Construction of a Human Immune Library from Gallbladder Cancer Patients for the Single-Chain Fragment Variable (scFv) Antibody Selection against Claudin 18.2 via Phage Display

Gallbladder cancer (GBC) is a very aggressive malignant neoplasm of the biliary tract with a poor prognosis. There are no specific therapies for the treatment of GBC or early diagnosis tools; for this reason, the development of strategies and technologies that facilitate or allow an early diagnosis of GBC continues to be decisive. Phage display is a robust technique used for the production of monoclonal antibodies (mAbs) involving (1) the generation of gene libraries, (2) the screening and selection of isoforms related to an immobilized antigen, and (3) the in vitro maturation of the affinity of the antibody for the antigen. This research aimed to construct a human immune library from PBMCs of GBC patients and the isolation of scFv-phage clones with specificity against the larger extracellular loop belonging to claudin 18.2, which is an important biomarker overexpressed in GBC as well as gastric cancer. The immune-library-denominated GALLBLA1 was constructed from seven GBC patients and has a diversity of 6.12 × 1010pfu mL-1. After three rounds of panning, we were able to identify clones with specificity against claudin 18.2. GALLBLA1 can contribute to the selection, isolation, and recombinant production of new human mAbs candidates for the treatment of gastrointestinal cancers.

Advances towards the use of gastrointestinal tumor patient-derived organoids as a therapeutic decision-making tool

In December 2022 the US Food and Drug Administration (FDA) removed the requirement that drugs in development must undergo animal testing before clinical evaluation, a declaration that now demands the establishment and verification of ex vivo preclinical models that closely represent tumor complexity and that can predict therapeutic response. Fortunately, the emergence of patient-derived organoid (PDOs) culture has enabled the ex vivo mimicking of the pathophysiology of human tumors with the reassembly of tissue-specific features. These features include histopathological variability, molecular expression profiles, genetic and cellular heterogeneity of parental tissue, and furthermore growing evidence suggests the ability to predict patient therapeutic response. Concentrating on the highly lethal and heterogeneous gastrointestinal (GI) tumors, herein we present the state-of-the-art and the current methodology of PDOs. We highlight the potential additions, improvements and testing required to allow the ex vivo of study the tumor microenvironment, as well as offering commentary on the predictive value of clinical response to treatments such as chemotherapy and immunotherapy.

Therapeutic Targets of Monoclonal Antibodies Used in the Treatment of Cancer: Current and Emerging

Cancer is one of the leading global causes of death and disease, and treatment options are constantly evolving. In this sense, the use of monoclonal antibodies (mAbs) in immunotherapy has been considered a fundamental aspect of modern cancer therapy. In order to avoid collateral damage, it is indispensable to identify specific molecular targets or biomarkers of therapy and/or diagnosis (theragnostic) when designing an appropriate immunotherapeutic regimen for any type of cancer. Furthermore, it is important to understand the currently employed mAbs in immunotherapy and their mechanisms of action in combating cancer. To achieve this, a comprehensive understanding of the biology of cancer cell antigens, domains, and functions is necessary, including both those presently utilized and those emerging as potential targets for the design of new mAbs in cancer treatment. This review aims to provide a description of the therapeutic targets utilized in cancer immunotherapy over the past 5 years, as well as emerging targets that hold promise as potential therapeutic options in the application of mAbs for immunotherapy. Additionally, the review explores the mechanisms of actin of the currently employed mAbs in immunotherapy.

A Novel Gemcitabine-Resistant Gallbladder Cancer Model Provides Insights into Molecular Changes Occurring during Acquired Resistance

Treatment options for advanced gallbladder cancer (GBC) are scarce and usually rely on cytotoxic chemotherapy, but the effectiveness of any regimen is limited and recurrence rates are high. Here, we investigated the molecular mechanisms of acquired resistance in GBC through the development and characterization of two gemcitabine-resistant GBC cell sublines (NOZ GemR and TGBC1 GemR). Morphological changes, cross-resistance, and migratory/invasive capabilities were evaluated. Then, microarray-based transcriptome profiling and quantitative SILAC-based phosphotyrosine proteomic analyses were performed to identify biological processes and signaling pathways dysregulated in gemcitabine-resistant GBC cells. The transcriptome profiling of parental and gemcitabine-resistant cells revealed the dysregulation of protein-coding genes that promote the enrichment of biological processes such as epithelial-to-mesenchymal transition and drug metabolism. On the other hand, the phosphoproteomics analysis of NOZ GemR identified aberrantly dysregulated signaling pathways in resistant cells as well as active kinases, such as ABL1, PDGFRA, and LYN, which could be novel therapeutic targets in GBC. Accordingly, NOZ GemR showed increased sensitivity toward the multikinase inhibitor dasatinib compared to parental cells. Our study describes transcriptome changes and altered signaling pathways occurring in gemcitabine-resistant GBC cells, which greatly expands our understanding of the underlying mechanisms of acquired drug resistance in GBC.

Professionals undergoing fitness-to-practise proceedings in the UK and the effects on their mental health: a narrative review

Introduction

Approximately 2% of health and social care professionals undergo fitness-to-practise proceedings through the UK professional regulatory system. Very little research has been carried out in this area even though it is increasingly being recognised that the mental health of registrants (including pharmacists, nurses, doctors and social workers) can be adversely affected by the process.

Aim

This review aims to address this gap through scoping the current literature on fitness-to-practise proceedings and regulation processes on four health and social care professional groups in the UK.

Methods

We performed a narrative review of the literature published between 2000 and 2021. A total of 1839 abstracts were initially identified (following PRISMA). After screening these abstracts, 412 full papers were obtained. Further screening resulted in a total of 32 studies included in this review. The following information was extracted from each included study: overall design and methods employed, population characteristics and key findings, and following the application of critical appraisal checklists potential limitations were noted. Ethical approval was obtained through Bournemouth University’s Research Ethics Panel (reference 16302).

Results

Of the 32 research studies we identified, 30 were single profession (for example 1, 2, 3), five explored the prevalence and nature of misconduct, six investigated the registrant characteristics and factors that are associated with an increased risk of appearing before a fitness-to-practise committee, nine examined the effectiveness of regulation, 10 tentatively assessed the impact of complaints and regulatory investigations on the welfare of registrants. Only two studies were multi-professional. Studies employed both quantitative and qualitative research methods to investigate the subject of regulation including: postal questionnaires (N=6), structured and semi-structured interviews- face-to-face and telephone (N=11), focus groups (N=3), case and document analysis (N=16), multivariable regression analysis (N=1) and, topic analysis (N=1). Mixed methods approach was followed by four studies. Most of the studies reported outcomes related to one or more of nine fitness-to-practise aspects of research interest including: complaints, gender, ethnicity, length of service, practice setting, nature of misdemeanours, attendance at hearing, legal representation and regulator fitness-to-practise decisions. These aspects are relevant to the registrant experience of the fitness-to-practise proceedings and ultimately the effectiveness of health and social care professional regulation. Opportunities for workforce development are limited by a narrow, legalistic accusatorial regulatory system that pharmacy and other care professionals are subject to.

Discussion/Conclusion

There is little understanding of the impact of UK Statutory Regulatory Bodies’ fitness-to-practise procedures upon pharmacy and other care professionals who go through the system. Empirical research related to the emotional and psychological effects on care professionals is sparse. To date, no research has been undertaken in relation to the impact of de-registration on health and social care professionals.

References

1. Hanna A, Hanna L-A. Topic Analysis of UK Fitness to Practise Cases: What Lessons Can Be Learnt? Pharmacy [online] 2019;7:e130.

2. Phipps D, Noyce P, Parker D, et al. Pharmacists subjected to disciplinary action: Characteristics and risk factors. Int J Pharm Pract 2011;19(5):367-373.

3. Tullett J, Rutter P, Brown D. A longitudinal study of United Kingdom pharmacists' misdemeanors- trials, tribulations and trends. Pharm World Sci 2003;25(2):43-51.

Characterization of microbial communities from gut microbiota of hypercholesterolemic and control subjects

Introduction

In recent years, several studies have evidenced the importance of the microbiome to host physiology as metabolism regulator, along with its potential role in triggering various diseases. In this study, we analyzed the gut microbiota in hypercholesterolemic (cases) and normocholesterolemic (controls) individuals to identify characteristic microbial signature for each condition.

Methods

Stool samples were obtained from 57 adult volunteers (27 hypercholesterolemic and 30 controls). The taxonomic profiling of microbial communities was performed using high-throughput sequencing of 16S rRNA V3-V4 amplicons, followed by data analysis using Quantitative Insights Into Microbial Ecology 2 (QIIME2) and linear discriminant analysis (LDA) effect size (LEfSe).

