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Volume 72, Issue 2 (May 2014)
Background: A balanced reciprocal translocation is a structural abnormality, which at least consist of breakage of two non-homologous chromosomes along with pieces exchange and form quadrivalant structure that can produce unbalanced chromosomes during meiosis I and result in a fetus abortion. The aim of the present study is to offer using preimplantation genetic diagnosis (PGD) 24sure array, which delivers aneuploidy screening of 24 chromosomes, within a few hours to increase fertility and bearing a child without chromosomal abnormality of this couple. This technique could replace embryo donation for child bearing of this couple. Case presentation: A young couple with recurrent pregnancy loss in 6th and 7th week of pregnancy without family history of recurrent miscarriage and any clinical signs had conferred. All laboratory tests including hormonal, infections, semen and hysterosalpingography were normal except karyotype that showed balanced reciprocal translocation between chromosomes 5 and 18 in male. Chromosomal study of male parents showed normal karyotype. Conclusion: A balanced reciprocal translocation carrier is phenotypically normal, but during meiosis І, carrier chromosomes cant pair normally and form quadrivalant instead of bivalant that depend on type of their segregation (alternate, adjacent 1, adjacent 2,3:1,4:0), produce gametes that are chromosomally unbalanced which can result in early fetus abortion. Considering the number of abnormal gametes, the most effective way to help couples with this problem seems to be PGD 24sure, since it can identify reciprocal and Robertsonian translocation and allows concurrent screening of all chromosomes for aneuploidy. Another technique that can be compared with PGD 24sure is fluorescence in situ hybridization (FISH), but it has several technical limitations such as it is expensive and complexity, in addition it has only few probes (for chromosomes 21, 13, 18, X, Y) so sometimes necessary to create patient specific protocols.
Volume 72, Issue 11 (February 2015)
Background: About 15% of couples have fertility problems and male factor in fertility accounts for half of the cases. In vitro generation of germ cells introduces a novel approach to male infertility and provides an effective system in gene tracking studies, however many aspects of this process have remained unclear. We aimed to promote mouse embryonic stem cells (mESCs) differentiation into germ cells and evaluate its effectiveness with tracking the expression of the Testis specific 10 (Tsga10) during this process. Methods: This is an in vitro study that was performed in department of Medical Genetics in Tehran University of Medical Sciences from February 2012 to March 2013. Mouse embryonic stem cells were cultured on mouse embryonic fibroblast as feeder layer. Then mESCs were differentiated into germ cells in the presence of Retinoic Acid. Based on developmental schedule of the postnatal testis, samples were taken on the 7th, 12th and 25th days of the culture and were subjected to expression analysis of a panel of germ cell specific genes (Stra8 as pre-meiotic, Dazl and Sycp3 as meiotic and Protamin1 and Spata19 as Post-meiotic). Expression of Testis Specific Gene 10 (Tsga10) at RNA and protein levels was then analyzed. Results: It was shown that transition of embryonic stem cells from mitosis to meiosis occurred between 7th and 12th days of mESC culture and post-meiotic gene expression did not occur until 25th day of the culture. Results showed low level of Tsga10 expression in undifferentiated stem cells. During transition from meiotic to post-meiotic phase, Tsga10 expression increased in 6.6 folds. This finding is in concordance with in vivo changes during transition from pre-pubertal to pubertal stage. Localization of processed and unprocessed form of the related protein was similar to those in vivo as well. Conclusion: Expression pattern of Tsga10, as a gene with critical function in spermatogenesis, is similar during in vitro and in vivo germ cell generation. The results suggest that in vitro derived germ cells could be a trusted model to study genes behavior during spermatogenesis.
