Genipin normalizes depression-like behavior induced by prenatal stress through inhibiting DNMT1

Toxoplasma gondii infection is associated with schizophrenia from the perspectives of seroepidemiology and serum metabolomics in Hunan Province, China

Toxoplasma gondii (T.gondii) can influence the host's neurotransmission, central immune responses, and brain structure, potentially impacting the onset and development of various psychiatric disorders such as schizophrenia. We employed Electrochemiluminescence Immunoassay (ECLIA) to measure anti-Toxoplasma antibodies in 451 schizophrenic patients and 478 individuals from the general population in Hunan, China. The incidence rate of T.gondii infection in schizophrenic patients (8.87 %) was higher than that in the general population (3.77 %). A significant difference was observed among females, but not in males. Age-stratified analysis revealed significant differences in the 21-40 and 41-60 age groups. The two populations had no significant difference in the antibody titer for T. gondii infection. Additionally, the profile of circulating metabolites in the serum of schizophrenic patients with or without T. gondii infection was examined using non-targeted metabolomics assay. A total of 68 metabolites were differentially expressed between Toxoplasma-positive and Toxoplasma-negative groups, potentially mediating the connection between T. gondii infection and schizophrenia. Our research suggests that schizophrenic patients are susceptible to T. gondii infection with distinct metabolic program.

Genipin's potential as an anti-cancer agent: from phytochemical origins to clinical prospects

This comprehensive review delves into the multifaceted aspects of genipin, a bioactive compound derived from medicinal plants, focusing on its anti-cancer potential. The review begins by detailing the sources and phytochemical properties of genipin, underscoring its significance in traditional medicine and its transition into contemporary cancer research. It then explores the intricate relationship between genipin's chemical structure and its observed anti-cancer activity, highlighting the molecular underpinnings contributing to its therapeutic potential. This is complemented by a thorough analysis of preclinical studies, which investigates genipin's efficacy against various cancer cell lines and its mechanisms of action at the cellular level. A crucial component of the review is the examination of genipin's bioavailability and pharmacokinetics, providing insights into how the compound is absorbed, distributed, metabolized, and excreted in the body. Then, this review offers a general and updated overview of the anti-cancer studies of genipin and its derivatives based on its basic molecular mechanisms, induction of apoptosis, inhibition of cell proliferation, and disruption of cancer cell signaling pathways. We include information that complements the genipin study, such as toxicity data, and we differentiate this review by including commercial status, disposition, and regulation. Also, this review of genipin stands out for incorporating information on proposals for a technological approach through its load in nanotechnology to improve its bioavailability. The culmination of this information positions genipin as a promising candidate for developing novel anti-cancer drugs capable of supplementing or enhancing current cancer therapies.

Nerolidol reduces depression-like behavior in mice and suppresses microglia activation by down-regulating DNA methyltransferase 1

Modern medicine has unveiled that essential oil made from Aquilaria possesses sedative and hypnotic effects. Among the chemical components in Aquilaria, nerolidol, a natural sesquiterpene alcohol, has shown promising effects. This study aimed to unravel the potential of nerolidol in treating depression. Chronic unpredictable mild stress (CUMS) was utilized to induce depression-like behavior in mice, and open field test, sucrose preference, and tail suspension test was conducted. The impacts of nerolidol on the inflammatory response, microglial activation, and DNA methyltransferase 1 (DNMT1) were assessed. To study the regulatory role of DNMT1, lipopolysaccharide (LPS) was used to treat BV2 cells, followed by the evaluation of cell viability and DNMT1 level. Additionally, the influence of DNMT1 overexpression on BV2 cell activation was determined. Behavioral analysis revealed that nerolidol reduced depression-like behavior in mice. Nerolidol reduced the levels of inflammatory factors and microglial activation caused by CUMS. Nerolidol treatment was found to reduce DNMT1 levels in mouse brain tissue and it also decrease the LPS-induced increase in DNMT1 levels in BV2 cells. DNMT1 overexpression reversed the impacts of nerolidol on the inflammation response and cell activation. This study underscores the potential of nerolidol in reducing CUMS-induced depressive-like behavior and inhibiting microglial activation by downregulating DNMT1. These findings offer valuable insights into the potential of nerolidol as a therapeutic option for depression.

