Phosphatase and Tensin Homolog Deleted on Chromosome Ten (PTEN) Derived from Bone Marrow Stromal Cells Promotes the Development of Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) remains a threat to women’s life with a lack of targeted therapy. This study aimed to explore the role of PTEN derived from BMSCs in TNBC. We carried out a retrospective analysis of 65 TNBC patients and 30 healthy subjects from October 2016 to January 2021 with a 10-year follow up. PTEN expression in TNBC tissues and cells was determined by RTqPCR. Functional experiments were conducted to evaluate PTEN’s effect on TNBC cell biological behaviors using MTT assay and Transwell assay, as well as on PI3K-Akt-HIF-1α-VEGF signaling transduction. PTEN was up-regulated in TNBC tissues relative to healthy controls and it was negatively associated with the survival rate. In in vitro experiments, PTEN overexpression increased cell viability and invasion and knocking down of PTEN exerted opposite effect. The expression of PI3K was directly regulated by PTEN. Up-regulation of PTEN resulted in a decline in HIF-1α, Akt and VEGF expressions, which were elevated after knocking down of PTEN. In conclusion, PTEN derived from BMSCs promotes TNBC cell development through blocking PI3K-Akt-HIF-1α-VEGF signaling pathway, providing a new theoretical basis for targeted therapy of TNBC.

Effects of Eight-Week Combined Resistance and Endurance Training on Serum Levels of Prostate Specific Antigen (PSA), Sex Hormone Binding Globulin (SHBG), and Phosphatase and Tensin Homolog (PTEN) in Men with Prostate Cancer

Background: Prostate cancer (PC) is the second most prevalent cancer and the sixth cancer leading to death in men worldwide. Objectives: The purpose of this study was to examine the effect of eight weeks of combined training on specific markers of prostate cancer in older adults. Methods: Twenty older adults (62 ± 7 years) with prostate cancer were divided randomly into the control (n = 10) and training (n = 10) groups. The training group performed exercise training in three sessions a week for eight weeks. Resistance training included two sets of 10 repetitions at 60 - 75% of one-repetition maximum, and endurance training contained treadmill running for 20 - 35 min at 60 - 75% of maximum heart rate. Bruce test, one-repetition maximum, and ELISA technique were used respectively to measure the aerobic performance, strength performance, and serum levels of prostate specific antigen (PSA), sex hormone binding globulin (SHBG), phosphatase and tensin homolog (PTEN), and testosterone (TS). A two-way analysis of variance with repeated measures was used to specify the differences. Results: Weight, fat percentage, Body Mass Index (BMI), waist-hip ratio (WHR), glucose, insulin, and PSA were significantly lower in the training group than the control group (P < 0.05). Furthermore, strength performance, aerobic performance, SHBG, TS, and PTEN were significantly higher in the training group than in the control group (P < 0.05). Conclusions: Combined training can have an influential role in physical condition improvement through decreasing the PSA serum level and increasing SHBG, TS, and PETEN serum levels, which helps patients with prostate cancer to be cured.

miR-338-3p Blocks TGFβ-Induced Myofibroblast Differentiation through the Induction of PTEN

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial lung disease. The pathogenesis of IPF is not completely understood. However, numerous genes are associated with the development and progression of pulmonary fibrosis, indicating there is a significant genetic component to the pathogenesis of IPF. Epigenetic influences on the development of human disease, including pulmonary fibrosis, remain to be fully elucidated. In this paper we identify miR-338-3p as a microRNA severely downregulated in the lungs of patients with pulmonary fibrosis and in experimental models of pulmonary fibrosis. Treatment of primary human lung fibroblasts with miR-338-3p inhibits myofibroblast differentiation and matrix protein production. Published and proposed targets of miR-338-3p such as TGFβ receptor 1, MEK/ERK 1/2, Cdk4 and Cyclin D are also not responsible for the regulation of pulmonary fibroblast behavior by miR-338-3p. miR-338-3p inhibits myofibroblast differentiation by preventing TGFβ-mediated downregulation of phosphatase and tensin homolog (PTEN), a known anti-fibrotic mediator.

PINK1 Alleviates Cognitive Impairments via Attenuating Pathological Tau Aggregation in a Mouse Model of Tauopathy

As a primary cause of dementia and death in older people, Alzheimer’s disease (AD) has become a common problem and challenge worldwide. Abnormal accumulation of tau proteins in the brain is a hallmark pathology of AD and is closely related to the clinical progression and severity of cognitive deficits. Here, we found that overexpression of phosphatase and tensin homolog (PTEN)-induced kinase 1 (PINK1) effectively promoted the degradation of tau, thereby rescuing neuron loss, synaptic damage, and cognitive impairments in a mouse model of tauopathy with AAV-full-length human Tau (hTau) injected into the hippocampal CA1 area (hTau mice). Overexpression of PINK1 activated autophagy, and chloroquine but not MG132 reversed the PINK1-induced decrease in human Tau levels and cognitive improvement in hTau mice. Furthermore, PINK1 also ameliorated mitochondrial dysfunction induced by hTau. Taken together, our data revealed that PINK1 overexpression promoted degradation of abnormal accumulated tau via the autophagy–lysosome pathway, indicating that PINK1 may be a potential target for AD treatment.

