Related Experiment Video
Updated: Aug 10, 2026
Potentiation of Anticancer Antibody Efficacy by Antineoplastic Drugs: Detection of Antibody-drug Synergism Using the Combination Index Equation
Published on: January 19, 2019
Suberoylanilide hydroxamic acid combined with gemcitabine enhances apoptosis in non-small cell lung cancer
Brian K Rundall1, Chadrick E Denlinger, David R Jones
1Department of Surgery, University of Virginia School of Medicine, Charlottesville 22908-0679, USA.
Background:
We have shown that non-small cell lung cancer (NSCLC) is resistant to the histone deacetylase inhibitor (HDI) suberoylanilide hydroxamic acid (SAHA) through upregulation of the antiapoptotic transcription factor nuclear factor-kappaB (NF-kappaB). HDIs also promote chromatin remodeling, potentially making the DNA more accessible to chemotherapy. We hypothesize that combined SAHA and gemcitabine sensitizes NSCLC to apoptosis.
Methods:
Three NSCLC cell lines (A549, H358, H460) were untreated, or treated with SAHA, gemcitabine, or both agents. NF-kappaB-dependent transcription was determined by reporter gene assays, reverse transcriptase-polymerase chain reaction RT-PCR, and Western blot analysis for the NF-kappaB-regulated antiapoptotic gene MnSOD. Survival of NSCLC cells overexpressing Bfl/A1, Bcl-X(L), or MnSOD and treated with SAHA and gemcitabine was determined in the presence or absence of NF-kappaB. Survival of treated cells overexpressing HDAC-1, 2, 3 or p/CAF was determined. Apoptosis was determined by fluorescence-activated cell sorter analysis, DNA fragmentation, and caspase-3 activity. Colony formation assays were performed on cells treated concurrently and sequentially with SAHA and gemcitabine. Assays were performed in triplicate, and the Student t test was applied as appropriate.
Results:
SAHA-activated NF-kappaB (P
Conclusions:
Combined SAHA and gemcitabine sensitized NSCLC cells to apoptosis. Potential "proapoptotic" mechanisms for this finding include gemcitabine inhibition of SAHA-induced NF-kappaB activation and chromatin remodeling mediated by the inhibition of histone deacetylases.
Insights
Combining suberoylanilide hydroxamic acid (SAHA) with gemcitabine enhances apoptosis in non-small cell lung cancer (NSCLC) cells. This combination therapy overcomes resistance by inhibiting nuclear factor-kappaB (NF-kappaB) activation.
Area of Science:
- Oncology
- Molecular Biology
- Cancer Therapeutics
Background:
- Non-small cell lung cancer (NSCLC) exhibits resistance to histone deacetylase inhibitors (HDIs) like suberoylanilide hydroxamic acid (SAHA).
- Resistance is mediated by the upregulation of the antiapoptotic transcription factor nuclear factor-kappaB (NF-kappaB).
- HDIs can remodel chromatin, potentially increasing DNA accessibility for chemotherapy.
Purpose of the Study:
- To investigate if combined SAHA and gemcitabine treatment sensitizes NSCLC cells to apoptosis.
- To explore the underlying mechanisms of sensitization, including NF-kappaB modulation and chromatin remodeling.
Main Methods:
- NSCLC cell lines were treated with SAHA, gemcitabine, or both.
- NF-kappaB activity and expression of NF-kappaB-regulated genes (e.g., MnSOD) were assessed.
- Apoptosis was quantified using flow cytometry, DNA fragmentation assays, and caspase-3 activity.
- Cell survival was evaluated in cells overexpressing specific antiapoptotic genes or HDACs.
- Colony formation assays assessed the efficacy of concurrent and sequential treatments.
Main Results:
- SAHA treatment activated NF-kappaB, while gemcitabine inhibited this activation.
- Overexpression of antiapoptotic genes or HDACs correlated with increased cell survival.
- Combined SAHA and gemcitabine significantly enhanced apoptosis compared to single-agent treatments.
- Concurrent treatment showed no significant difference compared to sequential treatment.
Conclusions:
- Combined SAHA and gemcitabine effectively sensitize NSCLC cells to apoptosis.
- Gemcitabine's inhibition of SAHA-induced NF-kappaB activation and histone deacetylase inhibition-mediated chromatin remodeling are potential proapoptotic mechanisms.
Related Concept Videos
02:57Targeted Cancer Therapies
There are several types of targeted therapies against specific...
02:50Combination Therapies and Personalized Medicine
The combination of the drug acetazolamide and sulforaphane is a good example of combination therapy to treat cancer. The cells in the interior of a large tumor often die due to the hypoxic and...