Increasing the effect of annonacin using nanodiamonds to inhibit breast cancer cells growth in rats (Rattus norvegicus)-Induced breast cancer

Background

Annonaceous acetogenins have been reported to have anti-cancer properties but low viability. In this study, we aimed to investigate the potency of nanodiamonds to be employed as a carrier of annonacin to help increase its viability and inhibit the growth of breast cancer cells.

Methods

The annonacin was coupled with nanodiamond and characterized using UV-Vis spectrophotometer, FTIR, SEM, and PSA, and determined their stability and drug release. A cell growth inhibition assay and cell migration assay was performed using the breast cancer MCF7 and T747D cell lines, and in vivo analysis was performed in rats (Rattus norvegicus). MCF7 and T747D cells were treated with 12.5 μg/mL annonacin coupled with nanodiamonds for 24 and 48 h and further analyzed by MTT, cell migration, and reactive oxygen species (ROS) assays. Twenty-five female rats were divided into five groups. Breast cancer was induced using two intraperitoneal doses of N-nitroso-N-methylurea (NMU) (50 and 30 mg/kg body weight). Annonacin coupled with nanodiamonds was administered by intraperitoneal injection (17.5 mg/kg body weight) for 5 weeks, one injection per 3 days.

Results

Administration of annonacin coupled with nanodiamonds significantly reduced MCF7 cell growth and reactive oxygen species (ROS) levels. The in vivo study showed that administration of annonacin coupled with nanodiamonds significantly reduced PI3KCA levels and increased p53 expression, reduced cancer antigen-15-3 (CA-15-3) levels in serum, increased caspase-3 expression, reduced Ki-67 levels, and reduced the thickness of the mammary ductal epithelium.

Conclusions

Collectively, this study demonstrated the effectiveness of nanodiamonds as a carrier of annonacin to inhibit breast cancer cell growth through inhibition of the PI3K/Akt signaling pathway.

Biophysical Evaluation of Water-Soluble Curcumin Encapsulated in β-Cyclodextrins on Colorectal Cancer Cells

Curcumin (CUR), a curcuminoid originating from turmeric root, possesses diverse pharmacological applications, including potent anticancer properties. However, the use of this efficacious agent in cancer therapy has been limited due to low water solubility and poor bioavailability. To overcome these problems, a drug delivery system was established as an excipient allowing improved dispersion in aqueous media coupled with enhanced in vitro anticancer effects. Different analyses such as UV-vis spectroscopy, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), solubility and dissolution assays were determined to monitor the successful encapsulation of CUR within the inner cavity of a β-cyclodextrin (β-CD) complex. The results indicated that water solubility was improved by 205.75-fold compared to pure CUR. Based on cytotoxicity data obtained from MTT assays, the inclusion complex exhibited a greater decrease in cancer cell viability compared to pure CUR. Moreover, cancer cell migration rates were decreased by 75.5% and 38.92%, invasion rates were decreased by 37.7% and 35.7%, while apoptosis rates were increased by 26.3% and 14.2%, and both caused caspase 3 activation toward colorectal cancer cells (SW480 and HCT116 cells). This efficacious formulation that enables improved aqueous dispersion is potentially useful and can be extended for various chemotherapeutic applications. Preliminary toxicity evaluation also indicated that its composition can be safely used in humans for cancer therapy.

Enhancing the Anticancer Activity of Squamocin for Breast Cancer Treatment Using Nanodiamond Nanoparticles: An In Vivo Study

Squamocin is one of the annonaceous acetogenins produced by the Annonaceae family and displays potent anti-cancer activity against cancer cell lines. This study aimed to investigate the growth inhibition activity of squamocin coupled with nanodiamond on rats (Rattus norvegicus)-induced breast cancer. Twenty-five female R. norvegicus were divided into five groups (n = 5), including normal control (without any treatment), negative control, group treated with nanodiamond only (ND), group treated with squamocin only (SQ), and the group treated with squamocin coupled with nanodiamond (NDSQ). All of the animal models were induced for breast cancer, except for the normal control group. Breast cancer induction was performed using two doses of N-nitroso-N-methylurea (NMU) injection (50 and 30 mg/kg body weight) intraperitoneally and waited for 22 weeks until the tumor was detected to formed. Nanodiamond coupled with squamocin were administered by intraperitoneal injection (1.5 mg/kg body weight) for 5 weeks, one injection per 3 days. This study showed that the treatment with squamocin coupled with nanodiamond (NDSQ) significantly reduced the proliferation (Ki-67) and induced apoptosis (Caspase-3) of breast cancer cells, corresponding to the reduction of the thickness of the mammary ductal epithelium (p<0.001) and the lower level of CA-153 in serum. In addition, the treatment significantly reduced the malondioldehyde (MDA) and PI3KCA and increased the p53 level significantly. Altogether, in this study, we are the first to report the anti-cancer activity of squamocin in rat-induced breast cancer and the potency of nanodiamond as a carrier of squamocin to increase its anti-cancer activity.

