LSD1-mediated epigenetic modification contributes to ovarian cancer cell migration and invasion

KDM1A-mediated ZFP64 demethylation activates CENPL to promote epithelial ovarian cancer progression

Lysine-specific histone demethylase 1A (KDM1A) has emerged as an attractive therapeutic target for treating various cancers, owing to its observed overexpression. However, its function in epithelial ovarian cancer (EOC) remains uncertain. The current study sought to investigate the function of KDM1A on malignant phenotypes of EOC cells as well as the underlying mechanism. Colony formation assay, cell counting kit-8, wound healing, Transwell assays, and TUNEL assays were performed to investigate the effects of KDM1A, Zinc finger protein 64 (ZFP64), and centromere protein L (CENPL) in vitro, while subcutaneous tumor formation models were established in nude mice to evaluate their roles in vivo. KDM1A, ZFP64, and CENPL were overexpressed in EOC tissues and cells. Knockdown of KDM1A, ZFP64, or CENPL inhibited the biological behavior of EOC cells. In addition, chromatin immunoprecipitation showed that KDM1A stimulated ZFP64 expression by removing the H3K9me2 mark from its promoter. Restoration of ZFP64 promoted EOC cell malignant phenotype in the presence of KDM1A knockdown. ZFP64 activated CENPL transcription. Reactivation of CENPL promoted the growth of EOC cells in vivo inhibited by knockdown of ZFP64. Collectively, KDM1A promoted EOC cell proliferation, migration, and invasion, and reduced apoptosis by activating the ZFP64/CENPL axis, which triggered EOC progression.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10616-024-00671-w.

LSD1 Demethylates and Destabilizes Autophagy Protein LC3B in Ovarian Cancer

Autophagy is a complex cellular process that can either promote or inhibit cancer progression and development, depending on the context and molecular regulation involved. This study investigates how LSD1 regulates autophagy in ovarian cancer by interacting with the autophagy protein LC3B. Utilizing the bioinformatic analysis of TCGA, CPTAC, and GEO datasets, as well as immunohistochemistry in ovarian cancer patients, we explored the expression association between LSD1 and LC3B. Molecular mechanisms were further analyzed using Western blotting, immunoprecipitation, and GST pull-down assays. Our findings reveal that LSD1 binds to LC3B via its SWIRM domain, and high levels of LSD1 are closely associated with aggressive ovarian cancer and poor patient outcomes. Mechanistically, LSD1 demethylates LC3B, leading to decreased LC3B stability. The observed inverse correlation between LSD1 expression and LC3B protein levels in clinical samples underscores the need for further investigation to elucidate how reduced LC3B protein levels induced by LSD1 demethylation may contribute to ovarian cancer.

KDM1A/LSD1 inhibition enhances chemotherapy response in ovarian cancer

Ovarian cancer (OCa) is the deadliest of all gynecological cancers. The standard treatment for OCa is platinum-based chemotherapy, such as carboplatin or cisplatin in combination with paclitaxel. Most patients are initially responsive to these treatments; however, nearly 90% will develop recurrence and inevitably succumb to chemotherapy-resistant disease. Recent studies have revealed that the epigenetic modifier lysine-specific histone demethylase 1A (KDM1A/LSD1) is highly overexpressed in OCa. However, the role of KDM1A in chemoresistance and whether its inhibition enhances chemotherapy response in OCa remains uncertain. Analysis of TCGA datasets revealed that KDM1A expression is high in patients who poorly respond to chemotherapy. Western blot analysis show that treatment with chemotherapy drugs cisplatin, carboplatin, and paclitaxel increased KDM1A expression in OCa cells. KDM1A knockdown (KD) or treatment with KDM1A inhibitors NCD38 and SP2509 sensitized established and patient-derived OCa cells to chemotherapy drugs in reducing cell viability and clonogenic survival and inducing apoptosis. Moreover, knockdown of KDM1A sensitized carboplatin-resistant A2780-CP70 cells to carboplatin treatment and paclitaxel-resistant SKOV3-TR cells to paclitaxel. RNA-seq analysis revealed that a combination of KDM1A-KD and cisplatin treatment resulted in the downregulation of genes related to epithelial-mesenchymal transition (EMT). Interestingly, cisplatin treatment increased a subset of NF-κB pathway genes, and KDM1A-KD or KDM1A inhibition reversed this effect. Importantly, KDM1A-KD, in combination with cisplatin, significantly reduced tumor growth compared to a single treatment in an orthotopic intrabursal OCa xenograft model. Collectively, these findings suggest that combination of KDM1A inhibitors with chemotherapy could be a promising therapeutic approach for the treatment of OCa.

