Quercetin synergistically induces sensitivity to 5-fluorouracil through p53 modulation in colorectal cancer cells

Colorectal tumors (CRC) with microsatellite instability (MSI) show resistance to chemotherapy with 5-fluorouracil (5-FU), the most widely used pharmacological drug for CRC treatment. The aims of this study were to identify compounds that increase sensitivity of MSI CRC cells to 5-FU and characterize their dependence on the p53 status of the cells. Two MSI human CRC derived cell lines were used: CO115 wildtype for p53 and HCT15 that harbors a p53 mutation. The sensitivity of these cells to 5-FU was evaluated by TUNEL assay and the effects on apoptosis induction of co-incubation of the flavonoids, quercetin (Q) or luteolin (L), with 5-FU were characterized. The mechanisms of apoptosis induction were assessed by western blot and p53 mediated effects confirmed by small interference RNA (siRNA) in CO115 and in HCT116 wt and p53 knockout cells. Our results demonstrate that CO115 is more sensitive to 5-FU than the p53 mutated HCT15. Additive effects on apoptosis were shown for L (in both cell lines) and Q (in HCT15). In CO115 Q synergistically induced apoptosis with 5-FU. Apoptosis induction was caspase dependent in CO115 cells but not in HCT15 cells. Both flavonoids increased p53 expression in both cell lines, an effect particularly remarkable for Q. The synergistic effect of Q and 5-FU in CO115 involved the activation of the mitochondrial pathway with an increase in the expression of cleaved caspase 9 and 3 and PARP, as well as a decrease in Bcl-2 expression. Importantly, knockdown of p53 by siRNA in CO115 cells and p53 knockout in HCT116 cells totally abrogated apoptosis induction, demonstrating the dependence on p53 modulation of apoptosis induction by Q. This study suggests the potential applicability of these phytochemicals for enhancement 5-FU efficiency in CRC therapy, especially Q in p53 wild-type tumors.Fundação para a Ciência e a Tecnologia (FCT

Hypericum androsaemum water extract inhibits proliferation in human colorectal cancer cells through effects on MAP kinases and PI3K/Akt pathway

MAP kinase and PI3K/Akt signalling pathways are commonly altered in colorectal carcinoma (CRC) leading to tumor growth due to increased cell proliferation and inhibition of apoptosis. Several species of the genus Hypericum are used in Portugal to prepare herbal teas to which digestive tract effects are attributed. In the present study, the antiproliferative and proapoptotic effects of the water extracts of H. androsaemum (HA) and H. perforatum (HP) were investigated in two human colon carcinoma-derived cell lines, HCT15 and CO115, which harbour activating mutations of KRAS and BRAF, respectively. Contrarily to HP, HA significantly inhibited cell proliferation and induced apoptosis in both cell lines. HA decreased BRAF and phospho-ERK expressions in CO115, but not in HCT15. HA also decreased Akt phosphorylation in CO115 and induced p38 and JNK in both cell lines. HA induced cell cycle arrest at S and G2/M phases as well as caspase-dependent apoptosis in both cell lines. Chlorogenic acid (CA), the main phenolic compound present in the HA extract and less represented in the HP water extract, did, however, not show any of those effects when used individually. In conclusion, water extract of HA, but not of HP, controlled CRC proliferation and specifically acted on mutant and not wild-type BRAF. The effect of HA was, however, not due to CA alone.CPRX was supported by the Foundation for Science and Technology (FCT), Portugal, through the grant SFRH/BD/27524/2006 and the work was supported by the FCT research grants PTDC/AGR-AAM/70418/2006 (HypericumBiotech) and PEst-C/BIA/UI4050/2011. All projects are co-funded by the program COMPETE from QREN with co-participation from the European Community fund FEDER

Salvia fruticosa, salvia officinalis and rosmarinic acid induce apoptosis and inhibit proliferation of human colorectal cell lines: the role in MAPK/ERK pathway

Epidemiologic studies have shown that nutrition is a key factor in modulating sporadic colorectal carcinoma (CRC) risk. Aromatic plants of the genus Salvia (sage) have been attributed many medicinal properties, which include anticancer activity. In the present study, the antiproliferative and pro-apoptotic effects of water extracts of Salvia fruticosa (SF) and Salvia officinalis (SO) and of their main phenolic compound rosmarinic acid (RA) were evaluated in two human colon carcinoma-derived cell lines, HCT15 and CO115, which have different mutations in the MAPK/ERK and PI3K/Akt signalling pathways. These pathways are commonly altered in CRC leading to increased proliferation and inhibition of apoptosis. Our results show that SF, SO and RA induce apoptosis in both cell lines, whereas cell proliferation was inhibited by the two sage extracts only in HCT15. SO, SF and RA inhibited ERK phosphorylation in HCT15 and had no effects on Akt phosphorylation in CO115 cells. The activity of sage extracts seems to be due, at least in part, to the inhibition of MAPK/ERK pathway.POCI/AGR/62040/2004. CPRX and CFLSFRH/BD/27524/2006 and SFRH/BPD/26316/2006Foundation for Science and Technology (FCT

