H19/let-7/LIN28 reciprocal negative regulatory circuit promotes breast cancer stem cell maintenance

Long noncoding RNA-H19 (H19), an imprinted oncofetal gene, has a central role in carcinogenesis. Hitherto, the mechanism by which H19 regulates cancer stem cells, remains elusive. Here we show that breast cancer stem cells (BCSCs) express high levels of H19, and ectopic overexpression of H19 significantly promotes breast cancer cell clonogenicity, migration and mammosphere-forming ability. Conversely, silencing of H19 represses these BCSC properties. In concordance, knockdown of H19 markedly inhibits tumor growth and suppresses tumorigenesis in nude mice. Mechanistically, we found that H19 functions as a competing endogenous RNA to sponge miRNA let-7, leading to an increase in expression of a let-7 target, the core pluripotency factor LIN28, which is enriched in BCSC populations and breast patient samples. Intriguingly, this gain of LIN28 expression can also feedback to reverse the H19 loss-mediated suppression of BCSC properties. Our data also reveal that LIN28 blocks mature let-7 production and, thereby, de-represses H19 expression in breast cancer cells. Appropriately, H19 and LIN28 expression exhibits strong correlations in primary breast carcinomas. Collectively, these findings reveal that lncRNA H19, miRNA let-7 and transcriptional factor LIN28 form a double-negative feedback loop, which has a critical role in the maintenance of BCSCs. Consequently, disrupting this pathway provides a novel therapeutic strategy for breast cancer.

Associations between single-nucleotide polymorphisms (+45T>G, +276G>T, -11377C>G, -11391G>A) of adiponectin gene and type 2 diabetes mellitus: a systematic review and meta-analysis

AIMS/HYPOTHESIS

The associations between adiponectin polymorphisms and type 2 diabetes have been studied widely; however, results are inconsistent.

METHODS

We searched electronic literature databases and reference lists of relevant articles. A fixed or random effects model was used on the basis of heterogeneity. Sub-group and meta-regression analyses were conducted to explore the sources of heterogeneity.

RESULTS

There were no statistically significant associations between +45T>G (rs2241766), +276G>T (rs1501299), -11391G>A (rs17300539) and type 2 diabetes risk. However, for -11377C>G (rs266729), the pooled OR (95% CI) for G vs C allele was 1.07 (1.03-1.11, p = 0.001). Subgroup analysis by study design revealed that -11377C>G (rs266729) dominant model (CG+GG vs CC, p = 0.0008) and G vs C allele (p = 0.0004) might be associated with type 2 diabetes risk in population-based case-control studies. After stratification by ethnicity, we found that -11377C>G (rs266729) dominant model (CG+GG vs CC, p = 0.004) and G vs C allele (p = 0.001) might be associated with type 2 diabetes risk in white individuals. In individuals with a family history of diabetes, the presence of -11391G>A (rs17300539) dominant model (GA+AA vs GG) and A vs G allele might be associated with increased risk of type 2 diabetes.

CONCLUSIONS/INTERPRETATION

The presence of +45T>G (rs2241766), +276G>T (rs1501299) and -11391G>A (rs17300539) do not appear to influence the development of type 2 diabetes. However, G vs C allele of -11377C>G (rs266729) might be a risk factor for type 2 diabetes.

Fermented milk supplemented with probiotics and prebiotics can effectively alter the intestinal microbiota and immunity of host animals

Fermented milk supplemented with 2 probiotic strains, Bifidobacterium lactis Bi-07 and Lactobacillus acidophilus NCFM, and a prebiotic, isomaltooligosaccharide, was orally administered to 100 healthy adults at 480 g/d for 2 wk in a randomized controlled trial. The fecal bacterial compositions of these subjects were examined by culture before and after the intervention. The same fermented milk was also orally fed to BALB/c mice, and immune as well as fecal bacteria analyses were conducted using the same culturing methods. After the intervention, increases in fecal bifidobacteria and lactobacilli were observed among the subjects compared with the subjects in the control group. In contrast, after the intervention, fecal enterobacilli were significantly decreased in the test group compared with the control group. The same effects on the composition of the intestinal microbiota were observed in mice. Furthermore, the tested mice were found to have significantly increased delayed-type hypersensitivity, plaque-forming cells, and half-hemolysis values after the intervention with the fermented milk. In summary, the synbiotic fermented milk containing probiotics and a prebiotic may contribute to improve intestinal health and may have a positive effect on the humoral and cell-mediated immunity of host animals.

