Protein B-cell Lymphoma Research Articles

Anticancer Effects of Gold Nanoparticles by Inducing Apoptosis in Bladder Cancer 5637 Cells

Nanotechnology is a developing and revolutionary science that has been widely recommended for diagnosis and treatment of cancer. Among the various nanoparticles used in nanotechnology, gold nanoparticles (AuNPs) have attracted much attentions due to their promising anticancer properties. Despite the potential advantages of AuNPs, their apoptotic and anti-angiogenic effects have not yet been reported on human bladder cancer 5637 cells. This motivated us to evaluate (reactive oxygen species) ROS-mediated apoptosis in 5637 cells. For this task, inhibitory effect of AuNPs was investigated after 24-h exposure to different concentrations of AuNPs by MTT assay. Also, apoptosis level was assessed by ROS production, flow cytometry, and Hoechst 33,258 staining. Besides, mRNA expression of B-cell lymphoma protein 2 (Bcl-2), Bcl-2-associated X (Bax), vascular endothelial growth factor A (VEGFA) genes, and caspase-3,7 activity were determined by qRT-PCR and colorimetric assay, respectively. Moreover, migration rate was evaluated by wound healing assay. MTT results demonstrate that AuNPs can reduce 5637-cell viability in a dose-dependent manner, while fluorimetric assay data show significant increased ROS production in 25 and 50µg/ml-treated cells. It is also observed that AuNPs lead to Bax overexpression and downregulation of Bcl-2 and VEGFA genes. In line with this, flow cytometry results show increased levels of apoptosis in 25 and 50µg/ml AuNP-treated cells (p < 0.05). Similarly, Hoechst staining indicates a remarkable increase in cells with apoptotic morphology after treating with AuNPs. Overall, our findings show that AuNPs significantly provoke ROS production, induce apoptosis, and suppress cell migration in bladder cancer 5637 cells.

Antiapoptotic and antioxidative effects of cerium oxide nanoparticles on the testicular tissues of streptozotocin-induced diabetic rats: An experimental study.

BackgroundCerium dioxide nanoparticles (CNPs) due to the antidiabetic and antioxidant activities are proposed for the treatment of oxidative stress-associated diseases.ObjectiveTo examine the impact of CNPs on hyperglycemia-induced apoptosis and oxidative stress in the testis of diabetic rats.Materials and MethodsTwenty-four male rats were divided into four groups (n = 6/each) as diabetic rats, CNPs group, diabetic + CNPs rats, and controls. The control group was fed only mouse food and water. Rats became diabetic through receiving streptozotocin (STZ) 60 mg/kg. CNPs were given to the rats at a dose of 30 mg/kg daily for 2 wk. Malondialdehyde and total thiol group (TTG) levels were measured using spectrofluorometer. Expression of b-cell lymphoma protein 2-associated X protein (BAX) and b-cell lymphoma protein 2 (Bcl-2) were investigated using quantitative real-time polymerase chain reaction. Western blot analysis was used to examine caspase 3 protein levels.ResultsThe content of malondialdehyde significantly increased in the STZ-diabetic rats, while TTG levels demonstrated a remarkable decrease. Caspase-3, BAX, and BAX/Bcl-2 mRNA ratio raised significantly in the STZ-diabetic rats. On the other hand, Bcl-2 mRNA levels reduced in the testis of diabetic rats (p = 0.006). Intervention with CNPs caused a substantial increase in the TTG levels, while the malondialdehyde contents, caspase-3, BAX levels, as well as BAX/Bcl-2 mRNA ratio were considerably decreased following CNPs treatment. Administration of CNPs increased mRNA levels of Bcl-2 (p 0.0001).ConclusionCNPs treatment attenuates testicular apoptosis and oxidative stress induced by diabetes. This nanoparticle might be suggested for the treatment of diabetes-associated reproductive disorders.

Discovery of potent and selective Bcl-2 inhibitors with acyl sulfonamide skeleton

The antiapoptotic protein B-cell lymphoma 2 (Bcl-2), overexpressed in many tumor cells, is an attractive target for potential small molecule anticancer drug discovery. Herein, a series of novel derivatives with acyl sulfonamide skeleton was designed, synthesized, and evaluated as Bcl-2 inhibitors by means of bioisosteric replacement. Among them, compound 24g demonstrated equal efficient inhibition activity against RS4;11 cell line compared to positive control ABT-199. Moreover, it showed improved selectivity for Bcl-2/Bcl-xL inhibitory effects, the result of which was consistent with platelet toxicity studies. In vitro and in vivo pharmacokinetic properties of compound 24g had a significantly improved profiles. Taken together, those results suggested it as a promising candidate for development of novel therapeutics targeting Bcl-2 in cancer.

