Anti-LGALS3BP antibody-drug conjugate treatment induces durable and potent antitumor response in a preclinical model of adenoid cystic carcinoma.

OBJECTIVES: Adenoid cystic carcinoma (ACC) is a rare type of cancer that typically arises from glandular tissues, most commonly in the salivary glands. Although relatively rare, it represents a serious clinical issue as the management of the disease is highly complex being the only therapeutic options represented by invasive surgery and/or radiotherapy. In the present study, we have explored the potential of galectin-3 binding protein (LGALS3BP) as a novel target for antibody-drug conjugate (ADC) therapy in ACC. MATERIALS AND METHODS: RNAseq was conducted on a panel of 10 ACC patient-derived xenografts (PDX)s tissues and 6 normal salivary glands to analyze LGALS3BP gene expression. Protein expression was assessed in ACC PDX and primary tumor tissues using immunohistochemistry. Anti-LGALS3BP ADC named 1959-sss/DM4, was tested in high LGALS3BP expressing ACC PDX model ST1502B. RESULTS: RNAseq analysis revealed that LGALS3BP expression was highly expressed in ACC PDX tissues compared to normal salivary gland tissues. As evaluated by immunohistochemical analysis, LGALS3BP protein was found to be heterogeneously expressed in 10 ACC PDX and in tumor tissues derived from a cohort of 37 ACC patients. Further, treatment with 1959-sss/DM4 ADC led to durable tumor growth inhibition (TGI) in 100% of animals without observed toxicity. CONCLUSIONS: Our study provides strong evidence that LGALS3BP is a promising therapeutic target for ACC, warranting further expedited preclinical and clinical investigation.

Hosts and Heterologous Expression Strategies of Recombinant Toxins for Therapeutic Purposes.

The production of therapeutic recombinant toxins requires careful host cell selection. Bacteria, yeast, and mammalian cells are common choices, but no universal solution exists. Achieving the delicate balance in toxin production is crucial due to potential self-intoxication. Recombinant toxins from various sources find applications in antimicrobials, biotechnology, cancer drugs, and vaccines. "Toxin-based therapy" targets diseased cells using three strategies. Targeted cancer therapy, like antibody-toxin conjugates, fusion toxins, or "suicide gene therapy", can selectively eliminate cancer cells, leaving healthy cells unharmed. Notable toxins from various biological sources may be used as full-length toxins, as plant (saporin) or animal (melittin) toxins, or as isolated domains that are typical of bacterial toxins, including Pseudomonas Exotoxin A (PE) and diphtheria toxin (DT). This paper outlines toxin expression methods and system advantages and disadvantages, emphasizing host cell selection's critical role.

HPLC-DAD validated method for DM4 and its metabolite S-Me-DM4 quantification in biological matrix for clinical and pharmaceutical applications.

The present study focuses on the development and validation of an HPLC-DAD methodology for the detection of a potent chemotherapeutic agent, Maytansinoid Ravtansine (DM4), and its metabolite, S-methyl-DM4 (S-Me-DM4), in plasma samples. Methodologically, after a simple protein precipitation with acetonitrile and after drying 1 mL of supernatant, the sample (suspended with N,N-Dimethylacetamide, DMA) was directly analyzed by HPLC under isocratic elution using a mobile phase comprising milliQ water and methanol (25:75, v:v), both acidified with 0.1 % v:v formic acid. Employing a flow rate of 1.0 mL/min and a reversed-phase GraceSmart RP18 column thermostated at 40 °C, we achieved complete resolution and separation of DM4 and S-Me-DM4 within 13 min. The optimized injection volume of 20 µL and the wavelength set at 254 nm were utilized for quantitative analyses. Rigorous validation has not only ensured its reliability and reproducibility but has also addressed potential limitations associated with methodological inconsistency. The limit of detection and quantification of the method were 0.025 and 0.06 µg/mL for both the analytes, respectively. The calibration curve showed a good linearity in the range 0.06-20 µg/mL. For both analytes, the intraday precision and trueness were 2.3-8.2 % and -1.1 to 3.1 %, respectively, while the interday values were 0.7-10.1 % and -10.4 to 7.5 %, respectively. The developed methodology enables the concurrent determination and quantification of free DM4 and its metabolite, free S-Me-DM4, making it a valuable tool for assessing the pharmacokinetics and pharmacodynamics of DM4-based therapies. In addition, the procedure was successfully applied to analyse the presence of free DM4 or its metabolite, free S-Me-DM4, in human plasma samples spiked with the 1959-sss/DM4 antibody-drug conjugate (ADC). The utilization of the herein validated methodology allowed to confirm the presence of these analytes, thereby providing insights into their potential release from the ADC structure.