Cloning and sequence analysis of dsRNA segments 5, 6 and 7 of a novel non-group A, B, C adult rotavirus that caused an outbreak of gastroenteritis in China

A diarrhoeal outbreak among adults in China was caused by a new rotavirus, termed ADRV-N, that does not react with antisera directed against group A, B or C rotaviruses [Zhonghua Liu Xing Bing Xue Za Zhi (Chin. Epidemiol.) 19 (1998) 336]. ADRV-N can be propagated in cell cultures [Zhonghua Yi Xue Za Zhi (Natl. Med. J. China) 82 (2002) 14]. We present the complete sequences for ADRV-N genome segments 5 and 6, and a full ORF sequence of genome segment 7. The deduced amino acid sequences suggest that these segments encode NSP1, VP6 and NSP3, respectively. These three ADRV-N genome segments have a unique -ACCCC-3' terminal sequence. The 5'-GG- terminus of segments 5 and 6 is the same as that of other rotaviruses. The amino acid similarity between VP6 and NSP3 of ADRV-N and the cognate sequences of their closest counterpart, group B IDIR, was 37 and 35%, respectively. The ADRV-N NSP1 has a double-stranded RNA binding motif (DSRM) and a putative autoproteolytic cleavage motif upstream from the DSRM. The putative ADRV-N NSP3 has a truncated C-terminus compared to the cognate protein of group B rotaviruses. All the available data demonstrate that ADRV-N differs significantly from the known rotaviruses and strongly suggest that ADRV-N is the first recognized member of a new group of rotaviruses infecting humans.

Reaction of pyridoxamine with malondialdehyde: Mechanism of inhibition of formation of advanced lipoxidation end-products

Advanced glycation end products (AGEs) and advanced lipoxidation end products (ALEs) are implicated in many age-related chronic diseases and in protein aging. Recent studies suggest that pyridoxamine (PM) is an efficient AGEs/ALEs inhibitor in various biological systems. Because malondialdehyde (MDA) is an important intermediate in the formation of ALEs during lipid peroxidation, the purpose of this study is to determine whether PM can trap MDA directly and thereby prevent ALEs formation. PM reacted readily with MDA under physiological conditions. Within 6 h, a 1-pyridoxamino-propenal adduct derived from reaction of equimolar PM + MDA was detected. A 1-amino-3-iminopropene complex and a dihydropyridine-pyridinium complex were also identified after 7 d incubation. PM also greatly inhibited the lipofuscin-like fluorescence formation induced by MDA reaction with bovine serum albumin (BSA). Our results showed clearly that PM inhibited the formation of ALEs by trapping MDA directly under physiological condition, and provide insight into the mechanism of action of PM in protecting proteins against carbonyl stress.

Effects of tebuconazole on morphology, structure, cell wall components and trichothecene production of Fusarium culmorum in vitro

The effects of tebuconazole, a systemic fungicide, on the morphology, structure, cell wall components and toxin production of Fusarium culmorum were investigated in vitro. Treatment was by application of four filter paper strips (0.75 cm x 5.0 cm) soaked in 20 micrograms ml-1 fungicide placed around a point inoculum in Petri dishes. Mycelial growth was strongly inhibited by fungicide treatment. Scanning electron microscopic observations showed that the fungicide caused irregular swelling and excessive branching of hyphae. The morphological changes induced by the fungicide at the ultrastructural level included considerable thickening of the hyphal cell walls, excessive septation, the formation of the incomplete septa, extensive vacuolisation, accumulation of lipid bodies and progressing necrosis or degeneration of the hyphal cytoplasm. Non-membrane inclusion bodies were often detected in the hyphal cytoplasm. Furthermore, the formation of new hyphae (daughter hyphae) inside collapsed hyphal cells was common following treatment. The daughter hyphae also displayed severe alterations such as irregular thickening of the cell walls and necrosis of the cytoplasm. Using cytochemical techniques, the labelling densities of chitin and beta-1,3-glucan in the cell walls of the fungicide-treated hyphae were more pronounced than in those of the control hyphae. Moreover, immunogold labelling with antiserum against deoxynivalenol (DON) revealed that Fusarium toxin DON was localized in the cell walls, cytoplasm, mitochondria and vacuoles of the hyphae from the control and the fungicide treatment, but the labelling density in the fungicide-treated hyphae decreased dramatically compared with the control hyphae, indicating that tebuconazole reduced Fusarium toxin production of the fungus.

