Targeting CCR3 with antagonist SB 328437 sensitizes 5‑fluorouracil‑resistant gastric cancer cells: Experimental evidence and computational insights

Gastric cancer (GC) ranks fifth globally in cancer diagnoses and third for cancer-related deaths. Chemotherapy with 5-fluorouracil (5-FU), a primary treatment, faces challenges due to the development of chemoresistance. Tumor microenvironment factors, including C-C motif chemokine receptor 3 (CCR3), can contribute to chemoresistance. The present study evaluated the effect of CCR3 receptor inhibition using the antagonist SB 328437 and the molecular dynamics of this interaction on resistance to 5-FU in gastric cancer cells. The 5-FU-resistant AGS cell line (AGS R-5FU) demonstrated notable tolerance to higher concentrations of 5-FU, with a 2.6-fold increase compared with the parental AGS cell line. Furthermore, the mRNA expression levels of thymidylate synthase (TS), a molecular marker for 5-FU resistance, were significantly elevated in AGS R-5FU cells. CCR3 was shown to be expressed at significantly higher levels in these resistant cells. Combining SB 328437 with 5-FU resulted in a significant decrease in cell viability, particularly at higher concentrations of 5-FU. Furthermore, when SB 328437 was combined with 5-FU at a high concentration, the relative mRNA expression levels of CCR3 and TS decreased significantly. Computational analysis of CCR3 demonstrated dynamic conformational changes, especially in extracellular loop 2 region, which indicated potential alterations in ligand recognition. Docking simulations demonstrated that SB 328437 bound to the allosteric site of CCR3, inducing a conformational change in ECL2 and hindering ligand recognition. The present study provides comprehensive information on the molecular and structural aspects of 5-FU resistance and CCR3 modulation, highlighting the potential for therapeutic application of SB 328437 in GC treatment.

Epigenetic modulation of cytokine expression in gastric cancer: influence on angiogenesis, metastasis and chemoresistance

Cytokines are proteins that act in the immune response and inflammation and have been associated with the development of some types of cancer, such as gastric cancer (GC). GC is a malignant neoplasm that ranks fifth in incidence and third in cancer-related mortality worldwide, making it a major public health issue. Recent studies have focused on the role these cytokines may play in GC associated with angiogenesis, metastasis, and chemoresistance, which are key factors that can affect carcinogenesis and tumor progression, quality, and patient survival. These inflammatory mediators can be regulated by epigenetic modifications such as DNA methylation, histone protein modification, and non-coding RNA, which results in the silencing or overexpression of key genes in GC, presenting different targets of action, either direct or mediated by modifications in key genes of cytokine-related signaling pathways. This review seeks insight into the relationship between cytokine-associated epigenetic regulation and its potential effects on the different stages of development and chemoresistance in GC.

Exploring the Genetic Diversity of Epstein-Barr Virus among Patients with Gastric Cancer in Southern Chile

The Epstein-Barr virus (EBV) has been associated with gastric cancer (GC), one of the deadliest malignancies in Chile and the world. Little is known about Chilean EBV strains. This study aims to investigate the frequency and genetic diversity of EBV in GC in patients in southern Chile. To evaluate the prevalence of EBV in GC patients from the Chilean population, we studied 54 GC samples using the gold standard detection method of EBV-encoded small RNA (EBER). The EBV-positive samples were subjected to amplification and sequencing of the Epstein-Barr virus nuclear protein 3A (EBNA3A) gene to evaluate the genetic diversity of EBV strains circulating in southern Chile. In total, 22.2% of the GC samples were EBV-positive and significantly associated with diffuse-type histology (p = 0.003). Phylogenetic analyses identified EBV-1 and EBV-2 in the GC samples, showing genetic diversity among Chilean isolates. This work provides important information for an epidemiological follow-up of the different EBV subtypes that may cause GC in southern Chile.

Abstract 1749: The synergic effect of cisplatin and a chemokine receptor antagonist sensitizes drug resistant gastric cancer cells and inhibits tumoroid formation

Introduction: Gastric cancer (GC) is an important cause of death worldwide. Cisplatin (CDDP) is the most used drug in the chemotherapy of advanced GC. However, CDDP resistance reduces GC survival. The CCR5/CCL5 axis has been associated with GC development, but its role in CDDP resistance in GC has not been elucidated. The aim of this study was to determine the effects of CCR5/CCL5 axis blockade by a chemokine receptor antagonist (CRA), alone and in combination with CDDP, on in vitro and 3D tumorid models from AGS R-CDDP cells.

Methodology: AGS R-CDDP cells (CDDP-resistant human gastric adenocarcinoma cells) were previously established using a stepwise drug dosing protocol and characterized. CCL5 was selected through transcriptomic analysis and its expression level was validated by qRT-PCR. Cytotoxicity assays were determined by using MTT. Apoptosis and cell cycle assays were evaluated by flow cytometry. Tumoroid formation was performed from AGS R-CDDP cells in low adhesion plates (NunclonTMSpheraTM). After 10 days in culture, tumoroid >150 µm in diameter were scored and pharmacological stimuli were added on days 14, 17 and 20. CRA was used alone and in combination with CDDP in all assays.

Results: CRA/CDDP combination triggered a re-sensitized phenotype in AGS R-CDDP cells, decreasing cell viability but not increasing apoptosis compared to independent treatments. AGS R-CDDP cells treated with CRA/CDDP were mainly arrested in S phase. CCL5 showed a decrease in mRNA levels after the CRA/CDDP combination compared to separate treatments. AGS R-CDDP cells showed a higher potential in the ability to form tumoroids compared to AGS WT cells. Finally, CRA/CDDP combination inhibited tumoroid formation compared to independent treatments.

Discussion and Conclusion: CCL5 showed a decrease in mRNA levels after the CRA/CDDP combination, possibly correlating with allosteric inhibition of the CCR5 receptor. CRA/CDDP combination has a synergic effect that sensitizes AGS R-CDDP cells and inhibits tumoroid formation. This combination could be used as a potential coadjuvant in GC therapy allowing to reduce the doses of CDDP and therefore to reduce side effects.

Citation Format: Bárbara Mora-Lagos, María Elena Reyes, Lorena Lobos-Gonzalez, Matías del Campo, Carmen Gloria Ili, Kurt Buchegger, Yuselin Mora, Louise Zanella, Ismael Riquelme, Priscilla Brebi. The synergic effect of cisplatin and a chemokine receptor antagonist sensitizes drug resistant gastric cancer cells and inhibits tumoroid formation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1749.

Abstract 2845: PpIX synthesis increases PDT resistant cells due to the modulating effect of EGCG on the heme synthesis pathway

Introduction: Photodynamic therapy (PDT) is a treatment for non melanoma skin cancer. PDT kills cells through reactive oxygen species (ROS), produced by interaction between cellular O2 and an excited photosensitizer (PS) by a specific light. One of the most used PS in dermatology is Protoporphyrin IX (PpIX) and its precursor methyl aminolevulinate (MAL). MAL enters into cells and is converted to PpIX by enzymes of the heme group synthesis pathway. The insertion of ferrous iron into PpIX forms a heme molecule, which has no PS action. A previous study shows that efficacy of PDT, in resistant cells, can be improved by addition of epigallocatechin gallate (EGCG), a green tea polyphenol. Therefore, the aim of this work is to evaluate the rol of EGCG on PPIX synthesis.

