Identification of downstream metastasis-associated target genes regulated by LSD1 in colon cancer cells

Role of the Forkhead box family protein FOXF2 in the progression of solid tumor: systematic review

BACKGROUND

FOXF2 was reported to involve in a variety of biological behaviors that include the development of the central nervous system, tissue homeostasis, epithelia-mesenchymal interactions, regulation of embryonic development, and organogenesis.

PURPOSE

Understanding how FOXF2 influences the growth and development of cancer could provide valuable insights for researchers to develop novel therapeutic strategies.

RESULTS

In this review, we investigate the underlying impact of FOXF2 on tumor cells, including the transformation of cellular phenotype, capacity for migration, invasion, and proliferation, colonization of circulating cells, and formation of metastatic nodules. In addition, we discuss the molecular mechanisms of FOXF2 in different cancers, including hepatocellular, esophageal, breast, colon, lung, prostate gland, as well as its role in embryonic development.

CONCLUSION

FOXF2 is a gene encoding a forkhead transcription factor belonging to the Forkhead Box family. The protein functions by recruiting activation transcription factors and basic components to activate the transcription of genes that interact with the complex. This review provides an in-depth analysis of the FOXF2's function and pleiotropic roles in cancer development and progression.

Transcription factor FOXF2 promotes the development and progression of pancreatic cancer by targeting MSI2

Pancreatic cancer (PC) is a malignant tumor possessing high mortality. The role of transcription factor Forkhead Box F2 (FOXF2) in PC remains unverified. The current study investigated the roles of FOXF2 in developing PC in vitro and in vivo. A xenograft tumor model was constructed with nude mice injected using FOXF2‑overexpressing PC cells or FOXF2‑silenced PC cells. High FOXF2 expression significantly enhanced the proliferation ability of PC cells in vitro and pancreatic tumor growth in vivo. The cell cycle analysis indicated that transition of G1‑S phase was promoted by FOXF2. The cell cycle‑associated proteins cyclin D1, CDK2, phosphorylated (p)‑CDK2 and p‑RB were upregulated in the FOXF2‑overexpressing cells and downregulated in the cells with FOXF2 knockdown. Flow cytometric analysis and Hoechst staining showed that the percentage of apoptotic cells was significantly increased after FOXF2 was silenced. FOXF2 knockdown promoted expression of pro‑apoptotic proteins (Bad, Bax and cleaved caspase‑3) while suppressing the anti‑apoptotic proteins (Bcl‑2 and Bcl‑xl) at the protein level. FOXF2 improved the migration and invasion of PC cells in vitro. Moreover, luciferase and chromatin immunoprecipitation assays revealed that FOXF2 binds to the MSI2 promoter, promoting its transcriptional expression. FOXF2 knockdown inhibited the MSI2 protein translation while enhancing the translation of NUMB protein, suppressing PC development in vivo. MSI2 silencing reversed the promotive effect mediated by FOXF2 on cell proliferation. These results demonstrated that FOXF2 is essential in PC progression, and the potential mechanism includes regulating MSI2 transcription.

LSD1 in drug discovery: From biological function to clinical application

Lysine-specific demethylase 1 (LSD1) is a flavin adenine dinucleotide (FAD) dependent monoamine oxidase (MAO) that erases the mono-, and dimethylation of histone 3 lysine 4 (H3K4), resulting in the suppression of target gene transcriptions. Besides, it can also demethylate some nonhistone substrates to regulate their biological functions. As reported, LSD1 is widely upregulated and plays a key role in several kinds of cancers, pharmacological or genetic ablation of LSD1 in cancer cells suppresses cell aggressiveness by several distinct mechanisms. Therefore, numerous LSD1 inhibitors, including covalent and noncovalent, have been developed and several of them have entered clinical trials. Herein, we systemically reviewed and discussed the biological function of LSD1 in tumors, lymphocytes as well as LSD1-targeting inhibitors in clinical trials, hoping to benefit the field of LSD1 and its inhibitors.

