Caracterización histológica del melanoma cutáneo en reportes de patología en la ciudad de Cali, 2016-2021 / Histological characterization of cutaneous melanoma in pathology reports in the city of Cali, 2016-2021

Introducción. El melanoma es la proliferación maligna de melanocitos asociado a un comportamiento agresivo. El objetivo de este estudio fue determinar las variables histológicas del melanoma cutáneo. Métodos. Estudio observacional retrospectivo, transversal descriptivo, realizado con reportes de patologías de pacientes con diagnóstico de melanoma cutáneo en un laboratorio de patología en Cali, Colombia, entre 2016-2021. Se incluyeron las variables edad, sexo, localización, subtipo, espesor de Breslow, ulceración, márgenes, mitosis, invasión linfovascular, neurotrofismo, regresión tumoral, nivel de Clark e infiltración tumoral por linfocitos. Resultados. Se obtuvieron 106 reportes y fueron excluidos 54 por duplicación. Se incluyeron 52 registros, la media de edad fue de 61 años, con una mayor frecuencia de mujeres (55,8 %). De los 33 casos donde se especificó el subtipo histológico, el más frecuente fue el de extensión superficial (66,6 %), seguido del acral lentiginoso (18,1 %) y nodular con (15,2 %). La localización más frecuente fue en extremidades (61,5 %). El espesor de Breslow más común fue IV (34,6 %) y el nivel de Clark más frecuente fue IV (34,6 %). La ulceración estuvo en el 40,4 %. El subtipo nodular fue el de presentación más agresiva, donde el 100 % presentaron espesor de Breslow IV. Conclusiones. El subtipo de melanoma más común en nuestra población fue el de extensión superficial; el segundo en frecuencia fue el subtipo acral lentiginoso, que se localizó siempre en extremidades. Más del 50 % de los melanomas tenían espesor de Breslow mayor o igual a III, lo que impacta en el pronóstico.

Background. Melanoma is the malignant proliferation of melanocytes associated with aggressive behavior. The objective of this study was to determine the histological variables of cutaneous melanoma. Methods. Observational, cross-sectional, descriptive, retrospective study carried out with reports of pathologies with a diagnosis of cutaneous melanoma in a pathology laboratory in Cali between 2016-2021. The variables were age, sex, location, subtype, Breslow thickness, ulceration, margins, mitosis, lymphovascular invasion, neurotropism, tumoral regression, Clark level and tumor infiltration by lymphocytes. Results. One hundred and six reports were obtained and 54 were excluded due to duplication. A descriptive analysis was made on the 52 records that were included, the mean age was 61 years, with a higher frequency in women with 55.8%. Of the 33 cases where the histological subtype was specified, the most frequent was superficial extension with 66.6%, followed by acral lentiginous with 18.1% and nodular with 15.2%. The most frequent location was in the extremities (61.5%); the most common Breslow was IV (34.6%), and the most frequent Clark was IV (34.6%). Ulceration was in 40.4%. The nodular subtype was the most aggressive presentation where 100% presented Breslow IV. Conclusions. The most common subtype of melanoma was that of superficial extension. In our population, the second most frequent was the acral lentiginous subtype, which was always located on the extremities. More than 50% of the melanomas had Breslow greater than or equal to III, which affects the prognosis.

Progress in the Study of Spindle Assembly Checkpoint in Lung Cancer / 中国肺癌杂志

Spindle assembly checkpoint (SAC) is a protective mechanism for cells to undergo accurate mitosis. SAC prevented chromosome segregation when kinetochores were not, or incorrectly attached to microtubules in the anaphase of mitosis, thus avoiding aneuploid chromosomes in daughter cells. Aneuploidy and altered expression of SAC component proteins are common in different cancers, including lung cancer. Therefore, SAC is a potential new target for lung cancer therapy. Five small molecule inhibitors of monopolar spindle 1 (MPS1), an upstream component protein of SAC, have entered clinical trials. This article introduces the biological functions of SAC, summarizes the abnormal expression of SAC component proteins in various cancers and the research progress of MPS1 inhibitors, and expects to provide a reference for the future development of lung cancer therapeutic strategies targeting SAC components.
.

