Mon1 Is Essential for Fungal Virulence and Stress Survival in Cryptococcus neoformans

Mon1 is a guanine nucleotide exchange factor subunit that activates the Ypt7 Rab GTPase and is essential for vacuole trafficking and autophagy in eukaryotic organisms. Here, we identified and characterized the function of Mon1, an ortholog of Saccharomyces cerevisiae Mon1, in a human fungal pathogen, Cryptococcus neoformans. Mutation in mon1 resulted in hypersensitivity to thermal stress. The mon1 deletion mutant exhibited increased sensitivity to cell wall and endoplasmic reticulum stress. However, the mon1 deletion mutant showed more resistance to the antifungal agent fluconazole. In vivo studies demonstrated that compared to the wild-type strain, the mon1 deletion mutant attenuated virulence in the Galleria mellonella insect model. Moreover, the mon1 deletion mutant was avirulent in the murine inhalation model. These results demonstrate that Mon1 plays a crucial role in stress survival and pathogenicity in C. neoformans.

Semi-Circumferential Decompression: Microsurgical Total en-bloc Ligamentum Flavectomy to Treat Lumbar Spinal Stenosis with Grade I Degenerative Spondylolisthesis

BACKGROUND: To describe and assess clinical outcomes of the semi-circumferential decompression technique for microsurgical en-bloc total ligamentum flavectomy with preservation of the facet joint to treat the patients who have a lumbar spinal stenosis with degenerative spondylolisthesis. METHODS: We retrospectively analyzed the clinical and radiologic outcomes of 19 patients who have a spinal stenosis with Meyerding grade I degenerative spondylolisthesis. They were treated using the "semi-circumferential decompression" method. We evaluated improvements in back and radiating pain using a visual analogue scale (VAS) and the Oswestry Disability Index (ODI). We also evaluated occurrence of spinal instability on radiological exam using percentage slip and slip angle. RESULTS: The mean VAS score for back pain decreased significantly from 6.3 to 4.3, although some patients had residual back pain. The mean VAS for radiating pain decreased significantly from 8.3 to 2.5. The ODI score improved significantly from 25.3 preoperatively to 10.8 postoperatively. No significant change in percentage slip was observed (10% preoperatively vs. 12.2% at the last follow-up). The dynamic percentage slip (gap in percentage slip between flexion and extension X-ray exams) did not change significantly (5.2% vs. 5.8%). Slip angle and dynamic slip angle did not change (3.2° and 8.2° vs. 3.6° and 9.2°, respectively). CONCLUSIONS: The results suggested that semi-circumferential decompression is a clinically recommendable procedure that can improve pain. This procedure does not cause spinal instability when treating patients who have a spinal stenosis with degenerative spondylolisthesis.

Mechanism Underlying Shikonin-induced Apoptosis and Cell Cycle Arrest on SCC25 Human Tongue Squamous Cell Carcinoma Cell Line

Shikonin, a major ingredient in the traditional Chinese herb Lithospermumerythrorhizon, exhibits multiple biological functions including antimicrobial, anti-inflammatory, and antitumor effects. It has recently been reported that shikonin displays antitumor properties in many cancers. This study was aimed to investigate whether shikonin could inhibit oral squamous carcinoma cell (OSCC) growth via mechanisms of apoptosis and cell cycle arrest. The effects of shikonin on the viability and growth of OSCC cell line, SCC25 cells were assessed by MTT assay and clonogenic assays, respectively. Hoechst staining and DNA electrophoresis indicated that the shikonin-treated SCC25 cells were undergoing apoptosis. Western blotting, immunocytochemistry, confocal microscopy, flow cytometry, MMP activity, and proteasome activity also supported the finding that shikonin induces apoptosis. Shikonin treatment of SCC25 cells resulted in a time- and dose-dependent decrease in cell viability, inhibition of cell growth, and increase in apoptotic cell death. The treated SCC25 cells showed several lines of apoptotic manifestation as follows: nuclear condensation; DNA fragmentation; reduced MMP and proteasome activity; decrease in DNA contents; release of cytochrome c into cytosol; translocation of AIF and DFF40 (CAD) onto the nuclei; a significant shift in Bax/Bcl-2 ratio; and activation of caspase-9, -7, -6, and -3, as well as PARP, lamin A/C, and DFF45 (ICAD). Shikonin treatment also resulted in down-regulation of the G1 cell cycle-related proteins and up-regulation of p27(KIP1). Taken together, our present findings demonstrate that shikonin strongly inhibits cell proliferation by modulating the expression of the G1 cell cycle-related proteins, and that it induces apoptosis via the proteasome, mitochondria, and caspase cascades in SCC25 cells.

