RESUMO
We previously have identified the ectopic expression of Rac1b, an activated and novel splice variant of Rac1, in a subset of human colorectal adenocarcinomas, as well as in inflammatory bowel diseases and in colitis mouse model. Rac1b overexpression has been further evidenced in breast, pancreatic, thyroid, ovarian, and lung cancers. In this context, the aim of our study was to investigate the physiopathological implications of Rac1b in intestinal inflammation and carcinogenesis in vivo. The ectopic expression of Rac1b was induced in mouse intestinal epithelial cells after crossing Rosa26-LSL-Rac1b and villin-Cre mice. These animals were let to age or were challenged with dextran sulfate sodium (DSS) to induce experimental colitis, or either received azoxymethane (AOM)/DSS treatment, or were bred with ApcMin/+ or Il10-/- mice to trigger intestinal tumors. Rac1b ectopic expression increased the intestinal epithelial cell proliferation and migration, enhanced the production of reactive oxygen species, and promoted the Paneth cell lineage. Although Rac1b overexpression alone was not sufficient to drive intestinal neoplasia, it enhanced Apc-dependent intestinal tumorigenesis. In the context of Il10 knockout, the Rac1b transgene strengthened colonic inflammation due to induced intestinal mucosa permeability and promoted cecum and proximal colon carcinogenesis. In contrast, Rac1b alleviated carcinogen/acute inflammation-associated colon carcinogenesis (AOM/DSS). This resulted at least partly from the early mucosal repair after resolution of inflammation. Our data highlight the critical role of Rac1b in driving wound-healing after resolution of intestinal inflammation, and in cooperating with Wnt pathway dysregulation and chronic inflammation to promote intestinal carcinogenesis.
Assuntos
Colo/patologia , Neoplasias do Colo/patologia , Mucosa Intestinal/patologia , Neuropeptídeos/genética , Proteínas rac1 de Ligação ao GTP/genética , Animais , Azoximetano/farmacologia , Carcinogênese/efeitos dos fármacos , Carcinogênese/patologia , Colite/genética , Colite/patologia , Colo/efeitos dos fármacos , Neoplasias do Colo/induzido quimicamente , Neoplasias do Colo/genética , Sulfato de Dextrana/farmacologia , Modelos Animais de Doenças , Progressão da Doença , Células Epiteliais/patologia , Inflamação/genética , Inflamação/patologia , Mucosa Intestinal/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genéticaRESUMO
Nanotechnology offers many possibilities to improve drug treatments, including with regard to drug pharmacology. The current study reports a simple approach to improve cisplatin efficacy in the treatment of colon cancer through the creation of orally administered squalenoylated nanoparticles loaded with cisplatin (SQ-CDDP NP). Cytotoxic effects of SQ-CDDP NP were assessed in human colonic cells and in mouse models of intestinal cancer. In cell culture, SQ-CDDP NP exhibited at least 10-fold greater cytotoxic potency compared with uncomplexed cisplatin, reflecting an enhancement in intracellular accumulation and DNA platination. Mechanistic investigations showed that SQ-CDDP NP stimulated ROS production, expression of heavy metal-inducible and stress-inducible genes, stress kinase cascades, and apoptosis. In ApcMin/+ mice, a model of intestinal tumorigenesis, oral administration of SQ-CDDP NP curtailed spontaneous tumor formation and azoxymethane-induced colon carcinogenesis with no apparent evidence of tissue toxicity. Our results offer preclinical validation of a nanocarrier formulation that can safely improve chemotherapeutic efficacy, address risks of drug resistance, and improve patient compliance by enabling oral administration. Cancer Res; 77(11); 2964-75. ©2017 AACR.
