Normal Cells Research Articles

Current Insights into Therapeutic Potential of Terpenoids as Anticancer Agents.

Cancer is regarded as one of the main causes of death globally. Future predictions indicate that the death rate from cancer will keep rising, which may reach 11.4 million in 2030. Carcinogenesis refers to the phenomenon of transforming a normal cell into a cancer cell. Cancer is characterized by unregulated and uncontrolled cell division due to alterations at the molecular and genetic levels. Gene mutations can speed up the rate of cell division, which leads to cancer. Metastasis entails the dissemination of cancer cells from the primary site to distant regions of the body via the circulatory or lymphatic systems. This review is mainly focusing on the anticancer properties of terpenoids. In the case of human beings, several types of cancers can be treated clinically based on the form and phase of the cancer. So, there are different types of treatment regimens available for the management of cancer, such as immunotherapy, hormonal therapy, radiation therapy, and chemotherapy. Several problems are associated with cancer therapy, including chemoresistance, severe toxicity, relapse, and metastasis. To minimize these complications, natural products like terpenoids seem to be beneficial for the effective management of cancer. Experimental results revealed that the anticancer potential of terpenoids is due to activation of apoptosis and stimulation of cell cycle arrest. Some of the terpenoids exhibit anticancer effects by inhibiting angiogenesis and metastasis via the regulation of several signaling pathways intracellularly. Certain terpenoids have been shown to work in concert with anticancer medications (doxorubicin, cisplatin, paclitaxel, and 5-fluorouracil) to provide synergistic effects. These terpenoids have also been shown to be effective against cancer cells that are resistant to several drug therapies. The current study will focus on signaling pathways and mode of action of several types of terpenoids as anticancer agents. Further, it will provide insights into the ongoing clinical trials and prospective pathways for the advancement of terpenoids as possible anti-cancer agents.

Synthesis and Characterization of TiO2 -CQDs Nanocomposites and Testing of Their Anticancer Potential

This work used a green approach to produce carbon quantum dots (CQDs). TiO2 nanoparticles (NPs) and TiO2–CQDs nanocomposites with different weight ratios of CQDs were organized through a facile sol-gel method. XRD showed that the anatase and rutile phases of TiO2 were polycrystalline with a tetragonal structure and that the CQDs exhibited a broad peak at (002) and a hexagonal structure. High resolution-transmission-electron microscopy revealed that the TiO2 NPs agglomerated in mostly spherical shapes and that the anatase and rutile phases of TiO2 had sizes of less than 15 and 25 nm, respectively. The CQDs had a relatively uniform diameter, a spherical shape with a highly crystalline structure, and a size below 2 nm. UV–visible spectroscopy revealed that the absorbance of the TiO2- CQDs nanocomposites increased with the increase in CQD ratio. The energy band gaps of the anatase and rutile phases were 3.07 and 2.7 eV, respectively, whereas that of CQDs was 3.14 eV. Meanwhile, the energy band gaps of the TiO2–CQDs nanocomposites decreased with the increase in CQDs ratio. The growth inhibition rates of the liver cancer HepG2 cell line and the normal cell line RD were measured after 24 hours of experience to the two TiO2 phases and TiO2–CQDs nanocomposites. The cytotoxicity test presented that the tested substances were extremely harmful to cells in cancer. Inhibition rates increased with the increase in CQDs ratio. The inhibition rate of growth in cancer cells, including the liver cancer HepG2 cell line and the normal cell line (RD), was measured for 24 hours after they were exposed to TiO2 (two phases) and TiO2-CQDs nanocomposites. The samples showed a slight effect on the normal line (RD) compared to HepG2 cancer. The highest inhibition rate was 12.11% for the CQD 0.7 sample.

AKT and the Hallmarks of Cancer.

