جستجوی مقالات مرتبط با کلیدواژه "tumor suppressor" در نشریات گروه "پزشکی"

 This research intended to discover the significance of miR-138 (microRNA 138) on the expression profile, proliferation, and the associated regulatory mechanisms in prostate cancer (PCa).

 Thirty-five specimens of prostate were studied to evaluate the expression level of miR138 by RT-qPCR (Quantitative reverse transcription polymerase chain reaction). Bioinformatics analysis was performed to search for the target genes of miR-138; and ABL1 (ABL proto-oncogene 1, non-receptor tyrosine kinase), CCND1 (cyclin D1), CCND3 (cyclin D3), VIM (vimentin), TWIST1 (twist family bHLH transcription factor 1), HIF1A (hypoxia-inducible factor 1 subunit alpha), and TERT (telomerase reverse transcriptase) genes were selected. Then, the biological role of miR-138 and CCND1 in the progression of PCa was investigated using RT-qPCR and luciferase reporter gene assay. Finally, overexpression of miR-138 on the proliferation in PCa cell lines was analyzed using the MTT (3-(4, 5-dimethylthiazol-2-Yl)-2, 5-diphenyltetrazolium bromide, Sigma, Germany) assay.

 RT-qPCR showed that the expression of miR-138 downregulated in PCa tissues and cell lines. Bioinformatics analysis and RT-qPCR assay demonstrated that CCND1 expression level was negatively correlated with miR-138 in PCa tissues and the PC3 cell line. Moreover, CCND1 was predicted to be the target gene of miR138 in the PC3 cell line based on the results of luciferase reporter gene assay. Substantially, over-expression of miR138-5p mimic could inhibit the expression level of CCND1 gene in PC3 cell lines. Lastly, over-expression of miR-138 inhibited the proliferative capacities in PC3 and DU-145 cells.

 Our research introduces miR-138 as a negative regulator of CCND1 in the progression of PCa with an inhibitory impact on the proliferation rate of PCa cell lines. This regulatory mechanism could be utilized for the design and target selection of remedial miRNA-based approaches.

Epigenetic alterations such as DNA methylation are known as the main cause of different types of cancers through inactivation of tumor suppressor genes, especially thyroid cancer. Identification of novel and effective markers are important in diagnosis and prevention of thyroid cancer. In the present study, the expression and methylation of Solute carrier family 5 member 8 (SLC5A8) in Papillary Thyroid Carcinoma (PTC) in comparison to multinodular goiter (MNG) have been studied.

Overall, 41 patients with PTC and 36 patients affected by MNG were recruitedfrom four hospitals in Tehran and Qazvin, Iran in 2018. Thyroid tissues were obtained during thyroidectomy. RNA and DNA were extracted from thyroid tissues. Quantitative RT-PCR assay was performed for determining the mRNA level of SLC5A8while Methylation-Sensitive High-Resolution Methylation was applied for assessing the methylation status.

Methylation status of three regions composed of 52 CpG islands in the promoter of SLC5A8gene was studied by HRM assay. SLC5A8level in PTC tissues was significantly downregulated in average 0.4 fold in comparisonwith MNG tissues (P=0.05). The aberrant methylation of SLC5A8(b) region was remarkably different in PTC and MNG cases. The promoter methylation of SLC5A8(c) was significantly related to BRAFmutations and vascular invasion in PTC patients.

The aberrant promoter hyper methylation of SLC5A8 was related to aggressive PTC. Therefore, there is some evidence to support the hypothesis that SLC5A8could be a paly important role in the develop-ment of PTC.

Psoriasis vulgaris (PsV) is an immune-mediated skin disease of unknown mechanism. Interleukin 33 (IL-33) is a member of IL-1 cytokine family and suppression of tumorigenicity 2 (ST2) is the specific ligand of IL-33. It has been found that IL33 and ST2 are increased in psoriatic lesions, but the expression levels in serum and their relationship to clinical features are still unclear. The aim of this study is to assess IL-33, ST2, IL-17 and IL-5 serum levels as well as serum concentration of blood glucose and blood lipids in PsV patients and their relationship with clinical characteristics.