Arsenic trioxide induces expression of BCL-2 expression via NF-κB and p38 MAPK signaling pathways in BEAS-2B cells during apoptosis

Inorganic arsenic compounds are environmental toxicants that are widely distributed in air, water, and food. B-cell lymphoma 2 (BCL-2) is an oncogene having anti-apoptotic function. In this study, we clarify that BCL-2, as a pro-apoptotic factor, participates in As2O3-induced apoptosis in BEAS-2B cells. Specifically, As2O3 stimulated the expression of BCL-2 mRNA and protein in a dose-dependent manner which was highly accumulated in the nucleus of BEAS-2B cell together with chromatin condensation and DNA fragmentation during apoptosis. Mechanistically, the process described above is mediated through the NF-κB and p38 MAPK signaling pathways, which can be abated by corresponding inhibitors, such as BAY11–7082 and SB203580, respectively. Additionally, BAY11–7082, actinomycin D, and cycloheximide have inhibitory effects on As2O3-induced expression of BCL-2 mRNA and protein, and restore the cell viability of BEAS-2B cells. Suppression of BCL-2 protein activation by ABT-199 also restored viability of BEAS-2B cell in As2O3-induced apoptosis. Furthermore, As2O3 increased the level of BCL-2 phosphorylation. These results suggest that in BEAS-2B cells, As2O3-induced apoptosis is mainly dominated by BCL-2 upregulation, nuclear localization and phosphorylation. The study presented here provides a novel insight into the molecular mechanism of BCL-2-induced apoptosis.

New phthalimide analog ameliorates CCl4 induced hepatic injury in mice via reducing ROS formation, inflammation, and apoptosis.

The present study aimed, for the first time, to examine the biochemical effects of new phthalimide analog, 2-[2-(2-Bromo-1-ethyl-1H-indol-3-yl) ethyl]-1H-isoindole-1,3(2H)-dione, compared to thalidomide drug against liver injury induced in mice. Carbon tetrachloride was intraperitoneal injected in mice for 6 consecutive weeks at a dose of 0.4mL/kg twice a week for liver injury induction. Histopathological examination, levels of malondialdehyde, nitric oxide, and antioxidant enzymes were determined. Additionally, the protein levels of vascular endothelial growth factor, proliferating cell nuclear protein, tumor necrosis factor-alfa, nuclear factor kappa B-p65, B-cell lymphoma-2, and cysteine-aspartic acid protease-3 were determined. Results revealed that the treatment with phthalimide analog improved the detected liver damage and presented an obvious antioxidant activity through decreasing malondialdehyde and nitric oxide levels accompanied by increasing the levels of the antioxidant enzymes. Furthermore, the analog exhibited an effective inhibitory activity towards the studied protein expressions in liver tissues. Moreover, the B-cell lymphoma-2 protein level was increased while the cysteine-aspartic acid protease-3 level was suppressed after the treatment with phthalimide analog. Together, these results propose that phthalimide analog can ameliorate carbon tetrachloride-induced liver injury in mice through its potent inhibition mediating effect in oxidative stress, inflammation, and apoptosis mechanisms.

Circ-PRKCI Alleviates Lipopolysaccharide-induced Human Kidney 2 Cell Injury by Regulating miR-106b-5p/GAB1 Axis.

