Lung cancer is the major cause of cancer-related mortality worldwide; can cannabis help?

A study published by The American Association for Cancer Research, titled "Δ-9 Tetrahydrocannabinol inhibits growth and metastasis of lung cancer. made discoveries that indicate that THC has anti-tumorigenic and anti-metastatic effects against lung cancer, and that future therapies against EGFR overexpressing, aggressive and chemotherapy resistant lung cancers may include targeting the cannabinoids receptors.

Anju Preet, Ramesh Ganju, and Jerome Groopman characterized the effect of THC on in vivo lung cancer growth and metastasis in a murine model by implanting A549 cells in SCID mice through subcutaneous and intravenous injections to generate subcutaneous and lung metastatic cancer, respectively. In just 21 days, a significant reduction (~50%) in tumor weight and volume were observed in THC treated animals compared to the vehicle treated animals. THC treated animals also showed a significant (~60%) reduction in macroscopic lesions on the lung surface in comparison to vehicle treated control.

Discoveries:

• Lung Cancer tumors express cannabinoids receptors CB1 and CB2, the known targets for THC action.
• THC attenuates EGF-stimulated chemotaxis and chemoinvasion.
• THC has anti-proliferative and anti-angiogenic effects.
• THC reduces staining significantly for Ki67, a proliferative biomarker
• THC reduces staining significantly for CD31, an endothelial biomarker indicative of vascularization.
• THC inhibits EGF-induced Akt phosphorylation.

Implications:

New therapies against EGFR overexpressing, aggressive and chemotherapy resistant lung cancers may include targeting the cannabinoids receptors.