Human Lipocalin-Type Prostaglandin D Synthase-Based Drug Delivery System for Poorly Water-Soluble Anti-Cancer Drug SN-38

Lipocalin-type prostaglandin D synthase (L-PGDS) is a member of the lipocalin superfamily, which is composed of secretory transporter proteins, and binds a wide variety of small hydrophobic molecules. Using this function, we have reported the feasibility of using L-PGDS as a novel drug delivery vehicle for poorly water-soluble drugs. In this study, we show the development of a drug delivery system using L-PGDS, one that enables the direct clinical use of 7-ethyl-10-hydroxy-camptothecin (SN-38), a poorly water-soluble anti-cancer drug. In the presence of 2 mM L-PGDS, the concentration of SN-38 in PBS increased 1,130-fold as compared with that in PBS. Calorimetric experiments revealed that L-PGDS bound SN-38 at a molecular ratio of 1:3 with a dissociation constant value of 60 μM. The results of an in vitro growth inhibition assay revealed that the SN-38/L-PGDS complexes showed high anti-tumor activity against 3 human cancer cell lines, i.e., Colo201, MDA-MB-231, and PC-3 with a potency similar to that of SN-38 used alone. The intravenous administration of SN-38/L-PGDS complexes to mice bearing Colo201 tumors showed a pronounced anti-tumor effect. Intestinal mucositis, which is one of the side effects of this drug, was not observed in mice administered SN-38/L-PGDS complexes. Taken together, L-PGDS enables the direct usage of SN-38 with reduced side effects.

Dataset of microarray analysis to identify endoglin-dependent bone morphogenetic protein-2-responsive genes in the murine periodontal ligament cell line PDL-L2

The periodontal ligament (PDL), connective tissue located between the cementum of teeth and alveolar bone of the mandibula, plays a crucial role in the maintenance and regeneration of periodontal tissues. We previously reported that endoglin was involved in the bone morphogenetic protein (BMP)-2-induced osteogenic differentiation of mouse PDL cells, which is associated with Smad-2 phosphorylation but not Smad-1/5/8 phosphorylation. Further, we found that the BMP-2-induced Smad-2 phosphorylation was, at least in part, dependent upon endoglin. In this study, to elucidate the detailed mechanism underlying the BMP-2-induced signaling pathway unique to PDL cells, we performed a cDNA microarray analysis to identify endoglin-dependent BMP-2-responsive genes in PDL-L2, a mouse PDL-derived cell line. Here we provide experimental methods and obtained dataset to correspond with our data in Gene Expression Omnibus (GEO) Datasets.

Complicated adult right-sided Bochdalek hernia with Chilaiditi's syndrome: a case report

An extremely rare adult case that underwent surgery for ileus caused by Bochdalek hernia associated with Chilaiditi’s syndrome is presented. A 65-year-old woman complaining of upper abdominal pain presented to our hospital. Abdominal plain radiography showed increased intestinal gas, and computed tomography (CT) showed the transverse colon located above the right lobe of the liver, representing Chilaiditi’s sign. She was diagnosed as having ileus and treated with decompression therapy by a nasoenteric tube. After hospitalization, the patient developed dyspnea, and CT showed intestinal herniation into the right thoracic cavity. She was diagnosed as having strangulated ileus caused by Bochdalek hernia. An emergent laparotomy was performed, and it showed a hole of 5 cm in diameter at the right hemi-diaphragm. The transverse colon was incarcerated through the hole, it was pulled back to the abdominal cavity, and a right hemicolectomy was performed because of necrotic changes. A small part of the liver was also herniated into the right thoracic cavity, and it was returned to the abdominal cavity. The defect in the diaphragm was closed by direct suture. Although the patient developed an abscess in the thoracic cavity postoperatively, she improved with antibiotic therapy and was discharged 2 months after the operation.

[A Case of Gastrointestinal Metastases of Breast Cancer Effectively Treated with Gemcitabine and Paclitaxel Combination Chemotherapy]

A 55-year-old woman was admitted to our hospital complaining of constipation and abdominal distention. She had a history of right breast surgery for cancer at the age of 48 years. An abdominalCT scan revealed tumors at the antrum of the stomach and the ascending colon, and the tumor at the ascending colon caused obstruction of the colon. She was diagnosed with breast cancer recurrence and was administered combination chemotherapy consisting of gemcitabine and paclitaxel. Ileus improved after this treatment, and she was discharged from the hospital and was able to receive outpatient chemotherapy. After 8 months, she experienced symptoms of ileus again, and conservative treatment was considered impossible. Therefore, she underwent distal gastrectomy and right hemicolectomy. Histological and immunohistological analyses confirmed that the tumors were breast cancer metastases. Chemotherapy with gemcitabine and paclitaxel helped our patient to return to daily life and improved her prognosis.

