TY - JOUR
T1 - Arginine starvation and docetaxel induce c-Myc–driven HENT1 surface expression to overcome gemcitabine resistance in AsS1-negative tumors
AU - Prudner, Bethany C.
AU - Rathore, Richa
AU - Robinson, Anthony M.
AU - Godec, Abigail
AU - Chang, Samuel F.
AU - Hawkins, William G.
AU - Hirbe, Angela C.
AU - Van Tine, Brian A.
N1 - Publisher Copyright:
© 2019 American Association for Cancer Research.
PY - 2019/8/15
Y1 - 2019/8/15
N2 - Purpose: The response to acute and long-term arginine starvation results in a conditional adaptive metabolic reprogramming that can be harnessed for therapeutic opportunities in ASS1-negative tumors. Here, we investigate the underlying biology of priming ASS1 tumors with arginine deiminase (ADI-PEG20) before treatment with gemcitabine (GEM) and docetaxel (DTX) in sarcoma, pancreatic cancer, and melanoma cell lines. Experimental Design: ASS1 tumor cell lines were treated to create LTAT (long-term ADI treated) cell lines (ASS1þ) and used for drug combination studies. Protein expression of ASS1, dCK, RRM2, E2F1, c-MYC, and hENT1 was measured. c-MYC activity was determined, live-cell immunofluorescent studies for hENT1, uptake assays of FITC-cytosine probe, and rescue studies with a c-MYC inhibitor were all determined in the presence or absence of the ADI-PEG20:GEM:DTX. Results: In examining modulations within the pyrimidine pathway, we identified that the addition of DTX to cells treated with ADI-PEG20 resulted in translocation of stabilized c-Myc to the nucleus. This resulted in an increase of hENT1 cell-surface expression and rendered the cells susceptible to GEM. In vivo studies demonstrate that the combination of ADI-PEG20:GEM: DTX was optimal for tumor growth inhibition, providing the preclinical mechanism and justification for the ongoing clinical trial of ADI-PEG20, GEM, and DTX in sarcoma. Conclusions: The priming of tumors with ADI-PEG20 and DTX results in the stabilization of c-MYC potentiating the effect of GEM treatment via an increase in hENT1 expression. This finding is applicable to ASS1-deficient cancers that are currently treated with GEM.
AB - Purpose: The response to acute and long-term arginine starvation results in a conditional adaptive metabolic reprogramming that can be harnessed for therapeutic opportunities in ASS1-negative tumors. Here, we investigate the underlying biology of priming ASS1 tumors with arginine deiminase (ADI-PEG20) before treatment with gemcitabine (GEM) and docetaxel (DTX) in sarcoma, pancreatic cancer, and melanoma cell lines. Experimental Design: ASS1 tumor cell lines were treated to create LTAT (long-term ADI treated) cell lines (ASS1þ) and used for drug combination studies. Protein expression of ASS1, dCK, RRM2, E2F1, c-MYC, and hENT1 was measured. c-MYC activity was determined, live-cell immunofluorescent studies for hENT1, uptake assays of FITC-cytosine probe, and rescue studies with a c-MYC inhibitor were all determined in the presence or absence of the ADI-PEG20:GEM:DTX. Results: In examining modulations within the pyrimidine pathway, we identified that the addition of DTX to cells treated with ADI-PEG20 resulted in translocation of stabilized c-Myc to the nucleus. This resulted in an increase of hENT1 cell-surface expression and rendered the cells susceptible to GEM. In vivo studies demonstrate that the combination of ADI-PEG20:GEM: DTX was optimal for tumor growth inhibition, providing the preclinical mechanism and justification for the ongoing clinical trial of ADI-PEG20, GEM, and DTX in sarcoma. Conclusions: The priming of tumors with ADI-PEG20 and DTX results in the stabilization of c-MYC potentiating the effect of GEM treatment via an increase in hENT1 expression. This finding is applicable to ASS1-deficient cancers that are currently treated with GEM.
UR - http://www.scopus.com/inward/record.url?scp=85070662733&partnerID=8YFLogxK
U2 - 10.1158/1078-0432.CCR-19-0206
DO - 10.1158/1078-0432.CCR-19-0206
M3 - Article
C2 - 31113844
AN - SCOPUS:85070662733
SN - 1078-0432
VL - 25
SP - 5122
EP - 5134
JO - Clinical Cancer Research
JF - Clinical Cancer Research
IS - 16
ER -