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.

SARS CoV-2 spike protein-guided exosome isolation facilitates detection of potential miRNA biomarkers in COVID-19 infections.

OBJECTIVES: Nearly three years into the pandemic, SARS-CoV-2 infections are occurring in vaccinated and naturally infected populations. While humoral and cellular responses in COVID-19 are being characterized, novel immune biomarkers also being identified. Recently, an increase in angiotensin-converting enzyme 2 expressing (aka, ACE2 positive) circulating exosomes (ExoACE2) were identified in the plasma of COVID-19 patients (El-Shennawy et al.). In this pilot study, we describe a method to characterize the exosome-associated microRNA (exo-miRNA) signature in ACE2-positive and ACE2-negative exosomal populations (non-ExoACE2). METHODS: We performed a sorting protocol using the recombinant biotin-conjugated SARS CoV-2 spike protein containing the receptor binding domain (RBD) on plasma samples from six patients. Following purification, exo-miRNA were characterized for ACE2-positive and ACE2-negative exosome subpopulations by RT-PCR. RESULTS: We identified differential expression of several miRNA. Specifically let-7g-5p and hsa-miR-4454+miR-7975 were upregulated, while hsa-miR-208a-3p and has-miR-323-3p were downregulated in ExoACE2 vs. non-ExoACE2. CONCLUSIONS: The SARS CoV-2 spike-protein guided exosome isolation permits isolation of ExoACE2 exosomes. Such purification facilitates detailed characterization of potential biomarkers (e.g. exo-miRNA) for COVID-19 patients. This method could be used for future studies to further the understanding mechanisms of host response against SARS CoV-2.

LRRK2 Kinase Inhibition Attenuates Astrocytic Activation in Response to Amyloid ß1-42 Fibrils.

Intracerebral accumulation of amyloid-ß in the extracellular plaques of Alzheimer's disease (AD) brains represents the main cause of reactive astrogliosis and neuroinflammatory response. Of relevance, leucine-rich repeat kinase 2 (LRRK2), a kinase linked to genetic and sporadic Parkinson's disease (PD), has been identified as a positive mediator of neuroinflammation upon different inflammatory stimuli, however its pathogenicity in AD remains mainly unexplored. In this study, by using pharmacological inhibition of LRRK2 and murine primary astrocytes, we explored whether LRRK2 regulates astrocytic activation in response to amyloid-ß1-42 (Aß1-42). Our results showed that murine primary astrocytes become reactive and recruit serine 935 phosphorylated LRRK2 upon Aß1-42 fibril exposure. Moreover, we found that pharmacological inhibition of LRRK2, with two different kinase inhibitors, can attenuate Aß1-42-mediated inflammation and favor the clearance of Aß1-42 fibrils in astrocytes. Overall, our findings report that LRRK2 kinase activity modulates astrocytic reactivity and functions in the presence of Aß1-42 deposits and indicate that PD-linked LRRK2 might contribute to AD-related neuroinflammation and pathogenesis.

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.

Genome-wide association studies on Northern Italy isolated populations provide further support concerning genetic susceptibility for major depressive disorder.

OBJECTIVES: Major depressive disorder (MDD) is a psychiatric disorder with pathogenesis influenced by both genetic and environmental factors. To date, the molecular-level understanding of its aetiology remains unclear. Thus, we aimed to identify genetic variants and susceptibility genes for MDD with a genome-wide association study (GWAS) approach. METHODS: We performed a meta-analysis of GWASs and a gene-based analysis on two Northern Italy isolated populations (cases/controls n = 166/472 and 33/320), followed by replication and polygenic risk score (PRS) analyses in Italian independent samples (cases n = 464, controls n = 339). RESULTS: We identified two novel MDD-associated genes, KCNQ5 (lead SNP rs867262, p = 3.82 × 10-9) and CTNNA2 (rs6729523, p = 1.25 × 10-8). The gene-based analysis revealed another six genes (p < 2.703 × 10-6): GRM7, CTNT4, SNRK, SRGAP3, TRAPPC9, and FHIT. No replication of the genome-wide significant SNPs was found in the independent cohort, even if 14 SNPs around CTNNA2 showed association with MDD and related phenotypes at the nominal level of p (<0.05). Furthermore, the PRS model developed in the discovery cohort discriminated cases and controls in the replication cohort. CONCLUSIONS: Our work suggests new possible genes associated with MDD, and the PRS analysis confirms the polygenic nature of this disorder. Future studies are required to better understand the role of these findings in MDD.

