Pharmacology of intracellular cytosine-arabinoside-5'-triphosphate in malignant cells of pediatric patients with initial or relapsed leukemia and in normal lymphocytes.

PURPOSE: The prodrug cytosinearabinoside (ara-C) is widely used in the treatment of acute leukemias. The active drug is the intracellular metabolite cytosine-arabinoside-5'-triphosphate (ara-CTP). The purpose of the present study was to investigate the relation between sensitivity and pharmacokinetic parameters Cmax, t1/2 and AUC of ara-CTP. The obtained results were compared to previous studies. EXPERIMENTAL DESIGN: Cmax, t1/2 and AUC of ara-CTP were assessed in leukemic cells of 17 pediatric patients with acute lymphoblastic leukemia (ALL) and in 6 lymphoblastic cell lines and compared with normal lymphocytes of 9 healthy donors by high pressure liquid chromatography (HPLC). The sensitivity of the cells against ara-C was determined by the MTT assay. RESULTS: The intracellular accumulation of ara-CTP was significantly lower in normal lymphocytes (Cmax 47.7-60.9 pmol/10(6) cells) compared to leukemic cell lines (Cmax 11-1128 pmol/10(6) cells) and leukemic cells of our patients (Cmax 85.9-631 pmol/10(6) cells). Similar results were found for the AUC. There was no significant difference between initial and relapsed leukemias in our small cohort. A correlation between sensitivity in terms of IC50 values and the intracellular ara-CTP accumulation was observed in cell lines, but not in leukemic cells and normal lymphocytes from healthy donors. CONCLUSIONS: Pharmacokinetic parameters varied tremendously in leukemic cells in contrast to normal lymphocytes without a difference in sensitivity. It is worthwhile to compare literature data to assess an optimal dosage of ara-C in pediatric patients.

Selective activity of BS-RNase against anaplastic thyroid cancer.

BACKGROUND: Anaplastic thyroid carcinoma is an aggressive solid tumor that fails to adequately respond to any known chemotherapeutic regimen. The development of effective chemotherapy agents would provide the best chance for long-term survival of patients. MATERIALS AND METHODS: The cytotoxic effects of bovine seminal ribonuclease (BS-RNase) against thyroid carcinoma cell lines with different degrees of differentiation in comparison to non-malignant cells, including human foreskin fibroblasts (HFF) and retinal pigment epithelial cells (RPE), were tested using the MTT dye reduction assay. Induction of apoptosis was demonstrated by annexin V assay and expression of proteins related to apoptosis was investigated by flow cytometry. The antitumoral in vivo effects of BS-RNase were assessed on established xenografts of anaplastic thyroid carcinoma cell line 8505C in nude mice using subcutaneous injections of BS-RNase (12.5 mg/kg once a day, on 20 consecutive days). RESULTS: All the tumor cell lines exhibited marked sensitivity against BS-RNase in comparison to HFF and RPE cells. The greatest growth inhibition was seen in the 8505C line, while IC50 values for papillary (B-CPAP) and poorly-differentiated thyroid carcinoma cells were about 6-fold higher. The cytotoxic action of BS-RNase was associated with induction of apoptosis. Expressions of Fas and Fas-ligand were not influenced by BS-RNase completely, while the down-regulation of Bcl-2 in treated cells was observed. In vivo treatment induced significant tumor regression after the course of 20 consecutive days. No apparent toxic effects of BS-RNase toward non-malignant cells were observed during the in vivo treatment. After cessation of therapy (day 20) tumor volume continued to decrease and the tumor was no longer detectable after 30 days of treatment induction in all animals. CONCLUSION: BS-RNase may have beneficial effects for treatment of aggressive anaplastic thyroid cancer.

Localized Ewing tumor of bone: final results of the cooperative Ewing's Sarcoma Study CESS 86.

