Tensin Homolog Research Articles

Clinicopathogenomic analysis of PI3K/AKT/PTEN-altered luminal metastatic breast cancer in Japan.

This rapid communication highlights the correlation between protein kinase B alpha (AKT1)-phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA)- phosphatase and tensin homolog (PTEN) alterations and clinicopathological factors in Japanese patients with metastatic recurrent breast cancer (mBC). This study analyzed 1967 patients with luminal-type breast cancer who underwent cancer gene panel testing. The results demonstrated that AKT pathway alterations, including PI3K/AKT/PTEN, occurred in 1038 (52.8%)cases. Patients with AKT pathway mutations were older (p = 0.002) and had a higher rate of invasive lobular carcinoma (ILC) histology (p = 0.001), progesterone receptor (PgR) positivity (p = 0.006), and bone metastases (p = 0.001), and a lower rate of germline BRCA2 (p < 0.001). Comprehensive genomic profile results demonstrated a higher tumor mutational burden (TMB) (< 0.001) and lower tumor BRCA1/2 expression (< 0.001) in patients with mutations in the AKT pathway. These results are crucial for characterizing candidates for AKT pathway-targeted molecular therapies and conceptualizing optimal treatment strategies. Clinical trial registration: This study is an observational study and is therefore not registered with the clinical trials registration.

MiRNA-519e promotes cardiomyocyte cell division accompanied by pro-angiogenic and anti-apoptotic effects

Abstract Background MicroRNAs have the therapeutic potential for heart repair after myocardial infarction(MI). Using a functional high-throughput screening approach, we identified microRNA-519e(miR-519e) as an inducer of cell-cycling in human-derived iPSC-cardiomyocytes(hiPSC-­CM). Purpose This study examines miR-519e for cell division in hiPSC-­CM, additional beneficial functions in heart-related non-CMs, and direct target identification and validation in vitro and in vivo. Methods MiR-519e-mimics or miR-scrambled(miR-scr) were transfected into hiPSC-­CM, human aortic endothelial cells(HAEC) and human cardiac fibroblasts(cFB). Proliferative markers (EdU(5-Ethynyl-2'- deoxyuridine), H3P(Phospho-Histone H3) and AURKB(Aurora B-kinase)) and apoptotic response using MTT assay after exposure to doxorubicin were assessed in hiPSC­-CMs. Angiogenic capacity of HAEC was evaluated by tube formation assay and fibrotic response of cFBs using EdU and α-SMA(smooth muscle actin) staining. In vivo, a mouse MI model with ligation of the left anterior descending followed by intramyocardial injection of miR-519e or miR-scr was used. Direct target identification of miR-519e was assessed using in silico analysis combined with RNA-Seq of miR-519e-mimic treated hiPSC-CMs and validated using Ago2-RNA immunoprecipitation(RIP) followed by qPCR. Results After transfection of miR-519e-mimics in hiPSC-­CM, a significant proliferative response indicative of cell division was observed in immunofluorescence staining and on protein level as compared with miR-scr treated hiPSC-CMs (EdU, H3P and AURKB, p&amp;lt;0.01). Apoptosis was blunted in miR-519e-treated hiPSC-CMs (p&amp;lt;0.05). MiR-519e-treatment of HAEC resulted in more meshes (p&amp;lt;0.01) and longer tube length (p&amp;lt;0.05), indicating enhanced pro-angiogenic capacity. Importantly, EdU-uptake and α-SMA were similar in miR-519e-treated cFB as compared to miR-scr, suggesting neutral effects of miR-519e on myofibroblast transition. In mice undergoing MI, injection of miR-519e-mimics significantly downregulated CDKN1A/P21(Cyclin dependent kinase inhibitor 1A) (p&amp;lt;0.05 vs. miR-scr), a direct target of miR-519e and negative master regulator of cell-cycling. For further novel target identification of miR-519e, we performed in silico analysis combined with RNA-Seq data from miR-519e-treated hiPSC-CM and validation using Ago2-RIP followed by qPCR. Herein, we identified PTEN(Phosphatase and tensin homolog) and TGFBR2(Transforming growth factor β receptor 2) that are involved in cardiomyocyte proliferation and hypoxic response, as direct targets of miR-519e. Conclusion Collectively, miR-519e is a potent inducer of cell division in human cardiomyocytes, with anti-apoptotic and pro-angiogenic capacity in the absence of pro-fibrotic effects. We show that miR-519e treatment downregulates key negative cell-cycle regulators in vivo and we identified novel direct targets of miR-519e that are involved in regulatory pathways for heart regeneration.

