STING activation increases the efficiency of temozolomide in PTEN harbouring glioblastoma cells.

Background/aim: Glioblastoma is one of the most aggressive tumours, resistant to all applied therapy regiments and prone to relapse. Median survival rates are therefore only expressed as months. STING agonists are immunomodulatory molecules that activate type I interferon expression, making them potentially useful in regulating the tumour microenvironment. Since PTEN serves as a critical phosphatase in activating interferon-regulating transcription factors and is frequently mutated in glioblastoma cells, this study aimed to investigate STING activation in glioblastoma cell lines, examining whether they harbour the PTEN protein or not.°. Materials and methods: T98G and U118MG glioblastoma cell lines were treated with the 2'3'-c-di-AM(PS)2(Rp,Rp) STING agonist together with or without the chemotherapeutic agent temozolomide. cGAS/STING pathway components were subsequently analysed using qRT-PCR, western blot, and ELISA methods. Results: Our results showed that PTEN-harbouring T98G cells responded well to STING activation, leading to increased temozolomide efficacy. In contrast, STING activation in U118MG cells did not affect the response to temozolomide. mRNA expression levels of STING, IRF3, NF-KB, and RELA genes were significantly increased at the combined treatment groups in T98G cell line. Conversely, combined treatment with STING agonist and temozolomide did not affect mRNA expression levels of cGAS/STING pathway genes in U118MG cells. Conclusion: Our data offers new evidence suggesting that STING agonists can effectively be used to increase temozolomide response in the presence of PTEN protein. Therefore, increased GBM therapy success rates can be achieved by employing the PTEN expression status as a predictive biomarker before treating patients with a chemotherapeutic agent in combination with STING agonist.

Mutations in glioblastoma proteins do not disrupt epitope presentation and recognition, maintaining a specific CD8 T cell immune response potential.

Antigen-specific cytotoxic CD8 T cells are extremely effective in controlling tumor growth and have been the focus of immunotherapy approaches. We leverage in silico tools to investigate whether the occurrence of mutations in proteins previously described as immunogenic and highly expressed by glioblastoma multiforme (GBM), such as Epidermal Growth Factor Receptor (EGFR), Isocitrate Dehydrogenase 1 (IDH1), Phosphatase and Tensin homolog (PTEN) and Tumor Protein 53 (TP53), may be contributing to the differential presentation of immunogenic epitopes. We recovered Class I MHC binding information from wild-type and mutated proteins using the Immune Epitope Database (IEDB). After that, we built peptide-MHC (pMHC-I) models in HLA-arena, followed by hierarchical clustering analysis based on electrostatic surface features from each complex. We identified point mutations that are determinants for the presentation of a set of peptides from TP53 protein. We point to structural features in the pMHC-I complexes of wild-type and mutated peptides, which may play a role in the recognition of CD8 T cells. To further explore these features, we performed 100 ns molecular dynamics simulations for the peptide pairs (wt/mut) selected. In pursuit of novel therapeutic targets for GBM treatment, we selected peptides where our predictive results indicated that mutations would not disrupt epitope presentation, thereby maintaining a specific CD8 T cell immune response. These peptides hold potential for future GBM interventions, including peptide-based or mRNA vaccine development applications.

WTAP/IGF2BP3 mediated m6A modification of the EGR1/PTEN axis regulates the malignant phenotypes of endometrial cancer stem cells.

Endometrial cancer (EC) stem cells (ECSCs) are pivotal in the oncogenesis, metastasis, immune escape, chemoresistance, and recurrence of EC. However, the specific mechanism of stem cell maintenance in EC cells (ECCs) has not been clarified. We found that WTAP and m6A levels decreased in both EC and ECSCs, and that knocking down WTAP promoted ECCs and ECSCs properties, including proliferation, invasion, migration, cisplatin resistance, and self-renewal. The downregulation of WTAP leads to a decrease in the m6A modification of EGR1 mRNA, and it is difficult for IGF2BP3, as an m6A reader, to recognize and bind to EGR1 mRNA that has lost m6A modification, resulting in a decrease in the stability of EGR1 mRNA. A decrease in the EGR1 level led to a decrease of in the expression tumor suppressor gene PTEN, resulting in deregulation and loss of cellular homeostasis and thereby fostering EC stem cell traits. Notably, the enforced overexpression of WTAP, EGR1, and PTEN inhibited the oncogenic effects of ECCs and ECSCs in vivo, and the combined overexpression of WTAP + EGR1 and EGR1 + PTEN further diminished the tumorigenic potential of these cells. Our findings revealed that the WTAP/EGR1/PTEN pathway is important regulator of EC stem cell maintenance, chemotherapeutic resistance, and tumorigenesis, suggesting a novel and promising therapeutic avenue for treating EC.

