Research progress on the source, production, and anti-cancer mechanisms of paclitaxel

Valorization Model of Yulania biondii Waste: Component Analysis and Antibacterial, Antioxidant, and Antitumor Activities of the Extracts

Yulania biondii contains diverse bioactive compounds with significant application potential in the pharmaceutical, food, and cosmetics industries. This study investigates the bioactivity and composition of extracts from Y. biondii. It gives us a way to think about how to use forestry waste resources in a more complete way. Extracts from Y. biondii branches, leaves, and fruits were obtained using solvents such as water, ethanol, and acetone. The chemical components were analyzed using Fourier transform infrared spectroscopy (FT-IR), gas chromatography-mass spectrometry (GC-MS), and high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (HPLC-QTOF-MS). The antimicrobial activity of the extracts was assessed using the minimum inhibitory concentration (MIC) method, whereas antioxidant capacity was evaluated using DPPH and ABTS radical scavenging assays. Antitumor activity against HeLa, K562, SGC-7901, MCF-7, and HepG2 cells was assessed using the MTT assay. The results indicate that Y. biondii extracts contain a high content of flavonoids, alkaloids, phenolic compounds, and organic acids, with the ethanol extract showing the highest proportion of bioactive components at 64.93%. Additionally, Y. biondii extracts exhibited antioxidant, antibacterial, and antitumor properties, with particularly strong antioxidant effects that increased with higher extract concentrations. Among the extraction parts, the branch extract demonstrated the strongest antioxidant capacity, followed by the fruit extract, with the leaf extract showing the lowest capacity. Regarding antibacterial activity, the ethanol and acetone extracts from leaves and branches displayed strong inhibitory effects against Gram-positive bacteria. The ethanol extract from branches showed the strongest inhibition against Staphylococcus aureus, whereas the acetone extract from leaves exhibited the best inhibition against Bacillus cereus. Both ethanol and water extracts displayed varying levels of inhibition against five common tumor cell lines, with the antitumor activity ranked as follows, from strongest to weakest: leukemia cells, human gastric cancer cells, cervical cancer cells, human liver cancer cells, and human breast cancer cells. Notably, the water extract from Y. biondii leaves exhibited the strongest inhibition against human gastric cancer cells, with an inhibition rate of 82.49%. This study revealed the compositional characteristics of Y. biondii extracts and preliminarily evaluated their potential in antibacterial, antioxidant, and antitumor applications, providing a theoretical reference for the further development and application of natural plant extracts.

From Plant Based Therapy to Plant-Derived Vesicle-Like Nanoparticles for Cancer Treatment: Past, Present and Future

Cancer stands as a formidable malady profoundly impacting human health. Throughout history, plant-based therapies have remained pivotal in the arsenal against cancer, evolving alongside the epochs. Presently, challenges such as the arduous extraction of active components and potential safety concerns impede the progression of plant-based anticancer therapies. The isolation of plant-derived vesicle-like nanoparticles (PDVLNs), a kind of lipid bilayer capsules isolated from plants, has brought plant-based anticancer therapy into a novel realm and has led to decades of research on PDVLNs. Accumulating evidence indicates that PDVLNs can deliver plant-derived active substances to human cells and regulate cellular functions. Regulating immunity, inducing cell cycle arrest, and promoting apoptosis in cancer cells are the most commonly reported mechanisms of PDVLNs in tumor suppression. Low immunogenicity and lack of tumorigenicity make PDVLNs a good platform for drug delivery. The molecules within the PDVLNs are all from source plants, so the selection of source plants is crucial. In recent years, there has been a clear trend that the source plants have changed from vegetables or fruits to medicinal plants. This review highlights the mechanisms of medicinal plant-based cancer therapies to identify candidate source plants. More importantly, the current research on PDVLN-based cancer therapy and the applications of PDVLNs for drug delivery are systematically discussed.

Investigation of the sensitivity of human A549 cells to paclitaxel and sesquiterpene lactone alantolactone via apoptosis induction

Alantolactone (ALA), a sesquiterpene lactone compound obtained from Inula helenium root, is known to have anticancer activity in many types of cancer. Paclitaxel (PAX) is an effective first-line chemotherapeutic drug and is widely used in the treatment of lung cancer. The in vitro anticancer efficacy of combined treatment of ALA with PAX was investigated in the A549 human lung cancer cell line. The results show that ALA potentiated the effect of PAX-induced growth restriction and apoptosis in A549 cells. The combined administration more effectively decreased the Bcl-2 expression and increased Bax gene expression in cells compared to ALA or PAX alone. Also, co-treatment of ALA and PAX caused apoptotic nuclear formations. Additionally, coadministration increased the caspase-3 and caspase-9 levels more than PAX or ALA alone. The increase in NF-κB gene expression levels suggests that an NF-κB-independent apoptotic trigger mechanism operates in cells. Together, the present in vitro findings suggest that ALA may contribute as a potential therapeutic strategy in the treatment of lung cancer.

Recent advances in paclitaxel biosynthesis and regulation

Paclitaxel (PTX) is a high value plant natural product derived from Taxus (yew) species. This plant specialized metabolite (PSM) and its derivatives constitute a cornerstone for the treatment of an increasing variety of cancers. New applications for PTX also continue to emerge, further promoting demand for this WHO-designated essential medicine. Here we review recent advances in our understanding of PTX biosynthesis and its cognate regulation, which have been enabled by the development of transcriptomic approaches and the recent sequencing and annotation of three Taxus genomes. Collectively, this has resulted in the elucidation of two functional gene sets for PTX biosynthesis, unlocking new potential for the use of heterologous hosts to produce PTX. Knowledge of the PTX pathway also provides a valuable resource for understanding the regulation of this key PSM. Epigenetic regulation of PSM in plant cell culture is a major concern for PTX production, given the loss of PSM production in long-term cell cultures. Recent developments aim to design tools for manipulating epigenetic regulation, potentially providing a means to reverse the silencing of PSM caused by DNA methylation. Exciting times clearly lie ahead for our understanding of this key PSM and improving its production potential.

Jaceosidin induces apoptosis and inhibits migration in AGS gastric cancer cells by regulating ROS-mediated signaling pathways

Jaceosidin (JAC) is a natural flavonoid with anti-oxidant and other pharmacological activities; however, its anti-cancer mechanism remains unclear. We investigated the mechanism of action of JAC in gastric cancer cells. Cytotoxicity and apoptosis assays showed that JAC effectively killed multiple gastric cancer cells and induced apoptosis in human gastric adenocarcinoma AGS cells via the mitochondrial pathway. Network pharmacological analysis suggested that its activity was linked to reactive oxygen species (ROS), AKT, and MAPK signaling pathways. Furthermore, JAC accumulated ROS to up-regulate p-JNK, p-p38, and IκB-α protein expressions and down-regulate the p-ERK, p-STAT3, and NF-κB protein expressions. Cell cycle assay results showed that JAC accumulated ROS to up-regulate p21 and p27 protein expressions and down-regulate p-AKT, CDK2, CDK4, CDK6, Cyclin D1, and Cyclin E protein expressions to induce G0/G1 phase arrest. Cell migration assay results showed JAC accumulated ROS to down-regulate Wnt-3a, p-GSK-3β, N-cadherin, and β-catenin protein expressions and up-regulate E-cadherin protein expression to inhibit migration. Furthermore, N-acetyl cysteine pre-treatment prevented the change of these protein expressions. In summary, JAC induced apoptosis and G0/G1 phase arrest and inhibited migration through ROS-mediated signaling pathways in AGS cells.

