Advanced Viral Research Corp's peptide nucleic-acid immunomodulator, Product R, induces differentiation of the human promyelocytic leukemia cell line HL-60 in cell culture. These research findings were being presented at a conference of the American Association for Cancer Research (AACR) entitled, "Proteases, Extracellular Matrix and Cancer", held in Hilton Head Island, South Carolina.

A prime property of cancers cells, such as leukemia cells, is that they exhibit undisciplined or "wild" growth patterns. Cancer cells are often termed as being "undifferentiated." Normal or "differentiated" cells exhibit orderly growth patterns, subject to the normal controls of cellular growth. Drugs that induce cellular differentiation and maturation, such as tretinoin, currently are utilized to treat promyelocytic leukemia.

"These exciting research findings suggest the potential of new cancer treatments with Product R. Moreover, these findings complement our clinical trial in Israel of Product R in patients with hematopoietic cancers," said Shalom Z. Hirschman, President and CEO of Advanced Viral Research Corp. "The use of targeted agents to induce the differentiation of cancer cells -- that is, to reverse the unruly growth of cancer cells -- is a relatively new field of cancer therapy with a growing market. These new research results indicate that Product R should be studied clinically for utilization in this type of cancer therapy."

To determine whether Product R induces differentiation of promyelocytic leukemia cells, scientists at Advanced Viral Research Corp. tested the effects of this drug on HL-60 cells, a promyelocytic leukemia cell line that has the ability to differentiate toward granulocytes or monocytes in cell culture. When undifferentiated HL-60 cells were cultured in the presence of Product R, it was found that Product R inhibited cell growth and induced cell differentiation, as measured by the expression of characteristic cell surface markers of cellular differentiation such as CD-14 and CD-35. Product R also stimulated the expression of other markers of cellular differentiation, resulting in functionally more mature cells.