Limits...
Mesenchymal phenotype predisposes lung cancer cells to impaired proliferation and redox stress in response to glutaminase inhibition.

Ulanet DB, Couto K, Jha A, Choe S, Wang A, Woo HK, Steadman M, DeLaBarre B, Gross S, Driggers E, Dorsch M, Hurov JB - PLoS ONE (2014)

Bottom Line: As a result, identification of tractable markers that predict GLS dependence is needed for translation of GLS inhibitors to the clinic.Furthermore, lung cancer cells induced to undergo epithelial to mesenchymal transition (EMT) acquire sensitivity to the GLS inhibitor.Metabolic studies suggest that the mesenchymal cells have a reduced capacity for oxidative phosphorylation and increased susceptibility to oxidative stress, rendering them unable to cope with the perturbations induced by GLS inhibition.

View Article: PubMed Central - PubMed

Affiliation: Agios Pharmaceuticals, Cambridge, Massachusetts, United States of America.

ABSTRACT
Recent work has highlighted glutaminase (GLS) as a key player in cancer cell metabolism, providing glutamine-derived carbon and nitrogen to pathways that support proliferation. There is significant interest in targeting GLS for cancer therapy, although the gene is not known to be mutated or amplified in tumors. As a result, identification of tractable markers that predict GLS dependence is needed for translation of GLS inhibitors to the clinic. Herein we validate a small molecule inhibitor of GLS and show that non-small cell lung cancer cells marked by low E-cadherin and high vimentin expression, hallmarks of a mesenchymal phenotype, are particularly sensitive to inhibition of the enzyme. Furthermore, lung cancer cells induced to undergo epithelial to mesenchymal transition (EMT) acquire sensitivity to the GLS inhibitor. Metabolic studies suggest that the mesenchymal cells have a reduced capacity for oxidative phosphorylation and increased susceptibility to oxidative stress, rendering them unable to cope with the perturbations induced by GLS inhibition. These findings elucidate selective metabolic dependencies of mesenchymal lung cancer cells and suggest novel pathways as potential targets in this aggressive cancer type.

No MeSH data available.


Related in: MedlinePlus

Association between EMT-related markers and BPTES sensitivity in NSCLC lines.(A) GeneGo analysis indicating four top-ranking mesenchymal signatures correlating with BPTES sensitivity. P-values are calculated within the GeneGo software using the hypergeometric distribution. (B) Anti-correlation between high E-cadherin low vimentin RNA expression levels and sensitivity to BPTES. (C) Mu/mumax values depicted following 72 hr treatment of NSCLC lines with 10 µM BPTES. Equal protein amounts of tumor cell line extracts were electrophoresed, with the group of more sensitive lines on the left and least sensitive on the right, and immunoblotted for the indicated proteins. Histone H3 was used as a loading control. (D) Quantitation of average GAC protein levels relative to PC protein expression (+/−SEM) in BPTES sensitive (n = 7), intermediate (n = 7), and insensitive (n = 7) lines. P = 0.03 comparing GAC/PC protein levels in sensitive compared to insensitive lines; P = 0.06 comparing sensitive to intermediate groups (unpaired 2-tail t-test).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4264947&req=5

pone-0115144-g002: Association between EMT-related markers and BPTES sensitivity in NSCLC lines.(A) GeneGo analysis indicating four top-ranking mesenchymal signatures correlating with BPTES sensitivity. P-values are calculated within the GeneGo software using the hypergeometric distribution. (B) Anti-correlation between high E-cadherin low vimentin RNA expression levels and sensitivity to BPTES. (C) Mu/mumax values depicted following 72 hr treatment of NSCLC lines with 10 µM BPTES. Equal protein amounts of tumor cell line extracts were electrophoresed, with the group of more sensitive lines on the left and least sensitive on the right, and immunoblotted for the indicated proteins. Histone H3 was used as a loading control. (D) Quantitation of average GAC protein levels relative to PC protein expression (+/−SEM) in BPTES sensitive (n = 7), intermediate (n = 7), and insensitive (n = 7) lines. P = 0.03 comparing GAC/PC protein levels in sensitive compared to insensitive lines; P = 0.06 comparing sensitive to intermediate groups (unpaired 2-tail t-test).

Mentions: Based on the range of BPTES sensitivity observed across the 62 cell lines (Fig. 1), we searched for transcriptional markers that associated with sensitivity or resistance using a publicly available dataset from the Broad Institute (https://array.nci.nih.gov/caarray/project/golub-00327). Of note, neither GLS1 nor GLS2 mRNA expression levels correlated with sensitivity. The top 200 probes showing most significant correlation with sensitivity were then submitted to GeneGO pathway analysis (http://portal.genego.com/cgi/data_manager.cgi). We noted that no metabolism-related pathways were strongly associated with BPTES responsiveness, indicating that any intrinsic differences in metabolism between sensitive and resistant cells are not broadly reflected at the transcriptional level (Table S2 in File_S2). Interestingly, 4 of the top 25 pathways were related to EMT (ranks 1, 15, 23, 25; Fig. 2A). Immune response pathways were also highly represented in this analysis. While we chose to focus our investigations on the link between EMT and GLS1 dependence, it is notable that a link between NF-κB and glutaminase activity has been demonstrated by others [11], [17].


