Peptidyl-prolyl Cis-trans Isomerase NIMA-interacting 1 Research Articles

Amentoflavone Induces Ferroptosis to Alleviate Proliferation, Migration, Invasion and Inflammation in Rheumatoid Arthritis Fibroblast-like Synoviocytes by Inhibiting PIN1.

Rheumatoid arthritis (RA) is a systemic autoimmune disease that is prevalent worldwide and seriously threatens human health. RA-fibroblast-like synoviocytes (FLS) play important roles in almost all aspects of RA progression. This study aimed to study the effect of Amentoflavone (AMF), a polyphenol compound derived from extracts of Selaginella tamariscina, on the abnormal biological behaviors of RA-FLS. The immortalized human RA-FLS cell line (MH7A) was treated with AMF or transfected with small interfering RNAs (siRNAs) targeting peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1). Then, cell viability was detected by CCK-8 assay. EDU staining, wound healing and transwell assays were employed to measure the capacities of MH7A cell proliferation, migration and invasion. The levels of inflammatory factors were assessed using ELISA kits. Additionally, ferroptosis was analyzed by detecting Fe2+ content, lipid reactive oxygen species (ROS) level and expression of ferroptosis-related proteins. Pull-down assay was employed to verify the targeted binding of AMF to PIN1. Further, PIN1 overexpression or ferroptosis inhibitor Ferrostatin-1 (Fer-1) addition was conducted to elucidate the regulatory mechanism of AMF on PIN1 and ferroptosis. Results revealed that AMF intervention or PIN1 knockdown inhibited the proliferation, migration, invasion and inflammation in MH7A cells. AMF facilitated lipid peroxidation and ferroptosis in MH7A cells. Moreover, AMF targeted inhibition of PIN1 expression, and PIN1 overexpression restored the promoting effect of AMF on lipid peroxidation and ferroptosis in MH7A cells. Besides, Fer-1 reversed the impacts of AMF on the abnormal biological behaviors of MH7A cells. In summary, AMF induced ferroptosis to inhibit the proliferation, migration, invasion and inflammation in RA-FLS by inhibiting PIN1, providing a promising candidate for RA treatment.

Re-Evaluating PIN1 as a Therapeutic Target in Oncology Using Neutral Inhibitors and PROTACs.

Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1) has emerged as a promising therapeutic target for cancer treatment. However, the current PIN1 inhibitors have shown limited efficacy in animal models, leaving the question of whether PIN1 is a proper oncologic target still unanswered. By screening a 1 trillion DNA-encoded library (DEL), we identified novel nonacidic compounds. Among resynthesized DEL compounds, DEL1067-56-469 (A0) is the most potent one (KD = 430 nM, IC50 = 420 nM). Further optimization of A0 resulted in compound C10 with much improved potency (KD = 25 nM, IC50 = 150 nM). As an alternative approach, C10 was then converted into proteolysis targeting chimeras (PROTACs) in order to achieve deeper downregulation of the PIN1 protein in cancer cell lines. Unfortunately, neither PIN1 inhibitors nor PIN1 PROTACs demonstrated meaningful antiproliferation activity. In addition, siRNA knock-down experiments provided unfavorable evidence of PIN1 as an oncologic target. Our findings highlight the complexity of targeting PIN1 for cancer therapy.

Metabolome in Tibialis and Soleus Muscles in Wild-Type and Pin1 Knockout Mice through High-Resolution Magic Angle Spinning 1H Nuclear Magnetic Resonance Spectroscopy.

Skeletal muscles are heterogenous tissues composed of different myofiber types that can be classified as slow oxidative, fast oxidative, and fast glycolytic which are distinguished on the basis of their contractile and metabolic properties. Improving oxidative metabolism in skeletal muscles can prevent metabolic diseases and plays a protective role against muscle wasting in a number of neuromuscular diseases. Therefore, achieving a detailed understanding of the factors that regulate myofiber metabolic properties might provide new therapeutic opportunities for these diseases. Here, we investigated whether peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1) is involved in the control of myofiber metabolic behaviors. Indeed, PIN1 controls glucose and lipid metabolism in a number of tissues, and it is also abundant in adult skeletal muscles; however, its role in the control of energy homeostasis in this tissue is still to be defined. To start clarifying this topic, we compared the metabolome of the tibialis anterior muscle (mainly glycolytic) and soleus muscle (oxidative) in wild-type and Pin1 knockout mice with High-Resolution Magic Angle Spinning (HR-MAS) NMR on intact tissues. Our analysis reveals a clear demarcation between the metabolomes in the two types of muscles and allows us to decode a signature able to discriminate the glycolytic versus oxidative muscle phenotype. We also detected some changes in Pin1-depleted muscles that suggest a role for PIN1 in regulating the metabolic phenotype of skeletal muscles.

