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1.
Int J Cancer ; 133(7): 1567-77, 2013 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-23536448

RESUMO

Dysregulation of nucleophosmin 1 (NPM1) has been found in numerous solid and hematological malignancies. Our previous meta-analysis of colorectal cancer (CRC) high throughput gene expression profiling studies identified it as a consistently reported up-regulated gene in the malignant state. Our aims were to compare NPM1 expression in normal colon, adenoma and CRC, to correlate their expressions with clinico-pathological parameters, and to assess the biological role of aberrant NPM1 expression in CRC cells. NPM1 transcript levels were studied in human CRC cell lines, whereas a tissue microarray of 57 normal human colon, 40 adenoma and 185 CRC samples were used to analyze NPM1 protein expression by immunohistochemistry. CRC cell lines were subjected to transient siRNA-mediated knockdown to study NPM1's roles on cell viability and senescence. NPM1 transcript levels were 7-11-folds higher in three different human CRC cell lines compared to normal colon cells. NPM1 protein expression was found to be progressively and significantly upregulated in CRC compared to adenomas and in adenomas compared to normal mucosa. Reducing NPM1 expression by siRNA had caused a significant decrease in cell viability, a concomitant increase in cellular senescence and cell cycle arrest. Cellular senescence induced under conditions of forced NPM1 suppression could be prevented by knocking down p53. The differential expression of NPM1 along the normal colon-adenoma-carcinoma progression and its involvement in resisting p53 related senescent growth arrest in CRC cell lines implicate its role in supporting CRC tumorigenesis.


Assuntos
Adenoma/metabolismo , Sobrevivência Celular/genética , Senescência Celular , Neoplasias Colorretais/metabolismo , Proteínas Nucleares/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Pontos de Checagem do Ciclo Celular/genética , Linhagem Celular Tumoral , Perfilação da Expressão Gênica , Humanos , Imuno-Histoquímica , Proteínas Nucleares/genética , Nucleofosmina , Interferência de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteína Supressora de Tumor p53/antagonistas & inibidores , Proteína Supressora de Tumor p53/genética , Regulação para Cima
2.
Nat Methods ; 7(10): 843-7, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20835245

RESUMO

In alternative expression analysis by sequencing (ALEXA-seq), we developed a method to analyze massively parallel RNA sequence data to catalog transcripts and assess differential and alternative expression of known and predicted mRNA isoforms in cells and tissues. As proof of principle, we used the approach to compare fluorouracil-resistant and -nonresistant human colorectal cancer cell lines. We assessed the sensitivity and specificity of the approach by comparison to exon tiling and splicing microarrays and validated the results with reverse transcription-PCR, quantitative PCR and Sanger sequencing. We observed global disruption of splicing in fluorouracil-resistant cells characterized by expression of new mRNA isoforms resulting from exon skipping, alternative splice site usage and intron retention. Alternative expression annotation databases, source code, a data viewer and other resources to facilitate analysis are available at http://www.alexaplatform.org/alexa_seq/.


Assuntos
Processamento Alternativo , RNA Mensageiro/genética , Análise de Sequência de RNA/métodos , Antimetabólitos Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Bases de Dados Genéticas , Resistencia a Medicamentos Antineoplásicos/genética , Etiquetas de Sequências Expressas , Fluoruracila/farmacologia , Expressão Gênica/efeitos dos fármacos , Perfilação da Expressão Gênica , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Isoformas de Proteínas , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência
3.
Opt Express ; 21(4): 5025-34, 2013 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-23482035

RESUMO

Raman systems have tremendous potential as adjunct devices for endoscopes to improve the identification of early colon cancers. However, the traditional low frequency (LF) measurement range has several obstacles that make it challenging to develop a routine clinical tool. An alternative is to use high frequency (HF) range. To test this idea Raman spectra were obtained in both the LF and HF ranges from the same colon lesions. Multivariate analyses predicted the pathology with high sensitivity and specificity for both the LF and HF data sets. This suggests that Raman systems that measure HF spectra, and are simpler to adopt into the clinic, could be used in vivo to improve the identification of neoplastic lesions.


