scholarly journals Lipid Specific Membrane Interaction of Aptamers and Cytotoxicity

Membranes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 37
Author(s):  
Md. Ashrafuzzaman ◽  
Hanouf A. M. AlMansour ◽  
Maha A. S. AlOtaibi ◽  
Zahid Khan ◽  
Gouse M. Shaik

We aim to discover diagnostic tools to detect phosphatidylserine (PS) externalization on apoptotic cell surface using PS binding aptamers, AAAGAC and TAAAGA, and hence to understand chemotherapy drug efficacy when inducing apoptosis into cancer cells. The entropic fragment-based approach designed aptamers have been investigated to inspect three aspects: lipid specificity in aptamers’ membrane binding and bilayer physical properties-induced regulation of binding mechanisms, the apoptosis-induced cancer cell surface binding of aptamers, and the aptamer-induced cytotoxicity. The liposome binding assays show preferred membrane binding of aptamers due to presence of PS in predominantly phosphatidylcholine-contained liposomes. Two membrane stiffness reducing amphiphiles triton X-100 and capsaicin were found to enhance membrane’s aptamer adsorption suggesting that bilayer physical properties influence membrane’s adsorption of drugs. Microscopic images of fluorescence-tagged aptamer treated LoVo cells show strong fluorescence intensity only if apoptosis is induced. Aptamers find enhanced PS molecules to bind with on the surface of apoptotic over nonapoptotic cells. In cytotoxicity experiments, TAAAGA (over poor PS binding aptamer CAGAAAAAAAC) was found cytotoxic towards RBL cells due to perhaps binding with nonapoptotic externalized PS randomly and thus slowly breaching plasma membrane integrity. In these three experimental investigations, we found aptamers to act on membranes at comparable concentrations and specifically with PS binding manner. Earlier, we reported the origins of actions through molecular mechanism studies—aptamers interact with lipids using mainly charge-based interactions. Lipids and aptamers hold distinguishable charge properties, and hence, lipid–aptamer association follows distinguishable energetics due to electrostatic and van der Waals interactions. We discover that our PS binding aptamers, due to lipid-specific interactions, appear as diagnostic tools capable of detecting drug-induced apoptosis in cancer cells.

2012 ◽  
Vol 287 (42) ◽  
pp. 35341-35350 ◽  
Author(s):  
Alyssa D. Gregory ◽  
Pamela Hale ◽  
David H. Perlmutter ◽  
A. McGarry Houghton

Neutrophil elastase (NE) is a neutrophil-derived serine proteinase with broad substrate specificity. We have recently demonstrated that NE is capable of entering tumor cell endosomes and processing novel intracellular substrates. In the current study, we sought to determine the mechanism by which NE enters tumor cells. Our results show that NE enters into early endosomal antigen-1+ endosomes in a dynamin- and clathrin-dependent but flotillin-1- and caveolin-1-independent fashion. Cathepsin G (but not proteinase-3) also enters tumor endosomes via the same mechanism. We utilized 125I-labeled NE to demonstrate that NE binds to the surface of cancer cells. Incubation of radiolabeled NE with lung cancer cells displays a dissociation constant (Kd) of 284 nm. Because NE is known to bind to heparan sulfate- and chondroitin sulfate-containing proteoglycans, we treated cells with glycanases to remove these confounding factors, which did not significantly diminish cell surface binding or endosomal entry. Thus, NE and CG bind to the surface of cancer cells, presumably to a cell surface receptor, and subsequently undergo clathrin pit-mediated endocytosis.


2013 ◽  
Vol 3 (3) ◽  
pp. 66 ◽  
Author(s):  
Vanessa Hörmann ◽  
Sivanesan Dhandayuthapani ◽  
James Kumi-Diaka ◽  
Appu Rathinavelu

Background: Prostate cancer is the second most common cancer in American men. The development of alternative preventative and/or treatment options utilizing a combination of phytochemicals and chemotherapeutic drugs could be an attractive alternative compared to conventional carcinoma treatments. Genistein isoflavone is the primary dietary phytochemical found in soy and has demonstrated anti-tumor activities in LNCaP prostate cancer cells. Topotecan Hydrochloride (Hycamtin) is an FDA-approved chemotherapy for secondary treatment of lung, ovarian and cervical cancers. The purpose of this study was to detail the potential activation of the intrinsic apoptotic pathway in LNCaP prostate cancer cells through genistein-topotecan combination treatments. Methods: LNCaP cells were cultured in complete RPMI medium in a monolayer (70-80% confluency) at 37ºC and 5% CO2. Treatment consisted of single and combination groups of genistein and topotecan for 24 hours. The treated cells were assayed for i) growth inhibition through trypan blue exclusion assay and microphotography, ii) classification of cellular death through acridine/ ethidium bromide fluorescent staining, and iii) activation of the intrinsic apoptotic pathway through Jc-1: mitochondrial membrane potential assay, cytochrome c release and Bcl-2 protein expression.Results: The overall data indicated that genistein-topotecan combination was significantly more efficacious in reducing the prostate carcinoma’s viability compared to the single treatment options. In all treatment groups, cell death occurred primarily through the activation of the intrinsic apoptotic pathway.Conclusion: The combination of topotecan and genistein has the potential to lead to treatment options with equal therapeutic efficiency as traditional chemo- and radiation therapies, but lower cell cytotoxicity and fewer side effects in patients. Key words: topotecan; genistein; intrinsic apoptotic cell death


