RESUMO
BACKGROUND: Poly(ADP-ribose) polymerase (PARP) inhibitors have emerged as promising chemotherapeutic drugs primarily against BRCA1/2-associated tumours, known as synthetic lethality. However, recent clinical trials reported patients' survival benefits from PARP inhibitor treatments, irrelevant to homologous recombination deficiency. Therefore, revealing the therapeutic mechanism of PARP inhibitors beyond DNA damage repair is urgently needed, which can facilitate precision medicine. METHODS: A CRISPR-based knock-in technology was used to establish stable BRCA1 mutant cancer cells. The effects of PARP inhibitors on BRCA1 mutant cancer cells were evaluated by biochemical and cell biological experiments. Finally, we validated its in vivo effects in xenograft and patient-derived xenograft (PDX) tumour mice. FINDINGS: In this study, we uncovered that the majority of clinical BRCA1 mutations in breast cancers were in and near the middle of the gene, rather than in essential regions for DNA damage repair. Representative mutations such as R1085I and E1222Q caused transient extra spindle poles during mitosis in cancer cells. PAR, which is synthesized by PARP2 but not PARP1 at mitotic centrosomes, clustered these transient extra poles, independent of DNA damage response. Common PARP inhibitors could effectively suppress PARP2-synthesized PAR and induce cell senescence by abrogating the correction of mitotic extra-pole error. INTERPRETATION: Our findings uncover an alternative mechanism by which PARP inhibitors efficiently suppress tumours, thereby pointing to a potential new therapeutic strategy for centrosome error-related tumours. FUNDING: Funded by National Natural Science Foundation of China (NSFC) (T2225006, 82272948, 82103106), Beijing Municipal Natural Science Foundation (Key program Z220011), and the National Clinical Key Specialty Construction Program, P. R. China (2023).
Assuntos
Proteína BRCA1 , Senescência Celular , Centrossomo , Dano ao DNA , Inibidores de Poli(ADP-Ribose) Polimerases , Ensaios Antitumorais Modelo de Xenoenxerto , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Humanos , Animais , Centrossomo/metabolismo , Centrossomo/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Camundongos , Proteína BRCA1/genética , Linhagem Celular Tumoral , Feminino , Mutação , Reparo do DNA/efeitos dos fármacos , Modelos Animais de Doenças , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Neoplasias da Mama/metabolismo , Poli(ADP-Ribose) Polimerases/metabolismo , Poli(ADP-Ribose) Polimerases/genética , Poli(ADP-Ribose) Polimerase-1/metabolismo , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Poli(ADP-Ribose) Polimerase-1/genéticaRESUMO
Chromosome instability, a hallmark of lung cancer, is a driving mechanism for hexavalent chromium [Cr(VI)] carcinogenesis in humans. Cr(VI) induces structural and numerical chromosome instability in human lung cells by inducing DNA double-strand breaks and inhibiting homologous recombination repair and causing spindle assembly checkpoint (SAC) bypass and centrosome amplification. Great whales are long-lived species with long-term exposures to Cr(VI) and accumulate Cr in their tissue, but exhibit a low incidence of cancer. Data show Cr(VI) induces fewer chromosome aberrations in whale cells after acute Cr(VI) exposure suggesting whale cells can evade Cr(VI)-induced chromosome instability. However, it is unknown if whales can evade Cr(VI)-induced chromosome instability. Thus, we tested the hypothesis that whale cells resist Cr(VI)-induced loss of homologous recombination repair activity and increased SAC bypass and centrosome amplification. We found Cr(VI) induces similar amounts of DNA double-strand breaks after acute (24 h) and prolonged (120 h) exposures in whale lung cells, but does not inhibit homologous recombination repair, SAC bypass, or centrosome amplification, and does not induce chromosome instability. These data indicate whale lung cells resist Cr(VI)-induced chromosome instability, the major driver for Cr(VI) carcinogenesis at a cellular level, consistent with observations that whales are resistant to cancer.