Assuntos
Algoritmos , Neoplasias do Colo/diagnóstico , Diagnóstico por Computador/métodos , Análise Espectral Raman/métodos , Interpretação Estatística de Dados , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
4.
J Immunol ; 184(5): 2305-13, 2010 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-20130217

RESUMO

Intestinal epithelial cells (IECs) are constantly exposed to enteric microbes. Although IECs express TLRs that recognize bacterial products, the activation of these TLRs is strictly controlled through poorly understood mechanisms, producing a state of hyporesponsiveness and preventing unwanted inflammation. The single IgG IL-1-related receptor (Sigirr) is a negative regulator of TLRs that is expressed by IECs and was recently shown to inhibit experimental colitis. However, the importance of Sigirr in IEC hyporesponsiveness and its distribution within the human colon is unknown. In this study, we investigated the role of Sigirr in regulating epithelial-specific TLR responses and characterized its expression in colonic biopsy specimens. Transformed and nontransformed human IECs were cultured as monolayers. Transient gene silencing and stable overexpression of Sigirr was performed to assess innate IEC responses. Sigirr expression in human colonic biopsy specimens was examined by immunohistochemistry. Bacterial infection of IECs and exposure to flagellin transiently decreased Sigirr protein expression, concurrent with secretion of the neutrophil chemokine IL-8. Sigirr gene silencing augmented chemokine responses to bacterial flagellin, Pam3Cys, and the cytokine IL-1beta. Conversely, stable overexpression of Sigirr diminished NF-kappaB-mediated IL-8 responses to TLR ligands. We also found that Sigirr expression increased as IECs differentiated in culture. This observation was confirmed in biopsy sections, in which Sigirr expression within colonic crypts was prominent in IECs at the apex and diminished at the base. Our findings show that Sigirr broadly regulates innate responses in differentiated human IECs; therefore, it may modulate epithelial involvement in infectious and inflammatory bowel diseases.


Assuntos
Células Epiteliais/metabolismo , Mucosa Intestinal/metabolismo , Receptores de Interleucina-1/metabolismo , Receptores Toll-Like/metabolismo , Animais , Western Blotting , Células CHO , Células CACO-2 , Diferenciação Celular , Linhagem Celular , Colo/metabolismo , Cricetinae , Cricetulus , Células Epiteliais/microbiologia , Flagelina/genética , Flagelina/metabolismo , Imunofluorescência , Células HT29 , Humanos , Imuno-Histoquímica , Interleucina-8/metabolismo , Mucosa Intestinal/citologia , NF-kappa B/metabolismo , Interferência de RNA , Receptores de Interleucina-1/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Receptores Toll-Like/genética
5.
Front Immunol ; 13: 978862, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36846019

RESUMO

Introduction: Colorectal cancer (CRC) is the third leading cause of cancer-related deaths globally. Tumour-infiltrating leukocytes play an important role in cancers, including CRC. We therefore sought to characterize the impact of tumour-infiltrating leukocytes on CRC prognosis. Methods: To determine whether the immune cell profile within CRC tissue could influence prognosis, we employed three computational methodologies (CIBERSORT, xCell and MCPcounter) to predict abundance of immune cell types, based on gene expression. This was done using two patient cohorts, TCGA and BC Cancer Personalized OncoGenomics (POG). Results: We observed significant differences in immune cell composition between CRC and normal adjacent colon tissue, as well as differences in based on method of analysis. Evaluation of survival based on immune cell types revealed dendritic cells as a positive prognostic marker, consistently across methodologies. Mast cells were also found to be a positive prognostic marker, but in a stage-dependent manner. Unsupervised cluster analysis demonstrated that significant differences in immune cell composition has a more pronounced effect on prognosis in early-stage CRC, compared to late-stage CRC. This analysis revealed a distinct group of individuals with early-stage CRC which have an immune infiltration signature that indicates better survival probability. Conclusions: Taken together, characterization of the immune landscape in CRC has provided a powerful tool to assess prognosis. We anticipate that further characterization of the immune landscape will facilitate use of immunotherapies in CRC.


