Aberrant HDAC3 expression correlates with brain metastasis in breast cancer patients

Histone acetylation risk model predicts prognosis and guides therapy selection in glioblastoma: implications for chemotherapy and anti-CTLA-4 immunotherapy

BACKGROUND

Glioblastoma is characterized by high aggressiveness, frequent recurrence, and poor prognosis. Histone acetylation-associated genes have been implicated in its occurrence and development, yet their predictive ability in glioblastoma prognosis remains unclear.

RESULTS

This study constructs a histone acetylation risk model using Cox and LASSO regression analyses to evaluate glioblastoma prognosis. We assessed the model's prognostic ability with univariate and multivariate Cox regression analyses. Additionally, immune infiltration was evaluated using ESTIMATE and TIMER algorithms, and the SubMAP algorithm was utilized to predict responses to CTLA4 inhibitor. Multiple drug databases were applied to assess drug sensitivity in high- and low-risk groups. Our results indicate that the histone acetylation risk model is independent and reliable in predicting prognosis.

CONCLUSIONS

Low-risk patients showed higher immune activity and longer overall survival, suggesting anti-CTLA4 immunotherapy suitability, while high-risk patients might benefit more from chemotherapy. This model could guide personalized therapy selection for glioblastoma patients.

Deciphering the Mysterious Relationship between the Cross-Pathogenetic Mechanisms of Neurodegenerative and Oncological Diseases

The relationship between oncological pathologies and neurodegenerative disorders is extremely complex and is a topic of concern among a growing number of researchers around the world. In recent years, convincing scientific evidence has accumulated that indicates the contribution of a number of etiological factors and pathophysiological processes to the pathogenesis of these two fundamentally different diseases, thus demonstrating an intriguing relationship between oncology and neurodegeneration. In this review, we establish the general links between three intersecting aspects of oncological pathologies and neurodegenerative disorders, i.e., oxidative stress, epigenetic dysregulation, and metabolic dysfunction, examining each process in detail to establish an unusual epidemiological relationship. We also focus on reviewing the current trends in the research and the clinical application of the most promising chemical structures and therapeutic platforms that have a modulating effect on the above processes. Thus, our comprehensive analysis of the set of molecular determinants that have obvious cross-functional pathways in the pathogenesis of oncological and neurodegenerative diseases can help in the creation of advanced diagnostic tools and in the development of innovative pharmacological strategies.

SERPINA3-ANKRD11-HDAC3 pathway induced aromatase inhibitor resistance in breast cancer can be reversed by HDAC3 inhibition

Endocrine resistance is a major challenge for breast cancer therapy. To identify the genes pivotal for endocrine-resistance progression, we screened five datasets and found 7 commonly dysregulated genes in endocrine-resistant breast cancer cells. Here we show that downregulation of serine protease inhibitor clade A member 3 (SERPINA3) which is a direct target gene of estrogen receptor α contributes to aromatase inhibitor resistance. Ankyrin repeat domain containing 11 (ANKRD11) works as a downstream effector of SERPINA3 in mediating endocrine-resistance. It induces aromatase inhibitor insensitivity by interacting with histone deacetylase 3 (HDAC3) and upregulating its activity. Our study suggests that aromatase inhibitor therapy downregulates SERPINA3 and leads to the ensuing upregulation of ANKRD11, which in turn promotes aromatase inhibitor resistance via binding to and activating HDAC3. HDAC3 inhibition may reverse the aromatase inhibitor resistance in ER-positive breast cancer with decreased SERPINA3 and increased ANKRD11 expression.

PDCD5 inhibits progression of renal cell carcinoma by promoting T cell immunity: with the involvement of the HDAC3/microRNA-195-5p/SGK1

BACKGROUND

Epigenetics exerts a vital role in the onset and development of renal cell carcinoma (RCC). Mounting evidence has shed light on the significance of human immune system in response to tumor infiltrating T cells. Hereby, we sought to unmask the immunomodulatory role of histone deacetylase 3 (HDAC3) and its potential upstream molecule, programmed cell death 5 (PDCD5) in RCC.

METHODS

RCC and adjacent non-cancerous tissues were clinically resected from 58 patients, in which the expression profile of microRNA-195-5p (miR-195-5p), PDCD5, HDAC3, and serum glucocorticoid-inducible kinase 1 (SGK1) was determined by RT-qPCR and Western blot analysis. Their relations were investigated by a series of luciferase assays in combination with ChIP and co-IP. RCC cells (A498) were intervened using gain- and loss-of-function approaches, followed by cell proliferation evaluation. After co-culture with CD3⁺ T cells, flow cytometry and interferon-γ (IFN-γ) determination were performed. A xenograft tumor mouse model was developed for in vivo validation.

RESULTS

PDCD5 was downregulated in RCC tissues and A498 cells. Upregulation of HDAC3, as well as of SGK1, resulted in suppression of A498 cell proliferation and promotion of T cell activation as evidenced by higher IFN-γ expression. Re-expression of PDCD5 downregulated HDAC3, causing a subsequent upregulation of miR-195-5p, while miR-195-5p could inversely modulate its target gene, SGK1. The regulatory mechanism appeared to be functional in vivo.