Isolated spleen recurrence in a patient with lung adenocarcinoma: A case report

Spleen metastasis is extremely rare in patients with lung cancer. However, recent improvements in imaging modalities may enable the antemortem diagnosis of spleen metastasis. The present study reports the case of a female patient with lung adenocarcinoma and spleen metastasis. The patient developed isolated spleen metastasis in the postoperative course. This rare metastasis was detected in a follow-up abdominal computed tomography (CT) scan without any symptoms, and was confirmed by fluorodeoxyglucose positron emission tomography (FDG-PET)/CT scan. Although very rare, chest physicians and thoracic surgeons should be alert to the possibility of spleen metastasis development when evaluating the follow-up abdominal CT scan. FDG-PET/CT scanning and an interventional approach should be considered to clarify the possibility of spleen metastasis.

miR-200a, miR-200b and miR-429 are onco-miRs that target the PTEN gene in endometrioid endometrial carcinoma

Endometrioid endometrial carcinoma (EEC) is a common malignancy of the female genital tract. However, no adequate biomarker is currently available for predicting the prognosis of this cancer. Recent studies have revealed dysregulated expression of several microRNAs (miRNAs) in various cancer tissues, and therefore, these cancer-associated miRNAs (also called onco-miRs) could be promising prognostic biomarkers of cancer progression or metastasis. In this study, in order to identify onco-miRs and their possible targets involved in EEC, we performed microarray-based integrative analyses of miRNA and mRNA expression in specimens excised from EEC lesions and adjacent normal endometrial tissues. Using integrated statistical analyses, we identified miR-200a, miR-200b and miR-429 as highly up-regulated onco-miRs in EECs. Conversely, we detected expression of a tumor-suppressor gene, phosphatase and tensin homolog (PTEN), which was predicted in silico using a miRNA-targeting mRNA prediction algorithm, as a target of the three miRNAs and which was down-regulated in EECs. Furthermore, these miRNAs were validated to target PTEN experimentally using luciferase assays and real-time polymerase chain reaction. These results suggest that the occurrence of EEC is, at least in part, mediated by miRNA-induced suppression of PTEN expression.

Identification of endoglin-dependent BMP-2-induced genes in the murine periodontal ligament cell line PDL-L2

Background

The periodontal ligament (PDL), connective tissue located between the cementum of teeth and alveolar bone of the mandibula, plays an important role in the maintenance and regeneration of periodontal tissues. We reported previously that endoglin was involved in the BMP-2-induced osteogenic differentiation of mouse PDL cells, which is associated with Smad-2 phosphorylation but not Smad-1/5/8 phosphorylation. In this study, to elucidate the detailed mechanism underlying the BMP-2 signalling pathway unique to PDL cells, we performed a microarray analysis to identify BMP-2-inducible genes in PDL-L2 cells, a mouse PDL-derived cell line, with or without endoglin knockdown.

Findings

Sixty-four genes were upregulated more than twofold by BMP-2 in PDL-L2 cells. Of these genes, 11 were endoglin-dependent, including Id4, which encodes ID4, a helix-loop-helix transcription factor closely associated with TGF-β signaling and osteoblast differentiation. The endoglin-dependent induction of ID4 by BMP-2 was also verified at a protein level.

Conclusion

Our findings indicate that ID4 could be a signal mediator involved in the BMP-2-induced endoglin-dependent osteogenic differentiation of PDL cells.

