HDAC2 promotes the migration and invasion of non-small cell lung cancer cells via upregulation of fibronectin

The HDAC2-MTA3 interaction induces nonsmall cell lung cancer cell migration and invasion by targeting c-Myc and cyclin D1

Genome-wide association studies have identified numerous single-nucleotide polymorphisms (SNPs) associated with lung cancer; however, the functions of histone deacetylase 2 (HDAC2) rs13213007 and HDAC2 in nonsmall cell lung cancer (NSCLC) remain unclear. Here we identified HDAC2 rs13213007 as a risk SNP and showed that HDAC2 was upregulated in both peripheral blood mononuclear cells (PBMCs) and NSCLC tissues with the rs13213007 A/A genotype compared with those with the rs13213007 G/G or G/A genotype. Patient clinical data indicated strong associations between rs13213007 genotype and N classification. Immunohistochemical staining confirmed that higher expression of HDAC2 was associated with NSCLC progression. Furthermore, we generated 293T cells with the rs13213007 A/A genotype using CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 gene editing. Chromatin immunoprecipitation sequencing followed by motif analysis showed that HDAC2 can bind to c-Myc in rs13213007 A/A 293T cells. Cell Counting Kit-8, colony formation, wound-healing, and Transwell assays revealed that HDAC2 upregulates c-Myc and cyclin D1 expression and promotes NSCLC cell proliferation, migration, and invasion. Co-immunoprecipitation, quantitative reverse transcription-polymerase chain reaction, and western blot analysis assays showed that MTA3 interacts with HDAC2, decreases HDAC2 expression, and rescues the migration and invasion abilities of NSCLC cells. Taken together, these findings identify HDAC2 as a potential therapeutic biomarker in NSCLC.

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.

The pathological significance and potential mechanism of ARHGEF6 in lung adenocarcinoma

BACKGROUND

Emerging evidences suggest that ARHGEF6 is involved in cancers but the exact significance and underlying mechanism are unclear. This study aimed to elucidate the pathological significance and potential mechanism of ARHGEF6 in lung adenocarcinoma (LUAD).

METHODS

Bioinformatics and experimental methods were used to analyze the expression, the clinical significance, the cellular function and potential mechanisms of ARHGEF6 in LUAD.

RESULTS

ARHGEF6 was downregulated in LUAD tumor tissues and correlated negatively with poor prognosis and tumor stemness, positively with the Stromal score, the Immune score and the ESTIMATE score. The expression level of ARHGEF6 was also associated with drug sensitivity, the abundance of immune cells, the expression levels of Immune checkpoint genes and immunotherapy response. Mast cells, T cells and NK cells were the first three cells with the highest expression of ARHGEF6 in LUAD tissues. Overexpression of ARHGEF6 reduced proliferation and migration of LUAD cells and the growth of xenografted tumors, which could be reversed by re-knockdown of ARHGEF6. Results of RNA sequencing revealed that ARHGEF6 overexpression induced significant changes in the expression profile of LUAD cells, and genes encoding uridine 5'-diphosphate-glucuronic acid transferases (UGTs) and extracellular matrix (ECM) components were downregulated.

CONCLUSIONS

ARHGEF6 functions as a tumor suppressor in LUAD and may serve as a new prognostic marker and potential therapeutic target. Regulating tumor microenvironment and immunity, inhibiting the expression of UGTs and ECM components in the cancer cells, and decreasing the stemness of the tumors may among the mechanisms underlying the function of ARHGEF6 in LUAD.

HDAC2 as a Target for developing Anti-cancer Drugs

Histone deacetylases (HDACs) deacetylate histones H3 and H4. An imbalance between histone acetylation and deacetylation can lead to various diseases. HDAC2 is present in the nucleus. It plays a critical role in modifying chromatin structures and regulates the expression of various genes by functioning as a transcriptional regulator. The roles of HDAC2 in tumorigenesis and anti-cancer drug resistance are discussed in this review. Several reports suggested that HDAC2 is a prognostic marker of various cancers. The roles of microRNAs (miRNAs) that directly regulate the expression of HDAC2 in tumorigenesis are also discussed in this review. This review also presents HDAC2 as a valuable target for developing anti-cancer drugs.

