System for analyzing MSI (microsatellite instability) state during tumor immunotherapy

A technology for microsatellite instability and immunotherapy, which is applied in the field of biomarker analysis system to achieve the effects of high specificity and sensitivity, simple conditions for variable temperature amplification and simple operation.

CN106834479AInactive Publication Date: 2017-06-13QIAGEN SUZHOU TRANSLATIONAL MEDICINE CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2017-06-13
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention relates to analysis of the MSI (microsatellite instability) state which can serve as an auxiliary diagnosis marker for tumor immunotherapy (PD-1 / PD-L1). The MSI of tumor cells of human beings is detected on the basis of a fluorescent PCR platform, and five of more mononucleotide repeat loci (NR-21, NR-24, BAT-25, BAT-26 and MONO27) reported in documents and internationally are selected for analysis of the MSI state. Besides, two pentanucleotide repeat loci (Penta C and Penta D) are selected for quality control of samples and are mainly used for detecting mixing and pollution of the samples. A fluorescently labeled primer is adopted, and besides, 7 loci are amplified; by comparison with other products, the amplification conditions are simplified, amplification can be performed on common PCR equipment, signals are stronger in combination with capillary electrophoresis analysis, the operation is simple, economical and practical properties are realized, the MSI state of a patient who receives or is going to receive tumor immunotherapy (PD-1 / PD-L1) can be detected within short time, and guiding significance is given as soon as possible for clinical treatment.
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Description

technical field

[0001] The invention belongs to the field of biotechnology, relates to an analysis system of biomarkers in tumor immunotherapy or disease diagnosis and treatment, and can provide guidance for treatment or diagnosis of related diseases. Background technique

[0002] Microsatellite (Microsatellite), also known as short tandem repeats (Short tandem repeats, STRs), simple repeat sequence, consists of 1 to 6 nucleotides, is highly polymorphic, and widely exists in prokaryotic and eukaryotic genomes. Microsatellite instability (MSI) refers to changes in the length of microsatellite DNA caused by replication errors (RER). Its occurrence is mainly due to a defect in the gene function involved in the pairing error repair (mismatch repair, MMR), resulting in a defective protein, which cannot normally correct the replication error, thereby causing changes in the microsatellite DNA, making it unable to play a regulatory role normally, resulting in Abnormal cell prolifer...

Examples

Embodiment Construction

[0083] Case 1

[0084] We selected a patient with colorectal cancer, and used the present invention to detect the microsatellite instability state of the tumor cells. At the same time, the MSI Analysis System, Version 1.2 of Promega Company was used as a control, and the following are the specific operation steps.

[0085] 1. DNA extraction from FFPE samples

[0086] The QIAamp DNA FFPE Tissue Kit from QIAGEN was used to extract DNA from tumor and paracancerous FFPE samples of colorectal cancer patients, respectively. Then use Nanodrop for DNA concentration and quality detection. The DNA extracted from FFPE samples is best re-quantified with Qubit, and finally diluted to a concentration of 1ng / μl.

[0087] 2. PCR amplification

[0088] 2.1 Preparation of 10×MSI primer mixture

[0089] First, use TE Buffer to dissolve the 7 pairs of fluorescently labeled primers into a 100 μM stock solution, and then configure it into a 10×MSI primer mixture according to the requirements in...