Epigenetic modification in radiotherapy and immunotherapy for cancers

Radiotherapy (RT) is one of the primary treatment modalities in managing cancer patients. Recently, combined RT and immunotherapy (IT) (i.e., radio-IT [RIT]) have been aggressively investigated in managing cancer patients. However, several issues in conducting RIT are challenging, such as incorporating advanced irradiation techniques, predictive/prognostic biomarkers, and other treatment modalities. Several clinical efforts and novel biomarkers have been introduced and developed to solve these challenges. For example, stereotactic radiosurgery/stereotactic radiotherapy, stereotactic body radiotherapy/stereotactic ablative body radiotherapy, and FLASH-RT have been applied for delivering precise irradiation to lung and liver tumors in conjunction with IT. Besides, several novel IT agents and incorporations of other therapies, such as targeted and thermal therapies, have been further investigated. The present study reviewed the emerging challenges of RIT in modern oncology. We also evaluated clinical practice, bench research, and multimodality treatments. In addition to several clinically applicable biomarkers, we emphasize the roles of advanced irradiation techniques and epigenetic modification as predictive/prognostic biomarkers and potential therapeutic targets. For example, 6(m) A-based epigenetic agents demonstrate the potential to enhance the treatment effects of RIT. However, further prospective randomized trials should be conducted to confirm their roles.

ARID5B promoted the histone demethylation of SORBS2 and hampered the metastasis of ovarian cancer

Ovarian cancer (OVCA) is the 4th most common female tumor after breast cancer, cervical cancer, and endometrial cancer, and now is mainly treated with debulking surgery and postoperative cisplatin and paclitaxel-based combination chemotherapy regimens. However, OVCA is insidious in its development and recurrence occurred in some patients after treatment. It is of great significance to study the pathogenesis of ovarian cancer and identify more biomarkers. Recently, the role of histone methyltransferase (HMT) and histone demethylase (HDM) in oncogenesis and development of malignant tumors has raised attention. Unlike other JMJC demethylases that have both JMJC and ARID domains in a single molecule, PHF2 requires assembly into a complex with a DNA-binding subunit (ARID5B) and exerts its enzymatic activity. Therefore, the aim of this manuscript is to investigate the role of histone demethylases ARID5B-PHF2 complex in the metastasis of OVCA. As result, we found ARID5B and PHF2 are both low expressed in OVCA tumor tissues and cell lines and associated with diagnosis and prognosis. Also, ARID5B suppressed rearrangement of the cytoskeleton in the process of EMT in OVCA cell lines. The role of PHF2 as a tumor suppressor was also confirmed both in vivo and in vitro. SORBS2 is low expressed in OVCA tumor tissues and cell lines and associated with diagnosis and prognosis. The expression of SORBS2 is positively corelated with the expression of ARID5B and PHF2. The promoter of SORBS2 is proved combined with ARID5B. The expression of SORBS2 was increased due to ARID5B-PHF2 complex promoted the histone demethylation by mainly binding in site H3K36me2 and therefore promoting the transcription of SORBS2. In conclusion, ARID5B-PHF2 complex promoted the histone demethylation of SORBS2 by mainly bind in site H3K36me2 and therefore promote the transcription of SORBS2 then hampered the process of EMT and tumor generation of OVCA. These results provided a new perspective on the molecular mechanisms of OVCA development and offered a new target of clinical diagnose and treatment of OVCA.

Repression of LSD1 potentiates homologous recombination-proficient ovarian cancer to PARP inhibitors through down-regulation of BRCA1/2 and RAD51

Poly (ADP-ribose) polymerase inhibitors (PARPi) are selectively active in ovarian cancer (OC) with homologous recombination (HR) deficiency (HRD) caused by mutations in BRCA1/2 and other DNA repair pathway members. We sought molecular targeted therapy that induce HRD in HR-proficient cells to induce synthetic lethality with PARPi and extend the utility of PARPi. Here, we demonstrate that lysine-specific demethylase 1 (LSD1) is an important regulator for OC. Importantly, genetic depletion or pharmacological inhibition of LSD1 induces HRD and sensitizes HR-proficient OC cells to PARPi in vitro and in multiple in vivo models. Mechanistically, LSD1 inhibition directly impairs transcription of BRCA1/2 and RAD51, three genes essential for HR, dependently of its canonical demethylase function. Collectively, our work indicates combination with LSD1 inhibitor could greatly expand the utility of PARPi to patients with HR-proficient tumor, warranting assessment in human clinical trials.

Pharmacological inhibition of KDM1A/LSD1 enhances estrogen receptor beta-mediated tumor suppression in ovarian cancer

Ovarian cancer (OCa) is the most lethal gynecologic cancer. Emerging data indicates that estrogen receptor beta (ERβ) functions as a tumor suppressor in OCa. Lysine-specific histone demethylase 1A (KDM1A) is an epigenetic modifier that acts as a coregulator for steroid hormone receptors. However, it remain unknown if KDM1A interacts with ERβ and regulates its expression/functions in OCa. Analysis of TCGA data sets indicated KDM1A and ERβ expression showed an inverse relationship in OCa. Knockout (KO), knockdown (KD), or inhibition of KDM1A increased ERβ isoform 1 expression in established and patient-derived OCa cells. Further, KDM1A interacts with and functions as a corepressor of ERβ, and its inhibition enhances ERβ target gene expression via alterations of histone methylation marks at their promoters. Importantly, KDM1A-KO or -KD enhanced the efficacy of ERβ agonist LY500307, and the combination of KDM1A inhibitor (KDM1Ai) NCD38 with ERβ agonist synergistically reduced the cell viability, colony formation, and invasion of OCa cells. RNA-seq and DIA mass spectrometry analyses showed that KDM1A-KO resulted in enhanced ERβ signaling and that genes altered by KDM1A-KO and ERβ agonist were related to apoptosis, cell cycle, and EMT. Moreover, combination treatment significantly reduced the tumor growth in OCa orthotopic, syngeneic, and patient-derived xenograft models and proliferation in patient-derived explant models. Our results demonstrate that KDM1A regulates ERβ expression/functions, and its inhibition improves ERβ mediated tumor suppression. Overall, our findings suggest that KDM1Ai and ERβ agonist combination therapy is a promising strategy for OCa.

