Pathobiology Research
Year:2014 | Volume:17 | Issue:3|Papers Count:9

Thyroid cancer, the most common endocrine malignancy worldwide, originates from follicular epithelial cells. It is classified as a well-differentiated thyroid carcinoma (WDTC) -follicular (FTC) and papillary types (PTC) -, poorly differentiated thyroid carcinomas (PDTC), anaplastic thyroid carcinoma (ATC), and parafollicular calcitonin producing cells include medullary thyroid carcinoma (MTC). “Epigenetic” refers to the study of heritable changes in gene expression that occur without any alteration in the pattern of the primary DNA sequence. Growing evidence shows that epigenetic changes play important roles in thyroid carcinomas and, together with genetic changes, lead to tumorigenesis. Epigenetic silencing of various genes specific for thyroid differentiation have been detected in thyroid tumors. These changes in tumor-promoting and tumor suppressor genes also contribute to the dysregulation of thyrocyte growth and other aspects of tumorigenesis. However, at present, no promising treatment is available for advanced thyroid cancer, which is unresponsive to radioiodine. Biologically targeted therapies for advanced thyroid carcinomas have been proposed based on the recognition of main oncogenic mutations. In this review we discuss the most frequent epigenetic variations in different types of thyroid cancer, epigenetic strategies for treating this carcinoma, and experimental data and clinical trials, particularly those that use deacetylase inhibitors and demethylating agents.

Objective: Recently, phage display libraries have received enormous attention for identification and isolation of pharmaceutical molecules with diagnostic and therapeutic properties. Peptide libraries are known as one of the most important and widely used types of phage display libraries. In the current study, we aimed to screen the Ph.D. TM-7 phage display peptide library through biopanning for the identification of human colon adenocarcinoma-binding peptide ligands.Methods: Three rounds of biopanning were performed on SW480 as the target cell and fibroblast (HF-SF-PI3), AGS, KYSE-30 and Huh-7 as control cells. The displayed peptide-encoding regions in the genome of SW480-binding phages obtained from the final round of panning were amplified by plaque-PCR and subsequently sequenced. Bioinformatic tools were used to determine the sequence of target cell-binding peptides and further characterization of these peptides.Results: Biopanning of the phage library led to the enrichment of several peptides among which the peptide with sequence “HAMRAQP” was the most dominant. Bioinformatic analysis of the isolated peptides indicated that they are not target unrelated peptides (TUP).Conclusion: The peptides, in particular those with the highest frequency, due to having the capability of specific binding to SW480 cells represent the potential for use in targeting of therapeutic genes and drugs to colon cancer cells.

Objective: Glioblastoma is an invasive tumor of the central nervous system. Epigenetic therapy of cancer is potentially very useful in reversing some of cancer defects due to reversibility of epigenetic alterations. MEG3 is a tumor suppressor long non-coding RNA (lncRNA) that expresses in the majority of normal tissues. Methylation of the MEG3 promoter region elicits a decrease in its expression in glioblastoma cells. Bioactive nutrients including curcumin offer great potential in altering DNA methylation status. Herein, we aim to investigate the epigenetic-based role of dendrosomal-curcumin (DNC) in upregulation of MEG3 expression in glioblastoma cells.Methods: We evaluated DNC entrance to U87MG cells with the use of the fluorescent characteristics of curcumin. Next we performed the MTT assay to evaluate DNC and dendrosome effects on cell viability. The ability of DNC to boost expression of MEG3 in DNA methylation regulation was accomplished by a study of the relative expressions of MEG3and DNA methylation regulator enzymes, DNA methyltransferases (DNMT1, DNMT3Aand 3B) using semi-quantitative and quantitative PCR.Results: We observed the entrance of DNC into U87MG cells. DNC significantly caused U87MG cell death in a time and dose-dependent manner. However dendrosome did not show any toxic effect on this cell line. Data acquired from gene expression assays determined that DNC upregulated MEG3 expression (P<0.05) and downregulated DNMT3B expression (P<0.05). There was no significant effect on DNMT1, 3A expression in U87MG cells.Conclusion: The data showed that DNC could awaken epigenetically silenced tumor suppressor genes through an ambiguous route in glioblastoma cells. Notwithstanding, DNA hypomethylation has occurred by downregulation of DNMTs, inactive DNA demethylation and or active DNA demethylation, subsequently tumor suppressor genes such as MEG3 a cell growth regulator overexpressed. We concluded that DNC has useful characteristics in epigenetic therapy of glioblastoma.

Objective: Breast cancer is one of the leading causes of death in women worldwide. Conventional treatments use cytotoxic drugs which have high numbers of side effects. Currently pharmacologists are searching for novel drugs with fewer side effects and maximum efficiency as breast cancer treatment. The aim of the current study is to clarify the cytotoxicity effect of the recombinantouter membrane inflammatory protein (oipA) of Helicobacter pylori (H. pylori)on a breast cancer cell line.Methods: We purified recombinant H. pylori oipA by Ni–NTA affinity chromatography. Breast cancer cells (4T1) were treated with different concentrations of recombinant oipA for various lengths of time. Cell viability was evaluated by the viability assay (MTT test).Results: SDS-PAGE analysis showed the expression of an approximately 34000 dalton protein. Statistical analysis showed oipA toxic effects on 4T1 cells at a concentration of 250 mg/ml after 24 h.Conclusion: These findings suggested that oipA had a direct toxic effect on a breast cancer cell line (4T1) in vitro. The oipA protein might be a new tool for future therapeutic strategies in cancer immunotherapy.

