Irofulven Induces Apoptosis in Breast Cancer Cells Regardless of Caspase-3 Status*

Caspase-3 deficiency can limit the efficiency of pro-apoptotic anticancer treatments. Irofulven (hydroxymethylacylfulvene, HMAF, MGI 114, NSC 683863) is an antitumor drug, currently in a Phase III and multiple Phase II trials, which can differentiate between tumor and normal cells in apoptosis induction. This study investigated whether apoptosis induced by irofulven requires caspase-3. Irofulven action was compared in breast cancer cells differing in caspase-3 status: deficient MCF-7 cells and proficient MDA-MB-231 cells and in normal human mammary epithelial cells, HMEC. Irofulven induces significant, concentration and time-dependent apoptotic DNA fragmentation in breast cancer cell lines, regardless of caspase-3 status. After 12, 24 and 48h incubation at 1M irofulven ( 3×GI₅₀), fragmented DNA comprised 3.7, 14.1 and 34.6% and 8.4, 12.6 and 20.3% of total DNA in MCF-7 and MDA-MB-231 cells, respectively. Cell viability (trypan blue exclusion) remained largely unaffected during the first 24h but decreased markedly after 48h, indicating secondary necrosis. Net losses in cell numbers were apparent at 48h. Normal HMEC cells were refractory to 1M drug with only 3–9% fragmented DNA after 12–48h, although apoptosis was observed at drug levels >3M. The broad-spectrum caspase inhibitor Z-VAD-fmk inhibited irofulven-induced apoptosis of all cell lines at 20M with nearly complete abrogation of apoptosis at 100M. Irofulven treatment resulted in marginal caspase-3 processing in MDA-MB-231 and HMEC cells. These results indicate that whereas the caspase cascade mediates irofulven- induced apoptosis, caspase-3 is dispensable (supported by NIH CA70091 and CA78706).     

New approach to metabolism of 5′-deoxy-5-fluorouridine in humans with fluorine-19 NMR

Summary The metabolism of 5-deoxy-5-fluorouridine (5dFUrd), an antitumor fluoropyrimidine, has been investigated in human biofluids (blood, plasma, urine) using a new method: fluorine-19 NMR spectrometry. This method allows direct study of the biological sample and simultaneous identification of all the fluorinated metabolites. In the blood of a patient treated with 5dFUrd during a 6-h continuous perfusion, we observed unmetabolized 5dFUrd, 5-fluorouracil, 5,6-dihydrofluorouracil, and another metabolite which has not previously been reported -fluoro--alanine. The two major metabolites in urine are unmetabolized 5dFUrd and -fluoro-alanine.     

Coexpression of c-kit and stem cell factor in breast cancer results in enhanced sensitivity to members of the EGF family of growth factors

Insulinlike growth factor (IGF)I protects many cell types from apoptosis. As a result, it is possible that IGFIresponsive cancer cells may be resistant to apoptosisinducing chemotherapies. Therefore, we examined the effects of IGFI on paclitaxel and doxorubicininduced apoptosis in the IGFIresponsive breast cancer cell line MCF7. Both drugs caused DNA laddering in a dosedependent fashion, and IGFI reduced the formation of ladders. We next examined the effects of IGFI and estradiol on cell survival following drug treatment in monolayer culture. IGFI, but not estradiol, increased survival of MCF7 cells in the presence of either drug. Cell cycle progression and counting of trypanblue stained cells showed that IGFI was inducing proliferation in paclitaxeltreated but not doxorubicintreated cells. However, IGFI decreased the fraction of apoptotic cells in doxorubicin but not paclitaxeltreated cells. Recent work has shown that mitogenactivated protein kinase (MAPK) and phosphotidylinositol3 (PI3) kinase are activated by IGFI in these cells. PI3 kinase activation has been linked to antiapoptotic functions while MAPK activation is associated with proliferation. We found that IGFI rescue of doxorubicininduced apoptosis required PI3 kinase but not MAPK function, suggesting that IGFI inhibited apoptosis. In contrast, IGFI rescue of paclitaxelinduced apoptosis required both PI3 kinase and MAPK, suggesting that IGFImediated protection was due to enhancement of proliferation. Therefore, IGFI attenuated the response of breast cancer cells to doxorubicin and paclitaxel by at least two mechanisms: induction of proliferation and inhibition of apoptosis. Thus, inhibition of IGFI action could be a useful adjuvant to cytotoxic chemotherapy in breast cancer.     