PURPOSE: Cooperative Ewing's Sarcoma Study (CESS) 86 aimed at improving event-free survival (EFS) in patients with high-risk localized Ewing tumor of bone. PATIENTS AND METHODS: We analyzed 301 patients recruited from January 1986 to July 1991 (60% male; median age 15 years). Tumors of volume >100 mL and/or at central-axis sites qualified patients for "high risk" (HR, n = 241), and small extremity lesions for "standard risk" (SR, n = 52). Standard-risk patients received 12 courses of vincristine, cyclophosphamide, and doxorubicin alternating with actinomycin D (VACA); HR patients received ifosfamide instead of cyclophosphamide (VAIA). Tumor sites were pelvis (27%), other central axis (28%), femur (19%), or other extremity (26%). The initial tumor volume was <100 mL in 33% of cases and > or =100 mL in 67%. Local therapy was surgery (23%), surgery plus radiotherapy (49%), or radiotherapy alone (28%). Event-free survival rates were estimated by Kaplan-Meier analyses, comparisons were done by log-rank test, and risk factors were analyzed by Cox models. RESULTS: On May 1, 1999 (median time under study, 133 months), the 10-year EFS was 0.52. Event-free survival did not differ between SR-VACA (0.52) and HR-VAIA (0.51, P =.92). Tumor volume of >200 mL (EFS, 0.36 v 0.63 for smaller tumors; P =.0001) and poor histologic response (EFS, 0.38 v 0.64 for good responders; P =.0007) had negative impacts on EFS. In multivariate analyses, small tumor volumes of <200 mL, good histologic response, and VAIA chemotherapy augured for fair outcome. Six of 301 patients (2%) died under treatment, and four patients (1.3%) developed second malignancies. CONCLUSION: Fifty-two percent of CESS 86 patients survived after risk-adapted therapy. High-risk patients seem to have benefited from intensified treatment that incorporated ifosfamide.

Antineoplastic activity of a novel multimeric gemcitabine-monophosphate prodrug against thyroid cancer cells in vitro.

Gemcitabine (Gem) is a deoxycytidine analog that is effective against pancreatic cancer and other malignancies following conversion to the 5'-O-mono-, di- and tri-phosphate forms. We evaluated the cytotoxicity of GemMP[10], a novel multimeric form of 2'-deoxy-2',2"-difluorocytidine-5'-O-monophosphate (gemcitabine monophosphate) against three thyroid carcinoma cell lines established from anaplastic (8505C), papillary (B-CPAP) and poorly-differentiated papillary (BHT-101) cancer. GemMP[10] decreased tumor cell growth at concentrations ranging from 1 to 50 nM. These concentrations were 5- to 10-fold lower than those required for inhibition of tumor cell growth by monomeric Gem. GemMP[10] cytotoxicity occurred via induction of apoptosis. Flow cytometric analysis of GemMP[10] treated cells revealed growth arrest in S-phase. Fas-antigen expression was increased in thyroid cancer cells treated with GemMP[10], whereas Fas-L and Bcl-2 expression were not significantly affected. These results demonstrated that GemMP[10] is a potent cytotoxic agent that serves to induce apoptosis in association with increased Fas expression in cultured thyroid cancer cell lines.

Improved outcome in childhood acute lymphoblastic leukemia despite reduced use of anthracyclines and cranial radiotherapy: results of trial ALL-BFM 90. German-Austrian-Swiss ALL-BFM Study Group.

Trial ALL-BFM 90 was designed to improve outcome in patients with childhood acute lymphoblastic leukemia (ALL) by using a reduced treatment regimen. Patients were stratified into a standard-risk group (SRG), a medium-risk group (MRG), both defined by adequate early treatment response; and a high-risk group (HRG), defined by inadequate response to the cytoreductive prednisone prephase, induction failure, or Philadelphia-chromosome-positive ALL. Four treatment modifications were evaluated: dose intensification in induction by a more rapid drug sequence; administration of L-asparaginase during consolidation therapy in the MRG (randomized); enforced consolidation by rotational elements in the HRG; and reduction in the dose of anthracyclines and use of only 12-Gy preventive cranial radiotherapy in the MRG and HRG, with the aim of avoiding toxicity. Among all 2178 patients (

Bovine seminal ribonuclease exerts selective cytotoxicity toward neuroblastoma cells both sensitive and resistant to chemotherapeutic drugs.