Levosimendan Ameliorates Hypoxia-Induced Brain Injury in Rats by Modulating PTEN/Akt Signaling Pathway-Mediated Ferroptosis.

BACKGROUND: Levosimendan (Levo) is a drug commonly used to treat heart failure. Recent studies have suggested that Levo may have neuroprotective effects, but it is still unknown how exactly it contributes to hypoxia-induced brain damage. Thus, the aim of this study was to investigate how Levo affects hypoxia-induced brain damage and to clarify any possible underlying mechanisms. METHODS: One group of rats (Levo group) was pretreated with Levo via oral force-feeding for four weeks. Another group (Ferrostatin-1 (Fer-1) group) was pretreated with intraperitoneal injections of Fer-1 for four weeks. A rat model of chronic hypoxia was created by treating rats with 13% O2 for 14 days in a closed hypoxia chamber. For each group (Control, Model, Levo, Fer-1), we evaluated learning and memory capacity and the morphology and structure of neurons in the rats' brain tissue. Other measurements included tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1ß), and interleukin-6 (IL-6); malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px); Fe2+; apoptosis; cleaved caspase-3, caspase-3; phosphatase and tensin homolog (PTEN), protein kinase B (Akt), phosphorylated Akt (p-Akt); and ferroptosis-related proteins Nuclear factor erythroid 2-related factor 2 (Nrf2), glutathione peroxidase 4 (GPX4), and solute carrier family 7 member 11 (SLC7A11). RESULTS: The Model group rats had considerably fewer neurons than the Control group, with loosely arranged cells, and markedly impaired learning and memory abilities (p < 0.05). Oxidative damage and inflammation in brain tissues of the Model group were significantly intensified, accompanied by a substantial increase in neuronal apoptosis (p < 0.05). PTEN protein, Fe2+ concentration, and cleaved caspase-3 expression were all significantly upregulated, whereas p-Akt, Nrf2, GPX4, and SLC7A11 proteins were dramatically downregulated (p < 0.05). Both the Levo and Fer-1 groups demonstrated significantly more neurons and closely arranged cells than the Model group, along with a notable improvement in learning and memory abilities (p < 0.05). Oxidative damage and inflammation in brain tissues of the Levo and Fer-1 groups were markedly alleviated, and neuronal apoptosis was suppressed (p < 0.05). p-Akt, Nrf2, GPX4, and SLC7A11 proteins were dramatically upregulated, whereas the expression of cleaved caspase-3, PTEN protein, and Fe2+ content was considerably downregulated (p < 0.05). CONCLUSIONS: Levo effectively mitigates brain injury in rats with chronic hypoxia, likely by regulating ferroptosis via the PTEN/Akt signaling pathway.

METTL3-m6A methylation inhibits the proliferation and viability of type II alveolar epithelial cells in acute lung injury by enhancing the stability and translation efficiency of Pten mRNA.

BACKGROUND: The pathogenesis of acute lung injury (ALI) involves a severe inflammatory response, leading to significant morbidity and mortality. N6-methylation of adenosine (m6A), an abundant mRNA nucleotide modification, plays a crucial role in regulating mRNA metabolism and function. However, the precise impact of m6A modifications on the progression of ALI remains elusive. METHODS: ALI models were induced by either intraperitoneal injection of lipopolysaccharide (LPS) into C57BL/6 mice or the LPS-treated alveolar type II epithelial cells (AECII) in vitro. The viability and proliferation of AECII were assessed using CCK-8 and EdU assays. The whole-body plethysmography was used to record the general respiratory functions. M6A RNA methylation level of AECII after LPS insults was detected, and then the "writer" of m6A modifications was screened. Afterwards, we successfully identified the targets that underwent m6A methylation mediated by METTL3, a methyltransferase-like enzyme. Last, we evaluated the regulatory role of METTL3-medited m6A methylation at phosphatase and tensin homolog (Pten) in ALI, by assessing the proliferation, viability and inflammation of AECII. RESULTS: LPS induced marked damages in respiratory functions and cellular injuries of AECII. The m6A modification level in mRNA and the expression of METTL3, an m6A methyltransferase, exhibited a notable rise in both lung tissues of ALI mice and cultured AECII cells subjected to LPS treatment. METTL3 knockdown or inhibition improved the viability and proliferation of LPS-treated AECII, and also reduced the m6A modification level. In addition, the stability and translation of Pten mRNA were enhanced by METTL3-mediated m6A modification, and over-expression of PTEN reversed the protective effect of METTL3 knockdown in the LPS-treated AECII. CONCLUSIONS: The progression of ALI can be attributed to the elevated levels of METTL3 in AECII, as it promotes the stability and translation of Pten mRNA through m6A modification. This suggests that targeting METTL3 could offer a novel approach for treating ALI.

