An autoregulatory loop controls the expression of the transcription factor NF-Y

The heterotrimeric NF-Y complex is a pioneer factor that binds to CCAAT-genes and regulates their transcription. NF-Y cooperates with multiple transcription factors and co-regulators in order to positively or negatively influence gene transcription. The recruitment of NF-Y to CCAAT box is significantly enriched in cancer-associated gene promoters loci and positively correlates with malignancy. NF-Y subunits, in particular the DNA-binding subunit NF-YA and the histone-fold subunit NF-YC, appear overexpressed in specific types of cancer. Here we demonstrate that NF-Y subunits expression is finely regulated through transcriptional and post-translational mechanisms thus allowing control over basal expression levels. NF-Y negatively regulates the transcription of the genes encoding for its subunits. DNA pull-down/affinity purification assay coupled with Mass Spectrometry identified putative co-regulators, such as Lamin A, involved in NF-YA gene transcription level. We also evidentiate how the stability of the complex is severely affected by the absence of one subunit. Our results identified for the first time one of the mechanisms responsible for NF-Y expression, which may be involved in the aberrant expression and activity observed in tumor cells and other pathological conditions

Potent Anti-Cancer Properties of Phthalimide-Based Curcumin Derivatives on Prostate Tumor Cells

Metastatic castration-resistant prostate cancer is commonly treated with chemotherapy, whose effect is less than satisfactory. This raised the need for novel agents for the treatment of prostate cancer. In the present study, five phthalimide-based curcumin derivatives were synthesized and completely characterized to assess improved stability, pharmacodynamics, and radical scavenging ability. To investigate the potential application in anti-cancer therapy, the anti-proliferative activity of the synthesized molecules was determined on aggressive prostate tumor cells. We demonstrated that the K3F21 derivative has increased potency compared to curcumin, in terms of GI50, anti-proliferative and anti-migrating activities. K3F21 inhibits anchorage-dependent and -independent growth of prostate cancer cells by altering the expression of key genes controlling cell proliferation, such as Cylins D1, B1 and B2, and apoptosis, among which Puma, Noxa, and Bcl-2 family members. Finally, the anti-cancer activity of K3F21 was demonstrated by the analysis of cancer-associated PI3K/AKT, ERK, and p38 signaling pathways

Alternative splicing of NF-YA promotes prostate cancer aggressiveness and represents a new molecular marker for clinical stratification of patients

Approaches based on expression signatures of prostate cancer (PCa) have been proposed to predict patient outcomes and response to treatments. The transcription factor NF-Y participates to the progression from benign epithelium to both localized and metastatic PCa and is associated with aggressive transcriptional profile. The gene encoding for NF-YA, the DNA-binding subunit of NF-Y, produces two alternatively spliced transcripts, NF-YAs and NF-YAl. Bioinformatic analyses pointed at NF-YA splicing as a key transcriptional signature to discriminate between different tumor molecular subtypes. In this study, we aimed to determine the pathophysiological role of NF-YA splice variants in PCa and their association with aggressive subtypes

NF-YA Overexpression in Lung Cancer: LUAD

The trimeric transcription factor (TF) NF-Y regulates the CCAAT box, a DNA element enriched in promoters of genes overexpressed in many types of cancer. The regulatory NF-YA is present in two major isoforms, NF-YAl (“long”) and NF-YAs (“short”). There is growing indication that NF-YA levels are increased in tumors. Here, we report interrogation of RNA-Seq TCGA (The Cancer Genome Atlas)—all 576 samples—and GEO (Gene Expression Ominibus) datasets of lung adenocarcinoma (LUAD). NF-YAs is overexpressed in the three subtypes, proliferative, inflammatory, and TRU (terminal respiratory unit). CCAAT is enriched in promoters of tumor differently expressed genes (DEG) and in the proliferative/inflammatory intersection, matching with KEGG (Kyoto Encyclopedia of Genes and Genomes) terms cell-cycle and signaling. Increasing levels of NF-YAs are observed from low to high CpG island methylator phenotypes (CIMP). We identified 166 genes overexpressed in LUAD cell lines with low NF-YAs/NF-YAl ratios: applying this centroid to TCGA samples faithfully predicted tumors’ isoform ratio. This signature lacks CCAAT in promoters. Finally, progression-free intervals and hazard ratios concurred with the worst prognosis of patients with either a low or high NF-YAs/NF-YAl ratio. In conclusion, global overexpression of NF-YAs is documented in LUAD and is associated with aggressive tumor behavior; however, a similar prognosis is recorded in tumors with high levels of NF-YAl and overexpressed CCAAT-less genes

