Cannabinol inhibits proliferation and induces cell cycle arrest and apoptosis in glioblastoma, hepatocellular carcinoma and breast cancer cells

Nuanying ZHONG,

Thesis, Master of Science in Biological Sciences

Faculty of Arts and Science, Department of Biological Sciences,

University of Lethbridge Research Repository, Canada

2020

https://hdl.handle.net/10133/5697

 

ABSTRACT

Cannabis sativa is an agriculturally and medicinally plant with many pharmaceutical properties. Cancer is a deadly disease; it is estimated that it will cause over 80 thousand deaths in 2019 in Canada. Although numerous studies have demonstrated that cannabinoids have anti-tumorous properties in various cancers, the anti-malignant activities of cannabinol (CBN) on carcinogenesis and underlying mechanisms remain largely unknown. In this study, we provide evidence that CBN inhibits proliferation of A172, HB8065 and HCC1806 cells in a dose- and time-dependent manner. CBN regulates expression of cannabinoid receptors, CB2, GPR55 and GPR18 in different cell lines, while reducing levels of phosphorylated ERK1/2 in HCC1806 and phosphorylated AKT in A172 and HB8065 cells. We find that CBN induces apoptosis through downregulation of p21 and p27 and a G1 or S-phase cell cycle arrest through downregulation of cyclin E1, CDK1 and CDK2. These data support the medicinal potential of CBN in anti-cancer therapy.

 

TABLE OF CONTENTS
SIGNATURE PAGE ………………………………………………………………………………………. ii
DEDICATION ………………………………………………………………………………………………. iii
ABSTRACT ………………………………………………………………………………………………….. vi
ACKNOWLEDGMENT ………………………………………………………………………………….. v
TABLE OF CONTENTS ………………………………………………………………………………… vi
LIST OF FIGURES ……………………………………………………………………………………… viii
LIST OF ABBREVIATIONS ………………………………………………………………………….. ix
1. INTRODUCTION ………………………………………………………………………………………… 1
1.1 Cannabis plants, cannabinoids, and cannabinol ……………………………………………… 1
1.2 Endocannabinoid system ……………………………………………………………………………. 5
1.2.1 Endocannabinoids ……………………………………………………………………………….. 5
1.2.2 Cannabinoid receptors …………………………………………………………………………. 5
1.2.3 Endocannabinoid signaling network ………………………………………………………. 7
1.3 Cancer and cannabinoids …………………………………………………………………………… 9
1.3.1 CB receptor signaling networks in cancer ……………………………………………… 9
1.3.2 Cell cycle and cannabinoids ………………………………………………………………… 11
1.3.3 Apoptosis and cannabinoids ………………………………………………………………… 14
1.3.4 The main challenges of cancer treatment ………………………………………………. 15
2. HYPOTHESIS ………………………………………………………………………………………….. 17
3. MATERIALS AND METHODS ………………………………………………………………….. 18
3.1 Main reagents …………………………………………………………………………………………. 18
3.2 Cell culture and maintenance ……………………………………………………………………. 18
3.3 Cell viability test …………………………………………………………………………………….. 19
3.4 Cell cycle arrest and apoptosis ………………………………………………………………….. 20
3.5 Exposure of cancer cells to CBN ………………………………………………………………. 22
3.6 Western blot analysis ……………………………………………………………………………….. 22
3.7 Statistical Analysis ………………………………………………………………………………….. 25
4. RESULTS ………………………………………………………………………………………………….. 27
4.1 CBN inhibits proliferation of cancer cells via AKT and ERK1/2 pathways ……. 27
4.2 CBN modulates cell cycle progression of cancer cells ………………………………….. 31
4.3 CBN induces apoptosis of cancer cells ……………………………………………………….. 33
5. DISCUSSION …………………………………………………………………………………………….. 36
6. LIMITATIONS AND FUTURE STUDIES ……………………………………………………. 42
REFERENCES …………………………………………………………………………………………….. 44
SUPPLEMENTARY INFORMATION …………………………………………………………… 53
APPENDIX A ………………………………………………………………………………………………. 54
APPENDIX B ………………………………………………………………………………………………. 56
APPENDIX C ………………………………………………………………………………………………. 58

 

ZHONG_NUANYING_MSC_2020