RESUMO
Active breast cancer-associated fibroblasts (CAFs), the most influential cells in breast tumor microenvironment, express/secrete high levels of the proinvasive/metastatic interleukin-6 (IL-6). Therefore, we have tested here the effect of the IL-6 receptor (IL-6R) inhibitor tocilizumab (TCZ; Actemra) on different active breast CAFs. We have shown that TCZ potently and persistently suppresses the expression of various CAF biomarkers, namely α-SMA, SDF-1 as well as the STAT3 pathway and its downstream target AUF1. TCZ also inhibited the proliferation, migration and invasion abilities of active breast CAF cells. Additionally, TCZ repressed the ability of CAF cells in promoting epithelial-to-mesenchymal transition, and enhancing the migratory/invasive and proliferative capacities of breast cancer cells in vitro. Importantly, these findings were confirmed in orthotopic humanized breast tumors in mice. Furthermore, TCZ suppressed the expression of the pro-angiogenic factor VEGF-A and its transactivator HIF-1α in CAF cells, and consequently inhibited the angiogenic-promoting effect of active CAFs both in vitro and in orthotopic tumor xenografts. These results indicate that inhibition of the IL-6/STAT3/AUF1 pathway by TCZ can normalize active breast CAFs and suppress their paracrine pro-carcinogenic effects, which paves the way toward development of specific CAF-targeting therapy, badly needed for more efficient breast cancer treatments.
Assuntos
Anticorpos Monoclonais Humanizados/farmacologia , Antineoplásicos Imunológicos/farmacologia , Fibroblastos Associados a Câncer/efeitos dos fármacos , Fibroblastos Associados a Câncer/metabolismo , Ribonucleoproteína Nuclear Heterogênea D0/metabolismo , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Fibroblastos Associados a Câncer/patologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Ribonucleoproteína Nuclear Heterogênea D0/genética , Humanos , Interleucina-6/metabolismo , Receptores de Interleucina-6/antagonistas & inibidores , Microambiente Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Several messenger ribonucleic acid (mRNA) and inactivated COVID-19 vaccines are available to the global population as of 2022. The acceptance of the COVID-19 vaccine will play a key role in combating the worldwide pandemic. Public confidence in this vaccine is largely based on its safety and effectiveness. This study was designed to provide independent evidence of the adverse effects associated with COVID-19 vaccines among healthcare workers in Iraq and to identify the attitudes of healthcare workers who rejected the vaccination. We conducted a cross-sectional study to collect data on the adverse effects of the Pfizer, AstraZeneca, and Sinopharm vaccines. Data were collected between October 2021 and February 2022. A total of 2,202 participants were enrolled in the study: (89.97%) received injections of the COVID-19 vaccines and (10.03%) were hesitant to receive the vaccination. Participants received either the Pfizer vaccine (62.9%), AstraZeneca vaccine (23.5%) or Sinopharm vaccine (13.6%). Most adverse effects were significantly less prevalent in the second dose than in the first dose. Notably, the adverse effects associated with the Pfizer vaccine were significantly more prevalent in females than in males. Following the first dose, the participants experienced more adverse effects with the AstraZeneca vaccine. Following the second dose, more adverse effects were associated with the Pfizer vaccine. Interestingly, the prevalence of COVID-19 infection in participants who received two doses of the Pfizer vaccine was significantly reduced compared to those who received two doses of either the AstraZeneca or Sinopharm vaccines. According to vaccine-hesitated participants, insufficient knowledge (29.9%), expeditious development (27.6%) and lack of trust in the vaccines (27.1%) were the three major reasons for refusing the vaccines. The results of our study indicated that these adverse effects do not present a significant problem and should not prevent successful control of the COVID-19 pandemic.