Cytogenetic study in sand spiders (Sicariidae) from the brazilian Caatinga: sex chromosome system diversity in closely related species / Estudio citogenético en arañas de arena (Sicariidae) de la Caatinga brasileña: diversidad del sistema de cromosomas sexuales en especies estrechamente relacionadas

ABSTRACT In this study, we investigated the chromosomes of three species of Sicarius spiders from the Brazilian Caatinga, using classical and molecular cytogenetic techniques. Based on the phylogenetic approach, we also discussed about the variation of diploid number, types of sex chromosome system and changes in the localization of ribosomal genes of Scytodoidea. Sicarius are Synspermiata spiders that together with the genera Loxosceles and Hexophthalma constitute the family Sicariidae. In this group, the available cytogenetic data showed a low diploid number range (2n♂=18 to 2n♂=23) and the presence of only multiple sex chromosome systems (X1X2Y and X1X20). Mitotic metaphase cells exhibited 2n♂=16+X1X2Y for Sicarius cariri and S. ornatus, and 2n♂=18+XY for S. tropicus. In these species, silver impregnation revealed nucleolar organizer region (Ag-NOR) on the terminal region of pair 1. In S. ornatus and S. tropicus, the results obtained with fluorescent in situ hybridization (FISH) using 18S rDNA probe were similar to Ag-NOR, however in S. cariri, the ribosomal sites were localized in the terminal region of the X1 sex chromosome. In this work, we presented the first description of a simple sex chromosome system for Sicariidae, helping to understand how the XY sex chromosome system evolved from the X1X2Y system. Additionally, FISH data incongruous with Ag-NOR indicate that the cytogenetic studies in Sicariidae allow investigating the relation between the karyotype evolution and the distribution and the activity of rDNA genes.

RESUMEN En este estudio, investigamos los cromosomas de tres especies de arañas Sicarius de la Caatinga brasileña, utilizando técnicas de citogenética clásica y molecular. Usando un enfoque filogenético, también discutimos la variación del número diploide, los tipos de sistema cromosómico sexual y los cambios en la localización de los genes ribosómicos en Scytodoidea. Los Sicarius son arañas Synspermiata que, junto con los géneros Loxosceles y Hexophthalma, constituyen a la familia Sicariidae. En este grupo, los datos citogenéticos disponibles mostraron un rango de número diploide bajo (2n♂=18 a 2n♂=23) y únicamente la presencia de sistemas de cromosomas sexuales múltiples (X1X2Y y X1X20). Las células mitóticas en metafase mostraron 2n♂=16+X1X2Y para Sicarius cariri y S. ornatus, y 2n♂=18+XY para S. tropicus. En estas especies, la impregnación de plata reveló la región organizadora nucleolar (Ag-NOR) en la región terminal del par 1. En S. ornatus y S. tropicus, los resultados obtenidos con la hibridación in situ fluorescente (FISH) utilizando la sonda de ADNr 18S fueron similares a los de Ag-NOR, sin embargo, en S. cariri los sitios ribosomales se localizaron en la región terminal del cromosoma sexual X1. En este trabajo, presentamos la primera descripción de un sistema cromosómico sexual simple para Sicariidae, ayudando a entender cómo el sistema cromosómico sexual XY evolucionó a partir del sistema X1X2Y. Además, los datos de FISH incongruentes con Ag-NOR indican que los estudios citogenéticos en Sicariidae permiten investigar la relación entre la evolución del cariotipo y la distribución y la actividad de los genes de ADNr.

cGAS guards against chromosome end-to-end fusions during mitosis and facilitates replicative senescence

As a sensor of cytosolic DNA, the role of cyclic GMP-AMP synthase (cGAS) in innate immune response is well established, yet how its functions in different biological conditions remain to be elucidated. Here, we identify cGAS as an essential regulator in inhibiting mitotic DNA double-strand break (DSB) repair and protecting short telomeres from end-to-end fusion independent of the canonical cGAS-STING pathway. cGAS associates with telomeric/subtelomeric DNA during mitosis when TRF1/TRF2/POT1 are deficient on telomeres. Depletion of cGAS leads to mitotic chromosome end-to-end fusions predominantly occurring between short telomeres. Mechanistically, cGAS interacts with CDK1 and positions them to chromosome ends. Thus, CDK1 inhibits mitotic non-homologous end joining (NHEJ) by blocking the recruitment of RNF8. cGAS-deficient human primary cells are defective in entering replicative senescence and display chromosome end-to-end fusions, genome instability and prolonged growth arrest. Altogether, cGAS safeguards genome stability by controlling mitotic DSB repair to inhibit mitotic chromosome end-to-end fusions, thus facilitating replicative senescence.

