers characterized by retraction (loss of cell-cell contact) mediated by cytoskeletal F-actin reorganization. Radiation induced reorganization of F-actin microfilament stress fibers was observed > or =30 minutes post irradiation and correlated positively with loss of cell-cell integrity. Cells of irradiated monolayers recovered to form contact inhibited monolayers > or =24 hours post irradiation; concomitantly, the depolymerized microfilaments organized to their pre-irradiated state as microfilament stress fibers arrayed parallel to the boundaries of adjacent contact-inhibited cells. Previous studies by other investigators have measured slight but significant increases in mouse lung wet weight >1 day post thoracic or whole body radiation (> or =500 cGy). Little or no data is available concerning time intervals <1 day post irradiation, possibly because of the presumption that edema is mediated, at least in part, by endothelial cell death or irreversible loss of barrier permeability functions which may only arise 1 day post irradiation. However, our in vitro data suggest that loss of endothelial barrier function may occur rapidly and at low dose levels (< or =200 cGy). Therefore, we determined radiation effects on lung wet weight and observed significant increases in wet weight (standardized per dry weight or per mouse weight) in < or =5 hours post thoracic exposure to 50 200 cGy x-radiation. We suggest that a single fraction of radiation even at low dose levels used in radiotherapy, may induce pulmonary edema by a reversible loss of endothelial cell-cell integrity and permeability barrier function. (+info)
Health-related quality of life 1 year after allogeneic or autologous stem-cell transplantation: a prospective study.
(5/1526)
PURPOSE: To evaluate health-related quality of life (HRQOL) in adults treated with high-dose chemotherapy followed by allogeneic (SCT) and autologous (ASCT) stem-cell transplantation 1 year after transplantation, using data from concurrent lymphoma patients receiving combination chemotherapy (CT) as a reference. MATERIALS AND METHODS: Forty-one leukemia patients (SCT group), 51 lymphoma patients (ASCT group), and 85 CT patients completed the European Organization for Research and Treatment of Cancer QLQ-C30 questionnaire at baseline and after 1 year. RESULTS: The SCT group (median age, 36 years) had better functioning scores and less symptomatology at baseline compared with the ASCT (median age, 41 years) and CT (median age, 37 years) groups. Statistically significant differences of 10 or more points on the 0 to 100 scales were found for 10 of 15 scales and items (P< or =.01) between the SCT and ASCT groups. Global quality of life (79 v 58, P<.0001), role function (83 v 65, P = .001), sleep disturbances (6 v 28, P<.0001), and fatigue (25 v 44, P = .0001) deviated most. The differences were 10 or more points for seven of 15 scales and items comparing the SCT and CT groups, with sleep disturbances (6 v 35, P<.0001) and pain (11 v 29, P<.01) deviating most. Differences across groups were smaller after 1 year; cognitive function was the only scale with a statistically significant difference (ASCT 80 v CT 89; P = .002). Patterns of change in HRQOL scores were different between groups during follow-up. A great improvement was found in the ASCT group (P<.01 for emotional and role function, fatigue, appetite, and constipation), whereas no significant changes were observed for the SCT group. CONCLUSION: Prospective studies with extended follow-up periods are necessary to separate a slow recovery process from more permanently reduced HRQOL after transplantation and to examine the late side effects from previous treatment. (+info)
High-dose therapy with autologous or allogeneic transplantation as salvage therapy for small cleaved cell lymphoma of follicular center cell origin.