Material and methods: It was used a A-431 cell line from skin squamous cell carcinoma. The EC50 of EGCG was determined by MTT assay after 24 hours. Clonogenic assay was carried out using EGCG 10, 20 and 40 μM, for 4 and 24 hours of incubation. To evaluate PpIX and ROS, A-431 cells were exposed to EGCG (10, 20, 40 μM) with or without MAL 2 mM. After 4 hours, some plates were irradiated with red light to generate ROS. PpIX and ROS were detected by flow cytometry. Gene expression of enzymes of heme synthesis was analyzed by RT-qPCR. Intracellular iron was measured using a commercial kit. 

Results: EC50 determined a concentration of 50 μM of EGCG at 24 hours. EGCG concentrations from 10 μM reduced cell clonogenic capacity, even with only 4 hours of incubation. A-431 cells show PDT resistance with MAL 2 mM and a fluence of 4 J/cm2. The addition of EGCG to MAL-PDT showed a decrement of cell viability with an increase of PpIX and ROS. Besides, incubation with EGCG for 4 hours, triggered an increment of HMBS enzyme and decrease of FECH. In addition, EGCG reduced intracellular iron concentrations.

Conclusion: These findings show that EGCG has a PDT enhancing effect, decreasing intracellular iron levels and modulating gene expression of heme synthesis enzymes, which are directly related with high levels of PpIX production and ROS levels, causing the death of resistant cells.Acknowledgements: Postdoctoral FONDECYT Nº 3210618, IDeA I+D FONDEF ID21I10027

Citation Format: Daniela León, Álvaro Gutiérrez, Helga Weber, Ramón Silva, María Elena Reyes, Tamara Viscarra, Kurt Buchegger, Carmen Ili, Priscilla Brebi. PpIX synthesis increases PDT resistant cells due to the modulating effect of EGCG on the heme synthesis pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2845.

Abstract 1740: CCR5/CCL5 axis inhibition reverses cisplatin-chemoresistance phenotye in gastric cancer cells

Gastric cancer (GC) is an important public health problem worldwide. Advanced GC treatment is mainly based in chemotherapy with Cisplatin (CDDP). Unfortunately, the high recurrence rate of GC is predominantly attributable to chemoresistance. The CCR5/CCL5 axis, that participates in inflammatory process, has been associated with the development and progression of cancer. However, its role in GC chemoresistance has not been fully elucidated. The objective of this work was to elucidate the role of CCR5/CCL5 axis on GC chemoresistance cells. AGS R-CDDP was established through a method based on stepwise increasing drug doses and characterized by functional assays. RNA-Sequencing (RNA-seq) was performed on Illumina HiSeq 4000. A fold change >2 and P<0.05 were used as cut-off to choose the differentially expressed genes (DEGs). Gene Ontology (GO) and signaling pathways analysis were analyzed by PANTHER. CCL5 candidate gene was validated by qRT-PCR. Signaling pathways such as STAT3, MAPK and PI3K, associated with cytokines, proliferation and survival were evaluated by western blot assays. Cell viability of CCR5/CCL5 axis inhibition was evaluated in AGS R-CDDP exposed to Chemokine receptor antagonist (CRA) alone and in combination with CDDP. Characterization studies have effectively demonstrated that AGS R-CDDP is a reliable CDDP-resistant model. Bioinformatics analyses identified a total of 189 DEGs associated mainly to molecular functions (GO) involved in CDDP-resistance. The most enriched signaling pathway was the inflammation mediated by chemokine and cytokine which could be involved in the development of CDDP resistance in GC. CCL5 was upregulated in AGS R-CDDP cells. The main signaling pathways associated with CCR5/CCL5 axis were not activated in resistant GC cells compared parental GC cells.The cytotoxicity assays showed that CRA/CDDP combination re-sensitized AGS R-CDDP cells, decreasing cell viability. Our results indicate that CCR5/CCL5 axis induce chemoresistance and CRA/CDDP combination sensitize AGS R-CDDP cells revealing its potential as coadjuvant in GC therapy.

Citation Format: Priscilla Brebi, Maria Elena Reyes, Carmen Gloria Ili, Yuselin Mora, Kurt Buchegger, Ismael Riquelme, Louise Zanella, Lorena Lobos-Gonzalez, Camila Burdiles, Barbara Mora-lagos. CCR5/CCL5 axis inhibition reverses cisplatin-chemoresistance phenotye in gastric cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1740.

Abstract 1978: Community Genomic Health Promotion Program evaluates precision DNA methylation biomarkers for use in self-testing and collection kits in urine, to increase cervical cancer screening rates among Latina women

Cervical cancer incidence is 32% higher among Latina women in the United States (US) and 78% higher among women in Puerto Rico compared to non-Latina White (NLW) women, yet it is largely preventable through screening. Latina women with public insurance or uninsured are significantly less likely to have had a Pap test, undergo fewer Pap and high-Risk Human Papilloma Virus (HPV) testing than NLW and Black women, and are less likely than women of other races/ethnicities to return for recommended follow-up after an abnormal Pap test. Utilizing the PRECEDE-PROCEED model, Community Based Participatory Research strategies and the NIH I-Corps hypothesis-driven research method of customer discovery, we implemented the Community Genomic Health Promotion Program in Federally Qualified Health Centers to evaluate cervical cancer screening needs in six rural municipalities in Puerto Rico. We recently validated in clinical liquid cytology samples that the CervicalMethDx test, a precision DNA methylation test, can identify HPV positive women most likely to be diagnosed with Cervical Intraepithelial Neoplasia (CIN) grades 2 and 3. We hypothesized that a molecular pathology test which identifies advanced premalignant cervical lesions in urine, can be distributed by commercial channels targeting populations with low screening rates. The CervicalMethDx quantitative Methylation Specific PCR (qMSP) test was used to quantify ZNF516, FKBP6 and INTS1 promoter DNA methylation in well-characterized, discarded, liquid cytology clinical samples from Puerto Rico. We then tested the CervicalMethDx test concordance on paired cytobrush (n=82) and urine samples (n=82) from Chile. The CervicalMethDx test correctly classified 86% of discarded liquid cytology clinical samples from HPV-positive women, when comparing DNA methylation in CIN2/CIN3 samples (n=47) to samples with a cervical pathology diagnosis of No Intraepithelial Lesions or Malignancy (n=18), with 83% Sensitivity, 94% Specificity, Area Under the Curve (AUC) of 0.88, and 98% positive predictive value (PPV). The concordance of the CervicalMethDx test in paired brush and urine samples was moderate (rho=0.45). The Wilcoxon signed-rank test showed no statistically significant differences for the CervicalMethDx test in paired brush and urine samples (p=0.14) These encouraging preliminary results show the successful identification of advanced premalignant cervical lesions in liquid cytology media and urine samples from Latina women. The data suggests that urine should be explored as a biofluid for cervical cancer screening. Future research may lead to expanded screening options, enabling women with low access to health care (public insurance or uninsured) to collect a specimen at home, and either send it to a testing facility or perform the test at home.

