Preferential location of sex chromosomes, their aneuploidy in human sperm, and their role in determining sex chromosome aneuploidy in embryos after ICSI.

BACKGROUND: In babies born after ICSI procedures, an increase of de-novo sex chromosome abnormalities has been observed. Several hypotheses have been proposed to explain these findings: an increased rate of sex chromosome aneuploidy in sperm of oligozoospermic men, or a preferential location of the sex chromosomes in the sub-acrosomal region of the sperm nucleus which leads to a reduced DNA decondensation of this region. In order to investigate which theory may be more reliable, we studied the localization of sex chromosomes and their aneuploidy rate in sperm in men undergoing ICSI. METHODS: Using fluorescent in-situ hybridization we studied sex chromosome localization and the aneuploidy rate for sex chromosomes and chromosome 18 in 20 oligospermic men undergoing ICSI and in 10 controls. RESULTS: In 40.94 and 52.92% of cases, the X and Y chromosomes respectively were localized in the sub-acrosomal region of the sperm nucleus compared with only 14.29% of cases of chromosome 18 (P < 0.001). An increase of sex chromosome aneuploidy in sperm of oligospermic men was observed; 2.91 versus 0.69% of controls (P < 0.001). CONCLUSIONS: Sex chromosomes are localized preferentially in the sub-acrosomal region of sperm and sex chromosome aneuploidy rate in the sperm of oligozoospermic men is higher than in controls.

In vitro antitumor effect of LAK cells and alpha interferon in combination on tumor cell lines.

In vitro antitumor effects of LAK cells and alpha-2b-Interferon (IFN) either alone or in combination were evaluated on NK resistant (K562) and NK sensitive (Namalwa, Raji) cell lines. Tumor cells were incubated with LAK cells for 4, 8 and 24 hours at a LAK: tumor cell ratio of 1:1, 10:1, 100:1, or with IFN for 48 and 96 h at the concentrations of 100, 1000, 10,000, 100,000 IU/ml. A clonogenic assay was utilised to enumerate residual cells after in vitro treatment. A positive correlation was found between tumor cell killing and effector: target ratio, IFN of 100:1 incubated for 4 h, and 100 IU/ml of IFN incubated for 48 h were further chosen. A synergistic effect was found when IFN was incubated before LAK cells or contemporarily, but not when IFN was incubated after LAK cells. These findings demonstrate that an additive or a synergistic effect in vitro can be obtained by adding the two agents in different sequences and suggest that a potential utility of LAK cells and IFN in vivo should be tested in clinical trials.

Pharmacological purging of syngeneic bone marrow ex vivo: effect of treatment with doxorubicin and lonidamine on normal and leukaemic cells of DBA/2 mice.

The in vivo effect of in vitro treatment with doxorubicin plus lonidamine on normal and leukaemic cells was investigated in a mouse model of syngeneic bone marrow transplantation. Different numbers of L5178Y tumour cells or normal bone marrow cells alone, or mixtures of bone marrow and leukaemic cells were incubated with doxorubicin (0.25, 0.5, 0.75, 1 microgram/ml) and/or lonidamine (50 micrograms/ml) and reinfused in DBA/2 mice. Lonidamine potentiated the cytotoxic effect of doxorubicin dependent on doxorubicin dosage and tumour cell concentration. Survival after injection of 10(4) in vitro-treated tumour cells was 42% for doxorubicin 0.75 micrograms/ml alone versus 100% for the combination with lonidamine and 50% for doxorubicin 1 microgram/ml alone versus 100% combination. Reinfusion of normal bone marrow incubated with doxorubicin alone or in combination with lonidamine in lethally irradiated mice did not occur in 12-14% of mice injected, indicating that the repopulating ability of stem cells was spared. These data suggest the potential usefulness of lonidamine in ex vivo purging of bone marrow before autologous bone marrow transplants in haemopoietic malignancies.

Production and characterization of two immunotoxins specific for M5b ANLL leukaemia.

We describe the production and functional characterization of 2 monocytic-cell-lineage-specific immunotoxins constructed with saporin emitoxin (SAP) from Saponaria officinalis. Interest in the production of these immunotoxins, of possible clinical relevance, has been raised by the availability of 2 MAbs of high specificity for circulating monocytes and M5b ANLL, thus envisaging their potential use in bone-marrow purging. SAP emitoxin was selected on the basis of the low cytotoxicity in unconjugated form, as opposed to highly specific cytotoxicity and favourable pharmacokinetical properties in the conjugated form. SPDP conjugation produced immunotoxins which retained serological specificity and protein-synthesis-inhibitory activity. The 2 immunotoxins did not interfere with bone-marrow progenitor-cell growth in a CFU-GM colony assay. On the contrary, they were capable of killing monocytic cells selectively, as demonstrated in phenotypical and functional assays. Thus these 2 novel immunotoxins appear to be promising reagents in purging autologous bone marrow prior to transplantation in patients suffering from monocytic leukaemia.

Prolonged suppression of myeloid progenitor cell numbers after stopping interferon treatment for CML may necessitate delay in harvesting marrow cells for autografting.