Reciprocal antagonism of PIN1-APC/CCDH1 governs mitotic protein stability and cell cycle entry

Induced oncoproteins degradation provides an attractive anti-cancer modality. Activation of anaphase-promoting complex (APC/CCDH1) prevents cell-cycle entry by targeting crucial mitotic proteins for degradation. Phosphorylation of its co-activator CDH1 modulates the E3 ligase activity, but little is known about its regulation after phosphorylation and how to effectively harness APC/CCDH1 activity to treat cancer. Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1)-catalyzed phosphorylation-dependent cis-trans prolyl isomerization drives tumor malignancy. However, the mechanisms controlling its protein turnover remain elusive. Through proteomic screens and structural characterizations, we identify a reciprocal antagonism of PIN1-APC/CCDH1 mediated by domain-oriented phosphorylation-dependent dual interactions as a fundamental mechanism governing mitotic protein stability and cell-cycle entry. Remarkably, combined PIN1 and cyclin-dependent protein kinases (CDKs) inhibition creates a positive feedback loop of PIN1 inhibition and APC/CCDH1 activation to irreversibly degrade PIN1 and other crucial mitotic proteins, which force permanent cell-cycle exit and trigger anti-tumor immunity, translating into synergistic efficacy against triple-negative breast cancer.

The PIN1-YTHDF1 axis promotes breast tumorigenesis via the m6A-dependent stabilization of AURKA mRNA.

The post-transcriptional processing of N6-methyladenosine (m6A)-modified mRNA by YTH domain-containing family protein 1 (YTHDF1) plays a crucial role in the regulation of gene expression. Although YTHDF1 expression is frequently upregulated in breast cancer, the regulatory mechanisms for this remain unclear. In this study, we examined the role of peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1) in regulating YTHDF1 stability in breast cancer cells. The WW domain of PIN1 interacted with YTHDF1 in a phosphorylation-dependent manner. Additionally, PIN1 overexpression increased YTHDF1 stability by preventing ubiquitin-dependent proteasomal degradation. Furthermore, using the MS2-tagged RNA pull-down assay, we identified Aurora kinase A (AURKA) mRNA as a bona fide substrate of YTHDF1. PIN1-mediated YTHDF1 stabilization increased the stability of AURKA mRNA in an m6A-dependent manner. Furthermore, YTHDF1 knockout reduced AURKA protein expression levels, resulting in anticancer effects in breast cancer cells, including decreased cell proliferation, cell cycle arrest at the G0/G1 phase, apoptotic cell death, and decreased spheroid formation. The anticancer effects induced by YTHDF1 knockout were reversed by AURKA overexpression. Similarly, the knockout of PIN1 produced comparable anticancer effects to those observed in YTHDF1-knockout cells, and these effects were reversed upon overexpression of YTHDF1. In conclusion, the findings of our study suggest that increased YTHDF1 stability induced by PIN1 promotes breast tumorigenesis via the stabilization of AURKA mRNA. Targeting the PIN1/YTHDF1 axis may represent a novel therapeutic strategy for breast cancer.

Sumoylation of methionine adenosyltransferase alpha 1 promotes mitochondrial dysfunction in alcohol-associated liver disease.

