Molecular cloning and RNA interference-mediated functional characterization of a Halloween gene spook in the white-backed planthopper Sogatella furcifera.

BACKGROUND: Ecdysteroid hormones ecdysone and 20-hydroxyecdysone play fundamental roles in insect postembryonic development and reproduction. Five cytochrome P450 monooxygenases (CYPs), encoded by Halloween genes, have been documented to be involved in the ecdysteroidogenesis in insect species of diverse orders such as Diptera, Lepidoptera and Orthoptera. Up to now, however, the involvement of the Halloween genes in ecdysteroid synthesis has not been confirmed in hemipteran insect species. RESULTS: In the present paper, a Halloween gene spook (Sfspo, Sfcyp307a1) was cloned in the hemipteran Sogatella furcifera. SfSPO has three insect conserved P450 motifs, i.e., Helix-K, PERF and heme-binding motifs. Temporal and spatial expression patterns of Sfspo were evaluated by qPCR. Sfspo showed three expression peaks in late second-, third- and fourth-instar stages. In contrast, the expression levels were lower and formed three troughs in the newly-molted second-, third- and fourth-instar nymphs. On day 3 of the fourth-instar nymphs, Sfspo clearly had a high transcript level in the thorax where PGs were located. Dietary introduction of double-stranded RNA (dsRNA) of Sfspo into the second instars successfully knocked down the target gene, and greatly reduced expression level of ecdysone receptor (EcR) gene. Moreover, knockdown of Sfspo caused lethality and delayed development during nymphal stages. Furthermore, application of 20-hydroxyecdysone on Sfspo-dsRNA-exposed nymphs did not increase Sfspo expression, but could almost completely rescue SfEcR expression, and relieved the negative effects on nymphal survival and development. CONCLUSION: In S. furcifera, Sfspo was cloned and the conservation of SfSPO is valid. Thus, SfSPO is probably also involved in ecdysteroidogenesis for hemiptera.

Identification of cytochrome P450 monooxygenase genes and their expression profiles in cyhalothrin-treated Colorado potato beetle, Leptinotarsa decemlineata.

Based on a Leptinotarsa decemlineata transcriptome dataset and the GenBank sequences, a total of 74 cytochrome P450 monooxygenase genes (Cyps) were identified. These genes fell into CYP2 clan, mitochondrial clan, CYP3 clan and CYP4 clan, and were classified into 19 families and 35 subfamilies according to standard nomenclature. Two new families were discovered in CYP4 clan, and were named CYP412 and CYP413 respectively. Four new families that were recently discovered in Tribolium castaneum, including mitochondrial family CYP353, CYP3 clan families CYP345 and CYP347, and CYP4 clan family CYP350, were also found in L. decemlineata. The phylogenetic trees of CYPs from L. decemlineata and other representative insect species were constructed, and these trees provided evolutionary insight for the genetic distance. Our results facilitate further researches to understand the functions and evolution of L. decemlineata Cyp genes. In order to find cyhalothrin-inducible Cyp genes, the expression levels of Cyps belonging to CYP12, CYP6, CYP9 and CYP4 families were determined by quantitative reverse transcriptase-PCR in cyhalothrin-treated and control fourth-instar larvae. Nine Cyp genes, i.e., Cyp12H2, Cyp6BH2, Cyp6BJ1, Cyp6BQ17, Cyp6EG1, Cyp6EH1, Cyp6EJ1 Cyp4BN13v1 and Cyp4BN15, were highly expressed in cyhalothrin-treated larvae. These CYPs are the candidates that are involved in cyhalothrin detoxification.

XPC Polymorphism Increases Risk of Digestive System Cancers: Current Evidence from A Meta-Analysis.

