Soluble Periostin is a potential surveillance biomarker for early and long-term response to chemotherapy in advanced breast cancer.

BACKGROUND: Noninvasive biomarkers for the assessment of response to chemotherapy in advanced breast cancer (BCa) are essential for optimized therapeutic decision-making. We evaluated the potential of soluble Periostin (POSTN) in circulation as a novel biomarker for chemotherapy efficacy monitoring. METHODS: Two hundred and thirty-one patients with different stages of BCa were included. Of those patients, 58 patients with inoperable metastatic disease receiving HER2-targeted or non-targeted chemotherapy were enrolled to assess the performances of markers in recapitulating the chemotherapy efficacy assessed by imaging. POSTN, together with CA153 or CEA at different time points (C0, C2, and C4) were determined. RESULTS: POSTN levels were significantly associated with tumor volume (P < 0.0001) and TNM stages (P < 0.0001) of BCa. For early monitoring, dynamics of POSTN could recapitulate the chemotherapy efficacy among all molecular subtypes (Cohen's weighted kappa = 0.638, P < 0.0001), much better than that of carcinoembryonic antigen (CEA) and cancer antigen 153 (CA15-3). For early partial response, superior performance of POSTN was observed (Cohen's weighted kappa = 0.827, P < 0.0001) in cases with baseline levels above 17.19 ng/mL. For long-term monitoring, the POSTN response was observed to be strongly consistent with the course of the disease. Moreover, progression free survival analysis showed that patients experienced a significant early decrease of POSTN tended to obtain more benefits from the treatments. CONCLUSIONS: The current study suggests that soluble POSTN is an informative serum biomarker to complement the current clinical approaches for early and long-term chemotherapy efficacy monitoring in advanced BCa.

A cross-nearest neighbor/Monte Carlo algorithm for single-molecule localization microscopy defines interactions between p53, Mdm2, and MEG3.

The functions of long noncoding (lnc)RNAs, such as MEG3, are defined by their interactions with other RNAs and proteins. These interactions, in turn, are shaped by their subcellular localization and temporal context. Therefore, it is important to be able to analyze the relationships of lncRNAs while preserving cellular architecture. The ability of MEG3 to suppress cell proliferation led to its recognition as a tumor suppressor. MEG3 has been proposed to activate p53 by disrupting the interaction of p53 with mouse double minute 2 homolog (Mdm2). To test this mechanism in the native cellular context, we employed two-color direct stochastic optical reconstruction microscopy, a single-molecule localization microscopy technique, to detect and quantify the localizations of p53, Mdm2, and MEG3 in U2OS cells. We developed a new cross-nearest neighbor/Monte Carlo algorithm to quantify the association of these molecules. Proof of concept for our method was obtained by examining the association between FKBP1A and mTOR, MEG3 and p53, and Mdm2 and p53. In contrast to previous models, our data support a model in which MEG3 modulates p53 independently of the interaction with Mdm2.

Soluble POSTN is a novel biomarker complementing CA153 and CEA for breast cancer diagnosis and metastasis prediction.