TP53 Codon 72 Polymorphism Impacts Macrophage Activation through Reactive Oxygen Species-Dependent Cell Signaling Alterations.

The role of the most common TP53 single-nucleotide polymorphism (SNP) at codon 72, which encodes for proline (P72) or arginine (R72), in the regulation of the immune system has not yet been thoroughly explored. We found that this SNP contributes to aggravated inflammatory response in COVID-19 patients resulting from biased macrophage activation. R72-P53 inhibits mitochondrial manganese superoxide dismutase, leading to impaired reactive oxygen species scavenging, oxidation of phosphatase and tensin homolog deleted on chromosome 10 (PTEN), and, consequently, its inhibition. Reduced PTEN activity causes constitutive activation of the PI3K/Akt pathway, which restricts proinflammatory (M1) and promotes anti-inflammatory (M2) phenotypes through NF-κB and p53 inhibition. In contrast, PTEN-reduced PI3K/Akt activity, in P72 carrying cells, favors M1 phenotypes. LPS-stimulated R72 macrophages fail to reduce tumor growth in a mouse model of cancer, in contrast with P72 macrophages, which preserve M1 phenotype invivo and reduce tumor growth by enhancing antitumor T cell responses, consistent with antitumor functions of M1 macrophages. In addition, P72 macrophages contributed to increased mortality in a mouse model of LPS-induced endotoxemia. Therefore, given the high frequency of P72 in African Americans, cell signaling alterations driven by codon 72 of TP53 SNP may potentially contribute to differences in clinical outcomes and health disparities in common diseases associated with dysregulated macrophage activation.

The oncogenic axis YAP/MYC/EZH2 impairs PTEN tumor suppression activity enhancing lung tumorigenicity

The tumor suppressor PTEN (phosphatase and tensin homolog deleted in chromosome 10) is genetically deleted or downregulated in many cancer types. Loss of PTEN protein expression is frequently found in lung cancer while genetic alterations are less abundant. PTEN expression is regulated at multiple genetic and epigenetic levels and even partial reduction of its expression increases cancer occurrence. We show that YAP and TAZ cooperate with EZH2, and MYC to transcriptionally repress onco-suppressor genes, including PTEN, in non-small cell lung cancer (NSCLC) cells. YAP/TAZ-EZH2-MYC transcriptional regulators form a nuclear complex that represses PTEN transcription, while their combinatorial targeting restores PTEN expression, attenuates NSCLC cell growth, and prevents compensatory responses induced by single treatments. Datasets analysis of NSCLC patients revealed that PTEN expression is negatively correlated to YAP/TAZ, EZH2 and MYC and that low expression of PTEN is predictive of poor prognosis, especially at earlier stages of the disease. These findings highlight the repressive role of the YAP/TAZ-EZH2-MYC axis on tumor-suppressor genes and offer a potential therapeutic strategy for lung cancer patients with low PTEN levels.

Decoding PTEN: from biological functions to signaling pathways in tumors.

The tumor suppressor gene Phosphatase and tensin homologue deleted on chromosome 10 (PTEN), possessing both protein and lipid phosphatase activities, is frequently mutated in various human cancers. PTEN aberrations disrupt critical cellular processes like proliferation, apoptosis, migration, and invasion, thereby promoting tumor growth. In the cells, PTEN localizes to the nucleus, cytoplasm, or cell membrane, and its roles depends on the subcellular localization. PTEN is regulated at the transcriptional, post-transcriptional, and post-translational levels, implying that its functions on the tumors are complex. The relationship between PTEN abnormalities and tumors has garnered significant interest in recent years. PTEN regulates essential cellular processes involved in tumorigenesis. Mutations or deletions in the PTEN gene often correlate with unfavorable prognosis and increased cancer recurrence. Numerous studies suggest that PTEN expression levels in tumors could be a valuable biomarker for cancer diagnosis, treatment, and predicting patient outcomes. This paper provides a comprehensive review of the biological function, regulatory mechanisms, and post-translational modifications of PTEN. Furthermore, this review explores the expression and regulation of PTEN in different tumor types, as well as its interactions with environmental factors in tumorigenesis. This comprehensive analysis aims to deepen our understanding of the signaling pathways between PTEN and cancer.

Alleviating vascular calcification with Bushen Huoxue formula in rats with chronic kidney disease by inhibiting the PTEN/PI3K/AKT signaling pathway through exosomal microRNA-32.