Results

Significant differences were observed in weight, height, body mass index (BMI) and serum levels of triglycerides, total cholesterol and low-density lipoprotein cholesterol (LDL-C) between the groups (p<0.05). LEfSe showed differentially abundant prokaryotic taxa (α=0.05, LDA score > 2.0) in the group of hypercholesterolemic individuals (Methanosphaera, Rothia, Chromatiales, Clostridiales, Bacillaceae and Coriobacteriaceae) and controls (Faecalibacterium, Victivallis and Selenomonas) at various taxonomic levels. In addition, through the application of Phylogenetic Investigation of Communities by Reconstruction of Unobserved States 2 (PICRUSt2), the predominance of pathways related to biosynthesis in hypercholesterolemic patients was established, compared to controls in which degradation pathways were predominant. Finally, in the analysis of co-occurrence networks, it was possible to identify associations between the microorganisms present in both studied groups.

Conclusion

Our results point out to unique microbial signatures, which likely play a role on the cholesterol metabolism in the studied population.

Controlled Release of Caffeic Acid and Pinocembrin by Use of nPSi-βCD Composites Improves Their Antiangiogenic Activity

Although polyphenols have great pharmacological potential, the main disadvantage is that they have low bioavailability at the desired site. Thus, the use of biocompatible systems for drug delivery is a strategy that is currently gaining great interest. The objective of this study is to evaluate the effect of microencapsulation of caffeic acid and pinocembrin on the antioxidant and antiangiogenic activity of both polyphenols, by the use of nPSi-βCD composite microparticles. For this HUVEC, cells were exposed to H₂O₂ and to treatments with polyphenols in solution and loaded in the composite microparticle. The polyphenols were incorporated into a microparticle using nanoporous silicon, chitosan and a β-cyclodextrin polymer as the biomaterial. The evaluation of the antiangiogenic effect of the treatments with polyphenols in solution and microencapsulated was carried out through functional tests, and the changes in the expression of target genes associated with the antioxidant pathway and angiogenesis was performed through qPCR. The results obtained show that the caffeic acid and pinocembrin have an antioxidant and antiangiogenic activity, both in solution as microencapsulated. In the caffeic acid, a greater biological effect was observed when it was incorporated into the nPSi-βCD composite microparticle. Our results suggest that the nPSi-βCD composite microparticle could be used as an alternative oral drug administration system.

Functional and genomic characterization of three novel cell lines derived from a metastatic gallbladder cancer tumor

Background

Gallbladder cancer (GBC) is the most common tumor of the biliary tract. The incidence of GBC shows a large geographic variability, being particularly frequent in Native American populations. In Chile, GBC represents the second cause of cancer-related death among women. We describe here the establishment of three novel cell lines derived from the ascitic fluid of a Chilean GBC patient, who presented 46% European, 36% Mapuche, 12% Aymara and 6% African ancestry.

Results

After immunocytochemical staining of the primary cell culture, we isolated and comprehensively characterized three independent clones (PUC-GBC1, PUC-GBC2 and PUC-GBC3) by short tandem repeat DNA profiling and RNA sequencing as well as karyotype, doubling time, chemosensitivity, in vitro migration capability and in vivo tumorigenicity assay. Primary culture cells showed high expression of CK7, CK19, CA 19-9, MUC1 and MUC16, and negative expression of mesothelial markers. The three isolated clones displayed an epithelial phenotype and an abnormal structure and number of chromosomes. RNA sequencing confirmed the increased expression of cytokeratin and mucin genes, and also of TP53 and ERBB2 with some differences among the three cells lines, and revealed a novel exonic mutation in NF1. The PUC-GBC3 clone was the most aggressive according to histopathological features and the tumorigenic capacity in NSG mice.

Conclusions

The first cell lines established from a Chilean GBC patient represent a new model for studying GBC in patients of Native American descent.

Hippo-YAP1 Is a Prognosis Marker and Potentially Targetable Pathway in Advanced Gallbladder Cancer

Gallbladder cancer is an aggressive disease with late diagnosis and no efficacious treatment. The Hippo-Yes-associated protein 1 (YAP1) signaling pathway has emerged as a target for the development of new therapeutic interventions in cancers. However, the role of the Hippo-targeted therapy has not been addressed in advanced gallbladder cancer (GBC). This study aimed to evaluate the expression of the major Hippo pathway components mammalian Ste20-like protein kinase 1 (MST1), YAP1 and transcriptional coactivator with PDZ-binding motif (TAZ) and examined the effects of Verteporfin (VP), a small molecular inhibitor of YAP1-TEA domain transcription factor (TEAD) protein interaction, in metastatic GBC cell lines and patient-derived organoids (PDOs). Immunohistochemical analysis revealed that advanced GBC patients had high nuclear expression of YAP1. High nuclear expression of YAP1 was associated with poor survival in GBC patients with subserosal invasion (pT2). Additionally, advanced GBC cases showed reduced expression of MST1 compared to chronic cholecystitis. Both VP treatment and YAP1 siRNA inhibited the migration ability in GBC cell lines. Interestingly, gemcitabine resistant PDOs with high nuclear expression of YAP1 were sensitive to VP treatment. Taken together, our results suggest that key components of the Hippo-YAP1 signaling pathway are dysregulated in advanced gallbladder cancer and reveal that the inhibition YAP1 may be a candidate for targeted therapy.

The Anti-Proliferative and Anti-Invasive Effect of Leaf Extracts of Blueberry Plants Treated with Methyl Jasmonate on Human Gastric Cancer In Vitro Is Related to Their Antioxidant Properties

Gastric cancer is the third main cause of cancerous tumors in humans in Chile. It is well-accepted that a diet rich in antioxidant plants could help in fighting cancer. Blueberry is a fruit crop with a high content of antioxidants. Methyl jasmonate (MeJA) is a phytohormone involved in plant defenses under stress conditions. The exogenous application of MeJA can improve the antioxidant properties in plants. We studied in vitro and in vivo anticancer action on human gastric cancer (cell line AGS) and the antioxidant properties of extracts from blueberry plants untreated and treated with MeJA. The results demonstrated that leaf extracts displayed a higher inhibition of cancer cell viability as well as greater antioxidant properties compared to fruit extracts. Besides, MeJA applications to plants improved the antioxidant properties of leaf extracts (mainly anthocyanins), increasing their inhibition levels on cell viability and migration. It is noteworthy that leaf extract from MeJA-treated plants significantly decreased cancer cell migration and expression of gastric cancer-related proteins, mainly related to the mitogen-activating protein kinase (MAPK) pathway. Interestingly, in all cases the anticancer and antioxidant properties of leaf extracts were strongly related. Despite highlighted outcomes, in vivo results did not indicate significant differences in Helicobacter pylori colonization nor inflammation levels in Mongolian gerbils unfed and fed with blueberry leaf extract. Our findings demonstrated that MeJA increased antioxidant compounds, mainly anthocyanins, and decreased the viability and migration capacity of AGS cells. In addition, leaf extracts from MeJA-treated plants were also able to decrease the expression of gastric cancer-related proteins. Our outcomes also revealed that the anthocyanin-rich fraction of blueberry leaf extracts showed higher in vitro antiproliferative and anti-invasive effects than the crude leaf extracts. However, it is still uncertain whether the leaf extracts rich in anthocyanins of blueberry plants are capable of exerting a chemopreventive or chemoprotective effect against gastric cancer on an in vivo model.

Mucin 5B, carbonic anhydrase 9 and claudin 18 are potential theranostic markers of gallbladder carcinoma

AIMS

Gallbladder cancer (GBC) is an aggressive tumour that is usually diagnosed at advanced stages and is characterised by a poor prognosis. Using public data of normal human tissues, we found that mRNA and protein levels of mucin 5B (MUC5B) and carbonic anhydrase 9 (CA9) were highly increased in gallbladder tissues. In addition, previous evidence has shown that claudin 18 (CLDN18) protein expression is higher in GBC. The aim of this study was to perform an analysis of these cell surface proteins during the histological progression of GBC in order to identify their theranostic potential.

METHODS AND RESULTS

MUC5B expression, CA9 expression and CLDN18 expression were examined by immunohistochemistry in a series of 179 chronic cholecystitis (including 16 metaplastic tissues), 15 dysplasia and 217 GBC samples by the use of tissue microarray analysis. A composite staining score was calculated from staining intensity and percentage of positive cells. Immunohistochemical analysis showed high expression of MUC5B and CA9 among normal epithelium, metaplastic tissues, and dysplastic tissues. However, expression of both proteins was observed in roughly 50% of GBC samples. In contrast, CLDN18 was absent in normal epithelium, but its expression was higher in metaplastic cells. Among GBC cases, approximately half showed high CLDN18 expression. No associations were found between MUC5B, CA9 and CLDN18 expression and any clinicopathological features.

