HNF4α, SP1 and c-myc are master regulators of CNS autoimmunity.

Hepatocyte nuclear factor 4 α (HNF4α), a transcription factor (TF) essential for embryonic development, has been recently shown to regulate the expression of inflammatory genes. To characterize HNF4a function in immunity, we measured the effect of HNF4α antagonists on immune cell responses in vitro and in vivo. HNF4α blockade reduced immune activation in vitro and disease severity in the experimental model of multiple sclerosis (MS). Network biology studies of human immune transcriptomes unraveled HNF4α together with SP1 and c-myc as master TF regulating differential expression at all MS stages. TF expression was boosted by immune cell activation, regulated by environmental MS risk factors and higher in MS immune cells compared to controls. Administration of compounds targeting TF expression or function demonstrated non-synergic, interdependent transcriptional control of CNS autoimmunity in vitro and in vivo. Collectively, we identified a coregulatory transcriptional network sustaining neuroinflammation and representing an attractive therapeutic target for MS and other inflammatory disorders.

Second-line therapy in pancreatic ductal adenocarcinoma (PDAC) patients with germline BRCA1-2 pathogenic variants (gBRCA1-2pv).

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) harbouring germline BRCA1-2 pathogenic variants (gBRCA1-2pv) is a distinct nosological entity. Information on second-line therapy (2LT) outcome in this setting is lacking. METHODS: Data of gBRCA1-2pv metastatic PDAC patients treated with chemotherapy were collected. A primary analysis of 2LT RECIST response, median progression-free survival (mPFS2) and overall survival (mOS2), was performed. A secondary analysis addressed the impact of timing of platinum introduction on the outcome of patients receiving at least a first-line combination chemotherapy (1LT). RESULTS: Eighty-four gBRCA1-2pv metastatic PDAC patients were enrolled. The primary analysis, including 43 patients, highlighted a significant improvement of mPFS2 and a doubled response rate, in the platinum-based 2LT subgroup as compared to the platinum-free (8.8 versus 3.7 months, p = 0.013). Seventy-seven patients were included in the secondary analysis. Median PFS1 of 3- and 4-drug platinum-based 1LT significantly outperformed both platinum-free combinations and platinum-based doublets (11.4 versus 6.4 versus 7.9 months, p = 0.01). Albeit still immature, data on mOS paralleled those on mPFS. CONCLUSIONS: This study highlighted the beneficial role of platinum agents in gBRCA1-2pv PDAC patients also in second-line treatment setting. However, our data suggest that early use of 3- and 4-drug platinum-based chemotherapy combinations provides a survival outcome advantage.

Epidemiology and geographic distribution of BRCA1-2 and DNA Damage response genes pathogenic variants in pancreatic ductal adenocarcinoma patients.

Incidence of pancreatic ductal adenocarcinoma (PDAC) is increasing over the last years, while patients prognosis remains grim. Recently germline BRCA1 and 2 pathogenic variants (gBRCA1-2) have emerged as risk factors for PDAC development, as well as new predictors of response to specific therapeutic interventions. However, data on gBRCA1-2 incidence in PDAC are currently sparse and limited to selected categories of patients, as for positive cancer history cases, for patients affected only by early or late stages of disease and mainly from the North-American population, thus generating incomplete information about the gBRCA1/2 epidemiology. In Western Countries gBRCA1-2 incidence ranges between 4.5% and 8% in unselected PDAC patients, raising up to 26% in cohorts with positive family cancer history. To date a limited number of studies from Asian countries are available, reporting a 10% as highest incidence of gBRCA1-2 in familiar PDAC, claiming at least in part a role of ethnicity in the gBRCA1-2 incidence and in other genes potentially implicated in the therapeutic decisions. Drawing a better defined map for the incidence of gBRCA1-2 and other germline pathogenic variants of DNA Damage Response genes (gDDR) might help assessing the therapeutic strategies for mutated patients according to the geographic areas. These informations may enhance the chance to predict efficacy and toxicity of selected chemotherapy regimens, fostering the development and implementation of the pharmaco-ethnicity knowledge in the routine-clinical practice, and increasing the awareness of the potential incorrect generalization of trials results outside of the geographic area where they are conducted.