Sixty-eight PsV samples and 60 healthy individuals were recruited. Serum levels of IL-33, ST2, IL-17 and IL-5 were measured by enzyme-linked immunosorbent assay and blood glucose and blood lipid were assayed by automatic biochemical analyzer.

Serum levels of IL-33, ST2, IL-17 and IL-5 were increased significantly in PsV patients compared with controls (P<0.01). Cytokines were overexpressed in PsV patients during active stages compared with controls (P<0.05). Expression levels of IL-33, ST2 and IL-17 confirmed a significance in different severity groups of PsV patients (P<0.05). Serum concentration of triglyceride (TG) was also increased compared with controls (P=0.024). IL-33 levels were positively correlated with total cholesterol (TC) levels (r=0.319, P=0.008).

IL-33/ST2 could generally reflect the activity and disease severity in PsV patients, which indicates that the IL-33/ST2 signaling pathway plays an important role in the pathogenesis of PsV.

Recent evidence presented the significant role of the microRNA-193 (miR-193) family in biological processes by the contribution of specific targeting, which mainly display as a tumor suppressor in various cancers. In the present study, we evaluated the effect of miR-193a-5p replacement on some metastasis gene expression in metastatic breast cancer (BC) cells.

For this purpose, firstly, the quantitative real-time polymerase chain reaction (qRTPCR) was used to detect the miR-193a-5p expression in the MDA-MB-231 BC cell line. Subsequently, miR-193a-5p was transfected into the cells, and the expression levels of ROCK1 (Rho‑associated, coiled‑coil containing protein kinase 1), CXCR4 (Chemokine Receptor-4), CD44, and vimentin genes were evaluated by qRT-PCR.

The expression level of miR-193a-5p strongly reduced in MDA-MB-231 cells. Interestingly, the ROCK1 (P < 0. 001), CD44 (P < 0.0001), CXCR4 (P < 0. 001) and vimentin (P < 0. 001) expression levels significantly decreased following miR-193a-5p transfection in MDA-MB-231 BC cells.

To conclude, it seems that miR-193a-5p restoration can attenuate the metastatic behavior of BC cells in vitro through decreased expression level of metastasis-related genes and may constitute an effective novel therapeutic strategy in miRNA-replacement therapy and treatment of metastatic breast adenocarcinoma in the future.

The basic unit of chromatin is a nucleosome included an octamer of the four core histones and 147 base pairs of DNA. Posttranslational histones modifications affect chromatin structure resulting in gene expression changes. CpG islands hypermethylation within the gene promoter regions and the deacetylation of histone proteins are the most common epigenetic modifications. The aberrant patterns of methylation localized in normally unmethylated CPG islands mediate chromatin compaction resulting in gene silencing and cancer induction. The current review article aimed to assess and analyze the available literature on the tumor suppressor genes (TSGs) hypermethylation in hepatocellular carcinoma (HCC). For this review article, the suitable studies were obtained by searching PubMed, SCOPUS, NCBI, and Ovid database from 1995 up to September 2018 with the MeSH terms combined with free terms.  A total 1483 Items were identified in SCOPUS (n = 459), PubMed (n = 832), Ovid (n = 118), and other reference sources (n = 74). After the assessment, 73 manuscripts were included in the current study. In total, 13 genes were found to have the most effect on HCC. Therefore, we selected them to evaluate as candidate genes in this cancer. TSGs can affect cell cycle during various stages of the cycle an at the cell cycle checkpoints. The hypermethylation of these genes results in chromatin compaction and TSGs silencing which induces HCC.

Thyroid cancer is the fourth most common cancer in the world. Papillary thyroid carcinoma (PTC) accounts for 80% of all types of thyroid neoplasm. Epigenetic alterations such as DNA methylation are known as the main cause of different types of cancers through inactivation of tumor suppressor genes.

In the present study, the expression and methylation of suggested gene namely nucleolar protein 4 (NOL4) in PTC in comparison to multi nodular goiter (MNG) have been studied.

Forty-one patients with PTC and 38 patients affected by MNG were recruited. Thyroid tissues were obtained during thyroidectomy. RNA and DNA were extracted from thyroid tissues. Quantitative RT-PCR assay was performed for determining the mRNA level of NOL4 while methylation-sensitive high resolution methylation was applied for assessing the methylation status with designing six pairs primers for six regions on gene promoter which were named from NOL4 (a) to NOL4 (f).

