[SICI-GISE/SICOA Consensus document: Clinical follow-up of patients after acute coronary syndrome or percutaneous coronary intervention]. / Documento di consenso SICI-GISE/SICOA: La gestione del follow-up del paziente dopo sindrome coronarica acuta e/o angioplastica coronarica.

In the last decades, advances in percutaneous coronary intervention (PCI) strategies have significantly reduced the risk of procedural complications and in-hospital mortality of patients with acute coronary syndromes (ACS), thus increasing the population of stable post-ACS patients. This novel epidemiological scenario emphasizes the importance of implementing secondary preventive and follow-up strategies. The follow-up of patients after ACS or elective PCI should be based on common pathways and on the close collaboration between hospital cardiologists and primary care physicians. However, the follow-up strategies of these patients are still poorly standardized. This SICI-GISE/SICOA consensus document was conceived as a proposal for the long-term management of post-ACS or post-PCI patients based on their individual residual risk of cardiovascular adverse events. We defined five patient risk classes and five follow-up strategies including medical visits and examinations according to a specific time schedule. We also provided a short guidance for the selection of the appropriate imaging technique for the assessment of left ventricular ejection fraction and of non-invasive anatomical or functional tests for the detection of obstructive coronary artery disease. Physical and pharmacological stress echocardiography was identified as the first-line imaging technique in most of cases, while cardiovascular magnetic resonance should be preferred when an accurate evaluation of left ventricular ejection fraction is needed. The standardization of the follow-up pathways of patients with a history of ACS or elective PCI, shared between hospital doctors and primary care physicians, could result in a more cost-effective use of resources and potentially improve patient's long-term outcome.

Accurate Identification of Mucinous Pancreatic Cystic Lesions Using Small-Volume Analytes.

INTRODUCTION: The accurate identification of mucinous pancreatic cystic lesions (PCLs) is paramount for cancer risk stratification. Cyst fluid carcinoembryonic antigen (CEA), the only routinely used test, requires high volumes and has low sensitivity. We aimed to compare the performance of two investigational small-volume biomarkers, glucose and the protease gastricsin, to CEA for PCL classification. METHODS: We obtained cyst fluid samples from 81 patients with pathologically confirmed PCLs from four institutions between 2003 and 2016. Gastricsin activity was measured using an internally quenched fluorescent substrate. Glucose levels were measured with a standard glucometer. CEA levels were obtained from the medical record. Models using Classification and Regression Trees were created to predict mucinous status. Model performance was evaluated using nested cross-validation. RESULTS: Gastricsin activity, CEA, and glucose levels from patients with mucinous (n = 50) and nonmucinous (n = 31) PCLs were analyzed. Area under the curve (AUC) was similar for individual classifiers (gastricsin volume normalized [GVN] 0.88; gastricsin protein concentration normalized [GPN] 0.95; glucose 0.83; CEA 0.84). The combination of two classifiers did not significantly improve AUC, with CEA + GVN (0.88) performing similarly to CEA + GPN (0.95), GVN + glucose (0.87), GPN + glucose (0.95), and CEA + glucose (0.84). The three-analyte combination performed similarly to single and dual classifiers (GPN + glucose + CEA AUC 0.95; GVN + glucose + CEA AUC 0.87). After multiple comparison corrections, there were no significant differences between the individual, dual, and triple classifiers. CONCLUSIONS: Gastricsin and glucose performed similarly to CEA and required <5% of the volume required for CEA; these classifiers may be useful in patients with limited cyst fluid. Future multicenter prospective studies are needed to validate and compare these novel small-volume biomarkers.

Current Use of Oral Anticoagulation Therapy in Elderly Patients with Atrial Fibrillation: Results from an Italian Multicenter Prospective Study-The ISNEP Study.