Unveiling the Longevity Potential of Natural Phytochemicals: A Comprehensive Review of Active Ingredients in Dietary Plants and Herbs

Ancient humans used dietary plants and herbs to treat disease and to pursue eternal life. Today, phytochemicals in dietary plants and herbs have been shown to be the active ingredients, some of which have antiaging and longevity-promoting effects. Here, we summarize 210 antiaging phytochemicals in dietary plants and herbs, systematically classify them into 8 groups. We found that all groups of phytochemicals can be categorized into six areas that regulate organism longevity: ROS levels, nutrient sensing network, mitochondria, autophagy, gut microbiota, and lipid metabolism. We review the role of these processes in aging and the molecular mechanism of the health benefits through phytochemical-mediated regulation. Among these, how phytochemicals promote longevity through the gut microbiota and lipid metabolism is rarely highlighted in the field. Our understanding of the mechanisms of phytochemicals based on the above six aspects may provide a theoretical basis for the further development of antiaging drugs and new insights into the promotion of human longevity.

Modulating the Self-Assembly of a Camptothecin Prodrug with Paclitaxel for Anticancer Combination Therapy: A Molecular Dynamics Approach

Camptothecin (CPT) and paclitaxel (PTX), derived from natural products, are recognized for their significant efficacy in clinical cancer treatments. Despite its therapeutic advantages, CPT is challenged by issues of toxicity and solubility, necessitating its use in conjugation with other compounds for enhanced compatibility. This study delves into the coassembly mechanism of Evans blue-conjugated camptothecin (EB-CPT) with PTX, aiming to elucidate their synergistic potential in combination therapy applications, employing all-atom molecular dynamics simulations. The EB-CPT prodrug is reported to form a self-aggregated cluster. Our findings suggest that increasing the PTX concentration induces a dispersion of EB-CPT clusters, thereby disrupting their inherent self-assembly. This disruption is explained to be facilitated by the coassembly of EB-CPT and PTX. With increasing concentration of PTX, a lengthening of the coassembled structures is observed, supporting the experimental findings of tube-like coassembled structures at higher weight ratios of PTX. Hydrophobic interactions and π-π stacking are the primary forces responsible for the formation of both self- and coassembled structures. Interestingly, the structural analysis reveals that the CPT moiety of EB-CPT is less involved in assemblies due to steric hindrances. Instead, the interaction and coassembly processes are predominantly mediated by the EB derivative component of the prodrug. This research underscores the critical role of the solubilizing agent, EB derivative, in mediating the flexibility and interaction of CPT in combination therapy strategies, particularly with PTX, thus emphasizing the importance of conjugates for therapeutic developments. Furthermore, the molecular insights into the interaction sites and mechanisms facilitating coassembly between EB-CPT and PTX contribute valuable knowledge to the field, highlighting the potential of these nanomedicine combinations in advancing cancer treatment modalities.

Hydrogen-Bond-Assisted Catalysis: Hydroxylation of Paclitaxel by Human CYP2C8

Paclitaxel (PTX, or Taxol), a chemotherapeutic agent widely employed in the treatment of various cancers, undergoes metabolic transformations through the cytochrome P450 enzymes CYP3A4 and CYP2C8. CYP3A4 catalyzes the aromatic hydroxylation reaction of PTX, whereas CYP2C8 demonstrates a distinct reactivity pattern, producing 6α-hydroxypaclitaxel via alkane hydroxylation. Despite the significant impact of PTX metabolism on its anticancer efficacy, the detailed mechanisms underlying these transformations have remained largely unclear. In this study, we employed hybrid quantum mechanics and molecular mechanics (QM/MM) calculations to elucidate the mechanism of PTX metabolism by human CYP2C8. Our QM/MM results reveal that the hydroxylation of PTX by CYP2C8 follows an atypical rebound mechanism. Either of the two hydrogen atoms at the C6 position of PTX can be abstracted, leading to a common radical intermediate. Although the subsequent rebound barrier is unusually high, stereochemical scrambling is unlikely, as the rebound barrier for the formation of the 6α-hydroxylated PTX─the actual product─is significantly lower than that for the 6β-hydroxylated metabolite. Thus, product selectivity is determined by the non-rate-determining rebound step. Furthermore, the hydroxyl group at the C7 position of PTX plays a catalytic role by facilitating the hydrogen abstraction and rebound steps. Our study also confirms a pronounced stability of the transition state in the high-spin sextet spin state, enabled by the enzyme's specific substrate positioning.

Herbal Therapies for Cancer Treatment: A Review of Phytotherapeutic Efficacy

Natural products have proven to be promising anti-cancer agents due to their diverse chemical structures and bioactivity. This review examines their central role in cancer treatment, focusing on their mechanisms of action and therapeutic benefits. Medicinal plants contain bioactive compounds, such as flavonoids, alkaloids, terpenoids and polyphenols, which exhibit various anticancer properties. These compounds induce apoptosis, inhibit cell proliferation and cell cycle progression, interfere with microtubule formation, act on topoisomerase targets, inhibit angiogenesis, modulate key signaling pathways, improve the tumor microenvironment, reverse drug resistance and activate immune cells. Herbal anti-cancer drugs offer therapeutic advantages, particularly selective toxicity against cancer cells, reducing the adverse side effects associated with conventional chemotherapy. Recent studies and clinical trials highlight the benefits of herbal medicines in alleviating side effects, improving tolerance to chemotherapy and the occurrence of synergistic effects with conventional treatments. For example, the herbal medicine SH003 was found to be safe and potentially effective in the treatment of solid cancers, while Fucoidan showed anti-inflammatory properties that are beneficial for patients with advanced cancer. The current research landscape on herbal anticancer agents is extensive. Numerous studies and clinical trials are investigating their efficacy, safety and mechanisms of action in various cancers such as lung, prostate, breast and hepatocellular carcinoma. Promising developments include the polypharmacological approach, combination therapies, immunomodulation and the improvement of quality of life. However, there are still challenges in the development and use of natural products as anti-cancer drugs, such as the need for further research into their mechanisms of action, possible drug interactions and optimal dosage. Standardizing herbal extracts, improving bioavailability and delivery, and overcoming regulatory and acceptance hurdles are critical issues that need to be addressed. Nonetheless, the promising anticancer effects and therapeutic benefits of natural products warrant further investigation and development. Multidisciplinary collaboration is essential to advance herbal cancer therapy and integrate these agents into mainstream cancer treatment.

Novel progressive deep learning algorithm for uncovering multiple single nucleotide polymorphism interactions to predict paclitaxel clearance in patients with nonsmall cell lung cancer

Background

The rate at which the anticancer drug paclitaxel is cleared from the body markedly impacts its dosage and chemotherapy effectiveness. Importantly, paclitaxel clearance varies among individuals, primarily because of genetic polymorphisms. This metabolic variability arises from a nonlinear process that is influenced by multiple single nucleotide polymorphisms (SNPs). Conventional bioinformatics methods struggle to accurately analyze this complex process and, currently, there is no established efficient algorithm for investigating SNP interactions.

Methods

We developed a novel machine-learning approach called GEP-CSIs data mining algorithm. This algorithm, an advanced version of GEP, uses linear algebra computations to handle discrete variables. The GEP-CSI algorithm calculates a fitness function score based on paclitaxel clearance data and genetic polymorphisms in patients with nonsmall cell lung cancer. The data were divided into a primary set and a validation set for the analysis.

