Colorectal cancer is one of the most aggressive cancers in the world. Cancer stem cells (NKM) play a key role in the disease. Will cannabis terpenes prove effective in eliminating NKM in colorectal cancer?
Current therapies are not effective in combating NKM. They act mainly on rapidly proliferating neoplastic cells, most often interfering with a single molecular pathway, which results in the survival of resistant, poorly proliferating neoplastic cells capable of tumor renewal. Therefore, targeted therapies in NKM are a challenge for modern oncological medicine. The influence of natural compounds on cancer stem cells will be investigated in more detail by Dr. Helena Moreira from the Chair and Department of Medical Sciences in the project Assessment of terpenes activity present in cannabis against colorectal cancer stem cells, under the Miniature 5 grant from the National Science Center.
Research shows that compounds of natural origin have a high anti-cancer potential
Due to their ability to simultaneously affect many signaling pathways involved in the functioning and survival of neoplastic cells, they can show high efficiency in the elimination of NKM and enhance the antitumor activity of known chemotherapeutic agents, thus improving the effectiveness of conventional therapy. Terpenes are secondary metabolites found in most plants and exhibit a number of medicinal properties, including anti-cancer activity. Paclitaxel (Taxol®), a terpene-based molecule isolated from Taxus brevifolia, used since 1993, continues to play an important role in cancer therapy. Several other terpenoids are in clinical trials. – Cannabis is known for its many healing properties, including anti-cancer properties. Terpenes, which are an important component of cannabis, are responsible for its multidirectional properties, including through synergistic actions with cannabinoids – says Dr. Helena Moreira.
Terpenes in the fight against colon cancer
– The aim of this project is to evaluate the antitumor efficacy of two cannabis terpenes, borneol and guaiol, in colorectal cancer with different degrees of malignancy: cytostatics-sensitive and induced resistance. The potential of these terpenes to eliminate neoplastic stem cells (NKMs) in monotherapy and in combination with irinotecan, belonging to the group of standard cytostatics in the treatment of colorectal cancer, whose clinical utility is limited by the mechanisms of innate and acquired immunity, will be investigated, explains Dr. Moreira.
The research will be conducted “in vitro” using colorectal cancer cell lines: sensitive (LoVo, ATCC® CCL-229 ™) and resistant (LoVo / DX) to cytostatics. 2D and 3D cell culture models (spheroid cultures and “liquid marbles” (pearl drops)) will be used. NKMs will be isolated from cell line cultures using the MACS magnetic isolator (Miltenyi) based on the expression of NKM surface markers: CD44 and CD133. In the first step, for both terpenes and irinotecan, a range of concentrations effective in the elimination of NKM, in the Presto blue assay and in the Colony forming assay will be determined. The selected terpene concentrations will then be combined with the specified irinotecan concentration and the effectiveness of these combinations in eliminating NKM will be assessed. Synergistic / additive effects will be analyzed by the Chou-Talalay method based on the ability to inhibit cell proliferation (Presto blue assay). Next, the influence of the tested terpenes and their combinations with irinotecan on the viability of NKM in 3D cultures will be assessed. To this end, NKMs will be isolated based on the markers CD133 and CD44 and grown in 3D in the presence of test compounds. 3D cultures will be monitored and assessed for their size, proliferation, cell viability by flow and imaging cytometry using Calcein AM dye.
The research will help to establish an effective therapeutic strategy targeting NKM in colorectal neoplasms of various degrees of malignancy. This strategy should balance the side effects associated with a high dose of cytostatics and enhance its action, minimizing drug resistance. Effective concentrations of tested terpenes will be determined for monotherapy and combination therapy. The obtained results will form the basis for further research, including in vivo, in scientific cooperation with the French research group from the Institut Pluridisciplinaire Hubert Curien, UMR 7178 CNRS Université de Strasbourg. It is planned to submit a joint project in the next edition of NCN calls, extended to other types of cancer.