MiR-1182 inhibited metastasis and proliferation of ovarian cancer by targeting hTERT.

OBJECTIVE: To investigate the potential effect of miR-1182 on the development of ovarian cancer and the relevant mechanism. PATIENTS AND METHODS: The expression levels of miR-1182 were detected in ovarian cancer tissues and cells (SKOV3) comparing with corresponding adjacent normal tissues and normal ovarian cell (IOSE80). Luciferase assay was performed to evaluate the interaction between miR-1182 and hTERT. The effects of the miR-1182/hTERT axis on SKOV3 cells were determined by subsequent experiments including cell proliferation, expression level of hTERT, the invasion and metastasis detection. RESULTS: miR-1182 was found repressed in ovarian cancer tissues and we got the same results at the cellular level. In order to research potential target of miR-1182, we checked it in three publicly available algorithms, TargetScan, miRDB and microRNA. We found that hTERT is a direct target of miR-1182, and luciferase assays confirmed our hypothesis. The subsequent experiments showed that decreased expression of hTERT resulting from the up-regulation of miR-1182 could decelerate cell proliferation, invasion, and metastasis in ovarian cancer cells. CONCLUSIONS: Our research discovers the suppressor function of miR-1182 in ovarian cancer by targeting hTERT, revealing that miR-1182/hTERT axis may be a potential therapeutic target for the treatment of ovarian cancer.

First Record of the Cereal Cyst Nematode Heterodera filipjevi in China.

Cereal cyst nematode (CCN) is now recognized as a widespread and often damaging parasite of wheat in China. Only Heterodera avenae has been reported in China (4). However, molecular analysis of four samples from Beijing and one from Shanxi Province indicated genetic differences from H. avenae and other named species (3). Here we report the detection of H. filipjevi at a site in Henan Province that was not included in any previous study or report. The infested crop was rainfed winter wheat (Triticum aestivum) cv. Wenmai 19 in a field near Banpopu Village in Xuchang County (34.0447°N, 113.7415°E) with a long-established maize-wheat semiannual crop rotation. During the winter growing season, the crop was patchy with uneven growth and cyst nematode females were observed on the roots. In June 2009, soil was collected and mature cysts were extracted for morphological and molecular identification. Cysts were also kept at 4°C for 2 months and then incubated in shallow water at 15°C for a month to obtain second-stage juveniles (J2). Measurements (range; mean ± sd) of 10 cysts were body length including neck (569 to 786 µm; 699 ± 56), body width (403 to 600 µm; 523 ± 55), length:width ratio (1.3 to 1.5; 1.3 ± 0.1), neck length (61 to 125 µm; 106 ± 19) and width (49 to 83 µm; 69 ± 13), fenestra length (52 to 59 µm; 57 ± 2.9) and width (24.5 to 34.4; 27.9 ± 3.5), underbridge (64 to 101 µm; 85 ± 10), and vulval slit (7.4 to 10.0 µm; 9.6 ± 1.0). Lemon-shaped cysts were brown with a surface zigzag pattern. The vulval cone was bifenestrate with horseshoe-shaped semifenestra, with heavy underbridge and many bullae. The J2 (n = 22) measurements were body length (496 to 590 µm; 552 ± 24), body width (20.0 to 23.8; 21.5 ± 0.9), stylet (22.8 to 25.3; 24.0 ± 1.0) with anchor-shaped basal knobs, tail (47 to 64; 61.6 ± 4.4), and hyaline tail terminus (32 to 43; 40.2 ± 3.0). The J2 had up to four lateral lines, but the inner two were often the only lines clearly visible, and the shape of the stylet knobs, tail, and tail terminus were consistent with H. filipjevi. All morphological data and characters were consistent with H. filipjevi (1). Specimens have been lodged with the Australian National Insect Collection. DNA from single cysts was extracted to amplify the internal transcribed spacer region of rDNA by PCR with forward primer TW81 (5'-GTTTCCGTAGGTGAACCTGC-3') and reverse primer AB28 (5'-ATATGCTTAAGTTCAGCGGGT-3') (2). The PCR product was sequenced (Genbank Accession No. HM027892) and digested by restriction enzymes (AluI, CfoI, HaeI, HinfI, PstI, RsaI, TaqI, and Tru9I) to obtain restriction fragment length polymorphism profiles (2). Profiles for the Xuchang population consistently matched those published for H. filipjevi and were distinct from those of H. avenae and other species (3). Phylogenic analysis of the sequence further indicated conspecificity with H. filipjevi. These morphological and molecular data confirmed that the specimens from Xuchang were H. filipjevi, which represents the first detection of H. filipjevi in China, and extends the known distribution of the species from Europe, North America, South Asia, and West Asia to East Asia. This finding adds complexity to the management of CCN in China, especially for control by host resistance, which now must consider both species and pathotype diversity. References: (1) Z. A. Handoo. J. Nematol. 34:250, 2002. (2) S. A. Subbotin et al. Nematology 2:153, 2000. (3) S. A. Subbotin et al. Nematology 5:515, 2003. (4) H. X. Yuan et al. Australas. Plant Pathol. 39:107, 2010.