Results

We identified and validated 1184 three-SNP combinations that had the highest fitness function values. Notably, SERPINA1, ATF3 and EGF were found to indirectly influence paclitaxel clearance by coordinating the activity of genes previously reported to be significant in paclitaxel clearance. Particularly intriguing was the discovery of a combination of three SNPs in genes FLT1, EGF and MUC16. These SNPs-related proteins were confirmed to interact with each other in the protein-protein interaction network, which formed the basis for further exploration of their functional roles and mechanisms.

Conclusion

We successfully developed an effective deep-learning algorithm tailored for the nuanced mining of SNP interactions, leveraging data on paclitaxel clearance and individual genetic polymorphisms.

Naringin protects against paclitaxel-induced toxicity in rat testicular tissues by regulating genes in pro-inflammatory cytokines, oxidative stress, apoptosis, and JNK/MAPK signaling pathways

Paclitaxel (PTX), which is actively used in the treatment of many types of cancer, has a toxic effect by causing increased oxidative stress in testicular tissues. Naringin (NRG) is a natural flavonoid found in plants, and its antioxidant properties are at the forefront. This study aims to investigate the protective feature of NRG in PTX-induced testicular toxicity. Thirty-five male Sprague rats were divided into five groups: control, NRG, PTX, PTX + NRG50, and PTX + NRG100. Rats were administered PTX (2 mg/kg, BW) intraperitoneally once daily for the first 5 days. Then, between the 6th and 14th days, NRG (50 and 100 mg/kg) was administered orally once a day. NRG reduced PTX-induced lipid peroxidation and increased testicular tissue antioxidant capacity (superoxide dismutase, catalase, glutathione peroxidase, and glutathione). While NRG reduces the mRNA expression levels of nuclear factor kappa B, tumor necrosis factor-alpha, interleukin-1 beta, cyclooxygenase-2, interleukin-6, inducible-nitric oxide synthase, mitogen-activated protein kinase 14 (MAPK)14, MAPK15, c-Jun N-terminal kinase, P53, Apaf1, Caspase3, Caspase6, Caspase9, and Bax in testicular tissues; it caused an increase in Nrf2, HO-1, NQO1 and Bcl-2 levels. NRG also improved the structural and functional integrity of testicular tissue disrupted by PTX. PTX-induced sperm damage was alleviated by NRG. NRG showed a protective effect by alleviating the PTX-induced testicular toxicity by increasing oxidative stress, inflammation, apoptosis, and autophagy.

Preparation and anti-tumor activity of paclitaxel silk protein nanoparticles encapsulated by biofilm

In order to overcome the poor bioavailability of paclitaxel (PTX), in this study, self-assembled paclitaxel silk fibronectin nanoparticles (PTX-SF-NPs) were encapsulated with outer membrane vesicles of Escherichia coli (E. coil), and biofilm-encapsulated paclitaxel silk fibronectin nanoparticles (OMV-PTX-SF-NPs) were prepared by high-pressure co-extrusion, the size and zeta potential of the OMV-PTX-SF-NPs were measured. The antitumor effects of OMV-PTX-SF-NPs were evaluated by cellular and pharmacodynamic assays, and pharmacokinetic experiments were performed. The results showed that hydrophobic forces and hydrogen bonding played a major role in the interaction between paclitaxel and filipin proteins, and the size of OMV-PTX-SF-NPs was 199.8 ± 2.8 nm, zeta potential was -17.8 ± 1.3 mv. The cellular and in vivo pharmacokinetic assays demonstrated that the OMV-PTX-SF-NPs possessed a promising antitumor effect. Pharmacokinetic experiments showed that the AUC0-∞ of OMV-PTX-SF-NPs was 5.314 ± 0.77, which was much larger than that of free PTX, which was 0.744 ± 0.14. Overall, we have successfully constructed a stable oral formulation of paclitaxel with a sustained-release effect, which is able to effectively increase the bioavailability of paclitaxel, improve the antitumor activity, and reduce the adverse effects.

Slow Sulfide Donor GYY4137 Increased the Sensitivity of Two Breast Cancer Cell Lines to Paclitaxel by Different Mechanisms

Paclitaxel (PTX) is a chemotherapeutic agent affecting microtubule polymerization. The efficacy of PTX depends on the type of tumor, and its improvement would be beneficial in patients' treatment. Therefore, we tested the effect of slow sulfide donor GYY4137 on paclitaxel sensitivity in two different breast cancer cell lines, MDA-MB-231, derived from a triple negative cell line, and JIMT1, which overexpresses HER2 and is resistant to trastuzumab. In JIMT1 and MDA-MB-231 cells, we compared IC50 and some metabolic (apoptosis induction, lactate/pyruvate conversion, production of reactive oxygen species, etc.), morphologic (changes in cytoskeleton), and functional (migration, angiogenesis) parameters for PTX and PTX/GYY4137, aiming to determine the mechanism of the sensitization of PTX. We observed improved sensitivity to paclitaxel in the presence of GYY4137 in both cell lines, but also some differences in apoptosis induction and pyruvate/lactate conversion between these cells. In MDA-MB-231 cells, GYY4137 increased apoptosis without affecting the IP3R1 protein, changing the morphology of the cytoskeleton. A mechanism of PTX sensitization by GYY4137 in JIMT1 cells is distinct from MDA-MB-231, and remains to be further elucidated. We suggest different mechanisms of action for H2S on the paclitaxel treatment of MDA-MB-231 and JIMT1 breast cancer cell lines.

Design of Novel 2-Phenylquinazolin-4-amines as Selective CYP1B1 Inhibitors for Overcoming Paclitaxel Resistance in A549 Cells

Cytochrome P450 1B1 (CYP1B1) contributes to the metabolic inactivation of chemotherapeutics when overexpressed in tumor cells. Selective inhibition of CYP1B1 holds promise for reversing drug resistance. In our pursuit of potent CYP1B1 inhibitors, we designed and synthesized a series of 2-phenylquinazolin-4-amines. A substantial proportion of these newly developed inhibitors demonstrated inhibitory activity against CYP1B1, accompanied by improved water solubility. Remarkably, compound 14b exhibited exceptional inhibitory efficacy and selectivity toward CYP1B1. Molecular docking studies suggested that the expansion of the π-system through aromatization, the introduction of an amine group, and iodine atom augmented the binding affinity. Furthermore, inhibitors 14a, 14b, and 14e demonstrated the ability to significantly reduce the resistance in A549 cells to paclitaxel, while also inhibiting the migration and invasion of these cells. Finally, radioiodine labeling experiments shed light on the metabolic pathway of compound 5l in mice, highlighting the potential of 125I-5l as a radioactive probe for future research endeavors.

Garlic-derived compounds: Epigenetic modulators and their antitumor effects

Cancer is a highly heterogeneous disease that poses a serious threat to human health worldwide. Despite significant advances in the diagnosis and treatment of cancer, the prognosis and survival rate of cancer remain poor due to late diagnosis, drug resistance, and adverse reactions. Therefore, it is very necessary to study the development mechanism of cancer and formulate effective therapeutic interventions. As widely available bioactive substances, natural products have shown obvious anticancer potential, especially by targeting abnormal epigenetic changes. The main active part of garlic is organic sulfur compounds, of which diallyl trisulfide (DATS) content is the highest, accounting for more than 40% of the total composition. The garlic-derived compounds have been recognized as an antioxidant for cancer prevention and treatment. However, the molecular mechanism of the antitumor effect of garlic-derived compounds remains unclear. Recent studies have identified garlic-derived compound DATS that plays critical roles in enhancing CpG demethylation or promoting histone acetylation as an epigenetic inhibitor. Here, we review the therapeutic progress of garlic-derived compounds against cancer through epigenetic pathways.