Alcohol consumption and risk of breast cancer: a cohort study

Objectives: To study the association between alcohol consumption and breast cancer risk. Methods: A case–cohort analysis was undertaken within the cohort of 56,837 women who were enrolled in the Canadian National Breast Screening Study (NBSS) and who completed a self-administered dietary questionnaire. (The NBSS is a randomized controlled trial of screening for breast cancer in women aged 40–59 at recruitment.) The cohort was recruited between 1980 and 1985, and during follow-up to the end of 1993 a total of 1469 women in the dietary cohort were diagnosed with biopsy-confirmed incident breast cancer. For comparative purposes a subcohort consisting of a random sample of 5681 women was selected from the full dietary cohort. After exclusions for various reasons the analyses were based on 1336 cases and 5238 noncases. Results: When compared to nondrinkers the adjusted incidence rate ratios (95% confidence intervals) for those consuming>0 and 10g of alcohol/day, >10 and 20g/day, >20 and thinsp;30g/day, >30 and 40g/day, >40 and 50g/day, and >50g/day were 1.01 (0.84–1.22), 1.16 (0.91–1.47), 1.27 (0.91–1.78), 0.77 (0.51–1.16), 1.00 (0.57–1.75), and 1.70 (0.97–2.98), respectively; the associated p value for the test for trend was 0.351. Similar findings were obtained when analyses were conducted separately in the screened and control arms of the NBSS, in premenopausal and postmenopausal women, for screen-detected and interval-detected breast cancer, and by levels of other breast cancer risk factors. Conclusions: The results of this study suggest that alcohol consumption might be associated with increased risk of breast cancer at relatively high levels of intake.     

17β‐hydroxysteroid dehydrogenases in normal human mammary epithelial cells and breast tissue

17hydroxysteroid dehydrogenase activity represents a group of several isoenzymes (17HSDs) that catalyze the interconversion between highly active 17hydroxy and low activity 17ketosteroids and thereby regulate the biological activity of sex steroids. The present study was carried out to characterize the expression of 17HSD isoenzymes in human mammary epithelial cells and breast tissue. In normal breast tissues 17HSD types 1 and 2 mRNAs were both evenly expressed in glandular epithelium. In two human mammary epithelial cell lines, mRNAs for 17HSD types 1, 2 and 4 were detected. In enzyme activity measurements only oxidative 17HSD activity, corresponding to either type 2 or type 4 enzyme, was present. The role of 17HSD type 4 in estrogen metabolism was further investigated, using several cell lines originating from various tissues. No correlation between the presence of 17HSD type 4mRNA and 17HSD activity in different cultured cell lines was detected. Instead, oxidative 17HSD activity appeared in cell lines where 17HSD type 2 was expressed and reductive 17HSD activity was present in cells expressing 17HSD type 1. These data strongly suggest that in mammary epithelial cell lines the oxidative activity is due to type 2 17HSD and that oxidation of 17hydroxysteroids is not the primary activity of the 17HSD type 4 enzyme.     

Down-regulation of transforming growth factor-β and interleukin-10 secretion from malignant glioma cells by cytokines and anticancer drugs

