Glioblastoma multiforme (GBM) has the highest mortality rate among patients with brain tumors, and radiotherapy forms an important part of its treatment. Thus, there is an urgent requirement to elucidate the mechanisms conferring GBM progression and radioresistance. In the present study, it was identified that antisense transcript of hypoxia-inducible factor-1α (AHIF) was significantly upregulated in GBM cancerous tissues, as well as in radioresistant GBM cells. The expression of AHIF was also upregulated in response to radiation. Knockdown of AHIF in GBM cells decreased viability and invasive capacities, and increased the proportion of apoptotic cells. By contrast, overexpression of AHIF in GBM cells increased viability and invasive capacities, and decreased the proportion of apoptotic cells. Furthermore, exosomes derived from AHIF-knockdown GBM cells inhibited viability, invasion and radioresistance, whereas exosomes derived from AHIF-overexpressing GBM cells promoted viability, invasion and radioresistance. Further biochemical analysis identified that AHIF regulates factors associated with migration and angiogenesis in exosomes. To the best of our knowledge, the present study is the first to establish that AHIF promotes glioblastoma progression and radioresistance via exosomes, which suggests that AHIF is a potential therapeutic target for GBM.

Peroxisome proliferator-activated receptor gamma (PPARγ) plays an important role in regulating energy balance, glucose and lipid metabolisms and inflammation. PPARγ also exerts multiple anti-cancer effects including tumor growth and angiogenesis inhibition, induction of cell differentiation, and apoptosis. Perturbed Wnt/β-catenin signaling likely plays a key role in tumorigenesis and the interaction between PPARγ and the transcriptional regulator β-catenin maybe important in this process. Phosphorylation of β-catenin by GSK-3β inactivates it and suppresses tumor cell proliferation and self-renewal of tumor stem cells. In combination with Frizzled, Wnt suppresses GSK-3β and causes degradation of β-catenin and activation of many tumor proliferation factors. In the present study, we investigated the effects of PPARγ agonist rosiglitazone (RGZ) and PPARγ antagonist GW9662 on the growth, mitotic cycle, and apoptosis of human lymphoma cell line, Raji cells. We also studied the influence of PPARγ ligands on the expression of β-catenin and GSK-3β in Raji cells to reveal whether Wnt/GSK-3β/β-catenin signaling pathways are involved in PPARγ ligands triggered Raji cell apoptosis. Results showed that both RGZ and GW9662 can inhibit the growth of Raji cells by inducing apoptosis and arresting cell cycle; however, there was no correlation between these effects and expression of PPARγ. Both the PPARγ ligands, RGZ and GW9662, appear to reciprocally regulate the mRNA and protein expressions of GSK-3β, which promotes apoptosis, and of β-catenin, which blocks apoptosis. These results suggest that PPARγ ligands mediate their effects via Wnt/GSK-3β/β-catenin signaling on Raji cell proliferation and survival.

Osteoarthritis (OA) is the most prevalent degenerative joint disease. The highly regulated balance of matrix synthesis and degradation is disrupted in OA, leading to progressive breakdown of articular cartilage. The molecular events and pathways involved in chondrocyte disfunction of cartilage in OA are not fully understood. It is known that 1,25-dihydroxyvitamin D₃ (1,25-(OH)2D3) is synthesized by macrophages derived from synovial fluid of patients with inflammatory arthritis. Vitmain D receptor is expressed in chondrocytes within osteoarthritic cartilage, suggesting a contributory role of 1,25-(OH)2D3 in the aberrant behavior of chondrocytes in OA. However, the physiological function of 1,25-(OH)2D3 on chondrocytes in OA remains obscure. Effect of 1,25-(OH)2D3 on gene expression in chondrocytes was investigated in this study. We found that 1,25-(OH)2D3 activated MMP13 expression in a dose-dependent and time-dependent manner, a major enzyme that targets cartilage for degradation. Interestingly, a specific mitogen-activated protein kinase p38 inhibitor SB203580, but not JNK kinase inhibitor SP600125, abrogated 1,25-(OH)2D3 activation of MMP13 expression. 1,25-(OH)2D3-induced increase in MMP13 protein level was in parallel with the phosphorylation of p38 in chondrocytes. To further address the effect of 1,25-(OH)2D3 on MMP13 expression, transfection assays were used to show that 1,25-(OH)2D3 activated the MMP13 promoter reporter expression. MMP13 is known to target type II collagen and aggrecan for degradation, two major components of cartilage matrix. We observed that the treatment of 1,25-(OH)2D3 in chondrocytes results in downregulation of both type II collagen and aggrecan while MMP13 was upregulated. Taken together, we provide the first evidence to demonstrate that 1,25-(OH)2D3 activates MMP13 expression through p38 pathway in chondrocytes. Since MMP13 plays a major role in cartilage degradation in OA, we speculate that the ability of 1,25-(OH)2D3 to potentiate MMP13 expression might facilitate cartilage erosion at the site of inflammatory arthritis.

A 29-year-old male patient was admitted into hospital with the main complaint of progressive visual disturbance. Both CT SCAN and MRI demonstrated a cystic-solid contrast-enhancing sellar-suprasellar mass with obvious calcification. Histopathological examination of the first resected specimen showed a typical appearance of adamantinomatous craniopharyngioma. The patient received gamma knife therapy after his first operation because of partial tumor removal. He experienced two relapses in the subsequent 2 years, for which only surgical resection was performed. The later histopathology presented malignant appearance with tumor cells moderate to severe pleomorphism, hyperchromasia, increased nuclear cytoplastic ratio, high mitotic activity (30/10 high power fields) and focal coagulative necrosis. The patient died 9 months after identification of histologic malignancy. Clinical and histopathological features, biological behavior of one case of malignant craniopharyngioma were discussed, with a brief review of the relevant literature.