The functional promoter polymorphism (-842G>C) in the PIN1 gene is associated with decreased risk of breast cancer in non-Hispanic white women 55 years and younger

Proline Isomerization: From the Chemistry and Biology to Therapeutic Opportunities

Proline isomerization, the process of interconversion between the cis- and trans-forms of proline, is an important and unique post-translational modification that can affect protein folding and conformations, and ultimately regulate protein functions and biological pathways. Although impactful, the importance and prevalence of proline isomerization as a regulation mechanism in biological systems have not been fully understood or recognized. Aiming to fill gaps and bring new awareness, we attempt to provide a wholistic review on proline isomerization that firstly covers what proline isomerization is and the basic chemistry behind it. In this section, we vividly show that the cause of the unique ability of proline to adopt both cis- and trans-conformations in significant abundance is rooted from the steric hindrance of these two forms being similar, which is different from that in linear residues. We then discuss how proline isomerization was discovered historically followed by an introduction to all three types of proline isomerases and how proline isomerization plays a role in various cellular responses, such as cell cycle regulation, DNA damage repair, T-cell activation, and ion channel gating. We then explore various human diseases that have been linked to the dysregulation of proline isomerization. Finally, we wrap up with the current stage of various inhibitors developed to target proline isomerases as a strategy for therapeutic development.

Predictive Values of the Selected Inflammatory Indexes in Colon Cancer

Purpose

Ample evidence has revealed that the lymphocyte-to-monocyte ratio (LMR), albumin-to-globulin ratio (AGR), and mean platelet volume (MPV) are cancer-related inflammatory markers. The present study aimed to combine these indicators to better assess the progression of colon cancer.

Methods

This retrospective study enrolled 251 patients with colon cancer, 171 patients with benign colon diseases, and 187 healthy control subjects. The receiver operating characteristic curve and area under the curve (AUC) were used to determine the diagnostic values of the selected inflammatory index.

Results

The levels of LMR, AGR, and MPV were decreased in the colon cancer group compared with the healthy control and benign colon disease groups. The LMR, AGR, and MPV were all correlated with tumor size. Moreover, LMR and AGR was associated with lymph node metastasis and clinical stage, AGR was related to distant metastasis. Both the LMR (P = .030) and AGR (P = .005) were negatively correlated with the concentration of carcinoembryonic antigen (CEA). The AUC value of MPV combined with CEA had a good diagnostic ability for distinguishing colon cancer cases (AUC = .950) and patients with benign colon diseases (AUC = .886) from controls. Meanwhile, the combination of LMR or AGR with CEA could enhance larger AUC (.746 for LMR + CEA, .737 for AGR + CEA) than CEA, LMR, or AGR alone in detecting colon cancer from benign colon diseases.

Conclusions

CEA combined with the LMR, AGR, or MPV may be used as better blood-based biomarkers in the progression of colon cancer patients.

Association of polymorphisms in PIN1 with progression and susceptibility in gastric cancer

Background: High expression of PIN1 is associated with gastric cancer progression and risk. Patients & methods: Two single-nucleotide polymorphisms in PIN1, rs2233678 and rs2233679, were examined in gastric cancer patients using PCR-restriction fragment length polymorphism. Results: The rs2233678 GC genotype and C alleles correlated with a decreased susceptibility to gastric cancer. The stratification analysis indicated that the rs2233678 GC genotype was inversely related to gastric cancer risk in never smokers, never drinkers and patients with stage I/II disease. Males and ever drinkers carrying the rs2233679 CT genotype had a mildly elevated susceptibility to gastric cancer. Conclusion: The PIN1 single-nucelotide polymorphisms rs2233678 and rs2233679 correlate with the risk of gastric cancer.

Peptidyl-Prolyl Cis/Trans Isomerase Pin1 and Alzheimer's Disease

Alzheimer’s disease (AD) is the most common cause of dementia with cognitive decline. The neuropathology of AD is characterized by intracellular aggregation of neurofibrillary tangles consisting of hyperphosphorylated tau and extracellular deposition of senile plaques composed of beta-amyloid peptides derived from amyloid precursor protein (APP). The peptidyl-prolyl cis/trans isomerase Pin1 binds to phosphorylated serine or threonine residues preceding proline and regulates the biological functions of its substrates. Although Pin1 is tightly regulated under physiological conditions, Pin1 deregulation in the brain contributes to the development of neurodegenerative diseases, including AD. In this review, we discuss the expression and regulatory mechanisms of Pin1 in AD. We also focus on the molecular mechanisms by which Pin1 controls two major proteins, tau and APP, after phosphorylation and their signaling cascades. Moreover, the major impact of Pin1 deregulation on the progression of AD in animal models is discussed. This information will lead to a better understanding of Pin1 signaling pathways in the brain and may provide therapeutic options for the treatment of AD.