FBXO24 Suppresses Breast Cancer Tumorigenesis by Targeting LSD1 for Ubiquitination

Lysine-specific demethylase 1 (LSD1), a critical chromatin modulator, functions as an oncogene by demethylation of H3K4me1/2. The stability of LSD1 is governed by a complex and intricate process involving ubiquitination and deubiquitination. Several deubiquitinases preserve LSD1 protein levels. However, the precise mechanism underlying the degradation of LSD1, which could mitigate its oncogenic function, remains unknown. To gain a better understanding of LSD1 degradation, we conducted an unbiased siRNA screening targeting all the human SCF family E3 ligases. Our screening identified FBXO24 as a genuine E3 ligase that ubiquitinates and degrades LSD1. As a result, FBXO24 inhibits LSD1-induced tumorigenesis and functions as a tumor suppressor in breast cancer cells. Moreover, FBXO24 exhibits an inverse correlation with LSD1 and is associated with a favorable prognosis in breast cancer patient samples. Taken together, our study uncovers the significant role of FBXO24 in impeding breast tumor progression by targeting LSD1 for degradation.

IMPLICATIONS

Our study provides comprehensive characterization of the significant role of FBXO24 in impeding breast tumor progression by targeting LSD1 for degradation.

LSD1 regulates the FOXF2-mediated Wnt/β-catenin signaling pathway by interacting with Ku80 to promote colon cancer progression

Lysine-specific demethylase 1 (LSD1) is widely involved in the proliferation, invasion, and metastasis of cancers. However, it is uncertain whether LSD1 plays a role in facilitating colon cancer progression. Here, we have clarified the molecular mechanism by which LSD1 interacts with X-ray repair cross complementing protein 5 (Ku80) to promote colon cancer progression by directly targeting forehead protein transcription factor 2 (FOXF2). First, the interacting proteins of LSD1 were identified by immunoprecipitation and mass spectrometry. The expression of Ku80 and FOXF2 in colon cancer was detected using immunohistochemistry, real-time quantitative transcription polymerase chain reaction, and western blot. Next, the proliferation, invasion, and metastasis of colon cancer in vitro and in vivo were detected by methyl thiazolyl tetrazolium, 5-ethynyl-20-deoxyuridine, colony formation, wound healing, and nude mice xenograft model assays, respectively. Chromatin immunoprecipitation (ChIP) and ChIP-PCR were performed to investigate the molecular mechanism of LSD1 and Ku80 in colon cancer. Our results indicated that Ku80 expression was positively correlated with the invasion and migration of colon cancer cells, and negatively correlated with FOXF2 expression. More importantly, the high expression of Ku80 and the low expression of FOXF2 were particularly associated with driving the progression of colon cancer. Ku80 knockdown and LSD1 silencing inhibited the proliferation, migration, and invasion of colon cancer in vitro and in vivo. Mechanically, LSD1 interacts with Ku80 and also binds directly to the 687-887-bp portion of the FOXF2 promoter region. The upregulated methylation level of H3K4me2 in the FOXF2 promoter region facilitated the transcriptional activation of FOXF2, and downregulated protein expression associated with the Wnt/β-catenin signaling pathway. In conclusion, our study suggests that LSD1 regulates the FOXF2-mediated Wnt/β-catenin signaling pathway by interacting with Ku80, promoting the malignant biological properties of colon cancer, highlighting the binding of LSD1 and Ku80 as a useful anti-cancer target for colon cancer.

The Role of LSD1 and LSD2 in Cancers of the Gastrointestinal System: An Update

Epigenetic mechanisms are known to play a key role in cancer progression. Specifically, histone methylation involves reversible post-translational modification of histones that govern chromatin structure remodelling, genomic imprinting, gene expression, DNA damage repair, and meiotic crossover recombination, among other chromatin-based activities. Demethylases are enzymes that catalyse the demethylation of their substrate using a flavin adenine dinucleotide-dependent amine oxidation process. Lysine-specific demethylase 1 (LSD1) and its homolog, lysine-specific demethylase 2 (LSD2), are overexpressed in a variety of human cancer types and, thus, regulate tumour progression. In this review, we focus on the literature from the last 5 years concerning the role of LSD1 and LSD2 in the main gastrointestinal cancers (i.e., gastric cancer, liver cancer, pancreatic cancer, and colorectal cancer).