Inhibition of autophagy overcomes glucocorticoid resistance in lymphoid malignant cells

Glucocorticoid (GC) resistance remains a major obstacle to successful treatment of lymphoid malignancies. Till now, the precise mechanism of GC resistance remains unclear. In the present study, dexamethasone (Dex) inhibited cell proliferation, arrested cell cycle in G0/G1-phase, and induced apoptosis in Dex-sensitive acute lymphoblastic leukemia cells. However, Dex failed to cause cell death in Dex-resistant lymphoid malignant cells. Intriguingly, we found that autophagy was induced by Dex in resistant cells, as indicated by autophagosomes formation, LC3-I to LC3-II conversion, p62 degradation, and formation of acidic autophagic vacuoles. Moreover, the results showed that Dex reduced the activity of mTOR pathway, as determined by decreased phosphorylation levels of mTOR, Akt, P70S6K and 4E-BP1 in resistant cells. Inhibition of autophagy by either chloroquine (CQ) or 3-methyladenine (3-MA) overcame Dex-resistance in lymphoid malignant cells by increasing apoptotic cell death in vitro. Consistently, inhibition of autophagy by stably knockdown of Beclin1 sensitized Dex-resistant lymphoid malignant cells to induction of apoptosis in vivo. Thus, inhibition of autophagy has the potential to improve lymphoid malignancy treatment by overcoming GC resistance.

Isolation and characterisation of cDNA encoding a wheat heavy metal-associated isoprenylated protein involved in stress responses

In cells, metallochaperones are important proteins that safely transport metal ions. Heavy metal-associated isoprenylated plant proteins (HIPPs) are metallochaperones that contain a metal binding domain and a CaaX isoprenylation motif at the carboxy-terminal end. To investigate the roles of wheat heavy metal-associated isoprenylated plant protein (TaHIPP) genes in plant development and in stress responses, we isolated cDNA encoding the wheat TaHIPP1 gene, which contains a heavy metal-associated domain, nuclear localisation signals and an isoprenylation motif (CaaX motif). Quantitative real-time PCR analysis indicated that the TaHIPP1 gene was differentially expressed under biotic and abiotic stresses. Specifically, TaHIPP1 expression was up-regulated by ABA exposure or wounding. Additionally, TaHIPP1 over-expression in yeast (Schizosaccharomyces pombe) significantly increased the cell growth rate under Cu(2+) and high salinity stresses. The nuclear localisation of the protein was confirmed with confocal laser scanning microscopy of epidermal onion cells after particle bombardment with chimeric TaHIPP1-GFP constructs. In addition, TaHIPP1 was shown to enhance the susceptibility of wheat to Pst as determined by virus-induced gene silencing. These data indicate that TaHIPP1 is an important component in defence signalling pathways and may play a crucial role in the defence response of wheat to biotic and certain abiotic stresses.

Insulin-like growth factor 1 receptor antibody induces rhabdomyosarcoma cell death via a process involving AKT and Bcl-x(L)

Insulin-like growth factors (IGFs) and their receptor, IGF-1 receptor (IGF1R), have important roles in growth, development, stress response, aging and cancer. There are many agents that inhibit IGF1R in oncology clinical development, and in some cases, they have been associated with rapid tumor regression. However, it is not clear by which process these targeted agents induce cancer cell death and how to predict such tumor responses. Here, we showed that IGF1R antibody led to rapid cell death and tumor regression in some rhabdomyosarcoma (RMS) cells. Mechanistic analysis revealed a rapid onset of mitochondrial-dependent apoptosis, including mitochondrial depolarization, cytochrome C release and the activation of specific caspases. The antibody sensitive cells had greater dependence on AKT for maintaining downstream signaling and the expression of a constitutively active AKT, which restored AKT-signaling in these cells, inhibited anti-IGF1R induced cell death. Further analysis showed IGF1R antibody-induced hypophosphorylation of BAD and activation of downstream BAX. Interestingly, the examination of RMS cell lines and tumors revealed an inverse correlation between elevated IGF1R and Bcl-2 level (P=0.033), with the sensitive cells lacking Bcl-2 expression. The overexpression of BAD specific target, Bcl-x(L), conferred resistance, whereas Bcl-x(L) knockdown sensitized cells lacking Bcl-2 to anti-IGF1R-induced cell death. We propose that RMS pathogenesis involves increased IGF1R expression that enhances AKT and Bcl-x(L)-mediated cell survival, and the blockage of IGF1R results in inhibition of survival signal from Bcl-x(L) and cell death in the sensitive Bcl-2 negative cells.