OBJECTIVE: Xeroderma pigmentosum complementation group C (XPC) participates in the initial recognition of DNA damage during nucleotide excision repair process in global genomic repair. Our meta-analysis was performed to evaluate the association between three polymorphisms (Lys939Gln, PAT+/- and Ala499Val) of XPC gene and risk of digestive system cancers. METHODS: All the relevant case-control studies published to April 2011 were identified through searching PubMed. Digestive system cancer risk with the three polymorphisms was estimated for each study by odds ratio (OR) with its 95% confidence interval (95% CI). RESULTS: We found an increased overall risk for digestive system cancers in all three models of Lys939Gln A>C (AC/CC vs. AA: OR, 1.20; 95% CI, 1.11-1.30; CC vs. AC/AA: OR, 1.24; 95% CI, 1.11-1.39; CC vs. AA: OR, 1.36; 95% CI, 1.21-1.53). When stratified by ethnicity, results remained significant in Asian population (AC/CC vs. AA: OR, 1.18; 95% CI, 1.02-1.37; CC vs. AC/AA: OR, 1.32; 95% CI, 1.1-1.51; CC vs. AA: OR, 1.35; 95% CI, 1.08-1.70), but not for Caucasians. However for Ala499Val C>T, a significant protective effect of T allele was only observed in the dominant model. Otherwise, no significant results were observed for PAT+/-. CONCLUSION: XPC Lys939Gln A>C polymorphism may play an important role in digestive system cancer susceptibility.

The prognostic significance of TP53 mutations in Chinese patients with chronic lymphocytic leukemia is independent of del(17p13).

The poor prognosis of chronic lymphocytic leukemia (CLL) patients with del(17p13) is well established. Several studies have shown that cases with TP53 mutations and TP53 mutations without del(17p13) may be adverse prognostic factors. We studied 173 well-characterized CLL patients by direct sequencing to detect TP53 mutations (exons 2-11). TP53 mutations were detected in 14.5% (25 of 173) of samples. Most patients with del(17p13) had TP53 mutations (72.2%). Mutations in the absence of del(17p13) were found in 8.3% in our cohort, which were higher than other countries. Compared with cases without TP53 alterations, TP53 mutations and deletions were both associated with advanced stages and unmutated immunoglobulin heavy-chain variable region status. Survival analysis showed that the occurrence of TP53 mutations and del(17p13) were associated with shorter overall survival (OS), treatment-free survival (TFS), and resistance to chemotherapy. TP53 mutations were the variables strongly associated with OS and TFS by multivariate Cox regression analysis. Moreover, we also found that cases with TP53 mutations in the absence of del(17p13) had a similar clinical and biological course and similar poor short OS as cases carrying del(17p13) in Chinese patients with CLL.

[SDF-1α/CXCR4 Mediated Drug Resistance Can be Reversed by Ibrutinib in Acute Lymphoblastic Leukemia].

OBJECTIVE: To explore the effect of Ibrutinib on the chemoresistance mediated by SDF-1α/CXCR4 axis in ALL cells. METHODS: Flow cytometry was used to detect the apoptosis of cell line and expression of surface membrane CXCR4, Western blot was used to determine the expression level of CXCR4, ERK and Bcl-xL proteins, qPCR was used to assay the mRNA level of CXCR4. RESULTS: Ibrutinib enhanced the apoptosis induced by adriamycin(ADR) (17.100±4.3% to 28.133±3.16%); Ibrutinib inhibited the phosphorylation of CXCR4 induced by SDF-1α and with concentration- and time- dependent manner (r24h=-0.99659, r48h=-0.99764, r=-0.99980). Ibrutinib inhibited the expression and activity of CXCR4 downstream signaling molecules pERK and BCL-xL. CONCLUSION: Ibrutinib can enhance the sensitivity of SUP-B15 to ADR, reverse SDF-1α/CXCR4-mediated chemoresistance in Ph+ acute lymphoblastic leukemia cells. This mechanism of ibrutinib may be assosiated with inhibiting CXCR4/ERK/BCL-xL.

[Expression of Btk and NFκB in Acute Lymphoblastic Leukemia Cells and Its Significance].