Assuntos
Vacinas contra COVID-19 , COVID-19 , Vacinas , Feminino , Humanos , Masculino , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinas contra COVID-19/administração & dosagem , Vacinas contra COVID-19/efeitos adversos , Estudos Transversais , Conhecimentos, Atitudes e Prática em Saúde , Pessoal de Saúde , Iraque/epidemiologia , Pandemias , Inquéritos e Questionários , Vacinação/efeitos adversosRESUMO
BACKGROUND: Pds5 is an abundant HEAT-repeat-containing protein that binds to cohesin and mediates sister chromatid cohesion. In vertebrates, Pds5A and Pds5B are known to protect DNA replication fork, as their loss leads to DNA damage. Pds5 interacts directly with Wapl, to remove cohesin during mitosis. AIM: To analyze the effects of the loss of Pds5 proteins-mediated DNA damage on the cell cycle checkpoints and to examine the possibility that Pds5 proteins have an overlapping function. METHODS: We first analyzed the cell cycle regulation of Pds5 proteins and defects in S-phase; DNA damage was confirmed after Pds5A/B knockdown. The activation of cell cycle checkpoints and apoptosis were examined by the level of p-Chk1S317, MAD2 localization, and the level of pro-apoptotic markers, respectively. RESULTS: Pds5 proteins dissociated from chromatin in a stepwise manner, and their loss led to activation of pro-apoptotic markers associated with the phosphorylation of Chk1S317 due to DNA damage. Depletion of either Pds5A or Pds5B alone increased Smc3 acetylation in perturbed cell cycle, while depletion of both proteins severely impaired Smc3 acetylation. Moreover, the loss of Pds5A/Pds5B activated the SAC in an ATR-Chk1-dependent manner and stabilized Wapl on chromatin. The depletion of Chk1 rescued the S-phase delay associated with Pds5 depletion and significantly increased mitotic catastrophe. CONCLUSION: Pds5A and Pds5B display overlapping functions in facilitating Smc3 acetylation. Somewhat paradoxically, they also have non-redundant functions in terms of cohesin removal due to the activated surveillance mechanism that leads to phosphorylation of Chk1S317.
RESUMO
Primary effusion lymphoma (PEL) is an incurable, aggressive B-cell malignancy that develops rapid resistance to conventional chemotherapy. In efforts to identify novel approaches to block proliferation of PEL cells, we found that sanguinarine, a natural compound isolated from the root plant Sanguinaria canadendid, inhibits cell proliferation and induces apoptosis in a dose-dependent manner in several PEL cell lines. Our data show that sanguinarine treatment of PEL cells results in up-regulation of death receptor 5 (DR5) expression via generation of reactive oxygen species (ROS) and causes activation of caspase-8 and truncation of Bid (tBid). Subsequently, tBid translocates to the mitochondria causing conformational changes in Bax, leading to loss of mitochondrial membrane potential and release of cytochrome c to the cytosol. Sanguinarine-induced release of cytochrome c results in activation of caspase-9 and caspase-3 and poly(ADP-ribose) polymerase (PARP) cleavage, leading to induction of caspase-dependent apoptosis. In addition, we show that pretreatment of PEL cells with carbobenzoxy-Val-Ala-Asp-fluoromethylketone, a universal inhibitor of caspases, abrogates caspase and PARP activation and prevents cell death induced by sanguinarine. Moreover, treatment of PEL cells with sanguinarine down-regulates expression of inhibitor of apoptosis proteins (IAP). Finally, N-acetylcysteine, an inhibitor of ROS, inhibits sanguinarine-induced generation of ROS, up-regulation of DR5, Bax conformational changes, activation of caspase-3, and down-regulation of IAPs. Taken together, our findings suggest that sanguinarine is a potent inducer of apoptosis of PEL cells via up-regulation of DR5 and raise the possibility that this agent may be of value in the development of novel therapeutic approaches for the treatment of PEL.
Assuntos
Alcaloides/farmacologia , Apoptose/efeitos dos fármacos , Benzofenantridinas/farmacologia , Isoquinolinas/farmacologia , Linfoma de Células B/tratamento farmacológico , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/metabolismo , Caspases/metabolismo , Processos de Crescimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Colágeno Tipo XI/metabolismo , Citocromos c/metabolismo , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Exsudatos e Transudatos/citologia , Humanos , Isoenzimas/metabolismo , Linfoma de Células B/metabolismo , Linfoma de Células B/patologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/fisiologia , Conformação Molecular , Espécies Reativas de Oxigênio/metabolismo , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/biossíntese , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/genética , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Proteína X Associada a bcl-2/metabolismoRESUMO
We provide evidence that curcumin, a natural compound isolated from rhizomes of plant Curcuma longa, induces apoptosis in several Burkitt's lymphoma cell lines expressing Bax protein (AS283A, KK124, and Pa682PB), whereas it has no effects in cell lines with no Bax expression (BML895 and CA46). Our data show that curcumin treatment results in down-regulation of constitutive activation of nuclear factor-kappaB (NF-kappaB) via generation of reactive oxygen species where it causes conformational changes in Bax protein leading to loss of mitochondrial membrane potential and release of cytochrome c to the cytosol. This leads to activation of caspase-9, caspase-3, and poly(ADP)-ribose polymerase cleavage leading to caspase-dependent apoptosis. In addition, curcumin treatment of Burkitt's lymphoma cell lines also causes up-regulation of DR5; however, this up-regulation does not result in apoptosis. Importantly, cotreatment with curcumin and TRAIL induces apoptosis in Bax-deficient cell lines. Taken together, our findings suggest that curcumin is able to induce apoptosis in Bax-positive cell lines, whereas combinations with TRAIL result in apoptosis in Bax-negative cell lines. These findings also raise the possibility that incorporation of curcumin in treatment regimens may provide a novel approach for the treatment of Burkitt's lymphomas and provide the molecular basis for such future translational efforts.
Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Linfoma de Burkitt/patologia , Curcumina/farmacologia , NF-kappa B/metabolismo , Proteína X Associada a bcl-2/metabolismo , Linfoma de Burkitt/enzimologia , Caspase 3/metabolismo , Caspase 9/metabolismo , Linhagem Celular Tumoral , Citocromos c/metabolismo , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Quinase I-kappa B/metabolismo , Proteínas I-kappa B/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Inibidor de NF-kappaB alfa , Fosforilação/efeitos dos fármacos , Poli(ADP-Ribose) Polimerases/metabolismo , Estrutura Quaternária de Proteína , Espécies Reativas de Oxigênio/metabolismo , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Transdução de Sinais/efeitos dos fármacos , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Regulação para Cima/efeitos dos fármacos , Proteína X Associada a bcl-2/químicaRESUMO
OBJECTIVE: To evaluate the overall incidence of microsatellite instability (MSI), hereditary non polyposis colorectal cancer, and tumor supressor gene (TP53) mutations in Saudi colorectal carcinomas. METHODS: We studied the MSI pathway in Saudi colorectal cancers (CRC) from 179 unselected patients using 2 methods: MSI by polymerase chain reaction, and immunohistochemistry detection of mutL homologs 1 and mutS homologs 2 proteins. The TP53 mutations were studied by sequencing exons 5, 6, 7, and 8. RESULTS: Of the 150 colorectal carcinomas analyzed for MSI, 16% of the tumors showed high level instability (MSI-H), 19.3% had low-level instability (MSI-L) and the remaining 64% tumors were stable. Survival of the MSI-H group was better as compared to the MSI-L or microsatellite stable group (p=0.0217). In the MSI-H group, 48% were familial MSI tumors, which could be attributable to the high incidence of consanguinity in the Saudi population. The TP53 mutations were found in 24% of the cases studied. CONCLUSION: A high proportion of familial MSI cases and a lower incidence of TP53 mutations are some of the hallmarks of the Saudi colorectal carcinomas, which need to be explored further.
Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/genética , Genes p53/genética , Instabilidade de Microssatélites , Distribuição de Qui-Quadrado , Neoplasias Colorretais Hereditárias sem Polipose/epidemiologia , Neoplasias Colorretais Hereditárias sem Polipose/etnologia , Marcadores Genéticos , Genética Populacional , Humanos , Imuno-Histoquímica , Incidência , Análise em Microsséries , Mutação , Projetos Piloto , Reação em Cadeia da Polimerase , Arábia Saudita/epidemiologiaRESUMO
OBJECTIVE: To document the incidence and role of p53 and DNA mismatch repair proteins in colorectal carcinomas, and to evaluate the relative frequency of major molecular pathways in colorectal cancers from Saudi Arabia. METHODS: We collected the formalin fixed, paraffin embedded tissues from 154 colorectal tumors (83 patients from King Faisal Specialist Hospital and Research Centre and 71 from Saudi Aramco Dhahran Health Centre) between January 1989 and December 2003. We analyzed the p53 and mismatch repair gene expression (hMSH-2, hMLH-1) by immunohistochemistry in tissue microarray format. RESULTS: Expression loss of at least one mismatch repair gene was found in 33.8% of cases and significantly associated with the right-sided tumor location (p=0.0047). The p53 positivity was observed in 57.5% of tumors, and was inversely linked to expression loss of mismatch repair genes (p=0.0102). CONCLUSION: The strong confirmation of the previously established associations between tumor phenotype, and mismatch repair gene alteration provided strong evidence for the validity of our experimental approach. Together with the higher incidence of right sided location in Saudi (46.6%) than in Western colon cancers (34.9%), the observed high prevalence of mismatch gene expression loss in Saudi tumors argues for a higher importance of microsatellite instability in this population. If confirmed, it will be interesting to see whether an increased level of familial or sporadic microsatellite instability cases is causing this variation.