Reduction of NANOG Mediates the Inhibitory Effect of Aspirin on Tumor Growth and Stemness in Colorectal Cancer

BACKGROUND/AIMS

Cancer stem cells (CSCs) are considered to be responsible for tumor relapse and metastasis, which serve as a potential therapeutic target for cancer. Aspirin has been shown to reduce cancer risk and mortality, particularly in colorectal cancer. However, the CSCs-suppressing effect of aspirin and its relevant mechanisms in colorectal cancer remain unclear.

METHODS

CCK8 assay was employed to detect the cell viability. Sphere formation assay, colony formation assay, and ALDH1 assay were performed to identify the effects of aspirin on CSC properties. Western blotting was performed to detect the expression of the stemness factors. Xenograft model was employed to identify the anti-cancer effects of aspirin in vivo. Unpaired Student t test, ANOVA test and Kruskal-Wallis test were used for the statistical comparisons.

RESULTS

Aspirin attenuated colonosphere formation and decreased the ALDH1 positive cell population of colorectal cancer cells. Aspirin inhibited xenograft tumor growth and reduced tumor cells stemness in nude mice. Consistently, aspirin decreased the protein expression of stemness-related transcription factors, including c-Myc, OCT4 and NANOG. Suppression of NANOG blocked the effect of aspirin on sphere formation. Conversely, ectopic expression of NANOG rescued the aspirin-repressed sphere formation, suggesting that NANOG is a key downstream target. Moreover, we found that aspirin repressed NANOG expression in protein level by decreasing its stability.

CONCLUSION

We have provided new evidence that aspirin attenuates CSC properties through down-regulation of NANOG, suggesting aspirin as a promising therapeutic agent for colorectal cancer treatment.

A comparison of the clinical characteristics of women with recurrent major depression with and without suicidal symptomatology

BACKGROUND

The relationship between recurrent major depression (MD) in women and suicidality is complex. We investigated the extent to which patients who suffered with various forms of suicidal symptomatology can be distinguished from those subjects without such symptoms.

METHOD

We examined the clinical features of the worst episode in 1970 Han Chinese women with recurrent DSM-IV MD between the ages of 30 and 60 years from across China. Student's t tests, and logistic and multiple logistic regression models were used to determine the association between suicidality and other clinical features of MD.

RESULTS

Suicidal symptomatology is significantly associated with a more severe form of MD, as indexed by both the number of episodes and number of MD symptoms. Patients reporting suicidal thoughts, plans or attempts experienced a significantly greater number of stressful life events. The depressive symptom most strongly associated with lifetime suicide attempt was feelings of worthlessness (odds ratio 4.25, 95% confidence interval 2.9-6.3). Excessive guilt, diminished concentration and impaired decision-making were also significantly associated with a suicide attempt.

CONCLUSIONS

This study contributes to the existing literature on risk factors for suicidal symptomatology in depressed women. Identifying specific depressive symptoms and co-morbid psychiatric disorders may help improve the clinical assessment of suicide risk in depressed patients. These findings could be helpful in identifying those who need more intense treatment strategies in order to prevent suicide.

Transient expression of somatostatin mRNA in developing ganglion cell layers of rat retina

