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Heterogeneous Mechanisms of Secondary Resistance and Clonal Selection in Sarcoma during Treatment with Nutlin.

Laroche A, Tran-Cong K, Chaire V, Lagarde P, Hostein I, Coindre JM, Chibon F, Neuville A, Lesluyes T, Lucchesi C, Italiano A - PLoS ONE (2015)

Bottom Line: Further, secondary resistance to nutlin was associated with deregulation of apoptosis-related genes and marked productive autophagy, the inhibition of which resulted in significant restoration of nutlin-induced cell death.Collectively, our findings argue that secondary resistance to nutlin in STS involved heterogeneous mechanisms resulting from clonal evolution and several biological pathways.Alternative dosing regimens and combination with other targeted agents are needed to achieve successful development of nutlin in the clinical setting.

View Article: PubMed Central - PubMed

Affiliation: INSERM U916, Institut Bergonié, Bordeaux, France; Sarcoma Unit, Institut Bergonié, Bordeaux, France.

ABSTRACT
Nutlin inhibits TP53-MDM2 interaction and is under investigation in soft-tissue sarcomas (STS) and other malignancies. Molecular mechanisms of secondary resistance to nutlin in STS are unknown. We performed whole-transcriptome sequencing (RNA-seq) on three pretreatment and secondary resistant STS cell lines selected based on their high primary sensitivity to nutlin. Our data identified a subset of cancer gene mutations and ploidy variations that were positively selected following treatment, including TP53 mutations in 2 out of 3 resistant cell lines. Further, secondary resistance to nutlin was associated with deregulation of apoptosis-related genes and marked productive autophagy, the inhibition of which resulted in significant restoration of nutlin-induced cell death. Collectively, our findings argue that secondary resistance to nutlin in STS involved heterogeneous mechanisms resulting from clonal evolution and several biological pathways. Alternative dosing regimens and combination with other targeted agents are needed to achieve successful development of nutlin in the clinical setting.

No MeSH data available.


Related in: MedlinePlus

Effect of RG7388 on cell cycle progression and cell viability in human STS cell lines.(A) Cell cycle profile before and after treatment with 1μM of RG7388 analyzed by PI incorporation and flow cytometry in the IB111, IB115 and IB128 cell lines. (B) Cell-cycle distribution was calculated from the flow cytogram. (C) Effect of RG7388 on loss of potential mitochondrial membrane with TMRM fluorescent assay in the IB111, IB115 and IB128 cell lines.
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pone.0137794.g002: Effect of RG7388 on cell cycle progression and cell viability in human STS cell lines.(A) Cell cycle profile before and after treatment with 1μM of RG7388 analyzed by PI incorporation and flow cytometry in the IB111, IB115 and IB128 cell lines. (B) Cell-cycle distribution was calculated from the flow cytogram. (C) Effect of RG7388 on loss of potential mitochondrial membrane with TMRM fluorescent assay in the IB111, IB115 and IB128 cell lines.

Mentions: One of the main cellular functions of activated TP53 is blocking cell cycle progression in the G1 and G2 phase. Treatment of exponentially proliferating STS cell lines with RG7388 for 48 hours led to a dose-dependent cell cycle block in G1 and G2/M phase and a depletion of the S phase compartment (Fig 2A and 2B). One of the other main functions of activated TP53 is induction of apoptosis. Exposure of exponentially proliferating STS cell lines to RG7388 RO5503781 for 72 hours led to the induction of apoptosis in a dose-dependent manner as revealed by an increase in the percentage of TMRM-staining cells (Fig 2C). The 3 STS cell lines that elicited the most significant apoptotic responses were IB111, IB115 and IB128.


Heterogeneous Mechanisms of Secondary Resistance and Clonal Selection in Sarcoma during Treatment with Nutlin.

Laroche A, Tran-Cong K, Chaire V, Lagarde P, Hostein I, Coindre JM, Chibon F, Neuville A, Lesluyes T, Lucchesi C, Italiano A - PLoS ONE (2015)

Effect of RG7388 on cell cycle progression and cell viability in human STS cell lines.(A) Cell cycle profile before and after treatment with 1μM of RG7388 analyzed by PI incorporation and flow cytometry in the IB111, IB115 and IB128 cell lines. (B) Cell-cycle distribution was calculated from the flow cytogram. (C) Effect of RG7388 on loss of potential mitochondrial membrane with TMRM fluorescent assay in the IB111, IB115 and IB128 cell lines.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4591276&req=5

pone.0137794.g002: Effect of RG7388 on cell cycle progression and cell viability in human STS cell lines.(A) Cell cycle profile before and after treatment with 1μM of RG7388 analyzed by PI incorporation and flow cytometry in the IB111, IB115 and IB128 cell lines. (B) Cell-cycle distribution was calculated from the flow cytogram. (C) Effect of RG7388 on loss of potential mitochondrial membrane with TMRM fluorescent assay in the IB111, IB115 and IB128 cell lines.
Mentions: One of the main cellular functions of activated TP53 is blocking cell cycle progression in the G1 and G2 phase. Treatment of exponentially proliferating STS cell lines with RG7388 for 48 hours led to a dose-dependent cell cycle block in G1 and G2/M phase and a depletion of the S phase compartment (Fig 2A and 2B). One of the other main functions of activated TP53 is induction of apoptosis. Exposure of exponentially proliferating STS cell lines to RG7388 RO5503781 for 72 hours led to the induction of apoptosis in a dose-dependent manner as revealed by an increase in the percentage of TMRM-staining cells (Fig 2C). The 3 STS cell lines that elicited the most significant apoptotic responses were IB111, IB115 and IB128.

Bottom Line: Further, secondary resistance to nutlin was associated with deregulation of apoptosis-related genes and marked productive autophagy, the inhibition of which resulted in significant restoration of nutlin-induced cell death.Collectively, our findings argue that secondary resistance to nutlin in STS involved heterogeneous mechanisms resulting from clonal evolution and several biological pathways.Alternative dosing regimens and combination with other targeted agents are needed to achieve successful development of nutlin in the clinical setting.

View Article: PubMed Central - PubMed

Affiliation: INSERM U916, Institut Bergonié, Bordeaux, France; Sarcoma Unit, Institut Bergonié, Bordeaux, France.

ABSTRACT
Nutlin inhibits TP53-MDM2 interaction and is under investigation in soft-tissue sarcomas (STS) and other malignancies. Molecular mechanisms of secondary resistance to nutlin in STS are unknown. We performed whole-transcriptome sequencing (RNA-seq) on three pretreatment and secondary resistant STS cell lines selected based on their high primary sensitivity to nutlin. Our data identified a subset of cancer gene mutations and ploidy variations that were positively selected following treatment, including TP53 mutations in 2 out of 3 resistant cell lines. Further, secondary resistance to nutlin was associated with deregulation of apoptosis-related genes and marked productive autophagy, the inhibition of which resulted in significant restoration of nutlin-induced cell death. Collectively, our findings argue that secondary resistance to nutlin in STS involved heterogeneous mechanisms resulting from clonal evolution and several biological pathways. Alternative dosing regimens and combination with other targeted agents are needed to achieve successful development of nutlin in the clinical setting.

No MeSH data available.


Related in: MedlinePlus