Significant Systemic Toxicity Research Articles

Arginine-Based Poly(I:C)-Loaded Nanocomplexes for the Polarization of Macrophages Toward M1-Antitumoral Effectors.

Background: Tumor-associated macrophages (TAMs), with M2-like immunosuppressive profiles, are key players in the development and dissemination of tumors. Hence, the induction of M1 pro-inflammatory and anti-tumoral states is critical to fight against cancer cells. The activation of the endosomal toll-like receptor 3 by its agonist poly(I:C) has shown to efficiently drive this polarization process. Unfortunately, poly(I:C) presents significant systemic toxicity, and its clinical use is restricted to a local administration. Therefore, the objective of this work has been to facilitate the delivery of poly(I:C) to macrophages through the use of nanotechnology, that will ultimately drive their phenotype toward pro-inflammatory states.Methods: Poly(I:C) was complexed to arginine-rich polypeptides, and then further enveloped with an anionic polymeric layer either by film hydration or incubation. Physicochemical characterization of the nanocomplexes was conducted by dynamic light scattering and transmission electron microscopy, and poly(I:C) association efficiency by gel electrophoresis. Primary human-derived macrophages were used as relevant in vitro cell model. Alamar Blue assay, ELISA, PCR and flow cytometry were used to determine macrophage viability, polarization, chemokine secretion and uptake of nanocomplexes. The cytotoxic activity of pre-treated macrophages against PANC-1 cancer cells was assessed by flow cytometry.Results: The final poly(I:C) nanocomplexes presented sizes lower than 200 nm, with surface charges ranging from +40 to −20 mV, depending on the envelopment. They all presented high poly(I:C) loading values, from 12 to 50%, and great stability in cell culture media. In vitro, poly(I:C) nanocomplexes were highly taken up by macrophages, in comparison to the free molecule. Macrophage treatment with these nanocomplexes did not reduce their viability and efficiently stimulated the secretion of the T-cell recruiter chemokines CXCL10 and CCL5, of great importance for an effective anti-tumor immune response. Finally, poly(I:C) nanocomplexes significantly increased the ability of treated macrophages to directly kill cancer cells.Conclusion: Overall, these enveloped poly(I:C) nanocomplexes might represent a therapeutic option to fight cancer through the induction of cytotoxic M1-polarized macrophages.

Tumor targeted delivery of umbelliferone via a smart mesoporous silica nanoparticles controlled-release drug delivery system for increased anticancer efficiency.

Herein, a mesoporous silica nanoparticle (MSN) based biocompatible, targeted and controlled drug delivery system has been synthesized for tumor tissue-specific drug delivery. Umbelliferone, a natural coumarin derivative was loaded into the pores of MSN and capped with pH-sensitive poly acrylic acid (PAA). For targeted delivery of umbelliferone in tumor tissue, folic acid (FA) was grafted onto the surface of drug-loaded and PAA-coated MSN. The successful construction of the nanohybrid (Umbe@MSN-PAA-FA) was confirmed by performing a series of characterization. The synthesized pH-responsive nanohybrid showed diameter of around 50nm with overall negative surface charge and drug loading content of 12.56%. In vitro study showed that the nanohybrid caused significant cytotoxicity through the induction of both oxidative stress as well as mitochondrial damage in folate receptor over-expressed in human breast cancer cell, MCF-7 compared with free umbelliferone. In vivo study also exhibited that the nanohybrid effectively reduced tumor growth in tumor-bearing mice compared with free umbelliferone due to the enlarged bioavailability of the drug in tumor tissue. Besides, the nanohybrid did not exhibit any significant sign of systemic toxicity in other vital organs. Together, the study denoted that PAA and FA functionalized MSN controlled-drug delivery system could assist to increase the anticancer potential of umbelliferone.

Development of a Pemetrexed/Folic Acid Nanoformulation: Synthesis, Characterization, and Efficacy in a Murine Colorectal Cancer Model.