4,5-Dimethoxycanthin-6-one is a novel LSD1 inhibitor that inhibits proliferation of glioblastoma cells and induces apoptosis and pyroptosis

BACKGROUND

Glioblastoma is one of the most common fatal intracranial malignancies. Lysine-specific demethylase 1 (LSD1) reportedly has therapeutic effects on a variety of tumors. This study explored the therapeutic effect of LSD1 inhibition on glioblastoma cell lines and the possible underlying mechanisms.

METHODS

The MTT assay was utilized to screen for the sensitivity of U87, U251 and T98G cells to 4, 5-dimethoxycarrageenin-6-one. qRT-PCR and western blot were used to measure the proliferation, apoptosis, and pyroptosis signaling pathway expression to observe the effect of LSD1 inhibition on U251 and T98G cells. Flow cytometry, immunofluorescence, immunohistochemistry, wound scratch, clone formation, and TUNEL assay were used to analyze the effects of 4, 5-dimethoxycanthin-6-one on glioblastoma cells. The effect of 4, 5-dimethoxycanthin-6-one was examined in vivo in BALB/c nude mice injected with U251 cells. HE staining was used to detect the histopathology of the tumor.

RESULTS

LSD1 specifically catalyzes the demethylation of monomethylated and demethylated histone H3 lysine at position 4 (h3k4me1, h3k4me2, h3k4me3) and lysine at position 9 (h3k9me1). This regulated the transcriptional activity of proliferation, apoptosis, and pyroptosis signaling pathway genes. In vitro, the proliferation of glioblastoma cells was decreased in the 4, 5-dimethoxycanthin-6-one group. The expression of Caspase1 in glioblastoma cells treated with 4, 5-dimethoxycanthin-6-one increased, and the number of apoptotic cells increased. The tumor volume of mice injected with 4, 5-dimethoxycanthin-6-one decreased significantly.

CONCLUSION

4, 5-Dimethoxycanthin-6-one could act as a novel inhibitor of LSD1 to regulate glioblastoma, which could inhibit the proliferation of U251 and T98G cells and induce their apoptosis and pyroptosis. It is a potential drug for the treatment of glioblastoma.

FOXF2 Regulates PRUNE2 Transcription in the Pathogenesis of Colorectal Cancer

Background: Forkhead box F2, a member of the Forkhead box transcription factor superfamily, plays an important role in several types of cancer. However, the mechanisms of Forkhead box F2 in the progression of colorectal cancer remain unclear. PRUNE2 is closely associated with prostate cancer, neuroblastoma, glioblastoma, and melanoma. The relationship between Forkhead box F2 and PRUNE2 in colorectal cancer remains unknown. Method: We investigated the effects of Forkhead box F2 upregulation on colorectal cancer cell behavior in vitro using Cell Counting Kit-8, colony formation, flow cytometry, Transwell, reverse transcription quantitative polymerase chain reaction and Western blot analyses. Nude mouse xenografts were established to investigate the effect of Forkhead box F2 upregulation on the growth of colorectal cancer cells. Dual-luciferase reporter assays were performed to confirm the Forkhead box F2 regulation of PRUNE2 transcription. A series of in vitro assays was performed in cells with Forkhead box F2 upregulation and PRUNE2 knockdown to elucidate the function and regulatory effects of Forkhead box F2 on PRUNE2 transcription in colorectal cancer. Results: Forkhead box F2 was downregulated in colorectal cancer tissues compared with adjacent tissues. Forkhead box F2 overexpression significantly suppressed the proliferation and invasion of colorectal cancer cells in vitro and in vivo. Moreover, Forkhead box F2 directly targeted PRUNE2 to promote its transcription in colorectal cancer cells. Furthermore, PRUNE2 mediated the Forkhead box F2-regulated proliferation and invasion of colorectal cancer cells. Additionally, we demonstrated a significant positive correlation between Forkhead box F2 and PRUNE2 mRNA levels in colorectal cancer tissues. Conclusion: These results indicated that Forkhead box F2 and PRUNE2 in combination may serve as a prognostic biomarker for colorectal cancer and that Forkhead box F2 upregulation inhibits the proliferation and invasion of colorectal cancer cells by upregulating PRUNE2.

