Systematic review with meta-analysis: the association between human papillomavirus infection and oesophageal cancer

BACKGROUND

Human papillomavirus (HPV) infection might be one of the potential risk factors for oesophageal cancer. However, the previous epidemiological findings were heterogeneous.

AIM

To explore the association between HPV infection and oesophageal cancer risk by means of meta-analysis.

METHODS

Studies on HPV infection and oesophageal cancer were identified, the prevalence of HPV infection and its association with oesophageal cancer risk were quantitatively summarised by meta-analysis.

RESULTS

A total of 8990 oesophageal squamous cell carcinoma (SCC) patients and 174 oesophageal adenocarcinomas patients were evaluated from 76 included studies. Summarised HPV prevalence in oesophageal SCC was 22.2% [95% confidence interval (CI), 18.3-26.7%], HPV-16 was the most frequently observed subtype with a summarised prevalence of 11.4% (95% CI: 8.2-15.7%). With respect to oesophageal adenocarcinoma, HPV prevalence was 35.0% (95% CI, 13.2-65.7%) and HPV-16 prevalence was 11.4% (95% CI: 8.2-15.7%). Due to the limited number of included studies on oesophageal adenocarcinoma, association analyses were performed to oesophageal SCC only. Significant association was observed between HPV infection and oesophageal SCC with a summarised odds ratio of 3.32 (95% CI, 2.26-4.87). According to HPV-16, the strength of the association was found to be 3.52 (95% CI, 2.04-6.07).

CONCLUSIONS

Human papillomavirus infection was observed to be associated with an increased risk of oesophageal SCC in this meta-analysis. However, due to the evident heterogeneity observed between the included studies and the strength of the association not as strong as observed for cervical cancer and laryngeal cancer, further studies are needed to clarify the relation and its underlying mechanisms.

The Bionanoprobe: hard X-ray fluorescence nanoprobe with cryogenic capabilities

Hard X-ray fluorescence microscopy is one of the most sensitive techniques for performing trace elemental analysis of biological samples such as whole cells and tissues. Conventional sample preparation methods usually involve dehydration, which removes cellular water and may consequently cause structural collapse, or invasive processes such as embedding. Radiation-induced artifacts may also become an issue, particularly as the spatial resolution increases beyond the sub-micrometer scale. To allow imaging under hydrated conditions, close to the `natural state', as well as to reduce structural radiation damage, the Bionanoprobe (BNP) has been developed, a hard X-ray fluorescence nanoprobe with cryogenic sample environment and cryo transfer capabilities, dedicated to studying trace elements in frozen-hydrated biological systems. The BNP is installed at an undulator beamline at sector 21 of the Advanced Photon Source. It provides a spatial resolution of 30 nm for two-dimensional fluorescence imaging. In this first demonstration the instrument design and motion control principles are described, the instrument performance is quantified, and the first results obtained with the BNP on frozen-hydrated whole cells are reported.

Development and characterization of new microsatellites for walnut (Juglans regia)

The expressed sequence tag (EST) database represents a potentially valuable resource for the development of simple sequence repeat (SSR) markers for use in evolutionary studies. EST-SSRs reveal polymorphisms not only within the source taxon, but in related taxa as well. In this paper, we describe a case study in which the publicly available walnut (Juglans regia) EST database was used to develop SSR markers for use in the genetic analysis of the widespread Juglans nigra and Carya cathayensis and an endangered species Annamocarya sinensis. A total of 7262 unigenes, including 1911 contigs and 5351 singletons, were obtained from 13,559 ESTs retrieved from the NCBI database. The 7262 unigenes were further reduced to 706 EST-SSR sequences containing 805 SSR loci. Then, 309 EST-SSR primers were randomly designed, and 77 were identified with five high across-species transferability cross-species: namely, J. regia, J. nigra, C. cathayensis, Carya dabieshanensis, and A. sinensis. Thirteen highly polymorphic EST-SSRs were further used for genetic analyses in these above five species.