The folate analogue pemetrexed (PEM) is an approved therapeutic for non-small cell lung cancer and malignant pleural mesothelioma with the potential for broader application in combination therapies. Here, we report the development of a nanoformulation of PEM and its efficacy against the CT26 murine colorectal cancer cell line in vitro and in vivo. Utilizing layer-by-layer deposition, we integrate PEM, along with folic acid (FA), onto a fluorescent polystyrene nanoparticle (NP) substrate. The final nanoformulation (PEM/FA-NP) has a size of ∼40 nm and a zeta potential of approximately −20 mV. Cell uptake studies indicated increased uptake in vitro for the PEM/FA-NP compared to the uncoated NP, likely due to the presence of PEM and FA. Viability studies were performed to determine the potency of the PEM/FA-NP formulation against CT26 cells. Syngeneic CT26 tumors in BALB/c mice showed reduced growth when treated once daily (2.1 mg/kg PEM) for 3 days with PEM/FA-NP versus the vehicle (uncoated) control, with no observable signs of systemic toxicity associated with the nanoformulation. Although the current study size is limited (n = 4 animals for each group), the overall performance and biocompatibility of the PEM/FA-NP observed suggest that further optimization and larger-scale studies may be warranted for this novel formulation.

Effect of dietary stress of emamectin benzoate on the fitness cost of American bollworm, Helicoverpa armigera (Hübner, 1808)

Present study assessed the effect of Emamectin benzoate (EMB) on the survival, growth and nutrition efficiency of Helicoverpa armigera. Dietary EMB exhibited a significant systemic toxicity in H. armigera larvae resulting in LD50 and LD90 value of 0.092 µg/mL and 0.156 µg/mL, respectively. Feeding with 0.05–0.2 µg/mL EMB caused 10–100% larval mortality in a dose-dependent manner. Feeding the IV instars of H. armigera with 0.1–1.6 µg/mL EMB-incorporated diet deterred feeding significantly. Substantial deterrent effects of EMB with lower LD50 values indicate the noteworthy systemic toxicity of EMB on the H. armigera larvae. Both choice and no-choice bioassay with dietary EMB showed a distinct preference of larvae towards control diet. Feeding the larvae with sublethal doses of 0.05 − 0.01 µg/mL EMB impaired ingestion and digestion, and induced considerable post-ingestive toxicity in larvae. Relative Consumption Rate (RCR) and the Relative Growth Rate (RGR) were recorded in the range of 1.653–3.985 and 0.385–0.978, respectively. The nutrition indices of larvae revealed reduction in Efficiency of Conversion of Ingested Food (ECI) by 10–24% and Efficiency of Conversion of Digested Food (ECD) by 2.0–52% and in Approximate Digestibility (AD) by 09–63%. The noticeable decrease in the food utilization, digestion and assimilation may have resulted in the observed reduced larval growth. The decreased metabolic efficiency in H. armigera larvae implicated that dietary EMB probably weakened the biochemical machinery of larval gut and reduced physiological fitness. The results suggest that use of EMB can be an effective tool in Integrated Pest Management program of H. armigera.

Intratumoral use of self-delivering RNAi to reprogram the tumor microenvironment and boost the antitumor response.

