B16F10 Cell Lines Research Articles

Fucoidan from Spatoglossum schröederi promotes B16-F10 malignancy features modulation and antimelanoma in vivo activities

Although recent advances in targeted and immunotherapy, metastatic melanoma treatment still poses as a challenge, with limited success and a variety of severe adverse effects. Polysaccharides from natural sources have been explored as a new approach to tackle cancer and melanoma treatment limitations, even reaching clinical trials. One prominent group of biological active polysaccharides are fucoidans - sulfated polysaccharides mainly constituted of fucose and obtained from brown seaweed. In the present study, we explored the antimelanoma activities of Fucan A, a highly sulfated fucoidan obtained from Spatoglossum schröederi. Fucan A presented a selective antiproliferative effect against murine melanoma B16-F10 cell line impacting cell cycle progression in concentrations of 100 and 1000 μg⸱mL−1 while also reducing its colony formation and invasive capacity, as well as modulating invasion mechanistically related genes - namely MMP-9, MMP-14, glypican-3 and perlecan. Fucan A also reduced in vivo solid tumor volume in a daily post-cell inoculation treatment regimen with a 100 mg⸱Kg−1 dosage. Additionally, using a 48 h pre-treatment regimen in a reduced dosage (30 mg⸱Kg−1), Fucan A reduced pulmonary metastasis colonization, with limited to non-detectable adverse effects. These results associated with the explorable commercial potential of S. schröederi indicate an interesting compound to be further explored as a possible antimelanoma drug.

Effects of Electrochemotherapy on Immunologically Important Modifications in Tumor Cells.

Electrochemotherapy (ECT) is a clinically acknowledged method that combines the use of anticancer drugs and electrical pulses. Electrochemotherapy with bleomycin (BLM) can induce immunogenic cell death (ICD) in certain settings. However, whether this is ubiquitous over different cancer types and for other clinically relevant chemotherapeutics used with electrochemotherapy is unknown. Here, we evaluated in vitro in the B16-F10, 4T1 and CT26 murine tumor cell lines, the electrochemotherapy triggered changes in the ICD-associated damage-associated molecular patterns (DAMPs): Calreticulin (CRT), ATP, High Mobility Group Box 1 (HMGB1), and four immunologically important cellular markers: MHCI, MHC II, PD-L1 and CD40. The changes in these markers were investigated in time up to 48 h after ECT. We showed that electrochemotherapy with all three tested chemotherapeutics induced ICD-associated DAMPs, but the induced DAMP signature was cell line and chemotherapeutic concentration specific. Similarly, electrochemotherapy with CDDP, OXA or BLM modified the expression of MHC I, MHC II, PD-L1 and CD40. The potential of electrochemotherapy to change their expression was also cell line and chemotherapeutic concentration specific. Our results thus put the electrochemotherapy with clinically relevant chemotherapeutics CDDP, OXA and BLM on the map of ICD inducing therapies.

Design and synthesis of γ‐Fe2O3@Ag‐S‐CH2‐COOH nanocatalyst for one‐pot synthesis of 2,3‐dihydroquinazolin‐4(1H)‐ones and their anti‐skin cancer activity

The ongoing work describes the catalytic evaluation of γ‐Fe2O3@Ag‐S‐CH2‐COOH magnetic nanoparticles utilizing γ‐Fe2O3 obtained from waste iron rust for one‐pot synthesis of 2,3‐dihydroquinazolin‐4(1H)‐ones. As‐prepared γ‐Fe2O3@Ag‐S‐CH2‐COOH nanoparticles were characterized by Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDX), dynamic light scattering (DLS), transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller (BET) technique. The catalytic performance of greener γ‐Fe2O3@Ag‐S‐CH2‐COOH nanoparticles was utilized in the synthesis of 2,3‐dihydroquinazolin‐4(1H)‐ones. The excellent catalytic performance was shown by magnetic nanoparticles in addition to its ease of separation by an external magnet and can be recycled for five consecutive turns without significant loss of catalytic activity. Furthermore, the synthesized 2,3‐dihydroquinazolin‐4(1H)‐ones were confirmed by FT‐IR, 1H, 13C nuclear magnetic resonance (NMR), and mass spectrometry. Moreover, the synthesized 2,3‐dihydroquinazolin‐4(1H)‐ones were evaluated for their anticancer efficiency against the human skin cancer cell line B16F10 along with molecular docking investigation.