A suppository for treating cervical erosion and its preparation method

OBJECTIVE

To study a suppository for treating cervical erosion, its preparation method, and to observe its therapeutic effect on cervical erosion in animal models.

METHODS

Twenty rats were divided into five groups: blank control group, model group, and three different therapeutic concentration groups. Phenol slurry was injected through the vagina to create cervical erosion animal models. After seven days of drug treatment, the difference of cervical histopathology was observed and compared between different groups.

RESULTS

Compared with the control group, the model group showed obvious cervical erosion, inflammatory cell infiltration, vascular dilatation, and congestion. Among the administration group, the high administration group had the least inflammation and cell infiltration in the mucous membrane.

CONCLUSIONS

There is a significant effect of therapeutic drugs in rats with cervical erosion, which is related to the concentration of drugs.

Inhibitory activities of baicalin against renin and angiotensin-converting enzyme

CONTEXT

Baicalin has been characterized as the active compound and quality control marker in Scutellaria baicalensis Georgi, traditionally used as a hypotensive herb.

OBJECTIVES

To investigate the inhibitory activities of baicalin against renin and angiotensin-I converting enzyme (ACE) and their molecule mechanism of interactions.

METHODS

The fluorescence method using renin substrate 1(R-2932) and the spectroscopy method by Cushman were used to determine renin and ACE activities, respectively. The fluorescence quench techniques were used to characterize their interactions.

RESULTS

The results showed that baicalin inhibited renin activity with an IC(50) value of 120.36 µM and inhibited ACE activity with an IC(50) value of 2.24 mM in vitro. The fluorescence emission of both renin and ACE were efficiently quenched by baicalin and a complete quenching was achieved at a high concentration of baicalin. Furthermore, baicalin was more effective in quenching the fluorescence of renin (K(SV) = 60 × 10(3) M(-1)) than ACE (K(SV) = 17.1 × 10(3) M(-1)). The quenching of fluorescence of renin and ACE involved static interactions, which was characterized by the formation of quencher-enzyme complex. The baicalin-renin complex formed through three-sites binding including the active site with a binding constant of 796.15 × 10(13) M(-1), but there was only one binding site for the baicalin-ACE complex with a much smaller binding constant of 6.8 × 10(5) M(-1).

CONCLUSION

The inhibition activity of baicalin against renin was a result of the formation of stable complex through multisites binding including the active site, which could explain the higher inhibitory efficiency.

IL28B genetic variants and gender are associated with spontaneous clearance of hepatitis C virus infection

Single nucleotide polymorphisms (SNPs) near the IL28B gene have been shown to be associated with response to treatment for chronic hepatitis C and also with spontaneous clearance of hepatitis C virus (HCV) infection. We analysed the association between IL28B genetic variants and spontaneous clearance of HCV infection in 376 HCV-infected Chinese paid plasma donors. Genotyping of eight SNPs near the IL28B region was performed by the iPLEX system (MassARRAY(®) SNP Genotyping; Sequenom) in all donors, and sequencing was performed on all 80 donors who cleared HCV and on 160 of 296 donors who did not clear HCV to validate the genotypes. Eighty (21.3%) donors spontaneously cleared HCV. Four SNPs were significantly associated with spontaneous HCV clearance: rs8099917 TT (vs GT), rs8105790 TT (vs CT), rs12980275 AA (vs AG) and rs10853728 CC (vs CG or GG) with OR (95% CI) 15.27 (2.07-112.50), 14.88 (2.02-109.72), 7.92 (1.88-33.32) and 2.32 (1.22-4.42) respectively. No association between the other four IL28B SNPs including rs12979860 and spontaneous HCV clearance was found. Women had a higher rate of spontaneous HCV clearance than men [56/213 (26.3%) vs 24/163 (14.6%), P = 0.007], and this was true even after stratification for IL28B genotypes with OR of 1.9-2.2 among those with favourable genotypes. Our results confirmed that IL28B polymorphism is associated with spontaneous clearance of HCV in Chinese subjects, but the SNPs that predict HCV clearance in Chinese subjects were different from those reported in Caucasians. Women were more likely to clear HCV infection regardless of IL28B genotypes.