Itga5-PTEN signaling regulates striatal synaptic strength and motor coordination in Parkinson's disease.

Background: Parkinson's disease (PD) is marked by the loss of dopaminergic neurons in the substantia nigra pars compacta, leading to motor and cognitive dysfunctions. The molecular mechanisms underlying synaptic alterations in PD remain elusive, with a focus on the role of Itga5 in synaptic integrity and motor coordination and TAT-Itga5 was designed to suppress PTEN activity in this investigation. Methods: This study utilized MPTP-induced PD animal models to investigate the expression and role of Itga5 in the striatum. Techniques included quantitative PCR, Western blotting, immunostaining, CRISPR-CasRx-mediated knockdown, electrophysiological assays, behavioral tests, and mass spectrometry. Results: Itga5 expression was significantly reduced in MPTP-induced PD models. In these models, a marked decrease in dendritic spine density and a shift towards thinner spines in striatal GABA neurons were observed, suggesting impaired synaptic integration. Knockdown of Itga5 resulted in reduced dendritic branching, decreased mushroom spines, and increased thin spines, altering synaptic architecture. Electrophysiological analyses revealed changes in action potential and spontaneous excitatory postsynaptic currents, indicating altered synaptic transmission. Motor behavior assessments showed that Itga5 deficiency led to impairments in fine motor control and coordination. Furthermore, Itga5 was found to interact with PTEN, affecting AKT signaling crucial for synaptic development and motor coordination. Conclusion: The study demonstrates that Itga5 plays a critical role in maintaining synaptic integrity and motor coordination in PD. The Itga5-PTEN-AKT pathway represents a potential therapeutic target for addressing synaptic and motor dysfunctions in PD.

CBLL1 promotes endometrial stromal cell senescence via inhibiting PTEN in recurrent spontaneous abortion.

Recurrent spontaneous abortion (RSA) is a common pregnancy-related disorder. Cbl proto-oncogene like 1 (CBLL1) is an E3 ubiquitin ligase, which has been reported to vary with the menstrual cycle in the endometrium. However, whether CBLL1 is involved in the occurrence and development of RSA remains unclear. This study aimed to investigate the effects of CBLL1 on RSA. We analyzed the expression of CBLL1 in the decidua of RSA patients, as well as its functional effects on cellular senescence, oxidative stress, and proliferation of human endometrial stromal cells (HESCs). RNA sequencing was employed to identify a key downstream target gene regulated by CBLL1. We found that CBLL1 was upregulated in the decidua of RSA patients. Additionally, overexpression of CBLL1 promoted HESC senescence, increased oxidative stress levels, and inhibited proliferation. Phosphatase and tensin homolog located on chromosome 10 (PTEN) was identified as one of the important downstream target genes of CBLL1. In vivo experiments demonstrated that CBLL1 overexpression in the endometrium caused higher embryo absorption rate in mice. Consequently, elevated CBLL1 expression is a potential cause of RSA, representing a novel therapeutic target for RSA.

[Mechanism of salidroside in inhibiting proliferation, migration and promoting phenotypic switching of arterial smooth muscle cells].

