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Pulmonary artery smooth muscle cells (PASMCs) proliferation caused by hypoxia is an important pathological process of pulmonary hypertension (PH). Prevention of PASMCs proliferation can effectively reduce PH mortality. Long non-coding RNAs (lncRNAs) are involved in the proliferation process. Recent evidence has demonstrated that functional peptides encoded by lncRNAs play important roles in cell pathophysiological process. Our previous study has demonstrated that lnc-Rps4l with high coding ability mediates the PASMCs proliferation under hypoxic conditions. We hypothesize in this study that a lnc-Rps4l-encoded peptide is involved in hypoxic-induced PASMCs proliferation. The presence of peptide 40S ribosomal protein S4 X isoform-like (RPS4XL) encoded by lnc-Rps4l in PASMCs under hypoxic conditions was confirmed by bioinformatics, immunofluorescence, and immunohistochemistry. Inhibition of proliferation by the peptide RPS4XL was demonstrated in hypoxic PASMCs by MTT, bromodeoxyuridine (BrdU) incorporation, and immunofluorescence assays. By using the bioinformatics, coimmunoprecipitation (coIP), and mass spectrometry, RPS6 was identified to interact with RPS4XL. Furthermore, lnc-Rps4l-encoded peptide RPS4XL inhibited the RPS6 process via binding to RPS6 and inhibiting RPS6 phosphorylation at p-RPS6 (Ser240+Ser244) phosphorylation site. These results systematically elucidate the role and regulatory network of Rps4l-encoded peptide RPS4XL in PASMCs proliferation. These discoveries provide potential targets for early diagnosis and a leading compound for treatment of hypoxic PH.

Pulmonary hypertension (PH) is a serious and fatal disease characterized by pulmonary vasoconstriction and pulmonary vascular remodeling. The excessive autophagy of pulmonary artery smooth muscle cells (PASMCs) is one of the important factors of pulmonary vascular remodeling. A number of studies have shown that circular RNA (circRNA) can participate in the onset of PH. Our previous studies have shown that circRNA calmodulin 4 (circ-calm4) is involved in the progression of hypoxic PH. However, the role of circ-calm4 on regulation of hypoxic PH autophagy has not been reported. In this study, we demonstrated for the first time that hypoxia-mediated upregulated circ-calm4 expression has a key regulatory effect on autophagy in hypoxia-induced PASMCs and hypoxic PH mouse models. Knockdown of circ-calm4 both in vivo and in vitro can inhibit the autophagy in PASMCs induced by hypoxia. We also performed bioinformatics predictions and conducted experiments to verify that circ-calm4 bound to the purine-rich binding protein (Purb) to promote its expression in the nucleus, thereby initiating the transcription of autophagy-related protein Beclin1. Interestingly, we found that Beclin1 transcription initiated by Purb was accompanied by a modification of Beclin1 super-enhancer to improve transcription activity and efficiency. Overall, our results confirm that the circ-calm4/Purb/Beclin1 signal axis is involved in the occurrence of hypoxia-induced PASMCs autophagy, and the novel regulatory mechanisms and signals transduction pathways in PASMC autophagy induced by hypoxia.

Pulmonary artery smooth muscle cell proliferation is the pathological basis of pulmonary vascular remodeling in hypoxic pulmonary hypertension. Recent studies suggest that circular RNA (circRNA) can regulate various biological processes, including cell proliferation. Therefore, it is possible that circRNA may have important roles in pulmonary artery smooth muscle cell proliferation in hypoxic pulmonary hypertension. In the present study, we aimed to identify functional circRNAs and clarify their roles and mechanisms in pulmonary artery smooth muscle cell proliferation in pulmonary hypertension. RNA sequencing identified 67 circRNAs that were differentially expressed in hypoxic lung tissues of mice. Screening by bioinformatics and quantitative polymerase chain reaction revealed significant elevation of a circRNA derived from alternative splicing of the calmodulin 4 gene (designated circ- calm4 ). Notably, this circRNA absorbed miR-337-3p . We further identified Myo10 (myosin 10) as a target protein of miR-337-3p . miR-337-3p bound to the 3′-untranslated region of Myo10 mRNA, thereby attenuating the translation of Myo10. Using loss-of-function and gain-of-function approaches, we found that circ- calm4 regulated cell proliferation by regulating the cell cycle. Additionally, we verified the functions of miR-337-3p and Myo10 in hypoxic pulmonary artery smooth muscle. Our results suggested that the circ- calm4 / miR-337-3p /Myo10 signal transduction axis modulated the proliferation of pulmonary artery smooth muscle cells at the molecular level, thus establishing potential targets for the early diagnosis and treatment of pulmonary hypertension.