Abstract 3104: Synthesis and optimization of small molecules designed to stimulate the immune system by inducing DNA damage and blocking PD-1/PD-L1

Abstract Introduction. Activating the immune system against cancer is becoming an increasingly effective therapy option that can result in dramatic and durable responses in several cancer types. One approach to achieve the reactivation of endogenous antitumor T cells is by blocking PD-1/PD-L1 immune checkpoints expressed on T cells and other leukocytes. However, only limited cancer patients (15-25%) respond to anti-PD-1/PD-L1 immunotherapy. One of the most pressing current clinical challenges is to convert nonresponsive, “cold” tumors to responsive, “hot” tumors. Interestingly, after DNA-damaging chemotherapy, the immune environment may be changed from “cold” tumors to “hot” tumors by increasing the tumor mutation burden and the generation of neoantigens on the surface of cancer cells. Therefore, we surmised that a molecule capable of inducing promutagenic DNA and block PD-1/PD-L1 could not only induce neoantigens but also synergistically enhance immune response against the targeted tumor. Using an approach developed in our laboratory termed the “combi-targeting” strategy, we designed and synthesized a series of “combi-molecules” programmed to generate the promutagenic species and a small molecule capable of blocking PD-1/PD-L1. Material and methods. Melanoma cell line B16-F10 was used to determine IC50 of the new molecules with SRB assay. Homogenous time-resolved fluorescence (HTRF) binding assay was used to determine the IC50 inhibition of PD-1/PD-L1. Drug metabolism in extracted cells was measured by LC-MS. Results. We discovered a structure activity relationship of the combi-molecules based on the substitution of the side chain of the alkylating agent and the PD-1/PD-L1 scaffold. By altering the scaffolds of the combi-molecules from sulfonamides to biphenyl derivatives, we optimized binding to PD-1/PD-L1 from millimolar to micromolar levels. In vitro growth inhibitory analysis showed that the combi-molecules with biphenyl scaffold were 24-fold more potent in B16-F10. Importantly, analysis of intracellular metabolites of the combi-molecules revealed three main metabolites that can only result from the release of the shortlived promutagenic species. Conclusions. The biphenyl scaffold is optimal for maintaining strong PD-1/PD-L1 binding potency and enough potent to contribute to cell death. Hydrolytic cleavage of the alkylating agent is an indirect evidence of the formation of the alkylating species required to induce promutagenic lesions. Citation Format: Ana Belen Fraga Timiraos, Caterina Facchin, Nadia Babaa, Anne-Laure Larroque-Lombard, Bertrand Jean-Claude. Synthesis and optimization of small molecules designed to stimulate the immune system by inducing DNA damage and blocking PD-1/PD-L1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3104.

Design, synthesis and biological activity of novel oxadiazole containing monoacylglycerols as potential bioactive lipids