Interactions between the non-seed region of siRNA and RNA-binding RLC/RISC proteins, Ago and TRBP, in mammalian cells

Small interfering RNA (siRNA)-based RNA interference (RNAi) is widely used for target gene silencing in various organisms. We previously showed that 8-nt-long 5′ proximal nucleotides, which include seed sequence (positions 2–8 from the 5′ end of guide strand), and the complementary sequence of the passenger strand are capable of being simultaneously replaced with cognate deoxyribonucleotides without any substantial loss of gene silencing. In the present study, examination was made of RNA requirements in the non-seed region of siRNA. The non-seed region of siRNA was found to be subdivided into four domains, in which two nucleotide pairs (positions 13 and 14) were replaceable with cognate deoxyribonucleotides without reducing RNAi activity. However, RNA sequences at positions 9-12 and 15-18 were essential for effective gene silencing, and these two double-stranded RNA cores are required for binding of the trans-activation response RNA-binding protein (TRBP). The terminal RNA (positions 19–21) provided Argonaute protein binding sites. Argonaute binding was enhanced by the presence of RNAs at positions 15–18. Knockdown experiments showed that, unlike Argonaute and TRBP, Dicer was dispensable for RNAi. Based on these observations, we discuss possible RNA/protein and protein/protein interactions in RNA-induced silencing complex formation.

Bone Morphogenetic Protein-2 Desensitizes MC3T3-E1 Osteoblastic Cells to Estrogen Through Transcriptional Downregulation of Estrogen Receptor 1

Background

Estrogens exert preferable effects on bone metabolism through two estrogen receptors (ERs), ER1 and ER2, which activate the transcription of a set of genes as ligand-dependent transcription factors. Thus, growth factors and hormones which modulate ER expression in the bone, if any, may possibly modulate the effect of estrogens on bone metabolism. However, research as to which of these molecules regulate the expression of ERs in osteoblasts has not been well documented.

Methods

A reporter assay system developed in this study was used to explore molecules that modulate ER1 expression in MC3T3-E1 osteoblastic cells. Gene expression was analyzed by reverse transcription-polymerase chain reaction.

Results

A pilot study using the reporter system revealed that bone morphogenetic protein (BMP)-2 negatively regulated ER1, but not ER2, expression in MC3T3-E1 cells. Consistently, estradiol-induced reporter activity via an estrogen responsive element was strongly suppressed in MC3T3-E1 cells pretreated with BMP-2.

Conclusions

BMP-2 desensitizes osteoblastic cells to estrogen through downregulation of ER1 expression.

Plasma level of hydroxysteroid (17-β) dehydrogenase 1 in the second trimester is an independent risk factor for predicting preeclampsia after adjusting for the effects of mean blood pressure, bilateral notching and plasma level of soluble fms-like tyrosine kinase 1/placental growth factor ratio

Mean blood pressure (MBP), bilateral notching (BN) in the uterine artery and increased circulating levels of soluble fms-like tyrosine kinase-1/placental growth factor (sFlt-1/PlGF) ratio are predictors of preeclampsia (PE). Recently, we disclosed that reducing the plasma level of hydroxysteroid (17-β) dehydrogenase 1 (HSD17B1), which is a steroidogenetic enzyme catalyzing the conversion of estrone to 17β-estradiol, is a potential prognostic factor for PE. Our aim was to evaluate whether HSD17B1 is an independent risk factor for predicting PE after adjusting for the effects of MBP, BN and the plasma level of the sFlt-1/PlGF ratio in the second trimester. One hundred and twenty-eight consecutive normal pregnant women without gestational hypertension (GH) or PE and 30 women with PE were selected from 1724 pregnant women. Multivariate logistic regression with a forward stepwise procedure was used to construct a prediction model. A past history of GH/PE, a family history of hypertension, pre-pregnancy body mass index, MBP, BN, plasma levels of sFlt-1/PlGF ratio and plasma levels of HSD17B1 were significantly associated with the occurrence of PE; however, only MBP (OR (95% confidence interval), 1.08 (1.03-1.14)), BN (7.5 (1.9-30)), sFlt-1/PlGF (21 (2.7-163)) and HSD17B1 (0.43 (0.22-0.85)) were independent risk factors for PE. The area under the receiver-operating-characteristic curve for the combination model was 0.89, yielding a sensitivity of 0.84, a specificity of 0.88 and a positive likelihood ratio of 7.2 (4.0-13). In conclusion, HSD17B1 is an independent risk factor for PE, and the combination of several risk factors including HSD17B1 in the second trimester may improve the prediction of PE.

