PTEN Loss Is Associated with Adverse Outcomes in the Setting of Salvage Radiation Therapy.

BACKGROUND: Salvage radiation therapy (SRT) is a mainstay of treatment for biochemical relapse following radical prostatectomy; however, few studies have examined genomic biomarkers in this context. OBJECTIVE: We characterized the prognostic impact of previously identified deleterious molecular phenotypes-loss of PTEN, ERG expression, and TP53 mutation-for patients undergoing SRT. DESIGN, SETTING, AND PARTICIPANTS: We leveraged an institutional database of 320 SRT patients with available tissue and follow-up. Tissue microarrays were used for genetically validated immunohistochemistry assays. INTERVENTION: All men underwent SRT with or without androgen deprivation therapy OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Univariable and multivariable Cox-proportional hazard models assessed the association of molecular phenotypes with biochemical recurrence-free (bRFS) and metastasis-free (MFS) survival after SRT. RESULTS AND LIMITATIONS: Loss of PTEN (n = 123, 43%) and ERG expression (n = 118, 39%) were common in this cohort, while p53 overexpression (signifying TP53 missense mutation) was infrequent (n = 21, 7%). In univariable analyses, any loss of PTEN portended worse bRFS (hazard ratio [HR] 1.86; 95% confidence interval 1.36-2.57) and MFS (HR 1.89; 1.21-2.94), with homogeneous PTEN loss being associated with the highest risk of MFS (HR 2.47; 1.54-3.95). Similarly, p53 overexpression predicted worse bRFS (HR 1.95; 1.14-3.32) and MFS (HR 2.79; 1.50-5.19). ERG expression was associated with worse MFS only (HR 1.6; 1.03-2.48). On the multivariable analysis adjusting for known prognostic features, homogeneous PTEN loss remained predictive of adverse bRFS (HR 1.82; 1.12-2.96) and MFS (HR 2.08; 1.06-4.86). The study is limited by its retrospective and single-institution design. CONCLUSIONS: PTEN loss by immunohistochemistry is an independent adverse prognostic factor for bRFS and MFS in prostate cancer patients treated with SRT. Future trials will determine the optimal approach to treating SRT patients with adverse molecular prognostic features. PATIENT SUMMARY: Loss of the PTEN tumor suppressor protein is associated with worse outcomes after salvage radiotherapy, independent of other clinical or pathologic patient characteristics.

Dysregulated Urinary Extracellular Vesicle Small RNAs in Diabetic Nephropathy: Implications for Diagnosis and Therapy.

Background: Diabetic nephropathy (DN) represents a major chronic kidney disorder and a leading cause of end-stage renal disease (ESRD). Small RNAs have been showing great promise as diagnostic markers as well as drug targets. Identifying dysregulated micro RNAs (miRNAs) could help in identifying disease biomarkers and investigation of downstream interactions, shedding light on the molecular pathophysiology of DN. In this study, we analyzed small RNAs within human urinary extracellular vesicles (ECVs) from DN patients using small RNA next-generation sequencing. Method: In this cross-sectional study, urine samples were collected from 88 participants who were divided into 3 groups: type 2 diabetes (T2D) with DN (T2D + DN, n = 20), T2D without DN (T2D - DN, n = 40), and healthy individuals (n = 28). The study focused on isolating urinary ECVs to extract and sequence small RNAs. Differentially expressed small RNAs were identified, and a functional enrichment analysis was conducted. Results: The study revealed a distinct subset of 13 miRNAs and 10 Piwi-interacting RNAs that were significantly dysregulated in urinary ECVs of the DN group when compared to other groups. Notably, miR-151a-3p and miR-182-5p exhibited a unique expression pattern, being downregulated in the T2D - DN group, and upregulated in the T2D + DN group, thus demonstrating their effectiveness in distinguishing patients between the 2 groups. Eight driver genes were identified PTEN, SMAD2, SMAD4, VEGFA, CCND2, CDK6, LIN28B, and CHD1. Conclusion: Our findings contribute valuable insights into the pathogenesis of DN, uncovering novel biomarkers and identifying potential therapeutic targets that may aid in managing and potentially decelerating the progression of the disease.