CONCLUSIONS

CLDN18 is a new metaplasia marker in gallbladder tissues, and is conserved in approximately half of GBC cases. MUC5B and CA9 are highly conserved during GBC histological progression. The three markers are potential theranostic markers, in particular CA9 and CLDN18, for which there are already targeted therapies available.

Ion chambers compliance results of Brazilian radiation therapy facilities

The Brazilian Nuclear Energy Commission (cnen) has been making a constant effort to keep up to date with international standards and national needs to strengthen the status of radiological protection of the country. The guidelines related to radiation therapy facilities have been revised in the last five years in order to take into consideration the most relevant aspects of the growing technology as well as to mitigate the accidents or incidents observed in practice. Hence, clinical dosimeters have gained special importance in this matter. In the present work, we discuss the effectiveness of regulation and inspections to the enforcement of instrument calibration accuracy for the improvement of patient dosimetry and quality control. As a result, we observed that the number of calibrated instruments, mainly well chambers, is increasing each year. The same behavior is observed for instruments employed in technologically advanced radiation treatments such as intensity modulated radiotherapy, volumetric therapy and stereotatic radiosurgery. We ascribe this behavior to the new regulation.

Rapamycin and WYE-354 suppress human gallbladder cancer xenografts in mice

Gallbladder cancer (GBC) is a highly malignant tumor characterized by a poor response to chemotherapy and radiotherapy. We evaluated the in vitro and in vivo antitumor efficacy of mTOR inhibitors, rapamycin and WYE-354. In vitro assays showed WYE-354 significantly reduced cell viability, migration and invasion and phospho-P70S6K expression in GBC cells. Mice harboring subcutaneous gallbladder tumors, treated with WYE-354 or rapamycin, exhibited a significant reduction in tumor mass. A short-term treatment with a higher dose of WYE-354 decreased the tumor size by 68.6% and 52.4%, in mice harboring G-415 or TGBC-2TKB tumors, respectively, compared to the control group. By contrast, treatment with a prolonged-low-dose regime of rapamycin almost abrogated tumor growth, exhibiting 92.7% and 97.1% reduction in tumor size, respectively, compared to control mice. These results were accompanied by a greater decrease in the phosphorylation status of P70S6K and a lower cell proliferation Ki67 index, compared to WYE-354 treated mice, suggesting a more effective mTOR pathway inhibition. These findings provide a proof of concept for the use of rapamycin or WYE-354 as potentially good candidates to be studied in clinical trials in GBC patients.

Abstract 4267: Establishment and biological characterization of a Chilean ascites-derived gallbladder cancer cell line

Gallbladder cancer is the most common biliary tract cancer. Globally, it is considered as a rare malignancy but shows a high incidence in certain geographic areas, such as Eastern and South Asia, Eastern Europe and Latin America. In Chile, this aggressive neoplasia is the second leading cause of cancer death among women, with a mortality rate of 15 deaths per 100.000 women, only slightly lower than breast cancer. Most patients with gallbladder cancer are diagnosed at advanced stages and the prognosis still remains low, even using the most current diagnostic techniques. Tumor biology of gallbladder cancer is still poorly understood and there are no therapeutic options to improve the prognosis of patients with advanced gallbladder cancer. The establishment of cell lines for their use as in vitro models is essential for the study of tumor biology and drug susceptibility. The aim of this study was to characterize and compare the malignant properties of three gallbladder cancer clones isolated from ascites-derived primary culture cells. Tumor cells were isolated from the ascites of an advanced gallbladder cancer patient using a previously established protocol. The primary culture cells were characterized to determine their epithelial origin by using immunohistochemical markers. Due to the heterogeneous nature of these cells, individual clones were isolated from them and maintained in culture until their establishment as immortal cell lines (less than 20 passages). Finally, three clones were obtained and evaluated in order to characterize and compare their malignant properties, determining their growth rate, chemosensitivity to gemcitabine, cisplatin and 5-fluoracil, migration capability and the in vivo tumorigenesis induction. The ascites-derived primary culture cells showed high expression of epithelial and tumor markers (Cytokeratin 7 and 19, CA 19-9, CA 125, CA 15-3) and negative expression of mesothelial markers (calretinin and mesothelin). Individual clones (clone 1, 2 and 3) derived from the primary culture showed differences from each other. The calculated doubling time was 60h for Clone 1, 35h for Clone 2, and 28h for Clone 3. All three clones were equally sensible to gemcitabine, cisplatin and 5-Fluoracil, compared to other established gallbladder cancer cell lines. Clone 5 exhibited the greater migration potential and Clone 6 resulted to have the most tumorigenic capability, although all were able to form xenograft tumors before 2 weeks. Conclusions: To our knowledge, these are the first gallbladder cancer cell lines established from a Chilean patient and they may provide a useful tool for the study of gallbladder cancer biology and for in vitro and in vivo analysis aimed at identification of new potential therapeutic targets. Research supported by FONDECYT 11130515, 1151008, 1130204, 3140426 and 3140308.

Citation Format: Javier Retamal, Carolina Bizama, Jaime Espinoza, Lorena Rosa, Francisca Alfaro, Diego Romero, María José Apud, Bruno Nervi, Pamela Leal, Helga Weber, Juan Carlos Roa, Patricia García. Establishment and biological characterization of a Chilean ascites-derived gallbladder cancer cell line. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4267.

Abstract 2274: Deregulated Hippo pathway is a potential therapeutic target for advanced gallbladder cancer

Gallbladder cancer (GBC) is lethal and aggressive disease characterized by late diagnosis, poor prognosis and lack of effective therapeutic options. An excellent candidate for targeting therapy in cancer is the Hippo signaling pathway that has been reported to be deregulated in different types of cancer and recently has emerged as a master regulator that plays a critical role in multiple processes such as tumorigenesis, apoptosis, tumor stem cell phenotype, drug cell resistance and metastatic potential. However, little is known about the status of the Hippo kinase pathway in human GBC. The aim of this study is determinate the Hippo pathway activity in GBC and evaluate the potential therapeutic role of YAP1 siRNA and the pharmacological inhibitor Verteporfin, a small molecule that inhibit TEAD-YAP interaction. Immunohistochemistry was used to analyze the expression of YAP1 and Survivin, a major downstream effector and transcriptional target gene of Hippo signaling pathway, in tissue microarray containing 198 advanced GBC samples. Then, we performed an exploratory analysis of Hippo pathway activity by qRT- PCR in advanced GBC and cholecystitis samples. The levels of expression of the Hippo core kinase proteins in GBC cell lines was studied by western blot and the inhibition of YAP1 was performed thought specific siRNA and Verteporfin. Immunohistochemistry showed high nuclear expression of YAP1 in vast majority of advanced GBC, which is correlated significantly with nuclear Survivin expression. The 5-year survival rates of patients with survivin-positive cancer were significantly lower compared with survivin-negative cancer patients (p&lt;0.05, Log-rank test). The gene expression analysis showed a significant down-regulation of the Hippo kinase core suppressor genes STK3 (MST2), STK4 (MST1), SAV1, LATS2 and up-regulation of GPCR5A and BIRC5 in GBC tissues compared with cholecystitis. In addition, western blot analysis show high levels of nuclear YAP1 in 4 GBC cells and its expression were associated with a reduction in the phosphorylation status of LATS1 and MOB. Our findings indicate that targeting YAP1 with siRNA reduced mRNA and protein levels of this oncogene in almost 80% and inhibited the clonogenic capacity of GBC cell lines. Otherwise, the in vitro pharmacological inhibition of YAP1 with Verterporfin reduces YAP1 protein in a dose-dependent manner and was associated with down-regulation of survivin. Our results showed that the Hippo- pathway is deregulated in advanced GBC and mediates its oncogenic effects through of attenuation of their suppressor core components, nuclear translocation of YAP1 and up-regulation of survivin expression. Targeting YAP1 by siRNA and Verteporfin leads to inactivation of YAP1 and survivin affecting cancer cell survival capacity. Targeting the Hippo/YAP has the potential to provide a novel strategy for GBC therapy. Research supported by FONDECYT 3140426, 1130204, 11130515, 3140308.

Citation Format: Carolina Bizama, Patricia García, Jaime A Espinoza, Nicole Elgueta, Ismael Riquelme, Francisca Alfaro, Diego Romero, Helga Weber, Pamela Leal, Javier Retamal, Lorena Rosa, Juan Carlos Roa. Deregulated Hippo pathway is a potential therapeutic target for advanced gallbladder cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2274.

