Post by Admin on Nov 13, 2021 0:13:37 GMT
Ivermectin has New Application in Inhibiting Colorectal Cancer Cell Growth
www.frontiersin.org/articles/10.3389/fphar.2021.717529/full
Colorectal cancer (CRC) is the third most common cancer worldwide and still lacks effective therapy. Ivermectin, an antiparasitic drug, has been shown to possess anti-inflammation, anti-virus, and antitumor properties. However, whether ivermectin affects CRC is still unclear. The objective of this study was to evaluate the influence of ivermectin on CRC using CRC cell lines SW480 and SW1116. We used CCK-8 assay to determine the cell viability, used an optical microscope to measure cell morphology, used Annexin V-FITC/7-AAD kit to determine cell apoptosis, used Caspase 3/7 Activity Apoptosis Assay Kit to evaluate Caspase 3/7 activity, used Western blot to determine apoptosis-associated protein expression, and used flow cytometry and fluorescence microscope to determine the reactive oxygen species (ROS) levels and cell cycle. The results demonstrated that ivermectin dose-dependently inhibited colorectal cancer SW480 and SW1116 cell growth, followed by promoting cell apoptosis and increasing Caspase-3/7 activity. Besides, ivermectin upregulated the expression of proapoptotic proteins Bax and cleaved PARP and downregulated antiapoptotic protein Bcl-2. Mechanism analysis showed that ivermectin promoted both total and mitochondrial ROS production in a dose-dependent manner, which could be eliminated by administering N-acetyl-l-cysteine (NAC) in CRC cells. Following NAC treatment, the inhibition of cell growth induced by ivermectin was reversed. Finally, ivermectin at low doses (2.5 and 5 µM) induced CRC cell arrest. Overall, ivermectin suppressed cell proliferation by promoting ROS-mediated mitochondrial apoptosis pathway and inducing S phase arrest in CRC cells, suggesting that ivermectin might be a new potential anticancer drug therapy for human colorectal cancer and other cancers.
Introduction
Colorectal cancer (CRC) refers to malignant tumors in the ascending colon, transverse colon, descending colon, sigmoid colon, and rectum and is one of the most common malignant tumors worldwide. Among all malignant tumors globally, CRC ranks third in incidence and second in mortality (Siegel et al., 2020). CRC has caused a heavy economic burden on the country and individuals (Maida et al., 2017). At present, the treatment of CRC mainly adopts a comprehensive treatment based on surgery, combined with radiotherapy, chemotherapy, targeted therapy, and other treatments (Modest et al., 2019). However, due to the complicated mechanism of the occurrence, development, and metastasis of CRC, there is still a lack of specific drugs for CRC treatment.
Ivermectin is a derivative of the 16-membered macrolide compound abamectin, which was first widely used in clinical practice as an antiparasitic drug (Laing et al., 2017). Ivermectin can increase the activity of γ-aminobutyric acid receptor or glutamate-chloride ion channel (Glu-Cl), increase the influx of chloride ions, and cause the cell membrane hyperpolarization, thereby blocking signal transmission between neurons and muscles (Martin et al., 2021), which exerts its antiparasitic effects. Ivermectin could be used, in addition to as an antiparasitic drug, as antiviral agents such as Flavivirus, HIV-1 virus, and SARS-CoV-2 virus (Mastrangelo et al., 2012; Wagstaff et al., 2012; Caly et al., 2020). Moreover, studies have shown that ivermectin has an inhibitory effect on various tumor cells and may be a potential broad-spectrum antitumor drug (Juarez et al., 2020). Juarez et al. (2020) have demonstrated that ivermectin is the most sensitive to breast cancer cells MDA-MB-231, MDA-MB-468, MCF-7, and ovarian SKOV-3; whereas ivermectin is the most nonsensitive to the prostate cancer cell line DU145. The induction of cell cycle arrest at G0/G1 mediates this effect of ivermectin on these sensitive cancer cells. Furthermore, ivermectin can inhibit the proliferation of cancer cells through p21-activated kinase 1 (PAK1)-induced autophagy, Caspase-dependent apoptosis, or immunogenic cell death regulate the signal pathways, including Hippo, Akt/mTOR, and WNT-TCF pathways to inhibit cancer cell proliferation (Liu et al., 2020). As known, ROS plays a vital role in the apoptosis caused by oxidative stress. ROS is a by-product of normal mitochondrial respiration. Stimuli such as infection, drought, cold, and ultraviolet light result in increased ROS in cells. Then, accumulative ROS could induce cells mitochondrial dysfunction and promote apoptosis in cells (Sinha et al., 2013). Evidence has shown that ivermectin-induced apoptosis is closely related to the production of ROS. Currently, there are few reports on the research of ivermectin in colorectal cancer.
