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PubMed1986

Prognostic factors in non-Hodgkin's lymphoma.

The results obtained with the various types of treatment in non-Hodgkin's lymphoma are reviewed and the data from the recent EORTC trials are summarized. In patients with Stage I follicular histology, regional radiotherapy (RT) alone gives excellent results. The long-term relapse-free survival (RFS) is high and relapsing patients can be rescued by aggressive combination chemotherapy; initial chemotherapy with CVP improves RFS but not total survival (TS). In patients with Stage I diffuse histology, the long-term survival is less satisfactory. CVP chemotherapy does not improve either RFS or TS; therefore if adjuvant chemotherapy is justified, it should be more aggressive than CVP. In patients with Stage II follicular type, regional radiotherapy alone gives good results. The addition of abdominal bath irradiation to regional RT increases RFS but not TS. After relapse, patients can be rescued by combination chemotherapy. In patients with Stage II diffuse histology, extended RT followed by CVP gives poor results and RT should be combined with more aggressive combination CT; the preliminary results of an integrated alternating regimen being excellent. In patients with Stage III and IV follicular type, the 8 year TS of patients treated with combination CT regimen (CHVP) followed by localized irradiation is approximately 55%, however the indications for the various types of treatment are still unclear. In patients with diffuse Stage III and IV, the results obtained with a combination CT regimen (CHVP) are still unsatisfactory, but are better in patients treated by a more aggressive CT regimen (CHVP-Bleo-VCR). Therefore aggressive CT associated with localized irradiation appears to be the best treatment. Further research should aim to identify the optimal combination CT regimen. In patients with high grade lymphomas who have relapsed the use of bone marrow autografts will be investigated. The present data show that besides histological type and age, the main prognostic factor is total tumor body burden as assessed by clinical stage, number of involved lymph node areas, and bulk of the disease. The study of the biological characteristics of the disease may provide more powerful prognostic indicators.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Low-dose total body irradiation versus combination chemotherapy for lymphomas with follicular growth pattern.

The treatment of Non-Hodgkin's lymphomas with follicular growth pattern and advanced stage of disease remains controversial. Treatments varying from no initial treatment up to aggressive combination chemotherapy have been advocated. The EORTC Lymphoma Cooperative Group has performed a randomized prospective trial comparing short duration low dose total body irradiation (TBI) vs combination chemotherapy (CHVmP) + consolidation radiotherapy. Ninety-three patients were entered; of 84 evaluable patients, 44 received TBI and 40 CHVmP. Complete remission (CR) rates were 36%--TBI and 55%--CHVmP, but overall response rates were identical, 76 versus 69%. No significant difference in freedom from progression or survival was observed. No unexpected toxicity was seen. Although numbers are small, we cannot conclude that aggressive combination chemo-radiotherapy resulted in a better survival. Our analysis confirms that there is a constant risk of relapse. Other approaches should be explored if survival benefit is the ultimate goal in treatment of this patient population.

Adolescent↗
PubMed1991

A shuttle vector for analysis of illegitimate recombination in mammalian cells: effects of DNA topoisomerase inhibitors on deletion frequency.

To study the mechanism of illegitimate recombination in mammalian cells, we have developed a shuttle vector, pNK1, that contains three bacterial markers, amp (ApR), galK, and neo (KmR). The frequency of deletions occurring in autonomously replicating pNK1 DNA during the growth of monkey COS1 cells was measured by transfecting the plasmid into Escherichia coli cells and counting the number of galK- ApS double mutants among total KmR cells. This method allowed us to test the effects of topoisomerase inhibitors on deletion formation in mammalian cells. The DNA topoisomerase II (TopII) inhibitor, 4'-dimethylepipodophyllotoxin thenylidene-beta-D-glucoside (VM26), stimulated deletions in pNK1 DNA in monkey cells. Since VM26 does not inhibit the strand-break activity of TopII, but rather stabilizes an enzyme-DNA complex in which DNA is cleaved upon treatment with sodium dodecyl sulfate, it is implicated that TopII participates in the deletion process in mammalian cells.

Amsacrine↗
PubMed1990

Isolation and characterization of VP-16 resistant human leukemia cell line.

VP-16 resistant cells, designated VP-16K6-1 (K6-1) were isolated from human acute lymphoblastic leukemia cell line RPMI 8402. IC50 value against VP-16 were 11-fold higher than their sensitive parental cell line. The membrane permeability of the drug was not responsible for resistance in K6-1 cells. K6-1 cells showed resistance in drug-induced DNA strand breaks (single strand breaks) determined by the alkaline sucrose gradient sedimentation method. Dot-blot analysis of RNA extracted from 2 cell lines showed that the mRNA levels of DNA topoisomerase II in K6-1 cells decreased slightly compared with that of parent cells. However, Topo II activities were similar in wild-type and K6-1 cells. In addition, K6-1 cells exhibited cross-resistance only to VM-26. These data suggest that a reduced intracellular Topo II level may contribute to drug resistance as an important factor in K6-1 cells.