(6/1526)
Between 1985 and 1996, 51 patients with relapsed or refractory small cleaved cell lymphoma (SCCL) received high-dose chemotherapy +/- TBI in conjunction with autologous (ABMT) (36 patients) or allogeneic transplantation (15 patients). Patients were eligible for ABMT if the bone marrow biopsy done prior to the planned transplant did not reveal microscopic involvement with SCCL. Patients receiving ABMT had a median age of 48 years, had received a median of 2.5 chemotherapy regimens prior to transplantation, and were transplanted a median of 35.5 months from diagnosis. Among patients receiving ABMT, 5 year actuarial survival was 56+/-11%. Median survival was 126+ months, and median survival from diagnosis was 191 months. Univariate and multivariate analysis identified sensitive disease as the best predictor of a favorable response. Five-year actuarial survival was 66+/-12% for patients with sensitive disease at the time of transplant as compared to 29+/-17% for patients with resistant disease, P = 0.015. Median survival in patients with sensitive disease at the time of ABMT was 126+ months. By univariate analysis, survival was significantly better for patients receiving ABMT as compared to patients receiving allogeneic transplants. Median survival following allogeneic transplantation was 5 months; 5 year actuarial survival was 15+/-13%. In a multivariate analysis, which considered autologous vs allogeneic transplantation, sensitive vs resistant disease, <3 vs > or = 3 prior treatments, and prior bone marrow involvement, allogeneic transplantation was significantly associated with poor survival. Treatment-related mortality occurred in eight of 15 patients receiving allogeneic transplantation and limited the effectiveness of this therapy. High-dose therapy in conjunction with ABMT is effective therapy for patients with SCCL whose disease is sensitive to chemotherapy and whose marrows are microscopically free of disease. Because of possible selection bias, it has not been proven that this approach increases survival in these patients. Treatment-related mortality limits the effectiveness of allogeneic transplantation in SCCL. (+info)
Ultrasound B-mode changes in the uterus and ovaries and Doppler changes in the uterus after total body irradiation and allogeneic bone marrow transplantation in childhood.
(7/1526)
Internal genitalia and uterine blood flow were assessed by ultrasound in 12 females 4.0-10.9 years after total body irradiation and allogeneic bone marrow transplantation for childhood leukaemia or lymphoma. Median age of the participants was 12.7 years (range 6.1-17.6) at bone marrow transplantation and 21.5 years (11.6-25.6) at the follow-up study. At follow-up all had entered puberty and 11/12 females had experienced the menarche. Eight females received sex steroid replacement therapy, three had spontaneous pubertal development and one woman experienced symptoms of estrogen deficiency. Median uterine and ovarian volumes were significantly reduced to -2.6 standard deviation scores (SDS) (-6.3 to -0.6), P = 0.002, and -2.6 SDS (-4.8 to -0.5), P = 0.002, respectively, compared with normal controls. Follicles were only detectable in two individuals. Uterine blood flow was impaired, as a systolic blood flow could be measured in 6/9 individuals, and a diastolic blood flow in 1/9 females. Our results indicate that the prescribed dosage of hormone replacement therapy, which was sufficient to induce bleeding and suppress other stigmata of premature menopause, was inadequate to generate normal uterine growth. In order to achieve uterine growth higher doses of hormone replacement therapy may be required. Our results confirm pelvic ultrasound as a reliable tool for investigation of internal female genitalia; however, in an infertility setting further tests are indicated. (+info)
Antiemetic efficacy of granisetron plus dexamethasone in bone marrow transplant patients receiving chemotherapy and total body irradiation.
(8/1526)
Few trials exist regarding the antiemetic efficacy of granisetron in bone marrow transplant (BMT) recipients conditioned with high-dose chemotherapy and total body irradiation (TBI). In this single-center, open-label, prospective, trial, the antiemetic efficacy and safety of granisetron plus dexamethasone were evaluated in 26 patients conditioned with cyclophosphamide-containing regimens (the majority receiving 60 mg/kg per day on 2 consecutive days), and TBI (12 Gy divided over 4 days). Daily intravenous doses of granisetron 1 mg plus dexamethasone 10 mg were given 30 min prior to chemotherapy or radiation, and continued for 24 h after the last conditioning treatment for a median of 6 days (range 3-9). Emetic control was defined by the number of emetic episodes occurring within a 24 h period, or the requirement for rescue medication for nausea or vomiting. A total of 25 patients completed 186 evaluable treatment days. Response (emetic control by treatment days) was complete in 50% of patients, major in 48%, minor in 2%, and there were no failures. Adverse effects were minor, with diarrhea (15%), headache (14%), and constipation (11%) reported most often. Based on these results, the antiemetic regimen of granisetron plus dexamethasone appears effective and well tolerated during BMT conditioning with high-dose cyclophosphamide and TBI. (+info)