Genetic and epigenetic analysis of the beta-2-microglobulin gene in microsatellite instable colorectal cancer

SNAHNICANOVA, Zuzana, Ivana KASUBOVA, Michal KALMAN, Marian GRENDAR, Peter MIKOLAJCIK, Eva GABONOVA, Ludovit LACA, Martin CAPRNDA, Luis RODRIGO, Rachele CICCOCIOPPO, Peter KRUŽLIAK, Lukas PLANK and Zora LASABOVA. Genetic and epigenetic analysis of the beta-2-microglobulin gene in microsatellite instable colorectal cancer. Clinical and Experimental Medicine. Milan: SPRINGER-VERLAG ITALIA SRL, 2020, vol. 20, No 1, p. 87-95. ISSN 1591-8890. Available from: https://dx.doi.org/10.1007/s10238-019-00601-7.

Basic information

• Original name: Genetic and epigenetic analysis of the beta-2-microglobulin gene in microsatellite instable colorectal cancer
• Authors: SNAHNICANOVA, Zuzana (703 Slovakia), Ivana KASUBOVA (703 Slovakia), Michal KALMAN (703 Slovakia), Marian GRENDAR (703 Slovakia), Peter MIKOLAJCIK (703 Slovakia), Eva GABONOVA (703 Slovakia), Ludovit LACA (703 Slovakia), Martin CAPRNDA (703 Slovakia), Luis RODRIGO (724 Spain), Rachele CICCOCIOPPO (380 Italy), Peter KRUŽLIAK (703 Slovakia, guarantor, belonging to the institution), Lukas PLANK (703 Slovakia) and Zora LASABOVA (703 Slovakia).
• Edition: Clinical and Experimental Medicine, Milan, SPRINGER-VERLAG ITALIA SRL, 2020, 1591-8890.

Other information

• Original language: English
• Type of outcome: Article in a journal
• Field of Study: 30109 Pathology
• Country of publisher: Italy
• Confidentiality degree: is not subject to a state or trade secret
• WWW: URL
• Impact factor: Impact factor: 3.984
• RIV identification code: RIV/00216224:14110/20:00115437
• Organization unit: Faculty of Medicine
• Doi: http://dx.doi.org/10.1007/s10238-019-00601-7
• UT WoS: 000511988900011
• Keywords in English: Colorectal cancer; Cancer immunogenicity; Microsatellite instability; Beta-2-microglobulin; Promoter methylation
• Tags: 14110121, rivok
• Tags: International impact, Reviewed

Abstract

One of the most common mechanisms of immune evasion in MSI colorectal cancers (CRCs) is loss of HLA class I expression due to mutations in B2M gene which can become a negative predictor for checkpoint blockade therapy. The aim of this study was the determination of prevalence of B2M somatic mutations in MSI CRC patients and relationship between B2M mutations and lymphocytes infiltration and other clinicopathological features as well as detection of methylation changes in B2M promoter region which can be another mechanism of immune escape. In our study, 37 MSI-H and 5 MSI-L patients were selected for screening of B2M mutational and methylation status. The characterization of patients was based on standard histopathological diagnosis and TNM classification; BRAF, KRAS mutations, tumor-infiltrating lymphocytes and peritumoral lymphoid reaction were also determined. MSI analysis was performed using fragment analysis. B2M mutations were identified by Sanger sequencing, and methylation of CpG islands in promoter region was detected by methylation-specific PCR. Heterozygous mutations in the B2M gene were detected in five MSI-H patients (13.5%), while the mutation c.45_48delTTCT was determined in four patients and mutation c.276delC was found in two patients. One of these five patients was compound heterozygote harboring both mutations. Methylation of the promoter region of the B2M gene was observed in one patient with MSI-H colorectal cancer. Detection of genetic and epigenetic changes in B2M gene could be important in personalized therapy for CRC patients as these changes may be one of the mechanisms of secondary resistance of MSI positive tumors to immunotherapy.