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A comparative clinical trial of 5-azacytidine and guanazole in previously treated adults with acute nonlymphocytic leukemia.

Adults with previously treated acute nonlymphocytic leukemia received either 5-azacytidine or guanazole in a randomized study. Eighteen patients were treated with 5-azacytidine at a dosage of 200-250 mg/m2/day X 5 intravenously (i.v.) and six achieved a remission (five complete). The median duration of complete remission was 100 days. Among the 12 patients who received guanazole, at a dosage of 25-30 g/m2/day X 5 by continuous i.v. infusion, only one partial remission ensued. Pm 600 WBC/mm3) than nonresponders (median 1700 WBC/mm3). Both the time taken to reach the nadir white blood coung (median, 14 days) and theduration of the nadir (median, 17 days) were long after each course of 5-azacytidine, particularly for those patients who achieved a remission. Principal toxicities seen after 5-azacytidine administration were gastrointestinal tolerance, fever, and neuromuscular toxicity. Fever was the principal toxicity observed after guanazole therapy; one patient developed erythema nodosum with arthralgias and another, recurrent pulmonary infiltrates. Survival from the start of therapy was clearly longer for the patients receiving 5-azacytidine (median 140 days) because of the prolongation of survival seen in the responding patients (median 266 + days). 5-Azacytidine has significant activity as an induction agent in adults with acute nonlymphocytic leukemia, but guanazole does not appear to be of particular value for patients with this disease.

Acute Disease↗

Diffuse pulmonary malignant mesothelioma: response to doxorubicin and 5-azacytidine.

A 46-year-old patient who developed a right pleural mesothelioma 18 years after asbestos exposure was found to have diffuse reticular nodular infiltrates in both lungs. Lung biopsy by fiberoptic bronchoscopy revealed alveolar and interstitial spread of the neoplastic cells. A dramatic clinical and radiologic response occurred after treatment with a combination of doxorubicin (Adriamycin) and 5-Azacytidine.

Azacitidine↗

5-azacytidine in acute leukemia.

101 patients with acute leukemia in relapse were treated with 5-azacytidine according to three schedules: Regimen A--300 mg/m2(day divided intravenously at 8 hour intervals for 5 days; Regimen B--750 mg/m2 as a single iv pulse dose administered at 2 to 3 weeks intervals; and Regimen C--300 mg/m2/day by continuous infusion daily for 5 days. Twelve patients achieved a complete remission (CR) and six achieved a partial remission (PR) for an overall 18% response rate. Of 78 patients receiving an adequate trial the response rate was 23%. An average of 1.5 courses and a median of 5 weeks were necessary to achieve a response. The median duration of CR patients was 21 weeks and for PR patients it was 5 weeks. Response rates were 24% for Regimen A, 0 for Regimen B, and 1 of 8 for Regimen C. The CR rate for AML and AMML was 13%. Two of eight AMoL patients achieved a CR. Only 2 of 23 ALL patients responded, one of whom achieved a CR. Toxicity included moderate to severe nausea and vomiting, diarrhea, stomatitis, skin rash, and prolonged myelosuppression. 5-azacytidine has significant activity in the acute nonlymphoblastic leukemias.

Acute Disease↗

Further experience in treating patients with hepatocellular carcinoma in Uganda.

One hundred and thirty nine patients with histologically proven hepatocellular carcinoma (HC) were admitted to the Uganda Cancer Institute for treatment. The patients were considerably younger and seemed to have more advanced disease than HC patients in Europe and in North America. Of the 99 evaluable patients, 50 received Adriamycin intravenously; of these, 44% responded, with 10% achieving complete responses. Intraarterial Adriamycin tended to increase the response rate to 75%, but this may be merely a reflection of patient selection. Combination of Adriamycin with other drugs (dichloromethotrexate, 5-azacytidine, Rezoxane and cyclophosphamide) did not enhance its therapeutic effectiveness. The alphafetoprotein response curves observed when Adriamycin was combined with dichloromethotrexate suggested possible antagonisms between the two drugs. Hepatic artery ligation (HAL) is a good and simple palliative procedure with response rates similar to i.v. Adriamycin. However, the administration of Adriamycin after HAL tended to improve on response rates and survival. The toxicities observed were mainly myelosuppression, gastrointestinal disturbance, alopecia, and hyperpigmentation of the skin and mucous membranes.

Adolescent↗

Effect of schedule on activity and toxicity of 5-azacytidine in acute leukemia: a Southwest Oncology Group Study.

