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.
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La técnica de transferencia de huso meiótico desde la perspectiva legal en la República Argentina / THE MEIOTIC SPINDLE TRANSFER TECHNIQUE FROM THE LEGAL PERSPECTIVE IN THE ARGENTINE REPUBLIC

La transferencia de huso permite evitar enfermedades de herencia mitocondria. El art. 57 del Código Civil y Comercial, que utiliza una redacción amplia para no quedar obsoleto, apuntaría la prohibición a la manipulación de embriones en busca de mejoras determinadas, pero no a aquellas prácticas que tienen un fin terapéutico. Sin embargo, hay que repensar los límites de la prohibición y la razonabilidad de este tratamiento.

Spindle transfer makes it possible to avoid diseases of mitochondrial inheritance. The art. 57 of the Civil and Commercial Code, which uses a broad wording so as not to become obsolete, would point the prohibition to the manipulation of embryos in search of certain improvements, but not to those practices that have a therapeutic purpose. However, it is necessary to rethink the limits of the prohibition and the reasonableness of this treatment.

Relationship between meiotic spindles visualization and intracytoplasmic sperm injection outcomes in human oocytes / 대한해부학회지

In assisted reproductive techniques, the operator attempts to select morphologically best embryos to predict embryo viability. Development of polarized light microscope, which evaluates the oocytes' spindles according to birefringence of living cells, had been helpful in oocyte selection. The aim of this study is evaluating the relationship between meiotic spindles visualization and intracytoplasmic sperm injection (ICSI) outcomes in human oocytes. In this study, 264 oocytes from 24 patients with an average age of 30.5±7.5 years with infertility duration of 1 to 10 years were collected. The oocytes were randomly allocated to the control injection group (n=126) and the oocyte imaging group (spindle-aligned group) (n=138). In the spindle-aligned group, the meiotic spindle was identified by means of polarized light microscope to align the spindle at 6 or 12 o'clock. Then the spindle-aligned group was divided into three sub-groups based on spindle morphology: fine, average, and (poor). After ICSI, embryos were checked every 24 hours and scored; 72 hours later, high-grade embryos were transferred intravaginally to uterus. This study showed that the fertilization rate in the spindle-aligned group was higher than the control group (P<0.05). After cleavage, a positive correlation was observed between spindle morphology and embryo morphology. Among the sub-groups of spindle-aligned group, the embryos' morphology of the fine group was better than the other subgroups and embryos of the poor group had lower quality and more fragmentation. The results revealed that the selection of oocytes based on meiotic spindle imaging can significantly improve the rate of fertilization and embryo cleavage and certainly increase the rate of implantation.

The p90 ribosomal S6 kinase 2 specifically affects mitotic progression by regulating the basal level, distribution and stability of mitotic spindles

RSK2, also known as RPS6KA3 (ribosomal protein S6 kinase, 90 kDa, polypeptide 3), is a downstream kinase of the mitogen-activated protein kinase (MAPK) pathway, which is important in regulating survival, transcription, growth and proliferation. However, its biological role in mitotic progression is not well understood. In this study, we examined the potential involvement of RSK2 in the regulation of mitotic progression. Interestingly, depletion of RSK2, but not RSK1, caused the accumulation of mitotic cells. Time-lapse analysis revealed that mitotic duration, particularly the duration for metaphase-to-anaphase transition was prolonged in RSK2-depleted cells, suggesting activation of spindle assembly checkpoint (SAC). Indeed, more BubR1 (Bub1-related kinase) was present on metaphase plate kinetochores in RSK2-depleted cells, and depletion of BubR1 abolished the mitotic accumulation caused by RSK2 depletion, confirming BubR1-dependent SAC activation. Along with the shortening of inter-kinetochore distance, these data suggested that weakening of the tension across sister kinetochores by RSK2 depletion led to the activation of SAC. To test this, we analyzed the RSK2 effects on the stability of kinetochore–microtubule interactions, and found that RSK2-depleted cells formed less kinetochore–microtubule fibers. Moreover, RSK2 depletion resulted in the decrease of basal level of microtubule as well as an irregular distribution of mitotic spindles, which might lead to observed several mitotic progression defects such as increase in unaligned chromosomes, defects in chromosome congression and a decrease in pole-to-pole distance in these cells. Taken together, our data reveal that RSK2 affects mitotic progression by regulating the distribution, basal level and the stability of mitotic spindles.