Strategic and Innovative Roles of lncRNAs Regulated by Naturally-derived Small Molecules in Cancer Therapy

In the field of precision and personalized medicine, the next generation sequencing method has begun to take an active place as genome-wide screening applications in the diagnosis and treatment of diseases. Studies based on the determination of the therapeutic efficacy of personalized drug use in cancer treatment in the size of the transcriptome and its extension, lncRNA, have been increasing rapidly in recent years. Targeting and/or regulating noncoding RNAs (ncRNAs) consisting of long noncoding RNAs (lncRNAs) are promising strategies for cancer treatment. Within the scope of rapidly increasing studies in recent years, it has been shown that many natural agents obtained from biological organisms can potentially alter the expression of many lncRNAs associated with oncogenic functions. Natural agents include effective small molecules that provide anti-cancer effects and have been used as chemotherapy drugs or in combination with standard anti-cancer drugs used in routine treatment. In this review, it was aimed to provide detailed information about the potential of natural agents to regulate and/or target non-coding RNAs and their mechanisms of action to provide an approach for cancer therapy. The discovery of novel anti-cancer targets and subsequent development of effective drugs or combination strategies that are still needed for most cancers will be promising for cancer treatment.

Fungi-derived natural antioxidants

In humans, exogenous antioxidants aid the endogenous antioxidant system to detoxify excess ROS generated during oxidative stress, thereby protecting the body against various diseases and stressful conditions. The majority of natural antioxidants available on the consumer market are plant-based; however, fungi are being recognized as alternative sources of various natural antioxidants such as polysaccharides, pigments, peptides, sterols, phenolics, alkaloids, and flavonoids. In addition, some exogenous antioxidants are exclusively found in fungi. Fungi-derived antioxidants exhibit scavenging activities against DPPH, ABTS, hydroxyl, superoxide, hydrogen peroxide, and nitric oxide radicals in vitro. Furthermore, in vivo models, application of fungal-derived antioxidants increase the level of various antioxidant enzymes, such as catalases, superoxide dismutases, and glutathione peroxidases, and reduce the level of malondialdehyde. Therefore, fungi-derived antioxidants have potential to be used in the food, cosmetic, and pharmaceutical industries. This review summarizes the antioxidant potential of different fungi (mushrooms, yeasts, and molds)-derived natural compounds such as polysaccharides, pigments, peptides, ergothioneine, ergosterol, phenolics, alkaloids, etc.

Computational redesign of taxane-10β-hydroxylase for de novo biosynthesis of a key paclitaxel intermediate

Paclitaxel (Taxol®) is the most popular anticancer diterpenoid predominantly present in Taxus. The core skeleton of paclitaxel is highly modified, but researches on the cytochrome P450s involved in post-modification process remain exceedingly limited. Herein, the taxane-10β-hydroxylase (T10βH) from Taxus cuspidata, which is the third post-modification enzyme that catalyzes the conversion of taxadiene-5α-yl-acetate (T5OAc) to taxadiene-5α-yl-acetoxy-10β-ol (T10OH), was investigated in Escherichia coli by combining computation-assisted protein engineering and metabolic engineering. The variant of T10βH, M3 (I75F/L226K/S345V), exhibited a remarkable 9.5-fold increase in protein expression, accompanied by respective 1.3-fold and 2.1-fold improvements in turnover frequency (TOF) and total turnover number (TTN). Upon integration into the engineered strain, the variant M3 resulted in a substantial enhancement in T10OH production from 0.97 to 2.23 mg/L. Ultimately, the titer of T10OH reached 3.89 mg/L by fed-batch culture in a 5-L bioreactor, representing the highest level reported so far for the microbial de novo synthesis of this key paclitaxel intermediate. This study can serve as a valuable reference for further investigation of other P450s associated with the artificial biosynthesis of paclitaxel and other terpenoids. KEY POINTS: • The T10βH from T. cuspidata was expressed and engineered in E. coli unprecedentedly. • The expression and activity of T10βH were improved through protein engineering. • De novo biosynthesis of T10OH was achieved in E. coli with a titer of 3.89 mg/L.

Exploring the mechanism by which quercetin re-sensitizes breast cancer to paclitaxel: network pharmacology, molecular docking, and experimental verification

This study is aimed to explore the potential molecular mechanism of quercetin reversing paclitaxel (PTX) resistance in breast cancer (BC) by network pharmacology, molecular docking, and experimental verification. Pharmacological platform databases are used to predict quercetin targets and BC PTX-resistance genes and constructed the expression profile of quercetin chemosensitization. The overlapping targets were input into the STRING database and used Cytoscape v3.9.0 to construct the protein-protein interaction (PPI) network. Subsequently, these targets were performed with Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analyses and molecular docking. Finally, we further detected the potential role of quercetin in improving PTX sensitivity in BC in vitro experiments. Compounds and targets screening hinted that 220 quercetin predicted targets, 244 BC PTX resistance-related genes, and 66 potential sensitive target genes (PSTGs). Network pharmacology screening revealed the top-15 crucial targets in PPI network of quercetin reversing the sensitivity of BC to PTX. KEGG analysis revealed that they were mainly enriched in the EGFR/ERK signaling pathway. Molecular docking showed that both quercetin and PTX could stably bind to the key targets in the EGFR/ERK signaling pathway. In vitro experiments further confirmed that quercetin inhibited the key targets in the EGFR/ERK axis to the suppression of cell proliferation and promotion of apoptosis in PTX-resistance BC cells, and restoring the activity of the resistant cells to PTX. Our results suggested that quercetin increased the sensitivity of BC to PTX through inhibiting EGFR/ERK axis, and it is an effective treatment for reversing PTX resistance.

Neurotoxicity induced by taxane-derived drugs: analysis of the FAERS database 2017-2021

OBJECTIVES

Taxane-related neurotoxicity is a frequent clinical problem but lacks postmarketing data regarding neurological disorders. This study aimed to evaluate the potential association between neurological adverse events and several taxanederived drugs via the Food and Drug Administration Adverse Event Reporting System (FAERS).

METHODS

Disproportionality analysis was applied to data mining of the suspected cases of neurological disorders after using different taxanes based on the FAERS data from January 2017 and December 2021. We also investigated the times to onset, fatality, and hospitalization proportions of taxanerelated neurotoxicity.

RESULTS

In total, 3,940 cases were screened out, which were more prevalent in elderly patients and females. Peripheral neuropathy was a common adverse event among all taxanes with relatively strong association. Generally, the median time to neurological adverse effect onset was 27 days (interquartile range, 11.0 ~ 78.0 days) following taxane regimens, and the majority of cases were detected within the first 30 days. Among cases of neurological adverse events treated with taxane, the fatality and hospitalization proportions were 6.13% and 28.63%, respectively.

CONCLUSION

By analyzing the FAERS data, we provided a detailed profile of neurotoxicity and different taxanes in detail in terms of clinical characteristics, time to onset, and patient outcomes.