Spotlight on a Short-Time Treatment with the IL-4/IL-13 Receptor Blocker in Patients with CRSwNP: microRNAs Modulations and Preliminary Clinical Evidence.

Already used for the treatment of some allergic and inflammatory diseases, such as asthma or atopic dermatitis, dupilumab has also been approved as add-on therapy for patients with CRSwNP, and it could represent the keystone to reducing the remission time as well as to improve healing and quality of life. On the other hand, the role of miRNAs as potential biomarkers of immune modulation is emerging. We analyzed the effects of a short-time treatment with dupilumab in patients with CRSwNP, analyzing the immune response modification as well as miRNAs modulations. First, in this early observation stage, all patients experienced remarkable improvement and were clinically stable. Indeed, we observed a significant decrease in CD4+ T cells and a significant reduction in total IgE (p < 0.05) and serum IL-8 levels (p < 0.01), indicating a reduction in the general inflammatory condition. In addition, we analyzed a panel of about 200 circulating miRNAs. After treatment, we noted a significant downregulation of hsa-mir-25-3p (p-value = 0.02415) and hsa-mir-185-5p (p-value = 0.04547), two miRNAs involved in the proliferation, inflammation, and dug-resistance, in accordance with the clinical status of patients. All these preliminary data aimed to identify new biomarkers of prognosis, identifiable with non-invasive procedures for patients. Further, these patients are still under observation, and others with different levels of responsiveness to treatment need to be enrolled to increase the statistical data.

Th17-Gene Expression Profile in Patients with Chronic Venous Disease and Venous Ulcers: Genetic Modulations and Preliminary Clinical Evidence.

Chronic venous disease is a condition globally widespread, resulting in a disabling pathological disorder. The CD4 + Th17+ (Cluster Differentiation 4) lymphocytes represent a regulative factor for innate immunity related to the development of complex diseases. Recently, these mechanisms have been associated with vascular disease. The aim of this work is to validate whether the Th17 response correlates with the development of CVI (Chronic venous insufficiency)and CVLUs (chronic venous limbs ulcers) and whether Th17 markers can be used, both as intrinsic risk factors and diagnostic markers, for disease development. PBL derived from peripheral blood samples of patients and controls were subjected to gene expression analysis for IL23R, IL17, SGK1, TGFß, RORγ, FOXO1, and RANBP1 by qRT-PCR and immunoblot. A post hoc correlation, the diagnostic performance of the target genes, and multivariable analyses were properly conducted. The main expression markers of the CD4 + Th17+ switch were strongly activated in chronic venous insufficiency and in advanced ulceration. The correlation analysis demonstrated the inter-dependence on Th17's signature modulation. ROC (Receiver Operating Characteristic) analysis defined, for the examined genes, a clinical value as the potential diagnostic markers. Multi-logistic regression studies showed that Th17 markers behave as empirical risk factors for CVD (chronic venous disease) development. Taken together, the present data provide a new hypothesis for the TH17-dependent pathogenesis of CVD, favoring the possibility for the development of new diagnostic, preventive, and therapeutic approaches.

Unmutated IGHV1-69 CLL Clone Displays a Distinct Gene Expression Profile by a Comparative qRT-PCR Assay.

Chronic Lymphocytic Leukemia (CLL) is a heterogeneous disease characterized by variable clinical courses among different patients. This notion was supported by the possible coexistence of two or more independent CLL clones within the same patients, identified by the characterization of the B cell receptor immunoglobulin (BcR IG) idiotypic sequence. By using the antigen-binding site of the BcR IG as bait, the identification and isolation of aggressive and drug-resistance leukemic B-cell clones could allow a deeper biological and molecular investigation. Indeed, by the screening of phage display libraries, we previously selected a peptide binder of the idiotypic region of CLL BCR IGs expressing the unmutated rearrangement IGHV1-69 and used it as a probe to perform a peptide-based cell sorting by flow cytometry in peripheral blood samples from patients with CLL. Since the IGHV1-69 clones persisted during the follow-up time in both patients, we explored the possibility of these clones having acquired an evolutive advantage compared to the other coexisting clones in terms of a higher expression of genes involved in the survival and apoptosis escape processes. To this end, we studied the expression patterns of a panel of genes involved in apoptosis regulation and in NF-kB-dependent pro-survival signals by comparative qRT-PCR assays. According to the results, IGHV1-69 clones showed a higher expression of pro-survival and anti-apoptotic genes as compared to the other CLL clones with different immunogenetic characteristics. Moreover, these IGHV1-69 clones did not carry any characteristic genetic lesions, indicating the relevance of our approach in performing a comprehensive molecular characterization of single tumor clones, as well as for designing new personalized therapeutic approaches for the most aggressive and persistent tumor clones.

