ROS-induced cell cycle arrest as a mechanism of resistance in polyaneuploid cancer cells (PACCs)

Revealing robust antioxidant defences of a mycoparasitic Trichoderma species

The fungal genus Trichoderma contains a vast array of species well known for their high opportunistic potential and adaptability to various ecological niches. The ability of many Trichoderma species to both colonize the rhizosphere and parasitize plant pathogenic fungi has led to their use in biological pathogen control for several decades. Reactive oxygen species (ROS) are linked to both the antagonism imposed by the mycoparasite Trichoderma and the elicited defence reaction by its fungal hosts during the mycoparasitic interaction. Trichoderma spp. likely tolerate higher levels of ROS compared with some of their host species, thereby giving them an advantage during the mycoparasitic interaction. In the present study, we investigated glutathione redox dynamics using the fluorescent reporter Grx1-roGFP2 stably expressed in Trichoderma asperellum following electrotransformation. Grx1-roGFP2 undergoes reversible changes in its excitation spectrum in response to variations in the cellular glutathione redox potential, providing a real-time indication of intracellular oxidative load. Considering the putative importance of ROS in mycoparasitic interactions, we performed live-cell imaging of the T. asperellum reporter strain interacting with the cereal pathogen Fusarium graminearum. Surprisingly, the glutathione redox potential did not change during this mycoparasitic interaction. We found no evidence that host-induced tip growth arrest within T. asperellum hyphae is induced by intracellular ROS accumulation. Furthermore, we show that the F. graminearum mycotoxins deoxynivalenol and zearalenone do not induce detectable changes in glutathione redox potential, even at very high concentrations. We infer that T. asperellum has a robust anti-oxidant defence system, supported by the observation that high concentrations of H2O2 are required to fully oxidize the reporter during in vivo calibration. We cannot rule out a role for ROS as a signal during mycoparasitic interactions, but, if present, this does not appear to be mediated by glutathione redox potential.

A review of pharmacological mechanisms, challenges and prospects of macromolecular glycopeptides

Macromolecular glycopeptides are natural products derived from various sources, distinguished by their structural diversity, multifaceted biological activities, and low toxicity. These compounds exhibit a wide range of biological functions, such as immunomodulation, antitumor effects, anti-inflammatory properties, antioxidant activity, and more. However, limited understanding of natural glycopeptides has hindered their development and practical application. To promote their advancement and utilization, it is crucial to thoroughly investigate the pharmacological mechanisms of glycopeptides and address the challenges in natural glycopeptide research. This review uniquely focuses on the primary biological activities and potential molecular mechanisms of glycopeptides as reported in recent literature. Moreover, we emphasize the current challenges in glycopeptide research, including extraction and isolation difficulties, purification challenges, structural analysis complexities, elucidation of structure-activity relationships, characterization of biosynthetic pathways, and ensuring bioavailability and stability. The future prospects for glycopeptide research are also explored. We argue that ongoing research into glycopeptides will significantly contribute to drug development and provide more effective therapeutic options and disease treatment alternatives for human health.

Reduction reactions dominate the interactions between Mg alloys and cells: Understanding the mechanisms

Magnesium (Mg) alloys are popular biodegradable metals studied for orthopedic and cardiovascular applications, mainly because Mg ions are essential trace elements known to promote angiogenesis and osteogenesis. However, Mg corrosion consists of oxidation and reduction reactions that produce by-products, such as hydrogen gas, reactive oxygen species, and hydroxides. It is still unclear how all these by-products and Mg ions concomitantly alter the microenvironment and cell behaviors spatially and temporally. This study shows that Mg corrosion can enhance cell proliferation by reducing intracellular ROS. However, Mg cannot decrease ROS and promote cell proliferation in simulated inflammatory conditions, meaning the microenvironment is critical. Furthermore, cells may respond to Mg ions differently in chronic or acute alkaline pH or oxidative stress. Depending on the corrosion rate, Mg modulates HIF1α and many signaling pathways like PI3K/AKT/mTOR, mitophagy, cell cycle, and oxidative phosphorylation. Therefore, this study provides a fundamental insight into the importance of reduction reactions in Mg alloys.

The regulation of cell metabolism by hypoxia and hypercapnia

Every cell in the body is exposed to a certain level of CO2 and O2. Hypercapnia and hypoxia elicit stress signals to influence cellular metabolism and function. Both conditions exert profound yet distinct effects on metabolic pathways and mitochondrial dynamics, highlighting the need for cells to adapt to changes in the gaseous microenvironment. The interplay between hypercapnia and hypoxia signaling is the key for dictating cellular homeostasis as microenvironmental CO2 and O2 levels are inextricably linked. Hypercapnia, characterized by elevated pCO2, introduces metabolic adaptations within the aerobic metabolism pathways, affecting tricarboxylic acid cycle flux, lipid, and amino acid metabolism, oxidative phosphorylation and the electron transport chain. Hypoxia, defined by reduced oxygen availability, necessitates a shift from oxidative phosphorylation to anaerobic glycolysis to sustain ATP production, a process orchestrated by the stabilization of hypoxia-inducible factor-1α. Given that hypoxia and hypercapnia are present in both physiological and cancerous microenvironments, how might the coexistence of hypercapnia and hypoxia influence metabolic pathways and cellular function in physiological niches and the tumor microenvironment?

Isoquinolinequinone N-oxides with diverging mechanisms of action induce collateral sensitivity against multidrug resistant cancer cells

Multidrug resistance (MDR) is a major challenge in cancer research. Collateral sensitizers, compounds that exploit the enhanced defense mechanisms of MDR cells as weaknesses, are a proposed strategy to overcome MDR. Our previous work reported the synthesis of two novel Isoquinolinequinone (IQQ) N-oxides that induce collateral sensitivity in MDR ABCB1-overexpressing non-small cell lung cancer (NSCLC) and colorectal cancer cells. Herein, we aimed to investigate underlying mechanisms of antitumor and collateral sensitivity activity of these compounds. We evaluated their effect on cancer cell viability, proliferation, cell cycle profile, and studied their cytotoxicity in non-tumorigenic cells. Their antitumor effect was further studied using NSCLC and colorectal cancer MDR spheroids. To understand underlying collateral sensitivity mechanisms, we assessed the effect on rhodamine-123 accumulation, ROS production, GSH/GSSG balance and expression of key proteins associated with metabolism and redox balance. Both compounds reduced the viability of MDR cells, as 2D cultures or as spheroids, without decreasing the growth of a human nontumorigenic cell line, and increased rhodamine-123 accumulation in MDR NCI-H460/R cells. Moreover, RK2 increased ROS, disrupted GSH balance, and altered expression of proteins associated with oxidative stress protection, particularly in NCI-H460/R cells. The collateral sensitivity effect of RK3 could not be attributed to redox balance disruption, but increased IDH1 expression following treatment suggests a potential metabolic shift in MDR cells. These findings highlight RK2 and RK3 as promising candidates for next stages of drug development. Their distinct mechanisms of action could lead to therapeutic solutions for MDR-related cancers, specifically linked to ABCB1 overexpression.

Phyto-mediated fabrication of silver nanoparticles from Scrophularia striata extract (AgNPs-SSE): a potential inducer of apoptosis in breast cancer cells

BACKGROUND

Breast carcinoma stands out as the most widespread invasive cancer and the top contributor to cancer-related mortality in women. Nanoparticles have emerged as promising tools in cancer detection, diagnosis, and prevention. In this study, the antitumor and apoptotic capability of silver nanoparticles synthesized through Scrophularia striata extract (AgNPs-SSE) was investigated toward breast cancer cells.

METHODS

The produced AgNPs-SSE were identified using scanning electron micrograph (SEM), energy-dispersive X-ray (EDAX) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD). The cell-killing effects of AgNPs-SSE on MDA-MB231 mammary carcinoma cells were evaluated in vitro using the MTT assay over 24 h. Apoptosis induction was conducted by cell cycle analysis, annexin V-FITC/PI staining, reactive oxygen species (ROS) generation, and Hoechst staining. Additionally, the gene expression of βcatenin, GSK3β, and CyclinD1 was analyzed using quantitative real-time PCR (qRT-PCR).