Alkaloids from Piper longum Exhibit Anti-inflammatory Activity and Synergistic Effects with Chemotherapeutic Agents against Cervical Cancer Cells

Piper longum L. is widely cultivated for food, medicine, and other purposes in tropical and subtropical regions. Sixteen compounds including nine new amide alkaloids were isolated from the roots of P. longum. The structures of these compounds were determined by spectroscopic data. All compounds showed better anti-inflammatory activities (IC₅₀ = 1.90 ± 0.68-40.22 ± 0.45 μM) compared to indomethacin (IC₅₀ = 52.88 ± 3.56 μM). Among the isolated compounds, five dimeric amide alkaloids exhibited synergistic effects with three chemotherapeutic drugs (paclitaxel, adriamycin, or vincristine) against cervical cancer cells. Moreover, these dimeric amide alkaloids also enhanced the efficacy of paclitaxel in paclitaxel-resistant cervical cancer cells. The combination treatment of one of these dimeric amide alkaloids and paclitaxel promoted cancer cell apoptosis, which is related to the Src/ERK/STAT3 signaling pathway.

Construction of Curcumin and Paclitaxel Co-Loaded Lipid Nano Platform and Evaluation of Its Anti-Hepatoma Activity in vitro and Pharmacokinetics in vivo

Purpose

The present study aimed to construct a co-loading platform encapsulating curcumin and paclitaxel at ratios of 2:1-80:1 (w/w) designated "CU-PTX-LNP" and explored the synergistic effects of CU-PTX at different composite proportions on liver cancer cells using the combination index (CI) method.

Methods

The CU lipid nanoplatform (CU-LNP) formulation was optimized via single-factor and orthogonal experiments. Various concentrations of PTX were added to the optimal formulation of CU-LNP to generate CU-PTX-LNP and the nanoplatform characterized via differential scanning calorimetry (DSC), transmission electron microscope (TEM), X-ray diffraction (XRD), zeta potential, polydispersity index (PDI), and size analyses. The cumulative release, stability, and cytotoxicity of CU-PTX-LNP in LO2, HepG2, and SMMC-7221 cells were assessed in vitro, followed by safety investigation and pharmacokinetic studies in vivo. The anti-tumor activity of CU-PTX-LNP was also evaluated using nude mice.

Results

CU-PTX-LNP formulations containing CU:PTX at a range of proportions (2:1-80:1; w/w) appeared as uniformly dispersed nanosized spherical particles with high entrapment efficiency (EE> 90%), sustained release and long-lasting stability. Data from in vitro cytotoxicity assays showed a decrease in the IC₅₀ value of PTX of CU-PTX-LNP (by 5.47-332.7 times in HepG2 and 4.29-143.21 times in SMMC-7221 cells) compared to free PTX. In vivo, CU-PTX-LNP displayed excellent biosafety, significant anti-tumor benefits and enhanced pharmacokinetic behavior with longer mean residence time (MRT_(0-t); CU: 4.31-fold, PTX: 4.61-fold) and half-life (t_1/2z; CU: 1.83-fold, PTX: 2.28-fold) relative to free drugs.

Conclusion

The newly designed CU-PTX-LNP platform may serve as a viable technological support system for the successful production of CU-PTX composite preparations.

Elimination of enzymes catalysis compartmentalization enhancing taxadiene production in Saccharomyces cerevisiae

Taxadiene is an important precursor in taxol biosynthesis pathway, but its biosynthesis in eukaryotic cell factories is limited, which seriously hinders the biosynthesis of taxol. In this study, it is found that there was the catalysis compartmentalization between two key exogenous enzymes of geranylgeranyl pyrophosphate synthase and taxadiene synthase (TS) for taxadiene synthesis progress, due to their different subcellular localization. Firstly, the enzyme-catalysis compartmentalization was overcome by means of the intracellular relocation strategies of taxadiene synthase, including N-terminal truncation of taxadiene synthase and enzyme fusion of GGPPS-TS. With the help of two strategies for enzyme relocation, the taxadiene yield was increased by 21% and 54% respectively, among them the GGPPS-TS fusion enzyme is more effective. Further, the expression of GGPPS-TS fusion enzyme was improved via the multi-copy plasmid, resulting that the taxadiene titer was increased by 38% to 21.8 mg/L at shake-flask level. Finally, the maximum taxadiene titer of 184.2 mg/L was achieved by optimization of the fed-batch fermentation conditions in 3 L bioreactor, which is the highest reported titer of taxadiene biosynthesis accomplished in eukaryotic microbes. This study provides a successful example for improving biosynthesis of complex natural products by solving the critical problem of multistep enzymes catalysis compartmentalization.

Discovery of a Flavonoid FM04 as a Potent Inhibitor to Reverse P-Glycoprotein-Mediated Drug Resistance in Xenografts and Improve Oral Bioavailability of Paclitaxel

Biotransformation of flavonoid dimer FD18 resulted in an active metabolite FM04. It was more druggable because of its improved physicochemical properties. FM04 (EC50 = 83 nM) was 1.8-fold more potent than FD18 in reversing P-glycoprotein (P-gp)-mediated paclitaxel (PTX) resistance in vitro. Similar to FD18, FM04 chemosensitized LCC6MDR cells towards multiple anticancer drugs by inhibiting the transport activity of P-gp and restoring intracellular drug levels. It stimulated the P-gp ATPase by 3.3-fold at 100 μM. Different from FD18, FM04 itself was not a transport substrate of P-gp and presumably, it cannot work as a competitive inhibitor. In the human melanoma MDA435/LCC6MDR xenograft, the co-administration of FM04 (28 mg/kg, I.P.) with PTX (12 mg/kg, I.V.) directly modulated P-gp-mediated PTX resistance and caused a 56% (*, p < 0.05) reduction in tumor volume without toxicity or animal death. When FM04 was administered orally at 45 mg/kg as a dual inhibitor of P-gp/CYP2C8 or 3A4 enzymes in the intestine, it increased the intestinal absorption of PTX from 0.2% to 14% in mice and caused about 57- to 66-fold improvement of AUC as compared to a single oral dose of PTX. Oral co-administration of FM04 (45 mg/kg) with PTX (40, 60 or 70 mg/kg) suppressed the human melanoma MDA435/LCC6 tumor growth with at least a 73% (***, p < 0.001) reduction in tumor volume without serious toxicity. Therefore, FM04 can be developed into a novel combination chemotherapy to treat cancer by directly targeting the P-gp overexpressed tumors or potentiating the oral bioavailability of P-gp substrate drugs.

Parvifloron D-based potential therapy for glioblastoma: Inducing apoptosis via the mitochondria dependent pathway

Glioblastoma (GB) is the most malignant and frequent primary tumor of the central nervous system. The lack of diagnostic tools and the poor prognosis associated with this tumor type leads to restricted and limited options of treatment, namely surgical resection and radio-chemotherapy. However, despite these treatments, in almost all cases, patients experience relapse, leading to survival rates shorter than 5 years (∼15-18 months after diagnosis). Novel therapeutic approaches are urgently required (either by discovering new medicines or by repurposing drugs) to surpass the limitations of conventional treatments and improve patients' survival rate and quality of life. In the present work, we investigated the antitumor potential of parvifloron D (ParvD), a drug lead of natural origin, in a GB cell line panel. This natural drug lead induced G2/M cell cycle arrest and apoptosis via activation of the intrinsic mitochondria-dependent pathway. Moreover, the necessary doses of ParvD to induce pronounced inhibitory effects were substantially lower than that of temozolomide (TMZ, first-line treatment) required to promote comparable effects. Therefore, ParvD may have the potential to overcome the resistance related to TMZ and contribute to the pursuit of hopeful treatments based on ParvD as a drug lead for future chemotherapeutics.