Nearly a quarter century ago, Hanahan and Weinberg conceived six unifying principles explaining how normal cells transform into malignant tumors. Their provisional set of biological capabilities acquired during tumor development  cancer hallmarks  would evolve to fourteen tenets as knowledge of cancer genomes, molecular mechanisms, and the tumor microenvironment expanded, most recently adding four emerging enabling characteristics: phenotypic plasticity, epigenetic reprogramming, polymorphic microbiomes, and senescent cells. AKT kinases are critical signaling molecules that regulate cellular physiology upon receptor tyrosine kinases and phosphatidylinositol 3-kinase activation. The complex branching of the AKT signaling network involves several critical downstream nodes that significantly magnify its functional impact, such that nearly every organ system and cell in the body may be affected by AKT activity. Conversely, tumor intrinsic dysregulation of AKT can have numerous adverse cellular and pathological ramifications, particularly in oncogenesis, as multiple tumor suppressors and oncogenic proteins regulate AKT signaling. Herein, we review the mounting evidence implicating the AKT pathway in the aggregate of currently recognized hallmarks of cancer underlying the complexities of human malignant diseases. The challenges, recent successes, and likely areas for exciting future advances in targeting this complex pathway are also discussed.

Evaluation Secondary Metabolite Extract Produced by Aspergillus terreus Isolated from Poultry Droppings as Anticancer Agent

Malignant diseases are considered one of the problems of our time, and cancer is defined as the abnormal growth of malignant cells. It is widely accepted as the leading cause of death. There is currently no proven cancer cure. As a result, scientists have concentrated on creating secure and efficient therapies. Research has been done on the effects of naturally occurring substances that have been extracted from living things, such fungus on cancer cells. This study sought to determine the natural products' efficacy against human cancer cell line MCF-7. After A. terreus was isolated from samples of chicken droppings, it was grown on potato and Sabouraud Dextrose Agars (SDA and PDA) with chloramphenicol media. It was then identified using the extracted genomic DNA, the internal transcribed spacer (ITS) region was amplified and sequenced. After 30 days of incubation at 27°C, natural metabolite products were also recovered from the fermentation medium using the ethyl acetate extraction technique. The effectiveness of the fungal extract against the human cancer cell line MCF-7 and the normal human cell line NHF cell was also determined after incubation for 27 hours with the natural extract. The treated human cancer cell line MCF-7 showed decrease of proliferation, whereas the normal human cell line NHF showed no effect. Significant inhibitor compared to cancer line. The IC50 values for MCF-7 cell lines and NHF normal human cell lines were 7.672 and 1431 μg/mL, respectively. In summary, MCF-7 was affected by the natural extract extracted from A. terreus, in contrast to the control. When these results were combined, they showed that the fungal extract is an effective anti-cancer treatment.

A pH-Sensitive cRGD-PEG-siRNA Conjugated Compound Targeting Glioblastoma.

Glioblastoma ranks among the most prevalent primary intracranial tumors, characterized by high mortality and poor prognosis. Chemotherapy remains a key treatment strategy for gliomas, though most current drugs suffer from limited efficacy and significant toxicity. This study focuses on a cRGD-siEGFR coupling compound synthesized in a previous stage. Prior research indicated that cRGD-siEGFR molecules exhibited certain targeting and antitumor properties but faced issues of inadequate targeting, low efficacy, and high renal toxicity. To enhance antitumor efficacy and mitigate side effects, a pH-responsive, long-circulating, and highly targeted siRNA delivery system, the cRGD-PEG-siEGFR conjugate, was developed. The targeting, antitumor effects, and biological distribution of cRGD-PEG-siEGFR were examined. The results demonstrated that cRGD-PEG-siEGFR was effectively taken up by αvβ3-positive U87MG cells, specifically silenced EGFR gene expression, and exhibited antitumor effects. In normal physiological conditions, it avoided uptake by normal cells, thereby reducing side effects. Furthermore, in vivo biodistribution experiments revealed that cRGD-PEG-siEGFR, compared to cRGD-siEGFR, significantly decreased renal accumulation and exhibited prolonged circulation. Consequently, cRGD-PEG-siRNA emerges as a promising drug candidate with attributes of long circulation, high targeting, pH responsiveness, and substantial antitumor efficacy.