BACKGROUND: Bovine seminal ribonuclease (BS-RNase) exerts selective cytotoxicity toward different types of tumor cells. In the present study, we tested the effects of BS-RNase on cultured neuroblastoma (NB) cells resistant to chemotherapeutic agents. The selectivity of the antitumoral activity of BS-RNase was evaluated using cultures of CD34+ hematopoietic stem cells. MATERIALS AND METHODS: Human NB cell lines including IMR-32, UKF-NB-2 and UKF-NB-3 were selected for resistance against vincristine, doxorubicin or cisplatin by exposure to increasing concentrations of the respective drug. The cytotoxicity of the drugs to NB cells was evaluated using a clonogenic assay in a methylcellulose medium. Peripheral blood progenitor cells were obtained from adult healthy donors by positive selection using specific anti-CD34+ antibodies. The toxicity of BS-RNase to CD34+ cells was assessed in the direct clonogenic assay using methylcellulose medium or in ex vivo expansion culture supplemented with hematopoietic growth factors. RESULTS: In the clonogenic assay it was shown that BS-RNase completely inhibits growth of both parental NB cells and their sublines resistant to chemotherapeutic drugs at concentrations (up to 50 micrograms/ml) which have no significant influence on the growth of colony-forming units, granulocyte macrophage and erythroid burst-forming units. Moreover, BS-RNase had no effect on the ex vivo expansion of total hematopoietic cells or of colony-forming cells from CD34+ progenitors. CONCLUSIONS: BS-RNase is a highly efficient agent against NB cells resistant to chemotherapeutic drugs. The lack of toxicity to hematopoietic progenitor cells suggests that BS-RNase is also likely to have tolerable hematopoietic toxicity.

Bovine seminal ribonuclease inhibits in vivo growth of human neuroblastoma cells.

Bovine seminal ribonuclease (BS-RNase) is a homologue of RNase A with specific antitumor activities. It is selectively toxic for neuroblastoma (NB) cells in vitro with no significant effects on the viability of normal human cells. We evaluated the antitumoral effects of BS-RNase on human NB xenografts from UKF-NB-3 cells in athymic (nude) mice. The efficacy of direct intraneoplastic, subcutaneous and systemic delivery of BS-RNase was explored. Systemic administration of BS-RNase (12.5 mg/kg/day intraperitoneally, for 20 days in the course of four weeks) suppressed tumor growth but was not able to induce any cures. Subcutaneous injections (12.5 mg/kg/day for 20 days in the course of four weeks) and intratumoral BS-RNase treatment using the same schedule resulted in complete tumor regression. During 30 days following cessation of treatment no tumor regrowth was observed and animals were free of tumors. Toxic effects of BS-RNase (e.g., on bone marrow and inner organs) were not apparent. This data indicates that BS-RNase fulfills important criteria for a candidate antitumor agent specific for NB.

Preliminary experiences with triple therapy including nelfinavir and two reverse transcriptase inhibitors in previously untreated HIV-infected children.

OBJECTIVE: In an intent-to-treat study increase in CD4 cell count, reduction of viral load, clinical benefit and adverse reactions were examined in HIV-infected previously treatment-naive children taking triple therapy. METHODS: sixteen HIV-infected children in category A or B on antiretroviral triple therapy were followed-up for a period of 12 months. In group I eight patients received zidovudine, lamivudine and nelfinavir; in group II eight patients received stavudine, didanosine and nelfinavir. Viral load and CD4 cell count were measured every 4-8 weeks. Plasma nelfinavir levels were assessed once in all patients at baseline and monitored in patients with increasing viral load. RESULTS: No significant differences were observed between treatment groups in terms of CD4 cell counts and viral load. A median viral load reduction of 2.8 log10 (range, 1.4-4.2 log10) was achieved over a period of 12 months in both groups. Viral load < 500 copies/ml was found in 69% of patients and viral load < 50 copies/ml in 44% of patients after 12 months. Median CD4 cell count increased from 656 x 10(6) to 850 x 10(6) cells/l after 3 months and was maintained at 813 x 10(6) cells/l after 12 months of treatment. Main side-effects were diarrhoea, rash and hyperlipidaemia. Except for application problems, both regimens were well tolerated. Appropriate formula and individual counselling must be performed during the first weeks of treatment in order to achieve good compliance in paediatric patients. CONCLUSION: Triple antiretroviral therapy shows a stronger and more sustained reduction of viral load in HIV-infected children compared with studies combining two nucleoside analogues.

