Toxicity and clinical tolerance of lonidamine.

The new anticancer agent lonidamine has been recently revisited for the treatment of various solid tumors, due to its peculiar and unusual mechanism of action (ie, interference with energy metabolism of tumor cells, morphologically displayed by the appearance of "condensed mitochondria"). First generation trials have in fact demonstrated therapeutic activity and an unusual toxicity profile. Lonidamine is devoid of conventional side effects induced by antiproliferative agents (ie, myelosuppression, stomatitis, cystitis, alopecia, renal, hepatic, and cardiac toxicity). No serious or life-threatening adverse reactions have been recorded even over long term treatment periods. Given as a single agent (in daily doses ranging between 300 and 900 mg) lonidamine induces the following side effects: myalgia, testicular pain, asthenia, ototoxicity, nausea and vomiting, gastric pain, and drowsiness. Hyperesthesia and photophobia have also been reported. In combination with radiotherapy (in oral daily doses ranging between 300 and 450 mg) lonidamine was well tolerated, without any reported evidence of additional toxicity. When associated with cytotoxic agents no enhanced toxicity was observed. In particular, myelosuppression and other conventional nonhematological adverse reactions were never greater than would be expected with chemotherapy alone. The same applies to toxicity and tolerance of lonidamine when used concurrently with hypertermia. The data collected from large series of cancer patients treated with this new agent show that lonidamine is a safe drug whether used alone or in combination with other effective anticancer treatments. The reported therapeutic efficacy and the peculiar toxic profile make lonidamine an interesting new drug for future clinical trials.

Hematopoietic stem cells from different sources: biological and technical aspects.

Hematopoietic stem cell (HSC) enumeration is crucial to predict the engraftment potential of a given HSC collection, and currently involves the surrogate count of nucleated cells, CFU or CD34+ cells. However, there is raising evidence that CFU are HSC involved in short-term but not in long-term reconstitution, and that only a small fraction of all CD34+ cells have long term multilineage engraftment potential. In this regard, there is evidence that cord blood (CB), bone marrow (BM) and peripheral blood (PB) derived HSC are highly heterogeneous for a number of antigens useful for HSC enumeration by flow cytometry. Moreover, there is a raising evidence that a CD34 human HSC might exist. The CD34 HSC has been already described in animals and in human Hoechst 33342 negative HSC. This notwithstanding, clinical data have clearly demonstrated that purified allogeneic CD34+ cells can reconstitute the myeloid and the lymphoid lineages in myeloablated recipients. In the lack of a suitable marker for CD34 HSC enumeration, it is hard to predict the role of CD34 HSC in hematopoietic reconstitution after transplantation. On the other hand, these cells might be a better target for HSC expansion and gene transfer.

Control of stem cell proliferation and differentiation to achieve stable gene transfer and expression.

Although the hematopoietic stem cell (HSC) seems to be a convenient target for gene therapy, data from human clinical trials have so far shown low levels of gene transduction. The new model of human stem cells, immunodeficient mice repopulating cells (SRC), has similarly demonstrated that SRC were rarely transduced by protocols used in past studies. Cytokines such as stem cell factor and interleukin-3, used so far to obtain cell proliferation in transduction protocols, might induce HSC to differentiate and impair their repopulating potential. In this scenario, there is a need for new gene transfer protocols associated with minimal cell differentiation and stable expression of the transduced gene in the majority of mature cells generated from transduced HSC.

Stem cell enumeration in cord blood vs bone marrow and peripheral blood.

Recent reports have suggested that the total number of autologous or allogeneic hematopoietic stem cell (HSC) infused after high-dose chemotherapy might predict survival, post-transplant morbidity and rate of hematopoietic engraftment. However, HSC capable of long-term multilineage potential are still poorly defined, and tools for accurate and reproducible HSC enumeration are highly warranted.

A new 'two step' procedure for 4.5 log depletion of T and B cells in allogeneic transplantation and of neoplastic cells in autologous transplantation.

To evaluate a new 'two step' method for purging T, B and neoplastic cells from hematopoietic progenitor cells (PC), PCs were collected by apheresis and some suspensions were deliberately contaminated with 2-5% breast cancer cells. PCs were first processed through CellPro columns for positive selection of cells that express CD34. After this first step, the mean CD34+ cell recovery was 68 +/- 12%, and CD34+ cell purity was 61 +/- 11%; CD3+ and neoplastic cell depletion were 2.1 +/- 0.4 and 1.9 +/0 0.4 logs, respectively. Cells were further processed through the StemSep device for direct depletion of T and B cells or of breast cancer cells. After the first and the second step, overall CD34+ cell recovery was 50 +/- 7%, T and B cell removal was 4.7 +/- 0.4 log and neoplastic cell purging was 4.4 +/- 0.3 log, ie significantly superior to methods described in the past.