BACKGROUND: Breast cancer (BCa) is the leading cause of cancer deaths among women. Reliable biomarkers for early diagnosis and metastasis prediction are essential to improve the prognosis of BCa. This study aimed to evaluate serum periostin (POSTN) as a novel biomarker complementing CA153 (carbohydrate antigen 153) and CEA (carcinoembryonic antigen) for BCa diagnosis and metastasis prediction. METHODS: To assess the potential of soluble POSTN as a circulating biomarker, 242 participants, including 173 patients with different stages of BCa and 69 healthy individuals, were enrolled in this study. Soluble POSTN, together with CA153 and CEA, were determined in serum by enzyme linked immunosorbent assay (ELISA) or electrochemiluminescence immunoassays. RESULTS: Serum POSTN levels in locoregional BCa patients were significantly higher than that in healthy controls. Receiver operating curve (ROC) analysis revealed that, to distinguish health controls from locoregional BCa, POSTN was observed with the highest AUC (area under curve) (AUCPOSTN = 0.72 [0.65 - 0.79], AUCCA153 = 0.57 [0.49 - 0.64], AUCCEA = 0.62 [0.55 - 0.69]), and both CA153 and CEA were observed with significantly improved AUCs by combination with POSTN (AUCPOSTN + CA153 = 0.74 [0.67 - 0.80], P < 0.001; AUCPOSTN + CEA = 0.77 [0.70 - 0.82], P < 0.001). Moreover, the performances of the POSTN were comparable with that of CA153 in predicting distant metastasis of BCa (AUCPOSTN = 0.78 [0.71 - 0.84], AUCCA153 = 0.82 [0.76 - 0.88]). Kaplan-Meier analysis indicated that elevated serum POSTN was associated with poor overall survival and progression-free survival. CONCLUSIONS: This study suggested that soluble POSTN is a promising potential biomarker for diagnosis and metastasis prediction of BCa.

A TTP-incorporated scoring model for predicting mortality of solid tumor patients with bloodstream infection caused by Escherichia coli.

BACKGROUND: Few mortality-scoring models are available for solid tumor patients who are predisposed to develop Escherichia coli-caused bloodstream infection (ECBSI). We aimed to develop a mortality-scoring model by using information from blood culture time to positivity (TTP) and other clinical variables. METHODS: A cohort of solid tumor patients who were admitted to hospital with ECBSI and received empirical antimicrobial therapy was enrolled. Survivors and non-survivors were compared to identify the risk factors of in-hospital mortality. Univariable and multivariable regression analyses were adopted to identify the mortality-associated predictors. Risk scores were assigned by weighting the regression coefficients with corresponding natural logarithm of the odds ratio for each predictor. RESULTS: Solid tumor patients with ECBSI were distributed in the development and validation groups, respectively. Six mortality-associated predictors were identified and included in the scoring model: acute respiratory distress (ARDS), TTP ≤ 8 h, inappropriate antibiotic therapy, blood transfusion, fever ≥ 39 °C, and metastasis. Prognostic scores were categorized into three groups that predicted mortality: low risk (< 10% mortality, 0-1 points), medium risk (10-20% mortality, 2 points), and high risk (> 20% mortality, ≥ 3 points). The TTP-incorporated scoring model showed excellent discrimination and calibration for both groups, with AUC being 0.833 vs 0.844, respectively, and no significant difference in the Hosmer-Lemeshow test (6.709, P = 0.48) and the chi-square test (6.993, P = 0.46). Youden index showed the best cutoff value of ≥ 3 with 76.11% sensitivity and 79.29% specificity. TTP-incorporated scoring model had higher AUC than no TTP-incorporated model (0.837 vs 0.817, P < 0.01). CONCLUSIONS: Our TTP-incorporated scoring model was associated with improving capability in predicting ECBSI-related mortality. It can be a practical tool for clinicians to identify and manage bacteremic solid tumor patients with high risk of mortality.

Meg3-DMR, not the Meg3 gene, regulates imprinting of the Dlk1-Dio3 locus.

The imprinted delta like 1 homolog (DLK1) - thyroxine deiodinase type III (DIO3) locus regulates development and growth. Its imprinting regulation involves two differentially methylated regions (DMRs), intergenic-DMR (IG-DMR) and maternally expressed gene 3-DMR (Meg3-DMR). In mice, a maternal deletion of the IG-DMR leads to LOI in the locus, proving that the IG-DMR is a cis-acting imprinting control region of the locus. However, the Meg3-DMR overlaps with the promoter, exon 1 and intron 1 of the Meg3 gene. Because deletion of the Meg3-DMR inactivates the Meg3 gene, their roles in imprinting regulation of Meg3-DMR mice is unknown. Therefore, we generated two mouse models: Meg3Δ(1-4) and Meg3Δ(2-4), respectively targeting exons 1-4 and exons 2-4 of the Meg3 gene. A maternal deletion of Meg3Δ(1-4) caused embryonic death and LOI in both embryos and placentas, but did not affect methylation status of the IG-DMR. In contrast, mice carrying a maternal deletion of Meg3Δ(2-4) were born normally and did not have LOI. These data indicate that it is the Meg3-DMR, not the Meg3 gene, which regulates imprinting of the Dlk1-Dio3 locus.