Circular RNAs have been reported to play significant roles in regulating pathophysiological processes while also guiding clinical diagnosis and treatment of hepatocellular carcinoma (HCC). However, only a few circRNAs have been identified thus far. Herein, we investigated the role of a specific closed-loop structure of hsa_circ_101555 that was generated by back-splicing of the host gene casein kinase 1 gamma 1 (CSNK1G1) in the development and proliferation of HCC. We investigated the expression of Hsa_circ_101555 in HCC and normal tissues using bioinformatics. The expression level of hsa_circ_101555 was further detected by fluorescence in situ hybridization and qRT-PCR in ten HCC patients. Transwell, migration, WST-1 assays, and colony formation assays were used to evaluate the role of hsa_circ_101555 in HCC development and proliferation. The regulatory mechanisms of hsa_circ_101555 in miR-145-5p and CDCA3 were determined by dual luciferase reporter assay. A mouse xenograft model was also used to determine the effect of hsa_circ_101555 on HCC growth in vivo. hsa_circ_101555 showed greater stability than the linear RNA; while in vitro and in vivo results demonstrated that hsa_circ_101555 silencing significantly suppressed cell proliferation, migration, and invasion of HCC cells. Rescue experiments further demonstrated that suppression of miR-145-5p significantly attenuated the biological effects of hsa_circ_101555 knockdown in HCC cells. We also identified a putative oncogene CDCA3 as a potential miR-145-5p target. Thus, our results demonstrated that hsa_circ_101555 might function as a competing endogenous RNA of miR-145-5p to upregulate CDCA3 expression in HCC. These findings suggest that hsa_circ_101555 may be a potential therapeutic target for patients with HCC.

Circular RNAs (circRNAs) are a class of non-coding RNAs with a loop structure; however, their functions remain largely unknown. Growing evidence suggests that circRNAs play a pivotal role in the progression of malignant diseases. However, the expression profiles and function of circRNAs in hepatocellular carcinoma (HCC) remain unclear. We investigated the expression of microtubule-associated serine/threonine kinase 1 (MAST1) circRNA (circMAST1) in HCC and healthy tissues using bioinformatics, quantitative real-time PCR (qRT-PCR), and fluorescence in situ hybridization. Luciferase reporter assays were performed to assess the interaction between circMAST1 and miR-1299. Proliferation assays, colony formation assays, flow cytometry, transwell assays, and western blotting were also performed. A mouse xenograft model was also used to determine the effect of circMAST1 on HCC growth in vivo. CircMAST1 was upregulated in HCC tissues and cell lines; silencing via small interfering RNA inhibited migration, invasion, and proliferation of HCC cell lines in vitro as well as tumor growth in vivo. Furthermore, the expression of circMAST1 was positively correlated with catenin delta-1 (CTNND1) and negatively correlated with microRNA (miR)-1299 in HCC clinical samples. Importantly, circMAST1 sponged miR-1299 to stabilize the expression of CTNND1 and promoted tumorigenic features in HCC cell lines. We found that circMAST1 may serve as a novel biomarker for HCC. Moreover, circMAST1 elicits HCC progression by sponging miRNA-1299 and stabilizing CTNND1. Our data provide potential options for therapeutic targets in patients with HCC.