Assuntos
Proteínas de Transporte/genética , Neoplasias Colorretais/genética , Genes p53 , Proteína 2 Homóloga a MutS/genética , Proteínas Nucleares/genética , Proteínas Adaptadoras de Transdução de Sinal , Adulto , Neoplasias Colorretais/epidemiologia , Feminino , Humanos , Imuno-Histoquímica , Incidência , Masculino , Proteína 1 Homóloga a MutL , Análise de Sequência com Séries de Oligonucleotídeos , Arábia Saudita/epidemiologiaRESUMO
Glioblastoma multiforme (GBM) is the most prevalent, highly malignant, invasive and difficult-to-treat primary brain tumor in adults. At the genetic level, it is characterized by a high degree of chromosomal instability and aneuploidy. It has been shown that defects in the mitotic spindle checkpoint could lead to the development of aneuploidy as well as tumorigenesis. Additional proteins regulating sister chromatid cohesion could also be involved in maintaining the fidelity of chromosome segregation. One such protein is the precocious dissociation of sisters 5A (Pds5A), also known as sister chromatid cohesion protein 112. It is a nuclear protein, expressed from the S right through to the mitotic phase. It is highly conserved from yeast to man and plays a role in the establishment, maintenance and dissolution of sister chromatid cohesion. The mutation of Pds5A orthologs in lower organisms results in chromosome missegregation, aneuploidy and DNA repair defects. It is considered that such defects can cause either cell death or contribute to the development of cancer cells. Indeed, altered expression levels of Pds5A have been observed in tumors of the breast, kidney, oesophagus, stomach, liver and colon. Malignant gliomas, however, have not been analysed so far. Herein, we report on the cloning of Rattus norvegicus Pds5A and on the analysis of its expression pattern in rat tissue. We also show that Pds5A is significantly overexpressed at both the mRNA and protein level and that this overexpression correlates positively with the WHO grade of human gliomas. However, functional assays show that the siRNA-mediated knockdown of Pds5A affects sister chromatid cohesion but does not influence mitotic checkpoint function or the proliferation and survival of GBM cells. Although the mechanism by which Pds5A functions in GBM cells remains unclear, its overexpression in high grade gliomas implies that it could play a pivotal role during the development and progression of astrocytic tumors.
Assuntos
Proteínas de Ciclo Celular/metabolismo , Cromátides/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Glioblastoma/genética , Proteínas Nucleares/metabolismo , Aneuploidia , Animais , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Instabilidade Cromossômica , Clonagem Molecular , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Mitose/fisiologia , Proteínas Nucleares/genética , Células PC12 , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual , CoesinasRESUMO
The last four decades have seen significant increase in the incidence of non-Hodgkin lymphoma (NHL) as a possible result of increasing environmental carcinogens exposure. Based on the increasing evidence for the association between carcinogen-exposure-related cancer risk and xenobiotic gene polymorphisms, we have undertaken a hospital based case-control study on xenobiotic gene polymorphisms in Saudi individuals with a diagnosis of diffuse large B-cell lymphoma (DLBCL). Polymorphisms in five genes (CYP1A1, GSTT1, GSTP1, GSTM1, and NQO1) were characterized in 182 individuals with DLBCL and 513 normal controls using PCR-RFLP method. The CYP1A1*2C (p = 0.011, OR: 6.62, and 95% CI: 1.56-28.10), GSTT1 null (p < or = 0.001, OR: 11.94, 95% CI: 7.88-18.12), and GSTP1 TT genotypes (p = 0.017, OR: 3.42, 95% CI 1.26-9.38) demonstrated significant association of DLBCL risk. None of the other alleles tested for proved to be significant indicators of DLBCL risk. Our findings suggest that polymorphisms of xenobiotic metabolizing enzyme genes may modify the individual susceptibility to develop DLBCL in Saudi Arabian population.