Post-translational modifications of histones: Mechanisms, biological functions, and therapeutic targets

Histones are DNA-binding basic proteins found in chromosomes. After the histone translation, its amino tail undergoes various modifications, such as methylation, acetylation, phosphorylation, ubiquitination, malonylation, propionylation, butyrylation, crotonylation, and lactylation, which together constitute the "histone code." The relationship between their combination and biological function can be used as an important epigenetic marker. Methylation and demethylation of the same histone residue, acetylation and deacetylation, phosphorylation and dephosphorylation, and even methylation and acetylation between different histone residues cooperate or antagonize with each other, forming a complex network. Histone-modifying enzymes, which cause numerous histone codes, have become a hot topic in the research on cancer therapeutic targets. Therefore, a thorough understanding of the role of histone post-translational modifications (PTMs) in cell life activities is very important for preventing and treating human diseases. In this review, several most thoroughly studied and newly discovered histone PTMs are introduced. Furthermore, we focus on the histone-modifying enzymes with carcinogenic potential, their abnormal modification sites in various tumors, and multiple essential molecular regulation mechanism. Finally, we summarize the missing areas of the current research and point out the direction of future research. We hope to provide a comprehensive understanding and promote further research in this field.

Epigenetic compounds targeting pharmacological target lysine specific demethylase 1 and its impact on immunotherapy, chemotherapy and radiotherapy for treatment of tumor recurrence and resistance

It has been proven that metastatic recurrence and therapeutic resistance are linked. Due to the variability of individuals and tumors, as well as the tumor's versatility in avoiding therapies, therapy resistance is more difficult to treat. Therapy resistance has significantly restricted the clinical feasibility and efficacy of tumor therapy, despite the discovery of novel compounds and therapy combinations with increasing efficacy. In several tumors, lysine specific demethylase 1 (LSD1) has been associated to metastatic recurrence and therapeutic resistance. For researchers to better comprehend how LSD1-mediated tumor therapy resistance occurs and how to overcome it in various tumors, this study focused on the role of LSD1 in tumor recurrence and therapeutic resistance. The importance of therapeutically targeted LSD1 was also discussed. Most gene pathway signatures are related to LSD1 inhibitor sensitivity. However, some gene pathway signatures, especially in AML, negatively correlate with LSD1 inhibitor sensitivity, but targeting LSD1 makes the therapy-resistant tumor sensitive to physiological doses of conventional therapy. We propose that combining LSD1 inhibitor with traditional tumor therapy can help patients attain a complete response and prevent cancer relapse.

Tackling drug resistance in ovarian cancer with epigenetic targeted drugs

Epigenetic dysregulation plays a crucial role in the development and progression of ovarian cancer. Since the first experiment conducted on resistant ovarian cancer cells using demethylating drugs, multiple clinical trials have revealed that epigenetic targeted drugs combined with chemotherapy, molecular-targeted drugs, or even immunotherapy could enhance tumor sensitivity and reverse acquired resistances. Here, we summarized the combination strategies of epigenetic targeted drugs with other treatment strategies of ovarian cancer and discussed the principles of combination therapy. Finally, we enumerated several reasonable clinical trial designs as well as future drug development strategies, which may provide promising ideas for the application of epigenetic drugs to ovarian cancer.

Systematic Review and Meta-Analysis of Lysine-Specific Demethylase 1 Expression as a Prognostic Biomarker of Cancer Survival and Disease Progression

Background

Numerous studies on the prognostic significance of lysine-specific demethylase 1 (LSD1) up-regulation in tumors have different outcomes. The inconsistency originated from various studies looking into the association between LSD1 and tumor cells has prompted the decision of this quantitative systematic review to decipher how up-regulated LSD1 and overall survival (OS) or recurrence-free survival (RFS) or disease-free survival (DFS) are linked in tumor patients.

Methods

Articles were searched from online databases such as Embase, Web of Science Core, PubMed, Google Scholar, and Scopus. The extraction of the hazard ratios (HR) with their 95% confidence intervals (CIs) was attained and survival data of 3151 tumor patients from 17 pieces of related research were used for this meta-analysis.

Results

To shed light on the link between LSD1 up-regulation and the prognosis of diverse tumors, the pooled hazard ratios (HRs) with their 95% confidence intervals (CIs) were determined. In this meta-analysis, it was observed that LSD1 up-regulation is linked with poor OS (HR = 2.08, 95% CI: 1.66–2.61, P < .01) and RFS (HR = 3.09, 95% CI: 1.81–5.26, P < .01) in tumor patients. However, LSD1 up-regulation was not linked to DFS (HR = 1.49, 95% CI: .83–2.69, P = .18) in tumor patients. The subcategory examination grouped by tumor type and ethnicity showed that LSD1 up-regulation was linked with a poor outcome in the esophageal tumor and hepatocellular carcinoma and Asian patients, respectively. For clinical-pathological factors, up-regulated LSD1 was significantly linked with Lymph node status.