The effect of treatment with interleukin-1 (IL-1), interferon- (IFN-), vincristine, and etoposide was evaluated on the secretion of transforming growth factor- (TGF-) and IL-10 and the expression of major histocompatibility complex (MHC) class I, intercellular adhesion molecule-1 (ICAM-1), and CD80 molecules by malignant glioma cells. Five malignant glioma cell lines were treated with IL-1, IFN-, and/or anticancer agents (vincristine and etoposide). Combined treatment with IL-1 and IFN- caused greater inhibition of TGF- secretion compared to treatment with IFN-, and almost the same levels of inhibition as treatment with vincristine and etoposide. The greatest inhibition of TGF- secretion was achieved by treatment with all agents. Low levels of IL-10 secretion were determined in two out of five malignant glioma cell lines. This IL-10 secretion was inhibited by treatment with IL-1, IFN-, vincristine, and/or etoposide. Treatment with both cytokines and anticancer agents increased the expression of MHC class I and ICAM-1 in all tumor cell lines. The mean increase of expression of MHC class I was 50% and that of ICAM-1 was 12-fold. No tumor cell lines expressed CD80 molecules on the cell surface, and no treatment caused CD80 expression. These results suggest that TGF- and IL-10 secretion by malignant glioma cells can be suppressed by treatment with a combination of IL-1, IFN-, vincristine, and etoposide, and the treatment up-regulates MHC class I and ICAM-1 expression on tumor cells. These results have implications for immunotherapy and chemotherapy in patients with malignant tumors.     

Transforming growth factor b as a potential tumor progression factor among hyperdiploid glioblastoma cultures: Evidence for the role of platelet-derived growth factor

Among early-passage, near-diploid gliomas in vitro, transforming growth factor type (TGF) has been previously shown to be an autocrine growth inhibitor. In contrast, hyperdiploid ( 57chromosomes/metaphase) glioblastoma multiforme (HD-GM) cultures were autocrinely stimulated by the TGF. The mechanism of this conversion from autocrine inhibitor to mitogen is not understood; previous studies have suggested that platelet-derived growth factor (PDGF) might be modulated by TGF. The similar expression of TGF types 1—3, PDGF-AA, — BB, as well as the PDGF receptor and subunits (a/PDGFR) between biopsies of the HD-GM and near-diploid, TGF-inhibited glioblastomas (GM) by immunohistochemistry did not explain the discrepancy in their regulatory responses. Flowcytometry demonstrated that TGF's mitogenic effect was selective for the aneuploid subpopulations of two of three selected HD-GM cultures,while the diploid cells were inhibited. Among the HD-GM, TGF1 induced the RNA of PDGF-A, c-sis and TGF1. The amount of PDGF-AA secreted following TGF treatment was sufficient to stimulate the proliferation of a HD-GM culture. Antibodies against PDGF-AA, -BB, -AB,PDGFR and/or PDGFR subunits effectively neutralized TGF's induction of DNA synthesis among the HD-GM cell lines, indicating that PDGF served as the principal mediator of TGF's growth stimulatory effect. By comparison, TGF induced only the RNA of PDGF-A and TGF1 among the near-diploid GM; c-sis was not expressed at all. However, the amount of PDGF-A which was secreted in response to TGF1 was insufficient to prevent TGF's arrest of the near-diploid cultures in G₁ phase. Thus, the emergence of hyperdiploidy was associated with qualitative and quantitative differences in TGF's modulation of PDGF-A and c-sis, which provided a mechanism by which the aneuploid glioma cellsmight achieve clonal dominance. We hypothesize that TGF may serve as an autocrine promoter of GM progression by providing a selective advantage to the hyperdiploid subpopulation through the loss of a tumor suppressor gene which mediates TGF's inhibitory effect.     

Glycogen‐rich carcinomas of the breast display unique characteristics with respect to proliferation and the frequency of oligonucleosomal fragments

We determined the proliferation rate and apoptotic activity of glycogenrich carcinomas of the breast as opposed to nonclear cell tumors by means of MIB1 immunohistochemistry and in situ detection of oligonucleosomal fragments (TUNEL reaction). The retrospective biopsy series included six invasive clear cell carcinomas of the glycogenrich type as well as 15 randomly selected cases of invasive ductal carcinoma without evidence of glycogen storage. Three patients in the clear cell group and seven patients in the control cohort developed lymphnode metastasis. The MIB1 labeling index of glycogenrich carcinomas averaged 9.05%, while that of the controls was 30.03%. Apoptotic nuclei were present in a mean of 1.26% of glycogenrich carcinoma cells. The control tumors exhibited an average apoptotic frequency of 5.85%. Tumor size, hormone receptor status, and presence or absence of lymph node involvement were found not to correlate with either proliferation or apoptosis. We conclude that glycogenrich breast carcinomas are characterized by a peculiar low proliferationlow apoptosis cell kinetic profile. The aggressive clinical behavior of these neoplasms may possibly be accounted for by an ineffective apoptotic elimination of otherwise slowly proliferating tumor cells.     

