TY  - THES
AB  - In 2002 lung cancer was diagnosed in over 45 000 persons, 39 000 fatalities were registered. According to these statistics, lung cancer prognosis is one of the poorest. Main reason for is the late detection due to diagnosis via optical methods by which a tumor cannot be found till 300 to 400 days after incidence.
In contrast, autoantibodies against tumorsuppressor p53 can be detected in blood serum 100 days after tumor development. As a diagnosis in this early stage is supposed to result in successful therapy in 80 percent of the cases. Hence, these antibodies are promising candidates in research of tumor markers. The antibodies are expected to be found in persons with mutated p53, but can be detected by standard ELISA in only about 40 percent of the persons with a diagnosed lung cancer although a p53 mutation is found in 65 percent. In this work a new immunoassay based on fluorescence tracing of p53 antibodies for the detection of lung cancer from human blood sera is presented.
The fluorescence microscopic detection of antibodies against p53 by a sandwich method using peptide epitopes of the tumorsuppressor was successfully performed for three epitopes of which one was known to be immunodominant. For this peptide 12 out of 19 sera from lung cancer patients (63 percent) showed a significant reaction towards the peptides, whereas only 2 out of 21 healthy donor sera (10 percent) were tested positive. Two other peptides were equal apart from acetylation of one lysine within the sequence, that occurs in vivo as a reaction to DNA-damage. In contrast to the epitope mentioned above, both of them evoked significant responses from healthy donors' sera, but the non acetylated one was hardly detected in cancer patients' sera. It could be shown that, depending on the considered epitope, healthy individuals produce antibodies against tumorsuppressor p53, too.
The sensitivity of the assay is about three times higher than the available ELISAs. Furthermore the new technique allows performance in less than three hours from undiluted sera and hence is less labor intensive. In contrast to standard ELISA, the new assay detects specifically antibodies against certain epitopes of the p53 protein. Hence it was possible to distinguish between epitopes that can be found in healthy blood donors and such ones, that are predominantly found in patients with lung cancer. The observed differences in the responses towards the two related epitopes proof, that posttranslational modifications are different in healthy individuals and cancer patients. As the new technique allows observation of in vivo p53 modification, it gives a tool for a deeper understanding of p53 regulation and tumor development.
DA  - 2007
KW  - Protein p53
KW  - Antikörper
KW  - Nachweis
KW  - Immunoassay
KW  - p53
KW  - Fluoreszenz
KW  - Lungenkrebs
KW  - Antibody
KW  - Detection
KW  - Fluorescence
KW  - Lung cancer
LA  - ger
PY  - 2007
TI  - Bead-basierte Fluoreszenz-Immunoassays zum Nachweis tumorinduzierter Proteine
UR  - https://nbn-resolving.org/urn:nbn:de:hbz:361-12754
Y2  - 2024-11-24T06:25:10
ER  -