Complementary and alternative groups contemplate the need for effectiveness, safety and cost-effectiveness research.

OBJECTIVE: To examine the views of complementary and alternative medicine (CAM) groups on the need to demonstrate the effectiveness, safety and cost-effectiveness of their therapies and practices. DESIGN: Qualitative interviews were conducted with 22 representatives of three CAM groups (chiropractic, homeopathy and Reiki). Qualitative content analysis was used to identify similarities and differences among and across groups. SETTING: Ontario, Canada. RESULTS: There were striking differences in the views of the three sets of respondents. The chiropractors agreed that it was essential for their group to provide scientific evidence that their interventions work, are safe and cost-effective. The leaders of the homeopathic group were divided on these points and the Reiki respondents showed virtually no interest in undertaking such research. CONCLUSIONS: CAM groups that are more formally organized are most likely to recognize the importance of scientific research on their practices and therapies.

Structure-activity studies of antitumor agent irofulven (hydroxymethylacylfulvene) and analogues.

Many analogues of the antitumor agent irofulven have been readily prepared by replacing the allylic hydroxyl with a variety of nucleophiles. Analogues of acylfulvene (the precursor to irofulven) were also prepared by Michael reaction with acrolein. The toxicity of the analogues was determined, as well as preclinical antitumor activity. Several analogues exhibited good activity in mouse xenografts. Structural requirements for activity are discussed.

Sesquiterpenes from the basidiomycete Omphalotus illudens.

A new sesquiterpene, omphadiol (4), has been isolated from cultures of Omphalotus illudens. Several known compounds, including illudosin (1), were also obtained. Structures were determined using MS, NMR, and X-ray techniques.

Preparation and biological activity of amino acid and peptide conjugates of antitumor hydroxymethylacylfulvene.

The primary hydroxyl group in hydroxymethylacylfulvene, a potent antitumor drug, is readily replaced by thiols including cysteine, N-acetylcysteine, homocysteine, and glutathione. Best yields are obtained when reaction is carried out in the presence of dilute sulfuric acid. A variety of sulfur-containing analogues have been prepared, and their toxicity to tumor cells was examined.

Efficacy of MGI 114 (HMAF) against the MRP+ metastatic MV522 lung carcinoma xenograft.

This study is part of an effort to evaluate efficacy of the novel agent MGI 114 (HMAF) against tumors resistant to conventional chemotherapeutic agents. MGI 114 is a novel semisynthetic anticancer agent currently in chemotherapeutic phase II trials to evaluate activity against various solid tumors. Previous studies indicate MGI 114 was active against human MDR1/gp170+ solid tumor xenografts. Recent evidence suggests overexpression of the MRP protein may also be clinically relevant to development of drug resistance in solid tumors. We evaluated the efficacy of MGI 114 against a human MRP+ lung carcinoma xenograft. Parent MV522 lung carcinoma cells were transfected with a MRP cDNA expression vector and resistant cells selected by exposure to vinblastine (30-fold resistance). Analysis of resistant clones indicated 20- to 40-fold increases in expression of both MRP mRNA and MRP protein. Administration of MGI 114 at the maximum tolerated dose (7 mg/kg, 5 x/week for 3 weeks) to MRP tumor-bearing mice demonstrated this novel agent was active against MRP+ tumors and significantly extended their lifespan (p<0.001). In contrast, other cytotoxic agents had minimal activity against this MRP+ xenograft. These results indicate MGI 114 should retain activity in vivo against MRP+ tumor types. The development of this MRP+ xenograft model, in conjunction with the parent MV522 and MDR1/gp170+ xenograft models, will be useful for screening new classes of agents for activity against multidrug-resistant tumors.

Structural organization of the human gastrointestinal glutathione peroxidase (GPX2) promoter and 3'-nontranscribed region: transcriptional response to exogenous redox agents.

The flanking upstream and downstream regions of the human GPX270%). The human GPX2 promoter region was not G-C rich (<50% G+C) and classical TATA/CCAAT elements were not present. The ubiquitous SP1 and AP elements were present. Several GATA elements as well as liver-specific sites (HNF series) were present. Despite the unique intestinal specific expression of GPX2, classical intestine-specific sites were not detected in the flanking 5' or 3' regions. The ability of the GPX2 promoter to direct transcription was confirmed. Exogenous agents capable of producing oxidative stress, such as paraquat, could induce the transcriptional activity of the GPX2 promoter. Analysis of three previously reported polymorphism sites revealed that they represented the most common polymorphisms. Surprisingly, the human GPX2 promoter could direct transcription and respond to oxidative stress in the murine NIH3T3 fibroblast cell line, which is devoid of the ability to bind to a variety of intestinal specific elements. This finding suggests that the unique intestinal specific expression of GPX2 may be due to elements in the intron, the flanking 3'-nontranslated region, or to elements existing even farther upstream. The ability of GPX2 to respond transcriptionally to redox stress is likely to be more physiologically relevant than post-transcriptional regulation which is dependent upon selenium availability.

