12 research outputs found
The intercultural dodo: a drawing from the School of Bundi, Rājasthān
The iconic dodo Raphus cucullatus once occurred on the isolated Mascarene Island of Mauritius, situated in the southwestern Indian Ocean. Mauritius was once a paradise for a unique flora and fauna that evolved in isolation for 8 million years. The dodo was sought after by seafarers who visited the island from the early sixteenth century onwards because we know from remains surviving in collections and a series of artworks that captive dodos were transported to Europe, India and Japan. This article presents a hitherto unpublished image of a dodo, preserved in the collection of the Trustees, Chhatrapati Shivaji Maharaj Vastu Sangrahalaya, Mumbai, the formerly Prince of Wales Museum of Western India. The bird is situated in a non-Mauritian environment together with other animals and it is named in Hindi. We further explore the background of this creation and its implication on the iconography of the dodo
Co-Treatment with a Novel Heat Shock Protein (hsp) 90 Inhibitor IPI504 and the Histone Deacetylase Inhibitor (HDI) Vorinostat (Suberoylanilide Hydroxamic Acid, SAHA): A Highly Active Combination Against Wild Type or Mutant Bcr-Abl-T315I or FLT-3-ITD-Containing Human Leukemia Cells.
Abstract
Hsp90 is an ATP-dependent molecular chaperone, which helps in folding its client proteins, e.g., Bcr-Abl, FLT-3, c-Raf and Akt, into active conformation. Geldanamycin analogue, 17-AAG (Kosan Biosciences Inc., Hayward, CA) inhibits the chaperone function of hsp90, which promotes polyubiquitylation and proteasomal degradation of the misfolded hsp90 client proteins. We recently reported that, by inhibiting the activity of histone deacetylase 6, the hydroxamate HDIs such as vorinostat (Merck & Co., Inc.) induce acetylation and inhibition of hsp90, thus also causing the depletion of its client proteins. In the present studies, we determined the anti-leukemia effects of the novel, highly soluble, hsp90 antagonist IPI504 (Infinity Pharmaceuticals), which, in vitro and in vivo, interconverts with 17-AAG, ± vorinostat, against human cultured or primary, wild type or mutant Bcr-Abl or mutant FLT-3 containing acute leukemia cells. Treatment with IPI504 (0.5 to 2.0 μM) for 24 to 48 hours, in a dose dependent manner, induced apoptosis of WT Bcr-Abl-expressing K562 and LAMA-84 cells. This was associated with attenuation of the levels of Bcr-Abl, pCrkL, pSTAT5, c-Raf and pAkt. In a dose dependent manner (50 to 500 nM for 48 hours), IPI504 also induced apoptosis of FLT-3 internal tandem duplication (ITD)-containing human acute leukemia MV4-11 cells, which was associated with attenuation of the levels of FLT-3, pAkt, pSTAT5, pERK1/2. Notably, treatment with IPI504 induced similar level of apoptosis of mouse bone marrow BaF3 cells, which had been transformed and rendered IL-3 independent for growth by ectopic expression of WT Bcr-Abl, its P-loop (Bcr-Abl-E255K) or highly imatinib mesylate (IM) resistant, contact-inhibition (Bcr-Abl-T315I) point mutant. This was also associated with attenuation of the levels of WT and mutant Bcr-Abl-E255K or Bcr-Abl-T315I. In previous studies we had demonstrated that treatment with vorinostat depletes WT and mutant Bcr-Abl levels and induces apoptosis of expressing human leukemia cells. Therefore, we determined the effect of the co-treatment of IPI504 (1.0 μM) and vorinostat (1.0 μM) against cultured or primary human CML cells. Co-treatment with IPI504 and vorinostat induced significantly more apoptosis of K562 and MV4-11 cells, which was associated with more depletion of WT-Bcr-Abl and FLT-3-ITD levels in K562 and MV4-11 cells, respectively. Notably, co-treatment with IPI504 and vorinostat, versus treatment with either agent alone, also induced more apoptosis of primary CML cells (4 samples) derived from patients with IM-resistant CML, including a sample of cells documented to have Bcr-Abl-T315I mutation. Additionally, as compared to treatment with either agent alone, the combination of IPI504 and vorinostat also induced more apoptosis of primary AML cells (4 samples), including two samples that contained FLT-3-ITD. These findings demonstrate that the combination of IPI504 with vorinostat exerts a high level of in vitro activity against FLT-3-ITD-containing acute leukemia, as well as against highly IM-resistant mutant Bcr-Abl-expressing leukemia cells.</jats:p
Co-Treatment with a Novel Heat Shock Protein (hsp) 90 Inhibitor IPI504 and the Histone Deacetylase Inhibitor (HDI) Vorinostat (Suberoylanilide Hydroxamic Acid, SAHA): A Highly Active Combination Against Wild Type or Mutant Bcr-Abl-T315I or FLT-3-ITD-Containing Human Leukemia Cells.