RESULTS

Microscopic analysis confirmed the successful fabrication of globular AgNPs-SSE, with a mean particle dimension of 19 ± 10 nm. The MTT assay revealed that IC50 value of AgNPs-SSE was 48.5 µg/mL for mammary carcinoma cells and 114 µg/mL for normal cells. Annexin V-FITC/PI staining specified that 85.88% of cancer cells treated with AgNPs-SSE underwent either early or late apoptosis. Treatment with AgNPs-SSE also caused a considerable rise in the subG1 cell cycle population and ROS production. Furthermore, the upregulation of βcatenin and downregulation of CyclinD1 gene expression confirmed the apoptotic mechanism.

CONCLUSIONS

In conclusion, the findings suggest that phyto-synthesized AgNPs-SSE can restrain the expansion of breast carcinoma cells and provoke apoptosis through oxidative stress. These results highlight the potential of AgNPs-SSE as an antitumor agent against breast cancer.

A novel cobalt oxide nanoparticle conjugated with ellagic acid arrests the cell cycle in human liver cancer cell line

The current chemotherapy treatments for liver cancer have shown limited effectiveness. Therefore, there is an urgent need to develop new drugs to combat this disease more effectively. This study reports synthesis of cobalt oxide nanoparticles coated with glucose, and conjugated with Ellagic acid. Physicochemical characterization of Co3O4@Glu-Ellagic acid nanoparticles was done using FT-IR, XRD, SEM, TEM, TGA, EDS-mapping, DLS, and zeta potential analyses, and the investigation of their anticancer potential on liver cancer cell lines involved the use of MTT, flow cytometry, and cell cycle analysis. The synthesized nanoparticles were somewhat spherical, arranged in a relatively cluster-shaped form, and were 33-46 nm in diameter. The zeta potential and particle hydrodynamic size were - 5.43 and 169 nm, respectively and had no elemental impurity. Also, the synthesized particles had proper thermal stability at temperatures below 100 °C. Treating cancer cells with the nanoparticles considerably increased ROS levels by 2.6 folds. Compared to normal human cells, Co3O4@Glu-Ellagic acid nanoparticles showed significantly higher toxicity for liver cancer and the 50% inhibitory concentration was 94 and 187 µg/mL for the cancer and normal cells, respectively. Co3O4@Glu-Ellagic acid increased cell apoptosis, from 0.87 to 9.24%, and the cells were mainly arrested at the G0/G1 and G2/M phases. Overall, the present work indicated that Co3O4@Glu-Ellagic acid has antiproliferative effects on liver cancer cells through an increased oxidative stress level, inhibition of cell cycle, and apoptosis induction.

Enhancing photodynamic and radionuclide therapy by small interfering RNA (siRNA)-RAD51 transfection via self-emulsifying delivery systems (SNEDDS)

BACKGROUND AIMS

Gene-silencing by small interfering RNA (siRNA) is an attractive therapy to regulate cancer death, tumor recurrence or metastasis. Because siRNAs are easily degraded, it is necessary to develop transport and delivery systems to achieve efficient tumor targeting. Self-nanoemulsifying systems (SNEDDS) have been successfully used for pDNA transport and delivery, so they may be useful for siRNA. The aim of this work is to introduce siRNA-RAD51 into a SNEDDS prepared with Phospholipon-90G, Labrafil-M1944-CS and Cremophor-RH40 and evaluate its efficacy in preventing homologous recombination of DNA double-strand breaks caused by photodynamic therapy (PDT) and ionizing radiation (IR).

METHODS

The siRNA-RAD51 was loaded into SNEDDS using chitosan. Transfection capacity was estimated by comparison with Lipofectamine-2000.

RESULTS

SNEDDS(siRNA-RAD51) induced gene silencing effect on the therapies evaluated by cell viability and clonogenic assays using T47D breast cancer cells.

CONCLUSIONS

SNEDDS(siRNA-RAD51) shown to be an effective siRNA-delivery system to decrease cellular resistance in PDT or IR.

SLC50A1 inhibits the doxorubicin sensitivity in hepatocellular carcinoma cells through regulating the tumor glycolysis

Metabolic reprogramming has been found to be closely associated with the occurrence and development of hepatocellular carcinoma (HCC). The relationship between SLC50A1, a member of the SLC family involved in glucose transmembrane transport, and HCC remains unclear. This study aims to investigate the function and underlying mechanisms of SLC50A1 in the occurrence and progression of HCC. Based on bioinformatics analysis and clinical sample testing, we observed a significant upregulation of SLC50A1 in HCC, which is correlated with unfavorable prognosis in HCC patients. Additionally, there is a noticeable correlation between the expressions of SLC50A1 and METTL3. Further in vitro and in vivo experiments confirmed that SLC50A1 can regulate cellular glycolysis and the cell cycle, thereby promoting the proliferation of HCC cells while reducing apoptosis. Moreover, our findings indicate that SLC50A1 enhances resistance of HCC cells to DOX and 2-DG. Furthermore, we discovered that the m6A methyltransferase METTL3 mediates the methylation modification of SLC50A1. The recognition and binding of the modified SLC50A1 by IGF2BP2 subsequently promote its stability and translational expression. Consequently, our research identifies the METTL3/SLC50A1 axis as a novel therapeutic target in the context of HCC.

Caffeic acid hinders the proliferation and migration through inhibition of IL-6 mediated JAK-STAT-3 signaling axis in human prostate cancer

Background

Caffeic acid (CA) is considered a promising phytochemical that has inhibited numerous cancer cell proliferation. Therefore, it is gaining increasing attention due to its safe and pharmacological applications. In this study, we investigated the role of CA in inhibiting the Interleukin-6 (IL-6)/Janus kinase (JAK)/Signal transducer and activator of transcription-3 (STAT-3) mediated suppression of the proliferation signaling in human prostate cancer cells.

Materials and Methods

The role of CA in proliferation and colony formation abilities was studied using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay and colony formation assays. Tumour cell death and cell cycle arrest were identified using flow cytometry techniques. CA treatment-associated protein expression of mitogen-activated protein kinase (MAPK) families, IL-6/JAK/STAT-3, proliferation, and apoptosis protein expressions in PC-3 and LNCaP cell lines were measured using Western blot investigation.

Results

We have obtained that treatment with CA inhibits prostate cancer cells (PC-3 and LNCaP) proliferation and induces reactive oxygen species (ROS), cell cycle arrest, and apoptosis cell death in a concentration-dependent manner. Moreover, CA treatment alleviates the expression phosphorylated form of MAPK families, i.e., extracellular signal-regulated kinase 1 (ERK1), c-Jun N-terminal kinase (JNK), and p38 in PC-3 cells. IL-6 mediated JAK/STAT3 expressions regulate the proliferation and antiapoptosis that leads to prostate cancer metastasis and migration. Therefore, to mitigate the expression of IL-6/JAK/STAT-3 is considered an important target for the treatment of prostate cancer. In this study, we have observed that CA inhibits the expression of IL-6, JAK1, and phosphorylated STAT-3 in both PC-3 and LNCaP cells. Due to the inhibitory effect of IL-6/JAK/STAT-3, it resulted in decreased expression of cyclin-D1, cyclin-D2, and CDK1 in both PC-3 cells. In addition, CA induces apoptosis by enhancing the expression of Bax and caspase-3; and decreased expression of Bcl-2 in prostate cancer cells.

Conclusions

Thus, CA might act as a therapeutical application against prostate cancer by targeting the IL-6/JAK/STAT3 signaling axis.