Histone methyltransferase SUV39H2 regulates LSD1-dependent CDH1 expression and promotes epithelial mesenchymal transition of osteosarcoma

OBJECTIVE

Osteosarcoma (OS) is a malignant tumor characterized by the direct production of bone or osteoid tissues by proliferating tumor cells. Suppressor of variegation 3-9 homolog 2 (SUV39H2) is implicated in the occurrence of OS. Therefore, we designed this study to investigate effects of SUV39H2 in OS meditated by the lysine specific demethylase-1/E-cadherin (LSD1/CDH1) axis.

METHODS

Clinical OS tissues and paracancerous tissues were collected for analysis of SUV39H2, LSD1 and CDH1 expression, and Kaplan-Meier survival analysis was applied to test the relationship between SUV39H2 expression and overall survival. Loss- and gain-of-function assays were conducted to determine the roles of SUV39H2, LSD1 and CDH1 in OS epithelial mesenchymal transition (EMT) and migration in OS cells, with quantitation of relevant proteins by immunofluorescence. We confirmed the effects of modulating the SUV39H2/CDH1 axis in a mouse OS tumor model.

RESULTS

SUV39H2 and LSD1 were highly expressed, while CDH1 was downregulated in OS tissues and cells. SUV39H2 expression correlated inversely with overall survival of patients with OS. SUV39H2 positively regulated LSD1 expression, while LSD1 negatively regulated CDH1 expression. SUV39H2 or LSD1 overexpression, or CDH1 silencing promoted migration and EMT, as indicated by reduced E-cadherin and dramatically upregulated Vimentin and N-cadherin of OS cells. SUV39H2 expedited the progression of OS, which was reversed by CDH1 repression in the setting of OS in vitro and in vivo.

CONCLUSIONS

Collectively, our results demonstrate highly expressed SUV39H2 in OS elevates the expression of LSD1 to downregulate CDH1 expression, thereby aggravating OS, providing a potential therapeutic target for treatment of OS.

Overexpression of protein regulator of cytokinesis 1 facilitates tumor growth and indicates unfavorable prognosis of patients with colon cancer

Background

Protein regulator of cytokinesis 1 (PRC1) has been reported to play important role in the pathogenesis of various cancers. However, its role in colon cancer has not been studied. Here, we aimed to investigate the biological functions and potential mechanism of PRC1 in colon cancer.

Methods

The expression level of PRC1 in colon cancer tissues and cell lines was detected by quantitative real-time polymerase chain reaction (qRT-PCR), Western blotting, and immunohistochemical (IHC) staining of a tissue microarray (TMA). Furthermore, colon cancer cell lines HCT116 and SW480 were treated with short hairpin RNAs against PRC1. The biological function of PRC1 was determined by MTT proliferation, colony formation assay, cell cycle, and apoptosis assays. Then, an in vivo tumor formation assay was conducted to explore the effects of PRC1 on tumor growth.

Results

The mRNA and protein expression levels of PRC1 were highly expressed in colon cancer tissues and cell lines. PRC1 expression was associated with clinicopathological characteristics and overall survival of patients with colon cancer. Knockdown of PRC1 could decrease proliferation and colony forming ability of colon cancer cells, as well as arrested more cells at G2/M phase and promoted cell apoptosis. In cancer cells, the expression pattern of protein regulators included in cell cycle and apoptosis progress were reverted by PRC1 down-regulation. Additionally, PRC1 down-regulation could suppress colon tumor growth and differentiation.

Conclusions

We confirmed that PRC1 was overexpressed in colon cancer and was associated with poor prognosis of colon cancer patients. PRC1 down-regulation could arrest cell cycle at G2/M stage, inhibit proliferation, and elicit apoptosis. These findings showed the potential of PRC1 to be used for therapeutic approaches in colon cancer.

Synergistic antitumor effect of 5-fluorouracil with the novel LSD1 inhibitor ZY0511 in colorectal cancer

Background

Lysine-specific histone demethylase 1 (LSD1) is a potential target of cancer therapy. In the present study, we aimed to investigate the combined antitumor activity of a novel LSD1 inhibitor (ZY0511) with 5-fluorouracil (5-FU) and elucidate the underlying mechanism in colorectal cancer (CRC).

