DEK promotes the proliferation and invasion of lung cancers and indicates poor prognosis in lung adenocarcinomas

Novel molecular mechanisms in Alzheimer’s disease: The potential role of DEK in disease pathogenesis

Alzheimer’s disease and age-related dementias (AD/ADRD) are debilitating diseases that exact a significant physical, emotional, cognitive, and financial toll on the individual and their social network. While genetic risk factors for early-onset AD have been identified, the molecular and genetic drivers of late-onset AD, the most common subtype, remain a mystery. Current treatment options are limited for the 35 million people in the United States with AD/ADRD. Thus, it is critically important to identify novel molecular mechanisms of dementia-related pathology that may be targets for the development of new interventions. Here, we summarize the overarching concepts regarding AD/ADRD pathogenesis. Then, we highlight one potential molecular driver of AD/ADRD, the chromatin remodeling protein DEK. We discuss in vitro, in vivo, and ex vivo findings, from our group and others, that link DEK loss with the cellular, molecular, and behavioral signatures of AD/ADRD. These include associations between DEK loss and cellular and molecular hallmarks of AD/ADRD, including apoptosis, Tau expression, and Tau hyperphosphorylation. We also briefly discuss work that suggests sex-specific differences in the role of DEK in AD/ADRD pathogenesis. Finally, we discuss future directions for exploiting the DEK protein as a novel player and potential therapeutic target for the treatment of AD/ADRD.

p21-activated kinase 2 binds to transcription factor SOX2 and up-regulates DEK to promote the progression of lung squamous cell carcinoma

Lung squamous cell carcinoma (LSCC) is a prevalent and progressive subtype of lung cancer. This study aimed to substantiate the regulatory effect of the PAK2/SOX2/DEK axis on the LSCC development. LSCC tissues (n = 83) and adjacent normal tissues were collected and SOX2 expression was determined by qRT-PCR and Western blotting. Correlation between SOX2 expression and the prognosis of LSCC patients was then explored utilizing Kaplan-Meier analysis. Co-immunoprecipitation and glutathione-S-transferase pull-down assays were conducted to validate the binding of SOX2 to DEK. Gain- and loss- of function assays were then performed on LSCC cells, with CCK-8 and Transwell assays applied to detect the malignant behaviors of cells. A mouse xenograft model of LSCC was further established for in vivo validation. The expression levels of SOX2, PAK2 and DEK were up-regulated in LSCC tissues and cells. SOX2 overexpression was correlated with poor prognosis of LSCC patients. Knockdown of SOX2 weakened the viability and the migratory and invasive potential of LSCC cells. Further, PAK2 directly interacted with SOX2. PAK2 overexpression accelerated the malignant phenotypes of LSCC cells through interplay with SOX2. Moreover, SOX2 activated the expression of DEK, and silencing DEK attenuated the malignant behaviors of LSCC cells. In conclusion, PAK2 could bind to the transcription factor SOX2 and thus activate the expression of DEK, thereby driving the malignant phenotypes of LSCC cells both in vivo and in vitro.

Crowberry inhibits cell proliferation and migration through a molecular mechanism that includes inhibition of DEK and Akt signaling in cholangiocarcinoma

Background

Cholangiocarcinoma (CCA) is a rare biliary adenocarcinoma related to poor clinical prognosis. Crowberry is an herbal medicine used to control inflammatory diseases and reestablish antioxidant enzyme activity. Although crowberry shows significant therapeutic efficacy in various tumors and diseases, its anticancer effects and specific molecular mechanisms in CCA are poorly understood.

Aim of the study

This study was conducted to characterize crowberry effects on CCA cells behavior.

Materials and methods

The chemical profiles of crowberry extract was qualitatively analyzed by high-performance liquid chromatography (HPLC) and HPLC–tandem mass spectrometry. MTT, colony formation and EdU assays were performed to measure cell proliferation. The effect of crowberry treatment on CCA cell migration was assessed by wound healing and migration assays. Moreover, Hoechst staining assay and flow cytometry were performed to assess the cell apoptosis rate. Western blotting was used to assess the protein expression levels of key factors associated with apoptosis, the Akt signaling pathway, and the epithelial-mesenchymal transition. A xenograft model was established and immunohistochemical and H&E staining was performed to assess crowberry antitumor effects in vivo.