Anti-cancer activity of an ethanolic extract of red okra pods (Abelmoschus esculentus L. Moench) in rats induced by N-methyl-N-nitrosourea

Background and Aim: Breast cancer is the most frequent malignancy in women. The consumption of phytochemical components from plants may play an essential role in preventing and treating this cancer. This study aimed to investigate the anti-cancer activity of an ethanolic extract of red okra pods (EEROP) in rats (Rattus norvegicus) induced by N-methyl-N-nitrosourea (MNU). Materials and Methods: The experimental animals were divided into six groups (n=5/group), namely, KN (normal control, without any treatment), K– (negative control, exposed to MNU without EEROP), K+ (positive control, exposed to MNU and Methotrexate), and the treatment Groups P1, P2, and P3 (exposed to MNU and EEROP at doses of 50, 100, and 200 mg/kg body weight [BW], respectively). Intraperitoneal delivery of MNU and EEROP oral administration was carried out for 8 weeks. After the end of treatment, the parameters of cytokines, CD4+ and CD8+ T cells, and mammary gland histology were measured. Results: The results showed that EEROP at doses of 100 and 200 mg/kg BW significantly downregulated interleukin (IL)-6, IL-1β, tumor necrosis factor (TNF)-α, IL-17, IL-10, and tumor growth factor-β (p<0.05). In addition, doses of 200 mg/kg BW significantly increased the activity of CD4+ and CD8+ T cells, prevented the proliferation of mammary gland epithelial cells, and yielded a significantly thinner epithelium of the mammary gland (p<0.05). Conclusion: It can be concluded that EEROP was an effective anti-cancer agent by modulating the immune response. Further studies using a nanoparticle system are warranted to achieve optimal working conditions for these bioactive compounds.

Effect of the Ethanol Extract of Red Okra Pods (Abelmoschus esculentus (L.) Moench) to Inhibit Cervical Cancer Cells Growth through Cell Cycle-Associated Oncogenes

This study aims to evaluate the potency of ethanol extract of red okra pods (EEROP) in inhibiting growth of cervical cancer cells through repression of the cell cycle-associated oncogenes. The EEROP treatment was given to HeLa cells cultured with RPMI medium and incubated at 37°C with 5% CO₂. The MTT method was used to measure HeLa cell growth and IC₅₀ values. The mRNA levels of the three cell cycle-associated oncogenes (MYC, TYMS, and MDM2) were evaluated by qRT-PCR to determine the effect of EEROP treatment on the cell cycle. The lowest percentage of viable cells at 24, 48, and 72 hours after EEROP treatment was in the dose of 1000 μg/mL with a growth percentage of 71.60% at 24 hours, 55.61% at 48 hours, and 46.97% at 72 hours. The IC₅₀ values were 2845, 1153, and 776.8 μg/mL for 24, 48, and 72 hours, respectively. The three oncogenes at a dose of 1000 μg/mL significantly decreased the lowest mRNA levels compared to other doses with MYC oncogene that experienced the greatest decrease. The mRNA level of dose 1000 μg/mL EEROP at the MYC oncogene was 0.014-fold changes, at the TYMS oncogene was 0.097-fold changes, and at the MDM2 oncogene was 0.028-fold changes. The EEROP has been shown to decrease the expression of three cell cycle-associated oncogenes. This is also supported by the growth of HeLa cells that did not increase throughout 24, 48, and 72 hours. However, further research is needed on the main active components in red okra that function as anticancer, so that in the future, okra can not only stop cancer cell growth but also induce cancer cell death.