Assuntos
Centrossomo , Cromo , Instabilidade Cromossômica , Quebras de DNA de Cadeia Dupla , Animais , Cromo/toxicidade , Instabilidade Cromossômica/efeitos dos fármacos , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Centrossomo/efeitos dos fármacos , Centrossomo/metabolismo , Baleias/genéticaRESUMO
Plants are a rich source for bioactive compounds. However, plant extracts can harbor a mixture of bioactive molecules that promote divergent phenotypes and potentially have confounding effects in bioassays. Even with further purification and identification, target deconvolution can be challenging. Corynoline and acetylcorynoline, are phytochemicals that were previously isolated through a screen for compounds able to induce mitotic arrest and polyploidy in oncogene expressing retinal pigment epithelial (RPE) cells. Here, we shed light on the mechanism by which these phytochemicals can attack human cancer cells. Mitotic arrest was coincident to the induction of centrosome amplification and declustering, causing multi-polar spindle formation. Corynoline was demonstrated to have true centrosome declustering activity in a model where A549 cells were chemically induced to have more than a regular complement of centrosomes. Corynoline could inhibit the centrosome clustering required for pseudo-bipolar spindle formation in these cells. The activity of AURKB, but not AURKA or polo-like kinase 4, was diminished by corynoline. It only partially inhibited AURKB, so it may be a partial antagonist or corynoline may work upstream on an unknown regulator of AURKB activity or localization. Nonetheless, corynoline and acetylcorynoline inhibited the viability of a variety of human cancer derived cell lines. These phytochemicals could serve as prototypes for a next-generation analog with improved potency, selectivity or in vivo bioavailability. Such an analog could be useful as a non-toxic component of combination therapies where inhibiting the chromosomal passenger protein complex is desired.
Assuntos
Aurora Quinase B/efeitos dos fármacos , Alcaloides de Berberina/farmacologia , Mitose/efeitos dos fármacos , Compostos Fitoquímicos/farmacologia , Poliploidia , Células A549 , Apoptose/efeitos dos fármacos , Aurora Quinase A/efeitos dos fármacos , Linhagem Celular Tumoral , Centrossomo/efeitos dos fármacos , HumanosRESUMO
The centrosome is a special organelle in human cells and an organizing unit for microtubules and signaling molecules. In addition, the centrosome is tightly restricted during the cell cycle and forms the basal body of the cilia in ciliated cells. Centrosome abnormality is frequently observed in malignant tumors. The dysregulation of centrosome-associated proteins leads to multipolar mitosis, aneuploidy, and nondirected cell migration, and therefore promotes cancer progression. The overduplication of primary centrosome and the accumulation of chromosome, comprise the majority cause of chromosomal mis-segregation in cancer cells. This review discusses the structure and function of the centrosome and the role of its associated proteins in the progression of solid tumors. We summarized the effects of centrosome amplification abnormalities and other centrosome-related phenotypes on tumors. The mechanism of the delineation of centrosome amplification with tumor malignancy remains to be decided. A better understanding of centrosome abnormality in tumorigenesis may be useful to screen novel therapeutic strategies for the treatment of solid tumors.
Assuntos
Proteínas de Ciclo Celular/metabolismo , Centrossomo/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Neoplasias/metabolismo , Animais , Antineoplásicos/uso terapêutico , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/genética , Centrossomo/efeitos dos fármacos , Centrossomo/patologia , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas Associadas aos Microtúbulos/antagonistas & inibidores , Proteínas Associadas aos Microtúbulos/genética , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/patologia , Transdução de SinaisRESUMO
Although nanomaterials have shown promising biomedical application potential, incomplete understanding of their molecular interactions with biological systems prevents their inclusion into mainstream clinical applications. Here we show that black phosphorus (BP) nanomaterials directly affect the cell cycle's centrosome machinery. BP destabilizes mitotic centrosomes by attenuating the cohesion of pericentriolar material and consequently leads to centrosome fragmentation within mitosis. As a result, BP-treated cells exhibit multipolar spindles and mitotic delay, and ultimately undergo apoptosis. Mechanistically, BP compromises centrosome integrity by deactivating the centrosome kinase polo-like kinase 1 (PLK1). BP directly binds to PLK1, inducing its aggregation, decreasing its cytosolic mobility and eventually restricting its recruitment to centrosomes for activation. With this mechanism, BP nanomaterials show great anticancer potential in tumour xenografted mice. Together, our study reveals a molecular mechanism for the tumoricidal properties of BP and proposes a direction for biomedical application of nanomaterials by exploring their intrinsic bioactivities.