Methylation assessment of 81 CpG islands in the promoter region of NOL4 gene revealed that NOL4 (f), the nearest region to the start codon, was significantly hypermethylated in PTC cases compared to MNG cases. NOL4 level in PTC cases in comparison with MNG cases were downregulated. The methylation status and mRNA level of NOL4 (f) were associated with age of diagnosis (Age of the patient at the time of diagnosis), lymph node metastasis, and advanced stages of disease.

These data suggested an aberrant promoter hyper-methylation of NOL4 in PTC cases may be linked with its downregulation. Therefore, NOL4 gene can be proposed as a potential tumor suppressor gene in PTC tissues.

Recent evidence presented the important role of microRNAs in health and disease particularly in human cancers. Among those, miR-193 family contributes as a tumor suppressor in different benign and malignant cancers like breast cancer (BC) via interaction with specific targets. On the other hand, it was stated that miR-193 is able to modulate some targets in chemoresistant cancer cells. Therefore, the aim of this study was to evaluate the potential function of miR-193a-5p and paclitaxel in the apoptosis induction by targeting P53 in BC cells.

At first, miR-193a-5p mimics were transfected to MDA-MB-231 BC cell line which indicated the lower expression level of miR-193a-5p. Subsequently, the transfected cells were treated with paclitaxel. Then, cell viability, apoptosis, and migration were evaluated by MTT, flow cytometry and DAPI staining, and scratch-wound motility assays, respectively. Moreover, the expression levels of P53 was evaluated by qRT-PCR.

The expression level of miR-193a-5p was restored in MDA-MB-231 cells which profoundly inhibited the proliferation (P<0.0001), induced apoptosis (P<0.0001) and harnessed migration (P<0.0001) in the BC cells and more effectiveness was observed in combination with paclitaxel. Interestingly, increased miR-193a-5p expression led to a reduction in P53 mRNA, offering that it can be a potential target of miR-193a.

Taken together, it is concluded that the combination of miR-193a-5p restoration and paclitaxel could be potentially considered as an effective therapeutic strategy to get over chemoresistance during paclitaxel chemotherapy

Breast cancer (BC) is one of the major causes of female cancer-related death. It has recently been demonstrated that metabolic reprogramming including alteration in lipid metabolism is indicated in various types of cancer. The enzymes of the acyl-coenzyme A synthetase long-chain family (ACSLs) are responsible for converting fatty acids to their corresponding fatty acyl-coenzyme A esters which are essential for some lipid metabolism pathways. ACSL4 is one of the isoforms of ACSLs and has            a marked preference for arachidonic and eicosapentaenoic acids. The objective of this study was to evaluate ACSL4 expression, its prognostic significance, and its correlation with p53 tumor suppressor in BC patients.
Experimental approach: In this study 55 pairs of fresh samples of BC and adjacent non-cancerous tissue were used to analyze ACSL4 expression, using real-time polymerase chain reaction and immunohistochemistry (IHC) staining. The expression of other studied variables was also examined using the IHC technique.

ACSL4 expression was significantly higher in BC tissues compared to the adjacent normal tissue. This upregulation was negatively correlated with Ki-67 and age, and positively correlated  with p53 status. The correlation between ACSL4 and p53 may indicate the role of p53 in the regulation of lipid metabolism in cancer cells, in addition to its role in the regulation of ferroptosis cell death.

 Our results indicated that the expression of ACSL4 may be considered as a prognostic indicator and potential therapeutic target in BC. However, further studies are needed to confirm the significance of these findings

microRNAs (miRNAs) play bifunctional roles in the initiation and progression of cancer, and recent evidence has confirmed that unusual expression of miRNAs is required for the progress of breast cancer. The regulatory role of aryl hydrocarbon receptor (AhR) and its endogenous ligand, 6-formylindolo[3,2-b]carbazole (FICZ) on the expression of tumor suppressor miRNAs, miR-22, miR-515-5p and miR-124-3p, as well as their association with the estrogen receptor alpha (ERα) were the aims of this study.

