Search Results (282)

Background: Oral leukoplakia (OL) and proliferative verrucous leukoplakia (PVL) remain challenging entities due to the absence of reliable prognostic biomarkers. All-trans retinoic acid (atRA), a pivotal modulator of epithelial differentiation and mucosal integrity, has been proposed as a candidate biomarker. This study sought to quantify plasma RA levels in patients with OL and PVL compared to healthy controls, assessing their potential clinical utility. Methods: A cohort of 40 participants was recruited, comprising 10 patients with OL, 10 with PVL, and 20 healthy controls. This nested case–control study was derived from previously characterized institutional databases of oral potentially malignant disorders. Plasma samples were analyzed for atRA concentration using high-precision mass spectrometry. Statistical comparisons were conducted to evaluate differences between groups and associations with clinical outcomes. Results: Patients with homogeneous OL exhibited significantly reduced plasma atRA concentrations (mean 2.17 ± 0.39 pg/mL) relative to both PVL patients (2.64 ± 0.56 pg/mL) and healthy controls (2.66 ± 0.92 pg/mL), with p-values of 0.009 and 0.039, respectively. No statistically significant difference was found between PVL patients and controls. Furthermore, atRA levels demonstrated no correlation with clinicopathological variables or malignant progression within the PVL cohort. Conclusions: These preliminary findings indicate that diminished plasma atRA levels may serve as a prognostic marker for homogeneous oral leukoplakia, whilst its role in PVL appears limited. However, effect estimates were imprecise, and additional studies are warranted. Full article

We present a 48-year-old female with a past medical history of endometrioid adenocarcinoma who presented with symptoms of spontaneous gum bleeding, post-coital bleeding, and upper extremities–lower extremities-abdomen ecchymosis. Initial laboratory findings were significant for cytopenia and disseminated intravascular coagulation (DIC). Due to a suspected case of acute promyelocytic leukemia (APL), conventional karyotyping and fluorescence in situ hybridization (FISH) were performed. FISH analysis confirmed an unusual chromosome rearrangement that affected chromosomes 3, 15, and 17. This t(3;15;17)(q29;q24;q21) was characterized by the presence of PML::RARA fusion on the derivative chromosome 15. Treatment at the hospital with standard APL therapy of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) was complicated by the development of differentiation syndrome, which necessitated the temporary stoppage of ATO. However, complete remission was achieved despite complications after starting consolidation treatment. Full article

Any failure in frontonasal development can lead to malformations at the middle facial region, such as frontonasal dysplasia, midfacial clefts, and hyper/hypotelorism. Various environmental factors influence morphogenesis through epigenetic regulations, including the action of noncoding microRNAs (miRNAs). However, it remains unclear how miRNAs are involved in the frontonasal development. In our analysis of publicly available miRNA-seq and RNA-seq datasets, we found that miR-28a-5p, miR-302a-3p, miR-302b-3p, and miR-302d-3p were differentially expressed in the frontonasal process during embryonic days 10.5 to 13.5 (E10.5–E13.5) in mice. Overexpression of these miRNAs led to a suppression of cell proliferation in cultured mouse embryonic frontonasal mesenchymal (MEFM) cells as well as in O9-1 cells, a cranial neural crest cell line. Through advanced bioinformatic analyses and miRNA-gene regulation assays, we identified that miR-28a-5p regulated a total of 25 genes, miR-302a-3p regulated 23 genes, miR-302b-3p regulated 22 genes, and miR-302d-3p regulated 20 genes. Notably, the expression of miR-302a/b/d-3p—unlike miR-28a-5p—was significantly upregulated by excessive exposure to all-trans retinoic acid (atRA) that induces craniofacial malformations. Inhibition of these miRNAs restored the reduced cell proliferation caused by atRA by normalizing the expression of target genes associated with frontonasal anomalies. Therefore, our findings suggest that miR-302a/b/d-3p plays a crucial role in the development of frontonasal malformations. Full article