Non-covalent inhibitors of thioredoxin glutathione reductase with schistosomicidal activity in vivo.

Only praziquantel is available for treating schistosomiasis, a disease affecting more than 200 million people. Praziquantel-resistant worms have been selected for in the lab and low cure rates from mass drug administration programs suggest that resistance is evolving in the field. Thioredoxin glutathione reductase (TGR) is essential for schistosome survival and a validated drug target. TGR inhibitors identified to date are irreversible and/or covalent inhibitors with unacceptable off-target effects. In this work, we identify noncovalent TGR inhibitors with efficacy against schistosome infections in mice, meeting the criteria for lead progression indicated by WHO. Comparisons with previous in vivo studies with praziquantel suggests that these inhibitors outperform the drug of choice for schistosomiasis against juvenile worms.

Visualizing Galectin-3 Binding Protein Expression with ImmunoPET.

Galectin-3 binding protein (Gal-3BP) is a glycoprotein that is overexpressed and secreted by several cancers and has been implicated as a marker of both tumor progression and poor prognosis in melanoma, non-small cell lung cancer, head and neck squamous cell carcinoma, and breast cancer. The expression of Gal-3BP by a variety of neoplasms makes it an enticing target for both diagnostics and therapeutics, including immuno-positron emission tomography (immunoPET) probes and antibody-drug conjugates (ADCs). Herein, we report the development, in vitro characterization, and in vivo evaluation of a pair of Gal-3BP-targeting radioimmunoconjugates for 89Zr-immunoPET. A humanized anti-Gal-3BP antibody, 1959, and its corresponding ADC, 1959-sss/DM4 (DM4 = ravtansine), were modified with desferrioxamine (DFO) to yield DFO-1959 and DFO-1959-sss/DM4 immunoconjugates bearing 1-2 DFO/monoclonal antibody. Both DFO-modified immunoconjugates retained their affinity for Gal-3BP in enzyme-linked immunosorbent assay experiments. The chelator-bearing antibodies were radiolabeled with zirconium-89 (t1/2 ≈ 3.3 d) to produce radioimmunoconjugates ─ [89Zr]Zr-DFO-1959 and [89Zr]Zr-DFO-1959-sss/DM4 ─ with high specific activity (>444 MBq/mg, >12 mCi/mg) and stability (>80% intact after 168 h in human serum at 37 °C). In mice bearing subcutaneous Gal-3BP-secreting A375-MA1 xenografts, [89Zr]Zr-DFO-1959 clearly delineated tumor tissue, reaching a maximum tumoral activity concentration (54.8 ± 15.8%ID/g) and tumor-to-background contrast (tumor-to-blood = 8.0 ± 4.6) at 120 h post-injection. The administration of [89Zr]Zr-DFO-1959 to mice bearing subcutaneous Gal-3BP-expressing melanoma patient-derived xenografts produced similarly promising results. [89Zr]Zr-DFO-1959 and [89Zr]Zr-DFO-1959-sss/DM4 exhibited nearly identical pharmacokinetic profiles in the mice bearing A375-MA1 tumors, though the latter produced higher uptake in the spleen and kidneys. Both [89Zr]Zr-DFO-1959 and [89Zr]Zr-DFO-1959-sss/DM4 effectively visualized Gal-3BP-secreting tumors in murine models of melanoma. These results suggest that both probes could play a role in the clinical imaging of Gal-3BP-expressing malignancies, particularly as companion theranostics for the identification of patients likely to respond to Gal-3BP-targeted therapeutics such as 1959-sss/DM4.

Extracellular LGALS3BP: a potential disease marker and actionable target for antibody-drug conjugate therapy in glioblastoma.