Background: Atrial fibrillation (AF) is the most common heart arrhythmia, and its prevalence increases with age. Oral Anticoagulant Therapy (OAT) with non-vitamin K antagonist oral anticoagulants (NOACs) or vitamin K antagonists (VKAs) is essential to avoid thromboembolic events in AF. However, this treatment is associated with a high risk of bleeding and low adherence in elderly patients. Aim: The aim was to evaluate the real-world use of OAT in a population of patients aged ≥80 years in twenty-three Italian centers and to investigate the tolerance of and patient satisfaction with this therapy. Methods: The ISNEP Study is a multicenter cross-sectional study enrolling patients with AF and aged ≥80 years and treated with either NOACs or VKAs. A written questionnaire was administered to each patient to evaluate the adherence to and patient satisfaction with this therapy. Results: The study included 641 patients with a mean age of 85 (82−87) years. The use of NOACs was reported in 93.0% of cases, with the remaining 7.0% treated with VKAs. A history of stroke events was reported in five (11.1%) and one (0.2%) patients in the VKA and NOAC groups, respectively. The rate of referred ecchymosis/epistaxis was significantly higher in the VKA group compared to the NOAC group (p < 0.001). Patients receiving NOACs reported a substantial improvement in their quality of life compared to the VKA group. Conclusions: A small, but not negligible, proportion of elderly AF patients is still treated with VKAs. Patients treated with NOAC have a higher level of satisfaction with the therapy and complete adherence.

Translation of a Protease Turnover Assay for Clinical Discrimination of Mucinous Pancreatic Cysts.

The classification of pancreatic cyst fluids can provide a basis for the early detection of pancreatic cancer while eliminating unnecessary procedures. A candidate biomarker, gastricsin (pepsin C), was found to be present in potentially malignant mucinous pancreatic cyst fluids. A gastricsin activity assay using a magnetic bead-based platform has been developed using immobilized peptide substrates selective for gastricsin bearing a dimeric rhodamine dye. The unique dye structure allows quantitation of enzyme-cleaved product by both fluorescence and surface enhanced Raman spectroscopy (SERS). The performance of this assay was compared with ELISA assays of pepsinogen C and the standard of care, carcinoembryonic antigen (CEA), in the same clinical sample cohort. A retrospective cohort of mucinous (n = 40) and non-mucinous (n = 29) classes of pancreatic cyst fluid samples were analyzed using the new protease activity assay. For both assay detection modes, successful differentiation of mucinous and non-mucinous cyst fluid was achieved using 1 µL clinical samples. The activity-based assays in combination with CEA exhibit optimal sensitivity and specificity of 87% and 93%, respectively. The use of this gastricsin activity assay requires a minimal volume of clinical specimen, offers a rapid assay time, and shows improvements in the differentiation of mucinous and non-mucinous cysts using an accurate standardized readout of product formation, all without interfering with the clinical standard of care.

Non-Invasive Assessment of Left Ventricle Ejection Fraction: Where Do We Stand?

The left ventricular (LV) ejection fraction (EF) is the preferred parameter applied for the non-invasive evaluation of LV systolic function in clinical practice. It has a well-recognized and extensive role in the clinical management of numerous cardiac conditions. Many imaging modalities are currently available for the non-invasive assessment of LVEF. The aim of this review is to describe their relative advantages and disadvantages, proposing a hierarchical application of the different imaging tests available for LVEF evaluation based on the level of accuracy/reproducibility clinically required.

[HCF-ANMCO/AICPR/GIEC/ITAHFA/SICOA/SICP/SIMG/SIT Cardiological Societies Council Consensus document: Anticoagulant therapy in venous thromboembolism and atrial fibrillation of the patient with cancer. Current knowledge and new evidence]. / Documento di consenso della Consulta delle Società Cardiologiche HCF-ANMCO/AICPR/GIEC/ITAHFA/SICOA/SICP/SIMG/SIT: La terapia anticoagulante nel tromboembolismo venoso e nella fibrillazione atriale del paziente con cancro. Le attuali conoscenze e le nuove evidenze.

