Search Results (254)

MicroRNA-221 (miR-221), a conserved small non-coding RNA, acts as a pivotal modulator of biological processes across multiple organ systems, the dysregulation of which is closely linked to the pathogenesis of various human diseases. This review systematically summarizes its multifaceted roles in cancer, cardiovascular diseases (CVDs), neurological disorders, digestive system diseases, respiratory conditions, and adipose-endocrine dysfunction. In cancer, miR-221 exerts context-dependent oncogenic/tumor-suppressive effects by targeting phosphatase and tensin homolog (PTEN), cyclin-dependent kinase inhibitor 1c (CDKN1C/p57), and BCL2 modifying factor (Bmf), thereby regulating cell proliferation, invasion, stemness, and resistance to cancer therapy; it also serves as a non-invasive biomarker for glioma, papillary thyroid carcinoma, and colorectal cancer. In the cardiovascular system, it balances antiviral defense in viral myocarditis, modulates ventricular fibrotic remodeling in heart failure, and regulates endothelial function in atherosclerosis, with cell-type/ventricle-specific effects. In neurological disorders, it protects dopaminergic neurons in Parkinson’s disease and modulates microglial activation in epilepsy. It also regulates hepatic pathogen defense and intestinal mucosal immunity. Mechanistically, miR-221 alters cellular phenotypes by targeting tumor suppressors or signaling components (e.g., PI3K/AKT, TGF-β/suppressor of mothers against decapentaplegic homolog(SMAD), Wnt/β-catenin). Therapeutically, miR-221-targeting strategies show preclinical promise in cancer and CVDs. Despite this progress, further studies are needed to resolve context-dependent functional discrepancies, validate biomarker utility, and develop cell-specific delivery systems. This review provides a framework to understand its pathophysiologcial roles and potential application as a biomarker and therapeutic target. Full article

Biliary tract carcinoma (BTC) is a group of highly heterogeneous malignancies arising from the biliary epithelium. Anatomically, BTC is categorized into gallbladder cancer (GBC) and cholangiocarcinoma (CCA), with the latter further subdivided into intrahepatic (iCCA), perihilar (pCCA), and distal cholangiocarcinoma (dCCA). Epidemiological studies reveal a dismal five-year survival rate of less than 20% for BTC patients, with limited responses to current chemotherapy regimens, underscoring the urgent need to unravel its complex molecular pathogenesis. Recent research has increasingly focused on the regulatory networks of post-translational modifications, particularly the ubiquitin-proteasome system (UPS), in tumorigenesis. As the largest subfamily of deubiquitinating enzymes (DUBs), ubiquitin-specific proteases (USPs) regulate the stability of key oncoproteins such as phosphatase and tensin homolog (PTEN) and c-Myc, playing pivotal roles in tumor cell proliferation, apoptosis evasion, invasion, and metastasis. This review systematically summarizes the differential expression profiles of USP family members (e.g., USP1, USP3, USP7, USP8, USP9X, USP21, and USP22) in BTC and their clinical significance, with a focus on elucidating how specific USPs regulate tumor progression through key substrates, including poly(ADP-ribose) polymerase 1 (PARP1), dynamin-1-like protein (DNM1L), and O-GlcNAc transferase (OGT). Furthermore, based on recent advances, we discuss the therapeutic potential of small-molecule USP inhibitors in BTC targeted therapy, providing a theoretical foundation for developing novel precision treatment strategies. Full article