Conclusion

Despite the shortfall of the present work, this meta-analysis proposes that LSD1 up-regulation may be a prognostic biomarker for patients with tumors including esophageal tumors and hepatocellular carcinoma. We propose that large-scale studies are vital to substantiate these outcomes.

LSD1 as a Biomarker and the Outcome of Its Inhibitors in the Clinical Trial: The Therapy Opportunity in Tumor

Tumors are the foremost cause of death worldwide. As a result of that, there has been a significant enhancement in the investigation, treatment methods, and good maintenance practices on cancer. However, the sensitivity and specificity of a lot of tumor biomarkers are not adequate. Hence, it is of inordinate significance to ascertain novel biomarkers to forecast the prognosis and therapy targets for tumors. This review characterized LSD1 as a biomarker in different tumors. LSD1 inhibitors in clinical trials were also discussed. The recent pattern advocates that LSD1 is engaged at sauce chromatin zones linking with complexes of multi-protein having an exact DNA-binding transcription factor, establishing LSD1 as a favorable epigenetic target, and also gives a large selection of therapeutic targets to treat different tumors. This review sturdily backing the oncogenic probable of LSD1 in different tumors indicated that LSD1 levels can be used to monitor and identify different tumors and can be a useful biomarker of progression and fair diagnosis in tumor patients. The clinical trials showed that inhibitors of LSD1 have growing evidence of clinical efficacy which is very encouraging and promising. However, for some of the inhibitors such as GSK2879552, though selective, potent, and effective, its disease control was poor as the rate of adverse events (AEs) was high in tumor patients causing clinical trial termination, and continuation could not be supported by the risk-benefit profile. Therefore, we propose that, to attain excellent clinical results of inhibitors of LSD1, much attention is required in designing appropriate dosing regimens, developing in-depth in vitro/in vivo mechanistic works of LSD1 inhibitors, and developing inhibitors of LSD1 that are reversible, safe, potent, and selective which may offer safer profiles.

Proteasomal degradation of polycomb-group protein CBX6 confers MMP-2 expression essential for mesothelioma invasion

The aggressive invasiveness of malignant mesothelioma limits cancer therapy, however, the molecular mechanisms underlying the invasiveness remain largely unknown. Here we found that the matrix metalloproteinase-2 (MMP-2) was required for the invasion of mesothelioma cells in the collagen matrix and the gene expression of MMP-2 was correlated with the invasive phenotype. The MMP-2 gene expression was regulated by DNA and histone methylation around the transcription start site, implicating the involvement of the polycomb repressive complex (PRC). Knockdown of PRC component chromobox 6 (CBX6) promoted MMP-2 expression and invasion of mesothelioma cells. Transcriptome analysis suggested that CBX6 regulates sets of genes involved in cancer cell migration and metastasis. In invasive but not non-invasive cells, CBX6 was constantly unstable owing to ubiquitination and protein degradation. In human tissues, CBX6 localized in the nuclei of normal mesothelium and benign mesothelioma, but the nuclear staining of CBX6 was lost in malignant mesothelioma. These results suggest involvement of proteasomal degradation of CBX6 in mesothelioma progression.

The identification of six risk genes for ovarian cancer platinum response based on global network algorithm and verification analysis

Ovarian cancer is the most lethal gynaecological cancer, and resistance of platinum‐based chemotherapy is the main reason for treatment failure. The aim of the present study was to identify candidate genes involved in ovarian cancer platinum response by analysing genes from homologous recombination and Fanconi anaemia pathways. Associations between these two functional genes were explored in the study, and we performed a random walk algorithm based on reconstructed gene‐gene network, including protein‐protein interaction and co‐expression relations. Following the random walk, all genes were ranked and GSEA analysis showed that the biological functions focused primarily on autophagy, histone modification and gluconeogenesis. Based on three types of seed nodes, the top two genes were utilized as examples. We selected a total of six candidate genes (FANCA, FANCG, POLD1, KDM1A, BLM and BRCA1) for subsequent verification. The validation results of the six candidate genes have significance in three independent ovarian cancer data sets with platinum‐resistant and platinum‐sensitive information. To explore the correlation between biomarkers and clinical prognostic factors, we performed differential analysis and multivariate clinical subgroup analysis for six candidate genes at both mRNA and protein levels. And each of the six candidate genes and their neighbouring genes with a mutation rate greater than 10% were also analysed by network construction and functional enrichment analysis. In the meanwhile, the survival analysis for platinum‐treated patients was performed in the current study. Finally, the RT‐qPCR assay was used to determine the performance of candidate genes in ovarian cancer platinum response. Taken together, this research demonstrated that comprehensive bioinformatics methods could help to understand the molecular mechanism of platinum response and provide new strategies for overcoming platinum resistance in ovarian cancer treatment.

Lysine-Specific Demethylase 1 Affects the Progression of Papillary Thyroid Carcinoma via HIF1α and microRNA-146a

CONTEXT

Lysine-specific demethylase 1 (LSD1) stabilizes hypoxia-inducible factor 1α (HIF1α) to advance tumor progression, while HIF1α functions as a transcription factor to increase the expression of microRNA-146a (miR-146a).