Assuntos
Proteínas de Ciclo Celular/genética , Centrossomo/efeitos dos fármacos , Nanoestruturas/química , Neoplasias/tratamento farmacológico , Fósforo/farmacologia , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Animais , Apoptose/efeitos dos fármacos , Proteínas de Ciclo Celular/antagonistas & inibidores , Células HeLa , Xenoenxertos , Humanos , Camundongos , Mitose/efeitos dos fármacos , Neoplasias/genética , Neoplasias/patologia , Fósforo/química , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Quinase 1 Polo-LikeRESUMO
Etoposide (ETO) has been used in treating adrenocortical tumor (ACT) cells. Our previous study showed that ETO inhibits ACT cell growth. In the present study, we show that ETO treatment at IC50 (10 µM) inhibited ACT cell growth by inducing cellular senescence rather than apoptosis. Several markers of cellular senescence, including enlarged nuclei, activated senescence-associated ß-galactosidase activity, elevated levels of p53 and p21, and down-regulation of Lamin B1, were observed. We further found that ETO induced multiple centrosomes. The inhibition of multiple centrosomes accomplished by treating cells with either roscovitine or centrinone or through the overexpression of NR5A1/SF-1 alleviated ETO-induced senescence, suggesting that ETO triggered senescence via multiple centrosomes. Primary cilia also played a role in ETO-induced senescence. In the mechanism, DNA-PK-Chk2 signaling was activated by ETO treatment; inhibition of this signaling cascade alleviated multiple ETO-induced centrosomes and primary cilia followed by reducing cellular senescence. In addition to DNA damage signaling, autophagy was also triggered by ETO treatment for centrosomal events and senescence. Importantly, the inactivation of DNA-PK-Chk2 signaling reduced ETO-triggered autophagy; however, the inhibition of autophagy did not affect DNA-PK-Chk2 activation. Thus, ETO activated the DNA-PK-Chk2 cascade to facilitate autophagy. The activated autophagy further induced multiple centrosomes and primary cilia followed by triggering senescence.
Assuntos
Neoplasias do Córtex Suprarrenal/patologia , Senescência Celular , Centrossomo/fisiologia , Cílios/efeitos dos fármacos , Etoposídeo/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias do Córtex Suprarrenal/tratamento farmacológico , Neoplasias do Córtex Suprarrenal/genética , Neoplasias do Córtex Suprarrenal/metabolismo , Antineoplásicos Fitogênicos/farmacologia , Apoptose , Autofagia , Proliferação de Células , Centrossomo/efeitos dos fármacos , Dano ao DNA , Humanos , Células Tumorais CultivadasRESUMO
Mitosis, under the control of the microtubule-based mitotic spindle, is an attractive target for anti-cancer treatments, as cancer cells undergo frequent and uncontrolled cell divisions. Microtubule targeting agents that disrupt mitosis or single molecule inhibitors of mitotic kinases or microtubule motors kill cancer cells with a high efficacy. These treatments have, nevertheless, severe disadvantages: they also target frequently dividing healthy tissues, such as the haematopoietic system, and they often lose their efficacy due to primary or acquired resistance mechanisms. An alternative target that has emerged in dividing cancer cells is their ability to "cluster" the poles of the mitotic spindle into a bipolar configuration. This mechanism is necessary for the specific survival of cancer cells that tend to form multipolar spindles due to the frequent presence of abnormal centrosome numbers or other spindle defects. Here we discuss the recent development of combinatorial treatments targeting spindle pole clustering that specifically target cancer cells bearing aberrant centrosome numbers and that have the potential to avoid resistance mechanism due their combinatorial nature.
Assuntos
Antineoplásicos/uso terapêutico , Morte Celular/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Polos do Fuso/efeitos dos fármacos , Antineoplásicos/farmacologia , Centrossomo/efeitos dos fármacos , Centrossomo/metabolismo , Combinação de Medicamentos , Sinergismo Farmacológico , Inibidores de Histona Desacetilases/farmacologia , Inibidores de Histona Desacetilases/uso terapêutico , Humanos , Mitose/efeitos dos fármacos , Neoplasias/patologia , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Polos do Fuso/metabolismoRESUMO
Neutrophils (also called polymorphonuclear leukocytes, PMNs) are heterogeneous and can exhibit considerable phenotypic and functional plasticity. In keeping with this, we discovered previously that Helicobacter pylori infection induces N1-like subtype differentiation of human PMNs that is notable for profound nuclear hypersegmentation. Herein, we utilized biochemical approaches and confocal and super-resolution microscopy to gain insight into the underlying molecular mechanisms. Sensitivity to inhibition by nocodazole and taxol indicated that microtubule dynamics were required to induce and sustain hypersegmentation, and super-resolution Stimulated Emission Depletion (STED) imaging demonstrated that microtubules were significantly more abundant and longer in hypersegmented cells. Dynein activity was also required, and enrichment of this motor protein at the nuclear periphery was enhanced following H. pylori infection. In contrast, centrosome splitting did not occur, and lamin B receptor abundance and ER morphology were unchanged. Finally, analysis of STED image stacks using Imaris software revealed that nuclear volume increased markedly prior to the onset of hypersegmentation and that nuclear size was differentially modulated by nocodazole and taxol in the presence and absence of infection. Taken together, our data define a new mechanism of hypersegmentation that is mediated by microtubules and dynein and as such advance understanding of processes that regulate nuclear morphology.