Citation Format: Carmen Ili, Priscilla Brebi, Jaime López, Fernando T. Zamunér, Ana Purcell-Wiltz, Amanda García-Negrón, Keilyn Vale-Lassalle, Keerthana Gosala, Mirla Otero-García, Camila Rivero-Maldonado, Teresa Torres-Rivera, Adriana Pérez-Vicente, Ashley Ramos-López, David Sidransky, Mariana Brait, Rafael E. Guerrero-Preston. Community Genomic Health Promotion Program evaluates precision DNA methylation biomarkers for use in self-testing and collection kits in urine, to increase cervical cancer screening rates among Latina women [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1978.

Abstract 2422: In vivo pilot study of the effect of EGCG in photodynamic therapy on non melanoma skin cancer

Non-melanoma skin cancer (NSCLC) is the most frequent cancer in humans worldwide. Solar UV radiation is main risk factor to NSCLC developing in areas such as the face, neck, arms, etc. Basal cell carcinoma and precursor lesions of squamous cell carcinoma (SCC), such as actinic keratosis, Bowen’s disease, etc. can be treated with Photodynamic Therapy (PDT). PDT consists of applying a cream containing a photosensitizer on the skin lesion, to then being irradiated with light at a specific wavelength. The most used PS in skin cancer is methyl aminolevulinate (MAL). Light excites the photosensitizer, which interacts with intracellular O2, producing reactive oxygen species (ROS), triggering cancer cell death. One of the main advantages of PDT is that it offers satisfactory cosmetic results. However, its effectiveness is variable. Our previous results, using a PDT-resistant SCC cell model, showed that the addition of epigallocatechin gallate (EGCG) to PDT has a potentiated effect, killing 100% of these cells. Therefore, the aim of this work was to evaluate the effect of an EGCG-enhanced cream for PDT on squamous cell carcinoma lesions in an animal model.A two-step chemical carcinogenesis protocol (DMBA/TPA) was used in male and female mice of the Balb/c strain (21 animals). Once the animals developed the desired lesions, they were randomly separated into three groups. The first group received conventional cream (MAL 20%), the second group cream A (MAL 20% + EGCG 1%) and the third group B cream (MAL 20% + EGCG 3%). PDT was performed as follows: cream was applied for 4 hours on the lesion and then protected from the light with a patch. Subsequently, the excess cream was removed and the lesions were irradiated with 630 nm red light. The lesions were followed up for one month, measuring the size of the tumor and taking a final biopsy.We successfully develop an in vivo model of NSCLC using chemical inducers. Mice develops two kind of lesions: plane and/or papillar. All mice were treated with PDT using the three different formulations. Lesions reduced its size until a 50% more when treated with PDT plus EGCG. Formulation B (MAL 20% + EGCG 3%), was the most effective, given it had a greater on the relative reduction of the volume of the lesion. In conclusion, this in vivo pilot study evidences the enhancing effect of EGCG on PDT, encouraging the pursue to continue with the investigations on this matter, in order to improve the PDT and the quality of life of skin cancer patients.

Citation Format: Carmen Gloria Ili, Daniela Leon, Maria Elena Reyes, Kurt Buchegger, Francisca Acevedo-Canala, Pablo Guzman, Claudia Nicklas, Cecicia Orlandi, Priscilla Brebi. In vivo pilot study of the effect of EGCG in photodynamic therapy on non melanoma skin cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2422.

Long Non-Coding RNAs (lncRNAs) as Regulators of the PI3K/AKT/mTOR Pathway in Gastric Carcinoma

Gastric cancer (GC) represents ~10% of the global cancer-related deaths, increasingly affecting the younger population in active stages of life. The high mortality of GC is due to late diagnosis, the presence of metastasis and drug resistance development. Additionally, current clinical markers do not guide the patient management adequately, thereby new and more reliable biomarkers and therapeutic targets are still needed for this disease. RNA-seq technology has allowed the discovery of new types of RNA transcripts including long non-coding RNAs (lncRNAs), which are able to regulate the gene/protein expression of many signaling pathways (e.g., the PI3K/AKT/mTOR pathway) in cancer cells by diverse molecular mechanisms. In addition, these lncRNAs might also be proposed as promising diagnostic or prognostic biomarkers or as potential therapeutic targets in GC. This review describes important topics about some lncRNAs that have been described as regulators of the PI3K/AKT/mTOR signaling pathway, and hence, their potential oncogenic role in the development of this malignancy.

The Emerging Role of PIWI-Interacting RNAs (piRNAs) in Gastrointestinal Cancers: An Updated Perspective

Gastrointestinal (GI) cancers produce ~3.4 million related deaths worldwide, comprising 35% of all cancer-related deaths. The high mortality among GI cancers is due to late diagnosis, the presence of metastasis and drug resistance development. Additionally, current clinical markers do not adequately guide patient management, thereby new and more reliable biomarkers and therapeutic targets are still needed for these diseases. RNA-seq technology has allowed the discovery of new types of RNA transcripts including PIWI-interacting RNAs (piRNAs), which have particular characteristics that enable these molecules to act via diverse molecular mechanisms for regulating gene expression. Cumulative evidence has described the potential role of piRNAs in the development of several tumor types as a likely explanation for certain genomic abnormalities and signaling pathways' deregulations observed in cancer. In addition, these piRNAs might be also proposed as promising diagnostic or prognostic biomarkers or as potential therapeutic targets in malignancies. This review describes important topics about piRNAs including their molecular characteristics, biosynthesis processes, gene expression silencing mechanisms, and the manner in which these transcripts have been studied in samples and cell lines of GI cancers to elucidate their implications in these diseases. Moreover, this article discusses the potential clinical usefulness of piRNAs as biomarkers and therapeutic targets in GI cancers.

Novel Methylation Biomarkers for Colorectal Cancer Prognosis

Colorectal cancer (CRC) comprises the third most common cancer worldwide and the second regarding number of deaths. In order to make a correct and early diagnosis to predict metastasis formation, biomarkers are an important tool. Although there are multiple signaling pathways associated with cancer progression, the most recognized are the MAPK pathway, p53 pathway, and TGF-β pathway. These pathways regulate many important functions in the cell, such as cell cycle regulation, proliferation, differentiation, and metastasis formation, among others. Changes in expression in genes belonging to these pathways are drivers of carcinogenesis. Often these expression changes are caused by mutations; however, epigenetic changes, such as DNA methylation, are increasingly acknowledged to play a role in the deregulation of oncogenic genes. This makes DNA methylation changes an interesting biomarkers in cancer. Among the newly identified biomarkers for CRC metastasis INHBB, SMOC2, BDNF, and TBRG4 are included, all of which are highly deregulated by methylation and closely associated with metastasis. The identification of such biomarkers in metastasis of CRC may allow a better treatment and early identification of cancer formation in order to perform better diagnostics and improve the life expectancy.