LIM domain protein-3 (LMP3) cooperates with BMP7 to promote tissue regeneration by ligament progenitor cells

Gene transfer of key regulators of osteogenesis for mesenchymal stem cells represents a promising strategy to regenerate bone. It has been reported that LMP3, a transcription variant of LIM domain mineralization protein (LMP) lacking LIM domains, can induce osteogenesis in vitro and in vivo. As little is known about the effects of LMP3 gene therapy on periodontal ligament (PDL) cell osteogenic differentiation, this study sought to explore whether gene delivery of LMP3 can promote PDL cell mineralization and bone formation. Our results showed that adenoviral mediated gene transfer of LMP3 (AdLMP3) significantly upregulated ALP (Alkaline Phosphatase), BSP (Bone Sialoprotein) and BMP2 gene expression and increased in vitro matrix mineralization in human PDL. Although AdLMP3 gene delivery to PDL cells did not induce ectopic bone formation in vivo, we found that AdLMP3 augments new bone formation, which co-delivered with AdBMP7 gene transfer. Our study provides the evidence that there is a synergistic effect between LMP3 and BMP-7 in vivo, suggesting that LMP3 delivery may be used to augment BMP-mediated osteogenesis. LMP3 and BMP-7 combinatory gene therapy may also have specific applications for oral and periodontal regenerative medicine.

P2-01-14: High Level of CD44 Expression and Soluble CD44 Secretion Mediate Trastuzumab Resistance in HER2 Positive Breast Cancer

Background: Overexpression of HER2 occurs in 15–25% of invasive breast cancer. Trastuzumab, a humanized monoclonal antibody targeting the extracellular domain of HER2, markedly improves disease-free and overall survival in patients with HER2−positive breast cancer. However, resistance to trastuzumab develops in most patients with HER2−overexpressing metastatic breast cancer. Breast cancer stem cells have been shown to express HER2, although its role in the development or maintenance of stem cells is not well characterized. CD44 is one of the proposed markers for breast cancer stem cells. We investigated the role of CD44 in acquired trastuzumab resistance in HER2 positive breast cancer.

Methods: CD44 mRNA expression was measured by quantitative real-time PCR. The proportion of CD44 positive cells was measured by fluorescence-activated cell sorting (FACS). Soluble CD44 level was detected by enzyme-linked immunosorbent assay (ELISA). In vitro tumorigenicity was evaluated by soft agar colony formation assay. Cell invasion was tested by using a matrigel invasion assay. In vivo tumor growth was evaluated using a mammary fat pad xenograft mouse model.

Results: CD44 mRNA expression, CD44 positive cell population by FACS, and CD44 secretion were significantly increased in both SKBR3 derived trastuzumab resistant SKBR3 clone 3 and BT474 derived trastuzumab resistant HR20 cells compared to parental, trastuzumab sensitive cells. Consistent with the increase in CD44, trastuzumab resistant cells showed an increase in soft agar colony formation and cell invasion, which were blocked by siRNA-induced downregulation of CD44 expression. Tumor growth and incidence were enhanced in mice injected with trastuzumab resistant HR20 cells compared to the mice injected with trastuzumab sensitive parental BT474 cells. Knock-down of CD44 expression by the transfection with CD44-specific siRNA suppressed in vivo tumor growth in the mice injected with trastuzumab resistant HR20 cells. Finally, we found high serum CD44 levels correlated with advanced tumor progression in HER2 positive breast cancer.

Conclusion: Our findings indicate that high levels of CD44 mediate trastuzumab resistance in HER2 positive breast cancer cells as well as tumor progression in mice. Circulating CD44 is prognostic in patients with HER2 positive breast cancer. CD44 may be a therapeutic target for HER2 positive breast cancer.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-01-14.