Quantification of thrombospondin-1 secretion and expression of αvβ3 and α3β1 integrins and syndecan-1 as cell-surface receptors for thrombospondin-1 in malignant glioma cells

Malignant glioma cells secrete thrombospondin-1 (TSP-1) which participates in the motility of glioma cells, and binds to cell surface v3 and 31 integrins, and syndecan-1. This study evaluated the amount of TSP-1 secretion from malignant glioma cells, and the expression of v3 and 31 integrins, and syndecan-1. The amounts of TSP-1 in the supernatants from 10 malignant glioma cell lines and eight non-glioma malignant tumor cell lines were measured by enzyme-linked immunosorbent assay. Expression of v3 and 31 integrins, and syndecan-1 were examined by flow cytometry. The amounts of TSP-1 secreted by malignant glioma cells were 43 to 2431 ng/1 × 10⁶ cells/24 h (mean ± SD=626 ± 792). Seven of 10 glioma cell lines secreted more than 100 ng of TSP-1 and three of these cell lines secreted more than 1 g. Seven of eight non-glioma cell lines secreted less than 100 0ng of TSP-1. All glioma cell lines expressed 31 integrin and syndecan-1, and seven of 10 glioma cell lines expressed v3 integrin. Treatment of the glioma cell lines with TGF-2 did not change the expression of v3 integrin. These results suggest that malignant glioma cells secrete high levels of TSP-1, which may be important in the migration of glioma cells via interactions with v3 and 31 integrins, and syndecan-1.     

Prevention of rat mammary carcinoma utilizing leuprolide as an equivalent to oophorectomy

A clinical trial is currently under way to examine the effectiveness of leuprolide as a breast cancer chemopreventive agent and contraceptive. This trial, as well as similar proposed studies, is based on the assumption that leuprolide is as effective as surgical castration in preventing the onset of mammary tumors; however, this has not been well documented in the DMBA animal model. We directly compared leuprolide and oophorectomy in this model and examined a combined therapy of leuprolide/bromocriptine. Twenty-seven day old female Sprague-Dawley rats were randomly allocated into one of eight groups. All rats received a 20-mg dose of DMBA at the age of 55 days. Group 1 (n=10), no treatment; Group 2 (n=9), leuprolide (100g/kg/day) for eight weeks beginning four weeks prior to DMBA; Group 3 (n=10), oophorectomy four weeks prior to DMBA with replacement estrogen beginning four weeks following DMBA. Estrogen replacement was achieved with a 0.05-mg estradiol tablet releasing 0.833g/day over a 60-day period. Group 4 (n=10), leuprolide (100g/kg/day) initiated two weeks prior to DMBA and continuing for two weeks following DMBA; Group 5 (n=9), oophorectomy two weeks prior to DMBA with 0.05mg of estradiol in depot form, releasing 0.833g/day, beginning four weeks following DMBA and continuing until week 16 of the study; Group 6 (n=10), leuprolide (100g/kg/day) beginning two weeks prior to DMBA and continuing for the duration of the experiment; Group 7 (n=10), leuprolide (100g/kg/day) for eight weeks beginning two weeks prior to DMBA; Group 8 (n=9), leuprolide (100g/kg/day) and bromocriptine (83g/day) for eight weeks beginning two weeks prior to DMBA. At nineteen weeks (15 weeks post DMBA), animals were sacrificed and autopsies performed. One hundred percent of untreated animals developed tumors. No animals undergoing oophorectomy four weeks prior to DMBA or receiving leuprolide four weeks prior to and simultaneously with DMBA developed tumors. In animals pretreated two weeks prior to DMBA with leuprolide or oophorectomy, each group had one animal with tumor development. No tumors developed in the animals receiving ongoing injections of leuprolide. However, one tumor developed in those receiving leuprolide for the first eight weeks beginning two weeks prior to DMBA administration. One animal receiving both leuprolide and bromocriptine developed one tumor. We conclude that chemical oophorectomy (with leuprolide) is as effective as surgical oophorectomy in inhibiting DMBA induced carcinogenesis.     