Fine-tuning cell organelle dynamics during mitosis by small GTPases / 医学前沿

During mitosis, the allocation of genetic material concurs with organelle transformation and distribution. The coordination of genetic material inheritance with organelle dynamics directs accurate mitotic progression, cell fate determination, and organismal homeostasis. Small GTPases belonging to the Ras superfamily regulate various cell organelles during division. Being the key regulators of membrane dynamics, the dysregulation of small GTPases is widely associated with cell organelle disruption in neoplastic and non-neoplastic diseases, such as cancer and Alzheimer's disease. Recent discoveries shed light on the molecular properties of small GTPases as sophisticated modulators of a remarkably complex and perfect adaptors for rapid structure reformation. This review collects current knowledge on small GTPases in the regulation of cell organelles during mitosis and highlights the mediator role of small GTPase in transducing cell cycle signaling to organelle dynamics during mitosis.

Cinobufagin disrupts mitosis and microtubule polymerization via targeting KATNB1 in cancer cells / 药学学报

Huachansu is a traditional Chinese medicine widely used in the clinic for cancer therapy, while the underlying mechanism is not fully clarified. This study was to investigate the targets and mechanisms of cinobufagin (CBG), an active component of Huachansu, in terms of blocking mitosis of cancer cells. Propidium iodide (PI) DNA staining was used to analyze the effect of CBG on cell cycle. The effect of CBG on mitosis of cancer cells was examined by α-tubulin and pericentrin staining after synchronization by a double thymidine block. Tubulin turbidity, tubulin polymerization and α‍-tubulin immunofluorescence assays were used to evaluate the effect of CBG on microtubule polymerization. CRISPR/Cas9 gene-editing technology was used to knockout microtubule-severing protein Katanin regulatory subunit B1 (KATNB1) in HCT116 cells, and the inhibitory effect of CBG on wild-type cells and knockout cells was measured by CCK-8. The engagement of CBG with KATNB1 was measured by CETSA and DARTS assays. The effect of CBG on KATNB1 protein and mRNA level was examined by Western blot and real-time PCR, respectively. Our data showed that CBG arrested HCT116 cell cycle at the G2/M phase, disrupted mitosis and induced centriole overduplication. CBG significantly inhibited tubulin polymerization in vitro and in vivo. The cytotoxicity of CBG inhibition on HCT116 was significantly attenuated upon KATNB1 depletion. Moreover, CBG bound to KATNB1 and decreased its protein level, while mutated KATNB1 weakened this effect. In conclusion, CBG inhibited microtubule polymerization via targeting KATNB1, thereby disrupting mitosis in cancer cells.

ESTUDIOS MORFO-ANATÓMICOS, CITOGENÉTICOS Y MOLECULARES EN Talinum (TALINACEAE): UNA NUEVA ENTIDAD PARA EL NOROESTE ARGENTINO / Morfo-anatomical, cytogenetic and molecular studies in Talinum (TALINACEAE): a new entity from the northwest of Argentina

RESUMEN Talinum paniculatum es una hierba adventicia ampliamente distribuida en Argentina, que tiene importancia económica como maleza de cultivos resistente a herbicidas. Esta especie se presenta en el campo con dos morfotipos y ellos se distinguen por la forma, tamaño y color de sus flores, frutos y hojas. El objetivo de este trabajo fue determinar las características morfo-anatómicas (de hoja y tallo), citogenéticas y moleculares en dos morfotipos de la provincia de Tucumán (Argentina), y establecer diferencias entre ellos. Se utilizaron técnicas morfo-anatómicas y citogenéticas clásicas y se realizaron análisis moleculares con el marcador ITS2. Los resultados evidencian que las características morfológicas, anatómicas, citogenéticas y moleculares de Talinum paniculatum permitieron diferenciar los morfotipos MT1 y MT2. Se concluye que el MT1 corresponde a T. paniculatum y el MT2 a un taxón diferente que aún no se mencionó para la flora de Argentina.