Venous thromboembolism (VTE), including pulmonary embolism and deep venous thrombosis, either symptomatic or incidental, is a common complication in the history of cancer disease. The risk of VTE is 4-7-fold higher in oncology patients, and it represents the second leading cause of death, after cancer itself. In cancer patients, compared with the general population, VTE therapy is associated with higher rates of recurrent thrombosis and/or major bleeding. The need for treatment of VTE in patients with cancer is a challenge for the clinician because of the multiplicity of types of cancer, the disease stage and the imbricated cancer treatment. Historically, in cancer patients, low molecular weight heparins have been preferred for treatment of VTE. More recently, in large randomized clinical trials, direct oral anticoagulants (DOACs) demonstrated to reduce the risk of VTE. However, in the "real life", uncertainties remain on the use of DOACs, especially for the bleeding risk in patients with gastrointestinal cancers and the potential drug-to-drug interactions with specific anticancer therapies.In cancer patients, atrial fibrillation can arise as a perioperative complication or for the side effect of some chemotherapy agents, as well as a consequence of some associated risk factors, including cancer itself. The current clinical scores for predicting thrombotic events (CHA2DS2-VASc) or for predicting bleeding (HAS-BLED), used to guide antithrombotic therapy in the general population, have not yet been validated in cancer patients. Encouraging data for DOAC prescription in patients with atrial fibrillation and cancer are emerging: recent post-hoc analysis showed safety and efficacy of DOACs for the prevention of embolic events compared to warfarin in cancer patients. Currently, anticoagulant therapy of cancer patients should be individualized with multidisciplinary follow-up and frequent reassessment. This consensus document represents an advanced state of the art on the subject and provides useful notes on clinical practice.

KH-Type Splicing Regulatory Protein Controls Colorectal Cancer Cell Growth and Modulates the Tumor Microenvironment.

KH-type splicing regulatory protein (KHSRP) is a multifunctional nucleic acid binding protein implicated in key aspects of cancer cell biology: inflammation and cell-fate determination. However, the role KHSRP plays in colorectal cancer (CRC) tumorigenesis remains largely unknown. Using a combination of in silico analysis of large data sets, ex vivo analysis of protein expression in patients, and mechanistic studies using in vitro models of CRC, we investigated the oncogenic role of KHSRP. We demonstrated KHSRP expression in the epithelial and stromal compartments of both primary and metastatic tumors. Elevated expression was found in tumor versus matched normal tissue, and these findings were validated in larger independent cohorts in silico. KHSRP expression was a prognostic indicator of worse overall survival (hazard ratio, 3.74; 95% CI, 1.43-22.97; P = 0.0138). Mechanistic data in CRC cell line models supported a role of KHSRP in driving epithelial cell proliferation in both a primary and metastatic setting, through control of the G1/S transition. In addition, KHSRP promoted a proangiogenic extracellular environment by regulating the secretion of oncogenic proteins involved in diverse cellular processes, such as migration and response to cellular stress. Our study provides novel mechanistic insight into the tumor-promoting effects of KHSRP in CRC.

The lysosomal aminopeptidase tripeptidyl peptidase 1 displays increased activity in malignant pancreatic cysts.

Incidental detection of pancreatic cysts has increased dramatically over the last decade, but risk stratification and clinical management remain a challenge. Mucinous cysts are precursor lesions to pancreatic cancer, however, the majority are indolent. Current diagnostics cannot identify mucinous cysts that harbor cancer or reliably differentiate these lesions from nonmucinous cysts, which present minimal risk of malignant progression. We previously determined that activity of two aspartyl proteases was increased in mucinous cysts. Using a global protease activity profiling technology, termed multiplex substrate profiling by mass spectrometry (MSP-MS), we now show that aminopeptidase activity is also elevated in mucinous cysts. The serine aminopeptidase, tripeptidyl peptidase 1 (TPP1), was detected by proteomic analysis of cyst fluid samples and quantitation using targeted MS demonstrated that this protease was significantly more abundant in mucinous cysts. In a cohort of 110 cyst fluid samples, TPP1 activity was increased more than 3-fold in mucinous cysts relative to nonmucinous cysts. Moreover, TPP1 activity is primarily associated with mucinous cysts that harbor high-grade dysplasia or invasive carcinoma. Although only 59% accurate for differentiating these lesions, measurement of TPP1 activity may improve early detection and treatment of high-risk pancreatic cysts when used in conjunction with other promising biomarkers.