Assuntos
Neoplasias Colorretais , Humanos , Neoplasias Colorretais/metabolismo , Leucócitos , Prognóstico , Macrófagos
6.
Int J Cancer ; 129(9): 2115-23, 2011 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-21618508

RESUMO

Vascular endothelial growth factor (VEGF) inhibitors, such as bevacizumab, have improved outcomes in metastatic colorectal cancer (CRC). Recent studies have suggested that VEGF can delay the onset of cellular senescence in human endothelial cells. As VEGF receptors are known to be upregulated in CRC, we hypothesized that VEGF inhibition may directly influence cellular senescence in this disease. In our study, we observed that treatment with bevacizumab caused a significant increase (p < 0.05) in cellular senescence in vitro in several CRC cells, such as MIP101, RKO, SW620 and SW480 cells, compared to untreated or human IgG-treated control cells. Similar results were also obtained from cells treated with a VEGFR2 kinase inhibitor Ki8751. In vivo, cellular senescence was detected in MIP101 tumor xenografts from 75% of mice treated with bevacizumab, while cellular senescence was undetectable in xenografts from mice treated with saline or human IgG (p < 0.05). Interestingly, we also observed that the proportion of senescent cells in colon cancer tissues obtained from patients treated with bevacizumab was 4.4-fold higher (p < 0.01) than those of untreated patients. To understand how VEGF inhibitors may regulate cellular senescence, we noted that among the two important regulators of senescent growth arrest of tumor cells, bevacizumab-associated increase in cellular senescence coincided with an upregulation of p16 but appeared to be independent of p53. siRNA silencing of p16 gene in MIP101 cells suppressed bevacizumab-induced cellular senescence, while silencing of p53 had no effect. These findings demonstrate a novel antitumor activity of VEGF inhibitors in CRC, involving p16.


Assuntos
Inibidores da Angiogênese/farmacologia , Anticorpos Monoclonais Humanizados/farmacologia , Senescência Celular/efeitos dos fármacos , Neoplasias Colorretais/metabolismo , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Inibidores da Angiogênese/administração & dosagem , Animais , Anticorpos Monoclonais Humanizados/administração & dosagem , Bevacizumab , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Inibidor p16 de Quinase Dependente de Ciclina/genética , Humanos , Camundongos , Camundongos Nus , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Front Oncol ; 11: 655479, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34277407

RESUMO

Cyclin-dependent kinase 10 (CDK10) is a CDC2-related serine/threonine kinase involved in cellular processes including cell proliferation, transcription regulation and cell cycle regulation. CDK10 has been identified as both a candidate tumor suppressor in hepatocellular carcinoma, biliary tract cancers and gastric cancer, and a candidate oncogene in colorectal cancer (CRC). CDK10 has been shown to be specifically involved in modulating cancer cell proliferation, motility and chemosensitivity. Specifically, in CRC, it may represent a viable biomarker and target for chemoresistance. The development of therapeutics targeting CDK10 has been hindered by lack a specific small molecule inhibitor for CDK10 kinase activity, due to a lack of a high throughput screening assay. Recently, a novel CDK10 kinase activity assay has been developed, which will aid in the development of small molecule inhibitors targeting CDK10 activity. Discovery of a small molecular inhibitor for CDK10 would facilitate further exploration of its biological functions and affirm its candidacy as a therapeutic target, specifically for CRC.

8.
Cancer Biol Ther ; 22(2): 112-123, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33446037

RESUMO

The nucleophosmin 1 (NPM1) protein is frequently overexpressed in various cancers compared to normal tissues and represents a potential biomarker for maliganancy. However, its role in colorectal cancer (CRC) is still not fully understood. In this report, we show that NPM1 levels in CRC correlate with prognosis and sensitivity to chemotherapy. NPM1 expression was found to be significantly increased in CRC tumors (P < .001) and was associated with poor overall 5-year survival (P < .05). For individuals with Stage IV disease, this represented a reduction in survival by 11 months (P < .01; HR = 0.38, CI [0.21, 0.69]. In vitro, we show that NPM1 gene silencing enhanced the chemosensitivity of CRC cells and that pharmacological inhibition of NPM1 by NSC348884 triggered the onset of programmed cell death. Our immunofluorescence microscopy and immunoblot analyses also revealed that blocking NPM1 function sensitized CRC cells to chemotherapy-induced apoptosis through a mechanism that involves proteins in the AKT pathway. Consistent with the in vitro data, our patient-derived CRC xenograft model showed that inhibition of NPM1 suppressed tumor growth and attenuated AKT signaling in vivo. Moreover, LY294002, an inhibitor of the PI3K/AKT pathway, restored the chemosensitivity of CRC cells expressing high levels of NPM1. The findings that NPM1's expression in CRC tissue correlates with prognosis and supports anti-apoptotic activity mediated by AKT signaling, further our understanding of the role of NPM1 in CRC.