Objective: Crocin, the carotenoid isolated from saffron, has numerous medicinal properties which include anticancer and antioxidant activities. Some antioxidants, such as carotenoids, can act as pro-oxidants at higher dosages and therefore induce tissue damage. In this situation antioxidant defense systems in the liver activate to prevent tissue damage. This study investigates the possible toxic effects of crocin on the liver of normal rats.Methods: Normal rats were randomly divided into four groups. Group 1 was treated with normal saline as the control and groups 2 to 4 were treated different doses of 50, 100 and 200 mg/kg crocin intraperitoneally once a week for four weeks. Animals were killed one week after the last injection. Serum profile of the rats that included ALT, AST, ALP, urea, uric acid and creatinine, as well as the activity of antioxidant enzymes (SOD, CAT and GPx), GSH content, and lipid and protein oxidation by measurement of MDA and protein carbonyl levels were assessed in the liver. In addition, we conducted histopathological examinations of the liver specimens.Results: We studied different crocin concentrations that have been used to treat various diseases. There were no significant changes in serum parameters, GSH, MDA, protein carbonyls and activities of CAT and SOD at the different crocin concentrations.Histopathological examination did not show any changes in the liver. Only the higher dose (200 mg/kg) decreased GPx activity which might be reversible over the long-term.Conclusion: Crocin, at the studied doses showed no toxic effects on the rat liver.

Objective: Since the identification of the two highly penetrant dominantly inherited genes, BRCA1/2, in the 1990s, a number of other genes have been identified which account for approximately 25% of the genetic basis for hereditary breast cancer. At least 75% are unidentified. The goal of this study is to investigate the presence or absence of a recessive pattern of inheritance in this heterogeneous disease whose possibility has been previously discussed by researchers.Methods: In this study we used exome sequencing as the most recent approach for identification of the genetic basis of any disease. The results of exome sequencing were confirmed by Sanger sequencing.Results: Although we did not find any homozygous mutation in this family, however a heterozygous 4bp deletion that led to a frame shift mutation was identified in exon 11 of the BRCA2 gene. Also identified was a heterozygous single nucleotide polymorphism in exon 9 of the STK11 gene.Conclusion: The rs80359352 variation identified in this family is one of the frequent pathogenic mutations in the BRCA2 gene that has been reported in the BIC database. This variation has been previously observed in other ethnic populations such as Caucasians, Hispanics and the Chinese. In this study, for the first time, we report this mutation in Iranian population and its segregation in hereditary breast cancer.

Objective: Oxidative stress as a consequence of aging can induce infertility in males. In this study, we have investigated the effects of aging on sperm parameters, intra-spermatic water soluble antioxidants, reactive oxygen species (ROS), and in vitro blastocyst formation.Methods: We chose 5 older NMRI male mice (10-12 months) and 5 younger NMRI male mice (2-3 months). Sperm parameters, ROS, soluble antioxidants level and in vitro fertilization rate were assessed in both groups. The results were analyzed by the independent sample and chi square tests. A correlation test was performed between ROS generation and soluble antioxidant levels.Results: Our data showed a significant decrease (P≤0.05) between sperm count, progressive motility and normal morphology. There was no significant difference in fertilization, blastocyst formation rates, ROS and water soluble antioxidant levels between the two groups. We observed a significant difference (P≤0.01), linear and inverted relation between both groups in terms of ROS and water soluble antioxidant levels.Conclusion: Aging causes a significant decrease in sperm count, progressive motility and normal morphology. The relationship between intra-spermatic oxidant and anti-oxidants is significant, linear and inverted in both young and aging mice. Thus, high levels of water soluble antioxidants are followed by decreased ROS levels. This study has shown that age of the male mouse did not affect the rates of in vitro fertilization and blastocyst formation.

Objectives: Long non-coding RNAs (lncRNAs), a vast class of recently discovered noncoding genes in the human genome, have been implicated in the regulation of several biological processes, including the maintenance of stem cell pluripotency and neurogenesis. New evidences have emerged that some long IncRNAs act as enhancers for their neighboring genes. Oct4, also known as POU5F1 and Oct3/4, functions as a master regulator in maintaining the properties of pluripotency and self-renewal of embryonic stem (ES) cells and embryonal carcinoma (EC) cells. Oct-4 expression must be tightly regulated; too much or too little expression can lead to cell differentiation.Methods: PSORS1C3, an IncRNA, is located upstream of the Oct4 gene. This IncRNA could potentially impact the level of Oct4 expression. Here, we have investigated potential expression of PSORS1C3 on 23 different human pluripotent and cancer cell lines by means of RT-PCR.Results: Our results revealed a noticeable expression of PSORS1C3 both in a well-known pluripotent cell line (NTera2/NT2) and five different cancer cell lines (AGS, 5637, Ht-29, HepG2 and PC3).Conclusion: We detected the expression of PSORS1C3 for the first time in both cancer cell lines and stem cells.