The apoptotic pathways in the curcumin analog MHMD-induced lung cancer cell death and the essential role of actin polymerization during apoptosis

SLC26A4 Mutation Promotes Cell Apoptosis by Inducing Pendrin Transfer, Reducing Cl- Transport, and Inhibiting PI3K/Akt/mTOR Pathway

Objective. Pendrin is encoded by SLC26A4, which is expressed in the apical membrane of inner ear epithelial cells and drives chloride reabsorption in the apical septum. In the inner ear, pendrin dysfunction and hypofunctional mutations lead to vestibular aqueduct (EVA) enlargement and sensory neural hearing loss. Mutations in SLC26A4 are a common reason of deafness. However, the underlying mechanisms of SLC26A4 mutants in hearing loss remain unknown. Methods. In the present study, pEGFP-N1 carrying wild-type and mutant SLC26A4 (c.85G>A, c.2006A>T, and c.853G>A) were transfected into HEK-293T cells. GFP fluorescence and GFP levels were determined. SLC26A4 mRNA levels were examined by quantitative real-time polymerase chain reaction (qRT-PCR). Then, the expression of chloride intracellular channel 1 (CLIC1) and CLIC2 was measured by Immunofluorescence assay. Intracellular chloride concentration and apoptotic rate were analyzed by flow cytometry. The levels of membrane/cytoplasmic pendrin, apoptosis-associated proteins, and the PI3K/Akt/mTOR pathway members were determined by Western blot. Results. Constructed SLC26A4 mutant 1 (c.85G>A), SLC26A4 mutant 2 (c.2006A>T), and SLC26A4 mutant 3 (c.853G>A). The wild-type and 3 mutations were stably expressed in HEK-293T. SLC26A4 mRNA expression was significantly increased after transfection with wild-type SLC26A4 and mutant SLC26A4 compared with the untransfected vector group ( $P<0.01$ ). Compared with the vector group, the expression levels of membrane pendrin, cytoplasmic pendrin, CLIC1, CLIC2, Bcl-2, p-PI3K, p-Akt, and p-mTOR were upregulated. Compared with the vector group, the chloride concentration, cell apoptotic rate, and the expression levels of caspase-3, caspase-9, and Bax were downregulated. Compared with the vector group, the above effects of SLC26A4 were reversed after the SLC26A4 mutant. Conclusion. After SLC26A4 mutation, pendrin was transferred from the membrane, the chloride intracellular channel function was reduced, and the excessive accumulation of chloride in the cytoplasm induced cell apoptosis by inhibited PI3K/Akt/mTOR pathway phosphorylation.

Recent Advances in Curcumin Treated Non-Small Cell Lung Cancers: An Impetus of Pleiotropic Traits and Nanocarrier Aided Delive ry

Characterized by the abysmal 18% five year survival chances, non-small cell lung cancers (NSCLCs) claim more than half of their sufferers within the first year of being diagnosed. Advances in biomedical engineering and molecular characterization have reduced the NSCLC diagnosis via timid screening of altered gene expressions and impaired cellular responses. While targeted chemotherapy remains a major option for NSCLCs complications, delayed diagnosis, and concurrent multi-drug resistance remain potent hurdles in regaining normalcy, ultimately resulting in relapse. Curcumin administration presents a benign resolve herein, via simultaneous interception of distinctly expressed pathological markers through its pleiotropic attributes and enhanced tumor cell internalization of chemotherapeutic drugs. Studies on NSCLC cell lines and related xenograft models have revealed a consistent decline in tumor progression owing to enhanced chemotherapeutics cellular internalization via co-delivery with curcumin. This presents an optimum readiness for screening the corresponding effectiveness in clinical subjects. Curcumin is delivered to NSCLC cells either (i) alone, (ii) in stoichiometrically optimal combination with chemotherapeutic drugs, (iii) through nanocarriers, and (iv) nanocarrier co-delivered curcumin and chemotherapeutic drugs. Nanocarriers protect the encapsulated drug from accidental and non-specific spillage. A unanimous trait of all nanocarriers is their moderate drug-interactions, whereby native structural expressions are not tampered. With such insights, this article focuses on the implicit NSCLC curative mechanisms viz-a-viz, free curcumin, nanocarrier delivered curcumin, curcumin + chemotherapeutic drug and nanocarrier assisted curcumin + chemotherapeutic drug delivery.