Involvement of breast epithelial-stromal interactions in the regulation of protein tyrosine phosphatase-γ (PTPγ) mRNA expression by estrogenically active agents

Background. Protein tyrosine phosphatase (PTP) has been implicated as a tumor suppressor gene in kidney and lung cancers. Our previous results indicate that estradiol-17 (E₂)-induced suppression of PTP may play a role in mammary tumorigenesis. Zeranol (Z), a nonsteroidal growth promoter with estrogenic activity that is used by the US meat industry, induces estrogenic responses in primary cultured breast cells and breast cancer cell lines. Methods. PTP mRNA expression in human breast tissues and cells isolated from surgical specimens of mammoplasty and breast cancer patients were detected and quantified by RT-PCR. Immunohistochemical staining was used to localize PTP in human breast tissues. Breast epithelial and stromal cells were isolated and co-cultured to determine the involvement of cell–cell interaction in the regulation of PTP mRNA expression by E₂ and Z. Results. PTP mRNA expression was lower in cancerous than in normal breast tissues. Both E₂ and Z suppressed PTP mRNA levels in cultured normal breast tissues by 80%, but had a lesser effect in cultured epithelial cells isolated from normal breast tissues. In the co-culture system, both E₂ and Z suppressed PTP mRNA to a greater degree in epithelial cells than in stromal cells. In whole breast tissues, PTP was immunolocalized to the epithelium. Treatment with E₂ or Z diminished PTP staining indicating reductions in PTP at the protein level. Conclusions. The results indicate that both E₂ and Z regulate PTP expression in human breast and that epithelial–stromal cells interaction is important in the regulation of PTP expression by estrogenically active agents.     

Biomarkers for local recurrence after breast‐conservation — a nested case‐control study

Purpose: A previous cohort study of 759 women with invasive T1T2 breast cancer operated on with breastconserving surgery in Stockholm between 1976 and 1986 indicated that age <50 years, no postoperative irradiation, and nodal involvement were independent risk factors for ipsilateral breast tumor recurrences (IBTR). The aim of the current study was to analyse if selected biological markers assayed in tumor specimens from these patients could add prognostic information, thereby helping to identify groups of patients at high versus low risk of IBTR.Methods: The study was designed as a casecontrol study nested within the cohort. The cohort was stratified according to nodal status and the use of postoperative irradiation. In these four strata, the cases were those 80 women who developed IBTR between 1977 and 1994. In each stratum, women without IBTR were randomly selected as controls (n=159). Median time at risk was 12 (8–18) years. The following factors were analysed: histopathological tumor grade according to Elston–Ellis, DNA ploidy, immunohistochemical staining for apoptosis, angiogenesis, Ki67 (MIB1), cerbB2, p53, waf1, and bcl2. The prognostic role of each factor was assessed using linear logistic regression methods.Results: In univariate analyses only age <50 years was identified as a significant risk factor for IBTR, whereas none of the studied biomarkers yielded statistically significant information. However, in a multivariate model, age, MIB-1-index, and tumor grade significantly influenced the risk for IBTR: the odds-ratio (OR) for age 50 years was 0.4, 95% confidence interval (CI)=0.2–0.9; for medium or high grade tumors it was 0.4 (CI=09–0.9); and for MIB-1-index >30%, 2.1 (CI=1.0–4.4). In women 50 years, MIB-1-index >30% was associated with an OR of 3.5 (CI=1.4–8.8) compared to those who were younger. Patients 50 years with MIB-1-index 30% were thus identified as a low-risk group with an OR of 0.2 (CI=0.1–0.5). A possible high-risk group was patients <50 years with tumors showing a combination of c-erbB-2 and waf-1 immunoreactivity, with an OR of 6.7 (CI=1.3–34.7).Conclusion: Women 50 years with MIB-1-index 30% constituted a subgroup with a low risk of IBTR. This observation raises the issue whether this group of patients might be spared postoperative irradiation following breast-conserving surgery. However, due to the methodology of the study, including the large number of comparisions, the presented results warrant cautious interpretation and should be regarded as tentative.     

