Inhibitors of SRC Kinases Impair Antitumor Activity of anti-CD20 Monoclonal Antibodies

MAbs. 2014;6(5):1300-13. doi: 10.4161/mabs.32106. Epub 2014 Oct 30.


Clinical trials with SRC family kinases (SFKs) inhibitors used alone or in a combination with anti-CD20 monoclonal antibodies (mAbs) are currently underway in the treatment of B-cell tumors. However, molecular interactions between these therapeutics have not been studied so far. A transcriptional profiling of tumor cells incubated with SFKs inhibitors revealed strong downregulation of MS4A1 gene encoding CD20 antigen. In a panel of primary and established B-cell tumors we observed that SFKs inhibitors strongly affect CD20 expression at the transcriptional level, leading to inhibition of anti-CD20 mAbs binding and increased resistance of tumor cells to complement-dependent cytotoxicity. Activation of the AKT signaling pathway significantly protected cells from dasatinib-triggered CD20 downregulation. Additionally, SFKs inhibitors suppressed antibody-dependent cell-mediated cytotoxicity by direct inhibition of natural killer cells. Abrogation of antitumor activity of rituximab was also observed in vivo in a mouse model. Noteworthy, the effects of SFKs inhibitors on NK cell function are largely reversible. The results of our studies indicate that development of optimal combinations of novel treatment modalities with anti-CD20 mAbs should be preceded by detailed preclinical evaluation of their effects on target cells.

Keywords: ADCC, antibody-dependent cell-mediated cytotoxicity; BCR, B-cell receptor; CD20; CDC, complement-dependent cytotoxicity; CFSE, carboxyfluorescein succinimidyl ester; CLL, chronic lymphocytic leukemia; DLBCL, diffuse large B-cell lymphoma; NHL, non-Hodgkin lymphoma; PBMC, peripheral blood mononuclear cells; SFKs, SRC family kinases; SRC family kinases; dasatinib; ofatumumab; rituximab.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Monoclonal / immunology*
  • Antibodies, Monoclonal / pharmacology
  • Antibodies, Monoclonal, Murine-Derived / immunology
  • Antibodies, Monoclonal, Murine-Derived / pharmacology
  • Antibody-Dependent Cell Cytotoxicity / drug effects
  • Antibody-Dependent Cell Cytotoxicity / immunology
  • Antigens, CD20 / genetics
  • Antigens, CD20 / immunology*
  • Antigens, CD20 / metabolism
  • Blotting, Western
  • Cell Line, Tumor
  • Dasatinib
  • Disease Models, Animal
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects
  • Gene Expression Regulation, Neoplastic / immunology
  • HEK293 Cells
  • Humans
  • K562 Cells
  • Killer Cells, Natural / drug effects
  • Killer Cells, Natural / immunology
  • Mice, Inbred C57BL
  • Neoplasms / drug therapy
  • Neoplasms / genetics
  • Neoplasms / immunology*
  • Oligonucleotide Array Sequence Analysis
  • Protein Kinase Inhibitors / immunology*
  • Protein Kinase Inhibitors / pharmacology
  • Proto-Oncogene Proteins c-akt / immunology
  • Proto-Oncogene Proteins c-akt / metabolism
  • Pyrimidines / immunology
  • Pyrimidines / pharmacology
  • Reverse Transcriptase Polymerase Chain Reaction
  • Rituximab
  • Signal Transduction / drug effects
  • Signal Transduction / immunology
  • Thiazoles / immunology
  • Thiazoles / pharmacology
  • Transcriptome / drug effects
  • Transcriptome / immunology
  • src-Family Kinases / antagonists & inhibitors
  • src-Family Kinases / immunology*
  • src-Family Kinases / metabolism


  • Antibodies, Monoclonal
  • Antibodies, Monoclonal, Murine-Derived
  • Antigens, CD20
  • Protein Kinase Inhibitors
  • Pyrimidines
  • Thiazoles
  • Rituximab
  • src-Family Kinases
  • Proto-Oncogene Proteins c-akt
  • Dasatinib