Floral MADS-box protein interactions in the early diverging angiosperm Aristolochia fimbriata Cham. (Aristolochiaceae: Piperales).

Floral identity MADS-box A, B, C, D, E, and AGL6 class genes are predominantly single copy in Magnoliids, and predate the whole genome duplication (WGD) events in monocots and eudicots. By comparison with the model species Arabidopsis thaliana, the expression patterns of B-, C-, and D-class genes in stamen, carpel, and ovules are conserved in Aristolochia fimbriata, whereas A-, E-class, and AGL6 genes have different expression patterns. Nevertheless, the interactions of these proteins that act through multimeric complexes remain poorly known in early divergent angiosperms. This study evaluates protein interactions among all floral MADS-box A. fimbriata proteins using the Yeast Two Hybrid System (Y2H). We found no homodimers and less heterodimers formed by AfimFUL when compared to AfimAGL6, which allowed us to suggest AGL6 homodimers in combination with AfimSEP2 as the most likely tetramer in sepal identity. We found AfimAP3-AfimPI obligate heterodimers and AfimAG-AfimSEP2 protein interactions intact suggesting conserved stamen and carpel tetrameric complexes in A. fimbriata. We observed a broader interaction partner set for AfimSEP2 than for its paralog AfimSEP1. We show conserved and exclusive MADS-box protein interactions in A. fimbriata in comparison with other eudicot and monocot model species in order to establish plesiomorphic MADS-box protein floral networks in angiosperms.

Deep into the Aristolochia Flower: Expression of C, D, and E-Class Genes in Aristolochia fimbriata (Aristolochiaceae).

Aristolochia fimbriata (Aristolochiaceae) is a member of an early diverging lineage of flowering plants and a promising candidate for evo-devo studies. Aristolochia flowers exhibit a unique floral synorganization that consists of a monosymmetric and petaloid calyx formed by three congenitally fused sepals, and a gynostemium formed by the congenital fusion between stamens and the stigmatic region of the carpels. This floral ground plan atypical in the magnoliids can be used to evaluate the role of floral organ identity MADS-box genes during early flower evolution. In this study, we present in situ hybridization experiments for the homologs of the canonical C-, D-, and E-class genes. Spatiotemporal expression of the C-class gene AfimAG is restricted to stamens, ovary, and ovules, suggesting a conserved stamen and carpel identity function, consistent with that reported in core-eudicots and monocots. The D-class gene AfimSTK is detected in the anthers, the stigmas, the ovary, the ovules, the fruit, and the seeds, suggesting conserved roles in ovule and seed identity and unique roles in stamens, ovary, and fruit development. In addition, AfimSTK expression patterns in areas of organ abscission and dehiscence zones suggest putative roles linked to senescence processes. We found that both E-class genes are expressed in the anthers and the ovary; however, AfimSEP2 exhibits higher expression compared to AfimSEP1. These findings provide a comprehensive picture of the ancestral expression patterns of the canonical MADS-box floral organ identity genes and the foundations for further comparative analyses in other magnoliids.

Expression of gynoecium patterning transcription factors in Aristolochia fimbriata (Aristolochiaceae) and their contribution to gynostemium development.

BACKGROUND: In Aristolochia (Aristolochiaceae) flowers, the congenital fusion of the anthers and the commissural, stigmatic lobes forms a gynostemium. Although the molecular bases associated to the apical-basal gynoecium patterning have been described in eudicots, comparative expression studies of the style and stigma regulatory genes have never been performed in early divergent angiosperms possessing a gynostemium. RESULTS: In this study, we assess the expression of five genes typically involved in gynoecium development in Aristolochia fimbriata. We found that all five genes (AfimCRC, AfimSPT, AfimNGA, AfimHEC1 and AfimHEC3) are expressed in the ovary, the placenta, the ovules and the transmitting tract. In addition, only AfimHEC3, AfimNGA and AfimSPT are temporarily expressed during the initiation of the stigma, while none of the genes studied is maintained during the elaboration of the stigmatic surfaces in the gynostemium. CONCLUSIONS: Expression patterns suggest that CRC, HEC, NGA and SPT homologs establish ovary and style identity in Aristolochia fimbriata. Only NGA,HEC3 and SPT genes may play a role in the early differentiation of the stigmatic lobes, but none of the genes studied seems to control late stigma differentiation in the gynostemium. The data gathered so far raises the possibility that such transient expression early on provides sufficient signal for late stigma differentiation or that unidentified late identity genes are controlling stigma development in the gynostemium. Our data does not rule out the possibility that stigmas could correspond to staminal filaments with convergent pollen-receptive surfaces.