This study aims to examine the effect of salidroside(SAL) on the phenotypic switching of human aortic smooth muscle cells(HASMC) induced by the platelet-derived growth factor-BB(PDGF-BB) and investigate the pharmacological mechanism. Firstly, the safe concentration of SAL was screened by the lactate dehydrogenase release assay. HASMC were divided into control, model, and SAL groups, and the cells in other groups except the control group were treated with PDGF-BB for the modeling of phenotypic switching. Cell proliferation and migration were detected by the cell-counting kit(CCK-8) assay and Transwell assay, respectively. The cytoskeletal structure was observed by F-actin staining with fluorescently labeled phalloidine. The protein levels of proliferating cell nuclear antigen(PCNA), migration-related protein matrix metalloprotein 9(MMP-9), fibronectin, α-smooth muscle actin(α-SMA), and osteopontin(OPN) were determined by Western blot. To further investigate the pharmacological mechanism of SAL, this study determined the expression of protein kinase B(Akt) and mammalian target of rapamycin(mTOR), as well as the upstream proteins phosphatase and tensin homologue(PTEN) and platelet-derived growth factor receptor ß(PDGFR-ß) and the downstream protein hypoxia-inducible factor-1α(HIF-1α) of the Akt/mTOR signaling pathway. The results showed that the HASMCs in the model group presented significantly increased proliferation and migration, the switching from a contractile phenotype to a secretory phenotype, and cytoskeletal disarrangement. Compared with the model group, SAL weakened the proliferation and migration of HASMC, promoted the expression of α-SMA(a contractile phenotype marker), inhibited the expression of OPN(a secretory phenotype marker), and repaired the cytoskeletal disarrangement. Furthermore, compared with the control group, the modeling up-regulated the levels of phosphorylated Akt and mTOR and the relative expression of PTEN, HIF-1α, and PDGFR-ß. Compared with the model group, SAL down-regulated the protein levels of phosphorylated Akt and mTOR, PTEN, PDGFR-ß, and HIF-1α. In conclusion, SAL exerts a protective effect on the HASMCs exposed to PDGF-BB by regulating the PDGFR-ß/Akt/mTOR/HIF-1α signaling pathway.

The roles of phosphorylation of signaling proteins in the prognosis of acute myeloid leukemia.

Signaling pathways of Retinoblastoma (Rb) protein, Akt-kinase, and Erk-kinase (extracellular signal-regulated kinase) have an important role in the pathogenesis of acute myeloid leukemia. Constitutive activation of these proteins by phosphorylation contributes to cell survival by regulation of cell cycle, proliferation and proapoptotic signaling processes. According to previous data phosphorylated forms of these proteins represent a worse outcome for cancer patients. We investigated the presence of phosphorylated Rb (P-Rb), Akt (P-Akt) and Erk (P-Erk) proteins by Western blot technique using phospho-specific antibodies in bone marrow or peripheral blood samples of 69 AML patients, 36 patients with myelodysplastic syndrome (MDS) and 10 healthy volunteers. Expression level of PTEN (Phosphatase and tensin homolog) and PHLPP (PH domain and leucine-rich repeat Protein Phosphatase) phosphatases, the negative regulators of Akt kinase pathway were also examined. We tested the effect of these proteins on survival and on the correlation with known prognostic features in AML. We found 46.3% of AML patients had detectable P-Rb, 34.7% had P-Akt and 28.9% had P-Erk protein. 66.1% of patients expressing PTEN, 38.9% PHLPP, 37.2% both PTEN and PHLPP and 32.2% neither PTEN nor PHLPP phosphatases. Compared to nucleophosmin mutation (NPMc) negative samples P-Erk was significantly less in nucleophosmin mutated patients, P-Rb was significantly less in patients' group with more than 30 G/L peripheral leukocyte count by diagnosis. PHLPP was significantly present in FAB type M5. The expression of P-Rb represented significant better overall survival (OS), while P-Akt represented significantly worse event-free survival (EFS) in unfavorable cytogenetics patients. The presence of both PHLPP and PTEN phosphatases contributes to better OS and EFS, although the differences were not statistically significant. We confirmed significant positive correlation between P-Akt and PHLPP. Assessing the phosphorylation of Rb, Akt and Erk may define a subgroup of AML patients who would benefit especially from new targeted treatment options complemented the standard chemotherapy, and it may contribute to monitoring remission, relapse or progression of AML.

MiR-22-3p Inhibits 5-Fluorouracil Resistance in Cholangiocarcinoma Cells Through PTEN/PI3K/AKT Axis.