Assuntos
Antineoplásicos/uso terapêutico , Neoplasias do Colo/tratamento farmacológico , Nanomedicina/métodos , Esqualeno/uso terapêutico , Administração Oral , Animais , Antineoplásicos/farmacologia , Apoptose , Proliferação de Células , Neoplasias do Colo/patologia , Modelos Animais de Doenças , Humanos , CamundongosRESUMO
Molecular and genetic investigations in endometrial carcinogenesis may have prognostic and therapeutic implications. We studied the expression of EGFR, c-Met, PTEN and the mTOR signalling pathway (phospho-AKT/phospho-mTOR/phospho-RPS6) in 69 consecutive tumours and 16 tissue microarrays. We also analysed PIK3CA, K-Ras mutations and microsatellite instability (MSI). We distinguished two groups: group 1 (grade 1 and 2 endometrioid cancers) and group 2 (grade 3 endometrioid and type II clear and serous cell cancers). We hypothesised that these histological groups might have different features. We found that a) survival was higher in group 1 with less aggressive tumours (P⟨0.03); b) EGFR (P=0.01), PTEN and the AKT/mTOR/RPS6 signalling pathway were increased in group 1 versus group 2 (P=0.05 for phospho-mTOR); c) conversely, c-Met was higher (P⟨0.03) in group 2 than in group 1; d) In group 1, EGFR was correlated with c-Met, phospho-mTOR, phospho-RPS6 and the global activity of the phospho-AKT/phospho-mTOR/phospho-RPS6 pathway. In group 2, EGFR was correlated only with the phospho-AKT/phospho-mTOR/phospho-RPS6 pathway, whereas c-Met was correlated with PTEN; e) survival was higher for tumours with more than 50% PTEN-positive cells; f) K-RAS and PIK3CA mutations occurred in 10-12% of the available tumours and MSI in 40.4%, with a loss of MLH1 and PMS2 expression. Our results for endometrial cancers provide the first evidence for a difference in status between groups 1 and 2. The patients may benefit from different targeted treatments, anti-EGFR agents and rapamycin derivatives (anti-mTOR) for group 1 and an anti c-MET/ligand complex for group 2.
Assuntos
Carcinoma/metabolismo , Neoplasias do Endométrio/metabolismo , Receptores ErbB/genética , Instabilidade de Microssatélites , PTEN Fosfo-Hidrolase/genética , Proteínas Proto-Oncogênicas c-met/genética , Serina-Treonina Quinases TOR/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma/genética , Classe I de Fosfatidilinositol 3-Quinases , Análise Mutacional de DNA , Neoplasias do Endométrio/genética , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Genes ras , Humanos , Imuno-Histoquímica , Antígeno Ki-67/metabolismo , Ligantes , Repetições de Microssatélites/genética , Pessoa de Meia-Idade , Mutação , Fosfatidilinositol 3-Quinases/genética , Estudos RetrospectivosRESUMO
Resistance to apoptosis is a recurrent theme in colon cancer. We have shown previously that the 7-transmembrane spanning receptor OX1R for orexins promotes robust apoptosis in the human colon cancer cell line HT29 through an entirely novel mechanism involving phosphorylation of tyrosine-based motifs in OX1R. Here, we investigated the status of OX1R in a large series of human colorectal tumors and hepatic metastases. All primary colorectal tumors regardless of their localization and Duke's stages and all hepatic metastases tested expressed OX1R mRNA and/or protein. In sharp contrast, adjacent normal colonocytes or hepatocytes as well as control normal tissues were negative. Next, we showed that nine human colon cancer cell lines established from primary tumors or metastases expressed OX1R mRNA and underwent important apoptosis on orexin-A challenge. Most interestingly, orexin-A also promoted robust apoptosis in cells that are resistant to the most commonly used drug in colon cancer chemotherapy, 5-fluorouracil. When human colon cancer cells were xenografted in nude mice, orexin-A administered at day 0 strongly slowed the tumor growth and even reversed the development of established tumors when administered 7 days after cell inoculation. Orexin-A also acts by promoting tumor apoptosis in vivo because caspase-3 is activated in tumors on orexin treatment of nude mice. These findings support that OX1R is an Achilles heel of colon cancers, even after metastasis or chemoresistance. They suggest that OX1R agonists might be novel candidates for colon cancer therapy.