DNA Replication↗
PubMed1996

Effects of DNA topoisomerase inhibitors on nonhomologous and homologous recombination in mammalian cells.

To study the involvement of DNA topoisomerases in recombination in mammalian cells, we used gene transfer assays to examine the effects of DNA topoisomerase inhibitors on nonhomologous (illegitimate) and homologous recombination. The assays were performed by transfecting adenine phosphoribosyltransferase-deficient (APRT-) CHO cells with plasmids carrying the wild-type or mutant aprt genes and by treating the cells with the inhibitors, followed by subsequent cultivation to select for APRT-positive (APRT+) colonies. Treatments with DNA topoisomerase II inhibitors such as VP-16, VM-26, ICRF-193 resulted in a 3- to 5-fold stimulation of integration of both closed-circular and linearized plasmids carrying the wild-type aprt gene into the recipient genome through nonhomologous recombination. The same treatments also increased 6- to 9-fold and 3-fold the number of APRT+ recombinant colonies that were generated by cotransfecting two closed-circular plasmids with nonoverlapping defective aprt genes and their linearized equivalents, respectively. However, this cotransfection assay involved intrinsically nonhomologous recombination processes; normalization of the frequencies by dividing them with those of the above nonhomologous recombination revealed 2-fold enhancement of homologous recombination events between the circular mutant genes but not between the linear ones. In contrast, DNA topoisomerase I inhibitor, camptothecin, showed no such effect on either recombination. From these results, we discuss the function of DNA topoisomerases on recombination in mammalian cells.

Adenine Phosphoribosyltransferase↗
PubMed2004

Podophyllotoxin: distribution, sources, applications and new cytotoxic derivatives.

Several podophyllotoxin derivatives modified in the A, B, C, D and E rings were prepared from podophyllotoxin and methyl isoxazopodophyllic acid and evaluated for their cytotoxicity on several neoplastic cell lines. Chemical transformations performed on these compounds have yielded derivatives more potent and more selective that the parent compound. Most of the compounds maintained their cytotoxicity at the microM level. Distribution, biosynthesis, production, biotechnology, applications and synthesis have also been reviewed.

Cytotoxins↗
PubMed2001

Diva/Boo is a negative regulator of cell death in human glioma cells.

Diva is a novel proapoptotic member of the Bcl-2 protein family which binds apoptosis activating factor-1 (APAF-1). Diva is identical with Boo which was identified as a novel antiapoptotic Bcl-2 family protein. Here, we report that Diva promotes the cell cycle exit of human glioma cells in response to serum deprivation and inhibits apoptosis of these cells induced by CD95 ligand or chemotherapeutic drugs. In glioma cells, Diva interferes with apoptotic signaling downstream of cytochrome c release, but upstream of caspase activation, consistent with an inhibitory effect on the mitochondrial amplification step involving the apoptosome and APAF-1.

Apoptotic Protease-Activating Factor 1↗
PubMed1998

CD95-mediated apoptosis: no variation in cellular sensitivity during cell cycle progression.

Sensitivity of CD95-mediated apoptosis has been reported to vary during cell cycle progression (FEBS Lett. (1997) 412, 91-93). Here, we report that three human glioma cell lines with different p53 status (i) undergo growth arrest and synchronous cell cycle re-entry after prolonged serum deprivation, (ii) do not exhibit cell cycle-related changes in CD95 expression at the cell surface, and (iii) do not exhibit cell cycle-related changes in susceptibility to DC95 ligand-induced apoptosis. In contrast, cell cycle-specific activity was demonstrated for various cancer chemotherapy drugs. Further, CD95 expression and susceptibility to CD95 ligand-induced apoptosis does not vary during cell cycle progression of Jurkat T cells, HeLa cervical carcinoma and HepG2 hepatocellular carcinoma cells. These results do not support a role for the cell cycle phase as an important predictor of vulnerability to CD95-mediated apoptosis.

Antibiotics, Antineoplastic↗
PubMed1984

Does intravesical chemotherapy prevent invasive bladder cancer?

Intravesical chemotherapy has been shown to prolong the interval free of disease and to reduce the tumor recurrence rates in patients with superficial bladder cancer. These observations led us to consider whether a course of intravesical chemotherapy might provide a long-term decrease in the recurrent tumor rate or reduce the incidence of progression to invasive carcinoma. The records of 123 patients entered into a randomized multicenter protocol between 1975 and 1978 were examined. Patients had received a 1-year course of thiotepa or VM26, or transurethral resection alone. Mean followup was 47 months. Patients receiving thiotepa or VM26 had a lower rate of tumor recurrence, expressed as recurrences per 100 patient-months, than those undergoing transurethral resection only (5.25 versus 5.71 versus 7.98) but this was not statistically significant. However, 28 per cent of the controls required therapy besides transurethral resection to control the bladder cancer and 19 per cent died of advanced bladder cancer during followup. Only 15 per cent of the patients undergoing intravesical chemotherapy required therapy other than transurethral resection and only 3 per cent died of advanced carcinoma of the bladder. This finding suggests that intravesical chemotherapy given for 1 year is associated with a significant decrease in the incidence of tumor progression, and provides the justification to conduct future trials with extended followup.