Can thyroid histomorphology identify patients with PTEN hamartoma tumour syndrome?

AIMS: The phosphatase and tensin homologue (PTEN) hamartoma tumour syndrome (PHTS) is a genetic disorder with variable clinical presentation and increased lifetime risk of multiorgan malignancies. The thyroid gland is commonly affected with follicular nodular disease (FND) and follicular cell-derived carcinomas. Histopathological and immunohistochemical assessment of thyroid disease in PHTS is essential to identify patients at-risk. METHODS AND RESULTS: In all, 30 PHTS patients with available thyroidectomy specimen material (2000-2023) and 31 control patients with FND and "adenomatous nodules" were retrieved. Histologic criteria, including the frequency of adenomatous-type nodules versus hyperplastic-type nodules, background and nodular lipomatous metaplasia, chronic lymphocytic thyroiditis, cytoplasmic clearing of follicular cells in nodules, nodule-in-nodule appearance, and spectrum of nuclear atypia between nodules were evaluated in both cohorts and a Thyroid Histomorphologic PHTS Score (THiPS) system was established with a cutoff of 4 points or higher being considered concerning for PHTS. In all, 27 PHTS (90%) and five control (16.1%) cases had THiPS ≥4. A PTEN immunohistochemical stain was evaluated in 25 cases of each cohort and showed nuclear and cytoplasmic loss of expression in all or most of the nodules of 24/25 PHTS cases. In 3/25 control cases, two with THiPS ≥4, had loss of expression in one to multiple nodules. Conventional papillary thyroid carcinomas in PHTS patients retained PTEN cytoplasmic expression. CONCLUSIONS: Our study supports that, although not specific, the finding of multiple histologic features is found more frequently in patients with PHTS compared to the non-PHTS control group. The THiPS system has high sensitivity for thyroid specimens from patients with PHTS.

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.

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.

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.

14-3-3σ/Stratifin and p21 limit AKT-related malignant progression in skin carcinogenesis following MDM2-associated p53 loss.

To study mechanisms driving/inhibiting skin carcinogenesis, stage-specific expression of 14-3-3σ (Stratifin) was analyzed in skin carcinogenesis driven by activated rasHa/fos expression (HK1.ras/fos) and ablation of PTEN-mediated AKT regulation (K14.creP/Δ5PTENflx/flx). Consistent with 14-3-3σ roles in epidermal differentiation, HK1.ras hyperplasia and papillomas displayed elevated 14-3-3σ expression in supra-basal keratinocytes, paralleled by supra-basal p-MDM2166 activation and sporadic p-AKT473 expression. In bi-genic HK1.fos/Δ5PTENflx/flx hyperplasia, basal-layer 14-3-3σ expression appeared, and alongside p53/p21, was associated with keratinocyte differentiation and keratoacanthoma etiology. Tri-genic HK1.ras/fos-Δ5PTENflx/flx hyperplasia/papillomas initially displayed increased basal-layer 14-3-3σ, suggesting attempts to maintain supra-basal p-MDM2166 and protect basal-layer p53. However, HK1.ras/fos-Δ5PTENflx/flx papillomas exhibited increasing basal-layer p-MDM2166 activation that reduced p53, which coincided with malignant conversion. Despite p53 loss, 14-3-3σ expression persisted in well-differentiated squamous cell carcinomas (wdSCCs) and alongside elevated p21, limited malignant progression via inhibiting p-AKT1473 expression; until 14-3-3σ/p21 loss facilitated progression to aggressive SCC exhibiting uniform p-AKT1473. Analysis of TPA-promoted HK1.ras-Δ5PTENflx/flx mouse skin, demonstrated early loss of 14-3-3σ/p53/p21 in hyperplasia and papillomas, with increased p-MDM2166/p-AKT1473 that resulted in rapid malignant conversion and progression to poorly differentiated SCC. In 2D/3D cultures, membranous 14-3-3σ expression observed in normal HaCaT and SP1ras61 papilloma keratinocytes was unexpectedly detected in malignant T52ras61/v-fos SCC cells cultured in monolayers, but not invasive 3D-cells. Collectively, these data suggest 14-3-3σ/Stratifin exerts suppressive roles in papillomatogenesis via MDM2/p53-dependent mechanisms; while persistent p53-independent expression in early wdSCC may involve p21-mediated AKT1 inhibition to limit malignant progression.