Translational bioinformatics and data science for biomarker discovery in mental health: an analytical review

Translational bioinformatics and data science play a crucial role in biomarker discovery as it enables translational research and helps to bridge the gap between the bench research and the bedside clinical applications. Thanks to newer and faster molecular profiling technologies and reducing costs, there are many opportunities for researchers to explore the molecular and physiological mechanisms of diseases. Biomarker discovery enables researchers to better characterize patients, enables early detection and intervention/prevention and predicts treatment responses. Due to increasing prevalence and rising treatment costs, mental health (MH) disorders have become an important venue for biomarker discovery with the goal of improved patient diagnostics, treatment and care. Exploration of underlying biological mechanisms is the key to the understanding of pathogenesis and pathophysiology of MH disorders. In an effort to better understand the underlying mechanisms of MH disorders, we reviewed the major accomplishments in the MH space from a bioinformatics and data science perspective, summarized existing knowledge derived from molecular and cellular data and described challenges and areas of opportunities in this space.

Exploring the multifocal role of phytoconstituents as antidepressants

Depression is the most prevalent and devastating neuropsychiatric disorder. There are several conventional antidepressants used for the treatment of depression. But due to their undesired adverse effects, patient compliance is very poor. Thus, developing novel medications for the treatment of depression is a critical strategic priority for meeting therapeutic demands. Current research is looking for alternatives to traditional antidepressants to reduce undesired side effects and increase efficacy. Phytoconstituents provide a wide research range in antidepressant treatments. In the present article, we have conducted a comprehensive assessment of neurological evidence, which supports the usefulness of phytoconstituents in the treatment of the depressive disorder. Secondary plant metabolites including alkaloids, polyphenols, glycosides, saponins, and terpenoids were found to exhibit antidepressant action. Most of the phytoconstituents were found to mediate their antidepressant effect through the upregulation of brain-derived neurotrophic factor (BDNF), serotonin, noradrenaline, and dopamine. Some were also found to exert antidepressant effects by inhibiting the monoamine oxidase (MAO) activity and hypothalamic-pituitary-adrenal (HPA) axis overactivity.

Neurotrophic basis to the pathogenesis of depression and phytotherapy

Depression is a major neuropsychiatric disease that considerably impacts individuals’ psychosocial function and life quality. Neurotrophic factors are now connected to the pathogenesis of depression, while the definitive neurotrophic basis remains elusive. Besides, phytotherapy is alternative to conventional antidepressants that may minimize undesirable adverse reactions. Thus, further research into the interaction between neurotrophic factors and depression and phytochemicals that repair neurotrophic factors deficit is highly required. This review highlighted the implication of neurotrophic factors in depression, with a focus on the brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), vascular endothelial growth factor (VEGF), and nerve growth factor (NGF), and detailed the antidepressant activities of various phytochemicals targeting neurotrophic factors. Additionally, we presented future opportunities for novel diagnostic and therapeutic strategies for depression and provided solutions to challenges in this area to accelerate the clinical translation of neurotrophic factors for the treatment of depression.

Quantitative proteomics reveals the therapeutic effects of RFAP against depression via pathway regulation of long-term depression and potentiation

Ethnopharmacological relevance

RFAP is a compound extraction complex of four Traditional Chinese Medicine (TCM), including the dry bark of Paeonia lactiflora Pall. (Radix Paeoniae Alba), Gardenia jasminoides J. Ellis (Fructus Gardeniae), Albizia julibrissin Durazz. (Albizia julibrissin Durazz), and Paeonia × suffruticosa Andrews (Peony bark). Not only RFAP but also the individual ingredients have been commonly used for the treatment of depression in the clinic. However, the underlying mechanism of pharmacology is difficult to interpret since its holistic and multidrug nature.