A series of novel 1,3,4-oxadiazole based 1-monoacylglycerol derivatives were synthesized and evaluated for their antimicrobial and anticancer activity. Eight different substituted benzoic acids were utilized for the synthesis of new fatty acids incorporating the 1,3,4-oxadiazole scaffold. These fatty acids were further employed for the preparation of 1-monoacylglycerols (10a-10 h) in an eight step synthetic route. The synthesized 1-monoacylglycerols were characterized by NMR, IR and MS spectral data and screened for their in vitro antimicrobial activity against selected bacterial and fungal strains. The best results were obtained for 3,4-dimethoxybenzoic acid (10c), benzoic acid (10a) and 4-methoxybenzoic acid (10b) derivatives with a noticeable zone of inhibition on all the tested organisms. In the in vitro cytotoxicity assay against B16-F10, DU145, Hep G2 and CHO-K1 cell lines, the 2,3,4-trimethoxybenzoic acid (10d) and 4-fluorobenzoic acid derivative (10e) showed a broad spectrum of cytotoxicity. Based on the preliminary screening it can be suggested that these novel lipidic oxadiazole derivatives could act as promising antitumor agents with some degree of therapeutic effect and further studies can help in designing potential analogs.

흰색 무궁화꽃과 분홍색 무궁화꽃 추출물의 항산화, 멜라닌 합성 저해 및 항균활성 비교

This study investigates the bioactivities of Hibiscus syriacus (H. syriacus) L. flower extracts on dermal cells and bacteria. The white and pink H. syriacus L. flower extracts showed no or minimal cytotoxicity on HaCaT (human keratinocyte) and B16F10 (mouse melanoma) cell lines. H. syriacus L. flower extract inhibited oxidative stress, and its effect was superior to the effect of glutathione. The antioxidant efficacy of pink H. syriacus L. flower extract was higher than the white flower extract. The chloroform layer of the white H. syriacus L. flower extract (40 μg/mL) inhibited melanin synthesis and showed remarkable antibacterial effects against Staphylococcus aureus. The extracted layer also exhibited antibacterial effects on Staphylococcus epidermidis and Pseudomonas aeruginosa. Based on the bioactivity experiment, the white H. syriacus L. flower extract was more effective than the pink flower extract in inhibiting melanin synthesis and antibacterial efficacy. The results of this study indicate potential applications of H. syriacus L. flowers in cosmetics.

Bioengineered dual fluorescent carbon nano dots from Indian long pepper leaves for multifaceted environmental and health utilities.

In this article, we present the synthesis of Piper longum leaves-derived ethanolic carbon dots (PLECDs) using the most simplistic environmentally friendly solvothermal carbonization method. The PLECDs fluoresced pink color with maximum emission at 670nm at 397nm excitation. Additionally, the dried PLECDs dissolved in water showed green fluorescence with higher emission at 452nm at 370nm excitation. The UV spectra showed peaks in the UV region (271.25nm and 320.79nm) and a noticeable tail in the visible region, signifying the efficient synthesis of nano-sized carbon particles and the Mie scattering effect. Various functional groups (-OH, -N-H, -C-H, -C = C, -C-N, and -C-O) were identified using Fourier transform infrared spectroscopy (FTIR). Its nanocrystalline property was revealed by the sharp peaks in the X-ray diffraction (XRD). High-resolution transmission electron microscopy (HRTEM) photomicrograph displayed a roughly spherical structure with a mean size of 2.835nm. The energy dispersive X-ray (EDAX) and X-ray photoelectron spectroscopy (XPS) revealed the elemental abundance of C, O, and N. The high-performance thin-layer chromatography (HPTLC) fingerprint of PLECDs showed an altered pattern than its precursor (Piper longum leaves ethanolic extract or PLLEE). The PLECDs sensed Cu2+ selectively with a limit of detection (LOD) and limit of quantification (LOQ) of 0.063μM and 0.193μM, respectively. It showed excellent cytotoxicity toward MDA-MB-231 (human breast cancer), SiHa (human cervical carcinoma), and B16F10 (murine melanoma) cell lines with excellent in vitro bioimaging outcomes. It also has free radical scavenging activity. The PLECDs also showed outstanding bacterial biocompatibility, pH-dependent fluorescence stability, photostability, physicochemical stability, and thermal stability.

