Heme oxygenase-1: a molecular brake on hepatocellular carcinoma cell migration

Hepatocellular carcinoma (HCC) is a fatal disease with great public health impact worldwide. Heme oxygenase (HO)-1 has recently been reported as an important player in tumor angiogenesis and metastasis. However, the role of HO-1 in liver cancer metastasis is unclear. In this study, we explored genetic differences and downstream signal transduction pathways of HO-1 in liver cancer cell lines. HO-1 wild-type and mutant cell lines were generated from human liver cancer cell line HepG2. The overexpression of wild-type HO-1 decreased the migration of HepG2 cells. In contrast, the overexpression of mutant HO-1G143H increased the migration of the cancer cells. Interleukin (IL)-6 is one of the major downstream molecules that mediated this process because IL-6 expression and migration are suppressed by HO-1 and increased when HO-1 is knocked down by shRNA. In addition, we demonstrated carbon monoxide (CO) and p38MAPK are the cofactors in this signal pathway. In vivo animal model demonstrated HO-1 inhibited the tumor growth. In conclusion, in vitro and in vivo data show HO-1 inhibits the human HCC cells migration and tumor growth by suppressing the expression of IL-6. The heme degradation product CO is a cofactor in this process and inhibits p38MAPK phosphorylation.

First Report of Yam mild mosaic virus in Yam in Guangxi Province, China

Yams (Dioscorea spp.) are widely grown in China as vegetables and herbal medicine. However, studies on viral diseases on yams are still limited. As a pilot project of a government initiative for improving yam productivity, a small study was conducted in Guangxi, a southern province of China, on viral disease in yams. Incidence of virus-like disease for the three extensively grown D. alata cultivars, GH2, GH5, and GH6, were 12 to 40%, 12 to 29%, and 11 to 25%, respectively, as found in a field survey with a five-plot sampling method in 2010. A total of 112 leaf samples showing mosaic or mottling or leaves without symptoms were collected from the cvs. GH2, GH5, GH6, and seven additional cultivars (D. alata cvs. GY2, GY23, GY47, GY69, GY62, GY72, and D. batatas cv. Tiegun). To determine if the symptoms were caused by Yam mild mosaic virus (YMMV; genus Potyvirus, family Potyviridae), total RNA was extracted from leaves with a commercial RNA purification kit (TIANGEN, Beijing, China), and reverse-transcription (RT)-PCR was conducted with a YMMV-specific primer pair (4) that amplifies the 3'-terminal portion of the viral genome. A PCR product with the predicted size of 262 bp was obtained from samples of GH5 (number testing positive of total number of leaves = 5 of 12), GH6 (24 of 42), and GY72 (1 of 1), but not from asymptomatic leaves. PCR products from a GH5 sample (YMMV-Nanning) and a GH6 sample (YMMV-Luzhai) were cloned and sequenced using an ABI PRISM 3770 DNA Sequencer. The two PCR products were 97% identical at nucleotide (nt) level and with the highest homology (89% identity) to a YMMV isolate (GenBank Accession No. AJ305466). To further characterize the isolates, degenerate primers (2) were used to amplify viral genome sequence corresponding to the C-terminal region of the nuclear inclusion protein b (NIb) and the N-terminal region of the coat protein (CP). These 781-nt fragments were sequenced and a new primer, YMMV For1 (5'-TTCATGTCGCACAAAGCAGTTAAG-3') corresponding to the NIb region, was designed and used together with primer YMMV UTR 1R to amplify a fragment that covers the complete CP region of YMMV by RT-PCR. These 1,278-nt fragments were sequenced (GenBank Accession Nos. JF357962 and JF357963). CP nucleotide sequences of the YMMV-Nanning and YMMV-Luzhai isolates were 94% similar, while amino acid sequences were 99% similar. BLAST searches revealed a nucleotide identity of 82 to 89% and a similarity of 88 to 97% for amino acids to sequences of YMMV isolates (AF548499 and AF548519 and AAQ12304 and BAA82070, respectively) in GenBank. YMMV is known to be prevalent on D. alata in Africa and the South Pacific, and has recently been identified in the Caribbean (1) and Colombia (3). To our knowledge, this is the first report of the natural occurrence of YMMV in China and it may have implications for yam production and germplasm exchange within China. References: (1) M. Bousalem and S. Dallot. Plant Dis. 84:200, 2000. (2) D. Colinet et al. Phytopathology 84:65, 1994. (3) S. Dallot et al. Plant Dis. 85:803, 2001. (4) R. A. Mumford and S. E. Seal. J. Virol. Methods 69:73, 1997.

