Renata Dalmaschio Daltoé

Evaluation of PvuII and XbaI polymorphisms in the estrogen receptor alpha gene (ESR1) in relation to menstrual cycle timing and reproductive parameters in post-menopausal women

OBJECTIVE To evaluate the association of -397T>C and -351A>G single nucleotide polymorphisms (SNPs) - also called PvuII and XbaI, respectively - located on estrogen receptor alpha (ERS1) gene with age at menarche, menopause onset, fertility and miscarriage in a population of post-menopausal women. STUDY DESIGN Cross-sectional study with 273 healthy, high miscegenated, post-menopausal women (mean age of 63.1±9.7 years old). Subjects were genotyped for PvuII and XbaI SNPs by PCR-RFLP and confirmed by automatic sequencing. Reproduction informations (age at menarche, age at menopause, number of pregnancies, fertility rate and miscarriages) were obtained by retrospective study using a questionnaire. RESULT(S) Age at menarche, menopause onset, number of pregnancies, total fertility rate, and parity did not seem to be influenced by any of the studied genotypes (chi-square, p>0.05). However, women carrying the xx genotype showed a 44% higher chance of miscarriage, whereas this value did not trespass 16% for any other genotype analyzed. It has been also observed a higher occurrence of miscarriage in association with combined xxpp genotype of ERS1 gene (chi-square, p<0.01). CONCLUSION(S) The present data indicate that the studied SNPs on ERS1 gene do not influence the menstrual cycle timing and parity but there is a strong relationship between the xx ERS1 SNP genotype and the incidence of miscarriage in the post-menopausal population analyzed.

Metformin synergistically enhances antiproliferative effects of cisplatin and etoposide in NCI-H460 human lung cancer cells.

OBJECTIVE: To test the effectiveness of combining conventional antineoplastic drugs (cisplatin and etoposide) with metformin in the treatment of non-small cell lung cancer in the NCI-H460 cell line, in order to develop new therapeutic options with high efficacy and low toxicity. METHODS: We used the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and calculated the combination index for the drugs studied. RESULTS: We found that the use of metformin as monotherapy reduced the metabolic viability of the cell line studied. Combining metformin with cisplatin or etoposide produced a synergistic effect and was more effective than was the use of cisplatin or etoposide as monotherapy. CONCLUSIONS: Metformin, due to its independent effects on liver kinase B1, had antiproliferative effects on the NCI-H460 cell line. When metformin was combined with cisplatin or etoposide, the cell death rate was even higher.

Estrogen receptor alpha (ERS1) SNPs c454-397T>C (PvuII) and c454-351A>G (XbaI) are risk biomarkers for breast cancer development

There are several risk factors related to Breast Cancer (BC) risks and response to chemotherapy with SERMs. Recently some single nucleotide polymorphisms (SNPs) on ESR1 gene have been associated to this disease. However, data are still inconclusive. The present study aimed to investigate the association of SNPs c454-397T>C (also called PvuII) and c454-351A>G (so called XbaI) to incidence of sporadic BC; ERα expression in BC; tamoxifen hormonetherapy (HT-TMX) responsiveness. To do so, a cohort of BC patients was analyzed through retrospective data collection, immunohistochemistry to ERα protein, and genotyping for PvuII and XbaI SNPs by PCR–RFLP, confirmed by sequencing. Significant difference in PvuII alleles frequencies were found BC patients when compared to control samples. Patients with P allele have a 5.14-fold increased BC risk. We found higher P and X alleles frequencies in ERα positive BC and the pp and xx genotypes were observed exclusively in patients with HT-TMX-responsive BC. Taken together, data indicates that P allele as a novel sporadic BC biomarker whereas p and x alleles enhanced chemotherapy responsiveness.

Prevalence of estrogen receptor alpha PvuII (c454-397T>C) and XbaI (c454A>G) polymorphisms in a population of Brazilian women

The aim of this work was to study the estrogen receptor alpha (ERS1) PvuII and XbaI gene polymorphisms prevalence in randomly selected women population from Rio de Janeiro and Espirito Santo states in Brazil by polymerase chain reaction restriction fragment lengths polymorphism (PCR_RFLP) methodology. It was shown that Rio de Janeiro women exhibited a significantly different prevalence of XbaI polymorphism comparing to Espirito Santo women. Nonetheless, similar prevalence of PvuII polymorphism was found in both women´s populations. Moreover, a strong linkage disequilibrium was observed between these SNPs reinforcing the hypothesis of differential pattern of inheritance observed on such populations.