Furthermore, new use of old drugs (that is, drug relocation) is a strategy for expanding old drugs and developing new uses, which has the advantages of low research and development cost and short development time (Pushpakom et al., 2019). Research on drug relocation of ivermectin is a shortcut to developing new antitumor drugs. Given this, we designed a study to explore the impact of ivermectin on the proliferation and apoptosis of CRC cells and the underlying mechanism.
Materials and Methods
Cell Culture
SW480 and SW1116 cells were acquired from ATCC and grown in DMEM medium (Biological Industries, Israel) supplemented with 10% FBS (Biological Industries, Israel), 1% penicillin/streptomycin (Coolaber, Beijing, China), and 2.5% HEPES buffer (Procell, Wuhan, China) in an incubator with a humidified air atmosphere of 5% CO2 at 37°C.
Cell Viability Assay
Cells were seeded at a density of 1 × 104 cells/well in a 96-well plate. After being cultured overnight, cells were treated with ivermectin (Figure 1) (MCE Chemicals, Shanghai, China) at the indicated concentrations for 12, 24, or 36 h or cells were pretreated with N-Acetyl-l-cysteine (NAC, 5 mM) (Aladdin, Shanghai, China) for 1 h and then were cultured in ivermectin (20 μM) for 6 h. Then, 10 μL of CCK-8 solution was added to each well and incubated at 37°C for 1 h. The absorbance was detected at 450 nm by a microplate reader (SpectraMax i3x, Molecular Devices, United States). The cell viability was calculated as follows: (absorbance of drug-treated sample/absorbance of control sample) × 100.
www.frontiersin.org/articles/10.3389/fphar.2021.717529/full
Colorectal cancer (CRC) is the third most common cancer worldwide and still lacks effective therapy. Ivermectin, an antiparasitic drug, has been shown to possess anti-inflammation, anti-virus, and antitumor properties. However, whether ivermectin affects CRC is still unclear. The objective of this study was to evaluate the influence of ivermectin on CRC using CRC cell lines SW480 and SW1116. We used CCK-8 assay to determine the cell viability, used an optical microscope to measure cell morphology, used Annexin V-FITC/7-AAD kit to determine cell apoptosis, used Caspase 3/7 Activity Apoptosis Assay Kit to evaluate Caspase 3/7 activity, used Western blot to determine apoptosis-associated protein expression, and used flow cytometry and fluorescence microscope to determine the reactive oxygen species (ROS) levels and cell cycle. The results demonstrated that ivermectin dose-dependently inhibited colorectal cancer SW480 and SW1116 cell growth, followed by promoting cell apoptosis and increasing Caspase-3/7 activity. Besides, ivermectin upregulated the expression of proapoptotic proteins Bax and cleaved PARP and downregulated antiapoptotic protein Bcl-2. Mechanism analysis showed that ivermectin promoted both total and mitochondrial ROS production in a dose-dependent manner, which could be eliminated by administering N-acetyl-l-cysteine (NAC) in CRC cells. Following NAC treatment, the inhibition of cell growth induced by ivermectin was reversed. Finally, ivermectin at low doses (2.5 and 5 µM) induced CRC cell arrest. Overall, ivermectin suppressed cell proliferation by promoting ROS-mediated mitochondrial apoptosis pathway and inducing S phase arrest in CRC cells, suggesting that ivermectin might be a new potential anticancer drug therapy for human colorectal cancer and other cancers.