Use of recombinant human erythropoietin after bone marrow transplantation in pediatric patients with acute leukemia: effect on erythroid repopulation in autologous versus allogeneic transplants.

We carried out a pilot study on the use of recombinant human erythropoietin (rHuEPO) in children undergoing allogeneic or mafosfamide-purged autologous BMT for ALL or AML. rHuEPO was administered intravenously at a dose of 75 U/kg/day for 30 days after transplant. Ten rHuEPO-treated patients receiving allogeneic BMT and 10 given autologous BMT were compared with 15 allogeneic and 10 autologous historical controls. Endogenous EPO production was appropriate for the degree of anemia after autologous BMT. In these patients, rHuEPO did not accelerate erythroid repopulation and did not modify transfusion requirements. With allogeneic BMT, erythroid marrow activity increased faster in patients given rHuEPO than in controls and resulted in higher red cell production, the mean reticulocyte count on day +30 being 187 +/- 51 x 10(9)/l in treated patients versus 107 +/- 63 x 10(9)/l in controls (p < 0.01). The total number of RBC units administered was 1.7 +/- 1.3 in the rHuEPO group versus 5.1 +/- 3.0 in the control group (p < 0.001). The total number of platelet transfusions was 4.0 +/- 2.3 for patients given allogeneic BMT and receiving rHuEPO versus 8.4 +/- 6.8 for historical controls (p < 0.05) whereas it was similar in rHuEPO-treated and control autologous BMT patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of tumor cells contaminating the graft in breast cancer recurrence after high-dose chemotherapy.

One of the possible drawbacks to autologous stem cell transplantation in breast cancer (BC) patients is the potential for tumor contamination in the transplanted product. We present a patient with advanced disease who received high-dose chemotherapy (HDC) and PBPC support as consolidation therapy after achieving complete remission with standard-dose first-line treatment, and suffered recurrence of the disease 6 months after transplantation. Retrospective analysis revealed the presence of contaminating cells in the leukapheretic product, and clinical evidence suggested a role for these cells in the tumor relapse.

A new method for placental/cord blood processing in the collection bag. I. Analysis of factors involved in red blood cell removal.

We describe a new procedure for large-scale CB processing in the collection bag, thus minimizing the risk of CB contamination. A solution of 6% hydroxyethyl starch (HES) was added directly to the CB containing bag. After RBC sedimentation at 4 degrees C, the WBC-rich supernatant was collected in a satellite bag and centrifuged. After supernatant removal, the cell pellet was resuspended and the percent recovery of total WBC, CD34+ progenitor cells, CFU-GM and cobblestone area-forming cells (CAFC) evaluated. Results obtained with three different types of CB collection bags (300, 600 and 1000 ml) were analyzed and compared with those of an open system in 50 ml tubes. CB processing procedures in 300 and 1000 ml bags were associated with better WBC, CFU, CD34+ cell and CAFC recovery (83-93%). This novel CB processing procedure appears to be easy, effective and particularly suitable for large-scale banking under GMP conditions.

Epithelial tumour cell detection and the unsolved problems of nested RT-PCR: a new sensitive one step method without false positive results.

Sensitive detection of circulating epithelial cancer cells might have important therapeutic and prognostic implications in patients with breast cancer (BC) receiving high-dose chemotherapy and PBSC support. We have compared the specificity and sensitivity of the recently developed 'one tube' reverse transcriptase PCR (RT-PCR) assay with the more widely used nested RT-PCR method for detection of cytokeratin 19 (CK19)-positive cells. The analysis of 30 control samples provides evidence that one tube RT-PCR is highly specific in contrast to the nested method which showed 23% false positive results. The sensitivity of both techniques to detect tumour contamination was 10(-6). PBSC harvests from 45 BC patients were tested with both RT-PCR methods and the results were compared with immunocytochemistry (ICC). The five samples found positive by ICC were also positive by one tube RT-PCR; in addition, 11 more samples were positive by one tube RT-PCR analysis. The greater number of PBSC found positive by one tube RT-PCR might be due to the larger number of cells analysed. We conclude that one tube RT-PCR is sensitive and reveals no false positive results. This method is less time consuming than the nested one, technically simpler and should be considered for tumour cell detection.