microRNAs (miRNAs) are known to play critical roles in the regulation of gene expression during neurodegenerative diseases and neurotropic viral infections. However, their specific contribution to the pathogenesis of Powassan virus (POWV) infection in the brain remains poorly understood. Understanding miRNA dynamics in the brain during POWV infection may reveal novel insights into viral neuropathogenesis and host antiviral responses. Therefore, in the present study, we analyzed miRNA expression profiles in the mouse brain at different time points following a peripheral POWV infection. A total of 599 miRNAs were examined at day 3, 6, and 9 post-infection. Infection with POWV resulted in the modulation of several miRNAs in the brain at all time points. There was a progressive increase in the number of dysregulated miRNAs over the course of infection. This correlated with POWV dissemination into the brain with a progressive increase in viral RNA levels that peaked at day 9 post-infection. There was an early upregulation of miR-1983, miR-19a, and miR-216b that persisted until day 9 post-infection. POWV infection also resulted in the downregulation of miR-500 at all examined time points. Using IPA, we determined the significant canonical pathways affected by miRNA dysregulation. POWV infection modulated the activation of the thyroid hormone receptor and retinoid X receptor (TR/RXR) and the regulation of the phosphatase and tensin homolog (PTEN). Additionally, macrophage classical activation and growth arrest and DNA damage-inducible 45 (GADD45) signaling were activated as early as day 3 post-infection and persisted until day 9 post-infection. Furthermore, our analysis revealed the activation of cell death pathways such as necrosis and apoptosis and the inhibition of cell cycle progression, as well as leukopoiesis. To our knowledge, this is the first study to evaluate the modulation of miRNAs in the brain following POWV infection. Full article

The regulation of T cell-mediated immune responses is essential for maintaining immune homeostasis and preventing autoimmune diseases. In multiple sclerosis (MS), impaired immunoregulatory control allows autoreactive T cells to persist, as effector T cells (Teff) display reduced susceptibility to regulatory T cells (Treg). This resistance to Treg-mediated tolerance is linked to altered IL-6 signaling and hyperactivation of protein kinase B (PKB/c-Akt). However, the mechanisms leading to increased PKB phosphorylation remain poorly understood. Here, we examined the expression of phosphatase and tensin homolog PTEN, a key phosphatase that negatively regulates PKB/c-Akt activation. We found that PTEN protein expression rapidly declines in activated Teff from MS patients. To clarify whether PTEN downregulation contributes to Treg resistance, we used PTEN-specific siRNA to modulate PTEN expression in Teff from healthy donors. PTEN knockdown resulted in accelerated IL-6 production, enhanced PKB phosphorylation, and reduced responsiveness to Treg-mediated suppression, similar to Treg resistance observed in MS. This study reports disrupted PTEN expression in activated Teff from MS patients. Our findings highlight that PTEN is critical for effective immune regulation of T cells, and suggest its dysregulation contributes to impaired immune tolerance in MS. Full article

Background/Objectives: Twin and family studies suggest that 90% of the risk for autism spectrum disorder (ASD) is due to genetic factors, with 800 genes recognized as playing a role. An important gene is phosphatase and tensin homolog (PTEN), which plays a significant role in cancer as a tumor suppressor best known for causing overgrowth and PTEN hamartoma tumor syndromes (PHTS). Less well known are PTEN germline mutations with adverse neurodevelopmental impacts of macrocephaly, intellectual disability, and ASD, as well as other behavioral and psychiatric disturbances. There remains a limited understanding of whether these gene variants are associated with differing manifestations of PTEN-associated neurodevelopmental disorders. Methods: This review utilized comprehensive literature searches such as PubMed, OMIM, and Gene Reviews with keywords of PTEN, genetic factors, autism, and human studies and by searching genomic-protein functional networks with STRING computer-based programs for functional and genetic mechanisms. Results: This review explored the genetic underpinnings of PTEN gene variants causing altered interactive proteins and their mechanisms, biological processes, molecular functions, pathways, and disease–gene associations. We characterized specific gene–gene or protein–protein interactions and their functions relating to neurodevelopment, psychiatric disorders, and ASD that were found to be increased with PTEN gene variants. Conclusions: PTEN gene defects are among the most recognized genetic causes of ASD. PTEN gene variants and altered protein interactions and mechanisms described in our study are associated with an increased risk for tissue and organ overgrowth, macrocephaly, and distinct brain anomalies, specifically newly identified abnormal CSF dynamics. These genetic underpinnings and impacts on neurodevelopment are discussed. The genetic and protein findings identified may offer clues to effective treatment interventions, particularly when instituted at a young age, to improve long-term outcomes. Full article

