Quantitative Top-Down Proteomics Reveals Significant Differences in Histone Proteoforms Between Metastatic and...

Area of Science:

• Proteomics
• Epigenetics
• Cancer Biology

Background:

• Colorectal cancer (CRC) progression involves genetic and epigenetic changes.
• Epigenetic modifications are crucial in CRC metastasis.
• Understanding histone proteoform alterations is key to identifying metastasis drivers.

Purpose of the Study:

• To investigate quantitative differences in histone proteoforms between metastatic and non-metastatic CRC cells.
• To identify specific histone proteoforms associated with CRC metastasis.
• To explore the potential of these proteoforms as biomarkers for CRC metastasis.

Main Methods:

• Quantitative top-down proteomics approach.
• Isolation and fractionation of histone proteins from SW480 and SW620 CRC cell lines using SDS-PAGE.
• Analysis of histone proteoforms by capillary zone electrophoresis-tandem mass spectrometry (CZE-MS/MS).

Main Results:

• Quantification of 230 histone proteoforms in SW480 and SW620 cells.
• Identification of 34 significantly altered histone proteoforms in metastatic SW620 cells.
• Upregulation of all nine differentially expressed histone H4 proteoforms and two specific histone H2A proteoforms in metastatic cells.

Conclusions:

• Significant transformation of histone proteoforms occurs during CRC metastasis.
• Differentially expressed histone proteoforms, especially H4 and H2A variants, are linked to CRC metastasis.
• These identified histone proteoforms represent potential novel biomarkers for detecting and understanding CRC metastasis.