Missense mutations in PML-RARA are critical for the lack of responsiveness to arsenic trioxide treatment.

Abstract

Arsenic trioxide (As₂O₃) is a highly effective treatment for patients with refractory/relapsed acute promyelocytic leukemia (APL), but resistance to As₂O₃ has recently been seen. In the present study, we report the findings that 2 of 15 patients with refractory/relapsed APL treated with As₂O₃ were clinically As₂O₃ resistant. Leukemia cells from these 2 patients harbored missense mutations in promyelocytic leukemia gene-retinoic acid receptor-α gene (PML-RARA) transcripts, resulting in amino acid substitutions of A216V and L218P in the PML B2 domain. When wild-type or mutated PML-RARA (PR-WT and PR-B/L-mut, respectively) were overexpressed in HeLa cells, immunoblotting showed SUMOylated and/or oligomerized protein bands in PR-WT but not in PR-B/L-mut after As₂O₃ treatment. Protein-localization analysis indicated that PR-WT in the soluble fraction was transferred to the insoluble fraction after treatment with As₂O₃, but PR-B/L-mut was stably detected in fractions both with and without As₂O₃. Immunofluorescent microscopy analysis showed PR-WT localization as a microgranular pattern in the cytoplasm without As₂O₃ and as a macrogranular pattern with As₂O₃. PR-B/L-mut was diffusely observed in the cytoplasm with and without As₂O₃. Nearly identical localization patterns were observed in patients' primary cells. Therefore, B2 domain mutations may play an important role in aberrant molecular responses toAs₂O₃ and may be critical for As₂O₃ resistance in APL.

• Authors: Emi Goto, Akihiro Tomita, Fumihiko Hayakawa, Akihide Atsumi, Hitoshi Kiyoi, Tomoki Naoe
• Journal: Blood (Blood) Vol. 118 Issue 6 Pg. 1600-9 (Aug 11 2011) ISSN: 1528-0020 [Electronic] United States
• PMID: 21613260 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antineoplastic Agents
• Arsenicals
• Nuclear Proteins
• Oncogene Proteins, Fusion
• Oxides
• Promyelocytic Leukemia Protein
• RARA protein, human
• Receptors, Retinoic Acid
• Retinoic Acid Receptor alpha
• Transcription Factors
• Tumor Suppressor Proteins
• promyelocytic leukemia-retinoic acid receptor alpha fusion oncoprotein
• PML protein, human
• Arsenic Trioxide

Topics

• Adult
• Antineoplastic Agents (pharmacology, therapeutic use)
• Arsenic Trioxide
• Arsenicals (pharmacology, therapeutic use)
• Binding Sites (genetics)
• Cytoplasm (drug effects, metabolism)
• Drug Resistance, Neoplasm (genetics)
• Female
• HeLa Cells
• Humans
• Immunoblotting
• Leukemia, Promyelocytic, Acute (drug therapy, genetics, pathology)
• Male
• Microscopy, Fluorescence
• Middle Aged
• Mutation, Missense
• Neoplasm Recurrence, Local (genetics)
• Nuclear Proteins (genetics, metabolism)
• Oncogene Proteins, Fusion (genetics, metabolism)
• Oxides (pharmacology, therapeutic use)
• Promyelocytic Leukemia Protein
• Receptors, Retinoic Acid (genetics, metabolism)
• Retinoic Acid Receptor alpha
• Reverse Transcriptase Polymerase Chain Reaction
• Sumoylation (drug effects)
• Transcription Factors (genetics, metabolism)
• Transcription, Genetic (drug effects)
• Tumor Suppressor Proteins (genetics, metabolism)
• U937 Cells
• Young Adult