The effects of p53 gene inactivation on mutant proteome expression in a human melanoma cell model

Jakub Faktor1, Giuseppa Grasso2, Filip Zavadil Kokas1

  • 1Research Centre for Applied Molecular Oncology (RECAMO), Masaryk Memorial Cancer Institute, 656 53 Brno, Czech Republic.

Abstract

Insights

This study developed a proteogenomic pipeline to identify mutated proteins in cancer cells, revealing p53-dependent and independent pathways in melanoma. This method enhances the detection of high-confidence mutant proteins for cancer research.

Area of Science:

  • Oncology
  • Proteomics
  • Genomics

Background:

  • Proteogenomics, the identification of mutated proteins in human cancer cells, relies on multiple independent technologies like DNA variant identification, RNA sequencing, and mass spectrometry.
  • Each methodology has limitations, and no single approach completely captures the landscape of potential mutated proteins.

Purpose of the Study:

  • To investigate the impact of p53 gene inactivation on mutant proteome expression in melanoma.
  • To establish a robust pipeline for identifying high-confidence mutated proteins in cancer cells.

Main Methods:

  • Created an isogenic melanoma cell line with a p53-null genotype using CRISPR/Cas9.
  • Developed a mutant peptide reference database by integrating DNA and RNA variant data from two detection platforms.
  • Utilized mass spectrometry (TripleTOF 5600+) for peptide identification against the curated database.

Main Results:

  • Identified approximately 190 mutated peptides in wild-type p53 cells and 187 in p53-null cells, with 147 common mutated peptides.
  • STRING analysis revealed distinct enriched mutant protein pathways, including CDC5L and POLR1B in wt-p53 cells, and EGF/YES, Ubiquitination, and RPL26/5 nodes in p53-null cells.

Conclusions:

  • Generated a well-annotated p53-dependent and p53-independent mutant proteome for a melanoma cell line model.
  • The integrated DNA/RNA variant detection and protein identification pipeline enables high-confidence detection of mutant proteins.
  • This pipeline serves as a foundational blueprint for identifying mutated proteins in various diseased cell systems.

Related Concept Videos

Abnormal Proliferation02:23

Abnormal Proliferation

Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the...
5.0K
DNA Damage can Stall the Cell Cycle02:37

DNA Damage can Stall the Cell Cycle

In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
9.8K
Loss of Tumor Suppressor Gene Functions01:12

Loss of Tumor Suppressor Gene Functions

Tumor suppressor genes are normal genes that can slow down cell division, repair DNA mistakes, or program the cells for apoptosis in case of irreparable damage. Hence, they play an essential role in preventing the proliferation of damaged cells.
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...
5.7K
The Intrinsic Apoptotic Pathway01:31

The Intrinsic Apoptotic Pathway

Internal cellular stress, such as cellular injury or hypoxia, triggers intrinsic apoptosis. The B-cell lymphoma 2 (Bcl-2) family of proteins are the primary regulators of the intrinsic apoptotic pathway. For example, during DNA damage, checkpoint proteins, such as Ataxia Telangiectasia Mutated (ATM protein) and Checkpoints Factor-2 (Chk2) proteins, are activated. These proteins phosphorylate p53 which further activates pro-apoptotic proteins, such as Bax, Bak, PUMA, and Noxa, and inhibits...
7.8K
Interactions Between Signaling Pathways01:19

Interactions Between Signaling Pathways

Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
7.0K
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.
37.8K