Cytotoxicity Of Paclitaxel Research Articles

Zein-PEG nanoparticles modified with hyaluronic acid for paclitaxel delivery in SKOV3 ovarian cancer cells

Ovarian cancer is a leading gynecological cancer globally. This study aimed to develop hyaluronic acid-modified polyethylene glycol conjugated zein nanoparticles (zein-PEG/HA NPs) to enhance paclitaxel (PTX) cytotoxicity in SKOV3 ovarian cancer cells. Zein-PEG, with its amphiphilic nature, self-assembled into micelles to encapsulate the hydrophobic PTX, while the PEG shell retained micelle stability and hemolytic resistance. PTX@zein-PEG micelles (17.2 ± 0.3 mV) were complexed with negatively charged HA through electrostatic interactions, resulting in PTX@zein-PEG/HA NPs with a negative zeta potential of −15.3 ± 1.1 mV. Cellular uptake of fluorescent zein-PEG/HA NPs was higher than zein-PEG micelles in CD44-overexpressing SKOV3 cells. Additionally, PTX@zein-PEG/HA NPs demonstrated significantly greater cytotoxicity than free PTX and PTX@zein-PEG micelles, with IC50 values reduced by 6.13-fold and 3.58-fold, respectively. PTX@zein-PEG/HA NPs induced the highest expression levels of apoptotic proteins, particularly PARP, in SKOV3 cells compared to PTX@zein-PEG NPs and free PTX. In summary, PTX@zein-PEG/HA NPs demonstrated potential as a delivery system for PTX in ovarian cancer.

Alkaloid-rich extract of jujube seed regenerate the antiproliferative effect of paclitaxel on paclitaxel-resistant MDA-MB-231 breast cancer cell line in 2D and 3D cultures

IntroductionCancer is the second leading cause of death globally, and among all types of cancer, triple-negative breast cancer (TNBC) has one of the worst prognoses. The repeated use of chemotherapeutic drugs often leads to drug resistance, complicating treatment outcomes. This study aimed to investigate the effect of jujube alkaloid-rich extract on drug sensitivity and its antitumor effects on paclitaxel-resistant MDA-MB-231 cells in vitro. Materials and methodsThis study utilized the MDA-MB-231 breast cancer cell line and its paclitaxel-resistant variant. Cell viability was measured using the XTT assay, while apoptosis was detected through Annexin-PI assays. Various concentrations of jujube extract, alone and combined with paclitaxel, were assessed for synergistic effects in 2D and 3D culture models. ResultsThe presence of alkaloids in the jujube seed extract was confirmed via the Dragendorff test, with 0.395 g of alkaloids present in 5 g of jujube seed powder. A combination of paclitaxel and jujube extract exhibited dose-dependent cytotoxic effects on paclitaxel-resistant MDA-MB-231 cells. The combination of jujube extract and paclitaxel significantly decreased IC50 from 541.3 μg/ml to 124.3 μg/ml, and the IC20 decreased from 92.1 μg/ml to 23.9 μg/ml when combined with paclitaxel in 2D culture model. The cytotoxicity of the combination was reduced in the 3D culture model. Apoptosis rates were 0.75% in the control group, 13.89% in the alkaloid-rich extract group, 2.59% in the paclitaxel group, and 42.90% in the combination group. ConclusionCombining alkaloid-rich jujube seed extract with paclitaxel regenerates the cytotoxicity and apoptotic ability of paclitaxel in the paclitaxel-resistant MDA-MB-231 breast cancer cells in both 2D and 3D culture models. This suggests that such combinations might be a viable strategy to overcome drug resistance in TNBC treatments.

PEGylated pH-Responsive Liposomes for Enhancing the Intracellular Uptake and Cytotoxicity of Paclitaxel in MCF-7 Breast Cancer Cells.