Methods

We evaluated LSD1 expression in CRC tissues from patients who received 5-FU treatment. The synergistic antitumor effect of 5-FU with ZY0511 against human CRC cells was detected both in vitro and in vivo. The underlying mechanism was explored based on mRNA sequencing (mRNA-seq) technology.

Results

Overexpression of LSD1 was observed in human CRC tissues, and correlated with CRC development and 5-FU resistance. ZY0511, a novel LSD1 inhibitor, effectively inhibited CRC cells proliferation, both in vitro and in vivo. Notably, the combination of ZY0511 and 5-FU synergistically reduced CRC cells viability and migration in vitro. It also suppressed Wnt/β-catenin signaling and DNA synthesis pathways, which finally induced apoptosis of CRC cells. In addition, the combination of ZY0511 with 5-FU significantly reduced CRC xenograft tumor growth, along with lung and liver metastases in vivo.

Conclusions

Our findings identify LSD1 as a potential marker for 5-FU resistance in CRC. ZY0511 is a promising candidate for CRC therapy as it potentiates 5-FU anticancer effects, thereby providing a new combinatorial strategy for treating CRC.

FOXF2 acts as a crucial molecule in tumours and embryonic development

As a key member of the forkhead box transcription factors, forkhead box F2 (FOXF2) serves as a transcriptional regulator and regulates downstream gene expression in embryonic development, metabolism and in some common diseases, such as stroke and gastroparesis. Recent studies have shown that aberrant expression of FOXF2 is associated with a variety of tumorigenic processes, such as proliferation, invasion and metastasis. The role of FOXF2 in the development of many different organs has been confirmed by studies and has been speculated about in case reports. We focus on the mechanisms and signal pathways of tumour development initiated by aberrant expression of FOXF2, and we summarize the diseases and signal pathways caused by aberrant expression of FOXF2 in embryogenesis. This article highlights the differences in the role of FOXF2 in different tumours and demonstrates that multiple factors can regulate FOXF2 levels. In addition, FOXF2 is considered a biomarker for the diagnosis or prognosis of various tumours. Therefore, regulating the level of FOXF2 is an ideal treatment for tumours. FOXF2 could also affect the expression of some organ-specific genes to modulate organogenesis and could serve as a biomarker for specific differentiated cells. Finally, we present prospects for the continued research focus of FOXF2.

Knocking down LSD1 inhibits the stemness features of colorectal cancer stem cells

As a top leading cause of cancer death in many countries, colorectal cancer (CRC) has drawn increasing attention to the study of the pathological mechanism. According to the “cancer stem cell hypothesis”, malignancies originate from a small fraction of cancer cells that show self-renewal properties to initiate and sustain tumor growth and tumor metastasis. Therefore, these cancer stem cells (CSC) probably play important roles in tumor recurrence, metastasis, and drug resistance. Previous research reported that lysine-specific histone demethylase 1 (LSD1) maintains cancer stemness through up-regulating stemness markers SOX2 and OCT4. CD133 is believed to be the most robust surface marker for CRC stem cells, however the regulatory effect of LSD1 on stemness of CD133+ CRC has never been reported. In this study, our objectives included: 1) to isolate pure CD133+ and CD133− cells from SW620 cell line; 2) to investigate the effect of LSD1 on the characteristics of CD133+ stem cancer cells by knocking down the target gene. Results suggested that the SW620 cell line had both CD133+ and CD133− subsets. The CD133+ subset exhibited more CSC-like characteristics compared with the CD133− subset with higher viability, colony formation rate, migration and invasion rate, resistance to anti-cancer drugs, and apoptosis in vitro. The CD133+ also induced faster tumor formation and larger tumors in vivo. In the LSD1-knockdown CD133+ cells, the CSC-like characteristics had been all weakened. We conclude that LSD1 was important for CSCs to maintain their “stemness” features, which could be a potential therapeutic target of CRC.