Assessing the recovery of steroid levels and gonadal histopathology of tilapia exposed to polystyrene particle pollution by supplementary feed

Background and Aim:

Water pollution caused by industrial waste and human activities has disrupted the reproductive health of aquatic organisms. This study aimed to analyze the effects of water pollution caused by polystyrene particles (PP) on the steroid (estradiol and testosterone) levels and histopathology of male tilapia gonads. In addition, we also analyzed the potential of supplementary feeding to remove and neutralize oxidants.

Materials and Methods:

Thirty-six tilapia fishes were taken for the study and were divided into 12 groups (n=3), including a control group (fed with commercial pellets only) and groups fed with a mixture of commercial-probiotic pellets (200 mL/kg, 1×10⁸ colony-forming unit [CFU]/mL) and commercial vitamin C pellets (100 mg/kg), respectively. The PP concentrations used for this study were 0, 0.1, 1, and 10 mg/L, and the treatment time was 2 weeks. The testosterone and estradiol concentrations were analyzed by enzyme-linked immunosorbent assay and histopathological analysis of the gonads.

Results:

Laboratory analysis performed using tilapia fishes showed that exposure to a PP concentration of <74 μm, mixed with feed for 14 days, could decrease estradiol and testosterone levels. Exposure to plastic particles could change the structure, shape, and size of male gonads. It can also affect the spermatogenic cell number and alter the diameter inside the cysts. Originally, plastic particles were believed to reduce the permeability of the cyst membrane, and this damages the membrane or ruptures the cyst. Supplementary feed containing probiotics (200 mL/kg, 1×108 CFU/mL) and vitamin C (100 mg/kg) can ameliorate the impact of PP exposure on steroid levels. The steroid levels increase with a concurrent improvement in cysts and seminiferous tubule structures.

Conclusion:

Overall, this study indicates that PP concentrations in the aquatic environment negatively affect tilapia reproduction, and this may pose a potential threat to the fish population in freshwater. Provision of supplementary feed containing probiotics and vitamin C may serve as an alternative way to counter the negative impact caused by plastic particles.

Dayak Onions (Eleutherine americana L Merr) Reduced Mesothelial Cell Detachment After Laparoscopy in Rats

Background: Laparoscopy induces changes and detachment of mesothelial structure. Studies on the prevention of mesothelial cell detachment are rarely found. The Dayak tribe uses the Dayak onion (Eleutherine americana L. Merr) as a wound-healing agent due to its anti-inflammatory and antioxidant activities. This study aimed to prove the anti-inflammatory and antioxidant activities of Dayak onions in preventing mesothelial cell damage after laparoscopy. Materials and methods: Thirty male Sprague-Dawley rats were classified into five groups (n = 6 per group), namely: (a) control, (b) Mediclore, (c) Dayak onion, 30-, (d) 60-, and (e) 90 mg/kg body weight, respectively. The transforming growth factor-beta (TGF-β) and total oxidant status in the peritoneal fluid were determined 24 hours after laparoscopy. Histopathological analysis of mesothelial cell numbers and the protein Zone Occludin-1 (ZO-1) expression in the peritoneum, small intestines, greater omentum, and liver were performed 7 days after the procedure. An in-silico study was conducted to analyze the anti-inflammatory effects of the components of Dayak onions. Results: The in-silico study showed that one of the Dayak onion active compounds, eleutherine, had a potential anti-inflammatory effect and acted as a modulator of TGF-β. Following Dayak onion administration, the TGF- level, the number of mesothelial cell detachments, and ZO-1 expression were all significantly reduced (p<0.05), whereas the total oxidant status (TOS) level was not (p>0.05). Conclusions: Our study showed that Dayak onion administration reduced TGF-β level, number of mesothelial cell detachment, and ZO-1 expression following laparoscopy.

The Regulation of Hypoxia Inducible Factor (HIF)1α Expression by Quercetin: an In Silico Study

Background:

Cancer disease is a growing health problem in developing and developed countries. Hypoxia-inducible factor-1a (HIF1α) is a transcription factor responsible for expressing several proteins involved in angiogenesis. Quercetin can suppress HIF1α expression due to the inhibition of protein synthesis. However, to date, the study exploring the potential of quercetin in repressing HIF1α through its degradation mechanism has never been done. An in silico study is needed as a preliminary study to understand the mechanism underlining this possibility.

Objective:

This study aimed to investigate the potential of quercetin in regulating HIF1α expression through the ubiquitin degradation pathway by in silico study.

