RESUMEN
AIMS: To analyse the essentiality of the ROM2 genes originating from the pathogenic yeasts Candida glabrata and Candida albicans by using temperature-sensitive (ts) mutants. METHODS AND RESULTS: Based on the general concepts that ts mutations are generated by virtue of point mutation within essential genes, we have previously established a novel method (termed 'ETS system' for screening and identification of essential genes using ts mutants of C. glabrata). According to this ETS system, the present study successfully identified a putative C. glabrata ROM2 homologue as an essential gene that complements its point mutation (Cys-1275/Tyr substitution). The C. albicans ROM2 mutant (Cys-1281/Tyr), constructed patterned after this point mutation, also displayed ts phenotype. Both ts mutants recovered colony-forming ability, with concomitant suppression of lysis phenotype, at the elevated temperature in the presence of 1 mol l(-1) sorbitol as an osmotic stabilizer. Sequence alignment revealed that human genome possesses relatively low homology against Rom2 homologues, which are highly conserved among yeast species. CONCLUSIONS: ROM2 genes of C. glabrata and C. albicans are essential for viability, probably involved in cell wall integrity. SIGNIFICANCE AND IMPACT OF THE STUDY: ROM2 genes essential for both Candida species may be a potentially useful antifungal targets from chemotherapeutic viewpoint.
Asunto(s)
Candida albicans/genética , Candida glabrata/genética , Candidiasis/microbiología , Proteínas Fúngicas/genética , Secuencia de Aminoácidos , Candida albicans/química , Candida albicans/metabolismo , Candida albicans/patogenicidad , Candida glabrata/química , Candida glabrata/metabolismo , Candida glabrata/patogenicidad , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Humanos , Datos de Secuencia Molecular , Mutación , Alineación de Secuencia , Temperatura , VirulenciaRESUMEN
A 53-year-old man who suffered from advanced hepatocellular carcinoma (HCC) was treated with hepatic arterial infusion (HAI) of Etoposide, Epirubicin and CDDP. Treatment consisted of a continuous HAI of Epirubicin (50 mg/body, day 1.7), CDDP (75 mg/body, day 2.8) and Etoposide (80 mg/body, day 4-6). He had two series of infusions and was treated by transarterial embolization using CDDP powder (100 mg) added to lipiodol and aluminum stearate as suspension following HAI. The tumor regression rate was about 60% after HAI, but the remaining tumor seemed to be almost necrotic. AFP and PIVKA-II reached the normal range after TAE. We could not find lipiodol accumulated in tumor on CT carried out eight weeks after TAE. No recurrence has been noticed in the following 8 months. Toxicity was not so severe and was well tolerated.