Cell Metastatic Activity Research Articles

LINC00963-FOSB-mediated transcription activation of UBE3C enhances radioresistance of breast cancer cells by inducing ubiquitination-dependent protein degradation of TP73

BackgroundThe ubiquitin protein ligase E3C (UBE3C) has been reported to play an oncogenic role in breast cancer (BRCA). This work further investigates the effect of UBE3C on the radioresistance of BRCA cells.MethodsMolecules linking to radioresistance in BRCA were identified by analyzing two GEO datasets, GSE31863 and GSE101920. UBE3C overexpression or knockdown was induced in parental or radioresistant BRCA cells, followed by irradiation treatment. The malignant properties of cells in vitro, and the growth and metastatic activity of cells in nude mice, were analyzed. Downstream target proteins, as well as upstream transcriptional regulators of UBE3C, were predicted by bioinformatics tools. Molecular interactions were confirmed by immunoprecipitation and immunofluorescence assays. Furthermore, artificial alterations of TP73 and FOSB were induced in the BRCA cells for functional rescue assays.ResultsAccording to bioinformatics analyses, UBE3C expression was linked to radioresistance in BRCA. UBE3C knockdown in radioresistant BRCA cells reduced while its overexpression in parental BRCA cells increased the radioresistance of cells in vitro and in vivo. UBE3C, which induced ubiquitination-dependent protein degradation of TP73, was transcriptionally activated by FOSB. The radioresistance of cancer cells was blocked by TP73 overexpression or FOSB knockdown. Additionally, LINC00963 was found to be responsible for the recruitment of FOSB to the UBE3C promoter for transcription activation.ConclusionThis work demonstrates that LINC00963 induces nuclear translocation of FOSB and the consequent transcription activation of UBE3C, which enhances radioresistance of BRCA cells by inducing ubiquitination-dependent protein degradation of TP73.Graphical

Abstract A41: Inhibition of aberrant YAP and TAZ activity to prevent metastasis formation and growth

Abstract Metastasis causes most cancer-related deaths, and few effective therapies exist for patients with metastatic disease. The development of such therapies requires the identification of proteins essential for the spread and subsequent growth of metastatic cancer cells. Previous work from us and other groups has clearly demonstrated that aberrant YAP or TAZ activity, negatively regulated by the Hippo pathway, promotes cancer development and metastasis. Moreover, many human cancers have abnormally high YAP/TAZ expression or nuclear localization, and this is associated with poor prognosis. We hypothesize that targeting YAP and TAZ or upstream activators will prevent metastasis formation and growth, and we have developed and optimized in vivo model systems to test this. Using these methods, we show that YAP and TAZ are required for metastasis formation in human melanoma and breast cancer cells. An ongoing study using our in vivo metastatic growth assay and inducible YAP/TAZ RNAi is testing if YAP and TAZ are collectively required for metastatic growth after dissemination, and we hope to include the results of this study on our poster. In addition to directly targeting YAP and TAZ, we are also interested in identifying proteins that promote YAP/TAZ activity in metastatic cells, and this could lead to more therapeutic targets. Our recently published work shows that Src signaling can promote YAP/TAZ activity and enhance tumor growth and metastasis. Since integrins promote Src activity and regulate YAP and TAZ, we want to test if there are specific integrins required for YAP/TAZ activity in metastatic cells. Therefore, we used a YAP/TAZ-TEAD transcriptional activity reporter assay to perform an unbiased RNAi screen to identify integrins that regulate YAP/TAZ activity in metastatic melanoma and breast cancer cells. Knockdown of integrin subunits α2, α3, α6, and αV each reduced YAP/TAZ-TEAD transcriptional activity in metastatic breast cancer cells. These results have been confirmed with qPCR for the YAP/TAZ target genes CTGF and CRY61. Interestingly, a different set of integrin subunits appears to be required for YAP/TAZ-TEAD transcriptional activity in metastatic melanoma cells, suggesting the regulation of YAP and TAZ is not the same in different cancer types. Current work aims to use in vivo multiplex metastasis assays, which our lab has developed, to test if knockdown of each integrin either alone, or in combination, prevents metastasis formation and growth. Concurrently, we are focused on elucidating the mechanism by which these integrins enhance YAP/TAZ activity in metastatic cells. Collectively, these studies show the importance of YAP and TAZ and their upstream regulators in metastasis formation and growth and suggest that targeting YAP/TAZ activity may treat metastatic disease. Citation Format: Janine S.A. Warren, Emily Norton, John M. Lamar. Inhibition of aberrant YAP and TAZ activity to prevent metastasis formation and growth [abstract]. In: Proceedings of the AACR Special Conference on the Hippo Pathway: Signaling, Cancer, and Beyond; 2019 May 8-11; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(8_Suppl):Abstract nr A41.