Cholangiocarcinoma (CCA) is a prevalent and highly lethal form of cancer globally. Although microRNAs (miRNAs) have been implicated in the advancement of CCA, their potential influence on 5-fluorouracil (5-Fu) resistance in CCA remains to be fully elucidated. Here, in this study, we investigated the impact of miR-22-3p on CCA resistance. Our investigation involved bioinformatics analysis, which revealed an association between miR-22-3p and the progression, diagnosis, and patient survival of CCA. Furthermore, we validated a notable downregulation of miR-22-3p expression in CCA cell lines. Elevated levels of miR-22-3p inhibit the activity and proliferation of 5-Fu-resistant CCA cell lines. In addition, we confirmed that phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a target gene of miR-22-3p, and its expression correlates with the survival of CCA patients. Reduced PTEN expression enhances apoptosis in 5-Fu-resistant CCA cells. Meanwhile, we verified the existence of the miR-22-3p/PTEN/phosphatidylinositol-3 kinase (PI3K)/Protein kinase B (AKT) regulatory networks in CCA, influencing the sensitivity of CCA cells to 5-Fu. In conclusion, our findings suggest that miR-22-3p acts as a tumor suppressor. Its overexpression inhibits the PTEN/PI3K/AKT axis, promoting cell apoptosis and enhancing CCA sensitivity to 5-Fu.

Unveiling the oncogenic role of LZTS1 in colorectal cancer.

Although leucine zipper tumour suppressor 1 (LZTS1) has been considered a potential tumour suppressor, accumulating evidence suggests that LZTS1 is highly expressed in many cancer types. To unravel the exact role of LZTS1 in colorectal carcinogenesis, we performed the bioinformatic analysis of LZTS1, including expression differences, correlations between expression levels and survival, methylation status of LZTS1 promoter and related cellular pathways based on TCGA dataset, GEO databases and our own CRC patient cohort. Furthermore, we confirmed the oncogenic function of LZTS1 in human mammalian cells by employing a series of assays including tissue microarray, immunoblotting, cell proliferation and migration assay. We found that the expression of LZTS1 is higher in tumour samples compared to paired normal tissue in CRC cancer and its different clinical subtypes, which is, at least in part, due to the low methylation status of LZTS1 promoter in CRC tumour samples. Functional analysis identified the close relationship between high expression of LZTS1 and PI3K-AKT pathway and the epithelial-mesenchymal transition (EMT) process. Consistently, we found that the expression of LZTS1 positively correlated with the expression PIK3CD, N-cadherin in CRC tumour samples, while the expression of LZTS1 negatively correlated with the expression of E-cadherin and PTEN in CRC tumour samples. Experimental data further confirmed that overexpression of LZTS1 upregulated activity of AKT and promoted EMT process. Furthermore, depletion of LZTS1 repressed the proliferation and migration rate of CRC cells. Thus, this study indicates that LZTS1 plays an oncogenic role in colorectal carcinogenesis.

A biochemical assessment of apoptosis-inducing impact of Salinomycin in combination with ciprofloxacin on human leukemia KG1-a stem-like cells in the presence and absence of insulin.

BACKGROUND: Acute Myeloid Leukemia (AML) is a fast-developing invading cancer that impacts the blood and bone marrow, marked by the rapid proliferation of abnormal white blood cells. Chemotherapeutic agents, a primary treatment for AML, encounter clinical limitations such as poor solubility and low bioavailability. Previous studies have highlighted antibiotics as effective in inducing cancer cell death and potentially preventing metastasis. Besides, insulin is known to activate the PI3K/Akt pathway, often disrupted in cancers, leading to enhanced cell survival and resistance to apoptosis. In light of the above-mentioned points, we examined the anti-cancer impact of antibiotics Ciprofloxacin (CP) and Salinomycin (SAL) and their combination on KG1-a cells in the presence and absence of insulin. METHODS: This was accomplished by exposing KG1-a cells to different doses of CP and SAL alone, in combination, and with or without insulin for 24-72 h. Cell viability was evaluated using the MTT assay. Besides, apoptotic effects were examined using Hoechst staining and Annexin-V/PI flow cytometry. The expression levels of Bax, p53, BIRC5, Akt, PTEN, and FOXO1 were analyzed through Real-Time PCR. RESULTS: CP and SAL demonstrated cytotoxic and notable pro-apoptotic impact on KG1-a cells by upregulating Bax and p53 and downregulating BIRC5, leading to G0/G1 cell cycle arrest and prevention of the PI3K-Akt signaling pathway. Our findings demonstrated that combination of CP and SAL promote apoptosis in the KG1-a cell line by down-regulating BIRC5 and Akt, as well as up-regulating Bax, p53, PTEN, and FOXO1. Additionally, the findings strongly indicated that insulin effectively mitigates apoptosis by enhancing Akt expression and reducing FOXO1 and PTEN gene expression in the cells treated with CP and SAL. CONCLUSION: Our findings showed that the combined treatment of CP and SAL exhibit a strong anti-cancer effect on leukemia KG1-a cells. Moreover, it was discovered that the PI3K-Akt signaling can be a promising target in leukemia treatment particularly in hyperinsulinemia condition.