Molecular landscape of borderline ovarian tumours: A systematic review.

Borderline ovarian tumours (BOTs) show intriguing characteristics distinguishing them from other ovarian tumours. The aim of the systematic review was to analyse the spectrum of molecular changes found in BOTs and discuss their significance in the context of the overall therapeutic approach. The systematic review included articles published between 2000 and 2023 in the databases: PubMed, EMBASE, and Cochrane. After a detailed analysis of the available publications, we qualified for the systematic review: 28 publications on proto-oncogenes: BRAF, KRAS, NRAS, ERBB2, and PIK3CA, 20 publications on tumour suppressor genes: BRCA1/2, ARID1A, CHEK2, PTEN, 4 on adhesion molecules: CADM1, 8 on proteins: B-catenin, claudin-1, and 5 on glycoproteins: E-Cadherin. In addition, in the further part of the systematic review, we included eight publications on microsatellite instability and three describing loss of heterozygosity in BOT. Molecular changes found in BOTs can vary on a case-by-case basis, identifying carcinogenic mutations through molecular analysis and developing targeted therapies represent significant advancements in the diagnosis and treatment of ovarian malignancies. Molecular studies have contributed significantly to our understanding of BOT pathogenesis, but substantial research is still required to elucidate the relationship between ovarian neoplasms and extraneous disease, identify accurate prognostic indicators, and develop targeted therapeutic approaches.

Histopathological phenotyping of cancers in PTEN Hamartoma Tumor Syndrome for improved recognition: A single-center study.

PTEN hamartoma tumor syndrome (PHTS) has a broad clinical spectrum including various benign and malignant tumors at varying age of diagnosis. Many patients remain unrecognized, unaware of their increased cancer risk. We aimed to describe the cancer spectrum, age of onset and histopathological cancer characteristics to assess whether specific cancer characteristics could improve PHTS recognition. Genetic testing results and pathology reports were collected for patients tested for germline PTEN variants between 1997 and 2020 from the diagnostic laboratory and the Dutch nationwide pathology databank (Palga). The cancer spectrum and age of onset were assessed in patients with (PTENpos) and without (PTENneg) a germline PTEN variant. Histopathological cancer characteristics were assessed in a nested cohort. 341 PTENpos patients (56% females) and 2882 PTENneg patients (66% females) were included. PTENpos patients presented mostly with female breast (BC, 30%), endometrial (EC, 6%), thyroid (TC, 4%) or colorectal cancer (4%). PTENpos were significantly younger at cancer onset (43 vs. 47 years) and had more often (46% vs. 18%) a second BC than PTENneg. PTEN detection rates were highest for BC <40 years (9%), TC <20 years (15%) and EC <50 years (28%), and dropped to 6%, 4%, and 15% by age 60. Histopathological characteristics were similar between groups. No histopathological cancer characteristics were distinctive for PHTS. However, PTENpos were significantly younger at cancer onset. Therefore early-onset BC, EC, or TC warrants consideration of PHTS diagnostics either through a pre-screen for other PHTS features or direct germline testing.

Loss of Cavin-2 destabilizes PTEN and enhances Akt signaling pathway in cardiomyocytes.