15-Lipoxygenase-2 (15-LOX-2) and 15(S)-hydroxyeicosatetraenoic acid (15(S)-HETE) have been considered as latent mediators of diverse biological processes including cancer. However, their functions in lung adenocarcinoma (LAC) are unclear. In this study, we aimed to determine whether 15-LOX-2/15(S)-HETE is involved in the proliferation and migration of A549 cells and to identify the signaling pathways that participate in this process. We used immunohistochemistry to identify the expression levels of 15-LOX-2 in lung cancer tissue samples. The effects of 15(S)-HETE on the proliferation and migration of A549 cells under hypoxic conditions were assessed by cell viability assays, immunofluorescence, western blotting, scratch wound assays and transwell assays. We found that the expression of 15-LOX-2 was significantly up-regulated in LAC tissue samples compared with adjacent normal tissue samples. The content of 15(S)-HETE in A549 cells was increased under hypoxic conditions. Moreover, 15(S)-HETE could stimulate the expression of PCNA, cyclin A and cyclin D. In addition, siRNA of 15-LOX-2 inhibited the proliferation and migration of A549 cells in vitro. Our data also provide novel evidence demonstrating that the STAT3 pathway participates in the 15(S)-HETE-induced proliferation and migration of A549 cells. This study may provide a greater understanding of LAC metastasis and shed new light on the mechanisms by which the 15(S)-HETE/STAT3 pathway is related to this disease.

Dysfunction and injury of endothelial cells play critical roles in pulmonary arterial hypertension, including aberrant proliferation, suppressed apoptosis, and excessive angiogenesis. The 12-lipoxygenase and 12-hydroxyeicosatetraenoic acid pathway, which has been considered as a crucial mediator, elevates pulmonary vascular resistance and pulmonary arterial pressure. However, the mechanisms underlying the bioactivity of 12-hydroxyeicosatetraenoic acid in pulmonary vasculature, especially in endothelial cells, are still elusive. Thus we aim to determine the key role of 12-lipoxygenase/12-hydroxyeicosatetraenoic acid in angiogenesis and survival of pulmonary artery endothelial cells and ascertain the signaling pathways participating in the pathological process. Here we establish that hypoxia increases the formation of endogenous 12-hydroxyeicosatetraenoic acid through stimulation of 12-lipoxygenase. Furthermore, we put forward new information that 12-hydroxyeicosatetraenoic acid promotes endothelial cell migration and tube formation, whereas it inhibits the serum deprivation-induced apoptotic responses under hypoxia. Particularly, the regulatory effects of 12-lipoxygenase/12-hydroxyeicosatetraenoic acid on pulmonary artery endothelial cells, at least in part, depend on phosphatidylinositol 3-kinase (PI3K)/Akt signaling activation. Taken together, these results may have significant implications for understanding of pulmonary hypertension and offer a potential therapeutic concept focusing on the 12-lipoxygenase/12-hydroxyeicosatetraenoic acid signaling system.

Piwi‐interacting RNAs (piRNAs) are thought to be germline‐specific and to be involved in maintaining genome stability during development. Recently, piRNA expression has been identified in somatic cells in diverse organisms. However, the roles of piRNAs in pulmonary arterial smooth muscle cell (PASMC) proliferation and the molecular mechanism underlying the hypoxia‐regulated pathological process of pulmonary hypertension are not well understood. Using hypoxic animal models, cell and molecular biology, we obtained the first evidence that the expression of piRNA‐63076 was up‐regulated in hypoxia and was positively correlated with cell proliferation. Subsequently, we showed that acyl‐CoA dehydrogenase (Acadm), which is negatively regulated by piRNA‐63076 and interacts with Piwi proteins, was involved in hypoxic PASMC proliferation. Finally, Acadm inhibition under hypoxia was partly attributed to DNA methylation of the Acadm promoter region mediated by piRNA‐63076. Overall, these findings represent invaluable resources for better understanding the role of epigenetics in pulmonary hypertension associated with piRNAs.

Many long noncoding RNAs (lncRNAs) have been identified as powerful regulators of lung adenocarcinoma (LAD). However, the role of HOXA-AS3, a novel lncRNA, in LAD is largely unknown. In this study, we showed that HOXA-AS3 was significantly upregulated in LAD tissues and A549 cells. After knockdown of HOXA-AS3, cell proliferation, migration, and invasion were inhibited. Xenografts derived from A549 cells transfected with shRNA/HOXA-AS3 had significantly lower tumor weights and smaller tumor volumes. We also demonstrated that HOXA-AS3 increased HOXA6 mRNA stability by forming an RNA duplex. In addition, HOXA6 promoted cell proliferation, migration, and invasion in vitro. Using a RNA pull-down assay, we found that HOXA-AS3 bonded with NF110, which regulated the cell localization of HOXA-AS3. Moreover, histone acetylation was involved in upregulation of HOXA-AS3. These results demonstrate that HOXA-AS3 was activated in LAD and supported cancer cell progression. Therefore, inhibition of HOXA-AS3 could be an effective targeted therapy for patients with LAD.