e15206 Background: Immunotherapy targeting immune checkpoints has shown significant benefit in many cancers. However, systemic delivery can result in severe auto-immune toxicities, the risk increasing with the combination of checkpoint inhibiting antibodies. Local delivery of immunotherapies allows for multiple combination therapies, while potentially preventing significant systemic toxicities. One approach is to use self-delivering RNAi technology, INTASYL™, which has been shown to be safe and effective in clinical applications following local administration. Here we show the use of the INTASYL platform as a checkpoint inhibiting immunotherapy for intratumoral applications, through a series of preclinical in vivo studies. Methods: INTASYL compounds were made against mouse PD-1, TIGIT, PD-L1 and BRD4. INTASYL comprises an asymmetric duplex, a small duplex region (≤ 15 base pairs), a single-stranded phosphorothioate tail and chemical modifications to confer stability resulting in efficient cellular uptake allowing in situ delivery. The efficacy and immunomodulation of these INTASYL compounds was evaluated in the Hepa1-6 and CT26 murine syngeneic tumor models following intratumoral administration. Tumor volumes were recorded throughout the study. Tumor-Infiltrating-Lymphocytes (TILs) were isolated twenty-four hours post the last dose and examined for gene silencing by RT-qPCR. Tumor microenvironment (TME) and T cell activation were analyzed by flow cytometry. Results: Results showed dose-dependent attenuated tumor growth compared to control groups. Relevant changes in the TME included an increase of CD8+ T cells and an increase of activation markers on TILs. Tumor growth reduction correlated with silencing of target mRNA and immune effector cell levels and activation. Conclusions: These studies demonstrate the feasibility of using INTASYL compounds intratumorally to overcome the immunosuppressive TME, resulting in changes in T cell composition and activation, and inhibition of tumor growth. Together, these novel findings support using intratumoral INTASYL as a viable approach to immunotherapy and warrants further investigation in patients.

Recombinant Costimulatory Fusion Proteins as Functional Immunomodulators Enhance Antitumor Activity in Murine B16F10 Melanoma.

Blocking inhibitory signaling and engaging stimulatory signaling have emerged as important therapeutic modalities for cancer immunotherapy. This study aimed to investigate immunomodulatory features of three recombinant costimulatory ligand proteins in a mouse model, which are extracellular domains of OX40-ligand (OX40L), 4-1BB-ligand (4-1BBL), or two domains in tandem, fused with the transmembrane domain of diphtheria toxin (DTT), named DTT-COS1, DTT-COS2, and DTT-COS12, respectively. In vitro study showed that DTT-COS1 and DTT-COS12 had immunological activity increasing the ratio of CD8/CD4 T cells. Treatments with DTT-COS1 and DTT-COS12 dramatically generated immune protection against the B16F10 tumor challenge in both prophylactic and therapeutic efficacy. Furthermore, regarding tumor microenvironment (TME) immunomodulation, DTT-COS1 treatment increased the proportion of CD4+ effector T cells (Teff) and decreased the expression of a suppressive cytokine. Meanwhile, DTT-COS12 reduced regulatory T cells (Treg) and improved the level of stimulatory cytokines. In addition, endogenous antibodies against OX40L/4-1BBL were generated, which may help with antitumor responses. Unexpectedly, DTT-COS2 lacked antitumor effects in vitro and in vivo. Importantly, serum analysis of liver-function associated factors and pro-inflammatory cytokines demonstrated that treatments were safe formulations in mice without signs of systemic toxicity. Remarkably, DTT-COS1 and DTT-COS12 are functional immunomodulators for mouse B16F10 melanoma, creating practical preclinical value in cancer immunotherapy.

Abstract B19: New tools to study the role of RAS/CRAF interaction in RAS-driven lung cancer