Functional polymorphism of PIN1 rs2233679 is associated with the progression of CIN to early cervical cancer in Hunan Chinese

OBJECTIVE

Peptidyl-prolyl cis/trans isomerase NIMA-interacting 1 (PIN1) involves alteration of the structure, function, intracellular localization and/or stability of the phosphorylated protein on serine or threonine residues which relates to inflammation and tumorigenesis. Association between PIN1 promoter polymorphisms and cancer risk were reported in several cancers. We intend to study the relationship between the polymorphism of PIN1 promoter and cervical cancer initiation and development.

MATERIALS AND METHODS

We genotyped two common single nucleotide polymorphisms (SNPs) (rs2233678 and rs2233679) in the promoter of the PIN1 gene in healthy controls, patients with CIN or cervical cancer. We used polymerase chain reaction and DNA sequencing methods to analyze these two SNPs in 179 patients and 223 healthy controls. Luciferase activity assay was used to detect PIN1 expression driven by the rs2233679.

RESULTS

The results revealed that the carriers of rs2233679 genotypes CT/TT had a significantly increased risk of cervical cancer in patients with CIN compared with genotype CC (odds ration [OR] = 2.924, 95% confidence interval [CI] = 1.093-7.819, P = 0.033). Luciferase activity assay results revealed that PIN1 expression driven by the rs2233679 genotype TT was higher than the genotype CC (P < 0.05). On the other hand, no significant correlation between the healthy controls and patients was found for PIN1 rs2233678 which showed that rs2233678 genotypes CG/GG is 95% in healthy controls and 100% in patients.

CONCLUSION

PIN1 rs2233679 genotype CT/TT may be a risk factor of early cervical cancer compared with genotype CC in Hunan populations. Our findings suggest that PIN1 rs2233679 genotype CT/TT might involve in the progression of the precancerous stage developing to early cancer by enhancing PIN1 expression.

Oncogenic Hijacking of the PIN1 Signaling Network

Cellular choices are determined by developmental and environmental stimuli through integrated signal transduction pathways. These critically depend on attainment of proper activation levels that in turn rely on post-translational modifications (PTMs) of single pathway members. Among these PTMs, post-phosphorylation prolyl-isomerization mediated by PIN1 represents a unique mechanism of spatial, temporal and quantitative control of signal transduction. Indeed PIN1 was shown to be crucial for determining activation levels of several pathways and biological outcomes downstream to a plethora of stimuli. Of note, studies performed in different model organisms and humans have shown that hormonal, nutrient, and oncogenic stimuli simultaneously affect both PIN1 activity and the pathways that depend on PIN1-mediated prolyl-isomerization, suggesting the existence of evolutionarily conserved molecular circuitries centered on this isomerase. This review focuses on molecular mechanisms and cellular processes like proliferation, metabolism, and stem cell fate, that are regulated by PIN1 in physiological conditions, discussing how these are subverted in and hijacked by cancer cells. Current status and open questions regarding the use of PIN1 as biomarker and target for cancer therapy as well as clinical development of PIN1 inhibitors are also addressed.

A Guide to PIN1 Function and Mutations Across Cancers

PIN1 is a member of a family of peptidylprolyl isomerases that bind phosphoproteins and catalyze the rapid cis-trans isomerization of proline peptidyl bonds, resulting in an alteration of protein structure, function, and stability. PIN1 is overexpressed in human cancers, suggesting it promotes tumorigenesis, but depending on the cellular context, it also acts as a tumor suppressor. Here, we review the role of PIN1 in cancer and the regulation of PIN1 expression, and catalog the single nucleotide polymorphisms, and mutations in PIN1 gene associated with cancer. In addition, we provide a 3D model of the protein to localize the mutated residues.

A novel controlled release formulation of the Pin1 inhibitor ATRA to improve liver cancer therapy by simultaneously blocking multiple cancer pathways