Assuntos
Apoptose/fisiologia , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/secundário , Neuropeptídeos/metabolismo , Receptores Acoplados a Proteínas G/biossíntese , Receptores de Neuropeptídeos/biossíntese , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Adenocarcinoma/secundário , Animais , Células CACO-2 , Linhagem Celular Tumoral , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/genética , Resistencia a Medicamentos Antineoplásicos , Fluoruracila/farmacologia , Células HCT116 , Células HT29 , Humanos , Neoplasias Hepáticas/genética , Receptores de Orexina , Orexinas , Ratos , Receptores Acoplados a Proteínas G/genética , Receptores de Neuropeptídeos/genéticaRESUMO
High prevalence of squamous anal lesions is linked to oncogenic human papillomavirus (HPV). Human immunodeficiency virus (HIV) promotes anal carcinogenesis. Epidermal growth factor receptor (EGFR), HER2/neu, c-Met, and vascular endothelial growth factor receptor-1 (VEGFR1) (tyrosine kinase growth factor receptors) are implicated in tumor progression, but little is known about their role in anal lesions. We investigated their expression and distribution in normal, dysplastic, and carcinomatous anal epithelium and then tried to analyze the effects on these variables of HPV and the HIV-positive status. Seventy-one HIV-positive and 47 HIV-negative patients were selected. We studied growth factor receptors, p16 and Ki67 expression, by in situ hybridization, fluorescent in situ hybridization (FISH) and chromogen in situ hybridization (CISH), immunocytochemistry, and morphological quantification in 226 lesions, either infected by HPV6 and 11 (31 condylomas acuminata) or infected with oncogenic HPVs (48 invasive cancers, 147 anal intraepithelial neoplasias). No HER2/neu was detected. Strong EGFR immunolabeling was not accompanied by gene amplification. The number and intensity of EGFR- and c-Met-immunoreactive cells increased significantly during lesion progression, highlighting the effects of oncogenic HPVs. EGFR, c-Met, VEGFR1, and p16 were coexpressed in 96% of invasive cancers. HIV-modified c-Met expression in condyloma acuminata (P < .008) and invasive cancers (P < .02). Strong HIV-related immunodeficiency and an absence of antiretroviral therapy increased c-Met and/or EGFR expression. HIV-positive anal cancers showed correlated c-Met and VEGFR1 (P < .003), strong p16 labeling, and an increased Ki67 proliferation. The finding that EGFR, c-Met, and VEGFR1 involved in carcinogenesis are well-represented and coexpressed in anal cancers, especially in HIV-positive population, suggests possible novel targeted treatments for anal diseases.
Assuntos
Neoplasias do Ânus/genética , Neoplasias do Ânus/virologia , Biomarcadores Tumorais/análise , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/virologia , Receptores de Fatores de Crescimento/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias do Ânus/patologia , Carcinoma de Células Escamosas/patologia , Inibidor p16 de Quinase Dependente de Ciclina/biossíntese , Inibidor p16 de Quinase Dependente de Ciclina/genética , Receptores ErbB/biossíntese , Receptores ErbB/genética , Feminino , HIV , Infecções por HIV/complicações , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Antígeno Ki-67/biossíntese , Antígeno Ki-67/genética , Masculino , Pessoa de Meia-Idade , Papillomaviridae , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/patologia , Proteínas Proto-Oncogênicas c-met/biossíntese , Proteínas Proto-Oncogênicas c-met/genética , Receptor ErbB-2/biossíntese , Receptor ErbB-2/genética , Receptores de Fatores de Crescimento/genética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/biossíntese , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/genéticaRESUMO
Thrombin is now recognized as an important factor in many cancers. Here, we examined the expression and role of the recently discovered thrombin receptor PAR4, in human colon cancer cells. PAR4 mRNA was found in 10 out of 14 (71%) human colon cancer cell lines tested but not in epithelial cells isolated from normal human colon. This finding is in line with immunostaining results of PAR4 in human colon tumors and its absence in normal human colonic mucosa. Investigation of the functional significance of the aberrant expression of PAR4 in colon cancer cells revealed (i) a prompt increase in intracellular calcium concentration on challenge with PAR4-specific agonist AP4 (100 microM) and (ii) marked mitogenic response (2.5-fold increase in cell number) in a dose-dependent manner on treatment with AP4 (0.1-300 microM). Analysis of the signaling pathways downstream of PAR4 activation in HT29 cells showed (i) a sustained phosphorylation of extracellular signal-related kinase 1/2 (ERK1/2) and (ii) the involvement of epidermal growth factor receptor B-2 (ErbB-2) but not of epidermal growth factor receptor in PAR4-induced mitogen-activated protein kinase activation. Tyrphostin AG1478, the ErbB inhibitor, reversed the action of AP4 on ERK1/2 and ErbB-2 phosphorylation and HT29 cell growth. Finally, the Src inhibitor PP2 abrogated ErbB-2 and ERK phosphorylation and HT29 cell proliferation, suggesting the essential role of Src activity in PAR4-induced phosphorylation of ErbB-2. These data highlight the role of PAR4 as a new important player in the control of colon tumors and underline the critical role of ErbB-2 transactivation.