Methionine adenosyltransferase alpha1 (MATα1) is responsible for the biosynthesis of S-adenosylmethionine in normal liver. Alcohol consumption enhances MATα1 interaction with peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1), which blocks MATα1 mitochondrial targeting, resulting in lower mitochondrial MATα1 content and mitochondrial dysfunction in alcohol-associated liver disease (ALD) in part through upregulation of cytochrome P450 2E1. Conversely, alcohol intake enhances SUMOylation, which enhances cytochrome P450 2E1 expression. MATα1 has potential SUMOylation sites, but whether MATα1 is regulated by SUMOylation in ALD is unknown. Here, we investigated if MATα1 is regulated by SUMOylation and, if so, how it impacts mitochondrial function in ALD. Proteomics profiling revealed hyper-SUMOylation of MATα1, and prediction software identified lysine 48 (K48) as the potential SUMOylation site in mice (K47 in humans). Experiments with primary hepatocytes, mouse, and human livers revealed that SUMOylation of MAT1α by SUMO2 depleted mitochondrial MATα1. Furthermore, mutation of MATα1 K48 prevented ethanol-induced mitochondrial membrane depolarization, MATα1 depletion, and triglyceride accumulation. Additionally, CRISPR/CRISPR associated protein 9 gene editing of MATα1 at K48 hindered ethanol-induced MATα1-PIN1 interaction, degradation, and phosphorylation of MATα1 in vitro. In vivo, CRISPR/CRISPR associated protein 9 MATα1 K48 gene-edited mice were protected from ethanol-induced fat accumulation, liver injury, MATα1-PIN1 interaction, mitochondrial MATα1 depletion, mitochondrial dysfunction, and low S-adenosylmethionine levels. Taken together, our findings demonstrate an essential role for SUMOylation of MATα1 K48 for interaction with PIN1 in ALD. Preventing MATα1 K48 SUMOylation may represent a potential treatment strategy for ALD.

Deep Proteomic Compound Profiling with the Orbitrap Ascend Tribrid Mass Spectrometer Using Tandem Mass Tags and Real-Time Search.

Tandem mass tags (TMT) and tribrid mass spectrometers are a powerful combination for high-throughput proteomics with high quantitative accuracy. Increasingly, this technology is being used to map the effects of drugs on the proteome. However, the depth of proteomic profiling is still limited by sensitivity and speed. The new Orbitrap Ascend mass spectrometer was designed to address these limitations with a combination of hardware and software improvements. We evaluated the performance of the Ascend in multiple contexts including deep proteomic profiling. We found that the Ascend exhibited increased sensitivity, yielding higher signal-to-noise ratios than the Orbitrap Eclipse with shorter injection times. As a result, higher numbers of peptides and proteins were identified and quantified, especially with low sample input. TMT measurements had significantly improved signal-to-noise ratios, improving quantitative precision. In a fractionated 16plex sample that profiled proteomic differences across four human cell lines, the Ascend was able to quantify hundreds more proteins than the Eclipse, many of them low-abundant proteins, and the Ascend was able to quantify >8000 proteins in 30% less instrument time. We used the Ascend to analyze 8881 proteins in HCT116 cancer cells treated with covalent sulfolane/sulfolene inhibitors of peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1), a phosphorylation-specific peptidyl-prolyl cis-trans isomerase implicated in several cancers. We characterized these PIN1 inhibitors' effects on the proteome and identified discrepancies among the different compounds, which will facilitate a better understanding of the structure-activity relationship of this class of compounds. The Ascend was able to quantify statistically significant, potentially therapeutically relevant changes in proteins that the Eclipse could not detect.

Covalent Inhibition by a Natural Product-Inspired Latent Electrophile.

Strategies to target specific protein cysteines are critical to covalent probe and drug discovery. 3-Bromo-4,5-dihydroisoxazole (BDHI) is a natural product-inspired, synthetically accessible electrophilic moiety that has previously been shown to react with nucleophilic cysteines in the active site of purified enzymes. Here, we define the global cysteine reactivity and selectivity of a set of BDHI-functionalized chemical fragments using competitive chemoproteomic profiling methods. Our study demonstrates that BDHIs capably engage reactive cysteine residues in the human proteome and the selectivity landscape of cysteines liganded by BDHI is distinct from that of haloacetamide electrophiles. Given its tempered reactivity, BDHIs showed restricted, selective engagement with proteins driven by interactions between a tunable binding element and the complementary protein sites. We validate that BDHI forms covalent conjugates with glutathione S-transferase Pi (GSTP1) and peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1), emerging anticancer targets. BDHI electrophile was further exploited in Bruton's tyrosine kinase (BTK) inhibitor design using a single-step late-stage installation of the warhead onto acrylamide-containing compounds. Together, this study expands the spectrum of optimizable chemical tools for covalent ligand discovery and highlights the utility of 3-bromo-4,5-dihydroisoxazole as a cysteine-reactive electrophile.