The Gene Expression Status of the PI3K/AKT/mTOR Pathway in Gastric Cancer Tissues and Cell Lines

The PI3K/AKT/mTOR pathway plays a crucial role in the regulation of multiple cellular functions including cell growth, proliferation, metabolism and angiogenesis. Emerging evidence has shown that deregulation of this pathway has a role promoting gastric cancer (GC). The aim was to assess the expression of genes involved in this pathway by qPCR in 23 tumor and 23 non-tumor gastric mucosa samples from advanced GC patients, and in AGS, MKN28 and MKN45 gastric cancer cell lines. Results showed a slight overexpression of PIK3CA, PIK3CB, AKT1, MTOR, RPS6KB1, EIF4EBP1 and EIF4E genes, and a slightly decreased PTEN and TSC1 expression. In AGS, MKN28 and MKN45 cells a significant gene overexpression of PIK3CA, PIK3CB, AKT1, MTOR, RPS6KB1 and EIF4E, and a significant repression of PTEN gene expression were observed. Immunoblotting showed that PI3K-β, AKT, p-AKT, PTEN, mTOR, p-mTOR, P70S6K1, p-P70S6K1, 4E-BP1, p-4E-BP1, eIF4E and p-eIF4E proteins were present in cell lines at different levels, confirming activation of this pathway in vitro. This is the first time this extensive panel of 9 genes within PI3K/AKT/mTOR pathway has been studied in GC to clarify the biological role of this pathway in GC and develop new strategies for this malignancy.

Molecular Cytotoxic Mechanisms of 1-(3,4,5-Trihydroxyphenyl)-dodecylbenzoate in Human Leukemia Cell Lines

Recent studies have shown that gallic acid and its alkylesters induce apoptosis in different cell lines. Since new compounds with biological activity and less cytotoxicity to normal cells are necessary for cancer therapy, the aim of this study was to evaluate the cytotoxic effect of 1-(3,4,5-trihydroxyphenyl)-dodecylbenzoate on human acute myeloid leukemia K562 cells and on human acute lymphoblastic leukemia Jurkat cells. The cell viability was determined by MTT method. The apoptosis induction was assessed by bromide and acridine orange staining and by Annexin V-FITC Apoptosis Detection kit. The cell cycle analysis was carried out by flow cytometry using propidium iodide. Cytometric analysis was also performed to evaluate the expression of the following proteins: AIF, p53, Bcl-2 and Bax. The mitochondrial potential was also assessed by flow cytometry using MitoView633 kit. The results showed that the compound significantly reduced the cell viability of K562 and Jurkat cells in a concentration and time dependent manner (IC50 of 30 μM). The compound induced cell cycle arrest in G0/G1phase and significantly increased the proportion of cells in the sub-G0/G1phase. Apoptosis was confirmed by the sight of morphological characteristics of apoptosis and by phosphatidylserine externalization (73.47±5.71% of cells expressing annexin). The results also showed that the compound promotes a modification in Bax:Bcl-2 ratio and increases p53 expression. Thus, it is possible to conclude that 1-(3,4,5-trihydroxyphenyl)-dodecylbenzoate induces apoptosis by inhibiting the antiapoptotic protein Bcl-2 and by increasing the release of AIF, Bax and p53. In addition, it blocks the cell cycle at G0/G1, stopping cell proliferation. So far, the results suggest that this compound may have a potential therapeutic effect against leukemia cells.

miR-101-2, miR-125b-2 and miR-451a act as potential tumor suppressors in gastric cancer through regulation of the PI3K/AKT/mTOR pathway

BACKGROUND

Gastric cancer (GC) is a deadly malignancy worldwide. In the past, it has been shown that cellular signaling pathway alterations play a crucial role in the development of GC. In particular, deregulation of the PI3K/AKT/mTOR pathway seems to affect multiple GC functions including growth, proliferation, metabolism, motility and angiogenesis. Targeting alterations in this pathway by microRNAs (miRNAs) represents a potential therapeutic strategy, especially in inhibitor-resistant tumors. The objective of this study was to evaluate the expression of 3 pre-selected miRNAs, miR-101-2, miR-125b-2 and miR-451a, in a series of primary GC tissues and matched non-GC tissues and in several GC-derived cell lines, and to subsequently evaluate the functional role of these miRNAs.

METHODS

Twenty-five primary GC samples, 25 matched non-GC samples and 3 GC-derived cell lines, i.e., AGS, MKN28 and MKN45, were included in this study. miRNA and target gene expression levels were assessed by quantitative RT-PCR and western blotting, respectively. Subsequently, cell viability, clone formation, cell death, migration and invasion assays were performed on AGS cells.

RESULTS

miR-101-2, miR-125b-2 and miR-451a were found to be down-regulated in the primary GC tissues and the GC-derived cell lines tested. MiRNA mimic transfections significantly reduced cell viability and colony formation, increased cell death and reduced cell migration and invasion in AGS cells. We also found that exogenous expression of miR-101-2, miR-125b-2 and miR-451a decreased the expression of their putative targets MTOR, PIK3CB and TSC1, respectively.

CONCLUSIONS

Our expression analyses and in vitro functional assays suggest that miR-101-2, miR-125b-2 and miR-451a act as potential tumor suppressors in primary GCs as well as in GC-derived AGS cells.

Targeting specific molecular pathways holds promise for advanced gallbladder cancer therapy

Gallbladder cancer is the most common and aggressive malignancy of the biliary tract. The complete surgical resection is the only potentially curative approach in early stage; however, most cases are diagnosed in advanced stages and the response to traditional chemotherapy and radiotherapy is extremely limited, with modest impact in overall survival. The recent progress in understanding the molecular alterations of gallbladder cancer has shown great promise for the development of more effective treatment strategies. This has mainly resulted from the identification of molecular alterations in relevant intracellular signaling pathways-Hedgehog, PI3K/AKT/mTOR, Notch, ErbB, MAPK and angiogenesis-which are potential tailored targets for gallbladder cancer patients. This review discusses the recent remarkable progress in understanding the molecular alterations that represent novel prognosis molecular markers and therapeutic targets for gallbladder cancer, which will provide opportunities for research and for developing innovative strategies that may enhance the benefit of conventional chemotherapy, or eventually modify the fatal natural history of this orphan disease.

The PI3K/AKT/mTOR pathway is activated in gastric cancer with potential prognostic and predictive significance

Signaling pathway alterations are important in the development of gastric cancer (GC). Deregulation of the PI3K/AKT/mTOR pathway plays a crucial role in the regulation of multiple cellular functions including cell growth, proliferation, metabolism, and angiogenesis. Our goal was to assess expression of proteins involved in the PI3K/AKT/mTOR pathway by immunohistochemistry (IHC) in tumor and nontumor gastric mucosa from patients with advanced GC. We evaluated 71 tumor and 71 nontumor gastric mucosa samples from advanced GC patients, selected from Hernán Henríquez Aravena Hospital (Temuco, Chile). The targets studied were PI3K, AKT, p-AKT, PTEN, mTOR, p-mTOR, P70S6K1, p-P70S6K1, 4E-BP1, p-4E-BP1, eIF4E, and p-eIF4E. Expression data were correlated with clinicomorphological data. Descriptive and analytical statistics were used (95 % confidence interval, p < 0.05). For survival analyses, the Kaplan-Meier method and the log-rank test were used. PI3K, AKT, p-AKT, p-mTOR, p-4E-BP1, P70S6K1, p-P70S6K1, eIF-4E, and p-eIF-4E proteins were significantly overexpressed in tumor tissue. Conversely, PTEN was underexpressed in tumor tissue, notably in pT3-pT4 tumors (p = 0.02) and tumors with lymph node metastases (p < 0.001). P70S6K1 expression was associated with pT3-pT4 tumors (p = 0.03). Moreover, PI3K (p = 0.004), AKT (p = 0.01), p-AKT (p = 0.01), P70S6K1 (p = 0.04), p-P70S6K1 (p = 0.001), and eIF-4E (p = 0.004) were overexpressed in tumors with lymph node metastases. Low expression of 4E-BP1 was associated with poor overall survival (p = 0.03). Our results suggest that the PI3K/AKT/mTOR pathway is activated in GC, with overexpression in tumor tissue of most of the studied proteins (total and phosphorylated). These might be considered as target for specific targeted therapy in GC.

miR-1 and miR-145 act as tumor suppressor microRNAs in gallbladder cancer

The development of miRNA-based therapeutics represents a new strategy in cancer treatment. The objectives of this study were to evaluate the differential expression of microRNAs in gallbladder cancer (GBC) and to assess the functional role of miR-1 and miR-145 in GBC cell behavior. A profile of miRNA expression was determined using DharmaconTM microarray technology. Differential expression of five microRNAs was validated by TaqMan reverse transcription quantitative-PCR in a separate cohort of 8 tumors and 3 non-cancerous samples. Then, we explored the functional role of miR-1 and miR-145 in tumor cell behavior by ectopic in vitro expression in the GBC NOZ cell line. Several miRNAs were found to be aberrantly expressed in GBC; most of these showed a significantly decreased expression compared to non-neoplastic tissues (Q value<0.05). The differential expression of 7 selected miRNAs was confirmed by real time PCR. Pathway enrichment analysis revealed that the most deregulated miRNAs (miR-1, miR-133, miR-143 and miR-145) collectively targeted a number of genes belonging to signaling pathways such as TGF-β, ErbB3, WNT and VEGF, and those regulating cell motility or adhesion. The ectopic expression of miR-1 and miR-145 in NOZ cells significantly inhibited cell viability and colony formation (P<0.01) and reduced gene expression of VEGF-A and AXL. This study represents the first investigation of the miRNA expression profile in gallbladder cancer, and our findings showed that several miRNAs are deregulated in this neoplasm. In vitro functional assays suggest that miR-1 and miR-145 act as tumor suppressor microRNAs in GBC.