This study aimed to develop paclitaxel (PTX)-loaded PEGylated (PEG)-pH-sensitive (SpH) liposomes to enhance drug delivery efficiency and cytotoxicity against MCF-7 breast cancer cells. PTX-loaded PEG-SpH liposomes were prepared using the thin film hydration method. ATR-FTIR compatibility studies revealed no significant interactions among liposome formulation components. TEM images confirmed spherical morphology, stability, and an ideal size range (180-200nm) for improved blood circulation. At pH 5.5, liposomes exhibited increased size and positive zeta potential, indicating pH-sensitive properties due to CHEMS response to the acidic tumor microenvironment. Conversely, at pH 7.4, liposomes showed a slightly larger size (199.25 ± 1.64nm) and a more negative zeta potential (-36.94 ± 0.32mV), suggesting successful PEG-SpH surface modification, enhancing stability, and reducing aggregation. PTX-loaded PEG-SpH liposomes demonstrated high encapsulation efficiency (84.57 ± 0.92% w/w) and drug loading capacity (4.12 ± 0.26% w/w). In-vitro drug release studies revealed accelerated first-order PTX release at pH 5.5 and a controlled zero-order release at pH 7.4. Cellular uptake studies on MCF-7 cells demonstrated enhanced PTX uptake, attributed to mPEG-PCL incorporation prolonging circulation time and CHEMS facilitating PTX release in the tumor microenvironment. Furthermore, PTX-loaded PEG-SpH liposomes exhibited significantly improved cytotoxicity with an IC50 value of 1.107µM after 72-h incubation, approximately 90% lower than plain PTX solution. Stability studies confirmed the robustness of the liposomal formulation under various storage conditions. These findings highlight the potential of PEGylated pH-responsive liposomes as effective nanocarriers for enhancing PTX therapy against breast cancer.

Evaluation of polyelectrolyte nanoparticles of chitosan and hyaluronic acid as topical delivery systems for cytotoxic agents

In this study, we developed polyelectrolyte complexes (PECs), composed of hyaluronic acid and chitosan, aiming at obtaining a bioadhesive topical formulation for potential application for skin cancer treatment. Selected nanocarriers were obtained at a 1:1 (w/w) ratio of polyelectrolytes (0.25 mg/mL each) and probe sonication, displayed nanometric size (209.4 nm, PDI = 0.19), and cationic zeta potential (+28.0 mV). PECs presented bioadhesive potential, demonstrated by shifts in size and zeta potential upon incubation with mucin, and reduced transepidermal water loss. Paclitaxel (PTX) and 5-fluorouracil (5-FU), cytotoxic drugs with distinct physical-chemical characteristics, were incorporated at 0.25 and 0.75 %, respectively; propylene glycol addition was necessary for PTX incorporation. Compared to the control, 2.3- (9.4±3.6 μg/cm2) and 4.5-fold (2.8±0.8 μg/cm2) increases in PTX penetration into the stratum corneum and viable skin layers, respectively, were observed after 12 hours. No increase in 5-FU penetration was demonstrated. Incorporation in PECs resulted in slight increases in the cytotoxicity of PTX and 5-FU against melanoma cells, reducing IC50 values by 1.5- and 1.2-fold (1.55 and 35.10 μM for PTX and 5-FU, respectively) compared to the control solutions. IC50 values found for keratinocytes were higher (5.74 and 162.6 μM for paclitaxel and 5-FU, respectively). At non-cytotoxic concentrations, drug-loaded PECs promoted 24–31 % reductions on cell migration, suggesting that drug incorporation in PECs did not hinder their biological effects.

A whole-genome CRISPR screen identifies the spindle accessory checkpoint as a locus of nab-paclitaxel resistance in a pancreatic cancer cell line

Pancreatic adenocarcinoma is one of the most aggressive and lethal forms of cancer. Chemotherapy is the primary treatment for pancreatic cancer, but resistance to the drugs used remains a major challenge. A genome-wide CRISPR interference and knockout screen in the PANC-1 cell line with the drug nab-paclitaxel has identified a group of spindle assembly checkpoint (SAC) genes that enhance survival in nab-paclitaxel. Knockdown of these SAC genes (BUB1B, BUB3, and TTK) attenuates paclitaxel-induced cell death. Cells treated with the small molecule inhibitors BAY 1217389 or MPI 0479605, targeting the threonine tyrosine kinase (TTK), also enhance survival in paclitaxel. Overexpression of these SAC genes does not affect sensitivity to paclitaxel. These discoveries have helped to elucidate the mechanisms behind paclitaxel cytotoxicity. The outcomes of this investigation may pave the way for a deeper comprehension of the diverse responses of pancreatic cancer to therapies including paclitaxel. Additionally, they could facilitate the formulation of novel treatment approaches for pancreatic cancer.