Methods:

This study was performed by in silico analysis, including biological activity prediction, 3D protein structure collection, protein-ligand and protein-protein docking, and the visualization of the docking results.

Results:

The probability activity (Pa) score of quercetin as an HIF1α expression inhibitor was 0.969. In the absence of quercetin, the center-weighted score of HIF1α - pVHL, HIF1α - FIH, and HIF1α - PHD2 was -699.4 kJ/mol, -846.0 kJ/mol, and -650.5 kJ/mol, respectively. In the presence of quercetin, the weighted score of HIF1α - pVHL, HIF1α - FIH, and HIF1α - PHD2 was reduced to -728.1 kJ/mol, -854.2 kJ/mol, and -650.5 kJ/mol, respectively.

Conclusion:

Quercetin could directly promote HIF1α and pVHL interaction, thus increasing the degradation of HIF1α by ubiquitin-dependent pathway.

The potential of A. Muricata Bioactive Compounds to Inhibit HIF1α Expression Via Disruption of Tyrosine Kinase Receptor Activity: an In Silico Study

Background:

Cancer is a debilitating disease that is on the increase in both developed and developing countries. The plant extract of A. muricata have been known to have a variety of anticancer effects, including anti-angiogenic potential. An in silico study is needed as a preliminary study to understand the mechanism underline this process.

Objective:

The aim of this study was to investigate the potential of the bioactive compounds of A. muricata in regulating angiogenesis process, primarily by the regulation of hypoxia inducible factor (HIF)-1α expression by in silico study.

Methods:

This study was performed by in silico analysis including the bioactive compounds preparation, biological activity prediction, protein target and pathway analysis, 3D protein modelling, protein-ligand and protein-protein docking, and the visualization of docking results.

Results:

There are 3 bioactive compounds of A. muricata with the ability to inhibit HIF-1α expression, including kaempferol, genistein, and glycitein. The inhibition of HIF-1α expression was associated with phosphoinositide 3-kinases (PI3K)/Akt signaling pathway, which involved tyrosine kinase receptor activity on the cell membrane. Based on the silico analysis in this study, we shown that kaempferol, genistein, and glycitein inhibit HIF-1α expression through the disruption of interleukin (IL)-6R and toll-like receptor (TLR)-4 and their respective ligands interaction.

Conclusion:

The findings of this study show that A. muricata bioactive compounds could inhibit HIF-1α expression through disruption of the tyrosine kinase receptor binding with its ligand.

Nucleoporin TPR (translocated promoter region, nuclear basket protein) upregulation alters MTOR-HSF1 trails and suppresses autophagy induction in ependymoma

Children with ependymoma have high mortality rates because ependymoma is resistant to conventional therapy. Genomic and transcriptomic studies have identified potential targets as significantly altered genes in ependymoma patients. Although several candidate oncogenes in ependymoma were recently reported, the detailed mechanisms for the roles of these candidate oncogenes in ependymoma progression remain unclear. Here, we report an oncogenic role of the nucleoporin TPR (translocated promoter region, nuclear basket protein) in regulating HSF1 (heat shock transcription factor 1) mRNA trafficking, maintaining MTORC1 activity to phosphorylate ULK1, and preventing macroautophagy/autophagy induction in ependymoma. High expression of TPR were associated with increased HSF1 and HSPA/HSP70 expression in ependymoma patients. In an ependymoma mouse xenograft model, MTOR inhibition by rapamycin therapeutically suppressed TPR expression and reduced tumor size in vivo. Together, these results suggest that TPR may act as a biomarker for ependymoma, and pharmacological interventions targeting TPR-HSF1-MTOR may have therapeutic potential for ependymoma treatment.

Abbreviations: ATG: autophagy related; BECN1: beclin 1; BSA: bovine serum albumin; CQ: chloroquine; DMSO: dimethyl sulfoxide; GEO: gene expression omnibus; GFP: green fluorescence protein; HSF1: heat shock transcription factor 1; HSPA/HSP70: heat shock protein family A (Hsp70); LMNB1: lamin B1; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MAPK: mitogen-activated protein kinase; MAPK8/JNK: mitogen-activated protein kinase 8; MTORC1: mechanistic target of rapamycin kinase complex 1; NPC: nuclear pore complex; NUP: nucleoporin; PBS: phosphate-buffered saline; q-PCR: quantitative real time PCR; SDS: sodium dodecyl sulfate; SQSTM1: sequestosome 1; STED: stimulated emission depletion microscopy; STX17: syntaxin 17; TCGA: the cancer genome atlas; TPR: translocated promoter region, nuclear basket protein; ULK1: unc-51 like autophagy activating kinase 1.

