A system for controlling gene expression was established in the pathogenic fungus Candida glabrata to elucidate the physiological functions of genes. T o Control the expression O f the gene O f interest, the c. glabrata Cells Were first transformed with the plasmid carrying the tetracycline repressortransactivator fusion tetR:: G A U , then with the DNA fragment containing the controllable cassette, the tetracycline operator chimeric promoter ( t e t 0 : :ScHOP7). The peptide elongation factor 3 (CgTEF3) and DNA topoisomerase II (CgTOP2) genes from C. glabrata were cloned and their expression assessed using this system. When the promoter of CgT€F3 or CgTOP2 was replaced with tet0: :ScHOP7, doxycycline almost completely repressed the expression of both mRNAs, and impaired growth. Repression of the TOP2 or T€F3 gene by doxycycline also hampered the survival of C. glabrata cells in mice; in mouse kidneys the number of C. glabrata cells, in which the TOP2 or T€F3 promoter was replaced with the tetO::ScHOP7 controllable cassette, did not increase when the mice were given doxycycline. Thus, it appears that the gene repression mediated by doxycycline occurred not only in culture media but also in animals; therefore, this system can be used to elucidate the function of the gene in fungal infections and pathogenesis.

Purpose: The phosphatidylinositol 3-kinase (PI3K) pathway plays a central role in cell proliferation and survival in human cancer. PIK3CA mutations, which are found in many cancer patients, activate the PI3K pathway, resulting in cancer development and progression. We previously identified CH5132799 as a novel PI3K inhibitor. Thus, this study aimed to clarify the biochemical and antitumor activity of CH5132799 and elucidate the correlation between CH5132799 response and genetic alterations in the PI3K pathway.Experimental Design: Kinase inhibitory activity was profiled in cell-free assays. A large panel of human breast, ovarian, prostate, and endometrial cancer cell lines, as well as xenograft models, were used to evaluate the antitumor activity of CH5132799, followed by analysis for genetic alterations. Effects on Akt phosphorylation induced by mTORC1 inhibition were tested with CH5132799 and compared with mTORC1 and PI3K/mTOR inhibitors.Results: CH5132799 selectively inhibited class I PI3Ks and PI3Ka mutants in in vitro kinase assays. Tumors harboring PIK3CA mutations were significantly sensitive to CH5132799 in vitro and were remarkably regressed by CH5132799 in in vivo mouse xenograft models. In combination with trastuzumab, tumors disappeared in the trastuzumab-insensitive breast cancer model with the PIK3CA mutation. Moreover, CH5132799 did not reverse a negative feedback loop of PI3K/Akt/mTOR signaling and induced regression against tumors regrown after long-term mTORC1 inhibitor treatment.Conclusions: CH5132799 is a selective class I PI3K inhibitor with potent antitumor activity against tumors harboring the PIK3CA mutations. Prediction of CH5132799 response on the basis of PIK3CA mutations could enable patient stratification in clinical settings. Clin Cancer Res; 17(10); 3272-81. Ó2011 AACR.

The data on visceral mycoses that had been reported in theAnnual of the Pathological Autopsy Cases in Japan from 1969 to 1994 by the Japanese Society of Pathology were analyzed epidemiologically. The frequency of visceral mycoses among the annual total number of pathological autopsy cases increased noticeably from 1.60% in 1969 to a peak of 4.66% in 1990. Among them, the incidences of candidiasis and aspergillosis increased the most. After 1990, however, the frequency of visceral mycoses decreased gradually. Until 1989, the predominant causative agent was Candida, followed in order by Aspergillus and Cryptococcus. Although the rate of candidiasis decreased by degrees from 1990, the rate of aspergillosis increased up to and then surpassed that of candidiasis in 1991. Leukemia was the major disease underlying the visceral mycoses, followed by solid cancers and other blood and hematopoietic system diseases. Severe mycotic infection has increased over the reported 25-year period, from 6.6% of the total visceral mycosis cases in 1969 to 71% in 1994. The reasons for this decrease of candidiasis combined with an increase of aspergillosis or of severe mycotic infection might be that (i) nonsevere (not disseminated) infections were excluded from the case totals, since they have become controllable by antifungal drugs such as fluconazole, but (ii) the available antifungal drugs were not efficacious against severe infections such as pulmonary aspergillosis, and (iii) the number of patients living longer in an immunocompromised state had increased because of developments in chemotherapy and progress in medical care.

No abstract

To study the relationship between the changes in visceral mycoses rates and recently advanced medical care in hematological settings, data on visceral mycosis cases with leukemia and myelodysplastic syndrome (MDS) that had been reported in the Annual of the Pathological Autopsy Cases in Japan in 1989, 1993 and 1997 were analyzed. The frequency rate of visceral mycoses with leukemia and MDS was 27.9% (435/1557) in 1989, 23.0% (319/1388) in 1993 and 22.3% (246/1105) in 1997. In comparing the rate of mycoses in recipients of organ or bone marrow transplantation with that of non-recipients, that of recipients was approximately 10% higher. The predominant causative agents were Candida and Aspergillus, at approximately the same rate as in 1989. The rate of candidosis decreased to one-half that of aspergillosis by 1993. Furthermore, severe mycotic infections clearly increased from 58.9% in 1989 to 75.6% in 1997. Among a total of 1000 cases with mycotic infection in those 3 years, acute lymphatic leukemia and acute myeloid leukemia were the major diseases (40.6% and 34.8%, respectively), followed by MDS (26.1%). The reasons for increased rates of aspergillosis and of severe mycotic infection can be surmised to be: (i) candidosis had become controllable by prophylaxis and by empiric therapy for mycoses with effective antifungal drugs; (ii) the marketed antifungal drugs were not sufficiently effective against severe infections or Aspergillus infections; and (iii) the number of patients surviving in an immunocompromised state had increased due to developments in chemotherapy and progress in medical care.