Glioblastoma multiforme (GBM) is a lethal disease characterized by an overall survival of about 1 year, making it one of the most aggressive tumours, with very limited therapeutic possibilities. Specific biomarkers for early diagnosis as well as innovative therapeutic strategies are urgently needed to improve the management of this deadly disease. In this work, we demonstrated that vesicular galectin-3-binding protein (LGALS3BP), a glycosylated protein overexpressed in a variety of human malignancies, is a potential GBM disease marker and can be efficiently targeted by a specific antibody-drug conjugate (ADC). Immunohistochemical analysis on patient tissues showed that LGALS3BP is highly expressed in GBM and, compared with healthy donors, the amount of vesicular but not total circulating protein is increased. Moreover, analysis of plasma-derived extracellular vesicles from mice harbouring human GBM revealed that LGALS3BP can be used for liquid biopsy as a marker of disease. Finally, an ADC targeting LGALS3BP, named 1959-sss/DM4, specifically accumulates in tumour tissue, producing a potent and dose-dependent antitumor activity. In conclusion, our work provides evidence that vesicular LGALS3BP is a potential novel GBM diagnostic biomarker and therapeutic target deserving further preclinical and clinical validation.

Recent Advances on Affibody- and DARPin-Conjugated Nanomaterials in Cancer Therapy.

Affibodies and designed ankyrin repeat proteins (DARPins) are synthetic proteins originally derived from the Staphylococcus aureus virulence factor protein A and the human ankyrin repeat proteins, respectively. The use of these molecules in healthcare has been recently proposed as they are endowed with biochemical and biophysical features heavily demanded to target and fight diseases, as they have a strong binding affinity, solubility, small size, multiple functionalization sites, biocompatibility, and are easy to produce; furthermore, impressive chemical and thermal stability can be achieved. especially when using affibodies. In this sense, several examples reporting on affibodies and DARPins conjugated to nanomaterials have been published, demonstrating their suitability and feasibility in nanomedicine for cancer therapy. This minireview provides a survey of the most recent studies describing affibody- and DARPin-conjugated zero-dimensional nanomaterials, including inorganic, organic, and biological nanoparticles, nanorods, quantum dots, liposomes, and protein- and DNA-based assemblies for targeted cancer therapy in vitro and in vivo.

Early-life exposure to environmentally relevant concentrations of triclocarban impairs ocular development in zebrafish larvae.

Triclocarban (TCC), is an antimicrobial component in personal care products and it is one of the emerging contaminants since it has been detected in various environmental matrices. Its presence in human cord blood, breast milk, and maternal urine raised issues about its possible impact on development and increased concerns about the safety of daily exposure. This study aims to provide additional information about the effects of zebrafish early-life exposure to TCC on eye development and visual function. Zebrafish embryos were exposed to two concentrations of TCC (5 and 50 µg/L) for 4 days. TCC-mediated toxicity was assessed in larvae at the end of exposure and in the long term (20 days post fertilization; dpf), through different biological end-points. The experiments showed that TCC exposure influences the retinal architecture. In 4 dpf treated larvae, we found a less organized ciliary marginal zone, a decrease in the inner nuclear and inner plexiform layers, and a decrease in the retinal ganglion cell layer. Photoreceptor and inner plexiform layers showed an increase in 20 dpf larvae at lower and both concentrations, respectively. The expression levels of two genes involved in eye development (mitfb and pax6a) were both decreased at the concentration of 5 µg/L in 4 dpf larvae, and an increase in mitfb was observed in 5 µg/L-exposed 20 dpf larvae. Interestingly, 20 dpf larvae failed to discriminate between visual stimuli, demonstrating notable visual perception impairments due to compound. The results prompt us to hypothesize that early-life exposure to TCC may have severe and potentially long-term effect on zebrafish visual function.

Truncating variants in the penultimate exon of TGFBR1 escaping nonsense-mediated mRNA decay cause Loeys-Dietz syndrome.