Depleted polymorphonuclear leukocytes in human metastatic liver reflect an altered immune microenvironment associated with recurrent metastasis.

BACKGROUND: Hepatic immunity, normally protective against neoplasia, is subverted in colorectal liver metastasis (CRLM). Here, we compare the inflammatory microenvironment of CRLM-bearing liver tissue to donor liver. METHODS: Twenty-five patients undergoing resection for CRLM were recruited, 13 of whom developed intrahepatic recurrence within 18 months. Biopsies were obtained from tumour and normal liver tissue adjacent to and distal from, the tumour. Donor liver biopsies were obtained during transplantation. Biopsies were cultured and conditioned media (CM) screened for 102 inflammatory mediators. Twelve of these were validated by Luminex assay. Transwell assays measured cancer cell chemotaxis. Polymorphonuclear leukocytes (PMN) and lymphocytes were quantified in H&E sections. RESULTS: Fewer periportal tissue-resident PMN were present in metastatic liver compared to donor liver. Patients with the fewest PMN in liver tissue distal to their tumour had a shorter time to intrahepatic recurrence (P < 0.001). IL-6, CXCL1, CXCL5, G-CSF, GM-CSF, VEGF, LIF, and CCL3 were higher in liver-bearing CRLM compared to donor tissue. Consequently, cancer cells migrated equally towards CM of all regions of metastatic liver but not towards donor liver CM. CONCLUSIONS: The local inflammatory environment may affect both immune cell infiltration and cancer cell migration contributing to recurrence following resection for CRLM.

Immunoproteasome functions explained by divergence in cleavage specificity and regulation.

The immunoproteasome (iP) has been proposed to perform specialized roles in MHC class I antigen presentation, cytokine modulation, and T cell differentiation and has emerged as a promising therapeutic target for autoimmune disorders and cancer. However, divergence in function between the iP and the constitutive proteasome (cP) has been unclear. A global peptide library-based screening strategy revealed that the proteasomes have overlapping but distinct substrate specificities. Differing iP specificity alters the quantity of production of certain MHC I epitopes but does not appear to be preferentially suited for antigen presentation. Furthermore, iP specificity was found to have likely arisen through genetic drift from the ancestral cP. Specificity differences were exploited to develop isoform-selective substrates. Cellular profiling using these substrates revealed that divergence in regulation of the iP balances its relative contribution to proteasome capacity in immune cells, resulting in selective recovery from inhibition. These findings have implications for iP-targeted therapeutic development.

[The Italian Survey on Cardiac Rehabilitation - 2013 (ISYDE.13-Directory): national availability and organization of cardiac rehabilitation facilities]. / Italian Survey on Cardiac Rehabilitation (ISYDE.13-Directory): report su strutture, organizzazione e programmi di cardiologia riabilitativa in Italia.