Role of lncRNAs in the Development of an Aggressive Phenotype in Gallbladder Cancer

Long non-coding RNAs are sequences longer than 200 nucleotides that are involved in different normal and abnormal biological processes exerting their effect on proliferation and differentiation, among other cell features. Functionally, lncRNAs can regulate gene expression within the cells by acting at transcriptional, post-transcriptional, translational, or post-translational levels. However, in pathological conditions such as cancer, the expression of these molecules is deregulated, becoming elements that can help in the acquisition of tumoral characteristics in the cells that trigger carcinogenesis and cancer progression. Specifically, in gallbladder cancer (GBC), recent publications have shown that lncRNAs participate in the acquisition of an aggressive phenotype in cancer cells, allowing them to acquire increased malignant capacities such as chemotherapy resistance or metastasis, inducing a worse survival in these patients. Furthermore, lncRNAs are useful as prognostic and diagnostic biomarkers since they have been shown to be differentially expressed in tumor tissues and serum of individuals with GBC. Therefore, this review will address different lncRNAs that could be promoting malignant phenotypic characteristics in GBC cells and lncRNAs that may be useful as markers due to their capability to predict a poor prognosis in GBC patients.

Resistance to platinum-based cancer drugs: a special focus on epigenetic mechanisms

Chemoresistance is a significant clinical challenge, limiting the drug response in cancer. Several mechanisms associated with drug resistance have been characterized, and the role of epigenetics in generating resistance to platinum-based drugs has been clarified. Epigenetic mechanisms such as DNA methylation, histone modification, long noncoding RNA, and microRNA affect the expression of genes implicated in absorption, distribution, metabolism and excretion (ADME) of drugs, and other non-ADME genes that encode enzymes involved in the processes of cell proliferation, DNA repair, apoptosis and signal transduction key in the development of chemoresistance in cancer, specifically in platinum-based drugs. This review summarizes current discoveries in epigenetic regulation implicated in platinum drug resistance in cancer and the main clinical trials based on epigenetic therapy, evaluating their potential synergy with platinum-based drugs.

Workflow optimization in a clinical laboratory using Lean management principles in the pre-analytical phase

Background

The application of the Lean methodology in clinical laboratories can improve workflow and user satisfaction through the efficient delivery of analytical results. The purpose of this study was to optimise delivery times of the test results at a clinical laboratory, using Lean management principles in the pre-analytical phase.

Methods

A prospective study with a quasi-experimental design was implemented. Staff functions were restructured and sample flows were modified. Delivery times of clinical results (glucose and haematocrit; 6648 data) from the Medicine and Adult Emergency services for years 2017 and 2018 were compared.

Results

A reduction (p < 0.05) in turnaround times in the delivery of glucose test results at the adult emergency service was observed (84 to 73 min, 13%, pre and post). In addition, there was a non-significant reduction in the turnaround times for glucose (Medicine) and haematocrit in both services. In the analytical and post-analytical phase (not intervened), an increase in turnaround times was observed in some cases.

Conclusions

Other studies have indicated that the application of the Lean methodology in clinical laboratories improves workflow, increasing effectiveness and efficiency. This study showed an improvement in the delivery time of test results (glucose - Emergency), giving rise to a culture of cooperation and continuous improvement. It would, however, be essential to address the management model integrating the analytical and post-analytical phases.

Landscape of Genome-Wide DNA Methylation of Colorectal Cancer Metastasis

Colorectal cancer is a heterogeneous disease caused by both genetic and epigenetics factors. Analysing DNA methylation changes occurring during colorectal cancer progression and metastasis formation is crucial for the identification of novel epigenetic markers of patient prognosis. Genome-wide methylation sequencing of paired samples of colon (normal adjacent, primary tumour and lymph node metastasis) showed global hypomethylation and CpG island (CGI) hypermethylation of primary tumours compared to normal. In metastasis we observed high global and non-CGI regions methylation, but lower CGI methylation, compared to primary tumours. Gene ontology analysis showed shared biological processes between hypermethylated CGIs in metastasis and primary tumours. After complementary analysis with The Cancer Genome Atlas (TCGA) cohort, FIGN, HTRA3, BDNF, HCN4 and STAC2 genes were found associated with poor survival. We mapped the methylation landscape of colon normal tissues, primary tumours and lymph node metastasis, being capable of identified methylation changes throughout the genome. Furthermore, we found five genes with potential for methylation biomarkers of poor prognosis in colorectal cancer patients.

Phylogenetic dating analysis of HTLV-1 from Chile suggests transmissions events related to ancient migrations and contemporary expansion

Human T-cell lymphotropic virus type 1 (HTLV-1) is a globally-spread virus. It is estimated that there are about 5–10 million infected people in the world. HTLV is endemic in Chile, with higher seroprevalence among indigenous people. However, little is known about HTLV-1 genetic diversity, its introduction and dispersion in this country. To gain insights into these issues, a phylogenetic dating analysis was conducted based on Chilean and closed related long terminal repeat sequences. The time tree reconstruction showed that the introduction of HTLV-1aA occurred several times in Chile. It was hypothesized that these introductions took place at least in two different historical moments: (i) during the ancient human migrations and (ii) during/after the European colonization of South America. The present study contributes toward understanding the evolutionary history of HTLV-1 in Chile and South America.

Role of CC Chemokines Subfamily in the Platinum Drugs Resistance Promotion in Cancer

Cancer is a significant medical issue, being one of the main causes of mortality around the world. The therapies for this pathology depend on the stage in which the cancer is found, but it is usually diagnosed at an advanced stage in which the treatment is chemotherapy. Platinum drugs are among the most commonly used in therapy, unfortunately, one of the main obstacles to this treatment is the development of chemoresistance, which is the ability of cancer cells to evade the effects of drugs. Although some molecular mechanisms involved in resistance to platinum drugs are described, elucidation is still required of others. Secretion of inflammatory mediators such as cytokines and chemokines, by tumor microenvironment components or tumor cells, show direct influence on proliferation, metastasis and progression of cancer and are related to chemoresistance and poor prognosis. In this review, the general mechanisms associated with resistance to platinum drugs, inflammation on cancer development and chemoresistance in various types of cancer will be approached with special emphasis on the current history of CC chemokines subfamily-mediated chemoresistance.

Epigallocatechin Gallate Enhances MAL-PDT Cytotoxic Effect on PDT-Resistant Skin Cancer Squamous Cells

Photodynamic therapy (PDT) has been used to treat certain types of non-melanoma skin cancer with promising results. However, some skin lesions have not fully responded to this treatment, suggesting a potential PDT-resistant phenotype. Therefore, novel therapeutic alternatives must be identified that improve PDT in resistant skin cancer. In this study, we analyzed the cell viability, intracellular protoporphyrin IX (PpIX) content and subcellular localization, proliferation profile, cell death, reactive oxygen species (ROS) detection and relative gene expression in PDT-resistant HSC-1 cells. PDT-resistant HSC-1 cells show a low quantity of protoporphyrin IX and low levels of ROS, and thus a low rate of death cell. Furthermore, the resistant phenotype showed a downregulation of HSPB1, SLC15A2, FECH, SOD2 and an upregulation of HMBS and BIRC5 genes. On the other hand, epigallocatechin gallate catechin enhanced the MAL-PDT effect, increasing levels of protoporphyrin IX and ROS, and killing 100% of resistant cells. The resistant MAL-PDT model of skin cancer squamous cells (HSC-1) is a reliable and useful tool to understand PDT cytotoxicity and cellular response. These resistant cells were successfully sensitized with epigallocatechin gallate catechin. The in vitro epigallocatechin gallate catechin effect as an enhancer of MAL-PDT in resistant cells is promising in the treatment of difficult skin cancer lesions.