AIMS: Specific cavins and caveolins, known as caveolae-related proteins, have been implicated in cardiac hypertrophy and myocardial injury. Cavin-2 forms complexes with other caveolae-related proteins, but the role of Cavin-2 in cardiomyocytes (CMs) is poorly understood. Here, we investigated an unknown function of Cavin-2 in CMs. METHODS AND RESULTS: Under cardiac stress-free conditions, systemic Cavin-2 knockout (KO) induced mild and significant CM hypertrophy. Cavin-2 KO suppressed phosphatase and tensin homolog (PTEN) associated with Akt signaling, whereas there was no difference in Akt activity between the hearts of the wild-type and the Cavin-2 KO mice under cardiac stress-free conditions. However, after swim training, CM hypertrophy was more facilitated with enhanced PI3K-Akt activity in the hearts of Cavin-2 KO mice. Cavin-2 knockdown neonatal rat CMs (NRCMs) using adenovirus expressing Cavin-2 shRNA were hypertrophied and resistant to hypoxia and H2O2-induced apoptosis. Cavin-2 knockdown increased Akt phosphorylation in NRCMs, and an Akt inhibitor inhibited Cavin-2 knockdown-induced anti-apoptotic responses in a dose-dependent manner. Cavin-2 knockdown increased PIP3 production and attenuated PTEN at the membrane fraction of NRCMs. Immunostaining and immunoprecipitation showed that Cavin-2 was associated with PTEN at the plasma membrane of NRCMs. A protein stability assay showed that Cavin-2 knockdown promoted PTEN destabilization in NRCMs. In an Angiotensin II (2-week continuous infusion)-induced pathological cardiac hypertrophy model, CM hypertrophy and CM apoptosis were suppressed in cardiomyocyte-specific Cavin-2 conditional KO (Cavin-2 cKO) mice. Because Cavin-2 cKO mouse hearts showed increased Akt activity but not decreased extracellular signal-regulated kinase activity, suppression of pathological hypertrophy by Cavin-2 loss may be due to increased survival of healthy CMs. CONCLUSIONS: Cavin-2 plays a negative regulator in the PI3K-Akt signaling in CMs through interaction with PTEN. Loss of Cavin-2 enhances Akt activity by promoting PTEN destabilization, which promotes physiological CM hypertrophy and may enhance Akt-mediated cardioprotective effects against pathological CM hypertrophy.

A comprehensive review of the PTEN/PI3K/Akt axis in multiple myeloma: From molecular interactions to potential therapeutic targets.

Phosphatase and tensin homolog (PTEN), phosphatidylinositol 3-kinase (PI3K), and protein kinase B (Akt) signaling pathways contribute to the development of several cancers, including multiple myeloma (MM). PTEN is a tumor suppressor that influences the PI3K/Akt/mTOR pathway, which in turn impacts vital cellular processes like growth, survival, and treatment resistance. The current study aims to present the role of PTEN and PI3K/Akt/mTOR signaling in the development of MM and its response to treatment. In addition, the molecular interactions in MM that underpin the PI3K/Akt/mTOR pathway and address potential implications for the development of successful treatment plans are also discussed in detail. We investigate their relationship to both upstream and downstream regulators, highlighting new developments in combined therapies that target the PTEN/PI3K/Akt axis to overcome drug resistance, including the use of PI3K and mitogen-activated protein kinase (MAPK) inhibitors. We also emphasize that PTEN/PI3K/Akt pathway elements may be used in MM diagnosis, prognosis, and therapeutic targets.

Rs12039395 Variant Influences the Expression of hsa-miR-181a-5p and PTEN Toward Colorectal Cancer Risk.

