Cancer progression is closely linked to the enhanced uptake of extracellular amino acids, mediated by specific transporters that support biosynthesis, metabolic activity, and energy production through the tricarboxylic acid cycle. By increasing the expression of these transporters, tumor cells secure a continuous amino acid supply that sustains the proliferation, metabolic balance, and activation of major signaling pathways. While most studies have emphasized post-translational control of amino acid transporters, such as phosphorylation, ubiquitination, glycosylation, and palmitoylation, emerging evidence highlights regulatory crosstalk between these transporters and other membrane proteins, including G protein-coupled receptors and receptor tyrosine kinases. This review summarizes the current literature on the receptor-mediated mechanisms governing amino acid uptake and explores how interactions among families of membrane proteins contribute to the regulation of transporter activity.
Adipose tissue fibrosis is associated with metabolic alterations in patients with obesity and involves three major collagen types: fibrillar collagens I and III and non-fibrillar collagen VI. In this study, fibrosis was found to be significantly increased only in visceral adipose tissue in patients with obesity (4.7% vs. 2.5% in controls, p < 0.001), whereas no significant difference was observed in subcutaneous adipose tissue. Transmission electron microscopy and high-resolution scanning electron microscopy suggested that hypertrophic adipocytes may contribute to the production of fibrillar collagens I and III. In vitro data were consistent with this interpretation. Expression of the COL6 gene, which encodes the non-fibrillar collagen VI, was reduced in adipose tissue from obese patients. Notably, patients carrying mutations in COL6 genes displayed increased fibrosis even in subcutaneous fat, approximately 6.5-fold higher than controls in the patient with the severe form (Ullrich) and 2.8-fold higher in two patients with the milder form (Bethlem). Approximately 15% of adipocytes in obese tissue appeared stressed or dead (perilipin-1 negative), and the associated infiltrating macrophages exhibited increased expression of CD38, an ectoenzyme implicated in systemic fibrosis. Correlations with gene expression also indicated the importance of myofibroblasts and the extracellular-matrix peptidase D. Taken together, our data suggest that obese adipocytes may contribute to fibrillar collagen production and identify collagen VI and CD38 as potential molecular contributors, consistent with the concept that adipose tissue fibrosis in humans has a multifactorial origin.
Fat fibrosis correlates to metabolic consequences in patients with obesity, and is due to three types of collagen: I and III (fibrillar) and VI (non-fibrillar). In this sudy the extent of fibrosis in obese patients (n 50) was significant only in visceral parenchymal fat (4.7% vs 2.5% in controls (n 15) P<0.0001) and not in subcutaneous fat. Electron microscopy, in vivo and in vitro data, suggested that obese adipocytes are responsible for fibrillar collagen (I and III) production. COL6 (gene producing the non fibrillar form) resulted less expressed. In line, patients with COL6 mutations, showed increased fibrotic tissue even in subcutaneous fat: about 6.5 times vs controls in the patient with the severe form (Ullrich) and 2.8 times in two patients with the milder form (Bethlem). Approximately 15% of obese adipocytes were dead (perilipin1 negative), and consequent infiltrating macrophages showed hyperexpression of CD38, an ectoenzyme implicated in systemic fibrosis. Correlations with gene expression confirmed the importance also of myofibroblasts and the extracellular matrix peptidase D. All together our data support a role for obese adipocytes in the fibrillar collagen production and evidentiate collagen VI and CD38 as new molecular determinants, reinforcing the idea of a multi-factorial origin of fat fibrosis. ### Competing Interest Statement The authors have declared no competing interest. ITALIAN PRIN, 2017L8Z2 University of Catania, https://ror.org/03a64bh57, 2020-2022
Metastatic colorectal cancer (mCRC) is a severe condition with high rates of illness and death. Current treatments are limited and not always effective because the cancer responds differently to drugs in different patients. This research aims to use artificial intelligence (AI) to improve treatment by predicting which therapies will work best for individual patients. By analyzing large sets of patient data and using machine learning, we hope to create a model that can identify which patients will respond to chemotherapy, either alone or combined with other targeted treatments. The study will involve dividing patients into training and validation sets to develop and test the models, avoiding overfitting. Various machine learning algorithms, like random survival forest and neural networks, will be integrated to develop a highly accurate and stable predictive model. The model’s performance will be evaluated using statistical measures such as sensitivity, specificity, and the area under the curve (AUC). The aim is to personalize treatments, improve patient outcomes, reduce healthcare costs, and make the treatment process more efficient. If successful, this research could significantly impact the medical community by providing a new tool for better managing and treating mCRC, leading to more personalized and effective cancer care. In addition, we examine the applicability of learning methods to biomarker discovery and therapy prediction by considering recent narrative publications.