Circular RNAs act as vital regulators in diverse diseases. However, the investigation of circular RNAs in sepsis-engendered acute kidney injury remains dismal. We aimed to explore the effects of circular RNA protein kinase C iota (circ-PRKCI) in lipopolysaccharide (LPS)-mediated HK2 cell injury. Sepsis in vitro model was established by LPS treatment. Quantitative real-time polymerase chain reaction assay was conducted for determining the levels of circ-PRKCI, microRNA-106b-5p (miR-106b-5p), and growth factor receptor binding 2-associated binding protein 1 (GAB1). Cell viability and apoptosis were evaluated using Cell Counting Kit-8 assay and flow cytometry analysis, respectively. The concentrations of interleukin-6, interleukin-1β, and tumor necrosis factor-α were measured with enzyme-linked immunosorbent assay kits. The levels of oxidative stress markers were determined using relevant commercial kits. Western blot assay was conducted for B-cell lymphoma-2 (Bcl-2), BCL2-Associated X (Bax), and GAB1 protein levels. Dual-luciferase reporter assay and RNA immunoprecipitation assay were used to verify the association between miR-106b-5p and circ-PRKCI or GAB1. We found the Circ-PRKCI level was decreased in sepsis patients and LPS-induced human kidney 2 (HK-2) cells. LPS exposure inhibited cell viability and facilitated apoptosis, inflammation, and oxidative stress in HK-2 cells. Circ-PRKCI overexpression abrogated the effects of LPS on cell apoptosis, inflammation, and oxidative stress in HK-2 cells. Furthermore, circ-PRKCI was identified as the sponge for miR-106b-5p to positively regulate GAB1 expression. Overexpression of circ-PRKCI relieved LPS-mediated HK-2 cell damage by sponging miR-106b-5p. MiR-106b-5p inhibition ameliorated the injury of HK-2 cells mediated by LPS, whereas GAB1 knockdown reversed the effect. Collectively, Circ-PRKCI overexpression attenuated LPS-induced HK-2 cell injury by regulating miR-106b-5p/GAB1 axis.

Application of Perfluorooctylbromide Nanoparticles with Ulinastatin for Early Brain Injury Caused by Carbon Monoxide Poisoning

ABSTRACTThis study aimed to explore the mechanism of perfluorooctylbromide (PFOB) nanoparticles (NPs) combined with ulinastatin (UTI) on early brain injury (EBI) caused by carbon monoxide poisoning (CMP). Firstly, PFOB NPs were prepared by high-speed dispersion and high-speed homogenization. The physicochemical characteristics of the particle size distribution and Zeta potential distribution of the NPs were analyzed using a laser particle size analyzer. The thermal and photoinduced phase transition characteristics of the NPs were analyzed under heating and laser irradiation conditions. Then, 50 Sprague Dawley (SD) rats were deemed as the research objects to establish the CMP rat models using hyperbaric oxygen chambers. According to different treatment methods, they were rolled into a healthy control group, a carbon monoxide (CO) model group, a PTOB treatment group, an UTI treatment group, and a PTOB + UTI treatment group. The brain tissues of each group of rats were collected 3 days after treatment. The neuronal cell apoptosis, expression of Caspase-3, messenger ribonucleic acid (mRNA) of inflammatory factors interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in rat brain tissue were detected through immunohistochemical staining, in situ cell apoptosis detection, Reverse transcription-polymerase chain reaction (RT-PCR), and Western blotting, so did the relative expression of target proteins B-cell lymphoma-2 (Bcl-2), Bcl2-Associated X (Bax) and myelin basic protein (MBP). As a result, the average particle size and the average Zeta potential of the prepared PFOB NPs was 103±31 nm and −23 ± 15 mV, respectively. When the PFOB NPs were heated to 80 °C, the particle size increased greatly and cracks appeared. The particle size of PFOB NPs also increased obviously after laser irradiation, and the PFOB inside the particles changed into gas phase. Compared to CO group, expression of Caspase-3, neuronal cell apoptosis rate, mRNA expression of IL-1β and TNF-α, and protein expression of Bax and Bcl-2 in the brain tissue of PTOB group, UTI group, and PFOB + UTI group were notably decreased (P &lt; 0.05), while the MBP protein expression increased considerably (P &lt; 0.05). Changes in PFOB + UTI group were more obvious than those in PTOB group and UTI group, and those indicators weren’t considerably different from the controls. In summary, PFOB NPs were successfully prepared with favorable phase transition characteristics. Moreover, PFOB NPs combined with UTI could reduce the apoptosis of brain neurons after CMP, improve the inflammatory response, and play a protective effect on EBI of CMP.

String Analysis to identify the Activity of Gyrinops versteegii derived Lauric Acid against Breast Cancer

Understanding the interactions between cellular proteins and compounds from agarwood (Gyrinops versteegii) could lead to effective approaches for the diagnosis and treatment of breast cancer. In this study, we aimed to identify the interaction between lauric acid, a compound derived from agarwood (G. versteegii) and its target proteins using String database analysis. String analysis showed that lauric acid affects cellular proliferation through interactions with the Androgen Receptor (AR) and binds to Aldo-Keto Reductase (AKR1C3). Lauric acid also interacted with mitogen-activated protein kinase 1 (MAPK1) and other proteins such as matrix metalloprotein (MMP2), chemokine (CXCL8), B-cell lymphoma protein (BCL2). Retinoid Acid Receptor (RARG) and Androgen Receptor (AR) sub network are bridging system of regulation in breast cancer molecular process. These results show that lauric acid may interact with many proteins by AR sub network to increase apoptosis and reduce cancer cell proliferation. These results show that lauric acid may interact with many proteins to increase apoptosis and reduce cancer cell proliferation.