Aim of the study

This study aimed to elucidate the potential antidepressant mechanism of RFAP in the treatment of chronic unpredictable mild stress (CUMS) rats' model via the quantitative proteomics approach.

Materials and methods

We established the CUMS rats' model and evaluated the efficacy of RFAP using multiple behavior assays, including the sugar preference test, open field test, and forced swimming test. Then label-free quantitative proteomics analyses were performed to evaluate the integrated changes of proteome profiling in control, CUMS, RFAP low dose, and RFAP high dose groups. Finally, we validated the critical changed proteins in the pathways of long-term depression and potentiation via RT-PCR and Western blotting assays.

Results

We successfully established the CUMS rats' model. The behavior assays indicated that the rats demonstrated a tendency to behavioral despair after four weeks. Label-free quantitative proteomics showed that 107 proteins were significantly upregulated and 163 proteins were downregulated in the CUMS group compared to the control group. These differentially expressed proteins were involved in long-term potentiation, long-term depression, nervous system development, neuronal synaptic structural constituent of ribosome, ATP metabolic process, learning or memory, and cellular lipid metabolic process. RFAP treatment partially restored the differentially expressed protein profile. The protective effect of RFAP on behavioral assessment were consistent with the results of proteomics.

Conclusions

The results indicated that RFAP exerted a synergistic effect on CUMS by regulating long-term inhibition and potentiation-related proteins.

Therapeutic potential of plant iridoids in depression: a review

CONTEXT

Depression is a mental disorder characterized by low mood, reduced interest, impaired cognitive function, and vegetative symptoms such as sleep disturbances or poor appetite. Iridoids are the active constituents in several Chinese classical antidepressant formulae such as Yueju Pill, Zhi-Zi-Hou-Po Decoction, Zhi-Zi-Chi Decoction, and Baihe Dihuang Decoction. Parallel to their wide usages, iridoids are considered potential lead compounds for the treatment of neurological diseases.

OBJECTIVE

The review summarizes the therapeutic potential and molecular mechanisms of iridoids in the prevention or treatment of depression and contributes to identifying research gaps in iridoids as potential antidepressant medication.

METHODS

The following key phrases were sought in PubMed, Google Scholar, Web of Science, and China National Knowledge Internet (CNKI) without time limitation to search all relevant articles with in vivo or in vitro experimental studies as comprehensively as possible: ('iridoid' or 'seciridoid' or 'depression'). This review extracted the experimental data on the therapeutic potential and molecular mechanism of plant-derived iridoids for depression.

RESULTS

Plant iridoids (i.e., catalpol, geniposide, loganin), and secoiridoids (i.e., morroniside, gentiopicroside, oleuropein, swertiamarin), all showed significant improvement effects on depression.

DISCUSSION AND CONCLUSIONS

Iridoids exert antidepressant effects by elevating monoamine neurotransmitters, reducing pro-inflammatory factors, inhibiting hypothalamic-pituitary-adrenal (HPA) axis hyperactivity, increasing brain-derived neurotrophic factor (BDNF) and its receptors, and elevating intestinal microbial abundance. Further detailed studies on the pharmacokinetics, bioavailability, and key molecular targets of iridoids are also required in future research, ultimately to provide improvements to current antidepressant medications.

DNA Methylation in Depression and Depressive-Like Phenotype: Biomarker or Target of Pharmacological Intervention?

Major depressive disorder (MDD) is a debilitating psychiatric disorder, the third leading global cause of disability. Regarding aetiopathogenetic mechanisms involved in the onset of depressive disorders, the interaction between genetic vulnerability traits and environmental factors is believed to play a major role. Although much is still to be elucidated about the mechanisms through which the environment can interact with genetic background shaping the disease risk, there is a general agreement about a key role of epigenetic marking. In this narrative review, we focused on the association between changes in DNA methylation patterns and MDD or depressive-like phenotype in animal models, as well as mechanisms of response to antidepressant drugs. We discussed studies presenting DNA methylation changes at specific genes of interest and profiling analyses in both patients and animal models of depression. Overall, we collected evidence showing that DNA methylation could not only be considered as a promising epigenetic biomarker of pathology but could also help in predicting antidepressant treatment efficacy. Finally, we discussed the hypothesis that specific changes in DNA methylation signature could play a role in aetiopathogenetic processes as well as in the induction of antidepressant effect.