Abstract The RAF/MAPK pathway is a major RAS effector pathway implicated in RAS oncogenic properties, regulating a diversity of cellular processes. As RAF kinases (A-, B-, CRAF) are thought to be attractive therapeutic targets for RAS-driven cancers, pan-RAF inhibitors are currently under development. However, preclinical studies focusing on targeting only the CRAF kinase by genetic inactivation revealed effective inhibition of tumor development without inducing significant systemic toxicities in a model of KRAS-driven lung tumor initiation. Recently, Sanclemente et al. further demonstrated that the complete ablation of CRAF in established advanced lung tumors (KrasG12V/Trp53) triggers sustainable tumor regression. Although this approach validates CRAF as a powerful therapeutic target for KRAS-driven lung cancer, specific CRAF inhibitors are not available yet. It was described more than 20 years ago that RAS GTPases strongly interact with CRAF kinase through its Ras Binding domain. This interaction is required to activate CRAF. Many efforts are being made to try to disrupt this interaction with small compounds, but currently none of those drugs are potent enough for further testing in vivo. Surprisingly, this therapeutic approach has never been proven to be efficient in vivo. Using CRISPR/Cas9 technology, we engineered a new mouse model in which the Ras binding domain of CRAF is constitutively mutated to completely abolish its interaction with RAS GTPases (CRAFR89L). We also engineered two murine lung cancer cell lines (KrasG12D/Trp53) that are heterozygous for this mutation (CRAFR89L/KO). Preliminary data confirm that CRAF interaction with RAS is minimally involved in 2D cell proliferation, as well as KRAS-driven MAPK pathway activation, but important for anchorage-independent cell growth. Citation Format: Romain Baer, Ian Rosewell, David Hancock, Miriam Molina-Arcas, Julian Downward. New tools to study the role of RAS/CRAF interaction in RAS-driven lung cancer [abstract]. In: Proceedings of the AACR Special Conference on Targeting RAS-Driven Cancers; 2018 Dec 9-12; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(5_Suppl):Abstract nr B19.

Aptamer-Conjugated Multifunctional Polymeric Nanoparticles as Cancer-Targeted, MRI-Ultrasensitive Drug Delivery Systems for Treatment of Castration-Resistant Prostate Cancer.

Nanoscopic therapeutic systems that incorporate therapeutic agents, molecular targeting, and imaging capabilities have gained momentum and exhibited significant therapeutic potential. In this study, multifunctional polymeric nanoparticles with controlled drug delivery, cancer-targeted capability, and efficient magnetic resonance imaging (MRI) contrast characteristics were formulated and applied in the treatment of castration-resistant prostate cancer (CRPC). The “core-shell” targeted nanoparticles (NPs) were synthesized by the self-assembly of a prefunctionalized amphiphilic triblock copolymer composed of poly(lactic-co-glycolic-acid) (PLGA), polyethylene glycol (PEG), and the Wy5a aptamer (Apt), which have been screened for targeting the CRPC cell line PC-3 by cell-SELEX technique as described in our previous study. Docetaxel (Dtxl) and a cluster of hydrophobic superparamagnetic iron oxide (SPIO) nanoparticles were simultaneously encapsulated into the targeted nanoparticles. The targeted NPs showed a controlled drug release and an increased contrast-enhanced MRI capability. The presence of Wy5a on the nanoparticle surface resulted in the cancer-targeted delivery to PC-3 cells in vitro and in vivo. In vitro MRI and cytotoxicity studies demonstrated the ultrasensitive MRI and increased cytotoxicity of these targeted NPs. In vivo studies revealed that the targeted NPs exhibited a more efficacious antitumor capability without significant systemic toxicity. Our data suggested that these targeted NPs may be a promising drug delivery system for the efficacious treatment of CRPC.

Polypeptide-Based Theranostics with Tumor-Microenvironment-Activatable Cascade Reaction for Chemo-ferroptosis Combination Therapy.

Nanoengineering of polymer-based therapeutic carriers is promising for precise cancer treatment. Herein, we report the fabrication of polypeptide vehicles encapsulated with anticancer drug of cisplatin (Pt drug) and Fe3O4 nanoparticles (denoted as Pt&Fe3O4@PP) as theranostics for T2-weighted magnetic resonance imaging (MRI)-guided chemo-ferroptosis combination therapy. The number of Fe3O4 nanoparticles per polypeptide vehicle is well controlled by adjusting the added amount of Fe3O4 nanoparticles. The tumor microenvironment can trigger the release of Pt drug and Fe2/3+, which could induce the intracellular cascade reaction to generate sufficient •OH for ferroptosis therapy. Moreover, the released Pt drug can cause the apoptosis of tumor cells. Meanwhile, the encapsulated Fe3O4 nanoparticles can also be used for T2-weighted MRI of tumor. Both in vitro and in vivo results indicate that the reported Pt&Fe3O4@PP can efficiently inhibit cancer cell growth without causing significant systemic toxicity. Importantly, polypeptide vehicles could significantly reduce the side effect of free Pt drug in vivo and therefore improve the drug delivery efficacy. Our findings suggest that polypeptide-based theranostics with tumor-microenvironment-activatable cascade reaction have great potential in biomedical applications.