Fourteen patients with chronic myelogenous leukemia in chronic phase who had achieved hematological remission after alpha-interferon (IFN) therapy were evaluated for their ability to form hemopoietic colonies in vitro. Patients were studied both before and after discontinuation of IFN to assess the optimal timing for a further therapeutic approach consisting of stem cell collection followed by autologous bone marrow transplantation (ABMT). Before stopping IFN a profound inhibition of CFU-GM and BFU-E growth was observed. The numbers of CFU-GM and BFU-E in the bone marrow recovered to 50 per 2 x 10(5) cells plated at a median of 158 and 122 days, respectively, after stopping IFN. At that time, 12 patients were submitted to stem cell harvest and subsequently to ABMT. All patients showed complete engraftment and hematological reconstitution; cytogenetic improvement was observed in eight (67%) cases; two patients displayed complete disappearance of the Ph1 chromosome, confirmed at the molecular level. Eleven of the 12 patients are still in hematological remission at a median of 18 months from autografting and a median of 48 months from diagnosis.

Autologous bone marrow or peripheral blood stem cell transplantation for patients with chronic myelogenous leukaemia in chronic phase.

The progressive and fatal course of chronic myelogenous leukemia has not been affected significantly by chemotherapeutic agents that control the benign phase of the disease. Combination chemotherapy and aggressive treatments may offer some advantages: however, these approaches do not appear to produce stable suppression of Ph1 chromosome or to prolong chronic phase and survival of these patients. Only allogeneic bone marrow transplantation has been demonstrated to be capable of inducing a stable, complete suppression of Ph1+ cells. Recently alpha Interferons (IFN) have been shown to control myeloid proliferation in patients with CML and to determine a progressive and persistent decline of Ph1+ bone marrow cells in some cases. The hypothesis that in most newly diagnosed patients with CML various amount of Ph1 negative cells must still be present, albeit in suppressed state in the bone marrow (BM) or in the peripheral blood (PB), have led some Authors to treat patients with high-dose chemotherapy followed by reinfusion of stem cells collected at diagnosis or after a response to cytoreductive treatments. We report 34 patients with CML treated in chronic phase with Busulohan and Melphalan conditioning regimen followed by reinfusion of BM or PB stem cells.

Monoclonal antibody purging and autologous bone marrow transplantation in acute myelogenous leukemia in complete remission.

A mouse monoclonal antibody (S4-7) reacting with human myelomonocytic cells has been previously shown to be suitable for bone marrow purging in selected acute myelogenous leukemia (AML) patients with S4-7 positive leukemic clonogenic cells at diagnosis. The results obtained in seven AML patients who underwent such a treatment, followed by autologous bone marrow transplantation (ABMT), are now reported. Six patients underwent ABMT in first complete remission (CR), one in second CR, after BAVC conditioning regimen. One patient died of infection 1 month after ABMT; in the other six a complete recovery of hemopoiesis was observed. In spite of S4-7 reactivity with normal myelomonocytic cells, a prompt recovery of granulopoiesis was however observed both in in vitro liquid culture and in vivo with a median time of 20 days to reach granulocyte values of 500 x 10(6)/l. The patient transplanted in 2nd CR relapsed 3 months after ABMT. Of the five evaluable patients transplanted in 1st CR, two relapsed 8 and 9 months post-ABMT while three remain in continuous CR at 35, 47, 57 months. Leukemic cells of two of the three patients with recurrent disease were studied at relapse and in both could be detected a significant percentage of S4-7 negative cells, detectable neither at diagnosis nor (one patient) at the time of first relapse after standard chemotherapy.

Prolonged effect of alpha-interferon after discontinuance of treatment in chronic myelogenous leukemia patients.

14 patients out of a group of 73 affected by CML and treated with alpha-2-IFN, who had obtained hematological and cytogenetic response, were selected to be submitted to autologous BMT. In all patients the IFN treatment was interrupted to obtain an increase of the peripheral WBC necessary for its collection by means of leukapheresis. After a median time of 20.5 weeks from discontinuance of therapy, most patients are still under hematological disease control. Serially performed cell cultures have shown deeply and persistently reduced growth patterns; cytogenetic analyses have displayed Ph' mosaicism, but with a progressive increase in time of Ph' + cells. Such findings reveal that the effect of alpha-2-IFN in CML patients can be unexpectedly prolonged after discontinuance of treatment. A possible explanation might be found in the complexity of the biological mechanisms of action of IFN, thus giving this drug promising therapeutic prospects in the treatment of CML.

In vitro effects of human recombinant alpha-2b interferon on Ph1+ chronic myelogenous leukemia cells maintained in long term marrow cultures: a functional and morphological analysis.