Assuntos
Neoplasias Colorretais/tratamento farmacológico , Nucleofosmina/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Humanos , Camundongos , Transdução de Sinais
9.
Carcinogenesis ; 31(5): 812-9, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20164124

RESUMO

Cellular senescence is another mechanism that can be exploited to achieve better chemosensitivity and greater tumor regression. Unlike apoptosis, cellular senescence can be induced at much lower concentrations of chemotherapy that are better tolerated by patients. We previously revealed that secreted protein acidic and rich in cysteine (SPARC), a matricellular protein, may function as a modulator of chemotherapy sensitivity by enhancing apoptosis. Here, we examine the effects of SPARC on cellular senescence in the presence of chemotherapy. Cellular senescence is induced only in sensitive colorectal cancer (CRC) cells with low concentrations of irinotecan (CPT-11). However, CPT-11-resistant cells exposed to endogenous or exogenous SPARC can also be triggered into cellular senescence. This induction is associated with higher levels of p16(INK4A) and phosphorylated p53. Knock down of p16(INK4A) reduces drug-induced senescence in all cells, but knock down and overexpression of p53 modulates senescence only in cells exposed to SPARC. Furthermore, treatment of mice with SPARC and CPT-11 leads to significantly increased cellular senescence and tumor regression. The chemosensitizing effects of SPARC in CRCs are, therefore, probably mediated in part by activating cellular senescence.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Camptotecina/análogos & derivados , Senescência Celular/efeitos dos fármacos , Neoplasias Colorretais/tratamento farmacológico , Osteonectina/farmacologia , Proteína Supressora de Tumor p53/fisiologia , Animais , Camptotecina/farmacologia , Neoplasias Colorretais/patologia , Inibidor p16 de Quinase Dependente de Ciclina/fisiologia , Dano ao DNA , Humanos , Irinotecano , Camundongos
10.
Biochem Biophys Res Commun ; 393(4): 773-8, 2010 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-20171161

RESUMO

Neurodegenerative disorders are a class of diseases that have been linked to apoptosis induced by elevated levels of reactive oxygen species (ROS). ROS activates the apoptotic cascade through mitochondrial dysfunction and damage to lipids, proteins and DNA. Recently, fruit and tea-derived polyphenols have been found to be beneficial in decreasing oxidative stress and increasing overall health. Further, polyphenols including epigallocatechin gallate (EGCG) have been reported to inhibit apoptotic signaling and increase neural cell survival. In an effort to better understand the beneficial properties associated with polyphenol consumption, the aim of this study was to explore the neuroprotective effects of EGCG, methyl gallate (MG), gallic acid (GA) and N-acetylcysteine (NAC) on H(2)O(2)-induced apoptosis in PC12 cells and elucidate potential protective mechanisms. Cell viability data demonstrates that MG and NAC pre-treatments significantly increase viability of H(2)O(2)-stressed cells, while pre-treatments with EGCG and GA exacerbates stress. Quantitation of apoptosis and mitochondrial membrane potential shows that MG pre-treatment prevents mitochondria depolarization, however does not inhibit apoptosis and is thus evidence that MG can inhibit mitochondria-mediated apoptosis. Subsequent analysis of DNA degradation and caspase activation reveals that MG inhibits activation of caspase 9 and has a partial inhibitory effect on DNA degradation. These findings confirm the involvement of both intrinsic and extrinsic apoptotic pathways in H(2)O(2)-induced apoptosis and suggest that MG may have potential therapeutic properties against mitochondria-mediated apoptosis.


