TY - JOUR
T1 - Mechanisms involved in development of resistance to adenovirus-mediated proapoptotic gene therapy in DLD1 human colon cancer cell line
AU - Zhang, L.
AU - Gu, J.
AU - Lin, T.
AU - Huang, X.
AU - Roth, J. A.
AU - Fang, B.
N1 - Funding Information:
This work was supported in part by a research project grant from the American Cancer Society (RPG-00-274-01-MGO to BF); an Institutional Start-Up Fund (to BF); a grant from the WM Keck Center for Cancer Gene Therapy, The University of Texas MD Anderson Cancer Center (BF); an NIH project grant (P01 CA78778-01A1, to JAR); and an NIH Core Grant (CA16672). JG is an MD Anderson Cancer Center Odyssey Program Fellow supported by the Kimberly-Clark Endowment for New and Innovative Research. We thank Allan Prejusa and Trupti Mehta for adenovirus propagation and quality control and Kate O Suilleabhain for editorial review.
PY - 2002/9
Y1 - 2002/9
N2 - To evaluate resistance that develops in cancer cells during treatment with adenoviral vectors expressing proapoptotic genes, we repeatedly treated the human colon cancer cell line DLD1 with adenoviral vectors expressing the human Bax gene and the human tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) gene. DLD1 cells resistant to the Bax- or TRAIL-expressing adenoviral vectors were then selected and designated as DLD1/Bax-R or DLD1/TRAIL-R cells, respectively. Further study showed that resistance in DLD1/Bax-R cells was caused by resistance to adenoviral infection, which can be overcome by dose escalation of the adenoviral vectors. However, resistance in DLD1/TRAIL-R cells was caused by resistance to the TRAIL gene. Therefore, different mechanisms are involved in the development of resistance during adenovirus-mediated proapoptotic gene therapy. A survey of molecules involved in TRAIL- or Bax-mediated apoptotic pathways showed no significant change in expression of death receptors, death decoy receptors; FLIP; Bcl-2, Bcl-xS, Bax; Bak; XIAP or caspase-2, -7, -8, or -9 in either DLD1/Bax-R or DLD1/TRAIL-R cells. Bcl-xL expression detected in both mRNA and protein level assays was three times higher in DLD1/TRAIL-R cells than in parental or DLD1/Bax-R cells. However, transfection of DLD1 cells with the Bcl-xL gene showed that overexpression of Bcl-xL is not sufficient for the resistance. Moreover, DLD1/Bax-R cells were sensitive to adenoviral vectors that expressed the TRAIL gene, but resistant to adenoviral vectors that expressed the Bak gene. In contrast, DLD1/TRAIL-R cells were sensitive to adenoviral vectors that expressed either Bax or Bak gene. Thus, alternative application of adenoviral vectors that expressed proapoptotic genes in different pathways or different cell killing models may delay or prevent development of resistance in adenovirus-mediated proapoptotic gene therapy.
AB - To evaluate resistance that develops in cancer cells during treatment with adenoviral vectors expressing proapoptotic genes, we repeatedly treated the human colon cancer cell line DLD1 with adenoviral vectors expressing the human Bax gene and the human tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) gene. DLD1 cells resistant to the Bax- or TRAIL-expressing adenoviral vectors were then selected and designated as DLD1/Bax-R or DLD1/TRAIL-R cells, respectively. Further study showed that resistance in DLD1/Bax-R cells was caused by resistance to adenoviral infection, which can be overcome by dose escalation of the adenoviral vectors. However, resistance in DLD1/TRAIL-R cells was caused by resistance to the TRAIL gene. Therefore, different mechanisms are involved in the development of resistance during adenovirus-mediated proapoptotic gene therapy. A survey of molecules involved in TRAIL- or Bax-mediated apoptotic pathways showed no significant change in expression of death receptors, death decoy receptors; FLIP; Bcl-2, Bcl-xS, Bax; Bak; XIAP or caspase-2, -7, -8, or -9 in either DLD1/Bax-R or DLD1/TRAIL-R cells. Bcl-xL expression detected in both mRNA and protein level assays was three times higher in DLD1/TRAIL-R cells than in parental or DLD1/Bax-R cells. However, transfection of DLD1 cells with the Bcl-xL gene showed that overexpression of Bcl-xL is not sufficient for the resistance. Moreover, DLD1/Bax-R cells were sensitive to adenoviral vectors that expressed the TRAIL gene, but resistant to adenoviral vectors that expressed the Bak gene. In contrast, DLD1/TRAIL-R cells were sensitive to adenoviral vectors that expressed either Bax or Bak gene. Thus, alternative application of adenoviral vectors that expressed proapoptotic genes in different pathways or different cell killing models may delay or prevent development of resistance in adenovirus-mediated proapoptotic gene therapy.
KW - Apoptosis
KW - Bax
KW - Cancer gene therapy
KW - TRAIL
UR - http://www.scopus.com/inward/record.url?scp=0036737751&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0036737751&partnerID=8YFLogxK
U2 - 10.1038/sj.gt.3301797
DO - 10.1038/sj.gt.3301797
M3 - Article
C2 - 12215894
AN - SCOPUS:0036737751
SN - 0969-7128
VL - 9
SP - 1262
EP - 1270
JO - Gene Therapy
JF - Gene Therapy
IS - 18
ER -