Bovine seminal ribonuclease selectively kills human multidrug-resistant neuroblastoma cells via induction of apoptosis.

Bovine seminal ribonuclease (BS-RNase) is a homologue of RNase A with specific antitumor activity. The cytotoxic action of this agent was examined in human neuroblastoma (NB) cell lines (SK-N-SH and UKF-NB-4) possessing the multidrug resistance (MDR) phenotype and NB cell lines (IMR-32, UKF-NB-1, UKF-NB-2 and UKF-NB-3) without MDR. Although MDR cells expressed large amounts of mdr-1 mRNA, contained functional P-glycoprotein and had 20- to 105-fold lower sensitivities to doxorubicin and vincristine than cells with non-MDR phenotypes, BS-RNase was equally toxic to all NB cells at concentrations employed (0.2 to 100 microg/ml). BS-RNase showed high selectivity for NB cells and was non-toxic to normal fibroblasts and epithelial cells. Ultrastructural investigation and annexin V assay showed that BS-RNase is a powerful inductor of apoptosis. The antitumoral effects of BS-RNase were also demonstrated in vivo using established subcutaneous xenografts in athymic (nude) mice of the MDR-1-bearing UKF-NB-4 cell line. Intratumoral injections (12.5 mg/kg) of BS-RNase over four weeks resulted in complete tumor regression and absence of tumor regrowth over a two-week observation period after cessation of treatment. The results show that BS-RNase selectively kills NB cells by inducing apoptosis and that this agent is active against mdr-1 expressing cells both in vitro and in vivo. BS-RNase fulfills important criteria for a candidate antitumor agent in NB patients with advanced disease.

wt1 gene expression in childhood leukemias.

The expression of the Wilms' tumor gene (wt1) was detected in various tissues during embryonic development. Mutations in the wt1 gene probably play an important role in certain tumors, e.g. the Wilms' tumor. Furthermore the expression of wt1 gene was found in some human leukemias. In the present study we investigated the expression of wt1 gene in several types of childhood leukemia by reverse transcriptase-polymerase chain reaction. Bone marrow or peripheral blood of 61 pediatric patients (48 at initial diagnosis, 13 at first or second relapse) were analyzed. wt1 gene expression was detected in 35/48 patients (73%) with newly diagnosed leukemias and in 12/13 cases (92%) who had suffered from relapse. The expression levels were higher for AML than for ALL. The frequency of wt1 expression in different subtypes of acute leukemia was compared with results found in adult patients. Our results show that the frequency of wt1 gene expression in acute childhood leukemias is similar to previous data reported for adults.

Functional results after partial pelvic resection in Ewing's sarcoma of the ilium.

Ewing's sarcoma of the pelvis has an unfavourable prognosis. The clinical and functional results of 7 patients who had a Ewing's sarcoma of the pelvis stage IIB were reviewed. All patients received multiple-agent chemotherapy pre- and postoperatively (modified T6 and T2 protocol according to Rosen) and underwent local resection of the pelvic tumour. According to Enneking, five patients had a type IA resection, one patient type I and another type IIA. One patient received a course of radiation therapy postoperatively (50 Gy). Six of seven patients showed a good regression of the tumour after preoperative chemotherapy. One patient who had a giant-cell Ewing's sarcoma died of local recurrence and lung metastases 29 months postoperatively. The remaining six patients were monitored radiographically and clinically according to Enneking's functional evaluation score after a follow-up period of 136 months (range 40-199 months). All were free of disease and had neither local recurrence nor metastases. In five patients the functional results were rated as "good" or "excellent". The good results depend mainly on the reconstruction of the pelvic girdle and its mechanical stability.

[Prevention of joint damage in hemophilic children with early prophylaxis]. / Prävention von Gelenkveränderungen bei hämophilen Kindern durch frühzeitige Prophylaxe.