Preparation and evaluation of PEGylated asiatic acid nanostructured lipid carriers on anti-fibrosis effects.

Liver fibrosis is a major pathological feature of chronic liver diseases, and effective therapies are limited at present. Asiatic acid (AA) is a triterpenoid isolated from Centella asiatica, which exhibits efficient anti-inflammatory and anti-oxidative activities. However, AA shows very low plasma levels after oral administration. In this study, AA loading PEGylated nanostructured lipid carriers (P-AA-NLCs) were prepared. P-AA-NLCs were characterized for particle size distribution, polydispersity index, entrapment efficiency, X-ray powder diffraction (XRD) pattern, differential scanning colorimeter (DSC), and transmission electron microscopy (TEM). The intestinal absorption, in vivo distribution, pharmacokinetics, and anti-fibrosis effects of P-AA-NLC were studied compared with that of AA-NLC. In situ single-pass intestinal perfusion model shows that there are significant differences in absorption between the free and NLCs formulation. The Peff values of P-AA-NLC were significantly enhanced in all four intestinal segments compared to AA-NLC and free AA (p < .05). fa% and Ka showed similar trends, suggesting the PEGylated NLC can improve the gastrointestinal absorption of the drug. The pharmacokinetic studies presented that P-AA-NLC prolonged blood circulation times with a 1.5-fold higher relative bioavailability compared with AA-NLC. In vivo distribution experiments demonstrated that the fluorescence concentration in the liver was higher than that in other organs and the fluorescence intensity in the liver of DIR-P-NLC was about 1.3 times that of DIR-NLC. In addition, oral administration of P-AA-NLC can significantly attenuate CCl4-induced liver fibrosis and functional impairment in a dosage-dependent manner, including an increase in the albumin (ALB) and decrease in aspartate aminotransferase (AST) and alanine transaminase (ALT). Moreover, the MDA and HYP in liver tissue were downregulated, while the SOD activity was upregulated. In conclusion, P-AA-NLC can increase gastrointestinal absorption of AA and enhance anti-liver fibrosis effects in SD rats.

UNC5D, suppressed by promoter hypermethylation, inhibits cell metastasis by activating death-associated protein kinase 1 in prostate cancer.

Prostate cancer (PCa) death primarily occurs due to metastasis of the cells, but little is known about the underlying molecular mechanisms. This study aimed to evaluate the expression of UNC5D, a newly identified tumor suppressor gene, analyze its epigenetic alterations, and elucidate its functional relevance to PCa metastasis. Meta-analysis of publicly available microarray datasets revealed that UNC5D expression was frequently downregulated in PCa tissues and inversely associated with PCa metastasis. These results were verified in clinical specimens by real-time PCR and immunohistochemistry assays. Through methylation analysis, the downregulated expression of UNC5D in PCa tissues and cell lines was found to be attributable to the hypermethylation of the promoter. A negative correlation was observed between methylation and UNC5D mRNA expression in PCa samples. The ectopic expression of UNC5D in PCa cells effectively reduced their ability to migrate and invade both in vitro and in vivo, and siRNA-mediated knockdown of UNC5D yielded consistent results. UNC5D can recruit and activate death-associated protein kinase 1, which remained to be essential for its metastatic suppressor function. In conclusion, these results suggested that UNC5D as a novel putative metastatic suppressor gene that is commonly down-regulated by hypermethylation in PCa.