OBJECTIVE

We aim to investigate whether LSD1 affects the development of papillary thyroid carcinoma (PTC) via HIF1α and miR-146a.

DESIGN

In vitro assays were performed with Nthy-ori 3-1, BHP5-16, BCPAP, K1, and BHP2-7 cell lines. In vivo assays were conducted with established xenograft tumors in nude mice.

SETTING

This study was conducted at our lab.

PATIENTS AND MATERIALS

PTC tissues and corresponding adjacent normal tissues were obtained from 45 patients hospitalized in Sun Yat-Sen Memorial Hospital. Assays were conducted using Nthy-ori 3-1, BHP5-16, BCPAP, K1, and BHP2-7 cell lines, as well as 50 male BALB/c nude mice.

INTERVENTION

Cells were transfected with sh-LSD1, sh-GABPA, oe-LSD1, oe-HIF1α, miR-146a mimic, and miR-146a inhibitor. In addition, K1 cells expressing lv-oe-LSD1, lv-miR-146a inhibitor, lv-oe-LSD1 or miR-146a inhibitor were injected into the right side of the mice. LSD1 gene and protein expression patterns were analyzed in 45 clinical PTC tissue samples.

MAIN OUTCOME MEASURE

Expression of LSD1, HIF1α, miR-146a, and GA-binding protein transcription factor alpha (GABPA), as well as their effects on PTC.

RESULTS

LSD1 was highly expressed in clinical PTC tissues. LSD1 stabilized HIF1α and inhibited the degradation of its ubiquitin proteasome. HIF1α was enriched in the promoter region of miR-146a, an upregulated miRNA in PTC. HIF1α increased miR-146a expression to promote PTC progression in vitro, which was achieved by inhibiting GABPA, a target gene of miR-146a. LSD1 upregulated miR-146a to enhance the development and metastasis of PTC in nude mice.

CONCLUSION

Our results show that LSD1 functions as an oncogene in PTC by upregulating HIF1α and miR-146a, elucidating an understanding of undefined mechanisms associated with tumor progression in PTC.

GATA3 as a master regulator for interactions of tumor-associated macrophages with high-grade serous ovarian carcinoma

High-grade serous ovarian carcinoma (HGSOC) is the most lethal gynecologic cancer. Emerging evidence suggests that tumor-associated macrophages (TAMs) play an immunosuppressive role in the tumor microenvironment and promote tumor growth, angiogenesis, and metastasis in ovarian cancer. Therefore, targeting TAMs in patients with ovarian cancer is an appealing strategy; however, all trials to date have failed. To improve the efficacy of this approach, we sought to elucidate the underlying mechanisms of the role of TAMs in ovarian cancer. We found that the developmental transcription factor GATA3 was highly expressed in HGSOC cell lines but not in the fallopian tube, which is the main origin of HGSOC. GATA3 expression was associated with poor prognosis in HGSOC patients (P < .05) and was found to promote proliferation and migration in HGSOC cell lines. GATA3 was released abundantly from TAM cells via exosomes and contributed to tumor growth in the tumor microenvironment. Moreover, GATA3 acted as a regulator for macrophage polarization and interactions between TAMs and HGSOC to support proliferation, motility, and cisplatin chemoresistance in mutant TP53 HGSOC cell lines. Furthermore, GATA3 played a critical role in the interactions between TAMs and mutant TP53 HGSOC to promote angiogenesis and epithelial-mesenchymal transition with epigenetic regulation. Targeting GATA3 using GATA3siRNA in TAMs impeded GATA3-driven proliferation, migration, cisplatin chemoresistance, and angiogenesis in mutant TP53 HGSOC cell lines. Our findings indicate that GATA3 plays a novel role in immunoediting of HGSOC and demonstrate that GATA3 may serve as a prognostic marker for HGSOC and a promising target in the treatment of HGSOC.

Basil polysaccharides: A review on extraction, bioactivities and pharmacological applications

Traditional Chinese Medicine has been widely used in China and is regarded as the most commonly used treatment. As a natural plant used in traditional Chinese Medicine, Basil has various functions associated with a number of its components. There are many compositions in basil including polysaccharides, naphtha, steroids, flavone, coumarins, vitamins, and so on. Among these, polysaccharides play a significant role in based therapeutics. The article summarizes that basil polysaccharides have a lot of biological activities and pharmacological applications, such as their antitumor activity, antioxidant activity, anti-aging activity, immunity enhancement effect, hypolipidemic and anti-atherosclerotic effects, antibacterial effect, treatment of diabetes mellitus, and so on. This review summarized the extraction method, purification method, compositions, pharmacological applications, molecular weight, biological activities, and prospects of basil polysaccharides, providing a basis for further study of basil and basil polysaccharides.