Sequence analysis and expression mapping of the rat clustered protocadherin gene repertoires

Three closely-linked clusters of protocadherin (Pcdh) genes (alpha, beta, and gamma) encoding more than 50 distinct mRNAs have been identified in humans and mice, and proposed to play important roles in neuronal connectivity in the CNS. The human and mouse Pcdh alpha and gamma clusters each span a region of about 300 kb genomic DNA, and are each organized into a tandem array of more than a dozen highly-similar "variable" exons, and three downstream "constant" exons. Little is known about the expression patterns of the alpha and gamma repertoires in the CNS. Here, we comprehensively analyzed the one megabase rat Pcdh genomic DNA sequences at the nucleotide level using various computational methods. We found that the clustered rat Pcdh genes display strict orthologous relationships with those of mice but not humans. Moreover, each rat Pcdh variable exon is preceded by a distinct promoter. We designed two complete sets of isoform-specific probes and extensively mapped the expression patterns for each member of the alpha and gamma repertoires in the adult rat CNS by non-isotopic in situ hybridization experiments. We found that most alpha and gamma mRNA isoforms are broadly expressed in similar patterns in subsets of cells (with some displaying interesting cortical layer-specific expression) throughout various CNS regions, including the olfactory bulb, cerebral cortex, hippocampus, cerebellum, and spinal cord. The broad expression of most alpha or gamma mRNAs throughout various regions of the CNS is consistent with the hypothesis that these genes may be used for neurons to establish their individuality and also provide the adhesive diversity required for complex synaptic connectivity in the mammalian CNS.

DSS1 is required for the stability of BRCA2

DSS1 is an evolutionarily conserved acidic protein that binds to BRCA2. However, study of the function of DSS1 in mammalian cells has been hampered because endogenous DSS1 has not been detectable by Western blotting. Here, we developed a modified Western blotting protocol that detects endogenous DSS1 protein, and used it to study the function of DSS1 and its interaction with BRCA2 in mammalian cells. We found that essentially all BRCA2 in human cell lines is associated with DSS1. Importantly, we found that RNAi knockdown of DSS1 in human cell lines led to dramatic loss of BRCA2 protein, mainly due to its increased degradation. Furthermore, the stability of BRCA2 mutant devoid of the DSS1-binding domain is unaffected by the depletion of DSS1. Most notably, like BRCA2 depletion, DSS1 depletion also led to hypersensitivity to DNA damage. These results demonstrated that the stability of BRCA2 protein in mammalian cells depends on the presence of DSS1. Deletion or mutation of DSS1 or suppression of its expression by other mechanisms are therefore potential causative mechanisms for human breast and ovarian cancer. Such mechanisms may be relevant to sporadic as well as familiar breast cancer where BRCA1 and BRCA2 mutations are not present.

[The significance and expression of EGF and its receptor in nasal inverted papillomas and the correlation with malignant phenotype]

OBJECTIVE

To determine the expression of epidermal growth factor (EGF) and its receptor in nasal inverted papillomas (NIP) and to clarify the function of EGF in the establishment of NIPs and the correlation with malignant phenotype.

METHOD

The expression of EGF and its receptor EGFR were examined by immunohistochemistry using LSAB method in sections of NIP from 24 patients and squamous carcinoma from 4 patients.

RESULT

Showed that all the epithelium in NIPs together with vascular and stroma adjacent to the epithelium, expressed different degree of EGF. The EGF, EGFR expression in epithelium was significantly stronger in severe atypical hyperplasia of NIP than that in mild atypical hyperplasia of NIP (P < 0.01).

