Tags

Type your tag names separated by a space and hit enter

Genetic disruption of the pHi-regulating proteins Na+/H+ exchanger 1 (SLC9A1) and carbonic anhydrase 9 severely reduces growth of colon cancer cells.
Oncotarget 2017; 8(6):10225-10237O

Abstract

Hypoxia and extracellular acidosis are pathophysiological hallmarks of aggressive solid tumors. Regulation of intracellular pH (pHi) is essential for the maintenance of tumor cell metabolism and proliferation in this microenvironment and key proteins involved in pHi regulation are of interest for therapeutic development. Carbonic anhydrase 9 (CA9) is one of the most robustly regulated proteins by the hypoxia inducible factor (HIF) and contributes to pHi regulation. Here, we have investigated for the first time, the role of CA9 via complete genomic knockout (ko) and compared its impact on tumor cell physiology with the essential pHi regulator Na+/H+ exchanger 1 (NHE1). Initially, we established NHE1-ko LS174 cells with inducible CA9 knockdown. While increased sensitivity to acidosis for cell survival in 2-dimensions was not observed, clonogenic proliferation and 3-dimensional spheroid growth in particular were greatly reduced. To avoid potential confounding variables with use of tetracycline-inducible CA9 knockdown, we established CA9-ko and NHE1/CA9-dko cells. NHE1-ko abolished recovery from NH4Cl pre-pulse cellular acid loading while both NHE1 and CA9 knockout reduced resting pHi. NHE1-ko significantly reduced tumor cell proliferation both in normoxia and hypoxia while CA9-ko dramatically reduced growth in hypoxic conditions. Tumor xenografts revealed substantial reductions in tumor growth for both NHE1-ko and CA9-ko. A notable induction of CA12 occurred in NHE1/CA9-dko tumors indicating a potential means to compensate for loss of pH regulating proteins to maintain growth. Overall, these genomic knockout results strengthen the pursuit of targeting tumor cell pH regulation as an effective anti-cancer strategy.

Authors+Show Affiliations

Medical Biology Department, Centre Scientifique de Monaco (CSM), Monaco.Medical Biology Department, Centre Scientifique de Monaco (CSM), Monaco.Medical Biology Department, Centre Scientifique de Monaco (CSM), Monaco.Medical Biology Department, Centre Scientifique de Monaco (CSM), Monaco. Institute for Research on Cancer & Aging (IRCAN), CNRS, INSERM, Centre A. Lacassagne, University of Nice-Sophia Antipolis, Nice, France.

Pub Type(s)

Journal Article

Language

eng

PubMed ID

28055960

Citation

Parks, Scott K., et al. "Genetic Disruption of the pHi-regulating Proteins Na+/H+ Exchanger 1 (SLC9A1) and Carbonic Anhydrase 9 Severely Reduces Growth of Colon Cancer Cells." Oncotarget, vol. 8, no. 6, 2017, pp. 10225-10237.
Parks SK, Cormerais Y, Durivault J, et al. Genetic disruption of the pHi-regulating proteins Na+/H+ exchanger 1 (SLC9A1) and carbonic anhydrase 9 severely reduces growth of colon cancer cells. Oncotarget. 2017;8(6):10225-10237.
Parks, S. K., Cormerais, Y., Durivault, J., & Pouyssegur, J. (2017). Genetic disruption of the pHi-regulating proteins Na+/H+ exchanger 1 (SLC9A1) and carbonic anhydrase 9 severely reduces growth of colon cancer cells. Oncotarget, 8(6), pp. 10225-10237. doi:10.18632/oncotarget.14379.
Parks SK, et al. Genetic Disruption of the pHi-regulating Proteins Na+/H+ Exchanger 1 (SLC9A1) and Carbonic Anhydrase 9 Severely Reduces Growth of Colon Cancer Cells. Oncotarget. 2017 Feb 7;8(6):10225-10237. PubMed PMID: 28055960.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Genetic disruption of the pHi-regulating proteins Na+/H+ exchanger 1 (SLC9A1) and carbonic anhydrase 9 severely reduces growth of colon cancer cells. AU - Parks,Scott K, AU - Cormerais,Yann, AU - Durivault,Jerome, AU - Pouyssegur,Jacques, PY - 2016/10/11/received PY - 2016/11/30/accepted PY - 2017/1/6/pubmed PY - 2018/2/21/medline PY - 2017/1/6/entrez KW - Carbonic Anhydrase 9 (CA9) KW - Na+/H+-exchanger (NHE1) KW - pH regulation KW - tumor growth KW - tumor hypoxia SP - 10225 EP - 10237 JF - Oncotarget JO - Oncotarget VL - 8 IS - 6 N2 - Hypoxia and extracellular acidosis are pathophysiological hallmarks of aggressive solid tumors. Regulation of intracellular pH (pHi) is essential for the maintenance of tumor cell metabolism and proliferation in this microenvironment and key proteins involved in pHi regulation are of interest for therapeutic development. Carbonic anhydrase 9 (CA9) is one of the most robustly regulated proteins by the hypoxia inducible factor (HIF) and contributes to pHi regulation. Here, we have investigated for the first time, the role of CA9 via complete genomic knockout (ko) and compared its impact on tumor cell physiology with the essential pHi regulator Na+/H+ exchanger 1 (NHE1). Initially, we established NHE1-ko LS174 cells with inducible CA9 knockdown. While increased sensitivity to acidosis for cell survival in 2-dimensions was not observed, clonogenic proliferation and 3-dimensional spheroid growth in particular were greatly reduced. To avoid potential confounding variables with use of tetracycline-inducible CA9 knockdown, we established CA9-ko and NHE1/CA9-dko cells. NHE1-ko abolished recovery from NH4Cl pre-pulse cellular acid loading while both NHE1 and CA9 knockout reduced resting pHi. NHE1-ko significantly reduced tumor cell proliferation both in normoxia and hypoxia while CA9-ko dramatically reduced growth in hypoxic conditions. Tumor xenografts revealed substantial reductions in tumor growth for both NHE1-ko and CA9-ko. A notable induction of CA12 occurred in NHE1/CA9-dko tumors indicating a potential means to compensate for loss of pH regulating proteins to maintain growth. Overall, these genomic knockout results strengthen the pursuit of targeting tumor cell pH regulation as an effective anti-cancer strategy. SN - 1949-2553 UR - https://www.unboundmedicine.com/medline/citation/28055960/Genetic_disruption_of_the_pHi_regulating_proteins_Na+/H+_exchanger_1__SLC9A1__and_carbonic_anhydrase_9_severely_reduces_growth_of_colon_cancer_cells_ L2 - http://www.impactjournals.com/oncotarget/misc/linkedout.php?pii=14379 DB - PRIME DP - Unbound Medicine ER -