RESUMEN
Matrix metalloproteinases (MMPs) and the epithelial-mesenchymal transition (EMT) contribute to metastasis. As shown in our previous studies, interleukin-6 (IL-6) induces ATM phosphorylation to increase MMP expression and metastasis in lung cancer. However, the exact roles of ATM activation in the IL-6-induced epithelial-mesenchymal transition and lung cancer metastasis are currently unclear. Here, ATM phosphorylation exerts its pro-metastatic effect via vimentin-mediated epithelial-mesenchymal transition, which was supported by the evidence described below. Firstly, IL-6 treatment increases vimentin expression via the ATM-NF-κB pathway. Second, ATM inactivation not only abolishes IL-6-induced increases in vimentin expression but also inhibits IL-6-induced nest formation in a xenograft lung metastasis model. Moreover, close positive correlations were observed between ATM phosphorylation and vimentin upregulation, IL-6 levels and metastasis in lung cancer specimens. Hence, ATM modulates vimentin expression to facilitate IL-6-induced epithelial-mesenchymal transition and metastasis in lung cancer, indicating that ATM and vimentin might be potential therapeutic targets for inflammation-associated lung cancer metastasis.
Asunto(s)
Proteínas de la Ataxia Telangiectasia Mutada/metabolismo , Transición Epitelial-Mesenquimal/efectos de los fármacos , Interleucina-6/farmacología , Neoplasias Pulmonares/patología , Carcinoma Pulmonar de Células Pequeñas/patología , Vimentina/genética , Células A549 , Animales , Proteínas de la Ataxia Telangiectasia Mutada/genética , Línea Celular Tumoral , Activación Enzimática/efectos de los fármacos , Transición Epitelial-Mesenquimal/genética , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Metástasis de la Neoplasia , Carcinoma Pulmonar de Células Pequeñas/genética , Carcinoma Pulmonar de Células Pequeñas/metabolismo , Activación Transcripcional/efectos de los fármacos , Activación Transcripcional/genética , Vimentina/metabolismoRESUMEN
Despite that ataxia-telangiectasia mutated (ATM) is involved in IL-6 promoted lung cancer chemotherapeutic resistance and metastasis, the exact role of ATM in tumor necrosis factor-alpha (TNF-α) increasing tumor migration is still elusive. In the present study, we demonstrated that TNF-α promoted lung cancer cell migration by up-regulation of matrix metalloproteinase-13 (MMP-13). Notably, by gene silencing or kinase inhibition, we proposed for the first time that ATM is a key up-stream regulator of TNF-α activated ERK/p38-NF-κB pathway. The existence of TNF-α secreted in autocrine or paracrine manner by components of tumor microenvironment highlights the significance of TNF-α in inflammation-associated tumor metastasis. Importantly, in vivo lung cancer metastasis test showed that ATM depletion actually reduce the number of metastatic nodules and cancer nests in lung tissues, verifying the critical role of ATM in metastasis. In conclusion, our findings demonstrate that ATM, which could be activated by lung cancer-associated TNF-α, up-regulate MMP-13 expression and thereby augment tumor metastasis. Therefore, ATM might be a promising target for prevention of inflammation-associated lung cancer metastasis.
Asunto(s)
Proteínas de la Ataxia Telangiectasia Mutada/metabolismo , Regulación Neoplásica de la Expresión Génica , Neoplasias Pulmonares/metabolismo , Metaloproteinasa 13 de la Matriz/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Células A549 , Animales , Proteínas de la Ataxia Telangiectasia Mutada/genética , Células de la Médula Ósea/metabolismo , Línea Celular Tumoral , Movimiento Celular , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Femenino , Silenciador del Gen , Humanos , Inflamación , Leucocitos Mononucleares/citología , Metaloproteinasa 13 de la Matriz/genética , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Desnudos , FN-kappa B/metabolismo , Metástasis de la Neoplasia , ARN Interferente Pequeño/metabolismo , Bazo/citología , Regulación hacia ArribaRESUMEN
Our previous studies show that the phosphorylation of ataxia-telangiectasia mutated (ATM) induced by interleukin 6 (IL-6) treatment contributes to multidrug resistance formation in lung cancer cells, but the exact role of ATM activation in IL-6 increased metastasis is still elusive. In the present study, matrix metalloproteinase-3 (MMP-3) and MMP-13 were firstly demonstrated to be involved in IL-6 correlated cell migration. Secondly, IL-6 treatment not only increased MMP-3/MMP-13 expression but also augmented its activities. Thirdly, the inhibition of ATM phosphorylation efficiently abolished IL-6 up-regulating MMP-3/MMP-13 expression and increasing abilities of cell migration. Most importantly, the in vivo test showed that the inhibition of ATM abrogate the effect of IL-6 on lung cancer metastasis via MMP-3/MMP-13 down-regulation. Taken together, these findings demonstrate that IL-6 inducing ATM phosphorylation increases the expression of MMP-3/MMP-13, augments the abilities of cell migration, and promotes lung cancer metastasis, indicating that ATM is a potential target molecule to overcome IL-6 correlated lung cancer metastasis.