Dynamic changes of γ-tubulin in mouse somatic cell nuclear transferred embryos / 生理学报

The aim of the present study is to observe the dynamic changes of γ-tubulin in mouse somatic nuclear transferred (SCNT) embryos. The γ-tubulin was detected and analyzed in the enucleated oocyte and SCNT embryos by immunofluorescence and laser confocal microscopy. The results showed that γ-tubulin distributed in the cortex of the enucleated MII oocytes, and decreased in this area during the activation of oocytes. Meanwhile cytoplasmic asters appeared, but there was no spindle formed. Spindle formation could be observed in the enucleated oocytes which were injected with cumulus cells and activated by SrCl2. The spots-like γ-tubulin signals spread between chromosomes at the prophase, and the signals arrayed with spindle or aggregated at two poles of the spindle at the early metaphase. Furthermore, γ-tubulin signals were localized between the segregated sister chromatids at anaphase or telophase. Some reconstructed embryos exhibited advanced activation, showing abnormal spindles and aberrant distribution of γ-tubulin and chromosomes. Two spindles would be formed when the cumulus cell was injected into an intact oocyte, and the distribution of γ-tubulin was similar to that of the normal SCNT. Moreover, advanced activation also occurred in this case and formed either two small spindles or one big barrel-shaped spindle. These results suggest that γ-tubulin plays a pivotal role in spindle assembling in mouse SCNT embryos. The reconstructed oocytes were easily to be activated, and aberrant distribution of γ-tubulin is associated with formation of abnormal spindles and chromosome misalignment.

Análise invasiva e não invasiva do fuso meiótico de oócitos humanos obtidos de ciclos estimulados: dados preliminares / Invasive and noninvasive analysis of the meiotic spindle of human oocytes obtained from stimulate cycles: preliminary results

OBJETIVOS: Avaliar a concordância entre as técnicas de microscopia de polarização e microscopia confocal na avaliação do fuso meiótico de oócitos humanos maturados in vivo. MÉTODOS: Estudo prospectivo que avaliou oócitos com o primeiro corpúsculo polar extruído obtidos de mulheres inférteis submetidas à estimulação ovariana para realização de injeção intracitoplasmática de espermatozoide. Os oócitos com o primeiro corpúsculo polar extruído foram avaliados por meio da microscopia de polarização e, imediatamente após, foram fixados e corados para avaliação dos microtúbulos e cromatina pela microscopia confocal de alto desempenho. Foram comparadas as técnicas de microscopia de polarização e confocal, de acordo com a visualização ou não do fuso meiótico pela microscopia de polarização e a presença ou não de anomalias meióticas à análise pela microscopia confocal. Foram calculados os intervalos de confiança, o índice de Kappa e a concordância entre as metodologias, considerando a análise da microscopia de imunofluorescência como padrão-ouro para avaliação de normalidade do fuso e distribuição cromossômica oocitária. RESULTADOS: Observou-se que 72,7% dos oócitos em metáfase II com fuso celular não visível à polarização apresentaram anormalidades meióticas à análise confocal e que 55,6% dos oócitos em metáfase II com fuso celular visível à polarização apresentaram-se como oócitos anormais à análise confocal. Somente 44,4% dos oócitos com fuso celular visível à polarização apresentaram-se como normais à análise confocal. A concordância entre os métodos foi de 51,1% (Kappa: 0,11; IC95% -0,0958 - 0,319). CONCLUSÕES: A baixa concordância entre a microscopia de polarização e a confocal na avaliação do fuso meiótico oocitário sugere que a visualização do fuso meiótico de oócitos humanos em metáfase II pela microscopia de polarização tem limitado o valor preditivo de normalidade meiótica oocitária.