Dynamic core crosslinked camptothecin prodrug micelles with reduction sensitivity and boronic acid-mediated enhanced endocytosis: An intelligent tumor-targeted delivery nanoplatform.

The physicochemical properties of camptothecin (CPT) limit its clinical application. To maximize drug efficacy, a novel intelligent prodrug delivery nanoplatform with a tumor microenvironment-cleavable core crosslinking strategy was proposed based on a phenylboronic acid (PBA) modified polyethylene glycol (PEG)-polyglutamic acid (PGlu) polymer with disulfide-bonded CPT, called PBA-PEG-P(Glu-co-GlussCPT). The fabricated nanoplatform was a spherical micelle that could withstand dilution and carry a large number of therapeutic molecules to the tumor tissues, thereby minimizing premature drug release. Moreover, the nanoplatform release 6.2±0.62, 12.4±1.8, 46.7±0.33, and 79.2±1.58% of CPT after incubation in 0.02, 1, 5, and 10mM dithiothreitol for 24h, respectively, exhibiting good reduction-sensitivity. Moreover, the nanoplatform exhibited significant antiproliferative activity against tumor cells. In addition, with PBA modification, the nanoplatform demonstrated enhanced endocytosis efficiency. This prodrug nanoplatform also exhibited significant in vivo antitumor efficacy on both murine and human hepatoma xenograft models, without showing significant systemic toxicity but demonstrating good biocompatibility. In other words, this novel intelligent prodrug delivery nanoplatform with tumor microenvironment-cleavable core crosslinking strategy and active targeting strategy based on prodrug polymer PBA-PEG-P(Glu-co-GlussCPT) demonstrated multiple functions and significant potential for antitumor drug delivery.

Intratumoral Delivery of Plasmid IL12 Via Electroporation Leads to Regression of Injected and Noninjected Tumors in Merkel Cell Carcinoma.

IL12 promotes adaptive type I immunity and has demonstrated antitumor efficacy, but systemic administration leads to severe adverse events (AE), including death. This pilot trial investigated safety, efficacy, and immunologic activity of intratumoral delivery of IL12 plasmid DNA (tavo) via in vivo electroporation (i.t.-tavo-EP) in patients with Merkel cell carcinoma (MCC), an aggressive virus-associated skin cancer. Fifteen patients with MCC with superficial injectable tumor(s) received i.t.-tavo-EP on days 1, 5, and 8 of each cycle. Patients with locoregional MCC (cohort A, N = 3) received one cycle before definitive surgery in week 4. Patients with metastatic MCC (cohort B, N = 12) received up to four cycles total, administered at least 6 weeks apart. Serial tumor and blood samples were collected. All patients successfully completed at least one cycle with transient, mild (grades 1 and 2) AEs and without significant systemic toxicity. Sustained (day 22) intratumoral expression of IL12 protein was observed along with local inflammation and increased tumor-specific CD8+ T-cell infiltration, which led to systemic immunologic and clinical responses. The overall response rate was 25% (3/12) in cohort B, with 2 patients experiencing durable clinical benefit (16 and 55+ months, respectively). Two cohort A patients (1 with pathologic complete remission) were recurrence-free at 44+ and 75+ months, respectively. I.t.-tavo-EP was safe and feasible without systemic toxicity. Sustained local expression of IL12 protein and local inflammation led to systemic immune responses and clinically meaningful benefit in some patients. Gene electrotransfer, specifically i.t.-tavo-EP, warrants further investigation for immunotherapy of cancer.