ABSTRACT Talinum paniculatum is an adventitious herb widely distributed in the Argentina. This plant is considered as an economically important herbicide-resistant weed. This species shows two morphotypes in the field which are differentiated by shape, size and colour of their flowers leaves and fruits. The aims of this work were to determinate morpho-anatomical (leave and stem), cytogenetic and molecular traits of two morphotypes from Tucumán province (Argentina) and to establish differences between them. Classical morpho-anatomical and cytogenetic techniques were used, molecular analysis based on the ITS2 marker were performed. The results showed that morphological, anatomical, cytogenetic and molecular traits of T. paniculatum allow us to differentiate the MT1 and MT2 morphotypes. We concluded that MT1 match with T. paniculatum and MT2 is a different taxon still not described for the flora of Argentina.

How does the mitotic index impact patients with T1 melanoma? Comparison between the 7th and 8th edition of the American Joint Committee on Cancer melanoma staging system

Abstract Background: The mitotic index is no longer used to classify T1 melanoma patients into T1a and T1b, so it should not be used to indicate sentinel node biopsy in these patients. Objectives: To evaluate patients with T1 melanoma who underwent sentinel lymph node biopsy and to compare those who were classified as T1a with those classified T1b, according to the 7th and 8th Edition of the melanoma staging system, regarding a positive biopsy result. The authors also aimed to assess whether there is any difference in the results in both staging systems. Material and methods: This was a retrospective analysis of 1213 patients who underwent sentinel lymph node biopsy for melanoma, from 2000 to 2015, in a single institution. Results: Of 399 patients with thin melanomas, 27 (6.7%) presented positive sentinel lymph nodes; there was no difference in positivity for sentinel node biopsy when comparing T1a vs. T1b in both staging systems. Furthermore, the clinical results were also similar between the two groups. However, in the complete cohort analysis, the mitotic index was associated with positivity for sentinel lymph node biopsy (p < 0.0001), positivity for non-sentinel lymph node (p < 0.0001), recurrence-free survival (p < 0.0001), and specific melanoma survival (p = 0.023). Study limitation: Unicentric study. Conclusion: The mitotic index was shown to be a very important prognostic factor in the present study, but it was not observed in patients classified as T1. The mitotic index should no longer be used as the only reason to refer sentinel lymph node biopsy in patients with thin melanoma.

Advances in studies on the relationship between Aurora kinases and gastrointestinal tumors / 中国肿瘤临床

Aurora kinases constitute a highly evolutionarily conserved family of serine/threonine kinases, which includes Aurora A, Aurora B, and Aurora C. These kinases are dynamically distributed throughout the cell cycle, and ensure the normal completion of the cell cycle by regulating centrosome maturation and separation, bipolar spindle assembly and stabilization, accurate separation of chromosomes, and efficient division of cytoplasm during mitosis. In recent years, it has been shown that Aurora kinases are overexpressed in a variety of solid tumors in the human body. The overexpression of Aurora kinases leads to abnormal mitosis, causes genetic instability, and is closely related to the occurrence, proliferation, and poor prognosis of tumors, which indicates that these kinases could be novel anti- tumor targets. Currently, Aurora kinase inhibitors are considered as novel candidates for molecular targeted therapies. Some of these inhibitors with strong anti-tumor activity have even entered clinical trials. In this article, we have reviewed the relationship between the biological characteristics of Aurora kinases, Aurora kinase inhibitors, and the occurrence and development of gastrointestinal tumors.

MIME-Mitosis instead of meiosis and its application in crop apomixis / 生物工程学报

Apomixis has been widely concerned because of its great potential in heterosis fixation. Artificial apomixis is an important direction of current apomixis research. Mitosis instead of Meiosis (MIME) produces diploid gametes that is identical with the maternal genetic composition and is a key step in the artificial creation of apomixes. This paper reviews the occurrence of MIME and its application in crop apomixis and the problems encountered, in an aim to provide reference for expanding the application of MIME in crop apomixis.