Role of Venetoclax in the Treatment of Relapsed and Refractory Multiple Myeloma.

Biomarker-driven targeted therapies have been an area of exploration for innovative therapeutic options in oncology. B-cell lymphoma-2 (BCL-2) protein is an anti-apoptotic protein expressed on the clonal plasma cells in patients with multiple myeloma (MM). MM subsets with t (11;14) have overexpression of BCL-2 and can benefit from venetoclax (VEN) when used either alone or in combination with other chemotherapeutic agents with an overall response rate (ORR) ranging from 40% to 100%. The most commonly reported grade ≥ 3 adverse effects include cytopenias and gastrointestinal side effects. This review highlights the meaningful efficacy and tolerable safety of VEN monotherapy and its combination regimens in the treatment of relapsed refractory MM.

Expression of BCL6 in paediatric B-cell acute lymphoblastic leukaemia and association with prognosis.

B-cell lineage acute lymphoblastic leukaemia (B-ALL) is the most common paediatric malignancy. Transcription factor B-cell lymphoma 6 (BCL6) is essential to germinal centre formation and antibody affinity maturation and plays a major role in mature B-cell malignancies. More recently, it was shown to act as a critical downstream regulator in pre-BCR+ B-ALL. We investigated the expression of the BCL6 protein in a population-based cohort of paediatric B-ALL cases and detected moderate to strong positivity through immunohistochemistry in 7% of cases (8/117); however, only two of eight BCL6 cases (25%) co-expressed the ZAP70 protein. In light of these data, the subtype with active pre-BCR signalling constitutes a rare entity in paediatric B-ALL. In three independent larger cohorts with gene expression data, high BCL6 mRNA levels were associated with the TCF3-PBX1, Ph-like, NUTM1, MEF2D and PAX5-alt subgroups and the 'metagene' signature for pre-BCR-associated genes. However, higher-than-median BCL6 mRNA level alone was associated with favourable event free survival in the Nordic paediatric cohort, indicating that using BCL6 as a diagnostic marker requires careful design, and evaluation of protein level is needed alongside the genetic or transcriptomic data.

The Effect of NeuroAid (MLC901) on Cholestasis-Induced Spatial Memory Impairment with Respect to the Expression of BAX, BCL-2, BAD, PGC-1α and TFAM Genes in the Hippocampus of Male Wistar Rats.

Cholestasis is a bile flow reduction that is induced following Bile Duct Ligation (BDL). Cholestasis impairs memory and induces apoptosis. Apoptosis consists of two pathways: intrinsic and extrinsic. The intrinsic pathway is modulated by BCL-2 (B cell lymphoma-2) family proteins. BCL-2 (a pro-survival BCL-2 protein) has anti-apoptotic effect, while BAD (BCL-2-associated death) and BAX (BCL-2-associated X), the other members of BCL-2 family have pro-apoptotic effect. Furthermore, TFAM (mitochondrial transcriptional factor A) is involved in transcription and maintenance of mitochondrial DNA and PGC-1α (peroxisome proliferator-activated receptor γ coactivator-1α) is a master regulator of mitochondrial biogenesis. On the other hand, NeuroAid is a Traditional Chinese Medicine with neuroprotective and anti-apoptosis effects. In this study, we evaluated the effect of cholestasis on spatial memory and expression of BCL-2, BAD, BAX, TFAM, and PGC-1α in the hippocampus of rats. Additionally, we assessed the effect of NeuroAid on cholestasis-induced cognitive and genetic alterations. Cholestasis was induced by BDL surgery and NeuroAid was injected intraperitoneal at the dose of 0.4mg/kg. Furthermore, spatial memory was evaluated using Morris Water Maze (MWM) apparatus. The results showed cholestasis impaired spatial memory, increased the expression of BAD and BAX, decreased the expression of TFAM and PGC-1α, and did not alter the expression of BCL-2. Also, NeuroAid decreased the expression of BAD and BAX and increased the expression of TFAM, PGC-1α, and BCL-2. In conclusion, cholestasis impaired spatial memory and increased the expression of pro-apoptotic genes. Also, cholestasis decreased the expression of TFAM and PGC-1α. Interestingly, NeuroAid restored the effects of cholestasis.