Selective mediation of ovarian cancer SKOV3 cells death by pristine carbon quantum dots/Cu2O composite through targeting matrix metalloproteinases, angiogenic cytokines and cytoskeleton

It was shown that some nanomaterials may have anticancer properties, but lack of selectivity is one of challenges, let alone selective suppression of cancer growth by regulating the cellular microenvironment. Herein, we demonstrated for the first time that carbon quantum dots/Cu2O composite (CQDs/Cu2O) selectively inhibited ovarian cancer SKOV3 cells by targeting cellular microenvironment, such as matrix metalloproteinases, angiogenic cytokines and cytoskeleton. The result was showed CQDs/Cu2O possessed anticancer properties against SKOV3 cells with IC50 = 0.85 μg mL-1, which was approximately threefold lower than other tested cancer cells and approximately 12-fold lower than normal cells. Compared with popular anticancer drugs, the IC50 of CQDs/Cu2O was approximately 114-fold and 75-fold lower than the IC50 of commercial artesunate (ART) and oxaliplatin (OXA). Furthermore, CQDs/Cu2O possessed the ability to decrease the expression of MMP-2/9 and induced alterations in the cytoskeleton of SKOV3 cells by disruption of F-actin. It also exhibited stronger antiangiogenic effects than commercial antiangiogenic inhibitor (SU5416) through down-regulating the expression of VEGFR2. In addition, CQDs/Cu2O has a vital function on transcriptional regulation of multiple genes in SKOV3 cells, where 495 genes were up-regulated and 756 genes were down-regulated. It is worth noting that CQDs/Cu2O also regulated angiogenesis-related genes in SKOV3 cells, such as Maspin and TSP1 gene, to suppress angiogenesis. Therefore, CQDs/Cu2O selectively mediated of ovarian cancer SKOV3 cells death mainly through decreasing the expression of MMP-2, MMP-9, F-actin, and VEGFR2, meanwhile CQDs/Cu2O caused apoptosis of SKOV3 via S phase cell cycle arrest. These findings reveal a new application for the use of CQDs/Cu2O composite as potential therapeutic interventions in ovarian cancer SKOV3 cells.

Pristine Cu-MOF Induces Mitotic Catastrophe and Alterations of Gene Expression and Cytoskeleton in Ovarian Cancer Cells

Metals-organic frameworks (MOFs) have been widely explored in biomedicine, mostly in drug delivery, biosensing, and bioimaging due to their large surface area, tunable porosity, readily chemical functionalization, and good biocompatibility. However, the underlining cellular mechanisms controlling the process for MOF cytotoxicity remains almost completely unknown. Here, we demonstrate that pristine Cu-MOF without any loaded drug selectively inhibited ovarian cancer mainly through promoting tubulin polymerization and destroying the cell actin cytoskeleton (F-actin) to trigger the mitotic catastrophe, accompanying by conventional programmed cell death. To our knowledge, this is the first report claiming that mitotic catastrophe may be an explaining mechanism of MOF cytotoxicity. Cu-MOF with an intrinsic protease-like activity also hydrolyzed cellular cytoskeleton proteins (F-actin). The RNA sequencing data indicated the differential expressional mRNA of cell proliferation and actin cytoskeleton (ACTA2, ACTN3, FSCN2, and SCIN) and mitotic spindles (PLK1 and TPX2) related genes. We found that Cu-MOF as a promising candidate in the disruption of cellular cytoskeleton and the change of the gene expression could be actin altering and antimitotic agents against cancer cells, allowing for fundamental biological and biophysical studies of MOFs.

Versatile role of curcumin and its derivatives in lung cancer therapy

Lung cancer is a main cause of death all over the world with a high incidence rate. Metastasis into neighboring and distant tissues as well as resistance of cancer cells to chemotherapy demand novel strategies in lung cancer therapy. Curcumin is a naturally occurring nutraceutical compound derived from Curcuma longa (turmeric) that has great pharmacological effects, such as anti-inflammatory, neuroprotective, and antidiabetic. The excellent antitumor activity of curcumin has led to its extensive application in the treatment of various cancers. In the present review, we describe the antitumor activity of curcumin against lung cancer. Curcumin affects different molecular pathways such as vascular endothelial growth factors, nuclear factor-κB (NF-κB), mammalian target of rapamycin, PI3/Akt, microRNAs, and long noncoding RNAs in treatment of lung cancer. Curcumin also can induce autophagy, apoptosis, and cell cycle arrest to reduce the viability and proliferation of lung cancer cells. Notably, curcumin supplementation sensitizes cancer cells to chemotherapy and enhances chemotherapy-mediated apoptosis. Curcumin can elevate the efficacy of radiotherapy in lung cancer therapy by targeting various signaling pathways, such as epidermal growth factor receptor and NF-κB. Curcumin-loaded nanocarriers enhance the bioavailability, cellular uptake, and antitumor activity of curcumin. The aforementioned effects are comprehensively discussed in the current review to further direct studies for applying curcumin in lung cancer therapy.