One-hundred-fifty-four patients with acute leukemia and extensive prior chemotherapy were treated with 5-Azacytidine and evaluated according to five different schedules. One-hundred-twenty patients received adequate trials; 34 patients died within 14 days of onset of treatment. Nine patients achieved a complete remission (CR) and two achieved a partial remission. Although two of the treatments have a higher remission rate, the data were not statistically significant. The median time to CR was 48 days (range 21-173). The median duration of CR was 65 days (range 39-369). There was no difference in response rate according to cell type. The median age of responders was 31 years, and 39 years for nonresponders. Proportionately there were more women among responders (5M/6F) and more men (70M/39F) among nonresponders. At onset of therapy the median leukocyte counts were similar between responding (5.4 X 10(3)) and nonresponding (5.7 X 10(3)) patients, but the proportion of leukemic cells was significantly higher among nonresponding patients (46% vs. 7%). Toxicities included nausea, vomiting, diarrhea, skin rash, myalgias, prolonged myelosuppression, hypotension, and central nervous system stupor and/or coma. Lower dose continuous infusion schedules of five-, seven-, and ten-days duration appear effective and were associated with less toxicity.

Acute Disease↗

Response to 5-azacytidine in patients with refractory acute nonlymphocytic leukemia and association with chromosome findings.

Fifteen patients with acute nonlymphocytic leukemia (ANLL) who either had a relapse after a previous complete remission (nine patients) or progressive disease after initial induction attempts with combination chemotherapy (six patients) were treated with 5-azacytidine. Five patients (33%) achieved a complete remission (CR); of these, three had a relapse and died 30, 35, and 38 weeks after 5-azacytidine therapy was begun. Two patients are still alive at 39 and 138 weeks. Chromosomes were analyzed at the time of diagnosis; ten patients had a normal karyotype and five had an abnormal karyotype. Three of the five CR patients had an abnormal karyotype initially. Two of these individuals had a translocation of chromosomal material from a No. 8 chromosome to a No. 21 chromosome, t(8;21); this particular translocation has been associated with a better prognosis than have other types of chromosomal abnormalities in patients with ANLL. Even when abnormal chromosomes are present, 5-azacytidine can induce complete remission in patients with previously treated ANLL.

Adult↗

Improvement in outcome for children with acute nonlymphocytic leukemia. A report from the Childrens Cancer Study Group.

The Childrens Cancer Study Group conducted four therapeutic studies on a total of 1006 children with acute nonlymphocytic leukemia from 1972 to 1983. This report describes the therapeutic strategies of these studies and examines trends in induction rates and long-term outcome over this period. The remission induction rate has changed from 58% in 1972 to 1975 to 80% for the period 1980 to 1983, and the induction mortality dropped from 20% to 6%. Four-year survival probabilities from time of diagnosis have almost doubled from 19% to 36%. Few deaths occurred more than 5 years after diagnosis: children surviving in first remission beyond 5 years had a 92% survival rate and an 86% relapse-free survival rate over the next 5 years. In contrast, median survival after a marrow relapse was less than 6 months and the 6-year survival probability was 4%. The leukocyte count was a significant prognostic factor, and although the mortality for infants was high initially, long-term survival was not decreased.

Antineoplastic Combined Chemotherapy Protocols↗

Patterns of differentiation in extraosseous Ewing's sarcoma cells. An in vitro study.

BACKGROUND: In vitro, tissue culture-associated differentiation assays have facilitated the identification of multiple tumor-cell types. METHODS: We have investigated the capability of differentiation of three extraosseous Ewing's sarcoma cell lines toward a neural and muscular direction by in vitro stimulation with dibutyryl cyclic adenosine-monophosphate (db cAMP) and 5-azacytidine, respectively. RESULTS: Elongation of cytoplasmic processes and increase of neural markers chromogranin, S-100 protein, and glial fibrillary acidic protein were observed after db cAMP treatment of these lines and neurosecretory granules as well as myelin figures were demonstrated ultrastructurally. These results support the existence of several pathways of neural differentiation in vitro--neuroblastic, Schwannian, and central glial--in stages of maturation more advanced than those previously reported in Ewing's sarcoma of bone. The cell lines showed no definitive myoblastic differentiation after 5-azacytidine treatment. CONCLUSIONS: These data suggest that these three extraosseous Ewing's sarcoma cell lines configurate a heterogeneous group of tumors with respect to capability of differentiation into the neural lineage, arrested at more advanced stages of neural crest development than Ewing's sarcoma of bone and without capability of myoblastic differentiation with 5-azacytidine.