Kayadiol exerted anticancer effects through p53-mediated ferroptosis in NKTCL cells

BACKGROUND

Extranodal natural killer/T cell lymphoma (NKTCL) is a highly aggressive type of non-Hodgkin lymphoma that facing the treatment challenges. Natural compounds are important sources for drug development because of their diverse biological and chemical properties, among which terpenoids have strong anticancer activities.

METHODS

The human NK/T cell lymphoma cell line YT and peripheral blood lymphocytes isolated from NKTCL patients were treated with different concentrations of kayadiol. Then, the following experiments were performed: CCK-8 assay for cell viability, reactive oxygen species (ROS) and glutathione (GSH) assay and co-treatment with NAC, reduced GSH, or ferrostatin-1 for ferroptosis, the proteome profiling for elucidating signaling pathways, and western blot for the expression of p53, SCL7A11, and GPX4. siRNA and CRISPR/Cas9 plasmid for p53 knockout was designed and transfected into YT cells to evaluate the causal role of p53 in kayadiol-induced ferroptosis. The synergistic effect was evaluated by CCK8 assay after co-treatment of kayadiol with L-asparaginase or cisplatin.

RESULTS

In this study, we found that kayadiol, a diterpenoid extracted from Torreya nucifera, exerted significant killing effect on NKTCL cells without killing the healthy lymphocytes. Subsequently, we observed that kayadiol treatment triggered significant ferroptosis events, including ROS accumulation and GSH depletion. ROS scavenger NAC, GSH, and ferroptosis inhibitor ferrostatin-1 (Fer-1) reversed kayadiol-induced cell death in NKTCL cells. Furthermore, kayadiol decreased the expression of SLC7A11 and GPX4, the negative regulatory proteins for ferroptosis. We then demonstrated that p53 was the key mediator of kayadiol-induced ferroptosis by SLC7A11/GPX4 axis through p53 knockout experiments. In addition, kayadiol exerted a synergistic effect with L-asparaginase and cisplatin in NKTCL cells.

CONCLUSION

Taken together, our results suggested that the natural product kayadiol exerted anticancer effects through p53-mediated ferroptosis in NK/T cell lymphoma cells. Hence, it can serve as an effective alternative in the treatment of NK/T cell lymphoma, especially for patients exhibiting chemoresistance.

Paklitakselin neden olduğu oksidatif hasara karşı farnesenin otoprotektif etkileri

Amaç: Bu çalışmanın amacı, güçlü serbest radikal süpürücü ve antioksidan özelliklere sahip farnesenin paklitaksel kaynaklı ototoksisite üzerindeki etkilerini biyokimyasal ve fonksiyonel yönden araştırmaktır. Gereç ve Yöntem: On sekiz erkek Wistar albino sıçan, altı sıçandan oluşan üç gruba rastgele ayrıldı. Araştırma boyunca kontrol grubuna paklitaksel veya farnesen verilmedi. Paklitaksel grubuna, 5mg/kg paklitaksel intraperitoneal olarak dört kez (1., 7., 14. ve 21. günlerde) verildi. Farnesen + paklitaksel grubuna, önce 5 mg/kg paklitaksel, 30 dakika sonra 50 mg/kg farnesen intraperitoneal olarak 4 kez (1., 7., 14. ve 21. günlerde) verildi. 0. ve 21. günlerde tüm sıçanların otoakustik emisyon ölçümü yapıldı. Daha sonra hayvanlar sakrifiye edildi ve biyokimyasal testler için kokleaları çıkarıldı. Bulgular: Paklitaksel, önemli ölçüde malondialdehit seviyelerini yükselterek ve glutatyon seviyelerini düşürerek kokleada oksidatif strese neden oldu. Ayrıca paklitaksel grubunun distorsiyon ürünü otoakustik emisyon değerleri diğer gruplara göre anlamlı derecede düşüktü. Farnesen+paklitaksel grubunda ise paklitakselin çeşitli biyokimyasal ve fonksiyonel parametrelerde oluşturduğu hasarda iyileşmeler gözlendi. Sonuç: Çalışma sonuçları doğal bir antioksidan olan farnesen’in sıçanlarda paklitaksel kaynaklı işitme kaybını azalttığını, farnesen ve paklitaksel kombinasyonunun gelecekte klinik kullanım için paklitaksel kaynaklı ototoksisiteden koruyabileceğini göstermektedir.

Shaoyao Gancao Decoction Ameliorates Paclitaxel-Induced Peripheral Neuropathy via Suppressing TRPV1 and TLR4 Signaling Expression in Rats

Purpose

Paclitaxel-induced peripheral neuropathy (PIPN) is increasingly becoming one of the most widespread adverse effects in the treatment of cancer patients, and further precipitate neuroinflammation in the nervous system. Interestingly, Shaoyao Gancao Decoction (SGD), a traditional Chinese analgesic prescription, has emerged as a primary adjuvant to chemotherapy in relieving side effects, especially in the case of PIPN. However, the underlying mechanism of SGD functioning in PIPN remains elusive. Accordingly, the current study set out to explore the potential axis implicated in the functioning of SGD in PIPN.

Methods

First, network pharmacology was adopted to predict the role of the transient receptor potential vanilloid type 1 (TRPV1) protein in treating PIPN with SGD. Subsequently, the effects of SGD treatment on mechanical allodynia and thermal hyperalgesia were evaluated in rat PIPN models. Based on the bioinformatics information and current literature, paclitaxel activates toll-like receptor 4 (TLR4) induces the sensitization of TRPV1 mechanistically. Thereafter, TLR4-myeloid-differentiation response gene 88 (MyD88) signaling and TRPV1 expression patterns in dorsal root ganglias (DRGs) were measured by means of Western blotting, qPCR and immunofluorescence.

Results

Initial bioinformatics reared a total of 105 bioactive compounds and 1075 target genes from SGD. In addition, 40 target genes intersected with PIPN were considered as potential therapeutic genes. Based on the network analysis, SGD was found to exert its analgesic effect by reducing the expression of TRPV1. Further experimentation validated that SGD exerted an analgesic effect on thermal hyperalgesia in PIPN models, such that this protective effect was associated with the suppression of TRPV1 and TLR4-MyD88 Signaling over-expression.

Conclusion

Collectively, our findings indicated that SGD ameliorates PIPN by inhibiting the over-expression of TLR4-MyD88 Signaling and TRPV1, and further highlights the use of SGD as a potential alternative treatment for PIPN.

Insights into Aptamer-Drug Delivery Systems against Prostate Cancer

Prostate cancer is a common cancer in elderly males. Significant progress has been made in the drug therapies for prostate cancer in recent years. However, side effects are still problems that have not been overcome by the currently used anti-prostate cancer drugs. Novel technologies can be applied to reduce or even eliminate the side effects of drugs. An aptamer may be a sequence of nucleic acids or peptides that can specifically recognize proteins or cells. Taking advantage of this feature, scientists have designed aptamer-drug delivery systems for the development of anti-prostate cancer agents. Theoretically, these aptamer-drug delivery systems can specifically recognize prostate cancer cells and then induce cell death without attacking normal cells. We collected the relevant literature in this field and found that at least nine compounds have been prepared as aptamer-drug delivery systems to evaluate their precise anti-prostate cancer effects. However, the currently studied aptamer-drug delivery systems have not yet entered the market due to defects. Here, we analyze the published data, summarize the characteristics of these delivery systems, and propose ways to promote their application, thus promoting the development of the aptamer-drug delivery systems against prostate cancer.