Radiological and orthopaedic outcome in severe and moderate haemophilia A and B patients undergoing long-term prophylactic treatment were prospectively investigated focusing on the age of onset of prophylaxis and the number of joint bleedings prior to treatment. We report on 21 patients with severe and moderate haemophilia A and B receiving prophylactic treatment of between 3.1 and 16.1 years duration. Three patient groups were evaluated according to the age at onset of prophylaxis. In group I (n = 8) prophylactic treatment was initiated in the first 2 years of life. Patients of group II (n = 6) received prophylaxis at the age of 3-6 years. Late-onset or secondary prophylactic treatment was started at the age of 6 years and above in 7 patients (group III). All patients received virus-inactivated F VIII or F IX concentrates at dosages of 30-40 IU, in some cases up to 50 IU/kg body weight i.v. three times per week for those with haemophilia A and twice per week for those with haemophilia B. Elbow, knee and ankle joints were investigated at 3-4 yearly intervals according to the radiological and orthopaedic scores recommended by the World Federation of Haemophilia (WFH). The total number of joint bleedings before and after start of prophylaxis were recorded in all patients. In group 17 out of 8 patients had unaffected joints with constant radiological and orthopaedic scores of zero or 1, after a median of 11.25 years of prophylactic treatment. One patient in this group demonstrated mild radiological alterations (score 4). Patients of group II showed neither radiological nor orthopaedic alterations at study entry. Worsening joint scores could be detected despite ongoing prophylaxis after the 3-year interval (median orthopaedic score 4, median radiological score 8). Treatment group III already showed considerable joint damage at study entry with a median radiological score of 11 (0-33) and a median orthopaedic score of 4 (0-11). Despite prophylactic treatment both, orthopaedic (median 8, range 2-12) and radiological scores (median 19.5, range 2-47) deteriorated after 3 years. Prior to onset of prophylaxis no or only one joint bleeding occurred in treatment group I. In group II, a median of 6 joint bleeds (range 1-8) were reported before prophylaxis was started. Patients of group III usually experienced a median of more than 10 joint haemorrhages (range 6-10 or more). Under prophylactic treatment the number of joint bleedings decreased significantly in groups II and III. However, radiological and orthopaedic scores increased as a sign of progressing osteoarthropathic alterations in patients reporting more than 6 joint haemorrhages before onset of prophylaxis whereas no joint alterations could be assessed in patients with no or only one joint bleeding episode prior to prophylaxis. Even a small number of joint bleedings seems to cause irreversible osteoarthropathic alterations leading to haemophilic arthropathy. Once apparent, further progression of joint damage could not be arrested despite of prophylactic treatment (group II and III). In order to prevent haemophilic arthropathy, effective prophylaxis should be started before or at least after the first joint bleeding in severe haemophilia A and B.

Selective cytotoxic activity of a novel ribonucleoside diphosphate reductase inhibitor MDL-101,731 against thyroid cancer in vitro.

The dramatically increased number of new cases of disseminated children thyroid cancer in Belarus after the Chernobyl accident requires development of novel strategies to treat this disease. In addition to conventional therapy using radioiodine, chemotherapy with new effective drugs can be an alternative kind of treatment. We tested the antitumor activity of (E)-2'-fluoromethylene-2'-deoxycytidine (MDL-101,731), a ribonucleoside diphosphate reductase inhibitor against three thyroid carcinoma cell lines established from anaplastic (8505C), papillary (B-CPAP) and poorly differentiated papillary (BHT-101) cancer. MDL-101,371 decreased both cell growth and DNA synthesis of tumor cells at concentrations lower than 100 nM, while the concentrations higher than 5000 nM showed only moderate effects on growth of normal human fibroblasts. The effects of MDL-101, 371 on tumor cells were associated with induction of apoptosis, as demonstrated by DNA fragmentation assay. Flow cytometric analysis of the expression of apoptosis-related genes revealed the increased levels of Fas-antigen, whereas the levels of Bcl-2 were not significantly influenced in thyroid cancer cells treated with MDL-101,731. These results demonstrated that MDL-101,731 is a potent antitumor agent against cultured thyroid cancer cells due to its ability to induce apoptosis in association with increased Fas expression.

