Approximately 5-10% of metastatic colorectal cancers harbor a BRAF-V600E mutation, which is correlated with resistance to EGFR-targeted therapies and worse clinical outcome. Vice versa, targeted inhibition of BRAF-V600E with the selective inhibitor PLX 4032 (Vemurafenib) is severely limited due to feedback re-activation of EGFR in these tumors. Mounting evidence indicates that upregulation of the ErbB-3 signaling axis may occur in response to several targeted therapeutics, including Vemurafenib, and NRG-1β-dependent re-activation of the PI3K/AKT survival pathway has been associated with therapy resistance.Here we show that colon CSCs express, next to EGFR and ErbB-2, also significant amounts of ErbB-3 on their membrane. This expression is functional as NRG-1β strongly induces AKT/PKB and ERK phosphorylation, cell proliferation, clonogenic growth and promotes resistance to Vemurafenib in BRAF-V600E mutant colon CSCs. This resistance was completely dependent on ErbB-3 expression, as evidenced by knockdown of ErbB-3. More importantly, resistance could be alleviated with therapeutic antibody blocking ErbB-3 activation, which impaired NRG-1β-driven AKT/PKB and ERK activation, clonogenic growth in vitro and tumor growth in xenograft models. In conclusion, our findings suggest that targeting ErbB-3 receptors could represent an effective therapeutic approach in BRAF-V600E mutant colon cancer.

We have previously shown that secreted BAG3 is a potential target for the treatment of pancreatic ductal adenocarcinoma and that pancreatic tumor growth and metastatic dissemination can be reduced by treatment with an anti-BAG3 murine antibody. Here, we used complementarity-determining region (CDR) grafting to generate a humanized version of the anti-BAG3 antibody that may be further developed for possible clinical use. We show that the humanized anti-BAG3 antibody, named BAG3-H2L4, abrogates BAG3 binding to macrophages and subsequent release of IL-6. Furthermore, it specifically localizes into tumor tissues and significantly inhibits the growth of Mia PaCa-2 pancreatic cancer cell xenografts. We propose BAG3-H2L4 antibody as a potential clinical candidate for BAG3-targeted therapy in pancreatic cancer.

Vav1 is one of the signalling proteins normally restricted to hematopoietic cells that results ectopically expressed in solid tumors, including breast cancer. By immunohistochemical analysis on TMAs containing invasive breast tumor from patients without lymph node involvement, we have found that Vav1 is expressed in almost all investigated cancers and shows a peculiar localization inside the nucleus of tumor cells. High amounts of nuclear Vav1 are positively correlated with low incidence of relapse, regardless phenotype and molecular subtype of breast neoplasia. In particular, Kaplan-Meier plots showed an elevated risk of distant metastasis in patients with low Vav1 expression compared with patients with high Vav1 expression in their tumors. Experiments performed with breast tumor-derived cells indicated that Vav1 negatively modulates their invasiveness in vitro and their metastatic efficiency in vivo, possibly by affecting the expression of genes involved in invasion and/or metastasis of breast tumors. Since the high heterogeneity of breast tumors makes difficult to predict the evolution of early breast neoplasias, the evaluation of nuclear Vav1 levels may help in the characterization and management of early breast cancer patients. In particular, Vav1 may serve as a prognostic biomarker and a target for new therapies aimed to prevent breast cancer progression.

Doxorubicin is employed alone or in combination for the treatment of several hematological and solid malignancies; despite its efficacy, there are associated cardiotoxicity limits both in its application in patients with heart disease risk factors and also in its long-term use. HFt-MP-PAS40 is a genetically engineered human ferritin heavy chain (HFt)-based construct able to efficiently entrap and deliver doxorubicin to cancer cells. HF-MP-PAS contains a short motif sequence (defined as MP) responsive to proteolytic cleavage by tumor matrix metalloproteases (MMPs), located between each HFt subunit and a masking polypeptide sequence rich in proline (P), alanine (A), and serine (S) residues (PAS). This carrier displayed excellent therapeutic efficacy in a xenogenic pancreatic cancer model in vivo, leading to a significant increase in overall animal survival in treated mice. Herein, we describe the HFt-MP-PAS40-Dox efficacy against squamous cell carcinomas of the head and neck (HNSCC) with the goal of validating the application of our nano-drug for the treatment of different solid tumors. In addition, a tolerability study in healthy mice was also performed. The results indicate that HFt-MP-PAS40-Dox produced increased anti-tumor effects both in vitro and in vivo in comparison to the free drug in several HNSCC cell lines. In the acute toxicity studies, the maximum tolerated dose (MTD) of HFt-MP-PAS40-Dox was about 3.5 higher than the free drug: 25 mg/kg versus 7 mg/kg doxorubicin equivalents. Importantly, evaluation of heart tissues provided evidence that doxorubicin is less cardio-toxic when encapsulated inside the ferritin carrier. In conclusion, HFt-MP-PAS40-Dox may be administered safely at higher doses compared with the free drug, resulting in superior efficacy to control HNSCC malignancies.