MicroRNA-150-5p inhibits the proliferation and invasion of human larynx epidermiod cancer cells though regulating peptidyl-prolyl cis/trans isomerase

ObjectiveThis study aimed to investigate the molecular mechanism of miR-150-5p regulating the malignant biological behavior of Human Epidermoid cancer cell (HEp-2) by targeting peptidyl-prolyl cis/trans isomerase NIMA-Interacting-1 (PIN1). MethodsFirstly, qRT-PCR and Western blot were adopted to detect the expression levels of miR-150-5p and PIN1 in cancer tissue and paracancerous tissues of patients with LSCC, and those in human bronchial epithelial cells (16 HBE) and HEp-2. Next, the targeted relationship between miR-150-5p and PIN1 was assessed by bioinformatics website and dual-luciferase reporter assay, followed by their correlation analysis. Besides, after interfering with miR-150-5p or PIN1 expression in HEp-2 cells, CCK-8, cell colony formation assay, and transwell assay were utilized to detect the proliferation, viability, and invasion of cells, respectively. Subsequently, the protein levels of MMP-2, MMP-9, and EMT-related proteins in HEp-2 cells were checked by Western blot. ResultsExpression of miR-150-5p was down-regulated in LSCC tissues and HEp-2 cells. Moreover, miR-150-5p suppressed proliferation and invasion of HEp-2 cells, affected protein expression related to MMP and EMT, thereby inhibiting development of cancer. The expression of PIN1 was significantly increased in cancer tissues and HEp-2 cells, and there was a targeted relationship and negative correlation between miR-150-5p and PIN1 in cancer tissue. However, overexpression of PIN1 could reverse the effect of miR-150-5p on the proliferation and invasion of HEp-2 cells. ConclusionIn a nutshell, there is a targeted relationship between PIN1 and miR-150-5p. Besides, miR-150-5p can inhibit the proliferation and invasion of HEp-2 cells by regulating the expression of PIN1. Level of evidence3.

PIN1 and CDK1 cooperatively govern pVHL stability and suppressive functions

The VHL protein (pVHL) functions as a tumor suppressor by regulating the degradation or activation of protein substrates such as HIF1α and Akt. In human cancers harboring wild-type VHL, the aberrant downregulation of pVHL is frequently detected and critically contributes to tumor progression. However, the underlying mechanism by which the stability of pVHL is deregulated in these cancers remains elusive. Here, we identify cyclin-dependent kinase 1 (CDK1) and peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1) as two previously uncharacterized regulators of pVHL in multiple types of human cancers harboring wild-type VHL including triple-negative breast cancer (TNBC). PIN1 and CDK1 cooperatively modulate the protein turnover of pVHL, thereby conferring tumor growth, chemotherapeutic resistance and metastasis both in vitro and in vivo. Mechanistically, CDK1 directly phosphorylates pVHL at Ser80, which primes the recognition of pVHL by PIN1. PIN1 then binds to phosphorylated pVHL and facilitates the recruitment of the E3 ligase WSB1, therefore targeting pVHL for ubiquitination and degradation. Furthermore, the genetic ablation or pharmacological inhibition of CDK1 by RO-3306 and PIN1 by all-trans retinoic acid (ATRA), the standard care for Acute Promyelocytic Leukemia could markedly suppress tumor growth, metastasis and sensitize cancer cells to chemotherapeutic drugs in a pVHL dependent manner. The histological analyses show that PIN1 and CDK1 are highly expressed in TNBC samples, which negatively correlate with the expression of pVHL. Taken together, our findings reveal the previous unrecognized tumor-promoting function of CDK1/PIN1 axis through destabilizing pVHL and provide the preclinical evidence that targeting CDK1/PIN1 is an appealing strategy in the treatment of multiple cancers with wild-type VHL.

METTL3 stabilization by PIN1 promotes breast tumorigenesis via enhanced m6A-dependent translation.

