Related Experiment Video
Updated: Aug 13, 2026
Colorectal Cancer Cell Surface Protein Profiling Using an Antibody Microarray and Fluorescence Multiplexing
Published on: September 25, 2011
Expression of the SART1 tumor-rejection antigens in colorectal cancers
T Sasatomi1, H Yamana, S Shichijo
1Department of Immunology, Kurume University School of Medicine, Fukuoka, Japan.
Purpose:
Colorectal cancer is one of the major causes of cancer death in the world, including in the United States and Japan. We recently identified the tumor-rejection antigen gene SART1, which encodes both the SART1(259) antigen expressed in the cytosol of epithelial cancers and the SART1(800) antigen expressed in the nucleus of the majority of proliferating cells. This study investigated the expression of these tumor antigens to explore a potential molecule for specific immunotherapy of colorectal cancer patients.
Methods:
SART1 antigens were investigated by Western blotting in six colorectal cancer cell lines and in 33 colorectal cancer tissues. The cancer cell lines were tested for their ability to stimulate interferon-gamma production by the human-leukocyte-antigen-A24-restricted and SART1-specific cytotoxic T lymphocytes and were also tested for their susceptibility to the lysis by the cytotoxic T lymphocytes.
Results:
The SART1(259) antigen was detected in the cytosol of four of six cancer cell lines, 13 of 33 (39 percent) cancer tissues, and 0 of 20 nontumorous colorectal tissues. The SART1(800) antigen was expressed in the nucleus of all the colorectal cancer cell lines, 18 of 33 (55 percent) cancer tissues, and 0 of 20 nontumorous tissues. The human-lymphocyte-antigen-A24-restricted and SART1-specific cytotoxic T lymphocytes killed the human-lymphocyte-antigen-A24+ SART1(259+) cancer cells.
Conclusions:
The SART1(259) antigen could be an appropriate target molecule for specific immunotherapy of approximately 40 percent of the human-lymphocyte-antigen-A24+ patients with colorectal cancer.
Insights
The SART1(259) antigen is expressed in nearly 40% of colorectal cancers, making it a potential target for immunotherapy. This antigen was effectively targeted by cytotoxic T lymphocytes, showing promise for specific cancer treatment.
Area of Science:
- Oncology
- Immunology
- Molecular Biology
Background:
- Colorectal cancer (CRC) is a leading cause of cancer mortality globally.
- The SART1 gene encodes tumor antigens SART1(259) (cytosolic) and SART1(800) (nuclear).
- Identifying specific tumor antigens is crucial for developing targeted immunotherapies.
Purpose of the Study:
- To investigate the expression of SART1(259) and SART1(800) tumor antigens in colorectal cancer.
- To evaluate the potential of these antigens as targets for specific immunotherapy in CRC patients.
Main Methods:
- Western blotting was used to detect SART1 antigens in CRC cell lines and tissues.
- Cytotoxic T lymphocyte (CTL) assays assessed the immune response against SART1-expressing cancer cells.
- Interferon-gamma production and cancer cell lysis by CTLs were measured.
Main Results:
- SART1(259) was found in the cytosol of 4/6 CRC cell lines and 39% of CRC tissues, but not in normal tissues.
- SART1(800) was detected in the nucleus of all CRC cell lines and 55% of CRC tissues, absent in normal tissues.
- Human-leukocyte-antigen-A24-restricted, SART1-specific CTLs effectively killed SART1(259)-positive CRC cells.
Conclusions:
- The SART1(259) antigen is a promising target molecule for specific immunotherapy in approximately 40% of human-leukocyte-antigen-A24-positive colorectal cancer patients.
- SART1(259) expression in a significant subset of CRC warrants further investigation for therapeutic development.