In this study in vitro results obtained with hu rec IFN-alpha 2b on Ph1+ stem cells from patients with chronic myelogenous leukemia in chronic phase (CML in CP) will be discussed: cells were incubated with different IFN concentrations (100, 1000, 10000 IU/ml) for different times (24, 96 hrs, 8, 15, days) and maintained in long term marrow cultures (LTMC); CFU-GM assay, cytochemistry and cytogenetic analyses were performed weekly. A high sensitivity of CML cells to the in vitro treatment with IFN was observed. Cell count in LTMC showed a progressive reduction inversely proportional to time of incubation and concentration of IFN; a marked decrease in colony growth was observed at the end of incubations and during the course of LTMC. Low concentrations of IFN permitted a morphological maturation and the expression of alkaline phosphatase. Cytogenetic analyses showed a marked reduction of mytoses in cultures treated with high concentrations of IFN as result of a combined cytostatic and cytolitic effect; the persistance of 100% Ph1+ cells in LTMC and in CFU-GM colonies might be related, as opposed to in vivo results, to different IFN exposure conditions or might be influenced by other factors.

Acute myelogenous leukemia in first relapse treated with two consecutive autologous bone marrow transplantations: a pilot study.

The feasibility and the antileukemic activity of a double sequential autograft has been evaluated in 3 patients affected by AML in first hematological relapse. Bone marrow collection and cryopreservation was performed twice: during first complete remission (CR) and during second CR. At the time of relapse patients underwent first ABMT with BAVC preparative regimen achieving a second CR without any remarkable complications. After 4, 5 and 4 months respectively a second ABMT was performed with a different preparative regimen, consisting of cyclophosphamide and fractionated total body irradiation (Cy + F-TBI). A delay in platelet recovery was observed after the second procedure as compared to the first, while neutrophils recovery was comparable. 1 patient died in CR (on day +91 after second ABMT) of interstitial pneumonitis. 2 patients are alive and well without evidence of disease after 46 and 53 months of unmaintained second CR. This experience shows the high antileukemic potential of treatment with a double sequential autograft; 2 relapsed patients in fact are long-term survivors with a second CR longer than the first.

In vitro pharmacological purging of human bone marrow is enhanced by the use of lonidamine.

Lonidamine (LND), previously reported as a useful antitumor substance in combination with physical or chemical agents, has been studied for its capacity in increasing pharmacological elimination in vitro of residual tumor cells from human bone marrow. Different drugs were tested in association with LND against mixtures of human bone marrow and a tumor cell line, clonogenic human leukemic blast progenitors, and normal human bone marrow precursors. The results demonstrated that LND increased the efficacy of anthracycline derivatives (Adriamycin, Mitoxantrone) both on the tumor cell line and on the leukemic blast progenitors, while VP-16 or ASTA-Z 7654 was not affected by the same substance. The toxicity on normal stem cells reflected that of each drug and was not modified by the addition of LND. While a consistent dose-dependent CFU-GM reduction was observed immediately after treatment with the different drugs, a complete recovery was reached after 7 and 14 days of long-term marrow cultures. Because of the low toxicity and the efficacy demonstrated in association with certain agents in increasing tumor cell elimination in vitro, LND could play an important role in in vitro purging prior to autologous bone marrow transplantation.

Results of two different conditioning regimens followed by ABMT in refractory acute lymphoblastic leukemia.

Thirty-one patients affected by advanced ALL entered this study. Twenty (1 in I CR, 9 in II CR, 6 in III CR and 4 extramedullary relapses) were treated with the BMVC conditioning regimen. Eleven (9 in II CR, 2 in III CR) received the Busulfan plus Cytoxan conditioning regimen. Asta-Z 7654-purged marrow was reinfused at day 0. Both protocols were well tolerated. Two patients treated with the BMVC regimen died in aplasia from sepsis; 1 patient died in CR 5 months after transplantation, 13 relapsed after a median time of 4 months (range 1-31). Four patients are in CCR with a median follow-up of 16 months (range 11-24). In the BU + CY treated group no toxic deaths were observed. Four patients relapsed after a median of 3 months (range 2-7) and 7 are in CCR with a median follow-up of 5 months (range 2-28).

Efficacy of a combined treatment with ASTA-Z 7654 and VP16-213 in vitro in eradicating clonogenic tumor cells from human bone marrow.

The efficacy of autologous bone marrow transplantation in leukemia and lymphoma may depend upon the selective elimination of malignant cells from human bone marrow in vivo and in vitro. A cyclophosphamide derivative (ASTA-Z 7654) and etoposide (VP16-213) have been tested on lymphoma and leukemia cell lines in a model that may represent a bone marrow situation in complete remission. The influence of different concentrations of normal mononuclear cells and tumor cells in this model and the activity of the two chemotherapeutic agents in the presence of bone marrow cells or peripheral blood cells were evaluated. A major inhibitory effect was observed using the two agents in combination; low doses of ASTA-Z and VP16 consecutively added to the mixture of malignant cells and normal mononuclear cells resulted in a greater elimination of tumor line cells than with ASTA-Z alone at the current 100 micrograms/ml dose. In contrast, no major toxicity on normal human bone marrow precursors was observed; the effect of treatment on hemopoietic recovery with the two agents either alone or in combination was evaluated on CFU-GM growth after long-term bone marrow cultures. Despite a profound growth inhibition at day 0, a recovery was observed in all cases after 7 or 14 days. The use of multiple chemotherapeutic agents in the treatment of bone marrow in vitro could decrease the possibility of malignant cells surviving while sparing normal bone marrow precursors.