The core pathology of coronavirus disease 2019 (COVID-19) is infection of airway cells by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that results in excessive inflammation and ...respiratory disease, with cytokine storm and acute respiratory distress syndrome implicated in the most severe cases. Thrombotic complications are a major cause of morbidity and mortality in patients with COVID-19. Patients with pre-existing cardiovascular disease and/or traditional cardiovascular risk factors, including obesity, diabetes mellitus, hypertension and advanced age, are at the highest risk of death from COVID-19. In this Review, we summarize new lines of evidence that point to both platelet and endothelial dysfunction as essential components of COVID-19 pathology and describe the mechanisms that might account for the contribution of cardiovascular risk factors to the most severe outcomes in COVID-19. We highlight the distinct contributions of coagulopathy, thrombocytopathy and endotheliopathy to the pathogenesis of COVID-19 and discuss potential therapeutic strategies in the management of patients with COVD-19. Harnessing the expertise of the biomedical and clinical communities is imperative to expand the available therapeutics beyond anticoagulants and to target both thrombocytopathy and endotheliopathy. Only with such collaborative efforts can we better prepare for further waves and for future coronavirus-related pandemics.
The expression of carbonic anhydrase XII (CA12) is associated with the expression of estrogen receptor alpha (ERα) in breast cancer and is linked to a good prognosis with a lower risk of metastasis. ...Transcription Factor Activator Protein 2γ (TFAP2C, AP-2γ) governs luminal breast cancer phenotype through direct and indirect regulation of ERα and ERα-associated genes, GATA3, FOXA1, EGFR, CDH1, DSP, KRT7, FBP1, MYB, RET, KRT8, MUC1, and ERBB2-genes which are responsible for the luminal signature in breast cancer. Herein, utilizing chromatin immunoprecipitation and direct sequencing (ChIP-seq), we show that CA12 is regulated by AP-2γ through binding with its promoter region in luminal breast cancer cell lines and indirectly through a distal estrogen-responsive region in ERα-positive cell lines by upregulation of ERα. CA12 is transcriptionally silenced in basal breast cancer cell lines through histone deacetylation and CpG methylation of the promoter region and can be re-activated with Trichostatin A (histone deacetylase inhibitor) and/or 5-aza-dC (an inhibitor of DNA methylation). Strong concordance in co-expression of CA12 and ESR1 (R
= 0.1128, p = 0486) and TFAP2C (R
= 0.1823, p = 0.0105) was found using a panel of primary breast tumor samples (n = 35), supporting a synergetic role of AP-2γ and ERα in activation of CA12. Our results highlight the essential role of AP-2γ in maintaining the luminal breast cancer phenotype and provide evidence that epigenetic mechanisms silence luminal gene expression in the basal phenotype. Additional studies to decipher mechanisms that drive epigenetic silencing of AP-2γ target genes are a critical area for further research.
Many solid cancers have an expanded CD44+/hi/CD24−/low cancer stem cell (CSC) population, which are relatively chemoresistant and drive recurrence and metastasis. Achieving a more durable response ...requires the development of therapies that specifically target CSCs. Recent evidence indicated that inhibiting the SUMO pathway repressed tumor growth and invasiveness, although the mechanism has yet to be clarified. Here, we demonstrate that inhibition of the SUMO pathway repressed MMP14 and CD44 with a concomitant reduction in cell invasiveness and functional loss of CSCs in basal breast cancer. Similar effects were demonstrated with a panel of E1 and E3 SUMO inhibitors. Identical results were obtained in a colorectal cancer cell line and primary colon cancer cells. In both breast and colon cancer, SUMO-unconjugated TFAP2A mediated the effects of SUMO inhibition. These data support the development of SUMO inhibitors as an approach to specifically target the CSC population in breast and colorectal cancer.
•Sumoylation regulates CD44 and MMP14 expression in basal breast and colon cancer•SUMO inhibition clears cancer stem cells, repressing invasiveness and tumor growth•Anacardic acid functions as a SUMO inhibitor to repress cancer stem cells•TFAP2A mediates anti-tumor effects of SUMO inhibition in breast and colon cancers
Weigel and colleagues provide substantial evidence for developing cancer stem cell-specific therapy based on inhibiting the SUMO pathway. They show that inhibition of sumoylation enzymes by knockdown or small-molecule inhibitors repressed cancer stem cells with loss of CD44 and MMP14, and reduced invasiveness and inhibition of tumor growth. Common SUMO-sensitive mechanisms were dependent upon TFAP2A in breast and colon cancer.