CONCLUSION

The results suggest that EGF, EGFR participate in the growth of NIPs, part of which shows the characteristics of containing plenty of blood vessels and being bloody in operation. The enhanted EGF, EGFR in the epithelium may be identified as one of the parameters of judging the propensity of NIPs malignant transformation.

[A study on apoptosis induced by As₂O₃ for small cell lung cancer]

BACKGROUND

To study apoptosis of small cell lung cancer (SCLC) cell induced by As₂O₃ and enhancement effect of interferon (IFN) on As₂O₃.

METHODS

DNA gel electrophoresis, terminal deoxynucleotidyl transferase nick end labeling (TUNEL) and immunocytochemistry were used to detect the apoptosis induced by As₂O₃ with different doses and time and the expression of Bcl-2 or PCNA.

RESULTS

Within certain extent of concentration, As₂O₃ could induce apoptosis of SCLC cells. And apoptotic cells increased and expression of Bcl 2 and PCNA decreased with time prolonged or dose increased. The apoptosis inducing effect of As₂O₃ combined with IFN was much higher than that of As₂O₃ alone.

CONCLUSIONS

As₂O₃ may induce apoptosis of SCLC cells and the efficiency of apoptosis is related to dose and time. IFNα-2b might enhance the effect of apoptosis on SCLC induced by As₂O₃.

A randomized clinical trial of 4-hydroxyphenylretinamide for high-grade squamous intraepithelial lesions of the cervix

PURPOSE

Previous trials of topical trans-retinoic acid treatment of cervical intraepithelial neoplasia (CIN) grades 2 and 3 led to a statistically significant regression of CIN 2, but not CIN 3. We tested N-(4-hydroxyphenyl)retinamide (4-HPR), a promising oral retinoid that has been shown to induce apoptosis through nonretinoic receptor acid-mediated pathways, for its toxicity and efficacy against CIN 2/3.

EXPERIMENTAL DESIGN

In a blinded randomized trial, 4-HPR at 200 mg/day for 6 months (with a 3-day/month drug holiday) was compared with placebo in patients with biopsy-proven CIN-2/3 [high-grade squamous intraepithelial lesions (HGSILs)]. Patients were treated with placebo or 4-HPR for 6 months, biopsied, and then followed for an additional 6 months. At the 12-month end point, they underwent either loop excision if a histological lesion was present or a biopsy from the original area of the lesion if no lesion was present.

RESULTS

An interim analysis of blinded data showed a significantly worse prognosis at 12 months for one group. When the code was broken because of the poorer outcomes, we discovered that the 4-HPR treatment arm was performing more poorly than was the placebo at 6 and 12 months (25 versus 44% response rates at 6 months; 14 versus 50% at 12 months). Toxicity was not significant in either arm.

CONCLUSIONS

4-HPR at 200 mg/day with a 3-day/month drug holiday is not active compared with placebo in the treatment of HGSIL. Because 4-HPR is active in the laboratory, the lack of effect in our trial may indicate that higher doses are needed in patients to achieve comparable results.

Effects of novel phenylretinamides on cell growth and apoptosis in bladder cancer

Superficial bladder cancer is a major target for chemoprevention. Retinoids are important modulators of epithelial differentiation and proliferation and are effective in the treatment and prevention of several epithelial cancers. One class of compounds, the retinamides, is structurally similar to other retinoids but have the added feature of being potent apoptosis inducers. Among these, fenretinide (N-[4-hydroxyphenyl]retinamide), or 4HPR, has promise for bladder cancer chemoprevention and is currently under Phase III study in this setting. In addition to 4HPR, there are several new structurally related phenylretinamides bearing hydroxyl, carboxyl, or methoxyl residues on carbons 2, 3, and 4 of the terminal phenylamine ring [designated N-(2-hydroxyphenyl)retinamide, N-(3-hydroxyphenyl)retin amide, N-(2-carboxyphenyl)retin- amide, N-(3-carboxyphenyl)retin amide, N-(4-carboxy- phenyl)retinamide, and N-(4-methoxyphenyl)retinamide, respectively]. The objective of this study was to compare the growth inhibitory and apoptotic effects of these phenylretinamides with 4HPR in human bladder transitional cell cancer-derived cell lines of varying histological grade (RT4, grade 1; UM-UC9 and UM-UC10, grade 3; and UM-UC14, grade 4) by cell counting, cell cycle fluorescence-activated cell sorter analysis and a dual stain apoptosis assay. All of the seven phenylretinamides reduced cell number, altered the cell cycle distribution, and induced apoptosis when administered at a concentration of 10 microM, which is within the pharmacologically achievable range. Although the relative potencies of the phenylretinamides varied depending on the cell line, N-(3-hydroxy phenyl)retin- amide was the most active with significantly greater growth inhibition than 4HPR in all of the four cell lines. These in vitro findings warrant further study of these novel phenylretinamides, which may have potential as preventive or therapeutic agents in transitional cell cancer.