[Genetic analysis of a Chinese pedigree affected with Cowden syndrome due to variant of PTEN gene].

OBJECTIVE: To explore the clinical features and genetic etiology of a Chinese pedigree affected with Cowden syndrome (CS). METHODS: A CS pedigree diagnosed in November 2022 at the Ningde Municipal Hospital Affiliated to Ningde Normal University was selected as the study subject. Clinical data were collected, and genetic testing was carried out for available members. Pathogenicity analysis was carried out for the candidate variant. RESULTS: The proband, a 7-year-old male, was found to have autism and intellectual disability. Whole exome sequencing revealed that he has harbored a c.462_463del (p.F154Lfs25) variant of the PTEN gene. The proband's 35-year-old mother, who was diagnosed with pulmonary hamartomas at our hospital, has manifested with lipomas, nodular goiter, and adenomas. Sanger sequencing confirmed that she was also heterozygous for the c.462_463del (p.F154Lfs25) variant of the PTEN gene. No other family members has carried the same variant. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was classified as pathogenic (PVS1+PM2_Supporting+PM6). CONCLUSION: The newly discovered c.462_463del (p.F154Lfs*25) variant of the PTEN gene probably underlay the CS in this pedigree. CS patients have higher risk for developing malignant tumors. Clinicians should be aware of this condition and emphasize follow-up of the patients.

A black phosphorus nanosheet-based RNA delivery system for prostate cancer therapy by increasing the expression level of tumor suppressor gene PTEN via CeRNA mechanism.

BACKGROUND: Prostate cancer (PCa) has a high incidence in men worldwide, and almost all PCa patients progress to the androgen-independent stage which lacks effective treatment measures. PTENP1, a long non-coding RNA, has been shown to suppress tumor growth through the rescuing of PTEN expression via a competitive endogenous RNA (ceRNA) mechanism. However, PTENP1 was limited to be applied in the treatment of PCa for the reason of rapid enzymatic degradation, poor intracellular uptake, and excessively long base sequence to be synthesized. Considering the unique advantages of artificial nanomaterials in drug loading and transport, black phosphorus (BP) nanosheet was employed as a gene-drug carrier in this study. RESULTS: The sequence of PTENP1 was adopted as a template which was randomly divided into four segments with a length of about 1000 nucleotide bases to synthesize four different RNA fragments as gene drugs, and loaded onto polyethyleneimine (PEI)-modified BP nanosheets to construct BP-PEI@RNA delivery platforms. The RNAs could be effectively delivered into PC3 cells by BP-PEI nanosheets and elevating PTEN expression by competitive binding microRNAs (miRNAs) which target PTEN mRNA, ultimately exerting anti-tumor effects. CONCLUSIONS: Therefore, this study demonstrated that BP-PEI@RNAs is a promising gene therapeutic platform for PCa treatment.

Mechanistic and therapeutic perspectives of miRNA-PTEN signaling axis in cancer therapy resistance.

Cancer, being one of the most lethal illnesses, presents an escalating clinical dilemma on a global scale. Despite significant efforts and advancements in cancer treatment over recent decades, the persistent challenge of resistance to traditional chemotherapeutic agents and/or emerging targeted drugs remains a prominent issue in the field of cancer therapies. Among the frequently inactivated tumor suppressor genes in cancer, phosphatase and Tensin Homolog (PTEN) stands out, and its decreased expression may contribute to the emergence of therapeutic resistance. MicroRNAs (miRNAs), characterized by their short length of 22 nucleotides, exert regulatory control over target mRNA expression by binding to complementary sequences. Recent findings indicate that microRNAs play varied regulatory roles, encompassing promotion, suppression, and dual functions on PTEN, and their aberration is implicated in heightened resistance to anticancer therapies. Significantly, recent research has revealed that competitive endogenous RNAs (ceRNAs) play a pivotal role in influencing PTEN expression, and the regulatory network involving circRNA/lncRNA-miRNA-PTEN is intricately linked to resistance in various cancer types to anticancer therapies. Finally, our findings showcase that diverse approaches, such as herbal medicine, small molecule inhibitors, low-intensity ultrasound, and engineered exosomes, can effectively overcome drug resistance in cancer by modulating the miRNA-PTEN axis.

Quercetin inhibits hypertonicity-induced inflammatory injury in human corneal epithelial cells via the PTEN/PI3K/AKT pathway.