A novel copper(II) complex with a salicylidene carbohydrazide ligand that promotes oxidative stress and apoptosis in triple negative breast cancer cells

We report the synthesis, characterization, anti-cancer activity and mechanism of action of a novel water-soluble Cu(II) complex with salicylidene carbohydrazide as the ligand and o-phenanthroline as the co-ligand. The synthesized complex (1) was characterized by FT-IR, EPR, and electronic spectroscopy, as well as single crystal X-ray diffraction. This compound was found to be paramagnetic from EPR spectra and X-ray crystallography revealed that the molecule crystallized in an orthorhombic crystal system. The crystal lattice was asymmetric containing two distinct binuclear copper complexes containing the Schiff base as the major ligand, o-phenanthroline as a co-ligand, two nitrate anions, and two water molecules. The Cu(II) in the first site coordinated with the enolised ligand comprising enolate O-, phenolate O-, and the imine N and N,N from o-phen. The major part of this complex exists as Cu(II) coordinated with two H2O molecules at the second site with nitrate acting as the counter anion. However, a smaller portion of the complex exists where Cu(II) is coordinated with NO3- and H2O, and the remaining water molecule acts as lattice water. It was tested for DNA binding and cleavage properties which revealed that it binds in an intercalative mode to CT-DNA with Kb value of 1.25 × 104 M-1. Furthermore, cleavage studies reveal that the complex has potential for efficient DNA cleavage under both oxidative and hydrolytic conditions. It was able to enhance the rate of cleavage by 2.8 × 108 times. The complex shows good cytotoxicity to breast cancer monolayer (2D) as well as spheroid (3D) systems. The IC50 values for MDA-MB-231 and MCF-7 monolayer culture was calculated as 1.86 ± 0.17 μM and 2.22 ± 0.08 μM, respectively, and in (3D) spheroids of MDA-MB-231 cells, the IC50 value was calculated to be 1.51 ± 0.29 μM. It was observed that the complex outperformed cisplatin in both breast cancer cell lines. The cells treated with complex 1 underwent severe DNA damage, increased oxidative stress and cell cycle arrest which finally led to programmed cell death or apoptosis in triple negative breast cancer cells through an intrinsic pathway.

Reactive oxygen species (ROS) are a crucial factor in the anticancer activity of Oliveria decumbens extract against the A431 human skin cell line

Globally, skin cancer is a main public health challenge whose incidence is continuously increasing. Given the limitations of conventional t herapies, new research and novel therapies may be promising for reducing skin cancer morbidity and mortality. Phytochemicals are attractive resources for new therapy design in cancer research due to their cost-effectiveness and lower side effects. In the present study, the anti-cancer activity of Oliveria decumbens (O. decumbens) extract was investigated on the human skin cancer A431 cell line A431. The aqueous extract of the O. decumbens plant was prepared using the traditional method. Then IC50 was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay under different concentrations of O. decumbens. Cell apoptosis was investigated by Annexin V-FITC/Propidium Iodide (PI) and flow cytometry. Cell cycle was investigated by PI staining and flow cytometry. Reactive oxygen species (ROS) production was analyzed by DCFH-DA (2', 7' -dichlorofluorescein-diacetate) staining and flowcytometry.IC50 for cell viability was determined 475g/ml. Cell cycle analyses showed G1 arrest in treated cells compared to control cell. Results also confirmed significant increase of apoptotic cells (8.2%1, P<0.05) under IC50 concentration of the extract in comparison to the control group (2.50.99%). A significant increase in ROS level was observed in O.ecumbens treated cells compared to control cells (738 170 vs 31655 in the control group, P<0.05.).Overall, the present results indicate that O. decumbens extract can inhibit skin cancer cell proliferation via inhibition of cell cycle and apoptosis. It seems that ROS production plays a critical role in the anticancer effect of O. decumbens extract. Therefore, its potential option for future treatment of skin cancer should be considered.

Recent advancement of autophagy in polyploid giant cancer cells and its interconnection with senescence and stemness for therapeutic opportunities

Recurrent chemotherapy-induced senescence and resistance are attributed to the polyploidization of cancer cells that involve genomic instability and poor prognosis due to their unique form of cellular plasticity. Autophagy, a pre-dominant cell survival mechanism, is crucial during carcinogenesis and chemotherapeutic stress, favouring polyploidization. The selective autophagic degradation of essential proteins associated with cell cycle progression checkpoints deregulate mitosis fidelity and genomic integrity, imparting polyploidization of cancer cells. In connection with cytokinesis failure and endoreduplication, autophagy promotes the formation, maintenance, and generation of the progeny of polyploid giant cancer cells. The polyploid cancer cells embark on autophagy-guarded elevation in the expression of stem cell markers, along with triggered epithelial and mesenchymal transition and senescence. The senescent polyploid escapers represent a high autophagic index than the polyploid progeny, suggesting regaining autophagy induction and subsequent autophagic degradation, which is essential for escaping from senescence/polyploidy, leading to a higher proliferative phenotypic progeny. This review documents the various causes of polyploidy and its consequences in cancer with relevance to autophagy modulation and its targeting for therapeutic intervention as a novel therapeutic strategy for personalized and precision medicine.

Autophagy and oxidative stress modulation mediate Bortezomib resistance in prostate cancer

Proteasome inhibitors such as Bortezomib represent an established type of targeted treatment for several types of hematological malignancies, including multiple myeloma, Waldenstrom's macroglobulinemia, and mantle cell lymphoma, based on the cancer cell's susceptibility to impairment of the proteasome-ubiquitin system. However, a major problem limiting their efficacy is the emergence of resistance. Their application to solid tumors is currently being studied, while simultaneously, a wide spectrum of hematological cancers, such as Myelodysplastic Syndromes show minimal or no response to Bortezomib treatment. In this study, we utilize the prostate cancer cell line DU-145 to establish a model of Bortezomib resistance, studying the underlying mechanisms. Evaluating the resulting resistant cell line, we observed restoration of proteasome chymotrypsin-like activity, regardless of drug presence, an induction of pro-survival pathways, and the substitution of the Ubiquitin-Proteasome System role in proteostasis by induction of autophagy. Finally, an estimation of the oxidative condition of the cells indicated that the resistant clones reduce the generation of reactive oxygen species induced by Bortezomib to levels even lower than those induced in non-resistant cells. Our findings highlight the role of autophagy and oxidative stress regulation in Bortezomib resistance and elucidate key proteins of signaling pathways as potential pharmaceutical targets, which could increase the efficiency of proteasome-targeting therapies, thus expanding the group of molecular targets for neoplastic disorders.

Cancer-cell-specific Self-Reporting Photosensitizer for Precise Identification and Ablation of Cancer Cells

Cancer-cell-specific fluorescent photosensitizers (PSs) are highly desired molecular tools for cancer ablation with minimal damage to normal cells. However, such PSs that can achieve cancer specification and ablation and a self-reporting manner concurrently are rarely reported and still an extremely challenging task. Herein, we have proposed a feasible strategy and conceived a series of fluorescent PSs based on simple chemical structures for identifying and killing cancer cells as well as monitoring the photodynamic therapy (PDT) process by visualizing the change of subcellular localization. All of the constructed cationic molecules could stain mitochondria in cancer cells, identify cancer cells specifically, and monitor cancer cell viability. Among these, IVP-Br has the strongest ability to produce ROS, which serves as a potent PS for specific recognition and killing of cancer cells. IVP-Br could translocate from mitochondria to the nucleolus during PDT, self-reporting the entire therapeutic process. Mechanism study confirms that IVP-Br with light irradiation causes cancer cell ablation via inducing cell cycle arrest, cell apoptosis, and autophagy. The efficient ablation of tumor through PDT induced by IVP-Br has been confirmed in the 3D tumor spheroid chip. Particularly, IVP-Br could discriminate cancer cells from white blood cells (WBCs), exhibiting great potential to identify circulating tumor cells (CTCs).

Optimized DOX Drug Deliveries via Chitosan-Mediated Nanoparticles and Stimuli Responses in Cancer Chemotherapy: A Review

Chitosan nanoparticles (NPs) serve as useful multidrug delivery carriers in cancer chemotherapy. Chitosan has considerable potential in drug delivery systems (DDSs) for targeting tumor cells. Doxorubicin (DOX) has limited application due to its resistance and lack of specificity. Chitosan NPs have been used for DOX delivery because of their biocompatibility, biodegradability, drug encapsulation efficiency, and target specificity. In this review, various types of chitosan derivatives are discussed in DDSs to enhance the effectiveness of cancer treatments. Modified chitosan-DOX NP drug deliveries with other compounds also increase the penetration and efficiency of DOX against tumor cells. We also highlight the endogenous stimuli (pH, redox, enzyme) and exogenous stimuli (light, magnetic, ultrasound), and their positive effect on DOX drug delivery via chitosan NPs. Our study sheds light on the importance of chitosan NPs for DOX drug delivery in cancer treatment and may inspire the development of more effective approaches for cancer chemotherapy.

[Icaritin increases radiosensitivity of nasopharyngeal carcinoma cells by regulating iron death]

OBJECTIVE

To explore the radiosensitizing effect of icaritin on nasopharyngeal carcinoma (NPC) cells and the underlying mechanism.