Assuntos
Dineínas/metabolismo , Infecções por Helicobacter/imunologia , Helicobacter pylori/imunologia , Microtúbulos/metabolismo , Neutrófilos/imunologia , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Células Cultivadas , Centrossomo/efeitos dos fármacos , Centrossomo/metabolismo , Infecções por Helicobacter/microbiologia , Humanos , Microscopia Intravital , Neutrófilos/citologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Nocodazol/farmacologia , Paclitaxel/farmacologia , Cultura Primária de Células , Moduladores de Tubulina/farmacologiaRESUMO
Local translation allows for a spatial control of gene expression. Here, we use high-throughput smFISH to screen centrosomal protein-coding genes, and we describe 8 human mRNAs accumulating at centrosomes. These mRNAs localize at different stages during cell cycle with a remarkable choreography, indicating a finely regulated translational program at centrosomes. Interestingly, drug treatments and reporter analyses reveal a common translation-dependent localization mechanism requiring the nascent protein. Using ASPM and NUMA1 as models, single mRNA and polysome imaging reveals active movements of endogenous polysomes towards the centrosome at the onset of mitosis, when these mRNAs start localizing. ASPM polysomes associate with microtubules and localize by either motor-driven transport or microtubule pulling. Remarkably, the Drosophila orthologs of the human centrosomal mRNAs also localize to centrosomes and also require translation. These data identify a conserved family of centrosomal mRNAs that localize by active polysome transport mediated by nascent proteins.
Assuntos
Centrossomo/metabolismo , Polirribossomos/metabolismo , Transporte de RNA , Animais , Proteínas de Ciclo Celular/metabolismo , Centrossomo/efeitos dos fármacos , Cicloeximida/farmacologia , Drosophila/genética , Células HeLa , Humanos , Mitose/efeitos dos fármacos , Fases de Leitura Aberta/genética , Polirribossomos/efeitos dos fármacos , Puromicina/farmacologia , Transporte de RNA/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fuso Acromático/efeitos dos fármacos , Fuso Acromático/metabolismoRESUMO
The monopolar spindle 1 ((hMps1/TTK) is a serine/threonine kinase that plays an important role in spindle assembly checkpoint signaling. To explore the possible relationship between TTK inhibition and radiosensitivity, we examined whether TTK inhibition influences cellular susceptibility of radiation. And we further revealed its mechanisms. We found that the expression of TTK was obviously higher in liver cancer tissues compared to the normal liver tissues. Kaplan-Meier Plotter demonstrated that patients with low TTK expression levels had a longer overall survival than patients with high TTK expression levels. TTK inhibitor AZ3146 could simulated liver cancer cells to accumulate in the G2/M phase, which ultimately enhances DNA damage with more γ-H2AX foci and more apoptosis and necrosis induced by radiation, which prompted that TTK inhibition sensitized liver cancer cells to radiation. In addition, TTK inhibition altered cell-cycle progression and exacerbated centrosome abnormalities, resulting in enhanced mitotic catastrophe (MC) induced by radiation in a p21-mediated manner. In this study, we present evidences that the TTK inhibitor promotes the radiosensitivity of liver cancer cells through regulating cell cycle in p21-mediated manner in vitro, indicating that TTK inhibitor may be an attractive radiosensitizer for the patients with liver cancer.
