RESUMO
Dickkopf (Dkk) family members are known as Wnt modulators involved in the development, cell growth/differentiation and cancer. REIC/Dkk-3, which does not interfere with Wnt signalling, has been proposed to be a tumor suppressor gene, but its physiological function has remained unclear. In this study, we analysed the expression of REIC/Dkk-3 in normal interfollicular epidermis (IFE) and hyperproliferative epidermis. REIC/Dkk-3 was expressed in human and mouse IFE, being localized at the interface of upper spinous layer and granular layer. Skin cancer cell lines lost REIC/Dkk-3 expression as reported previously. When we analysed patient samples, REIC/Dkk-3 expression was down-regulated in the hyperproliferative epidermis including skin cancers and non-cancerous proliferative diseases. REIC/Dkk-3 expression was also suppressed in the regenerative and inflammative epidermis of model mice. These findings will certainly contribute to the extension of studies on REIC/Dkk-3.
Assuntos
Epiderme/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Ceratose/metabolismo , Dermatopatias Papuloescamosas/metabolismo , Neoplasias Cutâneas/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Animais , Linhagem Celular Tumoral , Quimiocinas , Regulação para Baixo/fisiologia , Embrião de Mamíferos/metabolismo , Epiderme/embriologia , Folículo Piloso/metabolismo , Humanos , Inflamação/induzido quimicamente , Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Acetato de Tetradecanoilforbol/farmacologia , Cicatrização/fisiologiaRESUMO
Expression levels of the novel tumor suppressor gene REIC/Dkk-3 are reduced in many human cancers. We have previously showed that an adenovirus vector carrying REIC/Dkk-3 (Ad-REIC) induced apoptosis of cancer cells selectively and exerted bystander antitumor effects via ER stress. We examined possible effects of Ad-REIC in a peritoneal dissemination model of scirrhous gastric carcinoma (SGC). Among various types of gastric cancer, SGC continues to be associated with the worst prognosis due to a high incidence of metastases in the peritoneal cavity. We found that a single intraperitoneal injection of Ad-REIC suppressed tumor dissemination and disease progression. Immunomodulation by Ad-REIC led to recruitment of natural killer cells inside tumor nodules. We conclude that Ad-REIC gene therapy may be a potential tool in combinatorial approaches to achieve curative effects in SGC.
Assuntos
Adenocarcinoma Esquirroso/terapia , Terapia Genética , Vetores Genéticos/administração & dosagem , Peptídeos e Proteínas de Sinalização Intercelular/genética , Neoplasias Peritoneais/terapia , Neoplasias Gástricas/terapia , Proteínas Adaptadoras de Transdução de Sinal , Adenocarcinoma Esquirroso/genética , Adenocarcinoma Esquirroso/patologia , Adenoviridae/genética , Animais , Apoptose , Western Blotting , Linhagem Celular Tumoral , Quimiocinas , Feminino , Humanos , Técnicas Imunoenzimáticas , Injeções Intraperitoneais , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Peritoneais/genética , Neoplasias Peritoneais/secundário , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologiaRESUMO
We previously showed that the tumor suppressor gene REIC/Dkk-3, when overexpressed by an adenovirus (Ad-REIC), exhibited a dramatic therapeutic effect on human cancers through a mechanism triggered by endoplasmic reticulum stress. Adenovirus vectors show no target cell specificity and thus may elicit unfavorable side effects through infection of normal cells even upon intra-tumoral injection. In this study, we examined possible effects of Ad-REIC on normal cells. We found that infection of normal human fibroblasts (NHF) did not cause apoptosis but induced production of interleukin (IL)-7. The induction was triggered by endoplasmic reticulum stress and mediated through IRE1alpha, ASK1, p38, and IRF-1. When Ad-REIC-infected NHF were transplanted in a mixture with untreated human prostate cancer cells, the growth of the cancer cells was significantly suppressed. Injection of an IL-7 antibody partially abrogated the suppressive effect of Ad-REIC-infected NHF. These results indicate that Ad-REIC has another arm against human cancer, an indirect host-mediated effect because of overproduction of IL-7 by mis-targeted NHF, in addition to its direct effect on cancer cells.
Assuntos
Fibroblastos/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Interleucina-7/metabolismo , Neoplasias/patologia , Proteínas Adaptadoras de Transdução de Sinal , Adenoviridae , Animais , Linhagem Celular Tumoral , Proliferação de Células , Quimiocinas , Retículo Endoplasmático/patologia , Fibroblastos/enzimologia , Humanos , Fator Regulador 1 de Interferon/metabolismo , MAP Quinase Quinase Quinase 5/metabolismo , Camundongos , Fator de Transcrição STAT1/metabolismo , Transdução de Sinais , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
In the present study, we examined the possible utility of a three-dimensional culture system using a thermo-reversible gelation polymer to isolate and expand neural stem cells (NSCs). The polymer is a synthetic biologically inert polymer and gelates at temperatures higher than the gel-sol transition point ( approximately 20 degrees C). When fetal mouse brain cells were inoculated into the gel, spherical colonies were formed ( approximately 1% in primary culture and approximately 9% in passage cultures). The spheroid-forming cells were positive for expression of the NSC markers nestin and Musashi. Under conditions facilitating spontaneous neural differentiation, the spheroid-forming cells expressed genes characteristic to astrocytes, oligodendrocytes, and neurons. The cells could be successively propagated at least to 80 poly-D-lysines over a period of 20 weeks in the gel culture with a growth rate higher than that observed in suspension culture. The spheroids formed by fetal mouse brain cells in the gel were shown to be of clonal origin. These results indicate that the spheroid culture system is a convenient and powerful tool for isolation and clonal expansion of NSCs in vitro.