Vascular calcification (VC) significantly raises cardiovascular mortality in chronic kidney disease (CKD) patients. VC is characterized by the phenotypic transformation of vascular smooth muscle cells (VSMCs) to osteoblast-like cells, mediated by exosomes derived from calcified VSMCs and the exosomal microRNAs (miRNA) which may trigger some signals to recipient VSMCs. Bushen Huoxue (BSHX) formula has demonstrated its clinical efficacy in CKD and its protective role in CKD-VC rats has also been observed. However, little is known about its underlying mechanism. To establish a VC model, aortic VSMCs from rats were induced to osteogenic differentiation by high-level phosphate (HP) in vitro. The expression of exosome and calcification makers were analyzed by western blot, including CD9, CD63, α-SMA, BMP-2, and Runx2, respectively. Differential expression of exosomal miRNAs in normal and HP-induced VSMCs were identified by using whole miRNA microarray technology. GO and KEGG analyses were performed to determine the significant enrichment of functions and signaling pathways in the target genes. In vivo, the CKD-VC rat model was established by administering adenine gavage combined with a high phosphorus diet. The rats were divided into normal control, model, low-dose BSHX, medium-dose BSHX, high-dose BSHX groups, and sevelamer groups. The blood biochemical parameters were measured. Renal histopathology and aortic calcification were observed. Western blot detected the levels of the calcification markers. Quantitative real-time PCR (qPCR) assay detected exosomal microRNA-32 (miR-32) mRNA expression in the aorta, the most differentially expressed exosomal miRNA previously identified. Phosphatase and tensin homolog located on chromosome ten (PTEN)/phosphatidylinositol-3 kinase (PI3K)/protein kinase B (AKT) signaling pathway components were also tested by western blot. Exosomal miRNA-32 and PI3K/AKT signaling pathways were highly differentially expressed between normal and HP-induced VSMCs. In vivo, BSHX improved blood biochemical parameters, renal histopathology, and aortic calcification in CKD-VC rats. BSHX increased the expression level of α-SMA and decreased the level of BMP-2 and Runx2. BSHX also lowered the expression level of exosomal miR-32 mRNA, enhanced PTEN expression, therefore, reduced p-PI3K and p-AKT levels in the aorta. BSHX alleviated VC in CKD rats by downregulating exosomal miR-32 expression in the aorta, thereby promoting PTEN expression and inhibiting the PI3K/AKT signaling pathway.

Somatostatin interneuron fate-mapping and structure in a Pten knockout model of epilepsy

Disruption of inhibitory interneurons is common in the epileptic brain and is hypothesized to play a pivotal role in epileptogenesis. Abrupt disruption and loss of interneurons is well-characterized in status epilepticus models of epilepsy, however, status epilepticus is a relatively rare cause of epilepsy in humans. How interneuron disruption evolves in other forms of epilepsy is less clear. Here, we explored how somatostatin (SST) interneuron disruption evolves in quadruple transgenic Gli1-CreERT2, Ptenfl/fl, SST-FlpO, and frt-eGFP mice. In these animals, epilepsy develops following deletion of the mammalian target of rapamycin (mTOR) negative regulator phosphatase and tensin homolog (Pten) from a subset of dentate granule cells, while downstream Pten-expressing SST neurons are fate-mapped with green fluorescent protein (GFP). The model captures the genetic complexity of human mTORopathies, in which mutations can be restricted to excitatory neuron lineages, implying that interneuron involvement is later developing and secondary. In dentate granule cell (DGC)-Pten knockouts (KOs), the density of fate-mapped SST neurons was reduced in the hippocampus, but their molecular phenotype was unchanged, with similar percentages of GFP+ cells immunoreactive for SST and parvalbumin (PV). Surviving SST neurons in the dentate gyrus had larger somas, and the density of GFP+ processes in the dentate molecular layer was unchanged despite SST cell loss and expansion of the molecular layer, implying compensatory sprouting of surviving cells. The density of Znt3-immunolabeled puncta, a marker of granule cell presynaptic terminals, apposed to GFP+ processes in the hilus was increased, suggesting enhanced granule cell input to SST neurons. Finally, the percentage of GFP+ cells that were FosB positive was significantly increased, implying that surviving SST neurons are more active. Together, findings suggest that somatostatin-expressing interneurons exhibit a combination of pathological (cell loss) and adaptive (growth) responses to hyperexcitability and seizures driven by upstream Pten KO excitatory granule cells.

CORO1C Regulates the Malignant Biological Behavior of Ovarian Cancer Cells and Modulates the mRNA Expression Profile through the PI3K/AKT Signaling Pathway.

