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Acquired resistance to EGFR tyrosine kinase inhibitors alters the metabolism of human head and neck squamous carcinoma cells and xenograft tumours.

Beloueche-Babari M, Box C, Arunan V, Parkes HG, Valenti M, De Haven Brandon A, Jackson LE, Eccles SA, Leach MO - Br. J. Cancer (2015)

Bottom Line: Acquired resistance to molecularly targeted therapeutics is a key challenge in personalised cancer medicine, highlighting the need for identifying the underlying mechanisms and early biomarkers of relapse, in order to guide subsequent patient management.Our studies reveal metabolic signatures associated not only with acquired EGFR TKI resistance but also growth pattern, microenvironment and contributing mechanisms in HNSCC models.These findings warrant further investigation as metabolic biomarkers of disease relapse in the clinic.

View Article: PubMed Central - PubMed

Affiliation: Cancer Research UK Cancer Imaging Centre, Division of Radiotherapy and Imaging, The Institute of Cancer Research, London and The Royal Marsden NHS Foundation Trust, Sutton, Surrey SM2 5PT, UK.

ABSTRACT

Background: Acquired resistance to molecularly targeted therapeutics is a key challenge in personalised cancer medicine, highlighting the need for identifying the underlying mechanisms and early biomarkers of relapse, in order to guide subsequent patient management.

Methods: Here we use human head and neck squamous cell carcinoma (HNSCC) models and nuclear magnetic resonance (NMR) spectroscopy to assess the metabolic changes that follow acquired resistance to EGFR tyrosine kinase inhibitors (TKIs), and which could serve as potential metabolic biomarkers of drug resistance.

Results: Comparison of NMR metabolite profiles obtained from control (CAL(S)) and EGFR TKI-resistant (CAL(R)) cells grown as 2D monolayers, 3D spheroids or xenograft tumours in athymic mice revealed a number of differences between the sensitive and drug-resistant models. In particular, we observed elevated levels of glycerophosphocholine (GPC) in CAL(R) relative to CAL(S) monolayers, spheroids and tumours, independent of the growth rate or environment. In addition, there was an increase in alanine, aspartate and creatine+phosphocreatine in resistant spheroids and xenografts, and increased levels of lactate, branched-chain amino acids and a fall in phosphoethanolamine only in xenografts. The xenograft lactate build-up was associated with an increased expression of the glucose transporter GLUT-1, whereas the rise in GPC was attributed to inhibition of GPC phosphodiesterase. Reduced glycerophosphocholine (GPC) and phosphocholine were observed in a second HNSCC model probably indicative of a different drug resistance mechanism.

Conclusions: Our studies reveal metabolic signatures associated not only with acquired EGFR TKI resistance but also growth pattern, microenvironment and contributing mechanisms in HNSCC models. These findings warrant further investigation as metabolic biomarkers of disease relapse in the clinic.

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Related in: MedlinePlus

Comparison of metabolite changes induced in EGFR TKI resistance models. (A) Diagram summarising the metabolite signature observed in CALR relative to CALS tumours and its presence in 2D and 3D in vitro cultures. (B) 1H NMR spectra of the choline region showing an increased GPC in CALR relative to CALS models. (C) Changes in GPC following an acute exposure to gefitinib (24 h, 1 μM) in CALS and CALR cell lines grown in 2D. Φ: not measured in spheroids or 2D monolayers, *P=0.04, NS: P=0.58, n=3 at least.
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fig4: Comparison of metabolite changes induced in EGFR TKI resistance models. (A) Diagram summarising the metabolite signature observed in CALR relative to CALS tumours and its presence in 2D and 3D in vitro cultures. (B) 1H NMR spectra of the choline region showing an increased GPC in CALR relative to CALS models. (C) Changes in GPC following an acute exposure to gefitinib (24 h, 1 μM) in CALS and CALR cell lines grown in 2D. Φ: not measured in spheroids or 2D monolayers, *P=0.04, NS: P=0.58, n=3 at least.

Mentions: Comparison of the data obtained from 2D cultures, 3D spheroids and xenograft tumours indicate that, relative to CALS, CALR cells displayed increased levels of lactate, BCAA and decreased PE in vivo only, elevated PCr, alanine and aspartate levels in 3D spheroids and tumours, and increased GPC in all three experimental models (Figure 4A and B). Thus the rises in lactate and GLUT-1 expression, together with increased BCAA and decreased PE are associated with the in vivo growth environment while the increase in alanine, aspartate and Cr+PCr is associated with the aggressive growth phenotype seen in 3D and in vivo. The build up of GPC is associated with EGFR TKI resistance independently of differences in growth rates or environment.