Pretreatment of hepatetctomized rats with Coleus forskohlii did not interfere with the course of hepatic hyperplasia

Abstract Purpose Coleus forskohlii Briq., a medicinal plant originally from India, has been indicated against heart disease, expiratory disorders, convulsions, and hepatic changes, among others. In view of the broad pharmacological potential of the plant and the scarce information about its effects, the objective of the present study was to investigate the effect of its use for pretreatment of partially hepatectomized rats. Methods The animals were divided into two experimental groups: Control (CG) receiving physiological saline for 10 days before partial hepatetctomy, and Treated (TG) receiving 40 mg Coleus forskohlii/kg/day for 10 days before partial hepatectomy. The treatments were performed by gastric gavage. After the surgical procedure, treatment was continued according to the following groups: CG 24 h, CG 48 h, TG 24 h, and TG 48 hs, and liver tissue and intracardiac blood samples were obtained for histological and biochemical analysis, respectively. Results No significant differences were observed in mitotic or apoptotic index or in the concentrations of the enzymes AST, ALT and alkaline phosphatase, and no areas of fibrosis were detected. Conclusion Treatment with Coleus forskohlii did not interfere with the course of hepatic hyperplasia.

Progress of phosphohistone H3 in tumors / 肿瘤研究与临床

Phosphohistone H3 (PHH3) is one of the five newly discovered nucleocardial histones. PHH3 with other histones constitute the main protein components in chromatin in eukaryotic. For it reached the maximum value in G2 phase and M phase with mitosis, so it was considered as a specific nuclear fission marker. At present, PHH3 has been proved to be very useful to determine the nuclear fission images of tumor cells, and to distinguish the nuclear fission images from apoptotic bodies and nuclear fragments. This paper reviews the research status of PHH3 in tumors.

Natural products as new antimitotic compounds for anticancer drug development

Cell cycle control genes are frequently mutated in cancer cells, which usually display higher rates of proliferation than normal cells. Dysregulated mitosis leads to genomic instability, which contributes to tumor progression and aggressiveness. Many drugs that disrupt mitosis have been studied because they induce cell cycle arrest and tumor cell death. These antitumor compounds are referred to as antimitotics. Vinca alkaloids and taxanes are natural products that target microtubules and inhibit mitosis, and their derivatives are among the most commonly used drugs in cancer therapy worldwide. However, severe adverse effects such as neuropathies are frequently observed during treatment with microtubule-targeting agents. Many efforts have been directed at developing improved antimitotics with increased specificity and decreased likelihood of inducing side effects. These new drugs generally target specific components of mitotic regulation that are mainly or exclusively expressed during cell division, such as kinases, motor proteins and multiprotein complexes. Such small molecules are now in preclinical studies and clinical trials, and many are products or derivatives from natural sources. In this review, we focused on the most promising targets for the development of antimitotics and discussed the advantages and disadvantages of these targets. We also highlighted the novel natural antimitotic agents under investigation by our research group, including combretastatins, withanolides and pterocarpans, which show the potential to circumvent the main issues in antimitotic therapy.

Estudo retrospectivo dos pacientes portadores de melanoma cutâneo atendidos na Universidade Federal de São Paulo / Retrospective study of patients with cutaneous melanoma treated at the Federal University of São Paulo

RESUMO Objetivo: avaliar as características dos pacientes portadores de melanoma cutâneo atendidos no Hospital São Paulo - UNIFESP. Métodos: estudo retrospectivo de 184 casos de melanoma cutâneo. Foram analisadas as informações sobre sexo, idade, características do tumor, características histológicas e estadiamento. Resultados: a média de idade ao diagnóstico foi de 58,7 anos, com distribuição etária homogênea entre os sexos e predominância em indivíduos brancos (70,6%). Observou-se acometimento predominante de tronco, em homens (36,7%), e de membros inferiores, em mulheres (42%). A exposição solar, com queimaduras, foi mais comum entre homens (31,2%) do que entre mulheres (23,5%). Houve aumento de aproximadamente três vezes no acometimento linfonodal quando o índice mitótico subia de zero (11,9%) para uma ou mais mitoses por campo (36,2%), e aumento progressivo do acometimento linfonodal e de desfechos ruins quanto maior a espessura de Breslow: 10,2% quando menor do que 1mm e 59,2% quando maior do que 4mm. Conclusão: as características dos pacientes portadores de melanoma cutâneo atendidos no Hospital São Paulo são semelhantes às encontradas na literatura.