Identification of effective retinoids for inhibiting growth and inducing apoptosis in bladder cancer cells

PURPOSE

Retinoids modulate the growth and differentiation of normal and malignant epithelial cells in vitro and in vivo, and inhibit bladder carcinogenesis in animal models. Retinoid analogs have been used in several clinical chemoprevention trials of superficial bladder cancer recurrence. There is a clear need to identify new effective retinoids and develop novel approaches for the chemoprevention and treatment of superficial bladder cancer. We investigated the effects of various retinoids on growth inhibition and apoptosis induction in bladder cancer cell lines.

MATERIALS AND METHODS

Ten grades 1 to 3 bladder cancer cell lines and the 4 retinoids all-trans-retinoic acid, 9-cis retinoic acid, 4-(N-hydroxyphenyl) retinamide (4HPR) and LGD1069 were used in the study. We compared the ability of these retinoids to inhibit growth, induce apoptosis, affect the expression of nuclear retinoid receptors and modulate apoptosis related genes.

RESULTS

Most bladder cancer cell lines did not express retinoic acid receptor beta and were resistant to the effect of all-trans-retinoic acid and 9-cis retinoic acid on growth inhibition and apoptosis induction, even at a concentration of 10(-5) M. The 2 cell lines that expressed retinoic acid receptor beta were constitutively sensitive to the growth inhibitory effect of all-trans-retinoic acid. 4HPR inhibited cell growth by about 90% in all but 1 cell line and induced apoptosis at a concentration of 10(-5) M after a 24-hour treatment. LGD1069 had virtually no effect. All-trans-retinoic acid and 4HPR induced retinoic acid receptor beta expression in 1 bladder cancer cell line. However, the effect of 4HPR on cell growth and apoptosis were not related to the constitutive expression of retinoic acid receptor beta. 4HPR decreased bcl-2 expression in 6 of 8 bladder cancer cell lines but did not change p53 gene expression.

CONCLUSIONS

The results demonstrate that 4HPR is the most potent growth inhibitor and apoptosis inducer of the retinoids tested. Lack of retinoic acid receptor beta expression may be responsible for cell resistance to all-trans-retinoic acid but not to the other retinoids.

[Ecophysiological response of Pinus koraiensis seedlings to elevated CO2]

Studies on the ecophysiological response of Pinus koraiensis seedlings were conducted in open-top chambers which were controlled with CO2 concentration of about 500 and 700 mumol.mol-1. The result shows that there were different responses in net photosynthetic rate and stomatal conductance at high CO2(500 and 700 mumol.mol-1) and ambient CO2 concentrations. Under 500 mumol.mol-1 CO2, the carboxylase activity of RuBP was the highest, the photosynthesis showed "up-ward", the average daily net CO2 assimilation was the greatest, and the contents of chlorophyll and soluble sugars were the highest. While under 700 mumol.mol-1 CO2, the photosynthesis showed "down-ward" and was lower than that of the control, and the enzyme activity and the contents of substances were the lowest.