Assuntos
Neoplasias do Colo/metabolismo , Receptor ErbB-2/metabolismo , Receptores de Trombina/metabolismo , Transdução de Sinais/fisiologia , Quinases da Família src/metabolismo , Western Blotting , Sinalização do Cálcio/efeitos dos fármacos , Sinalização do Cálcio/fisiologia , Linhagem Celular Tumoral , Proliferação de Células , Neoplasias do Colo/patologia , Inibidores Enzimáticos/farmacologia , Imunofluorescência , Células HT29 , Humanos , Imuno-Histoquímica , Imunoprecipitação , RNA Mensageiro/análise , Receptor ErbB-2/efeitos dos fármacos , Receptores de Trombina/efeitos dos fármacos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/efeitos dos fármacos , Ativação Transcricional , Quinases da Família src/efeitos dos fármacosRESUMO
BACKGROUND: Resistin and resistin-like molecule (RELM)beta comprise a novel class of cysteine-rich proteins secreted into the circulation implicated in hepatic insulin resistance and inflammation. RELMbeta is specifically produced by intestinal goblet cells but regulation of its expression and much of its local function are not elucidated. RELMbeta has been suggested to regulate colonic inflammation susceptibility, which is dependent on the mucosal barrier integrity. METHODS: In this work we explored the physiopathological role of RELMbeta in the colon. Among agents tested, carbachol and gastrin were strong inhibitors of RELMbeta mRNA accumulation. We examined the effect of recombinant RELMbeta on mucin secretion by human mucus-secreting HT29-Cl.16E cells in culture and by mouse colonic goblet cells in vivo. RESULTS: RELMbeta upregulated MUC2 and M1/MUC5AC gene expression in HT29-Cl.16E cells. RELMbeta enhanced M1/MUC5AC secretion by human colonic HT29-Cl.16E cells and MUC2 secretion by murine intestinal goblet cells. RELMbeta exerted its action exclusively on the apical side of HT29-Cl.16E cells, in agreement with its luminal mucosecretagogue effect in mice. Its action required calcium, protein kinase C, tyrosine kinases, and extracellular-regulated protein kinase activities and was synergized by carbachol. An intracolonic RELMbeta challenge was performed in the trinitrobenzene sulfonic acid (TNBS)-murine model of colitis and macroscopic and histological scores were monitored. The macroscopic and histopathological severity of TNBS-induced colitis was significantly attenuated by RELMbeta pretreatment. CONCLUSIONS: A direct participation in maintaining the mucosal defense barrier can be ascribed to RELMbeta in line with a regulatory role in intestinal inflammation.
Assuntos
Colite/fisiopatologia , Hormônios Ectópicos/fisiologia , Mucosa Intestinal/metabolismo , Muco/metabolismo , Ácido Trinitrobenzenossulfônico , Animais , Western Blotting , Cálcio/fisiologia , Carbacol/farmacologia , Células Cultivadas , Colite/induzido quimicamente , Colite/patologia , Gastrinas/farmacologia , Expressão Gênica , Células Caliciformes/metabolismo , Hormônios Ectópicos/genética , Hormônios Ectópicos/farmacologia , Humanos , Peptídeos e Proteínas de Sinalização Intercelular , Intestinos , Camundongos , Mucina-5AC , Mucina-2 , Mucinas/genética , Proteína Quinase C/fisiologia , Proteínas Quinases/fisiologia , Proteínas Tirosina Quinases/fisiologia , RNA Mensageiro/efeitos dos fármacos , Proteínas Recombinantes/farmacologia , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
BACKGROUND: The BRCA1 caretaker gene is associated with poor prognostic features in hereditary breast cancer and may also play a role in sporadic breast cancer (SBC). HER-1 and HER-2 overexpression is associated with adverse prognosis in SBC. We studied whether BRCA1 expression was associated with HER1, HER2 and other prognostic features in SBC. PATIENTS AND METHODS: Fifty newly-diagnosed SBC patients were studied for prognostic features and immunohistochemical expressions of BRCA1, HER-1 and HER-2. RESULTS: Tumors were positive for BRCA1 in 26%, HER-1 in 32% and HER-2 in 20% of cases. Lack of BRCA1 expression was associated with node metastases and decreased estrogen receptor. HER-2 expression was associated with young age, HER-1, Ki67 and decreased hormone receptors. No correlation was observed between BRCA1 and HER-1 or HER-2. CONCLUSION: In SBC, the lack of BRCA1 expression was associated with poor prognostic features, but unrelated to HER-1 and HER-2. HER2 and HER-1 were, however, highly correlated.