Self-Reported Dietary Habits, Overall Dietary Quality and Symptomatology of Breast Cancer Survivors: a Cross-Sectional Examination

Little information is available about the relationship between quality of life of women who have survived breast cancer (specifically, symptoms including those of menopause and depression) and the quality of their diet. In this cross-sectional study, 117 women with known primary breast cancer completed a self-administered food frequency questionnaire (FFQ) reflecting usual diet during the past year, a Survey of Feelings and Attitudes using the Center for Epidemiologic Studies Depression scale (CES-D) and a survey that includes menopausal symptoms among others common to women with a history of breast cancer. When women's responses to the FFQ were scored using the Healthy Eating Index (HEI), most often diets were evaluated as those that need improvement with a mean total HEI score of 67.2. With regard to the CES-D scores, study women averaged 9.5, with 19 women being classified as clinically depressed. HEI and CES-D scores were inversely related (=–0.22, p=0.02). A negative correlation was also observed between energy-adjusted calcium intakes and CES-D scores (=–0.19, p=0.04). Clinical depressed women had not only lower HEI scores and calcium intakes, but also lower grain and variety scores. Comparisons to national data for disease-free women and that available for those with breast cancer suggest that our study women consumed diets low in energy and dietary variety. Diet quality may be an important factor influencing the manifestation of depressive symptoms in breast cancer survivors or conversely, poorer diet quality may be an outcome of depression.     

Low body mass index is an independent predictive factor of local recurrence after conservative treatment for breast cancer

Background. Obesity or increased body mass index (BMI) has been shown to have two important adverse effects related to breast cancer. First, several studies have identified an association between increased BMI and advanced stage breast cancer. Second, increased BMI has been shown to be associated with poorer prognosis. In a previous report, we had identified low BMI as a risk factor for local reccurence at five years. The objectives of this study were to evaluate the relationship between BMI and local control and to confirm this prognostic factor in a larger population with an important follow-up. Materials and methods. Between 1976 and 1988, 605 women with invasive breast carcinoma less than 4cm in diameter underwent conservative surgery with axillary dissection and radiation therapy. The median follow-up time was 82 months. The risk of local recurrence and distant metastasis was evaluated by univariate retrospective analysis using Kaplan–Meier method for the main clinical and histologic factors. Those found to be significant were entered in a Cox model for multivariate analysis. Results. Since the beginning of the study, 80 patients had developed local recurrence. The 5 years and 10 years local control rates were 91% and 83%, respectively. Four parameters were independent predictive factors of local recurrence: Age lower than 40 years (HR=2.42 95% CI=[1.35–4.34]), BMI: elevation of one unit reducing the local recurrence of 0.92 95%CI=[0.85–0.99], multifocality of the tumor on pathological examination (HR=2.12 95% CI=[1.16–3.88]) and positive axillary nodes HR=0.54 95% CI=[0.31–0.95]. Size of the breast was not a predictive factor for local cancer recurrence. Low BMI did not increase risk of distant. Conclusion. Our study offers new data concerning the possibility that thinness may be related to local recurrence of breast cancer.     

Cytokine‐regulated urokinase‐type‐plasminogen‐activator (uPA) production by human breast fibroblasts in vitro