Glioblastoma multiforme (GBM), the most aggressive primary brain tumor in adults, has a poor prognosis due to rapid recurrence and treatment resistance. This review examines the evolution of radiotherapy (RT) for GBM management, from whole-brain RT to modern techniques like intensity-modulated RT (IMRT) and volumetric modulated arc therapy (VMAT), guided by 2023 European Society for Radiotherapy and Oncology (ESTRO)-European Association of Neuro-Oncology (EANO) and 2025 American Society for Radiation Oncology (ASTRO) recommendations. The standard Stupp protocol (60 Gy/30 fractions with temozolomide [TMZ]) improves overall survival (OS) to 14.6 months, with greater benefits in O6-methylguanine-DNA methyltransferase (MGMT)-methylated tumors (21.7 months). Tumor Treating Fields (TTFields) extend median overall survival (mOS) to 31.6 months in MGMT-methylated patients and 20.9 months overall in supratentorial GBM (EF-14 trial). However, 80–90% of recurrences occur within 2 cm of the irradiated field due to tumor infiltration and radioresistance driven by epidermal growth factor receptor (EGFR) amplification, phosphatase and tensin homolog (PTEN) mutations, cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B) deletions, tumor hypoxia, and tumor stem cells. Pseudoprogression, distinguished using Response Assessment in Neuro-Oncology (RANO) criteria and positron emission tomography (PET), complicates response evaluation. Targeted therapies (e.g., bevacizumab; PARP inhibitors) and immunotherapies (e.g., pembrolizumab; oncolytic viruses), alongside advanced imaging (multiparametric magnetic resonance imaging [MRI], amino acid PET), support personalized RT. Ongoing trials evaluating reirradiation, hypofractionation, stereotactic radiosurgery, neoadjuvant therapies, proton therapy (PT), boron neutron capture therapy (BNCT), and AI-driven planning aim to enhance efficacy for GBM IDH-wildtype, but phase III trials are needed to improve survival and quality of life. Full article

Aims: Prostate cancer (PCa) presents ongoing challenges in differentiating aggressive from indolent disease using traditional biomarkers such as prostate-specific antigen (PSA). The Phosphatase and Tensin Homolog (PTEN), a key tumour suppressor involved in cellular growth regulation, is emerging as a promising biomarker for risk stratification. This meta-analysis aims to evaluate the prognostic significance of PTEN loss in PCa, particularly its relationship with Gleason grade groups (GG), as defined by the ISUP system, and clinical outcomes. Methods: A systematic review and meta-analysis of 16 studies encompassing 11,375 patients was conducted in accordance with PRISMA guidance. Studies included evaluated PTEN loss, stratified by hemizygous and homozygous deletions, and its association with GG and clinical endpoints such as biochemical recurrence and lethal progression. Pooled odds ratios (ORs) and hazard ratios (HRs) were calculated using a random-effects model. Results: PTEN loss was significantly associated with tumour aggressiveness. Compared to GG1 tumours, the odds of PTEN loss were markedly increased in Gleason GG 2 and 3(OR: 2.78, 95% CI: 1.95–3.61) and GG ≥ 4 (OR: 6.35, 95% CI: 5.37–7.33). Homozygous PTEN deletions were more strongly associated with high-grade tumours than hemizygous deletions. Clinically, PTEN loss was predictive of adverse outcomes, including increased risk of biochemical recurrence (HR: 1.78, 95% CI: 1.31–2.25) and lethal progression (HR: 2.57, 95% CI: 1.12–3.95). Conclusion: PTEN loss correlates with higher GG and poorer clinical outcomes in PCa. Incorporating PTEN assessment into clinical decision making could improve risk stratification, guiding early intervention strategies and identifying patients suitable for active surveillance. Full article

Tensins (TNS1–4) are pivotal molecular scaffolds bridging the actin cytoskeleton to integrin-based adhesions, orchestrating signal transduction and governing cellular processes in cancer. Structurally, the N-terminal actin-binding domain (ABD) in TNS1–3 enables cytoskeletal regulation and interactions with regulators like the Rho GAP DLC1, while ABD-deficient TNS4 functions as a focal adhesion signal amplifier. Functionally, TNS1–3 exhibit context-dependent duality as tumor promoters or suppressors, dictated by tissue-specific microenvironments and signaling crosstalk. In contrast, TNS4 acts predominantly as an oncoprotein across carcinomas by stabilizing epidermal growth factor receptor (EGFR), driving epithelial–mesenchymal transition and invasion, and sustaining proliferation. Clinically, tensin dysregulation correlates with metastasis and poor prognosis: TNS2 serves as a diagnostic biomarker for gastrointestinal stromal tumors, aberrant TNS1/TNS3 expression predicts metastasis risk, and TNS4 is recurrently embedded in multi-gene prognostic signatures. This review synthesizes their structural basis, regulatory mechanisms, and clinical relevance, highlighting context-dependent switches and TNS4’s therapeutic potential. Full article

