Regulation of ΔNp63α by NFκΒ

Tanusree Sen1, Xiaofei Chang, David Sidransky

  • 1Department of Otolaryngology-Head and Neck Surgery, Division of Head and Neck Cancer Research, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.

Insights

NF-κB activation triggers the degradation of ΔNp63α, a key survival factor in head and neck cancer. This process enhances the cellular response to DNA damage, making cancer cells more susceptible to chemotherapy.

Area of Science:

  • Molecular Biology
  • Oncology
  • Cellular Biology

Background:

  • ΔNp63α is a crucial survival factor in head and neck squamous cell carcinoma.
  • ΔNp63α expression is downregulated by DNA-damaging agents, facilitating cellular responses to genotoxicity.

Purpose of the Study:

  • To elucidate the molecular mechanism regulating ΔNp63α expression under chemotherapeutic treatment.
  • To investigate the role of NF-κB in the degradation of ΔNp63α.

Main Methods:

  • Studied the interaction between ΔNp63α and NF-κB in cisplatin-treated cells.
  • Utilized siRNA-mediated silencing to inhibit NF-κB expression.
  • Assessed the impact of NF-κB modulation on ΔNp63α levels and p53 family-induced gene expression.

Main Results:

  • ΔNp63α interacts with NF-κB in the presence of cisplatin.
  • NF-κB promotes the ubiquitin-mediated proteasomal degradation of ΔNp63α.
  • Chemotherapy-induced NF-κB activation leads to ΔNp63α degradation and enhanced trans-activation of DNA damage response genes.

Conclusions:

  • NF-κB plays a critical role in regulating ΔNp63α levels in response to extrinsic stimuli like chemotherapy.
  • NF-κB-mediated reduction of ΔNp63α levels sensitizes cancer cells to DNA damage and promotes cell death.

Related Concept Videos

NF-κB-dependent Signaling Pathway02:26

NF-κB-dependent Signaling Pathway

The transcription factor NF-κB was discovered in 1986 in the lab of Nobel laureate Professor David Baltimore, for its interaction with the immunoglobulin light chain enhancer in B-cells. After more than three decades of study, it is now evident that NF-κB regulates the expression of over 100 genes. Most of these genes play an essential role in the innate and adaptive immune responses as well as the inflammatory responses of animals.
NF-κB-dependent Signaling Mechanism
The heterodimer of NF-κB...
Regulation of Nuclear Protein Sorting01:45

Regulation of Nuclear Protein Sorting

Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...
NF-kB-dependent Signaling Pathway02:26

NF-kB-dependent Signaling Pathway

The transcription factor NF-κB was discovered in 1986 in the lab of Nobel laureate Professor David Baltimore, for its interaction with the immunoglobulin light chain enhancer in B-cells. After more than three decades of study, it is now evident that NF-κB regulates the expression of over 100 genes. Most of these genes play an essential role in the innate and adaptive immune responses as well as the inflammatory responses of animals.
NF-κB-dependent Signaling Mechanism
The heterodimer of NF-κB...
Co-activators and Co-repressors02:04

Co-activators and Co-repressors

Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into...
Negative Regulator Molecules01:23

Negative Regulator Molecules

Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria.
Regulation of Expression at Multiple Steps01:23

Regulation of Expression at Multiple Steps

The gene expression in cells is regulated at different stages: (i) transcription, (ii) RNA processing, (iii) RNA localization, and (iv) translation. Transcriptional regulation is mediated by regulatory proteins such as transcription factors, activators, or repressors—these control gene expression by initiating or inhibiting the transcription of genes. Once a precursor or pre-mRNA is produced, it undergoes post-transcriptional modification, including 5' capping, splicing, and the addition of a...