Octreotide modified liposomes that co-deliver paclitaxel and neferine effectively inhibit ovarian cancer metastasis by specifically binding to the SSTR2 receptors

Early detection of ovarian cancer is challenging, leading to high mortality rates. Paclitaxel has broad-spectrum anti-tumor activity and has been used clinically for the treatment of various cancers. However, the severe side effects of paclitaxel limit its use at high doses. Hence, it is imperative to develop a novel anti-neoplastic agent that can enhance therapeutic efficacy and selectively target tumor sites, thereby mitigating systemic toxicity. In this study, lipid nanoparticles with surface-modified octreotide were constructed by a thin film dispersion method to co-encapsulate paclitaxel and neferine, which are lipophilic compounds, within the phospholipid bilayer, improving their solubility. Liposomes modified with octreotide can increase its active targeting to SKOV3 cells through SSTR-mediated endocytosis and prolong the drug circulation time in vivo. The potential synergistic effects of paclitaxel and neferine were confirmed and quantified by Synergyfinder analysis software. In vitro experimental results showed that neferine can synergistically enhance the cytotoxicity of paclitaxel against human ovarian cancer cells, exerting anti-proliferative, apoptosis-inducing, invasion-suppressing, and angiogenesis-disrupting effects. The in vivo targeting and tumor inhibition of Octreotide-modified liposomes that co-deliver paclitaxel and neferine (OCT-PTX/Nef-Lips) were investigated in mice xenografted with SKOV3 cells. In vivo pharmacodynamic evaluation demonstrated the safe and effective ability of OCT-PTX/Nef-Lips to inhibit tumor volume growth, disrupt tumor tissue morphology, induce apoptosis in tumor cells, and suppress their proliferation. Furthermore, angiogenesis was inhibited through down-regulation of angiogenesis-related proteins (TIE-2, VEGFA, VE-Cadherin, Ang-2).

Serabelisib, sapanisertib (PIKTOR) and paclitaxel: A combinatorial approach to improve PI3K/mTOR/AKT pathway inhibition and treatment response in solid tumors.

e15134 Background: Despite high mutation rates in genes of the PI3K/mTOR/AKT pathway in cancer, therapeutic strategies to inhibit this pathway featuring single targeted therapies have achieved limited clinical success. An alternate approach inhibiting multiple parts of the pathway simultaneously demonstrated improved activity (Starks et al, GynOnc 2022). The Phase 1 study combined the targeted PI3K-alpha and mTOR inhibitors serabelisib and sapanisertib (PIKTOR) with paclitaxel showing reasonable safety and promising clinical efficacy in patients with advanced endometrial, breast and ovarian tumors that had progressed on prior taxane. The ORR was 47% including 3 complete responses, with a PFS of 11 months in 15 evaluable subjects (NCT03154294). We sought to better understand the mechanistic basis for the efficacy of this triplet drug combination in models of endometrial and breast cancer to support successful clinical development of this regimen. Methods: Signaling activity in PI3K/mTOR/AKT pathway was probed by western blot for phospho-S6 and phospho-4EBP1 in human endometrial and breast cancer cell lines with PI3K/mTOR/AKT mutations. Single and combinatorial dose-response curves were established for serabelisib, sapanisertib and paclitaxel versus FDA-approved pathway inhibitors. Mechanisms of cytotoxicity and paclitaxel sensitization were probed with cell death assays. The impact of single and combined agents on tumor growth was assessed with in vivo xenograft studies. Results: In human endometrial and breast cancer cell lines, the combination of serabelisib and sapanisertib achieved markedly improved PI3K/mTOR/AKT pathway inhibition versus FDA-approved single agents. Serabelisib and sapanisertib increased the cytotoxicity of paclitaxel, supporting prior work that identifies PI3K/mTOR/AKT pathway activation as a key mediator of taxane resistance. Further, interrogation of a range of clinically relevant doses and scheduling led to an optimized regimen in which serabelisib and sapanisertib substantially improved the response to paclitaxel in vivo. Conclusions: Simultaneous inhibition of PI3K-alpha, mTORC1 and mTORC2 with PIKTOR offers potential for superior PI3K/mTOR/AKT pathway inhibition, suggesting that rational drug combination approaches may offer two important benefits: (1) more complete PI3K/mTOR/AKT pathway inhibition by targeting multiple signaling nodes, and (2) greater tumor cell cytotoxicity by sensitization to taxanes. These data, combined with the promising efficacy and safety signal from PIKTOR plus paclitaxel in a Phase 1 trial (NCT03154294), provide a compelling rationale for further clinical investigation. Future studies will focus on tumors known to have high rates of PI3K mutations including gynecologic tumors where there is a high unmet need.