Oleaginous Yeast Extracts and Their Possible Effects on Human Health

Four non-conventional oleaginous and pigmented yeast strains of Metschnikowia pulcherrima, Cystofilobasidium infirmominiatum, Phaffia rhodozyma, and Rhodotorula kratochvilovae were used in this study. Complex yeast extracts were prepared and tested for biological activity, safety, and effect on human health. In this paper, we measured the antioxidant activity and antimicrobial effect of yeast biomass as a whole and their extracts to compare the influence of carotenoids and other bioactive substances in the studied biomass. All yeast extracts exhibited a significant dose-dependent antimicrobial effect against both G+ and G- bacteria and had a strong antioxidant effect. No cytotoxicity in the mouse melanoma B16F1 cell line was found in concentrations up to 20% of rehydrated biomass in cell medium. All of the extracts were cytotoxic at a concentration of 5 mg of extract/g of dry biomass. All the pigmented yeast extracts showed some positive results for apoptosis of murine melanoma cell lines and are therefore strong candidates positively effect human health. Red yeast cell biomass is a prospective material with many attractive biological functions and can be used in the food industry, as a pharmaceutical material, or in the feed industry.

Effectiveness of HM-3-HSA on Inhibiting Cancer Cell Migration and Metastasis.

Metastasis is the major cause of treatment failure in cancer patients and cancer- associated death, and an antimetastatic drug would be a beneficial therapy for cancer patients. HM-3-HSA is a fusion protein which improved the pharmacokinetics of HM-3 and exerted antitumor and anti-angiogenesis activity in multiple tumor models. However, the efficacy of HM-3-HSA in cancer cell migration and metastasis has not been elucidated. Herein, high-cell density fermentation of Pichiapink strain expressing HM- 3-HSA was performed for the first time. Then, the desired protein was purified by Butyl Sepharose High performance, Capto Blue, Phenyl Sepharose 6FF HS and DEAE Sepharose FF. Furthermore, the effect of HM-3-HSA on the migration and invasion of cancer cells was also evaluated, and B16F10 metastasis model was established to detected the anti- metastasis effect of HM-3-HSA in vivo. The results indicated that the yield of HM-3-HSA was 320 mg/L in a 10 L fermenter, which was a 46% increase over that expressed in flask cultivation. The desired protein was purified by fourstep, which yielded a 40% recovery of a product that had over 99% purity. Purified HM-3-HSA significantly suppressed the migration and invasion of HCT-116, SMMC-7721 and B16F10 cell lines. On the other hand, in the B16F10 metastasis model, HM-3-HSA significantly inhibited pulmonary metastases of B16F10 cells, suggesting that HM-3-HSA exerted the anti-metastasis effect in vivo.

Single-cell RNA sequencing reveals the suppressive effect of PPP1R15A inhibitor Sephin1 in antitumor immunity

Protein phosphatase 1 regulatory subunit 15A (PPP1R15A) is an important factor in the integrated stress response (ISR) in mammals and may play a crucial role in tumorigenesis. In our studies, we found an inhibitor of PPP1R15A, Sephin1, plays a protumorigenic role in mouse tumor models. By analyzing the single-cell transcriptome data of the mouse tumor models, we found that in C57BL/6 mice, Sephin1 treatment could lead to higher levels of ISR activity and lower levels of antitumor immune activities. Specifically, Sephin1 treatment caused reductions in antitumor immune cell types and lower expression levels of cytotoxicity-related genes. In addition, Tcell receptor (TCR) repertoire analysis demonstrated that the clonal expansion of tumor-specific Tcells was inhibited by Sephin1. A special TCR+ macrophage subtype in tumor was identified to be significantly depleted upon Sephin1 treatment, implying its key antitumor role. These results suggest that PPP1R15A has the potential to be an effective target for tumor therapy.