Kamikihito rescued depressive-like behaviors and hippocampus neurogenesis in chronic restraint stress rats

Background and aim

Substantial evidence suggests the effectiveness of plant-based medicine in stress-related diseases. Kamikihito (KKT), a Japanese traditional herbal medicine (Kampo), has been used for anemia, insomnia, and anxiety. Recent studies revealed its ameliorating effect on cognitive and memory dysfunction in several animal models. We, therefore, determined whether daily supplementation of KKT has an antidepressant-like effect on the stress-induced behavioral and neurological changes in rats.

Experimental procedure

The effect of KKT against the stress-induced changes in anxiety- and depressive-like behaviors and hippocampal neurogenesis were determined using a rat model of chronic restraint stress (CRS). KKT was orally administered daily at 300 or 1000 mg/kg during 21 consecutive days of CRS (6 h/day). The effect of CRS and KKT on physiological parameters, including body weight gain, food/water consumptions, plasma corticosterone (CORT) levels, and percentage of adrenal gland weight to body weight, were firstly measured. Anxiety- and depressive-like behaviors in rats were assessed in the open field test (OFT), sucrose preference test (SPT), and forced swimming test (FST). Hippocampal neurogenesis was determined by immunohistochemistry.

Results and conclusion

CRS for 21 days caused a significant decrease in body weight gain and increase in plasma CORT levels and percentage of adrenal gland weight to body weight, which were rescued by KKT treatment. KKT also suppressed the CRS-induced anxiety- and depressive-like behaviors and impairment of hippocampal neurogenesis. These results suggest that daily treatment of KKT has a protective effect against physiological, neurological, and behavioral changes in a rat model of depression.

Properties and molecular mechanisms underlying geniposide-mediated therapeutic effects in chronic inflammatory diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Geniposide (GE) is ubiquitous in nearly 40 species of plants, among which Gardenia jasminoides J. Ellis has the highest content, and has been used ethnopharmacologically to treat chronic inflammatory diseases. As a traditional Chinese medicine, Gardenia jasminoides J. Ellis has a long history of usage in detumescence and sedation, liver protection and cholestasis, hypotension and hemostasis. It is commonly used in the treatment of diabetes, hypertension, jaundice hepatitis, sprain and contusion. As a type of iridoid glycosides extracted from Gardenia jasminoides J. Ellis, GE has many pharmacological effects, such as anti-inflammatory, anti-angiogenesic, anti-oxidative, etc. AIM OF THE REVIEW: In this article, we reviewed the sources, traditional usage, pharmacokinetics, toxicity and therapeutic effect of GE on chronic inflammatory diseases, and discussed its potential regulatory mechanisms and clinical application.

RESULTS

GE is a common iridoid glycoside in medicinal plants, which has strong activity in the treatment of chronic inflammatory diseases. A large number of in vivo and in vitro experiments confirmed that GE has certain therapeutic value for a variety of chronic inflammation disease. Its mechanism of function is mainly based on its anti-inflammatory, anti-oxidant, neuroprotective properties, as well as regulation of apoptotsis. GE plays a role in the treatment of chronic inflammatory diseases by regulating cell proliferation and apoptosis, realizing the dynamic balance of pro/anti-inflammatory factors, improving the state of oxidative stress, and restoring abnormally expressed inflammation-related pathways.

CONCLUSION

According to its extensive pharmacological effects, GE is a promising drug for the treatment of chronic inflammatory diseases.

