scholarly journals The Inhibition by Oxaliplatin, a Platinum-Based Anti-Neoplastic Agent, of the Activity of Intermediate-Conductance Ca2+-Activated K+ Channels in Human Glioma Cells

2015 ◽  
Vol 37 (4) ◽  
pp. 1390-1406 ◽  
Author(s):  
Mei-Han Huang ◽  
Yan-Ming Huang ◽  
Sheng-Nan Wu

Oxaliplatin (OXAL) is a third-generation organoplatinum which is effective against advanced cancer cells including glioma cells. How this agent and other related compounds interacts with ion channels in glioma cells is poorly understood. OXAL (100 µM) suppressed the amplitude of whole-cell K+ currents (IK); and, either DCEBIO or ionomycin significantly reversed OXAL-mediated inhibition of IK in human 13-06-MG glioma cells. In OXAL-treated cells, TRAM-34 did not suppress IK amplitude in these cells. The intermediate-conductance Ca2+-activated K+ (IKCa) channels subject to activation by DCEBIO and to inhibition by TRAM-34 or clotrimazole were functionally expressed in these cells. Unlike cisplatin, OXAL decreased the probability of IKCa-channel openings in a concentration-dependent manner with an IC50 value of 67 µM. No significant change in single-channel conductance of IKCa channels in the presence of OXAL was demonstrated. Neither large-conductance Ca2+-activated K+ channels nor inwardly rectifying K+ currents in these cells were affected in the presence of OXAL. OXAL also suppressed the proliferation and migration of 13-06-MG cells in a concentration- and time-dependent manner. OXAL reduced IKCa-channel activity in LoVo colorectal cancer cells. Taken together, the inhibition by OXAL of IKCa channels would conceivably be an important mechanism through which it acts on the functional activities of glioma cells occurring in vivo.

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Ze Zhuang ◽  
Dongjie Yu ◽  
Zheng Chen ◽  
Dezhao Liu ◽  
Guohui Yuan ◽  
...  

Joint contracture is increasingly regarded as a clinical problem that leads to irreversible dysfunction of the joint. It is a pathophysiological process following joint injury, which is marked by the activation of myofibroblasts. There is currently no effective treatment for the prevention of joint contracture. Curcumin is a polyphenol pigment extracted from turmeric, which possesses anti-inflammatory, antioxidative, and antitumor properties. In the present study, we demonstrated that curcumin exerts a protective effect against joint contracture via the inhibition of myofibroblast proliferation and migration in a time- and concentration-dependent manner. Moreover, we indicated that phosphatase and tension homolog (PTEN) was downregulated in myofibroblasts in vitro and in the contracture capsule tissues of patients in vivo. Additionally, western blot analysis revealed a negative correlation between the expression levels of PTEN and the fibrosis marker protein alpha smooth muscle cell actin. Methylation-specific PCR results suggested that curcumin was able to demethylate PTEN in a similar manner to the demethylation agent 5-azacytidine, increasing PTEN expression and further inhibiting phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin signaling. In conclusion, our data illustrate part of the mechanism of curcumin inhibition in joint contracture. These results support the hypothesis that curcumin may potentially be used as a novel candidate for the treatment of joint contracture.


2006 ◽  
Vol 127 (3) ◽  
pp. 329-340 ◽  
Author(s):  
Joachim Scholz-Starke ◽  
Armando Carpaneto ◽  
Franco Gambale

This study investigates the interaction of the aminoglycoside antibiotic neomycin with the slow vacuolar (SV) channel in vacuoles from Arabidopsis thaliana mesophyll cells. Patch-clamp experiments in the excised patch configuration revealed a complex pattern of neomycin effects on the channel: applied at concentrations in the submicromolar to millimolar range neomycin (a) blocked macroscopic SV currents in a voltage- and concentration-dependent manner, (b) slowed down activation and deactivation kinetics of the channel, and most interestingly, (c) at concentrations above 10 μM, neomycin shifted the SV activation threshold towards negative membrane potentials, causing a two-phasic activation at high concentrations. Single channel experiments showed that neomycin causes these macroscopic effects by combining a decrease of the single channel conductance with a concomitant increase of the channel's open probability. Our results clearly demonstrate that the SV channel can be activated at physiologically relevant tonoplast potentials in the presence of an organic effector molecule. We therefore propose the existence of a cellular equivalent regulating the activity of the SV channel in vivo.