The thermophilic blue-green alga ETS-05 colonises the therapeutic thermal muds of Abano and Montegrotto, Italy. Following the isolation, purification and identification of monogalactosyldiacylglycerol (MGDG), digalactosyldiacylglycerol (DGDG), sulphoquinovosyldiacylglycerol (SQDG) and phosphatidylglycerol from ETS-05, we here examine their in vivo anti-inflammatory activities. MGDG, DGDG and SQDG inhibit croton-oil-induced ear oedema in the mouse in a dose-dependent manner. Inhibition by MGDG is greater than that of the reference drug, betamethasone 17,21-dipropionate, and is largely abrogated following acyl group saturation. SQDG is the least potent of these glycoglycerolipids, and shows an early transient effect. In the in vivo carrageenan-induced paw oedema model in the mouse, the inhibitory effects are again dose dependent, with an enhanced efficacy of MGDG over DGDG, SQDG and the reference drug, indomethacin. These compounds are all less toxic than indomethacin. The selective and enhanced inhibitory effects of MGDG over DGDG indicate the mechanisms behind these in vivo anti-inflammatory actions.

A previous report has shown that LGALS3BP (also known as 90K or Mac-2 BP) has antitumor activity in colorectal cancer (CRC) via suppression of Wnt signalling with a novel mechanism of ISGylation-dependent ubiquitination of β-catenin. The role of LGALS3BP in CRC prognosis was investigated.

The very aggressive nature and low survival rate of pancreatic ductal adenocarcinoma (PDAC) dictates the necessity to find novel efficacious therapies. Recent evidence suggests that phosphoinositide 3-kinase (PI3K) and 3-phosphoinositide-dependent protein kinase 1 (PDK1) are key effectors of oncogenic KRAS in PDAC. Herein, we report the role and mechanism of action of PDK1, a protein kinase of the AGC family, in PDAC.

Pancreatic Ductal Adenocarcinoma (PDAC) is an aggressive and lethal disease, lacking effective therapeutic approaches. Available therapies only marginally prolong patient survival and are frequently coupled with severe adverse events. It is therefore pivotal to investigate novel and safe pharmacological approaches. We have recently identified the ABC transporter, ABCC3, whose expression is dependent on mutation of TP53, as a novel target in PDAC. ABCC3-mediated regulation of PDAC cell proliferation and tumour growth in vivo was demonstrated and was shown to be conferred by upregulation of STAT3 signalling and regulation of apoptosis.

Ferritin receptor (CD71) is an example of a very attractive cancer target, since it is highly expressed in virtually all tumor types, including metastatic loci. However, this target can be considered to be inaccessible to conventional target therapies, due to its presence in many healthy tissues. Here, we describe the preclinical evaluation of a tumor proteases-activatable human ferritin (HFt)-based drug carrier (The-0504) that is able to selectively deliver the wide-spectrum topoisomerase I inhibitor Genz-644282 to CD71-expressing tumors, preventing the limiting toxic effects associated with CD71-targeting therapies.

Antibody-drug conjugates (ADCs) are designed to deliver potent cytotoxic agents into tumor tissues. During the last two decades, a plethora of ADCs have been successfully developed and used for several indications, including hematologic and solid tumors. In this work, we systematically reviewed the progress in ADC development for the treatment of HNC.

Cancer is still among the leading causes of death all over the world. Improving chemotherapy and minimizing associated toxicities are major unmet medical needs. Recently, we provided a preliminary preclinical evaluation of a human ferritin (HFt)-based drug carrier (The-0504) that selectively delivers the wide-spectrum topoisomerase I inhibitor Genz-644282 to CD71-expressing tumors. The-0504 has so far been evaluated on four different human tumor xenotransplant models (breast, colorectal, pancreatic and liver cancers).