Identification of prosaposin and transgelin as potential biomarkers for gallbladder cancer using quantitative proteomics

Gallbladder cancer is an uncommon but lethal malignancy with particularly high incidence in Chile, India, Japan and China. There is a paucity of unbiased large-scale studies investigating molecular basis of gallbladder cancer. To systematically identify differentially regulated proteins in gallbladder cancer, iTRAQ-based quantitative proteomics of gallbladder cancer was carried out using Fourier transform high resolution mass spectrometry. Of the 2575 proteins identified, proteins upregulated in gallbladder cancer included several lysosomal proteins such as prosaposin, cathepsin Z and cathepsin H. Downregulated proteins included serine protease HTRA1 and transgelin, which have been reported to be downregulated in several other cancers. Novel biomarker candidates including prosaposin and transgelin were validated to be upregulated and downregulated, respectively, in gallbladder cancer using tissue microarrays. Our study provides the first large scale proteomic characterization of gallbladder cancer which will serve as a resource for future discovery of biomarkers for gallbladder cancer.

mTOR/P70S6K signaling pathway as a potential target for advanced gallbladder cancer therapy

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Background: Gallbladder cancer (GBC) is a highly malignant tumor usually diagnosed at advanced stages and characterized by a poor prognosis. Effective therapeutic strategies are urgently needed to improve the prognosis of GBC patients. Our objective was to analyze the expression of mTOR/p70S6K pathway in primary tumors and GBC cell lines, and to evaluate the effect of mTOR inhibitors in in vitro and in vivo models of GBC. Methods: The expression of mTOR/p70S6K signaling pathway components was examined by immunohistochemistry in primary tumors and chronic cholecystitis (CC), and by Western blot in eight GBC cell lines. The in vitro effect of mTOR inhibitors (LY294002, Rapamycin, Everolimus and AZD8055) on cell viability and migration was assessed by MTS and Transwell chamber assays. The therapeutic effect of Rapamycin was evaluated in subcutaneous tumor models (NOD/SCID mice). Treatment started when tumor volumes had reached 100mm3. Animals (G-415 and TGBC-2TKB xenografts) were randomly divided (n=5 per group) and treated with Polietilenglicol solution as vehicle and 10mg/kg of Rapamycin, daily IP injection (5 days/week for 3 weeks). Mice were sacrificed 30 days after treatment and tumors were dissected and measured. Tumor volume was calculated as π/6 × (large diameter) × (small diameter)2. Results: Our findings indicate that mTOR/p70S6K pathway is frequently activated in GBC (>60% of tumors showed high expression of phospho-mTOR and phospho-p70S6K, compared to CC). GBC patients whose tumors overexpressed phospho-mTOR had a poorer prognosis (p=0.02). G-415 and TGBC-2TKB cells showed a constitutive activation of this pathway and the treatment with different mTOR inhibitors significantly reduced their viability and migration capacity (p<0.001). In subcutaneous tumor models, treatment with Rapamycin significantly reduced the weight and tumor volume compared with the control group (p<0.001). Conclusions: mTOR/p70S6K signaling pathway is frequently activated in gallbladder cancer tissues and cells lines, which suggest that this pathway is a potential therapeutic target for the treatment of advanced GBC, using Rapamycin or other specific inhibitors. Supported by FONDECYT 1090171 and DIUFRO DI11-0039.

Genome-wide methylation profiling reveals Zinc finger protein 516 (ZNF516) and FK-506-binding protein 6 (FKBP6) promoters frequently methylated in cervical neoplasia, associated with HPV status and ethnicity in a Chilean population

Cervical cancer is a major health concern among women in Latin America due to its high incidence and mortality. Therefore, the discovery of molecular markers for cervical cancer screening and triage is imperative. The aim of this study was to use a genome wide DNA methylation approach to identify novel methylation biomarkers in cervical cancer. DNA from normal cervical mucosa and cervical cancer tissue samples from Chile was enriched with Methylated DNA Immunoprecipitation (MeDIP), hybridized to oligonucleotide methylation microarrays and analyzed with a stringent bioinformatics pipeline to identify differentially methylated regions (DMRs) as candidate biomarkers. Quantitative Methylation Specific PCR (qMSP) was used to study promoter methylation of candidate DMRs in clinical samples from two independent cohorts. HPV detection and genotyping were performed by Reverse Line Blot analysis. Bioinformatics analysis revealed GGTLA4, FKBP6, ZNF516, SAP130, and INTS1 to be differentially methylated in cancer and normal tissues in the Discovery cohort. In the Validation cohort FKBP6 promoter methylation had 73% sensitivity and 80% specificity (AUC = 0.80). ZNF516 promoter methylation was the best biomarker, with both sensitivity and specificity of 90% (AUC = 0.92), results subsequently corroborated in a Prevalence cohort. Together, ZNF516 and FKBP6 exhibited a sensitivity of 84% and specificity of 81%, when considering both cohorts. Our genome wide DNA methylation assessment approach (MeDIP-chip) successfully identified novel biomarkers that differentiate between cervical cancer and normal samples, after adjusting for age and HPV status. These biomarkers need to be further explored in case-control and prospective cohorts to validate them as cervical cancer biomarkers.

AKT/mTOR substrate P70S6K is frequently phosphorylated in gallbladder cancer tissue and cell lines

Background

Gallbladder carcinoma is a highly malignant tumor and a public health problem in some parts of the world. It is characterized by a poor prognosis and its resistance to radio and chemotherapy. There is an urgent need to develop novel therapeutic alternatives for the treatment of gallbladder carcinoma. The mammalian target of the rapamycin (mTOR) signaling pathway is activated in about 50% of human malignancies, and its role in gallbladder carcinoma has previously been suggested. In the present study, we investigated the phosphorylation status of the mTOR substrate p70S6K in preneoplastic and neoplastic gallbladder tissues and evaluated the effect of three mTOR inhibitors on cell growth and migration in gallbladder carcinoma cell lines.

Methods

Immunohistochemical staining of phospho-p70S6K was analyzed in 181 gallbladder carcinoma cases, classified according to lesion type as dysplasia, early carcinoma, or advanced carcinoma. Protein expression of AKT/mTOR members was also evaluated in eight gallbladder carcinoma cell lines by Western blot analysis. We selected two gallbladder carcinoma cell lines (G415 and TGBC-2TKB) to evaluate the effect of rapamycin, RAD001, and AZD8055 on cell viability, cell migration, and protein expression.

Results

Our results showed that phospho-p70S6K is highly expressed in dysplasia (66.7%, 12/18), early cancer (84.6%, 22/26), and advanced cancer (88.3%, 121/137). No statistical correlation was observed between phospho-p70S6K status and any clinical or pathological features, including age, gender, ethnicity, wall infiltration level, or histological differentiation (P < 0.05). In vitro treatment with rapamycin, RAD001, and AZD8055 reduced cell growth, cell migration, and phospho-p70S6K expression significantly in G-415 and TGBC-2TKB cancer cells (P < 0.001).

Conclusion

Our findings confirm the upregulation of this signaling pathway in gallbladder carcinoma and provide a rationale for the potential use of mTOR inhibitors as a therapeutic strategy for human gallbladder carcinoma.

Immunohistochemical expression of phospho-mTOR is associated with poor prognosis in patients with gallbladder adenocarcinoma

CONTEXT

Advanced gallbladder carcinoma (GBC) is a highly fatal disease with poor prognosis and few therapeutic alternatives. The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that plays a central role in cell growth and homeostasis. Its regulation is frequently altered in various tumors and is an attractive target for cancer therapy; however, its status in GBC remains unclear.

OBJECTIVE

To characterize immunohistochemical expression and prognostic significance of phospho-mTOR in advanced gallbladder carcinoma.

DESIGN

Phospho-mTOR expression was examined by immunohistochemistry in tissue microarrays containing 128 advanced GBCs and 99 cases of chronic cholecystitis, which were divided into 2 groups according to the presence or absence of metaplasia. To evaluate the association of the level of phospho-mTOR expression with clinical variables and patient survival, the advanced GBCs were classified as having low or high expression. Statistical analysis was performed by using a significance level of P < .05, and Kaplan-Meier curves were constructed for survival analysis.

