The expression of carbonic anhydrase II in hematological malignancies.

PURPOSE: Carbonic anhydrases (CAs) are key enzymes that regulate acid-base homeostasis in both normal and pathological conditions. Recent studies have shown that they are functionally involved in the growth and invasion of cancer cells. However, there are only a few publications on CAs in hematological malignancies.

EXPERIMENTAL DESIGN: Here we investigated the presence of CA isozymes in six malignant hematopoietic cell lines and malignant blast cells of bone marrow samples collected from patients with acute myeloid leukemia, acute lymphoblastic leukemia, or chronic myelomonocytic leukemia.

RESULTS: Because three of the malignant hematopoietic cell lines expressed CA II, we also set out to examine its expression in a series of bone marrow samples. Positive reactions were found in 16 of 26 cases (62%) of acute myeloid leukemia, 11 of 15 cases (73%) of acute lymphoblastic leukemia, and 1 of 2 cases (50%) of chronic myelomonocytic leukemia.

CONCLUSIONS: The results indicate that CA II expression is not restricted to only one cell lineage but may result from a genetic aberration that occurs in both myeloid and lymphatic lineages or in their progenitor cell. Because CA II is expressed in most patients with leukemic blast cells, CA inhibitors may prove to be of value as an adjunct to chemotherapy for such cancers.