2019 ◽  
Vol 20 (5) ◽  
pp. 1027 ◽  
Author(s):  
Bijaya Upadhyaya ◽  
Yi Liu ◽  
Moul Dey

Aldehyde dehydrogenase 1 (ALDH1) is a cytosolic marker of cancer stem cells (CSCs), which are a sub-population within heterogeneous tumor cells. CSCs associate with therapy-resistance, self-renewal, malignancy, tumor-relapse, and reduced patient-survival window. ALDH1-mediated aldehyde scavenging helps CSCs to survive a higher level of oxidative stress than regular cancer cells. Cruciferous vegetable-derived phenethyl isothiocyanate (PEITC) selectively induces reactive oxygen species (ROS), leading to apoptosis of cancer cells, but not healthy cells. However, this pro-oxidant role of PEITC in CSCs is poorly understood and is investigated here. In a HeLa CSCs model (hCSCs), the sphere-culture and tumorsphere assay showed significantly enriched ALDHhi CSCs from HeLa parental cells (p < 0.05). Aldefluor assay and cell proliferation assay revealed that PEITC treatments resulted in a reduced number of ALDHhi hCSCs in a concentration-dependent manner (p < 0.05). In the ROS assay, PEITC promoted oxidative stress in hCSCs (p ≤ 0.001). Using immunoblotting and flow cytometry techniques, we reported that PEITC suppressed the cancer-associated transcription factor (Sp1) and a downstream multidrug resistance protein (P-glycoprotein) (both, p < 0.05). Furthermore, PEITC-treatment of hCSCs, prior to xenotransplantation in mice, lowered the in vivo tumor-initiating potential of hCSCs. In summary, PEITC treatment suppressed the proliferation of ALDH1 expressing cancer stem cells as well as key factors that are involved with drug-resistance, while promoting oxidative stress and apoptosis in hCSCs.


2002 ◽  
Vol 283 (1) ◽  
pp. H13-H21 ◽  
Author(s):  
Jin Han ◽  
Nari Kim ◽  
Hyun Joo ◽  
Euiyong Kim

Although ketamine inhibits ATP-sensitive K (KATP) channels in rat ventricular myocytes and abolishes the cardioprotective effect of ischemic preconditioning in isolated rat hearts and in rabbits in in vivo, no studies to date specifically address the precise mechanism of this prevention of ischemic preconditioning by ketamine. This study investigated the mechanism of the blockade of ischemic preconditioning by ketamine in rabbit ventricular myocytes using patch-clamp techniques and in rabbit heart slices model for simulated ischemia and preconditioning. In cell-attached and inside-out patches, ketamine inhibited sarcolemmal KATP channel activities in a concentration-dependent manner. Ketamine decreased the burst duration and increased the interburst duration without a change in the single-channel conductance. In the heart slice model of preconditioning, heart slices preconditioned with a single 5-min anoxia, pinacidil, or diazoxide, followed by 15-min reoxygenation, were protected against subsequent 30-min anoxia and 1-h reoxygenation, and the cardioprotection was blocked by the concomitant presence of ketamine. These data are consistent with the notion that inhibition of sarcolemmal or mitochondrial KATP channels may contribute, at least in part, to the mechanism of the blockade of ischemic preconditioning by ketamine.


2021 ◽  
Author(s):  
Ziyan Xu ◽  
Liru Huang ◽  
Tiantian Zhang ◽  
Yuwei Liu ◽  
Mei Gong ◽  
...  