In this experimental study, the expression levels of miR-22, miR-515-5p, miR-124-3p and miR-382-5p in MCF-7 cells were determined using the quantificational real time polymerase chain reaction (qRT-PCR) assay.

Our results revealed that miR-22, miR-515-5p, and miR-124-3p expressions were significantly increased in cells transfected with ERα siRNA. Our data also showed that miR-22, miR 515-5p, and miR-124-3p expression levels were significantly increased following FICZ treatment. Here, we found that AhR/ERα cross-talk plays a critical role in the expression of miR-22, miR-515-5p and miR-124-3p in MCF-7 cells.

Overall, our data demonstrated that FICZ, as an AhR agonist could induce the expression of tumor suppressor miRNAs, miR-22, miR-515-5p, and miR-124-3p; thus, FICZ might be regarded as a potential therapeutic agent for breast cancer treatment. 

 Zataria multiflora is a plant that belongs to Laminaceae family. It is traditionally believed to have several therapeutic effects. Acute promyelocytic leukemia is a distinct subtype of acute myeloid leukemia with dominancy of promyelocytes in bone marrow and blood stream. The aim of this study is to investigate the anticancer effects of Z. multiflora extract on acute promyelocytic leukemia cell lines.  Viability of NB4 cells was determined by trypane blue test after treatment with 20, 40 and 80µg/mL of Z. multiflora extract for 24 hours. Then, the metabolic activity of cells was determined by MTT assay after 24 hours of treatment with 80 µg/mL Z. multiflora. Finally, Real-time PCR was employed to study the effect of Z. multiflora extract on the expression of hTERT gene.  Z. multiflora extract decreased the viability of NB4 cells in a dose-dependent manner. Metabolic activity of NB4 cells significantly decreased following treatment with 80 µg/mL Z. multiflora. Gene expression analysis showed 59%±4% decrease in the expression of hTERT gene after treatment with 80 µg/mL of Z. multiflora.  Z. multiflora extract significantly decreased the viability and metabolic activity of NB4 cells. It also led to significant downregulation of hTERT gene compared to the control group. Therefore, Z. multiflora methanolic extract potentially has anticancer effect on acute promyelocytic leukemia cells through down regulation of hTERT. Further investigations are needed to explore other mechanisms of actions and the active ingredients.

Exposure to benzene would be associated with many diseases including leukemia. Epigenetic alterations seem to be among the main mechanisms involved.
To determine if chronic occupational exposure to low level of benzene would be associated with DNA methylation.
Global DNA methylation and promoter-specific methylation of the two tumor suppressor genes, p14ARF and p15INK4b, were assessed employing methylation-specific PCR using the DNA extracted from 40 petrochemical workers exposed to ambient benzene levels of While an increase in global DNA methylation of 5% in p14ARF (p=0.501) and 28% in p15INK4b (p=0.02) genes was observed in the exposed group, no hypermethylation in either of the studied genes was observed in the unexposed group. No significant association was found between the frequency of aberrant methylation and either of age, work experience, and smoking habit in the exposed group.
Chronic occupational exposure to lower than the permissible exposure limit of benzene may still result in DNA methylation of tumor suppressor genes that may ultimately lead to development of cancer.

Epigenetic and genetic alterations are two mechanisms participating in leukemia, which can inactivate genes involved in leukemia pathogenesis or progression. The purpose of this review was to introduce various inactivated genes and evaluate their possible role in leukemia pathogenesis and prognosis. By searching the mesh words “Gene, Silencing AND Leukemia” in PubMed website, relevant English articles dealt with human subjects as of 2000 were included in this study. Gene inactivation in leukemia is largely mediated by promoter’s hypermethylation of gene involving in cellular functions such as cell cycle, apoptosis, and gene transcription. Inactivated genes, such as ASPP1, TP53, IKZF1 and P15, may correlate with poor prognosis in acute lymphoid leukemia (ALL), chronic lymphoid leukemia (CLL), chronic myelogenous leukemia (CML) and acute myeloid leukemia (AML), respectively. Gene inactivation may play a considerable role in leukemia pathogenesis and prognosis, which can be considered as complementary diagnostic tests to differentiate different leukemia types, determine leukemia prognosis, and also detect response to therapy. In general, this review showed some genes inactivated only in leukemia (with differences between B-ALL, T-ALL, CLL, AML and CML). These differences could be of interest as an additional tool to better categorize leukemia types. Furthermore; based on inactivated genes, a diverse classification of Leukemias could represent a powerful method to address a targeted therapy of the patients, in order to minimize side effects of conventional therapies and to enhance new drug strategies.