Epigenetic Dysregulation at the Crossroad of Women's Cancer

An increasingly number of women of all age groups are affected by cancer, despite substantial progress in our understanding of cancer pathobiology, the underlying genomic alterations and signaling cascades, and cellular-environmental interactions. Though our understanding of women’s cancer is far more complete than ever before, there is no comprehensive model to explain the reasons behind the increased incidents of certain reproductive cancer among older as well as younger women. It is generally suspected that environmental and life-style factors affecting hormonal and growth control pathways might help account for the rise of women’s cancers in younger age, as well, via epigenetic mechanisms. Epigenetic regulators play an important role in orchestrating an orderly coordination of cellular signals in gene activity in response to upstream signaling and/or epigenetic modifiers present in a dynamic extracellular milieu. Here we will discuss the broad principles of epigenetic regulation of DNA methylation and demethylation, histone acetylation and deacetylation, and RNA methylation in women’s cancers in the context of gene expression, hormonal action, and the EGFR family of cell surface receptor tyrosine kinases. We anticipate that a better understanding of the epigenetics of women’s cancers may provide new regulatory leads and further fuel the development of new epigenetic biomarkers and therapeutic approaches.

LSD1 Inhibition Attenuates Tumor Growth by Disrupting PLK1 Mitotic Pathway

Lysine-specific demethylase 1 (LSD1) is a histone modifier that is highly overexpressed in lung adenocarcinoma, which results in aggressive tumor biology. Tumor cell proliferation and migration analysis after LSD1 inhibition in the lung adenocarcinoma cell line PC9, using the LSD1 inhibitor HCI-2509 and siRNA, demonstrated that LSD1 activity was essential for proliferation and migration capacities of tumor cells. Moreover, reduced proliferation rates after LSD1 inhibition were shown to be associated with a cell-cycle arrest of the tumor cells in the G2-M-phase. Expression profiling followed by functional classification and pathway analysis indicated prominent repression of the polo-like kinase 1 (PLK1) pathway upon LSD1 inhibition. In contrast, transient overexpression of exogenous PLK1 plasmid rescued the LSD1 inhibition-mediated downregulation of PLK1 pathway genes. Mechanistically, LSD1 directly regulates expression of PLK1 by binding to its promoter region that subsequently affects expression of its downstream target genes. Notably, using lung adenocarcinoma TCGA datasets a significant correlation between LSD1 and PLK1 along with its downstream targets was observed. Furthermore, the LSD1/PLK1 linkage was confirmed by IHC analysis in a clinical lung adenocarcinoma cohort (n = 43). Conclusively, this is the first study showing a direct transcriptional link between LSD1 and PLK1. IMPLICATIONS: These findings point to a role of LSD1 in regulating PLK1 and thus efficient G2-M-transition-mediating proliferation of tumor cells and suggest targeting the LSD1/PLK1 axis as a novel therapeutic approach for lung adenocarcinoma treatment.

Epigenetics in ovarian cancer: premise, properties, and perspectives

Malignant ovarian tumors bear the highest mortality rate among all gynecological cancers. Both late tumor diagnosis and tolerance to available chemical therapy increase patient mortality. Therefore, it is both urgent and important to identify biomarkers facilitating early identification and novel agents preventing recurrence. Accumulating evidence demonstrates that epigenetic aberrations (particularly histone modifications) are crucial in tumor initiation and development. Histone acetylation and methylation are respectively regulated by acetyltransferases-deacetylases and methyltransferases-demethylases, both of which are implicated in ovarian cancer pathogenesis. In this review, we summarize the most recent discoveries pertaining to ovarian cancer development arising from the imbalance of histone acetylation and methylation, and provide insight into novel therapeutic interventions for the treatment of ovarian carcinoma.

Inhibition of lysine-specific demethylase 1 prevents proliferation and mediates cisplatin sensitivity in ovarian cancer cells

Lysine-specific demethylase 1 (LSD1) functions as a transcriptional coregulator by modulating histone methylation and has been associated with numerous high-risk cancers. Previously, our group and others identified LSD1 as an upregulated gene in ovarian cancer, and reported that the upregulation of LSD1 was associated with poor prognosis of patients with ovarian cancer. However, the role of LSD1 in ovarian cancer requires further investigation. The present study revealed that the overexpression of LSD1 significantly promoted the proliferation of SKOV3 ovarian cancer cells, while knockdown of LSD1 markedly inhibited cell proliferation and potentiated cisplatin-induced cell apoptosis, supporting LSD1 as an oncogenic protein in ovarian cancer. Mechanistic studies have indicated that LSD1 modulates the expression of cyclin dependent kinase inhibitor 1, Survivin, B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X genes, which are known regulators of cell proliferation. Furthermore, LSD1 knockdown plus cisplatin synergistically impaired cell migration via the induction of the epithelial marker E-cadherin and inhibition of the mesenchymal markers, snail family transcriptional repressor 1 and Vimentin. These data of the present study indicated LSD1 as a potential regulator of ovarian cancer cell progression and suggested an unfavorable role of LSD1 in cisplatin-based regimens.

Lysine-specific demethylase 1 activation by vitamin B2 attenuates efficacy of apatinib for proliferation and migration of gastric cancer cell MGC-803

B vitamins play an essential role in the biosynthesis of nucleotides, replication of DNA, supply of methyl-groups, growth and repair of cells, aberrancies of which have all been implicated in carcinogenesis. Although the potential role of vitamin B in relation to the risk of cancer, including breast, and colorectal cancer, has been investigated in several observational studies, the mechanism of action is still unclear. In this study, vitamin B2 exhibited efficient activation of LSD1 by occupying the active sites where FAD stands. Interestingly, vitamin B2 significantly downregulated expression of CD86, a sensitive surrogate biomarker of LSD1 inhibition, and showed marked activation of gastric cancer cell migration and invasion. Meanwhile, vitamin B2 induced activation of LSD1 may attenuate the proliferation inhibition, and anti-migration effects of apatinib in gastric cancer cells. These findings suggested that vitamin B supplementation may interfere with the efficacy of apatinib in patients with gastric cancer.