PURPOSE: To evaluate the concordance between polarization microscopy and confocal microscopy techniques in the evaluation of the meiotic spindle of human oocytes matured in vivo. METHODS: Prospective study that evaluated oocytes with the first polar extruded body obtained from infertile women who had undergone ovarian stimulation for intracytoplasmic sperm injection. The oocytes with the first polar extruded body were evaluated by polarization microscopy and were then immediately fixed and stained for microtubule and chromatin evaluation by high-performance confocal microscopy. We determined the correlation of polarization microscopy with confocal microscopy in the detection of meiotic oocyte anomalies, and we also evaluated the percentage of oocytes with a visible and non-visible cell spindle by polarization microscopy and with meiotic normality and abnormalities by confocal microscopy. Confidence intervals, Kappa's index and concordance between the methodologies were calculated, considering immunofluorescence microscopy analysis as the golden-standard for evaluating normal spindle and oocyte chromosome distribution. RESULTS: We observed that 72.7% of metaphase II oocytes with a nonvisible meiotic spindle by polarization microscopy showed no meiotic abnormalities by confocal analysis and 55.6% of metaphase II oocytes with a visible meiotic spindle by polarization microscopy were found to be abnormal oocytes by the confocal analysis. Only 44.4% of oocytes with a visible meiotic spindle by polarization microscopy were found to be normal by confocal analysis. Concordance between the methods was 51.1% (Kappa: 0.11; 95%CI -0.0958 - 0.319). CONCLUSIONS: The low correlation between polarization microscopy and confocal microscopy in the assessment of oocyte meiotic spindle suggests that visualization of the meiotic spindle of human oocytes at metaphase II by polarization microscopy is not a good indicator of oocyte meiotic normality.

Estudo de proteínas relacionadas ao fuso mitótico (AURORA A e AURORA B) e ponto de checagem mitótico (CDC20 e MAD2L1) em pacientes portadores de Síndrome mielodisplásica / Mitotic spindle (AURORA A e AURORA B) and mitotic checkpoint (CDC20 and MAD2L1) related protein study in patients with myelodysplastic syndrome

Síndrome mielodisplásica (SMD) representa um grupo heterogêneo de doenças hematopoéticas clonais caracterizadas por alterações displásicas e citopenias no sangue periférico. A patogênese da SMD envolve múltiplas etapas e ainda não está claramente definido como a doença progride para o estágio avançado e para leucemia mielóide aguda. A presença de alterações citogenéticas desempenha importante papel no prognóstico e seguimento desses pacientes. Alguns estudos demonstram que alterações na expressão de proteínas relacionadas ao fuso mitótico (AURORA A e AURORA B) e ao ponto de checagem mitótico (CDC20 e MAD2L1) estão envolvidas na instabilidade cromossômica, aneuploidia e progressão tumoral em diferentes tumores sólidos e neoplasias hematológicas. No entanto, pesquisas que investiguem a expressão destes genes em pacientes com SMD são escassas, e estudos que avaliem essas proteínas podem contribuir para o endentimento da fisiopatologia da doença. Nesse sentido, este trabalho teve como objetivo avaliar o perfil de expressão destes genes em pacientes com SMD, e investigar sua relação com as variáveis clínicas e laboratoriais da doença. O estudo das alterações cromossômicas foi realizado por bandamento G, a análise de amplificação para os genes AURKA e AURKB foi realizada através da técnica de hidridização in situ por fluorescência (FISH), e a expressão dos genes AURKA, AURKB, CDC20 e MAD2L1 foi realizada, através de PCR Quantitativo em Tempo Real, em 61 amostras de medula óssea de pacientes portadores de SMD. Assim como em outras neoplasias, a maioria dos pacientes estudados (55,8%) apresentaram cariótipo alterado, refletindo a instabilidade cromossômica decorrentes do processo de patogênese da doença...

Research progress on spindle assembly checkpoint gene BubR1 / 浙江大学学报·医学版

BubR1 gene is a homologue of the mitotic checkpoint gene Mad3 in budding yeast which is highly conserved in mammalian. BubR1 protein is a key component mediating spindle assembly checkpoint activation. BubR1 safeguards accurate chromosome segregation during cell division by monitoring kinetochore-microtubule attachments and kinetochore tension. There is a dose-dependent effect between the level of BubR1 expression and the function of spindle assembly checkpoint. BubR1-deficient would lead to mitotic progression with compromised spindle assembly checkpoint because cells become progressively aneuploid. Recently, it has been reported that BubR1 also plays important roles in meiotic, DNA damage response, cancer, infertility, and early aging. This review briefly summarizes the current progresses in studies of BubR1 function.

The asymmetric division and tumorigenesis of stem cells / 癌症

Stem cells use asymmetric and symmetric cell division to generate progeny. Symmetric cell division is defined as the generation of daughter cells that are destined to acquire the same fate. Stem cells divide asymmetrically to generate one daughter with a stem-cell fate and one daughter with different fate. Disruption of the machinery that regulates asymmetric division may be a reason for the generation of cancer. The asymmetric mechanism is maintained by cell polarity factors, cell fate determinants, and the spindle apparatus. The mutation or dysregulation of these factors may change stem cells from asymmetric to symmetric cell division, then leading to tumorigenesis. Therefore, further study is needed on the mechanisms of stem cell control between asymmetric and symmetric cell division, as well as the relationships among stem cells, cancer stem cells, and tumor cells. It may bring us a new approach for the resistance, recurrence, and metastasis of tumors.