Cytotoxic chemotherapy preceding apheresis of peripheral blood progenitor cells can affect the early reconstitution phase of naive T cells after autologous transplantation.

Transient T cell immunodeficiency is a common complication following hematopoietic stem cell transplantation. In breast cancer patients transplanted with autologous peripheral blood progenitor cells (PBPC) harvested after cytotoxic treatment with either cyclophosphamide or epirubicin plus paclitaxel, we evaluated T cells infused in grafts and in peripheral blood during the early reconstitution phase. We found that PBPC grafts harvested after treatment with epirubicin plus paclitaxel contained substantially larger numbers of T cells with less altered composition than after cyclophosphamide. Three months after high-dose cytotoxic chemotherapy, the numbers and the kinetics of circulating naive T cells, but not of memory and CD28- T cells, correlated positively with the number of naive T cells infused PBPC grafts. Finally, retrospective analysis of two cohorts of patients transplanted in different clinical settings with PBPC grafts harvested following cyclophosphamide or epirubicin plus paclitaxel showed apparently different susceptibilities to develop endogenous varicella zoster virus reactivation in the first year after high-dose cytotoxic chemotherapy. On the whole, these data indicate that number and composition of T cells in PBPC grafts vary according to the former cytotoxic therapy, and suggest that autologous transfer of T cells may accelerate the early T cell reconstitution phase and possibly ameliorate immune competence in patients rendered lymphopenic by high-dose chemotherapy.

Combined effects of estradiol, leuprorelin, tamoxifen and medroxyprogesterone acetate on cell growth and steroid hormone receptors in breast cancer cells.

Both tamoxifen and medroxyprogesterone acetate have a direct antitumor effect and are widely used in breast cancer therapy. Luteinizing-hormone-releasing hormone analogs inhibit the growth of breast cancer cells and could represent an alternative treatment for patients affected by breast cancer. Our study was carried out to investigate the effect of leuprorelin (TAP-144) alone or combined with tamoxifen or medroxyprogesterone acetate in human breast cancer cells. Ineffective when used in the absence of estrogens, TAP-144 inhibited the estrogen-stimulated growth of MCF-7, CG-5 and ZR-75-1 cells cultured in medium supplemented with charcoal-treated serum. The growth of estrogen-unresponsive MDA-MB-231 cells was not affected by TAP-144. The combination of TAP-144 with tamoxifen in CG-5 cells did not determine any enhancement of inhibition of cell growth, whereas in both CG-5 and MCF-7 cells, when 1 microM TAP-144 was associated with 0.1 microM medroxyprogesterone acetate, cell growth inhibition was increased, resulting in a subadditive effect. Progesterone receptor levels of CG-5 cells were significantly increased by TAP-144 in the presence of 17 beta-estradiol with respect to those present in control and 17 beta-estradiol-treated cells.

Antiproliferative effect of leuprorelin acetate, alone or combined with tamoxifen or medroxyprogesterone acetate, on human breast cancer cell lines.

We have investigated the antiproliferative action of leuprorelin acetate (TAP-144) on human breast cancer cells, cultured in medium supplemented with charcoal-treated fetal calf serum. The analogue had no effect on cell growth of oestrogen receptor-negative MDA-MB-231 cells. Although ineffective when used alone, TAP-144 inhibited in a dose-dependent fashion the oestradiol-induced cell growth in oestrogen receptor-positive and oestrogen-sensitive MCF-7, ZR-75-1 and CG-5 cells. TAP-144 did not modify the growth inhibitory activity of tamoxifen on CG-5 cells. A high concentration of TAP-144 (10(-6) M) seemed to increase the antioestrogenic effect of medroxyprogesterone acetate (MPA) (10(-7) M) in the same model. The data reported indicate that, in our culture conditions, TAP-144 has a direct antitumour effect on breast tumour cells. Our findings concerning the promotion of the antiproliferative effect of MPA merit further investigation.

Pharmacokinetic evaluation of two different formulations of megestrol acetate in patients with advanced malignancies.