Abdominal Neoplasms↗

CpG hypermethylation of the promoter region inactivates the estrogen receptor-beta gene in patients with prostate carcinoma.

BACKGROUND: The down-regulation of the estrogen receptor-beta (ERbeta) gene is associated with several malignancies, including prostate carcinoma. The purpose of the current study was to investigate the mechanisms of ERbeta inactivation through the analysis of CpG methylation of the promoter region of ERbeta gene. METHODS: ERbeta protein expression was examined by immunohistochemistry in 23 cases of human prostate carcinoma and 40 cases of benign prostatic hyperplasia (BPH). DNA was extracted from these tissues and processed for sodium bisulfite genomic sequencing. The percentage of methylation of CpG sites in the promoter region of ERbeta (-376 to -117), which contains 19 CpG sites, was determined from genomic sequencing data. The prostate carcinoma cell lines DU145 and ND1 were treated with the demethylating agent 5-AZAC and ERbeta mRNA expression was analyzed by reverse transcriptase-polymerase chain reaction. RESULTS: In BPH tissues, ERbeta protein expression was found mainly in epithelial cells. ERbeta protein expression was lacking in 83% of prostate carcinoma samples (19 of 23 samples) whereas all cases of BPH (40 of 40) demonstrated expression of ERbeta protein. The mechanism of inactivation of the ERbeta gene in prostate carcinoma was CpG methylation because the degree of methylation at all CpG sites within the promoter region between -376 and -117 was higher in prostate carcinoma samples compared with BPH tissues. Nine of 19 CpG sites within the promoter region of ERbeta displayed significant differences in methylation between prostate carcinoma and BPH samples. The prostate carcinoma cell lines appeared to lack ERbeta expression. However, 5-AZAC treatment restored ERbeta expression in those cell lines, suggesting that methylation inactivates the ERbeta gene in prostate carcinoma. CONCLUSIONS: The results of the current study demonstrate, for what we believe to be the first time, that the inactivation of the ERbeta gene in prostate carcinoma occurs through CpG methylation of the promoter region of this gene.

Azacitidine↗

Unbalanced expression of HLA-A and -B antigens: a specific feature of cutaneous melanoma and other non-hemopoietic malignancies reverted by IFN-gamma.

Conflicting evidences suggested that levels of HLA-A and -B antigens expressed on normal and neoplastic cells of given individuals are genetically predetermined, or, on the other hand, regulated by molecular mechanisms generating the down-regulated expression of HLA-B antigens frequently observed on melanoma cells. In our study, we quantitated, both at the protein and mRNA level, the amounts of HLA-A and -B antigens constitutively expressed on 23 primary cultures of metastatic melanomas and on autologous peripheral blood mononuclear cells (PBMC). Flow cytometric analyses identified a significantly (p < 0.01) lower expression of HLA-B antigens on melanoma cell cultures but not on autologous PBMC. Consistently, lower amounts of HLA-B antigens mRNA were detected by RNase protection assay exclusively in neoplastic cells. This unbalanced expression of HLA-A and -B antigens was readily reverted by interferon (IFN)-gamma but not by the DNA hypomethylating agent 5-aza-2'-deoxycytidine in 4 melanoma cell cultures investigated. Significantly (p < 0.05) lower levels of HLA-B antigens were also detected on cells from solid malignancies of different histotypes but not on neoplastic cells from hemopoietic neoplasms; levels of HLA-B antigens were rapidly up-regulated by IFN-gamma exclusively on non-hemopoietic transformed cells. Together, these data strongly argue against a genetic predetermination of the amounts of HLA-A and -B antigens expressed on normal and neoplastic cells of distinct melanoma patients and suggest that constitutively low levels of HLA-B antigens are a specific feature of non-hemopoietic transformed cells that is controlled by common regulatory mechanism(s) and that is possibly shared by non-hemopoietic normal cells.

Antimetabolites, Antineoplastic↗

Silencing of the caspase-1 gene occurs in murine and human renal cancer cells and causes solid tumor growth in vivo.