Synthesis, Antitumor Activity and Docking of 2,3-(Substituted)-1,4-Naphthoquinone Derivatives Containing Nitrogen, Oxygen and Sulfur

Eleven 2,3-(substituted)-1,4-naphthoquinone derivatives were synthesized in yields ranging from 52-89%. These derivatives were evaluated for their cytotoxic effects on human lungs (H460), triple-negative breast (MDA-MB-231) and ovarian (A2780) cancer cell lines. Compounds 5f and 8 showed IC50values of 3.048 × 10-5 mol L-1 and 4.24 × 10-6 mol L-1 for H460; 5c and 8showed IC50 values of 2.16 × 10-5 mol L-1 and 1.60 × 10-5 mol L-1 for MDA-MB-231, and 5gand 8 showed IC50 values of 2.68 × 10-6 mol L-1 and 3.89 × 10-6 mol L-1 for A2780. Additionally, we conducted a docking study with the four most active compounds and the therapeutic targets PI3K and topoisomerase II showing the pharmacophoric conformation of these compounds.

Comparison of immunohistochemical analysis with estrogen receptor SP1 and 1D5 monoclonal antibodies in breast cancer

In the present study, we aimed to evaluate estrogen receptor ER-alpha status in 61 breast cancer cases using Sp1 and 1D5 monoclonal antibodies. Tissue array platforms were generated containing samples of breast cancer and positive controls that were assayed by immunohistochemistry applying monoclonal primary antibodies anti-ER alpha, SP1 and 1D5. We noted a high concordance rate (96.7%) between the referred antibodies. Moreover, we calculated the Kappa factor (0.921), indicating that 1D5 and SP1 provided overlapping ERα expression results. Indeed, we observed controversial results only in 2 samples studied, which were ER-negative when stained with 1D5 and ER-positive when assessed with SP1. Total concordance of PS was obtained (Pearson and intraclass CF, 0.7351 and 0.6193, respectively). However, concordance between the antibodies seems to be more accurate in higher PS values. An excellent IS correlation between antibodies was observed throughout the population (Spearmans CF, ρ=0.9150). Following the Allred score, 17 out of 42 positive BC samples diverged, with 1D5 always pointing to weaker staining than SP1. When calculating Spearmans CF of Total Score (TS) within the population, an excellent correlation between both the antibodies (ρ=0.9238) was noted. Nonetheless, the results were less concordant among the BC-positive cases (ρ=0.7743). Indeed, 20 samples were differentially classified using the antibodies (only 3 had higher TS with 1D5). Considering the mean TS of all samples or of invasive ductal carcinoma, SP1 provided higher scores than 1D5 (p<0.05). We recommend the use of the anti-ER RMAb SP1 due to the high probability that the BC ERα status can be determined accurately as the reagent provides higher IS. Therefore, the A-score was higher than the MMAb 1D5. Ultimately, higher IS and A-score decrease the possibility of ERα status misinterpretation and, consequently, inappropriate BC treatment that would compromise the patients quality of life and overall survival. We recommend the use of anti-ER RMAb SP1 due to the high probability that the BC ER status can be determined accurately as the reagent provides higher IS, therefore higher A-score, than the MMAb 1D5.

Conventional Cancer Treatment

Concurrently with the new discoveries of chemotherapeutic agents, the remarkable scientific and technological development allowed understanding of cell biology of human cancer cells and thereby the emergence of targeted therapy. Although the targeted therapy drugs have had outstanding successes in selected types of cancer, new therapies are not likely to replace cytotoxic agents in the foreseeable future. Rather, clinical trials have demonstrated potent synergy between targeted molecules and traditional cytotoxic agents.

Opening the door to the development of novel Abl kinase inhibitors

The discovery of the importance of kinase activity and its relationship to the emergence and proliferation of cancer cells, due to changes in normal physiology, opened a remarkable pathway for the treatment of chronic myelogenous leukemia through intense search of drug candidates. Six Abl kinase inhibitors have received the US FDA approval as chronic myelogenous leukemia treatment, and continuous efforts in obtaining new, more effective and selective molecules are being carried out. Herein we discuss the mechanisms of Abl inhibition, structural features and ligand/protein interactions that are important for the design of new Abl kinase inhibitors. This review provides a broad overview of binding mode predictions, through molecular docking, which can be an approach to discover novel Abl kinase inhibitors.

Abstract 2626: Novel naphtoquinone PIC21 targets PI3K in triple negative breast cancer cell line