Assuntos
Enzimas/genética , Predisposição Genética para Doença , Linfoma Difuso de Grandes Células B/genética , Polimorfismo Genético , Xenobióticos/metabolismo , Estudos de Casos e Controles , Citocromo P-450 CYP1A1/genética , Genótipo , Glutationa S-Transferase pi/genética , Glutationa Transferase/genética , Hospitais , Humanos , Epidemiologia Molecular , NAD(P)H Desidrogenase (Quinona)/genética , Reação em Cadeia da Polimerase , Arábia Saudita/epidemiologiaRESUMO
Recent studies have suggested a potential prognostic role of alterations of the fragile histidine triad (FHIT) gene in diffuse large B-cell lymphoma. To evaluate possible mechanisms of FHIT inactivation and to further clarify its potential prognostic relevance, we analyzed a set of 114 diffuse large B-cell lymphoma with clinical follow-up information. Tissue microarrays were analyzed by immunohistochemistry for protein expression, and corresponding DNA samples were analyzed for FHIT promotor hypermethlyation. Reduced or absent FHIT expression was found in 75 of 114 diffuse large B-cell lymphoma (66%), but was unrelated to clinical tumor stage or patient prognosis. FHIT promotor hypermethylation was observed in 29 of 93 (23%) interpretable diffuse large B-cell lymphoma. Hypermethylation was not significantly correlated to protein expression loss, which could be explained by competing mechanisms for FHIT inactivation in a substantial fraction of non FHIT hypermethylated diffuse large B-cell lymphoma. Hypermethylation was significantly associated with poor prognosis of diffuse large B-cell lymphoma patients and predominantly seen in nongerminal center diffuse large B-cell lymphoma (27%), but less frequent (13%) in germinal center diffuse large B-cell lymphoma. In summary, these data suggest that promotor hypermethylation is responsible for reduced FHIT expression in a substantial subset of diffuse large B-cell lymphoma, which is primarily composed of nongerminal center subtype with poor patient prognosis.
Assuntos
Hidrolases Anidrido Ácido/metabolismo , Genes Supressores de Tumor , Linfoma de Células B/metabolismo , Linfoma Difuso de Grandes Células B/metabolismo , Proteínas de Neoplasias/metabolismo , Análise Serial de Tecidos/métodos , Hidrolases Anidrido Ácido/genética , Adulto , Idoso , Biomarcadores Tumorais/metabolismo , Metilação de DNA , DNA de Neoplasias/análise , Inativação Gênica , Humanos , Imuno-Histoquímica , Linfoma de Células B/genética , Linfoma de Células B/mortalidade , Linfoma de Células B/patologia , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/mortalidade , Linfoma Difuso de Grandes Células B/patologia , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Prognóstico , Arábia Saudita , Taxa de SobrevidaRESUMO
Phosphatidylinositol 3'-kinase (PI3K) is a key player in cell-growth signaling in a number of lymphoid malignancies, but its role in diffuse large B-cell lymphoma (DLBCL) has not been fully elucidated. Therefore, we investigated the role of the PI3K/AKT pathway in a panel of 5 DLBCL cell lines and 100 clinical samples. Inhibition of PI3K by a specific inhibitor, LY294002, induced apoptosis in SUDHL4, SUDHL5, and SUDHL10 (LY-sensitive) cells, whereas SUDHL8 and OCI-LY19 (LY-resistant) cells were refractory to LY294002-induced apoptosis. AKT was phosphorylated in 5 of 5 DLBCL cell lines and inhibition of PI3K caused dephosphorylation/inactivation of constitutively active AKT, FOXO transcription factor, and GSK3 in LY-sensitive cell lines. In addition, there was a decrease in the expression level of inhibitory apoptotic protein, XIAP, in the DLBCL cell lines sensitive to LY294002 after treatment. However, no effect was observed in XIAP protein levels in the resistant DLBCL cell lines following LY294002 treatment. Finally, using immunohistochemistry, p-AKT was detected in 52% of DLBCL tumors tested. Furthermore, in univariate analysis, high p-AKT expression was associated with short survival. In multivariate analysis, this correlation was no longer significant. Altogether, these results suggest that the PI3K/AKT pathway may be a potential target for therapeutic intervention in DLBCL.