Renal cell cancer is a unique solid tumor that occasionally shows spontaneous regression even at an advanced stage, of which the underlying mechanism is not well understood. To investigate a potential role of the pro-apoptotic molecule caspase-1 in the growth regulation of renal cell cancer, we created transfectants expressing exogenous caspase-1 from a murine renal cancer cell line, Renca. Overexpression of caspase-1 did not affect the growth of Renca cells in vitro at the exponential phase but induced apoptotic cell death at 50% to 75% confluence, whereas control cells underwent apoptosis only after reaching 100% confluence. When implanted into the flank of a syngeneic BALB/c mouse, caspase-1-overexpressing Renca cells did not effectively establish growth as a solid tumor, forming a measurable tumor in only 7 of 11 (64%) animals, whereas control cells formed a tumor in 6 of 6 (100%) animals. The growth of tumors from caspase-1-overexpressing cells slowed down markedly after the tumors reached 5 to 10 mm in diameter, and histological examination of such tumors revealed numerous apoptotic cells positively stained by TUNEL assay. Interestingly, endogenous caspase-1 was not detected in the tumors from control cells, which re-expressed caspase-1 when they were re-cultured and exposed to a demethylation reagent, 5-aza-2'-deoxycytidine. Furthermore, treatment of a human renal cancer cell line, ACHN, with 5-aza-2'-deoxycytidine also caused recovery of caspase-1 expression, which was not detected before treatment. These data suggest that silencing of caspase-1 through DNA methylation may be involved in the oncogenesis of some renal cell cancers growing as a solid tumor.

Animals↗

PAX6 methylation and ectopic expression in human tumor cells.

The mechanisms underlying the de novo methylation of CpG islands in human cancer remain almost completely unknown. We used a methylation-sensitive arbitrarily primed polymerase chain reaction (Ms AP-PCR) technique to scan genomic DNA for differential methylation patterns and identified a 550 bp band that was hypermethylated in a majority of colon and bladder cancer cells. This band corresponded to a CpG-rich region in exon 5 of PAX6, which is a highly conserved transcription regulatory factor involved in embryogenesis. Interestingly, exon 5 was very frequently methylated in solid tumors compared with adjacent normal tissues, 17 out of 27 (63%) in bladder, and colon, but the promoter remained unmethylated in all these cases. This methylation was not effective in blocking transcription since ectopic expression of PAX6 was seen in several tumors and cell lines with extensive exon 5 methylation. De novo methylation of the promoter was only seen in tumor cell lines and was associated with gene silencing since treatment with 5-aza-2'-deoxycytidine restored expression to the cells and resulted in a less methylated promoter. Thus, ectopic expression and hypermethylation of exon 5 of PAX6 demonstrate that methylation within a transcribed region, as opposed to promoter methylation, does not block gene expression.

Antimetabolites, Antineoplastic↗

Inactivation of the human androgen receptor gene is associated with CpG hypermethylation in uterine endometrial cancer.

Androgens mediate their effects through the androgen receptor (AR) and have antiproliferative effects on uterine endometrial cells. In this report, we investigated methylation status and the expression of the AR gene in normal endometrium and uterine endometrial cancer (UEC) tissues using methylation-specific polymerase chain reaction (MSP) and immunohistochemical staining. Seventy of 89 cancer samples were AR negative, although 39 of 46 normal samples were AR positive by immunohistochemistry. By MSP, 64 of 89 cancer samples showed only methylated AR alleles, although all normal tissues showed both unmethylated and methylated AR alleles. To determine whether similar changes occurred in methylation status in the UEC carcinogenesis, we studied AR methylation using pairs of cancerous and normal samples from 28 patients. Twenty-three of 28 cancer samples showed only methylated AR alleles, although all normal samples showed both unmethylated and methylated alleles. All of the 23 cancer samples that lost unmethylated alleles were negative for AR by immunohistochemical analysis. Reverse transcription-polymerase chain reaction was performed by using UEC cell lines with and without treatment by the demethylating reagent 5-aza-2'-deoxycytidine. No AR expression was found in any of the UEC cell lines, except for MFE-296 without 5-aza-2'-deoxycytidine. Treatment with 5-aza-2'-deoxycytidine restored AR expression in all of the UEC cell lines that showed no AR expression before treatment. This study is the first to report that the possible mechanism of AR inactivation in endometrial cancer is through hypermethylation of the AR gene CpG islands.

Alleles↗

Two-dimensional database of a Burkitt lymphoma cell line (DG 75) proteins: protein pattern changes following treatment with 5'-azycytidine.