Design, Synthesis, Characterization, and Anti-Cancer Activity Evaluation of Novel Thiosemicarbazide Analogs

Abstract: Aim/Background: Across the world disease of cancer is one of the factors of death and to identify the emerging role of thiosemicarbazide analogs for the cancer disease it was decided to design, and synthesize novel thiosemicarbazide derivatives (5a-i) with in-vitro anticancer activity evaluation. Materials and Methods: Substituted benzoic acid, thionyl chloride, hydrazine hydrate, and ammonium thiocyanate were used to create a new series of thiosemicarbazide derivatives (5a-i). The final derivatives were characterized using 13C and 1H NMR, FTIR, and mass spectroscopy. The compounds were then analyzed for anticancer action with the in-vitro MTT assay method as well as by measuring the percentage of tumor growth on the B16F10 melanoma cell line, a clone of B16 cells. Results: Compounds 5a, 5b, and 5e outperformed and were comparable to the reference drug, doxorubicin. All three compounds have an electron-withdrawing group substitution and have shown remarkable anticancer effects. When compared to other substituted derivatives, the drug-likeness score evaluated by Swiss ADME online software confirmed the same fact that thiosemicarbazides with electronwithdrawing groups substitution like halogens, and nitro groups at different positions could work as excellent and promising anticancer agents. Conclusion: The study and the result of the study revealed that thiosemicarbazide moiety represents an important core and could be used as a template for further development of analogs having promising anti-cancer effects. Keywords: Anticancer, B16F10 cell line, Melanoma, Thiosemicarbazide, MTT assay.

High-Dose Ascorbate in Combination with Anti-PD1 Checkpoint Inhibition as Treatment Option for Malignant Melanoma.

Ascorbate acts as a prooxidant when administered parenterally at high supraphysiological doses, which results in the generation of hydrogen peroxide in dependence on oxygen. Most cancer cells are susceptible to the emerging reactive oxygen species (ROS). Accordingly, we evaluated high-dose ascorbate for the treatment of the B16F10 melanoma model. To investigate the effects of ascorbate on the B16F10 cell line in vitro, viability, cellular impedance, and ROS production were analyzed. In vivo, C57BL/6NCrl mice were subcutaneously injected into the right flank with B16F10 cells and tumor-bearing mice were treated intraperitoneally with ascorbate (3 g/kg bodyweight), immunotherapy (anti-programmed cell death protein 1 (PD1) antibody J43; 2 mg/kg bodyweight), or both treatments combined. The efficacy and toxicity were analyzed by measuring the respective tumor sizes and mouse weights accompanied by histological analysis of the protein levels of proliferating cell nuclear antigen (Pcna), glucose transporter 1 (Glut-1), and CD3. Treatment of B16F10 melanoma-carrying mice with high-dose ascorbate yielded plasma levels in the pharmacologically effective range, and ascorbate showed efficacy as a monotherapy and when combined with PD1 inhibition. Our data suggest the applicability of ascorbate as an additional therapeutic agent that can be safely combined with immunotherapy and has the potential to potentiate anti-PD1-based immune checkpoint blockades.