Curcumin-Loaded Solid Lipid Nanoparticles Bypass P-Glycoprotein Mediated Doxorubicin Resistance in Triple Negative Breast Cancer Cells.

Multidrug resistance (MDR) is a critical hindrance to the success of cancer chemotherapy. The main thing responsible for MDR phenotypes are plasma-membranes associated with adenosine triphosphate (ATP) Binding Cassette (ABC) drug efflux transporters, such as the P-glycoprotein (Pgp) transporter that has the broadest spectrum of substrates. Curcumin (CURC) is a Pgp inhibitor, but it is poorly soluble and bioavailable. To overcome these limitations, we validated the efficacy and safety of CURC, loaded in biocompatible solid lipid nanoparticles (SLNs), with or without chitosan coating, with the goal of increasing the stability, homogeneous water dispersibility, and cellular uptake. Both CURC-loaded SLNs were 5–10-fold more effective than free CURC in increasing the intracellular retention and toxicity of doxorubicin in Pgp-expressing triple negative breast cancer (TNBC). The effect was due to the decrease of intracellular reactive oxygen species, consequent inhibition of the Akt/IKKα-β/NF-kB axis, and reduced transcriptional activation of the Pgp promoter by p65/p50 NF-kB. CURC-loaded SLNs also effectively rescued the sensitivity to doxorubicin against drug-resistant TNBC tumors, without signs of systemic toxicity. These results suggest that the combination therapy, based on CURC-loaded SLNs and doxorubicin, is an effective and safe approach to overcome the Pgp-mediated chemoresistance in TNBC.

Food, Feed and Environmental Risk Assessment of Glufosinatetolerant Genetically Modified Oilseed Rape T45 for Food and Feed Uses, Import and Processing Under Regulation (EC) No 1829/2003 (Application EFSA/GMO/UK/2005/25)

Food, Feed and Environmental Risk Assessment of Glufosinatetolerant Genetically Modified Oilseed Rape T45 for Food and Feed Uses, Import and Processing Under Regulation (EC) No 1829/2003 (Application EFSA/GMO/UK/2005/25)

Effects of bleomycin on tooth eruption: a novel potential application

There are many kinds of potentially undesirable teeth. At present, surgical extraction is the most efficient way to eliminate these teeth, but it's very complex and invasive. In this study, we investigated the effects of bleomycin (BLM) on dental follicle and tooth eruption as a potential conservative therapy for undesirable teeth. Our data showed that local injection of 0.2 U/kg BLM had no significant effects on tooth eruption compared to the control group in Wistar rats. With higher dose of BLM (0.5 or 2 U/kg), the eruption of treated teeth was interrupted and their root formation failed until 4 weeks postnatal without significant systemic toxicity. Additionally, those effects were not depending on the toxicity of overdose evidenced by TUNEL assay. In summary, injecting BLM into dental follicle at an early stage could interrupt tooth development and eruption, and may prevent the potentially clinical problems resulting from undesirable teeth instead of surgical removal.

Megacolon in inflammatory bowel disease: response to infliximab

Megacolon is a serious complication of inflammatory bowel disease that often requires a colectomy. Infliximab is a therapeutic alternative when conventional treatment fails, before resorting to surgery. Its use is currently based on the publication of isolated cases. We present a series of 12 patients with megacolon treated with infliximab, five with signs of systemic toxicity. Seventy-five percent of the patients avoided a colectomy during their acute episode after early infliximab treatment, 2.45 days after the megacolon diagnosis. There was a greater risk of surgery among patients with ulcerative colitis and toxicity criteria. Two more patients required follow-up surgery despite long-term infliximab treatment. No patient suffered significant treatment-related adverse effects or significant post-surgery complications.