389 Combination Therapy With Paclitaxel, Carboplatin, and Low-Intensity Ultrasound for Recurrent Glioblastoma: Rationale for Ongoing Phase II Clinical Trial

INTRODUCTION: We recently participated in Phase 1/2 clinical trials where patients with recurrent glioblastoma received surgery for resection of the tumor followed by implantation of an ultrasound device (SonoCloud-9, Carthera, Lyon, France) into a window in the skull for subsequent repeated blood-brain barrier (BBB) opening and concomitant delivery of chemotherapy. Intraoperative experiments demonstrated a 4-6-fold increase in the brain concentration of paclitaxel (NCT04528680) and carboplatin (NCT03744026) after BBB disruption. METHODS: We analyzed the cytotoxicity of paclitaxel and carboplatin in vitro against five human cell lines and six patient-derived xenografts (PDX) as monotherapy and in combination at concentrations derived from our human intraoperative pharmacokinetic studies. Synergy was assessed using the Loewe model and survival benefit was evaluated in two xenografts where drugs were delivered with ultrasound. We also examined the effects on cell cycle progression, DNA damage, and apoptosis. RESULTS: Cell lines exhibited non-overlapping susceptibility to paclitaxel and carboplatin, with 27% being exclusively susceptible to one drug. The combination covered 81% of cell lines, demonstrating synergy in 55% of cell lines. Notably, paclitaxel, carboplatin, and ultrasound proved more effective than monotherapy in two xenograft models. Combination therapy led to distinct effects on cell cycle progression and enhanced DNA damage and apoptosis. CONCLUSIONS: Combination therapy may be more effective than monotherapy, as has been shown in other cancers, due to synergy and independent susceptibility to each drug in glioma cell lines. This strategy is currently under investigation in an ongoing phase II clinical trial to further evaluate the safety and efficacy of this approach in patients with recurrent glioblastoma (NCT04528680).

Abstract 3102: A high-throughput screening method for discovering potent P-glycoprotein modulators from the chemical library in Tohoku University

Abstract Background: Drug development is important for cancer therapy to improve patient outcomes. In most cases, drug development starts in discovering candidate compounds from a chemical library in high-throughput screening (HTS). Tohoku University Graduate School of Pharmaceutical Science owns the original chemical library consisting of thousands of original chemical compounds. P-glycoprotein (P-gp), a major drug efflux transporter mediates multi-drug resistance (MDR) in cancer cells. Therefore, P-gp modulators could revere MDR and increase chemosensitivity. The aim of this study is to reveal an adequate method of HTS for discovering potent P-gp modulators from the chemical library in Tohoku University. Methods: The chemical library in Tohoku University had 5861 compounds in the present study, and the collection contains over 7 thousand compounds in 2023. P-gp overexpressing KB-V1, human epidermal carcinoma cell lines were obtained, and calcein AM, P-gp substrate was employed for fluorescent substrate efflux assays. A plate reader-based calcein AM efflux assay for HTS was established to select candidate compounds as P-gp modulators. After the primary HTS, structures of the candidate compounds were analyzed, then several analogous compounds were extracted from the chemical library. For the validation of the hit compounds in HTS and the analogs, a flow cytometry-based calcein AM efflux assay was conducted. In addition, reversal effects of P-gp modulators on the cytotoxicity of paclitaxel were measured in a cell proliferation assay. Results: Of 5861 compounds in the chemical library, 53 compounds showed 2-fold or higher fluorescence intensity, and then 13 compounds showed 3-fold or higher fluorescence intensity in a plate reader-based assay for the HTS. Especially 2 candidate compounds showed over 5-fold fluorescence intensity. In the analysis for structures of the candidate compounds, 20 analogous compounds were extracted from the chemical library. To verify the result of the plate reader-based assay, a flow cytometry-based assay was conducted for 53 hits and 20 analogs. As a result, the 2 candidate compounds that selected in the plate reader-based assay showed 60-fold, the highest fluorescence intensity in a flow cytometry-based assay. The other compounds showed less fluorescence intensity than these 2 candidates. In addition, both candidates enhanced the paclitaxel-induced cytotoxicity in a cell proliferation assay. Conclusions: A plate reader-based calcein AM efflux assay in HTS was an adequate method for discovering potent P-gp modulators from the chemical library in Tohoku University. Citation Format: Norihiko Sugisawa, Shinobu Ohnuma, Takayuki Doi, Michiaki Unno. A high-throughput screening method for discovering potent P-glycoprotein modulators from the chemical library in Tohoku University [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3102.

Abstract A020: NAD+ Boosting through NRH supplementation enhances treatment efficacy in EOC

