Downregulation of bcl-2 expression in lymphoma cells by bcl-2 ARE-targeted modified,synthetic ribozyme

Synthetic ribozymes are catalytic RNA molecules designed to inhibit gene expression by cleaving specific mRNA sequences. We investigated the potential of synthetic ribozymes to inhibit bcl-2 expression in apoptosis defective bcl-2 overexpressing tumors. A chemically stabilized hammerhead ribozyme has been targeted to the A+U-rich regulative element of bcl-2 mRNA that is involved in bcl-2 gene switch-off during apoptosis. The design of the ribozyme was based on the results of probing accessibility of the RNA target in cellular extracts with antisense DNA. The ribozyme was lipotransfected to a bcl-2 overexpressing human lymphoma cell line (Raji). The cellular uptake of this ribozyme resulted in a marked reduction of both bcl-2 mRNA and BCL-2 protein levels and dramatically increased cellular death by apoptosis. Our results suggest a potential therapeutic application of such ribozyme for the treatment of bcl-2 overexpressing tumors.     

Feedback inhibition by RALT controls signal output by the ErbB network

The ErbB-2 interacting protein receptor-associated late transducer (RALT) was previously identified as a feedback inhibitor of ErbB-2 mitogenic signals. We now report that RALT binds to ligand-activated epidermal growth factor receptor (EGFR), ErbB-4 and ErbB-2.ErbB-3 dimers. When ectopically expressed in 32D cells reconstituted with the above ErbB receptor tyrosine kinases (RTKs) RALT behaved as a pan-ErbB inhibitor. Importantly, when tested in either cell proliferation assays or biochemical experiments measuring activation of ERK and AKT, RALT affected the signalling activity of distinct ErbB dimers with different relative potencies. RALT deltaEBR, a mutant unable to bind to ErbB RTKs, did not inhibit ErbB-dependent activation of ERK and AKT, consistent with RALT exerting its suppressive activity towards these pathways at a receptor-proximal level. Remarkably, RALT deltaEBR retained the ability to suppress largely the proliferative activity of ErbB-2.ErbB-3 dimers over a wide range of ligand concentrations, indicating that RALT can intercept ErbB-2.ErbB-3 mitogenic signals also at a receptor-distal level. A suppressive function of RALT deltaEBR towards the mitogenic activity of EGFR and ErbB-4 was detected at low levels of receptor occupancy, but was completely overcome by saturating concentrations of ligand. We propose that quantitative and qualitative aspects of RALT signalling concur in defining identity, strength and duration of signals generated by the ErbB network.     

Differential expression of galectin-3 in pituitary tumors

Galectin-3 (Gal-3), a beta-galactoside-binding protein, has been implicated in a variety of biological functions, including cell proliferation and differentiation, tumor cell adhesion, angiogenesis, apoptosis, tumor progression, and metastasis. We investigated the role of Gal-3 in the development and progression of pituitary tumors. Immunohistochemical and Western blot analysis of normal and neoplastic human pituitaries showed that only lactotroph (PRL) and corticotroph (ACTH) hormone-producing cells and tumors expressed Gal-3. Gal-3 was present in 24 of 38 (63.2%) PRL adenomas, 5 of 6 (83.3%) PRL carcinomas, 19 of 41 (46.3) ACTH adenomas, and 7 of 8 (87.5%) ACTH carcinomas, but not in 112 other pituitary adenomas and carcinomas. Pituitary folliculo-stellate cells, which have macrophage-type functions in the anterior pituitary, also expressed Gal-3. Hyperplastic and neoplastic pituitaries from p27(Kip1) (p27)-null mice, which produce mainly ACTH, showed increased Gal-3 expression levels compared with control mice. Treatment with transforming growth factor beta1, which regulates pituitary cell proliferation, reduced Gal-3 as well as p27 expression levels in cultured HP75 pituitary cells and Gal-3 in cultured pituitary cells from p27-null mice, suggesting that p27 is not necessary for the inhibitory effects of transforming growth factor beta1 on the cell cycle in the pituitary. The role of Gal-3 in pituitary cell function was examined by RNA interference experiments. Inhibition of Gal-3 gene expression by RNA interference decreased HP75 cell proliferation and increased apoptosis. These results indicate that Gal-3 has an important role in pituitary cell proliferation and tumor progression.     