Periostin and CA242 as potential diagnostic serum biomarkers complementing CA19.9 in detecting pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant tumor with few biomarkers to guide treatment options. Carbohydrate antigen 19.9 (CA19.9), the most frequently used biomarker for PDAC, is not sensitive and specific enough for the detection of the disease. This study aimed to evaluate serum periostin (POSTN) and CA242 as potential diagnostic biomarkers complementing CA19.9 in detecting pancreatic cancer. Blood samples were from 362 participants, including 213 patients with different stages of PDAC, 75 patients with benign pancreatic disease, and 74 healthy individuals. All samples were randomly divided into a training set and a validation set. Carbohydrate antigen 19.9, CA242, POSTN, as well as carcinoembryonic antigen, were measured by ELISA or automated immunoassay. The receiver operating characteristic curve analysis revealed that the performance of CA19.9 in the validation group were improved by the marker panel composed of CA19.9, POSTN, and CA242, to discriminate early stage PDAC not only from healthy controls (area under the curve [AUC]CA19.9 = 0.94 vs AUCCA19.9 + POSTN + CA242 = 0.98, P < .05) but also from benign conditions (AUCCA19.9 = 0.87 vs AUCCA19.9 + POSTN + CA242 = 0.90, P < .05). In addition, POSTN retained significant diagnostic capabilities to distinguish PDAC CA19.9-negative from healthy controls (AUCPOSTN = 0.87) as well as from benign conditions (AUCPOSTN = 0.84) in the whole set. This study suggested that POSTN and CA242 are potential diagnostic serum biomarkers complementing CA19.9 in detecting early pancreatic cancer.

Identification of Serum Periostin as a Potential Diagnostic and Prognostic Marker for Colorectal Cancer.

BACKGROUND: Periostin (POSTN) plays an important role in numerous cancers, especially in gastrointestinal malignancy. The objective of this study was to investigate the diagnostic and prognostic role of serum POSTN in colorectal cancer (CRC). METHODS: Serum periostin, together with CEA, CA19.9, CA72.4, and CA242 levels were measured in samples from 108 patients with CRC and 56 healthy controls, and their correlation with clinical characteristics was further analyzed. Receiver operating curves (ROC), Kaplan-Meier curves, and log-rank analyses were used to evaluate diagnostic and prognostic significance. RESULTS: Serum POSTN levels were significantly higher in patients with CRC compared with healthy controls (p < 0.0001) and associated with clinical stages (p < 0.001). ROC analysis revealed that POSTN was a biomarker comparable to CEA, CA19.9, and CA72.4 to distinguish all CRC from healthy controls (AUC = 0.75). Moreover, POSTN retained its diagnostic ability for CEA-negative (AUC = 0.69) and CA19.9-negative CRC patients (AUC = 0.71). Survival analysis revealed that patients with lower serum POSTN had longer overall survival than those with high serum POSTN (p = 0.0146). CONCLUSIONS: Serum POSTN might be a novel diagnostic and prognostic biomarker for patients with CRC.

Evaluating EFEMP1 in Cerebrospinal Fluid and Serum as a Potential Diagnosis Biomarker for Meningiomas.

BACKGROUND: The aim of this study was to determine the cerebrospinal fluid (CSF) and serum levels of EGF containing fibulin-like extracellular matrix protein 1 (EFEMP1) in the patients with meningiomas and explore its potential as a biomarker. METHODS: Forty-five patients with meningioma, 11 of whom underwent meningioma resection, as well as 30 healthy controls were enrolled in this study. CSF and blood samples were collected preoperatively and postoperatively. Expression levels of EFEMP1 were measured by enzyme-linked immunosorbent assay (ELISA). Receiver operating characteristic (ROC) curves were used to evaluate its discriminant ability. RESULTS: CSF EFEMP1 levels were significantly higher in the CSF samples (p < 0.0001) and serum samples (p = 0.0056) of meningioma patients compared to controls. To distinguish meningioma patients from controls by CSF and serum EFEMP1 levels, ROC/AUC analysis indicated an AUC of 0.945 (sensitivity 0.933; specificity 0.833) and an AUC of 0.674 (sensitivity 0.867; specificity 0.400), respectively. Moreover, the postoperative CSF levels of EFEMP1 were significantly decreased compared to the preoperative levels (p < 0.0001). CONCLUSIONS: The present study suggested that elevated EFEMP1 levels might be a novel diagnostic biomarker for meningioma patients.