Dynamic changes of gamma-tubulin in preimplantation development of parthenogenetic mouse embryos / 生理学报

Tubulin is the major protein of microtubule. alpha- and beta- tubulins form heterodimers, while gamma-tubulin regulates microtubule organization. The present study aimed to observe the dynamic changes of gamma-tubulin in preimplantation development of parthenogenetic mouse embryos. Immunofluorescence and laser confocal microscopy were used to detect the location of gamma-tubulin in preimplantation parthenogenetic embryos activated by SrCl2. The oocytes were collected at 13-14 h after hCG injection, and then activated with 10 mmol/L SrCl2 in Ca(2+)-free CZB medium with 5 mmol/L cytochalasin B (CB), fixed at 1 h intervals until 6 h after activation. The results showed that spindle was paralleled with the cell membrane all the time, when the meiosis of MII mouse oocytes resumed. The rotation of spindle was inhibited, but karyokinesis was not influenced. At 0 h after activation, i.e. at metaphase, gamma-tubulin was distributed mainly on the two poles of spindle. At 1 h after activation, i.e. at anaphase, following the separation of chromosomes, gamma-tubulin was transformed from dense to disperse. At 2 h after activation, gamma-tubulin was localized between the segregated sister chromatids at telophase. However, at 3-6 h after activation, gamma-tubulin concentrated around the two female pronuclei during their formation and juxtaposition. Moreover, another group of MII oocytes were activated for 6 h and cultured in droplets of KSOM medium under mineral oil in 5% CO2 in air at 37 degrees C to permit parthenogenetic development. The embryos were collected and fixed at 3 h, 14 h, 16 h, and 18 h of culture. At 3 h after culture, i.e. at mitotic interphase, it was shown that amorphous gamma-tubulin distributed around the nuclei of early parthenogenetic embryos. At 24 h after culture, i.e. at prometaphase, gamma-tubulin migrated along the spindle microtubule to the two poles. Our results showed that gamma-tubulin had similar location patterns at metaphase, anaphase and telophase in meiosis and mitosis. It was concluded that gamma-tubulin assembly in parthenogenetically activated oocytes facilitated the formation of negative pole cap and the stabilization of microtubule, thus promoting the spindle formation at meiosis and mitosis. The relocation of gamma-tubulin at anaphase and telophase might be induced by the event of segregation of homologous chromosome being pulled away by the spindle. gamma-tubulin might contribute to the migration and juxtaposition of the two female pronuclei as well.

Meiosis in a triploid hybrid of Gossypium: high frequency of secondary bipolar spindles at metaphase II.

Studies on meiosis in pollen mother cells (PMCs) of a triploid interspecific hybrid (3x = 39 chromosomes, AAD) between tetraploid Gossypium hirsutum (4n = 2x = 52,AADD) and diploid G. arboreum (2n = 2x = 26,AA) are reported. During meiotic metaphase I, 13 AA bivalents and 13 D univalents are expected in the hybrid. However, only 28% of the PMCs had this expected configuration. The rest of the PMCs had between 8 and 12 bivalents and between 12 and 17 univalents. Univalents lagged at anaphase I, and at metaphase II one or a group of univalents remained scattered in the cytoplasm and failed to assemble at a single metaphase plate. Primary bipolar spindles organized around the bivalents and multivalents. In addition to the primary spindle, several secondary and smaller bipolar spindles organized themselves around individual univalents and groups of univalents. Almost all (97%) of the PMCs showed secondary spindles. Each spindle functioned independently and despite their multiple numbers in a cell, meiosis I proceeded normally, with polyad formation. These observations strongly support the view that in plant meiocytes bilateral kinetochore symmetry is not required for establishing a bipolar spindle and that single unpaired chromosomes can initiate and stabilize the formation of a functional bipolar spindle.

