Genetic Patterns Found in the Nuclear Localization Signals (NLSs) Associated with EBV-1 and EBV-2 Provide New Insights into Their Contribution to Different Cell-Type Specificities.

The Epstein-Barr virus (EBV) is a globally dispersed pathogen involved in several human cancers of B-cell and non-B-cell origin. EBV has been classified into EBV-1 and EBV-2, which have differences in their transformative ability. EBV-1 can transform B-cells into LCL more efficiently than EBV-2, and EBV-2 preferentially infects T-cell lymphocytes. The EBNA3A oncoprotein is a transcriptional regulator of virus and host cell genes, and is required in order to transform B-cells. EBNA3A has six peptide motifs called nuclear localization signals (NLSs) that ensure nucleocytoplasmic protein trafficking. The presence of multiple NLSs has been suggested to enhance EBNA3 function or different specificities in different cell types. However, studies about the NLS variability associated with EBV types are scarce. Based on a systematic sequence analysis considering more than a thousand EBNA3A sequences of EBV from different human clinical manifestations and geographic locations, we found differences in NLSs' nucleotide structures among EBV types. Compared with the EBNA3A EBV-1, EBNA3A EBV-2 has two of the six NLSs altered, and these mutations were possibly acquired by recombination. These genetic patterns in the NLSs associated with EBV-1 and EBV-2 provide new information about the traits of EBNA3A in EBV biology.

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 5­10 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.

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.

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.

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/ß-catenin and integrin signaling pathway are the main metabolic pathway dysregulated in CBDCA-resistant A2780 cells.

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/3-catenin and integrin signaling pathway are the main metabolic pathway dysregulated in CBDCA-resistant A2780 cells.

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.

Reprimo, a Potential p53-Dependent Tumor Suppressor Gene, Is Frequently Hypermethylated in Estrogen Receptor α-Positive Breast Cancer.

Aberrant DNA methylation is a hallmark of many cancers. Currently, there are four intrinsic molecular subtypes in breast cancer (BC): Luminal A, B, Her2-positive, and triple negative (TNBC). Recently, The Cancer Genome Atlas (TCGA) project has revealed that Luminal subtypes have higher levels of genome-wide methylation that may be a result of Estrogen/Estrogen receptor α (E2/ERα) signaling pathway activation. In this study, we analyze promoter CpG-island (CGIs) of the Reprimo (RPRM) gene in breast cancers (n = 77), cell lines (n = 38), and normal breast tissue (n = 10) using a MBDCap-seq database. Then, a validation cohort (n = 26) was used to confirm the results found in the MBDCap-seq platform. A differential methylation pattern was found between BC and cell lines compared to normal breast tissue. In BC, a higher DNA methylation was observed in tissues that were ERα-positive than in ERα-negative ones; more precisely, subtypes Luminal A compared to TNBC. Also, significant reverse correlation was observed between DNA methylation and RPRM mRNA expression in BC. Our data suggest that ERα expression in BC may affect the DNA methylation of CGIs in the RPRM gene. This approach suggests that DNA methylation status in CGIs of some tumor suppressor genes could be driven by E2 availability, subsequently inducing the activation of the ERα pathway.

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.

Frecuencia de la infección por Chlamydia trachomatis en un grupo de mujeres de la Región de la Araucanía, Chile / Frequency of Chlamydia trachomatis infection in a group of women from Region of Araucanía, Chile