Assuntos
Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Citoproteção , Ácido Gálico/análogos & derivados , Peróxido de Hidrogênio/antagonistas & inibidores , Fármacos Neuroprotetores/farmacologia , Acetilcisteína/farmacologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Fragmentação do DNA/efeitos dos fármacos , Ácido Gálico/farmacologia , Peróxido de Hidrogênio/metabolismo , Peróxido de Hidrogênio/toxicidade , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Células PC12 , Ratos
11.
Cancer Biol Med ; 17(4): 842-863, 2020 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-33299639

RESUMO

Despite advances in cancer therapeutics and the integration of personalized medicine, the development of chemoresistance in many patients remains a significant contributing factor to cancer mortality. Upon treatment with chemotherapeutics, the disruption of homeostasis in cancer cells triggers the adaptive response which has emerged as a key resistance mechanism. In this review, we summarize the mechanistic studies investigating the three major components of the adaptive response, autophagy, endoplasmic reticulum (ER) stress signaling, and senescence, in response to cancer chemotherapy. We will discuss the development of potential cancer therapeutic strategies in the context of these adaptive resistance mechanisms, with the goal of stimulating research that may facilitate the development of effective cancer therapy.


Assuntos
Adaptação Fisiológica , Envelhecimento , Autofagia , Resistencia a Medicamentos Antineoplásicos , Estresse do Retículo Endoplasmático , Animais , Antineoplásicos/farmacologia , Apoptose , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/patologia
12.
Case Rep Gastrointest Med ; 2020: 8886817, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33294234

RESUMO

BACKGROUND: Colonoscopy is widely used for the diagnosis and management of colorectal disease and requires adequate bowel preparation. Ischemic colitis is a form of intestinal ischemia that presents with abdominal pain, diarrhea, and hematochezia. Risk factors include advanced age, cardiovascular disease, and diabetes. Both colonoscopy and bisacodyl bowel preparation have been described as rare causes of ischemic colitis with less than 35 cases collectively in the literature. Our review found that of these cases, there exists significant heterogeneity within individual patient characteristics. The majority of the cases are managed conservatively without complications or sequela. Due to the risk of ischemic colitis, the FDA has withdrawn bisacodyl bowel preparations from use in the USA. Bisacodyl bowel preparations are still used in Canada. CASES: Here, we present two cases of ischemic colitis in previously healthy women aged 57 and 69 who underwent screening colonoscopy using bisacodyl bowel preparation. Both were treated conservatively without complications. CONCLUSION: Thus far, there has been one documented case of ischemic colitis following colonoscopy with bisacodyl bowel preparation; here, we present two additional cases with one case occurring without the presence of known risk factors for ischemic colitis. Our literature review finds that there is limited evidence surrounding bisacodyl as a causative agent of ischemic colitis. Cases often contain confounding variables such as the presence of known risk factors for ischemic colitis. Our report aims to highlight the need for a more comprehensive analysis evaluating the safety of bowel preparations as well as increasing the clinical awareness surrounding the rare risk of colonoscopy-induced ischemic colitis.