Chromosomal instability is a hallmark of colorectal carcinogenesis and produces an accumulation of different forms of aneuploidies or broad copy number aberrations. Colorectal cancer is characterized by gain-type broad copy number aberrations, specifically in Chr20, Chr8q, Chr13 and Chr7, but their roles and mechanisms in cancer progression are not fully understood. It has been suggested that broad copy number gains might contribute to tumor development through the so-called caricature transcriptomic effect. We intend to investigate the impact of broad copy number gains on long non-coding RNAs’ expression in colorectal cancer, given their well-known role in oncogenesis. The influence of such chromosomal aberrations on lncRNAs’ transcriptome profile was investigated by SNP and transcriptome arrays in our series of colorectal cancer samples and cell lines. The correlation between aneuploidies and transcriptomic profiles led us to obtain a class of Over-UpT lncRNAs, which are transcripts upregulated in CRC and further overexpressed in colon tumors bearing specific chromosomal aberrations. The identified lncRNAs can contribute to a wide interaction network to establish the cancer driving effect of gain-type aneuploidies.
Cancer cells exhibit high levels of oxidative stress and consequently require a high amount of cysteine for glutathione synthesis. Solute Carrier Family 7 Member 11 (SLC7A11), or xCT, mediates the cellular uptake of cystine in exchange for intracellular glutamate; imported extracellular cystine is reduced to cysteine in the cytosol through a NADPH-consuming reduction reaction. SLC7A11/xCT expression is under the control of stress-inducing conditions and of several transcription factors, such as NRF2 and ATF4. Formyl-peptide receptor 2 (FPR2) belongs to the FPR family, which transduces chemotactic signals mediating either inflammatory or anti-inflammatory responses according to the nature of its ligands and/or FPR2 binding with other FPR isoforms. The repertoire of FPR2 agonists with anti-inflammatory activities comprises WKYMVm peptide and Annexin A1 (ANXA1), and the downstream effects of the intracellular signaling cascades triggered by FPR2 include NADPH oxidase (NOX)-dependent generation of reactive oxygen species. Herein, we demonstrate that stimulation of CaLu-6 cells with either WKYMVm or ANXA1: (i) induces the redox-regulated activation of SLC7A11/xCT; (ii) promotes the synthesis of glutathione; (iii) prevents lipid peroxidation; and (iv) favors NRF2 nuclear translocation and activation. In conclusion, our overall results demonstrate that FPR2 agonists and NOX modulate SLC7A11/xCT expression and activity, thereby identifying a novel regulative pathway of the cystine/glutamate antiport that represents a new potential therapeutical target for the treatment of human cancers.
This study describes two siblings from consanguineous parents who exhibit intellectual disability, microcephaly, photosensitivity, bilateral sensorineural hearing loss, numerous freckles, and other clinical features that suggest a potential disruption of the nucleotide excision repair (NER) pathway. Whole exome sequencing (WES) identified a novel homozygous missense variant in the ERCC4 gene, which was predicted to be pathogenic. However, a subsequent peculiar audiometric finding prompted further investigation, revealing a homozygous deletion in the OTOA gene linked to neurosensorial hearing loss. Both variants were located within a run of homozygosity (ROH) on chromosome 16p13.12-p12.2, implicating a complex genetic basis for the observed phenotype. While this study reports a potentially novel ERCC4 variant, it underscores the importance of comprehensive analysis and deep phenotyping in WES data to improve diagnostic accuracy. Our findings advocate for an expanded approach in WES analysis, ensuring more precise diagnoses and improved genetic counseling, particularly when specialized tests for structural variant analysis are unavailable.