Differences in DNA Methylation Reprogramming Underlie the Sexual Dimorphism of Behavioral Disorder Caused by Prenatal Stress in Rats

Prenatal stress (PS) can lead to neuroendocrine and emotional disorders later in adolescence. Sexual dimorphism in these neurodevelopmental outcomes have been observed; however, the underlying mechanisms are not fully understood. To address this issue, we investigated whether there are sex differences in epigenetic reprogramming in rats exposed to PS. Pregnant female rats were subjected to chronic restraint stress from gestational day (G)12 to G18. From postnatal day (P)38 to P45, subgroups of offspring including both males and females were subjected to behavioral testing and brain tissue specimens were analyzed by DNA pyrosequencing, western blotting, and Golgi staining to assess changes in methylation pattern of glucocorticoid receptor (GR) gene, expression of DNA methyltransferase (DNMT) and DNA demethylase, and dendrite morphology, respectively. The DNA methyltransferase inhibitor decitabine was administered to rats prior to PS to further evaluate the role of methylation in the sexually dimorphic effects of PS. The results showed that PS increased anxiety-like behavior in offspring, especially in females, while depression-like behavior was increased in male offspring compared to control littermates. The methylation pattern in the promoter region of the GR gene differed between males and females. Sex-specific changes in the expression of DNMTs (DNMT1 and DNMT3a) and DNA demethylase (Tet methylcytosine dioxygenase 2) were also observed. Interestingly, decitabine alleviated the behavioral disorder caused by PS and restored dendrite density and morphology in female but not male rats. These findings suggest that different change patterns of DNMT and demethylase in the two sexes after PS are responsible for the sexually dimorphism, which could have implications for the clinical management of stress-related disorders.

Prenatal stress induced chromatin remodeling and risk of psychopathology in adulthood

New insights into the pathophysiology of psychiatric disorders suggest the existence of a complex interplay between genetics and environment. This notion is supported by evidence suggesting that exposure to stress during pregnancy exerts profound effects on the neurodevelopment and behavior of the offspring and predisposes them to psychiatric disorders later in life. Accumulated evidence suggests that vulnerability to psychiatric disorders may result from permanent negative effects of long-term changes in synaptic plasticity due to altered epigenetic mechanisms (histone modifications and DNA methylation) that lead to condensed chromatin architecture, thereby decreasing the expression of candidate genes during early brain development. In this chapter, we have summarized the literature of clinical studies on psychiatric disorders induced by maternal stress during pregnancy. We also discussed the epigenetic alterations of gene regulations induced by prenatal stress. Because the clinical manifestations of psychiatric disorders are complex, it is obvious that the biological progression of these diseases cannot be studied only in postmortem brains of patients and the use of animal models is required. Therefore, in this chapter, we have introduced a well-established mouse model of prenatal stress (PRS) generated in restrained pregnant dams. The behavioral phenotypes of the offspring (PRS mice) born to the stressed dam and underlying epigenetic changes in key molecules related to synaptic activity were described and highlighted. PRS mice may serve as a useful model for investigating the pathogenesis of psychiatric disorders and may be a useful tool for screening for the potential compounds that may normalize aberrant epigenetic mechanisms induced by prenatal stress.

DNA Methyltransferases in Depression: An Update

Depression is one of the most common psychiatric disorders affecting public health. Studies over the past years suggest that the methylations of some specific genes such as BDNF, SLC6A4, and NR3C1 play an important role in the development of depression. Recently, epigenetic evidences suggest that the expression levels of DNA methyltransferases differ in several brain areas including the prefrontal cortex, hippocampus, amygdala, and nucleus accumbens in depression patients and animal models, but the potential link between the expression levels of DNA methylatransferases and the methylations of specific genes needs further investigation to clarify the pathogenesis of depression.

