Characterization and use of the novel human multiple myeloma cell line MC-B11/14 to study biological consequences of CRISPR-mediated loss of immunoglobulin A heavy chain

• Published in: Experimental hematology 2018-01, Vol.57, p.42-49.e1
• Main Authors: Walters, Denise K., Arendt, Bonnie K., Tschumper, Renee C., Wu, Xiaosheng, Jelinek, Diane F.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Antineoplastic Combined Chemotherapy Protocols - therapeutic use; Base Sequence; Bone Marrow Transplantation; Bortezomib - administration & dosage; Bortezomib - pharmacology; Cell Line, Tumor - drug effects; Cell Line, Tumor - metabolism; Chromosomes, Human, Pair 11 - genetics; Chromosomes, Human, Pair 11 - ultrastructure; Chromosomes, Human, Pair 14 - genetics; Chromosomes, Human, Pair 14 - ultrastructure; Combined Modality Therapy; CRISPR-Cas Systems; Fatal Outcome; Gene Expression Regulation, Neoplastic - drug effects; Gene Knockout Techniques; Genes, Immunoglobulin; Humans; Immunoglobulin A - genetics; Immunoglobulin Heavy Chains - genetics; Immunoglobulin kappa-Chains - biosynthesis; Immunoglobulin kappa-Chains - genetics; Immunophenotyping; Male; Middle Aged; Multiple Myeloma - drug therapy; Multiple Myeloma - pathology; Multiple Myeloma - therapy; Myeloma Proteins - biosynthesis; Myeloma Proteins - genetics; Sequence Alignment; Tetraploidy; Thalidomide - analogs & derivatives; Thalidomide - pharmacology; Translocation, Genetic
• ISSN: 0301-472X; 1873-2399
• DOI: 10.1016/j.exphem.2017.09.010

•A novel human monoclonal IgAκ MM cell line was established.•CRISPR-mediated gene editing was used to disrupt IgA HC expression.•Loss of IgA expression lessened sensitivity to bortezomib significantly. The genetic abnormalities underlying multiple myeloma (MM) are notoriously complex and intraclonal heterogeneity is a common disease feature. In the current study, we describe the establishment of a monoclonal immunoglobulin A (IgA) kappa (κ) MM cell line designated MC-B11/14. Cytogenetic and fluorescence in situ hybridization analyses of the original and relapse patient samples revealed that the MM clone was nonhyperdiploid and possessed an 11;14 chromosomal translocation. The MC-B11/14 cell line, established from the relapse sample, is tetraploid and houses the t(11;14) abnormality. Given our long-standing interest in Ig function and secretion, we next used CRISPR technology to knock out IgA heavy-chain expression in the MC-B11/14 cells to assess the biological consequences of converting this cell line to one only expressing κ light chains. As expected, secretion of intact IgA was undetectable from MC-B11/14IgA− cells. Sensitivity to pomalidomide treatment was similar between the MC-B11/14WT and MC-B11/14IgA− cells; however, MC-B11/14IgA− cells were found to be significantly more resistant to bortezomib treatment. This study describes the establishment of a new human MM cell line tool with which to study disease biology and the use of CRISPR technology to create a potentially useful model with which to study MM light-chain escape.