RESULTS

Immunostaining for phospho-mTOR was positive in 82 of 128 tumors (64.1%) and in 24% of chronic cholecystitis cases (16% nonmetaplasia and 32% with metaplasia) (P < .001). Survival analysis indicated that a high phospho-mTOR immunohistochemical expression was associated with poorer prognosis in patients with advanced GBC (P = .02).

CONCLUSIONS

Metaplasia is a common finding in chronic cholecystitis and is considered a precursor lesion of dysplasia. Our results suggest that the activation of mTOR occurs very early during the development of GBC, contributing to the carcinogenesis process. Phospho-mTOR expression is correlated with poor survival, supporting the potential of mTOR for targeted therapy.

Inhibition of connective tissue growth factor (CTGF/CCN2) in gallbladder cancer cells leads to decreased growth in vitro

Gallbladder cancer (GBC) is an aggressive neoplasm associated with late diagnosis, unsatisfactory treatment and poor prognosis. Previous work showed that connective tissue growth factor (CTGF) expression is increased in this malignancy. This matricellular protein plays an important role in various cellular processes and its involvement in the tumorigenesis of several human cancers has been demonstrated. However, the precise function of CTGF expression in cancer cells is yet to be determined. The aim of this study was to evaluate the CTGF expression in gallbladder cancer cell lines, and its effect on cell viability, colony formation and in vitro cell migration. CTGF expression was evaluated in seven GBC cell lines by Western blot assay. Endogenous CTGF expression was downregulated by lentiviral shRNA directed against CTGF mRNA in G-415 cells, and the effects on cell viability, anchorage-independent growth and migration was assessed by comparing them to scrambled vector-transfected cells. Knockdown of CTGF resulted in significant reduction in cell viability, colony formation and anchorage-independent growth (P < 0.05). An increased p27 expression was observed in G-415 cells with loss of CTGF function. Our results suggest that high expression of this protein in gallbladder cancer may confer a growth advantage for neoplastic cells.

Abstract 3907: Expression of vascular endothelial growth factor a (VEGF-A) in advanced gallbladder cancer

Gallbladder cancer (GBC) is a highly fatal disease with poor prognosis and few therapeutic alternatives. Molecular mechanisms involved in GBC pathogenesis remain poorly understood. The Vascular Endothelial Growth Factor A (VEGF) is a potent proangiogenic agent involved in the carcinogenesis of many human tumors and it is an attractive target for cancer therapy. The aim of this study was characterize VEGF expression in advanced gallbladder cancer and determine it's relationships with clinicopathologic features and utility as a prognostic factor. VEGF expression was examined by immunohistochemistry (IHC) in tissue microarrays containing 224 advanced gallbladder carcinomas and 39 cases of chronic cholecystitis (CC). The advanced GBC were classified as low or high expression to evaluate the association of VEGF expression level with clinical variables. Statistical analysis was performed using univariate analyses with a significance level of P&lt;0.05; survival analysis was performed by the Kaplan- Meier method with the log-rank test. High expression of VEGF was observed in 183 of 224 (81%) tumors and 2 of 39 (5.1%) of chronic cholecystitis (P&lt;0.0001). The VEGF expression had a significant relationship with clinical or pathological features included histological grade and TNM stage (P&lt;0.05). Moreover, 5-year survival analysis indicated that high expression of VEGF is associated with a poor prognosis in patients with advanced gallbladder cancer (P = 0.0116). Our results indicate that VEGF is highly expressed in gallbladder cancer and correlates with poor prognostic, suggesting that VEGF expression could be used as a biomarker for predicting malignant behavior and to identify a subset of patients who may benefit from anti-VEGF therapies.

Citation Format: Pablo Letelier, Kurt Buchegger, Carmen Ili, Patricia Garcia, Priscilla Brevi, Alejandra Sandoval, Pamela Leal, Ismael Riquelme, Juan Carlos Roa. Expression of vascular endothelial growth factor a (VEGF-A) in advanced gallbladder cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3907. doi:10.1158/1538-7445.AM2013-3907

Abstract 2956: c-FLIP (L) dual function in cervical cancer

Cellular FLICE-like inhibitory protein (c-FLIP) is a caspasa-8/10 homolog catalytically inactive that interferes with the efficient formation of DISC. There are three isoforms of this protein: c-FLIPL (long) of 55kDa, c-FLIPS (short) of 26kDa y c-FLIPR (Raji) of 24kDa. c-FLIPS and c-FLIPR functions have been well established: both can block extrinsic pathway of apoptosis by inhibiting procaspasa-8 activation in DISC. However, c-FLIPL function still remains unclear. When c-FLIPL is overexpressed, as in some cancers, has an anti-apoptotic function very similar to c-FLIPS, but also can be a proapoptotic molecule at low concentrations. The aim of this study is to characterize c-FLIP functions in cervical uterine carcinogenesis.

Three cervical cancer cell lines were used in this study: SiHa, C-4I and C-33A. c-FLIP expression in cell lines was determined by real time PCR and western blottting. c-FLIP expression was transiently downregulated by siRNA and the silencing effects on cell viability, proliferation and apoptosis were analysed, by comparing with a control negative siRNA-transfected cells.

Using MTS analysis, SiHa and C4I c-FLIP transfected cells showed a increment of viability compared with scramble, since 24 hours after transfection in C 4I and 72 hours in SiHa (P&lt;0.05), while C-33A cells do not show differences. Ki-67 immunocitochemestry was performed to evaluate proliferation in cervical cell lines. Statistical differences were found between SiHa and C 4I c-FLIP transfected cells compared with scramble (P&lt;0.05). All three c-FLIP transfected cell lines showed a higher level of apoptosis than scramble control (P&lt;0.05), using a TUNEL-based analyzed performed by flow cytometry.

Our results suggest that c-FLIPL could be having a dual function in cervical cancer cell lines, both inhibiting proliferation and apoptosis.

Grant Support: This investigation was financed by Proyect CORFO-INNOVA N°07CN13PBT-222 and Proyect CORFO N° 09CN14-5960 (CEGIN). CI is recipient of grants from FONDECYT Postdoctoral Proyect N° 3130630. PB is recipient of grants from FONDECYT Postdoctoral Proyect N° 3120141

Citation Format: Carmen G. Ili, Priscilla Brebi, Alejandra Andana, Patricia Garcia, Pamela Leal, Oscar Tapia, Tamara Viscarra, Helga Weber, Juan Roa. c-FLIP (L) dual function in cervical cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2956. doi:10.1158/1538-7445.AM2013-2956

Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.

Abstract 647: Novel promoter hypermethylation marker for prognostic in cervicouterine cancinogenesis

New biomarkers are needed to improve cervical cancer screening technologies, which are mostly based on cytological examination and HPV detection. However, PAP-smear has a low-sensitivity to detect low grade squamous intraepithelial lesions and not all HPV infected women will develop preneoplastic or neoplastic lesions. Previous results of our group showed that genes Gen Z (patent pending), CDH1 and MEGF9 could be hypermethylated in cervical cancer and not in normal epithelia. The aim of this study was to determinate if promoter methylation status of genes (Gen Z, CDH1 and MEGF9) are related with progression or diagnosis of cervical carcinogenesis.

For this study, 107 citobrush, urine and blood samples were collected from women who attended to gynecological care in a public health center in Temuco, Chile. Citobrush DNA from 50 normal, 40 low grade squamous intraepithelial lesion (LSIL), 40 high grade squamous intraepithelial lesion (HSIL) and 17 squamous cervical cancer were bisulfite converted for methylation specific PCR (MSP). Bisulfite conversion was confirmed by amplification of a 133-bp fragment of the β-actin. MSP primers were specifically design for CpG island of promotor region of each gene.

Gen Z was found 100% methylated in SCC samples, 65% in HSIL, 43% in LSIL and in normal samples only a 26%. MEGF9 and CDH1 genes were found methylated in 36% and 48% of normal samples, 45% and 55% of LSIL, 70% and 77% of HSIL and 47% and 71% of SCC, respectively.

All promoter regions studied showed a higher methylation frequency in LSIL, HSIL and SCC than normal samples. Significant statistical differences in Gen Z and CDH1 Methylation frequencies between normal and SCC samples were found (P&lt;0.05). Methylation of Gen Z increased in a sequential and cumulative way as the lesion progress.

