RESUMO
BACKGROUND: Accumulating evidence indicates that CD109, a glycosylphosphatidylinositol-anchored glycoprotein, is highly expressed in human epithelial carcinomas of multiple organs including the pancreas, but its functional role in carcinoma development has not yet been fully clarified. The aim of this study was to investigate the role of CD109 in the malignancy of pancreatic ductal adenocarcinoma (PDAC). METHODS: PDAC specimens of 145 cases were immunostained for CD109, and correlations between CD109 expression and clinicopathological conditions were analyzed. CD109 expression in PANC-1 cells, a PDAC-derived cell line, was decreased by siRNA or shRNA and its effect on the malignancy of PANC-1 cells was examined. RESULTS: Suppression of CD109 expression in PANC-1 cells resulted in reduction of in vitro cell motility and tumorigenicity in xenografts. Based on these results, we investigated the relationship between CD109 expression and metastasis of PDAC using tumor tissue specimens. Among 106 recurrent cases of 145 PDAC, there was a tendency for CD109-positive cases to be accompanied by distant metastasis. CONCLUSIONS: CD109 plays a critical role in the promotion of tumorigenic ability and cellular motility relating to metastasis of PDAC cells.
Assuntos
Antígenos CD/genética , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Proteínas de Neoplasias/genética , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Animais , Linhagem Celular Tumoral , Movimento Celular/genética , Feminino , Proteínas Ligadas por GPI/genética , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Metástase Neoplásica/genética , Metástase Neoplásica/patologia , RNA Interferente Pequeno/farmacologia , Cicatrização , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Carbonic anhydrase IX (CA9) is a membrane-associated carbonic anhydrase that regulates cellular pH, is upregulated in various solid tumors, and is considered to be a therapeutic target. Here, we describe the essential role of CA9 in the tumorigenicity of cells derived from human adult T-cell leukemia/lymphoma (ATL). We previously established the highly tumorigenic ST1-N6 subline from the ATL-derived ST1 cell line by serial xenotransplantation in NOG mice. In the present study, we first show that CA9 expression is strongly enhanced in ST1-N6 cells. We then sorted ST1 cells by high or low CA9 expression and established ST1-CA9high and ST1-CA9low sublines. ST1-CA9high cells, like ST1-N6 cells, were more strongly tumorigenic than ST1-CA9low or parental ST1 cells when injected into NOG mice. Knockdown of CA9 with shRNAs suppressed the ability of ST1-CA9high cells to initiate tumors, and the tumorigenicity of ST1 cells was significantly enhanced by introducing wild-type CA9 or a CA9 mutant with deletion of an intracytoplasmic domain. However, a CA9 with point mutations in the catalytic site did not increase the tumorigenicity of ST1 cells. Furthermore, we detected a small population of CA9+ CD25+ cells in lymph nodes of ATL patients. These findings suggest that CA9, and particularly its carbonic anhydrase activity, promotes the tumorigenicity of ATL-derived cells and may be involved in malignant development of lymphoma-type ATL.
Assuntos
Antígenos de Neoplasias/genética , Antígenos de Neoplasias/metabolismo , Anidrase Carbônica IX/genética , Anidrase Carbônica IX/metabolismo , Transformação Celular Neoplásica/patologia , Leucemia-Linfoma de Células T do Adulto/patologia , Animais , Domínio Catalítico/genética , Linhagem Celular Tumoral , Transformação Celular Neoplásica/genética , Humanos , Linfonodos/citologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Transplante de Neoplasias , Interferência de RNA , RNA Interferente Pequeno/genética , Transplante HeterólogoRESUMO
The transplantation of human cancer cells into immunodeficient NOD/SCID/IL-2Rγc(null) (NOG) mice often causes highly malignant cell populations like cancer stem cells to emerge. Here, by serial transplantation in NOG mice, we established two highly tumorigenic adult T-cell leukemia-derived cell lines, ST1-N6 and TL-Om1-N8. When transplanted s.c., these cells formed tumors significantly earlier and from fewer initial cells than their parental lines ST1 and TL-Om1. We found that protein kinase B (AKT) signaling was upregulated in ST1-N6 and TL-Om1-N8 cells, and that this upregulation was due to the decreased expression of a negative regulator, INPP5D. Furthermore, the introduction of a constitutively active AKT mutant expression vector into ST1 cells augmented the tumorigenicity of the cells, whereas treatment with the AKT inhibitor MK-2206 attenuated the progression of tumors induced by ST1-N6 cells. Collectively, our results reveal that the AKT signaling pathway plays a critical role in the malignancy of adult T-cell leukemia-derived cells.