Methyltransferase-like 3 (METTL3) is the catalytic subunit of the N6-adenosine methyltransferase complex responsible for N6-methyladenosine (m6A) modification of mRNA in mammalian cells. Although METTL3 expression is increased in several cancers, the regulatory mechanisms are unclear. We explored the regulatory roles of peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1) in METTL3 stability and m6A modification of mRNA. PIN1 interacted with METTL3 and prevented its ubiquitin-dependent proteasomal and lysosomal degradation. It stabilized METTL3, which increased the m6A modification of transcriptional coactivator with PDZ-binding motif (TAZ) and epidermal growth factor receptor (EGFR) mRNA, resulting in their efficient translation. PIN1 knockout altered the distribution of TAZ and EGFR mRNA from polysomes into monosomes. Inhibition of MEK1/2 kinases and PIN1 destabilized METTL3, which impeded breast cancer cell proliferation and induced cell cycle arrest at the G0/G1 phases. METTL3 knockout reduced PIN1 overexpression-induced colony formation in MCF7 cells and enhanced tumor growth in 4T1 cells in an orthotopic mouse model. In clinical settings, METTL3 expression significantly increased with tumor progression and was positively correlated with PIN1 expression in breast cancer tissues. Thus, PIN1 plays a regulatory role in mRNA translation, and the PIN1/METTL3 axis may be an alternative therapeutic target in breast cancer.

Abstract 1472: Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 directly binds and stabilizes Nrf2 in breast cancer

Abstract Nuclear factor E2-related factor 2 (NRF2) is a master regulator of cellular redox homeostasis. The sustained overactivation of NRF2 has been observed in many different types of human malignancy, conferring an advantage for growth and survival of cancer cells. Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1) recognizes phosphorylated serine or threonine of a target protein and isomerizes the adjacent proline residue, thereby altering the structure, stability, and function of target proteins. We identified the three specific serine residues (Ser215, 408, and 577) present in NRF2, each of which precedes proline and undergoes phosphorylation. This prompted us to investigate whether PIN1 could bind to NRF2 and thereby influence its stability. For this purpose, we initially co-transfected HEK293T cells with expression vectors for GST-PIN1 and HA-tagged wild-type Nrf2 or non-phosphorylatable mutant constructs (NRF2S215A, NRF2S408A, and NRF2S577A). Notably, there was the most pronounced ubiquitination with concomitant degradation of NRF2 in cells harbouring NRF2S215A which was associated with abrogation of its interaction with PIN1. We then investigated the clinical relevance of NRF2 and PIN1 interaction to breast cancer progression. Immunofluorescence analysis of tissue microarrays (90 breast cancer tissues and 10 adjacent normal ones) revealed much higher (P < 0.001) expression of both NRF2 and PIN1 in the invasive ductal carcinomas than in normal tissues, which correlated with disease stages. The overexpression of NRF2 and PIN1 in breast cancer patients was also confirmed by immunohistochemical and immunoblot analyses. Next, we compared the co-localization as well as expression of NRF2 and PIN1 in the two molecular subtype tissues (140 each). Both expression and co-localization of NRF2 and PIN1 were significantly higher (P < 0.001) in more aggressive TNBC than in the luminal type tissues. We also detected the significantly elevated levels of the Pin1-Nrf2 complex formed in human breast cancer specimens, compared with those in adjacent normal tissues. Silencing of Pin1 reduced the nuclear accumulation of NRF2 which was attributable to enhanced ubiquitination. The cycloheximide pulse-chase assay unravelled a significantly faster degradation of pre-existing NRF2 in PIN1-silenced MDA-MB-231 cells, corroborating the stabilization of NRF2 protein by PIN1. To explore the regulation of NRF2 by PIN1 and their interaction in vivo, we inoculated MDA-MB-231 cells into male BALB/c nude mice. Tumors derived from PIN1 knockdown cells displayed markedly reduced levels of NRF2. In conclusion, stabilization of NRF2 through direct interaction with PIN1 may provide a novel mechanism underlying their cooperative role in breast cancer growth and progression. Citation Format: Soma Saeidi, Su-Jung Kim, Yanymee N Guillen-Quispe, Achanta Sri Venkata Jagadeesh, Young-Joon Surh. Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 directly binds and stabilizes Nrf2 in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1472.

Circulating levels of PIN1 and glucose metabolism in young people with obesity.