Drosophila Jun relays the Jun amino-terminal kinase signal transduction pathway to the Decapentaplegic signal transduction pathway in regulating epithelial cell sheet movement.

We have characterized mutations in the Drosophila homolog of the mammalian proto-oncogene c-Jun gene (Djun). We demonstrate that DJUN in the embryo is a downstream target of the JNK signal transduction pathway during dorsal closure formation, and that the function of the JNK/DJUN pathway is to control the localized expression of decapentalegic (dpp), a member of the TGF-beta growth factor family. In contrast to previous observations, we find that both in the embryo and during photoreceptor cell determination, DJUN is not regulated by a pathway that involves MAPK.

The JAK-STAT pathway in Drosophila.

Recent studies in Drosophila have identified a single JAK and a single STAT protein. Genetic and biochemical analyses reveal that these two proteins operate in the same signal transduction pathway. Phenotypic analyses of JAK and STAT mutants implicate this pathway in a number of developmental decisions, in particular the regulation of pair-rule genes and fly hematopoiesis.

Marelle acts downstream of the Drosophila HOP/JAK kinase and encodes a protein similar to the mammalian STATs.

We have identified a putative Drosophila STAT protein named Marelle that exhibits mutant phenotypes identical to mutations in the Hopscotch/JAK kinase. We show that a reduction in the amount of marelle gene activity suppresses the phenotype associated with a gain-of-function mutation in hopscotch and enhances the phenotype associated with a weak hopscotch mutation. We propose that Hopscotch activates Marelle to regulate transcription of target genes such as the pair rule gene even-skipped. Our results demonstrate the existence of an invertebrate JAK/STAT system.

Dissection of the Torso signal transduction pathway in Drosophila.

Cell fate choice at the anterior and posterior embryonic termini of the Drosophila embryo requires the activation of a signal transduction pathway regulated by the receptor tyrosine kinase Torso. When Torso, which is uniformly distributed in the egg cell membrane, becomes activated locally at the termini, it triggers a phosphorylation cascade that culminates with localized expression of the transcription factors, tailless and huckebein. Expression of tailless and huckebein in turn determines terminal cell fates. Several genes have been characterized which encode proteins that are involved in Torso signaling: the adaptor protein Drk, the GTP-binding protein Ras1, the guanine nucleotide exchange factor Son of sevenless, and the kinases D-Raf and D-Mek. Genetic and molecular evidence supports a model in which these proteins lie in the same biochemical pathway. When activated by its ligand the membrane-bound receptor tyrosine kinase Torso initiates a signal transduction pathway mediated by Drk, Sos, and Ras1, which in turn activates a phosphorylation cascade mediated by the kinases D-Raf and D-Mek, which ultimately control the localized expression of the transcription factors tailless and huckebein. Recently, we found that D-Raf can be partially activated by Torso in the absence of Ras1, a finding supported by the phenotype of embryos lacking either Drk or Sos activity, as well as by the phenotype of a D-raf mutation that abolishes binding of Ras1 to D-Raf. These findings indicate that full D-Raf activation requires input not only from Ras1 but also from an as yet uncharacterized Ras1-independent pathway. In addition to these molecules we have characterized the putative protein tyrosine phosphatase Corkscrew as a positive transducer downstream of Torso.

The torso receptor tyrosine kinase can activate Raf in a Ras-independent pathway.

Activation of the receptor tyrosine kinase (RTK) torso defines the spatial domains of expression of the transcription factors tailless and huckebein. Previous analyses have demonstrated that Ras1 (p21ras) operates upstream of the D-Raf (Raf1) serine/threonine kinase in this signaling pathway. By using a recently developed technique of germline mosaics, we find that D-Raf can be activated by torso in the complete absence of Ras1. This result is supported by analysis of D-Raf activation in the absence of either the exchange factor Son of sevenless (Sos) or the adaptor protein drk (Grb2), as well as by the phenotype of a D-Raf mutation that abolishes binding of Ras1 to D-Raf. Our study provides in vivo evidence that Raf can be activated by an RTK in a Ras-independent pathway.