Myeloid Cell-Targeted Nanocarriers Efficiently Inhibit Cellular Inhibitor of Apoptosis for Cancer Immunotherapy

Immune-checkpoint blockers can promote sustained clinical responses in a subset of cancer patients. Recent research has shown that a subpopulation of tumor-infiltrating dendritic cells functions as gatekeepers, sensitizing tumors to anti-PD-1 treatment via production of interleukin-12 (IL-12). Hypothesizing that myeloid cell-targeted nanomaterials could be used to deliver small-molecule IL-12 inducers, we performed high-content image-based screening to identify the most efficacious small-molecule compounds. Using one lead candidate, LCL161, we created a myeloid-targeted nanoformulation that induced IL-12 production in intratumoral myeloid cells invivo, slowed tumor growth as a monotherapy, and had no significant systemic toxicity. These results pave the way for developing combination immunotherapeutics by harnessing IL-12 production for immunostimulation.

An ultralow dose of the NADPH oxidase inhibitor diphenyleneiodonium (DPI) is an economical and effective therapeutic agent for the treatment of colitis-associated colorectal cancer.

Long-term inflammatory stimulation is considered one of the most important causes of colorectal cancer. Diphenyleneiodonium (DPI), an NADPH oxidase inhibitor, can inhibit a variety of inflammatory responses. However, the systemic toxicity of DPI limits its clinical application. Whether DPI can inhibit colitis-associated colorectal cancer (CAC) at ultralow concentrations remains unknown.Methods: CAC was induced by azoxymethane (AOM) injection followed by treatment with dextran sulfate sodium (DSS), and DPI was intraperitoneally injected (i.p.) in the first cycle for 21 days. Colon tissue was collected and analyzed by western blotting. Immune cell infiltration and macrophage polarization were examined by immunohistochemistry, immunofluorescence, or real-time polymerase-chain reaction (PCR). Reactive oxygen species (ROS) production was measured by flow cytometry.Results: Ultralow dose DPI significantly ameliorated the DSS-induced colitis and attenuated the colon tumorigenesis in the mouse model of AOM/ DSS-induced CAC. Mechanistically, an ultralow dose of DPI inhibited the production of pro-inflammatory cytokines, (tumor necrosis factor (TNF)-α and interleukin (IL)-6), reduced the macrophage infiltration and classical polarization, and induced the ROS generation. These effects were found to be related to the inhibition of the phosphorylation of signal transducer and activator of transcription 3 (STAT3), mitogen-activated protein kinase (MAPK), and nuclear factor kappa B (NF -κB).Conclusion: The present study revealed that an ultralow dose of DPI, with no significant systemic toxicity involved, may be an effective way to prevent the occurrence and development of CAC.

Histone deacetylase inhibitor MGCD0103 causes cell cycle arrest, apoptosis, and autophagy in liver cancer cells.

Background: Liver cancer is a common cause of cancer-related death all over the world. MGCD0103, a histone deacetylase inhibitor, exerts antitumor effect on various cancers. However, its role in liver cancer remains unclear.Methods: The effect of MGCD0103 on HepG2 and Huh7 cells was verified by several experiments such as cell viability assay, colony formation assay, cell cycle analysis, apoptosis analysis, reactive oxygen species (ROS) assay, western blotting, immunohistochemistry, and xenograft assay.Results: Cell viability and colony formation assays showed that MGCD0103 inhibited the proliferation of liver cancer cells in vitro. Flow cytometry and western blotting analysis demonstrated that MGCD0103 induced G2/M phase arrest and mitochondrial-related apoptosis. A pan-caspase inhibitor and ROS scavenger inhibited apoptosis induced by MGCD0103. What's more, MGCD0103 led to autophagy associated with cell death and an autophagy inhibitor inhibited apoptosis and autophagy induced by MGCD0103. Ultimately, MGCD0103 attenuated tumor growth but did not show significant systemic toxicity in animal model.Conclusions: MGCD0103 suppressed the growth of liver cancer cells in vitro and in vivo. It could serve as a novel therapeutic approach for liver cancer.