Cytotoxicity of L-cycloserine against human neuroblastoma and medulloblastoma cells is associated with the suppression of ganglioside expression.

BACKGROUND: Human neuroblastoma and medulloblastoma express abnormal ganglioside patterns especially GD2 and GM2 which are important for tumour growth. We tested the effects of L-cycloserine (L-CS), a potent inhibitor of synthesis of glycosphingolipids, on the growth, viability and expression of GD2 and GM2 in neuroblastoma and medulloblastoma cells. MATERIALS AND METHODS: The cytotoxic effects of L-CS were tested using the MTT dye reduction assay on four neuroblastoma (IMR-32, SK-N-SH, UKF-NB-2 and UKF-NB-3), two medulloblastoma (D283 and D341) and normal human fibroblasts and epithelial cell lines. In some experiments cytotoxicity of L-CS was tested in the presence of exogenous GD2 and GM2. The expression of GD2 and GM2 was analysed by flow cytometry. The antitumoral effects of L-CS in vivo were assessed on established xenografts of UKF-NB-3 or D283 cells in athymic (nude) mice using systemic administration of the drug (150 mg/kg intraperitoneally, once per day on 20 consecutive days). RESULTS: In vitro experiments revealed that L-CS was toxic for tumour cells at concentrations ranging from 0.5 to 20 micrograms/ml without any significant effects on normal fibroblasts and epithelial cells. L-CS treatment of UKF-NB-3 and D283 cells significantly inhibited expression of GD2 and GM2. The addition of exogenous GD2 and GM2 to culture medium partially prevented cytotoxic effects of L-CS on tumour cells. In vivo treatment resulted in complete tumour regression of UKF-NB-3 xenografts whereas growth of D283 xenografts was reduced by 60%. CONCLUSIONS: L-CS is a selective antitumoral agent for neuroblastoma and medulloblastoma cells with the ability to reduce expression of tumour associated gangliosides. In vivo experiments suggest that L-CS may be effective drug for treatment of neuroblastoma and medulloblastoma.

Prevention of joint damage in hemophilic children with early prophylaxis.

Radiological and orthopaedic outcome in severe and moderate haemophilia A and B patients undergoing long-term prophylactic treatment were prospectively investigated focusing on the age of onset of prophylaxis and the number of joint bleedings prior to treatment. We report on 21 patients with severe and moderate haemophilia A and B receiving prophylactic treatment of between 3.1 and 16.1 years duration. Three patient groups were evaluated according to the age at onset of prophylaxis. In group I (n = 8) prophylactic treatment was initiated in the first 2 years of life. Patients of group II (n = 6) received prophylaxis at the age of 3-6 years. Late-onset or secondary prophylactic treatment was started at the age of 6 years and above in 7 patients (group III). All patients received virus-inactivated F VIII or F IX concentrates at dosages of 30-40 IU, in some cases up to 50 IU/kg body weight i. v. three times per week for those with haemophilia A and twice per week for those with haemophilia B. Elbow, knee and ankle joints were investigated at 3-4 yearly intervals according to the radiological and orthopaedic scores recommended by the World Federation of Haemophilia (WFH). The total number of joint bleedings before and after start of prophylaxis were recorded in all patients. In group I 7 out of 8 patients had unaffected joints with constant radiological and orthopaedic scores of zero or 1, after a median of 11.25 years of prophylactic treatment. One patient in this group demonstrated mild radiological alterations (score 4). Patients of group II showed neither radiological nor orthopaedic alterations at study entry. Worsening joint scores could be detected despite ongoing prophylaxis after the 3-year interval (median orthopaedic score 4, median radiological score 8). Treatment group III already showed considerable joint damage at study entry with a median radiological score of 11 (0-33) and a median orthopaedic score of 4 (0-11). Despite prophylactic treatment both, orthopaedic (median 8, range 2-12) and radiological scores (median 19.5, range 2-47) deteriorated after 3 years. Prior to onset of prophylaxis no or only one joint bleeding occurred in treatment group I. In group II, a median of 6 joint bleeds (range 1-8) were reported before prophylaxis was started. Patients of group III usually experienced a median of more than 10 joint haemorrhages (range 6-10 or more). Under prophylactic treatment the number of joint bleedings decreased significantly in groups II and III. However, radiological and orthopaedic scores increased as a sign of progressing osteoarthropathic alterations in patients reporting more than 6 joint haemorrhages before onset of prophylaxis whereas no joint alterations could be assessed in patients with no or only one joint bleeding episode prior to prophylaxis. Even a small number of joint bleedings seems to cause irreversible osteoarthropathic alterations leading to haemophilic arthropathy. Once apparent, further progression of joint damage could not be arrested despite of prophylactic treatment (group II and III). In order to prevent haemophilic arthropathy, effective prophylaxis should be started before or at least after the first joint bleeding in severe haemophilia A and B.