Assuntos
Proteínas de Ciclo Celular/antagonistas & inibidores , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/radioterapia , Proteínas Oncogênicas/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/antagonistas & inibidores , Tolerância a Radiação/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Centrossomo/efeitos dos fármacos , Centrossomo/metabolismo , Centrossomo/efeitos da radiação , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/efeitos da radiação , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos da radiação , Histonas/metabolismo , Humanos , Neoplasias Hepáticas/patologia , Pontos de Checagem da Fase M do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem da Fase M do Ciclo Celular/efeitos da radiação , Necrose/tratamento farmacológico , Necrose/radioterapia , Prognóstico , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/metabolismo , Análise de SobrevidaRESUMO
Bulbus of Fritillaria cirrhosa D. Don (BFC), an outstanding antitussive and expectorant herbal drug used in China and many other countries, has potential but less understood genotoxicity. Previously, we have reported that aqueous extract of BFC compromised the spindle assembly checkpoint and cytokinesis in NCM460 cells. Here, we found that one remarkable observation in BFC-treated NCM460 cells was multipolar mitosis, a trait classically compromises the fidelity of chromosome segregation. More detailed investigation revealed that BFC-induced spindle multipolarity in metaphases and ana-telophases in a dose- and time-dependent manner, suggesting BFC-induced multipolar spindle conformation was not transient. The frequency of multipolar metaphase correlated well to that of multipolar ana-telophases, indicating that BFC-induced multipolar metaphases often persisted through anaphase. Unexpectedly, BFC blocked the proliferation of binucleated cells, suggesting spindle multipolarity was not downstream of BFC-induced cytokinesis failure. Exposure of BFC to early mitotic cells, rather than S/G2 cells, contributed greatly to spindle multipolarity, indicating BFC might disrupt centrosome integrity rather than induce centrosome overduplication. The immunofluorescence results showed that the centrosomes were severely fragmented by a short-term treatment of BFC and the extent of centrosome fragmentation in early mitotic cells was larger than this in S/G2 cells. Consistently, several genes (e.g. p53, Rb centrin-2, Plk-4, Plk-1 and Aurora-A) involved in regulating centrosome integrity were significantly deregulated by BFC. Together, our results suggest that BFC causes multipolar spindles primarily by inducing centrosome fragmentation. Coupling these results to our previous observations, we recommend the risk/benefit ratio should be considered in the practical use of BFC.
Assuntos
Centrossomo/metabolismo , Colo/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Fritillaria/química , Mitose , Extratos Vegetais/farmacologia , Fuso Acromático/efeitos dos fármacos , Centrossomo/efeitos dos fármacos , Colo/metabolismo , Células Epiteliais/metabolismo , HumanosRESUMO
Septins play important roles in regulating development and differentiation. Septin 7 (SEPT7) is a crucial component in orchestrating the septin core complex into highly ordered filamentous structures. Here, we showed that genetic depletion of SEPT7 or treatment with forchlorfenuron (FCF; a compound known to affect septin filament assembly) led to reduced the S phase entry in cell models and zebrafish embryos. In addition to colocalizing with actin filaments, SEPT7 resided in the centrosome, and SEPT7 depletion led to aberrant mitotic spindle pole formation. This mitotic defect was rescued in SEPT7-deficient cells by wild-type SEPT7, suggesting that SEPT7 maintained mitotic spindle poles. In addition, we observed disorganized microtubule nucleation and reduced cell migration with SEPT7 depletion. Furthermore, SEPT7 formed a complex with and maintained the abundance of p150glued , the component of centriole subdistal appendages. Depletion of p150glued resulted in a phenotype reminiscent of SEPT7-deficient cells, and overexpression of p150glued reversed the defective phenotypes. Thus, SEPT7 is a centrosomal protein that maintains proper cell proliferation and microtubule array formation via maintaining the abundance of p150glued .
Assuntos
Proteínas de Ciclo Celular/metabolismo , Centrossomo/metabolismo , Complexo Dinactina/metabolismo , Microtúbulos/metabolismo , Fase S , Septinas/metabolismo , Animais , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Proliferação de Células , Centrossomo/efeitos dos fármacos , Complexo Dinactina/genética , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Microtúbulos/efeitos dos fármacos , Microtúbulos/genética , Compostos de Fenilureia/farmacologia , Piridinas/farmacologia , Fase S/efeitos dos fármacos , Pontos de Checagem da Fase S do Ciclo Celular , Septinas/genética , Transdução de Sinais , Peixe-Zebra/embriologia , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismoRESUMO
Centrosomes are the major microtubule organizing centers in a large number of animal cells. They are involved in diverse cellular functions like cell division, migration, sensing and motility. Despite being identified more than 100 years ago, they did not receive much attention until recent discoveries suggesting their association with human diseases. Centrosome-related defects have been observed in several human diseases including cancers, brain disorders and ciliopathies. Researchers in the field are trying to understand the relationship between centrosomes and these diseases. Accordingly, this review provides an overview of the current knowledge regarding the role of centrosomes during ciliogenesis and neural stem cell division. The review primarily focuses on the impairment of centrosome number, organization and functioning leading to a wide range of human diseases. Finally, we discuss the scope of targeting centrosomes for therapeutic purposes.