Ovarian cancer (OC) is a frequently occurring gynecological tumor, and its global incidence has recently increased. Coronin-like actin-binding protein 1C (CORO1C) is known to activate the phosphoinositide 3-kinase (PI3K)-protein kinase B (AKT) pathway and promote tumor progression. However, its role in OC remains unclear. This study investigated the role of CORO1C in OC malignancy. In this study, quantitative real-time polymerase chain reaction (qRT-PCR) was used to examine AKT and CORO1C mRNA expression in clinical OC tissues and cells. Immunohistochemical analysis and western blotting were used to examine protein expression in OC tissues and cells, respectively. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), scratch wound-healing, and Transwell assays were performed to examine cell proliferation and migration. RNA-Seq was used to validate the relationship between AKT and CORO1C expression. The results showed that CORO1C was highly expressed in clinical OC tissues and SKOV3 cells, correlating with the International Federation of Gynecology and Obstetrics (FIGO) stage. Furthermore, CORO1C knockout inhibited the proliferation, migration, and invasion of SKOV3 cells; altered the gene expression patterns in these cells; and was closely associated with the PI3K/AKT pathway. Western blotting confirmed that CORO1C knockout reduced the levels of phosphorylated PI3K and AKT. Additionally, CORO1C knockout increased phosphatase and tensin homologs deleted on chromosome 10 (PTEN) protein expression, whereas CORO1C overexpression decreased it. In conclusion, this study demonstrated that high CORO1C levels in OC are associated with greater metastasis and worse prognosis. CORO1C negatively regulates PTEN expression, activates the PI3K/AKT pathway, and promotes OC cell malignancy In patients with OC, CORO1C may function as an effective therapeutic and predictive biomarker.

The exploration of molecular mechanisms involved in the effect of Traditional Chinese Medicine in the treatment of intracerebral hemorrhage

Background: This study aimed to explore the underlying mechanism of the efficacy of Traditional Chinese Medicine (TCM) in alleviating intracerebral hemorrhage (ICH). Methods: Keywords for TCM treatment in ICH were searched in PubMed and CNKI, and relevant literature has been integrated to extract and collect related gene targets. These selected genes were further analyzed by Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG). Protein-protein interaction (PPI) analysis was performed on the target genes in the String database. Results: A total of 491 key genes were identified from 555 references. GO and KEGG analysis of these genes revealed that anti-apoptotic, anti-inflammatory, and anti-oxidative stress-related processes and pathways were significantly enriched. PPI network uncovered the crucial genes involved in these biological functions were phosphatase and tensin homolog (PTEN), signal transducer and activator of transcription 3 (STAT3), the rearranged during transfection (RET) gene, signal transducer and activator of transcription 1 (STAT1), apolipoprotein E (APOE), 5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), CXC chemokine receptor type 4 (CXCR4), Jun proto-oncogene (JUN), c-fos protein (FOS), and tumor necrosis factor (TNF). Conclusions: This study unveiled that TCM treatment plays an important role in the treatment of ICH via anti-inflammatory, anti-apoptotic, and anti-oxidative stress signaling.

Conditional Pten inactivation in pituitary results in sex-specific prolactinoma formation

Pituitary tumors, including prolactinomas, present significant clinical challenges that require a deeper understanding of their molecular roots for improved diagnostics and therapies. Here, we investigate the role of the phosphatase and tensin homolog (PTEN)/phosphoinositide 3-kinase (PI3K) pathway in pituitary tumorigenesis using a mouse model. Conditional knockout of Pten in all pituitary cell lineages resulted in prolactinoma formation exclusively in female mice, demonstrating the critical role of PTEN in pituitary homeostasis. While Pten inactivation induced Akt activation in all pituitary cells, only prolactin-producing cells exhibited tumorigenic changes, suggesting specific cell-type effects. Histological and molecular analyses of prolactinomas revealed similarities with human pituitary tumors, such as decreased vascularization and cell adhesion proteins and increased accumulation of cell cycle proteins. Notably, prolactinomas displayed diminished levels of phosphorylated extracellular signal-regulated kinase (ERK), implicating downregulation of ERK in tumorigenesis. Finally, we analyzed PTEN/PI3K activation in a collection of human pituitary tumors. Overall, our study delineates the intricate interplay between the PTEN and ERK signaling pathways, providing insights into sex-specific mechanisms of pituitary tumorigenesis and potential therapeutic strategies for prolactinomas.

The ketone body β-hydroxybutyrate ameliorates neurodevelopmental deficits in the GABAergic system of daf-18/PTEN Caenorhabditis elegans mutants.