Hepatocellular carcinoma (HCC) is the second leading cause of cancer deaths worldwide largely due to lack of effective targeted drugs to simultaneously block multiple cancer-driving pathways. The identification of all-trans retinoic acid (ATRA) as a potent Pin1 inhibitor provides a promising candidate for HCC targeted therapy because Pin1 is overexpressed in most HCC and activates numerous cancer-driving pathways. However, the efficacy of ATRA against solid tumors is limited due to its short half-life of 45min in humans. A slow-releasing ATRA formulation inhibits solid tumors such as HCC, but can be used only in animals. Here, we developed a one-step, cost-effective route to produce a novel biocompatible, biodegradable, and non-toxic controlled release formulation of ATRA for effective HCC therapy. We used supercritical carbon dioxide process to encapsulate ATRA in largely uniform poly L-lactic acid (PLLA) microparticles, with the efficiency of 91.4% and yield of 68.3%, and ~4-fold higher Cmax and AUC over the slow-releasing ATRA formulation. ATRA-PLLA microparticles had good biocompatibility, and significantly enhanced the inhibitory potency of ATRA on HCC cell growth, improving IC50 by over 3-fold. ATRA-PLLA microparticles exerted its efficacy likely through degrading Pin1 and inhibiting multiple Pin1-regulated cancer pathways and cell cycle progression. Indeed, Pin1 knock-down abolished ATRA inhibitory effects on HCC cells and ATRA-PLLA did not inhibit normal liver cells, as expected because ATRA selectively inhibits active Pin1 in cancer cells. Moreover ATRA-PLLA microparticles significantly enhanced the efficacy of ATRA against HCC tumor growth in mice through reducing Pin1, with a better potency than the slow-releasing ATRA formulation, consistent with its improved pharmacokinetic profiles. This study illustrates an effective platform to produce controlled release formulation of anti-cancer drugs, and ATRA-PLLA microparticles might be a promising targeted drug for HCC therapy as PLLA is biocompatible, biodegradable and nontoxic to humans.

Functional PIN1 promoter polymorphisms associated with risk of nasopharyngeal carcinoma in Southern Chinese populations

Our previous work reported the association between two single nucleotide polymorphisms (SNPs) in PIN1 promoter and nasopharyngeal carcinoma (NPC) risk with a small sample size in a low incidence area. This study investigated the association between the two SNPs and NPC risk in 733 patients and 895 controls from a high incidence area. The results indicated the genotype and allele frequencies of -842G > C and -667C > T were both significantly different between patients and controls even using the resampling statistics. The -842GC and -667TT genotypes showed a significantly increased risk of NPC (OR = 1.977, 95% CI = 1.339-2.919, P = 0.001 and OR = 1.438, 95% CI = 1.061-1.922, P = 0.019, respectively). Compared to the most common -842G-667C haplotype, -842G-667T haplotype and -842C-667C haplotype showed a significantly increased risk of NPC (OR = 1.215, 95% CI = 1.053-1.402, P = 0.008 and OR = 2.268, 95% CI = 1.530-3.362, P = 0.001, respectively). Further reporter gene expression suggested that variant -842C-667C and -842G-667T were associated with an enhanced transcriptional activity. In conclusion, our findings suggest that -842G > C and -667C > T in PIN1 promoter are associated with NPC risk; as well as the promoter activity is mediated by functional PIN1 variants.

Pin1 and secondary hyperparathyroidism of chronic kidney disease: gene polymorphisms and protein levels

BACKGROUND

Peptidyl-prolyl cis/trans isomerase NIMA-interacting 1 (Pin1) is a key regulator of PTH mRNA stability. Secondary hyperparathyroidism (SHPT), which is characterized by elevated serum PTH levels, is a common complication of CKD. We investigated the possible associations between CKD with SHPT (CKD SHPT) and single-nucleotide polymorphisms of the Pin1 gene and compared the levels of the Pin1 protein in the CKD SHPT patients with those of the controls.

METHODS

The study group included 251 CKD SHPT patients and 61 controls. One putative functional SNP (single nucleotide polymorphism) in the Pin1 promoter (rs2233679C > T: c.-667C > T) is the main object. Genotyping was performed on purified DNA using polymerase chain reaction-restriction (PCR) and restriction fragment length polymorphisms (RFLP). The levels of Pin1 were measured in serum using an enzyme-linked immunosorbent assay.

RESULTS

Genotyping showed that CT + TT in the Pin1 promoter was significantly more common in the CKD SHPT group than in the control group (p<.05). The correlation analysis demonstrated that a significant difference in the C to T transition in the Pin1 promoter contributed to CKD SHPT (χ²=12.47, p<.05; Odds ratios (OR) = 1.26, 95% confidence (CI) intervals =1.06-1.49). The multivariate logistic regression analysis reported that the OR and 95%CI were 12.693 and 2.029-75.819 (p<.05), respectively, in the Pin1 gene promoter -667T variant genotypes (CT + TT) after adjusting for other factors, and those values in Pin1 were 0.310 and 0.122-0.792 (p<.05).

CONCLUSION

The -667T genetic variants in the Pin1 promoter contribute to an increased risk of CKD SHPT and may be biomarkers of susceptibility to CKD SHPT.