Idiopathic pulmonary fibrosis (IPF) is a progressive and lethal lung disease with limited therapeutic options. This review focuses on the role of retinoids, particularly all-trans retinoic acid (atRA), and hypoxia in the pathogenesis of IPF. Despite an established understanding of genetic and environmental factors in IPF, the interplay between retinoid signaling and the response to hypoxia remains poorly explored due to its complexity. Preclinical evidence suggests that atRA could help reduce pulmonary fibrosis by modulating TGF-β signaling pathways and epithelial-to-mesenchymal transition (EMT). Additionally, we mention other diseases where a relationship between hypoxia and retinoids has been observed. We review how hypoxia, a key factor in the progression of IPF, may influence the efficacy of retinoid therapy. Combination strategies are explored to overcome hypoxia-induced treatment resistance. Finally, we address the complex role of retinoids in lung regeneration, balancing their potential benefits against the risk of exacerbating fibrotic processes. This review suggests that retinoids have potential as a treatment or adjuvant for IPF and highlights the need for further research to elucidate the precise mechanisms of retinoid action in IPF, particularly in hypoxia. Full article

Background: Glioblastoma (GBM) remains almost uniformly fatal, owing in part to therapy-resistant cancer stem-like cells (CSCs) and to temozolomide (TMZ) resistance driven by O⁶-methylguanine-DNA methyltransferase (MGMT). Differentiation therapy with all-trans retinoic acid (ATRA) has the potential to attenuate stemness and sensitize GBM to TMZ. We therefore asked whether ATRA reduces expression of key CSC markers and MGMT in established GBM lines. Methods: Two established human GBM cell lines, U87-MG and A172, were cultured under neurosphere-promoting conditions to enrich for potential stem-like subpopulations. Cells were treated with either 1 µM ATRA or vehicle control (DMSO) for 5 days. Total RNA was extracted, and cDNA was synthesized. Quantitative Real-Time PCR (qPCR) assessed relative mRNA expression levels of key stemness transcription factors (SOX2, NES) and the DNA repair gene MGMT and corresponding protein levels were measured by an Enzyme-Linked Immunosorbent Assay (ELISA). Gene expression was normalized to the geometric mean of two validated housekeeping genes (GAPDH, ACTB). Relative quantification was calculated using the ΔΔCt method, and statistical significance was determined using Student’s t-tests. Results: ATRA markedly suppressed stemness and MGMT in both lines. In U87-MG, SOX2 mRNA fell 3.7-fold (p = 0.0008) and protein 2.99-fold (148.3 ± 6.0 → 49.7 ± 2.7 pg µg⁻¹; p = 0.0002); Nestin dropped 4.1-fold (p = 0.0005) and 3.51-fold (450.0 ± 17.3 → 128.3 ± 4.4 pg µg⁻¹; p = 0.00008). MGMT decreased 2.6-fold at transcript level (p = 0.0065) and 2.11-fold at protein level (81.7 ± 4.4 → 38.7 ± 1.8 pg µg⁻¹; p = 0.0005). In A172, SOX2 was reduced 2.9-fold (p = 0.0041) and 2.31-fold (p = 0.0007); Nestin 3.3-fold (p = 0.0028) and 2.79-fold (p = 0.00009). MGMT declined 2.2-fold (p = 0.0132) and 1.82-fold (p = 0.0015), respectively. Conclusions: Five-day exposure to ATRA diminishes SOX2, Nestin, and MGMT at both mRNA and protein levels in stem-enriched GBM cultures, supporting the premise that ATRA-induced differentiation can concurrently blunt CSC traits and TMZ-resistance mechanisms. These data provide a molecular rationale for testing ATRA in combination regimens aimed at improving GBM therapy. Full article