Administration, Topical↗
PubMed2003

Dental abnormalities in children after chemotherapy treatment for acute lymphoid leukemia.

The frequency of dental abnormalities, such as delayed dental development, microdontia, hypoplasia, agenesis, V-shaped root and shortened root was evaluated in 76 acute lymphoblastic leukemia (ALL) pediatric patients who had been off chemotherapy for 6 months. These children had been subjected to one of the three Brazilian Protocols or the BFM86 Protocol. The patients were divided into three groups: Group I (GI; high risk) treated with one of the three Brazilian Protocols who received high-dose chemotherapy, intensive maintenance and cranial radiotherapy; Group II (GII; low risk) who were also treated with one of the three Brazilian Protocols using low-intensive chemotherapy with no radiotherapy; and Group III (GIII) based on the BFM86 Protocol. Of 76 children, 13 showed no dental abnormalities (8 were at the age of tooth formation). The remaining 63 children (82.9%) showed at least one dental anomaly. The abnormalities were probably caused by the type, intensity, frequency of the treatment and age of the patients at ALL diagnosis and this might have important consequences for the children's dental development.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1985

An alternating chemotherapy and radiotherapy combination for non-Hodgkin's lymphomas of unfavourable histologies: feasibility and preliminary results.

In 1980, on the basis of fundamental and clinical data, a protocol was developed at the Institut Gustave-Roussy, alternating eight monthly courses of chemotherapy (CHVP) and two or three radiotherapy sequences (15 Gy in 6 fractions of 10 days, each), to treat non-Hodgkin's lymphomas of unfavourable histologies, mainly stage II, presenting bulky tumours. Systemic, haematological and digestive tolerances were satisfactory. For 19 previously untreated stage II patients, overall survival and relapse-free survival after 30 months were 85 and 65%, respectively. Three of the relapses were observed in patients who did not receive the alternating schedule in an optimal way; this suggests that these results can be further improved.

Adolescent↗
PubMed2002

The role of caspases 9 and 9-short (9S) in death ligand- and drug-induced apoptosis in human astrocytoma cells.

Caspases are essential components of the mammalian cell death machinery. Caspase 9 is positioned at the apex of the pro-apoptotic signaling cascade induced by cytochrome c release from mitochondria. The splicing variant caspase 9-short (caspase 9S) lacks the catalytic domain and may therefore act as an endogenous inhibitor of caspase 9. Here, we report that human astrocytoma and neuroblastoma cell lines strongly express caspase 9 and 9S mRNA, whereas non-neoplastic human astrocytes show little caspase 9 and 9S mRNA expression. Transient overexpression of caspase 9S protects LN-229 astrocytoma cells from CD95 ligand (CD95L)-mediated apoptosis. However, stable overexpression of either caspase 9 or caspase 9S does not alter the sensitivity of LN-18 and LN-229 astrocytoma lines to CD95L or cytotoxic drugs. We conclude that the expression levels of caspase 9 or caspase 9S do not play a major role in determining vulnerability to apoptosis in human astrocytoma cells.

Alternative Splicing↗
PubMed2001

Topoisomerase IIalpha and other drug resistance markers in advanced non-small cell lung cancer.

Resistance to chemotherapy is common in non-small cell lung cancer. The aim of this study was to investigate the prognostic impact of in vitro established drug resistance markers on the response to chemotherapy in patients with advanced non-small cell lung cancer. Samples of 38 patients were analyzed by immunohistochemical staining, for topoisomerase IIalpha and IIbeta, Ki-67, MRP and LRP. In addition, mutation analysis of the topoisomerase IIalpha gene, the B/DNBS and the Tyr804 region, was performed. Lung tumor biopsies were taken prior for treatment with one of the following regimens; cisplatin/paclitaxel, cisplatin/VM26 or VP16, or carboplatin/VP16/ifosfamide. Seventeen patients obtained a partial response, 12 had stable disease and nine patients had progressive disease. None of the investigated markers was related with overall response rate. In one sample a point mutation in the B/DNBS region of the topo IIalpha gene was detected which substitutes IIe(510) with Val. This tumor had a partial response to four courses of cisplatin/VP16 treatment. The survival analysis showed that the patients with high topo IIalpha expressing tumors had a significantly worse survival compared with the patients with low or intermediate topo IIalpha expressing tumors. In conclusion, no relation was observed between expression of topoisomerase IIalpha, IIbeta, Ki-67, MRP or LRP and response rate. Furthermore, worse survival was seen in patients with high topoisomerase IIalpha expressing tumors. In one tumor sample, a newly described mutation in the B/DNBS region of the topo IIalpha gene was detected, which does not appear to be related to drug resistance.

ATP-Binding Cassette Transporters↗