TSGA10 Over Expression Decreases Metastasic and Metabolic Activity by Inhibiting HIF-1 in Breast Cancer Cells

HIF-1 is an important factor that play critical roles in metabolic and metastasis activity of cancer cells. HIF-1 activity can have regulated by TSGA10. Although decreased metastatic activity of cancer cells through TSGA10 inhibitory effect on HIF-1 have already been demonstrated, changes in cancer metabolism and its impact on metastasis in breast cancer is still not determined. So, we aimed to investigate TSGA10 overexpression effect on breast cancer metabolism as well as metastasis. TSGA10 vector was designed and stable transfected into MCF-7cells. The efficiency of transfection was assessed by Real-time PCR and western blot. After HIF-1 induction at high and low glucose conditions, cell proliferation, cell cycle profile, metabolic and metastasis activity of cells were assessed. Furthermore, biomarker expressions of ER, PR, HER2, Ki67 and E-cadherin in cancer cells were measured. Our results showed decrease of cell proliferation and cell cycle arrest in G2/M phase. Reduce expression of GLUT1, lactate production and reactive oxygen species (ROS) below their basal level indicated decreased metabolic activity. Furthermore, metastatic activity reduction was shown by decrease expression of different involve genes in metastasis, protelytic activity of MMOLP-2/9, carbonic anhydrase (CA) IX activity and increase of wound closure. Moreover, except for E-cadherin, expression of ER, PR, HER2 and Ki67 was declined in cells. Our findings indicated that TSGA10 overexpression could decrease the metastatic and metabolic activity of cancer cells through its inhibitory effect on HIF-1 activity. Therefore, TSGA10 could be considered in the research for therapeutic candidates in cancer.

CL-43, a New Inhibitor of HSF1 Activity, Inhibits Epithelial-Mesenchymal Transition of DLD1 Colon Cancer Cells

Colorectal cancer is highly metastatic. In a quarter of patients with tumors of this type, liver metastases are detected already at the time of diagnosis. Therefore, the search for drugs that can reduce the metastatic activity of cells is an important task. A tumor experiences constant stress, resulting in an increased activity of the transcription factor HSF1, which is able to trigger the synthesis of heat shock proteins. This increases the resistance of cancer cells to both stress and antitumor therapy. It has been shown recently that HSF1 plays a critical role in the process of the epithelial–mesenchymal transition (EMT) underling the formation of metastases. Here, we show that a new inhibitor of HSF1 activity, CL-43, is capable of suppressing EMT that is induced by TGFβ1. CL-43 significantly reduced the migration and proliferative potency of DLD1 cells treated with TGFβ1. Analysis of vimentin level showed that cell treatment with CL-43 cells reduced this EMT marker and returned the expression and localization of E-cadherin in the cells to the original pattern. These findings suggest that CL-43 has therapeutic potential for treatment of colorectal tumors.

Abstract C22: Differential Tks5 isoform expression contributes to metastatic invasion of lung adenocarcinoma

Abstract Metastasis accounts for the vast majority of cancer related deaths, yet the molecular mechanisms that drive metastatic spread remain poorly understood. Here we report that Tks5, which has been linked to formation of proteolytic cellular protrusions known as invadopodia, undergoes an isoform switch during metastatic progression in a genetically-engineered mouse model of lung adenocarcinoma. Non-metastatic primary tumor-derived cells predominantly expressed a short isoform Tks5short, while metastatic primary tumor- and metastasis-derived cells acquired increased expression of the full-length isoform Tks5long. This elevation of Tks5long-to-Tks5short ratio correlated with a commensurate increase in invadopodia activity in metastatic cells compared to non-metastatic cells. Further characterization of these isoforms by knockdown and over-expression experiments demonstrated that Tks5long promoted invadopodia in vitro and increased metastasis in transplant models and an autochthonous model of lung adenocarcinoma. Conversely, Tks5short decreased invadopodia stability and proteolysis, acting as a natural dominant-negative inhibitor to Tks5long. Importantly, high Tks5long and low Tks5short expressions in human lung adenocarcinomas correlated with metastatic disease and predicted worse survival of early-stage patients. These data indicate that tipping the Tks5 isoform balance to a high Tks5long-to-Tks5short ratio promotes invadopodia-mediated invasion and metastasis. Citation Format: Carman Man-Chung Li, Guoan Chen, Talya Dayton, Caroline Kim-Kiselak, David Beer, Monte Winslow, Tyler Jacks. Differential Tks5 isoform expression contributes to metastatic invasion of lung adenocarcinoma. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr C22.

Differential Tks5 isoform expression contributes to metastatic invasion of lung adenocarcinoma

Metastasis accounts for the vast majority of cancer-related deaths, yet the molecular mechanisms that drive metastatic spread remain poorly understood. Here we report that Tks5, which has been linked to the formation of proteolytic cellular protrusions known as invadopodia, undergoes an isoform switch during metastatic progression in a genetically engineered mouse model of lung adenocarcinoma. Nonmetastatic primary tumor-derived cells predominantly expressed a short isoform, Tks5short, while metastatic primary tumor- and metastasis-derived cells acquired increased expression of the full-length isoform Tks5long. This elevation of Tks5long to Tks5short ratio correlated with a commensurate increase in invadopodia activity in metastatic cells compared with nonmetastatic cells. Further characterization of these isoforms by knockdown and overexpression experiments demonstrated that Tks5long promoted invadopodia in vitro and increased metastasis in transplant models and an autochthonous model of lung adenocarcinoma. Conversely, Tks5short decreased invadopodia stability and proteolysis, acting as a natural dominant-negative inhibitor to Tks5long. Importantly, high Tks5long and low Tks5short expressions in human lung adenocarcinomas correlated with metastatic disease and predicted worse survival of early stage patients. These data indicate that tipping the Tks5 isoform balance to a high Tks5long to Tks5short ratio promotes invadopodia-mediated invasion and metastasis.