MiR-21 is enriched in the RNA-induced silencing complex and targets COL4A1 in human granulosa cell lines

MicroRNAs (miRNAs) are noncoding small RNAs that play important roles in a variety of physiological and pathological events. In this study, we performed large-scale profiling of EIF2C2-bound miRNAs in 3 human granulosa-derived cell lines (ie, KGN, HSOGT, and GC1a) by high-throughput sequencing and found that miR-21 accounted for more than 80% of EIF2C2-bound miRNAs, suggesting that it was enriched in the RNA-induced silencing complex (RISC) and played a functional role in human granulosa cell (GC) lines. We also found high expression levels of miR-21 in primary human GCs. Assuming that miR-21 target mRNAs are enriched in RISC, we performed cDNA cloning of EIF2C2-bound mRNAs in KGN cells. We identified COL4A1 mRNA as a miR-21 target in the GC lines. These data suggest that miR-21 is involved in the regulation of the synthesis of COL4A1, a component of the basement membrane surrounding the GC layer and granulosa-embedded extracellular structure.

Hydroxysteroid (17-β) dehydrogenase 1 is dysregulated by miR-210 and miR-518c that are aberrantly expressed in preeclamptic placentas: a novel marker for predicting preeclampsia

In this study, to search for novel preeclampsia (PE) biomarkers, we focused on microRNA expression and function in the human placenta complicated with PE. By comprehensive analyses of microRNA expression, we identified 22 microRNAs significantly upregulated in preeclamptic placentas, 5 of which were predicted in silico to commonly target the mRNA encoding hydroxysteroid (17-β) dehydrogenase 1 (HSD17B1), a steroidogenetic enzyme expressed predominantly in the placenta. In vivo HSD17B1 expression, at both the mRNA and protein levels, was significantly decreased in preeclamptic placentas. Of these microRNAs, miR-210 and miR-518c were experimentally validated to target HSD17B1 by luciferase assay, real-time PCR, and ELISA. Furthermore, we found that plasma HSD17B1 protein levels in preeclamptic pregnant women reflected the decrease of its placental expression. Moreover, a prospective cohort study of plasma HSD17B1 revealed a significant reduction of plasma HSD17B1 levels in pregnant women at 20 to 23 and 27 to 30 weeks of gestation before PE onset compared with those with normal pregnancies. The sensitivities/specificities for predicting PE at 20 to 23 and 27 to 30 weeks of gestation were 0.75/0.67 (cutoff value=21.9 ng/mL) and 0.88/0.51 (cutoff value=30.5 ng/mL), and the odds ratios were 6.09 (95% CI: 2.35-15.77) and 7.83 (95% CI: 1.70-36.14), respectively. We conclude that HSD17B1 is dysregulated by miR-210 and miR-518c that are aberrantly expressed in preeclamptic placenta and that reducing plasma level of HSD17B1 precedes the onset of PE and is a potential prognostic factor for PE.

Short RNA duplexes elicit RIG-I-mediated apoptosis in a cell type- and length-dependent manner

Short double-stranded RNAs (dsRNAs) induce type I interferon (IFN)-mediated innate immune responses. In functional studies with short interfering RNAs or synthetic mimics of microRNA precursors in vitro, we found that short dsRNAs readily induced apoptosis in cells derived from human granulosa cell tumors, but not in other cell types. Apoptosis was independent of the sequence of the dsRNA, but depended on its length, and was induced by 23- and 24-nucleotide (nt) dsRNAs, but not by shorter dsRNAs (< 22 nt) or by the long dsRNA polyinosinic-polycytidylic acid. Microarray analysis revealed that apoptosis was accompanied by the increased expression of IFN-stimulated genes; however, several lines of evidence showed that IFNs did not directly induce apoptosis. Subsequent analyses revealed that the short dsRNAs increased the expression of retinoic acid-inducible gene I (RIG-I) through dsRNA-activated protein kinase (PKR). Although these dsRNAs bore 3' overhangs and nontriphosphate 5' termini, which are not thought to be RIG-I-activating structures, the dsRNAs bound to RIG-I and triggered proapoptotic signaling mostly by activating RIG-I, which was followed by activation of the mitogen-activated protein kinase p38. Thus, we suggest that ligand recognition and subsequent signaling by RNA sensors are more complicated than previously believed. In addition, short dsRNAs may serve as pharmacological agents to target specific tumors, such as granulosa cell tumors.