Abstract Background: Dihydronicotinamide riboside (NRH), the reduced form of nicotinamide riboside (NR), is a recently identified, naturally occurring precursor of arguably the most crucial cofactor for cellular function, Nicotinamide Adenine Dinucleotide (NAD+). Recent investigation suggests that NRH is more adept at increasing NAD+ stores than traditional NAD precursors, and such extreme NAD+ boosting via NRH supplementation induces cytotoxicity in certain cellular contexts. It has also been shown that the lack of functional BRCA protein in epithelial ovarian cancer (EOC) directly impacts intracellular NAD+ levels. Given that altered cellular metabolism and DNA repair mechanisms are central alterations in EOC, and these processes are functionally dependent on NAD+, we sought to assess whether NRH supplementation in EOC cell lines enhanced cellular cytotoxicity alone and in combination with standard therapeutic agents. Methods: We supplemented 3 ovarian cancer cell lines (SKOV3, OVCAR8 and ES2) with NRH and traditional NAD precursor, NA (nicotinic acid) alone and in combination with carboplatin, paclitaxel, combination, and olaparib. Cytotoxicity was measured via CellTiter-Glo. RNA sequencing of EOC cell lines was performed to determine the differential expression of NAD+ anabolic and catabolic enzymes. Of note, all three cell lines are known to be BRCA1 &2 wildtype while OVCAR8 cells are hypermethylated and harbor loss of heterozygosity (LOH high) at the BRCA1 loci. Results: Significant cytotoxicity was noted in NRH treated cells (~40 %) with minimal cell death in the NA treated lines. Strikingly, NRH supplementation enhanced carboplatin cytotoxicity by 25-50 % depending on cell line, paclitaxel cytotoxicity by 10-25 %, and the combination by 10-35 % whereas NA supplementation had no effect on the baseline treatment induced cytotoxicity. Interestingly, the effect of NRH supplementation with olaparib differed between the ES2 and OVCAR8 cell lines, with a significant 20 % increase in cell death in ES2 vs OVCAR8 cells with a negligible increase in cell death. PARP inhibition by olaparib requires NAD+. RNA sequencing revealed an increased expression in NAMPT, an enzyme involved in the NAD+ salvage pathway in the ES2 cell line relative to the OVCAR8, suggesting that the ES2 cells harbor a baseline NAD+ deficit rendering them more vulnerable to PARP inhibition following NAD+ boosting. This is also consistent with the OVCAR8 data suggesting that hypermethylated BRCA1 results in a relative increase in NAD+ to the extent that NRH supplementation does not enhance the efficacy of PARP inhibition. Conclusions: Here we show that in the context of EOC, exploitation of the NAD+ bioenergetic phenotype through NRH supplementation is a biologically feasible strategy to enhance the response of traditional therapy with potentially minimal toxicity. This data suggests several potential mechanisms by which cellular NAD+ availability belies treatment efficacy and resistance and highlights the potential utility of NAD+ metabolomics as a biomarker to guide treatment decisions. Citation Format: Kevin Lee, Tanvi Joshi, Catherine Lyons, Mary Howard Singleton, Elizabeth Catranis, Sagar Chokshi, Luciana Madiera da Silva, Marie Migaud, Jennifer Scalici. NAD+ Boosting through NRH supplementation enhances treatment efficacy in EOC [abstract]. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr A020.

Deguelin and Paclitaxel Loaded PEG-PCL Nano-Micelles for Suppressing the Proliferation and Inducing Apoptosis of Breast Cancer Cells.

Deguelin (DGL) is a natural flavonoid reported to exhibit antitumor effects in breast cancer (BC). PEG-PCL (Polyethylene Glycol- Polycaprolactone), as polymeric micelles, has biodegradability and biocompatibility. The aim of this study was to investigate whether the nanoparticular delivery system, PEG-PCL could improve the bioavailability of DGL for suppressing proliferation of BC cells. PEG-PCL polymers were first prepared by ring-opening polymerization, and DGL and paclitaxel (PTX)-loaded PEG-PCL nano-micelles were formulated via the film dispersion method. The composition and molecular weight of PEG-PCL were analyzed by nuclear magnetic resonance and fourier Transform infrared spectroscopy (FTIR) spectra. Particle size, surface potential and hemolytic activity of micelles were assessed by dynamic light scattering, transmission electron microscopy and hemolysis assay, respectively. Then proliferation and apoptosis of MDA-MB-231 and MDA-MB-468 cells were tested with Edu staining, CCK-8, TUNEL staining, and Flow cytometer. Caspase 3 expression was also assessed by Western blot. Our results first indicated that PEG2000-PCL2000 was successfully synthesized. DGL and PTX-loaded PEG-PCL nano-micelles were rounded in shape with a particle size of 35.78 ± 0.35 nm and a surface potential of 2.84 ± 0.27 mV. The micelles had minimal hemolytic activity. Besides, we proved that DGL and PTX-loaded PEG-PCL nano-micelles could suppress proliferation and induce apoptosis in BC cells. The DGL and PTX-loaded PEG-PCL nano-micelles constructed in this study had a prominent inhibitory role on proliferation and a remarkable promotional role on apoptosis in BC cells. This study proposes that nano-micelles formed by PEG-PCL can enhance the cytotoxicity of Paclitaxel against breast cancer cells, and concurrently, the loading of Deguelin may further inhibit cell proliferation. This presents a potential for the development of a novel therapeutic strategy.