PIN1 in breast development and cancer: a clinical perspective

Mammary gland development, various stages of mammary tumorigenesis and breast cancer progression have the peptidyl-prolyl cis/trans isomerase PIN1 at their centerpiece, in virtue of the ability of this unique enzyme to fine-tune the dynamic crosstalk between multiple molecular pathways. PIN1 exerts its action by inducing conformational and functional changes on key cellular proteins, following proline-directed phosphorylation. Through this post-phosphorylation signal transduction mechanism, PIN1 controls the extent and direction of the cellular response to a variety of inputs, in physiology and disease. This review discusses PIN1's roles in normal mammary development and cancerous progression, as well as the clinical impact of targeting this enzyme in breast cancer patients.

PIN1 genetic polymorphisms and the susceptibility of HBV-related hepatocellular carcinoma in a Guangxi population

Peptidyl-prolyl cis/trans isomerase NIMA-interacting 1 (PIN1) plays a critical role in different signaling pathways, cell cycle progression and proliferation, and gene expression, and it has been found to overexpress in many tumor tissues. Recently, researchers have found that PIN1 gene polymorphisms may alter the function of protein and be associated with the risk of cancer. The present study analyzed three common polymorphisms in promoter regions (rs2233678 and rs2233679) and in exon2 (rs2233682) of the PIN1 gene in 254 patients with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) and 235 healthy controls in a Guangxi study population to determine whether any relationship exists between the polymorphisms and the risk of HBV-related HCC. The results revealed that the rs2233679 TT genotype was associated with increased risk of HCC with HBV infection [odds ratio (OR) = 2.04, 95 % confidence interval (95 % CI) = 1.13-3.69, p = 0.019]. This association was stronger in men than in women (OR = 2.17, 95 % CI = 1.09-4.34, p = 0.028) as well as in men 50 years of age and older (OR = 3.91, 95 % CI = 1.29-11.80, p = 0.016); moreover, for alcohol drinkers, being a carrier of the PIN1 rs2233679 CT genotype had a moderately increased risk of HCC (OR = 3.98, 95 % CI = 1.02-15.57, p = 0.047). In contrast, people carrying the rs2233682 GA genotype and A alleles were 0.23 times more likely to develop HCC (OR = 0.23, 95 % CI = 0.06-0.87, p = 0.031 and OR = 0.23, 95 % CI = 0.06-0.87, p = 0.030). No such associations were found in the PIN1 rs2233678 polymorphisms between the HBV-related HCC cases and the controls. In addition, the haplotype GCA was found to be a high protection factor for HCC with HBV infection (OR = 0.14, 95 % CI = 0.03-0.62, p = 0.003). In conclusion, this study's findings suggest that the PIN1 rs2233679 TT genotype, the rs2233682GA genotype, and A alleles might be associated with the HBV-related HCC in a Guangxi study population.

Interaction of p53 with prolyl isomerases: Healthy and unhealthy relationships

BACKGROUND

The p53 protein family, comprising p53, p63 and p73, is primarily involved in preserving genome integrity and preventing tumor onset, and also affects a range of physiological processes. Signal-dependent modifications of its members and of other pathway components provide cells with a sophisticated code to transduce a variety of stress signaling into appropriate responses. TP53 mutations are highly frequent in cancer and lead to the expression of mutant p53 proteins that are endowed with oncogenic activities and sensitive to stress signaling.

SCOPE OF REVIEW

p53 family proteins have unique structural and functional plasticity, and here we discuss the relevance of prolyl-isomerization to actively shape these features.

MAJOR CONCLUSIONS

The anti-proliferative functions of the p53 family are carefully activated upon severe stress and this involves the interaction with prolyl-isomerases. In particular, stress-induced stabilization of p53, activation of its transcriptional control over arrest- and cell death-related target genes and of its mitochondrial apoptotic function, as well as certain p63 and p73 functions, all require phosphorylation of specific S/T-P motifs and their subsequent isomerization by the prolyl-isomerase Pin1. While these functions of p53 counteract tumorigenesis, under some circumstances their activation by prolyl-isomerases may have negative repercussions (e.g. tissue damage induced by anticancer therapies and ischemia-reperfusion, neurodegeneration). Moreover, elevated Pin1 levels in tumor cells may transduce deregulated phosphorylation signaling into activation of mutant p53 oncogenic functions.

GENERAL SIGNIFICANCE

The complex repertoire of biological outcomes induced by p53 finds mechanistic explanations, at least in part, in the association between prolyl-isomerases and the p53 pathway. This article is part of a Special Issue entitled Proline-directed foldases: Cell signaling catalysts and drug targets.