Impaired activity of the peptidylprolyl cis/trans isomerase NIMA-interacting 1 (PIN1) isomerase might contribute to link disturbed glucose metabolism and risk of glucose related neurotoxicity, neurodegeneration and cognitive decline. The isomerase modulates also pathways of peripheral insulin sensitivity and secretion. We aimed at investigating the levels of circulating PIN1 in adolescents with obesity and any association with their glucose metabolism. We enrolled 145 adolescents (age 12-17.8years); 67 lean controls (46.2%) and 78 (53.8%) with overweight or obesity (males n = 62, 46%). We estimated glucose and insulin in fasting condition and after a standard oral glucose tolerance test; fasting serum levels of PIN1, amyloid β-protein 42 (Aβ42), presenilin 1 (PSEN1), glucagon-like peptide 1 (GLP1) and Non Esterified Fatty Acids (NEFA). We calculated the homeostasis model assessment of insulin resistance (HOMA-IR), the β cell function (HOMA-β) and the Adipo-IR. There was no difference in PIN1 serum levels between normal weight individuals and patients with obesity. However, there was an inverse correlation between serum fasting PIN1 and glucose (r -0.183 and p = 0.027). We confirmed levels of Aβ42 and PSEN1 were higher in teens with obesity than in lean controls and their correlation with the body mass index (Aβ42: r = 0.302, p = 0.0001, PSEN1 r = 0.231, p = 0.005) and the HOMA-IR (Aβ42: r = 0.219, p = 0.009, r = 0.170, p < 0.042). There was no significant rise of circulating PIN1 levels in young individuals with obesity. Increased levels reported in the literature in adult patients are likely to occur late in the natural history of the disease with the onset of an overt impairment of glucose homeostasis.

Phosphorylation and Stabilization of PIN1 by JNK Promote Intrahepatic Cholangiocarcinoma Growth.

Intrahepatic cholangiocarcinoma (ICC) is a highly aggressive type of liver cancer in urgent need of treatment options. Aberrant activation of the c-Jun N-terminal kinase (JNK) pathway is a key feature in ICC and an attractive candidate target for its treatment. However, the mechanisms by which constitutive JNK activation promotes ICC growth, and therefore the key downstream effectors of this pathway, remain unknown for their applicability as therapeutic targets. Our aim was to obtain a better mechanistic understanding of the role of JNK signaling in ICC that could open up therapeutic opportunities. Using loss-of-function and gain-of-function studies in vitro and in vivo, we show that activation of the JNK pathway promotes ICC cell proliferation by affecting the protein stability of peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1), a key driver of tumorigenesis. PIN1 is highly expressed in ICC primary tumors, and its expression positively correlates with active JNK. Mechanistically, the JNK kinases directly bind to and phosphorylate PIN1 at Ser115, and this phosphorylation prevents PIN1 mono-ubiquitination at Lys117 and its proteasomal degradation. Moreover, pharmacological inhibition of PIN1 through all-trans retinoic acid, a Food and Drug Administration-approved drug, impairs the growth of both cultured and xenografted ICC cells. Our findings implicate the JNK-PIN1 regulatory axis as a functionally important determinant for ICC growth, and provide a rationale for therapeutic targeting of JNK activation through PIN1 inhibition.

A Molecular Insight of the Role of PIN-1 Promoter Polymorphism (- 667C > T; rs2233679) in Chronic Kidney Disease Patients with Secondary Hyperparathyroidism.

Murine studies stipulate Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN-1) as a key mediator of PTH mRNA stability and is acknowledged by genome-wide-association-studies as secondary hyperparathyroidism defining trait in chronic kidney disease. Therefore, we hypothesize that molecular variants of the PIN-1 gene might affect the incidence and predisposition to secondary hyperparathyroidism in chronic renal insufficiency. A total of 281 adult participants, including 124 chronic kidney disease patients with secondary hyperparathyroidism and 157 healthy controls, were genotyped using polymerase chain reaction-restriction fragment length polymorphism method to unravel the effects of genetic risk loci (PIN-1 gene; - 667C > T; rs2233679) on the susceptibility to secondary hyperparathyroidism in chronic kidney disease. Suitable descriptive statistics was used for different variables. The genotype (x2: 8.03, 2 d. f. p = 0.0181) and allele distribution (x2: 7.27, 2 d. f. p: 0.007) of the - 667C > T variant differed significantly in cases and controls, with no deviation from Hardy-Weinberg equilibrium in either affected or control group. The observed frequencies of T allele of PIN-1 -667 C > T SNP was significantly high in CKD-SHPT group compared to control group (52.41% vs. 41.71%; p: 0.0118). TT variant of PIN-1 - 667C > T SNP was associated with increased risk for occurrence of CKD-SHPT in univariate analysis (OR: 4.6, p: 0.0032, 95% CI: 1.66-12.76). Further in multivariate analysis, both TT (OR: 3.84, p: 0.002, 95% CI: 0.79-9.26) and CT + TT (OR: 2.51, p: 0.031, 95% CI: 0.64-8.68) variants were independently associated with increased risk for CKD-SHPT, emphasizing the deleterious effect of minor T allele. Serum PTH, phosphorus levels were significantly high in CT and TT genotypes compared to CC genotype of PIN-1 -667C > T SNP (p = 0.001). PIN-1 promoter functional SNP (- 667C > T; rs2233679) appeared to be an important genetic determinant in etiopathogenesis of CKD-SHPT and genetic variants of this SNP influences the risk stratification and might serve as a predictive marker. Thus, rs2233679 can be useful for outcome predictions during diagnostic processes.