OBJECTIVE: To evaluate the role of Btk and NFκB in the incidence, development, prognosis and therapeutic efficacy for acute lymphoblastic leukemia(ALL) through detecting their expression in leukemia cells. METHODS: Bone marrow samples from 51 ALL patients were collected, and the mononuclear cells were separated by Ficoll density gradient centrifugation. The expressions of Btk and NFκB at RNA and protein levels were detected by RT-PCR and Western blot respectively. RESULTS: (1)At protein level, Btk and NFκB were expressed in all newly diagnosed 51 ALL patients, among them 38 patients had higher expression level of Btk, 34 patients had high NFκB expression level. The expression of Btk and NFκB was higher in the cells from newly diagnosed ALL patients than that in the cells from patients in CR(P<0.05), and the expression of Btk and NFκB was higher in relapsed ALL patients. (2)The expression of Btk and NFκB in the ALL patients was followed-up higher expression of Btk: among the 38 newly diagnosed B-ALL cases, 27 experienced CR (71%) and 12 of which achieved CR after one course chemotherapy (one course CR) (31%). Moreover, 16 out of the 27 CR patients relapsed after a short period (less than 6 months) (59%). On the contrary, among the 13 patients with low Btk expression, 11 achieved CR (84.6%) after one course and 1 relapsed (8 months after CR) (7.6%). A similar pattern of NFκB expression was observed. CONCLUSION: Btk and NFκ B may play an important role in the incidence and progression of ALL, possibly serving as the potential therapeutic targets of ALL and the indexes for prognosis.

Knockdown of juvenile hormone acid methyl transferase severely affects the performance of Leptinotarsa decemlineata (Say) larvae and adults.

BACKGROUND: Juvenile hormone (JH) plays a critical role in the regulation of metamorphosis in Leptinotarsa decemlineata, a notorious defoliator of potato. JH acid methyltransferase (JHAMT) is involved in one of the final steps of JH biosynthesis. RESULTS: A putative JHAMT cDNA (LdJHAMT) was cloned. Two double-stranded RNAs (dsRNAs) (dsJHAMT1 and dsJHAMT2) against LdJHAMT were constructed and bacterially expressed. Experiments were conducted to investigate the effectiveness of RNAi in both second- and fourth-instar larvae. Dietary introduction of dsJHAMT1 and dsJHAMT2 successfully knocked down the target gene, lowered JH titre in the haemolymph and reduced the transcript of Krüppel homologue 1 gene. Ingestion of dsJHAMT caused larval death and weight loss, shortened larval developmental period and impaired pupation. Moreover, the dsJHAMT-fed pupae exhibited lower adult emergence rates. The resulting adults weighed an average of 50 mg less than the control group, and the females did not deposit eggs. Application of pyriproxyfen to the dsJHAMT-fed insects rescued all the negative effects. CONCLUSIONS: LdJHAMT expresses functional JHAMT enzyme. The RNAi targeting LdJHAMT could be used for control of L. decemlineata. © 2015 Society of Chemical Industry.

[Influence of Co-inhibiting mTORC2 and HSP90 on Proliferation Apoptosis of Multiple Myeloma Cells].

UNLABELLED: Objective：To explore the influence of co-inhibiting mTORC2 and HSP90 on the proliferation and apoptosis of multiple myeloma(MM) cell line U266. METHODS: During culture, the human MM cell line U266 were treated with 20 nmol/L of rapamycin, 600 nmol/L 17-AAG, 20 nmol/L of rapamycin + 600 nmol/L 17-AGG and phosphate-buffered saline (PBS), then the growth inhibition rate, morphologic changes, apoptosis rate and the expression of caspase 3 and ATK protein in U266 cells were compared and analyzed. RESULTS: The rapamycin and 17-AAG both could inhibit the growth of U266 cells, while the inhibitory effect of rapamycin in combination with 17-AAG on growth of U266 cells was significantly higher them that of rapamycin and 17-AAG alone and control (PBS); the apoptosis rate of U266 cells treated with rapamycin, 17-AAG and their combination was higher than that of control PBS groups, and the efficacy of 2 drug conbination was higher than that of control PBS group, and the efficacy of 2 drug combination was superior to single drug. The expression levels of caspase 3 and ATK in U266 cells treated with rapamycin, 17-AAG and their combination were higher and lower than those in control group respectively, and the efficacy of 2 drug combination was superior to signle drug. There were significant difference between them (P<0.05). CONCLUSION: The co-inhibition of mTORC2 and HSP90 can suppress the proliferation and induce the apoptosis of MM cells.

RNA interference-mediated silencing of a Halloween gene spookier affects nymph performance in the small brown planthopper Laodelphax striatellus.

