NPFFR2 Contributes to the Malignancy of Hepatocellular Carcinoma Development by Activating RhoA/YAP Signaling.

G protein-coupled receptors (GPCRs) are a diverse family of cell surface receptors implicated in various physiological functions, making them common targets for approved drugs. Many GPCRs are abnormally activated in cancers and have emerged as therapeutic targets for cancer. Neuropeptide FF receptor 2 (NPFFR2) is a GPCR that helps regulate pain and modulates the opioid system; however, its function remains unknown in cancers. Here, we found that NPFFR2 is significantly up-regulated in liver cancer and its expression is related to poor prognosis. Silencing of NPFFR2 reduced the malignancy of liver cancer cells by decreasing cell survival, invasion, and migration, while its overexpression increased invasion, migration, and anchorage-independent cell growth. Moreover, we found that the malignant function of NPFFR2 depends on RhoA and YAP signaling. Inhibition of Rho kinase activity completely restored the phenotypes induced by NPFFR2, and RhoA/F-Actin/YAP signaling was controlled by NPFFR2. These findings demonstrate that NPFFR2 may be a potential target for the treatment of hepatocellular carcinoma.

Vam6/Vps39/TRAP1-domain proteins influence vacuolar morphology, iron acquisition and virulence in Cryptococcus neoformans.

The pathogenic fungus Cryptococcus neoformans must overcome iron limitation to cause disease in mammalian hosts. Previously, we reported a screen for insertion mutants with poor growth on haem as the sole iron source. In this study, we characterised one such mutant and found that the defective gene encoded a Vam6/Vps39/TRAP1 domain-containing protein required for robust growth on haem, an important iron source in host tissue. We designated this protein Vps3 based on reciprocal best matches with the corresponding protein in Saccharomyces cerevisiae. C. neoformans encodes a second Vam6/Vps39/TRAP1 domain-containing protein designated Vam6/Vlp1, and we found that this protein is also required for robust growth on haem as well as on inorganic iron sources. This protein is predicted to be a component of the homotypic fusion and vacuole protein sorting complex involved in endocytosis. Further characterisation of the vam6Δ and vps3Δ mutants revealed perturbed trafficking of iron acquisition functions (e.g., the high affinity iron permease Cft1) and impaired processing of the transcription factor Rim101, a regulator of haem and iron acquisition. The vps3Δ and vam6Δ mutants also had pleiotropic phenotypes including loss of virulence in a mouse model of cryptococcosis, reduced virulence factor elaboration and increased susceptibility to stress, indicating pleiotropic roles for Vps3 and Vam6 beyond haem use in C. neoformans. TAKE AWAYS: Two Vam6/Vps39/TRAP1-domain proteins, Vps3 and Vam6, support the growth of Cryptococcus neoformans on haem. Loss of Vps3 and Vam6 influences the trafficking and expression of iron uptake proteins. Loss of Vps3 or Vam6 eliminates the ability of C. neoformans to cause disease in a mouse model of cryptococcosis.

Spontaneous Peripheral Ameloblastic Odontoma in a Male Sprague-Dawley Rat.

Peripheral ameloblastic odontoma is a rare variant of odontogenic tumor occurring in the extraosseous region. The present report describes a spontaneous tumor in male Sprague-Dawley (SD) rats. The clinically confirmed nodule in the right mandibular region was first observed when the rat was 42 weeks and remained until the terminal sacrifice date when the animal was 48 weeks of age. At necropsy, a well demarcated nodule, approximately 2.5 × 2.0 × 2.0 cm, protruded from the ventral area of the right mandible. The nodule was not attached to mandibular bone and was not continuous with the normal teeth. Histopathologically, the tumor was characterized by the simultaneous occurrence of an ameloblastomatous component and composite odontoma-like elements within the same tumor. The epithelial portion formed islands or cords resembling the follicle or plexiform pattern typical of ameloblastoma and was surrounded by mesenchymal tissue. Formation of eosinophilic and basophilic hard tissue matrix (dentin and enamel) resembling odontoma was observed in the center of the tumor. Mitotic figures were rare, and areas of cystic degeneration were present. Immunohistochemically, the epithelial component was positive for cytokeratin AE1/AE3 (CK AE1/AE3), and the mesenchymal component and odontoblast-like cells were positive for vimentin, in the same manner as in normal teeth. On the basis of these findings, the tumor was diagnosed as a peripheral ameloblastic odontoma in an extraosseous mandibular region in a SD rat. In the present study, we report the uncommon spontaneous peripheral ameloblastic odontoma in the SD rat. We also discuss here the morphological characteristics, origin, histochemical, and immunohistochemical features for the diagnosis of this tumor.