International Collaborative Ovarian Neoplasm trial 1 and Adjuvant ChemoTherapy In Ovarian Neoplasm trial: two parallel randomized phase III trials of adjuvant chemotherapy in patients with early-stage ovarian carcinoma

BACKGROUND: Adjuvant chemotherapy has been suggested as a possible strategy to improve survival in women with early-stage ovarian cancer; however, all randomized studies to date have been too small to answer this question reliably. METHODS: We performed a preplanned combined analysis of two parallel randomized clinical trials (International Collaborative Ovarian Neoplasm 1 [ICON1] and Adjuvant ChemoTherapy In Ovarian Neoplasm [ACTION]) in early-stage ovarian cancer that compared platinum-based adjuvant chemotherapy with observation following surgery. Between November 1990 and January 2000, 925 patients (477 in ICON1 and 448 in ACTION) who had surgery for early-stage ovarian cancer were randomly assigned to receive platinum-based adjuvant chemotherapy (n = 465) or observation (n = 460) until chemotherapy was indicated. Kaplan-Meier analysis was used to compare overall and recurrence-free survival by treatment allocation. In subgroup analyses of pretreatment age, tumor stage, histologic cell type, and differentiation grade, the differences in relative size of effect were tested using a chi-square test for interaction or a chi-square test for trend. All tests of statistical significance were two-sided. RESULTS: After a median follow-up of over 4 years, 245 patients had died or had a recurrence (ICON1: 133, ACTION: 112). Overall survival at 5 years was 82% in the chemotherapy arm and 74% in the observation arm (difference = 8% [95% confidence interval (CI) = 2% to 12%]; hazard ratio [HR] = 0.67, 95% CI = 0.50 to 0.90; P =.008). Recurrence-free survival at 5 years was also better in the adjuvant chemotherapy arm than it was in the observation arm (76% versus 65%, difference = 11% [95% CI = 5% to 16%]; HR = 0.64, 95% CI = 0.50 to 0.82; P =.001). Subgroup analyses provided no evidence of a difference in the size of effect of chemotherapy on survival in any pretreatment subcategory. CONCLUSIONS: Platinum-based adjuvant chemotherapy improved overall survival and recurrence-free survival at 5 years in this combined group of patients with early-stage ovarian cancer defined by the inclusion criteria of the ICON1 and ACTION trials.     

Long-term follow-up of a phase I study of high-dose decitabine,busulfan, and cyclophosphamide plus allogeneic transplantation for the treatment of patients with leukemias

BACKGROUND: Decitabine is a hypomethylating agent that has activity in patients with leukemia. The authors combined decitabine with busulfan and cyclophosphamide as a conditioning regimen prior to allogeneic hematopoietic stem cell transplantation. METHODS: Patients with high-risk acute myeloid leukemia (AML) (n = 12 patients); chronic myelomonocytic leukemia (CMML) (n = 1 patient); acute lymphocytic leukemia (ALL) (n = 1 patient); or late chronic phase, accelerated, or blastic phase chronic myelogenous leukemia (n = 9 patients) were eligible for the study. The treatment plan was comprised of busulfan, 12 mg/kg orally; cyclophosphamide, 100 mg/kg (n = 4 patients) or 120 mg/kg (n = 19 patients); and decitabine, intravenously at 3 dose levels: 400 mg/m(2) (n = 10 patients), 600 mg/m(2) (n = 8 patients), and 800 mg/m(2) (n = 5 patients). Donors were human leukocyte antigen-identical siblings in all cases, and all but one patient received peripheral blood stem cells. Graft-versus-host disease (GVHD) prophylaxis was tacrolimus based in all but one patient. RESULTS: The median time to neutrophil and platelet engraftment was 12.5 days and 17.5 days, respectively. Twenty-one patients were engrafted and achieved disease remission. At a median of 3.3 years posttransplantation, 26% of patients (40% of patients with AML) were alive and disease free. The median survival for the group was 17.2 months, and the disease free survival for the group was 8.9 months. Causes of death were disease recurrence (nine patients), chronic GVHD (four patients), infections (three patients), and acute GVHD (one patient). The 100-day mortality rate was 9%. No decitabine dose-limiting toxicity was documented. The treatment-related mortality rate at 3 years was 35%. Responders were treated at all three decitabine dose levels, and no dose-response correlation was observed. CONCLUSIONS: There was a high response rate with low treatment-related mortality, with 26% of patients alive in remission 3.3 years after transplantation.     