Abstract Cervical cancer is one of the most common female cancers worldwide, and it is one of the most lethal malignancies of the female reproductive system. Shikonin, a natural pigment of theophyllin, has a variety of biological activities and has shown significant inhibitory effects on a variety of tumours in vitro and in vivo. However, there are few studies on Shikonin in cervical cancer. In the present study, we found that Shikonin inhibited not only the proliferation but also the migration of cervical cancer cells. Our data showed that Shikonin inhibited the proliferation of HeLa and SiHa cells in a concentration- and time-dependent manner. In cervical cancer cells, Shikonin not only inhibited the phosphorylation of FAK, AKT and GSK3β but also inhibited the phosphorylation of FAK, AKT and GSK3β induced by EGF. Further exploring the mechanism, we found that Shikonin could inhibit the proliferation of cervical cancer cells by regulating the phosphorylation of the FAK/AKT/GSK3β pathway. In addition, Shikonin significantly inhibited cell migration and reduced the expression of proteins such as MTA1, TGFβ1 and VEGF. In conclusion, our study elucidated that Shikonin has an inhibitory effect on the proliferation and migration of cervical cancer cells, which may be mediated by the FAK/AKT/GSK3β signalling pathway. Our results suggest that Shikonin has the potential to become a clinical treatment for cervical cancer.


2020 ◽  
Vol 48 (6) ◽  
pp. 030006052092883
Author(s):  
Jie Chen ◽  
Chun-Yan Kang ◽  
Zhao-Xia Niu ◽  
Hui-Cong Zhou ◽  
Hong-Mei Yang

Objective To investigate the in vitro and in vivo anticancer effects of a chalcone against KYSE-4 esophageal cancer cells. Methods A chalcone was synthesized via the molecular hybridization strategy based on the anticancer activity of chalcone and dithiocarbamate scaffolds. The anticancer effects of different concentrations of the chalcone derivative were compared in esophageal cancer cells. Results This chalcone displayed strong inhibitory effects on esophageal cancer cell growth with an IC50 of 1.06 μM in KYSE-4 cells. Analysis of the mechanism revealed that the derivative obviously inhibited KYSE-4 cell growth, migration, and invasion in a concentration-dependent manner. Furthermore, the compound regulated migration-related biomarkers (E-cadherin, N-cadherin, and Slug) and inhibited the Wnt/β-catenin pathway. According to western blotting, this chalcone suppressed the expression of proline-rich protein 11 (PRR11) in a concentration- and time-dependent manner. Conclusions This chalcone might be a leading candidate for suppressing the growth and metastasis of esophageal cancer by downregulating PRR11 expression and inhibiting Wnt/β-catenin signaling.


2021 ◽  
Vol 22 (20) ◽  
pp. 10930
Author(s):  
Shuai Guo ◽  
Xue Bai ◽  
Sai Shi ◽  
Yawen Deng ◽  
Xianjiang Kang ◽  
...  

Lung cancer has the highest rate of incidence and mortality among all cancers. Most chemotherapeutic drugs used to treat lung cancer cause serious side effects and are susceptible to drug resistance. Therefore, exploring novel therapeutic targets for lung cancer is important. In this study, we evaluated the potential of TMEM16A as a drug target for lung cancer. Homoharringtonine (HHT) was identified as a novel natural product inhibitor of TMEM16A. Patch-clamp experiments showed that HHT inhibited TMEM16A activity in a concentration-dependent manner. HHT significantly inhibited the proliferation and migration of lung cancer cells with high TMEM16A expression but did not affect the growth of normal lung cells in the absence of TMEM16A expression. In vivo experiments showed that HHT inhibited the growth of lung tumors in mice and did not reduce their body weight. Finally, the molecular mechanism through which HHT inhibits lung cancer was explored by western blotting. The findings showed that HHT has the potential to regulate TMEM16A activity both in vitro and in vivo and could be a new lead compound for the development of anti-lung-cancer drugs.


2019 ◽  
Vol 26 (7) ◽  
pp. 494-501 ◽  
Author(s):  
Sameer Suresh Bhagyawant ◽  
Dakshita Tanaji Narvekar ◽  
Neha Gupta ◽  
Amita Bhadkaria ◽  
Ajay Kumar Gautam ◽  
...  