Pin1-based diagnostic and therapeutic strategies for breast cancer

Pin1 is the only known cis-to-trans isomerase that recognizes the phosphorylated pThr/pSer-Pro motifs in many signaling molecules, playing unique roles in the pathogenesis of breast cancer. First, Pin1 is prevalently over-expressed in kinds of breast cancer cell lines and tissues, such as MDA-MB-231 cell, MCF-7 cell, Her2+, ERα+, and basal-like breast cancer subtypes. Second, Pin1 amplifies many oncogenic signaling pathways, inhibits multiple tumor suppressors, promotes the angiogenesis and metastasis of breast cancer cells, and enhances the resistance of breast cancer cells to anti-tumor medicines. Third, inhibiting Pin1 blocks most of these detrimental effects in a great number of breast cancer cell lines. These findings suggest Pin1 as a promising diagnostic biomarker as well as an efficient therapeutic target for breast cancer. It is strongly expected that a Pin1-positive subtype of breast cancers should be extremely concerned and that the therapeutic efficacy of Pin1 inhibitors on breast cancer patients should be evaluated as soon as possible. Nonetheless, Pin1-based therapeutic strategies for breast cancer still deserve some debates. Hence, we give the predictions of several important issues, such as application precondition, side effects, and personalized medication, when Pin1 inhibitors are used in the breast cancer therapy. These proposals are meaningful for the further development of Pin1-based diagnostic and therapeutic strategies in order to conquer breast cancer.

PIN1 promoter polymorphism (-842 G>C) contributes to a decreased risk of cancer: Evidence from meta-analysis

Peptidyl-prolylcis-trans isomerase NIMA-interacting 1 (encoded by the PIN1 gene) regulates the conformation of proline-directed phosphorylation sites and is important in the etiology of cancer. Since the identification of a functional polymorphism of PIN1, (-842 G>C; rs2233678), in the PIN1 promoter region, numerous studies have evaluated the association between the PIN1 promoter polymorphism (-842 G>C) and cancer risk. However, the available results are inconclusive. To derive a more precise estimation, a meta-analysis of seven previous case-control studies was performed, which included 4,524 cases exhibiting different tumor types and 4,561 control subjects. The published literature was retrieved from PubMed and EMBASE. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to evaluate the strength of the association. Overall, the results of the present study demonstrated that individuals carrying the variant C allele (G/C and C/C) were associated with a significantly decreased cancer risk (OR, 0.75; 95% CI, 0.62-0.90 for GC vs. GG; OR, 0.75; 95% CI, 0.64-0.88 for GC/CC vs. GG). In further stratified analyses, a decreased cancer risk was observed in the following subgroups: Breast and lung cancer patients, Asian individuals, and in studies with a sample size >500. The results indicated that the PIN1 promoter polymorphism (-842 G>C; rs2233678) contributes to a decreased risk of cancer via attenuating the transcriptional activity.

Prolyl isomerase Pin1 acts downstream of miR200c to promote cancer stem-like cell traits in breast cancer

Breast cancer stem-like cells (BCSC) have been implicated in tumor growth, metastasis, drug resistance, and relapse but druggable targets in appropriate subsets of this cell population have yet to be identified. Here we identify a fundamental role for the prolyl isomerase Pin1 in driving BCSC expansion, invasiveness, and tumorigenicity, defining it as a key target of miR200c, which is known to be a critical regulator in BCSC. Pin1 overexpression expanded the growth and tumorigenicity of BCSC and triggered epithelial-mesenchymal transition. Conversely, genetic or pharmacological inhibition of Pin1 reduced the abundance and self-renewal activity of BCSC. Moreover, moderate overexpression of miR200c-resistant Pin1 rescued the BCSC defect in miR200c-expressing cells. Genetic deletion of Pin1 also decreased the abundance and repopulating capability of normal mouse mammary stem cells. In human cells, freshly isolated from reduction mammoplasty tissues, Pin1 overexpression endowed BCSC traits to normal breast epithelial cells, expanding both luminal and basal/myoepithelial lineages in these cells. In contrast, Pin1 silencing in primary breast cancer cells freshly isolated from clinical samples inhibited the expansion, self-renewal activity, and tumorigenesis of BCSC in vitro and in vivo. Overall, our work demonstrated that Pin1 is a pivotal regulator acting downstream of miR200c to drive BCSC and breast tumorigenicity, highlighting a new therapeutic target to eradicate BCSC.