Spots on 1H‐Indazole Incorporation into Thiazole Moiety‐Hybrid Heterocycles, Strong Efficacy as Small Molecules with Antimicrobial, Antineoplastic Activity, and In‐Silico Studies

AbstractAmidst the escalating cancer cases and the relentless spread of multidrug‐resistant microbes, the urgency for effective medication is undeniable. In this context, our lab's continuous efforts have led to a promising discovery. We have conducted an extensive study on a series of new heterocycles with an indazolylthiazole component, which holds great promise as antimicrobial and anticancer drugs. The bioactivity tests, conducted with meticulous methodology, have demonstrated that the synthesized compounds possess remarkable antibacterial activity against various pathogenic strains. In a controlled lab setting, we have observed that derivatives 9, 11, and 12a effectively induce apoptosis in HCT‐166 and Huh‐7 (liver carcinoma) cell lines. Among these, derivative 11 has shown the highest selectivity (SI=14.54±1.2 and 16.51±1.4) and the lowest IC50 value. These compounds also exhibit broad‐spectrum antimicrobial activity. The anticancer activity of the synthesized compounds has been computationally confirmed through molecular modeling using MOE software and pharmacokinetic studies. Most of the tested compounds have shown significant cytotoxic activity against tumor cell lines, with high safety against normal human cells, thereby paving the way for a hopeful and promising future of antimicrobial and anticancer drugs, with potential applications in [specific_application_1] and [specific_application_2].

Synthesis and biological evaluation of quinoxaline derivatives as ASK1 inhibitors

Inhibiting apoptosis signal regulated kinase 1 (ASK1) is an attractive strategy for treating diseases such as non-alcoholic steatohepatitis and multiple sclerosis. Here, we report the discovery of a dibromo substituted quinoxaline fragment containing 26e as an effective small-molecule inhibitor of ASK1, with an IC50 value of 30.17 nM. In addition, the cell survival rate of 26e at different concentrations was greater than 80%, especially at 0.4 μM. Its cell survival rate was significantly higher than GS-4997, indicating its good safety in normal human liver LO2 cells. The Oil Red O staining experiment showed that 26e decreased the lipid droplets in a dose-dependent manner. Further biochemical analyses revealed that 26e could reduce the content of T-CHO, LDL, and TG in FFA-induced LO2 cells, and had the potential to treat non-alcoholic fatty disease. These findings provide a good choice for the future development of ASK1 inhibitors.

A Novel PTPRQ c.3697del Variant Causes Autosomal Dominant Progressive Hearing Loss in Both Humans and Mice.

PTPRQ plays an important role in the development of inner ear hair cell stereocilia. While many autosomal recessive variants in PTPRQ have been identified as the pathogenic cause for nonsyndromic hearing loss (DFNB84A), so far only one autosomal dominant PTPRQ variant, c.6881G>A (p.Trp2294*), has been reported for late-onset, mild-to-severe hearing loss (DFNA73). By using targeted next-generation sequencing, this study identified a novel PTPRQ truncating pathogenic variant, c.3697del (p.Leu1233Phefs*11), from a Chinese Han family that co-segregated with autosomal dominant, postlingual, progressive hearing loss. A Ptprq-3700del knock-in mouse model was generated by CRISPR-Cas9 and characterized for its hearing function and inner ear morphology. While the homozygous knock-in mice exhibit profound hearing loss at all frequencies at the age of 3 weeks, the heterozygous mutant mice resemble the human patients in mild, progressive hearing loss from age 3 to 12 weeks, primarily affecting high frequencies. At this stage, the homozygous knock-in mice have a normal hair cell count but disorganized stereocilia. Cochlear proteosome analysis of the homozygous mutant mice revealed differentially expressed genes and pathways involved in oxidative phosphorylation, regulation of angiogenesis and synaptic vesicle cycling. Our study provides a valuable animal model for further functional studies of the pathogenic mechanisms underlying DFNA73.

Self-supported electrochemical sensor based on uniform palladium nanoparticles functionalized porous graphene film for monitoring H2O2 released from living cells.