Therapeutic potentials of curcumin in the treatment of non-small-cell lung carcinoma

Non-small-cell lung carcinoma (NSCLC) is one of the most lethal malignancies that include more than 80% of lung cancer cases worldwide. During the past decades, plants and plant-derived products have attracted great interest in the treatment of various human diseases. Curcumin, the turmeric isolated natural phenolic compound, has shown a promising chemo-preventive and anticancer agent. Numerous studies have shown that curcumin delays the initiation and progression of NSCLC by affecting a wide range of molecular targets and cell signalling pathways including NF-kB, Akt, MAPKS, BCL-2, ROS and microRNAs (miRNAs). However, the poor oral bioavailability and low chemical stability of curcumin remain as major challenges in the utilisation of this compound as a therapeutic agent. Different analogs of curcumin and new delivery systems (e.g., micelles, nanoparticles and liposomes) provided promising solutions to overcome these obstacles and improve curcumin pharmacokinetic profile. The present review focuses on current reported studies about anti-NSCLC effects of curcumin. NSCLC involved miRNAs whose expression is regulated by curcumin has also been discussed. Furthermore, recent researches on the use of curcumin analogs and delivery systems to enhance the curcumin benefits in NSCLC are also described.

GPR75 receptor mediates 20-HETE-signaling and metastatic features of androgen-insensitive prostate cancer cells

PURPOSE

Recent studies have shown that 20-hydroxyeicosatetraenoic acid (20-HETE) is a key molecule in sustaining androgen-mediated prostate cancer cell survival. Thus, the aim of this study was to determine whether 20-HETE can affect the metastatic potential of androgen-insensitive prostate cancer cells, and the implication of the newly described 20-HETE receptor, GPR75, in mediating these effects.

METHODS

The expression of GPR75, protein phosphorylation, actin polymerization and protein distribution were assessed by western blot and/or fluorescence microscopy. Additionally, in vitro assays including epithelial-mesenchymal transition (EMT), metalloproteinase-2 (MMP-2) activity, scratch wound healing, transwell invasion and soft agar colony formation were used to evaluate the effects of 20-HETE agonists/antagonists or GPR75 gene silencing on the aggressive features of PC-3 cells.

RESULTS

20-HETE (0.1 nM) promoted the acquisition of a mesenchymal phenotype by increasing EMT, the release of MMP-2, cell migration and invasion, actin stress fiber formation and anchorage-independent growth. Also, 20-HETE augmented the expression of HIC-5, the phosphorylation of EGFR, NF-κB, AKT and p-38 and the intracellular redistribution of p-AKT and PKCα. These effects were impaired by GPR75 antagonism and/or silencing. Accordingly, the inhibition of 20-HETE formation with N-hydroxy-N'-(4-n-butyl-2-methylphenyl) formamidine (HET0016) elicited the opposite effects.

CONCLUSIONS

The present results show for the first time the involvement of the 20-HETE-GPR75 receptor in the activation of intracellular signaling known to be stimulated in cell malignant transformations leading to the differentiation of PC-3 cells towards a more aggressive phenotype. Targeting the 20-HETE/GPR75 pathway is a promising and novel approach to interfere with prostate tumor cell malignant progression.

Binding of Red Clover Isoflavones to Actin as A Potential Mechanism of Anti-Metastatic Activity Restricting the Migration of Cancer Cells

Actin functions are crucial for the ability of the cell to execute dynamic cytoskeleton reorganization and movement. Nutraceuticals that form complexes with actin and reduce its polymerization can be used in cancer therapy to prevent cell migration and metastasis of tumors. The aim of this study was to evaluate the ability of isoflavones to form complexes with actin. Docking simulation and isothermal titration calorimetry were used for this purpose. The formation of complexes by hydrogen bonds, hydrophobic and π-π interactions was demonstrated. Interactions occurred at the ATP binding site, which may limit the rotation of the actin molecule observed during polymerization and also at the site responsible for contacts during polymerization, reducing the ability of the molecule to form filaments. The greatest therapeutic potential was demonstrated by isoflavones occurring in red clover sprouts, i.e., biochanin A and formononetin, being methoxy derivatives of genistein and daidzein.