Multi-layer Complex networks are commonly used for modeling and analysing biological entities. This paper presents the advantage of using COMBO (Combining Multi Bio Omics) to suggest a new role of the chromosomal aberration as a cancer driver factor. Exploiting the heterogeneous multi-layer networks, COMBO integrates gene expression and DNA-methylation data in order to identify complex bilateral relationships between transcriptome and epigenome. We evaluated the multi-layer networks generated by COMBO on different TCGA cancer datasets (COAD, BLCA, BRCA, CESC, STAD) focusing on the effect of a specific chromosomal numerical aberration, broad gain in chromosome 20, on different cancer histotypes. In addition, the effect of chromosome 8q amplification was tested in the same TCGA cancer dataset. The results demonstrate the ability of COMBO to identify the chromosome 20 amplification cancer driver force in the different TCGA Pan Cancer project datasets.
Cyclodextrin dimers have been investigated as potential nanocapsules of biomolecules. The presence of two cavities can improve the stability of inclusion complexes, working as a hydrophilic sandwich of poorly water-soluble species. Here, we designed new β- and γ-cyclodextrin dimers functionalized with biotin as a targeting unit and tested the new bioconjugates as doxorubicin delivery systems in cancer cells. Biotin can recognize the Sodium-dependent Multivitamin Transporter (SMVT) receptor, encoded by the Solute Carrier Family 5 Member 6 (SLC5A6) gene and improve the uptake of drugs. We evaluated the expression of the SLC5A6 transcript in human cell lines to select the best cell model (MCF-7) for the in vitro studies. Furthermore, in the cell lines, we investigated the transcript levels of genes correlated to biotin cell availability, Holocarboxylase Synthetase (or HCS encoded by HLCS gene) and Biotinidase (encoded by BTD gene) enzymes. Moreover, the expression of ATP Binding Cassette Subfamily G Member 2 transporter (encoded by ABCG2 gene), which may play a role in doxorubicin resistance, has been investigated. The antiproliferative activity of the doxorubicin complexes with the dimers has been determined to study the effect of the biotin moiety on the cytotoxicity in MCF-7 cancer cells.
Astrocytic networks and gap junctional communication mediated by connexins (Cxs) have been repeatedly implicated in seizures, epileptogenesis, and epilepsy. However, the effect of seizures on Cx expression is controversial. The present study focused on the response of Cxs to status epilepticus (SE), which is in turn an epileptogenic insult. The expression of neuronal Cx36 and astrocytic Cx30 and Cx43 mRNAs was investigated in the brain of rats in the first day after pilocarpine-induced SE. In situ hybridization revealed a progressive decrease in Cx43 and Cx30 mRNA levels, significantly marked 24 h after SE onset in neocortical areas and the hippocampus, and in most thalamic domains, whereas Cx36 mRNA did not exhibit obvious changes. Regional evaluation with quantitative real-time-RT-PCR confirmed Cx43 and Cx30 mRNA downregulation 24 h after SE, when ongoing neuronal cell death was found in the same brain regions. Immunolabeling showed at the same time point marked a decrease in Cx43, microglia activation, and interleukin-1β induction in some microglial cells. The data showed a transient downregulation of astroglial Cxs in the cortical and thalamic areas in which SE triggers neurodegenerative events in concomitance with microglia activation and cytokine expression. This could potentially represent a protective response of neuroglial networks to SE-induced acute damage.
Multi-layer Complex networks are commonly used for modeling and analysing biological entities. This paper presents a new computational framework called COMBO (Combining Multi Bio Omics) for generating and analyzing heterogeneous multi-layer networks. Our model uses gene expression and DNA-methylation data. The power of COMBO relies on its ability to join different omics to study the complex interplay between various components in the disease. We tested the reliability and versatility ofCOMBOon colon and lung adenocarcinoma cancer data obtained from the TCGA database.
Protease temporary inhibitors are true substrates that bind the catalytic site with high affinity but are slowly degraded, thus acting as inhibitor for a defined time window. Serine peptidase inhibitor Kazal type (SPINK) family is endowed with such functional property whose physiological meaning is poorly explored. High expression of SPINK2 in some hematopoietic malignancies prompted us to investigate its role in adult human bone marrow. We report here the physiological expression of SPINK2 in hematopoietic stem and progenitor cells (HSPCs) and mobilized cluster differentiation 34 (CD34)+ cells. We determined the SPINK2 degradation constant and derived a mathematical relationship predicting the zone of inhibited target protease activity surrounding the SPINK2-secreting HSPCs. Analysis of putative target proteases for SPINK2 revealed the expression of PRSS2 and PRSS57 in HSPCs. Our combined results suggest that SPINK2 and its target serine proteases might play a role in the intercellular communication within the hematopoietic stem cell niche.
