BackgroundSea cucumbers are a special group of marine invertebrates. They occupy a taxonomic position that is believed to be important for understanding the origin and evolution of deuterostomes. Some of them such as Apostichopus japonicus represent commercially important aquaculture species in Asian countries. Many efforts have been devoted to increasing the number of expressed sequence tags (ESTs) for A. japonicus, but a comprehensive characterization of its transcriptome remains lacking. Here, we performed the large-scale transcriptome profiling and characterization by pyrosequencing diverse cDNA libraries from A. japonicus.ResultsIn total, 1,061,078 reads were obtained by 454 sequencing of eight cDNA libraries representing different developmental stages and adult tissues in A. japonicus. These reads were assembled into 29,666 isotigs, which were further clustered into 21,071 isogroups. Nearly 40% of the isogroups showed significant matches to known proteins based on sequence similarity. Gene ontology (GO) and KEGG pathway analyses recovered diverse biological functions and processes. Candidate genes that were potentially involved in aestivation were identified. Transcriptome comparison with the sea urchin Strongylocentrotus purpuratus revealed similar patterns of GO term representation. In addition, 4,882 putative orthologous genes were identified, of which 202 were not present in the non-echinoderm organisms. More than 700 simple sequence repeats (SSRs) and 54,000 single nucleotide polymorphisms (SNPs) were detected in the A. japonicus transcriptome.ConclusionPyrosequencing was proven to be efficient in rapidly identifying a large set of genes for the sea cucumber A. japonicus. Through the large-scale transcriptome sequencing as well as public EST data integration, we performed a comprehensive characterization of the A. japonicus transcriptome and identified candidate aestivation-related genes. A large number of potential genetic markers were also identified from the A. japonicus transcriptome. This transcriptome resource would lay an important foundation for future genetic or genomic studies on this species.

BackgroundCLCA2 was reported as a tumor suppressor and disregulated in breast cancer. However, its function in tumor growth and metastasis in NPC has rarely been reported. In this study, we investigated the functional and molecular mechanisms by which CLCA2 influences NPC.MethodsCLCA2 expression in human NPC cell lines and tissues was examined via real-time PCR (RT-PCR), Western blot and IHC. The biological roles of CLCA2 in proliferative, migration and invasion of NPC cell lines was evaluated in 5-8F, S18, S26 and SUNE-1 cells. Cell viability, migration and invasion were assessed in vitro by MTS, colony formation and transwell assay, respectively. CLCA2 in growth and metastasis of NPC were evaluated in vivo through NPC xenograft tumor growth, lung metastatic mice model and popliteal lymph node (LN) metastasis model.ResultsOverexpression of CLCA2 significantly decreased proliferation, migration and invasion of NPC cells. In contrast, knockdown of CLCA2 elicited the opposite effects. CLCA2 overexpression suppressed xenograft tumor growth and lung, popliteal lymph node (LN) metastasis in vivo. CLCA2 inhibited tumor metastasis through suppressing epithelial-Mesenchymal transition (EMT) and in-activating FAK/ERK1/2 signaling pathway in NPC cells. Immunohistochemical staining of 143 NPC samples revealed that CLCA2 expression was an independent, favorable prognostic factor for overall survival and distant metastasis-free survival of patients. In addition, inhibition of FAK and ERK1/2 reversed CLCA2 silencing-induced tumor cell migration. Furthermore, inhibitors against chloride channels suppressed NPC cellular migration which could have been enhanced by the presence of CLCA2.ConclusionCLCA2 suppress NPC proliferation, migration, invasion and epithelial-mesenchymal transition through inhibiting FAK/ERK signaling.Electronic supplementary materialThe online version of this article (10.1186/s13046-018-0692-8) contains supplementary material, which is available to authorized users.

The involvement of unfolded protein response (UPR) activation in tumor survival and resistance to chemotherapies suggests a new anticancer strategy targeting UPR pathway. Arctigenin, a natural product, has been recently identified for its antitumor activity with selective toxicity against cancer cells under glucose starvation with unknown mechanism. Here we found that arctigenin specifically blocks the transcriptional induction of two potential anticancer targets, namely glucose-regulated protein-78 (GRP78) and its analog GRP94, under glucose deprivation, but not by tunicamycin. The activation of other UPR pathways, e.g., XBP-1 and ATF4, by glucose deprivation was also suppressed by arctigenin. A further transgene experiment showed that ectopic expression of GRP78 at least partially rescued arctigenin/glucose starvation-mediated cell growth inhibition, suggesting the causal role of UPR suppression in arctigenin-mediated cytotoxicity under glucose starvation. These observations bring a new insight into the mechanism of action of arctigenin and may lead to the design of new anticancer therapeutics.

Curcumin is an anticancer compound that exerts anti-proliferative and apoptotic effects via multiple molecular targets. The purpose of the present study was to investigate the anticancer effects of curcumin in combination with 5-fluorouracil plus cisplatin (FP) on the MGC-803 human gastric cancer cell line. Following treatment with curcumin and/or FP for 24, 48 and 72 h, cell viability, cell cycle progression and the apoptosis rate were evaluated using an MTT assay, flow cytometry and dual acridine orange/ethidium bromide staining, respectively. In addition, colony formation, Transwell migration and caspase-3/caspase-8 activity assays were performed. The expression of the apoptosis regulator B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein (Bax) were detected by western blotting analysis. Following treatment with curcumin and/or FP, cell viability, colony formation and cell migration were significantly reduced compared with the untreated control group. The rate of apoptosis, caspase-3/caspase-8 activity and the expression of Bax were significantly increased, whereas Bcl-2 expression was significantly reduced following treatment with curcumin and/or FP, compared with the untreated control group. The efficacy of curcumin combined with low-dose FP was significantly increased, compared with that of curcumin combined with high-dose FP (P<0.05). Therefore, curcumin may enhance the anticancer effects of FP chemotherapy in MGC-803 cells through the promotion of apoptosis via the caspase-3/caspase-8, Bcl-2 and Bax signaling pathways. These results suggest that curcumin may serve as a synergistic drug with chemotherapy regimen FP for the treatment of gastric cancer.

Abstract-Intelligent transportation systems (ITS) are becoming more and more effective, benefiting from big data. Despite this, missing data is a problem that prevents many prediction algorithms in ITS from working effectively. Much work has been done to impute those missing data. Among different imputation methods, k-nearest neighbours (kNN) has shown excellent accuracy and efficiency. However, the general kNN is designed for matrix instead of time series so it lacks the usage of time series characteristics such as windows and weights that are gap-sensitive. This work introduces gap-sensitive windowed kNN (GSW-kNN) imputation for time series. The results show that GSW-kNN is 34% more accurate than benchmarking methods, and it is still robust even if the missing ratio increases to 90%.