Acquired resistance to EGFR tyrosine kinase inhibitors alters the metabolism of human head and neck squamous carcinoma cells and xenograft tumours.

Beloueche-Babari M, Box C, Arunan V, Parkes HG, Valenti M, De Haven Brandon A, Jackson LE, Eccles SA, Leach MO - Br. J. Cancer (2015)

Comparison of metabolite changes induced in EGFR TKI resistance models. (A) Diagram summarising the metabolite signature observed in CALR relative to CALS tumours and its presence in 2D and 3D in vitro cultures. (B) 1H NMR spectra of the choline region showing an increased GPC in CALR relative to CALS models. (C) Changes in GPC following an acute exposure to gefitinib (24 h, 1 μM) in CALS and CALR cell lines grown in 2D. Φ: not measured in spheroids or 2D monolayers, *P=0.04, NS: P=0.58, n=3 at least.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385966&req=5

fig4: Comparison of metabolite changes induced in EGFR TKI resistance models. (A) Diagram summarising the metabolite signature observed in CALR relative to CALS tumours and its presence in 2D and 3D in vitro cultures. (B) 1H NMR spectra of the choline region showing an increased GPC in CALR relative to CALS models. (C) Changes in GPC following an acute exposure to gefitinib (24 h, 1 μM) in CALS and CALR cell lines grown in 2D. Φ: not measured in spheroids or 2D monolayers, *P=0.04, NS: P=0.58, n=3 at least.
Mentions: Comparison of the data obtained from 2D cultures, 3D spheroids and xenograft tumours indicate that, relative to CALS, CALR cells displayed increased levels of lactate, BCAA and decreased PE in vivo only, elevated PCr, alanine and aspartate levels in 3D spheroids and tumours, and increased GPC in all three experimental models (Figure 4A and B). Thus the rises in lactate and GLUT-1 expression, together with increased BCAA and decreased PE are associated with the in vivo growth environment while the increase in alanine, aspartate and Cr+PCr is associated with the aggressive growth phenotype seen in 3D and in vivo. The build up of GPC is associated with EGFR TKI resistance independently of differences in growth rates or environment.

Bottom Line: Acquired resistance to molecularly targeted therapeutics is a key challenge in personalised cancer medicine, highlighting the need for identifying the underlying mechanisms and early biomarkers of relapse, in order to guide subsequent patient management.Our studies reveal metabolic signatures associated not only with acquired EGFR TKI resistance but also growth pattern, microenvironment and contributing mechanisms in HNSCC models.These findings warrant further investigation as metabolic biomarkers of disease relapse in the clinic.

View Article: PubMed Central - PubMed

Affiliation: Cancer Research UK Cancer Imaging Centre, Division of Radiotherapy and Imaging, The Institute of Cancer Research, London and The Royal Marsden NHS Foundation Trust, Sutton, Surrey SM2 5PT, UK.

ABSTRACT

Background: Acquired resistance to molecularly targeted therapeutics is a key challenge in personalised cancer medicine, highlighting the need for identifying the underlying mechanisms and early biomarkers of relapse, in order to guide subsequent patient management.

Methods: Here we use human head and neck squamous cell carcinoma (HNSCC) models and nuclear magnetic resonance (NMR) spectroscopy to assess the metabolic changes that follow acquired resistance to EGFR tyrosine kinase inhibitors (TKIs), and which could serve as potential metabolic biomarkers of drug resistance.

Results: Comparison of NMR metabolite profiles obtained from control (CAL(S)) and EGFR TKI-resistant (CAL(R)) cells grown as 2D monolayers, 3D spheroids or xenograft tumours in athymic mice revealed a number of differences between the sensitive and drug-resistant models. In particular, we observed elevated levels of glycerophosphocholine (GPC) in CAL(R) relative to CAL(S) monolayers, spheroids and tumours, independent of the growth rate or environment. In addition, there was an increase in alanine, aspartate and creatine+phosphocreatine in resistant spheroids and xenografts, and increased levels of lactate, branched-chain amino acids and a fall in phosphoethanolamine only in xenografts. The xenograft lactate build-up was associated with an increased expression of the glucose transporter GLUT-1, whereas the rise in GPC was attributed to inhibition of GPC phosphodiesterase. Reduced glycerophosphocholine (GPC) and phosphocholine were observed in a second HNSCC model probably indicative of a different drug resistance mechanism.

Conclusions: Our studies reveal metabolic signatures associated not only with acquired EGFR TKI resistance but also growth pattern, microenvironment and contributing mechanisms in HNSCC models. These findings warrant further investigation as metabolic biomarkers of disease relapse in the clinic.

Show MeSH
Related in: MedlinePlus