METHODS

MTT assay and clonal formation assay were used to evaluate the effect of icaritin on proliferation of human NPC HONE1 and HNE1 cells. The effects of icaritin treatment, γ-ray radiation, or both on production of reactive oxygen species (ROS), cell cycle distribution and apoptosis of the NPC cells were assessed using flow cytometry. The expressions of DNA damage markers γ-H2AX, cycle-related proteins CDC25C, p-CDC25C and cyclin B1, and ferroptosis markers ACSL4 and GXP4 were detected using Western blotting. A nude mouse model bearing subcutaneous HONE1 cell xenograft was used to observe the effect of icaritin and radiation on tumor growth.

RESULTS

Icaritin dose-dependently inhibited the viability of the NPC cells and enhanced the inhibitory effect of radiation on cell proliferation. Flow cytometry and Western blotting showed that icaritin treatment prior to radiation significantly promoted ROS production and γ-H2AX expression in the NPC cells (P<0.001). Compared with radiation exposure alone, the combined treatment caused cell cycle arrest in G2 phase, down-regulated CDC25C and cyclin B1 expression, and up-regulated p-CDC25C expression in the cells (P<0.01), resulting also in increased cell apoptosis, enhanced expression of ferroptosis protein ACSL4 and lowered expression of GXP4 (P<0.001). In the tumor-bearing mice, icaritin treatment, compared with radiation alone, significantly reduced the tumor growth rate and decreased tumor weight (P<0.001).

CONCLUSION

Icaritin can enhance radiosensitivity of NPC cells both in vitro and in nude mice possibly by enhancing ROS production to promote iron death of the cells.

A mathematical investigation of polyaneuploid cancer cell memory and cross-resistance in state-structured cancer populations

The polyaneuploid cancer cell (PACC) state promotes cancer lethality by contributing to survival in extreme conditions and metastasis. Recent experimental evidence suggests that post-therapy PACC-derived recurrent populations display cross-resistance to classes of therapies with independent mechanisms of action. We hypothesize that this can occur through PACC memory, whereby cancer cells that have undergone a polyaneuploid transition (PAT) reenter the PACC state more quickly or have higher levels of innate resistance. In this paper, we build on our prior mathematical models of the eco-evolutionary dynamics of cells in the 2N+ and PACC states to investigate these two hypotheses. We show that although an increase in innate resistance is more effective at promoting cross-resistance, this trend can also be produced via PACC memory. We also find that resensitization of cells that acquire increased innate resistance through the PAT have a considerable impact on eco-evolutionary dynamics and extinction probabilities. This study, though theoretical in nature, can help inspire future experimentation to tease apart hypotheses surrounding how cross-resistance in structured cancer populations arises.

Chronic oxidative stress adaptation in head and neck cancer cells generates slow-cyclers with decreased tumour growth in vivo

BACKGROUND

Reactive oxygen species (ROS) are implicated in cancer therapy and as drivers of microenvironmental tumour cell adaptations. Medical gas plasma is a multi-ROS generating technology that has been shown effective for palliative tumour control in head and neck cancer (HNC) patients before tumour cells adapted to the oxidative stress and growth regressed fatally.

METHODS

In a bedside-to-bench approach, we sought to explore the oxidative stress adaptation in two human squamous cell carcinoma cell lines. Gas plasma was utilised as a putative therapeutic agent and chronic oxidative stress inducer.

RESULTS

Cellular responses of single and multiple treated cells were compared regarding sensitivity, cellular senescence, redox state and cytokine release. Whole transcriptome analysis revealed a strong correlation of cancer cell adaption with increased interleukin 1 receptor type 2 (IL1R2) expression. Using magnetic resonance imaging, tumour growth and gas plasma treatment responses of wild-type (WT) and repeatedly exposed (RE) A431 cells were further investigated in a xenograft model in vivo. RE cells generated significantly smaller tumours with suppressed inflammatory secretion profiles and increased epidermal growth factor receptor (EGFR) activity showing significantly lower gas plasma sensitivity until day 8.

CONCLUSIONS

Clinically, combination treatments together with cetuximab, an EGFR inhibitor, may overcome acquired oxidative stress resistance in HNC.

Angiotensin II modulates THP-1-like macrophage phenotype and inflammatory signatures via angiotensin II type 1 receptor

Angiotensin II (Ang II) is a major component of the renin-angiotensin or renin-angiotensin-aldosterone system, which is the main element found to be involved in cardiopathology. Recently, long-term metabolomics studies have linked high levels of angiotensin plasma to inflammatory conditions such as coronary heart disease, obesity, and type 2 diabetes. Monocyte/macrophage cellular function and phenotype orchestrate the inflammatory response in various pathological conditions, most notably cardiometabolic disease. An activation of the Ang II system is usually associated with inflammation and cardiovascular disease; however, the direct effect on monocyte/macrophages has still not been well elucidated. Herein, we have evaluated the cellular effects of Ang II on THP-1-derived macrophages. Ang II stimulated the expression of markers involved in monocyte/macrophage cell differentiation (e.g., CD116), as well as adhesion, cell-cell interaction, chemotaxis, and phagocytosis (CD15, CD44, CD33, and CD49F). Yet, Ang II increased the expression of proinflammatory markers (HLA-DR, TNF-α, CD64, CD11c, and CD38) and decreased CD206 (mannose receptor), an M2 marker. Moreover, Ang II induced cytosolic calcium overload, increased reactive oxygen species, and arrested cells in the G1 phase. Most of these effects were induced via the angiotensin II type 1 receptor (AT1R). Collectively, our results provide new evidence in support of the effect of Ang II in inflammation associated with cardiometabolic diseases.

Chemoprevention curcumin analog 1.1 promotes metaphase arrest and enhances intracellular reactive oxygen species levels on TNBC MDA-MB-231 and HER2-positive HCC1954 cells

Background and purpose

Previous studies highlighted that chemoprevention curcumin analog-1.1 (CCA-1.1) demonstrated an antitumor effect on breast, leukemia, and colorectal cancer cells. By utilizing immortalized MDA-MB-231 and HCC1954 cells, we evaluated the anticancer properties of CCA-1.1 and its mediated activity to promote cellular death.

Experimental approach

Cytotoxicity and anti-proliferation were assayed using trypan blue exclusion. The cell cycle profile after CCA-1.1 treatment was established through flow cytometry. May-Grünwald-Giemsa and Hoechst staining were performed to determine the cell cycle arrest upon CCA-1.1 treatment. The involvement of CCA-1.1 in mitotic kinases (aurora A, p-aurora A, p-PLK1, and p-cyclin B1) expression was investigated by immunoblotting. CCA-1.1-treated cells were stained with the X-gal solution to examine the effect on senescence. ROS level and mitochondrial respiration were assessed by DCFDA assay and mitochondrial oxygen consumption rate, respectively.

Findings/Results

CCA-1.1 exerted cytotoxic activity and inhibited cell proliferation with an irreversible effect, and the flow cytometry analysis demonstrated that CCA-1.1 significantly halted during the G2/M phase, and further assessment revealed that CCA-1.1 caused metaphase arrest. Immunoblot assays confirmed CCA-1.1 suppressed aurora A kinase in MDA-MB-231 cells. The ROS level was elevated after treatment with CCA-1.1, which might promote cellular senescence and suppress basal mitochondrial respiration in MDA-MB-231 cells.

Conclusion and implications

Our data suggested the in vitro proof-of-concept that supports the involvement in cell cycle regulation and ROS generation as contributors to the effectiveness of CCA-1.1 in suppressing breast cancer cell growth.

