NF-κB targeting by way of IKK inhibition sensitizes lung cancer cells to adenovirus delivery of TRAIL.
BACKGROUND
Lung cancer causes the highest rate of cancer-related deaths both in men and women. As many current treatment modalities are inadequate in increasing patient survival, new therapeutic strategies are required. TNF-related apoptosis-inducing ligand (TRAIL) selectively induces apoptosis in tumor cells but not in normal cells, prompting its current evaluation in a number of clinical trials. The successful therapeutic employment of TRAIL is restricted by the fact that many tumor cells are resistant to TRAIL. The goal of the present study was to test a novel combinatorial gene therapy modality involving adenoviral delivery of TRAIL (Ad5hTRAIL) and IKK inhibition (AdIKKβKA) to overcome TRAIL resistance in lung cancer cells.


METHODS
Fluorescent microscopy and flow cytometry were used to detect optimum doses of adenovirus vectors to transduce lung cancer cells. Cell viability was assessed via a live/dead cell viability assay. Luciferase assays were employed to monitor cellular NF-κB activity. Apoptosis was confirmed using Annexin V binding.


RESULTS
Neither Ad5hTRAIL nor AdIKKβKA infection alone induced apoptosis in A549 lung cancer cells, but the combined use of Ad5hTRAIL and AdIKKβKA significantly increased the amount of A549 apoptosis. Luciferase assays demonstrated that both endogenous and TRAIL-induced NF-κB activity was down-regulated by AdIKKβKA expression.


CONCLUSIONS
Combination treatment with Ad5hTRAIL and AdIKKβKA induced significant apoptosis of TRAIL-resistant A549 cells, suggesting that dual gene therapy strategy involving exogenous TRAIL gene expression with concurrent IKK inhibition may be a promising novel gene therapy modality to treat lung cancer.
Department of Medical Biology and Genetics, Human Gene and Cell Therapy Center of Akdeniz University Hospitals and Clinics, Antalya 07058, Turkiye.
Cigdem
C
Aydin
Ahter D
AD
Sanlioglu
Atil
A
Bisgin
Burcak
B
Yoldas
Levent
L
Dertsiz
Bahri
B
Karacay
Thomas S
TS
Griffith
Salih
S
Sanlioglu
D000256:Adenoviridae / Q000235:genetics* / Q000378:metabolism; D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D051550:I-kappa B Kinase / Q000378:metabolism*; D008175:Lung Neoplasms / Q000378:metabolism*; D008297:Male; D008856:Microscopy, Fluorescence / Q000379:methods; D016328:NF-kappa B / Q000378:metabolism*; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000378:metabolism*
D016328:NF-kappa B; D053221:TNF-Related Apoptosis-Inducing Ligand; D051550:I-kappa B Kinase; D053148:Caspase 3