Expression of protein mediators of type I interferon signaling in human squamous cell carcinoma of the skin

IFN-based therapy has been shown to be active in the treatment of squamous cell carcinoma (SCC) of the skin and has promise for chemoprevention and treatment of several other cancers. In an effort to better understand the molecular mechanism of this activity, we have determined the expression pattern of several of the protein mediators of type I IFN signaling by immunohistochemistry in cutaneous SCC, SCC metastases, and adjacent nonmalignant epithelium from patient biopsies. All of the proteins, signal transducer and activator of transcription (STAT) 1alpha/beta, STAT2, p48, STAT3a, and STAT3beta, are expressed at varying levels in the adjacent epidermis, as well as in other epidermal and dermal cell types. For the majority of samples tested, the expression of one or more of these proteins was reduced in SCC primary tumors compared with the adjacent nonmalignant epithelial cells, as determined by manual scoring. Quantitative densitometry of several samples revealed differences that are statistically significant. Our study provides the first direct evidence for the expression of the IFN-stimulated gene factor 3 (STAT1alpha/beta, STAT2, and p48) and STAT3alpha and STAT3beta mediators of IFN-alpha/beta signaling in human skin and skin-derived SCCs. These data have led to the hypothesis that the loss of IFN sensitivity may contribute to the development and progression of skin SCC.

Inhibition of Fas-mediated apoptosis by Trypanosoma cruzi infection

Trypanosoma cruzi-infected and normal control mammalian cells were subjected to analysis of Fas-mediated apoptosis stimulated by an agonistic anti-Fas monoclonal antibody. The infected cells showed markedly hampered apoptotic changes in nuclear morphology, phosphatidylethanolamine translocation from the inside to the outside of the plasma membrane, and DNA fragmentation into multiples of 180 bp, relative to normal control cells. Upstream of these morphological and biochemical consequences, the caspase-3 activity was elevated by the Fas stimulation in a significantly greater proportion of intact control cells, but at a highly reduced rate of infected cells. The rapid elevation of caspase-8 activity in control, apoptotic cells was completely inhibited in infected cells. In an examination of the specificity of other stimulants, X-ray radiation or chemicals such as hydrogen peroxide, colchicine or etoposide did not cause significant differences in apoptotic rates between control and infected cells; tumor necrosis factor-alpha, however, induced a high rate of apoptosis in control cells, with an extremely lowered rate in infected cells. This study demonstrates, for the first time, that T. cruzi infection inhibits one of the earliest steps of death receptor-mediated apoptosis, an effect that most probably involves the inhibition of caspase-8. Differential apoptotic responses in cells infected with T. cruzi and other intracellular parasites are discussed.

Differential expression of egr-1 in osteoarthritic compared to normal adult human articular cartilage

OBJECTIVE

The purpose of this study was to identify genes that are differentially expressed in normal versus osteoarthritic human articular cartilage as either potential novel therapeutic targets or diagnostic markers of this disease.

DESIGN

mRNA was isolated from histologically normal and osteoarthritic adult human articular cartilage. The Differential Display technique was employed which identified differentially expressed genes in the normal and diseased tissue. Northern and reverse Northern hybridization were used to confirm the gene expression pattern. Immunohistochemistry and in-situ hybridization were used to localize expression of Egr-1 protein and mRNA respectively in cartilage.

RESULTS

A transcription factor, early growth response protein-1 (Egr-1) was found to be down-regulated more than six-fold in multiple human OA cartilage samples when compared to normal tissue. Immunohistochemistry indicated that Egr-1 was expressed throughout normal adult cartilage, in deep-, mid- and superficial-zones. In contrast, in OA cartilage there was expression of Egr-1 mRNA and protein only in the chondrocytes undergoing cloning.

CONCLUSIONS

Egr-1 is differentially expressed in OA versus normal cartilage and because of its role in transcriptional activation and repression and regulation of proliferation, differentiation and apoptosis, Egr-1 may play an important role in the pathogenesis of OA. Up-regulation of Egr-1 may therefore provide a novel therapeutic approach for either the prevention or treatment of OA.

CT via percutaneous splenoportography: experiment and application

OBJECTIVE

To introduce computed tomography via percutaneous splenoportography (CTSP), a new method for determining hepatic diseases.