Mael is essential for cancer cell survival and tumorigenesis through protection of genetic integrity.

Germ line-specific genes are activated in somatic cells during tumorigenesis, and are accordingly referred to as cancer germline genes. Such genes that act on piRNA (Piwi-interacting RNA) processing play an important role in the progression of cancer cells. Here, we show that the spermatogenic transposon silencer maelstrom (Mael), a piRNA-processing factor, is required for malignant transformation and survival of cancer cells. A specific Mael isoform was distinctively overexpressed in diverse human cancer cell lines and its depletion resulted in cancer-specific cell death, characterized by apoptosis and senescence, accompanied by an increase in reactive oxygen-species and DNA damage. These biochemical changes and death phenotypes induced by Mael depletion were dependent on ATM. Interestingly Mael was essential for Myc/Ras-induced transformation, and its overexpression inhibited Ras-induced senescence. In addition, Mael repressed retrotransposon activity in cancer cells. These results suggest that Mael depletion induces ATM-dependent DNA damage, consequently leading to cell death specifically in cancer cells. Moreover, Mael possesses oncogenic potential that can protect against genetic instability.

p31comet-Induced Cell Death Is Mediated by Binding and Inactivation of Mad2.

Mad2, a key component of the spindle checkpoint, is closely associated with chromosomal instability and poor prognosis in cancer. p31comet is a Mad2-interacting protein that serves as a spindle checkpoint silencer at mitosis. In this study, we showed that p31comet-induced apoptosis and senescence occur via counteraction of Mad2 activity. Upon retroviral transduction of p31comet, the majority of human cancer cell lines tested lost the ability to form colonies in a low-density seeding assay. Cancer cells with p31comet overexpression underwent distinct apoptosis and/or senescence, irrespective of p53 status, confirming the cytotoxicity of p31comet. Interestingly, both cytotoxic and Mad2 binding activities were eliminated upon deletion of the C-terminal 30 amino acids of p31comet. Point mutation or deletion of the region affecting Mad2 binding additionally abolished cytotoxic activity. Consistently, wild-type Mad2 interacting with p31comet, but not its non-binding mutant, inhibited cell death, indicating that the mechanism of p31comet-induced cell death involves Mad2 inactivation. Our results clearly suggest that the regions of p31comet affecting interactions with Mad2, including the C-terminus, are essential for induction of cell death. The finding that p31comet-induced cell death is mediated by interactions with Mad2 that lead to its inactivation is potentially applicable in anticancer therapy.

The spectrum of eosinophilic infiltration of the cecum and its relationship to other disorders of multiple granulomas and arteritis in Sprague-Dawley rat.

Spontaneous multiple granulomas were present in the animal under the SPF condition and without chemical treatment, in a 19-week-old male Sprague-Dawley control-group rat. Here we describe multiple granulomas and prominent diffuse infiltration by eosinophils in the cecal submucosa, and arteritis in the mesenteric arteries. The multiple granulomas were characterized by central eosinophilic degeneration or necrosis, prominent eosinophils, many multi-nucleated giant cells and abundant fibroblasts. They were restricted to the cecal submucosa. The mesenteric arteritis consisted of fibrinoid necrosis of the intima and media, intense inflammatory cell infiltration and fibrosis in the arterial wall. An affected artery in the cecum was continuous with the mesenteric artery. The foregoing tissue changes in this rat correlate with the high absolute blood eosinophil count found in this animal.

Deletion of the high-affinity cAMP phosphodiesterase encoded by PDE2 affects stress responses and virulence in Candida albicans.

Previously, we have shown that PDE2 is required for hyphal development and cell wall integrity in Candida albicans. In the present study, we have investigated the effects of its deletion by genome-wide transcriptome profiling. Changes in expression levels of genes involved in metabolism, transcription, protein and nucleic acids synthesis, as well as stress responses, cell wall and membrane biogenesis, adherence and virulence have been observed. By comparing these changes with previously reported transcriptome profiles of pde2Delta mutants of Saccharomyces cerevisiae, as well as cdc35Delta, ras1Delta and efg1Delta mutants of C. albicans, conserved and species-specific cAMP-regulated genes have been identified. The genes whose transcription is altered upon deletion of PDE2 in C. albicans has also allowed us to predict that the pde2Delta mutant would have a defective ability to adhere to, and invade host cells, and an impaired virulence as well as response to different stresses. Using appropriate assays, we have tested these predictions and compared the roles of the high- and low-affinity cAMP phosphodiesterases, Pde2p and Pde1p in stress, adhesion and virulence. We suggest that phosphodiesterases, and in particular the high-affinity cAMP phosphodiesterase encoded by PDE2, have real potential as targets for antifungal chemotherapy.