Post-embryonic development of insects is highly dependent on ecdysteroid hormone 20-hydroxyecdysone. Halloween gene spookier (spok, cyp307a2) has been documented to be involved in ecdysteroidogenesis in Drosophila melanogaster and Bombyx mori. We describe here the cloning and characterization of Halloween gene spookier (Lsspok, Lscyp307a2) in the small brown planthopper Laodelphax striatellus, a hemipteran insect species. LsSPOK has three insect-conserved P450 motifs, that is, Helix-K, PERF motif and heme-binding domain. Temporal and spatial expression patterns of Lsspok were evaluated by quantitative polymerase chain reaction. Through the fouth-instar and the early fifth-instar stages, Lsspok showed two expression peaks in the second- and fifth-day fourth-instar nymphs, and two troughs in the first-day fourth and fifth instars. On day 5 of the fourth-instar nymphs, Lsspok clearly had a high transcript level in the thorax where prothoracic glands were located. Dietary introduction of double-stranded RNA of Lsspok in the nymph stage successfully knocked down the target gene, decreased expression level of ecdysone receptor (LsEcR) gene, caused nymphal lethality and delayed development. Ingestion of 20-hydroxyecdysone in Lsspok-dsRNA-exposed nymphs did not increase Lsspok expression level, but almost completely rescued the LsEcR mRNA level and relieved the negative effects on survival and development. Thus, our data suggest that the ecdysteroidogenic pathway is conserved in insects and LsSPOK is responsible for specific steps in ecdysteroidogenesis in L. striatellus.

Knockdown of a putative Halloween gene Shade reveals its role in ecdysteroidogenesis in the small brown planthopper Laodelphax striatellus.

Ecdysteroid hormone 20-hydroxyecdysone (20E) plays fundamental roles in insect development and reproduction, whereas the primary role of ecdysone (E) is the precursor for 20E. A cytochrome P450 monooxygenase (CYP), encoded by a Halloween gene Shade (Shd, cyp314a1), catalyzes the conversion of E into 20E in representative insect species in Diptera, Lepidoptera and Orthoptera. We describe here the cloning and characterization of LsShd in a hemipteran insect species, the small brown planthopper Laodelphax striatellus. LsSHD has five insect conserved P450 motifs, i.e., Helix-C, Helix-I, Helix-K, PERF and heme-binding motifs. Temporal expression pattern of LsShd was determined through the fourth-instar and the early fifth-instar stages by qPCR. LsShd showed two expression peaks in day 2 and day 5 fourth-instar nymphs, and two troughs in day 1 fourth and fifth instars. Dietary introduction of double-stranded RNA (dsRNA) of LsShd into nymphs successfully knocked down the target gene, decreased expression level of ecdysone receptor (LsEcR) gene, and caused nymphal lethality and delayed development. Ingestion of 20E did not increase LsShd expression level, but almost completely rescued LsEcR mRNA level, and relieved the negative effects on the survival and development in LsShd-dsRNA-exposed nymphs. In contrast, dietary introduction of E had little rescue effects. Thus, our data suggest that the ecdysteroidogenic pathway is conserved in insects, and LsSHD functions to regulate metamorphotic processes by converting E to 20E even in a hemipteran insect, L. striatellus.

RNA interference of a putative S-adenosyl-L-homocysteine hydrolase gene affects larval performance in Leptinotarsa decemlineata (Say).

In Leptinotarsa decemlineata, juvenile hormones (JHs) play primary roles in the regulation of metamorphosis, reproduction and diapause. In JH biosynthetic pathway in insect corpora allata, methylation of farnesoic acid or JH acid using S-adenosyl-L-methionine generates a potent feedback inhibitor S-adenosyl-L-homocysteine (AdoHcy). Rapid removal of AdoHcy is hypothesized to be essential for JH synthesis. AdoHcy hydrolase (SAHase) is the only eukaryotic enzyme catalyzing the removal. In the present paper, we firstly cloned a putative LdSAHase gene from L. decemlineata. The cDNA consists of 1806 bp and encodes a 525 amino acid protein. LdSAHase was expressed in all developmental stages. The gene had the highest and the lowest level of transcription respectively in the 3rd- and 4th-instars' heads that contain corpora allata, which was positively correlated with JH titer in the haemolymph and the mRNA level of a JH early-inducible gene, the Krüppel homolog 1 gene (Kr-h1). Secondly, dietary ingestion of bacterially-expressed LdSAHase-dsRNA significantly decreased LdSAHase and LdKr-h1 mRNA levels, reduced JH titer, and caused the death of the larvae, and the failure of pupation and adult emergence. After continuous exposure for 12 days, 42% of the larvae died, 65% of the prepupae failed to pupate and 100% of the pupae failed to emerge. Moreover, RNAi-mediated LdSAHase knockdown also reduced larval developing time, and decreased larval weight. Lastly, application of JH analogue pyriproxyfen to LdSAHase-dsRNA-exposed larvae did not greatly increase LdSAHase expression level and JH content, but up-regulated LdKr-h1 mRNA level. Expectedly, pyriproxyfen application could partially rescue the negative effects on the survival and the development. Thus, our results support the hypothesis that SAHase plays a critical role in JH biosynthesis in insects.