13.
Cancer Biol Med ; 17(2): 343-356, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32587773

RESUMO

Objective: Heat shock protein 47 (HSP47) is a collagen-specific molecular chaperone that facilitates collagen maturation. Its role in cancer remains largely unknown. In this study, we investigated the roles of HSP47 in colorectal cancer (CRC) and therapy resistance. Methods: Expression of HSP47 in CRC tissues was examined (1) in paired human CRC/adjacent normal tissues, using real time quantitative reverse transcription polymerase chain reaction (qRT-PCR), The Cancer Genome Atlas (TCGA) database, and 22 independent microarray databases (curated CRC). In vitro studies on several CRC cell lines (HCT116, RKO and CCL228) with modulated HSP47 expression were conducted to assess cell viability and apoptosis (TUNEL assay and caspase-3/-7) during exposure to chemotherapy. AKT signaling and co-immunoprecipitation studies were performed to examine HSP47 and PHLPP1 interaction. In vivo studies using tumor xenografts were conducted to assess the effects of HSP47 modulation on tumor growth and therapy response. Results: HSP47 was upregulated in CRC and was associated with poor prognosis in individuals with CRC. In vitro, HSP47 overexpression supported the survival of CRC cells, whereas its knockdown sensitized cells to 5-fluorouracil (5-FU). HSP47 promoted survival by inhibiting apoptosis, enhancing AKT phosphorylation, and decreasing expression of the AKT-specific phosphatase PHLPP1 when cells were exposed to chemotherapy. These effects were partly results of the interaction between HSP47 and PHLPP1, which decreased PHLPP1 stability and led to more persistent AKT activity. In vivo, HSP47 supported tumor growth despite 5-FU treatment. Conclusions: HSP47 supports the growth of CRC tumors and suppresses the efficacy of chemotherapy via modulation of AKT signaling.


Assuntos
Sobrevivência Celular , Neoplasias Colorretais/metabolismo , Proteínas de Choque Térmico HSP47/metabolismo , Proteínas Nucleares/metabolismo , Fosfoproteínas Fosfatases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Apoptose , Linhagem Celular Tumoral , Neoplasias Colorretais/patologia , Bases de Dados Factuais , Feminino , Fluoruracila/farmacologia , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Camundongos Nus , Fosforilação , Transdução de Sinais , Regulação para Cima , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Drug Resist Updat ; 11(6): 231-46, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18849185

RESUMO

The ability to effectively target a tumor to achieve complete regression and cure is the ultimate goal that drives our need to better understand tumor biology. Recently, SPARC has generated considerable interest as a multi-faceted protein that belongs to a family of matricellular proteins. It functions not only to modulate cell-cell and cell-matrix interactions, but its de-adhesive and growth inhibitory properties in non-transformed cells have led to studies to assess its role in cancer. Its divergent actions reflect the complexity of this protein, because in certain types of cancers, such as melanomas and gliomas, SPARC is associated with a highly aggressive tumor phenotype, while in others, mainly ovarian, neuroblastomas and colorectal cancers, SPARC may function as a tumor suppressor. Recent studies have also demonstrated a role for SPARC in sensitizing therapy-resistant cancers. Here, the role of SPARC in cancer progression and its potential application in cancer therapy is discussed.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias/tratamento farmacológico , Osteonectina , Animais , Antineoplásicos/administração & dosagem , Apoptose/efeitos dos fármacos , Terapia Genética , Humanos , Invasividade Neoplásica , Metástase Neoplásica , Neoplasias/metabolismo , Neoplasias/patologia , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Osteonectina/biossíntese , Osteonectina/genética , Osteonectina/fisiologia , Osteonectina/uso terapêutico
15.
Cell Death Dis ; 10(7): 504, 2019 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-31243264

RESUMO

Therapy-refractory disease is one of the main contributors of treatment failure in cancer. In colorectal cancer (CRC), SPARC can function as a sensitizer to conventional chemotherapy by enhancing apoptosis by interfering with the activity of Bcl-2. Here, we examine a novel mechanism by which SPARC further potentiates apoptosis via its modulation of the unfolded protein response (UPR). Using mass spectrometry to identify SPARC-associated proteins, GRP78 was identified as a protein partner for SPARC in CRC. In vitro studies conducted to assess the signaling events resulting from this interaction, included induction of ER stress with tunicamycin, 5-fluorouracil (5-FU), and irinotecan (CPT-11). We found that the interaction between GRP78 and SPARC increased during exposure to 5-FU, CPT-11, and tunicamycin, resulting in an attenuation of GRP78's inhibition of apoptosis. In addition, we also show that SPARC can sensitize CRC cells to PERK/eIF2α and IRE1α/XBP-1 UPR signaling by interfering with ER stress following binding to GRP78, which leads to ER stress-associated cell death in CRC cells. In line with these findings, a lower expression of GRP78 relative to SPARC in CRC is associated with a lower IC50 for 5-FU in either sensitive or therapy-refractory CRC cells. Interestingly, this observation correlates with tissue microarray analysis of 143 human CRC, where low GRP78 to SPARC expression level was prognostic of higher survival rate (P = 0.01) in individuals with CRC. This study demonstrates that modulation of UPR signaling by SPARC promotes ER stress-associated death and potentiates apoptosis. This may be an effective strategy that can be combined with current treatment options to improve therapeutic efficacy in CRC.