Activating protein 2 alpha (AP-2α; encoded by
) functions as a tumor suppressor and influences response to therapy in several cancer types. We aimed to characterize regulation of the transcriptome by ...AP-2α in colon cancer. CRISPR-Cas9 and short hairpin RNA were used to eliminate
expression in HCT116 and a panel of colon cancer cell lines. AP-2α target genes were identified with RNA sequencing and chromatin immunoprecipitation sequencing. Effects on cell cycle were characterized in cells synchronized with aphidicolin and analyzed by FACS and Premo FUCCI. Effects on invasion and tumorigenesis were determined by invasion assay, growth of xenografts, and phosphorylated histone H3 (PHH3). Knockout of
induced significant alterations in the transcriptome including repression of
, identified as a primary gene target of AP-2α. Loss of AP-2α delayed progression through S-phase into G
-M and decreased phosphorylation of AKT, effects that were mediated through regulation of
. Buparlisib (BKM120) repressed
invasiveness of HCT116 and a panel of colon cancer cell lines; however, loss of AP-2α induced resistance to buparlisib. Similarly, buparlisib repressed PHH3 and growth of tumor xenografts and increased overall survival of tumor-bearing mice, whereas, loss of AP-2α induced resistance to the effect of PI3K inhibition. Loss of AP-2α in colon cancer leads to prolonged S-phase through altered activation of AKT leading to resistance to the PI3K inhibitor, Buparlisib. The findings demonstrate an important role for AP-2α in regulating progression through the cell cycle and indicates that AP-2α is a marker for response to PI3K inhibitors. IMPLICATIONS: AP-2α regulated cell cycle through the PI3K cascade and activation of AKT mediated through TGM2. AP-2α induced sensitivity to Buparlisib/BKM120, indicating that AP-2α is a biomarker predictive of response to PI3K inhibitors.
Expression of TFAP2C in luminal breast cancer is associated with reduced survival and hormone resistance, partially explained through regulation of RET. TFAP2C also regulates EGFR in HER2 breast ...cancer. We sought to elucidate the regulation and functional role of EGFR in luminal breast cancer. We used gene knockdown (KD) and treatment with a tyrosine kinase inhibitor (TKI) in cell lines and primary cancer isolates to determine the role of RET and EGFR in regulation of p-ERK and tumorigenesis. KD of TFAP2C decreased expression of EGFR in a panel of luminal breast cancers, and chromatin immunoprecipitation sequencing (ChIP-seq) confirmed that TFAP2C targets the EGFR gene. Stable KD of TFAP2C significantly decreased cell proliferation and tumor growth, mediated in part through EGFR. While KD of RET or EGFR reduced proliferation (31% and 34%, P < 0.01), combined KD reduced proliferation greater than either alone (52% reduction, P < 0.01). The effect of the TKI vandetanib on proliferation and tumor growth response of MCF-7 cells was dependent upon expression of TFAP2C, and dual KD of RET and EGFR eliminated the effects of vandetanib. The response of primary luminal breast cancers to TKIs assessed by ERK activation established a correlation with expression of RET and EGFR. We conclude that TFAP2C regulates EGFR in luminal breast cancer. Response to vandetanib was mediated through the TFAP2C target genes EGFR and RET. Vandetanib may provide a therapeutic effect in luminal breast cancer, and RET and EGFR can serve as molecular markers for response.
Mucopolysaccharidosis II (MPS II) is a rare lysosomal storage disease characterized by deficient activity of iduronate-2-sulfatase (I2S), leading to pathological accumulation of glycosaminoglycans ...(GAGs) in tissues. We used iduronate-2-sulfatase knockout (Ids KO) mice to investigate if liver-directed recombinant adeno-associated virus vectors (rAAV8-LSP-hIDSco) encoding human I2S (hI2S) could cross-correct I2S deficiency in Ids KO mouse tissues, and we then assessed the translation of mouse data to non-human primates (NHPs). Treated mice showed sustained hepatic hI2S production, accompanied by normalized GAG levels in somatic tissues (including critical tissues such as heart and lung), indicating systemic cross-correction from liver-secreted hI2S. Brain GAG levels in Ids KO mice were lowered but not normalized; higher doses were required to see improvements in brain histology and neurobehavioral testing. rAAV8-LSP-hIDSco administration in NHPs resulted in sustained hepatic hI2S production and therapeutic hI2S levels in cross-corrected somatic tissues but no hI2S exposure in the central nervous system, perhaps owing to lower levels of liver transduction in NHPs than in mice. Overall, we demonstrate the ability of rAAV8-LSP-hIDSco to cross-correct I2S deficiency in mouse somatic tissues and highlight the importance of showing translatability of gene therapy data from rodents to NHPs, which is critical for supporting translation to clinical development.