The role of the globular heads of the C1q receptor in paclitaxel-induced human ovarian cancer cells apoptosis by a mitochondria-dependent pathway

As a mitochondrial membrane protein, globular C1q receptor (gC1qR) can mediate a variety of biological responses. Our study aims to investigate the role of gC1qR in paclitaxel-induced apoptosis of human ovarian cancer cells and to elucidate its potential molecular mechanism. The level of gC1qR was examined using real-time PCR and western blot analyses. Human ovarian cancer cells viability, migration, and proliferation were detected using the water-soluble tetrazolium salt (WST-1) assay, the transwell assay, and H-thymidine incorporation into DNA (H-TdR) assay, respectively. Apoptosis in cells was assessed using flow cytometric analysis. The intracellular reactive oxygen species was estimated by the fluorescence of H2DCFDA and the mitochondrial membrane potential was tested using a JC-1 probe. The expression of the gC1qR gene decreased significantly in human ovarian cancer tissues relative to the surrounding non-neoplastic ovarian tissues. Cells treated with paclitaxel showed increased gC1qR gene expression, cell apoptosis, and mitochondria dysfunction, and the effects on these cells could be abrogated by the addition of gC1qR small-interfering RNA or α-lipoic acid that was used to protect the mitochondria function. In summary, these data support a mechanism that gC1qR-induced mitochondria dysfunction was involved in the paclitaxel-mediated apoptosis of ovarian cancer cells.

Cholesterol and Its Metabolites in Tumor Growth: Therapeutic Potential of Statins in Cancer Treatment

Cholesterol is essential for cell function and viability. It is a component of the plasma membrane and lipid rafts and is a precursor for bile acids, steroid hormones, and Vitamin D. As a ligand for estrogen-related receptor alpha (ESRRA), cholesterol becomes a signaling molecule. Furthermore, cholesterol-derived oxysterols activate liver X receptors (LXRs) or estrogen receptors (ERs). Several studies performed in cancer cells reveal that cholesterol synthesis is enhanced compared to normal cells. Additionally, high serum cholesterol levels are associated with increased risk for many cancers, but thus far, clinical trials with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) have had mixed results. Statins inhibit cholesterol synthesis within cells through the inhibition of HMG-CoA reductase, the rate-limiting enzyme in the mevalonate and cholesterol synthetic pathway. Many downstream products of mevalonate have a role in cell proliferation, since they are required for maintenance of membrane integrity; signaling, as some proteins to be active must undergo prenylation; protein synthesis, as isopentenyladenine is an essential substrate for the modification of certain tRNAs; and cell-cycle progression. In this review starting from recent acquired findings on the role that cholesterol and its metabolites fulfill in the contest of cancer cells, we discuss the results of studies focused to investigate the use of statins in order to prevent cancer growth and metastasis.

Basil polysaccharide attenuates hepatocellular carcinoma metastasis in rat by suppressing H3K9me2 histone methylation under hepatic artery ligation-induced hypoxia

Hepatocellular carcinoma (HCC) is one of the most common and fatal cancers in the world. Tumor metastasis is an important factor of poor prognosis in patients with HCC. Tumor hypoxia can promote tumor cell metastasis in HCC. Epigenetic modification is closely related to tumor hypoxia and metastasis. In our previous research, we found that basil polysaccharide suppressed migration and invasion of HCC cell by inhibiting hypoxia induced histone methylation in vitro. In the present study, we investigated the effect of basil polysaccharide on the walker 256 carcinoma cell metastasis in rat. We established an intratumoral hypoxic model in rat by hepatic artery ligation (HAL). Then rats were treated with basil polysaccharide (75, 150 and 300mg/kg). The results showed that HAL could promote tumor metastasis by aggravating tumor hypoxia. However, basil polysaccharide could inhibit tumor metastasis in intratumoral hypoxia. Further, we demonstrated that basil polysaccharide could down-regulate the expression of HIF-1α, G9a, LSD1, JMJD1A, JMJD2B, JARID1B and H3K9me2. Synchronously, basil polysaccharide could increase E-cadherin and VMP1 expression, and decrease N-cadherin, vimentin and β-catenin expression. The results indicated that histone modifying enzymes might be a new therapeutic target of basil polysaccharide on hepatocellular carcinoma metastasis.

Epithelial-to-Mesenchymal Transition: Epigenetic Reprogramming Driving Cellular Plasticity

Epithelial-to-mesenchymal transition (EMT) is a process in which epithelial cells lose their junctions and polarity to gain a motile mesenchymal phenotype. EMT is essential during embryogenesis and adult physiological processes like wound healing, but is aberrantly activated in pathological conditions like fibrosis and cancer. A series of transcription factors (EMT-inducing transcription factor; EMT-TF) regulate the induction of EMT by repressing the transcription of epithelial genes while activating mesenchymal genes through mechanisms still debated. The nuclear interaction of EMT-TFs with larger protein complexes involved in epigenetic genome modulation has attracted recent attention to explain functions of EMT-TFs during reprogramming and cellular differentiation. In this review, we discuss recent advances in understanding the interplay between epigenetic regulators and EMT transcription factors and how these findings could be used to establish new therapeutic approaches to tackle EMT-related diseases.