Graphene film has been considered a promising material for the construction of self-supported electrodes due to its favorable flexibility and high conductivity. However, the film fabricated from pristine graphene or conventional graphene sheet reduced graphene oxide processes limited electrocatalytic performance. Decorating active metal species or incorporating heteroatoms intothegraphene framework have been proved to be effective methods to enhance the electrocatalytic efficiency of graphene film-based self-supported electrodes. Herein, we present a freestanding electrode composed of uniform Pd nanoparticles decorating N,S co-doped porous graphene film (Pd/NSPGF) and explore its practical application in differentiating various human colon cell types by in situ tracking the amount of H2O2 secreted from live cells. Our findings reveal that, on the one hand, the NSPGF has abundant surface and inner pores, which promote active site exposure, and mass diffusion during electrochemical reactions; on the other hand, the substitutional doping ofthe graphene framework with heteroatoms (e.g., N or S) can tailor its electronic and chemical properties, and facilitate the uniform loading of high-density Pd nanoparticles. Moreover, the intrinsic activity of Pd/NSPGF is regulated by the interaction of Pd nanoparticles withtheNSPGF support. Taking the advantages of morphology and composition, the self-supported Pd/NSPGF electrode displays remarkable electrochemical performance with a wide linear range up to 2.0mM, low detection limit of 0.1μM (S/N = 3), high sensitivity of 665 µA cm-2mM-1, and good selectivity. When applied in real-time trackingofthe H2O2 released from normal human colon epithelial cells and human colorectal cancer cells, the Pd/NSPGF-based electrochemical sensing system can distinguish the cell types by testing the number of extracellular H2O2 molecules released per cell, which holds considerable potential for early detection and monitoring of disease-related clinical specimens.

Bee venom prompts the inhibition of gefitinib on proliferation, migration, and invasion of non-small cell lung cancer cells via EGFR-mediated autophagy

It has been confirmed that bee venom (BV) can inhibit tumor metastasis of lung cancer cells induced by epidermal growth factor, suggesting the inhibitory role of BV on the regulation of epidermal growth factor receptor (EGFR), and may synergistically promote the anti-lung cancer effect of EGFR tyrosine kinase inhibitor gefitinib. This paper aims to ascertain the therapeutic potentials of BV combined with gefitinib against non-small cell lung cancer (NSCLC) in vitro. As results, the content of the main component melittin in air-dried BV was determined by HPLC. Subsequently, it was found that BV significantly inhibited the proliferation of NSCLC PC-9 and NCI-H1299 cells, but not generated apparent toxicity to human normal lung epithelial BEAS-2B cells. Meanwhile, the combination of BV and gefitinib also significantly inhibited the proliferation of these two cells, and suppressed the migration and invasion of PC-9 cells. By bioinformatics analysis and molecular docking, it was predicted that the main component melittin in BV could act on the cell membrane and transmembrane protein EGFR. Ultimately, Western blot assays showed BV alone or combined with gefitinib significantly decreased the protein expression of phosphorylated EGFR (p-EGFR) and the protein expression ratio of p-EGFR to EGFR, and increased the protein expression ratio of LC3-II to LC3-I in PC-9 cells or epidermal growth factor-activated PC-9 cells. The results demonstrated that BV could prompt the inhibition of gefitinib on proliferation, migration, and invasion of NSCLC cells via EGFR-mediated autophagy, showing the synergistic anti-NSCLC potential when combined with gefitinib.

Crosstalk between 1,25(OH)2-Vitamin D3 and the growth factors EGF and PDGF-BB: Impact on CYP24A1 expression and cell proliferation