Volume 73, Issue 4 (July 2015)
Cancer/Testis antigens (CTAs) as a group of tumor antigens are the novel subjects for developing cancer vaccine and immunotherapy approaches. They aberrantly express in tumors with highest normal expression in testis, and limited or no expression in normal tissues. There are important similarities between the processes of germ-cell and cancer cell development Spermatogenesis begins at puberty when expression of novel cell-surface antigens occurs when the immune system has been refined the ability to distinguish self from non-self. Whereas macrophage and lymphocytes are commonly found within interstitial spaces of the testis, these antigen-presenting cells are rarely seen within the seminiferous tubules. These observations have led to the concept of the immune privileged site for testis. Localized normal expression of the CT genes in testis that makes them immunogenic for immune system, in one side, and their abnormal expression in different kinds of cancer cells, in the other side, has make them as promising target for developing cancer vaccines and new cancer therapeutics approaches. In malignancies, gene regulation is disrupted which results aberrant expression of CT antigen in a proportion of tumors of various types. For some CTAs, data support their fundamental role in tumorigenesis. Several authors believe it is not clear whether they have an essential role in tumorigenesis or they are by-products of chromatin variations in cancer. There is a growing list of CTAs within them advanced clinical trials are running by using some of them in cancers like lung cancer, malignant melanoma and neuroblastoma. In this review we discuss the gene TSGA10 as an example of CT genes. TSGA10 expresses in its highest levels in elongating spermatids and localized in the fibrous sheath of mature sperm. This gene is proposed as a serological biomarker in cutaneous lymphoma. Its abnormal expression has been reported in different cancers such as acute lymphoblastic leukemia, breast, brain, gastrointestinal and a range of other cancers either in mRNA or protein levels. It has an important role in angiogenesis in cancer tumors because of its effects in the gene hypoxia-inducible factor (HIF1). Absence or lack of TSGA10 expression has been reported in ascosporic infertile men.
Volume 74, Issue 2 (May 2016)
Stem cells are undifferentiated and multi pluripotent cells which can differentiate into a variety of mature cells and tissues such as nervous tissue, muscle tissue, epithelial tissue, skeletal tissue and etc. Stem cells from all different source have three unique features: 1) Proliferative capability: Stem cells are capable of self dividing and self renewing for long periods or more than six months at least that called immortalization. 2) Undifferentiated nature: It’s considered as one of the essential characteristics of stem cell, so it doesn't have any tissue-specific construction. 3) Differentiation to the different cells from all organs: This ability can Induced by tissue specific transcription factors. Because of that, they are so important in prevention and treatment of human disease. Depending on the sources from which they derive, they have different types which can be used to produce special cells and tissues. The most significant types of stem cells are; embryonic stem cells (ESCs) which are derived from embryos, adult stem cells (ASCs) which are derived from differentiated cells in a specific tissue, induced pluripotent stem cells (iPSs) which are produced from adult differentiated cells that have been genetically reprogrammed to act resemble to an embryonic stem cell and cord blood stem cells which contains haematopoietic stem cells and derived from the umbilical cord after gestation. By providing a medium containing of special growth factor, it is possible to orientated stem cell differentiation pathway and gained certain cells from them. The important uses of stem cells includes damaged heart tissue cells improvements and bone tissue repairing, cancer treatment, damaged neurological and spinal tissue repairing, improving burns and injuries and the treatment of diabetes, infertility and spermatogenesis dysfunction. Furthermore, the application of them in gene therapy is an important issue in the modern medicine science due to the role of them in transferring gene into different cells. Today, this method have had considerable progress in the treatment of many disease. In this review study, some aspect of stem cells like types and characteristic, origin, derivation techniques, storage conditions and differentiation to target tissues, current clinical usage and their therapeutic capabilities will be discussed.
Volume 74, Issue 2 (May 2016)
Background: Lots of vitamin D functions are mediated by its steroid family receptor (VDR). Vitamin D role in infertility is reported by significant fertility reduction in many male laboratory animals with vitamin D deficiency. The reason for reduced fertility in male VDR-null mouse model has been reported to be reduced sperm count and sperm motility. Vitamin D has effects on sperm motility, sperm-ovum coupling, and acrosome reaction stimulation. As VDR is expressed in human male reproductive system, the aim of the current study was to investigate the role of rs2228570 polymorphism of VDR gene in male infertility.
Methods: Investigation was done as a case-control study on infertile azoospermic or oligospermic men referring to Avicenna Research Institute from March 2014 to April 2015. Rs2228570 single nucleotide polymorphism (SNP) located in exon 1 of VDR gene was chosen according to its role on protein function. Blood sampling was done on cases and control groups and after DNA extraction the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) reaction was designed and performed on 100 normal cases, 100 azoospermic and 100 oigospermic control samples. Distribution of quantitative age variable was done using Student’s t-test and qualitative variables (genotype and allelic frequencies) was done using SPSS, ver. 22 (Chicago, IL, USA).