Dry eye is a prevalent ophthalmic disease. Ocular surface inflammation in the hyperosmolar environment of the tear film is critical in dry eye progression. Quercetin has strong anti-inflammatory effects; however, its exact mechanism of action in dry eye is not fully understood. Therefore, this study investigated whether quercetin could inhibit the damage sustained to human corneal epithelial cells (HCECs) in a hyperosmolar environment through its anti-inflammatory effects. HCECs were cultured in a complete medium and were divided into four groups: normal, model, quercetin, and inhibitor. The proliferation of HCECs was detected by Ki67 staining; the expression levels of PTEN, p-PI3K and p-AKT were detected by Western blotting and immunofluorescence staining; the relative mRNA expression levels of PTEN, PI3K, AKT, IL-6 and TNF-ɑ were detected by quantitative real-time PCR; the relative expression levels of IL-6 and TNF-α were detected by enzyme-linked immunosorbent assay. In this study, the proliferation of HCECs in the model group was found to be significantly inhibited compared with that in the normal group; however, quercetin was effective in improving the proliferation of HCECs, decreasing the relative expression of p-PI3K, p-AKT, IL-6, TNF-ɑ as well as increasing PTEN. In conclusion, this study demonstrated that quercetin could promote the proliferation of HCECs and reduce the expression of inflammatory factors by inhibiting the PTEN/PI3K/AKT pathway in the hyperosmolarity-induced HCECs model.

The Role of PTEN in Chemoresistance Mediated by the HIF-1α/YY1 Axis in Pediatric Acute Lymphoblastic Leukemia.

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer. Current chemotherapy treatment regimens have improved survival rates to approximately 80%; however, resistance development remains the primary cause of treatment failure, affecting around 20% of cases. Some studies indicate that loss of the phosphatase and tensin homolog (PTEN) leads to deregulation of the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway, increasing the expression of proteins involved in chemoresistance. PTEN loss results in deregulation of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and induces hypoxia-inducible factor 1-alpha (HIF-1α) expression in various cancers. Additionally, it triggers upregulation of the Yin Yang 1 (YY1) transcription factor, leading to chemoresistance mediated by glycoprotein p-170 (Gp-170). The aim of this study was to investigate the role of the PTEN/NF-κB axis in YY1 regulation via HIF-1α and its involvement in ALL. A PTEN inhibitor was administered in RS4;11 cells, followed by the evaluation of PTEN, NF-κB, HIF-1α, YY1, and Gp-170 expression, along with chemoresistance assessment. PTEN, HIF-1α, and YY1 expression levels were assessed in the peripheral blood mononuclear cells (PBMC) from pediatric ALL patients. The results reveal that the inhibition of PTEN activity significantly increases the expression of pAkt and NF-κB, which is consistent with the increase in the expression of HIF-1α and YY1 in RS4;11 cells. In turn, this inhibition increases the expression of the glycoprotein Gp-170, affecting doxorubicin accumulation in the cells treated with the inhibitor. Samples from pediatric ALL patients exhibit PTEN expression and higher HIF-1α and YY1 expression compared to controls. PTEN/Akt/NF-κB axis plays a critical role in the regulation of YY1 through HIF-1α, and this mechanism contributes to Gp-170-mediated chemoresistance in pediatric ALL.

[Solasonine promotes apoptosis of non-small cell lung cancer cells by regulating the Bcl-2/Bax/caspase-3 pathway].

OBJECTIVE: To investigate the effect of solasonine, an active component of Solanum nigrum, on proliferation and apoptosis of non-small cell lung cancer PC9 cells. METHODS: PC9 cells were treated with 2, 5, 10, 15, 20, or 25 µmol/L solasonine, and the changes in cell proliferation were examined using CCK-8 assay. Tetramethyl rhodamine ethyl ester (TMRE) was used to detect the changes in mitochondrial membrane potential, and caspase-3/7 detection kit and GreenNucTM caspase-3/Annexin V-mCherry kit for live cell were used to analyze the changes in caspase-3 of the cells. Annexin V-FITC/PI double staining was employed to analyze the apoptosis rate of the cells. The effect of PTEN inhibitors on solasonine-induced cell apoptosis was examined by detecting apoptosis-related protein expressions using Western blotting. RESULTS: Solasonine treatment for 24, 48, and 72 h significantly lowered the viability of PC9 cells. The cells treated with solasonine for 24 h showed significantly decreased mitochondrial membrane potential and increased cell apoptosis with enhanced caspase-3/7 and caspase-3 activities and expression of cleaved caspase-3. Solasonine treatment significantly decreased phosphorylation levels of PI3K and Akt, increased the protein expressions of PTEN and Bax, and lowered the expression of Bcl-2 protein in the cells. CONCLUSION: Solasonine inhibits proliferation and induces apoptosis of PC9 cells by regulating the Bcl-2/Bax/caspase-3 pathway and its upstream proteins.