A novel phage display based platform for exosome diversity characterization.

We present an innovative approach allowing the identification, isolation, and molecular characterization of disease-related exosomes based on their different antigenic reactivities. The designed strategy could be immediately translated into any disease in which exosomes are involved. The identification of specific markers and their subsequent association with exosome subtypes, together with the possibility to engineer target-guided exosome-like particles, could represent the key for the effective adoption of exosomes in clinical practice.

Clinical validation of a combinatorial PharmAcogeNomic approach in major Depressive disorder: an Observational prospective RAndomized, participant and rater-blinded, controlled trial (PANDORA trial).

BACKGROUND: Major depressive disorder (MDD) is a common, chronic, debilitating mood disorder that causes serious functional impairment and significantly decreased quality of life. Pharmacotherapy represents the first-line treatment option; however, only approximately one third of patients respond to the first treatment because of the ineffectiveness or side effects of antidepressants. Precision medicine in psychiatry might offer clinicians the possibility to tailor treatment according to the best possible evidence of efficacy and tolerability for each subject. In this context, our study aims to carry out a clinical validation of a combinatorial pharmacogenomics (PGx) test in an Italian MDD patient cohort with advocacy license independence. METHODS: Our study is a prospective participant- and rater-blinded, randomized, controlled clinical observational trial enrolling 300 MDD patients who are referred to psychiatric services to receive a new antidepressant due to the failure of their current treatment and/or the onset of adverse effects. Eligible participants are randomized to the TGTG group (Treated with Genetic Test Guide) or TAU group (Treated as Usual). For all subjects, DNA is collected with a buccal brush. The primary outcome is the reduction in depressive symptomatology. The secondary outcomes involve a range of scales that assess MDD symptoms and social functioning outcomes. The assessment is performed at four timepoints: baseline and 4, 8, and 12 weeks. DISCUSSION: This project represents the first randomized controlled clinical trial to investigate whether a non-commercial PGx test improves outcomes in an MDD naturalistic cohort. Moreover, the identification of new genetic variants associated with non-response or side effects will improve the efficacy of the test, leading to further cost-saving. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT04615234. Registered on November 4, 2020.

A Novel Splicing Variant of COL2A1 in a Fetus with Achondrogenesis Type II: Interpretation of Pathogenicity of In-Frame Deletions.

Achondrogenesis type II (ACG2) is a lethal skeletal dysplasia caused by dominant pathogenic variants in COL2A1. Most of the variants found in patients with ACG2 affect the glycine residue included in the Gly-X-Y tripeptide repeat that characterizes the type II collagen helix. In this study, we reported a case of a novel splicing variant of COL2A1 in a fetus with ACG2. An NGS analysis of fetal DNA revealed a heterozygous variant c.1267-2_1269del located in intron 20/exon 21. The variant occurred de novo since it was not detected in DNA from the blood samples of parents. We generated an appropriate minigene construct to study the effect of the variant detected. The minigene expression resulted in the synthesis of a COL2A1 messenger RNA lacking exon 21, which generated a predicted in-frame deleted protein. Usually, in-frame deletion variants of COL2A1 cause a phenotype such as Kniest dysplasia, which is milder than ACG2. Therefore, we propose that the size and position of an in-frame deletion in COL2A1 may be relevant in determining the phenotype of skeletal dysplasia.

Predominant VH1-69 IgBCR Clones Show Higher Expression of CD5 in Heterogeneous Chronic Lymphocytic Leukemia Populations.