Pathogenic variants in TGFBR1 are a common cause of Loeys-Dietz syndrome (LDS) characterized by life-threatening aortic and arterial disease. Generally, these are missense changes in highly conserved amino acids in the serine-threonine kinase domain. Conversely, nonsense, frameshift, or specific missense changes in the ligand-binding extracellular domain cause multiple self-healing squamous epithelioma (MSSE) lacking the cardiovascular phenotype. Here, we report on two novel variants in the penultimate exon 8 of TGFBR1 were identified in 3 patients from two unrelated LDS families: both were predicted to cause frameshift and premature stop codons (Gln448Profs*15 and Cys446Asnfs*4) resulting in truncated TGFBR1 proteins lacking the last 43 and 56 amino acid residues, respectively. These were classified as variants of uncertain significance based on current criteria. Transcript expression analyses revealed both mutant alleles escaped nonsense-mediated mRNA decay. Functional characterization in patient's dermal fibroblasts showed paradoxically enhanced TGFß signaling, as observed for pathogenic missense TGFBR1 changes causative of LDS. In summary, we expanded the allelic repertoire of LDS-associated TGFBR1 variants to include truncating variants escaping nonsense-mediated mRNA decay. Our data highlight the importance of functional studies in variants interpretation for correct clinical diagnosis.

Bio-Tailored Sensing at the Nanoscale: Biochemical Aspects and Applications.

The demonstration of the first enzyme-based electrode to detect glucose, published in 1967 by S. J. Updike and G. P. Hicks, kicked off huge efforts in building sensors where biomolecules are exploited as native or modified to achieve new or improved sensing performances. In this growing area, bionanotechnology has become prominent in demonstrating how nanomaterials can be tailored into responsive nanostructures using biomolecules and integrated into sensors to detect different analytes, e.g., biomarkers, antibiotics, toxins and organic compounds as well as whole cells and microorganisms with very high sensitivity. Accounting for the natural affinity between biomolecules and almost every type of nanomaterials and taking advantage of well-known crosslinking strategies to stabilize the resulting hybrid nanostructures, biosensors with broad applications and with unprecedented low detection limits have been realized. This review depicts a comprehensive collection of the most recent biochemical and biophysical strategies for building hybrid devices based on bioconjugated nanomaterials and their applications in label-free detection for diagnostics, food and environmental analysis.

From Immunotoxins to Suicide Toxin Delivery Approaches: Is There a Clinical Opportunity?

Suicide gene therapy is a relatively novel form of cancer therapy in which a gene coding for enzymes or protein toxins is delivered through targeting systems such as vesicles, nanoparticles, peptide or lipidic co-adjuvants. The use of toxin genes is particularly interesting since their catalytic activity can induce cell death, damaging in most cases the translation machinery (ribosomes or protein factors involved in protein synthesis) of quiescent or proliferating cells. Thus, toxin gene delivery appears to be a promising tool in fighting cancer. In this review we will give an overview, describing some of the bacterial and plant enzymes studied so far for their delivery and controlled expression in tumor models.

Rational design and synthesis of a novel BODIPY-based probe for selective imaging of tau tangles in human iPSC-derived cortical neurons.

Numerous studies have shown a strong correlation between the number of neurofibrillary tangles of the tau protein and Alzheimer's disease progression, making the quantitative detection of tau very promising from a clinical point of view. However, the lack of highly reliable fluorescent probes for selective imaging of tau neurofibrillary tangles is a major challenge due to sharing similar ß-sheet motifs with homologous Amyloid-ß fibrils. In the current work, we describe the rational design and the in silico evaluation of a small-size focused library of fluorescent probes, consisting of a BODIPY core (electron acceptor) featuring highly conjugated systems (electron donor) with a length in the range 13-19 Å at C3. Among the most promising probes in terms of binding mode, theoretical affinity and polarity, BT1 has been synthesized and tested in vitro onto human induced pluripotent stem cells derived neuronal cell cultures. The probe showed excellent photophysical properties and high selectivity allowing in vitro imaging of hyperphosphorylated tau protein filaments with minimal background noise. Our findings offer new insight into the structure-activity relationship of this class of tau selective fluorophores, paving the way for boosting tau tangle detection in patients possibly through retinal spectral scans.

Biochemical and structural characterizations of thioredoxin reductase selenoproteins of the parasitic filarial nematodes Brugia malayi and Onchocerca volvulus.