HER2-positive breast tumors are associated with a high risk of brain relapse. HER3 is thought to be an indispensible signaling substrate for HER2 (encoded by ERBB2) and is induced in breast cancer-brain metastases, though the molecular mechanisms by which this oncogenic dimer promotes the development of brain metastases are still elusive. We studied the effects of the HER3-HER2 ligand, heregulin (neuregulin-1, broadly expressed in the brain), on luminal breast cancer cell lines in vitro. Treatment of SKBr3 (ERBB2-amplified), MDA-MB-361 (ERBB2-amplified, metastatic brain tumor-derived) and MCF7 (HER2-positive, not ERBB2-amplified) cells with exogenous heregulin increased proliferation and adhesive potential, concomitant with induction of cyclin D1 and ICAM-1, and suppression of p27. All three cell lines invaded through matrigel toward a heregulin chemotactic signal in transwell experiments, associated with activation of extracellular cathepsin B and matrix metalloproteinase-9 (MMP-9). Moreover, heregulin induced breast cancer cell transmigration across a tight barrier of primary human brain microvascular endothelia. This was dependent on the activity of HER2, HER3 and MMPs, and was completely abrogated by combination HER2-HER3 blockade using Herceptin® and the humanized HER3 monoclonal antibody, EV20. Collectively these data suggest mechanisms by which the HER3-HER2 dimer promotes development of metastatic tumors in the heregulin-rich brain microenvironment.

The incidence and death rate of pancreatic ductal adenocarcinoma (PDAC) have increased in recent years, therefore the identification of novel targets for treatment is extremely important. Interactions between cancer and stromal cells are critically involved in tumour formation and development of metastasis. Here we report that PDAC cells secrete BAG3, which binds and activates macrophages, inducing their activation and the secretion of PDAC supporting factors. We also identify IFITM-2 as a BAG3 receptor and show that it signals through PI3K and the p38 MAPK pathways. Finally, we show that the use of an anti-BAG3 antibody results in reduced tumour growth and prevents metastasis formation in three different mouse models. In conclusion, we identify a paracrine loop involved in PDAC growth and metastatic spreading, and show that an anti-BAG3 antibody has therapeutic potential.

Airborne allergens can induce an immunological chronic disease characterized by airway hyper responsiveness and inflammation, mediated by exaggerated Th2 immune response. Allergen-specific immunotherapy (AIT) is effective for treating this condition because it is able to modify its natural course by opposing the underlying pathogenic mechanisms and determining immune suppression, immune deviation and tolerance. The rational for the present study was to investigate the possibility of improving allergoid-based IT in terms of efficacy and safety. Recently, 1α,25-dihydroxyvitamin D3 (VD3), the active metabolite of vitamin D3, was described to be a potent inducer of T regulatory cells and to be a good adjuvant in AIT settings.

Galectin-3-binding protein (Gal-3BP) has been identified as a cancer and metastasis-associated, secreted protein that is expressed by the large majority of cancers. The present study describes a special type of non-internalizing antibody-drug-conjugates that specifically target Gal-3BP. Here, we show that the humanized 1959 antibody, which specifically recognizes secreted Gal-3BP, selectively localized around tumor but not normal cells. A site specific disulfide linkage with thiol-maytansinoids to unpaired cysteine residues of 1959, resulting in a drug-antibody ratio of 2, yielded an ADC product, which cured A375m melanoma bearing mice. ADC products based on the non-internalizing 1959 antibody may be useful for the treatment of several human malignancies, as the cognate antigen is abundantly expressed and secreted by several cancers, while being present at low levels in most normal adult tissues.