CONCLUSION

Our results highlight the possible manipulation by PDCD5 on RCC cell proliferation and T cell activation, which provides new clues to better understand the immune balance in RCC progression.

Transcriptional Repression of Aerobic Glycolysis by OVOL2 in Breast Cancer

Aerobic glycolysis (Warburg effect), a hallmark of cancer, plays a critical role in cancer cell growth and metastasis; however, direct inhibition of the Warburg effect remains largely unknown. Herein, the transcription factor OVO-like zinc finger 2 (OVOL2) is demonstrated to directly repress the expression of several glycolytic genes, blocking the Warburg effect and breast tumor growth and metastasis in vitro and in vivo. OVOL2 inhibits glycolysis by recruiting the nuclear receptor co-repressor (NCoR) and histone deacetylase 3 (HDAC3). The tumor suppressor p53, a key regulator of cancer metabolism, activates OVOL2 by binding to the oncoprotein mouse double minute 2 homolog (MDM2) and inhibiting MDM2-mediated ubiquitination and degradation of OVOL2. OVOL2 expression is negatively correlated with glycolytic gene expression and can be a good predictor of prognosis in patients with breast cancer. Therefore, targeting the p53/MDM2/OVOL2 axis provides a potential avenue for cancer treatment, especially breast cancer.

The role of histone deacetylase 3 in breast cancer

It has been recently revealed that Histone Deacetylase (HDAC) 3, a unique member of the HDACs family, can trigger and progress cancers by alternation in genes expression and proteins activity. Epigenetic modifications by HDACs have been studied well in various cancer cells. Recent studies have focused on the HDAC enzymes as a possible target in cancer therapy. There are significant documents on upregulation of HDAC3 in breast cancer (BC) cells which suggest an oncogenic role for this enzyme. Interestingly, some studies showed that HDAC3 inhibition could be considered as a promising target in breast cancer therapy, and thus far, several inhibitors from different nature have been introduced. In this review, we discussed the function and highlight the existing inhibitors of HDAC3 in BC pathogenesis and therapy.

The role of protein acetylation in carcinogenesis and targeted drug discovery

Protein acetylation is a reversible post-translational modification, and is involved in many biological processes in cells, such as transcriptional regulation, DNA damage repair, and energy metabolism, which is an important molecular event and is associated with a wide range of diseases such as cancers. Protein acetylation is dynamically regulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs) in homeostasis. The abnormal acetylation level might lead to the occurrence and deterioration of a cancer, and is closely related to various pathophysiological characteristics of a cancer, such as malignant phenotypes, and promotes cancer cells to adapt to tumor microenvironment. Therapeutic modalities targeting protein acetylation are a potential therapeutic strategy. This article discussed the roles of protein acetylation in tumor pathology and therapeutic drugs targeting protein acetylation, which offers the contributions of protein acetylation in clarification of carcinogenesis, and discovery of therapeutic drugs for cancers, and lays the foundation for precision medicine in oncology.

Trichostatin A promotes esophageal squamous cell carcinoma cell migration and EMT through BRD4/ERK1/2-dependent pathway

Background

Histone deacetylases (HDACs) have been demonstrated to be aberrantly activated in tumorigenesis and cancer development. Thus, HDAC inhibitors (HDACIs) are considered to be promising anti‐cancer therapeutics. However, recent studies have shown that HDACIs promote the migration of many cancer cells. Therefore, there is a need to elucidate the underlying mechanisms of HDACIs on cancer cell migration to establish a combination therapy that overcomes HDACI‐induced cell migration.

Methods

KYSE‐150 and EC9706 cells were treated differently. Effects of drugs and siRNA treatment on tumor cell migration and cell signaling pathways were investigated by transwell migration assy. Gene expression for SNAI2 was tested by RT‐qPCR. Western blot analysis was employed to detect the level of E‐cadherin, β‐catenin, vimentin,Slug，ERK1/2, H3, PAI‐1 and BRD4. The effect of drugs on cell morphology was evaluated through phase‐contrast microscopic images.

Results

TSA promotes epithelial‐mesenchymal transition (EMT) in ESCC cells by downregulating the epithelial marker E‐cadherin and upregulating mesenchymal markers β‐catenin, vimentin, Slug, and PAI‐1. Knockdown of Slug by siRNA or inhibition of PAI‐1 clearly suppressed TSA‐induced ESCC cell migration and resulted in the reversal of TSA‐triggered E‐cadherin, β‐catenin, and vimentin expression. However, no crosstalk between Slug and PAI‐1 was observed in TSA‐treated ESCC cells. Blocking ERK1/2 activation also inhibited TSA‐induced ESCC cell migration, EMT, and upregulation of Slug and PAI‐1 levels in ESCC cells. Interestingly, inhibition of BRD4 suppressed TSA‐induced ESCC cell migration and attenuated TSA‐induced ERK1/2 activation and upregulation of Slug and PAI‐1 levels.

Conclusions

Our data indicate the existence of at least two separable ERK1/2‐dependent signaling pathways in TSA‐mediated ESCC cell migration: an ERK1/2–Slug branch and an ERK1/2‐PAI‐1 branch. Both branches of TSA‐induced ESCC cell migration appear to favor the EMT process, while BRD4 is responsible for two separable ERK1/2‐dependent signaling pathways in TSA‐mediated ESCC cell migration.