Relationship between altered expression levels of MIR21, MIR143, MIR145, and MIR205 and clinicopathologic features of esophageal squamous cell carcinoma

In spite of the undisputed importance of altered expression patterns of microRNAs (miRNAs) in various cancers, there is little information on the clinicopathologic significance of cancer-related miRNAs (MIR21, MIR143, MIR144, MIR145, and MIR205) in esophageal squamous cell carcinoma (ESCC). We examined the expression levels of the precursor and mature miRNA genes in ESCC using real-time polymerase chain reaction (PCR). We also investigated the mRNA expression levels of processing elements (RNASEN, DGCR8, and DICER1) that participate in miRNA-biogenesis pathway. Furthermore, we analyzed the relationships between the expression levels of these five miRNAs and the clinicopathologic parameters of ESCC patients. The expression levels of mature MIR21 and mature MIR145 were higher in ESCC than those in normal epithelium (P < 0.05). The mature/pre ratio of MIR21 in ESCC was higher than that in normal epithelium (P < 0.05). With regard to miRNA-processing elements, the expression level of RNASEN was higher in ESCC than in normal epithelium (P < 0.05). Furthermore, altered expression of these miRNAs was related to the clinicopathologic features of ESCC patients. The high expression of mature MIR21 and mature MIR205 was associated with lymph node positivity in ESCC patients (P < 0.05). The high levels of expression of mature MIR143 and mature MIR145 were associated with recurrence of metastasis in ESCC patients (P < 0.05). The findings may imply that miRNA biogenesis is aberrantly accelerated in ESCC. Analysis of the expression levels of miRNAs should provide useful information for evaluation of the staging, prognosis, and treatment of ESCC patients.

Real-time PCR-based analysis of the human bile microRNAome identifies miR-9 as a potential diagnostic biomarker for biliary tract cancer

Biliary tract cancer (BTC) is often difficult to diagnose definitively, even through histological examination. MicroRNAs (miRNAs) regulate a variety of physiological processes. In recent years, it has been suggested that profiles for circulating miRNAs, as well as those for tissue miRNAs, have the potential to be used as diagnostic biomarkers for cancer. The aim of this study was to confirm the existence of miRNAs in human bile and to assess their potential as clinical biomarkers for BTC. We sampled bile from patients who underwent biliary drainage for biliary diseases such as BTC and choledocholithiasis. PCR-based miRNA detection and miRNA cloning were performed to identify bile miRNAs. Using high-throughput real-time PCR-based miRNA microarrays, the expression profiles of 667 miRNAs were compared in patients with malignant disease (n = 9) and age-matched patients with the benign disease choledocholithiasis (n = 9). We subsequently characterized bile miRNAs in terms of stability and localization. Through cloning and using PCR methods, we confirmed that miRNAs exist in bile. Differential analysis of bile miRNAs demonstrated that 10 of the 667 miRNAs were significantly more highly expressed in the malignant group than in the benign group at P<0.0005. Setting the specificity threshold to 100% showed that some miRNAs (miR-9, miR-302c*, miR-199a-3p and miR-222*) had a sensitivity level of 88.9%, and receiver-operating characteristic analysis demonstrated that miR-9 and miR-145* could be useful diagnostic markers for BTC. Moreover, we verified the long-term stability of miRNAs in bile, a characteristic that makes them suitable for diagnostic use in clinical settings. We also confirmed that bile miRNAs are localized to the malignant/benign biliary epithelia. These findings suggest that bile miRNAs could be informative biomarkers for hepatobiliary disease and that some miRNAs, particularly miR-9, may be helpful in the diagnosis and clinical management of BTC.

Identification of obstructive jaundice-related microRNAs in mouse liver

BACKGROUND/AIMS

Although microRNAs are known to be post-transcriptional regulators in physiological and pathological events in the liver, their role in the obstructive jaundice liver remains unclear.

METHODOLOGY

We sequenced the small RNA libraries of the bile duct ligation (BDL) mouse liver to detect the in vivo microRNA expression profiles of obstructive jaundice. We also validated the differential expression of microRNAs in the BDL liver using real-time PCR. Laser microdissection was performed to identify the origin of BDL-related microRNAs. An IL6-treated normal intrahepatic biliary epithelial cell line was used as an in vitro model of obstructive jaundice.

RESULTS

We found microRNAs that were upregulated in the BDL liver (let-7a, let-7d, let-7f, let-7g, miR-21, miR-125a-5p, miR-125b-5p, miR-194, miR-199a-3p, miR-199a-5p, miR-214, miR-221, and miR-486). Furthermore, laser-microdissection analysis showed that miR-199a-5p was significantly upregulated in the intrahepatic bile duct of the BDL liver. The in vitro expression of miR-199a-5p was appreciably elevated in accordance with increased proliferation of IL6-treated cells.