A finely tuned balance between excitation and inhibition (E/I) is essential for proper brain function. Disruptions in the GABAergic system, which alter this equilibrium, are a common feature in various types of neurological disorders, including autism spectrum disorders (ASDs). Mutations in Phosphatase and Tensin Homolog (PTEN), the main negative regulator of the phosphatidylinositol 3-phosphate kinase/Akt pathway, are strongly associated with ASD. However, it is unclear whether PTEN deficiencies can differentially affect inhibitory and excitatory signaling. Using the Caenorhabditis elegans neuromuscular system, where both excitatory (cholinergic) and inhibitory (GABAergic) inputs regulate muscle activity, we found that daf-18/PTEN mutations impact GABAergic (but not cholinergic) neurodevelopment and function. This selective impact results in a deficiency in inhibitory signaling. The defects observed in the GABAergic system in daf-18/PTEN mutants are due to reduced activity of DAF-16/FOXO during development. Ketogenic diets (KGDs) have proven effective for disorders associated with E/I imbalances. However, the mechanisms underlying their action remain largely elusive. We found that a diet enriched with the ketone body β-hydroxybutyrate during early development induces DAF-16/FOXO activity, therefore improving GABAergic neurodevelopment and function in daf-18/PTEN mutants. Our study provides valuable insights into the link between PTEN mutations and neurodevelopmental defects and delves into the mechanisms underlying the potential therapeutic effects of KGDs.

The ketone body β-hydroxybutyrate ameliorates neurodevelopmental deficits in the GABAergic system of daf-18/PTEN Caenorhabditis elegans mutants

A finely tuned balance between excitation and inhibition (E/I) is essential for proper brain function. Disruptions in the GABAergic system, which alter this equilibrium, are a common feature in various types of neurological disorders, including autism spectrum disorders (ASDs). Mutations in Phosphatase and Tensin Homolog (PTEN), the main negative regulator of the phosphatidylinositol 3-phosphate kinase/Akt pathway, are strongly associated with ASD. However, it is unclear whether PTEN deficiencies can differentially affect inhibitory and excitatory signaling. Using the Caenorhabditis elegans neuromuscular system, where both excitatory (cholinergic) and inhibitory (GABAergic) inputs regulate muscle activity, we found that daf-18/PTEN mutations impact GABAergic (but not cholinergic) neurodevelopment and function. This selective impact results in a deficiency in inhibitory signaling. The defects observed in the GABAergic system in daf-18/PTEN mutants are due to reduced activity of DAF-16/FOXO during development. Ketogenic diets (KGDs) have proven effective for disorders associated with E/I imbalances. However, the mechanisms underlying their action remain largely elusive. We found that a diet enriched with the ketone body β-hydroxybutyrate during early development induces DAF-16/FOXO activity, therefore improving GABAergic neurodevelopment and function in daf-18/PTEN mutants. Our study provides valuable insights into the link between PTEN mutations and neurodevelopmental defects and delves into the mechanisms underlying the potential therapeutic effects of KGDs.

Editorial Comment to Loss of phosphatase and tensin homolog expression in castration-sensitive prostate cancer predicts outcomes in men after prostatectomy.

Editorial Comment to Loss of phosphatase and tensin homolog expression in castration-sensitive prostate cancer predicts outcomes in men after prostatectomy.

Loss of PI5P4Kα slows the progression of a Pten mutant basal cell model of prostate cancer.

While early prostate cancer (PCa) depends on the androgen receptor (AR) signaling pathway, which is predominant in luminal cells, there is much to be understood about the contribution of epithelial basal cells in cancer progression. Herein, we observe cell-type specific differences in the importance of the metabolic enzyme phosphatidylinositol 5-phosphate 4-kinase alpha (PI5P4Kα β ; gene name PIP4K2A) in the prostate epithelium. We report the development of a basal-cell-specific genetically engineered mouse model (GEMM) targeting Pip4k2a alone or in combination with the tumor suppressor phosphatase and tensin homolog (Pten). PI5P4Kα is enriched in basal cells, and no major histopathological changes were detectable following gene deletion. Notably, the combined loss of Pip4k2a slowed the development of Pten mutant mouse prostatic intraepithelial neoplasia (mPIN). Through the inclusion of a lineage tracing reporter, we utilize single-cell RNA sequencing to evaluate changes resulting from in vivo downregulation of Pip4k2a and characterize cell populations influenced in the established Probasin-Cre and Cytokeratin 5 (CK5)-Cre driven GEMMs. Transcriptomic pathway analysis points towards the disruption of lipid metabolism as a mechanism for reduced tumor progression. This was functionally supported by shifts of carnitine lipids in LNCaP PCa cells treated with siPIP4K2A. Overall, these data nominate PI5P4Kα as a target for PTEN mutant PCa. Implications: PI5P4Kα is enriched in prostate basal cells and its targeted loss slows the progression of a model of advanced PCa.