Evaluation of Serological Indicators and Glomerular Filtration Rate Equations in Chinese Cancer Patients.

BACKGROUND The performance of estimated glomerular filtration rate (eGFR) have been proved to vary according to the races of the target population. The eGFR equations have not been validated in the Chinese cancer population received chemotherapy. Meanwhile, serum cystatin C (CysC), urea, ß2 microglobulin (ß2-MG), and creatinine (SCr) were also evaluated in a cohort of Chinese cancer patients. MATERIAL AND METHODS A total of 1000 cancer patients undergoing combination chemotherapy and 108 healthy volunteers were included in this study, and their renal function parameters were evaluated. The eGFR values were compared with reference GFR (rGFR) according to correlation, consistency, precision, and accuracy. Receiver operating characteristic (ROC) curves were used to evaluate the discriminating ability of the GFR equations and serological indicators of renal function. RESULTS (1) The equations contained CysC had the same varying tendency as rGFR in relation to the chemotherapeutic cycle. (2) eGFRscr+cysc and eGFRChinese scr+cysc worked better than the other equations, as indicated by a stronger correlation, less bias, improved precision, higher accuracy, and greater AUC. (3) CysC was more sensitive than the other serological indicators for identifying early renal injury. (4) Each parameter showed different characteristics in subgroups of Chinese cancer patients. CONCLUSIONS CysC was the most sensitive marker for early renal injury. Among the 8 most commonly used eGFR equations, the combination equation eGFRscr+cysc and eGFRChinese scr+cysc exhibited the best performance in the assessment of the renal function of Chinese cancer patients.

Nanocapsule assemblies as effective enzyme delivery systems against hyperuricemia.

The uricase nanocapsule assemblies (UNAs) were developed as effective delivery systems against hyperuricemia following parenteral enzyme therapy. UNAs were characterized in terms of micromorphology, size, catalytic activity, stability, and enzymatic kinetics. The pharmacokinetics/pharmacodynamics in rats after intravenous or subcutaneous injection was investigated. Immunogenicity, hemolysis and stimulation were determined. UNA was composed of many nanocapsules, and thus had higher loading efficiencies and stabilities than a single nanocapsule. The uricase molecules entrapped inside nanocapsules were separated from the circulating bloodstream to retain catalytic activities for a longer time than free uricase. UNAs increased the bioavailability and uric acid-lowering efficacy of uricase, while the immunogenicity and hemolysis rate of uricase were decreased. The superior properties of UNAs might be ascribed to the favorable conformational changes of uricase. Nanocapsule assemblies appeared to be able to deliver uricase effectively. This study also highlighted the importance of suitable systems for therapeutic enzyme delivery.

Effect of truncated neurokinin-1 receptor expression changes on the interaction between human breast cancer and bone marrow-derived mesenchymal stem cells.

Previous studies in breast cancer cell lines showed that truncated neurokinin receptor-1 (NK1R-Tr) was able to promote malignant transformation of breast cells, and NK1R-Tr may contribute to tumor progression and promote distant metastasis in human breast cancer. A co-culture model of breast cancer and bone marrow-derived human mesenchymal stem (HMSC-bm) cells showed that HMSC-bm inhibited the growth of breast cancer cells and entered the bone marrow at early stages. Down-regulation of NK1R-Tr may be a key factor in maintaining the quiescent phenotype of breast cancer cells among bone marrow stroma. Stromal-derived factor (SDF)-1α expression was negatively correlated with NK1R-Tr expression in breast cancer cells. Secretion of SDF-1α by HMSC-bm may maintain the quiescent phenotype of breast cancer cells among bone marrow stroma by down-regulating NK1R-Tr expression. Transforming growth factor (TGF)-ß1 expression was positively associated with NK1R-Tr expression in breast cancer cells. In a co-culture system, MDA-MB-231-TGF-ß1I (TGF-ß genes were suppressed using specific shRNA) cells were able to attach to HMSC-bm quickly, indicating that TGF-ß1 was also a key factor for maintaining the quiescent phenotype of breast cancer cells in bone marrow stroma. However, the detailed mechanism still remained unclear and could involve other molecules, in addition to NK1R-Tr.