Enzymes in the thiol redox systems of microbial pathogens are promising targets for drug development. In this study we characterized the thioredoxin reductase (TrxR) selenoproteins from Brugia malayi and Onchocerca volvulus, filarial nematode parasites and causative agents of lymphatic filariasis and onchocerciasis, respectively. The two filarial enzymes showed similar turnover numbers and affinities for different thioredoxin (Trx) proteins, but with a clear preference for the autologous Trx. Human TrxR1 (hTrxR1) had a high and similar specific activity versus the human and filarial Trxs, suggesting that, in vivo, hTrxR1 could possibly be the reducing agent of parasite Trxs once they are released into the host. Both filarial TrxRs were efficiently inhibited by auranofin and by a recently described inhibitor of human TrxR1 (TRi-1), but not as efficiently by the alternative compound TRi-2. The enzyme from B. malayi was structurally characterized also in complex with NADPH and auranofin, producing the first crystallographic structure of a nematode TrxR. The protein represents an unusual fusion of a mammalian-type TrxR protein architecture with an N-terminal glutaredoxin-like (Grx) domain lacking typical Grx motifs. Unlike thioredoxin glutathione reductases (TGRs) found in platyhelminths and mammals, which are also Grx-TrxR domain fusion proteins, the TrxRs from the filarial nematodes lacked glutathione disulfide reductase and Grx activities. The structural determinations revealed that the Grx domain of TrxR from B. malayi contains a cysteine (C22), conserved in TrxRs from clade IIIc nematodes, that directly interacts with the C-terminal cysteine-selenocysteine motif of the homo-dimeric subunit. Interestingly, despite this finding we found that altering C22 by mutation to serine did not affect enzyme catalysis. Thus, although the function of the Grx domain in these filarial TrxRs remains to be determined, the results obtained provide insights on key properties of this important family of selenoprotein flavoenzymes that are potential drug targets for treatment of filariasis.

Distance education during COVID 19: an Italian survey on the university teachers' perspectives and their emotional conditions.

BACKGROUND: Following the COVID-19 pandemic, distance education (DE) replaced traditional "face-to-face" teaching and has become the main method of teaching. The aim of this study was to 1) evaluate the impact of DE by teachers in our department during the second semester of the 2019-20 academic year following the March-May 2020 Italian national lockdown and 2) evaluate the relationship between DE and the emotional well-being of teachers during the period of home confinement. METHODS: Ninety-seven university teachers (51.5% women; most represented age group 60-69 years range, 40.2%) responded to an anonymous online cross-sectional survey between July 15 - September 30, 2020, on the advantages and disadvantages of DE, developed by one online teacher focus group. The emotional conditions were assessed by a short version of the Beck Depression Inventory-II (BDI-II). The internal consistency reliability survey and the 10-item BDI-II were measured by Cronbach's alpha. A correlation analysis (r-Pearson) was conducted between the overall evaluation of the experience of DE and the variables included in the study. RESULTS: Teachers reported difficulties in technical aspects, and in psychological factors, as the discomfort of "speaking in the void" (64.7%). The absence of "face-to-face" eye contact with the students was complained by 81% of teachers. Significant impairments in sleep patterns and loss of energy were reported, with female teachers having greater difficulty concentrating than their male colleagues. A quarter of teachers showed depressive symptoms of varying severity. The most satisfied teachers were those most stimulated by DE (r = 0.752, p < 0.000), who showed a lower impact of depressive symptoms (r = - 0.289, p = 0.005). The teaching load in hours influenced the perception of disadvantages (r = 0.214, p = 0.035) and contributed to a lower appreciation of the challenges of DE. The more significant the manifestation of depressive symptoms during the lockdown was, the greater the subjective recovery of a good emotional condition once the domestic confinement was over (r = 0.344, p = 0.001), despite maintaining DE. CONCLUSIONS: Our study highlights the impact of technical, didactic, and psychological difficulties of DE, reported by our teachers. The appreciation of their new learning promoted by DE seemed related to better emotional well-being of university teachers accepting this "challenge" in their important role in the high-education system, influencing good learning and promoting students' professional success.

Aptamer-Driven Toxin Gene Delivery in U87 Model Glioblastoma Cells.

