Effects and Related Mechanisms of the Senolytic Agent ABT-263 on the Survival of Irradiated A549 and Ca9-22 Cancer Cells

Senolytic agents eliminate senescent cells and are expected to reduce senescent cell-mediated adverse effects in cancer therapy. However, the effects of senolytic agents on the survival of irradiated cancer cells remain unknown. Here, the effects of the senolytic agent ABT-263 on the survival of irradiated A549 and Ca9-22 cancer cells were investigated. ABT-263 was added to the culture medium after irradiation. SA-β-gal activity and cell size, which are hallmarks of cell senescence, were evaluated using a flow cytometer. The colony-forming assay and annexin V staining were performed to test cell survival. We first confirmed that radiation increased the proportion of cells with high SA-β-gal activity and that ABT-263 decreased it. Of note, ABT-263 decreased the survival of irradiated cancer cells and increased the proportion of radiation-induced annexin V+ cells. Furthermore, the caspase inhibitor suppressed the ABT-263-induced decrease in the survival of irradiated cells. Intriguingly, ABT-263 decreased the proportion of SA-β-gal low-activity/large cells in the irradiated A549 cells, which was recovered by the caspase inhibitor. Together, these findings suggest that populations maintaining the ability to proliferate existed among the irradiated cancer cells showing senescence-related features and that ABT-263 eliminated the population, which led to decreased survival of irradiated cancer cells.

Chrysophanol Inhibits the Progression of Gastric Cancer by Activating NLRP3

AimGastric cancer is one of the most common malignant tumors.Chrysophanol has been reported to have antitumor effects on a variety of cancers, but the role of chrysophanol in gastric cancer remains unclear. The aim of this study was to investigate the effects of chrysophanol on proliferation, pyroptosis, migration and invasion of gastric cancer cells.MethodsMKN 28 and AGS cells were treatde with different concentrations of chrysophanol, then cell proliferation, migration,invasion and pyroptosis were decteed by CCK-8, Colony-forming assay, Wound Healing assay, Transwell and flow cytometry, respectively.Subsequently, NLRP3 siRNA was transfected into MKN 28 cells, cell proliferation pyroptosis, migration and invasion were reassessed in these transfected cells. The expression of caspase-1 and IL-1β in the downstream of NLRP3 was detected by qRT PCR and Western blot.ResultsChrysophanol significantly inhibited the proliferation of GC cells, promoted pyroptosis, inhibited cell migration and invasion, and up-regulated the expression level of NLRP3 inflammasome in GC cells. Silencing NLRP3 inhibited the effects of chrysophanol on proliferation, pyroptosis, migration and invasion of MKN 28 cells. Chrysophanol plays an anti-cancer role through high expression of NLRP3.CoclusionsChrysophanol can inhibit the proliferation, migration and invasion of gastric cancer cells by regulating NLRP3, promote the death of gastric cancer cells, and play an anti-tumor role,which is a clinical strategy with great potential for the treatment of gastric cancer.

Targeting the hallmarks of cancer: the effects of silibinin on proliferation, cell death, angiogenesis, and migration in colorectal cancer

Background Silibinin, as a chemopreventive agent, has shown anti-cancer efficacy against different types of cancers. In the present study, we investigated the anti-cancer activities of silibinin on CT26 mouse colon cell line. Methods CT26 cells were treated with different concentrations of silibinin. To examine the cytotoxic effect of silibinin on proliferation, apoptosis, autophagy, angiogenesis, and migration, MTT, colony-forming assay, Annexin V/PI flow cytometry, RT-qPCR, and Scratch assay were used. Results Silibinin was found to significantly reduce CT26 cells survival. Furthermore, silibinin strongly induced apoptosis and autophagy by up-regulating the expression of Bax, Caspase-3, Atg5, Atg7 and BECN1 and down-regulating Bcl-2. Silibinin considerably down-regulated the expression of COX-2, HIF-1α, VEGF, Ang-2, and Ang-4 as well as the expression of MMP-2, MMP-9, CCR-2 and CXCR-4. Conclusions The present study revealed that silibinin shows anticancer activities by targeting proliferation, cell survival, angiogenesis, and migration of CT26 cells.

Protective Effect of Ethanol Extract of Legundi (Vitex trifolia L.) Leaves against Staphylococcus aureus in Drosophila Infection Model

Research to discover certain medicinal plants' antibacterial activity against Staphylococcus aureus was mostly performed in vitro. The purpose of this research was to investigate the antibacterial activity of ethanol extract of legundi leaves (EELL) against S. aureus using model organism Drosophila melanogaster. The extract was prepared by the maceration method using 70% ethanol. The antibacterial activities of EELL were determined by using fly survival assay and bacterial colony-forming assay. Fly survival assay was conducted to investigate the extracts' ability to enhance the survival of D. melanogaster (host) upon S. aureus infection. The results demonstrated that both EELL were able to increase the survival rate of the S. aureus-infected Drosophila. Furthermore, a colony-forming assay was carried out to determine the growth of bacteria in the host body that has been considered an important pathogenic factor for the host. The result found that the number of bacteria recovered from the EELL-treated infected flies was significantly lower than the ones obtained from the infected flies without any treatments. Overall, EELL protects the S. aureus-infected hosts, suggesting the potential antibacterial effect of EELL against S. aureus.