High-dose sequential chemotherapy and peripheral blood progenitor cell autografting in patients with refractory and/or recurrent Hodgkin lymphoma: a multicenter study of the intergruppo Italiano Linfomi showing prolonged disease free survival in patients treated at first recurrence

BACKGROUND: The objective of the current study was to evaluate in a multicenter setting the feasibility and efficacy of a high-dose sequential (HDS) chemotherapy regimen that combined intensive debulking and high-dose therapy (HDT) with peripheral blood progenitor cell (PBPC) autografting in patients with refractory or recurrent Hodgkin lymphoma (HL). METHODS: Data were collected from 102 patients with HL who were treated with the HDS regimen at 14 centers associated with the Intergruppo Italiano Linfomi. Twenty-four patients had primary refractory HL, 59 patients had their first recurrence of HL (within 1 year in 32 patients and > 1 year in 27 patients), and 19 patients had multiple disease recurrences. The HDS regimen included the sequential delivery of high-dose (hd) cyclophosphamide with PBPC harvesting, methotrexate, etoposide, then HDT (usually hd mitoxantrone plus L-phenylalanine mustard) with PBPC autografting. In addition, radiotherapy was delivered to 36 patients at sites of bulky or persistent disease. RESULTS: Ninety-two patients (90%) completed the HDS program. There were five toxic deaths (treatment-related mortality rate, 4.9%) and six secondary malignan cies (five patients developed myelodysplastic syndrome/acute myelogenous leukemia, and one patient developed colorectal carcinoma). At a median follow-up of 5 years, the 5-year overall survival (OS) and event-free survival (EFS) projections were 64% (95% confidence interval [95% CI], 54-74%) and 53% (95% CI, 43-63%), respectively. Patients with their first recurrence had the most favorable outcome, with 5-year OS and EFS projections of 77% (95% CI, 66-88%) and 63% (95% CI, 50-76%), respectively. There were no significant differences between patients with early first recurrence and late first recurrence. The poorest outcome was observed in patients with refractory HL, with 5-year OS and EFS projections of 36% (95% CI, 16-55%) and 33% (95% CI, 14-52%), respectively. Patients who received HDS chemotherapy after multiple recurrences had an intermediate outcome. Multivariate analysis showed that refractory disease and systemic symptoms at the time of initial presentation were associated significantly associated with poor OS and EFS. CONCLUSIONS: The use of HDS chemotherapy for patients with refractory and/or recurrent HL is feasible at the multicenter level. The combination of intensive debulking and HDT with PBPC autografting offers a good chance of prolonged disease free survival for patients with their first recurrence of HL.     

A novel atypical retinoid endowed with proapoptotic and antitumor activity

The novel atypical retinoid E-3-(4'-hydroxy-3'-adamantylbiphenyl-4-yl)acrylic acid (ST1926, 4) exhibited a potent antiproliferative activity on a large panel of human tumor cells. Despite almost complete loss of ability to activate RARs, the compound was an effective apoptosis inducer and surprisingly produced DNA damage, that likely contributes to the proapoptotic activity. Following oral administration, 4 was well tolerated and caused tumor growth inhibition in the ovarian carcinoma, A2780/DX, and in the human melanoma, MeWo, growing in nude mice, thus supporting the therapeutic interest of the novel agent.     

Antibacterial evaluation of cnicin and some natural and semisynthetic analogues

Some ester derivatives of salonitenolide have been prepared from cnicin, a germacranolide sesquiterpenoid. The compounds were tested for their antibacterial activity. The 8,15-diesters showed a good activity, comparable with that of cnicin. The 15-monoester compounds were not very active showing that esterification at the C-8 position is an important structural feature for antibacterial properties.     