CONCLUSIONS

We revealed dynamic changes in microRNA expression during obstructive jaundice using the BDL model. MiR-199a-5p was likely associated with the proliferation of intrahepatic bile ducts. Our data will facilitate further study of the pathophysiological role(s) of microRNAs in the obstructive jaundice liver.

Endoglin is involved in BMP-2-induced osteogenic differentiation of periodontal ligament cells through a pathway independent of Smad-1/5/8 phosphorylation

The periodontal ligament (PDL), a connective tissue located between the cementum of teeth and the alveolar bone of mandibula, plays a crucial role in the maintenance and regeneration of periodontal tissues. The PDL contains fibroblastic cells of a heterogeneous cell population, from which we have established several cell lines previously. To analyze characteristics unique for PDL at a molecular level, we performed cDNA microarray analysis of the PDL cells versus MC3T3-E1 osteoblastic cells. The analysis followed by validation by reverse transcription-polymerase chain reaction and immunochemical staining revealed that endoglin, which had been shown to associate with transforming growth factor (TGF)-beta and bone morphogenetic proteins (BMPs) as signaling modulators, was abundantly expressed in PDL cells but absent in osteoblastic cells. The knockdown of endoglin greatly suppressed the BMP-2-induced osteoblastic differentiation of PDL cells and subsequent mineralization. Interestingly, the endoglin knockdown did not alter the level of Smad-1/5/8 phosphorylation induced by BMP-2, while it suppressed the BMP-2-induced expression of Id1, a representative BMP-responsive gene. Therefore, it is conceivable that endoglin regulates the expression of BMP-2-responsive genes in PDL cells at some site downstream of Smad-1/5/8 phosphorylation. Alternatively, we found that Smad-2 as well as Smad-1/5/8 was phosphorylated by BMP-2 in the PDL cells, and that the BMP-2-induced Smad-2 phosphorylation was suppressed by the endoglin knockdown. These results, taken together, raise a possibility that PDL cells respond to BMP-2 via a unique signaling pathway dependent on endoglin, which is involved in the osteoblastic differentiation and mineralization of the cells.

MicroRNA profiling of human intrahepatic cholangiocarcinoma cell lines reveals biliary epithelial cell-specific microRNAs

Intrahepatic cholangiocarcinoma (ICC), which arises in the small bile ducts of the liver, is the second most common liver malignancy. Although modulation of microRNA (miRNA) expression has been shown to be a potent sign of malignant tumors, miRNA profiles of ICC remains unclear. We performed sequencing analysis of the small RNA libraries of 2 ICC cell lines (HuCCT1 and MEC) and one normal intrahepatic biliary epithelial cell line (HIBEpiC) to produce the miRNA profiles of ICC in vitro. Furthermore, by means of the real-time polymerase chain reaction (PCR) we validated the differential expression of miRNAs cloned exclusively or predominantly from each of the cell lines. A total of 35,759 small RNA clones were obtained from the 3 cell lines. We identified 27 miRNAs that were expressed exclusively or predominantly in each cell line. Subsequent validation with the real-time PCR confirmed that the miRNAs hsa-miR-22, -125a, -127, -199a, -199a*, -214, -376a, and -424 were expressed specifically in HIBEpiC but were downregulated in the ICC cell lines. Our study provides important information for facilitating studies of the functional role(s) of miRNAs in carcinogenesis of the hepatobiliary system. The biliary epithelial cell-specific miRNAs identified in this study may serve as potential biomarkers for ICC.

Human villous trophoblasts express and secrete placenta-specific microRNAs into maternal circulation via exosomes

In this study, we performed small RNA library sequencing using human placental tissues to identify placenta-specific miRNAs. We also tested the hypothesis that human chorionic villi could secrete miRNAs extracellularly via exosomes, which in turn enter into maternal circulation. By small RNA library sequencing, most placenta-specific miRNAs (e.g., MIR517A) were linked to a miRNA cluster on chromosome 19. The miRNA cluster genes were differentially expressed in placental development. Subsequent validation by real-time PCR and in situ hybridization revealed that villous trophoblasts express placenta-specific miRNAs. The analysis of small RNA libraries from the blood plasma showed that the placenta-specific miRNAs are abundant in the plasma of pregnant women. By real-time PCR, we confirmed the rapid clearance of the placenta-specific miRNAs from the plasma after delivery, indicating that such miRNAs enter into maternal circulation. By using the trophoblast cell line BeWo in culture, we demonstrated that miRNAs are indeed extracellularly released via exosomes. Taken together, our findings suggest that miRNAs are exported from the human placental syncytiotrophoblast into maternal circulation, where they could target maternal tissues. Finally, to address the biological functions of placenta-specific miRNAs, we performed a proteome analysis of BeWo cells transfected with MIR517A. Bioinformatic analysis suggests that this miRNA is possibly involved in tumor necrosis factor-mediated signaling. Our data provide important insights into miRNA biology of the human placenta.