Mesenchymal phenotype predisposes lung cancer cells to impaired proliferation and redox stress in response to glutaminase inhibition.

Ulanet DB, Couto K, Jha A, Choe S, Wang A, Woo HK, Steadman M, DeLaBarre B, Gross S, Driggers E, Dorsch M, Hurov JB - PLoS ONE (2014)

Association between EMT-related markers and BPTES sensitivity in NSCLC lines.(A) GeneGo analysis indicating four top-ranking mesenchymal signatures correlating with BPTES sensitivity. P-values are calculated within the GeneGo software using the hypergeometric distribution. (B) Anti-correlation between high E-cadherin low vimentin RNA expression levels and sensitivity to BPTES. (C) Mu/mumax values depicted following 72 hr treatment of NSCLC lines with 10 µM BPTES. Equal protein amounts of tumor cell line extracts were electrophoresed, with the group of more sensitive lines on the left and least sensitive on the right, and immunoblotted for the indicated proteins. Histone H3 was used as a loading control. (D) Quantitation of average GAC protein levels relative to PC protein expression (+/−SEM) in BPTES sensitive (n = 7), intermediate (n = 7), and insensitive (n = 7) lines. P = 0.03 comparing GAC/PC protein levels in sensitive compared to insensitive lines; P = 0.06 comparing sensitive to intermediate groups (unpaired 2-tail t-test).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4264947&req=5

pone-0115144-g002: Association between EMT-related markers and BPTES sensitivity in NSCLC lines.(A) GeneGo analysis indicating four top-ranking mesenchymal signatures correlating with BPTES sensitivity. P-values are calculated within the GeneGo software using the hypergeometric distribution. (B) Anti-correlation between high E-cadherin low vimentin RNA expression levels and sensitivity to BPTES. (C) Mu/mumax values depicted following 72 hr treatment of NSCLC lines with 10 µM BPTES. Equal protein amounts of tumor cell line extracts were electrophoresed, with the group of more sensitive lines on the left and least sensitive on the right, and immunoblotted for the indicated proteins. Histone H3 was used as a loading control. (D) Quantitation of average GAC protein levels relative to PC protein expression (+/−SEM) in BPTES sensitive (n = 7), intermediate (n = 7), and insensitive (n = 7) lines. P = 0.03 comparing GAC/PC protein levels in sensitive compared to insensitive lines; P = 0.06 comparing sensitive to intermediate groups (unpaired 2-tail t-test).
Mentions: Based on the range of BPTES sensitivity observed across the 62 cell lines (Fig. 1), we searched for transcriptional markers that associated with sensitivity or resistance using a publicly available dataset from the Broad Institute (https://array.nci.nih.gov/caarray/project/golub-00327). Of note, neither GLS1 nor GLS2 mRNA expression levels correlated with sensitivity. The top 200 probes showing most significant correlation with sensitivity were then submitted to GeneGO pathway analysis (http://portal.genego.com/cgi/data_manager.cgi). We noted that no metabolism-related pathways were strongly associated with BPTES responsiveness, indicating that any intrinsic differences in metabolism between sensitive and resistant cells are not broadly reflected at the transcriptional level (Table S2 in File_S2). Interestingly, 4 of the top 25 pathways were related to EMT (ranks 1, 15, 23, 25; Fig. 2A). Immune response pathways were also highly represented in this analysis. While we chose to focus our investigations on the link between EMT and GLS1 dependence, it is notable that a link between NF-κB and glutaminase activity has been demonstrated by others [11], [17].

Bottom Line: As a result, identification of tractable markers that predict GLS dependence is needed for translation of GLS inhibitors to the clinic.Furthermore, lung cancer cells induced to undergo epithelial to mesenchymal transition (EMT) acquire sensitivity to the GLS inhibitor.Metabolic studies suggest that the mesenchymal cells have a reduced capacity for oxidative phosphorylation and increased susceptibility to oxidative stress, rendering them unable to cope with the perturbations induced by GLS inhibition.

View Article: PubMed Central - PubMed

Affiliation: Agios Pharmaceuticals, Cambridge, Massachusetts, United States of America.

ABSTRACT
Recent work has highlighted glutaminase (GLS) as a key player in cancer cell metabolism, providing glutamine-derived carbon and nitrogen to pathways that support proliferation. There is significant interest in targeting GLS for cancer therapy, although the gene is not known to be mutated or amplified in tumors. As a result, identification of tractable markers that predict GLS dependence is needed for translation of GLS inhibitors to the clinic. Herein we validate a small molecule inhibitor of GLS and show that non-small cell lung cancer cells marked by low E-cadherin and high vimentin expression, hallmarks of a mesenchymal phenotype, are particularly sensitive to inhibition of the enzyme. Furthermore, lung cancer cells induced to undergo epithelial to mesenchymal transition (EMT) acquire sensitivity to the GLS inhibitor. Metabolic studies suggest that the mesenchymal cells have a reduced capacity for oxidative phosphorylation and increased susceptibility to oxidative stress, rendering them unable to cope with the perturbations induced by GLS inhibition. These findings elucidate selective metabolic dependencies of mesenchymal lung cancer cells and suggest novel pathways as potential targets in this aggressive cancer type.

No MeSH data available.


Related in: MedlinePlus