METHODS

Ten hybrid dogs and 31 patients with primary hepatic cancer (PHC) were included in the study. Each dog was examined by CT, computed tomography via arterial portography (CTAP), and CTSP to compare the enhanced density of the liver. The 31 patients were examined by CTSP and the appearance of PHC was compared with their pathological results to evaluate the diagnostic significance of CTSP.

RESULTS

The animal experiment showed that both CTAP and CTSP could obviously enhance the density of the liver (P < 0.01), but no significant difference was observed in the enhanced densities between the two methods (P > 0.05). On the CTSP images of the 31 patients, the density of the livers was increased to 168-192 Hu, whereas the density of the cancers was as low as that on the images of CT scans (< 58 Hu). The CTSP findings were consistent with the surgical ones from space occupying lesions. The diagnostic value of CTSP was obviously superior to that of general enhanced CT. However, it was difficult for CTSP to show nodules less than 1 cm in size located on the surface of the liver or the hepatic portal zone.

CONCLUSIONS

Like CTAP, CTSP is also a sensitive method for showing occupant in the liver. But the equipments and the procedures are simpler for CTSP than for CTAP. CTSP is an alternative procedure in clinical practice.

[Clinical study on relationship of blood stasis syndrome with plasma endothelin and nitric oxide changes in acute pancreatitis patients]

OBJECTIVE

To study the relationship of blood stasis Syndrome with plasma endothelin (ET) and nitric oxide (NO) in acute pancreatitis patients.

METHODS

A healthy control group and three groups of patients with three different Syndromes of TCM were established. Patients' ET and NO were determined by radioimmunoassay and reversed-phase high performance liquid chromatography respectively before and after treatment. The NO level was represented by the sum of NO2 and NO3.

RESULTS

ET and ET/NO ratio were not changed significantly in patients with Liver-Spleen Qi Stagnant Syndrome, but increased significantly in patients with Liver-Spleen Damp-Heat Syndrome or with Spleen Stomach excessive Heat Syndrome (P < 0.05 or P < 0.01).

CONCLUSION

ET and ET/NO ratio might be the important objective markers of the existence of blood stasis Syndrome in acute pancreatitis patients.

The first immunoglobulin-like domain of HveC is sufficient to bind herpes simplex virus gD with full affinity, while the third domain is involved in oligomerization of HveC

The human herpesvirus entry mediator C (HveC/PRR1) is a member of the immunoglobulin family used as a cellular receptor by the alphaherpesviruses herpes simplex virus (HSV), pseudorabies virus, and bovine herpesvirus type 1. We previously demonstrated direct binding of the purified HveC ectodomain to purified HSV type 1 (HSV-1) and HSV-2 glycoprotein D (gD). Here, using a baculovirus expression system, we constructed and purified truncated forms of the receptor containing one [HveC(143t)], two [HveC(245t)], or all three immunoglobulin-like domains [HveC(346t)] of the extracellular region. All three constructs were equally able to compete with HveC(346t) for gD binding. The variable domain bound to virions and blocked HSV infection as well as HveC(346t). Thus, all of the binding to the receptor occurs within the first immunoglobulin-like domain, or V-domain, of HveC. These data confirm and extend those of Cocchi et al. (F. Cocchi, M. Lopez, L. Menotti, M. Aoubala, P. Dubreuil, and G. Campadelli-Fiume, Proc. Natl. Acad. Sci. USA 95:15700, 1998). Using biosensor analysis, we measured the affinity of binding of gD from HSV strains KOS and rid1 to two forms of HveC. Soluble gDs from the KOS strain of HSV-1 had the same affinity for HveC(346t) and HveC(143t). The mutant gD(rid1t) had an increased affinity for HveC(346t) and HveC(143t) due to a faster rate of complex formation. Interestingly, we found that HveC(346t) was a tetramer in solution, whereas HveC(143t) and HveC(245t) formed dimers, suggesting a role for the third immunoglobulin-like domain of HveC in oligomerization. In addition, the stoichiometry between gD and HveC appeared to be influenced by the level of HveC oligomerization.