Somatostatin (SOM) mRNA in developing ganglion cell layer (GCL) detected by in situ hybridization histochemistry and SOM peptide in developing optic chiasma and optic tract detected by immunocytochemistry were monitored to explore whether ganglion cells expressing SOM project to the visual center. Most of these cells in the developing GCL expressed SOM transiently from embryonic day 13 (E13) to E21. The cells expressing SOM mRNA initially followed a central-to-peripheral pattern of development. The cells expressing SOM mRNA in the retinas of fetuses became detectable at E13. From E14 to E17 the number of cells expressing SOM mRNA increased rapidly. At E17 most of the cells in the developing GCL expressed SOM mRNA. From E18 to postnatal days the positive cells became sparse except at the postnatal day 0 (PND0) the positive cells decreased dramatically in comparison with that at the E21. At PND15, the positive cells only can be found in the inner neuroblastic layer and in the ganglion cell layer. At PND20 the distribution pattern and the number of the positive cells were essentially the same as that in adult rat. SOM immunoreactivity was detectable at E16 in the developing optic chiasma and optic tract; the majority of the fibers in these area were SOM positive. From E16 to E18 the density of the immunostaining increased rapidly, whereas from E19 to E21 the density decreased. At PND0 no positive fibers were seen. The transient presence of SOM in most of the ganglion cells in the developing ganglion cell layer has prompted us to study the role of SOM in generation and differentiation of the retinal ganglion cells, and formation of the retina-visual center projections.

Effect of a traditional Chinese medicine Liu Wei Di Huang Wan on the activities of CYP2C19, CYP2D6 and CYP3A4 in healthy volunteers

Liu Wei Di Huang Wan (LDW), a well-known traditional Chinese medicine, is widely used for the treatment of various diseases in China. This study was designed to investigate the potential herb-drug interactions of LDW in healthy volunteers and attempted to ascertain whether the interaction might be affected by genotypes. We assessed the effect of LDW on the activities of CYP2C19, CYP2D6 and CYP3A4 in 12 Chinese healthy subjects in a single-center, controlled, non-blinded, two-way crossover clinical trial. The subject pool consisted of six extensive metabolizers with CYP2C19*1/*1 and six poor metabolizers with CYP2C19*2/*2. Placebo or 4.8 g LDW (12 pills, 0.2 g/pill, twice daily) was given to each participant for 14 continuous days with a wash-out period of 2 weeks after an oral administration of 30 mg omeprazole, 30 mg dextromethorphan hydrobromide and 7.5 mg midazolam. The activities of CYP2C19, CYP2D6 and CYP3A4 were ascertained by their respective plasma or urinary metabolic ratios on day 14 post-treatment. There is no difference in the activities of the three tested enzymes before or after a 14-day administration of LDW. LDW had no effect on the pharmacokinetic parameters of the substrates and their metabolites. A 14-day administration of LDW did not affect the activities of CYP2C19, CYP2D6 and CYP3A4. LDW is unlikely to cause pharmacokinetic interaction when it is combined with other medications predominantly metabolized by these enzymes.

Association analysis of the IL2RA gene with alopecia areata in a Chinese population

BACKGROUND

Interleukin-2 receptor subunit alpha (IL2RA) is highly expressed on CD4+CD25+ regulatory T cells and is important for immune homeostasis and the suppression of autoimmune responses. It has been suggested that the single nucleotide polymorphism in IL2RA may affect the pathogenesis of alopecia areata (AA).

OBJECTIVE

Our aim was to investigate the link between IL2RA polymorphism and AA in a Chinese population.

METHODS

We examined 427 patients and 430 controls in this study. The rs3118470 polymorphism was evaluated using high-resolution melting analysis and direct sequencing.

RESULTS

The prevalence of the C/C, T/C and T/T genotypes was 16.2, 48.2 and 35.6%, respectively. The genotype distribution and allele frequencies were significantly different between AA and control subjects (p < 0.0001). The C allele frequency was significantly higher in the AA group (p < 0.0001), and the frequencies of C allele and C/C genotype were higher in the patients with family history (p = 0.034; p < 0.0001).

CONCLUSIONS

The rs3118470 single nucleotide polymorphism of IL2RA may be a genetic marker to assess the risk of AA in a Chinese population.

Recombinant latcripin 11 of Lentinula edodes C91-3 suppresses the proliferation of various cancer cells