Results: Chi-square test didn’t show significant difference between two case groups and controls (Azoosperm and control P=0.5 and oligosperm and control P=0.09). Comparing CC genotype frequency with TT and CT genotypes (azoosperm and control P=0.48 OR=0.77, oligosperm and control, P=0.17 OR=0.77) and in comparing between TT genotype with CT and CC genotypes (azoosperm and control P=0.49 OR=3.03, oligosperm and control P=0.19 OR=7.21) the difference between these groups was not significant and didn’t increase the probability of disease and didn’t show protective role against it.
Conclusion: According to the findings, the association between rs2228570 polymorphism of vitamin D receptor gene and infertility was not significant and investigation of other polymorphisms might show a relationship with male infertility.
Volume 74, Issue 9 (December 2016)
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Breast cancer that is caused by the accumulation of genetic and epigenetic alterations, is one of the main causes of death resulted from cancer. Various therapeutic approaches have been introduced for this cancer and the traditional diagnosis and treatment is based on the prognosis estimation using cancer anatomic features (TNM system) and clinical results, but studies show different responses of these treatments and recurrence after those in some patients. This diversity is resulted by the differences in biological and molecular characteristics. So genomic and molecular studies became more important and the role of targeted treatment based on an individual's genome was highlighted. Today, the progression in personalized medicine using specific individual genome profile has been possible. The ultimate goal of such studies, in the setting of the personalized medicine, is providing markers which can be used to risk assessment of progressing disease. This new science cause great development in the treatment of breast cancer by recognition of specific markers and application of targeted therapy. Trastuzumab and tamoxifen are the most common monoclonal antibodies applied in these patients depends on their biological and molecular profile. The good response to tamoxifen is seen only in patients with estrogen receptor (ER+) which inhibits the binding of estrogen to its receptor. Defect in the metabolizer enzyme of tamoxifen (CYP2D6), which convert it to the active forms, results in the increased risk of recurrence after treatment. Fulvestrant is another monoclonal antibody which its effect is similar to tamoxifen. Trastuzumab suppresses the cell growth by binding inhibition of epidermal growth factor to HER2 receptors. In the metastatic form of disease, the patients may show resistance to trastuzumab, so lapatinib is suitable alternative in these cases. Pertuzumab combination with trastuzumab and chemotherapy with taxane blocks the dimerization of HER2 with another form of HER receptors. The application of personalized medicine in triple negative phenotype is limited due to the lack of appropriate targets and biomarkers, it makes necessary to do further studies. The aim of this review was to describing the different aspects of personalized medicine and introducing the most important biomarkers and targets in the treatment of breast cancer. |
Volume 78, Issue 3 (June 2020)
Methods: The current research was a case-control study. Fecal samples were provided from 31 healthy individuals, 42 adenomatous polyposis patients and 20 colorectal cancer cases that were referred to Taleghani Hospital, Tehran, Iran, from August 2016 to August 2017 for colorectal cancer screening tests. Fecal samples were collected to analyze intestinal bacteria including, Lactobacillus, Escherichia coli, and Prevotella by absolute quantitative real-time polymerase chain reaction (PCR). The number of these gut bacteria was precisely determined by this method of real-time PCR.
Results: Higher number of Prevotella with 24.6 CT number (P<0.005) and E.coli with 20.4 CT number (P<0.015) were achieved in colorectal cancer cases and adenomatous polyposis patients in contrast to samples from normal individuals. On the contrary, the opposite range was observed for the quantification of Lactobacillus and greater numbers of bacteria (CT=28.6) were detected in normal, compared to the colorectal cancer cases and adenomatous polyposis (P<0.001).
Conclusion: The gut microbiota composition of individuals with colorectal cancer and adenomatous polyposis differs from that of healthy individuals, and the higher numbers of pathogenic microbiota versus beneficial microbiota present in those with colorectal cancer and adenomatous polyposis. In contrast, healthy individuals have higher numbers of beneficial gut microbiota than pathogenic microbes. These findings need more experimental analysis and investigation to better clarify.
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