A member of homeodomain protein namely TGIF2LX has been implicated as a tumor suppressor gene in human malignancy as well as in spermatogenesis. However, to our knowledge, dynamic functional evidence of the TGIF2LX has not yet been provided. The aim of the present study was to investigate the human TGIF2LX target gene(s) using a cDNA-AFLP as a differential display method. A pEGFP-TGIF2LX construct containing the wild-type TGIF2LX cDNA was stably transfected into SW48 cells. UV microscopic analysis and Real-time RT-PCR were used to confirm TGIF2LX expression. The mRNA expressions of TGIF2LX in transfected SW48 cells, the cells containing empty vector (pEGFP-N), and untransfected cells were compared. Also, a Real-time PCR technique was applied to validate cDNA-AFLP results. The results revealed a significant down-regulation and up-regulationby TGIF2LX of Nir1 and Nir2 genes, respectively. The genes are engaged in the cell morphogenesis process. Our findings may provide new insight into the complex molecular pathways underlying colorectal cancer development.

PML (Promyelotic Leukemia) protein is a tumor suppressor protein encoded by the PML gene. This protein is known as one of the main components of PML nuclear bodies (PML-NBs) in the nucleolus. The number and morphology of these structures vary in different cells. Due to alternative splicing, post-translational modifications, and interactions with different partners, this protein has acquired different localizations and functions in the cell. Most studies have focused on the role of this protein in tumor suppression and myeloid differentiation. In this article, we review the role of this protein in cellular activity, and its importance in stem cell characteristics and neural development.

Fragile histidine triad (FHIT) is considered as a member of the histidine triad (HIT) nucleotidebinding protein superfamily regarded as a putative tumor suppressor executing crucial role in inhibiting p53 degradation by MDM2. Accumulating evidences indicate FHIT interaction with p53 or MDM2; however, there is no certain study deciphering functional domains of FHIT involving in the interaction with MDM2 and/or p53. In this regard, such evident interaction can spring in mind determining important domains of FHIT binding to MDM2 with regard to p53.

Since there were not any previous studies appraising complete three-dimensional structures of target molecules, molecular modeling was carried out to construct three-dimensional models of full FHIT, MDM2, P53 and also FHIT segments. Truncated structures of FHIT were created to reveal critical regions engaging in FHIT interaction.

Given the shape and shape/electrostatic total energy, FHIT structures (β1-5), (β3-7, α1), and (β5-7, α1) appeared to be better candidates than other structures in interaction with full MDM2. Furthermore, FHIT structures (β6-7), (β6-7, α1), (β4-7, α1) were considered to be better than other structures in interaction with p53. FHIT truncates that interact with MDM2 presented lower energy levels than FHIT truncates interacting with p53.

These findings are beneficial to understand the mechanism of the FHIT-MDM2-p53 complex activation for designing inhibitory compounds.

Multiple myeloma (MM), is the second most common blood cancer after non-Hodgkin’s lymphoma. Genetic changes, structural and numerical chromosome anomalies, are involved in pathogenesis of MM, and are among the most important prognostic factors of disease-associated patient survival. MicroRNAs (miRNAs) are small 19-22 nucleotide single-stranded RNAs involved in important cellular processes. Cytogenetic changes in plasma cells alter miRNA expression and function. MiRNAs act as tumor suppressors and oncogenes by affecting intracellular signaling pathways. MiRNA expression is associated with a specific genetic change and may assist with diagnosis and disease prognosis. This study aims to evaluate recent findings in MM-associated cytogenetic changes and their relationship with changes in the expression of miRNAs. We have determined that MM-associated cytogenetic changes are related to changes in the expression of miRNAs and CD markers (cluster of differentiation) are associated with disease survival. Information about these changes can be used for therapeutic purposes and disease prognosis.