Our results suggest that the Gen Z could be useful tool for identifying women with a higher risk of progression to cervical cancer. Examination of these biomarkers in a larger, independent cohort is warranted. Grant Support: This investigation was financed by Proyect CORFO-INNOVA N°07CN13PBT-222 and Proyect CORFO N° 09CN14-5960 (CEGIN). CI is recipient of grants from FONDECYT Postdoctoral Proyect N° 3130630. PB is recipient of grants from FONDECYT Postdoctoral Proyect N° 3120141

Citation Format: Priscilla Brebi, Alejandra Andana, Rene Hoffstetter, Carmen Ili, Tamara Viscarra, Ramon Silva, Patricia Garcia, Pamela Leal, Helga Weber, Juan C. Roa. Novel promoter hypermethylation marker for prognostic in cervicouterine cancinogenesis. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 647. doi:10.1158/1538-7445.AM2013-647

Connective tissue growth factor immunohistochemical expression is associated with gallbladder cancer progression

CONTEXT

Gallbladder cancer (GBC) is an aggressive neoplasia associated with late diagnosis, unsatisfactory treatment, and poor prognosis. Molecular mechanisms involved in GBC pathogenesis remain poorly understood. Connective tissue growth factor (CTGF) is thought to play a role in the pathologic processes and is overexpressed in several human cancers, including GBC. No information is available about CTGF expression in early stages of gallbladder carcinogenesis. Objective.- To evaluate the expression level of CTGF in benign and malignant lesions of gallbladder and its correlation with clinicopathologic features and GBC prognosis.

DESIGN

Connective tissue growth factor protein was examined by immunohistochemistry on tissue microarrays containing tissue samples of chronic cholecystitis (n = 51), dysplasia (n = 15), and GBC (n = 169). The samples were scored according to intensity of staining as low/absent and high CTGF expressers. Statistical analysis was performed using the χ(2) test or Fisher exact probability test with a significance level of P < .05. Survival analysis was assessed by the Kaplan-Meier method and the log-rank test.

RESULTS

Connective tissue growth factor expression showed a progressive increase from chronic cholecystitis to dysplasia and then to early and advanced carcinoma. Immunohistochemical expression (score ≥2) was significantly higher in advanced tumors, in comparison with chronic cholecystitis (P < .001) and dysplasia (P = .03). High levels of CTGF expression correlated with better survival (P = .04).

CONCLUSIONS

Our results suggest a role for CTGF in GBC progression and a positive association with better prognosis. In addition, they underscore the importance of considering the involvement of inflammation on GBC development.

Abstract 5574: ZNF516 and FKBP6 promoter hypermethylation as a potential companion diagnostic panel for HPV-positive and inconclusive-Pap women

New biomarkers are needed to improve cervical cancer screening technologies, which are mostly based on cytological examination since the 1940's. HPV testing has been adopted for the triage of patients after a cervical cytology-screening test. HPV testing is now also increasingly used for screening in conjunction with cervical cytology. However, a percentage of HPV-positive and inconclusive-Pap women have negative biopsies when refered to colposcopy clinics. The aim of this study was to use a genome-wide discovery approach to identify novel epigenetic biomarkers for cervical cancer, which could be used as companion diagnostic panels to HPV and PAP. DNA from twelve normal and seven cervical cancer samples was enriched with Methylated DNA Immunoprecipitation (MeDIP), hybridized to Nimblegen 385K CpG Islands plus Promoter arrays and validated by quantitative Methylation Specific PCR in discovery (n=49) and prevalence cohorts (n=108). After correction and normalization performed using Nimblegen algorithms genes methylated in tumor and not in normal samples were ranked by methylation peak values and sequence homology. The most significant loci were verified against a report by Ongenaert et al. (BMC Med Genomics, 2008) that uses a relaxation ranking algorithm to identify re-expressed genes in cervical cancer cell lines after treatment with demethyalting agents. Two genes, ZNF516 and FKBP6, were identified as candidate epigenomic biomarkers after rigourous bioinformatics and in-silico analyses. These genes were also found to be re-expressed by Ongenaert et al. Using the most optimal cut-off as determined by ROC, ZNF516 promoter methylation had 90% sensitivity and 95% specificity (AUC=0.95) in the discovery cohort. FKBP6 promoter methylation had a sensitivity of 73% and a specificity of 79% in the same cohort. Promoter methylation of FKBP6 (OR=4.51, 95%C.I.=2.04-9.97, P&lt;0.001) and ZNF516 (OR=11.84, 95%C.I.=4.59-30.57, P&lt;0.001) was associated to HPV infection in the prevalence cohort. FKBP6 (OR=7.15, 95%C.I.=1.45-35.34, P=0.01) and ZNF516 (OR=26.72, 95%C.I.=2.61-273.05, P &lt;0.01) promoter methylation was associated with histological diagnosis of cervical cancer in the overall cohort, after controlling for age and HPV infection. Promoter methylation of ZNF516 and FKBP6 performed better than HPV at identifying normal from tumor tissue in the overall cohort. Our results suggest that a genome-wide approach using MeDIP-Chip and qMSP is useful for identifying novel screening and diagnostic markers. ZNF516 and FKBP6 were identified as a potential companion diagnostic panel for HPV-positive and inconclusive-Pap women. Examination of these biomarkers in a larger, independent cohort is warranted.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5574. doi:1538-7445.AM2012-5574

Abstract 4037: Downregulation of ZNF516 and INTS1 is related with promoter methylation in cervical uterine cancer cell lines

Introduction: One of the most common neoplasia in developing countries is cervical uterine carcinoma (CC). HPV infection is recognized as the major risk factor for carcinogenesis of cervix. However, not all infected women will develop a cervical cancer. Several studies have proposed DNA methylation as early biomarker in CC. A higher promoter methylation is associated with lower gene expression. Aim: To evaluate the association between DNA methylation and gene expression of ZNF516 and INTS1 in cervical cancer cell lines. Materials and Methods: DNA isolated from 12 normal and 7 cervical cancer tissue samples was enriched by Methylated DNA Immunoprecipitation (MeDIP) and hybridized to Nimblegen 385K CpG Islands plus Promoter arrays (MeDIP-chip). Bioinformatics strategies were used for background correction, array normalization and data analysis of differentially methylated genomic regions by Methylation Specific PCR in a cohort of 221 normal, premalignant, and cervical cancer samples. Relative expression analysis was performed in a normal cervical epithelium cell line (ECT1 E6/E7) and three cervical cancer cell lines (C-4I, SiHa and C-33A) using real time PCR. MSP was also used to examine promoter methylation in normal cervical and cervical cancer cells lines. Results: ZNF516 and INTS1 were differential methylated in the promoter region of normal and cervical cancer samples in the MeDIP-chip discovery project. The methylation frequency was 100% in cervical cancer cell lines. Relative expression of ZNF516 was significantly lower in C-4I and SiHa (p &lt;0.05) in relation with the normal cell line. C-33A showed elevated promoter methylation and a low expression of ZNF516, however, this result was not significant. INTS1 expression was significantly lower in C-33A and SiHa (p &lt;0.05) in relation with the normal cell line. C-4I showed a high promoter methylation and a low expression of INTS1, however, this result was not significant. Conclusions: We have identified ZNF516 and INTS1 as potentials biomarkers for cervical cancer. These genes may be a useful tool for diagnosis and clinical management of cervical cancer. These results need to be confirmed in clinical samples, from an independent laboratory before the gene panel is examined in a Phase II Biomarker Development Trial. Work sponsored by CORFO Project 09CN14-5960 and Postdoctoral Fondecyt Research Project 3120141.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4037. doi:1538-7445.AM2012-4037

Abstract 4780: c-FLIP knockdown increases apoptosis in cervical cancer cell lines

Cervical Uterine cancer is a leading cause of cancer deaths in women worldwide. Its natural history begins gradually from low-grade and high-grades squamous intraepithelial lesions to an invasive disease. Decades of studies have confirmed a directly association between persistent high-risk Human Papillomavirus (HPV) infections and cervical cancer. However, high-risk HPV infections are not sufficient to induce cellular transformation and tumor occurrence. The cellular FLICE-like inhibitory protein (c-FLIP) has been founded overexpressed in several cancers and could be associated with cervical carcinogenesis. c-FLIP is a catalytically inactive caspase-8/-10 homologue, and when is overexpressed has the ability to inhibit the extrinsic pathway of apoptosis. Aim: To characterize c-FLIP participation in cervical carcinogenesis.Materials and Methods: Four cell lines were used in this study: ECT1 E6/E7 (squamous normal cervical epithelial), SiHa (cervical carcinoma containing an integrated HPV 16 genome), C-4I (cervical carcinoma containing an integrated HPV 18 genome) and C-33A (cervical carcinoma without HPV). c-FLIP expression in cell lines was determined by real time PCR and western blot. c-FLIP expression was transiently downregulated by siRNA directed against c-FLIP mRNA and the silencing effects on cell viability and apoptosis were analysed, by comparing with a control negative siRNA-transfected cells.Results: c-FLIP was found to be overexpressed in SiHa and C-4I cell lines and repressed in C-33A cell line. Only the long variant of c-FLIP was found in cervical cancer cell lines. Transient knockdown of c-FLIP resulted in significant reduction in cell viability (p&lt; 0.001), compared with negative control siRNA-transfected cells. Knockdown cells lines exhibited an increased apoptotic rate in comparison with controls (p&lt;0,001). Conclusions: The long variant of c-FLIP is overexpressed in cervical cancer cell lines with integrated genome of a high-risk HPV. Furthermore, the siRNA-mediated downregulation of c-FLIP expression induces apoptosis and decreases cell viability in cervical cancer cell lines. Therefore, this protein could be a potential therapeutic target in cervical cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4780. doi:10.1158/1538-7445.AM2011-4780

Abstract 3026: Concurrent gene promoter hypermethylation and reduced immunohistochemical expression of potential biomarkers in cervical cancer: A Phase I biomarker development trial

Introduction: Cervical cancer (CC) is the second most common neoplasia in women and it is the fifth cause of death by cancer in this population. Pap smears and HPV infection tests have been the most widely used tools to detect cytological abnormalities and women's risk of developing cervical cancer. However, they cannot distinguish between lesions that will progress to an invasive carcinoma and those that will not. Methylation biomarkers could be useful in early detection and progression for cervical carcinoma. Several studies have shown an association between promoter DNA hypermethylation and decreased gene expression.