Nanostructured lipid carriers loaded into in situ gels for breast cancer local treatment

In this study, nanostructured lipid carriers (NLC) were developed and employed to obtain in situ thermosensitive formulations for the ductal administration and prolonged retention of drugs as a new strategy for breast cancer local treatment. NLC size was influenced by the type and concentration of the oil phase, surfactants, and drug incorporation, ranging from 221.6 to 467.5 nm. The type of liquid lipid influenced paclitaxel and 5-fluorouracil cytotoxicity, with tributyrin-containing NLC reducing IC50 values by 2.0–7.0-fold compared to tricaprylin NLC in MCF-7, T-47D and MDA-MB-231 cells. In spheroids, the NLCs reduced IC50 compared to either drug solution (3.2–6.2-fold). Although a significant reduction (1.26 points, p < 0.001) on the health index of Galleria mellonella larvae was observed 5 days after NLC administration, survival was not significantly reduced. To produce thermosensitive gels, the NLCs were incorporated in a poloxamer (11 %, w/w) dispersion, which gained viscosity (2-fold) at 37 °C. After 24 h, ∼53 % of paclitaxel and 83 % of 5-fluorouracil were released from the NLC; incorporation in the poloxamer gel further prolonged release. Intraductal administration of NLC-loaded gel increased the permanence of hydrophilic (2.2–3.0-fold) and lipophilic (2.1–2.3-fold) fluorescent markers in the mammary tissue compared to the NLC (as dispersion) and the markers solutions. In conclusion, these results contribute to improving our understanding of nanocarrier design with increased cytotoxicity and prolonged retention for the intraductal route. Tributyrin incorporation increased the cytotoxicity of paclitaxel and 5-fluorouracil in monolayer and spheroids, while NLC incorporation in thermosensitive gels prolonged tissue retention of both hydrophilic and hydrophobic compounds.

Enzyme-Responsive Branched Glycopolymer-Based Nanoassembly for Co-Delivery of Paclitaxel and Akt Inhibitor toward Synergistic Therapy of Gastric Cancer.

Combined chemotherapy and targeted therapy holds immense potential in the management of advanced gastric cancer (GC). GC tissues exhibit an elevated expression level of protein kinase B (AKT), which contributes to disease progression and poor chemotherapeutic responsiveness. Inhibition of AKT expression through an AKT inhibitor, capivasertib (CAP), to enhance cytotoxicity of paclitaxel (PTX) toward GC cells is demonstrated in this study. A cathepsin B-responsive polymeric nanoparticle prodrug system is employed for co-delivery of PTX and CAP, resulting in a polymeric nano-drug BPGP@CAP. The release of PTX and CAP is triggered in an environment with overexpressed cathepsin B upon lysosomal uptake of BPGP@CAP. A synergistic therapeutic effect of PTX and CAP on killing GC cells is confirmed by in vitro and in vivo experiments. Mechanistic investigations suggested that CAP may inhibit AKT expression, leading to suppression of the phosphoinositide 3-kinase (PI3K)/AKT signaling pathway. Encouragingly, CAP can synergize with PTX to exert potent antitumor effects against GC after they are co-delivered via a polymeric drug delivery system, and this delivery system helped reduce their toxic side effects, which provides an effective therapeutic strategy for treating GC.

Optimizing adjuvant inhaled chemotherapy: Synergistic enhancement in paclitaxel cytotoxicity by flubendazole nanocrystals in a cycle model approach

Lung cancer is the leading cause of cancer-related death. In addition to new innovative approaches, practical strategies that improve the efficacy of already available drugs are urgently needed. In this study, an inhalable dry powder formulation is used to repurpose flubendazole, a poorly soluble anthelmintic drug with potential against a variety of cancer lineages. Flubendazole nanocrystals were obtained through nanoprecipitation, and dry powder was produced by spray drying. Through fractional factorial design, the spray drying parameters were optimized and the impact of formulation on aerolization properties was clarified. The loading limitations were clarified through response surface methodology, and a 15% flubendazole loading was feasible through the addition of 20% L-leucine, leading to a flubendazole particle size of 388.6 nm, median mass aerodynamic diameter of 2.9 μm, 50.3% FPF, emitted dose of 83.2% and triple the initial solubility. Although the cytotoxicity of this formulation in A549 cells was limited, the formulation showed a synergistic effect when associated with paclitaxel, leading to a surprising 1000-fold reduction in the IC50. Compared to 3 cycles of paclitaxel alone, a 3-cycle model combined treatment increased the threshold of cytotoxicity by 25% for the same dose. Our study suggests, for the first time, that orally inhaled flubendazole nanocrystals show high potential as adjuvants to increase cytotoxic agents’ potency and reduce adverse effects.