Combining full-length transcriptome sequencing and next generation sequencing to provide insight into the growth superiority of the hybrid grouper (Cromileptes altivelas (♀) × Epinephelus lanceolatus (♂)).

The hybrid grouper (Cromileptes altivelas, ♀ × Epinephelus lanceolatus, ♂) is an economically important aquaculture species that exhibits certain growth advantages compared to its female parent, Cromileptes altivelas. However, the current understanding of the molecular mechanisms underlying the growth of hybrid groupers is lacking. Herein, we performed full-length transcriptome sequencing and next-generation sequencing on the hybrid grouper and its parents to identify growth-related genes and comprehensively analyze the regulatory mechanism of growth heterosis in the hybrid grouper. Approximately 44.70, 40.44, and 45.32 Gb of single-molecule real-time sequencing data were generated in C. altivelas (Cal), E. lanceolatus (Ela), and the hybrid (Hyb), which were combined into 204,322 non-redundant isoforms using the PacBio sequencing platform. Differentially expressed genes (DEGs) were identified between Hyb and Cal (3,494, 2,125, and 1,487 in brain, liver, and muscle tissues, respectively) and Hyb and Ela (3,415, 2,351, and 1,675 in brain, liver, and muscle tissues, respectively). Then, 27 DEGs (13 in the brain and 14 in the muscle) related to growth traits were identified using cluster and correlation network analysis. Quantitative RT-PCR validated 15 DEGs consistent with transcriptome sequencing (RNA-seq) trends. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that these 15 genes were mainly involved in regulating the actin cytoskeleton, suggesting that this pathway plays an essential role in fish growth. In addition, we found that the phosphatase and tensin homologue (PTEN) is a key regulator of growth heterosis in Hyb. These results shed light on the regulatory mechanism of growth in the Hyb, which is important for marker-assisted selection programs to improve the growth quality of groupers.

12345 Staying Ahead of Cowden’s Syndrome in Differentiated Thyroid Cancer

Abstract Disclosure: M.S. Gordon: None. M.B. Gordon: None. Cowden’s syndrome or multiple hamartoma syndrome, is an uncommon autosomal dominant genodermatosis and is a member of the spectrum of disorders involving mutations in the phosphatase and tensin homolog gene (PTEN). It is associated with differentiated thyroid cancer (DTC), ¾ papillary, including follicular variant (FVPTC), 1/4 follicular (FTC), and other malignancies, including breast (most common), colorectal, renal cell, endometrial and skin cancers. We report a case of Cowden’s syndrome in which the patient presented with FVPTC but had no other apparent indication of a genetic abnormality until she was found to have a melanoma and was noted to have macrocephaly. The patient presented at age 26 with a thyroid nodule of 2.7 cm in maximal dimension. FNA was benign. By age 31 the lesion had grown to 3.3 cm and a repeat FNA showed a follicular neoplasm. She underwent left lobectomy and isthmusectomy revealing a 3.0 cm FVPTC with focal Hurthle cell features. There was capsular irregularity, and subsequently she underwent completion thyroidectomy showing a right sided 8mm FVPTC. She then received 30 mCi I 131. There were no apparent pathologic mucocutaneous lesions, intellectual deficits, and no family history of Cowden’s syndrome. At age 39 she was found to have a Stage IA malignant melanoma of the periumbilical skin which was resected. With two malignancies diagnosed at a relatively young age, she was evaluated for genetic syndromes and it was simultaneously noted that she had macrocephaly with head circumference of 66 cm. (&amp;gt;99 percentile). An analysis of 69 genes by Ambry genetics revealed a pathogenic variant in the PTEN gene (c.388 C&amp;gt;T (p.R130*). PTEN R130* results in a premature truncation of the PTEN protein at amino acid 130 of 403 within the phosphatase tensin-type domain resulting in loss of function. Macrocephaly (2% population frequency) is seen in 80% of patients with PTEN mutations. Twenty percent of patients with thyroid carcinoma and macrocephaly have a PTEN mutation and lifetime risk of melanoma in DTC is 25%. BRAF and RAS mutations may cooperate with PTEN loss and explain the increased co-occurrence of malignancies with BRAF and RAS mutations such as melanoma, FTC, and PTC in Cowden’s syndrome. In conclusion, we suggest that head circumference should be measured in all patients with DTC to screen for PTEN abnormalities. Patients with DTC also should have a thorough skin examination. Presentation: 6/2/2024

B-328 A Novel Pathway of Akt-Dependent PARP1 Activation Through the Nuclear Localization of EPRS1