Circular RNA CDR1as promotes tumor progression by regulating miR-432-5p/E2F3 axis in pancreatic cancer

Background Pancreatic cancer (PC), characterized with high growth rate and metastatic rate. It’s urgently necessary to explore new mechanism of PC. Circular RNA/miRNA/mRNA network was widely reported to participate in the cancer progression. Methods In this research, circular RNA CDR1as (circCDR1as) was identified by microarray analysis and detected in pancreatic cancer (PC) tissues and cells. Transwell, colony-forming assay, nude mouse tumorigenicity assay were used to determine the function of circCDR1as in PC. Western blot, dual luciferase reporting test were applied to investigate the mechanism. Results We found that circCDR1as was highly expressed in PC tissues. The levels of circCDR1as in PC tissues and cells were higher than those in controls. CircCDR1as promoted the migration, invasion and proliferation of PC cells in vitro and tumor growth in vivo via mediating E2F3 expression by sponging miR-432-5p. Conclusions In conclusion, circCDR1as could promote the development of PC and might be a novel diagnostic target for PC.

The effect of titanium carbide used in implants on stemness and senescence of mouse bone marrow derived mesenchymal stem cells

Background: The aim of the present study was to determine the effect of Titanium carbide nanoparticles on stemness and senescence markers of mouse bone marrow derived mesenchymal stem cells. Methods: After isolation of mesenchymal stem cells from mouse’s bone marrow, their surface markers were studied using flowcytometry. MTT assay, cell cycle analysis; colony forming assay, and senescent beta galactosidase staining were performed for cells treated with titanium carbide nanoparticles. Then, the expression of OCT-4 and Nanog genes were studied by qRT-PCR in titanium carbide treated mouse’s bone marrow mesenchymal stem cells (mBMSCs). Results: All mBMSCs showed spindle shaped morphology. Their identity was confirmed by flow cytometry of stained cells for CD11b, CD90, CD45, and CD44 markers. The MTT assay results showed that titanium carbide effect is time-dependent and no cytotoxic effects were observed in short treatment times. But toxic effects were observed after 72 or 144 hours of post treatment with doses range from 0.1 to 1 mM (P<0.05). Besides, cell cycle study detected more cell populations in G0/G1 and less percentage in S phase. The colony forming assay in treated cells exhibited smaller size of colonies. The beta galactosidase staining of treated cells demonstrated more positive cells (more aged cells). Finally, qRT-PCR showed significant down regulation of OCT-4 and Nanog (p<0.05). Conclusion: Titanium carbide as an implant material could affect the viability, stemness and senescence of mBMSCs in negative manner.

A Comparative Assessment of Mechanisms and Effectiveness of Radiosensitization by Titanium Peroxide and Gold Nanoparticles

The development of potentially safe radiosensitizing agents is essential to enhance the treatment outcomes of radioresistant cancers. The titanium peroxide nanoparticle (TiOxNP) was originally produced using the titanium dioxide nanoparticle, and it showed excellent reactive oxygen species (ROS) generation in response to ionizing radiation. Surface coating the TiOxNPs with polyacrylic acid (PAA) showed low toxicity to the living body and excellent radiosensitizing effect on cancer cells. Herein, we evaluated the mechanism of radiosensitization by PAA-TiOxNPs in comparison with gold nanoparticles (AuNPs) which represent high-atomic-number nanoparticles that show a radiosensitizing effect through the emission of secondary electrons. The anticancer effects of both nanoparticles were compared by induction of apoptosis, colony-forming assay, and the inhibition of tumor growth. PAA-TiOxNPs showed a significantly more radiosensitizing effect than that of AuNPs. A comparison of the types and amounts of ROS generated showed that hydrogen peroxide generation by PAA-TiOxNPs was the major factor that contributed to the nanoparticle radiosensitization. Importantly, PAA-TiOxNPs were generally nontoxic to healthy mice and caused no histological abnormalities in the liver, kidney, lung, and heart tissues.

The Cytotoxic Effect of Newly Synthesized Ferrocenes against Cervical Carcinoma Cells Alone and in Combination with Radiotherapy

Cervical cancer is one of the most common types of cancer in women, with approximately 500,000 new cases and 250,000 deaths every year. Radiotherapy combined with chemotherapy represents the treatment of choice for advanced cervical carcinomas. The role of the chemotherapy is to increase the sensitivity of the cancer cells to irradiation. Cisplatin, the most commonly used drug for this purpose, has its limitations. Thus, we used a family of ferrocene derivatives (in addition, one new species was prepared using standard Schlenk techniques) and studied their effects on cervical cancer cells alone and in combination with irradiation. We applied colorimetric assay to determine the cytotoxicity of the compounds; flow cytometry to analyze the production of reactive oxygen species (ROS), cell cycle, and mitochondrial membrane potential (MMP); immunochemistry to study protein expression; and colony forming assay to evaluate changes in radiosensitivity. Treatment with ferrocenes exhibited significant cytotoxicity against cervical cancer cells, associated with increasing ROS production and MMP changes, suggesting the induction of apoptosis. The combined activity of ferrocenes and ionizing radiation highlighted ferrocenes as potential radiosensitizing drugs, while their higher single-agent toxicity in comparison with routinely used cisplatin could also be promising. Our results demonstrate antitumor activity of several tested ferrocenes both alone and in combination with radiotherapy.