The bioequivalence of two megestrol acetate formulations, 160-mg "tablets" and 160-mg "sachets," was investigated in a single-dose, open-label, balanced-for-sequence cross-over study involving 12 advanced-cancer patients. The observed plasma megestrol-acetate time course obtained with both formulations was consistent with the literature data. The main source of variability in the pharmacokinetic parameters was intersubject variability; drug formulation played only a minor (and nonsignificant) role. The width of the 90% confidence interval of the area-under-the-curve (AUC) ratio (sachets: tablets) computed according to Schuirmann (0.9-1.4) was mainly due to the presence of a single outlier, showing an AUC ratio of 2.7. The trend to higher bioavailability of the new formulation was not significant, especially as compared with the dose-response data reported in the literature.

Pharmacokinetic approach to the selection of dose schedules for medroxyprogesterone acetate in clinical oncology.

The pharmacokinetic and bioavailability properties of medroxyprogesterone acetate (MPA) after single PO and IM doses in man were used as a basis to predict, on a theoretical pharmacokinetic basis, the blood level profile of the drug during repeated dose administration with various dosage schedules. Because of the unusually long-lasting depot effect of IM MPA, a different build-up process of blood levels is expected during repeated IM or PO administration, and this should be taken into account when dose schedules for use in clinical oncology are selected. As regards the IM route, dose schedules based on 4 weeks' treatment with daily injections of 500-1,000 mg followed by a maintenance therapy with 1,000 mg/week are suggested, since they permit rapid achievement and maintenance of relatively high plasma levels. A similar plasma level profile can be obtained with oral MPA provided that daily doses twice as large as the IM doses are given during the first month of treatment and continued during the maintenance period. The serum levels observed in 25 patients with advanced breast cancer treated with MPA given IM or PO according to various dose schedules and recent literature data are very close to the serum level profiles predicted on a theoretical pharmacokinetic basis.

Clinical toxicity of combined modality treatment with nitrosourea derivatives for central nervous system tumors.

Two nitrosourea compounds--1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU)--have been used in the treatment of primary and metastatic brain tumors after operation and/or radiotherapy. Hematological and nonhematological toxicity were recorded in 272 patients treated between May 1973 and June 1978. BCNU was given to 135 patients (80 mg/m2 i.v. daily for 3 days) and CCNU was given to 137 patients (130 mg/m2 orally, single dose) every 8 weeks until progression of the primary disease process or for a total of 12 cycles. Radiation therapy (5500 +/- 500 rads in 6 to 7 weeks) was carried out after the first course of chemotherapy. BCNU and CCNU induced the same hematological and clinical toxicity. The bone marrow toxicity seemed to be dose-related, delayed, and cumulative. One case of acute nonlymphoblastic leukemia arising 2 months after the end of CCNU therapy is reported.

Characteristics and biological role of steroid hormone receptors in neuroepithelial tumors.

Tissue samples from 57 patients with neuroepithelial tumors (25 glioblastomas, 18 anaplastic astrocytomas, and 14 astrocytomas) were analyzed in order to evaluate the presence of estrogen, progesterone, glucocorticoid, and androgen receptors. Glucocorticoid- and androgen-specific binding proteins were present in 38.6% and 21.6% of the cases, respectively. Only a few tumors showed estrogen or progesterone receptors. A correlation was found between grade of anaplasia, patient's sex and age, and presence of glucocorticoid and androgen receptors. The biological role of these two receptors was investigated in 10 primary cell cultures derived from neuroepithelial tumors. For this purpose, dexamethasone and testosterone were added to culture medium at different concentrations (from 50 to 0.016 micrograms/ml). A significant stimulation of the cell growth was observed in four of five glucocorticoid receptor-positive cultures when dexamethasone in doses ranging from 2 to 0.016 microgram/ml was added to the culture. No modulation of the growth was observed in glucocorticoid receptor-negative cultures at the same doses. Higher dexamethasone doses induced a significant decrease of the growth index independently from the glucocorticoid receptor status. All of the cultures tested for testosterone activity were negative for androgen receptors. This hormone induced an inhibition of the growth index at doses ranging from 50 to 0.4 micrograms/ml. The data suggest that neuroepithelial tumors contain specific glucocorticoid and androgen binding proteins. Glucocorticoid receptors modulate the growth of cultured neuroepithelial tumors in the presence of different concentrations of dexamethasone.

Cytotoxic T-lymphocyte responses in melanoma through in vitro stimulation with the Melan-A peptide analogue A27L: a qualitative analysis.