Lack of association between the PIN1 promoter -667T>C (rs2233679) polymorphism and cancer risk: Evidence from meta-analysis

Peptidyl-prolylcis-trans isomerase NIMA-interacting 1 (PIN1) is a critical catalyst involved in multiple oncogenic signaling pathways. The PIN1 promoter -667T>C (rs2233679) polymorphism plays a role in cancer risk. The association between PIN1 (-667T>C) polymorphism and cancer risk has been previously investigated. However, the available results are inconclusive. To derive a more precise estimation, a meta-analysis of seven published case-control studies including 4,524 cases with different tumor types and 4,561 controls was performed. Published literature from PubMed and EMBASE was retrieved. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to evaluate the strength of the association. Overall, the results did not suggest any associations between the PIN1 promoter (-667T>C) polymorphism and cancer susceptibility (OR=1.04, 95% CI: 0.91-1.18 for CC vs. TT; OR=0.98, 95% CI: 0.89-1.09 for TC vs. TT; OR=1.00, 95% CI: 0.91-1.10 for TC/CC vs. TT; OR=1.07, 95% CI: 0.97-1.18 for CC vs. TC/TT). Further stratified analysis by cancer type, ethnicity and sample size did not reveal any significant associations in the genetic models. The results of the present study demonstrate that the PIN1 promoter (-667T>C; rs2233679) polymorphism is not associated with cancer susceptibility.

Genetic variant rs16430 6bp > 0bp at the microRNA-binding site in TYMS and risk of sporadic breast cancer risk in non-Hispanic white women aged ≤ 55 years

Thymidylate synthase (TYMS) is involved in the folate metabolism and provision of nucleotides needed for DNA synthesis and repair. Thus, functional genetic variants in TYMS may alter cancer risk. In the study, we evaluated associations of three germline variants (rs2790 A > G, rs16430 6 bp > 0 bp, and rs1059394 C > T) in the predicted miRNA-binding sites of TYMS with risk of sporadic breast cancer in non-Hispanic white women aged ≤ 55. We found that carriers of the rs16430 0 bp variant allele had an increased risk of breast cancer [adjusted odd ratio (OR) = 1.37, 95% confidence interval (CI): 1.08-1.73; P = 0.010], compared with carriers of the 6 bp/6 bp genotype. This increased risk was more evident in older subjects (OR = 1.47, 95% CI = 1.06-2.03, P = 0.022), never smokers (OR = 1.67, 95% CI = 1.23-2.25, P < 0.001), never drinkers (OR = 1.44, 95% CI = 1.01-2.05, P = 0.043), and estrogen receptor-positive patients (OR = 1.46, 95% CI = 1.11-1.92, P = 0.006), regardless of tumor stages. The results are consistent with the functional analyses of rs16430 as previously reported, which showed that the 0 bp allele had a decrease in both luciferase activity by ∼ 70% and mRNA levels by ∼ 50% compared with the 6bp allele. Additionally, the rs16430 variant was predicted to influence the binding activity of miR-561. Taken together, these findings indicate that the TYMS rs16430 may contribute to the etiology of sporadic breast cancer in non-Hispanic white women aged ≤ 55 yr. Further validation in large population-based or cohort studies is needed.

Association of rs2233678 and rs2233679 polymorphisms in the PIN1 gene with cancer risk: a meta-analysis

To data, epidemiological studies have assessed the association between peptidyl-propyl-cis/trans isomerase 1 (PIN1) gene polymorphisms and cancer risk, including breast cancer, hepatocellular carcinoma, lung cancer, esophageal cancer, head and neck squamous cell carcinoma, and laryngeal squamous cell cancer. However, the results of these studies remain controversial. We aimed to examine the associations between two SNPs (rs2233678 and rs2233679) of PIN1 gene and cancer risk by conducting a meta-analysis of case-control studies. A total of seven publications were included in this meta-analysis for both rs2233678 and rs2233679. Overall, rs2233678 polymorphism was found to be associated with decreased cancer risk in four genetic models (C-allele vs. G-allele: odd ratio (OR) = 0.73, 95% confidence interval (CI): 0.60-0.88; CC vs. GG: OR = 0.55, 95% CI: 0.36-0.84; CC+CG vs. GG: OR = 0.72, 95% CI 0.58-0.90; CC vs. CG+GG: OR = 0.58, 95% CI 0.38-0.89). However, the rs2233679 polymorphism of PIN1 gene did not appear to have an influence on caner susceptibility. In the subgroup analysis by cancer type, we observed that the PIN1 rs2233678 polymorphism was significantly associated with decreased breast cancer risk (C-allele vs. G-allele: OR = 0.73, 95% CI: 0.60-0.89; CC+CG vs. GG: OR = 0.71, 95% CI 0.57-0.89). Further subgroup analyses showed that the PIN1 rs2233678 polymorphism was associated with decreased cancer risk among Asian people (C-allele vs. G-allele: OR = 0.63, 95% CI: 0.51-0.79; CC vs. GG: OR = 0.44, 95% CI: 0.25-0.80; CC+CG vs. GG: OR = 0.63, 95% CI 0.50-0.79; CC vs. CG+GG: OR = 0.47, 95% CI 0.26-0.86). In conclusion, PIN1 rs2233678 polymorphism might be a potential biomarker for cancer risk among Asians, especially for breast cancer. Further large and well-designed studies are needed to confirm this conclusion.