[The Pharmacokinetics and Pharmacodynamics of Intravenous Uricase Multivesicular Liposomes].

OBJECTIVE: To determine and compare the pharmacokinetics and pharmacodynamics of uricase-multivesicular liposomes (UOMVLs) with free uricase (UOX) in rats. METHODS: UOMVLs were prepared by the double emulsion method and confirmed with its entrapment efficiency, size and Zeta potential. Twelve healthy rats were randomly divided into two groups: one with i. v. injection of UOMVLs, and the other with i. v. injection of UOX. Their serum activity of uricase was assayed. The pharmacokinetic parameters were calculated using software DAS 2. 1. 1. Another 24 male SD rats were enrolled, the rat model of hyperuricemia was established with hypoxanthine and potassium oxonate, while normal group (n=6) was set as control. Injection of UOMVLs (1 mL, 0. 47 U/mL), UOX (1 mL, 0. 47 U/mL) and nothiy were given 1 h later in UOMVLs group (n=6), UOX group (n=6) and model group (n=6), and their serum uric acid levels were determined 1, 2, 3, 5, 7, 9, 12, 24, 36, 48 h after the establishment of hyperuricemia model. RESULTS: The entrapment efficiency of UOMVLs was (63. 75 ± 3. 65) %, with an average particle size of (22. 56 ± 1. 70) µm and Zeta potential of (-41. 81±6. 59) mV. The pharmacokinetic parameters of UOMVLs and UOX were as follows, respectively: area under time-concentration curve from 0 to infinity time (AUC0-∞) (498. 83 ± 58. 85) U/L . h and (28. 49 ± 9. 95) U/L . h; time to peak concentration (Tmax) (1. 00±0. 00) h and (0. 00±0. 00) h; peak concentration (Cmax) (73. 04±6. 35) U/L and (31. 00±6. 03) U/L; elimination half-life (t1/2) (3. 49±0. 80) h and (1. 17±0. 33) h. The relative bioavailability of UOMVLs was (1 750. 90±206. 56) %. UOMVLs decreased serum uric to normal in 9 h; whereas it took 48 h for the UOX group and the model group to return to normal. CONCLUSION: UOMVLs can prolong tmax and t1/2 and improve the relative bioavailability. UOMVLs decrease serum uric acid levels in rats with hyperuricemia more effectively than UOX.

Azithromycin cationic non-lecithoid nano/microparticles improve bioavailability and targeting efficiency.

PURPOSE: The purpose of this study was to develop and evaluate the azithromycin cationic non-lecithoid nano/microparticles with high bioavailability and lung targeting efficiency. METHODS: The cationic niosomes with different sizes (AMCNS-S and AMCNS-L) along with varied built-in characteristics were produced to achieve high bioavailability and lung targeting efficiency of azithromycin (AM) via two administration routes widely used in clinical practice, i.e., oral and intravenous routes, instead of transdermal route (by which the only marketed niosome-based drug delivery dermatologic products were given). The possible explanations for improved bioavailability and lung targeting efficacy were put forward here. RESULTS: AMCNS-S (or AMCNS-L) had high bioavailability, for example, the oral (or intravenous) relative bioavailability of AMCNS-S (or AMCNS-L) to free AM increased to 273.19% (or 163.50%). After intravenous administration, AMCNS-S (or AMCNS-L) had obvious lung targeting efficiency, for example, the lung AM concentration of AMCNS-S (or AMCNS-L) increased 16 (or 28) times that of free AM at 12 h; the AM concentration of AMCNS-S (or AMCNS-L) in lung was higher than that in heart and kidney all the time. CONCLUSIONS: The development of niosome-based AM nanocarriers provides valuable tactics in antibacterial therapy and in non-lecithoid niosomal application.