Brown Seaweed Fucoidan in Cancer: Implications in Metastasis and Drug Resistance

Fucoidans are sulphated polysaccharides that can be obtained from brown seaweed and marine invertebrates. They have anti-cancer properties, through their targeting of several signaling pathways and molecular mechanisms within malignant cells. This review describes the chemical structure diversity of fucoidans and their similarity with other molecules such as glycosaminoglycan, which enable them to participation in diverse biological processes. Furthermore, this review summarizes their influence on the development of metastasis and drug resistance, which are the main obstacles to cure cancer. Finally, this article discusses how fucoidans have been used in clinical trials to evaluate their potential synergy with other anti-cancer therapies.

The Role of Clock Genes in Fibrinolysis Regulation: Circadian Disturbance and Its Effect on Fibrinolytic Activity

The fibrinolytic system is critical during the onset of fibrinolysis, a fundamental mechanism for fibrin degradation. Both tissue plasminogen activator (tPA) and urokinase plasminogen activator (uPA) trigger fibrinolysis, leading to proteolytic activation of plasminogen to plasmin and subsequently fibrin proteolysis. This system is regulated by several inhibitors; plasminogen activator inhibitor-1 (PAI-1), the most studied, binds to and inactivates both tPA and uPA. Through the action of plasmin, this system regulates several physiological processes: embryogenesis, activation of inflammatory cells, cell proliferation and death, synaptic plasticity, wound healing, and others. The deregulated intervention of fibrinolysis in the pathophysiology of various diseases has been widely studied; findings of altered functioning have been reported in different chronic non-communicable diseases (NCD), reinforcing its pleiotropic character and the importance of its physiology and regulation. The evidence indicates that fundamental elements of the fibrinolytic system, such as tPA and PAI-1, show a circadian rhythm in their plasmatic levels and their gene expression are regulated by circadian system elements, known as clock genes – Bmal, Clock, Cry-, and accessory clock genes such as Rev-Erb and Ror. The disturbance in the molecular machinery of the clock by exposure to light during the night alters the natural light/dark cycle and causes disruption of the circadian rhythm. Such exposure affects the synchronization and functioning of peripheral clocks responsible for the expression of the components of the fibrinolytic system. So, this circadian disturbance could be critical in the pathophysiology of chronic diseases where this system has been found to be deregulated.

Functional and transcriptomic characterization of cisplatin-resistant AGS and MKN-28 gastric cancer cell lines

Gastric cancer (GC) is a significant cancer-related cause of death worldwide. The most used chemotherapeutic regimen in GC is based on platinum drugs such as cisplatin (CDDP). However, CDDP resistance reduces advanced GC survival. In vitro drug-resistant cell model would help in the understanding of molecular mechanisms underlying this drug-resistance phenomenon. The aim of this study was to characterize new models of CDDP-resistant GC cell lines (AGS R-CDDP and MKN-28 R-CDDP) obtained through a stepwise increasing drug doses method, in order to understand the molecular mechanisms underlying chemoresistance as well as identify new therapeutic targets for the treatment of GC. Cell viability assays, cell death assays and the expression of resistance molecular markers confirmed that AGS R-CDDP and MKN-28 R-CDDP are reliable CDDP-resistant models. RNA-seq and bioinformatics analyses identified a total of 189 DEGs, including 178 up-regulated genes and 11 down-regulated genes, associated mainly to molecular functions involved in CDDP-resistance. DEGs were enriched in 23 metabolic pathways, among which the most enriched was the inflammation mediated by chemokine and cytokine signaling pathway. Finally, the higher mRNA expression of SERPINA1, BTC and CCL5, three up-regulated DEGs associated to CDDP resistance found by RNA-seq analysis was confirmed. In summary, this study showed that AGS R-CDDP and MKN-28 R-CDDP are reliable models of CDDP resistance because resemble many of resistant phenotype in GC, being also useful to assess potential therapeutic targets for the treatment of gastric cancers resistant to CDDP. In addition, we identified several DEGs associated with molecular functions such as binding, catalytic activity, transcription regulator activity and transporter activity, as well as signaling pathways associated with inflammation process, which could be involved in the development of CDDP resistance in GC. Further studies are necessary to clarify the role of inflammatory processes in GC resistant to CDDP and these models could be useful for these purposes.

Long-Term Effects of Altered Photoperiod During Pregnancy on Liver Gene Expression of the Progeny

Experimental and epidemiological studies have revealed a relationship between an adverse intrauterine environment and chronic non-communicable disease (NCD) like cardiovascular disease (CVD) in adulthood. An important risk factor for CVD is the deregulation of the fibrinolytic system particularly high levels of expression of plasminogen activator inhibitor 1 (Pai-1). Chronic exposure to altered photoperiod disrupts the circadian organization of physiology in the pregnant female, known as gestational chronodisruption, and cause long-term effects on the adult offspring's circadian physiology. The Pai-1 expression is regulated by the molecular components of the circadian system, termed clock genes. The present study aimed to evaluate the long-term effects of chronic photoperiod shifts (CPS) during pregnancy on the expression of the clock genes and the fibrinolytic system in the liver of adult male offspring. Our results using an animal model demonstrated statistically significant differences at the transcriptional level in males gestated under CPS. At 90 days of postnatal age, the liver transcript levels of the clock gene Bmal1 were downregulated, whereas Rorα, Rorγ, Nfil3, and Pai-1 were upregulated. Our data indicate that CPS during pregnancy affects gene expression in the liver of male adult progeny, showing that alteration of the photoperiod in the mother's environment leads to persistent effects in the offspring. In conclusion, these results reveal for the first time the long-term effects of gestational chronodisruption on the transcriptional activity of one well-established risk factor associated with CVD in the adult male offspring.

A reliable Epstein-Barr Virus classification based on phylogenomic and population analyses

The Epstein-Barr virus (EBV) infects more than 90% of the human population, playing a key role in the origin and progression of malignant and non-malignant diseases. Many attempts have been made to classify EBV according to clinical or epidemiological information; however, these classifications show frequent incongruences. For instance, they use a small subset of genes for sorting strains but fail to consider the enormous genomic variability and abundant recombinant regions present in the EBV genome. These could lead to diversity overestimation, alter the tree topology and misinterpret viral types when classified, therefore, a reliable EBV phylogenetic classification is needed to minimize recombination signals. Recombination events occur 2.5-times more often than mutation events, suggesting that recombination has a much stronger impact than mutation in EBV genomic diversity, detected within common ancestral node positions. The Hierarchical Bayesian Analysis of Population Structure (hierBAPS) resulted in the differentiation of 12 EBV populations showed seven monophyletic and five paraphyletic. The populations identified were related to geographic location, of which three populations (EBV-p1/Asia/GC, EBV-p2/Asia II/Tumors and EBV-p4/China/NPC) were related to tumor development. Therefore, we proposed a new consistent and non-simplistic EBV classification, beneficial in minimizing the recombination signal in the phylogeny reconstruction, investigating geography relationship and even infer associations to human diseases. These EBV classifications could also be useful in developing diagnostic applications or defining which strains need epidemiological surveillance.