Switch of NF-YA splice variants in prostate cancer development and progression

The pioneer transcription factor NF-Y is a heterotrimer composed by NF-YA, -YB and -YC subunits: NF-YA is the limiting subunit and harbors the DNA CCAAT-box binding domain. NF-Y is a master transcriptional regulator that ensures proper cell proliferation, controlling cell cycle, DNA replication, apoptosis and metabolism. Recent analyses pointed out that NF-Y binding site is over-represented in promoters of genes overexpressed during the progression from benign epithelium to Prostate Cancer (PC). Moreover, cell cycle regulation genes have emerged as a signature that can discriminate between metastatic and benign prostate tissues. The analysis of TCGA-RNAseq data highlighted a slight but significant increase of NF-YA levels in PC tumor vs normal tissues, particularly in high Gleason score specimens. Since the NF-YA gene encodes for two splice isoforms, NF-YAl (long) and NF-YAs (short), we generated untransformed and cancer prostate cell lines stably over-expressing NF-YA isoforms, to dissect the functional role of NF-YA in PC development and progression. Our data indicate that NF-YAl and NF-YAs could play different activities in cancer-associated processes, such as clonogenic ability, anchorage-independent growth, 3D cell growth, migration and invasion. In particular, in cancer cells NF-YAl improves invasion ability, while NF-YAs seems to enhance the proliferation of tumor spheroids. These results are consistent with increased NF-YAs/NF-YAl splice ratio observed in the progression from normal to malignant prostatectomy samples. Besides, normal prostate cell lines preferentially express the long NF-YA isoform, while an increase in NF-YAs/NF-YAl ratio can be observed in PC cell lines. These results prompt us to speculate that NF-YAl could participate to metastatization, while NF-YAs could have a major role in tumor growth and colonization. Disclosing this dualism could be crucial to better stratify PC patients and identify new specific anti-cancer treatments

Endocytosis of Nanomedicines: The Case of Glycopeptide Engineered PLGA Nanoparticles

The success of nanomedicine as a new strategy for drug delivery and targeting prompted the interest in developing approaches toward basic and clinical neuroscience. Despite enormous advances on brain research, central nervous system (CNS) disorders remain the world’s leading cause of disability, in part due to the inability of the majority of drugs to reach the brain parenchyma. Many attempts to use nanomedicines as CNS drug delivery systems (DDS) were made; among the various non-invasive approaches, nanoparticulate carriers and, particularly, polymeric nanoparticles (NPs) seem to be the most interesting strategies. In particular, the ability of poly-lactide-co-glycolide NPs (PLGA-NPs) specifically engineered with a glycopeptide (g7), conferring to NPs’ ability to cross the blood brain barrier (BBB) in rodents at a concentration of up to 10% of the injected dose, was demonstrated in previous studies using different routes of administrations. Most of the evidence on NP uptake mechanisms reported in the literature about intracellular pathways and processes of cell entry is based on in vitro studies. Therefore, beside the particular attention devoted to increasing the knowledge of the rate of in vivo BBB crossing of nanocarriers, the subsequent exocytosis in the brain compartments, their fate and trafficking in the brain surely represent major topics in this field

PIN1: a putative molecular target to protect skeletal muscle against age-related muscle loss

Aging is associated with a progressive loss in skeletal muscle mass and strength, known as sarcopenia. Sarcopenia results in a decrease in mobility and an increased risk of developing chronic metabolic disease, thus it represents a major socio-economical problem. Age-related muscle loss cannot be consistently prevented by physical therapy and a pharmacologic therapy does not exist, probably because the molecular basis of this condition is still largely unknown. Many factors such as mitochondrial dysfunction, oxidative stress, inflammation, changes in the innervation of muscle fibers probably play an important role in age-related muscle decline. PIN1 is a widely expressed Peptydyl Prolyl cis/trans isomerase, involved in post-phosphorylation control of the function of multiple target proteins. Many evidences indicate that PIN1 controls signaling pathways involved in skeletal muscle wasting. Our results indicate that skeletal muscle of Pin1 KO mice is protected against muscle loss and weakness during aging. At the molecular level, we found 1) an increased expression of Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α), a transcription factor that promotes mitochondrial biogenesis, in skeletal muscle of Pin1 KO mice. Coherently with their resistance to muscle loss, we also found 2) an increase in the expression of the protein synthetic signaling proteins p70 ribosomal S6 kinase (S6K) and of its phosphorylated form in aged skeletal muscle of Pin1 KO mice compared to the wild type controls, suggesting that in these mice protein synthesis is maintained efficient. We also found 3) a significant decrease of Myostatin levels in skeletal muscle of aged Pin1 KO mice. It is well known that Myostatin is upregulated sarcopenia, it activates SMAD2/3 signaling and contributes to protein degradation and muscle atrophy. The transcriptional effects of Pin1 depletion on PGC1α and S6K genes must be mediated by a transcription factor. A putative candidate to mediate these effects is represented by the transcription factor Myocyte Enhancer Factor 2C (MEF2C), a known PIN1 target. In skeletal muscle cells a specific splice variant of MEF2C, MEF2C α1, activates the increase of skeletal muscle mass by activating the expression of IGF1 and S6K. These activities are repressed by its phosphorylation, that renders it a target for the inhibitory effect of PIN1 on its protein stability and activity. Coherently with these premises, we found 4) a decrease of MEF2C protein phosphorylation levels in aged KO mice compared to the control animals. This might at least partially contribute to the increased expression of PGC1α and of S6K. Our results indicate that PIN1 could represent a valuable pharmacological target to counteract age-related muscle loss, simultaneously modulating multiple targets in a concerted way