Microglia, as the immune guardians of the central nervous system (CNS), have the ability to maintain neural homeostasis, respond to environmental changes, and remodel the synaptic landscape. However, persistent microglial activation can lead to chronic neuroinflammation, which can alter neuronal signaling pathways, resulting in accelerated cognitive decline. Phosphoinositol 3-kinase (PI3K) has emerged as a critical driver, connecting inflammation to neurodegeneration, serving as the nexus of numerous intracellular processes that govern microglial activation. This review focuses on the relationship between PI3K signaling and microglial activation, which might lead to cognitive impairment, inflammation, or even neurodegeneration. The review delves into the components of the PI3K signaling cascade, isoforms, and receptors of PI3K, as well as the downstream effects of PI3K signaling, including its effectors such as protein kinase B (Akt) and mammalian target of rapamycin (mTOR) and the negative regulator phosphatase and tensin homolog (PTEN). Experiments have shown that the overproduction of certain cytokines, coupled with abnormal oxidative stress, is a consequence of poor PI3K regulation, resulting in excessive synapse pruning and, consequently, impacting learning and memory functions. The review also highlights the implications of autonomously activated microglia exhibiting M1/M2 polarization driven by PI3K on hippocampal, cortical, and subcortical circuits. Conclusions from behavioral studies, electrophysiology, and neuroimaging linking cognitive performance and PI3K activity were evaluated, along with new approaches to therapy using selective inhibitors or gene editing. The review concludes by highlighting important knowledge gaps, including the specific effects of different isoforms, the risks associated with long-term pathway modulation, and the limitations of translational potential, underscoring the crucial role of PI3K in mitigating cognitive impairment driven by neuroinflammation. Full article

Health outcomes for people with HIV (PWH) have improved significantly with combination antiretroviral therapy (ART), yet the risk of lung cancer remains elevated. While a single case cannot establish causality, we describe here an investigation of a 74-year-old male PWH with de novo high-grade neuroendocrine small cell lung carcinoma. To investigate the potential contribution of HIV to cancer development, we performed HIV integration site sequencing on blood, tumor, and non-tumor tissue samples from the patient. We analyzed integration site distribution, clonal expansion, and associated gene disruption. Phosphatase and Tensin Homolog (PTEN) expression was evaluated using immunofluorescence and microscopy. A total of 174 unique HIV integration sites were identified, with 29.9% (52/174) located in clonally expanded cells. The most frequent integration site in clonally expanded cells was within the PTEN gene, representing 4.2% to 16.7% of all HIV-infected cells across samples. PTEN expression was markedly reduced in tumor regions relative to non-tumor tissue. Areas positive for HIV p24 antigen showed minimal PTEN expression. These findings suggest that HIV integration into the PTEN gene, coupled with clonal expansion of HIV-infected cells, may impair anti-tumor immune responses and promote cancer progression in PWH. Full article

Ovarian clear cell carcinoma (OCCC) represents a distinct histological subtype with a high prevalence in Asian populations and poor chemotherapy response. This study investigated molecular interactions between phosphatase and tensin homolog (PTEN), AT-rich interactive domain 1A (ARID1A), programmed death-ligand 1 (PD-L1), and mismatch repair (MMR) proteins in Asian patients with OCCC. Immunohistochemical analysis was performed on tissue microarrays from 69 OCCC cases. The expression of PTEN, ARID1A, PD-L1, and four MMR proteins was evaluated alongside clinical data. A high prevalence of PTEN loss (78.3%) and ARID1A deficiency (48.8%), with PD-L1 expression in 26.1% and MMR deficiency in 10.1% of cases, was observed. All PD-L1-positive tumors demonstrated concurrent PTEN loss (p = 0.007). MMR deficiency was significantly associated with ARID1A loss (p = 0.049). PTEN loss correlated with worse progression-free survival (PFS) in early-stage disease (p = 0.039). PTEN and ARID1A alterations represent early pathogenic events in Asian OCCC, with PTEN loss significantly impacting PFS in early-stage disease. The correlation between PTEN loss and PD-L1 expression, alongside ARID1A-MMR deficiency association, provides insights into OCCC’s immunological landscape and therapeutic vulnerabilities. Full article