Modifications in tumour antigen-derived epitopes that stabilize the major histocompatibility complex (MHC)-peptide complex result in enhanced stimulatory capacity and improved immunogenicity of the altered peptide. These epitope analogues are attractive candidates for the development of peptide-based vaccine trials. Any modification, however, in tumour antigens may induce T-cell responses that could either fail to react against the naturally occurring peptides or represent only a subset of the total antigen-specific repertoire. In the present study, we performed a critical analysis of the ability of cytotoxic T-lymphocyte (CTL) clones, derived from two melanoma patients through stimulation with the A27L peptide analogue, to cross-react with the naturally processed Melan-A/MART-1 (Melan-A) peptides in terms of T-cell receptor (TCR) affinity, functional avidity and fine antigen specificity. We found that all the A27L-specific clones analysed possessed a very low avidity for the natural Melan-A peptides, and that their binding affinity for human leukocyte antigen (HLA) tetramers complexed with both the modified and the natural Melan-A peptides did not strictly correlate with their functional avidity. We also observed that these clones were able to cross-recognize both natural Melan-A peptides in one patient, but only one peptide in the second patient. We discuss the capability of the A27L peptide analogue to stimulate all the available Melan-A-specific repertoire.

Epirubicin versus mitoxantrone in combination chemotherapy for metastatic breast cancer.

As valid therapeutic alternatives to adriamycin, with a more favourable safety profile, epirubicin (E) and novantrone (N) were compared in combination with fluorouracil (F) and cyclophosphamide (C) in a prospective randomized clinical trial as first-line treatment for metastatic breast cancer (mbc). 158 women with mbc were randomly allocated to receive FEC or FNC regimen; the dosage in mg/m2 was as follows: 500 for C and F, 75 for E and 10 for N. All drugs were administered iv. on day 1 and recycled on day 21. In 141 evaluable patients the response rate (CR+PR) was better in the FEC (43.6%) than in the FNC regimen (30.3%) (95% C.I. of 32% to 55% versus 14% to 34%), without any statistically significant difference. Differences in response rate were significantly in favour of FEC group in previously untreated patients (57.6% versus 25%, p = .02), and in postmenopausal women (46.1% versus 23.6%, p = .01). No significant differences between the two treatment arms were observed in terms of either time to progression or duration of response and survival. The most important dose-limiting toxicity was hematological (leuko-and thrombocytopenia were significantly higher in FNC-treated patients). This difference in hematological toxicity sustained a significantly different incidence of delays in administering chemotherapy courses, which precluded the administration of comparable doses of all drugs in both groups. The incidence of complete alopecia was significantly higher in FEC-treated patients, while no clinical or instrumental evidence of CHF was observed with either regimen. Due to its more favourable therapeutic profile, the E-containing regimen seems a suitable first-line treatment for previously untreated patients with mbc, while the FNC combination should be offered to women refusing hair loss.

Proliferative effect of dexamethasone on a human glioblastoma cell line (HU 197) is mediated by glucocorticoid receptors.

The relationship between Dexamethasone proliferative activity and the presence of glucocorticoid receptors was studied on a human glioblastoma cell line (HU 197). For this purpose, the 17 beta-Carboxamide steroid DXB, a glucocorticoid antagonist that competes with Dexamethasone for binding to the intracellular glucocorticoid receptor but does not trigger the glucocorticoid effect, was used. Concurrent treatments with Dexamethasone and DXB caused an inhibition of the proliferative effect obtained by Dexamethasone. The results obtained demonstrated that the Dexamethasone activity on cell proliferation is a specific receptor-mediated effect.

Morphological and biochemical features of a medroxyprogesterone acetate (MPA)-resistant MCF-7 breast cancer cell line.

An MCF-7 human breast cancer line variant (MCF-7/MPA), resistant to medroxyprogesterone-acetate (MPA), was obtained by continuous exposure in vitro to the drug. MCF-7/MPA cells were grown in the presence of 12.5 x 10(-6) M MPA and were selected by increasing the concentration of the drug in the growth medium in a stepwise manner from 0.025 x 10(-6) M up to 12.5 x 10(-6) M. Comparative studies of cellular morphology, cytosolic steroid receptor content and P-Glycoprotein expression were performed on both MCF-7 parental line and MCF-7/MPA variant. MCF-7/MPA cells, when compared to the parental line, exhibit a different morphology in terms of membrane alterations, reduced content of cytosolic progesterone receptor, increased expression of P-glycoprotein along with reduction of Doxorubicin (Dx) activity on the growth of MCF-7/MPA resistant cells.