Studying a Chinese Herb’s Effect on Cancer Cells
While traditional Chinese medicine for centuries has used triptolide, an extract of the Chinese herb known as “Thunder God Vine,” to treat inflammatory conditions like rheumatoid arthritis and autoimmune disorders, it also has powerful anticancer properties.
Biology Professor Reginald Halaby has been studying the herb’s effects on breast cancer cells — the targets of chemotherapy, radiation, hormone therapy or other cancer-fighting protocols — that are resistant to apoptosis, or programmed cell death.
“We postulate that the results from our studies will lead to novel, effective anticancer treatments that specifically target tumor cells — while sparing healthy cells,” he explains.
Halaby notes that since cancer results from the uncontrollable growth of normal, not foreign, cells, our immune system will not mount a response against them. Chemotherapy, which is nonspecific, kills all rapidly dividing cells — even healthy ones.
Halaby is building on previously funded research, which showed that minute concentrations of triptolide cause apoptosis in a human breast cancer cell lines. “Interestingly, triptolide is more potent than most chemotherapeutic drugs, which are administered at 1,000 times higher concentrations,” says Halaby.
His lab has demonstrated that triptolide causes cell death via a pathway involving tiny cellular organs known as lysosomes, which contain digestive enzymes that contribute to cellular degradation. Cancer cells have larger and more active lysosomes than normal cells.
“We’ve shown that triptolide targets the lysosomal membrane and causes it to become porous, allowing the digestive enzymes to enter the cell’s cytoplasm,” he says. “This shift of lysosomal enzymes from lysosomes to the cytoplasm is sufficient to trigger cell death.”
Halaby’s research indicates that this process, when triggered by triptolide, is an effective way to kill cancer cells that have evaded therapeutically induced apoptosis.
“We now plan to investigate the effects of triptolide on apoptosis in additional cancers, including prostate and ovarian tumor cell lines,” he says.