MiR-448-5p/VEGFA Axis Protects Cardiomyocytes from Hypoxia Through Regulating the FAS/FAS-L Signaling Pathway.

Bioinformatics analysis showed that miR-448-5p expression in the myocardial tissue of rats with myocardial infarction significantly increased, suggesting that it may participate in myocardial cell apoptosis in myocardial infarction. This study aimed to explore the protective effects of miR-448-5p on hypoxic myocardial cells.H9C2 cells were cultured and subjected to anoxia for 2, 4, and 8 hours to establish a hypoxia model. MiR-448-5p mimic and inhibitor were transfected into the cells; then, a dual-luciferase experiment was conducted to verify the targeting relationship between miR-448-5p and VEGFA. Cell viability and apoptosis was detected by cell counting kit-8 and flow cytometry, respectively. The expressions of apoptosis-related proteins, miR-448-5p, FAS, and FAS-L were measured using western blotting and quantitative reverse transcription-polymerase chain reaction (qRT-PCR).Hypoxia-reduced H9C2 cell viability and promoted apoptosis. MiR-448-5p expression was increased after H9C2 cell hypoxia. MiR-448-5p mimic significantly inhibited the viability and promoted the apoptosis of hypoxia-induced model cells. Hypoxia promoted the expression of apoptosis-related protein B-cell lymphoma-2 (Bcl-2) and inhibited the expressions of Bcl-2-associated x protein (Bax), cleaved caspase-3, and caspase-3, whereas the effect of inhibitor on hypoxia-reduced H9C2 cell and apoptotic protein expression were opposite to miR-448-5p mimic. MiR-448-5p targeted VEGFA and regulated its expression. Silenced VEGFA expression significantly inhibited inhibitor effect on increasing cell viability and promoted apoptosis. In addition, miR-448-5p mimic inhibited the effect of hypoxia on promoting the expressions of FAS and FAS-L of H9C2 cells. Inhibitors had the opposite effect on cell hypoxia model.The miR-448-5p/VEGFA axis could protect cardiomyocytes from hypoxia through inhibiting the FAS/FAS-L signaling pathway.

Mechanisms and Neuroprotective Activities of Stigmasterol Against Oxidative Stress-Induced Neuronal Cell Death via Sirtuin Family.

Background: Accumulating studies have confirmed that oxidative stress leads to the death of neuronal cells and is associated with the progression of neurodegenerative diseases, including Alzheimer's disease (AD). Despite the compelling evidence, there is a drawback to the use of the antioxidant approach for AD treatment, partly due to limited blood-brain barrier (BBB) permeability. Phytosterol is known to exhibit BBB penetration and exerts various bioactivities such as antioxidant and anticancer effects, and displays a potential treatment for dyslipidemia, cardiovascular disease, and dementia.Objective: In this study, the protective effects of stigmasterol, a phytosterol compound, on cell death induced by hydrogen peroxide (H2O2) were examined in vitro using human neuronal cells (SH-SY5Y cells).Methods: MTT assay, reactive oxygen species measurement, mitochondrial membrane potential assay, apoptotic cell measurement, and protein expression profiles were performed to determine the neuroprotective properties of stigmasterol.Results: H2O2 exposure significantly increased the levels of reactive oxygen species (ROS) within the cells thereby inducing apoptosis. On the contrary, pretreatment with stigmasterol maintained ROS levels inside the cells and prevented oxidative stress-induced cell death. It was found that pre-incubation with stigmasterol also facilitated the upregulation of forkhead box O (FoxO) 3a, catalase, and anti-apoptotic protein B-cell lymphoma 2 (Bcl-2) in the neurons. In addition, the expression levels of sirtuin 1 (SIRT1) were also increased while acetylated lysine levels were decreased, indicating that SIRT1 activity was stimulated by stigmasterol, and the result was comparable with the known SIRT1 activator, resveratrol.Conclusion: Taken together, these results suggest that stigmasterol could be potentially useful to alleviate neurodegeneration induced by oxidative stress.