Despite impressive clinical benefit obtained with anti-HER2-targeted therapies, in advances stages, especially in the metastatic setting, HER2-positive tumors remain incurable. Therefore, it is important to develop novel strategies to fight these tumors, especially when they become resistant to available therapies. We show here that the anti-HER3 antibody-drug conjugate EV20/MMAF exerted potent anti-tumoral properties against several models of primary resistance and secondary resistance to common anti-HER2 available therapies, including trastuzumab, lapatinib, neratinib, and trastuzumab-emtansine. HER3 was expressed in these HER2+ breast cancer cells and knockdown experiments demonstrated that HER3 expression was required for the action of EV20/MMAF. In mice injected with trastuzumab-resistant HER2+ cells, a single dose of EV20/MMAF caused complete and long-lasting tumor regression. Mechanistically, EV20/MMAF bound to cell surface HER3 and became internalized to the lysosomes. Treatment with EV20/MMAF caused cell cycle arrest in mitosis and promoted cell death through mitotic catastrophe. These findings encourage the clinical testing of EV20/MMAF for several indications in the HER2+ cancer clinic, including situations in which HER2+ tumors become refractory to approved anti-HER2 therapies.

Neuroblastoma is the most common extra-cranial solid tumor in infants and children, which accounts for approximately 15% of all cancer-related deaths in the pediatric population. New therapeutic modalities are urgently needed. Antibody-Drug Conjugates (ADC)s-based therapy has been proposed as potential strategy to treat this pediatric malignancy. LGALS3BP is a highly glycosylated protein involved in tumor growth and progression. Studies have shown that LGALS3BP is enriched in extracellular vesicles (EV)s derived by most neuroblastoma cells, where it plays a critical role in preparing a favorable tumor microenvironment (TME) through direct cross talk between cancer and stroma cells. Here, we describe the development of a non-internalizing LGALS3BP ADC, named 1959-sss/DM3, which selectively targets LGALS3BP expressing neuroblastoma. 1959-sss/DM3 mediated potent therapeutic activity in different types of neuroblastoma models. Notably, we found that treatments were well tolerated at efficacious doses that were fully curative. These results offer preclinical proof-of-concept for an ADC targeting exosomal LGALS3BP approach for neuroblastomas.

Tumours can be viewed as aberrant tissues or organs sustained by tumorigenic stem-like cells that engage into dysregulated histo/organogenetic processes. Paragangliomas, prototypical organoid tumours constituted by dysmorphic variants of the vascular and neural tissues found in normal paraganglia, provide a model to test this hypothesis. To understand the origin of paragangliomas, we built a biobank comprising 77 cases, 18 primary cultures, 4 derived cell lines, 80 patient-derived xenografts and 11 cell-derived xenografts. We comparatively investigated these unique complementary materials using morphofunctional, ultrastructural and flow cytometric assays accompanied by microRNA studies. We found that paragangliomas contain stem-like cells with hybrid mesenchymal/vasculoneural phenotype, stabilized and expanded in the derived cultures. The viability and growth of such cultures depended on the downregulation of the miR-200 and miR-34 families, which allowed high PDGFRA and ZEB1 protein expression levels. Both tumour tissue- and cell culture-derived xenografts recapitulated the vasculoneural paraganglioma structure and arose from mesenchymal-like cells through a fixed developmental sequence. First, vasculoangiogenesis organized the microenvironment, building a perivascular niche which in turn supported neurogenesis. Neuroepithelial differentiation was associated with severe mitochondrial dysfunction, not present in cultured paraganglioma cells, but acquired in vivo during xenograft formation. Vasculogenesis was the Achilles' heel of xenograft development. In fact, imatinib, that targets endothelial-mural signalling, blocked paraganglioma xenograft formation (11 xenografts from 12 cell transplants in the control group versus 2 out of 10 in the treated group, P = 0.0015). Overall our key results were unaffected by the SDHx gene carrier status of the patient, characterized for 70 out of 77 cases. In conclusion, we explain the biphasic vasculoneural structure of paragangliomas and identify an early and pharmacologically actionable phase of paraganglioma organization.

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.

Mir-205 plays an important role in epithelial biogenesis and in mammary gland development but its role in cancer still remains controversial depending on the specific cellular context and target genes. We have previously reported that miR-205-5p is upregulated in breast cancer stem cells targeting ERBB pathway and leading to targeted therapy resistance. Here we show that miR-205-5p regulates tumorigenic properties of breast cancer cells, as well as epithelial to mesenchymal transition. Silencing this miRNA in breast cancer results in reduced tumor growth and metastatic spreading in mouse models. Moreover, we show that miR-205-5p knock-down can be obtained with the use of specific locked nucleic acids oligonucleotides in vivo suggesting a future potential use of this approach in therapy.