[MiR-224-5p overexpression inhibits oxidative stress by regulating the PI3K/Akt/FoxO1 axis to attenuate hypoxia/reoxygenation-induced cardiomyocyte injury].

OBJECTIVES: To investigate the regulatory role of miRNA-224-5p in hypoxia/reoxygenation (H/R) -induced H9c2 cardiomyocyte injury. METHODS: Plasma samples were collected from 160 patients with acute myocardial infarction and 80 healthy controls(HC) to measure miRNA-224-5p levels and other biochemical parameters. In cultured H9c2 cells with H/R injury, the effects of transfection with miR-224-5p mimics or a negative control sequence on cell viability, malondialdehyde (MDA) content, and superoxide dismutase 2 (SOD2) and lactate dehydrogenase (LDH) activities were tested. Dual luciferase reporter gene assay was performed to verify the targeting relationship between miR-224-5p and PTEN. Bioinformatics methods were used to analyze the potential mechanisms of the target genes. The expression of miRNA-224-5p in the treated cells was detected with qRT-PCR, the protein expressions of PTEN, Bcl-2, Bax, cleaved caspase-3, SOD2, p-PI3K/PI3K, p-Akt/Ak and p-FoxO1/FoxO1 were determined using Western blotting, and cell apoptosis was analysed with flow cytometry. RESULTS: The levels of blood glucose, C-reactive protein, CK, CK-MB and cTnI were significantly higher in the AMI group compared with the HC group (P < 0.05). The expression level of miR-224-5p was significantly lowered in patients with STEMI and NSTEMI and in H9c2 cells with H/R injury. The viability of H9c2 cells decreased time-dependently following H/R injury. PTEN was a target gene of miR-224-5p, and the PI3K/Akt pathway was the most significantly enriched pathway. H9c2 cells with H/R injury showed significantly decreased SOD2 activity, increased LDH activity and MDA content, increased cell apoptosis, decreased protein expression levels of p-PI3K, p-Akt, p-FoxO1, SOD2, and Bcl-2, and increased expressions of PTEN, Bax, and cleaved caspase-3. These changes were obviously attenuated by trasnfection of the cells with miR-224-5p mimics prior to H/R exposure. CONCLUSION: MiR-224-5p overexpression upregulates the expression of the antioxidant gene SOD2 through the PI3K/Akt/FoxO1 axis to relieve H/R-induced oxidative stress and reduce apoptosis of H9c2 cells.

SOLAMEN syndrome with cardiovascular damage.

SOLAMEN syndrome is a rare, recently recognized congenital syndrome that is characterized by progressive and hypertrophic diseases involving multiple systems, including segmental overgrowth, lipomatosis, arteriovenous malformation (AVM) and epidermal nevus. According to literatures, SOLAMEN syndrome is caused by heterozygous PTEN mutation. Phenotypic overlap complicates the clinical identification of diseases associated with PTEN heterozygous mutations, making the diagnosis of SOLAMEN more challenging. In addition, SOLAMEN often presents with segmental tissue overgrowth and vascular malformations, increasing the possibility of misdiagnosis as klipple-trenaunay syndrome or Parks-Weber syndrome. Here, we present a case of a child presenting with macrocephaly, patchy lymphatic malformation on the right chest, marked subcutaneous varicosities and capillaries involving the whole body, overgrowth of the left lower limb, a liner epidermal nevus on the middle of the right lower limb, and a large AVM on the right cranial thoracic entrance. Based on the typical phenotypes, the child was diagnosed as SOLAMEN syndrome. detailed clinical, imaging and genetic diagnoses of SOLAMEN syndrome was rendered. Next-generation sequencing (NGS) data revealed that except for a germline PTEN mutation, a PDGFRB variant was also identified. A subsequent echocardiographic examination detected potential cardiac defects. We suggested that given the progressive nature of AVM and the potential severity of cardiac damage, regular echocardiographic evaluation, imaging follow-up and appropriate interventional therapy for AVM are recommended.