Cells in the polyaneuploid cancer cell (PACC) state have increased metastatic potential

Although metastasis is the leading cause of cancer deaths, it is quite rare at the cellular level. Only a rare subset of cancer cells (~ 1 in 1.5 billion) can complete the entire metastatic cascade: invasion, intravasation, survival in the circulation, extravasation, and colonization (i.e. are metastasis competent). We propose that cells engaging a Polyaneuploid Cancer Cell (PACC) phenotype are metastasis competent. Cells in the PACC state are enlarged, endocycling (i.e. non-dividing) cells with increased genomic content that form in response to stress. Single-cell tracking using time lapse microscopy reveals that PACC state cells have increased motility. Additionally, cells in the PACC state exhibit increased capacity for environment-sensing and directional migration in chemotactic environments, predicting successful invasion. Magnetic Twisting Cytometry and Atomic Force Microscopy reveal that cells in the PACC state display hyper-elastic properties like increased peripheral deformability and maintained peri-nuclear cortical integrity that predict successful intravasation and extravasation. Furthermore, four orthogonal methods reveal that cells in the PACC state have increased expression of vimentin, a hyper-elastic biomolecule known to modulate biomechanical properties and induce mesenchymal-like motility. Taken together, these data indicate that cells in the PACC state have increased metastatic potential and are worthy of further in vivo analysis.

Pro-Apoptotic Activity and Cell Cycle Arrest of Caulerpa sertularioides against SKLU-1 Cancer Cell in 2D and 3D Cultures

Cancer is a disease with the highest mortality and morbidity rate worldwide. First-line drugs induce several side effects that drastically reduce the quality of life of people with this disease. Finding molecules to prevent it or generate less aggressiveness or no side effects is significant to counteract this problem. Therefore, this work searched for bioactive compounds of marine macroalgae as an alternative treatment. An 80% ethanol extract of dried Caulerpa sertularioides (CSE) was analyzed by HPLS-MS to identify the chemical components. CSE was utilized through a comparative 2D versus 3D culture model. Cisplatin (Cis) was used as a standard drug. The effects on cell viability, apoptosis, cell cycle, and tumor invasion were evaluated. The IC₅₀ of CSE for the 2D model was 80.28 μg/mL versus 530 μg/mL for the 3D model after 24 h of treatment exposure. These results confirmed that the 3D model is more resistant to treatments and complex than the 2D model. CSE generated a loss of mitochondrial membrane potential, induced apoptosis by extrinsic and intrinsic pathways, upregulated caspases-3 and -7, and significantly decreased tumor invasion of a 3D SKLU-1 lung adenocarcinoma cell line. CSE generates biochemical and morphological changes in the plasma membrane and causes cell cycle arrest at the S and G2/M phases. These findings conclude that C. sertularioides is a potential candidate for alternative treatment against lung cancer. This work reinforced the use of complex models for drug screening and suggested using CSE's primary component, caulerpin, to determine its effect and mechanism of action on SKLU-1 in the future. A multi-approach with molecular and histological analysis and combination with first-line drugs must be included.

Elevated Methionine Flux Drives Pyroptosis Evasion in Persister Cancer Cells

Induction of cell death represents a primary goal of most anticancer treatments. Despite the efficacy of such approaches, a small population of "persisters" develop evasion strategies to therapy-induced cell death. While previous studies have identified mechanisms of resistance to apoptosis, the mechanisms by which persisters dampen other forms of cell death, such as pyroptosis, remain to be elucidated. Pyroptosis is a form of inflammatory cell death that involves formation of membrane pores, ion gradient imbalance, water inflow, and membrane rupture. Herein, we investigate mechanisms by which cancer persisters resist pyroptosis, survive, then proliferate in the presence of tyrosine kinase inhibitors (TKI). Lung, prostate, and esophageal cancer persister cells remaining after treatments exhibited several hallmarks indicative of pyroptosis resistance. The inflammatory attributes of persisters included chronic activation of inflammasome, STING, and type I interferons. Comprehensive metabolomic characterization uncovered that TKI-induced pyroptotic persisters display high methionine consumption and excessive taurine production. Elevated methionine flux or exogenous taurine preserved plasma membrane integrity via osmolyte-mediated effects. Increased dependency on methionine flux decreased the level of one carbon metabolism intermediate S-(5'-adenosyl)-L-homocysteine, a determinant of cell methylation capacity. The consequent increase in methylation potential induced DNA hypermethylation of genes regulating metal ion balance and intrinsic immune response. This enabled thwarting TKI resistance by using the hypomethylating agent decitabine. In summary, the evolution of resistance to pyroptosis can occur via a stepwise process of physical acclimation and epigenetic changes without existing or recurrent mutations.

SIGNIFICANCE

Methionine enables cancer cells to persist by evading pyroptotic osmotic lysis, which leads to genome-wide hypermethylation that allows persisters to gain proliferative advantages.

Flavonoid-Rich Extract of Oldenlandia diffusa (Willd.) Roxb. Inhibits Gastric Cancer by Activation of Caspase-Dependent Mitochondrial Apoptosis

OBJECTIVE

To evaluate the apoptosis and cycle arrest effects of Oldenlandia diffusa flavonoids on human gastric cancer cells, determine the action mechanisms in association with the mitochondrial dependent signal transduction pathway that controls production of reactive oxygen species (ROS), and evaluate the pharmacodynamics of a mouse xenotransplantation model to provide a reference for the use of flavonoids in prevention and treatment of gastric cancer.

METHODS

Flavonoids were extracted by an enzymatic-ultrasonic assisted method and purified with D-101 resin. Bioactive components were characterized by high-performance liquid chromatography. Cell lines MKN-45, AGS, and GES-1 were treated with different concentrations of flavonoids (64, 96, 128, 160 µg/mL). The effect of flavonoids on cell viability was evaluated by MTT method, and cell nuclear morphology was observed by Hoechst staining. The apoptosis rate and cell cycle phases were measured by flow cytometry, the production of ROS was detected by laser confocal microscope, the mitochondrial membrane potential (MMP) were observed by fluorescence microscope, and the expression of apoptotic proteins related to activation of mitochondrial pathway were measured by immunoblotting. MKN-45 cells were transplanted into BALB/c nude mice to establish a xenograft tumor model. Hematoxylin and eosin staining was used to reveal the subcutaneous tumor tissue. The tumor volume and tumor weight were measured, the expression levels of proliferation markers proliferating cell nuclear antigen (PCNA) and Ki-67 were detected by immunohistochemistry, and the expression levels of CA72-4 were measured by enzyme linked immunosorbent assay.

RESULTS

Oldenlandia diffusa flavonoids inhibited proliferation of MKN-45 and AGS human gastric cancer cells, arrested the cell cycle in G₁/S phase, induced accumulation of ROS in the process of apoptosis, and altered MMP. In addition, flavonoids increased Apaf-1, Cleaved-Caspase-3, and Bax, and decreased Cyclin A, Cdk2, Bcl-2, Pro-Caspase-9, and Mitochondrial Cytochrome C (P<0.05). The MKN-45 cell mouse xenotransplantation model further clarified the growth inhibitory effect of flavonoids towards tumors. The expression levels of PCNA and Ki-67 decreased in each flavonoid dose group, the expression level of CA72-4 decreased (P<0.05).

CONCLUSION

Flavonoids derived from Oldenlandia diffusa can inhibit proliferation and induce apoptosis of human gastric cancer cells by activating the mitochondrial controlled signal transduction pathway.

Doxorubicin-An Agent with Multiple Mechanisms of Anticancer Activity

Doxorubicin (DOX) constitutes the major constituent of anti-cancer treatment regimens currently in clinical use. However, the precise mechanisms of DOX's action are not fully understood. Emerging evidence points to the pleiotropic anticancer activity of DOX, including its contribution to DNA damage, reactive oxygen species (ROS) production, apoptosis, senescence, autophagy, ferroptosis, and pyroptosis induction, as well as its immunomodulatory role. This review aims to collect information on the anticancer mechanisms of DOX as well as its influence on anti-tumor immune response, providing a rationale behind the importance of DOX in modern cancer therapy.