Aim: To identify potential epigenetic biomarkers for diagnosis and clinical management of cervical cancer.

Materials and Methods: Isolated DNA from 12 normal samples and 7 cervical cancers was enriched with Methylated DNA Immunoprecipitation (MeDIP) and hybridized to Nimblegen 385K CpG Islands plus Promoter arrays (MeDIP-chip). Bioinformatics strategies were used for background correction, array normalization and data analysis of differentially methylated genomic regions between tumor and normal tissue. Methylation Specific PCR (MSP) validated promoter methylation frequency in the 221 samples: 25 normal, 66 Low Grade Lesions (LSIL), 91 High Grade Lesions (HSIL) and 39 cervical cancers (CC). Immunohistochemistry (IHQ) was performed to identify expression of genes at protein level in a separate cohort of 122 samples: 59 normal and 63 CC. Immunoreactivity score was determined by tabulating the percentage of cells with different levels of reactivity to the target antibodies.

Results. Two hypermethylated genes were identified as potential biomarkers after validation by MSP: GGTLA4 and ZNF516. The methylation frequency for the two genes was higher in tumor: GGTLA4 (100%) and ZNF516 (96%); than in normal samples: GGTLA4 (12%) and ZNF516 (16%). The methylation status of GGTLA4 showed a progression in methylation frequency from normal samples to invasive carcinoma. The immunohistochemical expression for the two genes was lower in tumor: GGTLA4 (50.8 %) and ZNF516 (66.2%); than in normal samples: GGTLA4 (71.2%) and ZNF516 (88.1%) (p&lt;0.05).

Conclusions: We have identified two potential methylation markers for cervical cancer, GGTLA4 and ZNF516, with the use of MeDIP-chip and confirmed the results with IHQ in an independent cohort. These genes may be useful tools for diagnosis and clinical management cervical cancer. These results need to be confirmed in an independent laboratory before the genes are examined in a Phase II Biomarker Development Trial.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3026. doi:10.1158/1538-7445.AM2011-3026

Genotyping of human papillomavirus in cervical intraepithelial neoplasia in a high-risk population

Infection with the human papillomavirus (HPV) is responsible for 99.7% of cervical cancers, the second most prevalent neoplasia in women worldwide and the fifth leading cause of death by cancer in this population. In Chile, the incidence rate is 14.4 cases per 100,000 women per year and it is considered a significant public health problem. The natural history of cervical cancer begins gradually from low-grade and high-grade squamous intraepithelial lesions to an invasive disease. In this study the frequency of HPV types was determined by HPV genotyping with reverse line blot hybridization in 200 cytobrushes of women with preneoplastic lesions in a high-risk population. HPV DNA was found in 89% of the lesions (83.3% of low-grade squamous intraepithelial lesions and 93.6% of high-grade squamous intraepithelial lesions). Multiple HPV infections were found in 14.4% and 15.5% of low- and high-grade lesions, respectively. HPV 16 was the most frequent genotype in single infections, followed by HPV 18. These results show that most of the preneoplastic lesions of the cervix (60%) were associated with HPV 16 and/or HPV 18, supporting the implementation of an HPV vaccination program in this high-risk population.

Identification and characterization of three novel cold acclimation-responsive genes from the extremophile hair grass Deschampsia antarctica Desv

Deschampsia antarctica Desv. is the only monocot that thrives in the harsh conditions of the Antarctic Peninsula and represents an invaluable resource for the identification of genes associated with freezing tolerance. In order to identify genes regulated by low temperature, we have initiated a detailed analysis of its gene expression. Preliminary 2-D gels of in vivo-labeled leaf proteins showed qualitative and quantitative differences between cold-acclimated and non-acclimated plants, suggesting differential gene expression. Similarly, cold-acclimation-related transcripts were screened by a differential display method. Of the 38 cDNAs initially identified, three cDNA clones were characterized for their protein encoding, expression pattern, response to several stresses, and for their tissue-specific expression. Northern blot analysis of DaGrx, DaRub1, and DaPyk1 encoding a glutaredoxin, a related-to-ubiquitin protein, and a pyruvate kinase-like protein, respectively, showed a distinct regulation pattern during the cold-acclimation process, and in some cases, their cold response seemed to be tissue specific. All three transcripts seem to be responsive to water stress as their levels were up-regulated with polyethyleneglycol treatment. DaRUB1 and DaPyk1 expression was up-regulated in leaf and crown, but down-regulated in roots from cold-acclimated plants. The significance of these results during the cold-acclimation process will be discussed.

What is the cost utility of screening for hepatitis C virus (HCV) in intravenous drug users?

OBJECTIVES

To model the likely cost utility of the prevalence round of a screening programme for hepatitis C (HCV) in intravenous drug users (IVDUs) in contact with services in the South and West health region of the UK.

METHODS

Information on the prevalence of HCV, performance of diagnostic tests, and effectiveness of interferon alpha (IFN alpha) for treatment of chronic hepatitis were brought together with estimates of the costs of service provision. A simple spreadsheet model was used to estimate cost utility (cost/quality adjusted life year (QALY)). Assumptions (including use of ribavirin plus IFN alpha combination therapy) were tested by a one way sensitivity analysis.

RESULTS

About 5600 IVDUs live in the region. A combination of enzyme linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) testing has high sensitivity and specificity for detecting HCV. There is excellent evidence that IFN alpha is effective in producing sustained normalisation of liver function and, by inference, eradicating HCV. Evidence for long term benefits comes from modelling studies based on progression of HBV or non-A, non-B hepatitis and is considerably less robust. The cost of the prevalence round of screening in IVDUs would be about 700,000 Pounds and is likely to identify about 1400 people, of whom about 270 would be eligible for treatment and 20 would respond to IFN alpha. This gives a cost/QALY of 9300 Pounds for the screening programme. However, much uncertainty around the estimates used to inform the cost utility calculation limits confidence in the value of screening IVDUs for HCV. Sensitivity analysis shows a range of possible cost utility from 3333 Pounds to 81,438 Pounds. Estimates are particularly sensitive to adherence to liver biopsy and treatment and to discounting of benefits.

CONCLUSIONS

Although potentially cost effective, many important uncertainties surround the assumptions used to estimate the long term effectiveness of screening and treatment. There is insufficient evidence to inform policy development and further research is required in this rapidly changing field.

Bottled mineral waters polluted by protozoa in Mexico

A survey of protozoa polluting bottled mineral water in Mexico was carried out using samples obtained form the three best-selling brands of bottled mineral water in the country. The organisms were concentrated through filtration procedures and subsequently cultured in the sterile media. The cultures were observed over four weeks, with identification to the level of genus and species. Most commonly found were the amoebae Naegleria gruberi, Acanthamoeba astronyxis, and Vahlkampfia vahlkampfi (trophic as well as cystic stages) plus one flagellate, Bodomorpha minima. No ciliates were detected. The public health importance of the findings is obvious, since some strains of Naegleria and Acanthamoeba have the potential to cause human disease that may lead to death.

Infusion tomography of the gallbladder

Infusion tomography of the gallbladder has proved to be more specific in the detection of pathologic disease as compared with conventional roentgenologic examinations by showing the wall of the organ instead of the contents. Infusion tomography of the gallbladder has been a useful initial procedure in patients with acute cholecystitis and in those with obstructive jaundice. It has helped to confirm diagnosis in patients with chronic lithiasic cholecystitis and nonvisualized gallbladder or with gallstones with documented on oral or intravenous studies. Infusion tomography of the gallbladder can be done on an emergency basis; it requires no prior preparation of the patient and usually yields an answer within 30 minutes. No significant complications have resulted from the high dose of iodized contrast material. There have been only two false results, one negative and one positive, so the procedure can be regarded as a highly reliable one.