Background: Chlamydia trachomatis infection is the most commonly reported sexually transmitted bacterial infection worldwide. Between 70 and 90% of women are asymptomatic, however, untreated and persistent infections can lead to the development of urethritis, pelvic inflammatory disease, infertility and ectopic pregnancy. Aims: To determine C. trachomatis infection frequency in a group of women in Chile, using quantitative real time PCR (qPCR) and to compare the usefulness of endocervical and urine samples for C. trachomatis detection. Methods: 87 asymptomatic women aged 15-64 years were included. Every woman donated one endocervical sample and one urine sample. Detection and quantification of C. trachomatis was performed by qPCR. Results: Of 87 endocervical samples, the frequency was 11.49% (n = 10). Of these samples, 5 cases were found in women < 35 years old. About urine samples, 16 samples were positive (18.39%). Ten women < 35 years old yielded positive urine samples. Only four women had both samples positive for C. trachomatis (4.6%). There was no statistically significant relationship between age and C. trachomatis infection. Cryptic plasmid quantification was found between 3.55 - 96.050 copies/μL for endocervical samples and 7.22-633.1 copies/μL for urine samples. Conclusion: Estimated frequency of C. trachomatis in Chilean women was higher than previous Chilean studies. Both types of samples are complementary for screening and diagnosis strategies using sensitive techniques, because silent infection can be present in either urinary or genital tract or in both in women.

Introducción: La infección por Chlamydia trachomatis es la infección bacteriana de transmisión sexual más frecuente en el mundo. Entre 70 y 90% de las mujeres son asintomáticas; sin embargo, las infecciones sin tratar y persistentes permiten el desarrollo de uretritis, enfermedad inflamatoria pélvica, infertilidad y embarazo ectópico. Objetivos: Determinar la frecuencia de infección por C. trachomatis en un grupo de mujeres chilenas, mediante RPC en tiempo real cuantitativa (qPCR) y comparar la utilidad de muestras endo-cervicales y de orina para la detección de C. trachomatis. Metodología: Participaron 87 mujeres asintomáticas (15-64 años). Cada mujer donó una muestra endo-cervical y una de orina. Se realizó detección y cuantificación C. trachomatis mediante qPCR. Resultados: La frecuencia de infección por C. trachomatis en muestras endo-cervicales fue de 11,49% (n: 10) y en muestras de orina de 18,39% (n: 16). El mayor número de casos se encontró en mujeres < 35 años. Sólo en cuatro mujeres se detectó C. trachomatis en ambas muestras (4,6%). La cuantificación de plásmido críptico se encontró en un rango 3,55 - 96.050 copias/μL. Conclusión: La frecuencia estimada de C. trachomatis fue más alta que en otros estudios chilenos. Ambos tipos de muestra deberían ser complementarias para estrategias de tamizaje y diagnóstico de C. trachomatis usando técnicas sensibles de detección, ya que la infección puede desarrollarse en el tracto genital y/o en el tracto urinario en mujeres.

[Frequency of Chlamydia trachomatis infection in a group of women from Region of Araucanía, Chile]. / Frecuencia de la infección por Chlamydia trachomatis en un grupo de mujeres de la Región de la Araucanía, Chile.

BACKGROUND: Chlamydia trachomatis infection is the most commonly reported sexually transmitted bacterial infection worldwide. Between 70 and 90% of women are asymptomatic, however, untreated and persistent infections can lead to the development of urethritis, pelvic inflammatory disease, infertility and ectopic pregnancy. AIMS: To determine C. trachomatis infection frequency in a group of women in Chile, using quantitative real time PCR (qPCR) and to compare the usefulness of endocervical and urine samples for C. trachomatis detection. METHODS: 87 asymptomatic women aged 15-64 years were included. Every woman donated one endocervical sample and one urine sample. Detection and quantification of C. trachomatis was performed by qPCR. RESULTS: Of 87 endocervical samples, the frequency was 11.49% (n = 10). Of these samples, 5 cases were found in women < 35 years old. About urine samples, 16 samples were positive (18.39%). Ten women < 35 years old yielded positive urine samples. Only four women had both samples positive for C. trachomatis (4.6%). There was no statistically significant relationship between age and C. trachomatis infection. Cryptic plasmid quantification was found between 3.55 - 96.050 copies/µL for endocervical samples and 7.22-633.1 copies/µL for urine samples. CONCLUSION: Estimated frequency of C. trachomatis in Chilean women was higher than previous Chilean studies. Both types of samples are complementary for screening and diagnosis strategies using sensitive techniques, because silent infection can be present in either urinary or genital tract or in both in women.