This study explored the signaling interplay between the vitamin D receptor (VDR) and receptor tyrosine kinases (RTKs). Epidermal growth factor (EGF) and platelet-derived growth factor (PDGF)-BB promotes cell proliferation in normal and cancer cells. At the same time, the active form of vitamin D (1,25(OH)2-vitamin D3) inhibits proliferation in some cells. Although EGF receptors (EGFR) and PDGF receptors (PDGFR) activate similar downstream pathways, we found that they interact with VDR signaling in distinct ways. We confirmed that 1,25(OH)2-vitamin D3 induces CYP24A1 gene expression in U2OS, T98G, and U251 cells. We found this to be potentiated when combined with EGF. In contrast, PDGF-BB did not impact 1,25(OH)2-vitamin D3-induced CYP24A1 expression in U2OS cells. The increase in CYP24A1 expression due to the combined action of EGF and 1,25(OH)2-vitamin D3 was dependent on AKT and ERK1/2 activation. Another VDR-responsive gene, CYP27B1, was unaffected by the addition of EGF, suggesting that EGF may have gene-specific effects on VDR signaling. While PDGF-BB did not influence CYP24A1 expression, 1,25(OH)2-vitamin D3 significantly influenced PDGF-BB-induced receptor phosphorylation and cell proliferation. In summary, we found that EGF, but not PDGF-BB, influenced the expression of the VDR-dependent gene CYP24A1, while 1,25(OH)2-vitamin D3 had an inhibitory effect on PDGFR signaling and proliferation. These findings highlight unique crosstalk between 1,25(OH)2-vitamin D3 signaling and EGF or PDGF-BB.

Lack of Association Between BsmI and FokI Polymorphisms of the VDR Gene and Sporadic Colorectal Cancer in a Romanian Cohort-A Preliminary Study.

Colorectal cancer (CRC) is a major public health problem worldwide, currently ranking third in cancer incidence and second in mortality. Multiple genes and environmental factors have been involved in the complex and multifactorial process of CRC carcinogenesis. VDR is an intracellular hormone receptor expressed in both normal epithelial and cancer colon cells at various levels. Several VDR gene polymorphisms, including FokI and BsmI, have been evaluated for their possible association with CRC susceptibility. The aim of our study was to investigate these two SNPs for the first time in Romanian CRC patients. FokI (rs228570 C>T) and BsmI (rs1544410 A>G) were genotyped by real-time polymerase chain reaction (RT-PCR) in 384-well plates using specific TaqMan predesigned probes on a ViiA™ 7 RT-PCR System. A total of 441 subjects (166 CRC patients and 275 healthy controls) were included. No statistically significant difference was observed between CRC patients and controls when we compared the wild-type genotype with heterozygous and mutant genotypes for both FokI (OR 0.85, 95% CI: 0.56-1.28; OR 0.95, 95% CI: 0.51-1.79, respectively) and BsmI (OR 0.97, 95% CI: 0.63-1.49; OR 1.10, 95% CI: 0.65-1.87, respectively) or in the dominant and recessive models. Also, we compared allele frequencies, and no correlation was found. Moreover, the association between these SNPs and the tumor site, TNM stage, and histological type was examined separately, and there was no statistically significant difference. In conclusion, our study did not show any association between FokI and BsmI SNPs and CRC susceptibility in a Romanian population. Further studies including a larger number of samples are needed to improve our knowledge regarding the influence of VDR polymorphism on CRC susceptibility.

Development of β‐Carboline‐Coumarin Based Hybrids as Potential Cytotoxic and Topoisomerase IIα Inhibitors

AbstractCancer remains a global health concern, prompting extensive efforts to develop novel inhibitors targeting the enzyme topoisomerase IIα as potential anti‐cancer agents. Herein, we strategically combined the pharmacophores from natural (β‐carboline) and (coumarin) sources, diversifying them at two distinct points. The in vitro evaluation of cytotoxic properties were estimated on human cancer cell lines, reveals that among the tested compounds, 13 r (isopropyl‐substituted β‐carboline) exhibited remarkable potency with IC50 value of 4.37 μM in the HCT116 cell line. Its selectivity for cancer cells was validated against normal keratinocyte cells, establishing a favourable selectivity index. Further, SAR studies indicate that no substitution (13 r) at C‐6 and C‐7 of β‐carboline, enhance anticancer activity. Assays confirmed its ability to intercalate with DNA, inhibit topoisomerase IIα, induce apoptosis, and disrupt mitochondrial membrane potential in HCT116 cells. Flow cytometric assays gauged the induction of apoptosis using Annexin‐V/PI dual staining and the disruption of mitochondrial membrane potential through JC staining. Results demonstrated that compound 13 r induced apoptosis and dose‐dependent depolarization of the mitochondrial membrane in HCT116 cells. Molecular docking studies further validated that compound 13 r binds within the active site of DNA when complexed with topo IIα, and this binding was stabilized through interactions with DNA base pairs and amino acid residues.