Ursolic acid, a dietary phytochemical, decreases KRAS signaling and modulates cell death pathways in resistant CRC cells

Publicado em "BMC Proceedings 2012, 6(Suppl 3)"KRAS mutations are frequent in colorectal cancer (CRC) and have the potential to activate proliferation and inhibit cell death through effects on MAPK/ERK and PI3K/Akt signaling pathways. Because diet is one of the most important determinants of CRC incidence and progression, we studied the effects of the dietary triterpenoid ursolic acid (UA) on proliferation and cell death induction in human CRC derived KRAS mutated cell lines. Our results show that UA decreases cell proliferation and induces cell death while decreasing signaling through KRAS as indicated by a decrease in ERK and Akt phosphorylation (western blot). UA also induced cell death. TP53 mutated cells are known to be resistant to the chemotherapeutic drug 5-FU. Caspase independent apoptosis (Tunel assay), was increased 6 fold by co-incubation of UA with 5-FU. However, apoptosis was only a small percentage of the total cell death induced by UA. In order to explain these observations, we looked into effects on autophagy. Autophagy is emerging as a promising therapeutic target for drug resistant tumors. UA modulated autophagy by inducing the accumulation of LC3 II and p62 levels an effect dependent on JNK activation. In conclusion, this study shows UA’s anticancer potential as a modulator of KRAS signaling and cell death mechanisms increasing sensitivity to the chemotherapeutic drug 5-FU

Cytogenetic Analysis Of Four Central Amazonian Species Of Colostethus (anura - Dendrobatidae) With A Diploid Complement Of 22 Chromosomes.

Colostethus marchesianus from the type locality and three related species had 2n = 22 chromosomes, which differed from most other Colostethus species that have 2n = 24 chromosomes. The species analyzed were morphologically similar and showed a conservative karyotype, although they could be distinguished from each other by their C-banding pattern. Additional NOR sites, heteromorphism in NOR size and heterochromatin, and an additional rDNA site detected by FISH, were observed. These data suggest that chromosomal rearrangements and hetrochromatin-related events may have contributed to the karyotype differentiation of these Colostethus.139189-9

Luteolin, quercetin and ursolic acid are potent inhibitors of proliferation and inducers of apoptosis in both KRAS and BRAF mutated human colorectal cancer cells

KRAS and BRAF mutations are frequent in colorectal carcinoma (CRC) and have the potential to activate proliferation and survival through MAPK/ERK and/or PI3K signalling pathways. Because diet is one of the most important determinants of CRC incidence and progression, we studied the effects of the dietary phytochemicals quercetin (Q), luteolin (L) and ursolic acid (UA) on cell proliferation and apoptosis in two human CRC derived cell lines, HCT15 and CO115, harboring KRAS and BRAF activating mutations, respectively. In KRAS mutated HCT15 cells, Q and L significantly decreased ERK phosphorylation, whereas in BRAF mutated CO115 cells the three compounds decreased Akt phosphorylation but had no effect on phospho-ERK. Our findings show that these natural compounds have antiproliferative and proapoptotic effects and simultaneously seem to act on KRAS and PI3K but not on BRAF. These results shed light on the molecular mechanisms of action of Q, L and UA and emphasize the potential of dietary choices for the control of CRC progression.This work was supported by the Foundation for Science and Technology, Portugal, by the research Grant POCI/AGR/62040/2004. CPRX and CFL were supported by the Foundation for Science and Technology, Portugal, through the Grants SFRH/BD/ 27524/2006 and SFRH/BPD/26316/2006, respectively

Neonatal alloimmune thrombocytopenia: two different neonatal manifestations of the same disease

Fetal and neonatal alloimmune thrombocytopenia is a rare disorder in which maternal alloantibodies cross the placenta and cause fetal thrombocytopenia. Most cases are mild but can be potentially fatal if there is an intracranial haemorrhage. Usually, the mother is asymptomatic during pregnancy and no screening is routinely recommended unless there is obstetric or family history. After birth, prompt identification is crucial so that the newborn is closely monitored and treatment is given, if needed, to prevent serious complications. In this article we present two clinical cases of fetal and neonatal alloimmune thrombocytopenia in first-born children, after uneventful pregnancies, with different outcomes and discuss the obstetric management and follow-up in future pregnancies

Ursolic acid induces cell death and modulates autophagy through JNK pathway in apoptosis-resistant colorectal cancer cells