Azidothymidine resistance of H9 human T-cell lymphoma cells is associated with decreased sensitivity to antitumor agents and inhibition of apoptosis.

Biology of HIV-1 associated neoplasias is modulated by viral and host factors. In addition the development of tumors and their response to therapy may be further influenced by long-term treatment of HIV-1 patients with nucleoside analogs such as AZT (3'-azido-3'deoxythymidine), ddI (2',3'-dideoxyinosine), ddC (2',3'-dideoxycytidine), d4T (2',3'-didehydro-2'3'-dideoxythymidine), and 3TC [(-)-beta-L-2',3'-dideoxy-3'-thiacytidine] alone or in combination. As these compounds can trigger mechanisms involved in chemoresistance, we tested whether prolonged in vitro treatment of H9 cells (T-cell lymphoma) with AZT alters sensitivity of lymphoma cells to antitumor agents used for AIDS-associated malignancies. H9 cells grown for more than two years in medium containing 250 microM AZT developed resistance to the toxic effects of AZT while retaining sensitivity for other nucleoside analogs including ddC or cytosine arabinoside (ARA-C). These cells designated H9rAZT250 were 2 to 10-fold less sensitive to the toxic effects of antitumor agents, including cisplatin (CDDP), vincristine (VCR), doxorubicin (DOX) and etoposide (VP-16), when compared with parental H9 cells. The resistance of H9rAZT250 cells to antitumor agents was associated with inhibition of apoptosis as demonstrated by ultrastructural investigations and DNA-fragmentation assay (ELISA). The expression of the antiapoptotic gene bcl-2 was increased in H9rAZT250 cells while expression of other genes involved in the regulation of apoptosis such as c-myc, p53 and Fas was not changed. These results demonstrate that prolonged in vitro treatment of H9 lymphoma cells with AZT results in the development of resistance to antitumor agents in association with inhibition of apoptosis and increased expression of bcl-2. Therefore AZT long-term treatment of some HIV-1 patients with malignancies may have affected behavior of tumor cells including response to therapy.

Radiological and orthopedic score in pediatric hemophilic patients with early and late prophylaxis.

In order to evaluate joint alteration, 17 patients with hemophilia A and B were investigated over a period of 4 years (1993-1997). Patients were subdivided into two groups, according to therapy regimens. In group 1 (n=10) prophylactic treatment was initiated until the third year of life. In group 2 (n=7) patients received prophylactic treatment at the age of 5 years and above. To assess alterations in knee, elbow, and ankle joints, the radiological score and the physical examination score of the Orthopedic Advisory Committee of the World Federation of Hemophilia were used. The sum of the scores of these six joints was defined as the patient-dependent score. Patients of group 1 (median age at the end of observation: 10 years) reached a median radiological score of 1.0 (range: 0-13) and an orthopedic score of 0 (range: 0-4), whereas patients of group 2 (median age: 14 years) had a radiological score of 20 (range: 2-47) and an orthopedic score of 8 (range: 0-12), which shows a significant difference (p <0.01). In both treatment groups a manifestation or progression of arthropathic alteration was seen in those children who had repeated joint bleeding (>5) prior to the onset of prophylactic treatment (r=0.90, p>0.01). Altogether, two of 60 joints in group 1 and 12 of 42 joints in group 2 had a radiological score > or = 4. Elbow joints were more often affected than knee and ankle joints. In conclusion, the number of joint bleedings before prophylactic treatment was started influenced the progression of arthropathy even in patients with early onset of prophylaxis. The aim of treatment in severe hemophilia should be early prophylaxis before repeated joint bleeding occurs in order to prevent osteoarthropathic alteration.