Chondromodulin-1 directly suppresses growth of human cancer cells

Background

Chondromodulin-1 (ChM1), an endogenous anti-angiogenic factor expressed in cartilage, has been suggested to inhibit invasion of endothelial cells into cartilage. In addition, the ectopic administration of ChM1 has been reported to suppress tumorigenesis in vivo. However, it is unclear whether the anti-tumor effect is due to not only the anti-vascularization effect of ChM1, but also its direct action against oncocytes. In the present study, we sought to determine whether ChM1 has a direct action on tumor cells.

Methods

BrdU incorporation assay was performed on human umbilical vein endothelial cells (HUVECs), normal human dermal fibroblasts (NHDFs), HepG2 cells and HeLa cells in the presence or absence of recombinant human ChM1 (rhChM1). An adenovirus that expresses ChM1, Ad-ChM1, was established and applied to the tumor xenografted in vivo, and to in vitro tumor cells cultured on plates or in soft agar. Cell cycle-related proteins and the phosphorylation of Erk, Akt, and GSK3β, the downstream molecules of the extracellular matrix-integrin signaling pathways, in HepG2 cells treated with or without Ad-ChM1 were detected by western blot analysis. Luciferase reporter assays of STAT, GAS, and ISRE, which participate in another cytokine signaling pathway, ware performed in HepG2, HeLa, and HUVEC cells.

Results

ChM1 suppressed BrdU incorporation in HUVECs and in HepG2 cells dose-dependently, but did not suppress BrdU incorporation in NHDFs and HeLa cells cultured on plates. In soft agar, however, ChM1 suppressed the growth of HeLa cells, as well as HepG2 cells. Western blot analyses demonstrated that ChM1 decreased the levels of cyclin D1, cyclin D3, and cdk6 and increased those of p21^cip1 without affecting the phosphorylation levels of Erk, Akt, and GSK3β in HepG2 cells. The luciferase reporter assay demonstrated that ChM1 suppressed the transcriptional activities of STAT and GAS but not of ISRE.

Conclusion

ChM1 directly suppressed the proliferation of tumor cells in an anchorage-independent manner. However, ChM1 did not alter the phosphorylation of downstream molecules, at which the signaling pathways through growth factor and cytokine receptors converge with the anchorage-dependent pathway. Our results show that ChM1 has a direct anti-tumor effect; moreover, this effect occurs by inhibiting the STAT signaling pathway.

MicroRNA (miRNA) cloning analysis reveals sex differences in miRNA expression profiles between adult mouse testis and ovary

MicroRNAs (miRNAs) are endogenous non-coding small RNAs that can regulate the expression of complementary mRNA targets. Identifying tissue-specific miRNAs is the first step toward understanding the biological functions of miRNAs, which include the regulation of tissue differentiation and the maintenance of tissue identity. In this study, we performed small RNA library sequencing in adult mouse testis and ovary to reveal their characteristic organ- and gender-specific profiles and to elucidate the characteristics of the miRNAs expressed in the reproductive system. We obtained 10,852 and 11 744 small RNA clones from mouse testis and ovary respectively (greater than 10,000 clones per organ), which included 6630 (159 genes) and 10,192 (154 genes) known miRNAs. A high level of efficiency of miRNA library sequencing was achieved: 61% (6630 miRNA clones/10,852 small RNA clones) and 87% (10,192/11,744) for adult mouse testis and ovary respectively. We obtained characteristic miRNA signatures in testis and ovary; 55 miRNAs were detected highly, exclusively, or predominantly in adult mouse testis and ovary, and discovered two novel miRNAs. Male-biased expression of miRNAs occurred on the X-chromosome. Our data provide important information on sex differences in miRNA expression that should facilitate studies of the reproductive organ-specific roles of miRNAs.