Pulmonary arterial hypertension (PAH) is a lethal disease characterized by pulmonary vascular obstruction due in part to excessive pulmonary artery endothelial cells (PAECs) migration and proliferation. The mitochondrial fission protein dynamin-related protein-1 (DRP1) has important influence on pulmonary vascular remodeling. However, whether DRP1 participates in the development and progression of pulmonary vascular angiogenesis has not been reported previously. To test the hypothesis that DRP1 promotes the angiogenesis via promoting the proliferation, stimulating migration, and inhibiting the apoptosis of PAECs in mitochondrial Ca(2+)-dependent manner, we performed following studies. Using hemodynamic analysis and morphometric assay, we found that DRP1 mediated the elevation of right ventricular systemic pressure (RVSP), right heart hypertrophy, and increase of pulmonary microvessels induced by hypoxia. DRP1 inhibition reversed tube network formation in vitro stimulated by hypoxia. The mitochondrial Ca(2+) inhibited by hypoxia was recovered by DRP1 silencing. Moreover, pulmonary vascular angiogenesis promoted by DRP1 was reversed by the specific mitochondrial Ca(2+) uniporter inhibitor Ru360. In addition, DRP1 promoted the proliferation and migration of PAECs in mitochondrial Ca(2+)-dependent manner. Besides, DRP1 decreased mitochondrial membrane potential, reduced the DNA fragmentation, and inhibited the caspase-3 activation, which were all aggravated by Ru360. Therefore, these results indicate that the mitochondrial fission machinery promotes migration, facilitates proliferation, and prevents from apoptosis via mitochondrial Ca(2+)-dependent pathway in endothelial cells leading to pulmonary angiogenesis.

Our laboratory has previously demonstrated that 15-lipoxygenase (15-LO)/15-hydroxyeicosatetr-aenoic acid (15-HETE) is involved in hypoxic pulmonary arterial hypertension (PAH). Phenotypical alterations of vascular smooth muscle cells are considered to be an important stage in the development of PAH, whereas the underlying mechanisms and signaling systems are still unclear. Here, we determined the contribution of 15-LO/15-HETE signaling in the hypoxia-induced phenotype changes of pulmonary arterial smooth muscle cells (PASMCs). To accomplish this, cellular and molecular changes in pulmonary vascular remodeling were detected in PAH patients and rats exposed to hypoxia. We found that the hypoxia-induced alterations in PASMCs phenotypes were reversed by the inhibition of 15-LO/15-HETE or inhibition of BMP4/BMPRI. Hypoxia-induced 15-LO1/2 expression in rat PASMCs was significantly abolished by small interfering RNA targeted at BMP4. Meanwhile, BMP4/BMPRI-15-LO/15-HETE had a positive feedback mechanism. Furthermore, ERK and p38MAPK act as the downstream of the 15-LO/15-HETE-BMP4/BMPRI signaling. Our results suggest that chronic hypoxia promotes phenotypical alterations of PASMCs due to the interaction between 15-LO/15-HETE and BMP4/BMPRI. Our study reveals a novel mechanism of hypoxia-induced pulmonary vascular remodeling and suggested new therapeutic strategies for the targeting of 15-LO/15-HETE and BMP4/BMPRI in PAH treatment.