HDAC inhibitor ITF2357 reduces resistance of mutant-KRAS non-small cell lung cancer to pemetrexed through a HDAC2/miR-130a-3p-dependent mechanism

BACKGROUND

Histone deacetylases (HDAC) contribute to oncogenic program, pointing to their inhibitors as a potential strategy against cancers. We, thus, studied the mechanism of HDAC inhibitor ITF2357 in resistance of mutant (mut)-KRAS non-small cell lung cancer (NSCLC) to pemetrexed (Pem).

METHODS

We first determined the expression of NSCLC tumorigenesis-related HDAC2 and Rad51 in NSCLC tissues and cells. Next, we illustrated the effect of ITF2357 on the Pem resistance in wild type-KARS NSCLC cell line H1299, mut-KARS NSCLC cell line A549 and Pem-resistant mut-KARS cell line A549R in vitro and in xenografts of nude mice in vivo.

RESULTS

Expression of HDAC2 and Rad51 was upregulated in NSCLC tissues and cells. Accordingly, it was revealed that ITF2357 downregulated HDAC2 expression to diminish the resistance of H1299, A549 and A549R cells to Pem. HDAC2 bound to miR-130a-3p to upregulate its target gene Rad51. The in vitro findings were reproduced in vivo, where ITF2357 inhibited the HDAC2/miR-130a-3p/Rad51 axis to reduce the resistance of mut-KRAS NSCLC to Pem.

CONCLUSION

Taken together, HDAC inhibitor ITF2357 restores miR-130a-3p expression by inhibiting HDAC2, thereby repressing Rad51 and ultimately diminishing resistance of mut-KRAS NSCLC to Pem. Our findings suggested HDAC inhibitor ITF2357 as a promising adjuvant strategy to enhance the sensitivity of mut-KRAS NSCLC to Pem.

Signatures of Co-Deregulated Genes and Their Transcriptional Regulators in Lung Cancer

Despite the significant progress made towards comprehending the deregulated signatures in lung cancer, these vary from study to study. We reanalyzed 25 studies from the Gene Expression Omnibus (GEO) to detect and annotate co-deregulated signatures in lung cancer and in single-gene or single-drug perturbation experiments. We aimed to decipher the networks that these co-deregulated genes (co-DEGs) form along with their upstream regulators. Differential expression and upstream regulators were computed using Characteristic Direction and Systems Biology tools, including GEO2Enrichr and X2K. Co-deregulated gene expression profiles were further validated across different molecular and immune subtypes in lung adenocarcinoma (TCGA-LUAD) and lung adenocarcinoma (TCGA-LUSC) datasets, as well as using immunohistochemistry data from the Human Protein Atlas, before being subjected to subsequent GO and KEGG enrichment analysis. The functional alterations of the co-upregulated genes in lung cancer were mostly related to immune response regulating the cell surface signaling pathway, in contrast to the co-downregulated genes, which were related to S-nitrosylation. Networks of hub proteins across the co-DEGs consisted of overlapping TFs (SOX2, MYC, KAT2A) and kinases (MAPK14, CSNK2A1 and CDKs). Furthermore, using Connectivity Map we highlighted putative repurposing drugs, including valproic acid, betonicine and astemizole. Similarly, we analyzed the co-DEG signatures in single-gene and single-drug perturbation experiments in lung cancer cell lines. In summary, we identified critical co-DEGs in lung cancer providing an innovative framework for their potential use in developing personalized therapeutic strategies.

