Honokiol inhibits proliferation of colorectal cancer cells by targeting anoctamin 1/TMEM16A Ca²⁺‐activated Cl⁻ channels

Abstract

Background and Purpose Ca2+‐activated Cl− channels (Ano1 channels) contribute to the pathogenesis of colorectal cancer. Honokiol is known to inhibit cell proliferation and tumour growth in colorectal cancer. However, the molecular target of honokiol remains unclear. This study aimed to investigate whether honokiol inhibited cell proliferation of colorectal cancer by targeting Ano1 channels. Experimental Approach Patch‐clamp techniques were performed to study the effect of honokiol on Ca2+‐activated Cl− currents in HEK293 cells overexpressing Ano1‐ or Ano2‐containing plasmids or in human colorectal carcinoma SW620 cells. Site‐directed mutagenesis was used to identify the critical residues for honokiol‐induced Ano1 inhibition. Proliferation of SW620 cells or human intestinal epithelial NCM460 cells by CCK‐8 assays. Key Results Honokiol blocked Ano1 currents in Ano1‐overexpressing HEK293 cells and SW620 cells. Honokiol more potently inhibited Ano1 currents than Ano2 currents. Three amino acids (R429, K430 and N435) were critical for honokiol‐induced Ano1 inhibition. The R429A/K430L/N435G mutation reduced the sensitivity of Ano1 to honokiol. Honokiol inhibited SW620 cell proliferation, and this effect was reduced by Ano1‐shRNAs. Furthermore, Ano1 overexpression promoted proliferation in NCM460 cells with low Ano1 endogenous expression and resulted in an increased sensitivity to honokiol. Overexpression of the R429A/K430L/N435G mutation reduced WT Ano1‐induced increase in the sensitivity of NCM460 cells to honokiol. Conclusion and Implications We identified a new anticancer mechanism of honokiol, through the inhibition of cell proliferation, by targeting Ano1 Ca2+‐activated Cl− channels.

Honokiol Prevents Intestinal Barrier Dysfunction in Mice with Severe Acute Pancreatitis and Inhibits the JAK/STAT1 Pathway and Acetylation of HMGB1

“…HON is a natural product isolated from the bark of Houpu magnolia (Magnolia officinalis) and has been used as a traditional Chinese medicine. Recent studies reported that HON inhibited cancer cell proliferation and in vivo tumor growth, regulated the progression of inflammation, and inhibited bacterial growth over a wide range of temperatures and pH, and thereby reduced biofilm formation and antibiotic resistance (Chen et al, 2021;Chiu et al, 2021;Wang et al, 2021). Our results showed that HON treatment decreased the level of HMGB1 and inflammatory factors, and protected against intestinal barrier dysfunction.…”

Identification of a druggable pocket of the calcium-activated chloride channel TMEM16A in its open state

“…High-throughput drug screening and computer-aided drug design have identified an array of TMEM16A activators and potentiators, among which ETX001, a potentiator of TMEM16A, has entered clinical trials as therapeutic agent for cystic fibrosis ( 7 ). Meanwhile, a large number of TMEM16A inhibitors have been identified, including natural products Cepharanthine ( 8 ), Evodiamine ( 9 ), Honokiol ( 10 ), and Luteolin ( 11 ) and synthetic compounds Ani9 ( 12 ), CaCC inh -A01 ( 13 ), T16A inh -A01 ( 14 ), Monna ( 15 ), and 4-arylthiophene-3-carboxylic acid ( 16 ). These inhibitors have shown potential therapeutic effects in the laboratory against TMEM16A-related diseases such as hypertension, cancer, and secretory diarrhea ( 7 ).…”

Targeting Annexin A1 as a Druggable Player to Enhance the Anti-Tumor Role of Honokiol in Colon Cancer through Autophagic Pathway

“…The role of honokiol includes the induction of apoptosis and autophagy in osteosarcoma cells by ROS/ERK1/2 signaling [ 30 ], suppression of pancreatic cancer progression, and invasion by miR-101/Mcl-1 and SMAD2/3 axis [ 27 , 43 ], reduction of gastric tumor growth and peritoneal dissemination by inhibiting Tpl2 [ 44 ], and antagonism of doxorubicin resistance in breast cancer through miR-188-5p/FBXW7/c-Myc pathway [ 45 ]. It has also been reported that honokiol can inhibit colon cancer cell proliferation through signals such as TGF-β1/p53 [ 21 , 46 ], but only one paper revealed that the death mode induced by honokiol might be iron death [ 47 ]. Honokiol can also increase the sensitivity of tumor cells to cisplatin and oxaliplatin [ 47 , 48 ].…”