Retinol and retinol-related compounds are essential for human health, particularly in cellular protection, skin health, and the management of medical conditions. Retinol—a vital form of vitamin A—is obtained through the diet as preformed vitamin A or provitamin A carotenoids, retinyl esters. These compounds are indispensable for vision, immune function, and skin health. While retinoic acid has important known biological roles, its presence is limited in the body as it is rapidly metabolized rather than stored, emphasizing the need for sufficient dietary intake. This paper is divided into chapters that highlight important aspects of retinol and retinoid-related compounds, such as their sufficient intake through food sources. The nutritional value of carotenoids is influenced by the balance between trans- and cis-isomers in food, with food processing affecting their bioactivity. Next, it is metabolism in the digestive tract. The bioavailability and efficacy of retinoids are further influenced by gut microbiota, which can modulate immune function and the expression of the genes involved in retinoid metabolism. A third important property greatly influencing their biological function is their structure, predisposing them to certain biological activities. Both retinoids and carotenoids exert key antioxidant functions by protecting cells from oxidative damage, quenching singlet oxygen, and stabilizing free radicals. However, the oxidation of carotenoids can result in various metabolites, such as epoxides and hydroxyketones, that further create a higher demand for antioxidant defenses. Additionally, carotenoids interact with lipoxygenases (LOXs), thus influencing oxidative stress, although this interaction may reduce their antioxidant efficacy. First- and second-generation retinoids regulate gene expression related to skin cell function and oncological diseases. Despite their therapeutic benefits, long-term use carries risks, such as teratogenicity. Ongoing research should aim to enhance the safety, precision, and effectiveness of retinoid therapies, expanding their therapeutic potential. Full article

PEIG-1/GPRC5A (phorbol ester induced gene-1/G-protein Coupled Receptor Class C Group 5 Member A) was the first identified member of the orphan G protein-coupled receptor family GPRC5. Deregulation of its expression is associated with the development and progression of various types of tumours, particularly colon carcinoma. In this work, we study the effects of vitamin D (VD, cholecalciferol) and retinoic acid (RA) on GPRC5A mRNA expression in the colorectal cancer cell lines Caco-2 and T84. Both VD (10 µM) and all-trans retinoic acid (ATRA, atRA, RA) (10 µM) increased GPRC5A mRNA levels. Protein kinase C (PKC) inhibition with Gö6983 (10 µM) completely abolished the effects of VD and RA on GPRC5A expression. In parallel, VD and RA increased cytosolic and mitochondrial ROS levels (cROS and mtROS). However, the antioxidants NAC (10 mM) and MitoTEMPO (10 µM) raised GPRC5A gene expression levels in the presence of VD or RA, suggesting that elevated ROS may inhibit GPRC5A expression. In conclusion, both VD and RA stimulate GPRC5A expression. The mechanisms involve a common and essential PKC signalling pathway, as Gö6983 inhibited both VD- and RA-induced signalling. Full article

Retinoic acid receptor (RAR) γ expression is restricted during adult haematopoiesis to haematopoietic stem cells and their immediate offspring and is required for their maintenance. From zebrafish studies, RARγ is selectively expressed by stem cells and agonism in the absence of exogenous all-trans retinoic acid blocked stem cell development. Recent findings for the expression of RARγ have revealed an oncogenic role in acute myeloid leukaemia and cholangiocarcinoma and colorectal, head and neck, hepatocellular, ovarian, pancreatic, prostate, and renal cancer. Overexpression and agonism of RARγ enhanced cell proliferation for head and neck, hepatocellular, and prostate cancer. RARγ antagonism, pan-RAR antagonism, and RARγ downregulation led to cell growth which was often followed by cell death for acute myeloid leukaemia, astrocytoma, and cholangiocarcinoma as well as hepatocellular, primitive, neuroectodermal ovarian, and prostate cancer. Histological studies have associated high level RARγ expression with high-grade disease, metastasis, and a poor prognosis for cholangiocarcinoma and ovarian, pancreatic, and prostate cancer. RARγ is expressed by cancer stem cells and is a targetable drive of cancer cell growth and survival. Full article

Candida albicans (C. albicans) is the most common pathogen responsible for a wide spectrum of human infections ranging from superficial mucocutaneous mycoses to systemic life-threatening diseases. Its main virulence factors are the morphological transition between yeast and hyphal forms and the ability to produce biofilm. Novel antifungal strategies are required given the severity of systemic candidiasis, especially in immunocompromised patients, and the lack of effective anti-biofilm treatments. We previously demonstrated that all-trans retinoic acid (ATRA), an active metabolite of vitamin A, exerted an inhibitory effect on Candida growth, yeast–hyphal transition and biofilm formation. Here, we further investigated the possible anti-Candida potential of trifarotene and tazarotene, which are the other two molecules belonging to the retinoid family, compared to ATRA. The results indicate that both drugs were able to suppress Candida growth, germination and biofilm production, although trifarotene was proven to be more effective than tazarotene, showing effectiveness comparable to ATRA. In silico studies suggest that all three retinoids may exert antifungal activity through their molecular interactions with the heat shock protein (Hsp) 90 and 14α-demethylase of C. albicans. Moreover, interactions between retinoids and ergosterol have been observed, suggesting that those compounds have great potential against C. albicans infections. Full article

