Tumor Budding en cáncer rectal. Relación entre la densidad de los brotes tumorales y otros factores pronósticos / Budding tumor in rectal cancer. Relationship between tumor outbreak density and other prognostic factors

Introducción: El budding tumor (BT) es la presencia de células tumorales aisladas o en pequeños grupos situadas en el frente de invasión del tumor. Su hallazgo en alto grado es un factor de mal pronóstico independiente del cáncer colorrectal. El objetivo de este trabajo es determinar si el grado de BT está asociado con otros factores pronósticos del cáncer rectal. Material y métodos: Se incluyen las resecciones oncológicas de recto en el período 2013-2017. Los casos se agruparon según la densidad en la formación de los BT en 3 grupos, los de grado bajo, intermedio y alto. Se utilizó como valor estadístico el cálculo del odds ratio (OR). Resultados: Se analizaron las piezas de resección de 27 pacientes (15 mujeres y 12 hombres) con una media de edad de 68,4 años (40-86). Se calculó el OR para invasión ganglionar, vascular y recidiva en función del grado de budding tumoral. Discusión: Se observó una tendencia a la presencia de factores histológicos de mal pronóstico en relación al budding de alto grado, si bien el bajo número de casos no permitió demostrarlo en este estudio. Conclusiones: El análisis del grado de tumor budding es reproducible y podría ayudar a identificar pacientes con cáncer rectal de peor pronóstico. (AU)

Introduction: Tumor budding (BT) is defined as isolated or small groups of neoplastic cells located at the invasive front of the tumor. High-grade BT is a poor prognostic factor in colorectal cancer. Objective: To determine if the degree of BT is associated with other prognostic factors in rectal cancer. Materials and methods: Rectal oncological resections during the 2013-2017 period were included. Cases were stratified according to the density in the formation of BT in 3 groups: low, intermediate and high. The calculation of the odds ratio (OR) was used as a statistical value. Results: The resection specimens of 27 patients (15 women and 12 men) with a mean age of 68.4 years (40-86) were analyzed. OR for node metastases, vascular invasion and relapse was calculated according to tumor budding grade. Discussion: High-grade tumor budding seems to associate with the presence of poor prognostic factors. However, it was not possible to demonstrate it because of the small sample size. Conclusions: Tumor budding is a reproducible marker and could help to identify rectal cancer patients with a worse prognosis. (AU)

Characterization of Oct4-GFP transgenic mice as a model to study the effect of environmental estrogens on the maturation of male germ cells by using flow cytometry.

Oct4 is involved in regulation of pluripotency during normal development and is down-regulated during formation of postnatal reservoir of germ cells. We propose thatOct4/GFP transgenic mouse, which mimics the endogenous expression pattern of Oct4, could be used as a mammalian model to study the effects of environmental estrogens on the development of male germ cells. Oct4/GFP maturation profile was assessed during postnatal days -PND- 3, 5, 7, 10, 14 and 80, using flow cytometry. Then, we exposed pregnant mothers to 17α-ethinylestradiol (EE2) from day post coitum (dpc) 5 to PND7. Percentage of Oct4/GFP-expressing cells and levels of expression of Oct4/GPF were increased in PND7 after EE2 exposure. These observations were confirmed by analysis of GFP and endogenous Oct4 protein in the seminiferous tubules and by a reduction in epididymal sperm count in adult mice. We introduced Oct4/GFP mouse together with flow cytometry as a tool to evaluate changes in male germ cells development.

Quantitation of yeast cell-cell fusion using multicolor flow cytometry.

