RANBP1, a member of the nuclear-cytoplasmic trafficking-regulator complex, is the terminal-striking point of the SGK1-dependent Th17+ pathological differentiation

The Th17+ arrangement is critical for orchestrating both innate and acquired immune responses. In this context, the serum and glucocorticoid regulated kinase 1 (SGK1) exerts a key role in the governance of IL-23R-dependent Th17+ maturation, through the phosphorylation-dependent control of FOXO1 localization. Our previous work has shown that some of the SGK1-key functions are dependent on RAN-binding protein 1 (RANBP1), a terminal gene in the nuclear transport regulation. Here, we show that RANBP1, similarly to SGK1, is modulated during Th17+ differentiation and that RANBP1 fluctuations mediate the SGK1-dependent effects on Th17+ maturation. RANBP1, as the final effector of the SGK1 pathway, affects FOXO1 transport from the nucleus to the cytoplasm, thus enabling RORγt activation. In this light, RANBP1 represents the missing piece, in an essential and rate-limiting manner, underlying the Th17+ immune asset.

Uncovering Novel Capsaicin Inhibitory Activity towards Human Carbonic Anhydrase Isoforms IX and XII by Combining In Silico and In Vitro Studies

Hot pepper (Capsicum annuum) represents one of the most widespread functional foods of the Mediterranean diet, and is associated with a reduced risk of developing cardiovascular disease, cancer, and mental disorders. In particular, its bioactive spicy molecules, named Capsaicinoids, exhibit polypharmacological properties. Among them, Capsaicin (trans-8-methyl-N-vanillyl-6-nonenamide) is the most studied and reported in variegated scientific contributions for its beneficial effects, often linked to mechanisms of action unrelated to the activation of Transient Receptor Potential Vanilloid 1 (TRPV1). In this study, we present the application of in silico methods to Capsaicin for evaluating its inhibitory activity against the tumor-associated human (h) expressed CA IX and XII. In vitro assays confirmed Capsaicin inhibitory activity towards the most relevant tumor-related hCA isoforms. In particular, the hCAs IX and XII showed an experimental K_I value of 0.28 μM and 0.064 μM, respectively. Then, an A549 model of non-small cell lung cancer, typically characterized by an elevated expression of hCA IX and XII, was employed to test the inhibitory effects of Capsaicin in vitro under both normoxic and hypoxic conditions. Finally, the migration assay revealed that Capsaicin [10 µM] inhibits cells from moving in the A549 cells model.

Kinase Inhibitors in Genetic Diseases

Over the years, several studies have shown that kinase-regulated signaling pathways are involved in the development of rare genetic diseases. The study of the mechanisms underlying the onset of these diseases has opened a possible way for the development of targeted therapies using particular kinase inhibitors. Some of these are currently used to treat other diseases, such as cancer. This review aims to describe the possibilities of using kinase inhibitors in genetic pathologies such as tuberous sclerosis, RASopathies, and ciliopathies, describing the various pathways involved and the possible targets already identified or currently under study.

RANBP1 (RAN Binding Protein 1): The Missing Genetic Piece in Cancer Pathophysiology and Other Complex Diseases

RANBP1 encoded by RANBP1 or HTF9A (Hpall Tiny Fragments Locus 9A), plays regulatory functions of the RAN-network, belonging to the RAS superfamily of small GTPases. Through this function, RANBP1 regulates the RANGAP1 activity and, thus, the fluctuations between GTP-RAN and GDP-RAN. In the light of this, RANBP1 take actions in maintaining the nucleus-cytoplasmic gradient, thus making nuclear import-export functional. RANBP1 has been implicated in the inter-nuclear transport of proteins, nucleic acids and microRNAs, fully contributing to cellular epigenomic signature. Recently, a RANBP1 diriment role in spindle checkpoint formation and nucleation has emerged, thus constituting an essential element in the control of mitotic stability. Over time, RANBP1 has been demonstrated to be variously involved in human cancers both for the role in controlling nuclear transport and RAN activity and for its ability to determine the efficiency of the mitotic process. RANBP1 also appears to be implicated in chemo-hormone and radio-resistance. A key role of this small-GTPases related protein has also been demonstrated in alterations of axonal flow and neuronal plasticity, as well as in viral and bacterial metabolism and in embryological maturation. In conclusion, RANBP1 appears not only to be an interesting factor in several pathological conditions but also a putative target of clinical interest.

Abstract B122: The CD98hc oncoprotein as a target of new anticancer therapy

Among the proteins putatively interacting with PTPRJ, a tyrosine phosphatase with tumor suppressor activity, we focused on the oncoprotein CD98hc as a very interesting candidate for the development of innovative targeted drugs. In fact, CD98hc, representing the heavy chain of a transmembrane aminoacid transporter, is overexpressed in several human cancers. Furthermore, CD98hc higher expression is associated with poor prognosis in lung cancer patients. CD98hc is linked to light chains (LATs, xCT) by disulfide bridge, polar and hydrophobic interactions. The light chain confers substrate specificity, and ERK, AKT, FAK and mTOR pathways are involved in CD98hc-LATs/xCT downstream signals. Moreover, CD98hc is a coreceptor of b-integrins and it is involved in cell proliferation, migration and invasion. We identified two peptides and 15 small molecules (putatively targeting the disulfide bridge) as candidate CD98hc inhibitors by phage display and in silico screenings, respectively, and validated in vitro the binding between peptides and transmembrane fraction of CD98hc by cytofluorimetric assay. Then, we tested the capability of both types of compounds to affect cell viability and proliferation through MTT and CFSE assays, respectively. We observed that the targeting of CD98hc through both peptides and small molecules reduced cell proliferation in A549 human lung cancer cells, strongly encouraging a deeper characterization of these candidate anticancer molecules. Indeed, our next goals will be the assessment of biochemical activity of CD98hc following to its inhibition, as well as the evaluation of compounds toxicity, both in vitro and in vivo. The final aim is to identify lead compounds inhibiting CD98hc, in order to develop novel molecules to be translated in the clinical setting and to be used as monotherapy and/or in a combinatorial approaches for the treatment of cancer patients.

Citation Format: Delia Lanzillotta, Enrico Iaccino, Anna Artese, Selena Mimmi, Sabrina D'Agostino, Isabella Romeo, Patrizia Cantafio, Vincenzo Dattilo, Giosuè Costa, Carolina Brescia, Eugenio Gaudio, Stefano Alcaro, Francesco Trapasso. The CD98hc oncoprotein as a target of new anticancer therapy [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr B122. doi:10.1158/1535-7163.TARG-19-B122