Inhibitory effect of miR-140-5p on doxorubicin resistance of hepatocellular carcinoma.

To investigate the role of microRNA (miR)-140-5p in doxorubicin (DOX) sensitivity in hepatocellular carcinoma, miR-140-5p and peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1) expression was first evaluated in hepatocellular carcinoma tissues using starBase. Next, in vitro experiments were performed. Cell line expression of miR-140-5p and PIN1 expression was detected by reverse transcription polymerase chain reaction. Cell viability and proliferation were determined by the Cell Counting Kit-8 and EdU assays. The relationship between miR-140-5p and PIN1 was evaluated by TargetScan and a luciferase reporter system. Western blotting was used to detect the expression of PIN1. It was observed that miR-140-5p was downregulated in hepatocellular carcinoma tissues and cell lines compared with normal samples in HCC or normal liver cells. Gain-of-function experiments revealed that miR-140-5p mimics were able to enhance DOX sensitivity of hepatocellular carcinoma cells. Further studies revealed that PIN1 was a target gene of miR-140-5p. Suppression of PIN1 led to higher DOX sensitivity in hepatocellular carcinoma cells. Finally, when comparing a PIN1-siRNA alone group and a PIN1-siRNA plus miR-140-5p inhibitor group, there was no significant difference in cell viability. Furthermore, miR-140-5p mimics did not reduce the sensitivity of PIN1mut plasmid to DOX in HUH7 and SNU449 cells. The present study demonstrated that miR-140-5p could enhance DOX sensitivity in hepatocellular carcinoma cells by targeting PIN1.

Rational design of PIN1 inhibitors for cancer treatment based on conformational diversity analysis and docking based virtual screening

The parvulin PIN1 (peptidyl-prolyl cis-trans isomerase NIMA-interacting 1), is the only enzyme capable of isomerizing prolines of phospho-Serine/Threonine-Proline motifs. PIN1 binds to a subset of proteins and plays an essential role in regulating protein function post-phosphorylation control. Furthermore, the activity of PIN1 regulates the outcome of the signalling of proline-directed kinases (e.g. MAPK, CDK, or GSK3) and thus regulates cell proliferation and cell survival. For these reasons, PIN1 inhibitors are interesting since they may have therapeutic implications for cancer. Several authors have already reported that the non-structural point mutation Trp34Ala prevents PIN1 from interacting with its downstream effector proteins. In this work, we characterized PIN1 structurally, intending to explore new inhibition targets for the rational design of pharmacological activity compounds. Through a conformational diversity analysis of PIN1, we identified and characterized a highly specific druggable pocket around the residue Trp34. This pocket was used in a high-throughput docking screening of 450,000 drug-like compounds, and the top 10 were selected for re-docking studies on the previously used conformers. Finally, we evaluated the binding of each compound by thermal shift assay and found four molecules with a high affinity for PIN1 and potential inhibitory activity. Through this strategy, we achieved novel drug candidates with the ability to interfere with the phosphorylation-dependent actions of PIN1 and with potential applications in the treatment of cancer. Communicated by Ramaswamy H. Sarma

Long Noncoding RNA FBXL19-AS1 Expedites Cell Growth, Migration and Invasion in Cervical Cancer by miR-193a-5p/PIN1 Signaling.

