Dihydromethysticin, a natural molecule from Kava, suppresses the growth of colorectal cancer via the NLRC3/PI3K pathway

Abstract

Dihydromethysticin (DHM), a natural compound derived from Kava, has been reported to be effective against mental disorders and some malignant tu mors. However, little is known about the inhibitory effect of DHM on colorectal cancer (CRC). First, we examined the impact of DHM on human colon cancer cell lines, which demonstrated that DHM inhibits proliferation, migration, and invasion and promotes apoptosis and cell cycle arrest in colon cancer cells in vitro. Using small hairpin RNA, we inhibited nucleotide-oligomerization domain-like receptor subfamily C3 (NLRC3)/phosphoinositide 3-kinase (PI3K) pathway to elucidate the partial signaling of DHM-mediated tumor suppression. Additionally, using an ectopic human CRC model, we verified whether DHM inhibits tumor growth and angiogenesis via the NLRC3/PI3K pathway in vivo. Overall, DHM showed an inhibitory effect on CRC by altering cell proliferation, migration, invasion, apoptosis, cell cycle, and angiogenesis, possibly via the NLRC3/PI3K pathway. Thus, DHM may be a promising candidate for CRC therapy. K E Y W O R D S colorectal cancer, dihydromethysticin, NLRC3 1 | INTRODUCTION Colorectal cancer (CRC) is third most prevailing malignant tumor in the world. In 2016, approximately 134 490 individuals were diagnosed with CRC in the United States, and it was responsible for mortality of more than one-third. 1 In the past few decades, remarkable progress has been made in the treatment of CRC with variety of chemotherapy drugs and immunotherapies constantly emerging. However, due to drug resistance and dose-limiting toxicity, limited success has been achieved in treating advanced CRC. 2 Abbreviations: ALT, alanine aminotransferase; AST, aspartate aminotransferase; CDK4, cyclin-dependent kinase 4; CK, creatine kinase.; CRC, colorectal cancer; DAPI, 4′, 6-diamidino-2-phenylindole; DHM, dihydromethysticin; H&E staining, hematoxylin and eosin staining; JNK, c-Jun NH2 terminal kinase; LDH, lactate dehydrogenase; MMP2, matrix metallopeptidase 2; MMP9, matrix metallopeptidase 9; mTOR, mammalian target of rapamycin; NF-κB, nuclear factor-kappa B; NLRC3, nucleotide-oligomerization domain-like receptor subfamily C3; PBS, phosphate-buffered saline; PI3K, phosphoinositide 3-kinase; RIPA, radio immunoprecipitation assay; TUNEL, terminal dUTP nick-end labeling; VEGF, vascular endothelial growth factor. Huayang Pan, Fukai Liu, and Jinge Wang contributed equally to this work. Terminal dUTP nick-end labeling (TUNEL) assay was performed according to the manufacturer's instructions (Roche, Shanghai, China). CRC cells were washed once with PBS, fixed with formalin for 30 minutes, and washed again with PBS. Cells were then suspended 576 | PAN ET AL.

Kava as a Clinical Nutrient: Promises and Challenges

“…Several kavalactones were also reported to have anti-cancer potential [ 147 , 148 , 149 ]. For instance, DHM induced apoptosis in osteosarcoma cells through the modulation of the PI3K/Akt pathway, the disruption of mitochondrial membrane potential and the induction of cell cycle arrest at 25–100 μM [ 147 ].…”

“…For instance, DHM induced apoptosis in osteosarcoma cells through the modulation of the PI3K/Akt pathway, the disruption of mitochondrial membrane potential and the induction of cell cycle arrest at 25–100 μM [ 147 ]. It also suppressed the growth of colorectal cancer via the NLRC3/PI3K pathway at 25–100 μM [ 148 ]. Yangonin at 200 μM induced autophagy and sensitizes bladder cancer cells to flavokavain A and docetaxel via inhibition of the mTOR pathway [ 149 ].…”

Anticancer effects of 7,8-dihydromethysticin in human leukemia cells are mediated via cell-cycle dysregulation, inhibition of cell migration and invasion and targeting JAK/STAT pathway

“…Therefore, cell migration and invasion play a key role in deciding the fate of malignant metastatic cancers. 7,8-Dihydromethysticin was previously reported to inhibit cell migration and invasion in human colorectal cancer cells via suppression of NLRC3/PI3K signalling (22). Herein, the cell migration tendency of leukemia HL-60 cells was assessed post-7,8-dihydromethysticin treatment.…”

“…Leukemia treatment remains a big challenge for researchers since a higher number of side-effects, disease reoccurrence and lower survival present the key drawbacks of currently accessible treatment modalities. 7,8-Dihydromethysticin has been previously reported of inducing antiproliferative effects against different human cancer cells including colorectal cancer and osteosarcoma (21,22). It was also reported to exhibit proapoptotic effects and modulated a number of cancer cell survival pathways.…”

An Updated Review on the Psychoactive, Toxic and Anticancer Properties of Kava

“…Despite being studied more in the scope of lung cancer, dihydromethysticin has also shown inhibitory effects in colorectal cancer, mainly in terms of proliferation, migration, and invasion. It was also shown to induce apoptosis and cell cycle arrest in the G0/G1 phase, via the NLRC3/PI3K pathway, where it activates nucleotide oligomerization domain-like receptor subfamily C3 (NLRC3) and inhibits PI3K and cyclin D1-CDK4, leading to G0/G1 arrest [ 124 ].…”