Single nucleotide polymorphisms of PIN1 promoter region and cancer risk: evidence from a meta-analysis

Background

Peptidylprolyl cis/trans isomerase NIMA-interacting 1 (PIN1) is involved in the process of tumorigenesis. The two single nucleotide polymorphisms (−677T>C, −842G>C) in the PIN1 promoter region have been suspected of being associated with cancer risk for years, but the conclusion is still inconclusive.

Methods

Eligible case-control studies were retrieved by searching databases and references of related reviews and studies. Genotype distribution data, adjusted odds ratios (ORs) and 95% confidence (CIs) intervals were extracted to calculate pooled ORs.

Results

A total of 4619 cancer cases and 4661 controls were included in this meta-analysis. Overall, the PIN1 −667T>C polymorphism was not associated with cancer risk, while the −842C allele was significantly associated with reduced cancer risk (CC+GC vs. GG, OR = 0.725, 95% CI: 0.607–0.865; P_{heterogeneity} = 0.012 and GC vs. GG: OR = 0.721, 95% CI: 0.591–0.880; P_{heterogeneity} = 0.003). Results from genotype distribution data were in agreement with those calculated with adjusted ORs and 95% CIs. No publication bias was detected.

Conclusions

Results of this meta-analysis suggest that the PIN1 −842G>C polymorphism is associated with decreased cancer risk, but that the −667T>C polymorphism is not.

The -842G/C polymorphisms of PIN1 contributes to cancer risk: a meta-analysis of 10 case-control studies

BACKGROUND

Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (PIN1) plays an important role in cancer development. The relationship between PIN1 -842G/C (rs2233678) polymorphism and cancer risk was inconclusive according to published literature.

METHODOLOGY/PRINCIPAL FINDINGS

A literature search, up to February 2013, was carried out using PubMed, EMBASE and the China National Knowledge Infrastructure (CNKI) database. A total of 10 case-control studies including 4619 cases and 4661 controls contributed to the quantitative analysis. Odds ratio (OR) and 95% confidence intervals (95% CI) were used to assess the strength of association. Overall, individuals with the variant CG (OR = 0.728, 95% CI: 0.585,0.906; Pheterogeneity<0.01) and CG/CC (OR = 0.731, 95% CI: 0.602,0.888; Pheterogeneity<0.01) genotypes were associated with a significantly reduced cancer risk compared with those with wild GG genotype. Sub-group analysis revealed that the variant CG (OR = 0.635, 95% CI: 0.548,0.735; Pheterogeneity = 0.240) and CG/CC (OR = 0.645, 95% CI: 0.559,0.744, Pheterogeneity = 0.258) genotypes still showed an reduced risk of cancer in Asians; while no significant association was observed in Caucasians (CG vs.GG: OR = 0.926, 95% CI: 0.572,1.499, Pheterogeneity<0.01; CG/CC vs. GG: OR = 0.892, 95% CI: 0.589,1.353; Pheterogeneity<0.01). Furthermore, sensitivity analysis confirmed the stability of results. Begg's funnel plot and Egger's test did not reveal any publication bias.

CONCLUSIONS

This meta-analysis suggests that the PIN1 -842G/C polymorphism is associated with a significantly reduced risk of cancer, especially in Asian populations.

The rs2233678 polymorphism in PIN1 promoter region reduced cancer risk: a meta-analysis

BACKGROUND

Published evidence suggests that the rs2233678 (-842 G>C) polymorphism in the PIN1 (peptidyl-prolyl cis/trans somerase NIMA-interacting 1) promoter region may be associated with cancer risk; however, the conclusion is still inconclusive.

METHODS

We conducted a meta-analysis to determine whether -842 G>C polymorphism was associated with cancer risk. Odds ratio (OR) and 95% confidence intervals (95% CI) were used to assess the strength of association. Genotype distribution data and adjusted ORs were collected to calculate the pooled ORs. Meta-regression was conducted to detect the source of heterogeneity. Publication bias was evaluated by Egger's test and Begg's test.