Transcriptional and epigenetic changes of brain derived neurotrophic factor following prenatal stress: A systematic review of animal studies

Gestational period plays critical role in neuropsychological development. One of the genes that undergoes changes by prenatal stress (PNS) exposure, is the gene coding brain derived neurotrophic factor (BDNF). Studies have reported different patterns of change following PNS in BDNF, which emphasizes the complexity of the issue. In this review, systematic search of PubMed, Scopus, Web of Science and Cochrane CENTRAL databases was performed. Primary searches resulted in 2132 studies and finally 43 studies were found to meet the inclusion criteria. Transcriptional and epigenetic changes of BDNF gene in the brain were recorded. Decreased or unchanged BDNF total mRNA and BDNF mature protein, with hypermethylation of the coding exons were the most reported changes. However, stress paradigm, gender of the fetus and the day of sacrifice were found to significantly affect the results. Hippocampus and prefrontal cortex are the most vulnerable regions. They can show long lasting and persistent transcriptional and epigenetics changes of BDNF gene following PNS. Further studies evaluating the importance of these findings in humans are essential.

Altered methylation pattern of the SRD5A2 gene in the cerebrospinal fluid of post-finasteride patients: a pilot study

CONTEXT

Post-finasteride syndrome (PFS) occurs in patients with androgenic alopecia after suspension of the finasteride treatment, leading to a large variety of persistent side effects. Despite the severity of the clinical picture, the mechanism underlying the PFS symptoms onset and persistence is still unclear.

OBJECTIVE

To study whether epigenetic modifications occur in PFS patients.

METHODS

Retrospective analysis of a multicentric, prospective, longitudinal, case-control clinical trial, enrolling 16 PFS patients, compared to 20 age-matched healthy men. Main outcomes were methylation pattern of SRD5A1 and SRD5A2 promoters and concentration of 11 neuroactive steroids, measured by liquid chromatography-tandem mass spectrometry, in blood and cerebrospinal fluid (CSF) samples.

RESULTS

SRD5A1 and SRD5A2 methylation analysis was performed in all blood samples (n = 16 PFS patients and n = 20 controls), in 16 CSF samples from PFS patients and in 13 CSF samples from controls. The SRD5A2 promoter was more frequently methylated in CSF of PFS patients compared to controls (56.3 vs 7.7%). No promoter methylation was detected in blood samples in both groups. No methylation occurred in the SRD5A1 promoter of both groups. Unmethylated controls compared to unmethylated SRD5A2 patients showed higher pregnenolone, dihydrotestosterone and dihydroprogesterone, together with lower testosterone CSF levels. Andrological and neurological assessments did not differ between methylated and unmethylated subjects.

CONCLUSIONS

For the first time, we demonstrate a tissue-specific methylation pattern of SRD5A2 promoter in PFS patients. Although we cannot conclude whether this pattern is prenatally established or induced by finasteride treatment, it could represent an important mechanism of neuroactive steroid levels and behavioural disturbances previously described in PFS.

The Akt/mTOR cascade mediates high glucose-induced reductions in BDNF via DNMT1 in Schwann cells in diabetic peripheral neuropathy

Brain-derived neurotropic factor (BDNF) deficiency in Schwann cells plays an important role in the pathogenesis of diabetic peripheral neuropathy (DPN). Little is known about the mechanism involved in BDNF downregulation in Schwann cells in DPN. In this study, we first confirmed downregulation of BDNF and neurotrophin 3 expression in the sciatic nerves of diabetic mice, which was accompanied by myelin sheath abnormalities. Moreover, in vitro, high glucose was revealed to cause downregulation of BDNF, but not neurotrophin 3, expression in RSC96 cells, which was accompanied by DNA hypermethylation of BDNF promoters I and II. DNMT1 was subsequently revealed to be enhanced at the mRNA and protein levels in high glucose-stimulated RSC96 cells, and inhibition of DNMT1 with 5-Aza treatment or shRNA vector transfection reversed high glucose-induced reductions in BDNF expression. Furthermore, the mTOR and upstream Akt pathways were indicated to mediate high glucose-induced DNMT1 and BDNF expression in RSC96 cells. Taken together, our results suggest that the Akt/mTOR cascade mediates high glucose-induced reductions in BDNF via DNMT1 in Schwann cells in DPN.