ABSTRACT Objective: to evaluate the characteristics of the patients with cutaneous melanoma treated at the São Paulo Hospital - UNIFESP. Methods: we conducted a retrospective study of 184 cases of cutaneous melanoma. We analyzed information on gender, age, tumor characteristics, histological characteristics and staging. Results: mean age at diagnosis was 58.7 years, with homogeneous age distribution between genders and predominance in white individuals (70.6%). There was a predominance of trunk involvement in men (36.7%) and lower limbs in women (42%). Sun exposure, with sunburns, was more common among males (31.2%) than among females (23.5%). There was an approximately three-fold increase in lymph node involvement when the mitotic index rose from zero (11.9%) to one or more mitosis per field (36.2%). In addition, the greater the Breslow thickness, the greater the lymph node involvement and poor the outcomes: 10.2% when less than 1mm and 59.2% when greater than 4mm. Conclusion: the characteristics of patients with cutaneous melanoma treated at Hospital São Paulo are similar to those found in the literature.

The role and clinical significance of migration and invasion inhibitory protein in the de-velopment and progression of tumors / 中国肿瘤临床

Migration and invasion inhibitory protein(MIIP)inhibits cell proliferation,migration,and invasion,impeding tumorigenesis and tumor progression,by interacting with insulin-like growth factor binding protein 2(IGFBP2),histone deacetylase 6(HDAC6),p21 activated kinase 1(PAK1),epidermal growth factor receptor(EGFR),cell division cycle 20(CDC20),and topoisomerase.Recent studies revealed potential roles of MIIP in viral infection and cellular immunity.MIIP has become a research hotspot owing to its involvement in multiple signaling pathways and as a potential therapeutic target for tumors.This review summarizes the characteristics,functions, clinical significance,and possible pathogenic mechanisms of MIIP in multiple carcinomas.

Roles of SIRT2 in the tumorigenesis and development of hepatocellular carcinoma / 上海交通大学学报（医学版）

Silence information regulators (sirtuins) are highly conserved nicotinamide adenine dinucleotide (NAD+) dependent histone deacetylases, which play important roles in the process of aging, metabolism, apoptosis, gene transcription, and inflammation. There are seven kinds of sirtuins in mammals, SIRT1-SIRT7. These proteins have different subcellular localization and play diverse roles in metabolism. SIRT2, one of the members of sirtuins family, is mainly located in the cytoplasm and participates in the cell cycle control, oxidative stress and glycolipid metabolism. In addition, the expression level of SIRT2 has been widely associated with the development of cancers, including hepatocellular carcinoma. SIRT2 possesses a dual role in tumorigenesis, with both tumor-promoting and tumor-suppressing function. However, the mechanisms in which SIRT2 plays the roles in cancer are still controversial. In this review, the conflicting roles of SIRT2 in the tumorigenesis and development of hepatocellular carcinoma were mainly discussed.

Differential regulation of H3S10 phosphorylation, mitosis progression and cell fate by Aurora Kinase B and C in mouse preimplantation embryos

Coordination of cell division and cell fate is crucial for the successful development of mammalian early embryos. Aurora kinases are evolutionarily conserved serine/threonine kinases and key regulators of mitosis. Aurora kinase B (AurkB) is ubiquitously expressed while Aurora kinase C (AurkC) is specifically expressed in gametes and preimplantation embryos. We found that increasing AurkC level in one blastomere of the 2-cell embryo accelerated cell division and decreasing AurkC level slowed down mitosis. Changing AurkB level had the opposite effect. The kinase domains of AurkB and AurkC were responsible for their different ability to phosphorylate Histone H3 Serine 10 (H3S10P) and regulate metaphase timing. Using an Oct4-photoactivatable GFP fusion protein (Oct4-paGFP) and fluorescence decay after photoactivation assay, we found that AurkB overexpression reduced Oct4 retention in the nucleus. Finally, we show that blastomeres with higher AurkC level elevated pluripotency gene expression, which were inclined to enter the inner cell mass lineage and subsequently contributed to the embryo proper. Collectively, our results are the first demonstration that the activity of mitotic kinases can influence cell fate decisions in mammalian preimplantation embryos and have important implications to assisted reproduction.