A novel synthetic curcumin derivative MHMM-41 induces ROS-mediated apoptosis and migration blocking of human lung cancer cells A549

Many curcumin derivatives were produced and characterized to improve the physiochemical instability and low solubility of curcumin. Here, MHMM-41 (a novel curcumin derivative) was used to treat non-small lung cancer cells of human (known as A549) and to identify its anti-proliferative activities. Our results suggested that MHMM-41 display no significant cytotoxicity toward normal human lung fibroblast 2BS cells and mouse embryonal fibroblast 3T3 cells. It also had better anti-proliferative activity than curcumin in A549 cells. Further study showed a significant increase of apoptotic A549 cells in time and dose dependent manners. The activation of caspase-3, 8, 9, 12, Bax and PARP proteins were detected. Consequently, MHMM-41 treatment led to the reduction of mitochondrial membrane potential by JC-1 staining and characteristic nuclei fragmentation by Hoechst 33,342 staining, respectively, which showed that A549 apoptosis could be triggered by the extrinsic and intrinsic mitochondrial pathways. The release of ROS was also measured by flow cytometry. Further, wound healing assay and transwell experiments confirmed the anti-migration ability of MHMM-41 in A549 cells. Our current study suggested the potentials of MHMM-41 to inhibit the A549 cell proliferation. However, the intensive mechanical research on the anti-proliferation of A549 cells needs to be performed in the future.

Oxymatrine induces A549 human non‑small lung cancer cell apoptosis via extrinsic and intrinsic pathways

Oxymatrine is one of the primary natural compounds extracted from the Sophora flavescens, and has been reported to exhibit numerous pharmacological properties including cancer‑preventive and anti‑cancer effects, however the mechanisms as to how oxymatrine exhibits anti‑proliferative activity in non‑small cell lung carcinoma cells remains uncertain. The present study aimed to explore the mechanism of its anti‑cancer effect, and whether it is due to apoptosis induction and anti‑migration in the A549 lung cancer cell line. Detection of morphological alterations, MTT analysis, Hoechst/propidium iodide dual staining and terminal deoxynucleotidyl transferase dUTP nick end labeling assays verified that oxymatrine induced A549 cell apoptosis. The caspase pan‑inhibitor z‑VAD‑FMK resulted in disappearance of oxymatrine‑elicited nuclei fragmentation via Hoechst 33342 staining. JC‑1 staining demonstrated a decrease in mitochondrial membrane potential which further verified the induction of apoptosis by oxymatrine. The caspase‑3, 8 and 9 activities of oxymatrine‑treated cells were activated, which suggested that extrinsic and intrinsic apoptotic pathways were involved in the anti‑proliferative effects of oxymatrine in A549 cells. Furthermore, the wound healing assay verified the anti‑migratory effects of oxymatrine in A549 cells.

Cucurmin, anticancer, & antitumor perspectives: A comprehensive review

Cucurmin, a naturally yellow component isolated from turmeric, ability to prevent various life-style related disorders. The current review article mainly emphasizes on different anticancer perspectives of cucurmin, i.e., colon, cervical, uterine, ovarian, prostate head and neck, breast, pulmonary, stomach and gastric, pancreatic, bladder oral, oesophageal, and bone cancer. It holds a mixture of strong bioactive molecule known as cucurminoids that has ability to reduce cancer/tumor at initial, promotion and progression stages of tumor development. In particular, these compounds block several enzymes required for the growth of tumors and may therefore involve in tumor treatments. Moreover, it modulates an array of cellular progressions, i.e., nitric oxide synthetase activity, protein kinase C activity, epidermal growth factor (EGF) receptor intrinsic kinase activity, nuclear factor kappa (NF-kB) activity, inhibiting lipid peroxidation and production of reactive oxygen species. However, current manuscript summarizes most of the recent investigations of cucurmin but still further research should be conducted to explore the role of curcumin to mitigate various cancers.

Geranylgeranylacetone induces apoptosis via the intrinsic pathway in human melanoma cells

The aim of this study was to test the anti-cancer effects of geranylgeranylacetone (GGA), an isoprenoid compound, on human melanoma cells. Human melanoma cell lines G361, SK-MEL-2, and SK-MEL-5 were treated with GGA at various doses (1-100μM). Cell viability was measured by crystal violet assay. Western blot analysis was adopted to detect marker proteins of apoptosis. GGA significantly reduced the viability of G361, SK-MEL-2, and SK-MEL-5 human melanoma cells at concentrations above 10μM. Western blot analysis showed the phosphorylation of p38 MAPK and c-Jun N-terminal kinase (JNK) after GGA treatment, as well as activation of caspase-9, caspase-3, and poly(ADP-ribose) polymerase (PARP) cleavage. GGA also induced p53 and Bax expression, but did not affect expression of Bcl-2 and MITF. These findings suggest that GGA induces apoptosis through the intrinsic pathway. Accordingly, GGA should be considered for further development as a potential agent for melanoma.