In Silico Interaction of the Active Compounds of Scurrula Atropurpurea with the RANK/RANKL/OPG System in Diabetoporosis

Introduction:

Diabetoporosis is a very complex health problem in Indonesia. One approach to the problem is through native Indonesian herbal medicine. The application of Scurrula atropurpurea in the treatment of diabetoporosis has not been revealed, so preliminary in silico study needs to be done.

Aim:

The purpose of the present study was to analyze the interaction between the active compound of Scurrula atropurpurea and the RANKL/RANK/OPG system in the pathomechanism of osteoporosis in diabetes mellitus.

Methods:

The procedures of the study included the search for the constituent amino acid of the RANK/RANKL/OPG system, the search for the structure of the active component of Scurrula atropurpurea, 3D modeling of protein structure, protein-ligand docking and visualization, and analysis of protein-ligand bonding interactions.

Results:

Those bond energies were RANKL-aviculin (–274.96 kJ/mol), RANKL-rutin (–263.12 kJ/mol), RANKL-quercitrin (–256.98 kJ/mol), RANKL-quercetin (–226,50 kJ/mol), RANKL-kaempferol (–221,65 kJ/mol), RANKL-catechin (–214,85 kJ/mol), RANKL-epicatechin (–211.66 kJ/mol), RANKL-caffeine (-171.73 kJ/mol), and RANKL-theobromine (-161.14 kJ/mol). The bond energies were RANK-rutin (-719.26 kJ/mol), RANK-catechin (-680.15 kJ/mol), RANK-caffeine (-654.48 kJ/mol), RANK-theobromine (-651.77 kJ/mol), RANK-quercitrin (-650.68 kJ/mol), RANK-kaempferol (-643.03 kJ/mol), RANK-epicatechin (-641.86 kJ/mol), RANK-quercetin (-641.76 kJ/mol), and RANK-aviculin (-628.62 kJ/mol). Those bond energies were OPG-epicatechin (-590.09 kJ/mol), OPG-theobromine (-578.08 kJ/mol), OPG-caffeine (-568.88 kJ/mol), RANKL-catechin (-560.63 kJ/mol), OPG-quercitrin (-554.50 kJ/mol), OPG-rutin (-547.91 kJ/mol), OPG-quercetin (-545.75 kJ/mol), OPG-kaempferol (-544.48 kJ/mol), and OPG-aviculin (-539.15 kJ/mol).

Conclusion:

The nine active ingredients of Scurrula atropurpurea do not interfere with the physiological function of RANKL to interact with RANK. The initial interaction of RANK with catechin or rutin will facilitate the bond of RANK to RANKL. When forming a complex with OPG, epicatechin will facilitate its interaction with RANKL.

ROCK-dependent phosphorylation of NUP62 regulates p63 nuclear transport and squamous cell carcinoma proliferation

p63, more specifically its ΔNp63α isoform, plays essential roles in squamous cell carcinomas (SCCs), yet the mechanisms controlling its nuclear transport remain unknown. Nucleoporins (NUPs) are a family of proteins building nuclear pore complexes (NPC) and mediating nuclear transport across the nuclear envelope. Recent evidence suggests a cell type-specific function for certain NUPs; however, the significance of NUPs in SCC biology remains unknown. In this study, we show that nucleoporin 62 (NUP62) is highly expressed in stratified squamous epithelia and is further elevated in SCCs. Depletion of NUP62 inhibits proliferation and augments differentiation of SCC cells. The impaired ability to maintain the undifferentiated status is associated with defects in ΔNp63α nuclear transport. We further find that differentiation-inducible Rho kinase reduces the interaction between NUP62 and ΔNp63α by phosphorylation of phenylalanine-glycine regions of NUP62, attenuating ΔNp63α nuclear import. Our results characterize NUP62 as a gatekeeper for ΔNp63α and uncover its role in the control of cell fate through regulation of ΔNp63α nuclear transport in SCC.