Influence of maternal age on meiotic spindle and chromosome configuration of oocytes / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the effect of maternal age on meiotic spindle and chromosome configuration of oocytes.</p><p><b>METHODS</b>Spindle and chromosome configuration was examined in day 1 unfertilized human oocytes after in vitro fertilization (IVF) and intracytoplasmic sperm injection(ICSI) by immunocytochemistry and visualized by laser confocal microscopy.</p><p><b>RESULTS</b>Statistically significant differences were observed on normal spindle and chromosome configurations of oocytes between 25-29 maternal age group (33% and 31%, respectively), and 30-34 age group (P< 0.05) as well as 35-40 age group(0%, P<0.01). The incidence of abnormal spindle and chromosome configurations of oocytes from 30-34 and 35-40 maternal age groups was much higher than that of oocytes from 25-29 age group (P<0.01, P<0.05).</p><p><b>CONCLUSION</b>Incidence of abnormal spindle and chromosome configuration of oocytes is related to maternal age. It could be an important reason of age related oocyte aneuploidy.</p>

Application of spindle-view in the enucleation porcine of oocytes / 生物工程学报

The Spindle-view, a specialized instrument for observing spindle image, was applied to observe the meiotic spindles of vitro matured porcine oocytes at 36, 42, 44, 48h, and enucleation from porcine, comparing to the previously methods (McGrath-Solter's method and two-step-squeezing method) in the enucleated. The results showed that: (1) there was no noticeable differences at vicinity of spindle images and 1st polar body among in vitro matured porcine oocytes at 40-48 h under the instrument; (2) Spindle-view is suitable for the observation of meiotic spindles of matured oocytes and enucleation from porcine; the modified Spindle-view method for enucleation is significantly better than McGrath-Solter' s method and two-step-squeezing method in the enucleated rates (95.5%, 42.1%, 74.2%, P < 0.0l) of absolutely removing nuclei matter; (3) the spindle images could be used to monitor the oocyte qualities.

Influence of two different vitrification cryopreservation methods on spindles of mouse oocytes / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the influence of two different vitrification cryopreservation methods on the spindles of mouse M II oocytes.</p><p><b>METHODS</b>Three groups were included in the experiment, Group A, Group B and the control ( fresh oocytes). Mouse oocytes were vitrified by using cryoloop, with ethylene glycol( EG) in Group A and with EG + dimethyl sulphoxide ( DMSO) in Group B as cryoprotectants, and then the oocytes were placed directly into liquid nitrogen. Three hours after the frozen oocytes were thawed they were fixed, and the microtubule and chromosome were stained by indirect immunofluorescent method.</p><p><b>RESULTS</b>The survival rates of the oocytes after treated by the two vitrification cryopreservation methods had no difference ( 80. 3% vs 87. 5% , P > 0. 05) . The rate of the intact spindles in Group A was much lower than that of the control and Group B ( 15. 2% vs 78.7% , 15. 2% vs 77. 5% , P < 0. 05). But there was no difference between the latter two groups (78. 7% vs 77. 5% , P >0. 05). The oocytes with normal chromosome in Group A were much less than in the control and Group B (17.4% vs 76. 6% , 17. 4% vs 72. 5% , P <0. 05) , with no difference between the latter two groups(76. 6% vs 72. 5% , P >0. 05) ; The oocytes with abnormal chromosome were more in Group A than in the control and Group B (82. 6% vs 19. 1% , 82. 6% vs 27. 5% , P <0. 05) , with no difference between the latter two groups (19.1% vs 27.5% , P >0.05).</p><p><b>CONCLUSION</b>The changed vitrification cryopreservation method helps conserve the intact spindle configuration of mouse oocytes.</p>

Sec13 induces genomic instability in U2OS cells

Sec13p has been known as an endoplasmic reticulum-Golgi transport protein. Recently, it has also been shown to be required for the formation of septation in the fission yeast Schizosaccharomyces pombe. In the present study, we focused on the role of a human homolog of Saccharomyces cerevisiae SEC13, Sec13 protein during mitosis in U2OS cells. We found that the expression of Sec13 was constant throughout the cell cycle, and localized to the kinetochores at metaphase during mitosis. By using green fluorescent protein technology, we observed that Sec13 is required for evasion of mitotic arrest in response to spindle damage, leading to G1-like phase and apoptotic cell death. In addition, cells expressing exogenous Sec13 showed giant nuclei compared to endogenous ones in the absence of nocodazole. These results demonstrate that Sec13 is involved in the regulation of the metaphase/anaphase transition and may be functionally associated with mitotic machinery to maintain genomic stability during mitosis.