Synthesis, Anticancer, and Antimicrobial Evaluation of Integerrimide‐A

Integerrimide‐A (IG‐A) is a cyclic heptapeptide that was recently synthesized after being recovered from the latex of the Jatropha integerrima tree. This was achieved by first coupling a tetrapeptide unit (Boc‐Gly‐L‐Leu‐L‐Leu‐L‐Leu‐OMe) with a tripeptide unit (L‐Thr‐L‐Pro‐L‐Trp‐OMe). The characterization was done by using spectral techniques like FT‐IR, 1H‐NMR, mass spectrometry, and elemental analysis of the newly synthesized cyclic molecule. Antimicrobial and anticancer properties of IG‐A were tested using a biological screening. Gram +ve bacteria (B. subtilis and S. aureus) and Gram ‐ve bacteria (P. aeruginosa and E. coli) were used in the antibacterial testing. Fungal strains such as C. albicans, A. niger, T. mentagrophytes, and M. audouinii were used to test the antifungal activities. Antimicrobial activity analysis revealed that cyclic peptide—IG‐A (8)—has modest antibacterial activity and antifungal activities, when compared with the standard drugs ciprofloxacin and griseofulvin, respectively. Comparable MTT assays were performed on HCT116 (human colon carcinoma) and B16F10 (melanoma cells) cell lines with doxorubicin as the standard drug to determine the cytotoxic activity of the synthesized cyclic peptide. Inhibition of growth of HCT116 and B16F10 cell lines was used to calculate the cytotoxic effect. At a dosage of 120 μg/mL, the cyclopeptide IG‐A (8) inhibited cell proliferation by 87.5 and 72.5 percent, respectively. Cyclopeptide IG‐A had CTC50 values of 77.65 μM and 68.63 μM against HCT116 and B16F10, respectively. The % growth inhibitions at lesser levels are 72.5 and 50 at 60 μg/mL, respectively. The standard drug inhibited growth by 100 percent with CTC50 values of 48.63 μM and 43.25 μM against HCT116 and B16F10, respectively. From the results, it is concluded that IG‐A has considerable antimicrobial and cytotoxic effects. Internucleosomal DNA fragmentation may be the underlying mechanism in HCT116 cells, whereas the suppression of eumelanin synthesis in B16F10 cells is another possibility.

Synthesis, molecular docking, and biological evaluation of [3,2-b]indole fused 18β-glycyrrhetinic acid derivatives against skin melanoma.

Melanoma, the most serious yet uncommon type of cancer, originates in melanocytes. Risk factors include UV radiation, genetic factors, tanning lamps and beds. Here, we described the synthesis and selective anti melanoma activity of [3,2-b]indole fused 18β-glycyrrhetinic acid, a derivative of 18β-glycyrrhetinic acid in murine B16F10 and A375 human melanoma cell lines. Among the 14 molecules, GPD-12 showed significant selective cytotoxic activity against A375 and B16F10 cell lines with IC50 of 13.38 μM and 15.20 μM respectively. GPD 12 induced the formation of reactive oxygen species in A375 cells that could trigger oxidative stress mediated cell death as is evident from the increased expression of apoptosis related proteins such as caspase-9 and caspase-3 and the increased ratio of Bax to Bcl2. The results showed that GPD 12 can be used as an effective therapeutic agent against melanoma.

Evaluation of anti-oxidant and antimelanogenic effects of the essential oil and extracts of Rosa × damascena in B16F10 murine melanoma cell line.

Rosa × damascena Herrm. belonging to the Rosaceae family has demonstrated anti-inflammatory and anti-oxidant effects previously. Excessive production of free radicals and activation of tyrosinase enzyme caused by UV induces excessive concentration of melanin pigment and skin spots in the long term. Therefore, finding natural sources with anti-oxidant and antityrosinase effects helps to regulate the melanogenesis process. In the current research, we investigated the antimelanogenic, anti-oxidant, and anti-tyrosinase effects of its essential oil, methanol extract (MeOH), and different fractions including n-hexane, dichloromethane (CH2Cl2), n-butanol (BuOH), ethyl acetate (EtOAc), and H2O of R. × damascena in B16F10 cell line. For this purpose, impacts of extracts and essential oil of R. × damascena were investigated on cell viability, cellular tyrosinase, melanin content, mushroom tyrosinase, reactive oxygen species (ROS) production, as well as the amount of tyrosinase protein in the B16F10 murine melanoma cell line. Essential oil, MeOH, and different fractions of R. × damascena were not cytotoxic on B16F10 cells. However, they had significant reducing effects on mushroom tyrosinase activity, melanin content, and ROS production. Also, there is a significant decrease in tyrosinase protein levels at 200 µg/ml but not at other concentrations. Therefore, the essential oil, MeOH, and different fractions of R. × damascena had promising antimelanogenic activity via repression of mushroom tyrosinase activity and ROS production.

Anti-Melanogenesis Effects of a Cyclic Peptide Derived from Flaxseed via Inhibition of CREB Pathway.