Background: Diabetes and hypertension are the major health concern and alleged to be of epidemic proportions. This has made it a numero uno subject at various levels of investigation. Glucosidase inhibitor provides the reasonable option in treatment of Diabetes Mellitus (DM) as it specifically targets post prandial hyperglycemia. The Angiotensin Converting Enzyme (ACE) plays an important role in hypertension. Therefore, inhibition of ACE in treatment of elevated blood pressure attracts special interest of the scientific community. Chickpea is a food legume and seeds contain carbohydrate binding protein- a lectin. Some of the biological properties of this lectin hitherto been elucidated. Methods: Purified by ion exchange chromatography, chickpea lectin was tested for its in vitro antioxidant, ACE-I inhibitory and anti-diabetic characteristic. Results: Lectin shows a characteristic improvement over the synthetic drugs like acarbose (oral anti-diabetic drug) and captopril (standard antihypertensive drug) when, their IC50 values are compared. Lectin significantly inhibited α-glucosidase and α-amylase in a concentration dependent manner with IC50 values of 85.41 ± 1.21 ҝg/ml and 65.05 ± 1.2 µg/ml compared to acarbose having IC50 70.20 ± 0.47 value of µg/ml and 50.52 ± 1.01 µg/ml respectively. β-Carotene bleaching assay showed antioxidant activity of lectin (72.3%) to be as active as Butylated Hydroxylanisole (BHA). In addition, lectin demonstrated inhibition against ACE-I with IC50 value of 57.43 ± 1.20 µg/ml compared to captopril. Conclusion: Lectin demonstrated its antioxidant character, ACE-I inhibition and significantly inhibitory for α-glucosidase and α-amylase seems to qualify as an anti-hyperglycemic therapeutic molecule. The biological effects of chickpea lectin display potential for reducing the parameters of medically debilitating conditions. These characteristics however needs to be established under in vivo systems too viz. animals through to humans.


2021 ◽  
Vol 20 ◽  
pp. 153303382110278
Author(s):  
Yayan Yang ◽  
Qian Feng ◽  
Chuanfeng Ding ◽  
Wei Kang ◽  
Xiufeng Xiao ◽  
...  

Although Epirubicin (EPI) is a commonly used anthracycline for the treatment of breast cancer in clinic, the serious side effects limit its long-term administration including myelosuppression and cardiomyopathy. Nanomedicines have been widely utilized as drug delivery vehicles to achieve precise targeting of breast cancer cells. Herein, we prepared a DSPE-PEG nanocarrier conjugated a peptide, which targeted the breast cancer overexpression protein Na+/K+ ATPase α1 (NKA-α1). The nanocarrier encapsulated the EPI and grafted with the NKA-α1 targeting peptide through the click reaction between maleimide and thiol groups. The EPI was slowly released from the nanocarrier after entering the breast cancer cells with the guidance of the targeting NKA-α1 peptide. The precise and controllable delivery and release of the EPI into the breast cancer cells dramatically inhibited the cells proliferation and migration in vitro and suppressed the tumor volume in vivo. These results demonstrate significant prospects for this nanocarrier as a promising platform for numerous chemotherapy drugs.


2021 ◽  
pp. 1-9
Author(s):  
Huan Guo ◽  
Baozhen Zeng ◽  
Liqiong Wang ◽  
Chunlei Ge ◽  
Xianglin Zuo ◽  
...  

BACKGROUND: The incidence of lung cancer in Yunnan area ranks firstly in the world and underlying molecular mechanisms of lung cancer in Yunnan region are still unclear. We screened a novel potential oncogene CYP2S1 used mRNA microassay and bioinformation database. The function of CYP2S1 in lung cancer has not been reported. OBJECTIVE: To investigate the functions of CYP2S1 in lung cancer. METHODS: Immunohistochemistry and Real-time PCR were used to verify the expression of CYP2S1. Colony formation and Transwell assays were used to determine cell proliferation, invasion and migration. Xenograft assays were used to detected cell growth in vivo. RESULTS: CYP2S1 is significantly up-regulated in lung cancer tissues and cells. Knockdown CYP2S1 in lung cancer cells resulted in decrease cell proliferation, invasion and migration in vitro. Animal experiments showed downregulation of CYP2S1 inhibited lung cancer cell growth in vivo. GSEA analysis suggested that CYP2S1 played functions by regulating E2F targets and G2M checkpoint pathway which involved in cell cycle. Kaplan-Meier analysis indicated that patients with high CYP2S1 had markedly shorter event overall survival (OS) time. CONCLUSIONS: Our data demonstrate that CYP2S1 exerts tumor suppressor function in lung cancer. The high expression of CYP2S1 is an unfavorable prognostic marker for patient survival.


Sign in / Sign up

Export Citation Format

Share Document