Structural basis of tethered agonism and G protein coupling of protease-activated receptors.

Protease-activated receptors (PARs) are a unique group within the G protein-coupled receptor superfamily, orchestrating cellular responses to extracellular proteases via enzymatic cleavage, which triggers intracellular signaling pathways. Protease-activated receptor 1 (PAR1) is a key member of this family and is recognized as a critical pharmacological target for managing thrombotic disorders. In this study, we present cryo-electron microscopy structures of PAR1 in its activated state, induced by its natural tethered agonist (TA), in complex with two distinct downstream proteins, the Gq and Gi heterotrimers, respectively. The TA peptide is positioned within a surface pocket, prompting PAR1 activation through notable conformational shifts. Contrary to the typical receptor activation that involves the outward movement of transmembrane helix 6 (TM6), PAR1 activation is characterized by the simultaneous downward shift of TM6 and TM7, coupled with the rotation of a group of aromatic residues. This results in the displacement of an intracellular anion, creating space for downstream G protein binding. Our findings delineate the TA recognition pattern and highlight a distinct role of the second extracellular loop in forming ß-sheets with TA within the PAR family, a feature not observed in other TA-activated receptors. Moreover, the nuanced differences in the interactions between intracellular loops 2/3 and the Gα subunit of different G proteins are crucial for determining the specificity of G protein coupling. These insights contribute to our understanding of the ligand binding and activation mechanisms of PARs, illuminating the basis for PAR1's versatility in G protein coupling.

Activation of paternally expressed genes and perinatal death caused by deletion of the Gtl2 gene.

The Dlk1-Gtl2 imprinting locus is located on mouse distal chromosome 12 and consists of multiple maternally expressed non-coding RNAs and several paternally expressed protein-coding genes. The imprinting of this locus plays a crucial role in embryonic development and postnatal growth. At least one cis-element, the intergenic differentially methylated region (IG-DMR) is required for expression of maternally expressed genes and repression of silenced paternally expressed genes. The mechanism by which the IG-DMR functions is largely unknown. However, it has been suggested that the unmethylated IG-DMR acts as a positive regulator activating expression of non-coding RNAs. Gtl2 is the first non-coding RNA gene downstream of the IG-DMR. Although its in vivo function in the mouse is largely unknown, its human ortholog MEG3 has been linked to tumor suppression in human tumor-derived cell lines. We generated a knockout mouse model, in which the first five exons and adjacent promoter region of the Gtl2 gene were deleted. Maternal deletion of Gtl2 resulted in perinatal death and skeletal muscle defects, indicating that Gtl2 plays an important role in embryonic development. The maternal deletion also completely abolished expression of downstream maternally expressed genes, activated expression of silenced paternally expressed genes and resulted in methylation of the IG-DMR. By contrast, the paternal inherited deletion did not have this effect. These data strongly indicate that activation of Gtl2 and its downstream maternal genes play an essential role in regulating Dlk1-Gtl2 imprinting, possibly by maintaining active status of the IG-DMR.

Roles of full-length and truncated neurokinin-1 receptors on tumor progression and distant metastasis in human breast cancer.