BackgroundCervical cancer is one of the most prevalent malignancies in gynecology with increasing incidence in recent years. Long noncoding RNAs (lncRNAs) have been reported to regulate human cancers including cervical cancer. F-box and leucine-rich repeat protein 19 antisense RNA 1 (FBXL19-AS1) have been unmasked to exert carcinogenic functions in several cancers except cervical cancer.AimPresent study hammered at investigating the function and mechanism of FBXL19-AS1 in cervical cancer.MethodsRT-qPCR was utilized to test gene expression. EdU staining, colony formation, transwell, flow cytometry and TUNEL assays were applied for measuring the impact of FBXL19-AS1 on cervical cancer cell functions. Moreover, RIP, RNA pull-down and luciferase reporter assays were utilized for detecting the correlations among FBXL19-AS1, miR-193a-5p and PIN1 (peptidylprolyl cis/trans isomerase, NIMA-interacting 1).ResultsFBXL19-AS1 exhibited elevated expression in cervical cancer tissues and cells. Silencing FBXL19-AS1 repressed cell proliferation through arresting cell cycle and stimulating apoptosis, and losing FBXL19-AS1 also restrained cell migration and invasion. Also, we discovered FBXL19-AS1 as a miR-193a-5p sponge, while miR-193a-5p was a tumor inhibitor in cervical cancer. Further, PIN1 was proved as the miR-193a-5p target, and FBXL19-AS1 augmented PIN1 expression in cervical cancer via sequestering miR-193a-5p. Of note, PIN1 accelerated the progression of cervical cancer, and its upregulation counteracted the impacts of depleted FBXL19-AS1 on cervical cancer cell functions.ConclusionFBXL19-AS1 contributes to malignant phenotypes in cervical cancer by sponging miR-193a-5p and regulating PIN1.

Mini Review: Opposing Pathologies in Cancer and Alzheimer's Disease: Does the PI3K/Akt Pathway Provide Clues?

This minireview is a brief overview examining the roles of insulin-like growth factors (IGFs) and the PI3K/Akt pathway in two apparently unconnected diseases: Alzheimer's dementia and cancer. For both, increased age is a major risk factor, and, in accord with the global rise in average life expectancy, their prevalence is also increasing. Cancer, however, involves excessive cell proliferation and metastasis, whereas Alzheimer's disease (AD) involves cell death and tissue destruction. The apparent “inverse” nature of these disease states is examined here, but also some important commonalities in terms of the PI3K/Akt pathway, glucose utilization and cell deregulation/death. The focus here is on four key molecules associated with this pathway; notably, the insulin receptor substrate 1 (IRS-1), cellular tumor antigen p53 (p53), peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1) and low-density lipoprotein receptor–related protein-1 (LRP1), all previously identified as potential therapeutic targets for both diseases. The insulin-resistant state, commonly reported in AD brain, results in neuronal glucose deprivation, due to a dampening down of the PI3K/Akt pathway, including overactivity of the mammalian target of rapamycin 1 (mTORC1) complex, hyperphosphorylation of p53 and neuronal death. This contrasts with cancer, where there is overstimulation of the PI3K/Akt pathway and the suppression of mTORC1 and p53, enabling abundant energy and unrestrained cell proliferation. Although these disease states appear to be diametrically opposed, the same key molecules are controlling pathology and, with differential targeting of therapeutics, may yet provide a beneficial outcome for both.

Peptidyl-prolyl cis/trans isomerase NIMA-interacting 1 as a molecular target in breast cancer: a therapeutic perspective of gynecological cancer.

Peptidyl-prolyl cis/trans isomerase NIMA-interacting 1 (PIN1) induces conformational and functional changes to numerous key signaling molecules following proline-directed phosphorylation and its deregulation contributes to disease, particularly cancer. PIN1 is overexpressed in breast cancer, promoting cell proliferation and transformation in collaboration with several oncogenic signaling pathways, and is correlated with a poor clinical outcome. PIN1 level is also increased in certain gynecological cancers such as cervical, ovarian, and endometrial cancers. Although women with breast cancer are at risk of developing a second primary gynecological malignancy, particularly of the endometrium and ovary, the common oncogenic signaling pathway mediated by PIN1 has not been noted to date. This review discusses the roles of PIN1 in breast tumorigenesis and gynecological cancer progression, as well as the clinical effect of targeting this enzyme in breast and gynecological cancers.