Moving pharmacoepigenetics tools for depression toward clinical use

BACKGROUND

Major depressive disorder (MDD) is a leading cause of disability worldwide, and over half of patients do not achieve symptom remission following an initial antidepressant course. Despite evidence implicating a strong genetic basis for the pathophysiology of MDD, there are no adequately validated biomarkers of treatment response routinely used in clinical practice. Pharmacoepigenetics is an emerging field that has the potential to combine both genetic and environmental information into treatment selection and further the goal of precision psychiatry. However, this field is in its infancy compared to the more established pharmacogenetics approaches.

METHODS

We prepared a narrative review using literature searches of studies in English pertaining to pharmacoepigenetics and treatment of depressive disorders conducted in PubMed, Google Scholar, PsychINFO, and Ovid Medicine from inception through January 2019. We reviewed studies of DNA methylation and histone modifications in both humans and animal models of depression.

RESULTS

Emerging evidence from human and animal work suggests a key role for epigenetic marks, including DNA methylation and histone modifications, in the prediction of antidepressant response. The challenges of heterogeneity of patient characteristics and loci studied as well as lack of replication that have impacted the field of pharmacogenetics also pose challenges to the development of pharmacoepigenetic tools. Additionally, given the tissue specific nature of epigenetic marks as well as their susceptibility to change in response to environmental factors and aging, pharmacoepigenetic tools face additional challenges to their development.

LIMITATIONS

This is a narrative and not systematic review of the literature on the pharmacoepigenetics of antidepressant response. We highlight key studies pertaining to pharmacoepigenetics and treatment of depressive disorders in humans and depressive-like behaviors in animal models, regardless of sample size or methodology. While we discuss DNA methylation and histone modifications, we do not cover microRNAs, which have been reviewed elsewhere recently.

CONCLUSIONS

Utilization of genome-wide approaches and reproducible epigenetic assays, careful selection of the tissue assessed, and integration of genetic and clinical information into pharmacoepigenetic tools will improve the likelihood of developing clinically useful tests.

Methylenetetrahydrofolate Dehydrogenase 1 Silencing Expedites the Apoptosis of Non-Small Cell Lung Cancer Cells via Modulating DNA Methylation

BACKGROUND Non-small cell lung cancer (NSCLC) accounts for about 85% of all types of lung cancer. Methylenetetrahydrofolate dehydrogenase 1 (MTHFD1) is involved in DNA methylation, and DNA methylation is related to tumorigenesis. The role of MTHFD1 in NSCLC was examined in our study. MATERIAL AND METHODS The correlation between the expression of MTHFD1 and the clinicopathological features of patients diagnosed with lung cancer was investigated using the chi-square test. The viability and apoptosis of NCI-H1299 cells was respectively detected using cell counting kit-8 and flow cytometry assays. The expression levels of MTHFD1, apoptosis-related factors and DNA methyltransferase-related factors were assessed by quantitative real-time PCR (qRT-PCR) and western blot assays. RESULTS We found that MTHFD1 expression in the tumor tissues and cells was higher than that of adjacent normal tissues and cells. The survival time of patients with high MTHFD1 expression was shorter than those with low MTHFD1 expression. The expression level of MTHFD1 was related to tumor size, TNM stage, histologic grade, and metastasis, but not linked to gender and age. Besides, si-MTHFD1 significantly decreased the viability of cells in a time-dependent manner, and increased cell apoptosis. When cells were transfected with MTHFD1-siRNA, the levels of surviving and B-cell lymphoma-2 (Bcl-2) were attenuated, while p53 and Bcl-2 associated X protein (Bax) levels were enhanced. Moreover, si-MTHFD1 markedly downregulated the expression levels of DNA methyltransferase 1 (DNMT1), DNMT3a, and DNMT3b. CONCLUSIONS Collectively, our results proved that MTHFD1 silencing obviously reduced the proliferation and enhanced the apoptosis of NSCLC via suppressing DNA methylation.