Cinnamomum burmanini Blume increases bone turnover marker and induces tibia's granule formation in ovariectomized rats

Background

Bone fragility and an increase in susceptibility to fracture osteoporosis is characterized by a reduction in bone mass and the micro-architectural deterioration of bone tissue. There is no previous study regarding the effect of Cinnamomum burmanini Blume on osteoporosis.

Objective

This study was aimed to investigate the effect of C. burmanini Blume on bone turnover marker, mineral elements, and mesostructure of ovariectomized rats.

Materials and methods

Thirty female Wistar rats were randomly divided into five groups, which included a control group (sham surgery), ovariectomy group (OVX), and ovariectomy groups in the presence of ethanolic extract of C. burmanini Blume (EECB) at doses of 12.5; 25; 50 mg/kg body weight (BW). Analysis of serum C-telopeptide collagen type I (CTX) and osteocalcin (OC) were done by enzyme-linked immunosorbent assay (ELISA). Tibia mineral elements and mesostructure were analyzed by X-ray Fluorescence and Scanning Electron Microscopy, respectively. In silico study was performed by modeling protein structure using SWISS-MODEL server and Ramachandran plot analysis.

Results

The increase in OC and CTX were significantly attenuated by treatments of EECB. Ovariectomy significantly decreased Cu/Zn ratio compared to sham-operated rats (p < 0.05). Mesostructure of ovariectomized rats was significantly different compared with the control group.

Conclusion

Cinnamon was able to normalize bone turnover markers, but, the mesostructure of hydroxyapatite crystal growth was achieved at the highest dose extract. In silico study showed that the active compound of EECB could not only support osteoclastogenesis process by decreasing the binding energy between RANKL and RANK, but also by inhibiting the interaction between OPG and RANK.

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Administration EECB significantly increased OC and CTX level compared to OVX group.

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The ratio of Cu/Zn was lower significantly in OVX rats compared to sham-operated rats.

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Hydroxyapatite crystal growth can reach at the highest dose of Cinnamon.

Regulation by Phloroglucinol of Nrf2/Maf-Mediated Expression of Antioxidant Enzymes and Inhibition of Osteoclastogenesis via the RANKL/RANK Signaling Pathway: In Silico study

Introduction:

Phloroglucinol is an antioxidant compound with many positive effects on health. The purpose of this study was to determine the role of phloroglucinol in osteoclastogenesis via the RANKL/RANK signaling pathway and the activity of the transcription factor Nrf2.

Material and methods:

Analysis was performed in silico using the primary method of docking by the use of Hex 8.0 software and Haddock web server. Analysis of interactions was then performed to determine interactions between the ligand and its receptors by using the software LigPlus and LigandScout 3.1.

Results:

Results indicated that phloroglucinol compound was thought to inhibit osteoclastogenesis via three mechanisms: inhibiting RANKL−RANK interaction, sustaining the RANKL−OPG bond, and increasing the activity of the transcription factor Nrf2.

Methylation impact analysis of erythropoietin (EPO) Gene to hypoxia inducible factor-1α (HIF-1α) activity

Erythropoietin (EPO) is a glycoprotein hormone that play a role as key regulator in the production of red blood cells. The promoter region of EPO is methylated in normoxic (non-hypoxia) condition, but not in hypoxic condition. Methylation of the EPO enhancer region decline the transcription activity of EPO gene. The aim of this study is to investigate how different methylation percentage affected on the regulation and transcriptional activity of EPO gene. The DNA sequence of erythropoietin gene and protein sequence was retrieved from the sequence database of NCBI. DNA structure was constructed using 3D-DART web server and modeling structure of HIF1 predicted using SWISS-MODEL web server. Methylated DNA sequence of EPO gene using performed with YASARA View software and docking of EPO gene and transcription factor HIF1 analyzed by using HADDOCK webserver. Our result showed that binding energy in 46% methylated DNA was higher (-161,45 kcal/mol) than in unmethylated DNA (-194,16 kcal/mol) and 8% methylated DNA (-175,94 kcal/mol). So, we presume that a silencing mechanism of the Epo gene by methylation is correlated with the binding energy, which is required for interaction. A higher methylation percentage correlates with a higher binding energy which can cause an unstable interaction between DNA and transcription factor. In conclution, methylation of promoter and enhancer region of Epo gene leads to silencing.