Downregulated microRNAs in the colorectal cancer: diagnostic and therapeutic perspectives

Colorectal cancer (CRC), the third most common cancer in the world, has no specific biomarkers that facilitate its diagnosis and subsequent treatment. The miRNAs, small single-stranded RNAs that repress the mRNA translation and trigger the mRNA degradation, show aberrant levels in the CRC, by which these molecules have been related with the initiation, progression, and drug-resistance of this cancer type. Numerous studies show the microRNAs influence the cellular mechanisms related to the cell cycle, differentiation, apoptosis, and migration of the cancer cells through the post-transcriptionally regulated gene expression. Specific patterns of the upregulated and down-regulated miRNA have been associated with the CRC diagnosis, prognosis, and therapeutic response. Concretely, the downregulated miRNAs represent attractive candidates, not only for the CRC diagnosis, but for the targeted therapies via the tumor-suppressing microRNA replacement. This review shows a general overview of the potential uses of the miRNAs in the CRC diagnosis, prognosis, and treatment with a special focus on the downregulated ones. [BMB Reports 2018; 51(11): 563-571].

Downregulation of PRMT1, a histone arginine methyltransferase, by sodium propionate induces cell apoptosis in colon cancer

The microbiota and bacterial metabolites in the colon are regarded as alternative targets for colon cancer prevention and therapy. Among these metabolites, short-chain fatty acids (SCFAs) exhibit anticancer effects and suppress inflammation in the colon. However, the molecular mechanisms and target development of SCFAs require additional study. In the present study, using RNA-seq results from colon cancer samples derived from the Cancer Genome Atlas (TCGA) portal, overexpressed epigenetic modifiers were identified and RT-PCR and qRT-PCR analysis was performed to select target genes that responded to treatment with propionate in HCT116 cells. Downregulation of protein arginine methyltransferase 1 (PRMT1), a histone arginine methyltransferase, was observed after sodium propionate (SP) treatment. Moreover, phospho-array analysis demonstrated that the mTOR pathway was involved in propionate and siPRMT1 treatment, and regulation of this pathway was associated with apoptosis in HCT116 cells. The present study, to the best of our knowledge, was the first to demonstrate that PRMT1 levels were reduced by propionate treatment in HCT116 cells and that downregulation of PRMT1 induced cell apoptosis. Thus, this novel mechanism of sodium propionate treatment for colon cancer therapy may indicate more effective approaches, such as dietary therapy, for CRC patients.

Prognostic value of histone marks H3K27me3 and H3K9me3 and modifying enzymes EZH2, SETDB1 and LSD-1 in colorectal cancer

PURPOSE

Studies on the performance of epigenetic-based biomarkers in colorectal cancer (CRC) are scarce and have shown contradictory results. Thus, we sought to examine the prognostic value of histone-modifying enzymes (EZH2, SETDB1 and LSD-1) and histone post-translational marks (H3K27me3 and H3K9me3) in CRC.

METHODS

A retrospective series of 207 CRC patients primarily submitted to surgery in a cancer center was included in this study. Clinicopathological data were retrieved. One representative paraffin block per case was selected for immunohistochemistry, including normal and CRC tissues whenever possible. The percentage of positive nuclear staining (digital image analysis) was used to classify patients into "low" and "high" expression groups for each biomarker. Correlations between immunoexpression levels, clinicopathological features and clinical outcomes [disease-specific (DSS) and disease-free (DFS) survival] were examined. Statistical significance was set at p < 0.05.

RESULTS

CRC tissues showed significantly lower expression of SETDB1 and higher expression of the remainder four biomarkers compared to normal mucosa. High EZH2 expression correlated with disease recurrence/progression, whereas low LSD1 expression and high H3K9me3 and H3K27me3 expression were associated with more advanced stage. In multivariable analysis, cases with high LSD1 expression displayed significantly better DSS and DFS (HR 0.477, 95% confidence interval: 0.247-0.923) adjusted for pathological TNM stage.

CONCLUSION

EZH2, SETDB1, LSD1, H3K9me3 and H3K27me3 expression are altered in CRC and may play a role in colorectal carcinogenesis. LSD1 immunoexpression levels independently predicted patient outcome in this cohort. Further investigations, using larger series, are warranted to confirm its potential clinical value and unravel underlying molecular mechanisms.