Assuntos
Centrossomo/metabolismo , Cílios/metabolismo , Ciliopatias/genética , Neoplasias/genética , Proteínas do Tecido Nervoso/genética , Animais , Antineoplásicos/farmacologia , Azepinas/farmacologia , Centrossomo/efeitos dos fármacos , Centrossomo/patologia , Centrossomo/ultraestrutura , Cílios/efeitos dos fármacos , Cílios/patologia , Cílios/ultraestrutura , Ciliopatias/metabolismo , Ciliopatias/patologia , Regulação da Expressão Gênica , Humanos , Cirrose Hepática/genética , Cirrose Hepática/metabolismo , Cirrose Hepática/patologia , Microcefalia/genética , Microcefalia/metabolismo , Microcefalia/patologia , Microtúbulos/metabolismo , Microtúbulos/ultraestrutura , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/patologia , Proteínas do Tecido Nervoso/metabolismo , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Ftalazinas/farmacologia , Pirimidinas/farmacologia , Degeneração Retiniana/genética , Degeneração Retiniana/metabolismo , Degeneração Retiniana/patologia , Transdução de SinaisRESUMO
1-Methylpyrene (1-MP) is a common environmental pollutant and animal carcinogen. After sequential activation by cytochromes P450 and sulfotransferases, it induced gene mutations and micronuclei in mammalian cells. The type of micronuclei formed, entire chromosomes or fragments, was not analysed. In this study, 1-MP and its primary metabolite, 1-hydroxymethylpyrene (1-HMP), were investigated for the induction of centromere-positive and -negative micronuclei in the human hepatoma cell line HepG2 and its derivative C3A, expressing relevant enzymes at higher levels. Under a short-exposure (9 h)/long-recovery regime (2 cell cycles in total), 1-MP and 1-HMP provided negative test results in HepG2 cells. However, they induced micronuclei in C3A cells, the effect being blocked by 1-aminobenzotriazole (inhibitor of cytochromes P450s) and reduced by pentachlorophenol (inhibitor of sulfotransferases). Immunofluorescence staining of centromere protein B in the micronuclei revealed purely clastogenic effects under this regime. Unexpectedly, 1-MP and 1-HMP at concentrations 1/5-1/4 of that required for micronuclei formation led to mitotic arrest and spindle aberrations, as detected by immunofluorescence staining of ß- and γ-tubulin. Following extended exposure (72 h, 2 cell cycles, no recovery), damage to the spindle apparatus and centrosomes was detected at even lower concentrations, with concurrent formation of micronuclei. At low concentrations (1-8 µM 1-MP, 0.25-0.5 µM 1-HMP), the micronuclei induced were unexceptionally centromere-positive. Thus, the chromosome-damaging mechanism of 1-MP was regime and concentration dependent: potently aneugenic under persistent exposure, while clastogenic at higher concentrations following a short-exposure/long-recovery regime. This is a convincing evidence for the existence of metabolic activation-dependent aneugens.
Assuntos
Micronúcleos com Defeito Cromossômico/efeitos dos fármacos , Mitose/efeitos dos fármacos , Pirenos/toxicidade , Ativação Metabólica/efeitos dos fármacos , Aneugênicos/metabolismo , Aneugênicos/toxicidade , Linhagem Celular Tumoral , Proteína B de Centrômero/metabolismo , Centrossomo/efeitos dos fármacos , Células Hep G2 , Humanos , Testes para Micronúcleos , Microscopia de Fluorescência , Mutagênicos , Pirenos/metabolismo , Fuso Acromático/efeitos dos fármacosRESUMO
Centrosome amplification (CA) is a common feature of human tumors, but it is not clear whether this is a cause or a consequence of cancer. The centrosome amplification observed in tumor cells may be explained by a series of events, such as failure of cell division, dysregulation of centrosome cycle checkpoints, and de novo centriole biogenesis disorder. The formation and progression of breast cancer are characterized by genomic abnormality. The centrosomes in breast cancer cells show characteristic structural aberrations, caused by centrosome amplification, which include: an increase in the number and volume of centrosomes, excessive increase of pericentriolar material (PCM), inappropriate phosphorylation of centrosomal molecular, and centrosome clustering formation induced by the dysregulation of important genes. The mechanism of intracellular centrosome amplification, the impact of which on breast cancer and the latest breast cancer target treatment options for centrosome amplification are exhaustively elaborated in this review.
