SUMMARY Despite extensive study, few therapeutic targets have been identified for glioblastoma (GBM). Here we show that patient derived glioma sphere cultures (GSCs) that resemble either the proneural (PN) or mesenchymal (MES) transcriptomal subtypes differ significantly in their biological characteristics. Moreover, we found that a subset of the PN GSCs undergo differentiation to a MES state in a TNFα/NF-κB dependent manner with an associated enrichment of CD44 subpopulations and radio-resistant phenotypes. We present data to suggest that the tumor microenvironment cell types such as macrophages/microglia may play an integral role in this process. We further show that the MES signature, CD44 expression, and NF-κB activation correlate with poor radiation response and shorter survival in patients with GBM.

Tumor heterogeneity of high-grade glioma (HGG) is recognized by four clinically relevant subtypes based on core gene signatures. However, molecular signaling in glioma stem cells (GSCs) in individual HGG subtypes is poorly characterized. Here we identified and characterized two mutually exclusive GSC subtypes with distinct dysregulated signaling pathways. Analysis of mRNA profiles distinguished proneural (PN) from mesenchymal (Mes) GSCs and revealed a pronounced correlation with the corresponding PN or Mes HGGs. Mes GSCs displayed more aggressive phenotypes in vitro and as intracranial xenografts in mice. Further, Mes GSCs were markedly resistant to radiation compared with PN GSCs. The glycolytic pathway, comprising aldehyde dehydrogenase (ALDH) family genes and in particular ALDH1A3, were enriched in Mes GSCs. Glycolytic activity and ALDH activity were significantly elevated in Mes GSCs but not in PN GSCs. Expression of ALDH1A3 was also increased in clinical HGG compared with low-grade glioma or normal brain tissue. Moreover, inhibition of ALDH1A3 attenuated the growth of Mes but not PN GSCs. Last, radiation treatment of PN GSCs up-regulated Mes-associated markers and downregulated PN-associated markers, whereas inhibition of ALDH1A3 attenuated an irradiation-induced gain of Mes identity in PN GSCs. Taken together, our data suggest that two subtypes of GSCs, harboring distinct metabolic signaling pathways, represent intertumoral glioma heterogeneity and highlight previously unidentified roles of ALDH1A3-associated signaling that promotes aberrant proliferation of Mes HGGs and GSCs. Inhibition of ALDH1A3-mediated pathways therefore might provide a promising therapeutic approach for a subset of HGGs with the Mes signature.cancer stem cell | epithelial-to-mesenchymal transition | glioblastoma multiforme | glioblastoma | proneural-to-mesenchymal transition

Idiopathic membranous nephropathy (IMN) is the most common cause of nephrotic syndrome in adults. Universal consensus regarding the need for and the modality of therapy has not been formed because of a lack of controlled trials of sufficient size, quality, and duration. This study compared the effect of a 6-mo course of alternating prednisolone and cyclophosphamide with supportive treatment in adults with nephrotic syndrome caused by IMN on doubling of serum creatinine, development of ESRD, and quality of life in a randomized, controlled trial. Patients were followed up for 10 yr. Data were analyzed on an intention-to-treat basis. A total of 93 patients completed the study. Of the 47 patients who received the experimental protocol, 34 achieved remission (15 complete and 19 partial), compared with 16 (five complete, 11 partial) of 46 in the control group (P < 0.0001). The 10-yr dialysis-free survival was 89 and 65% (P ‫؍‬ 0.016), and the likelihood of survival without death, dialysis, and doubling of serum creatinine were 79 and 44% (P ‫؍‬ 0.0006) in the two groups. Treated patients exhibited significantly lower prevalence of edema, hypertension, hypoalbuminemia, hyperlipidemia that required therapy, angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker use, and better quality of life on follow-up. The incidence of infections was similar in the two groups. In conclusion, untreated IMN with nephrotic syndrome is associated with a high risk for deterioration of renal function. A 6-mo regimen of cyclophosphamide and steroids induces remissions in a high proportion, arrests progression of renal insufficiency, and improves quality of life. 18: 189918: -190418: , 200718: . doi: 10.1681 I diopathic membranous nephropathy (IMN) is the most common cause of nephrotic syndrome in adults (1). Although clinical trials on therapy for this disease have spanned more than two decades, universal consensus regarding the need for and the modality of therapy to decrease proteinuria and halt the progression of renal disease does not exist (2). A number of therapeutic measures have been tried, including nonspecific antiproteinuric agents; corticosteroids, either alone or with alkylating agents; cyclosporine; intravenous Ig; mycophenolate mofetil; and rituximab (3-16). The only regimen that showed a clear short-and long-term benefit is the one that consists of a 6-mo course of alternating months of oral chlorambucil and corticosteroids (15,17). Others, however, have pointed to the relatively benign course of IMN (18) and favor a conservative approach. A recent systematic review (19) failed to find a beneficial effect of treatment on renal or patient survival. J Am Soc NephrolA major lacuna that limits the value of this meta-analysis is the lack of controlled trials of sufficient size, quality, and duration. Because ESRD usually develops only after 5 to 10 yr, studies that aim to evaluate the effect of treatment on development of ESRD need a sufficiently long follow-up. We conducted a randomized, controlled trial (R...

Glioblastoma multiforme (GBM) is a life-threatening brain tumor. Accumulating evidence suggests that eradication of glioma stem-like cells (GSCs) in GBM is essential to achieve cure. The transcription factor FOXM1 has recently gained attention as a master regulator of mitotic progression of cancer cells in various organs. Here, we demonstrate that FOXM1 forms a protein complex with the mitotic kinase MELK in GSCs, leading to phosphorylation and activation of FOXM1 in a MELK kinase-dependent manner. This MELK-dependent activation of FOXM1 results in a subsequent increase in mitotic regulatory genes in GSCs. MELK-driven FOXM1 activation is regulated by the binding and subsequent trans-phosphorylation of FOXM1 by another kinase PLK1. Using mouse neural progenitor cells (NPCs), we found that transgenic expression of FOXM1 enhances, while siRNA-mediated gene silencing diminishes neurosphere formation, suggesting that FOXM1 is required for NPC growth. During tumorigenesis, FOXM1 expression sequentially increases as cells progress from NPCs, to pretumorigenic progenitors and GSCs. The antibiotic Siomycin A disrupts MELK-mediated FOXM1 signaling with a greater sensitivity in GSC compared to neural stem cell. Treatment with the first-line chemotherapy agent for GBM, Temozolomide, paradoxically enriches for both FOXM1 (+) and MELK (+) cells in GBM cells, and addition of Siomycin A to Temozolomide treatment in mice harboring GSC-derived intracranial tumors enhances the effects of the latter. Collectively, our data indicate that FOXM1 signaling through its direct interaction with MELK regulates key mitotic genes in GSCs in a PLK1-dependent manner and thus, this protein complex is a potential therapeutic target for GBM. Stem Cells 2013;31:1051–1063