Functional and transcriptomic characterization of carboplatin-resistant A2780 ovarian cancer cell line

Background

Ovarian cancer is a significant cancer-related cause of death in women worldwide. The most used chemotherapeutic regimen is based on carboplatin (CBDCA). However, CBDCA resistance is the main obstacle to a better prognosis. An in vitro drug-resistant cell model would help in the understanding of molecular mechanisms underlying this drug-resistance phenomenon. The aim of this study was to characterize cellular and molecular changes of induced CBDCA-resistant ovarian cancer cell line A2780.

Methods

The cell selection strategy used in this study was a dose-per-pulse method using a concentration of 100 μM for 2 h. Once 20 cycles of exposure to the drug were completed, the cell cultures showed a resistant phenotype. Then, the ovarian cancer cell line A2780 was grown with 100 μM of CBDCA (CBDCA-resistant cells) or without CBDCA (parental cells). After, a drug sensitivity assay, morphological analyses, cell death assays and a RNA-seq analysis were performed in CBDCA-resistant A2780 cells.

Results

Microscopy on both parental and CBDCA-resistant A2780 cells showed similar characteristics in morphology and F-actin distribution within cells. In cell-death assays, parental A2780 cells showed a significant increase in phosphatidylserine translocation and caspase-3/7 cleavage compared to CBDCA-resistant A2780 cells (P < 0.05 and P < 0.005, respectively). Cell viability in parental A2780 cells was significantly decreased compared to CBDCA-resistant A2780 cells (P < 0.0005). The RNA-seq analysis showed 156 differentially expressed genes (DEGs) associated mainly to molecular functions.

Conclusion

CBDCA-resistant A2780 ovarian cancer cells is a reliable model of CBDCA resistance that shows several DEGs involved in molecular functions such as transmembrane activity, protein binding to cell surface receptor and catalytic activity. Also, we found that the Wnt/β-catenin and integrin signaling pathway are the main metabolic pathway dysregulated in CBDCA-resistant A2780 cells.

Electronic supplementary material

The online version of this article (10.1186/s40659-019-0220-0) contains supplementary material, which is available to authorized users.

Loss of ZNF516 protein expression is related with HR-HPV infection and cervical preneoplastic lesions

PURPOSE

Cervical cancer is an important health issue among women worldwide. Cervical smear and human papillomavirus detection are the most used screening methods to detect preneoplastic and neoplastic lesions. However, as neither can predict cervical development, new markers are needed for this disease. ZNF516, a potential tumor suppressor gene, has been found altered in cervical cancer. The objective of this study was to determine ZNF516 immunohistochemistry frequency in cervical biopsies and its association with clinicopathological parameters, to evaluate its potential as marker in cervical lesions.

METHODS

A retrospective series of 452 formalin-fixed, paraffin-embedded (FFPE) cervical biopsies, obtained between 2002 and 2007, were selected for immunohistochemistry of ZNF516, p16 and Ki-67 markers. Human papillomavirus genotyping was performed on 272 of these samples through reverse line blot assay.

RESULTS

An inverse relation between ZNF516 expression and cervical lesions grade (P < 0.001) was observed, given this protein was found mainly expressed in normal tissues, while was decreased in cervical lesions. As expected, the proliferation markers p16 and Ki-67 were found highly expressed in cervical cancer compared to normal tissues, and inversely correlated to ZNF516 expression (P < 0.01). High oncogenic risk-Human papillomavirus presence also was related to the lack of ZNF516 expression in cervical lesions (P < 0.05), and the detection of these two parameters showed a high sensitivity (70.9%) for preneoplastic lesions detection.

CONCLUSIONS

The loss of ZNF516 expression was found in cervical lesions, and its detection potentially could be used as a complementary marker of early diagnosis in cervical lesions.

Detection and genotyping of human papillomavirus virus (HPV): a comparative analysis of clinical performance in cervical and urine samples in Chilean women

Human papillomavirus (HPV) is the most common sexually transmitted infectious agent and is the main cause of cervical cancer (CC). In Chile, CC is the second leading cause of death by cancer in women aged 20-44 years, four times higher than in developed countries. Currently, the detection of HPV infection using a cervical brush is recommended; however, this is an invasive procedure that many women try to avoid. The aim of this study was to evaluate the clinical performance of a self-collected, urine-based HPV detection method using conventional PCR followed by a reverse line blot. A PCR-based HPV genotyping was performed on 190 paired cervical and urine samples from gynecological exams at public health centers in the Araucania Region, Chile. HPV DNA detection and genotyping were performed by PCR and reverse line blot assay. Carcinogenic HPV types were present in 64.7% and 65.8% of the cervical and urine samples; the infection rates of HPV16 were 34.7% and 33.2%, respectively. The overall percent agreement between carcinogenic HPV detection in cervical and urine samples was 73.7%, with a moderate concordance rate of carcinogenic HPV detection (kappa = 0.42). Clinical sensitivities for cervical and urine-based sampling methods to diagnose cervical intraepithelial neoplasia 2/3 (CIN2/3) by histology were 93.4% and 90.2%, respectively. These results suggest that both cervical brush and urine-based sampling show a good clinical performance in the detection of HPV infection. The urine-based sampling method represents a valuable alternative with a great impact on public health, allowing increased cervical cancer screening coverage among women who do not undergo pelvic examinations.

Frequency of Human papillomavirus in women attending cervical cancer screening program in Chile

Background

Human papillomavirus (HPV) is the etiological factor for cervical cancer and its precursor lesions. The characterization of HPV genotypes in preneoplastic lesions and cervical cancer could establishes the effectiveness of vaccination plan in Chilean population. The aim of this study was to determine HPV frequency in a group of women including in a cervical screening program in the public health care system in Chile.

Methods

We analyzed 985 cervical smears samples from women with different histological diagnosis, attending to public health care in Temuco-Chile between 2004 and 2012, to detect HPV genotypes, through PCR followed by reverse line blotting assay.

Results

HPV was found present in 80.8% (n = 796) of samples. Only a 5.6% of 985 samples were infected with a low-risk HPV, considering multiple infections. 10.5% (n = 8/76) of normal cervical epithelia, 83.5% (n = 208/249) and 87.6% (n = 557/636) of low and high grade squamous intraepithelial lesions, respectively, and 95.8% (n = 23/24) of squamous cervical carcinomas tested positive for HPV. HPV 16 was the most frequent genotype found (Overall 44.9%, n = 442/985; SCC: 62.5%, n = 15/24). A high variability of HPV types was also found in preneoplastic lesions, whereas there was a selection of genotypes in neoplasia. Also, there was a higher risk of infection with HPV 16 in women ≤26 years and 34–41 years old (p < 0.05), meanwhile infections with HPV 16 or HPV 18 have related with cancer development (p < 0.01).

Conclusions

These data provide further information about the frequency of HPV genotypes in women with cervical lesions in Chile, and the introduction of new targeted vaccines against a wider spectrum of HPV is suggested.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3496-x) contains supplementary material, which is available to authorized users.

[Molecular detection of sexually transmitted agents in a symptomatic group of men and its relationship with sexual behavior]

BACKGROUND

Sexually transmitted infections (STIs) affect sexual and reproductive health of millions of men. Pathogens such as human papillomavirus (HPV), herpes simplex virus type 1 and 2 (HSV-1 y HSV-2), Chlamydia trachomatis,Mycoplasmagenitalium,Mycoplasma hominis and Ureaplasma urealyticum are associated with STIs.