Nanozymes as Antibacterial Agents: New Concerns in Design and Enhancement Strategies.

Nanozymes exhibiting natural enzyme-mimicking catalytic activities as antibacterial agents present several advantages, including high stability, low cost, broad-spectrum antibacterial activity, ease of preparation and storage, and minimal bacterial resistance. Consequently, they have attracted significant attention in recent years. However, the rapid expansion of antimicrobial nanozyme research has resulted in pioneering reviews that do not comprehensively address emerging concerns and enhancement strategies within this field. This paper first summarizes the factors influencing the intrinsic activity of nanozymes; subsequently, we outline new research considerations for designing antibacterial nanozymes with enhanced functionality and biosafety features such as degradable, imageable, targeted, and bacterial-binding nanozymes as well as those capable of selectively targeting pathogenic bacteria while sparing normal cells and probiotics. Furthermore, we review novel enhancement strategies involving external physical stimuli (light or ultrasound), the introduction of extrinsic small molecules, and self-supplying H2O2 to enhance the activity of antibacterial nanozymes under physiological conditions characterized by low concentrations of H2O2 and O2. Additionally, we present non-redox nanozymes that operate independently of highly toxic reactive oxygen species (ROS) alongside those designed to combat less common pathogenic bacteria. Finally, we discuss current issues, challenges faced in the field, and future prospects for antibacterial nanozymes.

Investigation of Apoptosis-mediated Cytotoxic Effects of Royal Jelly on HL-60 Cells

In recent years, the use of nontoxic natural products that can be effective on cancer cells as new agents has attracted the attention of scientists in order to reduce the negative side effects of existing cancer drugs and their toxicity to normal cells. Some in vivo and in vitro studies have shown that royal jelly (RJ) inhibits cell proliferation and induces apoptosis. In this research, we aimed to investigate the effects of RJ on proliferative and apoptotic processes in the human acute promyelocytic leukemia cell line (HL-60). The HL60 cell line was treated with different concentrations of RJ for 24, 48, and 72 hours. The half maximum inhibitory concentration (IC50) of RJ was determined using 3-(4.5 dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide test (MTT) and the proliferation activity of HL-60 cells was evaluated. Flow cytometry analysis was performed to measure apoptosis in HL-60 cells. IC50 values for RJ were calculated as 13.98, 6.45, and 2.06 mg/mL for 24, 48, and 72 hours, respectively. Flow cytometry results also showed that RJ had apoptotic effects at the concentrations found. The results showed that RJ treatment significantly induced apoptosis and reduced the proliferation of HL-60 cells. This study shows that RJ can be a complementary treatment against HL-60 acute myeloid leukemia cells due to its anticancer and antiproliferative effects.

To Reveal the Potential Mechanism of Quercetin against NSCLC Based on Network Pharmacology and Experimental Validation.

This study aimed to initially clarify the potential mechanism of quercetin in the treatment of non-small cell lung cancer (NSCLC) based on network pharmacology, molecular docking and in vitro experiments. TCMSP, SwissTargetPrediction, TCMIP, STITCH, and ETCM databases were applied to obtain the targets of quercetin. NSCLC-related targets were retrieved from GeneCards, OMIM, PharmGKB, TTD, and NCBI databases. Their intersection targets were imported into the STRING database to construct a protein-protein interaction (PPI) network and core targets were identified through the Cytoscape 3.10.0 soft and the CytoHubba tool. Furthermore, Gene Ontology (GO) functional analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed on the intersection targets. A compound-targetspathways network was subsequently constructed to screen for key targets and pathways. Molecular docking was performed with Discovery Studio software to verify the interactions between quercetin and core targets. In vitro validations were conducted employing CCK-8 assays, flow cytometry, and Western blotting (WB). 193 potential targets of quercetin for treating NSCLC were obtained. The top ten core targets identified within the PPI network included TP53, HSP90AA1, AKT1, JUN, SRC, EGFR, ACTB, TNF, MAPK1, and VEGFA. GO analysis yielded 2319 items, and KEGG analysis resulted in 211 enriched pathways. Molecular docking results demonstrated a high affinity of quercetin towards the core targets. Based on the compound-targets-pathways network and molecular docking, the PI3K/AKT/P53 pathway and its key-related proteins (PIK3R1, AKT1, and TP53) were selected for further validation. Quercetin(20 and 40 μg/mL) significantly decreased the viability of A549 NSCLC cells but not BEAS-2B normal cells via CCK-8 assays. Flow cytometry and WB analyses further corroborated that quercetin could promote apoptosis of A549 cells by downregulating and upregulating the expression of Bcl-2 and Bax (P<0.05), respectively. Notably, quercetin did not significantly alter the total protein levels of PI3K, AKT, and P53 but downregulated the phosphorylation levels of PI3K and AKT (P<0.05) and upregulated the phosphorylation level of P53 (P<0.05). Quercetin exhibits therapeutic potential in NSCLC by regulating the PI3K/AKT/P53 pathway to promote cell apoptosis.

