Expression patterns of proteins involved in serine and glycine metabolism, and correlations of these patterns with clinicopathologic factors in phyllodes tumor were investigated. Tissue microarrays were prepared from 203 phyllodes tumors (PT) and stained with antibodies specific for glycine decarboxylase (GLDC), phosphoserine aminotransferase 1 (PSAT1), phosphoserine phosphatase (PSPH), phosphoglycerate dehydrogenase (PHGDH), and serine hydroxymethyltransferase 1 (SHMT1). These immunohistochemical results and clinicopathologic parameters were analyzed for correlation. Numbers of benign, borderline, and malignant tumors were 155, 32, and 16, respectively. Stromal expression of PHGDH, PSAT1, PSPH, SHMT1, and GLDC increased with increasing tumor grade, and epithelial expression of SHMT1 also increased with increasing tumor grade (p<0.001, and p=0.005, respectively). On univariate analysis, positive stainings for stromal PHGDH (p<0.001), stromal PSAT1 (p<0.001), stromal PSPH (p=0.003), epithelial SHMT1 (p=0.001), stromal SHMT1 (p=0.022), and stromal GLDC (p<0.001) were each associated with shorter disease-free survival. Stromal GLDC was associated with shorter overall survival (p<0.001). In conclusion, expression of proteins related to serine and glycine metabolism increased with increasing histologic grade in stromal components of phyllodes tumor.

26The acquisition of iron and the maintenance of iron homeostasis are important aspects of 27 the virulence in the pathogenic fungus Cryptococcus neoformans. In this study, we identified 28 the monothiol glutaredoxin Grx4 as a binding partner of Cir1, a master regulator of iron-29 responsive genes and virulence factor elaboration in C. neoformans. Monothiol glutaredoxins 30 are important regulators of iron homeostasis because of their conserved roles in [2Fe-2S] cluster 31 sensing and trafficking. We confirmed that Grx4 binds Cir1 and demonstrated that iron 32 repletion promotes the relocalization of Grx4 from the nucleus to the cytoplasm. Nuclear 33 retention is partially dependent on Cir1 and also influenced by treatment with the proteasome 34 inhibitor bortezomib. Cir1 remains in the nucleus in both iron replete and iron limiting 35 conditions. We also found that a grx4Δ mutant displayed iron-related phenotypes similar to 36 those of a cir1Δ mutant, including poor growth upon iron deprivation. Importantly, a grx4Δ 37 mutant was avirulent in mice, a phenotype consistent with observed defects in the key virulence 38 determinants, capsule and melanin, and poor growth at 37°C. A comparative transcriptome 39 analysis of a grx4Δ mutant and the WT strain in low iron and iron-replete conditions confirmed 40 a central role for Grx4 in iron homeostasis. Dysregulation of iron-related metabolism was 41 consistent with grx4Δ mutant phenotypes related to oxidative stress, mitochondrial function, and 42 DNA repair. Overall, the phenotypes of the grx4Δ mutant and the RNA-Seq analysis support 43 the hypothesis that Grx4 functions as a sensor of iron levels, in part through an interaction with 44 Cir1, to extensively regulate iron homeostasis and contribute to virulence. 45 46 Importance 47 48Fungal pathogens cause life-threatening diseases in humans, particularly in 49 immunocompromised people, and there is a tremendous need for a greater understanding of 50 pathogenesis to support new therapies. One prominent fungal pathogen, Cryptococcus 51 neoformans, causes menigitis in people suffering from HIV/AIDS. In the current study, we 52 focused on characterizing mechanisms by which C. neoformans senses iron availability because 53 iron is both a key nutrient and a signal for proliferation of the pathogen in vertebrate hosts. 54 Specifically, we characterized a monothiol glutaredoxin protein Grx4 that functions as a sensor 55 3 of iron, and that interacts with regulatory factors to control the ability of C. neoformans to cause 56 disease. Grx4 regulates key virulence factors and a mutant is unable to cause disease in a mouse 57 model of cryptococcosis. Overall, our study provides new insights into nutrient sensing and the 58 role of iron in the pathogenesis of fungal diseases. 59 60 61 62 63 65 meningoencephalitis in immunocompromised people including those with HIV/AIDS (1-3). 66Despite the use of highly active antiretroviral therapy (HAART), there are still ~200,000 cases 67 of cryptococcal meningoencephalitis per year, and...