Display omitted
Chen and colleagues show that gene therapy for mucopolysaccharidosis II through administration of a liver-directed recombinant adeno-associated virus vector encoding human iduronate-2-sulfatase (rAAV8-LSP-hIDSco) is able to cross-correct iduronate-2-sulfatase deficiency in somatic tissues of Ids knockout mice and demonstrate promising translational potential from the mouse model to non-human primates.
Mammary gland ductal morphogenesis depends on the differentiation of mammary stem cells (MaSCs) into basal and luminal lineages. The AP-2γ transcription factor, encoded by Tfap2c, has a central role ...in mammary gland development but its effect in mammary lineages and specifically MaSCs is largely unknown. Here, we utilized an inducible, conditional knockout of Tfap2c to elucidate the role of AP-2γ in maintenance and differentiation of MaSCs. Loss of AP-2γ in the basal epithelium profoundly altered the transcriptomes and decreased the number of cells within several clusters of mammary epithelial cells, including adult MaSCs and luminal progenitors. AP-2γ regulated the expression of genes known to be required for mammary development, including Cebpb, Nfkbia, and Rspo1. As a result, AP-2γ-deficient mice exhibited repressed mammary gland ductal outgrowth and inhibition of regenerative capacity. The findings demonstrate that AP-2γ can regulate development of mammary gland structures potentially regulating maintenance and differentiation of multipotent MaSCs.
•AP-2γ-deficient mice exhibit repressed ductal outgrowth and regenerative capacity•Loss of AP-2γ reduced cells within mammary stem and luminal progenitor clusters•AP-2γ target genes, including Cebpb, Nfkbia, and Rspo1, regulate mammary development•AP-2γ potentially regulates maintenance of multipotent mammary stem cells
Gu and colleagues utilized a conditional knockout of Tfap2c to examine transcriptional effects of AP-2γ on mammary development. AP-2γ-deficient mice have decreased numbers of cell populations harboring mammary stem cells and have altered expression of genes required for mammary development, including Cebpb, Nfkbia, and Rspo1. They demonstrate that AP-2γ is implicated in maintenance of multipotent mammary stem cells.
Cancer stem cells (CSCs) are expanded in anaplastic thyroid cancer (ATC) and standard treatment approaches have failed to improve survival, suggesting a need to specifically target the CSC ...population. Recent studies in breast and colorectal cancer demonstrated that inhibition of the SUMO pathway repressed CD44 and cleared the CSC population, mediated through SUMO-unconjugated TFAP2A. We sought to evaluate effects of inhibiting the SUMO pathway in ATC. ATC cell lines and primary ATC tumor samples were evaluated. The SUMO pathway was inhibited by knockdown of PIAS1 and use of SUMO inhibitors anacardic acid and PYR-41. The expression of TFAP2A in primary ATC was examined by immunohistochemistry. All ATC cell lines expressed TFAP2A but only 8505C expressed SUMO-conjugated TFAP2A. In 8505C only, inhibition of the SUMO pathway by knockdown of PIAS1 or treatment with SUMO inhibitors repressed expression of CD44 with a concomitant loss of SUMO-conjugated TFAP2A. The effect of SUMO inhibition on CD44 expression was dependent upon TFAP2A. Treatment with SUMO inhibitors resulted in a statistically improved tumor-free survival in mice harboring 8505C xenografts. An examination of primary ATC tissue determined that TFAP2A was expressed in 4 of 11 tumors surveyed. We conclude that inhibition of the SUMO pathway repressed the CSC population, delaying the outgrowth of tumor xenografts in ATC. The effect of SUMO inhibition was dependent upon expression of SUMO-conjugated TFAP2A, which may serve as a molecular marker for therapeutic effects of SUMO inhibitors. The findings provide pre-clinical evidence for development of SUMO inhibitors for the treatment of ATC.
PDF