Lysine-specific demethylase 1 (LSD1) destabilizes p62 and inhibits autophagy in gynecologic malignancies

Lysine-specific demethylase 1 (LSD1) – also known as KDM1A – is the first identified histone demethylase. LSD1 is highly expressed in numerous human malignancies and has recently emerged as a target for anticancer drugs. Owing to the presence of several functional domains, we speculated that LSD1 could have additional functions other than histone demethylation. P62 – also termed sequestasome 1 (SQSTM1) – plays a key role in malignant transformation, apoptosis, and autophagy. Here, we show that a high LSD1 expression promotes tumorigenesis in gynecologic malignancies. Notably, LSD1 inhibition with either siRNA or pharmacological agents activates autophagy. Mechanistically, LSD1 decreases p62 protein stability in a demethylation-independent manner. Inhibition of LSD1 reduces both tumor growth and p62 protein degradation in vivo. The combination of LSD1 inhibition and p62 knockdown exerts additive anticancer effects. We conclude that LSD1 destabilizes p62 and inhibits autophagy in gynecologic cancers. LSD1 inhibition reduces malignant cell growth and activates autophagy. The combinations of LSD1 inhibition and autophagy blockade display additive inhibitory effect on cancer cell viability. A better understanding of the role played by p62 will shed more light on the anticancer effects of LSD1 inhibitors.

A comprehensive review of lysine-specific demethylase 1 and its roles in cancer

Histone methylation plays a key role in the regulation of chromatin structure, and its dynamics regulates important cellular processes. The investigation of the role of alterations in histone methylation in cancer has led to the identification of histone methyltransferases and demethylases as promising novel targets for therapy. Lysine-specific demethylase 1(LSD1, also known as KDM1A) is the first discovered histone lysine demethylase, with the ability to demethylase H3K4me1/2 and H3K9me1/2 at target loci in a context-dependent manner. LSD1 regulates the balance between self-renewal and differentiation of stem cells, and is highly expressed in various cancers, playing an important role in differentiation and self-renewal of tumor cells. In this review, we summarize recent studies about the LSD1, its role in normal and tumor cells, and the potential use of small molecule LSD1 inhibitors in therapy.

Upregulation of CD11b and CD86 through LSD1 inhibition promotes myeloid differentiation and suppresses cell proliferation in human monocytic leukemia cells

LSD1 (Lysine Specific Demethylase1)/KDM1A (Lysine Demethylase 1A), a flavin adenine dinucleotide (FAD)-dependent histone H3K4/K9 demethylase, sustains oncogenic potential of leukemia stem cells in primary human leukemia cells. However, the pro-differentiation and anti-proliferation effects of LSD1 inhibition in acute myeloid leukemia (AML) are not yet fully understood. Here, we report that small hairpin RNA (shRNA) mediated LSD1 inhibition causes a remarkable transcriptional activation of myeloid lineage marker genes (CD11b/ITGAM and CD86), reduction of cell proliferation and decrease of clonogenic ability of human AML cells. Cell surface expression of CD11b and CD86 is significantly and dynamically increased in human AML cells upon sustained LSD1 inhibition. Chromatin immunoprecipitation and quantitative PCR (ChIP-qPCR) analyses of histone marks revealed that there is a specific increase of H3K4me2 modification and an accompanied increase of H3K4me3 modification at the respective CD11b and CD86 promoter region, whereas the global H3K4me2 level remains constant. Consistently, inhibition of LSD1 in vivo significantly blocks tumor growth and induces a prominent increase of CD11b and CD86. Taken together, our results demonstrate the anti-tumor properties of LSD1 inhibition on human AML cell line and mouse xenograft model. Our findings provide mechanistic insights into the LSD1 functions in controlling both differentiation and proliferation in AML.

Androgen and AR contribute to breast cancer development and metastasis: an insight of mechanisms

The role of androgen and androgen receptor (AR) in breast carcinogenesis has long been a disputed issue. This report provides a mechanistic insight into how androgen and AR contributes to invasion and metastasis of breast cancer. We find that dihydrotestosterone (DHT) is able to induce the epithelial-to-mesenchymal transition in breast cancer cells in an AR-dependent/estrogen receptor-independent manner. This process is dependent on the demethylation activity of lysine-specific demethylase 1A (LSD1) by epigenetically regulating the target genes E-cadherin and vimentin. In vivo, DHT promotes metastasis in a nude mouse model, and AR and LSD1 are indispensable in this process. We establish that higher expression of nucleus AR to cytoplasm AR associated with worse prognostic outcomes in breast cancer patient samples. This study maps an 'androgen-AR/LSD1-target genes' pathway in breast carcinogenesis, implicating the importance of hormonal balance in women, and the potential clinical significance of serum androgen and AR in prediction of breast cancer and selection of breast cancer therapy.