Cancer initiation, growth, and progression are sustained by multiple types of genetic alterations, ranging in size from single point mutations, focal genomic errors to broad chromosomal copy number alterations, gains, and losses [...].
Genomic instability is a hallmark of cancer. Oncogenes may trigger the generation of genomic damage through alterations of the dynamics of DNA replication, transcription and DNA damage response. However, despite their potential importance in cancer development, the molecular mechanisms that underlie oncogene-induced genomic damage are still poorly understood.
Confocal fluorescence microscopy is a well-established imaging technique capable of generating thin optical sections of biological specimens. Optical sectioning in confocal microscopy is mainly determined by the size of the pinhole, a small aperture placed in front of a point detector. In principle, imaging with a closed pinhole provides the highest degree of optical sectioning. In practice, the dramatic reduction of signal-to-noise ratio (SNR) at smaller pinhole sizes makes challenging the use of pinhole sizes significantly smaller than 1 Airy Unit (AU). Here, we introduce a simple method to "virtually" perform confocal imaging at smaller pinhole sizes without the dramatic reduction of SNR. The method is based on the sequential acquisition of multiple confocal images acquired at different pinhole aperture sizes and image processing based on a phasor analysis. The implementation is conceptually similar to separation of photons by lifetime tuning (SPLIT), a technique that exploits the phasor analysis to achieve super-resolution, and for this reason we call this method SPLIT-pinhole (SPLIT-PIN). We show with simulated data that the SPLIT-PIN image can provide improved optical sectioning (i.e., virtually smaller pinhole size) but better SNR with respect to an image obtained with closed pinhole. For instance, two images acquired at 2 and 1 AU can be combined to obtain a SPLIT-PIN image with a virtual pinhole size of 0.2 AU but with better SNR. As an example of application to biological imaging, we show that SPLIT-PIN improves confocal imaging of the apical membrane in an in vitro model of the intestinal epithelium.
The development of novel target therapies based on the use of RNA interference (RNAi) and antisense oligonucleotides (ASOs) is growing in an exponential way, challenging the chance for the treatment of the genetic diseases and cancer by hitting selectively targeted RNA in a sequence-dependent manner. Multiple opportunities are taking shape, able to remove defective protein by silencing RNA (e.g., Inclisiran targets mRNA of protein PCSK9, permitting a longer half-life of LDL receptors in heterozygous familial hypercholesteremia), by arresting mRNA translation (i.e., Fomivirsen that binds to UL123-RNA and blocks the translation into IE2 protein in CMV-retinitis), or by reactivating modified functional protein (e.g., Eteplirsen able to restore a functional shorter dystrophin by skipping the exon 51 in Duchenne muscular dystrophy) or a not very functional protein. In this last case, the use of ASOs permits modifying the expression of specific proteins by modulating splicing of specific pre-RNAs (e.g., Nusinersen acts on the splicing of exon 7 in SMN2 mRNA normally not expressed; it is used for spinal muscular atrophy) or by downregulation of transcript levels (e.g., Inotersen acts on the transthryretin mRNA to reduce its expression; it is prescribed for the treatment of hereditary transthyretin amyloidosis) in order to restore the biochemical/physiological condition and ameliorate quality of life. In the era of precision medicine, recently, an experimental splice-modulating antisense oligonucleotide, Milasen, was designed and used to treat an 8-year-old girl affected by a rare, fatal, progressive form of neurodegenerative disease leading to death during adolescence. In this review, we summarize the main transcriptional therapeutic drugs approved to date for the treatment of genetic diseases by principal regulatory government agencies and recent clinical trials aimed at the treatment of cancer. Their mechanism of action, chemical structure, administration, and biomedical performance are predominantly discussed.
Conventional chemotherapy for acute myeloid leukemia regimens generally encompass an intensive induction phase, in order to achieve a morphological remission in terms of bone marrow blasts (<5%). The majority of cases are classified as Primary Induction Response (PIR); unfortunately, 15% of children do not achieve remission and are defined Primary Induction Failure (PIF). This study aims to characterize the gene expression profile of PIF in children with Acute Myeloid Leukemia (AML), in order to detect molecular pathways dysfunctions and identify potential biomarkers. Given that NUP98-rearrangements are enriched in PIF-AML patients, we investigated the association of NUP98-driven genes in primary chemoresistance. Therefore, 85 expression arrays, deposited on GEO database, and 358 RNAseq AML samples, from TARGET program, were analyzed for "Differentially Expressed Genes" (DEGs) between NUP98+ and NUP98-, identifying 110 highly confident NUP98/PIF-associated DEGs. We confirmed, by qRT-PCR, the overexpression of nine DEGs, selected on the bases of the diagnostic accuracy, in a local cohort of PIF patients: SPINK2, TMA7, SPCS2, CDCP1, CAPZA1, FGFR1OP2, MAN1A2, NT5C3A and SRP54. In conclusion, the integrated analysis of NUP98 mutational analysis and transcriptome profiles allowed the identification of novel putative biomarkers for the prediction of PIF in AML.