RESULTS

A total of 11 eligible studies, including 9280 participants, were identified and analyzed. Overall, we found that carriers of the -842 C allele were associated with significantly decreased cancer risk (C vs. G, OR = 0.750, 95% CI: 0.639-0.880, P(heterogeneity )= 0.014, estimated by genotype distribution data; CC+GC vs. GG, OR = 0.668, 95% CI: 0.594-0.751, P(heterogeneity) = 0.638, estimated by adjusted ORs). No evidence of publication bias was observed. Meta-regression revealed that ethnicities (p = 0.021) and sample size (p = 0.02) but not sources of control (p = 0.069) were the source of heterogeneity.

CONCLUSION

These results suggest that the PIN1 rs2233678 (-842 G>C) polymorphism significantly reduces cancer risk.

SENP1 deSUMOylates and regulates Pin1 protein activity and cellular function

The Pin1 prolyl isomerase regulates phosphorylation signaling by controlling protein conformation after phosphorylation, and its upregulation promotes oncogenesis via acting on numerous oncogenic molecules. SUMOylation and deSUMOylation are dynamic mechanisms regulating a spectrum of protein activities. The SUMO proteases (SENP) remove SUMO conjugate from proteins, and their expression is deregulated in cancers. However, nothing is known about the role of SUMOylation in regulating Pin1 function. Here, we show that Pin1 is SUMOylated on Lys6 in the WW domain and on Lys63 in the PPIase domain. Pin1 SUMOylation inhibits its protein activity and oncogenic function. We further identify that SENP1 binds to and deSUMOylates Pin1. Importantly, either overexpression of SENP1 or disruption of Pin1 SUMOylation promotes the ability of Pin1 to induce centrosome amplification and cell transformation. Moreover, SENP1 also increases Pin1 protein stability in cell cultures, and Pin1 levels are positively correlated with SENP1 levels in human breast cancer specimens. These results not only uncover Pin1 SUMOylation on Lys6/63 as a novel mechanism to inhibit its activity and function but also identify a critical role for SENP1-mediated deSUMOylation in promoting Pin1 function during tumorigenesis.

Peptidyl-prolyl cis–trans isomerase Pin1 in ageing, cancer and Alzheimer disease

Phosphorylation of proteins on serine or threonine residues preceding proline is a key signalling mechanism in diverse physiological and pathological processes. Pin1 (peptidyl-prolyl cis–trans isomerase) is the only enzyme known that can isomerise specific Ser/Thr-Pro peptide bonds after phosphorylation and regulate their conformational changes with high efficiency. These Pin1-catalysed conformational changes can have profound effects on phosphorylation signalling by regulating a spectrum of target activities. Interestingly, Pin1 deregulation is implicated in a number of diseases, notably ageing and age-related diseases, including cancer and Alzheimer disease. Pin1 is overexpressed in most human cancers; it activates numerous oncogenes or growth enhancers and also inactivates a large number of tumour suppressors or growth inhibitors. By contrast, ablation of Pin1 prevents cancer, but eventually leads to premature ageing and neurodegeneration. Consistent with its neuroprotective role, Pin1 has been shown to be inactivated in neurons of patients with Alzheimer disease. Therefore, Pin1-mediated phosphorylation-dependent prolyl isomerisation represents a unique signalling mechanism that has a pivotal role in the development of human diseases, and might offer an attractive new diagnostic and therapeutic target.

A PIN1 polymorphism that prevents its suppression by AP4 associates with delayed onset of Alzheimer's disease

Alzheimer's disease (AD), the most common form of dementia, is characterized by the presence of neurofibrillary tangles composed of tau and senile plaques of amyloid-beta peptides (Aβ) derived from amyloid precursor protein (APP). Pin1 is a unique prolyl isomerase that has been shown to protect against age-dependent neurodegeneration by acting on phosphorylated tau and APP to suppress tangle formation and amyloidogenic APP processing. Here we report a functional polymorphism, rs2287839, in the Pin1 promoter that is significantly associated with a 3-year delay in the average age at onset (AAO) of late-onset AD in a Chinese population. More significantly, the Pin1 polymorphism rs2287839 is located within the consensus binding motif for the brain-selective transcription factor, AP4 (CAGCTG) and almost completely abolishes the ability of AP4 to bind and suppress the Pin1 promoter, as shown by chromatin immunoprecipitation, electrophoretic mobility shift assay, and promoter luciferase assay. Moreover, overexpression or knockdown of AP4 resulted in an 80% reduction or 2-fold increase in endogenous Pin1 levels, respectively. Thus, AP4 is a novel transcriptional repressor of Pin1 expression and the Pin1 promoter single nucleotide polymorphism (SNP) identified in this study that prevents such suppression is associated with delayed onset of AD. These results indicate that regulation of Pin1 by AP4 plays a critical role in determining age at onset of AD and might be a novel therapeutic target to delay the onset of AD.