Ratiometric codelivery of Paclitaxel and Baicalein loaded nanoemulsion for enhancement of breast cancer treatment

The most prevalent clinical option for treating cancer is combination chemotherapy. In combination therapy, assessment and optimization for obtaining a synergistic ratio could be obtained by various preclinical setups. Currently, in vitro optimization is used to get synergistic cytotoxicity while constructing combinations. Herein, we co-encapsulated Paclitaxel (PTX) and Baicalein (BCLN) with TPP-TPGS1000 containing nanoemulsion (TPP-TPGS1000-PTX-BCLN-NE) for breast cancer treatment. The assessment of cytotoxicity of PTX and BCLN at different molar weight ratios provided an optimized synergistic ratio (1:5). Quality by Design (QbD) approach was later applied for the optimization as well as characterization of nanoformulation for its droplet size, zeta potential and drug content. TPP-TPGS1000-PTX-BCLN-NE significantly enhanced cellular ROS, cell cycle arrest, and depolarization of mitochondrial membrane potential in the 4T1 breast cancer cell line compared to other treatments. In the syngeneic 4T1 BALB/c tumor model, TPP-TPGS1000-PTX-BCLN-NE outperformed other nanoformulation treatments. The pharmacokinetic, biodistribution and live imaging studies pivoted TPP-TPGS1000-PTX-BCLN-NE enhanced bioavailability and PTX accumulation at tumor site. Later, histology studies confirmed nanoemulsion non-toxicity, expressing new opportunities and potential to treat breast cancer. These results suggested that current nanoformulation can be a potential therapeutic approach to effectively address breast cancer therapy.

PEGylated Paclitaxel Nanomedicine Meets 3D Confinement: Cytotoxicity and Cell Behaviors

Investigating the effect of nanomedicines on cancer cell behavior in three-dimensional (3D) platforms is beneficial for evaluating and developing novel antitumor nanomedicines in vitro. While the cytotoxicity of nanomedicines on cancer cells has been widely studied on two-dimensional flat surfaces, there is little work using 3D confinement to assess their effects. This study aims to address this gap by applying PEGylated paclitaxel nanoparticles (PEG-PTX NPs) for the first time to treat nasopharyngeal carcinoma (NPC43) cells in 3D confinement consisting of microwells with different sizes and a glass cover. The cytotoxicity of the small molecule drug paclitaxel (PTX) and PEG-PTX NPs was studied in microwells with sizes of 50 × 50, 100 × 100, and 150 × 150 μm2 both with and without a concealed top cover. The impact of microwell confinement with varying sizes and concealment on the cytotoxicity of PTX and PEG-PTX NPs was analyzed by assessing NPC43 cell viability, migration speed, and cell morphology following treatment. Overall, microwell isolation was found to suppress drug cytotoxicity, and differences were observed in the time-dependent effects of PTX and PEG-PTX NPs on NPC43 cells in isolated and concealed microenvironments. These results not only demonstrate the effect of 3D confinement on nanomedicine cytotoxicity and cell behaviors but also provide a novel method to screen anticancer drugs and evaluate cell behaviors in vitro.

A Dual-Targeting Liposome Enhances Triple-Negative Breast Cancer Chemoimmunotherapy through Inducing Immunogenic Cell Death and Inhibiting STAT3 Activation.

Immunotherapy gains increasing focus in treating triple-negative breast cancer (TNBC), while its efficacy is greatly restricted owing to low tumor immunogenicity and immunosuppressive tumor microenvironment (ITM). Herein, a LyP-1 and chondroitin sulfate (CS) dual-modified liposome co-loaded with paclitaxel (PTX) and cryptotanshinone (CTS), namely CS/LyP-1-PC Lip, is engineered for TNBC chemoimmunotherapy via induction of immunogenic cell death (ICD) and inhibition of signal transducer and activator of transcript-3 (STAT3) activation. CS/LyP-1-PC Lip enhances cellular uptake through p32 and CD44 dual receptor-mediated endocytosis. Within the tumor, the CS layer is continuously detached by hyaluronidase to release drugs. Subsequently, CTS sensitizes the cytotoxicity of PTX to 4T1 tumor cells. PTX induces ICD of tumor cells and facilitates infiltration of cytotoxic T lymphocyte to provoke immune response. Meanwhile, the concomitant delivery of CTS inhibits STAT3 activation to decrease infiltration of regulatory T cell, M2-type tumor-associated macrophage, and myeloid-derived suppressor cell, thus reversing ITM. Markedly, the dual-targeting liposome shows superior anti-tumor efficacy in subcutaneous TNBC mice and significant lung metastasis suppression in tumor metastasis model. Overall, this work offers a feasible combination regimen and a promising nanoplatform for the development of TNBC chemoimmunotherapy.