Results

Crowberry clearly inhibited CCA cells proliferation and migration in a dose-dependent manner and induced apoptosis in vitro. Crowberry inactivated the PI3K/Akt signaling pathway by regulating DEK in vitro and significantly inhibited tumor growth by downregulating the DEK expression in xenograft models.

Conclusion

Crowberry inhibits CCA cells proliferation and migration through a molecular mechanism that includes inhibition of DEK and Akt signaling pathway inhibition in vitro and in vivo.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-022-00623-6.

Crowberry alterd expression levels of key mediators in PI3K/Akt signaling pathway.

Crowberry alterd expression levels of key mediators in PI3K/Akt signaling pathway.

Crowberry suppressed the expression of the proto-oncogene DEK in vivo and in vitro.

Crowberry inhibited CCA progression and migration through a molecular mechanism that includes inhibition of DEK and the Akt signaling pathway in vivo and in vitro.

Long Noncoding RNA NR2F1-AS1 Enhances the Migration and Invasion of Hepatocellular Carcinoma via Modulating miR-642a/DEK Pathway

Purpose

Hepatocellular carcinoma (HCC), a malignant tumor that exists worldwide, has a high morbidity and mortality rate. Previous studies have reported that lncRNA NR2F1-AS1 plays a critical role in several cancers. Here, we aimed to investigate the biological function of NR2F1-AS1 and its molecular mechanism in the migration and invasion of HCC.

Methods

Quantitative real-time PCR (qRT-PCR) was performed to analyze NR2F1-AS1 expression in HCC. The biological function was investigated by transwell invasion and migration assays. The protein level was identified by Western blot. In addition, the downstream targets of NR2F1-AS1 and miR-642a were confirmed by luciferase reporter assays.

Results

NR2F1-AS1 was significantly upregulated in HCC and associated with the poor prognosis of HCC patients. Biological function experiments revealed that the silence of NR2F1-AS1 suppressed cell invasion and migration in HCC. More importantly, NR2F1-AS1 directly interacted with miR-642a and negatively regulated miR-642a. DEK was the target of miR-642a, and NR2F1-AS1 positively regulated DEK expression by suppressing miR-642a.

Conclusion

Taken together, it is the first time we discovered the interaction of NR2F1-AS1 with miR-642a in modulating HCC cell invasion and migration.

DEK Expression in Breast Cancer Cells Leads to the Alternative Activation of Tumor Associated Macrophages

Breast cancer (BC) is the second leading cause of cancer deaths among women. DEK is a known oncoprotein that is highly expressed in over 60% of breast cancers and is an independent marker of poor prognosis. However, the molecular mechanisms by which DEK promotes tumor progression are poorly understood. To identify novel oncogenic functions of DEK, we performed RNA-Seq analysis on isogenic Dek-knockout and complemented murine BC cells. Gene ontology analyses identified gene sets associated with immune system regulation and cytokine-mediated signaling and differential cytokine and chemokine expression was confirmed across Dek-proficient versus Dek-deficient cells. By exposing murine bone marrow-derived macrophages (BMDM) to tumor cell conditioned media (TCM) to mimic a tumor microenvironment, we showed that Dek-expressing breast cancer cells produce a cytokine milieu, including up-regulated Tslp and Ccl5 and down-regulated Cxcl1, Il-6, and GM-CSF, that drives the M2 polarization of macrophages. We validated this finding in primary murine mammary tumors and show that Dek expression in vivo is also associated with increased expression of M2 macrophage markers in murine tumors. Using TCGA data, we verified that DEK expression in primary human breast cancers correlates with the expression of several genes identified by RNA-Seq in our murine model and with M2 macrophage phenotypes. Together, our data demonstrate that by regulating the production of multiple secreted factors, DEK expression in BC cells creates a potentially immune suppressed tumor microenvironment, particularly by inducing M2 tumor associated macrophage (TAM) polarization.