Mating of haploid Saccharomyces cerevisiae cells of opposite sex provides a powerful model system to study the cell-cell fusion. However, a rapid and standardized method is much needed for quantitative assessment of fusion efficiency. The gold standard method relies on counting mating pairs in fluorescence microscopy images. This current method is limited by expectancy bias and it is time consuming, restricting the number of both cell-cell fusion events and strains that can be analyzed at once. Automatic approaches present a solution to these limitations. Here, we describe a novel flow cytometric approach that is able to quickly both identify mating pairs within a mixture of gametes and quantify cell fusion efficiency. This method is based on staining the cell wall of yeast populations with different Concanavalin A-fluorophore conjugates. The mating subpopulation is identified as the two-colored events set and fused and unfused mating pairs are subsequently discriminated by green fluorescent protein bimolecular complementation. A series of experiments was conducted to validate a simple and reliable protocol. Mating efficiency in each sample was determined by flow cytometry and compared with the one obtained with the current gold standard technique. The results show that mating pair counts using both methods produce indistinguishable outcomes and that the flow cytometry-based method provides quantitative relevant information in a short time, making possible to quickly analyze many different cell populations. In conclusion, our data show multicolor flow cytometry-based fusion quantitation to be a fast, robust, and reliable method to quantify the cell-cell fusion in yeast.

High expression of AID and active class switch recombination might account for a more aggressive disease in unmutated CLL patients: link with an activated microenvironment in CLL disease.

Interaction of chronic lymphocytic leukemia (CLL) B cells with tissue microenvironment has been suggested to favor disease progression by promoting malignant B-cell growth. Previous work has shown expression in peripheral blood (PB) of CLL B cells of activation-induced cytidine deaminase (AID) among CLL patients with an unmutated (UM) profile of immunoglobulin genes and with ongoing class switch recombination (CSR) process. Because AID expression results from interaction with activated tissue microenvironment, we speculated whether the small subset with ongoing CSR is responsible for high levels of AID expression and could be derived from this particular microenvironment. In this work, we quantified AID expression and ongoing CSR in PB of 50 CLL patients and characterized the expression of different molecules related to microenvironment interaction. Our results show that among UM patients (1) high AID expression is restricted to the subpopulation of tumoral cells ongoing CSR; (2) this small subset expresses high levels of proliferation, antiapoptotic and progression markers (Ki-67, c-myc, Bcl-2, CD49d, and CCL3/4 chemokines). Overall, this work outlines the importance of a cellular subset in PB of UM CLL patients with a poor clinical outcome, high AID levels, and ongoing CSR, whose presence might be a hallmark of a recent contact with the microenvironment.

Ultra-fast and optimized method for the preparation of rodent testicular cells for flow cytometric analysis.

UNLABELLED: Homogeneity of cell populations is a prerequisite for the analysis of biochemical and molecular events during male gamete differentiation. Given the complex organization of the mammalian testicular tissue, various methods have been used to obtain enriched or purified cell populations, including flow cell sorting. Current protocols are usually time-consuming and may imply loss of short-lived RNAs, which is undesirable for expression profiling. We describe an optimized method to speed up the preparation of suitable testicular cell suspensions for cytometric analysis of different spermatogenic stages from rodents. The procedure takes only 15 min including testis dissection, tissue cutting, and processing through the Medimachine System (Becton Dickinson). This method could be a substitute for the more tedious and time-consuming cell preparation techniques currently in use. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (DOI:10.1007/s12575-009-9003-2) contains supplementary material, which is available to authorized users.

Genetic diversity and DNA content of three South American and three Eurasiatic Trifolium species

Six species of Trifolium (T. polymorphum Poir., T. riograndense Burkart, T. argentinense Speg., T. medium L., T. pratense L. and T. repens L.) were analyzed using inter-simple sequence repeats (ISSR) markers. Six selected primers generated 186 polymerase chain reaction (PCR) products exploring 112 loci in 34 genotypes analyzed with molecular sizes ranging from 200 to 1300 bp. These primers were able to discriminate among and within species, with the PCR products being on average 41.6 percent species-specific and 59.9 percent polymorphic at the within species level. Nuclear DNA content was determined by flow cytometry and revealed variation among species. The 1Cx genome size values were calculated and were found to range from 0.46 pg (T. pratense) to 0.96 pg (T. polymorphum). Genome size values of South American species were higher than those of Eurasiatic origin. The analyses of the molecular data grouped the six species in agreement with their geographical origin and clearly differentiate T. polymorphum from T. argentinense. The Eurasiatic group showed the highest average of species-specific bands (45.3 percent) and the South American group exhibited the highest amount of total bands (59.7). The highest level of intra-species polymorphisms was detected in T. argentinense (92.9 percent), followed by T. medium (89.5 percent).