BACKGROUND: Single nucleotide polymorphisms (SNPs) in microRNA (miRNA) genes could alter miRNA expression levels or processing and, thus, may contribute to colorectal cancer (CRC) development. Therefore, this study aimed to examine whether the MIR181A1 genomic sequence possesses SNPs that can affect the expression of hsa-miR-181a-5p and, subsequently, impact its targets and associate with CRC risk. METHODS: The NCBI dbSNP database was searched for possible SNPs associated with MIR181A1. One SNP with a minor allele frequency > 5%, rs12039395 G > T was identified. In silico analyses determined the effect of the SNP on the secondary structure of the miRNA and predicted the hsa-miR-181a-5p target genes. The SNP was genotyped using allelic discrimination assay, the relative hsa-miR-181a-5p expression level was determined using quantitative real-time PCR, and immunohistochemical staining was used to detect target genes in 192 paraffin-embedded specimens collected from 160 CRC patients and 32 healthy subjects. RESULTS: The rs6505162 SNP conferred protection against CRC, and the G-allele presence provides may provide accessibility for the transcriptional machinery. Hsa-miR-181a-5p was significantly over-expressed in the CRC group compared to controls and in samples carrying the G-allele compared to those with T-allele. PTEN, identified as the only hsa-miR-181a-5p target implicated in CRC, was significantly diminished in the CRC group compared to controls and showed an inverse relationship with hsa-miR-181a-5p expression level as well as negatively associated with the G-allele presence in CRC. CONCLUSION: This study highlights that rs12039395 G > T may protect against CRC by influencing the expression of hsa-mir-181a-5p and its target gene, PTEN.

Mechanisms Underlying the Development of Murine T-Cell Lymphoblastic Lymphoma/Leukemia Induced by Total-Body Irradiation.

Exposure to ionizing radiation is associated with an increased risk of hematologic malignancies in myeloid and lymphoid lineages in humans and experimental mice. Given that substantial evidence links radiation exposure with the risk of hematologic malignancies, it is imperative to deeply understand the mechanisms underlying cellular and molecular changes during the latency period between radiation exposure and the emergence of fully transformed malignant cells. One experimental model widely used in the field of radiation and cancer biology to study hematologic malignancies induced by radiation exposure is mouse models of radiation-induced thymic lymphoma. Murine radiation-induced thymic lymphoma is primarily driven by aberrant activation of Notch signaling, which occurs frequently in human precursor T-cell lymphoblastic lymphoma (T-LBL) and T-cell lymphoblastic leukemia (T-ALL). Here, we summarize the literature elucidating cell-autonomous and non-cell-autonomous mechanisms underlying cancer initiation, progression, and malignant transformation in the thymus following total-body irradiation (TBI) in mice.

High glucose-induced downregulation of PTEN-Long is sufficient for proximal tubular cell injury in diabetic kidney disease.

During the progression of diabetic kidney disease, proximal tubular epithelial cells respond to high glucose to induce hypertrophy and matrix expansion leading to renal fibrosis. Recently, a non-canonical PTEN has been shown to be translated from an upstream initiation codon CUG (leucine) to produce a longer protein called PTEN-Long (PTEN-L). Interestingly, the extended sequence present in PTEN-L contains cell secretion/penetration signal. Role of this non-canonical PTEN-L in diabetic renal tubular injury is not known. We show that high glucose decreases expression of PTEN-L. As a mechanism of its function, we find that reduced PTEN-L activates Akt-2, which phosphorylates and inactivate tuberin and PRAS40, resulting in activation of mTORC1 in tubular cells. Antibacterial agent acriflavine and antiviral agent ATA regulate translation from CUG codon. Acriflavine and ATA, respectively, decreased and increased expression of PTEN-L to altering Akt-2 and mTORC1 activation in the absence of change in expression of canonical PTEN. Consequently, acriflavine and ATA modulated high glucose-induced tubular cell hypertrophy and lamininγ1 expression. Importantly, expression of PTEN-L inhibited high glucose-stimulated Akt/mTORC1 activity to abrogate these processes. Since PTEN-L contains secretion/penetration signals, addition of conditioned medium containing PTEN-L blocked Akt-2/mTORC1 activity. Notably, in renal cortex of diabetic mice, we found reduced PTEN-L concomitant with Akt-2/mTORC1 activation, leading to renal hypertrophy and lamininγ1 expression. These results present first evidence for involvement of PTEN-L in diabetic kidney disease.