Abstract Background Glutamyl-prolyl-tRNA synthetase (EPRS1) is the only bifunctional aminoacyl-tRNA synthetase (aaRS) and is essential for interpreting the genetic code. EPRS1, along with seven other aaRSs, forms the multi-tRNA synthetase complex (MSC). EPRS1 consists of two catalytic domains, GluRS and ProRS, connected by a linker region. Several aaRSs within the MSC, including EPRS1, can dissociate from the MSC in response to specific stimuli. This dissociation enables non-canonical activities distinct from their primary role in protein synthesis. Breast cancer cells harboring a loss-of-function mutation in phosphatase and tensin homolog (PTEN) are known to have more activity in the serine/threonine kinase Akt. Poly-(ADP)-ribose polymerase 1 (PARP1), plays a vital role in DNA damage repair (DDR). PARP1 deposits one or more ADP-Ribose moieties onto damaged DNA or other proteins in a process referred to as PARylation. We hope to connect Akt activation and PARP1 activity through the nuclear localization and noncanonical function of EPRS1. We hypothesize, that when Akt is activated, either through the loss of PTEN function or through stimuli such as heat shock or H2O2 treatment, will stimulate the nuclear localization of EPRS1 and modulate PARP1 activity. Methods To test our hypothesis, we evaluate Akt activation, EPRS1 localization, and PARP1 activity. Using pharmacological activators and inhibitors of Akt, we test if inhibitors and activators alone are sufficient to cause the nuclear localization of EPRS1. Biochemically, we isolate nuclear and cytosolic fractions used in various western blot analysis. We use a variety of assays for PARP1 activity and DDR that include immobilized histones, calculating IC50s of PARP1 inhibitors, comet assay, and confocal microscopy. To ascertain the connection between PARP1 and EPRS1 we use LC-MS/MS analysis and immunoprecipitation. Results We show, in both patient-derived and cultured breast cancer cells, elevated levels of EPRS1 not only in the cytoplasm, but also within the nucleus. We find that nuclear localization EPRS1 is facilitated by a nuclear localization sequence (NLS) located within the linker region of the protein. Breast cancer cells harboring a loss-of-function in PTEN exhibit higher levels of EPRS1 in the nucleus compared to PTEN-positive cells. In EPRS1 knockdown cells, there is diminished expression of multiple tumor-related transcription factors, DNA-damage repair, tumor cell survival, and PARP1 auto-PARylation. We demonstrate that nuclear EPRS1 binds to and shares an interactome with PARP1. Conclusions EPRS1-mediated regulation of PARP1 activity provides a new mechanistic link between PTEN loss in breast cancer cells, PARP1 activation, and cell survival and tumor growth. Targeting the non-canonical activity of EPRS1, without inhibiting canonical tRNA ligase activity, might provide a new therapeutic approach in breast and other forms of cancer, potentially supplementing existing cancer therapeutics.

Quantitative evaluation of DNA damage repair dynamics to elucidate predictors of autism vs. cancer in individuals with germline PTEN variants.

Persons with germline variants in the tumor suppressor gene phosphatase and tensin homolog, PTEN, are molecularly diagnosed with PTEN hamartoma tumor syndrome (PHTS). PHTS confers high risks of specific malignancies, and up to 23% of the patients are diagnosed with autism spectrum disorder (ASD) and/or developmental delay (DD). The accurate prediction of these two seemingly disparate phenotypes (cancer vs. ASD/DD) for PHTS at the individual level remains elusive despite the available statistical prevalence of specific phenotypes of the syndrome at the population level. The pleiotropy of the syndrome may, in part, be due to the alterations of the key multi-functions of PTEN. Maintenance of genome integrity is one of the key biological functions of PTEN, but no integrative studies have been conducted to quantify the DNA damage response (DDR) in individuals with PHTS and to relate to phenotypes and genotypes. In this study, we used 43 PHTS patient-derived lymphoblastoid cell lines (LCLs) to investigate the associations between DDR and PTEN genotypes and/or clinical phenotypes ASD/DD vs. cancer. The dynamics of DDR of γ-irradiated LCLs were analyzed using the exponential decay mathematical model to fit temporal changes in γH2AX levels which report the degree of DNA damage. We found that PTEN nonsense variants are associated with less efficient DNA damage repair ability resulting in higher DNA damage levels at 24 hours after irradiation compared to PTEN missense variants. Regarding PHTS phenotypes, LCLs from PHTS individuals with ASD/DD showed faster DNA damage repairing rate than those from patients without ASD/DD or cancer. We also applied the reaction-diffusion partial differential equation (PDE) mathematical model, a cell growth model with a DNA damage term, to accurately describe the DDR process in the LCLs. For each LCL, we can derive parameters of the PDE. Then we averaged the numerical results by PHTS phenotypes. By performing simple subtraction of two subgroup average results, we found that PHTS-ASD/DD is associated with higher live cell density at lower DNA damage level but lower cell density level at higher DNA damage level compared to LCLs from individuals with PHTS-cancer and PHTS-neither.