S2-7: Mechanisms of Action and Biological Significance of HER2 Mutations in HER2−Overexpressing Breast Cancer

Background: Trastuzumab is the most successful HER2−directed therapy in patients with early-stage and advanced HER2 positive breast cancer. Although trastuzumab improves survival in the adjuvant setting, 15–20% of the patients develop metastasis. Lapatinib is currently the only tyrosine kinase inhibitor approved for the treatment of patients with metastatic breast cancer after trastuzumab progression. However, progression eventually occurs and the disease remains incurable for the majority of patients. Recently, somatic mutations in the HER2 kinase domain have been reported in lung adenocarcinomas which result in constitutive phosphorylation of HER2, EGFR and cellular substrates. Activation of these receptors and pathways in lung cancer was associated with tumor progression and trastuzumab resistance, but tumors remained sensitive to a tyrosine kinase inhibitor. Because there are many different types of breast cancer that respond differently to treatments, more approaches are needed to predict which patients will most likely respond to a given therapy.

Material and Methods: Using gene sequencing on 78 HER2 positive breast tumors, our laboratory identified 4 novel missense variants in the kinase domain of HER2. None of the patients whose tumors carried one of these mutations achieved objective response to trastuzumab. Mutants were created using directed mutagenesis, inserted in a lentiviral expression plasmid and stably expressed in different breast cancer or non-tumorigenic cell lines. An ATP-based assay was used for cell survival studies. Migration studies were performed using Boyden-chambers coated with Matrigel. Anchorage-independent colony formation was assessed in soft-agar. Signaling pathways and phosphorylation status were analyzed by Western blot. Localization results were obtained by immunofluorescence and confocal microscopy followed by deconvolution analysis.

Results: Two of the mutants were dramatically under-phosphorylated and presented an altered cellular localization revealed by immunofluorescence studies in both cell lines and patient surgical samples. Also, cells expressing HER2 mutants showed an increased ability to invade Matrigel and migrate and to form colonies in soft-agar, suggesting the induction of a more aggressive behavior. In particular, one of the mutations was strongly associated with resistance to lapatinib treatment in cell survival and soft-agar assays, and higher doses of lapatinib were necessary to inhibit the ERK and AKT pathways. Computational analysis revealed that the mechanism of lapatinib resistance could be explained by a sterical obstruction of the ATP-binding pocket of the protein kinase domain that would impede the binding of lapatinib.

Conclusion: HER2 mutations confer a more aggressive phenotype. A specific mutation directly interacts with Lapatinib binding to HER2 and predicts resistance to Lapatinib in HER2−overexpressing breast cancer cells. Further characterization of novel HER2 mutations may have a direct implication in the development of novel markers for early diagnostics, patient selection and characterization of more appropriate and personalized treatment.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr S2-7.

Direct pathogen detection from swab samples using a new high-throughput sequencing technology

The detection of emerging infectious diseases has been a continuing concern, especially with the novel influenza A (H1N1) viral pandemic of 2009. In the present study, we validated a ‘second-generation’ parallel sequencing platform for viral detection in swab samples collected during recent influenza virus infections in Beijing. This operation yielded millions of valid reads per sample and resulted in an almost complete spectrum of nucleotide information. Importantly, novel A (H1N1) and seasonal A (H3N2) influenza virus-derived sequences were detected without prior knowledge or use of genetic information in advance, suggesting that this approach could be a valuable tool for diagnosing emerging infectious diseases.

Association of polymorphisms of the <i>DCN</i> gene with growth traits in cattle (Brief Report)

Abstract. Mammalian decorin (DCN) consists of a protein core and a single dermatan or chondroitin sulfate glycosaminoglycan chain (CHOPRA et al. 1985), contributing multifunctionally to processes like matrix assembly, modulation of the activity of growth factors and cell migration and proliferation. Recently, LINDA et al. (2008) have reported that eight SNPs were identified in human. However, the related information in bovine is scarce. Hence, in the present experiment the exons and intron/exon boundaries of DCN were scanned for SNPs in the predominant cattle breeds of China.