ITPR1 Protects Renal Cancer Cells against Natural Killer Cells by Inducing Autophagy
Abstract
Clear cell renal cell carcinomas (RCC) frequently display inactivation of von Hippel-Lindau (VHL) gene leading to increased level of hypoxia-inducible factors (HIF). In this study, we investigated the potential role of HIF2α in regulating RCC susceptibility to natural killer (NK) cell–mediated killing. We demonstrated that the RCC cell line 786-0 with mutated VHL was resistant to NK-mediated lysis as compared with the VHL-corrected cell line (WT7). This resistance was found to require HIF2α stabilization. On the basis of global gene expression profiling and chromatin immunoprecipitation assay, we found ITPR1 (inositol 1,4,5-trisphosphate receptor, type 1) as a direct novel target of HIF2α and that targeting ITPR1 significantly increased susceptibility of 786-0 cells to NK-mediated lysis. Mechanistically, HIF2α in 786-0 cells lead to overexpression of ITPR1, which subsequently regulated the NK-mediated killing through the activation of autophagy in target cells by NK-derived signal. Interestingly, both ITPR1 and Beclin-1 silencing in 786-0 cells inhibited NK-induced autophagy and subsequently increased granzyme B activity in target cells. Finally, in vivo ITPR1 targeting significantly enhanced the NK-mediated tumor regression. Our data provide insight into the link between HIF2α, the ITPR1-related pathway, and natural immunity and strongly suggest a role for the HIF2α/ITPR1 axis in regulating RCC cell survival. Cancer Res; 74(23); 6820–32. ©2014 AACR.</jats:p
Supplemental video 2 from ITPR1 Protects Renal Cancer Cells against Natural Killer Cells by Inducing Autophagy
<p>Supplemental video 2. 786-0 cells described in Figure 3B were recorded by time-lapse video microscopy</p></jats:p
Array comparative genomic hybridization identifies high level of PI3K/Akt/mTOR pathway alterations in anal cancer recurrences
Abstract Genomic alterations of anal squamous cell carcinoma (ASCC) remain poorly understood due to the rarity of this tumor. Array comparative genomic hybridization and targeted gene sequencing were performed in 49 cases of ASCC. The most frequently altered regions (with a frequency greater than 25%) were 10 deleted regions (2q35, 2q36.3, 3p21.2, 4p16.3, 4p31.21, 7q36.1, 8p23.3, 10q23.2, 11q22.3, and 13q14.11) and 8 gained regions (1p36.33, 1q21.1, 3q26.32, 5p15.33, 8q24.3, 9q34.3, 16p13.3, and 19p13.3). The most frequent minimal regions of deletion (55%) encompassed the 11q22.3 region containing ATM, while the most frequent minimal regions of gain (57%) encompassed the 3q26.32 region containing PIK3CA. Recurrent homozygous deletions were observed for 5 loci (ie, TGFR2 in 4 cases), and recurrent focal amplifications were observed for 8 loci (ie, DDR2 and CCND1 in 3 cases, respectively). Several of the focal amplified genes are targets for specific therapies. Integrated analysis showed that the PI3K/Akt/mTOR signaling pathway was the pathway most extensively affected, particularly in recurrences compared to treatment‐naive tumors (64% vs 30%; P = .017). In patients with ASCC recurrences, poor overall survival (OS) was significantly correlated with a large number of altered regions (P = .024). These findings provide insight into the somatic genomic alterations in ASCC and highlight the key role of the druggable PI3K/Akt/mTOR signaling pathway
Mutational analysis of anal cancers demonstrates frequent PIK3CA mutations associated with poor outcome after salvage abdominoperineal resection
International audienceBackground: A better understanding of the molecular profile of anal squamous cell carcinomas (ASCCs) is necessary to consider new therapeutic approaches, and the identification of prognostic and predictive factors for response to treatment. Methods: We retrospectively analysed tumours from ASCC patients for mutational analysis of KRAS, NRAS, HRAS, BRAF, PIK3CA, MET, TP53 and FBXW7 genes by HRM and Sanger sequencing analysis. Results: Specimens from 148 patients were analysed: 96 treatment-naive tumours and 52 recurrences after initial radiotherapy (RT) or chemoradiotherapy (CRT). Mutations of KRAS, PIK3CA, FBXW7 and TP53 genes were present in 3 (2.0%), 30 (20.3%), 9 (6.1%) and 7 tumours (4.7%), respectively. The distribution of the mutations was similar between treatment-naive tumours and recurrences, except for TP53 mutations being more frequent in recurrences (P = 0.0005). In patients treated with abdominoperineal resection (APR) after relapse (n = 38, median follow-up of 18.2 years), overall survival (OS) was significantly correlated with HPV16 status (P = 0.048), gender (P = 0.045) and PIK3CA mutation (P = 0.037). The PIK3CA status retained its prognostic significance in Cox multivariate regression analysis (P = 0.025). Conclusions: Our study identified PIK3CA mutation as an independent prognostic factor in patients who underwent APR for ASCC recurrence, suggesting a potential benefit from adjuvant treatment and the evaluation of targeted therapies with PI3K/Akt/mTor inhibitors in PIK3CA-mutated patients
Supplementary Figures S1-S5 from ITPR1 Protects Renal Cancer Cells against Natural Killer Cells by Inducing Autophagy
<p>Supplementary Figures S1-S5. Figure S1. Differential susceptibility of 786-0, PRC3, and WT7 cell lines to NK-mediated lysis. Figure S2. Role of ANGPTL4 and ADM in RCC cell susceptibility to NK-mediated lysis. Figure S3. VHL and NK ligand expression in RCC cells. Figure S4. Silencing of HIF-2α and NK ligand expression in 786-0 cells. Figure S5. VHL status, targeting of HIF-2α or silencing of ITPR1 does not regulate autophagy in 786-0 cells.</p></jats:p