Functionalized Hybrid Iron Oxide-Gold Nanoparticles Targeting Membrane Hsp70 Radiosensitize Triple-Negative Breast Cancer Cells by ROS-Mediated Apoptosis

Triple-negative breast cancer (TNBC) a highly aggressive tumor entity with an unfavorable prognosis, is treated by multimodal therapies, including ionizing radiation (IR). Radiation-resistant tumor cells, as well as induced normal tissue toxicity, contribute to the poor clinical outcome of the disease. In this study, we investigated the potential of novel hybrid iron oxide (Fe₃O₄)-gold (Au) nanoparticles (FeAuNPs) functionalized with the heat shock protein 70 (Hsp70) tumor-penetrating peptide (TPP) and coupled via a PEG4 linker (TPP-PEG4-FeAuNPs) to improve tumor targeting and uptake of NPs and to break radioresistance in TNBC cell lines 4T1 and MDA-MB-231. Hsp70 is overexpressed in the cytosol and abundantly presented on the cell membrane (mHsp70) of highly aggressive tumor cells, including TNBCs, but not on corresponding normal cells, thus providing a tumor-specific target. The Fe₃O₄ core of the NPs can serve as a contrast agent enabling magnetic resonance imaging (MRI) of the tumor, and the nanogold shell radiosensitizes tumor cells by the release of secondary electrons (Auger electrons) upon X-ray irradiation. We demonstrated that the accumulation of TPP-PEG4-FeAuNPs into mHsp70-positive TNBC cells was superior to that of non-conjugated FeAuNPs and FeAuNPs functionalized with a non-specific, scrambled peptide (NGL). After a 24 h co-incubation period of 4T1 and MDA-MB-231 cells with TPP-PEG4-FeAuNPs, but not with control hybrid NPs, ionizing irradiation (IR) causes a cell cycle arrest at G2/M and induces DNA double-strand breaks, thus triggering apoptotic cell death. Since the radiosensitizing effect was completely abolished in the presence of the ROS inhibitor N-acetyl-L-cysteine (NAC), we assume that the TPP-PEG4-FeAuNP-induced apoptosis is mediated via an increased production of ROS.

Combination of PAKs inhibitors IPA-3 and PF-3758309 effectively suppresses colon carcinoma cell growth by perturbing DNA damage response

PURPOSE

PAKs proteins are speculated as new promising targets for cancer therapy due to their central role in many oncogenic pathways. Because PAKs proteins are very significant during carcinogenesis, we aimed to investigate the hypothesis that inhibition of PAKs with IPA-3 and PF-3758309 treatment could synergistically reduce colon carcinoma cell growth.

MATERIALS AND METHODS

The cytotoxic effects of both drugs were determined by a cell viability assay. Cell cycle and apoptosis were analyzed by flow cytometry. The effects of inhibitor drugs on marker genes of apoptosis, autophagy, cell cycle, and DNA damage were tested via immunoblotting.

RESULTS AND CONCLUSIONS

We found out the synergistic effect of these drugs in pair on five colon cancer cell lines. Combined treatment with IPA-3+PF-3758309 in SW620 and Colo 205 cells markedly suppressed colon formation and induced apoptosis, cell cycle arrest, and autophagy compared with treatment with each drug alone. Additionally, this combination sensitized colon cancer cells to ionizing radiation that resulted in inhibition of cell growth.

SIGNIFICANCE

Collectively, our findings show for the first time that cotreatment of IPA-3 with PF-3758309 exhibits superior inhibitory effects on colon carcinoma cell growth via inducing DNA damage-related cell death and also enforces a cell cycle arrest.

Phytochemical Analysis and Anticancer Properties of Drimia maritima Bulb Extracts on Colorectal Cancer Cells

Cancer is a worldwide health problem and is the second leading cause of death after heart disease. Due to the high cost and severe side effects associated with chemotherapy treatments, natural products with anticancer therapeutic potential may play a promising role in anticancer therapy. The purpose of this study was to investigate the cytotoxic and apoptotic characteristics of the aqueous Drimia maritima bulb extract on Caco-2 and COLO-205 colorectal cancer cells. In order to reach such a purpose, the chemical composition was examined using the GC-MS method, and the selective antiproliferative effect was determined in colon cancer cell lines in normal gingival fibroblasts. The intracellular ROS, mitochondrial membrane potential, and gene expression changes in selected genes (CASP8, TNF-α, and IL-6 genes) were assessed to determine the molecular mechanism of the antitumor effect of the extract. GC-MS results revealed the presence of fifty-seven compounds, and Proscillaridin A was the predominant secondary metabolite in the extract. The IC₅₀ of D. maritima bulb extract on Caco-2, COLO-205, and the normal human gingival fibroblasts were obtained at 0.9 µg/mL, 2.3 µg/mL, and 13.1 µg/mL, respectively. The apoptotic effect assay indicated that the bulb extract induced apoptosis in both colon cancer cell lines. D. maritima bulb extract was only able to induce statistically significant ROS levels in COLO-205 cells in a dose-dependent manner. The mitochondrial membrane potential (MMP) revealed a significant decrease in the MMP of Caco-2 and COLO-205 to various concentrations of the bulb extract. At the molecular level, RT-qPCR was used to assess gene expression of CASP8, TNF-α, and IL-6 genes in Caco-2 and COLO-205 cancer cells. The results showed that the expression of pro-inflammatory genes TNF-α and IL-6 were upregulated. The apoptotic initiator gene CASP8 was also upregulated in the Caco-2 cell line and did not reach significance in COLO-205 cells. These results lead to the conclusion that D. maritima extract induced cell death in both cell lines and may have the potential to be used in CRC therapy in the future.

The Assessment of the Phototoxic Action of Chlortetracycline and Doxycycline as a Potential Treatment of Melanotic Melanoma-Biochemical and Molecular Studies on COLO 829 and G-361 Cell Lines

Melanoma is still one of the most dangerous cancers. New methods of treatment are sought due to its high aggressiveness and the relatively low effectiveness of therapies. Tetracyclines are drugs exhibiting anticancer activity. Previous studies have also shown their activity against melanoma cells. The possibility of tetracycline accumulation in pigmented tissues and the increase in their toxicity under the influence of UVA radiation creates the possibility of developing a new anti-melanoma therapy. This study aimed to analyze the phototoxic effect of doxycycline and chlortetracycline on melanotic melanoma cells COLO 829 and G-361. The results indicated that tetracycline-induced phototoxicity significantly decreased the number of live cells by cell cycle arrest as well as a decrease in cell viability. The simultaneous exposure of cells to drugs and UVA caused the depolarization of mitochondria as well as inducing oxidative stress and apoptosis. It was found that the combined treatment activated initiator and effector caspases, caused DNA fragmentation and elevated p53 level. Finally, it was concluded that doxycycline demonstrated a stronger cytotoxic and phototoxic effect. UVA irradiation of melanoma cells treated with doxycycline and chlortetracycline allows for the reduction of therapeutic drug concentrations and increases the effectiveness of tested tetracyclines.

Raddeanin A Improves the Therapeutic Effect of Osimertinib in NSCLC by Accelerating ROS/NLRP3-mediated Pyroptosis

BACKGROUND

Osimertinib (Osm) is the preferred treatment for non-small cell lung cancer (NSCLC) patients with the epidermal growth factor receptor (EGFR) T790M mutation. Nevertheless, the resistance of NSCLC cells to Osm will eventually develop, which remains the biggest obstacle to treating such diseases. Raddeanin A (RA) exhibits a potent anti-tumor effect on various types of cancer cells. In this study, we aimed to investigate whether RA suppresses NSCLC growth and increases the therapeutic effect of Osm.

METHODS

The effects of RA on inhibiting NSCLC cell viability and proliferation were tested using cell counting kit 8 (CCK-8) and EdU assay. The roles of RA in improving the anti-tumor effect of Osm were tested with CCK-8 and colony formation assays. The roles of RA in regulating reactive oxygen species (ROS)/NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3)-mediated pyroptosis were assessed using quantitative real- time PCR (qRT-PCR) and western blotting analysis.

RESULTS

RA treatment decreased A549 and H1975 cell viability in a dose- and time-dependent way. RA inhibited NSCLC cell proliferation and tumor growth in vivo. Mechanistically, RA induced ROS overgeneration and resulted in subsequent NLRP3-mediated pyroptosis. In particular, combination treatment with Osm and RA reduced cell viability and clonogenic growth capacity more efficiently than Osm mono treatment in A549 and H1975 cells. Combination treatment also promoted NLRP3-mediated pyroptosis more efficiently than Osm mono treatment.

CONCLUSION

RA inhibited the NSCLC growth and increased the anti-tumor role of Osm in NSCLC by facilitating ROS/NLRP3-mediated pyroptosis. These results suggested that combination therapy with RA and Osm might be an effective strategy to treat Osm-resistant NSCLC.