Quercetin inhibits breast cancer cell proliferation and survival by targeting Akt/mTOR/PTEN signaling pathway.

Recently, natural compounds such as quercetin have gained an increasing amount of attention in treating breast cancer. However, the exact mechanisms responsible for the antiproliferative functions of quercetin are not completely understood. Therefore, we aimed to examine quercetin impacts on breast cancer cell proliferation and survival and the involvement of PI3K/Akt/mTOR pathway. Breast cancer MDA-MB-231 and MCF-7 cells were exposed to quercetin, and cell proliferation was assessed by MTT assay. ELISA was applied to evaluate cell apoptosis. The expression levels of apoptotic mediators such as caspase-3, Bcl-2, Bax and PI3K, Akt, mTOR, and PTEN were assessed via qRT-PCR and western blot. We found that quercetin suppressed dose dependently cell growth capacity in MDA-MB-231 and MCF-7 cells. In addition, quercetin treatment increase apoptosis in both cells lines via modulating the pro- and antiapoptotic markers. Quercetin upregulated PTEN and downregulated PI3K, Akt, and mTOR, hence suppressing this signaling pathway in cells. In conclusion, we showed antiproliferative and pro-apoptotic function of quercetin in breast cancer cell lines, which is mediated by targeting and suppressing PI3K/Akt/mTOR signal transduction.

LncRNA AFAP1-AS1 mediates breast cancer cell proliferation and migration through the miR-21/PTEN axis.

LncRNAs play various effects, mostly by sponging with miRNAs. Based on public databases integrating bioinformatics analyses and further validation in breast cancer (BC) tissue and cell lines, the effect of lncRNA AFAP1-AS1 on breast cancer cell proliferation and migration was verified. It might work via the miR-21/PTEN axis. The expression of AFAP1-AS1, which was significantly upregulated in BC tissues and cell lines, was correlated with old age and lymph node metastasis of patients with BC. Knockdown of AFAP1-AS1 inhibited the proliferation and migration of BC cells in vitro and in vivo. And downregulated miR-21 expression and upregulated PTEN expression additionally. Mechanistically, the knockdown of lncRNA AFAP1-AS1 upregulated PTEN expression and consequently attenuated miR-21-mediated enhanced BC cell proliferation and migration. LncRNA AFAP1-AS1 is a potential prognostic biomarker for BC patients.

Cytotoxic and molecular differences of anticancer agents on 2D and 3D cell culture.

BACKGROUND: Cancer and multidrug resistance are regarded as concerns related to poor health outcomes. It was found that the monolayer of 2D cancer cell cultures lacks many important features compared to Multicellular Tumor Spheroids (MCTS) or 3D cell cultures which instead have the ability to mimic more closely the in vivo tumor microenvironment. This study aimed to produce 3D cell cultures from different cancer cell lines and to examine the cytotoxic activity of anticancer medications on both 2D and 3D systems, as well as to detect alterations in the expression of certain genes levels. METHOD: 3D cell culture was produced using 3D microtissue molds. The cytotoxic activities of colchicine, cisplatin, doxorubicin, and paclitaxel were tested on 2D and 3D cell culture systems obtained from different cell lines (A549, H1299, MCF-7, and DU-145). IC50 values were determined by MTT assay. In addition, gene expression levels of PIK3CA, AKT1, and PTEN were evaluated by qPCR. RESULTS: Similar cytotoxic activities were observed on both 3D and 2D cell cultures, however, higher concentrations of anticancer medications were needed for the 3D system. For instance, paclitaxel showed an IC50 of 6.234 µM and of 13.87 µM on 2D and 3D H1299 cell cultures, respectively. Gene expression of PIK3CA in H1299 cells also showed a higher fold change in 3D cell culture compared to 2D system upon treatment with doxorubicin. CONCLUSION: When compared to 2D cell cultures, the behavior of cells in the 3D system showed to be more resistant to anticancer treatments. Due to their shape, growth pattern, hypoxic core features, interaction between cells, biomarkers synthesis, and resistance to treatment penetration, the MCTS have the advantage of better simulating the in vivo tumor conditions. As a result, it is reasonable to conclude that 3D cell cultures may be a more promising model than the traditional 2D system, offering a better understanding of the in vivo molecular changes in response to different potential treatments and multidrug resistance development.