Loss of phosphatase and tensin homolog expression castration-sensitive prostate cancer predicts outcomes in men after prostatectomy.

This study aimed to investigate the potential for using the phosphatase and tensin homolog (PTEN) gene as a prognostic marker in post-prostatectomy patients with castration-sensitive prostate cancer (PCa). A total of 180 patients with castration-sensitive PCa who underwent radical prostatectomy at our institution were included in this study. PTEN expression was evaluated using immunohistochemistry, and patients were classified into two groups based on the staining intensity: PTEN-Normal and PTEN-Loss. The association between PTEN expression and biochemical recurrence was analyzed using the Cox proportional hazards model. Patients in the PTEN-Loss group had a higher risk of biochemical recurrence (hazard ratio, 4.642; 95% confidence interval, 2.137-10.083; p < 0.001) and a lower recurrence-free rate compared to the PTEN-Normal group (35% vs. 75%). In addition to clinicopathological factors, such as the serum prostate-specific antigen level, Gleason score, and T stage, evaluation of PTEN expression improved the prediction of biochemical recurrence after prostatectomy (area under the curve, 0.577 vs. 0.688). Low PTEN expression is a significant predictor of biochemical recurrence in patients with castration-sensitive PCa who have already undergone prostatectomy.

Po-Ge-Jiu-Xin decoction alleviate sepsis-induced cardiomyopathy via regulating phosphatase and tensin homolog-induced putative kinase 1 /parkin-mediated mitophagy

Ethnopharmacological relevanceSepsis is a life-threatening systemic syndrome usually accompanied by myocardial dysfunction. Po-Ge-Jiu-Xin decoction (PGJXD), a traditional Chinese prescription medicine, has been used clinically to treat cardiovascular disease including heart failure, sepsis-induced cardiomyopathy (SIC) and even septic shock. Previous clinical studies suggested PGJXD has shown promising results in improving cardiac function and treating heart failure in sepsis. However, more research is needed to elucidate the mechanisms underlying PGJXD's therapeutic effects in sepsis-induced cardiomyopathy. Materials and MethodsInitially, we identified the major compounds of PGJXD through ultra-performance liquid chromatography-mass spectrometry technology analysis. We established in a SIC rat model using cecal ligation and puncture(CLP) and treated by PGJXD and levosimendan. We evaluated pathological damage by hematoxylin and eosin staining and measured serum myocardial injury biomarkers. Myocardial apoptosis was detected by Tunel staining and quantifying specific biomarker protein levels. Subsequently, we evaluated myocardium mitochondrial quality using Transmission electron microscope (TEM), antioxidant stress indexes and tissue adenosine triphosphate(ATP) content. We detected the expression of phosphatase and tensin homolog (PTEN)-induced putative kinase 1 (PINK1), parkin, LC3, and p62 using Western blotting and Quantitative real time polymerase chain reaction(qRT-PCR). (Lipopolysaccharides, LPS)-induced H9c2 cell model was established to further explore the mechanism of PGJXD on SIC. In addition to measuring cell viability, we measured mitochondrial membrane potential using JC-1 staining. Additionally, Parkin-siRNA transfected into H9c2 cells to validate whether PGJXD conducted protective effects against SIC through PINK1/Parkin-mediated mitophagy. ResultsIt has been demonstrated that PGJXD reduced mortality in septic rat, contributed to ameliorating myocardium injury, suppressed inflammatory response and ameliorated the myocardial apoptosis. PGJXD could also alleviate mitochondrial structural abnormality, mitigated oxidative stress injury and promoted energy synthesis in CLP models. Western blotting and qRT-PCR have further confirmed that PGJXD can activate PINK1/parkin pathway-mediated mitophagy, resulting in preserving mitochondrial quality in the myocardium. Furthermore, Parkin siRNA partially reversed the beneficial effect of PGJXD on mitochondrial fission/fusion and mitophagy in vitro. Therefore, the cardioprotective effect of PGJXD is achieved by inducing PINK1/Parkin-mediated mitophagy in maintaining mitochondrial homeostasis. ConclusionsThese results suggest that the potential therapeutic effect of PGJXD on cardiac dysfunction during sepsis and support its mechanism of targeted induction of PINK1-Parkin-mediated mitophagy.