Cryptococcus neoformans is an opportunistic fungal pathogen that causes meningoencephalitis in immunocompromised patients. Recently, we reported that Toll-like receptor 9 (TLR9) is involved in host defense against C. neoformans: specifically, it detects the pathogen's DNA. In the present study, we aimed to elucidate the mechanisms underlying TLR9-mediated activation of innate immune responses by using the URA5 gene, which encodes a virulent component of this fungal pathogen. A PCRamplified 345-bp URA5 gene fragment induced interleukin-12 p40 (IL-12p40) production by bone marrow-derived dendritic cells (BM-DCs) in a TLR9-dependent manner. Similar activity was detected in the 5= 129-bp DNA fragment of URA5 and in a synthesized oligodeoxynucleotide (ODN) with the same sequence. Shorter ODN fragments, which contained GTCGGT or GAC-GAT but had only 24 or 21 bases, induced IL-12p40 production and CD40 expression by BM-DCs, but this activity vanished when the CG sequence was replaced by GC or when a phosphorothioate modification was introduced. IL-12p40 production caused by active ODN was strikingly enhanced by treatment with DOTAP, a cationic lipid that increases the uptake of DNA by BM-DCs, though DOTAP failed to induce IL-12p40 production by inactive ODN and did not affect the activity of an ODNcontaining canonical CpG motif. There was no apparent difference in intracellular trafficking between active and inactive ODNs. Finally, an extremely high dose of inactive ODN suppressed IL-12p40 production by BM-DCs that had been stimulated with active ODN. These results suggest that the C. neoformans URA5 gene activates BM-DCs through a TLR9-mediated signaling pathway, using a mechanism possibly independent of the canonical CpG motif.

Endometrial cancer is one of the most common female pelvic cancers and has been considered an androgen-related malignancy. Several studies have demonstrated the anti-cell proliferative effect of androgen on endometrial cancer cells; however, the mechanisms of the anti-cancer effect of androgen remain largely unclear. 17β-hydroxysteroid dehydrogenase type 2 (17β-HSD2), which catalyzes the conversion of E2 to E1, is known to be upregulated by androgen treatment in breast cancer cells. In this study, we therefore focused on the role of androgen on estrogen dependence in endometrial cancer. Dihydrotestosterone (DHT) was found to induce 17β-HSD2 mRNA and protein expression in HEC-1B endometrial cancer cells. DHT could also inhibit cell proliferation of HEC-1B when induced by estradiol treatment. In 19 endometrioid endometrial adenocarcinoma (EEA) tissues, intratumoral DHT concentration was measured by liquid chromatography/electrospray tandem mass spectrometry and was found to be significantly correlated with 17β-HSD2 immunohistochemical status. We further examined the correlations between 17β-HSD2 immunoreactivity and clinicopathological parameters in 53 EEA tissues. 17β-HSD2 status was inversely associated with the histological grade, clinical stage, and cell proliferation marker Ki-67, and positively correlated with progesterone receptor expression. 17β-HSD2 status tended to be positively associated with androgen receptor status. In 53 EEA cases, the 17β-HSD2-positive group tended to have better prognosis than that for the negative group with respect to progression-free survival and endometrial cancer-specific survival. These findings suggest that androgen suppresses the estrogen dependence of endometrial cancer through the induction of 17β-HSD2 in endometrial cancer.

Relaxin is known to play an important role in animal pregnancies, including those of humans. It is suggested that relaxin induces aggressive cell growth and invasiveness in several types of cancer, including endometrial cancer. However, the mechanisms of relaxin remain largely unclear. In this study, we examined the effects of relaxin 2 (RLN2), the major circulating relaxin in humans, on human endometrial carcinoma cell lines. RLN2 treatment induced invasion in HEC-1B and Ishikawa cells. RLN2-induced cell invasion was significantly decreased by transfection of relaxin receptor 1 (RXFP1) siRNAs. The β-catenin inhibitor, XAV939, also significantly inhibited the RLN2-induced cell invasions. Both a decrease of cadherin expression and an increase of β-catenin phosphorylation were observed in response to the RLN2 treatment in HEC-1B and Ishikawa cells. We then examined RLN2 and RXFP1 expression in 80 human endometrioid endometrial carcinoma tissues. RLN2 immunoreactivity was detected in the human endometrial carcinoma cells and had a correlative tendency with histological grade and RXFP1. These results suggest that adherens junctions in cancer cells are weakened by the breakdown of the cadherin/catenin complex, which is induced by β-catenin phosphorylation via RLN2/RXFP1 signaling.

Retinoic acid might have multiple antitumor effects, and RARβ may be a potent therapeutic target in RA treatment for endometrial cancers.

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