Recent progress on FAK inhibitors with dual targeting capabilities for cancer treatment

Focal adhesion kinase (FAK, also known as PTK2) is a tyrosine kinase that regulates integrin and growth factor signaling pathways and is involved in the migration, proliferation and survival of cancer cells. FAK is a promising target for cancer treatment. Many small molecule FAK inhibitors have been identified and proven in both preclinical and clinical studies to be effective inhibitors of tumor growth and metastasis. There are many signaling pathways, such as those involving FAK, Src, AKT, MAPK, PI3K, and EGFR/HER-2, that provide survival signals in cancer cells. Dual inhibitors that simultaneously block FAK and another factor can significantly improve efficacy and overcome some of the shortcomings of single-target inhibitors, including drug resistance. In this review, the antitumor mechanisms and research status of dual inhibitors of FAK and other targets, such as Pyk2, IGF-IR, ALK, VEGFR-3, JAK2, EGFR, S6K1, and HDAC2, are summarized, providing new ideas for the development of effective FAK dual-target preparations.

High Histone Deacetylase 2/3 Expression in Non-Functioning Pituitary Tumors

Epigenetic modification of chromatin is involved in non-malignant pituitary neoplasia by causing abnormal expression of tumor suppressors and oncogenes. These changes are potentially reversible, suggesting the possibility of targeting tumor cells by restoring the expression of epigenetically silenced tumor suppressors. The role of the histone deacetylase (HDAC) family in pituitary tumorigenesis is not known. We report that HDAC2 and 3, Class I HDAC members, are highly expressed in clinically non-functioning pituitary adenomas (NFPAs) compared to normal pituitary (NP) samples as determined by RT-PCR and immunohistochemical staining (IHC). Treatment of a human NFPA derived folliculostellate cell line, PDFS, with the HDAC3 inhibitor RGFP966 for 96 hours resulted in inhibition of cell proliferation by 70%. Furthermore, the combination of RGFP966 with a methyltransferase/DNMT inhibitor, 5’-aza-2’-deoxycytidine, led to the restoration of the expression of several tumor suppressor genes, including STAT1, P16, PTEN, and the large non-coding RNA tumor suppressor MEG3, in PDFS cells. Our data support the hypothesis that both histone modification and DNA methylation are involved in the pathogenesis of human NFPAs and suggest that targeting HDACs and DNA methylation can be incorporated into future therapies.

Roles of HDAC2, eIF5, and eIF6 in Lung Cancer Tumorigenesis

OBJECTIVE

The expression levels of histone deacetylase 2 (HDAC2), eukaryotic initiation factor 5 (eIF5), and eukaryotic initiation factor 6 (eIF6), and relationship between HDAC2 and eIF5 or eIF6 in lung cancer tissues were investigated, in order to charify the relationship between HDAC2 and the prognosis of lung cancer patients and its influence on the expression of eIF5 and eIF6.

METHODS

The expression of HDAC2, eIF5, and eIF6 in lung cancer tissues was detected by quantitative reverse transcription polymerase chain reaction. The expression correlation between HDAC2 and eIF5 or eIF6 was tested using a t test. The correlation between HDAC2 and eIF5 or eIF6 was analyzed using the TCGA database. The identified cells were constructed with small interfering siRNA and HDAC2 overexpression plasmid. The proliferation and migration ability of the identified cells was investigated by CCK8 and Transwell assays, respectively.

RESULTS

HDAC2, eIF5, and eIF6 were overexpressed in lung cancer tissues, and HDAC2 expression level was negatively correlated with the prognosis of lung cancer patients. HDAC2 expression level was positively correlated with eIF5 and eIF6 expression levels. HDAC2 could regulate the expression of eIF5 and eIF6. The regulation of proliferation and invasion of lung cancer cells by HDAC2 depended on eIF5 and eIF6.

CONCLUSION

HDAC2, eIF5, and eIF6 were closely related with lung cancer tumorigenesis, which might be potential biological markers and therapeutic targets for lung cancer.

