Abstract
Background
Colorectal cancer represents one of the most common cancers worldwide. Novel minimal-invasive diagnostic assays are currently developed for early diagnosis of cancer. We are focusing on the analysis of tumor autoantibodies, which occur in many tumor patients due to altered protein expression of the tumor cells, presenting then tumor-associated antigens (TAAs) to the immune system.
Methods
Tumor autoantibody profiling has been conducted on AIT’s 16k protein-microarray for different cancer indications (colon, lung, breast, and lung cancer). Based on the profiling results, we have designed a high-density peptide array presenting 179,000 peptides deduced from 2,090 candidate antigenic-protein-markers and 6,000 peptides derived from frequently mutated genes in cancer (COSMIC). IgG was purified from plasma samples of a cohort, comprising 24 colorectal cancer patients, 24 polyps, and 24 cancer-free controls. The reactivity of the IgG of the patient cohort to the peptides on the microarray was tested and analyzed. A high number of differentially reactive peptides could be identified between patient groups and 360 peptides were selected for further validation using Luminex®-technology, where 190 clinical samples were tested. Moreover, the reactivity of 66 mutated peptide sequences, deduced from the COSMIC database, was compared to the wild-type sequence.
Results:
Although a high number of differentially reactive peptides could be retrieved from the high-density peptide microarray, during validation, when analytical platform was changed, only a classification success with AUC values ranging between 0.68 – 0.75 could be achieved. Platform transfer in biomarker screening studies is a critical step and requires elaborated protocols for wet lab and statistical analysis.
Conclusions:
High density peptide arrays enable efficient screening of antibodies directed against specific amino acid sequences derived from whole antigens or in cancer specifically mutated proteins. We are developing our technology further to also achieve best performance in validation using targeted bead arrays and peptide-microarrays.
Colorectal cancer represents one of the most common cancers worldwide. Novel minimal-invasive diagnostic assays are currently developed for early diagnosis of cancer. We are focusing on the analysis of tumor autoantibodies, which occur in many tumor patients due to altered protein expression of the tumor cells, presenting then tumor-associated antigens (TAAs) to the immune system.
Methods
Tumor autoantibody profiling has been conducted on AIT’s 16k protein-microarray for different cancer indications (colon, lung, breast, and lung cancer). Based on the profiling results, we have designed a high-density peptide array presenting 179,000 peptides deduced from 2,090 candidate antigenic-protein-markers and 6,000 peptides derived from frequently mutated genes in cancer (COSMIC). IgG was purified from plasma samples of a cohort, comprising 24 colorectal cancer patients, 24 polyps, and 24 cancer-free controls. The reactivity of the IgG of the patient cohort to the peptides on the microarray was tested and analyzed. A high number of differentially reactive peptides could be identified between patient groups and 360 peptides were selected for further validation using Luminex®-technology, where 190 clinical samples were tested. Moreover, the reactivity of 66 mutated peptide sequences, deduced from the COSMIC database, was compared to the wild-type sequence.
Results:
Although a high number of differentially reactive peptides could be retrieved from the high-density peptide microarray, during validation, when analytical platform was changed, only a classification success with AUC values ranging between 0.68 – 0.75 could be achieved. Platform transfer in biomarker screening studies is a critical step and requires elaborated protocols for wet lab and statistical analysis.
Conclusions:
High density peptide arrays enable efficient screening of antibodies directed against specific amino acid sequences derived from whole antigens or in cancer specifically mutated proteins. We are developing our technology further to also achieve best performance in validation using targeted bead arrays and peptide-microarrays.
| Original language | English |
|---|---|
| Publication status | Published - 28 Apr 2023 |
| Event | CCC-TRIO 2023: Translational Oncology & Immuno-Oncology + Onkologischer Pflegefachtag - Vienna, Austria Duration: 27 Apr 2023 → 28 Apr 2023 https://www.meduniwien.ac.at/web/ueber-uns/events/2023/ccc-trio-2023/ |
Conference
| Conference | CCC-TRIO 2023 |
|---|---|
| Country/Territory | Austria |
| City | Vienna |
| Period | 27/04/23 → 28/04/23 |
| Internet address |
Research Field
- Molecular Diagnostics