Structural organization of the microsomal glutathione S-transferase gene (MGST1) on chromosome 12p13.1-13.2. Identification of the correct promoter region and demonstration of transcriptional regulation in response to oxidative stress.

The structure and regulation of the microsomal glutathione S-transferase gene (MGST1) are considerably more complex than originally perceived to be. The MGST1 gene has two alternative first exons and is located in the 12p13.1-13.2 region. Two other potential first exons were determined to be nonfunctional. The region between the functional first exons cannot direct transcription. Thus, one common promoter element directing transcription exists, and RNA splicing occurs such that only one of the first exons (containing only untranslated mRNA) is incorporated into each mRNA species with common downstream exons. MGST1 expression and regulation are therefore similar to those of other hepatic xenobiotic handling enzymes, which also produce mRNA species differing only in the 5'-untranslated regions to yield identical proteins. MGST1 was previously considered a "housekeeping" gene, as non-oxidant inducers had little effect on activity. However, the promoter region immediately upstream of the dominant first exon transcriptionally responds to oxidative stress. In this respect, MGST1 is similar to glutathione peroxidases that also transcriptionally respond to oxidative stress. The discovery that MGST1 utilizes alternative first exon splicing eliminates a problem with the first description of MGST1 cDNA in that it appeared that MGST1 expression was in violation of the ribosomal scanning model. The identification that the first exon originally noted is in fact a minor alternative first exon far downstream of the primary first exon eliminates this conundrum.

Structural organization of the human glutathione reductase gene: determination of correct cDNA sequence and identification of a mitochondrial leader sequence.

The primary structure of human glutathione reductase gene (GSR) was determined by genomic cloning. The gene structure of human GSR spans 50 kb, consists of 13 exons, and was found to be highly similar to the mouse GSR gene. The coding sequence of human GSR resides on all 13 exons. An N-terminal arginine-rich mitochondrial leader sequence was present, with high homology to the murine leader sequence, between two in-frame start codons in the first exon. The 5' and 3' intron/exon splice junctions, with one exception, followed the general consensus sequences for intron spliced donor and acceptance sites.

Anti-leukemic action of the novel agent MGI 114 (HMAF) and synergistic action with topotecan.

The illudin derivative MGI 114 (6-hydroxymethylacylfulvene or HMAF) is currently in phase II chemotherapeutic clinical trials for a variety of solid tumors. The illudins were originally thought to be potentially useful agents for myeloid leukemias, because hematopoietic tumor cells were markedly sensitive whereas normal bone marrow progenitors were relatively resistant to the cytotoxic effects of illudins. Due to the marked preclinical efficacy of MGI 114 against a variety of solid tumor xenografts, the current phase II human trials are restricted to solid tumor (breast, lung, colon, ovarian, pancreas, prostate, etc) malignancies. The present studies were undertaken to evaluate the efficacy of MGI 114 in the HL60/MRI myeloid leukemia xenograft. In addition, because of the reported synergistic cytotoxic activity between MGI 114 and the topoisomerase I inhibitor topotecan towards pediatric human tumor cell lines, we tested the activity of MGI 114 and topotecan combinations against HL60 cells in vitro and the HL60/MRI myelocytic xenograft. Our results indicate that MGI 114 at maximum tolerated doses (MTD) of 7 mg/kg, five times per week for 3 weeks does display anti-myeloid leukemic properties in the HL60/MRI xenograft model which exceeds activity noted with other conventional agents (TGI > 70%). A marked therapeutic synergistic action was observed with MGI 114 and topotecan combinations of (1/2) MTD of each agent producing complete tumor remission in 50% of animals, without development of excessive or additive toxicity in animals. These results support further in vitro and clinical investigation into both the anti-myeloid leukemic activity of MGI-114, and the cooperative pharmacologic interaction noted between MGI-114 and topoisomerase I inhibitors. Leukemia (2000) 14, 136-141.