2020 ◽  
Vol 20 (5) ◽  
pp. 372-381
Author(s):  
Yoshiaki Sato ◽  
Hironori Yoshino ◽  
Eichi Tsuruga ◽  
Ikuo Kashiwakura

Background: Retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs) play key roles in the antiviral response, but recent works show that RLR activation elicits anticancer activity as well, including apoptosis. Previously, we demonstrated that the anticancer activity of the RLR agonist Poly(I:C)-HMW/LyoVec™ [Poly(I:C)-HMW] against human lung cancer cells was enhanced by cotreatment with ionizing radiation (IR). In addition, cotreatment with Poly(I:C)-HMW and IR induced apoptosis in a Fas-independent manner, and increased Fas expression on the cell surface. Objective: The current study investigated the resultant hypothesis that Fas ligand (FasL) may enhance apoptosis in lung cancer cells cotreated with Poly(I:C)-HMW+IR. Methods: FasL was added into culture medium at 24 h following cotreatment with Poly(I:C)- HMW+IR, after upregulation of cell surface Fas expression on human lung cancer cells A549 and H1299 have already been discussed. Results: FasL enhanced the apoptosis of A549 and H1299 cells treated with Poly(I:C)-HMW+IR. Similarly, IR alone - and not Poly(I:C)-HMW - resulted in the upregulation of cell surface Fas expression followed by a high response to FasL-induced apoptosis, thus suggesting that the high sensitivity of cells treated with Poly(I:C)-HMW+IR to FasL-induced apoptosis resulted from the cellular response to IR. Finally, knockdown of Fas by siRNA confirmed that the high response of treated cells to FasL-induced apoptosis is dependent on Fas expression. Conclusion: In summary, the present study indicates that upregulated Fas expression following cotreatment with Poly(I:C)-HMW and IR is responsive to FasL-induced apoptosis, and a combination of RLR agonist, IR, and FasL could be a potential promising cancer therapy.


2020 ◽  
Vol 13 ◽  
Author(s):  
Milad Ashrafizadeh ◽  
Saeed Samarghandian ◽  
Kiavash Hushmandi ◽  
Amirhossein Zabolian ◽  
Md Shahinozzaman ◽  
...  

Background: Ischemia/reperfusion (I/R) injury is a serious pathologic event that occurs due to restriction in blood supply to an organ, followed by hypoxia. This condition leads to enhanced levels of pro-inflammatory cytokines such as IL-6 and TNF-, and stimulation of oxidative stress via enhancing reactive oxygen species (ROS) levels. Upon reperfusion, blood supply increases, but it deteriorates condition, and leads to generation of ROS, cell membrane disruption and finally, cell death. Plant derived-natural compounds are well-known due to their excellent antioxidant and anti-inflammatory activities. Quercetin is a flavonoid exclusively found in different vegetables, herbs, and fruits. This naturally occurring compound possesses different pharmacological activities making it appropriate option in disease therapy. Quercetin can also demonstrate therapeutic effects via affecting molecular pathways such as NF-B, PI3K/Akt and so on. Methods: In the present review, we demonstrate that quercetin administration is beneficial in ameliorating I/R injury via reducing ROS levels, inhibition of inflammation, and affecting molecular pathways such as TLR4/NF-B, MAPK and so on. Results and conclusion: Quercetin can improve cell membrane integrity via decreasing lipid peroxidation. Apoptotic cell death is inhibited by quercetin via down-regulation of Bax, and caspases, and upregulation of Bcl-2. Quercetin is able to modulate autophagy (inhibition/induction) in decreasing I/R injury. Nanoparticles have been applied for delivery of quercetin, enhancing its bioavailability and efficacy in alleviation of I/R injury. Noteworthy, clinical trials have also confirmed the capability of quercetin in reducing I/R injury.


2016 ◽  
Vol 129 (22) ◽  
pp. 4238-4251 ◽  
Author(s):  
Linyu Zhu ◽  
Xiahui Xiong ◽  
Yongsoon Kim ◽  
Naomi Okada ◽  
Fei Lu ◽  
...  

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yu-An Chen ◽  
Yong-Da Sie ◽  
Tsung-Yun Liu ◽  
Hsiang-Ling Kuo ◽  
Pei-Yi Chou ◽  
...  