Regulation of Metastasis and Growth of Colorectal Cancer via Targeting the PTEN Pathway: An Update on the Progress of LncRNA MLLT4-AS1.

BACKGROUND: Globally, colorectal cancer (CRC) is known as the primary cause of mortality. Recent studies have reported that long non-coding RNAs (lncRNAs) are essential in assessing the survival of CRC patients. However, the function of the novel lncRNA MLLT4-AS1 in CRC is still unknown. OBJECTIVE: This study aimed to identify the expression and the clinical significance of lncRNA MLLT4-AS1 in CRC. METHODS: The level of MLLT4-AS1 in CRC was evaluated via the TCGA database. The relative level of MLLT4-AS1 in CRC cell lines was assessed by RT qPCR analysis. In cell culture, HT29 cells were transfected with MLLT4-AS1 siRNA, negative control, overexpressed MLLT4-AS1, or PTEN plasmids. Flow cytometry, CCK 8 assay, wound healing analysis, and transwell assay were used to quantify apoptosis, cell propagation, migration, and invasion, respectively. A nude mouse xenograft model was developed to evaluate the in vivo impact of MLLT4-AS1 plasmids on tumor growth. RNA pull-down analysis was used to search for possible targets of MLLT4-AS1. RESULTS: MLLT4-AS1 was substantially increased in CRC cell lines and patients. It inhibited CRC cell apoptosis and accelerated their proliferative, migration, and invasive properties. In in vivo analysis, MLLT4-AS1 also enhanced the metastasis and proliferation of CRC cells. It was found that PTEN was substantially enriched by biotin-labeled PTEN, as identified via an RNA pull-- down analysis. The expression of phosphatase and PTEN was suppressed by MLLT4-AS1 by ubiquitination proteasome-dependent RNA degradation. Thus, PTEN is considered a potential target of MLLT4-AS1. By targeting PTEN, MLLT4-AS1 intensified the biological behavior of malignant CRC. CONCLUSION: The study concluded that the MLLT4-AS1/PTEN axis may represent an innovative therapeutic intervention for CRC patients.

Taurine Improved Autism-Like Behaviours and Defective Neurogenesis of the Hippocampus in BTBR Mice through the PTEN/mTOR/AKT Signalling Pathway.

Effective treatment of patients with autism spectrum disorder (ASD) is still absent so far. Taurine exhibits therapeutic effects towards the autism-like behaviour in ASD model animals. Here, we determined the mechanism of taurine effect on hippocampal neurogenesis in genetically inbred BTBR T+ tf/J (BTBR) mice, a proposed model of ASD. In this ASD mouse model, we explored the effect of oral taurine supplementation on ASD-like behaviours in an open field test, elevated plus maze, marble burying test, self-grooming test, and three-chamber test. The mice were divided into four groups of normal controls (WT) and models (BTBR), who did or did not receive 6-week taurine supplementation in water (WT, WT+ Taurine, BTBR, and BTBR+Taurine). Neurogenesis-related effects were determined by Ki67 immunofluorescence staining. Western blot analysis was performed to detect the expression of phosphatase and tensin homologue deleted from chromosome 10 (PTEN)/mTOR/AKT pathway-associated proteins. Our results showed that taurine improved the autism-like behaviour, increased the proliferation of hippocampal cells, promoted PTEN expression, and reduced phosphorylation of mTOR and AKT in hippocampal tissue of the BTBR mice. In conclusion, taurine reduced the autism-like behaviour in partially inherited autism model mice, which may be associa-ted with improving the defective neural precursor cell proliferation and enhancing the PTEN-associated pathway in hippocampal tissue.