Assuntos
Proteína BRCA1/biossíntese , Neoplasias da Mama/metabolismo , Receptores ErbB/biossíntese , Receptor ErbB-2/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , Proteína BRCA1/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Receptores ErbB/genética , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Prognóstico , Receptor ErbB-2/genéticaRESUMO
PURPOSE: Increasing risk of squamous cervical intraepithelial neoplasia (CIN) exits in HIV-infected women. However, the relatively low incidence of invasive carcinoma in the untreated HIV-infected population suggests an imbalance between cell proliferation and apoptosis. We investigated apoptosis and caspases in cervical samples from this population comparatively to non-HIV-infected and control subjects. EXPERIMENTAL DESIGN: Apoptotic terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling method, immunohistochemistry for caspase-2, caspase-3, caspase-8, caspase-9, and other apoptosis markers were done on 12 normal cervical samples and 103 low- and high-grade cervical lesions, containing human papillomavirus(es) from 35 HIV-negative and 33 HIV-positive women before tritherapy advent. RESULTS: (a) The apoptotic index (AI) in epithelial cells did not vary between normal mucosa and condyloma acuminata infected or not with HIV. (b) AI augmented with the CIN severity in HIV-positive and HIV-negative women. (c) AI dramatically increased in oncogenic human papillomavirus-infected CIN of HIV-positive population compared with the CIN of similar grade in HIV-negative one. This was associated with a greater expression of caspase-8, active caspase-9, and active caspase-3 in those samples. Moreover, densities of Langerhans' cells, involved in apoptotic bodies engulfment, were greatly reduced in CIN of HIV-positive women. In samples, these densities were highly inversely correlated with AI (r = -0.88, P < 0.002). CONCLUSIONS: This study provides the first evidence for the strongly enhanced apoptosis levels and caspase expression in CIN of untreated HIV-infected women. We suggest that the reduction in Langerhans' cell number could contribute at least partly to apoptotic cell accumulation.
Assuntos
Apoptose , Infecções por HIV/complicações , Displasia do Colo do Útero/patologia , Neoplasias do Colo do Útero/patologia , Antígenos CD1/análise , Caspases/metabolismo , Epitélio/metabolismo , Epitélio/patologia , Epitélio/virologia , Feminino , Humanos , Imuno-Histoquímica , Células de Langerhans/metabolismo , Células de Langerhans/patologia , Células de Langerhans/virologia , Mucosa/metabolismo , Mucosa/patologia , Mucosa/virologia , Papillomaviridae , Infecções por Papillomavirus/metabolismo , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Neoplasias do Colo do Útero/complicações , Displasia do Colo do Útero/complicaçõesRESUMO
BACKGROUND & AIMS: Recent studies suggest that leptin, a hormone involved in food intake regulation, released into the circulation and gastrointestinal juice, may be a growth factor for intestine and may be involved in carcinogenesis; however, data are contradictory. This study investigates in rat colonic mucosa (1) the effects of hyperleptinemia on epithelial cell proliferation and development of aberrant crypts, earliest preneoplastic lesions, and (2) whether luminal leptin affects cell proliferation. METHODS: Leptin (1 mg/kg/d) or vehicle was administered systemically by miniosmotic pump in Fischer 344 rats either for 7 days (BrdU-labeling indices study) or 23 days (azoxymethane-induced colonic lesions study). The effects of injections or continuous infusion of leptin into the colon were also studied. RESULTS: In systemic leptin-treated rats, plasma leptin levels were 4- to 5-fold increased (P < 0.008 to P < 0.001); labeling indices were higher in proximal colon than in pair-fed control rats (P = 0.006) but unaffected in distal colon. Unexpectedly, in azoxymethane-treated rats, leptin significantly inhibited aberrant crypt foci formation in the middle and distal colon compared with controls (P = 0.006). Under these conditions, plasma insulin levels were reduced by 41%-58%, but gastrin levels were unchanged. In controls, luminal immunoreactive leptin reached the colon. A 3.6-fold increase in intraluminal leptin had no effect on epithelial cell proliferation. CONCLUSIONS: This study provides the first evidence that leptin reduces the development of chemically induced precancerous lesions in colon, perhaps through decreased insulinemia, and thus does not support an important role for leptin in carcinogenesis promotion. Moreover, the study indicates that leptin is not a potent growth factor for normal intestine.