Treatment opportunities and future perspectives for pancreatic cancer patients with germline BRCA1-2 pathogenic variants.

Personalized treatments and predictive biomarkers of pancreatic cancer (PDAC) are still lacking. Recently germline mutations in BRCA 1 and 2 genes, leading to homologous repair deficiency, have emerged as new targets for more specific and effective therapies, exploiting the increased susceptibility to platinum salts and PARP inhibitors. In addition to BRCA, pathogenic variants in PALB2 and in other genes involved in the DNA damage response pathway (DDR) represent potential targets, as well as their respective somatic alterations. This enlarged molecularly-selected population sharing the BRCAness phenotype, is expected to show a higher sensibility to a number of DNA damaging agents and DDR inhibitors. However, the possibility of new therapeutic opportunities for DDR defective PDAC patients has to face the lack of solid evidence about the proper type and timing of targeted-treatments, the potential combination strategies and most importantly, the lack of informations on the functional impact of each specific pathogenic variant on the DDR pathway. This review summarizes the current and near-future options for the clinical management of PDAC patients harboring a DDR deficiency, analyzing the state of the art of the indications of platinum salts and other cytotoxic agents in the advanced and early stage PDAC, the development of PARP inhibitors and the rational for new combinations with immunotherapy and cycle checkpoint inhibitors, as well as the strategy to overcome the development of resistance over treatments.

Exploring chemotherapy holiday and drugs re-challenge in advanced pancreatic cancer patients.

PURPOSE: We aimed to explore the role of drugs re-challenge at the disease progression after a chemotherapy-free interval for pancreatic adenocarcinoma (PDAC) patients. METHODS: We retrospectively analyzed the outcome of re-treatments at the progression in two cohorts of advanced PDAC patients who had disease control (DC) and a treatment holiday ≥ 3 months after upfront chemotherapy. RESULTS: Between 2015 and 2019, 66 advanced PDAC patients (cohort A) had DC with nab-paclitaxel-based chemotherapy (i.e. AG or PAXG = cisplatin, nab-paclitaxel, gemcitabine, capecitabine). At the time of progressive disease (PD), 34 patients were re-treated with AG (A1) and 32 were treated with other regimens (A2). The median (m) duration of chemotherapy holiday was 6.1 and 5.9 months in A1 and A2, respectively. Partial response (PR) and stable disease (SD) were found in 14 (41%) and 12 (35%) of patients in A1 and in 8 (25%) and 6 (19%) patients in A2. CA19-9 response was recorded in 23/33 evaluable patients (70%) in A1 and in 5/20 (25%) in A2. mPFS2 and mOS2, defined as the time between the second line of treatment start and the disease progression or death, were 4.8 and 12.2 months in A1 and 3.9 and 8.4 months in A2, respectively. Similarly, between 2006 and 2013, 64 patients (cohort B) had DC with upfront PEFG/PEXG/PDXG regimens (epirubicin or docetaxel, cisplatin, gemcitabine, capecitabine or 5-fluorouracil) and were re-treated at PD with either 4-drug (B1; N = 30) or other regimens (B2; N = 34), yielding a mOS2 of 10.9 and 7.2 months, respectively. CONCLUSION: Our data endorse the strategy of resuming prior drugs after a chemotherapy holiday ≥ 3 months in advanced PDAC patients who achieved a  durable disease control after upfront treatments.

Multidrug regimens for treatment of older patients with metastatic pancreatic cancer.

BACKGROUND AND AIMS: Older patients with metastatic pancreatic adenocarcinoma (MPDAC) are under-represented in clinical trials. METHODS: Our single-center, retrospective study enrolled MPDAC patients ≥ 70 treated with chemotherapy RESULTS: 105 patients were divided in groups based on the received treatments: 44 gemcitabine or capecitabine monotherapy (A), 34 nabpaclitaxel-gemcitabine (B) 27 4-drugs combinations (gemcitabine, cisplatin, capecitabine plus either nab-paclitaxel or epirubicin or docetaxel) (C). Group A: median age was 78 (70-87) and Karnofsky performance status (KPS) ≥80 was found in 84% of patients; Group B: median age 77 (71-84) and KPS ≥ 80 in 88% of patients; Group C: median age 73 (70-78) and KPS ≥ 80 in 93% of patients. Median OS was 7.9, 11.7 and 14.2 months in group A, B and C respectively; 1 and 2-year OS were 27% and 8% in group A; 44% and 5% in group B; 52% and 22% in group C. When lung metastatic only patients were excluded, patients <75 and ≥ 75 had similar OS in group A (6.4 vs 5.6 months) and in group B (12.3 vs 11.1 months). In group B grade 3 thrombocytopenia, fatigue and peripheral neuropathy were more frequent in patients ≥ 75. CONCLUSIONS: In older patients, combination chemotherapy shows acceptable feasibility and promising efficacy.