Targeting Histone Modifications in Bone and Lung Metastatic Cancers

PURPOSE OF REVIEW

Breast cancer frequently metastasizes to the bone and lung, but the ability to treat metastatic tumor cells remains a pressing clinical challenge. Histone deacetylases (HDACs) and histone acetyltransferases (HATs) have emerged as promising targets since these enzymes are aberrantly expressed in numerous cancers and regulate the expression of genes that drive tumorigenesis and metastasis. This review focuses on the abnormal expression of histone-modifying enzymes in cancers that have a high tropism for the bone and lung and explores the clinical use of histone deacetylase inhibitors for the treatment and prevention of metastasis to these sites.

RECENT FINDINGS

Preclinical studies have demonstrated that the role for HDACs is highly dependent on tumor type and stage of disease progression. HDAC inhibitors can induce apoptosis, senescence, cell differentiation, and tumor dormancy genes and inhibit angiogenesis, making these promising therapeutics for the treatment of metastatic disease. HDAC inhibitors are already FDA approved for hematologic malignancies and are in clinical trials with standard-of-care chemotherapies and targeted agents for several solid tumors, including cases of metastatic disease. However, these drugs can negatively impact bone homeostasis. Although HDAC inhibitors are not currently administered for the treatment of bone and lung metastatic disease, preclinical studies have shown that these drugs can reduce distant metastasis by targeting molecular factors and signaling pathways that drive tumor cell dissemination to these sites. Thus, HDAC inhibitors in combination with bone protective therapies may be beneficial in the treatment of bone metastatic cancers.

A first-in-class anticancer dual HDAC2/FAK inhibitors bearing hydroxamates/benzamides capped by pyridinyl-1,2,4-triazoles

Novel 5-pyridinyl-1,2,4-triazoles were designed as dual inhibitors of histone deacetylase 2 (HDAC2) and focal adhesion kinase (FAK). Compounds 5d, 6a, 7c, and 11c were determined as potential inhibitors of both HDAC2 (IC₅₀ = 0.09-1.40 μM) and FAK (IC₅₀ = 12.59-36.11 nM); 6a revealed the highest activity with IC₅₀ values of 0.09 μM and 12.59 nM for HDAC2 and FAK, respectively. Compound 6a was superior to reference drugs vorinostat and valproic acid in its ability to inhibit growth/proliferation of A-498 and Caki-1 renal cancer cells. Further investigation proved that 6a strongly arrests the cell cycle at the G2/M phase and triggers apoptosis in both A-498 and Caki-1 cells. Moreover, the enhanced Akt activity that is observed upon chronic application of HDAC inhibitors was effectively suppressed by the dual HDAC2/FAK inhibitor. Finally, the high potency and selectivity of 6a towards HDAC2 and FAK proteins were rationalized by molecular docking. Taken together, these findings highlight the potential of 6a as a promising dual-acting HDAC2/FAK inhibitor that could benefit from further optimization.

Long non-coding RNA DBH-AS1 promotes cancer progression in diffuse large B-cell lymphoma by targeting FN1 via RNA-binding protein BUD13

Diffuse large B-cell lymphoma (DLBC) is a subtype of lymphoma with the worst prognosis. Existing treatment methods are not effective enough due to its high occurrence of metastasis. Therefore, identification of effective therapeutic targets is becoming increasingly important. In this research, long non-coding RNA dopamine β hydroxylase antisense RNA 1 (DBH-AS1) was found to be upregulated in DLBC tissues and cells. Knockdown of DBH-AS1 suppressed the proliferation, migration, and invasion of cancer cells. Afterwards, RNA-binding protein BUD13 homolog (BUD13) was found to be upregulated in cancer tissues and cells while binding to DBH-AS1. Fibronectin 1 (FN1) was the downstream messenger RNA (mRNA) of BUD13. FN1 was upregulated in DLBC and was positively correlated with DBH-AS1. Further rescue assays proved that DBH-AS1 mediated FN1 expression by recruiting BUD13. In the meantime, BUD13 stabilized FN1 mRNA to promote FN1 expression. In this way, DBH-AS1/BUD13/FN1 axis was confirmed. A set of rescue assays proved that DBH-AS1 regulated DLBC progression via BUD13 and FN1. The function and mechanism of DBH-AS1 were investigated for the first time in DLBC. DBH-AS1 might become a therapeutic target in lymphoma treatment in the future.