Assuntos
Azoximetano , Carcinógenos , Neoplasias do Colo/induzido quimicamente , Neoplasias do Colo/prevenção & controle , Mucosa Intestinal/efeitos dos fármacos , Leptina/farmacologia , Lesões Pré-Cancerosas/induzido quimicamente , Lesões Pré-Cancerosas/prevenção & controle , Animais , Divisão Celular/efeitos dos fármacos , Neoplasias do Colo/patologia , Bombas de Infusão , Injeções , Mucosa Intestinal/patologia , Leptina/administração & dosagem , Masculino , Lesões Pré-Cancerosas/patologia , Ratos , Ratos Endogâmicos F344 , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/farmacologiaRESUMO
The traditional view on the role of serine proteases in tumor biology has changed with the recent discovery of a family of protease-activated receptors (PARs). In this study we explored the expression and functional role of the thrombin receptor PAR-1 in human colon cancer cells. Reverse transcriptase-polymerase chain reaction analysis showed that PAR-1 mRNAs are present in 11 of 14 human colon cancer cell lines tested but not in normal human colonic epithelial cells. This is in line with the immunolocalization of PAR-1 in human colon tumors and its absence in normal human colonic mucosa. The functional significance of the aberrant expression of PAR-1 in colon cancer cells was then investigated. We found that 1) a prompt increase in intracellular calcium concentration was observed on thrombin (10 nmol/L) or PAR-1 agonist AP1 (100 micro mol/L) challenge of HT29 cells; 2) HT29 quiescent cells treated with thrombin (0.01 to 20 nmol/L) or AP1 (1 to 300 micro mol/L) exhibited dramatic mitogenic responses (3.5-fold increase in cell number). Proliferative effects of thrombin or AP1 were also observed in other colon cancer cell lines expressing PAR-1. This effect was reversed by the MEK inhibitor PD98059 in consonance with the ability of thrombin or AP1 to induce phosphorylation of p42/p44 extracellular-regulated protein kinases. 3) PAR-1 activation by thrombin or AP1 led to a two-fold increase in cell motility of wounded HT29-D4. Our results demonstrate for the first time the aberrant expression of the functional thrombin receptor PAR-1 in colon cancers and its important involvement in cell proliferation and motility. Thrombin should now be considered as a growth factor for human colon cancer.
Assuntos
Neoplasias do Colo/patologia , Neoplasias do Colo/fisiopatologia , Regulação Neoplásica da Expressão Gênica , Receptores de Trombina/genética , Cálcio/análise , Divisão Celular , Movimento Celular , Neoplasias do Colo/genética , Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Hirudinas/farmacologia , Humanos , Cinética , Receptor PAR-1 , Receptores de Trombina/efeitos dos fármacos , Receptores de Trombina/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Trombina/farmacologia , Células Tumorais CultivadasRESUMO
PURPOSE: High prevalence of squamous cervical intraepithelial neoplasia (CIN) linked to oncogenic human papillomavirus (HPV) exits in HIV-infected women. Hepatocyte growth factor (HGF) and its receptor, c-Met, promote cell proliferation and are involved in tumor progression. Nothing is yet known about their expression in low- and high-grade CIN. Therefore, the expression, localization, and behavior of HGF and c-Met in normal and dysplastic cervical epithelium were investigated. EXPERIMENTAL DESIGN: We studied normal cervical mucosa from 10 healthy women, and low- and high-grade cervical lesions, uninfected (condyloma acuminata) or infected with oncogenic HPVs, from 40 HIV-negative and 48 HIV-positive women, using in situ molecular techniques, immunocytochemistry and morphoquantitative methods. RESULTS: In 154 oncogenic HPV-infected CIN encountered in biopsy samples, the total number of epithelial cell layers increased significantly during lesion progression. This number was significantly higher in HIV-positive than in HIV-negative women for CIN1 and CIN2 (P < 0.025 to P < 0.01). In HIV-negative women, the number and percentage of HGF and c-Met immunostained cell layers, and the intensity of immunostaining were enhanced in oncogenic HPV-infected lesions as compared with normal mucosa and condyloma acuminata. The latter parameters were significantly higher in tissues of HIV-positive women (oncogenic HPV-infected CIN1 and CIN2, normal-appearing mucosa contiguous to CIN, condyloma acuminata) than in the corresponding tissues of HIV-negative women (P < 0.025 to P < 0.0001). CONCLUSIONS: Overexpression of HGF/c-Met complex strongly correlates with oncogenic HPV and HIV infection. This overexpressed complex may stimulate cell proliferation in condyloma acuminata and participate in tumor progression in oncogenic HPV-infected lesions.