MECP2 mutations affect ciliogenesis: a novel perspective for Rett syndrome and related disorders.

Mutations in MECP2 cause several neurological disorders of which Rett syndrome (RTT) represents the best-defined condition. Although mainly working as a transcriptional repressor, MeCP2 is a multifunctional protein revealing several activities, the involvement of which in RTT remains obscure. Besides being mainly localized in the nucleus, MeCP2 associates with the centrosome, an organelle from which primary cilia originate. Primary cilia function as "sensory antennae" protruding from most cells, and a link between primary cilia and mental illness has recently been reported. We herein demonstrate that MeCP2 deficiency affects ciliogenesis in cultured cells, including neurons and RTT fibroblasts, and in the mouse brain. Consequently, the cilium-related Sonic Hedgehog pathway, which is essential for brain development and functioning, is impaired. Microtubule instability participates in these phenotypes that can be rescued by HDAC6 inhibition together with the recovery of RTT-related neuronal defects. Our data indicate defects of primary cilium as a novel pathogenic mechanism that by contributing to the clinical features of RTT might impact on proper cerebellum/brain development and functioning, thus providing a novel therapeutic target.

Role of human forkhead box P3 in early thymic maturation and peripheral T-cell homeostasis.

BACKGROUND: Forkhead box P3 (FOXP3) is a key transcription factor in regulatory T (Treg) cell function. FOXP3 gene mutations cause immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome, a fatal autoimmune syndrome. FOXP3 has also been proposed to act in effector T (Teff) cells, but to date, this role has not been confirmed. OBJECTIVE: We sought to evaluate the effect of reduced FOXP3 expression on human Treg and Teff cell development and correlate it with IPEX syndrome immune pathology. METHODS: We developed a model of humanized mice (huMice) in which the human hematopoietic system is stably knocked down or knocked out for the FOXP3 gene (knockdown [KD]/knockout [KO] huMice). RESULTS: Because FOXP3-KD/KO was not 100% effective, residual FOXP3 expression in hematopoietic stem progenitor cells was sufficient to give rise to Treg cells with normal expression of FOXP3. However, numerous defects appeared in the Teff cell compartment. Compared with control mice, FOXP3-KD/KO huMice showed altered thymocyte differentiation, with KD/KO thymocytes displaying significantly reduced T-cell receptor (TCR) signaling strength and increased TCR repertoire diversity. Peripheral KD/KO Teff cells were expanded and showed signs of homeostatic proliferation, such as a significantly contracted TCR repertoire, a severely reduced naive compartment, decreased telomeric repeat-binding factor 2 expression, and a skew toward a TH2 profile, resembling an aged immune system. Consistent with results in FOXP3-KD/KO huMice, analysis of patients with IPEX syndrome provided evidence of defects in the Teff cell compartment at both the thymic and peripheral levels. CONCLUSIONS: These findings support an intrinsic role for human FOXP3 in controlling thymocyte maturation and peripheral expansion of Teff cells and reveal a previously undescribed pathogenic mechanism through an altered Teff cell compartment in patients with IPEX syndrome.

The MMP-1/PAR-1 Axis Enhances Proliferation and Neuronal Differentiation of Adult Hippocampal Neural Progenitor Cells.

