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Updated: Mar 12, 2026
Quantitative Analysis of Autophagy using Advanced 3D Fluorescence Microscopy
Published on: May 3, 2013
Autophagy is associated with chemoresistance in neuroblastoma
Assila Belounis1,2, Carine Nyalendo3, Roxane Le Gall1
1Research centre of the Sainte Justine university hospital, Montreal, QC, Canada.
Background:
Neuroblastoma (NB) is a frequent pediatric tumor characterized by a poor prognosis where a majority of tumors progress despite intensive multimodality treatments. Autophagy, a self-degradative process in cells, could be induced by chemotherapy and be associated with chemoresistance. The aim of this study was to determine whether: 1) autophagy is present in NB, 2) chemotherapy modified its levels, and 3) its inhibition decreased chemoresistance.
Methods:
Immunohistochemical stainings were performed on samples from 184 NB patients in order to verify the expression of LC3B, a specific marker for autophagy, and Beclin 1, a positive regulator of autophagy. In addition, we performed an in vitro study with six NB cell lines and six drugs (vincristine, doxorubicin, cisplatin temozolomide, LY294002 and syrolimus). Inhibition of autophagy was performed using ATG5 knockdown cells or hydroxychloroquine (HCQ). Cell survival was measured using the MTT cell proliferation assay. Autophagy was detected by monodansylcadaverine, confocal microscopy and Western blot. In vivo study with tumor xenografts in NSG mice was performed.
Results:
Our results have indicated that autophagy was present at low levels in NB and was not a prognostic factor, while Beclin 1 was highly expressed in children with poor NB prognosis. However, autophagy levels increased after chemotherapy in vitro and in vivo. Tumor progression was significantly decreased in mice treated with a combination of HCQ and vincristine.
Conclusions:
Taken together, autophagy is present in NB, induced by chemotherapy and associated with chemoresistance, which is significantly reduced by its inhibition. Therefore, targeting autophagy represents a very attractive approach to develop new therapeutic strategies in NB.
Insights
Autophagy is present in neuroblastoma (NB) and increases with chemotherapy, contributing to chemoresistance. Inhibiting autophagy, using hydroxychloroquine (HCQ), significantly reduced tumor progression in preclinical models, offering new therapeutic strategies.
Area of Science:
- Oncology
- Cell Biology
- Molecular Medicine
Background:
- Neuroblastoma (NB) is a prevalent pediatric cancer with a poor prognosis, often progressing despite aggressive treatments.
- Autophagy, a cellular degradation process, can be induced by chemotherapy and may contribute to chemoresistance in NB.
- Understanding autophagy's role is crucial for developing more effective NB therapies.
Purpose of the Study:
- To investigate the presence and levels of autophagy in NB.
- To determine if chemotherapy affects autophagy in NB.
- To assess if inhibiting autophagy can overcome chemoresistance in NB.
Main Methods:
- Analyzed 184 NB patient samples for autophagy markers (LC3B, Beclin 1) via immunohistochemistry.
- Conducted in vitro studies using NB cell lines and various chemotherapeutic agents.
- Inhibited autophagy using ATG5 knockdown or hydroxychloroquine (HCQ) and measured cell survival.
- Performed in vivo studies using NB tumor xenografts in NSG mice.
Main Results:
- Autophagy was detected at low levels in NB, with high Beclin 1 expression correlating with poor prognosis.
- Chemotherapy significantly increased autophagy levels both in vitro and in vivo.
- Combined treatment with HCQ and vincristine markedly reduced tumor progression in mice.
Conclusions:
- Autophagy is present in NB, induced by chemotherapy, and linked to chemoresistance.
- Inhibiting autophagy, particularly with HCQ, demonstrates therapeutic potential by reducing chemoresistance.
- Targeting autophagy presents a promising strategy for novel neuroblastoma treatments.
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