NOS1 inhibits the interferon response of cancer cells by S-nitrosylation of HDAC2

Background

The dysfunction of type I interferon (IFN) signaling is an important mechanism of immune escape and metastasis in tumors. Increased NOS1 expression has been detected in melanoma, which correlated with dysfunctional IFN signaling and poor response to immunotherapy, but the specific mechanism has not been determined. In this study, we investigated the regulation of NOS1 on the interferon response and clarified the relevant molecular mechanisms.

Methods

After stable transfection of A375 cells with NOS1 expression plasmids, the transcription and expression of IFNα-stimulated genes (ISGs) were assessed using pISRE luciferase reporter gene analysis, RT-PCR, and western blotting, respectively. The effect of NOS1 on lung metastasis was assessed in melanoma mouse models. A biotin-switch assay was performed to detect the S-nitrosylation of HDAC2 by NOS1. ChIP-qPCR was conducted to measure the binding of HDAC2, H4K16ac, H4K5ac, H3ac, and RNA polymerase II in the promoters of ISGs after IFNα stimulation. This effect was further evaluated by altering the expression level of HDAC2 or by transfecting the HDAC2-C262A/C274A site mutant plasmids into cells. The coimmunoprecipitation assay was performed to detect the interaction of HDAC2 with STAT1 and STAT2. Loss-of-function and gain-of-function approaches were used to examine the effect of HDAC2-C262A/C274A on lung metastasis. Tumor infiltrating lymphocytes were analyzed by flow cytometry.

Results

HDAC2 is recruited to the promoter of ISGs and deacetylates H4K16 for the optimal expression of ISGs in response to IFNα treatment. Overexpression of NOS1 in melanoma cells decreases IFNα-responsiveness and induces the S-nitrosylation of HDAC2-C262/C274. This modification decreases the binding of HDAC2 with STAT1, thereby reducing the recruitment of HDAC2 to the ISG promoter and the deacetylation of H4K16. Moreover, expression of a mutant form of HDAC2, which cannot be nitrosylated, reverses the inhibition of ISG expression by NOS1 in vitro and decreases NOS1-induced lung metastasis and inhibition of tumor infiltrating lymphocytes in a melanoma mouse model.

Conclusions

This study provides evidence that NOS1 induces dysfunctional IFN signaling to promote lung metastasis in melanoma, highlighting NOS1-induced S-nitrosylation of HDAC2 in the regulation of IFN signaling via histone modification.

Histone deacetylase inhibitors differentially regulate c-Myc expression in retinoblastoma cells

Retinoblastoma (RB) is the most prevalent childhood intraocular cancer type. Previous studies have demonstrated that c-myc (a proto-oncogene) is associated with tumorigenesis. However, at present, the influence of the expression profile and bioactivity of c-Myc on RB occurrence and progression is yet to be characterised. Notably, the present study demonstrated that c-myc is downregulated in the RB cell line WERI-Rb1. However, treatment with the histone deacetylase (HDAC) inhibitor trichostatin A (TSA) was revealed to significantly upregulate the expression of c-Myc mRNA and protein in WERI-Rb1 cells. Moreover, TSA increased the activity of the c-myc promoter in WERI-Rb1 cells, and the expression of c-Myc was also regulated by other HDAC inhibitors, including vorinostat (SAHA), valproic acid sodium salt (VPA) and entinostat. Notably, although c-myc was silenced in the Y79 cell line, the HDAC inhibitor TSA did not induce upregulation of mRNA and protein in Y79 cells. By contrast, certain HDAC inhibitors (TSA, VPA and SAHA) were discovered to significantly decrease the activity of the c-myc promoter in Y79 cells. Furthermore, the current data indicated that exogenous c-myc expression has a mild inhibitory effect on WERI-Rb1 and Y79 cell viability. Therefore, the present study revealed novel insights into the expression mechanism and bioactivity of c-Myc in RB cells.