Humanin Inactivates Pro‐Apoptotic BCL‐2 Proteins Through a Common Fibril‐Forming Mechanism

Neurodegenerative diseases such as Alzheimer's, Parkinson's, and Huntington's are associated with accumulation of amyloid plaques or amyloid-like complexes that foster cellular dysregulation. For example, neurons with amyloid inclusions often undergo premature apoptosis resulting from excessive expression of p38 mitogen-activated protein kinase. The increased abundance of this enzyme leads to mass phosphorylation and activation of a protein from the B-cell lymphoma 2 (BCL-2) family, BAX. BAX is the central regulatory protein for mitochondrial outer membrane permeabilization (MOMP), a poration process that commits cells to apoptosis by releasing death-propagating factors from the mitochondria. Thus, it may be possible to prevent premature neuronal apoptosis by identifying endogenous factors that decrease the MOMP capacity of BAX and other pro-apoptotic BCL-2 proteins. Humanin (HN) is a mitochondria-derived peptide that is released by the organelle in response to several stress stimuli. In the cytosol or on the mitochondrial membrane HN can counteract the death signal by forming specific complexes with some of the BCL-2 proteins. We recently reported the in vitro amyloid-like fibrillation of BAX and a second pro-apoptotic family member, BID, with HN. We proposed this as a novel anti-apoptotic mechanism that inhibits pro-apoptotic BCL-2 proteins from initiating MOMP by sequestering them into fibrils, a heretofore unprecedented phenomenon that involves refolding globular BCL-2 proteins into fibrils where they undergo significant alpha-helix to beta-sheet fold-switching. These fibrils represent a new direction for the field of cell death and elucidating mechanisms of the BCL-2 family. The existence of this fold-switching mechanism and fibrillation insists that at least some pro-apoptotic members of the BCL-2 family have unappreciated, functional beta-sheet conformations. We hypothesize that in the membrane-bound conformations these pro-apoptotic BCL-2 proteins might adopt beta-sheet structures. Perhaps their fold-switching dynamics may play a role in the pore-forming process in the mitochondrial membrane, altering its membrane potential and leading up to the release of death factors into the cytosol. Therapeutics that can affect BCL-2 protein propensity for either secondary structure state may prove to be fruitful toward ameliorating disease states where BCL-2 family activity has become misregulated.

Pevonedistat and azacitidine upregulate NOXA (PMAIP1) to increase sensitivity to venetoclax in preclinical models of acute myeloid leukemia.

Dysregulation of apoptotic machinery is one mechanism by which acute myeloid leukemia (AML) acquires a clonal survival advantage. B-cell lymphoma protein-2 (BCL2) overexpression is a common feature in hematologic malignancies. The selective BCL2 inhibitor, venetoclax (VEN) is used in combination with azacitidine (AZA), a DNAmethyltransferase inhibitor (DNMTi), to treat patients with AML. Despite promising response rates to VEN/AZA, resistance to the agent is common. One identified mechanism of resistance is the upregulation of myeloid cell leukemia-1 protein (MCL1). Pevonedistat (PEV), a novel agent that inhibits NEDD8-activating enzyme, and AZA both upregulate NOXA (PMAIP1), a BCL2 family protein that competes with effector molecules at the BH3 binding site of MCL1. We demonstrate that PEV/AZA combination induces NOXA to a greater degree than either PEV or AZA alone, which enhances VEN-mediated apoptosis. Herein, using AML cell lines and primary AML patient samples ex vivo, including in cells with genetic alterations linked to treatment resistance, we demonstrate robust activity of the PEV/VEN/AZA triplet. These findings were corroborated in preclinical systemic engrafted models of AML. Collectively, these results provide rational for combining PEV/VEN/AZA as a novel therapeutic approach in overcoming AML resistance in current therapies.

MicroRNA-221 Upregulates the Expression of P-gp and Bcl-2 by Activating the Stat3 Pathway to Promote Doxorubicin Resistance in Osteosarcoma Cells.