Substance P (SP) regulates various physiologic and pathophysiologic responses predominantly by acting through its primary receptor, the neurokinin-1 receptor (NK1R). There are two naturally occurring forms of NK1R: full-length NK1R-FL and truncated NK1R-Tr. SP-coupled NK1R can directly or indirectly regulate the proliferation and metastatic progression of many types of human cancer cells. However, the exact roles played by the two isoforms of NK1R in breast carcinogenesis still remain largely unclear. In the present study, we first examined the expression profile of total NK1Rs, NK1R-FL and NK1R-Tr in multiple breast cancer cell lines as well as in breast tumor samples. We found that total NK1Rs are present in normal, benign and breast tumor tissues; while, NK1R-FL expression are significantly decreased in tumor specimens, particularly in metastatic carcinomas. More interestingly, NK1R-FL is highly expressed in nontumorigenic HBL-100 breast cells, whereas MDA-MB-231, MCF-7 and T47D breast cancer cells express only NK1R-Tr. To further investigate potential implications of NK1R-FL and NK1R-Tr in the malignant phenotypes of breast cancer, we studied the impacts of ectopically overexpressed NK1R-FL and NK1R-Tr in MDA-MB-231 and HBL-100 cells, respectively. Our in vitro and in vivo data showed that NK1R-FL expression was inversely associated with proliferation, invasiveness and metastasis of MDA-MB-231 cells, but overexpression of NK1R-Tr was able to promote malignant transformation of HBL-100 cells and NK1R-Tr may contribute to tumor progression and promote distant metastasis in human breast cancer. A long-term treatment of NK1R antagonist ASN-1377642 exerted antitumor action in breast cancer cells with NK1R-Tr high expression.

Silencing of the imprinted DLK1-MEG3 locus in human clinically nonfunctioning pituitary adenomas.

DLK1-MEG3 is an imprinted locus consisting of multiple maternally expressed noncoding RNA genes and paternally expressed protein-coding genes. The expression of maternally expressed gene 3 (MEG3) is selectively lost in clinically nonfunctioning adenomas (NFAs) of gonadotroph origin; however, expression status of other genes at this locus in human pituitary adenomas has not previously been reported. Using quantitative real-time RT-PCR, we evaluated expression of 24 genes from the DLK1-MEG3 locus in 44 human pituitary adenomas (25 NFAs, 7 ACTH-secreting, 7 GH-secreting, and 5 PRL-secreting adenomas) and 10 normal pituitaries. The effects on cell proliferation of five miRNAs whose expression was lost in NFAs were investigated by flow cytometry analysis. We found that 18 genes, including 13 miRNAs at the DLK1-MEG3 locus, were significantly down-regulated in human NFAs. In ACTH-secreting and PRL-secreting adenomas, 12 and 7 genes were significantly down-regulated, respectively; no genes were significantly down-regulated in GH-secreting tumors. One of the five miRNAs tested induced cell cycle arrest at the G2/M phase in PDFS cells derived from a human NFA. Our data indicate that the DLK1-MEG3 locus is silenced in NFAs. The growth suppression by miRNAs in PDFS cells is consistent with the hypothesis that the DLK1-MEG3 locus plays a tumor suppressor role in human NFAs.

High Histone Deacetylase 2/3 Expression in Non-Functioning Pituitary Tumors.

Epigenetic modification of chromatin is involved in non-malignant pituitary neoplasia by causing abnormal expression of tumor suppressors and oncogenes. These changes are potentially reversible, suggesting the possibility of targeting tumor cells by restoring the expression of epigenetically silenced tumor suppressors. The role of the histone deacetylase (HDAC) family in pituitary tumorigenesis is not known. We report that HDAC2 and 3, Class I HDAC members, are highly expressed in clinically non-functioning pituitary adenomas (NFPAs) compared to normal pituitary (NP) samples as determined by RT-PCR and immunohistochemical staining (IHC). Treatment of a human NFPA derived folliculostellate cell line, PDFS, with the HDAC3 inhibitor RGFP966 for 96 hours resulted in inhibition of cell proliferation by 70%. Furthermore, the combination of RGFP966 with a methyltransferase/DNMT inhibitor, 5'-aza-2'-deoxycytidine, led to the restoration of the expression of several tumor suppressor genes, including STAT1, P16, PTEN, and the large non-coding RNA tumor suppressor MEG3, in PDFS cells. Our data support the hypothesis that both histone modification and DNA methylation are involved in the pathogenesis of human NFPAs and suggest that targeting HDACs and DNA methylation can be incorporated into future therapies.