An overview of the intracellular localization of high-Z nanoradiosensitizers

Radiation therapy (RT) is a method commonly used for cancer treatment worldwide. Commonly, RT utilizes two routes for combating cancers: 1) high-energy radiation to generate toxic reactive oxygen species (ROS) (through the dissociation of water molecules) for damaging the deoxyribonucleic acid (DNA) inside the nucleus 2) direct degradation of the DNA. However, cancer cells have mechanisms to survive under intense RT, which can considerably decrease its therapeutic efficacy. Excessive radiation energy damages healthy tissues, and hence, low doses are applied for cancer treatment. Additionally, different radiosensitizers were used to sensitize cancer cells towards RT through individual mechanisms. Following this route, nanoparticle-based radiosensitizers (herein called nanoradiosensitizers) have recently gained attention owing to their ability to produce massive electrons which leads to the production of a huge amount of ROS. The success of the nanoradiosensitizer effect is closely correlated to its interaction with cells and its localization within the cells. In other words, tumor treatment is affected from the chain of events which is started from cell-nanoparticle interaction followed by the nanoparticles direction and homing inside the cell. Therefore, passive or active targeting of the nanoradiosensitizers in the subcellular level and the cell-nano interaction would determine the efficacy of the radiation therapy. The importance of the nanoradiosensitizer's targeting is increased while the organelles beyond nucleus are recently recognized as the mediators of the cancer cell death or resistance under RT. In this review, the principals of cell-nanomaterial interactions and which dominate nanoradiosensitizer efficiency in cancer therapy, are thoroughly discussed.

The Anticancer Potential of Chlorine Dioxide in Small-Cell Lung Cancer Cells

Background Chlorine dioxide (ClO2) is an effective disinfectant consisting of oxygen, chloride, and potassium. Because of its high oxidative capacity, ClO2 exerts antimicrobial, antiviral, and antifungal effects. However, its anticancer effects remain to be elucidated. Methodology The anticancer activity of CIO2 was assessed on DMS114 small-cell lung cancer (SCLC) cells and human umbilical vein endothelial cells (HUVEC) as control by WST-1, Annexin V, cell cycle analysis, and acridine orange staining. We for the first time investigated the possible therapeutic effects of long-term stabilized ClO2 solution (LTSCD). Results Our preliminary findings showed that LTSCD significantly inhibited the proliferation of SCLC cells (p < 0.01) with less toxicity in HUVEC cells. Additionally, LTSCD induced apoptotic cell death in SCLC cells through nuclear blebbing and vacuolar formation. However, LTSCD treatment did not induce cell cycle arrest in both cell lines. Conclusions LTSCD can be a therapeutic potential for the treatment of SCLC. However, further investigations are required to assess the LTSCD-induced cell death in SCLC both in vitro and in vivo.

Anticancer activity of an Artemisia annua L. hydroalcoholic extract on canine osteosarcoma cell lines

Since ancient times, Artemisia annua (A. annua) has been used as a medicinal plant in Traditional Chinese Medicine. In addition, recent studies have investigated the cytotoxic effects of A. annua extracts towards cancer cells. The leading aim of the present research is to evaluate the cytotoxic effects of an hydroalcoholic extract of A. annua on two canine osteosarcoma (OSA) cell lines, OSCA-8 and OSCA-40, focusing on the possible involvement of ferroptosis. The quantitative determination of artemisinin concentration in the extract, culture medium and OSA cells was carried out through the use of an instrumental analytical method based on liquid chromatography coupled with spectrophotometric detection and tandem mass spectrometry (LC-DAD-MS/MS). OSCA-8 and OSCA-40 were exposed to different dilutions of the extract for the EC₅₀ calculation then the uptake of artemisinin by the cells, the effects on the cell cycle, the intracellular iron level, the cellular morphology and the lipid oxidation state were evaluated. A concentration of artemisinin of 63.8 ± 3.4 μg/mL was detected in the extract. A dose-dependent cytotoxic effect was evidenced. In OSCA-40 alterations of the cell cycle and a significantly higher intracellular iron content were observed. In both cell lines the treatment with the extract was associated with lipid peroxidation and with the appearance of a "ballooning" phenotype suggesting the activation of ferroptosis. In conclusion the A. annua idroalcoholic extract utilized in this study showed anticancer activity on canine OSA cell lines that could be useful in treating drug resistant canine OSAs.

EZH2 Regulates ANXA6 Expression via H3K27me3 and Is Involved in Angiotensin II-Induced Vascular Smooth Muscle Cell Senescence

Objectives

Abdominal aortic aneurysm (AAA) has a high risk of rupture of the aorta and is one of the leading causes of death in older adults. This study is aimed at confirming the influence and mechanism of the abnormally expressed ANXA6 gene in AAA.

Methods

Clinical samples were collected for proteome sequencing to screen for differentially expressed proteins. An Ang II-induced vascular smooth muscle cell (VSMC) aging model as well as an AAA animal model was used. Using RT-qPCR to detect the mRNA levels of EZH2, ANXA6, IK-6, and IL-8 in cells and tissues were assessed. Western blotting and immunohistochemistry staining were used apply for the expression of associated proteins in cells and tissues. SA-β-gal staining, flow cytometry, and DHE staining were used to detect senescent cells and the level of ROS. The cell cycle was assessed by flow cytometry. Arterial pathology was observed by HE staining. The aging of VSMCs in arterial tissue was assessed by coimmunofluorescence for α-SMA and p53.

Results

There were 24 differentially expressed proteins in the AAA clinical samples, including 10 upregulated protein and 14 downregulated protein, and the differential expression of ANXA6 was associated with vascular disease. Our study found that ANXA6 was highly expressed and EZH2 was lowly expressed in an Ang II-induced VSMC aging model. Knockdown of ANXA6 or overexpression of EZH2 inhibited Ang II-induced ROS, inhibited cell senescence, decreased Ang II evoked G1 arrest, and increased cells in G2 phase, while overexpression of ANXA6 played the opposite role. Overexpression of EZH2 inhibited ANXA6 expression by increasing H3K27me3 modification at the ANXA6 promoter. Simultaneous overexpression of EZH2 and the protective effect of EZH2 on cell senescence were partially reversed by ANXA6. Similarly, ANXA6 was highly expressed and EZH2 was lowly expressed in an Ang II-induced AAA animal model. Knockdown of ANXA6 and overexpression of EZH2 alleviated Ang II-induced VSMC senescence and inhibited AAA progression, while simultaneous overexpression of EZH2 and ANXA6 partially reversed the protective effect of EZH2 on AAA.

Conclusion

EZH2 regulates the ANXA6 promoter H3K27me3 modification, inhibits ANXA6 expression, alleviates Ang II-induced VSMC senescence, and inhibits AAA progression.

Methanol Extract of Clavularia inflata Exerts Apoptosis and DNA Damage to Oral Cancer Cells

Antiproliferation effects of Clavularia-derived natural products against cancer cells have been reported on, but most studies have focused on identifying bioactive compounds, lacking a detailed investigation of the molecular mechanism. Crude extracts generally exhibit multiple targeting potentials for anticancer effects, but they have rarely been assessed for methanol extracts of Clavularia inflata (MECI). This investigation aims to evaluate the antiproliferation of MECI and to examine several potential mechanisms between oral cancer and normal cells. A 24 h MTS assay demonstrated that MECI decreased cell viability in several oral cancer cell lines more than in normal cells. N-acetylcysteine (NAC), an oxidative stress inhibitor, recovered these antiproliferation effects. Higher oxidative stress was stimulated by MECI in oral cancer cells than in normal cells, as proven by examining reactive oxygen species and mitochondrial superoxide. This preferential induction of oxidative stress was partly explained by downregulating more cellular antioxidants, such as glutathione, in oral cancer cells than in normal cells. Consequently, the MECI-generated high oxidative stress in oral cancer cells was preferred to trigger more subG1 population, apoptosis expression (annexin V and caspase activation), and DNA damage, reverted by NAC. In conclusion, MECI is a potent marine natural product showing preferential antiproliferation against oral cancer cells.

Colchicine as a novel drug for the treatment of osteosarcoma through drug repositioning based on an FDA drug library

Background

Colchicine is a traditional medication that is currently approved to treat gout and familial Mediterranean fever (FMF). However, colchicine has a wide range of anti-inflammatory activities, and several studies have indicated that it may be useful in a variety of other conditions, such as rheumatic disease, cardiac disease, and cancer. Osteosarcoma, the most common type of bone sarcoma, is derived from primitive bone-forming mesenchymal cells. In this study, we investigated whether colchicine could be used to treat osteosarcoma through the regulation of cell cycle signaling.