AIM

To detect pathogens associated with STIs in symptomatic men and its relationship with sexual behavior.

METHODOLOGY

DNA was obtained from exfoliated cells of penis from 20 symptomatic men. Pathogens were detected using qPCR or PCR followed by reverse line blot. Sexual behavior was evaluated through a survey.

RESULTS

Two or more infectious agents were detected in 50% of samples. U. urealyticum was found in 25%, meanwhile C. trachomatis and M. hominis were detected in 15%. VHS-1, VHS-2 andM. genitalium were detected only in 5%. HPV was found in all samples. The most frequent HPV genotypes were VPH 16, 11, 70. There were no statistical link found between sexual behavior and the studied microorganisms Conclusion: Infectious agents associated with STIs were detected in symptomatic men. HPV was the most frequent pathogen and it was detected in multiple genotypes. It is necessary to increase the sample size to associate significantly the sexual behavior with the results.

Abstract B29: ZNF516 a potential tumor suppressor gene candidate is implied in tumor progression in cervical cancer

Background: In Cervical Cancer (CC) the role of HPV is fundamental; however, not all HPV infected women will develop this disease. Therefore, other mechanisms, such as silencing of tumor suppressor genes (TSG), could be implied in cervical carcinogenesis. In a previous study, we constructed methylation microarrays, where we found promoter aberrant hypermethylation of ZNF516 gen in CC, postulating it as TSG candidate. The aim of this study was to characterizer ZNF516 role in cervical carcinogenesis and cell cycle.

Materials and methods: ECT1 E6/E7 (immortalized normal squamous epithelia cell line) and three CC cell lines: SiHa, C-4I and C-33A were cultivated for experiments. ZNF516 expression was determined by qRT-PCR and western blot. Treatment with 10 μM 5-aza-2′deoxycytidine (5- aza) was performed to evaluate a possible epigenetic regulation. Transfection with pCMV6-ZNF516-GFP (ZNF516) and pCMV6-GFP (Empty) was carried out in C-33A cell line through lipofection followed by G418 selection to obtain stable transfection. Viability and clonogenic assay was performed to evaluate transfected cell behaviour. Also, immnunohistochemical analysis was performed in 509 cervical biopsy tissues (55 normal; 188 low-squamous intraepithelial lesions; 205 high- squamous intraepithelial lesions and 57 squamous cervical cancers).

Results: ZNF516 mRNA expression was significantly downregulated in SiHa (p&lt;0.01) and C-33A (p&lt;0.001) respect to ECT1 E6/E7. Western blot showed a deregulated protein expression of ZNF516 in all CC cell lines. After treatment with 5-aza, mRNA (p&lt;0.05) and protein expression of ZNF516 of all CC cell lines were restored. ZNF516 transfected C-33A showed a significant colony formation (p&lt;0.01) and viability (p&lt;0.01) decrease compared with C-33A transfected with the empty vector. Nuclear expression of ZNF516 in cervical biopsies showed a diminished expression in SCC respect to normal epithelia (p&lt;0.001)

Conclusions: There is a clear ZNF516 dysregulation in CC cell lines, and the inactivation mechanism seem to be methylation. Restored expression of ZNF516 in C-33A cell line modifies the tumor phenotype, decreasing cellular viability and colony formation. These results suggest that ZNF516 could be a TSG, and its inactivation promotes CC developing.

Citation Format: Carmen Gloria Ili, Tamara Viscarra, Juan Carlos Araya, Jaime Lopez, Barbara Mora, Javier Retamal, Enrique Bellolio, Susana Aedo, Juan Carlos Roa, Priscilla Brebi. ZNF516 a potential tumor suppressor gene candidate is implied in tumor progression in cervical cancer. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr B29.

Abstract A31: Reprimo, a potential tumor suppressor gene TP53-dependent, modulates negatively cell migration and invasion in the MDA-MB-231 breast cancer cell line

Background: Reprimo, a highly glycosylated protein, is a new downstream effector of p53-induced cell cycle arrest at the G2/M checkpoint, and a putative tumor suppressor gene frequently silenced via methylation of its promoter region in several malignances. The aim of this study was to characterize the epigenetic inactivation and its biological function in BC cell lines.

Methods: The correlation between Reprimo methylation and loss of mRNA expression was assessed in six breast cancer cell lines by methylation specific PCR (MSP), 5-Aza-2′-deoxycytidine treatment and qRT-PCR assays. MDA-MB-231 cells were chosen to investigate the phenotypic effect of Reprimo in cell proliferation, cell cycle, cell death, cell migration and invasion.

Results: In the cancer methylome system (CMS) (web-based system for visualizing and analyzing genome-wide methylation data of human cancers), the CpG island region of RPRM (1,1Kb) was hypermethylated in breast cancer compared to normal breast tissue. Downregulation of RPRM mRNA by methylation was confirmed in MDA-MB-231 and BT-20 cell lines. In addition, overexpression of RPRM in MDA-MB-231 cells resulted in decreased rates of cell migration, wound healing and invasion in vitro (P &lt; 0.0001). However, RPRM overexpression did not alter cell viability, rate of death cell and G2/M cell cycle transition in this biological model.

Conclusion: Taken together, these data suggest that RPRM is involved in decreased cell migration and invasion in vitro, acting as a potential tumor suppressor gene in the MDA-MB-231 cell line.

Citation Format: Kurt Buchegger, Tamara Viscarra, Carmen Gloria Ili, Ismael Riquelme, Pablo Letelier, Alejandro Corvalan, Priscilla Brebi, Tim Hui-Ming Huang, Juan Carlos Roa. Reprimo, a potential tumor suppressor gene TP53-dependent, modulates negatively cell migration and invasion in the MDA-MB-231 breast cancer cell line. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr A31.

Abstract B30: Resistance to Photodynamic Therapy in Non-Melanoma Skin Cancer Cells

Introduction: Squamous skin cancer is one of the most common neoplasia worldwide and may be preceded by Bowen's disease (BD) and Actinic Keratosis (AK). These preneoplastic lesions can be treated with photodynamic therapy (PDT). PDT causes cell death mainly by reactive oxygen species (ROS) produced through a combination of O2, a photosensitizer and light. BD and AK have well overcomes after PDT. However, high recurrence rates of some lesions have been reported.

Objective: To generate resistant cells to PDT as an in vitro model for future studies.

Methodology: HSC-1 cells from human squamous cell cancer (SCC) of skin were used. Cells were treated with a total of 16 cycles of PDT. Every PDT cycle was carried out incubating cells with methyl aminolevulinate (MAL), as a protoporphyrin IX (PpIX) precursor, for 4 hours in the dark. Then, cells were irradiated with red light (630 nm). The light fluence used for the four first cycles was 1 J/cm2, for subsequent cycles light fluence increased to 2, 3 and 4 J/cm2. Cell viability was evaluated 1 and 24 hours after PDT by flow cytometry and MTT assay respectively. Intracellular PpIX was detected by flow cytometry and the PpIX content was quantified using a standard curve. By flow cytometry using a CM-H2DCFDA probe intracellular ROS was detected.