Impacto del Score de Recurrencia de 21 genes en la indicación de tratamiento sistémico adyuvante: nuestra experiencia en el Hospital Italiano de Buenos Aires / Impact of the Recurrence Score on clinical decision-making about chemotherapy in the adjuvant setting: our experience at Hospital Italiano of Buenos Aires (Argentina)

Introducción Las plataformas genómicas han tomado gran relevancia como factores pronósticos y predictivos para definir tratamiento adyuvante en pacientes con cáncer de mama. Su uso permitiría discriminar un subgrupo de pacientes en quienes la indicación de quimioterapia podría ofrecer más morbilidad que verdadero beneficio. Objetivos Describir las características de las pacientes en quienes se utilizó la plataforma Oncotype DX® y evaluar el impacto del Score de Recurrencia (Recurrence Score) como herramienta de decisión para la indicación de adyuvancia. Material y método Se consideraron pacientes operadas entre 2013 y 2017 en el Hospital Italiano de Buenos Aires, Argentina, con diagnóstico de carcinoma invasor primario de mama de subtipo Luminal A o B, her2neu negativas. Se seleccionaron los casos en los que se solicitó Oncotype DX® y se describieron sus características clínicas e histológicas. Resultados Se utilizó Oncotype DX® en 47 pacientes con cáncer de mama invasor. En el 48,9% se obtuvo un Recurrence Score de riesgo bajo, en el 40,4% de riesgo intermedio y en el 10,6% de riesgo alto. En 22 casos (46,8%) consideramos que hubo un cambio de conducta en la indicación de adyuvancia. Conclusiones En nuestra experiencia, hemos visto que la plataforma genómica Oncotype DX® sería una herramienta útil para definir tratamiento adyuvante en tumores de tipo Luminal, her2neu negativo.

Introduction Over the past decade, gene expression assays have become relevant prognostic factors for guiding clinical decision-making in patients with breast cancer. Their use allows to discriminate which patients are most likely to benefit from chemotherapy in the adjuvant setting, avoiding unnecessary toxicity. Objectives To describe the clinical and pathologic characteristics of patients in whom Oncotype DX® was used as a prognostic factor and assess the impact of the Recurrence Score on clinical decision-making. Materials and method Patients who underwent surgery at the Hospital Italiano de Buenos Aires, Argentina, between 2013 and 2017 for Estrogen-Receptor positive (er+), her2neu negative primary breast cancer were considered eligible. We evaluated the cases in which Oncotype DX® was ordered and described the clinical and pathologic characteristics, as well as whether Recurrence Score (rs) modified the prescription of adjuvant therapy. Results Oncotype DX® was performed in 47 patients. The distribution of patients according to rs was as follows: low risk rs 48,9%, intermediate risk 40,4% and high risk 10,6%. We considered that adjuvant therapy decision was modified after rs in 22 patients (46,8%). Conclusions Oncotype DX® and its resulting Recurrence Score appear to be a clinically useful tool for decision-making in the adjuvant setting for patients with er+, her2neu negative breast cancer.

Experiencia monoinstitucional en carcinoma de pulmón de células no pequeñas con reordenamiento EML4-ALK / Monoinstitutional experience in non-small cell lung carcinoma with EML4-ALK rearrangement

El gen de fusión EML4-ALK es producto de la inversión dentro del brazo corto del cromosoma 2 que da lugar a una proteína quimérica con actividad tirosinquinasa y oncogénica. EML4-ALK está presente en una pequeña proporción de pacientes con carcinoma no microcítico de pulmón (aproximadamente el 5%), principalmente en histología de adenocarcinoma y ausencia de hábito tabáquico. De 2012 a 2016 se analizó el reordenamiento EML4-ALK en 340 casos en nuestro centro. Se analizaron los pacientes con el reordenamiento por sexo, edad, hábito tabáquico, estadio diagnóstico, sitios metastásicos, respuesta al tratamiento y tiempo del mismo con inhibidores específicos. Del análisis de 340 casos, se detectó el reordenamiento EML4-ALK en 22 (6.4%), 10 de ellos de sexo masculino, edad promedio 52.4 años (23 a 86 años), 13 no tabaquistas, 13 con enfermedad metastásica al diagnóstico. De estos 22, 15 iniciaron tratamiento con crizotinib, presentando 10 de ellos beneficio clínico, con un tiempo promedio de tratamiento de 18 meses. Entre los pacientes con re arreglo cromosómico ALK, 2/22 casos presentaron concomitantemente la mutación ALK más la del gen EGFR, ambos en posición L858R del exon 21. El reordenamiento EML4-ALK es una condición infrecuente, vista generalmente en pacientes con adenocarcinoma, aunque puede presentarse en pacientes con carcinoma indiferenciado o epidermoide; en tres encontramos alteraciones del EGFR, de distinta significancia clínica. El tratamiento con inhibidores específicos es bien tolerado, con alta tasa de respuesta y beneficio clínico prolongado (AU)

The fusion oncogene EML4-ALK, results by a small inversion in the short arm region of chromosome 2, resulting in a chimeric protein with tyrosine kinase and oncogenic activity. EML4-ALK was found in a small proportion of patients with non-small cell lung carcinoma (about 5%), mainly in adenocarcinoma histology and never on light smokers. Between 2012 and 2016 we evaluated EML4-ALK rearrangement in 340 patients in our center. We analized sex, age, smoke habit, tumoral stage, metastasic sites, treatment response and treatment duration with specific inhibitors. Of 340 cases, the EML4-ALK rearrangement was found in 22 (6.4%), all diagnosed with adenocarcinoma, 10 of them male, mean age 52.4 years (23-86 years), 13 were nonsmokers and 13 with metastatic disease at diagnosis. The 15 patients started treatment with crizotinib, 10 of them presented clinical benefit (stable disease or partial response) and an average treatment time of 18 months; 2/22 patients with ALK mutations had concomitant in the EGFR gene, both L858R mutation in exon 21. The EML4-ALK rearrangement is a rare condition, which is usually seen in patients with adenocarcinoma and no history of smoking;although our experience with the use of specific inhibitors is limited, this treatment appears to be well tolerated with prolonged clinical responses (AU)