Acute promyelocytic leukemia (APML) is one of the most curable leukemia subtypes, where the majority of patients achieve complete remission and also deep molecular remission after therapy, characterized by a PCR-undetectable state. Similarly, chronic myelogenous leukemia (CML) is a leukemia where, thanks to effective targeted treatment with tyrosine kinase inhibitors (TKIs), deep remission detectable only by PCR has become part of the routine management of these patients. Here, we describe a patient who was PCR-negative after induction and consolidation with arsenic trioxide (ATO) and all-trans retinoic acid (ATRA) and stayed PCR-undetectable for 13 months post-consolidation, later experiencing molecular relapse following mild SARS-CoV-2 infection. The patient was able to reestablish molecular remission again without anti-leukemic therapy several weeks later. She remained PCR-negative for the next 42 months. Viral infection-triggered immunosuppression, as in our case, offers a possible explanation for the temporary loss of molecular remission seen in leukemia patients monitored by PCR. Our first case illustrates this period of convalescence from viral infection, which was maybe accompanied by loss of molecular response. Viral infections and temporary immunosuppression may be a culprit in cases where molecular responses are lost temporarily. This loss of the PCR-undetectable state may have implications for other cancer patients where PCR monitoring is used. Thus, our observation may have broader implications for other patients, especially those with CML. We further enforce these findings by describing a second patient with CML who experienced temporary molecular relapse in the setting of post-viral syndrome. Full article

Background: Acute promyelocytic leukemia (APL) is characterized by abnormal promyelocytes and t(15;17)(q24;q21) PML::RARA. Rarely, patients may have cryptic or variant rearrangements. All-trans retinoic acid (ATRA)/arsenic trioxide (ATO) is largely curative provided that the diagnosis is established early. Methods: We present the case of a 36-year-old male who presented with features concerning for disseminated intravascular coagulation. Although the initial diagnostic work-up, including pathology and flow cytometry evaluation, suggested a diagnosis of APL, karyotype and fluorescence in situ hybridization (FISH), using the PML/RARA dual fusion and RARA breakapart probes, were negative. We performed real-time polymerase chain reaction (RT-PCR) and optical genome mapping (OGM) to further confirm the clinicopathological findings. Results: RT-PCR revealed a cryptic PML::RARA fusion transcript. OGM further confirmed the nature and orientation of a cryptic rearrangement with an insertion of RARA into PML at intron 3 (bcr3). In light of these findings, we performed a systematic literature review to understand the prevalence, diagnosis, and prognosis of APL with cryptic PML::RARA rearrangements. Conclusions: This case, in conjunction with the results of our systematic literature review, highlights the importance of performing confirmatory testing in FISH-negative cases of suspected APL to enable prompt diagnosis and appropriate treatment. Full article