Vitamin D receptor genetic polymorphisms and tuberculosis: updated systematic review and meta-analysis

BACKGROUND

Host genetic susceptibility has been suggested as one of the most important explanations for inter-individual differences in tuberculosis (TB) risk. The vitamin D receptor (VDR) gene has been studied as a candidate locus due to genetic polymorphisms that affects the activity of the receptor and subsequent downstream vitamin D-mediated effects.

METHODS

We reviewed published studies on VDR polymorphisms and TB susceptibility up to 15 April 2009 and quantitatively summarised associations of the most widely studied polymorphisms (FokI, TaqI, ApaI and BsmI) using meta-analysis.

RESULTS

A total of 23 eligible studies were included in this review. Heterogeneous results were observed, which may be partly explained by the differences between populations. Among Asians, the FokI ff genotype showed a pronounced positive association (OR 2.0, 95%CI 1.3-3.2), a significant inverse association was observed for the BsmI bb genotype (OR 0.5, 95%CI 0.4-0.8), and marginal significant associations were found for TaqI and ApaI polymorphisms. However, none of the polymorphisms was significantly related to TB among Africans or South Americans.

CONCLUSIONS

The association of VDR polymorphisms with risk of TB observed in our analyses supports the hypothesis that vitamin D deficiency might play a role as risk factor during the development of TB.

PDGF-B gene therapy accelerates bone engineering and oral implant osseointegration

Platelet-derived growth factor-BB (PDGF-BB) stimulates repair of healing-impaired chronic wounds such as diabetic ulcers and periodontal lesions. However, limitations in predictability of tissue regeneration occur due in part to transient growth factor bioavailability in vivo. Here, we report that gene delivery of PDGF-B stimulates repair of oral implant extraction socket defects. Alveolar ridge defects were created in rats and were treated at the time of titanium implant installation with a collagen matrix containing an adenoviral (Ad) vector encoding PDGF-B (5.5×10⁸ or 5.5×10⁹ pfu/ml), Ad encoding luciferase (Ad-Luc; 5.5×10⁹ pfu/ml; control) or recombinant human PDGF-BB protein (rhPDGF-BB, 0.3 mg/ml). Bone repair and osseointegration were measured via backscattered SEM, histomorphometry, microcomputed tomography, and biomechanical assessments. Further, a panel of local and systemic safety assessments was performed. Results demonstrated bone repair was accelerated by Ad-PDGF-B and rhPDGF-BB delivery compared to Ad-Luc, with the high dose of Ad-PDGF-B more effective than the low dose. No significant dissemination of the vector construct or alteration of systemic parameters was noted. In summary, gene delivery of Ad-PDGF-B demonstrates regenerative and safety capabilities for bone tissue engineering and osseointegration in alveolar bone defects comparable to rhPDGF-BB protein delivery in vivo.

Prevalence of human respiratory viruses in adults with acute respiratory tract infections in Beijing, 2005-2007

To determine the aetiological role and epidemiological profile of common respiratory viruses in adults with acute respiratory tract infections (ARTIs), a 2-year study was conducted in Beijing, China, from May 2005 to July 2007. Nose and throat swab samples from 5808 ARTI patients were analysed by PCR methods for common respiratory viruses, including influenza viruses (IFVs) A, B, and C, parainfluenza viruses (PIVs) 1-4, enteroviruses (EVs), human rhinoviruses (HRVs), respiratory syncytial virus (RSV), human metapneumovirus (HMPV), human coronaviruses (HCoVs) OC43, 229E, NL63, and HKU1, and adenoviruses (ADVs). Viral pathogens were detected in 34.6% of patient samples, and 1.6% of the patients tested positive for more than one virus. IFVs (19.3%) were the dominant agents detected, followed by HRVs (6.5%), PIVs (4.3%), EVs (3.2%), and HCoVs (1.1%). ADVs, RSV and HMPV were also detected (<1%). The viral detection rates differed significantly between infections of the lower and upper respiratory tracts in the sample population: PIVs, the second most commonly detected viral agents in lower acute respiratory tract infections (LRTIs), were more prevalent than in upper acute respiratory tract infections, indicating that the pathogenic role of PIVs in LRTIs should be investigated. Currently, this study is the largest-scale investigation of respiratory virus infections in China with multiple agent detection, providing baseline data for further studies of respiratory virus infections in adults with ARTIs.