Lentinula edodes C91-3 is an edible mushroom that has demonstrated a remarkable anti-tumor effect in various cancer cells both in vitro and in vivo. In the present study, we report the ability of recombinant thioredoxin-like latcripin 11 (LP-11) of Lentinula edodes C91-3 to suppress the proliferation of various cancer cells. The LP-11 gene of Lentinula edodes C91-3 was cloned in the pET-32a(+) expression vector and expressed in a prokaryotic system. The expressed protein was refolded by gradual dialysis and purified by affinity gel filtration chromatography. The antioxidant activity of LP-11 was tested by 1,1-dipheny l-2-picrylhydrazyl (DPPH) assay. The anti-tumor activity of recombinant LP-11 was tested in eight kinds of tumor cell lines by CCK-8 assay. Recombinant LP-11 significantly suppressed the proliferation of various cancer cells, but not normal human umbilical vein endothelial cells. Human lymphoma U937 cells exhibited the most sensitivity to LP-11 protein. U937 cell apoptosis was assessed by Annexin V staining coupled with flow cytometry, and mitochondrial morphology was analyzed by light and electron microscopy. It was revealed that recombinant LP-11 induced apoptosis in human leukemic monocyte lymphoma U937 cells. Our findings suggest that recombinant LP-11 is a promising agent for the treatment of lymphoma.

Extracellular beta-1,3-Glucanases in Stem Rust-Affected and Abiotically Stressed Wheat Leaves : Immunocytochemical Localization of the Enzyme and Detection of Multiple Forms in Gels by Activity Staining with Dye-Labeled Laminarin

Endo-beta-1,3-glucanase activity in intercellular washing fluid (IWF) from leaves of wheat (Triticum aestivum) increased 10-fold 4 days after leaves were infected with the wheat stem rust fungus (Puccinia graminis f.sp. tritici), while exo-beta-1,3-glucanase activity remained unchanged at a low level. Heat and ethylene stress had no effect, whereas mercury treatment resulted in a 2-fold increase in endo-beta-1,3-glucanase activity. With a new method of activity staining using laminarin-Remazol brilliant blue as substrate in overlay gels, 18 electrophoretic forms of endo-beta-1,3-glucanase were detected in IWF from unstressed leaves and up to 24 forms in IWF from stem rust-infected leaves. Most of the increase in beta-1,3-glucanase activity and in the number of beta-1,3-glucanases after rust infection was due to a nonspecific, stress-related effect on the plant, but two major forms of the enzyme probably originated from the fungus. beta-1,3-Glucanase was localized cytochemically with anti-barley-beta-1,3-glucanase antibodies. With preembedding labeling, the enzyme was demonstrated on the outside of host and fungal cell walls. Postembedding labeling localized the enzyme in the host plasmalemma and in the domain of host cell walls adjoining the plasmalemma, throughout walls of intercellular hyphal cells and haustoria, in the fungal cytoplasm, and in the extrahaustorial matrix. Cross-reactivity of beta-1,3-glucanases from wheat and germinated uredospores of the rust fungus with the anti-barley-beta-1,3-glucanase antibodies was confirmed in dot blot assays and on Western blots.

Targeting cancer cell plasticity by HDAC inhibition to reverse EBV-induced dedifferentiation in nasopharyngeal carcinoma

Application of differentiation therapy targeting cellular plasticity for the treatment of solid malignancies has been lagging. Nasopharyngeal carcinoma (NPC) is a distinctive cancer with poor differentiation and high prevalence of Epstein-Barr virus (EBV) infection. Here, we show that the expression of EBV latent protein LMP1 induces dedifferentiated and stem-like status with high plasticity through the transcriptional inhibition of CEBPA. Mechanistically, LMP1 upregulates STAT5A and recruits HDAC1/2 to the CEBPA locus to reduce its histone acetylation. HDAC inhibition restored CEBPA expression, reversing cellular dedifferentiation and stem-like status in mouse xenograft models. These findings provide a novel mechanistic epigenetic-based insight into virus-induced cellular plasticity and propose a promising concept of differentiation therapy in solid tumor by using HDAC inhibitors to target cellular plasticity.

Homoharringtonine Exerts Anti-tumor Effects in Hepatocellular Carcinoma Through Activation of the Hippo Pathway