PARP-1 Targeted Alpha-emitting Radiotherapeutics: An Examination of Potential Toxicity

Radiolabeling poly-ADP ribose polymerase 1 (PARP-1) inhibitors potentially enables targeted delivery of alpha-emitting isotopes directly to cancer cells overexpressing PARP-1. However, there is concern for bone marrow toxicity due to its intrinsically high PARP-1 expression. Therefore, we examined bone marrow toxicity at therapeutically relevant doses of an astatine-211 labeled PARP-1 inhibitor, [211At]MM4. Male and female C57BL6 mice received 0, 12, 24, and 36 MBq/kg of [211At]MM4 and then were sacrificed after 24 hours, 2 weeks, and 4 weeks. The red marrow-containing femur was harvested and was analyzed with colony formation assay, immunofluorescent (IF) microscopy, histopathology, and immunohistochemistry (IHC). Peripheral blood samples were analyzed for complete blood count (CBC). Additionally, we performed [211At]MM4 biodistribution assay on another set of 20 C57BL6 mice at post-injection time points of 5, 30, 60, 180, and 360 minutes. With the biodistribution data, OLINDA/EXM v1.1 was used for radiation dosimetry calculations in reference to human pediatric models. The CBC revealed significant lymphopenia only in the 2-week group treated with 24 MBq/kg. A slight decrease in lymphocyte percentage was observed in the 24 MBq/kg mice at 2 weeks and the 36 MBq/kg at 2 and 4 weeks. Significant neutrophilia was observed in all 2-week groups, as well as the 4-week group treated at 36 MBq/kg. Colony formation assay revealed no reduction, but rather significant increase in granulocyte, macrophage, and burst forming unit-erythroid colonies. Histopathology revealed maintained bone marrow cellularity across the treatment groups. IF and IHC demonstrated heterogeneous PARP-1 expression in the bone marrow. The biodistribution and subsequent dosimetry calculations found significantly higher, but nonlethal organ radiation dose per injected activity levels in the red bone marrow, spleen, and thyroid in both 1 and 5-year-old human models. Overall, the results suggest that doses up to 36 MBq/kg of [211At]MM4 can be administered to C57BL6 mouse models without producing significant systemic or bone marrow toxicity. These results provide promising developments for understanding toxicity associated with the alpha-emitting compound [211At]MM4 in vivo. Future studies using fractionated dosing regimens in pre-clinical tumor models will evaluate therapeutic efficacy and further evaluate associated toxicities.

New Therapeutic Perspective for Bladder Cancer in Dogs: Toxicological and Clinical Effects of OncoTherad Nanostructured Immunotherapy

Bladder cancer (BC) comprehends around 2% of all spontaneously occurring cancers in dogs. BC treatment remains a challenge since recurrence and progression of the disease, as well as the pronounced side effects associated to the available therapeutic modalities are present. In this scenario, a new perspective is represented by OncoTherad nanostructured immunomodulator. Thus, the aims of this study were to characterize and to evaluate the efficacy and possible toxicological effects of OncoTherad intravesical immunotherapy in 6 dogs with BC. Our results demonstrated that before the first instillation of OncoTherad, all dogs presented irregular tumor mass, mixed echogenicity, and hyperechoic echotexture, with a mean tumor volume of 9.38 cm3. After 6 instillations of OncoTherad, the tumor mass reduced 62.34% of its volume in relation to the initial ultrasound. At the end of 24 instillations, the tumor mass reduced 84.54% of its volume. Hematuria was decreased throughout OncoTherad treatment, disappearing on average after the eighteenth application and not returning after the last application. OncoTherad treatment showed no signs of systemic toxicity at the proposed therapeutic dose. In conclusion, OncoTherad intravesical immunotherapy seems a safe and effective treatment option for spontaneous canine bladder cancer and may provide benefit for preventing tumor recurrence.