Atractylodin Induces Apoptosis and Inhibits the Migration of A549 Lung Cancer Cells by Regulating ROS-Mediated Signaling Pathways

Atractylodin (ATR) has anticancer effects on some tumor cells by inducing apoptosis, but its mechanism in lung cancer remains unclear. This study investigates the inhibitory effect of ATR on A549 lung cancer cells. Cell viability was detected by the Cell Counting Kit-8 assay, and results showed that ATR could significantly inhibit the proliferation of A549 cells. Apoptosis was detected by Annexin V-FITC/PI staining, and apoptosis rate and mitochondrial membrane potential were detected by flow cytometry. Results showed that the effect of ATR on the apoptosis of A549 cells was negatively correlated with the change in mitochondrial membrane potential. Western blot analysis showed that ATR regulated apoptosis induced by mitogen-activated protein kinase, signal transducer and activator of transcription 3, and nuclear factor kappa B signaling pathways. Analyses of reactive oxygen species (ROS), cell cycle, and cell migration showed that ATR induced intracellular ROS accumulation as an initiation signal to induce cell cycle arrest regulated by the AKT signaling pathway and cell migration inhibition regulated by the Wnt signaling pathway. Results showed that ATR can inhibit cell proliferation, induce cell apoptosis, induce cell cycle arrest, and inhibit the migration of A549 cells (p < 0.05 was considered statistically significant, * p < 0.05, ** p < 0.01 and *** p < 0.001).

Reptiles as Promising Sources of Medicinal Natural Products for Cancer Therapeutic Drugs

Natural products have historically played an important role as a source of therapeutic drugs for various diseases, and the development of medicinal natural products is still a field with high potential. Although diverse drugs have been developed for incurable diseases for several decades, discovering safe and efficient anticancer drugs remains a formidable challenge. Reptiles, as one source of Asian traditional medicines, are known to possess anticancer properties and have been used for a long time without a clarified scientific background. Recently, it has been reported that extracts, crude peptides, sera, and venom isolated from reptiles could effectively inhibit the survival and proliferation of various cancer cells. In this article, we summarize recent studies applying ingredients derived from reptiles in cancer therapy and discuss the difficulties and prospective development of natural product research.

The Employment of Genera Vaccinium, Citrus, Olea, and Cynara Polyphenols for the Reduction of Selected Anti-Cancer Drug Side Effects

Cancer is one of the most widespread diseases globally and one of the leading causes of death. Known cancer treatments are chemotherapy, surgery, radiation therapy, targeted hormonal therapy, or a combination of these methods. Antitumor drugs, with different mechanisms, interfere with cancer growth by destroying cancer cells. However, anticancer drugs are dangerous, as they significantly affect both cancer cells and healthy cells. In addition, there may be the onset of systemic side effects perceived and mutagenicity, teratogenicity, and further carcinogenicity. Many polyphenolic extracts, taken on top of common anti-tumor drugs, can participate in the anti-proliferative effect of drugs and significantly reduce the side effects developed. This review aims to discuss the current scientific knowledge of the protective effects of polyphenols of the genera Vaccinium, Citrus, Olea, and Cynara on the side effects induced by four known chemotherapy, Cisplatin, Doxorubicin, Tamoxifen, and Paclitaxel. In particular, the summarized data will help to understand whether polyphenols can be used as adjuvants in cancer therapy, although further clinical trials will provide crucial information.

Nanosized paclitaxel-loaded niosomes: formulation, in vitro cytotoxicity, and apoptosis gene expression in breast cancer cell lines

BACKGROUND

In this study, the optimized niosomal formulation containing paclitaxel using non-ionic surfactants and cholesterol was designed and its cytotoxic effects against different breast cancer cell lines and apoptosis gene expression analysis were also investigated.

METHODS AND RESULTS

Due to enhancing equation variables, the Box-Behnken method has been applied. Lipid/drug molar ratio, the amounts of Span 60, and cholesterol were selected as the target for optimization. The particle size of niosome loaded paclitaxel and entrapment efficiency proportion have been considered in the role of dependent variables. Then the cytotoxic activity of the optimized formulation was evaluated using an MTT assay against different breast cancer cell lines including MCF-7, T-47D, SkBr3, and MDA-MB-231. The expression level of Bax and Bcl-2 apoptosis genes was determined by Real-Time PCR. In this study, the optimized niosomal formulation revealed that the synthesized niosomes had a spherical appearance and had an average size of 192.73 ± 5.50 nm so that the percentage of drug loading was 94.71 ± 1.56%. Moreover, this formulation showed a controlled and slowed release of paclitaxel at different pH (7.4, 6.5, and 5.4). The cytotoxicity results demonstrated that cell viability in all concentrations of niosome loaded paclitaxel had profound cytotoxic effects on all studied breast cancer cell lines compared to the free paclitaxel (p < 0.05). In addition, the expression of apoptosis genes was much higher than that of free paclitaxel indicating the susceptibility of cells to apoptosis.

CONCLUSIONS

As a result, niosomal formulations containing paclitaxel can be used as a new drug delivery system to increase cytotoxicity and treatment of breast cancer in the upcoming future.

FOXM1 Promotes Drug Resistance in Cervical Cancer Cells by Regulating ABCC5 Gene Transcription

Objective

The aim of the present study was to investigate the effect of forkhead box M1 (FOXM1) to paclitaxel resistance in cervical cancer cells, to determine the underlying mechanism, and to identify novel targets for the treatment of paclitaxel-resistant cervical cancer.

Methods

Paclitaxel-resistant Caski cells (Caski/Taxol cells) were established by intermittently exposing the Caski cells to gradually increasing concentrations of paclitaxel. The association between FOXM1, ATP-binding cassette subfamily C member 5 (ABCC5), and cervical cancer cell drug resistance was assessed by overexpressing or knocking down the expression of FOXM1 in Caski or Caski/Taxol cells. The protein and mRNA expression levels, the ratio of cellular apoptosis, and cell migration as well as intracellular drug concentrations were measured in cells following the different treatments.

Results

After the successful establishment of resistant Caski/Taxol cells, cell cycle distribution analysis showed that a significantly larger percentage of Caski/Taxol cells was in the G0/G1 stage compared with the Caski cells (P < 0.01), whereas a significantly larger percentage of Caski cells was in the S and G2/M stage compared with the Caski/Taxol cells following treatment with paclitaxel (P < 0.01). Both the protein and mRNA expression levels of FOXM1 and ABCC5 transporters were significantly higher in the paclitaxel-resistant Caski/Taxol cells compared with Caski cells (P < 0.05). Knockdown of FOXM1 significantly lowered the protein expression levels of FOXM1 and ABCC5. Intracellular paclitaxel concentrations were significantly higher amongst the Caski/Taxol cells following the knockdown of FOXM1 by shRNA or Siomycin A (P < 0.05).