O6-Alkylguanine-DNA Alkyltransferase Maintains Genome Integrity by Forming DNA-Protein Cross-Links during Inflammation-Associated Peroxynitrite-Mediated DNA Damage.

Inflammation is an early immune response against invading pathogens and damaged tissue. Although beneficial, uncontrolled inflammation leads to various diseases including cancer in a chronic setting. Peroxynitrite (PN) is a major reactive nitrogen species generated during inflammation. It produces various DNA lesions including 8-nitro-guanine which spontaneously converts into abasic sites, resulting in DNA strand breakage, and is suspected to be mutagenic. Here, we report the discovery of a previously unrecognized function of the human repair protein O6-alkylguanine-DNA alkyltransferase (hAGT or MGMT). We showed that hAGT through its active site nucleophilic Cys145 thiolate spontaneously reacts with 8-nitro-guanine in DNA to form a stable DNA-protein cross-link (DPC). Interestingly, the process of DPC formation provided protection from PN-mediated genome instability, growth arrest, and apoptosis. The Cys145 mutant of hAGT failed to form a DPC and was unable to protect cells from inflammation-associated PN-mediated cytotoxicity. Gel-shift, dot blot, and UV-vis assays showed formation of a covalent linkage between PN-damaged DNA and hAGT through its active site Cys145. Finally, expression of hAGT was found to be significantly increased by induced macrophages and PN. The data presented here clearly demonstrated hAGT as a dual-function protein that along with DNA repair is capable of maintaining genomic integrity and providing protection from the toxicity caused by PN-mediated DNA damage. Although DPCs are known to be detrimental to the cell, recently, multiple pathways have been identified in normal cells for their repair.

Synthesis and Physicochemical Properties of Poly(2‐Alkyl‐2‐Oxazoline)‐Conjugated Hemoglobins as an Artificial O2 Carrier: Comparison with Polyethylene Glycol Conjugates

AbstractPolyethylene glycol (PEG) is a biocompatible polymer extensively employed to prolong blood circulation and mitigate the immunogenicity of the protein therapeutics. Nonetheless, there are reports of anti‐PEG antibody production. Poly(2‐alkyl‐2‐oxazoline) (PROx) exhibits analogous immunological stealth properties and represents a potential substitute for PEG. This study details the synthesis of PROx‐conjugated hemoglobins (PROxm‐Hbs, R = Me, Et) as artificial O2 carriers, functioning as red blood cell (RBC) substitutes, and evaluates their O2 affinities and solution properties. The average number of polymers bound is designed to be 6 or 11. The O2 affinities (P50) of PMeOxm‐Hbs and PEtOxm‐Hbs are ascertained as 9 Torr, comparable to those of PEG‐conjugated Hbs (PEGm‐Hbs). The PEtOx6‐HbT, synthesized under an N2 atmosphere, exhibited a low O2 affinity (P50 = 57 Torr). Through the admixture of PEtOx6‐Hb and PEtOx6‐HbT, the P50 value of the formulation to range from 9 to 57 Tor can be tailored as desired. The colloid osmotic pressures and viscosities of PMeOxm‐Hb and PEtOxm‐Hb solutions are lower than those of the corresponding PEGm‐Hb solutions. Furthermore, the PROx conjugates evinced no cytotoxicity against normal cells. PMeOxm‐Hbs and PEtOxm‐Hbs, characterized by their appropriate O2 affinities and solution properties, present themselves as promising alternative materials to RBCs.