AbstractMetastatic cancer cells are frequently deficient in WWOX protein or express dysfunctional WWOX (designated WWOXd). Here, we determined that functional WWOX-expressing (WWOXf) cells migrate collectively and expel the individually migrating WWOXd cells. For return, WWOXd cells induces apoptosis of WWOXf cells from a remote distance. Survival of WWOXd from the cell-to-cell encounter is due to activation of the survival IκBα/ERK/WWOX signaling. Mechanistically, cell surface epitope WWOX286-299 (repl) in WWOXf repels the invading WWOXd to undergo retrograde migration. However, when epitope WWOX7-21 (gre) is exposed, WWOXf greets WWOXd to migrate forward for merge. WWOX binds membrane type II TGFβ receptor (TβRII), and TβRII IgG-pretreated WWOXf greet WWOXd to migrate forward and merge with each other. In contrast, TβRII IgG-pretreated WWOXd loses recognition by WWOXf, and WWOXf mediates apoptosis of WWOXd. The observatons suggest that normal cells can be activated to attack metastatic cancer cells. WWOXd cells are less efficient in generating Ca2+ influx and undergo non-apoptotic explosion in response to UV irradiation in room temperature. WWOXf cells exhibit bubbling cell death and Ca2+ influx effectively caused by UV or apoptotic stress. Together, membrane WWOX/TβRII complex is needed for cell-to-cell recognition, maintaining the efficacy of Ca2+ influx, and control of cell invasiveness.


2021 ◽  
Vol 22 (15) ◽  
pp. 8117
Author(s):  
Nunzia D’Onofrio ◽  
Elisa Martino ◽  
Luigi Mele ◽  
Antonino Colloca ◽  
Martina Maione ◽  
...  

Understanding the mechanisms of colorectal cancer progression is crucial in the setting of strategies for its prevention. δ-Valerobetaine (δVB) is an emerging dietary metabolite showing cytotoxic activity in colon cancer cells via autophagy and apoptosis. Here, we aimed to deepen current knowledge on the mechanism of δVB-induced colon cancer cell death by investigating the apoptotic cascade in colorectal adenocarcinoma SW480 and SW620 cells and evaluating the molecular players of mitochondrial dysfunction. Results indicated that δVB reduced cell viability in a time-dependent manner, reaching IC50 after 72 h of incubation with δVB 1.5 mM, and caused a G2/M cell cycle arrest with upregulation of cyclin A and cyclin B protein levels. The increased apoptotic cell rate occurred via caspase-3 activation with a concomitant loss in mitochondrial membrane potential and SIRT3 downregulation. Functional studies indicated that δVB activated mitochondrial apoptosis through PINK1/Parkin pathways, as upregulation of PINK1, Parkin, and LC3B protein levels was observed (p < 0.0001). Together, these findings support a critical role of PINK1/Parkin-mediated mitophagy in mitochondrial dysfunction and apoptosis induced by δVB in SW480 and SW620 colon cancer cells.


Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2004
Author(s):  
Prabhu Thirusangu ◽  
Christopher L. Pathoulas ◽  
Upasana Ray ◽  
Yinan Xiao ◽  
Julie Staub ◽  
...  

We previously reported that the antimalarial compound quinacrine (QC) induces autophagy in ovarian cancer cells. In the current study, we uncovered that QC significantly upregulates cathepsin L (CTSL) but not cathepsin B and D levels, implicating the specific role of CTSL in promoting QC-induced autophagic flux and apoptotic cell death in OC cells. Using a Magic Red® cathepsin L activity assay and LysoTracker red, we discerned that QC-induced CTSL activation promotes lysosomal membrane permeability (LMP) resulting in the release of active CTSL into the cytosol to promote apoptotic cell death. We found that QC-induced LMP and CTSL activation promotes Bid cleavage, mitochondrial outer membrane permeabilization (MOMP), and mitochondrial cytochrome-c release. Genetic (shRNA) and pharmacological (Z-FY(tBU)-DMK) inhibition of CTSL markedly reduces QC-induced autophagy, LMP, MOMP, apoptosis, and cell death; whereas induced overexpression of CTSL in ovarian cancer cell lines has an opposite effect. Using recombinant CTSL, we identified p62/SQSTM1 as a novel substrate of CTSL, suggesting that CTSL promotes QC-induced autophagic flux. CTSL activation is specific to QC-induced autophagy since no CTSL activation is seen in ATG5 knockout cells or with the anti-malarial autophagy-inhibiting drug chloroquine. Importantly, we showed that upregulation of CTSL in QC-treated HeyA8MDR xenografts corresponds with attenuation of p62, upregulation of LC3BII, cytochrome-c, tBid, cleaved PARP, and caspase3. Taken together, the data suggest that QC-induced autophagy and CTSL upregulation promote a positive feedback loop leading to excessive autophagic flux, LMP, and MOMP to promote QC-induced cell death in ovarian cancer cells.


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