It has been shown that, in breast stroma, urokinasetype plasminogen activator (uPA) mRNA is predominantly expressed by myofibroblasts located at the invasive areas of the tumor. To examine which factors present in a tumor environment are candidates responsible for the induction of these uPAproducing myofibroblasts, we studied in vitro the capacity of a paired panel of normal and tumorderived human breast fibroblasts to produce uPA protein and the myofibroblast marker smoothmuscleactin (SMA) in response to various cytokines implicated in the process of tissueremodeling during malignant transformation.We found that fibroblasts produced increased amounts of uPA protein after exposure to aFGF, bFGF, EGF, PDGFBB, and IFN, were unaffected in this respect by IL6, MCSF, GMCSF and Oncostatin M, and produced decreased amounts of uPA protein after exposure to IL1, TNF, IGFI, and IGFII. None of these cytokines were able to induce a striking increase in the fraction of SMApositive fibroblasts. On the other hand, 25pM TGF₁ increased the fraction of SMApositive fibroblasts 5fold in both normal and tumortissuederived fibroblasts. Nonetheless, the normalderived fibroblasts were unaffected in their uPAproducing capacity by TGF₁, and the tumorderived fibroblasts produced decreased amounts of uPA protein after exposure to this cytokine, implying that at least in vitro the myofibroblast phenotype is not a prerequisite for the production of uPA by human breast fibroblasts. In addition, we established that the basaluPAproduction of both normal and tumorderived fibroblasts was increased by autocrinely produced bFGFlike activity, and that the basaluPAproduction of at least the normalderived fibroblasts was decreased by autocrinely produced IGFlike activity.Altogether, our data suggest an active role for fibroblasts in the process of uPAdirected breast tumor proteolysis.     

Phase II of doxorubicin/taxol in metastatic breast cancer

Purpose. To assess the response rate, survival, and toxicity of Taxol®(paclitaxel) as 1h infusion plus doxorubicin as firstline treatment for patients with metastatic breast cancer (MBC).Patients and methods. Seventysix patients with untreated MBC were recruited. All of them had measurable disease and were evaluable for toxicity. Fiftyfive percent of the patients had visceral involvement. The dose of doxorubicin was fixed at 50mg/m² as a short intravenous infusion, followed by 200mg/m² of Taxol as a 1h intravenous infusion. Doxorubicin was administered during the first seven cycles, continuing with Taxol only up to a maximum of ten cycles.Results. Neutropenia was the most important toxicity: 30% grade 3 and 18% grade 4. Only 2 patients showed a decrease in the left ventricular ejection fraction (LVEF) which caused discontinuing the treatment. No clinical congestive heart failure (CHF) was observed. Seventyfour patients were eligible for response evaluation: 10 (14%) achieved complete response (CR) and 46 (62%) achieved partial response (PR). The mean duration of response was 13.47± 1.35 months (95% confidence interval (CI): 10.82; 16.12) and the mean survival was 21.50± 1.42 months (95% CI: 18.72; 24.29).Conclusion. The overall response (OR) rate was 76%. No CHF was assessed and 2 patients stopped treatment due to LVEF decrease. Although doxorubicin 50mg/m² followed by Taxol 200mg/m² in 1h intravenous infusion presents a toxicity profile which demands a close followup, it represents a convenient outpatient schedule with similar activity rate compared to longer Taxol infusions.     

Phenotypic analysis of 1-B-d-arabinofuranosylcytosine deamination in patients treated with high doses and correlation with response

Summary Two phenotypes for 1-B-d-arabinofuranosylcytosine (ara-C) deamination corresponding to a ratio of distribution for slow (ratio, 14) vs fast (ratio, >14) deaminators of 70%30%, have been determined on the basis of studies on plasma ratios of 1-B-d-arabinofuranosyluracil/ara-C (ara-U/ara-C) in 56 subjects treated with high-dose ara-C (3 g/m² infused i.v. over 3 h). A positive correlation of age with the concentration of ara-U was observed. In a subgroup of 36 patients with leukemia, the ara-U/ara-C pattern was similar to that observed for all 56 subjects. In these leukemic patients, who were treated with combinations of ara-C plus other conventional agents, a tendency toward a positive response (complete response +partial response) was found for those showing low ara-U/ara-C ratios (slow deaminators). The phenotypic effect of deamination in acute leukemia needs to be evaluated prospectively.This work was supported by the Don Monti Memorial Research Foundation     

Overexpression of the p73 gene is a novel finding in high-risk B-cell chronic lymphocytic leukemia