Results: After 24 hours of PDT (4 J/cm2), viability in parental HSC-1 cells was 5%, meanwhile in resistant cells was 70% (P &lt; 0.05). On the other hand, 88% of parental cells produced PpIX (40 ng/mg protein) and 18% of resistant cells produced PpIX (17 ng/mg protein) (P &lt; 0.05). No significant differences were found in ROS detection in both parental and resistant cells.

Conclusion: The results indicate that it was possible to obtain HSC-1 cells two-fold resistant to PDT compared to their parental cells.

Acknowledgments: Financial support by CONICYT. CONICYT-PCHA/Doctorado Nacional/2012-21120665, CORFO 09CN14-5960, Corfo N°12IDL2-18157, FONDECYT N° 11150802, FONDECYT N°11150622.

Citation Format: Daniela Leon, Ramon Silva, Natalia Inada, Cristina Kurachi, Carmen Gloria Ili, Priscilla Brebi, Juan Carlos Roa. Resistance to Photodynamic Therapy in Non-Melanoma Skin Cancer Cells. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr B30.

Reprimo as a modulator of cell migration and invasion in the MDA-MB-231 breast cancer cell line

Background

Reprimo (RPRM), a highly glycosylated protein, is a new downstream effector of p53-induced cell cycle arrest at the G2/M checkpoint, and a putative tumor suppressor gene frequently silenced via methylation of its promoter region in several malignances. The aim of this study was to characterize the epigenetic inactivation and its biological function in BC cell lines.

Methods

The correlation between RPRM methylation and loss of mRNA expression was assessed in six breast cancer cell lines by methylation specific PCR (MSP), 5′-Aza-2′-deoxycytidine treatment and RT-PCR assays. MDA-MB-231 cells were chosen to investigate the phenotypic effect of RPRM in cell proliferation, cell cycle, cell death, cell migration and invasion.

Results

In the cancer methylome system (CMS) (web-based system for visualizing and analyzing genome-wide methylation data of human cancers), the CpG island region of RPRM (1.1 kb) was hypermethylated in breast cancer compared to normal breast tissue; more interesting still was that ERα(+) tumors showed higher methylation intensity than ERα(−). Downregulation of RPRM mRNA by methylation was confirmed in MDA-MB-231 and BT-20 cell lines. In addition, overexpression of RPRM in MDA-MB-231 cells resulted in decreased rates of cell migration, wound healing and invasion in vitro. However, RPRM overexpression did not alter cell viability, phosphatidylserine (PS) translocation or G2/M cell cycle transition.

Conclusion

Taken together, these data suggest that RPRM is involved in decreased cell migration and invasion in vitro, acting as a potential tumor suppressor gene in the MDA-MB-231 cell line.

Evaluation of ZAR1 and SFRP4 methylation status as potentials biomarkers for diagnosis in cervical cancer: exploratory study phase I

CONTEXT

Aberrant hypermethylation of promoter region of tumor suppressor genes could be used as cancer biomarkers.

OBJECTIVE

To test methylation status of ZAR1 and SFRP4 promoter regions as potentials biomarkers for diagnosis of preneoplastic and neoplastic lesions of cervix.

MATERIALS AND METHODS

Cytobrush samples were evaluated by Methylation specific PCR (MSP) and quantitative MSP (qMSP).

RESULTS

ZAR1 and SFRP4 methylation frequency increased as the grade of lesion increased and the differences between normal and cervical cancer (CC) are statistically significant (p < 0.0001). qMSP showed higher ZAR1 and SFRP4 methylation levels in cancer than normal epithelia (p < 0.001) and preneoplastics lesions (p < 0.01).

DISCUSSION

qMSP quantify methylation levels and have high sensitivity and specificity.

CONCLUSION

ZAR1 and SFRP4 qMSP could be used as potential biomarker for CC diagnosis.

[Genotyping of human papillomavirus in women under 25 years old treated in the screening program for cervical cancer]

BACKGROUND

In Chile, cervical cancer (CC) is the second leading cause of death from malignancy in women. The main causal agent of cervical cancer is the human papillomavirus (HPV). This virus is the most common sexually transmitted infection among sexually active youth. An early onset of sexual life increases the chances of HPV infection; this may involve a possible early development of cervical intraepithelial neoplasia and CC, creating a major public health problem.

OBJECTIVE

To present HPV frequency in women under the age of 25, treated in the CC screening program and their follow-up after histopathological diagnosis.

METHODS

173 cervical samples were genotyped by polymerase chain reaction and non-radioactive reverse hybridization (line blot).

RESULTS

The overall frequency of HPV was 84.8%. HPV16 was the most prevalent. In 12.1% of women the cervical lesion persisted or progressed. 28.9% of women had irregular follow-up; in this group, 88% were HPV(+) and 52% had no record of Pap smear in the past 3 years.

DISCUSSION

The results reaffirm the usefulness of complementing the Pap and HPV detection as a primary screening tool in sexually active women. They also suggest the possibility of extending the age coverage of the national screening program.

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.

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.

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 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

Abstract 4789: Human papillomavirus genotyping in urine samples of women with squamous intraepithelial lesions of cervix

Human papillomavirus (HPV) is the most frequent microorganism sexually transmitted and is the causal agent of cervical carcinoma were it could be found in 99.7% of cases. The detection of HPV en women with or without lesions of cervix is generally performed in biopsies and cytobrush, which are invasive samples; therefore many patients do not attend to health care to get HPV test. The aim of this study was to develop a technique capable of detect and genotype HPV in urine samples of women with squamous intraepithelial lesions of cervix.

For this study, 87 urine samples from patients with normal epithelia of cervix (25), low grade squamous intraepithelial lesion (LSIL) (24), high grade squamous intraepithelial lesion (HSIL) (38) were collected from women who attended to gynecological care in a public health center in Temuco, Chile. DNA extraction was performed with a manual method. For protein precipitation, Phenol-Chloroform and ammonium acetate were used. DNA precipitation was performed with absolute ethanol. HPV detection and genotyping was performed with the kit HPV Typing (patent pending) which is capable of detect 18 more frequent HPV types and beta globin gen as control of DNA integrity.

20% of urines from normal epithelia women were positive for HPV. Three genotypes were found in normal samples: HPV52, HPV42 and HPV53. LSIL there was a 92% of HPV positivity and the most frequent genotypes were HPV16 and HPV18. In HSIL, 95% of urine sample were positive for HPV. HPV16, HPV18 and HPV31 were the most frequent genotypes in HSIL. Genotypes found in urine samples were similar to world reports.

Using the DNA extraction described before and HPV easy typing kit it is possible to detect and genotype HPV in urine samples. These results suggest that is possible a HPV primary screening test in non-invasive sample, complementing PAP smear in order to determinate which women have a higher risk of developing preneoplastic and neoplastics lesions.

Grant Support: 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: Tamara Viscarra, Alejandra Andana, Priscilla Brebi, Doris Menzel, Carmen G. Ili, Ramon Silva, Juan C. Roa, Raul Sanchez. Human papillomavirus genotyping in urine samples of women with squamous intraepithelial lesions of cervix. [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 4789. doi:10.1158/1538-7445.AM2013-4789