Methods

Two human osteosarcoma cell lines, U2OS and Saos-2, were used. A clonogenic assay was used to determine the antiproliferative effects of colchicine on osteosarcoma cells. Reactive oxygen species (ROS) production and apoptosis were measured by flow cytometry. Migration and invasion assays were performed to investigate the inhibitory effects of colchicine. The signaling pathways related to colchicine treatment were verified by GO biological process (GOBP) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses.

Results

Colchicine was selected as the lead compound based on the results of initial screening and cell viability assays conducted in Saos-2 and U2Os cells. Colchicine reduced the viability of Saos-2 and U2OS cells in a concentration-dependent manner. It also significantly inhibited colony-forming ability and induced ROS production and apoptosis. It also inhibited the migration and invasion of both Saos-2 and U2OS cells. GOBP and KEGG enrichment analyses indicated the involvement of microtubule-based processes and cancer-related pathways.

Conclusions

These findings suggest that colchicine has therapeutic potential in osteosarcoma.

A life history model of the ecological and evolutionary dynamics of polyaneuploid cancer cells

Therapeutic resistance is one of the main reasons for treatment failure in cancer patients. The polyaneuploid cancer cell (PACC) state has been shown to promote resistance by providing a refuge for cancer cells from the effects of therapy and by helping them adapt to a variety of environmental stressors. This state is the result of aneuploid cancer cells undergoing whole genome doubling and skipping mitosis, cytokinesis, or both. In this paper, we create a novel mathematical framework for modeling the eco-evolutionary dynamics of state-structured populations and use this framework to construct a model of cancer populations with an aneuploid and a PACC state. Using in silico simulations, we explore how the PACC state allows cancer cells to (1) survive extreme environmental conditions by exiting the cell cycle after S phase and protecting genomic material and (2) aid in adaptation to environmental stressors by increasing the cancer cell's ability to generate heritable variation (evolvability) through the increase in genomic content that accompanies polyploidization. In doing so, we demonstrate the ability of the PACC state to allow cancer cells to persist under therapy and evolve therapeutic resistance. By eliminating cells in the PACC state through appropriately-timed PACC-targeted therapies, we show how we can prevent the emergence of resistance and promote cancer eradication.

Stochastic models of Mendelian and reverse transcriptional inheritance in state-structured cancer populations

Recent evidence suggests that a polyaneuploid cancer cell (PACC) state may play a key role in the adaptation of cancer cells to stressful environments and in promoting therapeutic resistance. The PACC state allows cancer cells to pause cell division and to avoid DNA damage and programmed cell death. Transition to the PACC state may also lead to an increase in the cancer cell’s ability to generate heritable variation (evolvability). One way this can occur is through evolutionary triage. Under this framework, cells gradually gain resistance by scaling hills on a fitness landscape through a process of mutation and selection. Another way this can happen is through self-genetic modification whereby cells in the PACC state find a viable solution to the stressor and then undergo depolyploidization, passing it on to their heritably resistant progeny. Here, we develop a stochastic model to simulate both of these evolutionary frameworks. We examine the impact of treatment dosage and extent of self-genetic modification on eco-evolutionary dynamics of cancer cells with aneuploid and PACC states. We find that under low doses of therapy, evolutionary triage performs better whereas under high doses of therapy, self-genetic modification is favored. This study generates predictions for teasing apart these biological hypotheses, examines the implications of each in the context of cancer, and provides a modeling framework to compare Mendelian and non-traditional forms of inheritance.

Cedrus libani tar prompts reactive oxygen species toxicity and DNA damage in colon cancer cells

BACKGROUND

Many chemotherapeutic drugs used in cancer treatment have anticancer properties by inducing reactive oxygen species (ROS). However, the same effect occurs in normal cells, limiting the availability of these drugs. Therefore, studies on the detection of new herbal anticancer agents that have selective effects on cancer cells are of great importance. The aim of this study is to investigate the metabolite profile of Cedrus libani tar and its mechanism of anticancer effect on colon cancer cells.

METHODS AND RESULTS

Effect of cedar tar on cells (12 cancers and 5 normal cell lines) viability was determined by MTT, apoptosis induction was determined by Annexin-V, ROS and MMP determined by flow cytometry assay. Cleaved caspase-8, 9 and Ɣ-H2AX expression determined by western blot. Apoptotic and antioxidant genes expression level determined by qPCR. Metabolite profiling was performed with LC-MS/MS and GC-MS. Cedar tar showed the highest cytotoxic effect among cancer cells in colon cancer (HCT-116, IC₅₀: 30.4 μg/mL) and its toxic effect on normal cells (HUVEC, IC₅₀: 74.07 μg/mL) was less than cancer cell. Cedar tar increases ROS production in colon cancer cells. The metabolite profile of the cedar tar contains high amounts of metabolites such as fatty acids mainly (Duprezianene, Himachalene and Chamigrene), phenolic compounds (mostly Coumarin, p-coumaric acid, Vanillic acid and tr-Ferulic acid etc.) and organic acids (mainly 3-oh propanoic acid, 2-oh butyric acid and 3-oh isovaleric acid etc.).

CONCLUSION

As a result, it has been found that cedar tar has the potential to be used in the treatment of colon cancer.

Auranofin induces urothelial carcinoma cell death via reactive oxygen species production and synergy with cisplatin

Urothelial carcinoma (UC) is one of the most common cancer types of the urinary tract. UC is associated with poor 5-year survival rate, and resistance to cisplatin-based therapy remains a challenge for invasive bladder cancer treatment. Therefore, there is an urgent need to develop new drugs for advanced UC therapy. Auranofin (AF) was developed over 30 years ago for the treatment of rheumatoid arthritis and has been reported to exert an antitumor effect by increasing the level of reactive oxygen species (ROS) in cancer cells. The aim of the present study was to examine the effects of AF on cancer cell proliferation, cell cycle and apoptosis, either alone or in combination with cisplatin. AF induced cell death in two separate cell lines, HT 1376 and BFTC 909, in a concentration- and time-dependent manner by inducing cell cycle arrest. However, the distribution of cells in different phases of the cell cycle differed between the two cell lines, with G0/G1 cell cycle arrest in HT 1376 cells and S phase arrest in BFTC 909 cells. In addition, AF induced apoptosis in HT 1376, as well as redox imbalance in both HT 1376 and BFTC 909 cells. Cell viability was rescued following treatment with N-acetyl-L-cysteine, a ROS scavenger. Furthermore, AF treatment synergistically increased the cytotoxicity of HT 1376 and BFTC 909 cells when combined with cisplatin treatment. These findings suggest that AF may represent a potential candidate drug against UC and increase the therapeutic effect of cisplatin.

The potential inhibitory effect of ginsenoside Rh2 on mitophagy in UV-irradiated human dermal fibroblasts

Background

In addition to its use as a health food, ginseng is used in cosmetics and shampoo because of its extensive health benefits. The ginsenoside, Rh2, is a component of ginseng that inhibits tumor cell proliferation and differentiation, promotes insulin secretion, improves insulin sensitivity, and shows antioxidant effects.

Methods

The effects of Rh2 on cell survival, extracellular matrix (ECM) protein expression, and cell differentiation were examined. The antioxidant effects of Rh2 in UV-irradiated normal human dermal fibroblast (NHDF) cells were also examined. The effects of Rh2 on mitochondrial function, morphology, and mitophagy were investigated in UV-irradiated NHDF cells.

Results

Rh2 treatment promoted the proliferation of NHDF cells. Additionally, Rh2 increased the expression levels of ECM proteins and growth-associated immediate-early genes in ultraviolet (UV)-irradiated NHDF cells. Rh2 also affected antioxidant protein expression and increased total antioxidant capacity. Furthermore, treatment with Rh2 ameliorated the changes in mitochondrial morphology, induced the recovery of mitochondrial function, and inhibited the initiation of mitophagy in UV-irradiated NHDF cells.

Conclusion

Rh2 inhibits mitophagy and reinstates mitochondrial ATP production and membrane potential in NHDF cells damaged by UV exposure, leading to the recovery of ECM, cell proliferation, and antioxidant capacity.