The p73 protein shares structural and functional similarities with thetumour-suppressor p53, but its role in neoplastic transformation is unknown.Alternative splicing leads to the expression of at least nine p73 C-terminalmRNA splice variants (, , , , , , ,1, ). In this survey, we analyse the expression of p73 byreal-time quantitative RT–PCR, its known C-terminal variants with anRT–PCR-Southern technique and by Western blot in samples of 51 patientswith B-CLL, normal B lymphocytes from eight individuals, and fivehaematopoetic cell lines. p73 protein expression positively correlatedwith higher risk B-CLL stages (P = 0.046). Total p73 mRNAexpression was higher (P = 0.01) and p73 protein morefrequently detected (P = 0.008) in B-CLL compared with normalCD19+–B-lymphocytes. p73 C-terminal mRNA variants were expressed bothin B-CLL and in normal B-lymphocytes, but their expression was biased sincethe (P = 0.041), the (P <0.001), and the variant (P = 0.033) prevailed in normalB-lymphocytes. In summary, we conclude that the accumulation of p73, theexpression pattern of particular p73 variants and its link to progression mayplay a distinct role in the molecular pathology B-CLL.     

Increased risk of second cancers following breast cancer: Role of the initial treatment

Objectives and methods.The risk of second primary malignancies (SMN) was studied in a cohort of 4,416 one-year survivors of a breast cancer. The role of the menopausal status and of the initial treatment modalities (surgery, radiotherapy, and chemotherapy) was investigated. Results.Excluding second primary breast cancer and non-melanoma skin cancer, a total of 193 (4.4%) patients developed a SMN between 1973 and 1992, compared with 136 expected (Standardised Incidence Ratio, SIR=1.4, 95% CI (1.2–1.6)). No trend towards either an increase or a decrease was noted in the SIR with time after treatment (p=0.2). The greatest increase in the relative risk concerned soft tissue cancers (SIR=13.0, 95% CI: 6.8–22.3), followed by leukaemia (SIR=3.1, 95% CI: 1.7–5.0), melanoma (SIR = 2.7, 95% CI: 1.4–4.8), kidney (SIR=2.5, 95% CI: 1.2–4.5), ovary (SIR=2.0, 95% CI: 1.2–3.1) and uterine tumours (SIR=1.9, 95% CI: 1.4–2.5). The SIR was 3.0 (95% CI 1.8–4.7) in women under 40 at the time of the breast cancer, 1.9 (95% CI : 1.4 – 2.4) in those aged 40–49 and 1.2 (95% CI 1.0–1.4) in those aged 50 or more. In the 2,514 women who had received radiotherapy as initial treatment without chemotherapy, the SIR for all SMN was 1.6 (95% CI: 1.1–2.3) fold higher than in those who had not received radiotherapy as initial treatment. Conclusion.In conclusion, this study confirms the increased risk of second malignancies in women treated for a breast cancer, and particularly in those who were younger at the time of treatment for breast cancer. Our results also suggest that radiotherapy may play a role in the onset of these second lesions.     

Histamine H1 Receptor Activation Stimulates Mitogenesis in Human Astrocytoma U373 MG Cells

In human astrocytoma U373 MG cells that express histamine H₁ receptors (180 ± 6fmol/mg protein) but not H₂ or H₃ receptors, histamine stimulated mitogenesis as assessed by [³H]-thymidine incorporation (173 ± 2% of basal; EC₅₀, 2.5 ± 0.4M). The effect of 100M histamine was fully blocked by the selective H₁ antagonist mepyramine (1M) and was markedly reduced (93 ± 4% inhibition) by the phospholipase C inhibitor U73122 (10M).The activator of protein kinase C (PKC) phorbol 12-tetradecanoyl-13-acetate (TPA, 100nM) stimulated [³H]-thymidine incorporation (270 ± 8% of basal), and this response was not additive with that to 100M histamine. The incorporation of [³H]-thymidine induced by 100M histamine was partially reduced by the PKC inhibitor Ro 31-8220 (57 ± 7% inhibition at 300nM) and by the compound PD 098,059 (30M, 62 ± 14% inhibition), an inhibitor of the mitogen-activated kinase (MAPK) kinases MEK1/MEK2.These results show that histamine H₁receptor activation stimulates the proliferation of human astrocytoma U373 MG cells. The action of histamine appears to be partially mediated by PKC stimulation and MAPK activation.