China
Africa
Explore chapters and articles related to this topic
Introduction
Published in Victor A. Bernstam, Pocket Guide to GENE LEVEL DIAGNOSTICS in Clinical Practice, 2019
Identification and isolation of TSGs can be achieved by differential or subtractive hybridization, which is based on the comparison of gene expression in two related cell populations. Examples of the use of subtractive hybridization are the isolation of TSGs from Syrian hamster embryo (SHE) cells undergoing carcinogen-induced neoplastic transformation, and from human breast tissue where the genes uniquely or preferentially expressed in one of a pair of closely related cell populations were selected for and recovered from breast carcinoma cells.
Toxicogenomic and Toxicoproteomic Approaches for Biomarkers
Published in Anthony P. DeCaprio, Toxicologic Biomarkers, 2006
Subsequently, other methods were developed to allow a more global examination of the biological response to a given treatment. One early approach was the development of subtractive hybridization of expression libraries, in which RNA pools isolated from control and treated samples were hybridized to each other to subtract out mRNAs that were expressed at equal levels in the two samples (30). The goal of this design was to enrich for those RNAs that were differentially expressed in the two samples, which would allow subsequent cloning and sequencing to reveal those genes that were of greatest interest. One of the first published experiments to apply this technique examined the effects of cadmium on gene expression in mammalian cell culture (31). The majority of the sequenced clones coded for the same mRNA, metallothionein, which is a moderately expressed mRNA and protein known to be strongly upregulated in response to cadmium, zinc, and other divalent metals. Thus, while identification of metallothionein as the major cadmium-inducible gene in this study validated this overall experimental approach, it also pointed out two major drawbacks to its use in identifying novel responsive genes. First, by its very design, this technique strongly favors the selection of those mRNAs that are most abundantly expressed, and second, it tends to select for those mRNAs whose expression is most dramatically altered in response to a given treatment.
Unfolding the Role of Splicing Factors and RNA Debranching in AID Mediated Antibody Diversification
Published in International Reviews of Immunology, 2021
Ankit Jaiswal, Amit Kumar Singh, Anubhav Tamrakar, Prashant Kodgire
Until the mid-90s, it was not very clear how a limited set of Ig genes produce such a large number of antibodies. The breakthrough came when AID was discovered in 1999 by Honjo group via subtractive hybridization technique [3], a method used for the detection of differences between the RNA/cDNA of two cells. It led to the quest for finding the AID structure, its function, as well as targeting. AID was originally thought to be an RNA editing enzyme due to its similarity with the APOBEC family. AID consists of four domains, namely, nuclear localization signal (NLS), AID catalytic domain, APOBEC like domain and nuclear export signal. N-terminal and C-terminal domains of AID are indispensable for SHM [21] and CSR [4, 22–24] respectively. In vitro and cell-free studies had shown that AID preferentially deaminates cytosine in WRC (W = A/T and R = A/G) region also known as a hot spot, compared to cold spot in SYC (S = G/C and Y = C/T) [25–27]. Furthermore, AID preference for WRC inside the cell at Ig genes is also reported [28]. In fact, the AID mediated mutation frequency at hotspot is 4.6 times higher than at cold spot [27]. Nevertheless, why AID preferentially deaminates C in WRC hotspot is still to be explored.
Orlistat as a FASN inhibitor and multitargeted agent for cancer therapy
Published in Expert Opinion on Investigational Drugs, 2018
Alejandro Schcolnik-Cabrera, Alma Chávez-Blanco, Guadalupe Domínguez-Gómez, Lucia Taja-Chayeb, Rocio Morales-Barcenas, Catalina Trejo-Becerril, Enrique Perez-Cardenas, Aurora Gonzalez-Fierro, Alfonso Dueñas-González
RPL7a was identified in a subtractive hybridization screen as a gene up-regulated in human colorectal cancer. Expression of RPL7a was greater than two-fold higher in tumors compared to the adjacent normal mucosa in 72% of the patients studied [106]. RPL7a has been found to be recombined with the proto-oncogene trk, contributing with the amino-terminal-activating sequence to the receptor kinase domain of trk, which allows for its oncogenic activation [107]. RPL7a has also been demonstrated to be over-expressed in T47D breast cancer cells as compared to normal cells and can be induced by ethanol, a known risk factor for breast cancer [108]. Though it remains to be more information gathered on the role of these three ribosomal proteins in carcinogenesis, it could be expected that orlistat may exert some of its effects on cancer cells through targeting these proteins.
Current status of sperm functional genomics and its diagnostic potential of fertility in bovine (Bos taurus)
Published in Systems Biology in Reproductive Medicine, 2018
Sellappan Selvaraju, Sivashanmugam Parthipan, Lakshminarayana Somashekar, B. Krishnan Binsila, Atul P. Kolte, Arunachalam Arangasamy, Janivara Parameshwaraiah Ravindra, Stephen A. Krawetz
Though PCR based techniques can appear more quantitative, the main limitations are the prior knowledge of the gene sequences to be assessed and thus studied. This has been further developed using suppression subtractive hybridization (SSH) and employed to study sperm RNA population between bulls varying in fertility status (Lalancette et al. 2008). The same technique was used to identify differentially expressed genes between X and Y bearing spermatozoa (Chen et al. 2015).