Asunto(s)
Proteínas de la Ataxia Telangiectasia Mutada/metabolismo , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Interleucina-6/farmacología , Neoplasias Pulmonares/secundario , Metaloproteinasa 13 de la Matriz/metabolismo , Metaloproteinasa 3 de la Matriz/metabolismo , Animales , Apoptosis/efectos de los fármacos , Proteínas de la Ataxia Telangiectasia Mutada/genética , Western Blotting , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Humanos , Técnicas para Inmunoenzimas , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/metabolismo , Metaloproteinasa 13 de la Matriz/genética , Metaloproteinasa 3 de la Matriz/genética , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Fosforilación/efectos de los fármacos , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Tumor necrosis factor-α-induced protein 8-like 2 (TNFAIP8L2, TIPE2), which belongs to the TNF-α-induced protein 8 family, is a negative regulator of immune homeostasis. Although pro-inflammatory cytokines such as TNF-α have been reported to be involved in liver carcinoma metastasis, the effect of TIPE2 on hepatocellular carcinoma metastasis remains unknown. We demonstrate that TNF-α clearly augments MMP-13/MMP-3 expression and promotes cell migration in HepG2 cells through activation of the Erk1/2-NF-κB pathways. Interestingly, in addition to human PBLs, macrophages and fibroblasts, liver cancer cells specifically express TNF-α following LPS treatment. Most importantly, TIPE2 overexpression efficiently abrogates the effects of LPS on TNF-α secretion and abolishes the effects of TNF-α on MMP-13/MMP-3 upregulation, cell migration and Erk1/2-NF-κB activation. Taken together, these findings demonstrate that TIPE2 was able to suppress TNF-α-induced hepatocellular carcinoma metastasis by inhibiting Erk1/2 and NF-κB activation, indicating that both TNF-α and TIPE2 might be potential targets for the treatment of HCC metastasis.
Asunto(s)
Carcinoma Hepatocelular/patología , Péptidos y Proteínas de Señalización Intracelular/fisiología , Neoplasias Hepáticas/patología , Factor de Necrosis Tumoral alfa/farmacología , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Movimiento Celular/efectos de los fármacos , Movimiento Celular/genética , Regulación hacia Abajo/efectos de los fármacos , Regulación hacia Abajo/genética , Células Hep G2 , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/genética , Metaloproteinasa 13 de la Matriz/metabolismo , Metaloproteinasa 3 de la Matriz/metabolismo , FN-kappa B/metabolismo , Metástasis de la Neoplasia , TransfecciónRESUMEN
Although it is known that ataxia-telangiectasia mutated (ATM) and interleukin 6 (IL-6) contribute to multiple drug resistance (MDR) in tumor chemotherapy, the exact role of ATM activation in MDR resulting from increased IL-6 expression is still unclear. In the present study, we demonstrate that the activation of the ATM-NF-kappaB pathway, resulting from increased IL-6 expression, plays a central role in augmented chemoresistance in lung cancer cell lines. This result was supported by the increased expressions of Bcl-2, Mcl-1, Bcl-xl, and the upregulation of MDR-associated protein ABCG2. The higher level of IL-6 reveals not only higher ATM/NF-kappaB activity but also increased expressions of ABCG2, Bcl-2, Mcl-1 and Bcl-xl. Most importantly, lung cancer cells themselves upregulated IL-6 secretion by activating the p38/NF-kappaB pathway through treatment with cisplatin and camptothecin. Taken together, these findings demonstrate that chemotherapeutic agents increase IL-6 expression, hence activating the ATM/NF-kappaB pathway, augmenting anti-apoptotic protein expression and contributing to MDR. This indicates that both IL-6 and ATM are potential targets for the treatment of chemotherapeutic resistance in lung cancer.