Hepatocellular carcinoma (HCC) is the most prevalent subtype of liver cancer with a mortality rate of approximately 3–6/100,000 and is the third leading cause of cancer-related death worldwide. Although several small-molecule drugs have been developed for the treatment of HCC, the choice of an agent for patients who require systemic chemotherapy at an advanced stage is still limited. The Hippo pathway is an evolutionarily conserved tumor suppressive pathway commonly dysregulated in HCC, which makes it a promising target for anti-HCC therapies. Homoharringtonine (HHT) is an FDA-approved anti-leukemia drug with proven strong anti-tumor activity in solid tumors. In this study, we found that HHT could significantly inhibit HCC cell growth by suppressing cell proliferation and colony formation. Moreover, HHT repressed cell invasion and migration remarkably. Additionally, HHT induced cell cycle arrest at S phase and promoted apoptosis. Most importantly, we showed that HHT-induced apoptosis was a consequence of the Hippo pathway activation. Consistently, the MST1/2 inhibitor, XMU-MP-1, could restore cell viability and reverse HHT-induced cell apoptosis. Furthermore, in vivo results confirmed the tumor inhibitory effect of HHT. Taken together, our findings suggest that HHT is a potential alternative therapeutic agent for the treatment of HCC.

Expression patterns of the prolactin receptor gene in chicken lymphoid tissues during embryogenesis and posthatch period

Prolactin (PRL) is a pituitary hormone with multiple homeostatic roles among vertebrates. Although it has mainly been studied in relation to its role during the initiation and maintenance of incubation behavior in avian species, it has also been shown to act on the immune system. In this study, levels of PRL receptor (PRLR) mRNA were quantified by real-time PCR, and tissue expression was localized by in situ hybridization in primary and secondary lymphoid organs. Prolactin receptor was shown to be expressed in the bursa follicles, thymus lobules, and splenic pulp at all stages of development examined. Levels of PRLR expression were consistently higher in the bursa of Fabricius when compared with other lymphoid organs, suggesting that PRL acts primarily on bursal development. Furthermore, levels of PRLR mRNA appeared to fluctuate during embryogenesis, with a significant increase observed at embryonic day 19 in the bursa, at 7 d of age in the thymus, and on hatching day in the spleen. Thus, PRL might play an important role during the development of the immune system in chickens.

Methylation and expression analysis of mismatch repair genes in extramammary Paget's disease

BACKGROUND

Extramammary Paget's disease (EMPD) is a rare skin cancer with relative high frequencies of germline and somatic mismatch repair (MMR) genes mutations. However, the methylation and expression of these genes have not been validated in EMPD.

OBJECTIVE

This study aims to confirm the methylation and expression of MMR genes in EMPD.

METHODS

Immunohistochemical (IHC) staining detection and Methylation-specific PCR (MSP) were used to analyse MLH1, MSH2, MSH6 and PMS2 proteins' expression and promoters' methylation in 57 EMMD samples, and pyro-sequence was used to find highly methylated CpG sites in MSH2 promoter.

RESULTS

Immunohistochemical detection displayed reduced expression of MSH2 in 38.6% EMPD cases but normal expression of MLH1, MSH6 and PMS2 in all tumour tissues. Hypermethylation also was found in the promoter of MSH2 but not in other MMR genes. Pyrosequencing of MSH2 promoter showed CpG6 (-87) and CpG3 (-98) were the most common two methylated CpG dinucleotides. There is a significant correlation between reduced MSH2 expression and MSH2 methylation.

CONCLUSION

Reduced MSH2 expression and hypermethylation in this gene promoter were common genetic changes in EMPD, which expands our understanding of the role of MMR function in this skin cancer.

Multinucleate condition of Puccinia striiformis in colonies isolated from infected wheat leaves with macerating enzymes

A fluorescence microscopy study was carried out to examine the multinuclear condition in parasitic colonies of one isolate of Puccinia striiformis in leaf tissue of a susceptible wheat. At 5 and 10 days after inoculation, colonies were isolated with macerating enzymes and sequentially stained with 4′-6-diamidino-2-phenylindole and Calcofluor for nuclear counts in the intercellular hyphal cells, haustorium mother cells, and urediniospores. In 10-day-old colonies, more than 98% of the hyphal cells located adjacent to the uredinia were binucleate. Elsewhere in the colonies, the hyphal cells were highly variable in nuclear number; approximately 20% contained two nuclei, 18% contained four, 26% contained six, and 28% contained eight. In 5-day-old colonies, the hyphal cells were also highly variable in nuclear number, regardless of where they were located in the colony. The nuclear condition of haustorium mother cells was less variable; the majority contained either two or four nuclei. All urediniospores examined were binucleate. In the parasitic state, the multinucleate condition apparently occurs only in P. striiformis and not in other cereal rust fungi. Key words: multinucleate condition, stripe rust, Puccinia striiformis, DAPI, Calcofluor.