Medical marijuana has gained attention in recent years for its potential to relieve pain and short-term anxiety and depression. Now, Penn State College of Medicine researchers say some cannabinoid compounds may actually inhibit the growth of colon cancer cells in the lab.

Cancer properties.

The researchers tested the effects of synthetic cannabinoid compounds on colon cancer cells in an experiment in test tubes. While the compounds most commonly associated with cannabis THC and CBD showed little to no effect; 10 other compounds were effective at inhibiting cancer cell growth.

Kent Vrana, chair of the Department of Pharmacology at Penn State College of Medicine; said the study recently published in Cannabis and Cannabinoid Research helped identify compounds that is test further to understand their anti-cancer properties.

“Now that we’ve identified the compounds that we think have this activity; we can take these compounds and start trying to alter them to make them more potent against cancer cells,” Vrana said. “And then eventually; we can explore the potential for using these compounds to develop drugs for treating cancer.”

Different cause

Colorectal cancer is one of the most common cancers diagnosed in the United States, according to the National Cancer Institute, with an estimated 140,250 newly diagnosed cases and 50,630 deaths in 2018. While medical cannabis has largely been used in recent years for palliative care, the researchers said some previous studies suggested that certain cannabinoid compounds may have the potential to inhibit or prevent the growth of tumors.

To explore how effective cannabinoids are at reducing the viability of colon cancer cells specifically, the researchers test how 370 different synthetic cannabinoid compounds affected seven types of human colon cancer cells. “There are many different ways cells can become cancerous,” Vrana said. “Each of the seven cells we tested had a different cause or mutation that led to the cancer, even though they were all colon cells. We didn’t want to test these compounds on just one mutation or pathway to cancer.”

Signs of reducing the viability

The researchers incubated the cancer cells in a lab for eight hours before ;treating them with the cannabinoid compounds for 48 hours. Any compounds that shows signs of reducing the viability of one kind of cancer cell; is then use to treat all seven kinds of cells.
After further screening and analysis; the researchers identified 10 compounds that inhibited the growth of almost all seven types of colon cancer types tested. But while the researchers were able to identify these compounds; Vrana says they are still unsure about how exactly the compounds work to reduce the viability of the cancer cells.
“The 10 compounds we found to be effective fall into three classes, so they’re similar to each other but with small changes;” Vrana said. “We know how one of them works; which is by inhibiting the division of cells in general. We also found that the most potent and effective compounds don’t seem to work through traditional marijuana receptors; although we’re not sure of the exact mechanism yet.”