MicroRNA-221 (miRNA-221) is upregulated in several malignant tumors and is associated with poor patient prognosis. Therefore, the present study aimed to investigate the role and underlying mechanism of miRNA-221 in doxorubicin (DOX) resistance in osteosarcoma cells. We constructed DOX-resistant Saos-2/DOX cells and treated them with DOX. Cell viability was determined by performing a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cells were transfected with either miRNA-221 mimic or miRNA-221 inhibitor; quantitative (q)RT-PCR was performed to detect the expression of miRNA-221. Flow cytometry and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-digoxigenin nick-end labeling (TUNEL) staining were used to detect cell apoptosis. The immunofluorescence method was also used to detect cell signal transduction and activator of transcription 3 (Stat3) protein expression distribution. In addition, Western blotting was used to detect changes in the expression of each protein. We found that miRNA-221 was upregulated in Saos-2/DOX cells. Moreover, the miRNA-221 mimic induced DOX resistance in Saos-2 cells, whereas the miRNA-221 inhibitor enhanced DOX sensitivity in Saos-2/DOX cells. The miRNA-221 mimic upregulated the expression of phosphorylated-Stat3, P-glycoprotein (P-gp), and B-cell lymphoma-2 (Bcl-2) proteins in Saos-2 cells and induced the entry of Stat3 into the nucleus, whereas the miRNA-221 inhibitor exerted the opposite effect. Pretreatment with the Stat3 chemical inhibitor, STAT3-IN-3, significantly inhibited the upregulation of P-gp and Bcl-2 protein expression induced by the miRNA-221 mimic in Saos-2 cells; it also caused the Saos-2 cells to overcome DOX resistance induced by the miRNA-221 mimic. Thus, miRNA-221 increased the expression of P-gp and Bcl-2 by activating the Stat3 pathway to promote DOX resistance in osteosarcoma cells, indicating a potential use of miRNA-221 in osteosarcoma treatment.

MicroRNA-181a promotes the proliferation of hypertrophic scar fibroblasts and inhibits their apoptosis via targeting phosphatase and tensin homolog.

This study aimed to compare the expression of microRNA (miR)-181a and phosphatase and tensin homolog (PTEN) in hypertrophic scar tissue and cells and to explore the effects of miR-181a and PTEN on the proliferation and apoptosis of the human scar fibroblast cell line HSFb. HSFb cells were transfected with miR-negative control (miR-NC), miR-181a mimics, miR-181a inhibitor, pcDNA3.1-PTEN (pc-PTEN), or small interfence-PTEN (si-PTEN) plasmid using a Lipofectamine 2000 transfection kit. The effects of miR-181a and PTEN on the proliferation and apoptosis of HSFb were determined using a Cell Counting Kit (CCK)-8 experiment and flow cytometry, respectively. The effects of miR-181a and PTEN on the expression of apoptosis-related proteins in HSFb, including type I collagen (Col-1) and type III collagen (Col-3), were measured by western blot. Finally, the relationship between miR-181a and PTEN was explored by the dual-luciferase reporter gene experiment. The miR-181a in hypertrophic scar tissues and HSFb were significantly up-regulated compared to embryo skin fibroblast (ESF-1) cells and normal tissues (P<0.05), whereas the opposite results were seen for PTEN expression (P<0.05). Inhibiting miR-181a or upregulating the expression of PTEN significantly suppressed the proliferation of HSFb (P<0.05) and induced their apoptosis (P<0.05). Western blot revealed that inhibiting and upregulating miR-181a and PTEN, respectively, decreased the expression of the B-cell lymphoma-2 (Bcl-2), Col-1, and Col-3 proteins in HSFb, but significantly up-regulated the expression of Bcl-2-associated X protein (Bax), cleaved caspase-3 (c-caspase-3), and cleaved caspase-9 (c-caspase-9) (P<0.05). The dual-luciferase reporter gene experiment results confirmed PTEN to be the downstream target gene of miR-181a. Simultaneous upregulation of miR-181a and PTEN expression had no significant effect on the proliferation and apoptosis of HSFb. miR-181a promotes the up-regulation of Col-1 and Col-3, and regulates the proliferation and apoptosis of HSFb by targeting PTEN, thereby enhancing the formation of hypertrophic scarring (HS). Therefore, miR-181a and PTEN may be potential therapeutic targets for the treatment of HS.

Calycosin Induces Gastric Cancer Cell Apoptosis via the ROS-Mediated MAPK/STAT3/NF-κB Pathway.