Meta-analysis: prevalence of HIV infection and syphilis among MSM in China

OBJECTIVES

The prevalence of HIV/AIDS and other sexually transmitted diseases is rapidly rising among men who have sex with men (MSM) in China. The aim is to systematically review the published studies and summarise the estimates of HIV prevalence among MSM in China.

METHODS

Published articles, both in English and in Chinese, on HIV prevalence among MSM in China until 15 September 2008 were systematically reviewed. Meta-analysis was used to quantitatively summarise the estimates, and the prevalence of syphilis presented in the included studies was also analysed.

RESULTS

Twenty-six eligible studies, published during 2001-2008, were included in this review. Their results were frequently heterogeneous. The meta-analyses showed that MSM form a high-risk population for HIV infection in China with a summary prevalence of 2.5% (95% CI 0.9% to 3.3%). A much higher prevalence of syphilis (9.1%) may indicate a potential of more severe HIV epidemic in the future because of their common high-risk behaviours.

CONCLUSIONS

MSM are a high-risk population for HIV infection in China. An effective strategy for prevention and control is required for this specific population. Differences between sampling methods, sample sizes and study locations may explain some of the inconsistencies found in the included studies.

Platelet-derived growth factor-B gene delivery sustains gingival fibroblast signal transduction

BACKGROUND AND OBJECTIVE

Platelet-derived growth factor-BB is a potent mediator of tooth-supporting periodontal tissue repair and regeneration. A limitation of the effects of topical platelet-derived growth factor-BB application is its short half-life in vivo. Gene therapy has shown strong promise for the long-term delivery of platelet-derived growth factor in both skin ulcer healing and periodontal tissue engineering. However, little is known regarding the extended effects of platelet-derived growth factor-B on cell signaling via gene delivery, especially at the level of phosphorylation of intracellular kinases. This study sought to evaluate the effect of gene transfer by Ad-PDGF-B on human gingival fibroblasts (HGFs) and the subsequent regulation of genes and cell-surface proteins associated with cellular signaling.

MATERIAL AND METHODS

HGFs from human subjects were treated by adenoviral PDGF-B, PDGF-1308 (a dominant negative mutant of PDGF) and recombinant human platelet-derived growth factor-BB, and then incubated in serum-free conditions for various time points and harvested at 1, 6, 12, 24, 48, 72 and 96 h. Exogenous PDGF-B was measured by RT-PCR and Western blot. Cell proliferation was evaluated by [methyl-3H]thymidine incorporation assay. We used proteomic arrays to explore phosphorylation patterns of 23 different intracellular kinases after PDGF-B gene transfer. The expression of alpha and beta PDGFR and Akt were measured by Western blot analysis.

RESULTS

Sustained in vitro expression of PDGF-B in HGFs by Ad-PDGF-B transduction was seen at both the mRNA and protein levels. Compared to rhPDGF-BB and Ad-PDGF-1308, Ad-PDGF-B maintained cell growth in serum-free conditions, with robust increases in DNA synthesis. Gene delivery of PDGF-B also prolonged downregulation of the growth arrest specific gene (gas) PDGF alpha R. Of the 23 intracellular kinases that we tested in proteomic arrays, Akt revealed the most notable long-term cell signaling effect as a result of the over-expression of Ad-PDGF-B, compared with pulse recombinant human platelet-derived growth factor BB. Prolonged Akt phosphorylation was induced by treatment with Ad-PDGF-B, for at least up to 96 h.

CONCLUSION

These findings further demonstrate that gene delivery of PDGF-B displays sustained signal transduction effects in human gingival fibroblasts that are higher than those conveyed by treatment with recombinant human platelet-derived growth factor-BB protein. These data on platelet-derived growth factor gene delivery contribute to an improved understanding of these pathways that are likely to play a role in the control of clinical outcomes of periodontal regenerative therapy.