Colorectal carcinomas (CRCs) with P53 mutations have been shown to be resistant to chemotherapy with 5-fluorouracil (5-FU), the most widely used chemotherapeutic drug for CRC treatment. Autophagy is emerging as a promising therapeutic target for drug-resistant tumors. In the present study, we tested the effects of ursolic acid (UA), a natural triterpenoid, on cell death mechanisms and its effects in combination with 5-FU in the HCT15 p53 mutant apoptosis-resistant CRC cell line. The involvement of UA in autophagy and its in vivo efficacy were evaluated. Our data show that UA induces apoptosis independent of caspases in HCT15 cells and enhances 5-FU effects associated with an activation of c-jun N-terminal kinase (JNK). In this cell line, where this compound has a more pronounced effect on the induction of cell death compared to 5-FU, apoptosis corresponds only to a small percentage of the total cell death induced by UA. UA also modulated autophagy by inducing the accumulation of LC3 and p62 levels with involvement of JNK pathway, which indicates a contribution of autophagy on JNK-dependent induction of cell death by UA. By using nude mice xenografted with HCT15 cells, we verified that UA was also active in vivo decreasing tumor growth rate. In conclusion, this study shows UA's anticancer potential both in vitro and in vivo. Induction of cell death and modulation of autophagy in CRC-resistant cells were shown to involve JNK signaling.C.P.R.X. and D.F.N.P. were supported by the Foundation for Science and Technology (FCT), Portugal, through grants SFRH/BD/27524/2006 and SFRH/BD/64817/2009, respectively. C.P.W. was guest professor at University of Copenhagen through the grant SFRH/BSAB/918/2009. The work was supported by FCT research grants PTDC/QUI-BIQ/101392/2008 (NaturAge) and PEst-C/BIA/UI4050/2011. All projects are co-funded by the program COMPETE from QREN with co-participation from the European Community fund FEDER

Editorial: Microplastics in the marine environment: Sources, distribution, biological effects and socio-economic impacts

inexistenteinfo:eu-repo/semantics/publishedVersio

Monozygotic twins discordant for Goldenhar syndrome

OBJECTIVE: To report on a pair of monozygotic female twins discordant for Goldenhar syndrome. DESCRIPTION: The affected twin was a girl, who was delivered by caesarean section at 35 weeks' gestation. Her birth weight was 2,170 g, length 42.5 cm, head circumference 30 cm and her Apgar scores were 3/7. After birth the child developed severe respiratory distress and had to be moved to the neonatal intensive care unit (ICU). The other twin was a girl, born weighing 3,200 g with a length of 49 cm, head circumference of 34 cm and Apgar scores of 8/10. She was transferred to the mother-baby unit soon after birth and was discharged two days later. There was no consanguinity between the twins' parents, who were young and healthy at the time of their conception. The affected child's dysmorphic features included left hemifacial microsomia, severe micrognathia, abnormal ears, bilateral preauricular tags and epibulbar dermoid in the right eye. She developed obstructive apnea due to micrognathia and required tracheostomy. Abdominal and cranial ultrasound findings were normal, as was an ophthalmological assessment. Spine x-ray showed hemivertebra at T9 and T10. An echocardiogram showed Tetralogy of Fallot. GTG-banded karyotyping was performed on peripheral blood cells and revealed 46,XX. Zygosity testing established the pair of twins to be monozygotic with a probability greater than 99:1. COMMENT: Goldenhar syndrome was diagnosed in one of the twins described here. There are several reports of twins discordant for this disorder and therefore non-genetic factors may also play an important role, for instance vascular disruption during morphogenesis.OBJETIVO: Relatar um par de gêmeas monozigóticas, no qual uma das crianças é afetada pela síndrome de Goldenhar, enquanto a outra é saudável. DESCRIÇÃO: Paciente do sexo feminino, filha de pais sadios, jovens e não consangüíneos. A propósita nasceu de parto cesáreo pré-termo com Capurro somático de 35 semanas e 2 dias, pesando 2.170 g, com 42,5 cm de comprimento, perímetro cefálico de 30 cm e Apgar 3/7. Ao nascimento, a criança evoluiu com desconforto respiratório grave, sendo transferida para unidade de tratamento intensivo neonatal. A outra gemelar nasceu com 3.200 g, 49 cm de comprimento, 34 cm de perímetro cefálico e Apgar 8/10. Foi transferida junto com a mãe para o alojamento conjunto da maternidade e recebeu alta com 2 dias de vida. A criança afetada apresentava hipoplasia facial esquerda, micrognatia importante, displasia de pavilhão auricular e apêndices pré-auriculares bilaterais e dermóide epibulbar à direita. Evoluiu com apnéia obstrutiva, em conseqüência da micrognatia, e necessitou de traqueostomia. As ultra-sonografias de crânio e abdome foram normais, a radiografia de coluna total mostrou hemivértebra em T9/T10, o ecocardiograma detectou tetralogia de Fallot, e o cariótipo realizado a partir de linfócitos de sangue periférico com bandeamento GTG foi 46,XX. A avaliação oftalmológica foi normal. O exame molecular provou tratar-se de gêmeas monozigóticas com 99,99% de probabilidade. COMENTÁRIO: A clínica e os exames complementares levaram ao diagnóstico de síndrome de Goldenhar. Existem relatos de gemelares afetados por essa condição com expressividade variável, o que corrobora a hipótese de que a etiologia não é puramente genética, mas resultado de um processo de disrupção vascular no período de morfogênese.Centro Universitário Barão de Mauá Faculdade de MedicinaHospital Santa Casa de Misericórdia de Ribeirão PretoUniversidade Federal de São Paulo (UNIFESP)UNIFESPSciEL