Assuntos
Neoplasias Colorretais/metabolismo , Fator de Iniciação 2 em Eucariotos/metabolismo , Proteínas de Choque Térmico/metabolismo , Osteonectina/metabolismo , Proteína 1 de Ligação a X-Box/metabolismo , eIF-2 Quinase/metabolismo , Apoptose/genética , Apoptose/fisiologia , Western Blotting , Linhagem Celular Tumoral , Sobrevivência Celular/genética , Sobrevivência Celular/fisiologia , Neoplasias Colorretais/genética , Chaperona BiP do Retículo Endoplasmático , Estresse do Retículo Endoplasmático/genética , Estresse do Retículo Endoplasmático/fisiologia , Fator de Iniciação 2 em Eucariotos/genética , Imunofluorescência , Células HCT116 , Proteínas de Choque Térmico/genética , Humanos , Imuno-Histoquímica , Imunoprecipitação , Espectrometria de Massas , Osteonectina/genética , Interferência de RNA , Análise Serial de Tecidos , Proteína 1 de Ligação a X-Box/genética , eIF-2 Quinase/genética
16.
J Clin Invest ; 115(6): 1492-502, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15902309

RESUMO

Overcoming resistance to chemotherapy and radiation therapy has been a difficult but important goal in the effort to cure cancer. We used gene-expression microarrays to identify differentially expressed genes involved in colorectal cancer resistance to chemotherapy and identified secreted protein, acidic and rich in cysteine (osteonectin) (SPARC) as a putative resistance-reversal gene by demonstrating low SPARC expression in refractory human MIP101 colon cancer cells. We were able to achieve restoration of their radiosensitivity and sensitivity to 5-fluorouracil and irinotecan by reexpression of SPARC in tumor xenografts. Moreover, treatment of mice with SPARC conferred increased sensitivity to chemotherapy and led to significant regression of xenografted tumors. The results show that modulation of SPARC expression affects colorectal cancer sensitivity to radiation and chemotherapy. SPARC-based gene or protein therapy may ameliorate the emergence of resistant clones and eradicate existing refractory clones and offers a novel approach to treating cancer.


Assuntos
Antineoplásicos/administração & dosagem , Camptotecina/análogos & derivados , Neoplasias do Colo/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Neoplasias Experimentais/tratamento farmacológico , Osteonectina/administração & dosagem , Animais , Camptotecina/administração & dosagem , Linhagem Celular Tumoral , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Fluoruracila/administração & dosagem , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Irinotecano , Camundongos , Camundongos Nus , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Análise de Sequência com Séries de Oligonucleotídeos , Osteonectina/metabolismo , Transplante Heterólogo
17.
Cancer Epidemiol Biomarkers Prev ; 17(3): 543-52, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18349271

RESUMO

PURPOSE: Elucidation of candidate colorectal cancer biomarkers often begins by comparing the expression profiles of cancerous and normal tissue by performing gene expression profiling. Although many such studies have been done, the resulting lists of differentially expressed genes tend to be inconsistent with each other, suggesting that there are some false positives and false negatives. One solution is to take the intersection of the lists from independent studies. However, often times, the statistical significance of the observed intersection are not assessed. METHODS: Recently, we developed a meta-analysis method that ranked differentially expressed genes in thyroid cancer based on the intersection among studies, total sample sizes, average fold change, and direction of differential expression. We applied an improved version of the method to 25 independent colorectal cancer profiling studies that compared cancer versus normal, adenoma versus normal, and cancer versus adenoma to highlight genes that were consistently reported as differentially expressed at a statistically significant frequency. RESULTS: We observed that some genes were consistently reported as differentially expressed with a statistically significant frequency (P < 0.05) in cancer versus normal and adenoma versus normal comparisons but not in the cancer versus adenoma comparison. CONCLUSION: Our meta-analysis method identified genes that were consistently reported as differentially expressed. A review of some of the candidates revealed genes described previously as having diagnostic and/or prognostic value as well as novel candidate biomarkers. The genes presented here will aid in the identification of highly sensitive and specific biomarkers in colorectal cancer.