Stromal cell-derived factor 1 (CXCL12) and its receptor CXC chemokine receptor 4 (CXCR4) are known to modulate hypoxia-induced pulmonary hypertension (PH) and vascular remodeling by mobilization and recruitment of progenitor cells to the pulmonary vasculature. However, little is known about CXCL12/CXCR4 regulating proliferation and cell cycle progression of pulmonary arterial smooth muscle cells (PASMCs). To determine whether CXCL12/CXCR4 regulates PASMC proliferation and the cell cycle, immunohistochemistry, Western blot, bromodeoxyuridine incorporation and cell cycle analysis were preformed in this study. Our results showed that CXCR4 was induced by hypoxia in pulmonary arteries and PASMCs of rats. Hypoxia-increased cell viability, DNA synthesis and proliferating cell nuclear antigen expression were blocked by administration of CXCR4 antagonist AMD3100, silencing CXCR4 or CXCL12. Furthermore, inhibition of CXCL12/CXCR4 suppressed cell cycle progression, decreased the number of cells in S+G2/M phase and attenuated the expression of proteins that regulate the cell cycle progression at these phases. In addition, PI3K/Akt signaling mediated CXCL12/CXCR4 regulating proliferation and cell cycle progression in PASMCs. Thus, these results indicate that blockade of CXCL12/CXCR4 inhibited PASMC proliferation and cell cycle progression in hypoxia-induced PH via PI3K/Akt signaling pathway.

We have established that 15-hydroxyeicosatetraenoic acid is an important factor in regulation of pulmonary vascular remodeling (PVR) associated with hypoxia-induced pulmonary hypertension (PH), which is further metabolized by 15-hydroxyprostaglandin dehydrogenase (15-PGDH) to form 15-ketoeicosatetraenoic acid (15-KETE). However, the role of 15-PGDH and 15-KETE on PH has not been identified. The purpose of this study was to investigate whether 15-PGDH/15-KETE pathway regulates hypoxia-induced PVR in PH and to characterize the underlying mechanisms. To accomplish this, Immunohistochemistry, Ultra Performance Liquid Chromatography, Western blot, bromodeoxyuridine incorporation and cell cycle analysis were preformed. Our results showed that the levels of 15-PGDH expression and endogenous 15-KETE were drastically elevated in the lungs of humans with PH and hypoxic PH rats. Hypoxia stimulated pulmonary arterial smooth muscle cell (PASMC) proliferation, which seemed to be due to the increased 15-PGDH/15-KETE. 15-PGDH/15-KETE pathway was also capable of stimulating the cell cycle progression and promoting the cell cycle-related protein expression. Furthermore, 15-KETE-promoted cell cycle progression and proliferation in PASMCs depended on protease-activated receptor 2 (PAR-2). ERK1/2 signaling was likely required for 15-PGDH/15-KETE-induced PAR-2 expression under hypoxia. Our study indicates that 15-PGDH/15-KETE stimulates the cell cycle progression and proliferation of PASMCs involving ERK1/2-mediated PAR-2 expression, and contributes to hypoxia-induced PVR.

Background Autophagy is a major intracellular degradation and recycling process that maintains cellular homeostasis, which is involved in structural and functional abnormalities of pulmonary vasculature in hypoxic pulmonary arterial hypertension (HPAH). Cyclophilin A (CyPA) is a secreted, oxidative stress-induced factor. Its role in inducing autophagy and augmenting endothelial cell dysfunction has never been explored. Methods Lungs from rats exposed to chronic hypoxia were examined for autophagy with electron microscopy, western blotting, and fluorescence microscopy. Results Activated autophagy was seen in the endothelium of the pulmonary artery from experimental rat models of HPAH and cultured bovine pulmonary arterial endothelial cells under hypoxia. Inhibiting autophagy attenuated the pathological progression of HPAH and repressed endothelial cell migration and angiogenesis. We also showed that CyPA was upregulated and acetylated under hypoxia and led to the abnormal occurrence of autophagy through its interaction with autophagy protein 5 and autophagy protein 7. Moreover, acetylated CyPA was essential for the excessive proliferation, migration, and tube formation networks of pulmonary arterial endothelial cells. Conclusion Our results indicate the crucial role of acetylated CyPA in the abnormal occurrence of autophagy and subsequent pulmonary vascular angiogenesis.