Hypermethylation is an important mechanism for repression of tumor gene suppressor in cancer. The drug 5'-azacytidine (AZC) has been used as demethylating agent to induce the expression of previously silencing genes. In the present work, we attempted to determine, using proteomics, the changes in protein expression profiles following a treatment of an Epstein Barr virus (EBV)-negative Burkitt lymphoma (BL) cell line DG 75. The effects of the treatment in terms of cell viability and growth were first examined. The following observations were made: AZC treatment led to (i) a decrease in cell growth with an arrest of the cell at G0/G1 phase of the cell cycle, (ii) the expression of p16, a tumor-suppressor gene whose expression was dependent on its promoter demethylation. Proteomic study evidenced that AZC treatment affected protein expression in two different ways. Twenty-one polypeptides were down-expressed, while 14 showed an increased expression. Some of the upregulated proteins appeared related to the energy metabolism, to organization of cytoskeletal structures, and to cell viability and protein synthesis. We also established a reference map for proteins in DG 75 cell line, comprising 74 different polypeptides corresponding to 67 proteins. This map will be accessible via Internet as a resource for proteome analyses of B-cells. Taken together, the results presented here highlight new insights into lymphoma cell gene regulations following a treatment of lymphoma cells with AZC and illustrate a use of proteomics to evidence the direct and indirect effects of a drug and the pathways it possibly regulates.

Antimetabolites, Antineoplastic↗

Demethylation in the 5'-flanking region of mouse cellular retinoic acid binding protein-I gene is associated with its high level of expression in mouse embryos and facilitates its induction by retinoic acid in P19 embryonal carcinoma cells.

The mouse cellular retinoic acid binding protein-I (CRABP-I) gene is specifically up-regulated by retinoic acid (RA) in P19 mouse embryonal carcinoma cells, and its expression in animals is spatially and temporally restricted to RA-sensitive tissues during embryonic development. This study demonstrates that, in adult mouse tissues and P19 cells where the expression of CRABP-I is detected at the basal level, the 5'-flanking region of the CRABP-I gene is hypermethylated at the C residues of all the Hpa II sites. Conversely, in mouse embryos during early stages of development when the expression of CRABP-I gene is detected at a much higher level, this region is demethylated at these Hpa II sites. In P19, enhancement on the RA-induced up-regulation of CRABP-I can be observed in cells treated with 5-azacytidine (5-AzaC) in conjunction with RA, where partial demethylation in the 5'-flanking region of CRABP-I gene is observed. Nuclear run-on experiments indicate that increased message levels of CRABP-I in P19 cells can be accounted for, at least partially, by increases in its transcription rates. The induction of retinoic acid receptor (RAR) beta by RA can also be enhanced by 5-AzaC, but to a much lesser degree. In contrast, all the Hpa II sites in the structural gene portion, at least in the first two exons, are fully demethylated at the C residues.

Animals↗

5-Azacytidine supports the long-term repopulating activity of cord blood CD34(+) cells.

DNA methylation plays important roles in a wide range of biological phenomena, especially in the embryonic development and tumorigenesis. However, correlations between differentiation and DNA methylation have not been clarified well in each differentiation system. In this study, we focused our attention on regulatory roles of DNA methylation in normal hematopoietic differentiation using a demethylating reagent, 5-azacytidine (5-AzaC). As a source of hematopoietic progenitor cells, we used CD34(+) cells prepared from human umbilical cord blood and examined the effects of 5-AzaC on the colony-forming activity and the long-term culture-initiating (LTC-IC) activity of these cells. 5-AzaC treatment increased LTC-IC frequency 1.57- to 2.50-fold as compared to the nontreated control. In parallel to this, immunoblotting analysis showed that the intensity of overall DNA methylation decreased after 5-AzaC treatment. These results indicated the involvement of DNA methylation and demethylation in controlling immaturity of hematopoietic progenitor cells and the usefulness of 5-AzaC for regulating this immaturity.

Antigens, CD34↗

Second complete remission in an elderly patient with acute myeloid leukemia retreated with decitabine.

A 67-year-old man with acute myeloid leukemia (AML) was treated with low-dose decitabine. He achieved a complete remission (CR) after two cycles of therapy, and he remained in remission during 1 year of treatment. He developed recurrent AML after discontinuation of decitabine. He was retreated with decitabine and again achieved a CR, which has been maintained for 6 months. This case demonstrates that durable responses can occur upon retreatment with decitabine.

Aged↗