BackgroundCalycosin, an active compound in plants, can promote the apoptosis of various cancer cells; however, the mechanism by which it regulates reactive oxygen species (ROS) in gastric cancer (GC) cells remains unclear.PurposeIn this study, we investigated the effects of calycosin on apoptosis, the cell cycle, and migration in GC cells under ROS regulation.ResultsThe results of the Cell Counting Kit-8 assay suggested that calycosin had significant cytotoxic effects on 12 gastric cancer cells, but no significant cytotoxic effects on normal cells. Hoechst 33342/propidium iodide (PI) double staining and flow cytometry showed that calycosin had clear pro-apoptotic effects on AGS cells. Western blotting revealed that the expression of cytochrome C and pro-apoptotic proteins B-cell lymphoma 2 (Bcl-2)-associated agonist of cell death (Bad), cleaved (cle)-caspase-3, and cle-poly (ADP-ribose) polymerase gradually increased, and the expression of anti-apoptotic protein Bcl-2 gradually decreased. Calycosin also decreased the expression of extracellular signal-regulated kinase, nuclear factor kappa B (NF-κB), and signal transducer and activator of transcription 3 (STAT3), and increased the phosphorylation levels of p38, c-Jun N-terminal kinase, and inhibitor of NF-κB. In addition, calycosin markedly increased ROS accumulation, and pretreatment with active oxygen scavenger n-acetyl-l-cysteine (NAC) clearly inhibited apoptosis. Calycosin downregulated the cell cycle proteins cyclin-dependent kinase 2 (CDK2), CDK4, CDK6, cyclin D1, and cyclin E; upregulated p21 and p27; and arrested cells in the G0/G1 phase. Similarly, calycosin also downregulated Snail family transcriptional repressor 1, E-cadherin, and β-catenin and inhibited cell migration. However, pretreatment with NAC inhibited the calycosin-induced effects of cycle arrest and migration.ConclusionIn summary, calycosin induces apoptosis via ROS-mediated MAPK/STAT3/NF-κB pathways, thereby exerting its anti-carcinogenic functions in GC cells.

Inducible fold-switching as a mechanism to fibrillate pro-apoptotic BCL-2 proteins.

Neurodegenerative diseases often are associated with cellular dysregulation that results in premature cell death or apoptosis. A common example is the accumulation of amyloid plaques that promotes the excessive expression of p38 mitogen-activated protein kinase. The increased abundance of this enzyme leads to mass phosphorylation and activation of a protein from the B-cell lymphoma 2 (BCL-2) family, BAX. BAX is the central regulatory protein for mitochondrial outer membrane permeabilization (MOMP), a poration process that commits cells to apoptosis by releasing death-propagating factors from the mitochondria. Recent reports identify a naturally occurring peptide, Humanin (HN), that could block amyloid-beta-associated neuronal apoptosis by interacting with BCL-2 proteins. We recently showed humanin interaction leads to the amyloid-like fibrillation of BAX and a second BCL-2 family member, BID. We proposed this as a novel anti-apoptotic mechanism that inhibits pro-apoptotic BCL-2 proteins from initiating MOMP by sequestering them into fibrils, a heretofore unprecedented phenomenon that involves refolding globular BCL-2 proteins rapidly into fibrils where they undergo significant alpha-helix to beta-sheet fold-switching. Here we seek to further characterize the fibrillation and fold-switch in conditions that are known to induce amyloid fibrillation.

Allicin mitigates hepatic injury following cyclophosphamide administration via activation of Nrf2/ARE pathways and through inhibition of inflammatory and apoptotic machinery.

Treatment with anti-neoplastic agents, including cyclophosphamide (CP), is associated with several adverse reactions. Here, we distinguished the potential protective effect of allicin against CP-mediated hepatotoxicity in rats. To assess the effect of allicin, four experimental groups were used, with 7 rats per group, including control, allicin (10 mg/kg), CP (200 mg/kg), and allicin + CP-treated groups. All groups were treated for 10 days. Blood and liver samples were collected for biochemical, molecular, and histological analyses. Treatment with CP led to deformations in the liver tissue that were associated with higher liver function markers (alanine transaminase, aspartate transaminase, and alkaline phosphatase). Additionally, a disturbance in the redox balance was observed after CP exposure, as indicated by increased levels of oxidants, including malondialdehyde and nitric oxide, and the decreased levels of endogenous antioxidants, including glutathione, glutathione peroxidase, glutathione reductase, superoxide dismutase, and catalase. At the molecular level, CP treatment resulted in reduced expression of the Nrf2/ARE pathway and other genes related to this pathway, including NAD(P)H quinone dehydrogenase 1 and glutamate-cysteine ligase catalytic subunit. CP also led to a hyper-inflammatory response in hepatic tissue, with increased production of pro-inflammatory cytokines, including tumor necrosis factor-alpha and interlukin-1beta, and upregulation of nitric oxide synthase 2. CP also enhanced the immunoreactivity of the profibrogenic cytokine, transforming growth factor-beta, in liver tissue. Upregulation of caspase 3 and Bcl-2-associated X protein and downregulation of B-cell lymphoma 2 were also observed in response to CP treatment. Treatment with allicin reversed the molecular, biochemical, and histological changes that occurred with CP exposure. These results suggest that allicin can be used in combination with CP to avoid hepatotoxicity.