We previously reported that 15-lipoxygenase (15-LO) and its metabolite 15-hydroxyeicosatetraenoic acid (15-HETE) were up-regulated in pulmonary arterial cells from both pulmonary artery hypertension patients and hypoxic rats and that these factors mediated the progression of pulmonary hypertension (PH) by affecting the proliferation and apoptosis of pulmonary arterial (PA) cells. However, the underlying mechanisms of the remodeling induced by 15-HETE have remained unclear. As reactive oxygen species (ROS) and 15-LO are both induced by hypoxia, it is possible that ROS are involved in the events of hypoxia-induced 15-LO expression that lead to PH. We employed immunohistochemistry, tube formation assays, bromodeoxyuridine (BrdU) incorporation assays, and cell cycle analyses to explore the role of ROS in the process of 15-HETE-mediated hypoxic pulmonary hypertension (HPH). We found that exogenous 15-HETE facilitated the generation of ROS and that this effect was mainly localized to mitochondria. In particular, the mitochondrial electron transport chain and nicotinamide-adenine dinucleotide phosphate oxidase 4 (Nox4) were responsible for the significant 15-HETE-stimulated increase in ROS production. Moreover, ROS induced by 15-HETE stimulated endothelial cell (EC) migration and promoted pulmonary artery smooth muscle cell (PASMC) proliferation under hypoxia via the p38 MAPK pathway. These results indicated that 15-HETE-regulated ROS mediated hypoxia-induced pulmonary vascular remodeling (PVR) via the p38 MAPK pathway.

Endothelial-to-mesenchymal transition (EndoMT) has been recognized as a major reason for the pulmonary artery remodeling (PAR) in pulmonary artery hypertension (PAH). However, the molecular mechanisms and regulatory pathways involved in the EndoMT remain undefined. In the present study, we have confirmed that EndoMT was occurred in pulmonary arteries of rats induced by hypoxia and monocrotaline and in hypoxic pulmonary artery endothelial cells (PAECs). Moreover, hypoxia increased the expression of platelet-derived growth factor (PDGF) and transforming growth factor-β1 (TGF-β1) and decreased the expression of neprilysin (NEP), which contributed to the hypoxia-induced EndoMT of PAECs. Furthermore, a reciprocal regulation of PDGF-B and TGF-β1 induced by decreasing NEP promoted the EndoMT of PAECs under hypoxia, which was a novel molecular mechanism to reveal the EndoMT participating in PAR. More importantly, imatinib, a PDGF receptor antagonist, relieved PAR and EndoMT in PAH rats. Thus, our results identify a novel mechanism to reveal the formation of EndoMT in PAH, and imply that imatinib may serve as a new therapeutic approach for treatment of the third cardiovascular disease.

Pulmonary arterial hypertension (PAH) is a disease characterized by thickening of pulmonary artery walls, elevated pulmonary vascular resistance, pulmonary vascular thrombotic lesions, and right heart failure. Recent studies suggest that 15-lipoxygenase (15-LO)/15-hydroxyeicosatetraenoic acid (15-HETE) play an important role in PAH, acting on arterial walls. Here, we show evidence for the action of the 15-LO/15-HETE signaling in the pulmonary vascular thrombotic lesions in the experimental PAH models. Platelet deposition was augmented in rats exposed to hypoxia and Sugen 5416, which were both prevented by nordihydroguaiaretic acid (NDGA), a 15-LO inhibitor. Chronic hypoxic resulted in the platelet deposition specifically in pulmonary vasculature, which was reversed by 15-LO inhibitor. The 15-LO pathway mediated in the endothelial dysfunction induced by hypoxia in vivo. Meanwhile, 15-HETE positively regulated the generation of IL-6 and monocyte chemoattractant protein-1 (MCP-1). The coagulation and platelet activation induced by hypoxia were reversed by 15-LO inhibitor NDGA or the MCP-1 inhibitor synthesis inhibitor bindarit in rats. The 15-LO/15-HETE signaling promoted the coagulation and platelet activation, which was suppressed by MCP-1 inhibition. These results therefore suggest that 15-LO/15-HETE signaling plays a role in platelet activation and pulmonary vascular thrombosis in PAH, involving MCP-1.