Assuntos
Neoplasias da Mama/metabolismo , Proteínas de Ciclo Celular/metabolismo , Centrossomo/metabolismo , Animais , Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Proteínas de Ciclo Celular/genética , Centrossomo/efeitos dos fármacos , Centrossomo/patologia , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Mitose , Terapia de Alvo Molecular , Via de Sinalização WntRESUMO
Genomic instability is a hallmark of cancer, and has a central role in the initiation and development of breast cancer1,2. The success of poly-ADP ribose polymerase inhibitors in the treatment of breast cancers that are deficient in homologous recombination exemplifies the utility of synthetically lethal genetic interactions in the treatment of breast cancers that are driven by genomic instability3. Given that defects in homologous recombination are present in only a subset of breast cancers, there is a need to identify additional driver mechanisms for genomic instability and targeted strategies to exploit these defects in the treatment of cancer. Here we show that centrosome depletion induces synthetic lethality in cancer cells that contain the 17q23 amplicon, a recurrent copy number aberration that defines about 9% of all primary breast cancer tumours and is associated with high levels of genomic instability4-6. Specifically, inhibition of polo-like kinase 4 (PLK4) using small molecules leads to centrosome depletion, which triggers mitotic catastrophe in cells that exhibit amplicon-directed overexpression of TRIM37. To explain this effect, we identify TRIM37 as a negative regulator of centrosomal pericentriolar material. In 17q23-amplified cells that lack centrosomes, increased levels of TRIM37 block the formation of foci that comprise pericentriolar material-these foci are structures with a microtubule-nucleating capacity that are required for successful cell division in the absence of centrosomes. Finally, we find that the overexpression of TRIM37 causes genomic instability by delaying centrosome maturation and separation at mitotic entry, and thereby increases the frequency of mitotic errors. Collectively, these findings highlight TRIM37-dependent genomic instability as a putative driver event in 17q23-amplified breast cancer and provide a rationale for the use of centrosome-targeting therapeutic agents in treating these cancers.
Assuntos
Neoplasias da Mama/genética , Centrossomo/metabolismo , Centrossomo/patologia , Cromossomos Humanos Par 17/genética , Proteínas com Motivo Tripartido/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Antineoplásicos/farmacologia , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Centrossomo/efeitos dos fármacos , Feminino , Fase G2 , Instabilidade Genômica , Humanos , Mitose/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas com Motivo Tripartido/genética , Ubiquitina-Proteína Ligases/genéticaRESUMO
INTRODUCTION: Human gestational choriocarcinoma, a type of gestational trophoblastic disease, occurs after miscarriage, abortion, ectopic pregnancy, or molar pregnancy. Despite recent advances in the mechanism of anticancer drugs that induce human gestational choriocarcinoma apoptosis or block its growth, new therapeutic approaches are needed to be established. Cordycepin is an active anti-cancer component extracted from Cordyceps sinensis. It prevents cell proliferation both in vitro and in vivo. MATERIALS AND METHODS: Here, we examined cell growth by counting cell numbers, and performing a flow cytometry assay and EdU incorporation assay. Centrosome and cytoskeleton-related structures were observed by immunofluorescence assay. The DNA damage-related signaling was examined by Western blot assay. RESULTS: Here, we showed that cordycepin inhibited human gestational choriocarcinoma cell proliferation and induced cell death. In addition, treatment with cordycepin activated DNA-PK and ERK, thus inducing centrosome amplification and aberrant mitosis. These amplified centrosomes also disrupted microtubule arrays and actin networks, thus leading to defective cell adhesion. Furthermore, cordycepin induced autophagy for triggering cell death. CONCLUSION: Thus, our study demonstrates that cordycepin inhibits cell proliferation and disrupts the cytoskeleton by triggering centrosome amplification.