The immunoglobulin B cell receptor (IgBCR) expressed by chronic lymphocytic leukemia (CLL) B cells plays a pivotal role in tumorigenesis, supporting neoplastic transformation, survival, and expansion of tumor clones. We demonstrated that in the same patient, two or more CLL clones could coexist, recognized by the expression of different variable regions of the heavy chain of IgBCR, composing the antigen-binding site. In this regard, phage display screening could be considered the easier and most advantageous methodology for the identification of small peptide molecules able to mimic the natural antigen of the tumor IgBCRs. These molecules, properly functionalized, could be used as a probe to specifically identify and isolate single CLL subpopulations, for a deeper analysis in terms of drug resistance, phenotype, and gene expression. Furthermore, CLL cells express another surface membrane receptor, the CD5, which is commonly expressed by normal T cells. Piece of evidence supports a possible contribution of CD5 to the selection and maintenance of autoreactivity in B cells and the constitutive expression of CD5 on CLL cells could induce pro-survival stimuli. In this brief research report, we describe a peptide-based single-cell sorting using as bait the IgBCR of tumor cells; in the next step, we performed a quantitative analysis of CD5 expression by qRT-PCR related to the expressed IgBCR. Our approach could open a new perspective for the identification, isolation, and investigation of all subsets of IgBCR-related CLL clones, with particular attention to the more aggressive clones.

Pathogenic variants in THSD4, encoding the ADAMTS-like 6 protein, predispose to inherited thoracic aortic aneurysm.

PURPOSE: Thoracic aortic aneurysm and dissection (TAAD) is a life-threatening disease with often unrecognized inherited forms. We sought to identify novel pathogenic variants associated with autosomal dominant inheritance of TAAD. METHODS: We analyzed exome sequencing data from 35 French TAAD families and performed next-generation sequencing capture panel of genes in 1114 unrelated TAAD patients. Functional effects of pathogenic variants identified were validated in cell, tissue, and mouse models. RESULTS: We identified five functional variants in THSD4 of which two heterozygous variants lead to a premature termination codon. THSD4 encodes ADAMTSL6 (member of the ADAMTS/L superfamily), a microfibril-associated protein that promotes fibrillin-1 matrix assembly. The THSD4 variants studied lead to haploinsufficiency or impaired assembly of fibrillin-1 microfibrils. Thsd4+/- mice showed progressive dilation of the thoracic aorta. Histologic examination of aortic samples from a patient carrying a THSD4 variant and from Thsd4+/- mice, revealed typical medial degeneration and diffuse disruption of extracellular matrix. CONCLUSION: These findings highlight the role of ADAMTSL6 in aortic physiology and TAAD pathogenesis. They will improve TAAD management and help develop new targeted therapies.

The Emerging Role of SGK1 (Serum- and Glucocorticoid-Regulated Kinase 1) in Major Depressive Disorder: Hypothesis and Mechanisms.

Major depressive disorder (MDD) is a heterogeneous psychiatric disease characterized by persistent low mood, diminished interests, and impaired cognitive and social functions. The multifactorial etiology of MDD is still largely unknown because of the complex genetic and environmental interactions involved. Therefore, no established mechanism can explain all the aspects of the disease. In this light, an extensive research about the pathophysiology of MDD has been carried out. Several pathogenic hypotheses, such as monoamines deficiency and neurobiological alterations in the stress-responsive system, including the hypothalamic-pituitary-adrenal (HPA) axis and the immune system, have been proposed for MDD. Over time, remarkable studies, mainly on preclinical rodent models, linked the serum- and glucocorticoid-regulated kinase 1 (SGK1) to the main features of MDD. SGK1 is a serine/threonine kinase belonging to the AGK Kinase family. SGK1 is ubiquitously expressed, which plays a pivotal role in the hormonal regulation of several ion channels, carriers, pumps, and transcription factors or regulators. SGK1 expression is modulated by cell stress and hormones, including gluco- and mineralocorticoids. Compelling evidence suggests that increased SGK1 expression or function is related to the pathogenic stress hypothesis of major depression. Therefore, the first part of the present review highlights the putative role of SGK1 as a critical mediator in the dysregulation of the HPA axis, observed under chronic stress conditions, and its controversial role in the neuroinflammation as well. The second part depicts the negative regulation exerted by SGK1 in the expression of both the brain-derived neurotrophic factor (BDNF) and the vascular endothelial growth factor (VEGF), resulting in an anti-neurogenic activity. Finally, the review focuses on the antidepressant-like effects of anti-oxidative nutraceuticals in several preclinical model of depression, resulting from the restoration of the physiological expression and/or activity of SGK1, which leads to an increase in neurogenesis. In summary, the purpose of this review is a systematic analysis of literature depicting SGK1 as molecular junction of the complex mechanisms underlying the MDD in an effort to suggest the kinase as a potential biomarker and strategic target in modern molecular antidepressant therapy.