A novel suicide gene therapy approach was tested in U87 MG glioblastoma multiforme cells. A 26nt G-rich double-stranded DNA aptamer (AS1411) was integrated into a vector at the 5' of a mammalian codon-optimized saporin gene, under CMV promoter. With this plasmid termed "APTSAP", the gene encoding ribosome-inactivating protein saporin is driven intracellularly by the glioma-specific aptamer that binds to cell surface-exposed nucleolin and efficiently kills target cells, more effectively as a polyethyleneimine (PEI)-polyplex. Cells that do not expose nucleolin at the cell surface such as 3T3 cells, used as a control, remain unaffected. Suicide gene-induced cell killing was not observed when the inactive saporin mutant SAPKQ DNA was used in the (PEI)-polyplex, indicating that saporin catalytic activity mediates the cytotoxic effect. Rather than apoptosis, cell death has features resembling autophagic or methuosis-like mechanisms. These main findings support the proof-of-concept of using PEI-polyplexed APTSAP for local delivery in rat glioblastoma models.

Probing the Surface of a Parasite Drug Target Thioredoxin Glutathione Reductase Using Small Molecule Fragments.

Fragment screening is a powerful drug discovery approach particularly useful for enzymes difficult to inhibit selectively, such as the thiol/selenol-dependent thioredoxin reductases (TrxRs), which are essential and druggable in several infectious diseases. Several known inhibitors are reactive electrophiles targeting the selenocysteine-containing C-terminus and thus often suffering from off-target reactivity in vivo. The lack of structural information on the interaction modalities of the C-terminus-targeting inhibitors, due to the high mobility of this domain and the lack of alternative druggable sites, prevents the development of selective inhibitors for TrxRs. In this work, fragments selected from actives identified in a large screen carried out against Thioredoxin Glutathione Reductase from Schistosoma mansoni (SmTGR) were probed by X-ray crystallography. SmTGR is one of the most promising drug targets for schistosomiasis, a devastating, neglected disease. Utilizing a multicrystal method to analyze electron density maps, structural analysis, and functional studies, three binding sites were characterized in SmTGR: two sites are close to or partially superposable with the NADPH binding site, while the third one is found between two symmetry related SmTGR subunits of the crystal lattice. Surprisingly, one compound bound to this latter site stabilizes, through allosteric effects mediated by the so-called guiding bar residues, the crucial redox active C-terminus of SmTGR, making it finally visible at high resolution. These results further promote fragments as small molecule probes for investigating functional aspects of the target protein, exemplified by the allosteric effect on the C-terminus, and providing fundamental chemical information exploitable in drug discovery.

PPARα-Selective Antagonist GW6471 Inhibits Cell Growth in Breast Cancer Stem Cells Inducing Energy Imbalance and Metabolic Stress.

Breast cancer is the most frequent cancer and the second leading cause of death among women. Triple-negative breast cancer is the most aggressive subtype of breast cancer and is characterized by the absence of hormone receptors and human epithelial growth factor receptor 2. Cancer stem cells (CSCs) represent a small population of tumor cells showing a crucial role in tumor progression, metastasis, recurrence, and drug resistance. The presence of CSCs can explain the failure of conventional therapies to completely eradicate cancer. Thus, to overcome this limit, targeting CSCs may constitute a promising approach for breast cancer treatment, especially in the triple-negative form. To this purpose, we isolated and characterized breast cancer stem cells from a triple-negative breast cancer cell line, MDA-MB-231. The obtained mammospheres were then treated with the specific PPARα antagonist GW6471, after which, glucose, lipid metabolism, and invasiveness were analyzed. Notably, GW6471 reduced cancer stem cell viability, proliferation, and spheroid formation, leading to apoptosis and metabolic impairment. Overall, our findings suggest that GW6471 may be used as a potent adjuvant for gold standard therapies for triple-negative breast cancer, opening the possibility for preclinical and clinical trials for this class of compounds.

Taking Advantage of the Morpheein Behavior of Peroxiredoxin in Bionanotechnology.