Linosorbs (Los) are cyclic peptides from flaxseed oil composed of the LO mixture (LOMIX). The activity of LO has been reported as being anti-cancer and anti-inflammatory. However, the study of skin protection has still not proceeded. In particular, there are poorly understood mechanisms of melanogenesis to LO. Therefore, we investigated the anti-melanogenesis effects of LOMIX and LO, and its activity was examined in mouse melanoma cell lines. The treatment of LOMIX (50 and 100 μg/mL) and LO (6.25-50 μM) suppressed melanin secretion and synthesis, which were 3-fold increased, in a dose-dependent manner, up to 95%. In particular, [1-9-NαC]-linusorb B3 (LO1) and [1-9-NαC]-linusorb B2 (LO2) treatment (12.5 and 25 μM) highly suppressed the synthesis of melanin in B16F10 cell lines up to 90%, without toxicity. LOMIX and LOs decreased the 2- or 3-fold increased mRNA levels, including the microphthalmia-associated transcription factor (MITF), Tyrosinase, tyrosinase-related protein 1 (TYRP1), and tyrosinase-related protein 2 (TYRP2) at the highest concentration (25 μM). Moreover, the treatment of 25 μM LO1 and LO2 inhibited the expression of MITF and phosphorylation of upper regulatory proteins such as CREB and PKA. Taken together, these results suggested that LOMIX and its individual LO could inhibit melanin synthesis via downregulating the CREB-dependent signaling pathways, and it could be used for novel therapeutic materials in hyperpigmentation.

Plasmid DNA cationic non-viral vector complexes induce cytotoxicity-associated PD-L1 expression up-regulation in cancer cells in vitro

Non-viral vectors are promising nucleic acid carriers which have been utilized in gene-based cancer immunotherapy. The aim of this study is to compare the transfection efficiency and cytotoxicity of three cationic non-viral vectors namely Polyethylenimine (PEI), Lipofectamine 2000 (LPF) and stable nucleic acid lipid particles (SNALPs) of different lipid compositions, for the delivery of plasmid DNA (pDNA) expressing immunostimulatory molecules, OX40L or 4-1BBL, to cancer cells in vitro. The results indicate that PEI and LPF are efficient vectors for pDNA delivery with high transfection efficiency obtained. However, pDNA-PEI and pDNA-LPF complexes up-regulated the expression of programmed death ligand-1 (PD-L1) and induced significant cytotoxicity in both B16F10 and CT26 cell lines. The up-regulation of PD-L1 expression induced by pDNA-PEI and pDNA-LPF complexes was independent of cancer cell line, nor was it linked to the presence of GpC motifs in the pDNA. In contrast, the use of biocompatible SNALPs (MC3 and KC2 types) resulted in lower pDNA transfection efficiency, however no significant up-regulation of PD-L1 or cytotoxicity was observed. A strong correlation was found between up-regulation of PD-L1 expression and cytotoxicity. Up-regulation of PD-L1 expression could be mitigated with RNAi, maintaining expression at basal levels. Due to the improved biocompatibility and the absence of PD-L1 up-regulation, SNALPs represent a viable non-viral nucleic acid vector for delivery of pDNA encoding immunostimulatory molecules. The results of this study suggest that PD-L1 expression should be monitored when selecting commercial transfection reagents as pDNA vectors for cancer immunotherapy in vitro.

Melanin Treatment Effect of Vacuoles-Zinc Oxide Nanoparticles Combined with Ascorbic Acid.