Identification of differentially expressed microRNAs in the skin of experimentally sensitized naturally affected atopic beagles by next-generation sequencing.

Canine atopic dermatitis (AD) is a very common inflammatory skin disease, but limited data are available on the genetic characterization (somatic mutations, microarrays, and genome-wide association study (GWAS)) of skin lesions in affected dogs. microRNAs are good biomarkers in inflammatory and neoplastic diseases in people. The aim of this study was to evaluate microRNA expression in the skin of atopic beagles, before and after exposure to Dermatophagoides farinae. Four atopic and four unrelated age-matched healthy beagle dogs were enrolled. Total RNA was extracted from flash-frozen skin biopsies of healthy and atopic dogs. For the atopic dogs, skin biopsies were taken from non-lesional (day 0) and lesional skin (day 28 of weekly environmental challenge with Dermatophagoides farinae). Small RNA libraries were constructed and sequenced. The microRNA sequences were aligned to CanFam3.1 genome. Differential expressed microRNAs were selected on the basis of fold-change and statistical significance (fold-change ≥ 1.5 and p ≤ 0.05 as thresholds. A total of 277 microRNAs were sequenced. One hundred and twenty-one differentially regulated microRNAs were identified between non-lesional and healthy skin. Among these, two were increased amount and 119 were decreased amount. A total of 45 differentially regulated microRNAs between lesional and healthy skin were identified, 44 were decreased amount and one was increased amount. Finally, only two increased amount microRNAs were present in lesional skin when compared with that of non-lesional skin. This is the first study in which dysregulation of microRNAs has been associated with lesional and non-lesional canine AD. Larger studies are needed to understand the role of microRNA in canine AD.

Expression of Serum Exosomal miRNA 122 and Lipoprotein Levels in Dogs Naturally Infected by Leishmania infantum: A Preliminary Study.

Current knowledge on the role of exosomal microRNA (miRNA) in canine leishmaniasis (CL), with particular regards to the interaction between miR-122 and lipid alterations, is limited. The aim of this study was to isolate/characterize exosomes in canine serum and evaluate the expression of miR-122 in ten healthy and ten leishmaniotic dogs. Serum exosomes were isolated using a polymer-based kit, ExoQuick® and characterized by flow cytometry and transmission electron microscopy, whereas miR-122-5p expression was evaluated by quantitative reverse-transcriptase polymerase chain reaction. A significant decreased expression of exosomal miR-122-5p, decreased serum levels of high-density lipoproteins, and increased serum levels of low-density lipoproteins were seen in leishmaniotic dogs when compared with healthy dogs. These results suggest that hepatic dysfunctions induced by the parasite interfere with lipoprotein status. The decreased expression of exosomal miR122 represents an additional effect of Leishmania infection in dogs as in people.

Review about the multi-target profile of resveratrol and its implication in the SGK1 inhibition.

Resveratrol (trans-3,4',5-trihydroxystilbene) is a polyphenolic natural product with a well-known polypharmacological profile that places it among the multi-target-directed ligands (MTDLs). Given its protective action against a wide number of chronic diseases, in this review, we introduce a general overview about the cardioprotective and antioxidant effects, the antidiabetic, neuroprotective and anti-inflammatory effects of this polyphenol. In the second part of the manuscript, we focused our attention on the anticancer activity of Resveratrol, given the alteration of many different signaling pathways, leading to suppression of tumor cell proliferation in numerous cancer types. Among the several anticancer targets involved in the mechanism of action of Resveratrol, here we introduce experimental and molecular modeling studies performed against the SGK1 protein as a novel anticancer target of Resveratrol. SGK1 inhibitors have been demonstrated to inhibit cell growth of different cancer cells. We demonstrated that resveratrol inhibits SGK1 in vitro and in intact cells, affecting proliferation and survival of HUH7 human hepatoma cells. Our findings demonstrate that resveratrol may function as a SGK1 inhibitor, suggesting possible applications in sodium retention and cancer.