Elevated SAA1 promotes the development of insulin resistance in ovarian granulosa cells in polycystic ovary syndrome

Background Insulin resistance (IR) contributes to ovarian dysfunctions in polycystic ovarian syndrome (PCOS) patients. Serum amyloid A1 (SAA1) is an acute phase protein produced primarily by the liver in response to inflammation. In addition to its role in inflammation, SAA1 may participate in IR development in peripheral tissues. Yet, expressional regulation of SAA1 in the ovary and its role in the pathogenesis of ovarian IR in PCOS remain elusive. Methods Follicular fluid, granulosa cells and peripheral venous blood were collected from PCOS and non-PCOS patients with and without IR to measure SAA1 abundance for analysis of its correlation with IR status. The effects of SAA1 on its own expression and insulin signaling pathway were investigated in cultured primary granulosa cells. Results Ovarian granulosa cells were capable of producing SAA1, which could be induced by SAA1 per se. Moreover, the abundance of SAA1 significantly increased in granulosa cells and follicular fluid in PCOS patients with IR. SAA1 treatment significantly attenuated insulin-stimulated membrane translocation of glucose transporter 4 and glucose uptake in granulosa cells through induction of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression with subsequent inhibition of Akt phosphorylation. These effects of SAA1 could be blocked by inhibitors for toll-like receptors 2/4 (TLR 2/4) and nuclear factor kappa light chain enhancer of activated B (NF-κB). Conclusions Human granulosa cells are capable of feedforward production of SAA1, which significantly increased in PCOS patients with IR. Excessive SAA1 reduces insulin sensitivity in granulosa cells via induction of PTEN and subsequent inhibition of Akt phosphorylation upon activation of TLR2/4 and NF-κB pathway. These findings highlight that elevation of SAA1 in the ovary promotes the development of IR in granulosa cells of PCOS patients.

OsFH3 Encodes a Type II Formin Required for Rice Morphogenesis

The actin cytoskeleton is crucial for plant morphogenesis, and organization of actin filaments (AF) is dynamically regulated by actin-binding proteins. However, the roles of actin-binding proteins, particularly type II formins, in this process remain poorly understood in plants. Here, we report that a type II formin in rice, Oryza sativa formin homolog 3 (OsFH3), acts as a major player to modulate AF dynamics and contributes to rice morphogenesis. osfh3 mutants were semi-dwarf with reduced size of seeds and unchanged responses to light or gravity compared with mutants of osfh5, another type II formin in rice. osfh3 osfh5 mutants were dwarf with more severe developmental defectiveness. Recombinant OsFH3 could nucleate actin, promote AF bundling, and cap the barbed end of AF to prevent elongation and depolymerization, but in the absence of profilin, OsFH3 could inhibit AF elongation. Different from other reported type II formins, OsFH3 could bind, but not bundle, microtubules directly. Furthermore, its N-terminal phosphatase and tensin homolog domain played a key role in modulating OsFH3 localization at intersections of AF and punctate structures of microtubules, which differed from other reported plant formins. Our results, thus, provide insights into the biological function of type II formins in modulating plant morphology by acting on AF dynamics.

The Novel Phosphatase Domain Mutations Q171R and Y65S Switch PTEN from Tumor Suppressor to Oncogene

Phosphatase and tensin homolog deleted on chromosome 10, or PTEN, is a well-characterized tumor suppressor with both lipid and protein phosphatase activities. PTEN is often downregulated by epigenetic mechanisms such as hypermethylation, which leads to constitutive activation of the PI3K–Akt pathway. Large datasets from next-generation sequencing, however, revealed that mutations in PTEN may not only hamper protein function but may also affect interactions with downstream effectors, leading to variable oncogenic readouts. Here, two novel PTEN mutations, Q171R and Y65S, identified in Filipino colorectal cancer patients, were phenotypically characterized in NIH3T3 and HCT116 cells, alongside the C124S canonical mutant and wild-type controls. The novel mutants increased cellular proliferation, resistance to apoptosis and migratory capacity. They induced gross morphological changes including cytoplasmic shrinkage, increased cellular protrusions and extensive cytoskeletal reorganization. The mutants also induced a modest increase in Akt phosphorylation. Further mechanistic studies will help determine the differential oncogenic potencies of these mutants, and resolve whether the structural constraints imposed by the mutations may have altered associations with downstream effectors.

ALKBH5-mediated m6A demethylation of KCNK15-AS1 inhibits pancreatic cancer progression via regulating KCNK15 and PTEN/AKT signaling

Long noncoding RNAs (lncRNAs) are regarded as crucial regulators in tumor progression. Potassium two pore domain channel subfamily K member 15 and WISP2 antisense RNA 1 (KCNK15-AS1) has been confirmed to inhibit the migration and invasion of pancreatic cancer (PC) cells. However, its downstream mechanism and effect on other cellular functions in PC remain unknown. This study probed the function and potential mechanism of KCNK15-AS1 in PC cell growth. RT-qPCR and western blot were employed to measure gene expression in PC cells. ISH was applied to analyze KCNK15-AS1 expression in PC tissues. Functional assays were utilized to evaluate PC cell proliferation, apoptosis, migration and EMT. Mechanical experiments were adopted to detect gene interaction in PC cells. The obtained data indicated that KCNK15-AS1 was down-regulated in PC cells and tissues. Overexpressing KCNK15-AS1 hindered cell proliferation, migration and EMT while facilitated cell apoptosis in PC. Mechanically, alkylation repair homolog protein 5 (ALKBH5) was verified to induce m6A demethylation of KCNK15-AS1 to mediate KCNK15-AS1 up-regulation. KCNK15-AS1 combined with KCNK15 5’UTR to inhibit KCNK15 translation. Moreover, KCNK15-AS1 recruited MDM2 proto-oncogene (MDM2) to promote RE1 silencing transcription factor (REST) ubiquitination, thus transcriptionally upregulating phosphatase and tensin homolog (PTEN) to inactivate AKT pathway. In conclusion, our study first confirmed that KCNK15-AS1 hinders PC cell growth by regulating KCNK15 and PTEN, suggesting KCNK15-AS1 as a potential biomarker of PC.