Evaluation of potential cytotoxic and apoptotic effects of paclitaxel and docetaxel in human Burkitt lymphoma cell lines

Purpose: To study the cytotoxicity of paclitaxel and docetaxel on cell viability and apoptosis in Burkitt lymphoma cell lines.&#x0D; Methods: The cytotoxic activity of Paclitaxel and Docetaxel against Burkitt lymphoma cells was evaluated using the XTT cell viability test. The cells were exposed to increasing concentrations of paclitaxel and docetaxel ranging from 0.0001 to 10 μM for 48 h. Cell cycle analysis and apoptosis were also assessed using flow cytometry-based experiments.&#x0D; Results: Both paclitaxel and docetaxel exhibited a concentration-dependent cytotoxic effect with IC50 of 5.32 and 6.58 μM, respectively. Furthermore, paclitaxel and docetaxel were shown to have a significant apoptotic effect on Burkitt lymphoma cells (p &lt; 0.01). Furthermore, paclitaxel and docetaxel arrested Burkitt lymphoma cells at the G2/M phase.&#x0D; Conclusion: Paclitaxel and docetaxel are potential candidates for the treatment of Burkitt lymphoma. Since both drugs are already licensed for many indications, the addition of Burkitt lymphoma to the list of indications of these drugs would be a much easier and faster process. However, there is a need for further in vitro and in vivo research to fully elucidate their mechanisms of action.

2,6-Disubstituted Piperidine Alkaloids with Neuroprotective Activity from Hippobroma longiflora.

Three new alkaloids, hipporidine A (1: ), hipporidine B (2: ), and (-)-lobeline N-oxide (3: ), were discovered from the whole plant of Hippobroma longiflora together with five known compounds (4: -8: ). Their 2,6-disubstituted piperidine structures were established based on the HRESIMS, NMR (COSY, HMBC, HSQC, NOESY), and UV spectroscopic data. Hipporidines A (1: ) and B (2: ) possess a rare 1,3-oxazinane moiety. Compound 3: is the N-oxide derivative of (-)-lobeline (6: ). Moreover, the absolute configuration of norlobeline (5: ) was established by single-crystal X-ray diffraction analysis. Three major secondary metabolites (6: -8: ) were evaluated for their neuroprotective effect against paclitaxel-induced neurotoxicity. Consequently, pretreatment with compound 8: at a concentration of 1.0 µM displayed significant attenuation on paclitaxel-damaged neurite outgrowth of dorsal root ganglion neurons without interfering with the cytotoxicity of paclitaxel on cervical cancer SiHa cells.

Combinatorial effects of melatonin and paclitaxel differ depending on the treatment scheme in colorectal cancer in vitro

AimsColorectal carcinoma (CRC) is the third most prevalent cancer with high mortality. Besides regulating the circadian rhythm, melatonin (MTN) exerts anticancer activities. Paclitaxel (PTX) is successful against different malignancies, however, acquired resistance and variability in patient response restrict its use. mTOR and MAPK pathways are often deregulated in human cancers. We aimed to investigate whether MTN enhances or sensitizes the chemotherapeutic activity of PTX and if so, determine the underlying possible mechanisms in CRC in vitro. Main methodsAntiproliferative and cytotoxic activities of PTX and MTN were assessed alone and in combination, as well as with different treatment regimens (renewal or replacement of the treatment after 24 h), up to 48 h. Apoptosis, viability and autophagy were assessed by flow cytometry. mTOR and MAPK pathway activities were investigated by immunoblotting. Key findingsBoth drugs reduced cell viability in a dose-dependent manner at 24 and 48 h. Only the highest dose of MTN (500 μM) potentiated the cytotoxicity of PTX (50 nM). Replacement of PTX after 24 h with MTN was superior in reducing cell viability than vice versa via apoptosis induction. Renewal of MTN treatment every 24 h reduced autophagy compared to the control group, while other treatments did not alter the autophagic activity. A 24 h MTN treatment followed by 24 h PTX treatment increased S6 phosphorylation in a mTOR-independent manner and increased Erk1/2 phosphorylation. SignificanceThe present study suggests that sequential treatment with MTN and PTX distinctly affect apoptosis and cytotoxicity via regulating mTOR and MAPK pathways differentially in CRC.