Comparing the efficacy and safety of fixed versus weight-based dosing of epoetin alpha in anemic cancer patients receiving platinum-based chemotherapy

Fixed dosing is potentially more convenient than weight-based dosing for both patients and physicians. Therefore, this open-label, randomized (1:1), multicenter study was conducted to compare the effectiveness, safety, and quality-of-life benefits of fixed vs. weight-based dosing of epoetin alpha in anemic cancer patients undergoing chemotherapy. Five hundred forty-six anemic patients undergoing platinum-based chemotherapy for solid malignancies were enrolled. Patients received epoetin alpha, either a fixed dose of 10,000 IU or a weight-based dose of 150 IU/kg, administered subcutaneously 3 times weekly for up to 12 weeks. Endpoints were transfusion requirements over days 29-84, change in hemoglobin (Hb) level from baseline, and change in quality-of-life (QOL) scores from baseline as measured using the Cancer Linear Analog Scale (CLAS). Five hundred and thirty-two patients received at least 1 dose of epoetin alpha, and 510 of these (255 in each treatment group) were considered evaluable for efficacy. At day 84, rates for freedom from transfusion were similar between the fixed-dose and the weight-based dose group (84% vs. 87%, respectively, p=0.32), as calculated by the lifetable method. These rates were also similar between patients in the 45-63 kg weight group receiving the fixed 10,000 IU dose or 7,000-9,000 IU on a per-weight basis (83% vs. 87%, respectively), and those in the 70-100 kg weight group receiving the fixed 10,000 IU dose or 11,000-15,000 IU on a per-weight basis (85% vs. 83%, respectively). Mean Hb increases from baseline to last observation were 2.10 g/dl [95% confidence intervals (CI95) 1.85-2.35] in the 10,000 IU group (from 9.64-11.74 g/dl) and 2.06 g/dl (CI95 1.82-2.30) in the 150 IU/kg group (from 9.70-11.76 g/dl). QOL results were similar for both groups and cumulative data have been reported. For 275 patients (in both groups combined) with CLAS QOL scores both at baseline and 29-98 days thereafter, the QOL index (average of scores for the 3 QOL parameters: energy level, ability to do daily activities and overall QOL) increased by 10.4 mm (CI95 7.5-13.2), from 46.2 mm at baseline to 56.6 mm at the final observation. QOL improvements were directly associated with Hb increases (p<0.001, multiple linear regression analysis) within all chemotherapy response classes. Epoetin alpha was well tolerated in both groups. Fixed (10,000 IU) and weight-based (150 IU/kg) dosing regimens of epoetin alpha demonstrated similar efficacy in maintaining freedom from transfusion, increasing Hb levels, and improving QOL in anemic cancer patients undergoing platinum-based chemotherapy. QOL improvements were directly associated with Hb increases. These findings support the use of a fixed-dose regimen of epoetin alpha, which may offer greater convenience for physicians and patients than weight-based dosing with this agent.     

La asociación entre metaplasia intestinal de la unión esofagogástrica y enfermedad for reflujo gastroesofágico en el Instituto Nacional de Cancerología

Introduction

Intestinal metaplasia in the oesophagus-gastric junction can originate in the distal oesophagus causing oesophagus-gastric reflux, or in the proximal portion of the stomach. This pre-malignant lesion can progress to cancer.

Objective

To determine the frequency of intestinal metaplasia of the oesophagus-gastric junction in patients with clinical gastric-oesophageal reflux and to evaluate the relationship with the chronic gastritis andHelicobacter pylori infection.

Material and Methods

Between March 2000 and June 2001, all patients who were referred to the Service of Endoscopy, without a diagnosis of cancer of the digestive tract and who, according to the Carlsson-Dent questionnaire, were classified as having oesophageal-gastric reflux were included in the study. Conventional endoscopy was performed and biopsies were obtained from the oesophagus-gastric junction. The pathologist who evaluated the samples was blinded with respect to the clinical details of the patients.

Results

The patients (n=51) included 20 men and 31 women, with a mean age of 53,7 years. The junction type was squamous-columnar in 30 patients and heterotopic “Z” type in 21. There were 17 patients with hiatus hernia and 12 with acute oesophagitis. Endoscopy indicated 6 patients with acute gastritis, 19 with chronic gastritis and 5 cases of Barrett's oesophagus. Histology indicated 3 patients with Barrett's oesophagus, 48 with chronic gastritis, 12 with cardial metaplasia and 34 withHelicobacter pylori infection.

Conclusions

Twelve (23.5%) patients presented intestinal metaplasia. In 66.6% there wasH. pylori infection and 48 patients (94.1%) had chronic gastritis. Endoscopically, the more frequent squamous-columnar junction was the heterotopic type in 58.8% with the type “Z” in 41.2% of patients.