Bizarre Parosteal Osteochondromatous Proliferation in the First Metatarsal Bone: A Case Report / 대한골관절종양학회지

Bizarre parosteal osteochondromatous proliferation (Nora's lesion) is a rare benign tumor and known to be primarily occur in the small tubular bone of the hands and feet. However, it is very unusual to be reported that it occurs in metatarsal bone in Korea. Thus, we report this tumor of metatarsal bone including the literature review because we have experienced this example.

The Role of HS-1200 Induced Autophagy in Oral Cancer Cells

Bile acids and synthetic bile acid derivatives induce apoptosis in various kinds of cancer cells and thus have anticancer properties. Recently, it has been suggested that autophagy may play an important role in cancer therapy. However, few data are available regarding the role of autophagy in oral cancers and there have been no reports of autophagic cell death in OSCCs (oral squamous cell carcinoma cells) induced by HS-1200, a synthetic bile acid derivative. We thus examine whether HS-1200 modulates autophagy in OSCCs. Our findings indicate that HS-1200 has anticancer effects in OSCCs, and we observed in these cells that autophagic vacuoles were visible by monodansylcadaverine (MDC)and acridine orange staining. When we analyzed HS-1200-treated OSCC cells for the presence of biochemical markers, we observed that this treatment directly affects the conversion of LC-3II, degradation of p62/SQSTM1 and full-length beclin-1, cleavage of ATG5-12 and the activation of caspase. An autophagy inhibitor suppressed HS-1200-induced cell death in OSCCs, confirming that autophagy acts as a pro-death signal in these cells. Furthermore, HS-1200 shows anticancer activity against OSCCs via both autophagy and apoptosis. Our current findings suggest that HS-1200 may potentially contribute to oral cancer treatment and thus provide useful information for the future development of a new therapeutic agent.

Apoptotic Effects of Co-Treatment with a Chios Gum Mastic and Eugenol on G361 Human Melanoma Cells

We investigated the synergistic apoptotic effects of co-treatments with Chios gum mastic (CGM) and eugenol on G361 human melanoma cells. An MTT assay was conducted to investigate whether this co-treatment efficiently reduces the viability of G361 cells compared with each single treatment. The induction and augmentation of apoptosis were confirmed by DNA electrophoresis, Hoechst staining, and analyses of DNA hypoploidy. Western blot analysis and immunofluorescent staining were also performed to evaluate expression and translocation of apoptosis-related proteins following CGM and eugenol co-treatment. Proteasome activity and mitochondrial membrane potential (MMP) changes were also assayed.The results indicated that the co-treatment of CGM and eugenol induces multiple pathways and processes associated with an apoptotic response in G361 cells. These include nuclear condensation, DNA fragmentation, a reduction in MMP and proteasome activity, an increase of Bax and decrease of Bcl-2, a decreased DNA content, cytochrome c release into the cytosol, the translocation of AIF and DFF40 (CAD) into the nucleus, and the activation of caspase-9, caspase-7, caspase-3, PARP and DFF45 (ICAD). In contrast, separate treatments of 40 microg/ml CGM or 300 microM eugenol for 24 hours did not induce apoptosis. Our present data thus suggest that a combination therapy of CGM and eugenol is a potential treatment strategy for human melanoma.

Radical Subtotal Gastrectomy in Early Gastric Cancer Patient with Situs Inversus Totalis

Situs inversus totalis is a complete mirror image of the thoracic and abdominal viscera. There are many cases of malignant neoplasms being found in patients with situs inversus totalis. We report a case of situs inversus totalis with an early gastric cancer. The patient was a 50-year-old woman who presented with epigastric discomfort with a one-month duration. The chest X-ray showed dextrocardia and the abdomen CT revealed situs inversus totalis with wall thickening of the gastric antrum. The resected specimen showed a 2 cm sized eroded lesion in the antrum. Histologically, gastric cancer was diagnosed as a well differentiated tubular adenocarcinoma that was confined to the mucosal layer. The patient was treated successfully with a radical subtotal gastrectomy, even though situs inversus totalis was not familiar to the surgeon.