Hypoxia activates nuclear factor of activated T cells isoforms c3 (NFATc3), a Ca(2+)-dependent transcription factor in murine pulmonary arteries (PAs), and NFATc3 has been proved to be implicated in hypoxia-induced pulmonary arterial smooth muscle cells (PASMCs) proliferation, but it remains unclear whether NFATc3 acts on the apoptosis of PASMCs, an important step in PAs remodeling. Our laboratory has demonstrated that 15-hydroxyeicosatetraenoic acid (15-HETE) is a key factor in hypoxia-induced PA remodeling and can increase PASMC intracellular Ca(2+) ([Ca(2+)](i)) in rats. It is possible that NFATc3 is related with the function of 15-HETE anti-apoptosis during hypoxia. Our results identified that NFATc3 was mainly localized in rat PASMCs and was upregulated in PAs during hypoxia-induced rat pulmonary hypertension (PH), while this effect was inhibited by administration of nordihydroguaiaretic acid (NDGA), a 15-lipoxygenase (15-LO) inhibitor. Moreover, hypoxia and exogenous 15-HETE promoted the expression and nuclear translocation of NFATc3 in PASMCs, which was inhibited by NDGA or small interfering RNA targeted to rat 15-LO1 or 15-LO2. Furthermore, endogenous 15-HETE induced by hypoxia and exogenous 15-HETE suppressed serum deprivation-induced loss of rat PASMCs survival and prevented annexin V binding, mitochondrial membrane potential depolarization, DNA nick end labeling and chromatin condensation. Although all these effects were suppressed after the cells were treated with cyclosporin A (a calcineurin/NFAT inhibitor), it aggravated the apoptosis induced by serum deprivation. Thus, all these results indicate that 15-HETE-mediated PASMCs anti-apoptosis in hypoxic PH via the Ca(2+)-NFATc3 pathway.

Dear Editor, In current cancer treatment, fighting against cancer with cytotoxic drug is often challenged by the emergence of chemotherapy resistance, because the patients are usually treated by standard protocols without considering individual response to chemotherapy.1 As a promising field of personalized therapy of cancer, microRNA pharmacogenomics promotes to understand different individual responses to certain drugs and provides reasonable reference for clinical treatment.2, 3 However, it is still lacking comprehensive resource to discover and deposit such chemotherapy resistance-associated miRSNPs (CRmiRSNPs). Therefore, we constructed an omnibus repository named CREAM (Chemotherapy ResistancE-Associated MiRSNP), which furnishes a user-friendly interface for a convenient retrieval of CRmiRSNP. The CREAM is freely available at http://bioinfo.hrbmu.edu.cn/CREAM/. In CREAM, two types of CRmiRSNP (SNP that locates in the precursor of microRNA or 3′ UTR of microRNA target gene transcript, in which all these SNP, microRNA or gene are associated with chemotherapy response for the same compound) were mainly focused on, because both of these two CRmiRSNPs have been proven to influence the function of microRNA and may convert a sensible tumor cell into a resistant one by changing the expression of microRNA or their targets.2 Through utilizing genomic location and microRNA regulatory information, we have identified 150 CRmiRSNPs (Supplementary Figure 1a) across 1164 compounds from the chemotherapy response data as well as SNP genotyping, gene expression and microRNA expression profiles (more details in the ‘Technical Implementation' section of Supplementary Information). As an efficient search platform, CREAM supports four types of query (including compound, gene, microRNA and SNP) for a convenient retrieval of each record, which not only offers the complete details of CRmiRSNP we have discovered, but also extends to display each compound with the elaborative descriptions and genomic distribution maps of chemotherapy resistance-associated molecules (including SNP, gene and microRNA). For instance, an interested compound can be queried to access which miRSNPs, genes, microRNAs and SNPs are associated with the chemotherapy response of this compound. Additionally, users can further visualize the chromosomal location and statistical significance of chemotherapy resistance-associated molecules for the queried compound (Supplementary Figure 1b). Finally, full entries in CREAM can be easily downloaded for systematic analysis (more details in the ‘Practical Example' section of Supplementary Information). Several miRSNP-related databases, centered on miRSNP's location and function, have been built recently.4, 5 However, the resource that discovers the link between miRSNP and chemotherapy resistance has not been reported. The database of CREAM may contribute to systematic analysis of abundant chemicals (in this version it includes 1164 chemicals) in basic drug discovery, and the proposed strategy of identifying CRmiRSNP is in favor of precise selection of proper treatment in clinical cancer therapy. With constant expansion and improvement, we hope this resource will become a bridge between the laboratory investigation and clinical practice in the field of chemotherapy resistance research and stimulate further interest on the role of interactions among multi-level molecules in the individual chemoresponse network.