Currently, ascorbic acid (AA) is widely used as a skin whitening material, but, AA, an unstable hydrophilic molecule, cannot penetrate the skin easily, due to the hydrophobic character of the stratum corneum. Therefore, we conjugated AA with hydrated zinc oxide-an inorganic matrix with positive surface charge, to improve the stability of AA. The metal-conjugated-ascorbic acid (ZnAA) was then combined with yeast vacuole through the vacuolar membrane proteins that relate to metal transportation to create an enhanced vacuole that contained ZnAA. The characteristics of vacuole with ZnAA (ZnAA_Vac) were next examined by various tests that included X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Field emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray (EDX) analysis. Furthermore, the ability of ZnAA_Vac to degrade melanin was confirmed in both melanoma cell line B16F10, and the artificial human skin MelanoDerm. The results showed that ZnAA_Vac possessed a higher depigmenting effect than the wild-type vacuole or ascorbic acid by reducing 75% of melanin color. Interestingly, ZnAA_Vac was found to be harmless, and did not cause any cytotoxicity to the cells. Overall, ZnAA_Vac is expected to provide a robust, harmless, and effective whitening agent for the skin.

Peptide-Based [68Ga]Ga Labeled PET Tracer for Tumor Imaging by Targeting Tumor-Associated Macrophages.

Tumor-associated macrophages (TAMs) are known to promote cancer development and metastasis. In this study, a TAMs-targeting peptide named M2pep was selected to investigate the feasibility of [68Ga]Ga-labeled M2pep as a noninvasive probe in targeted TAMs imaging. The peptide M2pep was conjugated with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) and radiolabeled with 68Ga. The cellular uptake and binding assay were assessed in M2 macrophages and in the B16F10 cell line. Micro-PET imaging and a biodistribution study were performed on B16F10 tumor-bearing mice. High radiochemical purity [68Ga]Ga-DOTA-M2pep (>95%) was prepared and was stabilized in saline and bovine serum at 37 °C for 2 h. In vitro studies demonstrated high uptake of [68Ga]Ga-DOTA-M2pep in M2 macrophages, which was effectively blocked by the "cold" M2pep (free peptide). The micro-PET imaging and biodistribution study revealed that [68Ga]Ga-DOTA-M2pep reached the tumor site rapidly and showed high accumulation in the tumor at 1 h post-injection. In addition, the probe was rapidly cleared from the blood and mainly excreted via the kidneys, resulting in a high tumor/background ratio. Preclinical studies have shown that [68Ga]Ga-DOTA-M2pep specifically targets TAMs and might be a promising molecular probe for the noninvasive visualization of TAMs expression.

T-cell engaging poly(lactic-co-glycolic acid) nanoparticles as a modular platform to induce a potent cytotoxic immunogenic response against PD-L1 overexpressing cancer

Bispecific nanoparticles (NPs) are conjugated with two antibodies that enhance T cell cytotoxicity by sequentially targeting CD3 and tumor-specific proteins. This interaction redirects T cells to specific tumor antigens and activates them to lyse tumor cells by blocking two different signaling pathways simultaneously. This study developed NP-based bispecific T-cell engagers (nanoBiTEs), which are R848-loaded bispecific poly(lactic-co-glycolic acid) NPs decorated with anti-CD3 antibody targeting T cells and anti-PD-L1 antibody targeting PD-L1 ligands (bis-R848-PLGA-NPs). Bis-R848-PLGA-NPs enhance the immunogenic response in destroying cancer cells by restoring the T cell effector functions. These interactions allow T cells to come in close proximity to the tumor cells. Finally, the release of R848 from PLGA-NPs activates dendritic cells, enhancing T cell activation. In vitro results show maximum internalization of bis-R848-PLGA-NPs in SK-OV3 and B16F10 cell lines, attributed to high PD-L1 expression in both cells. Furthermore, bis-R848-PLGA-NPs-treated CD8+ T cells exhibit a significantly increased total amount of CD8+/CD25+, CD8+/CD69+, and cytokine expression that leads to the robust inhibition of PD-L1 expressed cancer cells. Additionally, tumor growth is significantly inhibited by bis-R848-PLGA-NPs in the B16F10 xenograft mouse model and significantly enhanced intratumoral infiltration of CD4+ and CD8+ T cells, as well as tumor-infiltrated cytokines.