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Background: Triple negative breast cancer (TNBC) is a heterogeneous subgroup (ER-, PR-, and HER2-) of aggressive breast cancer, which poor prognosis is partially due to chemoresistance to available drugs. We have synthesized and screened 43 novel naphtoquinone-derived drugs (patent-protected), rationally designed to act through multiple pathways to avoid tumor chemoresistance, in MDA-MB231 by cellular metabolic viability and IC50 calculation. Of these, the most promising drugs PIC20 and PIC21 showed significantly higher AE than cisplatin, doxorubicin and paclitaxel in the lineage. Methods: Based on the crystalline structure of protein deposited on Protein Data Bank ( 1E7U, PI3K), and PIC20 and PIC21 tridimensional structures, computational molecular dock studies were conducted to investigate the molecules PIC20 e PIC21 tridimensional conformation and bounding energy to PI3K (Autodock Vina software). In vitro PI3K inhibition by PIC21 in MDA-MB231 was assessed using the Flowcellect PI3K/Mapk Dual Pathway Activation and Cancer Marker Detection. For PI3K/Akt and MAPK signaling pathways, cells were pre treated with PIC21 (0,1mM, 2h) or Wortmannin (Wort) (0,1μM, 30 min). Cells were then treated with insulin (0,6μM, 5 min) for stimulation of PI3K/Akt and MAPK pathways and incubated with Anti-phospho-Akt1/PKBα Alexa Fluor® 488 Conjugated Antibody and Anti-phospho-Erk1/2- R- Phycoerythrin conjugated antibody. A FACSCanto II cytometer was used for the flow cytometric analysis. FSC and SSC were used to establish size gates and exclude cellular debris from the analysis. In each measurement, a minimum of 30000 events were analyzed. Data were acquired and analyzed using BD FACSDiva and DeNovo FCS software. Findings: PIC21 targeting of PI3K was confirmed by docking studies, which data demonstrated that the interaction energy (E) for PI3K and PIC21, and PI3K inhibitors, LY294002 and Wort, was: PIC20 (E=-8.9), PIC21(E=-8.2), LY294002 (E=-9.5), Wort (E=-8.8). Cell treatment with PIC21 and Wort decreased the pAkt+ cell population (control=23.02%, PIC21 treated=6.63%, Wort treated=4.20%), whereas the pERK+ cell population increased (control=0,58%, PIC21 treated=6,41%, Wort treated=10,14%. This is due to the pathways crosstalk, by which pAkt inhibits the MAPK/ERK pathway. Conclusions: Our data strongly points to PIC21 as a novel PI3K inhibitor. A high prevalence of PI3K mutation, leading to its constitutive activation, has been described in TNBC, favoring tumor cells growth, proliferation, metabolism, and survival. Therefore, PIC21 opens a new avenue to overcome TNBC dramatic epidemiological scenario, bringing hope to improve patients overall outcome and quality of life. Citation Format: Renata D. Daltoe, Klesia P. Madeira, Murilo F. Cerri, Joao F. Allochio Filho, Maicon Delarmelina, Marcella L. Porto, Silvana S. Meirelles, Silvana S. Meirelles, Ian V. Silva, Sandro J. Greco, Leticia B A Rangel. Novel naphtoquinone PIC21 targets PI3K in triple negative breast cancer cell line. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2626. doi:10.1158/1538-7445.AM2014-2626

Abstract 3343: Anomalous expression of claudin 16 in ovarian cancer: Role of PKC, PI3K and estrogen

Background: We have demonstrated that 63% of primary epithelial ovarian cancer (EOC) anomalously overexpressed CLDN16 in the cell cytoplasm, regardless of tumor histological type or grade, thus suggesting that this is an early event in EOC development, and might serve as an EOC marker. The present work aimed to enlighten cellular mechanisms that modulate CLDN16 expression in EOC. Methods: PKA, PKC, and PI3K pathways affect CLDNs cellular localization and function, cancer development and progression. We investigated the effect of the pathways, and of intra-tumoral estrogen (0.5, 5, 50 and 500 nM), on CLDN16 expression in the serous and platinum-resistant EOC model, the OVCAR3 cell line. Immunofluorescence experiments were carried out to determine the cellular localization of CLDN16 in OVCAR3. CLDN16 expression was assessed by real-time RT-PCR, in the presence or absence of the pathway modulators cAMP (PKA activator, 10-6M), KT5720 (PKA inhibitor, 10-7M), PMA (PKC activator, 10-8M), and Wortmannin (WORT: PI3K activator, 10-7M). CLDN16 relative expression analyses followed the CT method of Pffalf, using the REST program (Version 2.0.13, 2009). Data, expressed as mean ± SE, were analyzed by Bonferroni and Dunnet multiple comparisons tests. Findings: OVCAR3 expressed CLDN16 exclusively in the cytoplasm compartment, resembling primary tumors, so being a reliable in vitro model to our expression study. While the PKA pathway did not affect CLDN16 expression in OVCAR3, the PKC pathway lead to an increase of the transcript by1.95-fold (PMA; p Conclusions: Our data strongly suggest that the expression of CLDN16 is stimulated by the PKC and PI3K, and intra-tumoral aromatase-produced estrogen in EOC. Whereas the anomalous cytoplasm overexpression of CLDN16 still puzzles us, we speculate that fragments of the molecule could be possibly secreted. If this is the case, screening for circulatory portions of the protein could serve as an EOC screening molecule, considering that it is overexpressed early in disease course. Despite the fact that more studies are necessary to elighten the mechanisms that control the expression and function of CLDN16 in EOC, our study opens a new avenue to overcome EOC dramatic epidemiological scenario, bringing hope to improve patients overall outcome and quality of life. Citation Format: Nayara G. Tessarollo, Marcela Paes, Murilo Cerri, Alice Herlinger, Klesia Madeira, Renata Daltoe, Ian Silva, Leticia Rangel. Anomalous expression of claudin 16 in ovarian cancer: Role of PKC, PI3K and estrogen. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3343. doi:10.1158/1538-7445.AM2014-3343