Assuntos
Biomarcadores Tumorais/análise , Neoplasias Colorretais/genética , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos
18.
Mol Cancer Ther ; 6(1): 309-17, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17237289

RESUMO

Patients with advanced colorectal cancer continue to have poor outcomes because of therapy-refractory disease. We previously showed that secreted protein acidic and rich in cysteine (SPARC) gene and protein could function as a chemotherapy sensitizer by enhancing tumor regression in response to radiation and chemotherapy in tumor xenograft models of chemotherapy-resistant tumors. This function of SPARC was gleamed from a microarray analysis that also revealed down-regulation of the vitamin D receptor (VDR) in therapy-refractory colorectal cancer cells. This study examines the potential synergistic effect of SPARC and vitamin D, which up-regulates VDR, in enhancing chemotherapy response in colorectal cancer. Using MIP101 colorectal cancer cell lines and SPARC-overexpressing MIP101 cells, we were able to show that, in the presence of SPARC, exposure to low doses of 1alpha,25-dihydroxyvitamin D(3) significantly reduces cell viability, enhances chemotherapy-induced apoptosis, and inhibits the growth of colorectal cancer cells. Moreover, in tumor xenograft mouse models, up-regulation of VDR was seen in tumors that had the greatest regression following treatment that combined SPARC with chemotherapy. Therefore, our findings reveal a synergistic effect between SPARC and low doses of 1alpha,25-dihydroxyvitamin D(3) that further augments the sensitivity of tumors to chemotherapy. This combination may prove to be a useful adjunct in the treatment of colorectal cancer, especially in those patients with therapy-refractory disease.


Assuntos
Apoptose/efeitos dos fármacos , Neoplasias Colorretais/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos , Osteonectina/metabolismo , Osteonectina/farmacologia , Vitamina D/análogos & derivados , Animais , Ciclo Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Neoplasias Colorretais/patologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HCT116 , Humanos , Camundongos , Osteonectina/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo , Vitamina D/farmacologia , Vitamina D/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto
19.
Mol Cancer Ther ; 16(10): 2292-2303, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28663269

RESUMO

Cyclin-dependent kinase 10 (CDK10), a CDC2-related kinase, is highly expressed in colorectal cancer. Its role in the pathogenesis of colorectal cancer is unknown. This study examines the function of CDK10 in colorectal cancer, and demonstrates its role in suppressing apoptosis and in promoting tumor growth in vitro and in vivo Modulation of CDK10 expression in colorectal cancer cell lines demonstrates that CDK10 promotes cell growth, reduces chemosensitivity and inhibits apoptosis by upregulating the expression of Bcl-2. This effect appears to depend on its kinase activity, as kinase-defective mutant colorectal cancer cell lines have an exaggerated apoptotic response and reduced proliferative capacity. In vivo, inhibiting CDK10 in colorectal cancer following intratumoral injections of lentivirus-mediated CDK10 siRNA in a patient-derived xenograft mouse model demonstrated its efficacy in suppressing tumor growth. Furthermore, using a tissue microarray of human colorectal cancer tissues, the potential for CDK10 to be a prognostic biomarker in colorectal cancer was explored. In tumors of individuals with colorectal cancer, high expression of CDK10 correlates with earlier relapse and shorter overall survival. The findings of this study indicate that CDK10 plays a role in the pathogenesis in colorectal cancer and may be a potential therapeutic target for treatment. Mol Cancer Ther; 16(10); 2292-303. ©2017 AACR.


Assuntos
Biomarcadores Tumorais/genética , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/tratamento farmacológico , Quinases Ciclina-Dependentes/genética , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Quinases Ciclina-Dependentes/antagonistas & inibidores , Quinases Ciclina-Dependentes/química , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Domínios Proteicos/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Ensaios Antitumorais Modelo de Xenoenxerto
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