On the effects of CP 55-940 and other cannabinoid receptor agonists in C6 and U373 cell lines.

“Cannabinoid receptor (CBs) agonists affect the growth of tumor cells via activation of deadly cascades. The spectrum of action of these agents and the precise role of the endocannabinoid system (ECS) on oncogenic processes remain elusive.

Herein we compared the effects of synthetic (CP 55-940 and WIN 55,212-2) and endogenous (anandamide or AEA) CBs agonists (10-20 μM) on morphological changes, cell viability, and induction of apoptosis in primary astrocytes and in two glioblastoma cell lines (C6 and U373 cells) in order to characterize their possible differential actions on brain tumor cells.

None of the CBs agonist tested induced changes in cell viability or morphology in primary astrocytes.

In contrast, CP 55-940 significantly decreased cell viability in C6 and U373 cells at 5 days of treatment, whereas AEA and WIN 55,212-2 moderately decreased cell viability in both cell lines. Treatment of U373 and C6 for 3 and 5 days with AEA or WIN 55,212-2 produced discrete morphological changes in cell bodies, whereas the exposure to CP 55-940 induced soma degradation. CP 55-940 also induced apoptosis in both C6 and U373 cell lines.

Our results support a more effective action of CP 55-940 to produce cell death of both cell lines through apoptotic mechanisms. Comparative aspects between cannabinoids with different profiles are necessary for the design of potential treatments against glial tumors.”

http://www.ncbi.nlm.nih.gov/pubmed/26255146

Cannabinoids Halt Pancreatic Cancer, Breast Cancer Growth, Studies Say

“Compounds in cannabis inhibit cancer cell growth in human breast cancer cell lines and in pancreatic tumor cell lines, according to a pair of preclinical trials published in the July issue of the journal of the American Association for Cancer Research.

In one trial, investigators at Complutense University in Spain and the Institut National de la Sante et de la Recherche Medicale (INSERM) in France assessed the anti-cancer activity of cannabinoids in pancreatic cancer cell lines and in animals. Cannabinoid administration selectively increased apoptosis (programmed cell death) in pancreatic tumor cells while ignoring healthy cells, researchers found. In addition, “cannabinoid treatment inhibited the spreading of pancreatic tumor cells … and reduced the growth of tumor cells” in animals.

“These findings may contribute to … a new therapeutic approach for the treatment of pancreatic cancer,” authors concluded.

In the second trial, investigators at Spain’s Complutense University reported that THC administration “reduces human breast cancer cell proliferation [in vitro] by blocking the progression of the cell cycle and by inducing apoptosis.” Authors concluded that their findings “may set the bases for a cannabinoid therapy for the management of breast cancer.”

Previous preclinical data published in May in the Journal of Pharmacological and Experimental Therapeutics reported that non-psychoactive cannabinoids, particularly cannabidiol (CBD), dramatically halt the spread of breast cancer cells and recommended their use in cancer therapy.

Separate trials have also shown cannabinoids to reduce the size and halt the spread of glioma (brain tumor) cells in animals and humans in a dose dependent manner. Additional preclinical studies have demonstrated cannabinoids to inhibit cancer cell growth and selectively trigger malignant cell death in skin cancer cells, leukemic cells, lung cancer cells, and prostate carcinoma cells, among other cancerous cell lines.”

http://norml.org/news/2006/07/06/cannabinoids-halt-pancreatic-cancer-breast-cancer-growth-studies-say

Gemcitabine/cannabinoid combination triggers autophagy in pancreatic cancer cells through a ROS-mediated mechanism

“Pancreatic adenocarcinoma is one of the most aggressive and devastating human malignancies with a death-to-incidence ratio of 0.99. Although it represents only 2–3% of all cancers, pancreatic adenocarcinoma is the fourth cause of death by tumors…

In recent years, there has been increasing interest in cannabinoids as therapeutic drugs for their antineoplastic, anticachectic, and analgesic potential. Growth inhibitory activities of cannabinoids have been demonstrated for various malignancies, including brain, breast, prostate, colorectal, skin and, recently, pancreatic cancer…

In the present study, we have demonstrated that the combination between the standard chemotherapy agent GEM and cannabinoids synergistically inhibited pancreatic adenocarcinoma cell growth by a ROS-dependent autophagic cell death.

These findings support a key role of the ROS-dependent activation of an autophagic program in the synergistic growth inhibition induced by GEM/cannabinoid combination in human pancreatic cancer cells.

GEM and cannabinoids strongly inhibited growth of human pancreatic adenocarcinoma cells in vivo.”

Read more: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3122066/

Cannabinoid receptor agonists are mitochondrial inhibitors: a unified hypothesis of how cannabinoids modulate mitochondrial function and induce cell death.

  “Time-lapse microscopy of human lung cancer (H460) cells showed that the endogenous cannabinoid anandamide (AEA), the phyto-cannabinoid Delta-9-tetrahydrocannabinol (THC) and a synthetic cannabinoid HU 210 all caused morphological changes characteristic of apoptosis… These data demonstrate that AEA, THC, and HU 210 are all able to cause changes in integrated mitochondrial function, directly, in the absence of cannabinoid receptors.”

http://www.ncbi.nlm.nih.gov/pubmed/17931597

Cannabidiol-induced apoptosis in primary lymphocytes is associated with oxidative stress-dependent activation of caspase-8

“Cannabidiol-induced apoptosis in primary lymphocytes is associated with oxidative stress-dependent activation of caspase-8” and “The non-psychoactive cannabidiol triggers caspase activation and oxidative stress in human glioma cells… we have shown that the non-psychoactive cannabinoid compound cannabidiol (CBD) induces apoptosis (cell death) of glioma cells in vitro and tumor regression…”

http://www.ncbi.nlm.nih.gov/pubmed/17950393