BACKGROUND: The Italian Association for Cardiovascular Prevention, Rehabilitation and Epidemiology (GICR-IACPR) and the Italian Society of Cardiologists of Accredited Hospitals (SICOA) developed the ISYDE.13 survey with the purpose to take a detailed snapshot of number, distribution, facilities, staffing levels, organization, and program details of cardiac rehabilitation (CR) units in Italy. METHODS: The study was carried out using a web-based questionnaire running on the GICR-IACPR website for 4 weeks from September 2 to 29, 2013. RESULTS: Out of 221 CR centers existing in Italy (+14% vs 2008), 191 (86%) participated in the survey. On a national basis, there is a CR unit every 268 852 inhabitants. The majority of CR units are located in public hospitals (57.1%), the remaining 42.9% in private hospitals; 130 CR centers (68%) provide inpatients care and account for 3527 beds (5.9 per 100 000 inhabitants): of these 374 are day-hospital beds and 408 are sub-intensive beds. Forty-one of the Italian in-hospital CR centers offer also outpatient programs and 61 centers (32%) offer only outpatient CR programs; 131 of the CR units (68.6%) are linked to dedicated cardiology divisions and in 77% of cases the head is a cardiologist. Home-based programs are offered by 9 centers (4.7%) and CR programs with telecare supervision by 16 (8.4%). Long-term secondary prevention follow-up programs are provided by 94 of CR services (49.2%). During one week of activity, the 191 centers completed 1335 inpatient CR programs and 971 outpatient CR programs. According to these data, it may be assumed that in Italy approximately 100 000 patients are referred annually to CR programs. CONCLUSIONS: ISYDE.13 showed an incremental trend of CR provision in Italy, particularly in outpatient programs. However, at present, the national network of CR units covers only one third of the potential requirements defined by current secondary prevention recommendations.

Preclinical evaluation of the AR inhibitor enzalutamide in triple-negative breast cancer cells.

The androgen receptor (AR) is present in approximately 80% of invasive breast cancer patients and in up to 30% of patients with triple-negative breast cancer (TNBC). Therefore, our aim was to investigate the targeting of AR as a possible hormonal approach to the treatment of TNBC. Analysis of 2091 patients revealed an association between AR expression and poor overall survival, selectively in patients with the basal subtype of breast cancer, the vast majority of which are TNBC. IC50 values for the second-generation anti-androgen enzalutamide across 11 breast cancer cell lines varied from 4 µM to >50 µM. The activity of enzalutamide was similar in TN and non-TN cell lines but was dependent on the presence of AR. Enzalutamide reduced clonogenic potential and cell growth in a 3D matrix in AR-positive cells. In addition, enzalutamide also inhibited cell migration and invasion in an AR-dependent manner. Enzalutamide appeared to mediate these processes through down-regulation of the transcription factors AP-1 and SP-1. The first-generation anti-androgen flutamide similarly blocked cell growth, migration and invasion. AR-positive TNBC cells clustered separately from AR-negative cells based on an androgen-related gene expression signature, independently of TNBC subtype. We conclude that targeting of the AR with drugs such as enzalutamide may provide an alternative treatment strategy for patients with AR-positive TNBC.

Incidence and clinical presentation of myocardial ischemia in patients with chronic CAD in Italy: the ISPICA survey study.

AIM: This survey study was performed to provide an overall picture on the incidence of symptoms, with or without typical angina, in the real-life clinical practice and to identify clinical factors associated with atypical presentations in an unselected population of consecutive outpatients with chronic coronary artery disease (CAD). METHODS: Thirty-six cardiology units located in different geographic areas of Italy enrolled a total of 1475 outpatients (73.6% men and 26.3% women; mean age 71 ±â€Š10 and 67 ±â€Š9 years in men and women, respectively) with a documented diagnosis of chronic CAD. Each patient underwent a medical history, with a detailed investigation as to the presence of typical angina or ischemic equivalents defined as sensation of chest pressure, or arm, neck, or jaw pain. RESULTS: At admission, symptoms suggesting ischemic episodes were reported by 24.4% of patients. After an in-depth medical history collection by the specialist, the prevalence of combined typical or atypical myocardial ischemic episodes was ascertained in 39.3% of the overall population.Typical angina was reported by 13.6% of men and 22.7% of women (P < 0.0001), whereas ischemic equivalents were present in 7.3 and 12.9% of male and female patients, respectively (P < 0.001). Previous coronary artery bypass grafting (CABG; P < 0.001) and fewer medical visits by cardiologists (P = 0.02) were independent predictors of atypical presentations. CONCLUSION: The ISPICA study shows that in an Italian population of real-world patients with chronic CAD, ischemic episodes, with both typical and atypical presentation, are still present in nearly 50% of patients, despite optimal medical therapy, and that atypical presentations of angina are linked to fewer visits by specialists and previous CABG. These findings would suggest to encourage patients with chronic CAD and general practitioners to consider more frequent cardiology specialist visits and to take into account the possibility of atypical presentations, particularly in patients with previous CABG.