Prevention of CNS recurrence in childhood ALL: results with reduced radiotherapy combined with CNS-directed chemotherapy in four consecutive ALL-BFM trials.

BACKGROUND: The introduction of cranial radiotherapy (CRT) has provided efficient control of overt or subclinical meningeosis in acute lymphoblastic leukemia (ALL). Especially due to the long-term toxicity of CRT, reduction or elimination of radiotherapy appeared mandatory after cure rates of more than 70% had been achieved in ALL. The Berlin-Frankfurt-Münster (BFM) Study Group initiated several attempts in certain ALL subgroups to omit or reduce CRT while using more CNS-directed chemotherapy but without extended intrathecal treatment during maintenance therapy. This analysis summarizes the essential results that are in particular relevant because irradiation of the central nervous system (CNS) has been further reduced in the most recent trial ALL-BFM 95. PATIENTS AND METHODS: More than 4000 patients enrolled between 1981 and 1995 in one of the last four ALL-BFM trials have been analyzed to demonstrate the efficiency of intensive systemic and intrathecal chemotherapy with or without reduced CRT in the prevention of CNS relapses. RESULTS: In trial ALL-BFM81, it was shown that only in low-risk (LR) patients preventive radiotherapy can be replaced safely by intermediate dose (0.5 g/m2) methotrexate (MHD-MTX). In intermediate risk (IR) patients this attempt failed: IR pts had 8 times more CNS relapses if treated by MHD-MTX without CRT. In the subsequent trial ALL-BFM 83, all pts received MHD-MTX. IR pts were randomly treated with 12 or 18 Gy of preventive CRT which did not result in a significantly different outcome. The results from the subsequent trial ALL-BFM 86, using a more intensive consolidation with high-dose methotrexate (HD-MTX), demonstrated that the elimination of CRT in low-risk ALL, the reduced CRT of 12 Gy for IR, 18 Gy for medium (MR), and the reduced CRT with 18 Gy for high risk (HR) ALL, respectively, was justified: the incidence of relapses with CNS involvement was reduced to less than 5% (Reiter et al. 1994, Blood 84: 3122). When even less intensive preventive CRT (12 Gy for all medium and high risk patients) was used in trial ALL-BFM 90, the rate of CNS-related relapses was again below 5%. HR patients now treated with more CNS-directed chemotherapy had the lowest rate of CNS-related relapses observed so far in the BFM trials, even though CRT was also reduced to 12 Gy. Patients with T-cell ALL were shown to be protected from CNS recurrence by the combination of CRT (12 Gy) and HD-MTX more effectively than by HD-MTX in consolidation and TIT therapy during maintenance, especially if they presented with high WBC as shown in a joint AIEOP/BFM analysis (Conter et al. 1997, JCO 15: 2786). Patients with overt meningeosis which are characterized by a high leukemic cell load at diagnosis had a rate of recurrences that was comparable to that of patients with high WBC but no CNS disease. CONCLUSION: Low-risk ALL patients can be efficiently prevented from CNS relapse by intensive systemic and intrathecal chemotherapy without CRT. Patients with intermediate or medium risk ALL, including T-cell ALL, did not suffer from more CNS or systemic relapses when CRT was reduced to only 12 Gy. Patients with inadequate response to therapy are at particularly high risk for relapse with CNS involvement. Therefore, more CNS-directed systemic and intrathecal chemotherapy was applied in trial ALL-BFM 90, combined with only 12 Gy cranial irradiation, and improved the control of CNS recurrence. It seems likely that larger subsets of B-precursor ALL can be protected from CNS-related relapse by intensive chemotherapy without extended IT treatment and without CRT. This is being investigated in the ongoing trial ALL-BFM 95.