Morpheeins are proteins that reversibly assemble into different oligomers, whose architectures are governed by conformational changes of the subunits. This property could be utilized in bionanotechnology where the building of nanometric and new high-ordered structures is required. By capitalizing on the adaptability of morpheeins to create patterned structures and exploiting their inborn affinity toward inorganic and living matter, "bottom-up" creation of nanostructures could be achieved using a single protein building block, which may be useful as such or as scaffolds for more complex materials. Peroxiredoxins represent the paradigm of a morpheein that can be applied to bionanotechnology. This review describes the structural and functional transitions that peroxiredoxins undergo to form high-order oligomers, e.g., rings, tubes, particles, and catenanes, and reports on the chemical and genetic engineering approaches to employ them in the generation of responsive nanostructures and nanodevices. The usefulness of the morpheeins' behavior is emphasized, supporting their use in future applications.

EV20­sss­vc/MMAF, an HER­3 targeting antibody­drug conjugate displays antitumor activity in liver cancer.

Liver cancer (LC) is an aggressive disease with a markedly poor prognosis. Therapeutic options are limited, and, until recently the only FDA­approved agent for first­line treatment of patients with LC was the multi­kinase inhibitor sorafenib, which exhibits limited activity and an increased overall survival (OS) of only 3 months over placebo. Therefore, the development of alternative therapeutic molecules for the treatment of LC is an urgent medical need. Antibody­drug conjugates (ADCs) are an emerging class of novel anticancer agents, which have been developed recently for the treatment of malignant conditions, including LC, and are being studied in preclinical and clinical settings. Our group has recently generated an ADC [EV20/monomethyl auristatin F (MMAF)] by coupling the HER3 targeting antibody (EV20) to MMAF via a non­cleavable maleimidocaproyl linker. This ADC was revealed to possess potent therapeutic activity in melanoma and breast carcinoma. In the present study, using western blot and flow cytometric analysis, it was reported that HER­3 receptor was highly expressed in LC and activated by its ligand NRG­1ß in a panel of LC cell lines, thus indicating that this receptor may serve as a suitable target for ADC therapy. A novel ADC [EV20­sss­valine­citrulline (vc)/MMAF] was generated, in which the cytotoxic payload MMAF was site­specifically coupled to an engineered variant of EV20 via a vc cleavable linker. Cytotoxicity assays were performed to investigate in vitro antitumor activity of EV20­sss­vc/MMAF and it was compared to EV20/MMAF, which revealed only modest activity in LC.EV20­sss­vc/MMAF exhibited a significant cell killing activity in several LC cell lines. Additionally, in vivo xenograft experiments revealed that EV20­sss­vc/MMAF inhibited growth of LC tumors. The present data indicated that EV20­sss­vc/MMAF is a worthy candidate for the treatment of HER­3 positive LC.

Olive leaf extract impairs mitochondria by pro-oxidant activity in MDA-MB-231 and OVCAR-3 cancer cells.

Breast and ovarian cancers are the leading and fifth reason for tumor death among females, respectively. Recently, many studies demonstrated antiproliferative activities of natural aliments in cancer. In this study, we investigated the antitumor potential of Olive Leaf Extract (OLE) in triple-negative breast and ovarian cancer cells. A HPLC/DAD analysis on OLE has been performed to assess the total polyphenolics and other secondary metabolites content. HCEpiC, MDA-MB-231, and OVCAR-3 cell lines were used. MTS, Cytofluorimetric, Western Blot analysis were performed to analyze cell viability, cell proliferation, apoptosis, and oxidative stress. Fluorimetric and IncuCyte® analyses were carried out to evaluate apoptosis and mitochondrial function. We confirmed that OLE, containing a quantity of oleuropein of 87 % of the total extract, shows anti-proliferative and pro-apoptotic activity on MDA-MB-231 cells. For the first time, our results indicate that OLE inhibits OVCAR-3 cell viability inducing cell cycle arrest, and it also increases apoptotic cell death up-regulating the protein level of cleaved-PARP and caspase 9. Moreover, our data show that OLE treatment causes a significant decrease in mitochondrial functionality, paralleled by a reduction of mitochondrial membrane potential. Interestingly, OLE increased the level of intracellular and mitochondrial reactive oxygen species (ROS) together with a decreased activity of ROS scavenging enzymes, confirming oxidative stress in both models. Our data demonstrate that mitochondrial ROS generation represented the primary mechanism of OLE antitumor activity, as pretreatment with antioxidant N-acetylcysteine prevented OLE-induced cell cycle arrest and apoptosis.