Targeting EGFR in metastatic colorectal cancer beyond the limitations of KRAS status: alternative biomarkers and therapeutic strategies.

Patients with metastatic colorectal cancer have a very poor prognosis. Incorporation of targeted molecular therapies, such as the anti-EGFR receptor monoclonal antibodies cetuximab and panitumumab, into treatment regimens has improved outcomes for patients with wild-type RAS tumors. Yet, response rates remain low and overall survival times are short. Increased understanding of oncogenic signaling pathways within the tumor, and how these are regulated by the inflammatory tumor microenvironment, is a priority to facilitate the development of biomarkers to better guide the use of existing therapies and to develop new ones. Here, we review recent preclinical and clinical progress in the development of biomarkers for predicting response to anti-EGFR therapy in metastatic colorectal cancer.

Estrogen receptors and their implications in colorectal carcinogenesis.

Upon binding their cognate receptors, ERα (ESR1) and ERß (ESR2), estrogens activate intracellular signaling cascades that have important consequences for cellular behavior. Historically linked to carcinogenesis in reproductive organs, estrogens have also been implicated in the pathogenesis of different cancer types of non-reproductive tissues including the colon. ERß is the predominant estrogen receptor expressed in both normal and malignant colonic epithelium. However, during colon cancer progression, ERß expression is lost, suggesting that estrogen signaling may play a role in disease progression. Estrogens may in fact exert an anti-tumor effect through selective activation of pro-apoptotic signaling mediated by ERß, inhibition of inflammatory signals and modulation of the tumor microenvironment. In this review, we analyze the estrogen pathway as a possible therapeutic avenue in colorectal cancer, we report the most recent experimental evidence to explain the cellular and molecular mechanisms of estrogen-mediated protection against colorectal tumorigenesis, and we discuss future challenges and potential avenues for targeted therapy.

Oocyte maturation: a story of arrest and release.

The release of a mature healthy egg for fertilization is the center of the entire reproductive process. From the time of embryonic development till fertilization, the oocyte undergoes several stop-and-go periods. In most animals, oocytes are held in meiotic arrest in prophase I prior to ovulation. The ovulatory luteinizing hormone (LH) surge promotes the resumption of meiosis of the arrested oocytes and their progression through the second meiotic cycle, only to be arrested again at metaphase II until fertilization. This review addresses the underlying mechanisms involved in maintaining the oocyte in meiotic arrest as well as the signaling pathways responsible for releasing it from the arrested phase just prior to ovulation until the completion of meiosis at the time of fertilization.

Cytosolic phospholipase A2 activation correlates with HER2 overexpression and mediates estrogen-dependent breast cancer cell growth.

Cytosolic phospholipase A(2)alpha (cPLA(2)alpha) catalyzes the hydrolysis of membrane glycerol-phospholipids to release arachidonic acid as the first step of the eicosanoid signaling pathway. This pathway contributes to proliferation in breast cancer, and numerous studies have demonstrated a crucial role of cyclooxygenase 2 and prostaglandin E(2) release in breast cancer progression. The role of cPLA(2)alpha activation is less clear, and we recently showed that 17beta-estradiol (E2) can rapidly activate cPLA(2)alpha in MCF-7 breast cancer cells. Overexpression or gene amplification of HER2 is found in approximately 30% of breast cancer patients and correlates with a poor clinical outcome and resistance to endocrine therapy. This study reports the first evidence for a correlation between cPLA(2)alpha enzymatic activity and overexpression of the HER2 receptor. The activation of cPLA(2)alpha in response to E2 treatment was biphasic with the first phase dependent on trans-activation through the matrix metalloproteinase-dependent release of heparin-bound epidermal growth factor. EGFR/HER2 heterodimerization resulted in downstream signaling through the ERK1/2 cascade to promote cPLA(2)alpha phosphorylation at Ser505. There was a correlation between HER2 and cPLA(2)alpha expression in six breast cancer cell lines examined, and inhibition of HER2 activation or expression in the SKBR3 cell line using herceptin or HER2-specific small interfering RNA, respectively, resulted in decreased activation and expression of cPLA(2)alpha. Pharmacological blockade of cPLA(2)alpha using a specific antagonist suppressed the growth of both MCF-7 and SKBR3 cells by reducing E2-induced proliferation and by stimulating cellular apoptosis and necrosis. This study highlights cPLAalpha(2) as a potential target for therapeutic intervention in endocrine-dependent and endocrine-independent breast cancer.