Immunotherapy has become one of the primary forms of cancer treatment. The inhibition of immune checkpoint molecules, including indoleamine 2,3-dioxygenase (IDO), is a promising approach for immunotherapy. Phosphatase and tensin homolog (PTEN) is well known as a tumor suppressor that antagonizes oncogenic signaling molecules/pathways and plays a key role in the prognosis and (immuno)therapy of the disease. In this study, twenty healthy and tumorous renal tissue pairs were investigated, and the mRNA (RT-qPCR) and protein (Western blot) expression of IDO and PTEN were analyzed. In two cancer cell lines (CAKI-2; A-498), the protein of IDO and PTEN was measured followed by IDO induction with interferon alpha-2 (IFN-α2). According to our results, a significantly higher mRNA expression of IDO and PTEN was found in tumorous tissues compared to the adjacent healthy kidney specimens. The mRNA expression of IDO and PTEN showed a positive correlation in 80% of the sample pairs. Western blot results confirmed the protein expression of both IDO and PTEN. In the cell lines, immunocytochemistry showed that IDO is inducible with IFN-α2. In summary, our results suggest that IDO expression may play a role in the development of renal cancer, and IDO as well as PTEN might be potential biomarkers for patients with RCC. Full article

Ras signaling regulates many cellular processes in cancer development. While well-known Ras-related oncogenes, such as KRAS, have been extensively explored, the role of other Ras-related genes in cancer remains poorly studied. Dexamethasone-induced Ras-related protein 1 (RASD1), a member of the Ras superfamily, is widely expressed across various tissues and is involved in inhibiting cell growth and inducing apoptosis, suggesting a potential role as a tumor suppressor. Here, we investigated RASD1 expression across multiple tissues and cancers, utilizing data from The Cancer Genome Atlas (TCGA), Human Protein Atlas, and Genotype-Tissue Expression (GTEx) databases. Our analysis revealed a significant downregulation of RASD1 mRNA expression in several cancer types compared to normal tissues, correlating with low levels of promoter methylation. Interestingly, high RASD1 expression correlated with a favorable prognosis in multiple cancers. Immune cell infiltration analysis indicated that elevated RASD1 expression is associated with an increased infiltration of CD4⁺ T cells and myeloid-derived dendritic cells in cancer. Furthermore, the expression of genes exhibiting similar expression patterns as RASD1 suggest that RASD1 may play a role in interleukin-4-mediated apoptosis and could regulate the transcription of the phosphatase and tensin homolog (PTEN) gene. Overall, these findings suggest that RASD1 may modulate immune signaling and tumor suppressive pathways. Full article

Cowden syndrome (CS) is a rare hereditary disorder characterized by benign overgrowth in various tissues and a high risk of breast and thyroid cancer. CS is closely associated with pathogenic variants (PVs) in the phosphatase and tensin homolog (PTEN) tumor suppressor gene. PVs in PTEN are usually inherited and estimates of de novo frequencies remain inconclusive. The diagnosis of PTEN-associated syndromes remains a challenge in clinical practice, due to patients showing seemingly unrelated symptoms. We report on the clinical management of a now 18-year-old female CS patient, who initially presented with macrosomia, motor development delay and later, lipomas on the abdominal wall. Genetic testing revealed a de novo PTEN PV c.1003C>T(p.Arg335X). The PV was detected in leukocyte DNA of the patient. Using direct DNA sequencing, as well as NGS, the PV was not found in any of the tissues derived from immediate family members. However, the PV was detected in multiple samples representing other germ layers of the affected patient, which renders constitutional mosaicism unlikely. This case constitutes the first description of a de novo PTEN PV, in which constitutional mosaicism was systematically ruled out and underscores the importance of timely genetic testing of patients and their relatives. The diagnosis of a PTEN PV in early childhood allows for the implementation of a comprehensive, lifelong care plan that addresses both pediatric and adult medical needs as well as cancer risk surveillance and family planning. This not only accounts for the affected patients, but also their close family members who might be susceptible to the same PV. Full article