Δ9-Tetrahydrocannabinol enhances MCF-7 cell proliferation via cannabinoid receptor-independent signaling

Modulation of Δ9-tetrahydrocannabinol-induced MCF-7 breast cancer cell growth by cyclooxygenase and aromatase

“…Although two different cannabinoid receptors (CB1 and CB2) have been discovered and cloned, we have recently reported that 9 -THC is able to stimulate the proliferation of MCF-7 cells cultured in low E 2 media through CB receptor-independent signaling (Watanabe et al, 2005;Takeda et al, 2008a). The responsiveness of MCF-7 cells to 9 -THC-treatment is quite complex, since there are conflicting reports that the cells are (1) sensitive (i.e., decrease in growth rate), (2) resistant, or (3) sensitive (i.e., increase in growth rate) (McKallip et al, 2005;Watanabe et al, 2005;Ligresti et al, 2006;Takeda et al, 2008a;von Bueren et al, 2008).…”

Δ9-Tetrahydrocannabinol and Its Major Metabolite Δ9-Tetrahydrocannabinol-11-oic Acid as 15-Lipoxygenase Inhibitors

“…12 The binding affinities of 9 -THC to CB2 receptor are reported to be from 5.05 to 80.3 nM. 42 Accumulating evidence suggests that the expression of CB receptors can be modulated by some diseases and physiological conditions, 30,43,44 suggesting that the action of 9 -THC would be modulated by the expression status of CB receptors. Until now, there is no experimental evidence demonstrating the relationship between the expression status of CB2 receptor and the diseases.…”

Δ⁹-Tetrahydrocannabinol Targeting Estrogen Receptor Signaling: The Possible Mechanism of Action Coupled with Endocrine Disruption

“…[1][2][3][4][5][6][7][8][9][10][11] Given that Δ 9 -THC utilizes both these receptors in the induction of ERβ, specific respective antagonists would be effective in inhibiting ERβ induction stimulated by the cannabinoid. Because antagonists against CB1 and CB2 receptors (SR14716A and SR144528, respectively) were not effective in the abrogation of Δ 9 -THC induction of ERβ in human breast cancer MDA-MB-231 cells that express the two CB receptors (Takeda et al, unpublished observations), and because Δ 9 -THC also induced ERβ in human breast cancer MCF-7 cells that express very low or undetectable levels of CB receptors, 4,42) taken together, it is suggested that the two types of receptors are not essentially involved in the cannabinoid-mediated ERβ induction pathway(s) in breast cancer cells. (Fig.…”

“…Δ 9 -THC exhibits a variety of pharmacological and toxicological effects: e.g., analgesia, hypotension, reduction of inflammation, and anticancer effects (anti-proliferative and anti-migration effects). [1][2][3][4][5][6][7][8][9][10][11] Among Δ 9 -THC's biological activities, its recognized endocrine-disrupting effects, including anti-estrogenic activity, have been the subjects of previous investigations. It has been reported that chronic oral administration of marijuana resin is able to reduce fertility in female rats.…”