Estrogen, phospholipase A and breast cancer.

The development of breast cancer is promoted by diverse factors that impact on intracellular signaling to promote proliferation and cell survival. The role of eicosanoid signaling through prostaglandin release and the up-regulation of cyclooxygenase-2 (COX-2) is established, however, the impact of phospholipase A (PLA) activity and over-expression is less certain. Here we review current literature concerning the role of PLA in breast cancer and describe how eicosanoid signaling may be a facet of estrogen-stimulated breast cancer etiology and progression.

17Beta-estradiol induces ERbeta up-regulation via p38/MAPK activation in colon cancer cells.

Estrogen receptors (ERalpha and ERbeta) mediate opposite functions on cancer growth induced by 17beta-estradiol (E2). E2 binding to ERalpha induces a cancer promoting response, whereas E2 binding to ERbeta exerts a protective action against cancer growth. Moreover, E2 can diversely modulate the ERalpha and ERbeta levels intensifying or decreasing their actions in target tissues. Only molecular mechanisms at the root of E2 ability to down-regulate the ERalpha levels are known. Here, we report the first molecular mechanism underlying E2-induced ERbeta up-regulation in DLD-1 colon cancer cells. E2 induces a short term (2 and 4h after stimulation) translation of ERbeta mRNA followed by a late (24h after stimulation) enhanced transcription. Both processes required the E2-induced persistent and palmitoylation-dependent p38/MAPK activation. Overall, our data suggest a finely tuned control exerted by rapid signals on different cellular molecular events important for the protective effects of E2 against colon cancer growth.

Role of ERbeta palmitoylation in the inhibition of human colon cancer cell proliferation.

The cellular functions regulated by 17beta-estradiol (E2) start after the hormone binds to its receptors (i.e., ERalpha and ERbeta). These act as ligand-dependent transcription factor transactivating target genes. In addition, E2 induces non-genomic actions, whose activation is triggered by a fraction of the ERs localized at the plasma membrane. Palmitoylation allows ERalpha to localize at the plasma membrane, to associate with caveolin-1, and, upon E2 stimulation, to activate rapid signals relevant for cell proliferation. The existence of a mechanism, which allows ERbeta localization at the plasma membrane and its putative role in anti-proliferative E2 effects is completely unknown. Here, the susceptibility of ERbeta to undergo palmitoylation and the role played by this process has been analyzed in DLD-1 containing endogenous ERbeta or in HeLa cells transiently transfected with ERbeta or ERalpha expression vectors. As for ERalpha, palmitoylation is necessary for ERbeta localization at the plasma membrane and its association with caveolin-1 but, in contrast to ERalpha, the E2 binding increases ERbeta association with caveolin-1 and the p38 member of MAPK family. Moreover, the palmitoyl acyl transferase (PAT) inhibitor blocks the ability of ERbeta-E2 complex to activate p38 impairing the receptor-dependent activation of downstream proapoptotic cascade (i.e., caspase-3 activation and poly(ADP-ribose)polymerase (PARP) cleavage). Consequently, palmitoylation must be considered to be a molecular device for ERbeta, which allows these receptors to interact with the plasma membrane and to regulate E2-induced non-genomic functions relevant to the anti-proliferative effect of this hormone.