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases that play a role in varied forms of developmental and postnatal neuroplasticity. MMP substrates include protease-activated receptor-1 (PAR-1), a G-protein coupled receptor expressed in hippocampus. We examined proliferation and differentiation of adult neural progenitor cells (aNPCs) from hippocampi of mice that overexpress the potent PAR-1 agonist MMP-1. We found that, as compared to aNPCs from littermate controls, MMP-1 tg aNPCs display enhanced proliferation. Under differentiating conditions, these cells give rise to a higher percentage of MAP-2(+) neurons and a reduced number of oligodendrocyte precursors, and no change in the number of astrocytes. The fact that these results are MMP and PAR-1 dependent is supported by studies with distinct antagonists. Moreover, JSH-23, an inhibitor of NF-κB p65 nuclear translocation, counteracted both the proliferation and differentiation changes seen in MMP-1 tg-derived NPCs. In complementary studies, we found that the percentage of Sox2(+) undifferentiated progenitor cells is increased in hippocampi of MMP-1 tg animals, compared to wt mice. Together, these results add to a growing body of data suggesting that MMPs are effectors of hippocampal neuroplasticity in the adult CNS and that the MMP-1/PAR-1 axis may play a role in neurogenesis following physiological and/or pathological stimuli.

Upregulation of mGlu2 receptors via NF-κB p65 acetylation is involved in the Proneurogenic and antidepressant effects of acetyl-L-carnitine.

Acetyl-L-carnitine (ALC) is a naturally occurring molecule with an important role in cellular bioenergetics and as donor of acetyl groups to proteins, including NF-κB p65. In humans, exogenously administered ALC has been shown to be effective in mood disturbances, with a good tolerability profile. No current information is available on the antidepressant effect of ALC in animal models of depression and on the putative mechanism involved in such effect. Here we report that ALC is a proneurogenic molecule, whose effect on neuronal differentiation of adult hippocampal neural progenitors is independent of its neuroprotective activity. The in vitro proneurogenic effects of ALC appear to be mediated by activation of the NF-κB pathway, and in particular by p65 acetylation, and subsequent NF-κB-mediated upregulation of metabotropic glutamate receptor 2 (mGlu2) expression. When tested in vivo, chronic ALC treatment could revert depressive-like behavior caused by unpredictable chronic mild stress, a rodent model of depression with high face validity and predictivity, and its behavioral effect correlated with upregulated expression of mGlu2 receptor in hippocampi of stressed mice. Moreover, chronic, but not acute or subchronic, drug treatment significantly increased adult born neurons in hippocampi of stressed and unstressed mice. We now propose that this mechanism could be potentially involved in the antidepressant effect of ALC in humans. These results are potentially relevant from a clinical perspective, as for its high tolerability profile ALC may be ideally employed in patient subpopulations who are sensitive to the side effects associated with classical antidepressants.

α2δ ligands act as positive modulators of adult hippocampal neurogenesis and prevent depression-like behavior induced by chronic restraint stress.

Although the role of adult hippocampal neurogenesis remains to be fully elucidated, several studies suggested that the process is involved in cognitive and emotional functions and is deregulated in various neuropsychiatric disorders, including major depression. Several psychoactive drugs, including antidepressants, can modulate adult neurogenesis. Here we show for the first time that the α2δ ligands gabapentin [1-(aminomethyl)cyclohexaneacetic acid] and pregabalin (PGB) [(S)-(+)-3-isobutyl-GABA or (S)-3-(aminomethyl)-5-methylhexanoic acid] can produce concentration-dependent increases in the numbers of newborn mature and immature neurons generated in vitro from adult hippocampal neural progenitor cells and, in parallel, a decrease in the number of undifferentiated precursor cells. These effects were confirmed in vivo, because significantly increased numbers of adult cell-generated neurons were observed in the hippocampal region of mice receiving prolonged treatment with PGB (10 mg/kg i.p. for 21 days), compared with vehicle-treated mice. We demonstrated that PGB administration prevented the appearance of depression-like behaviors induced by chronic restraint stress and, in parallel, promoted hippocampal neurogenesis in adult stressed mice. Finally, we provided data suggesting involvement of the α2δ1 subunit and the nuclear factor-κB signaling pathway in drug-mediated proneurogenic effects. The new pharmacological activities of α2δ ligands may help explain their therapeutic activity as supplemental therapy for major depression and depressive symptoms in post-traumatic stress disorder and generalized anxiety disorders. These data contribute to the identification of novel molecular pathways that may represent potential targets for pharmacological modulation in depression.