Centrosome amplification and multinuclear phenotypes are Induced by hydrogen peroxide

Multinucleated cells resulted from mitosis defect have been noted in pathophysiological states of the cells such as inflammation, senescence and cancer. Since oxidative stress has been known to correlate with these pathophysiological conditions, we tested the effect of H2O2 on the cell cycle progression and formation of multinucleated cells. H2O2 induced a significant delay in cell cycle progression in Chang liver cells. Interestingly, H2O2 actively induced hyperamplification of centrosomes (> or =3) and multipolar spindle formation during mitosis and subsequently increased the generation of multinucleated cells. A significant increase of the phospho-ERK level was observed upon H2O2 treatment but PD98059, an MEK1/2 inhibitor, didn't reduce the frequency of cells with hyperamplified centrosomes. On the other hand, treatment of either H2O2 or adriamycin increased intracellular ROS levels and multinucleated cells, which were significantly suppressed by antioxidants, N-acetylcysteine and PDTC. Thus, our results suggest that oxidative stress can trigger centrosome hyperamplification and multinucleated cell formation, which may promote pathophysiological progression.

Kinesin superfamily protein member 4 (KIF4) is localized to midzone and midbody in dividing cells

In association with microtubules, a variety of kinesins play important roles in cellular functions such as intracellular transport of organelles or vesicles, signal transduction, and cell division. In a previous study we revealed that human kinesin superfamily protein member 4 (KIF4) is a chromokinesin that binds to chromosomes. Since localization of several kinds of kinesin at midzone called central spindle, or midbody that connects two daughter cells, or both, suggests their implication in cell division, we investigated KIF4 localization of during mitosis and cytokinesis in Hela cells. In addition to association with segregating chromosomes through entire mitosis, it also localized to the midzone and to midbody at ana/telophase through cytokinesis. Especially in cells at cytokinesis, KIF4 appeared as a doublet facing each other at the apical ends of two daughter cells. Three- dimensional analysis of architectural relationship between microtubule bundles and KIF4 indicated that KIF4 forms a ring structure wrapping around the microtubule bundles. These results suggest that KIF4 is involved in cytokinesis, although direct evidence was not provided in this study.

The Differential Gene Expression Profiles between Sensitive and Resistant Breast Cancer Cells to Adriamycin by cDNA Microarray / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Adriamycin(R) is one of the most commonly used drugs in the treatment of breast cancer. This study was performed to understand the molecular mechanisms of drug resistance in breast cancer cells. MATERIALS AND METHODS: We have analyzed the MCF-7 breast cell line and its adriamycin-resistant variants, MCF-7/ADR using human 10 K element cDNA microarrays. RESULTS: We defined 68 genes that were up-regulated (14 genes) or down-regulated (54 genes) in adriamycin resistant breast cancer cells. Several genes, such as G protein-coupled receptor kinase 5, phospholipase A2, guanylate cyclase 1, vimentin, matrix metalloproteinase 1 are up-regulated in drug resistant cells. Several genes, such as interferon, alpha-inducible protein 27, forkhead box M1, mitogen-activated protein kinase 6, regulator of mitotic spindle assembly 1 and tumor necrosis factor superfamily are down-regulated in adriamycin resistant cells. The altered expression of genes observed in microarray was verified by RT-PCR. CONCLUSION: These findings show that cDNA microarray analysis can be used to obtain gene expression profiles reflecting the effect of anticancer drugs on breast cancer cells. Such data may lead to the assigning of signature expression profiles of drug-resistant tumors which may help predict responses to drugs and assist in the design of tailored therapeutic regimens to overcome drug resistance.

Damage of Intracytoplasmic Meiotic Spindles in Cryopreserved-Thawed Mouse Oocytes / 대한산부인과학회잡지

OBJECTIVE: To investigate the extent of meiotic spindle damages in cryopreserved-thawed mouse mature oocytes. METHODS: After slow freezing and ultra-rapid thawing using 1.5M dimethylsulfoxide(DMSO), mouse mature oocytes were stained by anti-alpha tubulin monoclonal antibody. The meiotic spindle and chromosomes configuration were assessed using confocal microscope. The influence of time to post-hCG oocytes retrieval (i.e. 12 hrs vs 17 hrs) was also evaluated. RESULTS: The normal meiotic spindles were observed in 89.8% of post-hCG 12 hrs group, and 80.1% of post-hCG 17 hrs group, and these were significantly lower than that of each unfreezed control. Post-hCG 12 hrs group showed a significantly higher incidence of normal meiotic spindles, compared with post-hCG 17 hrs group. CONCLUSION: The extent of meiotic spindle damages was significantly increased after cryopreservation in mouse mature oocytes. We proposed that 12 hrs interval of post-hCG oocytes retrieval may be more beneficial.