Derivative chromosome der(1;16), isochromosome 1q, and deleted 16q—producing arm-level 1q-gain and/or 16q-loss—are recurrent cytogenetic abnormalities in breast cancer, but their exact role in determining the malignant phenotype is still largely unknown. We exploited The Cancer Genome Atlas (TCGA) data to generate and analyze groups of breast invasive carcinomas, called 1,16-chromogroups, that are characterized by a pattern of arm-level somatic copy number aberrations congruent with known cytogenetic aberrations of chromosome 1 and 16. Substantial differences were found among 1,16-chromogroups in terms of other chromosomal aberrations, aneuploidy scores, transcriptomic data, single-point mutations, histotypes, and molecular subtypes. Breast cancers with a co-occurrence of 1q-gain and 16q-loss can be distinguished in a “low aneuploidy score” group, congruent to der(1;16), and a “high aneuploidy score” group, congruent to the co-occurrence of isochromosome 1q and deleted 16q. Another three groups are formed by cancers showing separately 1q-gain or 16q-loss or no aberrations of 1q and 16q. Transcriptome comparisons among the 1,16-chromogroups, integrated with functional pathway analysis, suggested the cooperation of overexpressed 1q genes and underexpressed 16q genes in the genesis of both ductal and lobular carcinomas, thus highlighting the putative role of genes encoding gamma-secretase subunits (APH1A, PSEN2, and NCSTN) and Wnt enhanceosome components (BCL9 and PYGO2) in 1q, and the glycoprotein E-cadherin (CDH1), the E3 ubiquitin-protein ligase WWP2, the deubiquitinating enzyme CYLD, and the transcription factor CBFB in 16q. The analysis of 1,16-chromogroups is a strategy with far-reaching implications for the selection of cancer cell models and novel experimental therapies.
Honokiol (2) is a natural bisphenol neolignan showing a variety of biological properties, including antitumor activity. Some studies pointed out 2 as a potential anticancer agent in view of its antiproliferative and pro-apoptotic activity towards tumor cells. As a further contribution to these studies, we report here the synthesis of a small library of bisphenol neolignans inspired by honokiol and the evaluation of their antiproliferative activity. The natural lead was hence subjected to simple chemical modifications to obtain the derivatives 3-9; further neolignans (12a-c, 13a-c, 14a-c, and 15a) were synthesized employing the Suzuki-Miyaura reaction, thus obtaining bisphenols with a substitution pattern different from honokiol. These compounds and the natural lead were subjected to antiproliferative assay towards HCT-116, HT-29, and PC3 tumor cell lines. Six of the neolignans show GI50 values lower than those of 2 towards all cell lines. Compounds 14a, 14c, and 15a are the most effective antiproliferative agents, with GI50 in the range of 3.6-19.1 µM, in some cases it is lower than those of the anticancer drug 5-fluorouracil. Flow cytometry experiments performed on these neolignans showed that the inhibition of proliferation is mainly due to an apoptotic process. These results indicate that the structural modification of honokiol may open the way to obtaining antitumor neolignans more potent than the natural lead.
A new series of di(heteroaryl)ethenes was designed and synthesized by combining 5-(dichlorophenyl)-furan-2-yl and N-substituted pyridinum moieties. All the synthesized compounds were screened for their anticancer activity against the MCF-7 human breast cancer cell line. Most of the tested compounds showed moderate to potent cell growth inhibition; in particular, four of these exhibited promising cytotoxicity against this cell line, with IC50 values in the range of 0.30-0.005 mu M. In addition, the potential mechanism of cell growth inhibition and apoptotic induction by these compounds was investigated by using flow cytometry and confocal microscopy. Based on these results, we identified a new and alternative class of anticancer agents that have the potential to be developed as leads.