Synergistic pH-responsive MUC-1 aptamer-conjugated Ag/MSN Janus nanoparticles for targeted chemotherapy, photothermal therapy, and gene therapy in breast cancer

Drug resistance in cancer treatment, primarily attributed to the overexpression of the multidrug resistance (MDR) gene, significantly hampers the effectiveness of chemotherapy. This mechanism, driven by the increased production of P-glycoprotein (P-gp) efflux pumps, highlights the urgent need for innovative strategies to combat drug resistance in cancer patients. This study explores the application of antisense technology to suppress MDR gene expression, while addressing the challenges of instability and limited cellular uptake associated with antisense oligonucleotides. We synthesized Janus silver-mesoporous silica nanoparticles (Ag/MSN JNPs) using a sol-gel method, characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS), revealing uniformly sized, dumbbell-shaped nanoparticles with an average size of 285 ± 5.12 nm. Doxorubicin (DOX) was loaded into the porous structure of the mesoporous silica, and JNPs were functionalized with chitosan (CS) to incorporate P-gp antisense and a MUC-1 aptamer, serving as a pH-responsive gatekeeper. Our findings indicate that the Ap-As-DOX-JNPs achieved a remarkable 89 ± 0.59 % cell death in drug-resistant MCF-7/ADR cells after 48 h, alongside an 80 % reduction in P-gp expression. The combination of DOX, antisense technology, and photothermal therapy utilizing these JNPs demonstrates a promising strategy to effectively overcome drug resistance. Notably, normal MCF-7 cells exhibited reduced viability from 39.11 ± 1.12 % to 30.05 ± 1.07 % when treated with DOX-JNPs under near-infrared (NIR) irradiation. These results underscore the potential of utilizing MUC-1 aptamer-conjugated Janus nanoparticles in conjunction with chitosan as a gatekeeper to enhance the efficacy of chemotherapy, photothermal therapy, and gene therapy in overcoming multidrug resistance in cancer treatment.

AdipoRon Alleviates Liver Injury by Protecting Hepatocytes from Mitochondrial Damage Caused by Ionizing Radiation

Radiation liver injury is a common complication of hepatocellular carcinoma radiotherapy. It is mainly caused by irreversible damage to the DNA of hepatocellular cells directly by radiation, which seriously interferes with metabolism and causes cell death. AdipoRon can maintain lipid metabolism and stabilize blood sugar by activating adiponectin receptor 1 (AdipoR1). However, the role of AdipoRon/AdipoR1 in the regulation of ionizing radiation (IR)-induced mitochondrial damage remains unclear. In this study, we aimed to elucidate the roles of AdipoRon/AdipoR1 in IR-induced mitochondrial damage in normal hepatocyte cells. We found that AdipoRon treatment rescued IR-induced liver damage in mice and mitochondrial damage in normal hepatocytes in vivo and in vitro. AdipoR1 deficiency exacerbated IR-induced oxidative stress, mitochondrial dynamics, and biogenesis disorder. Mechanistically, the absence of AdipoR1 inhibits the activity of adenosine monophosphate-activated protein kinase α (AMPKα), subsequently leading to disrupted mitochondrial dynamics by decreasing mitofusin (MFN) and increasing dynamin-related protein 1 (DRP1) protein expression. It also controls mitochondrial biogenesis by suppressing the peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC1α) and transcription factor A (TFAM) signaling pathway, ultimately resulting in impaired mitochondrial function. To sum up, AdipoRon/AdipoR1 maintain mitochondrial function by regulating mitochondrial dynamics and biogenesis through the AdipoR1-AMPKα signaling pathway. This study reveals the significant role of AdipoR1 in regulating IR-induced mitochondrial damage in hepatocytes and offers a novel approach to protecting against damage caused by IR.