A novel ABCC6 variant causative of pseudoxanthoma elasticum.

Pseudoxanthoma elasticum is an autosomal recessive heritable disorder caused by mutations in ABCC6. We describe two siblings showing typical skin lesions and a clinical diagnosis of pseudoxanthoma elasticum. Genetic analysis of ABCC6 revealed a novel homozygous c.4041G > A variant located in the last position of exon 28 that compromises the splicing donor site, resulting in a shorter messenger RNA. The deletion impairs the nucleotide-binding fold region, which is crucial for ABCC6 function.

In Preclinical Model of Ovarian Cancer, the SGK1 Inhibitor SI113 Counteracts the Development of Paclitaxel Resistance and Restores Drug Sensitivity.

Ovarian cancer is the second most common gynecological malignancy worldwide. Paclitaxel is particularly important in the therapy of ovarian carcinomas, but the treatment efficacy is counteracted by the development of resistance to chemotherapy. The identification of target molecules that can prevent or control the development of chemoresistance might provide important tools for the management of patients affected by ovarian cancer. Serum- and glucocorticoid-regulated kinase 1 (SGK1) appears to be a key determinant of resistance to chemo- and radiotherapy. Specifically, SGK1 affects paclitaxel sensitivity in RKO colon carcinoma cells by modulating the specificity protein 1 (SP1)-dependent expression of Ran-specific GTPase-activating protein (RANBP1), a member of the GTP-binding nuclear protein Ran (RAN) network that is required for the organization and function of the mitotic spindle. SGK1 inhibition might thus be useful for counteracting the development of paclitaxel resistance. Here, we present in vitro data obtained using ovarian carcinoma cell lines that indicate that the SGK1 inhibitor SI113 inhibits cancer cell proliferation, potentiates the effects of paclitaxel-based chemotherapy, counteracts the development of paclitaxel resistance, and restores paclitaxel sensitivity in paclitaxel-resistant A2780 ovarian cancer cells. The results were corroborated by preclinical studies of xenografts generated in nude mice through the implantation of paclitaxel-resistant human ovarian cancer cells. The SGK1 inhibitor SI113 synergizes with paclitaxel in the treatment of xenografted ovarian cancer cells. Taken together, these data suggest that SGK1 inhibition should be investigated in clinical trials for the treatment of paclitaxel-resistant ovarian cancer.

Deregulation of SGK1 in Ulcerative Colitis: A Paradoxical Relationship Between Immune Cells and Colonic Epithelial Cells.

BACKGROUND: Inflammatory bowel disease (IBD) is due to the interaction of genetic and environmental factors that trigger an unbalanced immune response ultimately resulting in the peculiar inflammatory reaction. Experimental models of IBD point to a role of T-cell-derived cytokines (Th17) and to SGK1 as mediator of the Th17 switch. We hypothesize that SGK1, a salt inducible kinase, directs lymphocytic behavior and tissue damage. METHODS: Eleven controls and 32 ulcerative colitis (UC) patients were randomized according to endoscopic Mayo score. Mucosal biopsies from different intestinal tracts were analyzed by immunohistochemistry and quantitative real-time polymerase chain reaction to check the expression of disease markers including SGK1. Peripheral blood mononuclear cells (PBMCs) from patients and controls were analyzed by fluorescence-activated cell sorting. Finally, an in vitro cell model was developed to test the hypothesis. RESULTS: SGK1 mRNA and protein expression in lesional areas of UC patients were lower than in normal peri-lesional areas of the same patients and in normal tissues of healthy controls. SGK1 expression was increased in PBMCs from UC patients, particularly in the CD4+ cell population, enriched in Th17 cells. IL17/IL13 was increased in patients and correlated with SGK1 expression. Genetically engineered Jurkat cells confirmed the effect of SGK1 overexpression on viability of RKO cells. CONCLUSIONS: These observations suggest a pathogenic mechanism whereby SGK1 overexpression in CD4+ T cells induces the secretion of the inflammatory cytokines IL17 and IL13, which downregulate the expression of SGK1 in target tissues. Our data suggest a novel hypothesis in the pathogenesis of UC, integrating colonic epithelial cells and lymphocytes.