Ophiopogonin-B inhibited cell mitosis by Myt / Cdc2 pathway in H460 cells / 中国药理学通报

Aim To explore the effects of ophiopogo-nin-B (OP-B)on cell cycle and mitosis in non-small cell lung cancer (NSCLC)H460 cells in vitro and the underlying mechanisms. Methods TUNEL immuno-histochemical assay was used to detect the change of the nuclear matter. DAPI staining was used to detect the change of the nuclear morphology and the mitosis status. Meanwhile,Western blot was performed to de-termine the protein level of the proteins regulating cell cycle and mitosis. Results OP-B significantly arres-ted cell cycle in G0 / G1 phase and inhibited the mitosis in H460 cells at the concentration of 10 μmol·L - 1 . Meanwhile,it inhibited the protein level of cyclinD1, cyclinB1,and up-regulated the expression of Myt and the phosphorylation level of Cdc2. Conclusion OP-B inhibits cell mitosis in A549 cells through Myt/ Cdc2 signaling pathway.

The function of Aurora A and its role in the development of liver cancer / 中华肝脏病杂志

Aurora A plays a key role in cellular mitosis. It is located in the centrosome and spindle, and is mainly involved in the processes of centrosome maturation and separation, bipolar spindle assembly, and the regulation of mitotic progression. Recent studies have suggested that Aurora A is involved in tumorigenesis and tumor development through multiple mechanisms. Overexpression of Aurora A could cause abnormal centrosome amplification, aneuploidy formation, and G2/M checkpoint defects, which result in chromosome instability and imbalance between cell division and apoptosis, and eventually leads to abnormal cell proliferation. Aurora A also participates in the regulation of the p53 and BRCA1 pathways, leading to suppressor gene dysfunction and changes in cell viability, and it induces telomerase activity by upregulating c-Myc, resulting in tumorigenesis. In addition, Aurora A also induces drug resistance in liver cancer cells. Thus, Aurora A has gradually become a new target for cancer therapy in recent years. This paper has summarized the recent studies on Aurora A, and reviewed its biological functions in cell mitosis and roles in liver tumorigenesis.

Composição Química e Atividade Antioxidante de Agaricus blazei e seu Efeito Sobre a Modulação da Mitose / Chemical Composition and Antioxidant Activity of Agaricus blazei and its Effect on Mitosis Modulation

Este estudo teve como objetivo verificar a composição química e atividade antioxidante do Cogumelo do Sol (Agaricus blazei) e seu efeito sobre o ciclo celular de Allium cepa. A análise da composição química revelou uma elevada concentração em compostos fenólicos (65,36 mg/ EAG), ácido ascórbico (1,74mg/g), ß-caroteno (384,28µg/mg) e licopeno (33,61µg/mg). A eficiência no sequestro de radicais livres do DPPH foi considerada primária (68,15%) e a análise do ciclo celular mostrou que o tratamento com Agaricus blazei promove atraso na fase de anáfase da mitose em células meristemáticas de Allium cepa. Os resultados sugerem que a composição química e antioxidante de Agaricus blazei pode influenciar na modulação do ciclo celular de Allium cepa e possivelmente reduz a taxa de mutação espontânea, por diminuir a velocidade de disjunção e migração dos cromossomos durante a mitose. (AU)

The chemical composition and antioxidant activity of mushrooms Agaricus blazei and its effect on the Allium cepa cell cycle was investigated. Chemical analysis showed high concentration of phenolic compounds (65.36 mg/GAE), ascorbic acid (1.74 mg/g), ß-carotene (384.28 µg/mg) and lycopene (33.61 µg/mg). The efficiency free radical DPPH scavenging acitvity was primary (68.15%). Analysis of cell cycle demonstrated that treatment with Agaricus blazei delayed the mitosis anaphase phase in meristem cells of Allium cepa. The results suggest that the chemical composition and antioxidant activity of Agaricus blazei may affect the modulation of the Allium cepa cell cycle, and possibly reduce the spontaneous mutation rate, by decreasing the disjunction and migration speed of chromosomes during mitosis. (AU)