Conclusion

FOXM1 promotes drug resistance in cervical cancer cells by regulating ABCC5 gene transcription. The knockdown of FOXM1 with shRNA or Siomycin A promotes paclitaxel-induced cell death by regulating ABCC5 gene transcription.

Synergistic antitumor efficacy of PD-1-conjugated PTX- and ZSQ-loaded nanoliposomes against multidrug-resistant liver cancers

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide with poor chemotherapeutic efficiency due to multidrug resistance (MDR); it is very important to develop a targeted nanocarrier for the treatment of HCC. In this study, a programmed death ligand 1 (PD-L1)-conjugated nanoliposome was constructed for co-delivery of paclitaxel (PTX) and P-glycoprotein (P-gp) inhibitor zosuquidar (ZSQ) to overcome MDR in human HCC cells and tumors in vivo. Transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA) were used to examine the nanoparticles morphology and size; PD-1-conjugated PTX and ZSQ-loaded nanoliposomes (PD-PZLP) revealed a spherical shape with a size of 139.5 ± 10.7 nm. Then, the physicochemical properties, as well as the drug loading capacity, release profile, cellular uptake, and cytotoxicity of the dual drug-encapsulated nanoliposomes were characterized. PD-PZLP displayed a high drug loading capacity of 20 ~ 30% for both PTX and ZSQ; the drug release of PTX and ZSQ in pH 5.0 was significantly faster than in pH 7.4. Cellular uptake study demonstrated PD-PZLP had higher internalization efficiency than non-targeted PZLP. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and reactive oxygen species (ROS) analysis demonstrated that PD-PZLP triggered an excessive ROS reaction and cell apoptosis compared with that of free PTX or ZSQ, which was also consistent with the cell antiproliferative effects in MTT assay. Furthermore, PD-PZLP could enhance synergistic antitumor effects on 7721/ADM xenograft tumor model, which also significantly alleviated hepatotoxicity as evident from the decreased aspartate transaminase (AST) and alanine transaminase (ALT) levels. Overall, PD-PZLP exhibited high loading capacity, significant synergistic effects, promising antitumor efficacy, and the lowest toxicity, which provide a promising strategy to overcome MDR in HCC.

7-Epitaxol Induces Apoptosis and Autophagy in Head and Neck Squamous Cell Carcinoma through Inhibition of the ERK Pathway

As the main derivative of paclitaxel, 7-Epitaxol is known to a have higher stability and cytotoxicity. However, the anticancer effect of 7-Epitaxol is still unclear. The purpose of this study was to explore the anticancer effects of 7-Epitaxol in squamous cell carcinoma of the head and neck (HNSCC). Our study findings revealed that 7-Epitaxol potently suppressed cell viability in SCC-9 and SCC-47 cells by inducing cell cycle arrest. Flow cytometry and DAPI staining demonstrated that 7-Epitaxol treatment induced cell death, mitochondrial membrane potential and chromatin condensation in OSCC cell lines. The compound regulated the proteins of extrinsic and intrinsic pathways at the highest concentration, and also increased the activation of caspases 3, 8, 9, and PARP in OSCC cell lines. Interestingly, a 7-Epitaxol-mediated induction of LC3-I/II expression and suppression of p62 expression were observed in OSCC cells lines. Furthermore, the MAPK inhibitors indicated that 7-Epitaxol induces apoptosis and autophagy marker proteins (cleaved-PARP and LC3-I/II) by reducing the phosphorylation of ERK1/2. In conclusion, these findings indicate the involvement of 7-Epitaxol in inducing apoptosis and autophagy through ERK1/2 signaling pathway, which identify 7-Epitaxol as a potent cytotoxic agent in HNSCC.

pH responsive release of paclitaxel by self-assembling Chitosan-ethyl vanillin@GNRs nanocomposites

Carboxylation chitosan achieved by alkalization linked with ethyl vanillin to obtain Chitosan-ethyl vanillin (EV-CMCS) compound through Schiff base reaction and confirmed by FT-IR, UV, XRD, TG and NMR. EV-CMCS refluxed with GNRs for acquisition of EV-CMCS@GNRs nanocomposites for PTX Loading and release. Results demonstrated that both EV-CMCS and EV-CMCS@GNRs are nanoscale composites with excellent solubilization due to their micelle structure taking CMC values of 0.06683 mg/mL and 0.06537 mg/mL. It was found that the loading and encapsulation rate of EV-CMCS and EV-CMCS@GNRs for PTX are 19.59~37.64% and 60.36~80.79% as well as 20.99~37.02% and 58.78~79.77%. Compared with only the delayed release of EV-CMCS that it have 11.5% and 18.7% accumulative release amount for 24 h and 14.9% and 23.7% for 48 h under both pH 6.8 and 7.4, the EV-CMCS@GNRs represent sudden release that it have an accumulative release amount of 90.2% for 24 h and 96.0% for 48 h at pH 6.8. It deduced that the broken Schiff base under acidic condition can increase CMC of EV-CMCS@GNRs, which offered an alternative way for paclitaxel delivery for tumor therapy.

Vorinostat (SAHA) and Breast Cancer: An Overview

Vorinostat (SAHA), an inhibitor of class I and II of histone deacetylases, is the first histone deacetylase inhibitor (HDI) approved for the treatment of cutaneous T-cell lymphoma in 2006. HDIs are promising anticancer agents that inhibit the proliferation of many types of cancer cells including breast carcinoma (BC). BC is a heterogeneous disease with variable biological behavior, morphological features, and response to therapy. Although significant progress in the treatment of BC has been made, high toxicity to normal cells, serious side effects, and the occurrence of multi-drug resistance limit the effective therapy of BC patients. Therefore, new active agents which improve the effectiveness of currently used regimens are highly needed. This manuscript analyzes preclinical and clinical trials data of SAHA, applied individually or in combination with other anticancer agents, considering different histological subtypes of BC.

A Dansyl-Modified Sphingosine Kinase Inhibitor DPF-543 Enhanced De Novo Ceramide Generation

Sphingosine-1-phosphate (S1P) synthesized by sphingosine kinase (SPHK) is a signaling molecule, involved in cell proliferation, growth, differentiation, and survival. Indeed, a sharp increase of S1P is linked to a pathological outcome with inflammation, cancer metastasis, or angiogenesis, etc. In this regard, SPHK/S1P axis regulation has been a specific issue in the anticancer strategy to turn accumulated sphingosine (SPN) into cytotoxic ceramides (Cers). For these purposes, there have been numerous chemicals synthesized for SPHK inhibition. In this study, we investigated the comparative efficiency of dansylated PF-543 (DPF-543) on the Cers synthesis along with PF-543. DPF-543 deserved attention in strong cytotoxicity, due to the cytotoxic Cers accumulation by ceramide synthase (CerSs). DPF-543 exhibited dual actions on Cers synthesis by enhancing serine palmitoyltransferase (SPT) activity, and by inhibiting SPHKs, which eventually induced an unusual environment with a high amount of 3-ketosphinganine and sphinganine (SPA). SPA in turn was consumed to synthesize Cers via de novo pathway. Interestingly, PF-543 increased only the SPN level, but not for SPA. In addition, DPF-543 mildly activates acid sphingomyelinase (aSMase), which contributes a partial increase in Cers. Collectively, a dansyl-modified DPF-543 relatively enhanced Cers accumulation via de novo pathway which was not observed in PF-543. Our results demonstrated that the structural modification on SPHK inhibitors is still an attractive anticancer strategy by regulating sphingolipid metabolism.