Validation of reference genes for expression analysis by quantitative real-time PCR in Leptinotarsa decemlineata (Say).

BACKGROUND: L. decemlineata is an exotic invasive insect pest, and invaded in Xinjiang Uygur autonomous region in China in the 1990s from Kazakhstan. It is a notorious defoliator of potato throughout most of the northern Xinjiang in current, and often causes extremely large yield losses of potato. RESULTS: The expression stability of nine L. decemlineata house-keeping genes (Actin, ACT1 and ACT2; ADP-ribosylation factor, ARF1 and ARF4; TATA box binding protein, TBP1 and TBP2; ribosomal protein RP4 and RP18; translation elongation factor 1α EF1α) was evaluated by quantitative real-time polymerase chain reaction (qRT-PCR) in seven developmental stages, three larval tissues and two insecticide treatments. The results were analyzed using three software programs: geNorm, NormFinder and BestKeeper. Although there was no consistent ranking observed among the house-keeping genes across the samples, the overall analysis revealed that RP18, RP4, ARF1, and ARF4 were the four most stable house-keeping genes. In contrast, ACT1 and ACT2, two of the most widely used reference genes, had the least stability. Our results suggest that the combined use of the four most stably expressed genes may produce optimal normalization for qRT-PCR. CONCLUSIONS: The expression stability of the house-keeping genes varies among different developing stages, in different tissues and under different experimental conditions. Our results will enable a more accurate and reliable normalization of qRT-PCR data in L. decemlineata.

TP53 mutation is not an independent prognostic factor in patients with mantle cell lymphoma at advanced stage.

Mantle cell lymphoma (MCL) is incurable in most patients. Several molecular markers have been identified as possible prognostic factors in MCL, including TP53 mutations. Direct sequencing was used to detect 32 cases with leukemic presentation of MCL form exons 2-11 in order to explore the prognostic significance of TP53 mutations in Chinese patients. Within the MCL cohort, 6(18.8%) patients harbored TP53 mutations. TP53 mutations in the absence of del(17p13) were found in 5.0% of MCL cases (1 of 20) compared with 83.3% of MCL cases (5 of 6) with del(17p13). Compared with patients without TP53 mutations, TP53 mutations were associated with risk factors including age, higher serum lactate dehydrogenase, lymphocytosis, high-risk (HR) international prognostic index, HR mantle cell lymphoma international prognostic index, complex karyotype, and higher occurrence of TP53 deletions. In contrast, it is found that TP53 mutations were correlated with mutated immunoglobulin heavy-chain variable region status and CD38 negative. TP53 mutations were the significant factors in predicting survival in univariate analysis, but unfortunately they were not the unique variable associated with overall survival by multivariate Cox regression analysis. TP53 mutation was insufficiently an independent prognostic factor in patients with MCL at advanced stage.

[Research advance of p53 gene in mantle cell lymphoma].

Mantle cell lymphoma(MCL) is an independent uncommon subtype of B-cell non-Hodgkin's lymphoma (NHL) according to World Health Organization classification of hematopoietic and lymphoid tissue tumors. The genetic hallmark of MCL is the chromosomal translocation t(11;14)(q13;q32) that leads to upregulation of cyclin D1, an important regulator of the G(1) phase in the cell cycle. This genetic aberration is virtually present in all cases of MCL. It is characterized by distinct clinical features and outcome which is affected by a series of additional genetic aberration including the genomic guardian-P53 gene. This article reviews the effects of P53 gene aberrations including P53 deletion, mutation and their mutual relationship in MCL, and novel therapeutic regimens for MCL patients with P53 aberrations.