Introduction
Colorectal cancer (CRC) refers to malignant tumors in the ascending colon, transverse colon, descending colon, sigmoid colon, and rectum and is one of the most common malignant tumors worldwide. Among all malignant tumors globally, CRC ranks third in incidence and second in mortality (Siegel et al., 2020). CRC has caused a heavy economic burden on the country and individuals (Maida et al., 2017). At present, the treatment of CRC mainly adopts a comprehensive treatment based on surgery, combined with radiotherapy, chemotherapy, targeted therapy, and other treatments (Modest et al., 2019). However, due to the complicated mechanism of the occurrence, development, and metastasis of CRC, there is still a lack of specific drugs for CRC treatment.
Ivermectin is a derivative of the 16-membered macrolide compound abamectin, which was first widely used in clinical practice as an antiparasitic drug (Laing et al., 2017). Ivermectin can increase the activity of γ-aminobutyric acid receptor or glutamate-chloride ion channel (Glu-Cl), increase the influx of chloride ions, and cause the cell membrane hyperpolarization, thereby blocking signal transmission between neurons and muscles (Martin et al., 2021), which exerts its antiparasitic effects. Ivermectin could be used, in addition to as an antiparasitic drug, as antiviral agents such as Flavivirus, HIV-1 virus, and SARS-CoV-2 virus (Mastrangelo et al., 2012; Wagstaff et al., 2012; Caly et al., 2020). Moreover, studies have shown that ivermectin has an inhibitory effect on various tumor cells and may be a potential broad-spectrum antitumor drug (Juarez et al., 2020). Juarez et al. (2020) have demonstrated that ivermectin is the most sensitive to breast cancer cells MDA-MB-231, MDA-MB-468, MCF-7, and ovarian SKOV-3; whereas ivermectin is the most nonsensitive to the prostate cancer cell line DU145. The induction of cell cycle arrest at G0/G1 mediates this effect of ivermectin on these sensitive cancer cells. Furthermore, ivermectin can inhibit the proliferation of cancer cells through p21-activated kinase 1 (PAK1)-induced autophagy, Caspase-dependent apoptosis, or immunogenic cell death regulate the signal pathways, including Hippo, Akt/mTOR, and WNT-TCF pathways to inhibit cancer cell proliferation (Liu et al., 2020). As known, ROS plays a vital role in the apoptosis caused by oxidative stress. ROS is a by-product of normal mitochondrial respiration. Stimuli such as infection, drought, cold, and ultraviolet light result in increased ROS in cells. Then, accumulative ROS could induce cells mitochondrial dysfunction and promote apoptosis in cells (Sinha et al., 2013). Evidence has shown that ivermectin-induced apoptosis is closely related to the production of ROS. Currently, there are few reports on the research of ivermectin in colorectal cancer.
Furthermore, new use of old drugs (that is, drug relocation) is a strategy for expanding old drugs and developing new uses, which has the advantages of low research and development cost and short development time (Pushpakom et al., 2019). Research on drug relocation of ivermectin is a shortcut to developing new antitumor drugs. Given this, we designed a study to explore the impact of ivermectin on the proliferation and apoptosis of CRC cells and the underlying mechanism.
Materials and Methods
Cell Culture
SW480 and SW1116 cells were acquired from ATCC and grown in DMEM medium (Biological Industries, Israel) supplemented with 10% FBS (Biological Industries, Israel), 1% penicillin/streptomycin (Coolaber, Beijing, China), and 2.5% HEPES buffer (Procell, Wuhan, China) in an incubator with a humidified air atmosphere of 5% CO2 at 37°C.
Cell Viability Assay
Cells were seeded at a density of 1 × 104 cells/well in a 96-well plate. After being cultured overnight, cells were treated with ivermectin (Figure 1) (MCE Chemicals, Shanghai, China) at the indicated concentrations for 12, 24, or 36 h or cells were pretreated with N-Acetyl-l-cysteine (NAC, 5 mM) (Aladdin, Shanghai, China) for 1 h and then were cultured in ivermectin (20 μM) for 6 h. Then, 10 μL of CCK-8 solution was added to each well and incubated at 37°C for 1 h. The absorbance was detected at 450 nm by a microplate reader (SpectraMax i3x, Molecular Devices, United States). The cell viability was calculated as follows: (absorbance of drug-treated sample/absorbance of control sample) × 100.