Assuntos
Antineoplásicos/farmacologia , Centrossomo/efeitos dos fármacos , Coriocarcinoma/tratamento farmacológico , Desoxiadenosinas/farmacologia , Doença Trofoblástica Gestacional/tratamento farmacológico , Homeostase/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Coriocarcinoma/patologia , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Doença Trofoblástica Gestacional/patologia , Humanos , GravidezRESUMO
Kinesin 14 family member KIFC1 is a mitotic kinesin which contains a C-terminal motor domain and plays a vital role for clustering the amplified centrosomes. Overexpression of KIFC1 in prostate cancer (PCa) cells showed resistance to docetaxel (DTX). The present study revealed that small KIFC1 inhibitor AZ82 suppresed the transcription and translation of KIFC1 significantly in PCa cells. AZ82 inhibited the KIFC1 expression both in the cytoplasm and nucleus of PCa cells. Inhibition of KIFC1 by AZ82 caused multipolar mitosis in PCa cells via de-clustering the amplified centrosomes and decreased the rate of cancer cell growth and proliferation. Moreover, depletion of KIFC1 reduced cells entering the cell cycle and caused PCa cells death through apoptosis by increasing the expression of Bax and Cytochrome C. Thereby, KIFC1 silencing and inhibition decreased the PCa cells survival by inducing multipolar mitosis as well as apoptosis, suggesting inhibition of KIFC1 using AZ82 might be a strategy to treat PCa by controlling the cancer cell proliferation.
Assuntos
Alanina/análogos & derivados , Centrossomo/efeitos dos fármacos , Cinesinas/antagonistas & inibidores , Neoplasias da Próstata/tratamento farmacológico , Piridinas/farmacologia , Alanina/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Centrossomo/metabolismo , Dineínas/metabolismo , Humanos , Cinesinas/genética , Cinesinas/metabolismo , Masculino , Mitose/efeitos dos fármacos , Miosinas/metabolismo , Próstata/patologia , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologiaRESUMO
Centrosomes must resist microtubule-mediated forces for mitotic chromosome segregation. During mitotic exit, however, centrosomes are deformed and fractured by those same forces, which is a key step in centrosome disassembly. How the functional material properties of centrosomes change throughout the cell cycle, and how they are molecularly tuned, remain unknown. Here, we used optically induced flow perturbations to determine the molecular basis of centrosome strength and ductility in C. elegans embryos. We found that both properties declined sharply at anaphase onset, long before natural disassembly. This mechanical transition required PP2A phosphatase and correlated with inactivation of PLK-1 (Polo kinase) and SPD-2 (Cep192). In vitro, PLK-1 and SPD-2 directly protected centrosome scaffolds from force-induced disassembly. Our results suggest that, before anaphase, PLK-1 and SPD-2 respectively confer strength and ductility to the centrosome scaffold so that it can resist microtubule-pulling forces. In anaphase, centrosomes lose PLK-1 and SPD-2 and transition to a weak, brittle state that enables force-mediated centrosome disassembly.
Assuntos
Caenorhabditis elegans/citologia , Centrossomo/metabolismo , Mitose , Animais , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/enzimologia , Caenorhabditis elegans/genética , Centrossomo/efeitos dos fármacos , Leupeptinas/farmacologia , Mitose/efeitos dos fármacos , Mitose/genéticaRESUMO
Type 2 diabetes increases the risk for cancer. Centrosome amplification can initiate tumorigenesis. We have described that type 2 diabetes increases the centrosome amplification of peripheral blood mononuclear cells, with high glucose, insulin, and palmitic acid as the triggers, which suggests that centrosome amplification is a candidate biological mechanism linking diabetes to cancer. In this study, we aimed to further investigate the signaling pathways of the diabetes-associated centrosome amplification and to examine whether and how resveratrol inhibits the centrosome amplification. The results showed that treatment with high glucose, insulin, and palmitic acid, alone or in combination, could increase the protein levels of phospho-protein kinase C alpha (p-PKCα), phospho-p38 mitogen-activated protein kinases (p-p38), c-myc, and c-jun, as well as the mRNA levels of c-myc and c-jun. PKCα inhibitor could inhibit the treatment-induced increase in the protein levels of p-p38, c-myc, and c-jun. Inhibitor or siRNA of p38 was also able to inhibit the treatment-induced increase in the levels of p-p38, c-myc, and c-jun. Meanwhile, knockdown of c-myc or c-jun did not alter the treatment-induced increase in the phosphorylation of PKCα or p38. Importantly, inhibition of the phosphorylation of PKCα or p38 and knockdown of c-myc or c-jun could attenuate the centrosome amplification. In diabetic mice, the levels of p-PKCα, p-p38, c-myc, and c-jun were all increased in the colon tissues. Interestingly, resveratrol, but not metformin, was able to attenuate the treatment-induced increase in the levels of p-PKCα, p-p38, c-myc, and c-jun, as well as the centrosome amplification. In conclusion, our results suggest that PKCα-p38 to c-myc/c-jun is the signaling pathway of the diabetes-associated centrosome amplification, and resveratrol attenuates the centrosome amplification by inhibiting this signaling pathway.