Background: Acute promyelocytic leukemia (APL) is frequently associated with disseminated intravascular coagulation (DIC), leading to potentially life-threatening bleeding. Compared to bleeding, thromboses are a less commonly encountered problem. Objective: The objective of our study was to identify the incidence and predictive value of demographic data, clinical–laboratory parameters, and thrombosis risk assessment models (RAMs) for venous thromboembolism (VTE) in patients with APL. Methods: This study was a retrospective study conducted on adult patients with APL who were treated between 2006 and 2024 at the Clinic of Hematology UCCS with all-trans retinoic acid (ATRA) and anthracycline. The demographic and clinical–laboratory data related to VTE were collected and analyzed alongside the predictive value of two RAMs proposed by Al-Ani and Paterno and colleagues. Results: Among the one-hundred-fifty-five adult patients with APL, VTE was diagnosed in twenty-eight cases (18.1%). The most common location for thrombosis was in the central venous catheter (CVC), which affected twelve (42.8%) patients. A total of six (21.4%) patients had deep vein thrombosis (DVT), one patient (3.6%) showed a pulmonary embolism (PE), and thrombosis at unusual sites was present in nine (32.1%) patients. Our analyses showed that neither Al-Ani’s RAM nor the RAM proposed by Paterno and colleagues were predictive for VTE in patients with APL. The C statistics value for the Al-Ani model was ROC = 0.514, and, for Paterno’s RAM, it was ROC = 0.521. The independent risk factors for VTE, identified via multivariate analysis, were CD114 expression (p = 0.005, OR = 6.4 IC 95%: [1.8–23.2]) and the absence of bleeding at presentation (p = 0.013, OR = 0.086 IC 95%: [0.01–0.59]). Conclusions: To the best of our knowledge, this is the first study showing that a higher expression of CD114 increases the risk of VTE. The absence of bleeding at presentation in patients with APL correlates with thrombosis. Further analyses are needed to confirm these findings and help to develop therapeutic strategies to prevent VTE complications. So far, no risk assessment model has been sufficient to stratify patients with APL according to their risk of VTE. Full article

Acute promyelocytic leukemia (APL) is a rare type of AML, characterized by the t(15;17) translocation and accounting for 8–15% of cases. The introduction of target therapies, such as all-trans retinoic acid (ATRA) and arsenic trioxide (ATO), radically changed the management of APL, making it the most curable AML subtype. However, a small percentage (estimated to be 2%) of AML presenting with APL-like morphology and/or immunophenotype lacks t(15;17). This rare APL-like AML group, whose first case was described in the early 1990s, now includes over 40 entities. These diseases present great heterogeneity in terms of genetic lesions, clinical presentation, sensitivity to targeted agents and chemotherapy, and prognosis. Furthermore, the diagnosis is very challenging. Thus, in this paper, we aim to comprehensively review the literature reports and studies addressing APL-like entities, investigate the biological mechanisms of leukemogenesis, evaluate the clinical characteristics, and discuss future lines of research and possible clinical approaches. Full article

Acute promyelocytic leukemia (APL) accounts for approximately 10–15% of newly diagnosed acute myeloid leukemia cases and presents with coagulopathy and bleeding. Prompt diagnosis and treatment are required to minimize early mortality in APL as initiation of all-trans retinoic acid therapy rapidly reverses coagulopathy. The PML::RARA fusion is a hallmark of APL and its rapid identification is essential for rapid initiation of specific treatment to prevent early deaths from coagulopathy and bleeding and optimize patient outcomes. Given limitations and long turnaround time of current gene fusion diagnostic strategies, we have developed a novel amplification-free nanopore sequencing-based approach with low cost, easy setup, and fast turnaround time. We termed the approach CRISPR/Cas9-enriched nanopore sequencing with adaptive sampling (CENAS). Using CENAS, we successfully sequenced breakpoints of typical and atypical PML::RARA fusions in APL patients. Compared with the standard-of-care genetic diagnostic tests, CENAS achieved good concordance in detecting PML::RARA fusions in this study. CENAS allowed for the identification of sequence information of fusion breakpoints involved in typical and atypical PML::RARA fusions and identified additional genes (ANKFN1 and JOSD1) and genomic regions (13q14.13) involving the atypical fusions. To the best of our knowledge, involvements of the ANKFN1 gene, the JOSD1 gene, and the 13q14.13 genomic region flanking with the SIAH3 and ZC3H13 genes have not been reported in the atypical PML::RARA fusions. CENAS has great potential to develop as a point-of-care test enabling immediate, low-cost bedside diagnosis of APL patients with a PML::RARA fusion. Given the early death rate in APL patients still reaches 15%, and ~10% of APL patients are resistant to initial therapy or prone to relapse, further sequencing studies of typical and atypical PML::RARA fusion might shed light on the pathophysiology of the disease and its responsiveness to treatment. Understanding the involvement of additional genes and positional effects related to the PML and RARA genes could shed light on their role in APL and may aid in the development of novel targeted therapies. Full article