3-Chloro-N'-(2-hydroxybenzylidene) benzohydrazide: An LSD1-Selective Inhibitor and Iron-Chelating Agent for Anticancer Therapy

Despite the discovery and development of novel therapies, cancer is still a leading cause of death worldwide. In order to grow, tumor cells require large quantities of nutrients involved in metabolic processes, and an increase in iron levels is known to contribute to cancer proliferation. Iron plays an important role in the active site of a number of proteins involved in energy metabolism, DNA synthesis and repair, such as ribonucleotide reductase, which induce G0/S phase arrest and exert a marked antineoplastic effect, particularly in leukemia and neuroblastoma. Iron-depletion strategies using iron chelators have been shown to result in cell cycle arrest and apoptosis. Deferoxamine (DFO) was the first FDA-approved drug for the treatment of iron overload pathologies, and has also been recognized as having anticancer properties. The high cost, low permeability and short plasma half-life of DFO led to the development of other iron-chelating drugs. Pyridoxal isonicotinoyl hydrazone (PIH) and its analogs chelate cellular iron by tridentate binding, and inhibit DNA synthesis more robustly than DFO, demonstrating an effective antiproliferative activity. Here, we investigated the biological effects of a PIH derivative, 3-chloro-N′-(2-hydroxybenzylidene)benzohydrazide (CHBH), known to be a lysine-specific histone demethylase 1A inhibitor. We showed that CHBH is able to induce cell proliferation arrest in several human cancer cell lines, including lung, colon, pancreas and breast cancer, at micromolar levels. Our findings indicate that CHBH exerts a dual anticancer action by strongly impairing iron metabolism and modulating chromatin structure and function.

Ubiquitin Regulation: The Histone Modifying Enzyme's Story

Histone post-translational modifications influence many fundamental cellular events by regulating chromatin structure and gene transcriptional activity. These modifications are highly dynamic and tightly controlled, with many enzymes devoted to the addition and removal of these modifications. Interestingly, these modifying enzymes are themselves fine-tuned and precisely regulated at the level of protein turnover by ubiquitin-proteasomal processing. Here, we focus on recent progress centered on the mechanisms regulating ubiquitination of histone modifying enzymes, including ubiquitin proteasomal degradation and the reverse process of deubiquitination. We will also discuss the potential pathophysiological significance of these processes.

Screening and identification of key biomarkers in bladder carcinoma: Evidence from bioinformatics analysis

Bladder cancer (BC) is one of the most common urogenital malignancies. However, present studies of its multiple gene interaction and cellular pathways remain unable to accurately verify the genesis and the development of BC. The aim of the present study was to investigate the genetic signatures of BC and identify its potential molecular mechanisms. The gene expression profiles of GSE31189 were downloaded from the Gene Expression Omnibus database. The GSE31189 dataset contained 92 samples, including 52 BC and 40 non-cancerous urothelial cells. To further examine the biological functions of the identified differentially expressed genes (DEGs), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses were performed, and a protein-protein interaction (PPI) network was mapped using Cytoscape software. In total, 976 DEGs were identified in BC, including 457 upregulated genes and 519 downregulated genes. GO and KEGG pathway enrichment analyses indicated that upregulated genes were significantly enriched in the cell cycle and the negative regulation of the apoptotic process, while the downregulated genes were mainly involved in cell proliferation, cell adhesion molecules and oxidative phosphorylation pathways (P<0.05). From the PPI network, the 12 nodes with the highest degrees were screened as hub genes; these genes were involved in certain pathways, including the chemokine-mediated signaling pathway, fever generation, inflammatory response and the immune response nucleotide oligomerization domain-like receptor signaling pathway. The present study used bioinformatics analysis of gene profile datasets and identified potential therapeutic targets for BC.

Prominent role of histone lysine demethylases in cancer epigenetics and therapy

Protein methylation has an important role in the regulation of chromatin, gene expression and regulation. The protein methyl transferases are genetically altered in various human cancers. The enzymes that remove histone methylation have led to increased awareness of protein interactions as potential drug targets. Specifically, Lysine Specific Demethylases (LSD) removes methylated histone H3 lysine 4 (H3K4) and H3 lysine 9 (H3K9) through formaldehyde-generating oxidation. It has been reported that LSD1 and its downstream targets are involved in tumor-cell growth and metastasis. Functional studies of LSD1 indicate that it regulates activation and inhibition of gene transcription in the nucleus. Here we made a discussion about the summary of histone lysine demethylase and their functions in various human cancers.