17-AAG and Apoptosis, Autophagy, and Mitophagy in Canine Osteosarcoma Cell Lines

Abstract

Canine osteosarcoma is highly resistant to current chemotherapy; thus, clarifying the mechanisms of tumor cell resistance to treatments is an urgent need. We tested the geldanamycin derivative 17-AAG (17-allylamino-17-demethoxygeldanamycin) prototype of Hsp90 (heat shock protein 90) inhibitors in 2 canine osteosarcoma cell lines, D22 and D17, derived from primary and metastatic tumors, respectively. With the aim to understand the interplay between cell death, autophagy, and mitophagy, in light of the dual effect of autophagy in regulating cancer cell viability and death, D22 and D17 cells were treated with different concentrations of 17-AAG (0.5 μM, 1 μM) for 24 and 48 hours. 17-AAG-induced apoptosis, necrosis, autophagy, and mitophagy were assessed by transmission electron microscopy, flow cytometry, and immunofluorescence. A simultaneous increase in apoptosis, autophagy, and mitophagy was observed only in the D22 cell line, while D17 cells showed low levels of apoptotic cell death. These results reveal differential cell response to drug-induced stress depending on tumor cell type. Therefore, pharmacological treatments based on proapoptotic chemotherapy in association with autophagy regulators would benefit from a predictive in vitro screening of the target cell type.

Establishment of three‐dimensional canine osteosarcoma cell lines showing vasculogenic mimicry and evaluation of biological properties after treatment with 17‐AAG

“…42 We have previously showed that Hsp90 is over-expressed in canine OSA tissues, suggesting a role in tumour progression and that in vitro treatment with 17-AAG induced autophagy and apoptosis in D17 cell line. 21,25 As showed in these results, 17-AAG induced a significant decrease of VM features in a time-dependent manner in D17 cell line, confirming the relevant biologic effect mediated by overcitated molecule on this canine OSA cell line.…”

“…The Hsp90 inhibitor 17‐AAG (17‐N‐allylamino‐17‐demethoxygeldanamycin), is able to reduce migration, tubular differentiation, invasion through Matrigel and VEGFR1 expression of human vascular endothelial cells . We have also recently demonstrated that 17‐AAG is able to induce apoptosis and autophagy in canine OSA cell lines, suggesting an anti‐proliferative effect of this drug on canine OSA cell lines …”

“…20 We have also recently demonstrated that 17-AAG is able to induce apoptosis and autophagy in canine OSA cell lines, suggesting an anti-proliferative effect of this drug on canine OSA cell lines. 21 As canine OSA represents an excellent model in comparative oncology, the aim of this study was to verify the ability of two canine OSA cell lines to perform VM in 3D cultures, to identify specific markers of endothelial-like cells and to evaluate how these cells respond to 17-AAG treatment in relation to tubular-like structure formation in vitro. 22 2 | MATERIALS AND METHODS…”

Sex and Gender Aspects for Patient Stratification in Allergy Prevention and Treatment

“…Several studies suggest that androgens suppress leukotriene levels, and female sex is associated with higher biosynthesis of these molecules. Hence, the suggestion of a possible gender tailored treatment of leukotriene related disorders such as asthma and allergic rhinitis [29]. Montelukast a cysteinyl leukotriene receptor 1 antagonist reduced days with worse asthma symptoms in girls reaching puberty respect to peers boys in a clinical trial [29], so it appears to be more beneficial in women than in men [30].…”

Does Allergy Break Bones? Osteoporosis and Its Connection to Allergy

“…An increasing evidence suggest a key role of autophagy in several human diseases: it has emerged as a fundamental process in tissue and cellular homeostasis [39] and participates in the maintenance of bone marrow hematopoietic stem cell niche; it is critical for a well-balanced inflammatory response [40]. Autophagy seems to play a role in asthma pathogenesis where it may act as a potential contributor to airway inflammation, fibrotic airway remodelling [41], and airway hyper-responsiveness [42].…”