Breast Cancer Essay Example | Topics and Well Written Essays - 1250 words - 2

Breast Cancer - Essay Example When transcription is not sufficiently balanced, it becomes detrimental to the cell and can cause cancer (Cox & Goding, 1991). It is therefore important to secure a comprehensive understanding of transcription because efforts to carry out corrections to the process can be implemented in instances when issues in the process are apparent. Discussed specifically, the first stage of the transcription process, is seen when the RNA Polymerase-Promoter Complex would bind to the promoter gene in the DNA (Mukakami, et.al., 2001). Such binding also leads to the initiation of the RNA polymerase. The sigma protein has to be present in order for the promoter enzyme to work. Particular sequences on the non-coding strand of the DNA are considered as a signal which would start the unwinding process (Mukakami, et.al., 2001). When the process has been started, the RNA polymerase elongation enzyme then takes over and the second stage of the transcription process manifests. ... f the transcription process or the termination stage the uracil triphosphate or the UTP is added to the RNA through a pairing with the adenine (A) nucleotide on the template DNA strand (Gnatt, et.al., 2001). A phosphodiester bond is then formed and the RNA chain is stretched to 10 nucleotides; the excess diphosphate is expected to dissociate (Gnatt, et.al., 2001). A recent study in embryonic stem cells has revealed a transcription control mechanism that is pervasive and regulated by the gene c-Myc which causes cancer. This study has also discovered a pausing step in the transcription process which regulates the expression of about 80% of genes in mammal cells (Medical News, 2010). The long-accepted perception is that DNA-binding transcription factors include the RNA polymerase Pol II to promoters in order to start off the transcription process. Researchers now claim that additional factors for promoters stop transcription as soon as it begins its process (Medical News, 2010). This means that even as the normal cell processes are being carried out transcription already has faulty qualities. There is a need to engage the transcription process - and this can be a function of factor c-Myc. The pause-release role of the c-Myc is relevant in transcription because over-expression of c-Myc is seen in different tumors and the c-Myc's failure to releas e transcriptional pausing is associated with the increase of cancer cells (Medical News, 2010). These results from various studies are however, still not definitive. I am now interested in investigating the relationship of the over-expression of c-Myc in causing tumors, or more particularly, breast cancer. I propose that c-Myc has a major role in causing tumors, including breast cancer.

Bioinformatics Essay Example | Topics and Well Written Essays - 1500 words

Bioinformatics - Essay Example To function correctly, each cell depends on thousands of proteins to function in the right places at the right times. When a mutation alters a protein that plays a critical role in the body, a medical condition can result. A condition caused by mutations in one or more genes is called a genetic disorder. Some mutations alter a gene's DNA base sequence but do not change the function of the protein made by the gene. Studies in the fly Drosophila melanogaster suggest that if a mutation does change a protein, this will probably be harmful, with about 70 percent of these mutations having damaging effects, and the remainder being either neutral or weakly beneficial (Sawyer , et al 2007).If a mutation is present in a germ cell, it can give rise to offspring that carries the mutation in all of its cells. This is the case in hereditary diseases. On the other hand, a mutation can occur in a somatic cell of an organism. Such mutations will be present in all descendants of this cell, and certain mutations can cause the cell to become malignant, and thus cause cancer (Ionov , et al 1993). Although many mutations are deleterious, mutations may have a positive effect given certain selective pressures in a population. For example, a specific 32 base pair deletion in human CCR5 (CCR5-32) confers HIV resistance to homozygotes and delays AIDS onset in heterozygotes(Sawyer , et al 2007). The CCR5 mutation is more common in those of European descent. One theory for the etiology of the relatively high frequency of CCR5-32 in the European population is that it conferred resistance to the bubonic plague in mid-14th century Europe. People who had this mutation were able to survive infection; thus, its frequency in the population increased(Ionov , et al 1993). It could also explain why this mutation is not found in Africa where the bubonic plague never reached. Newer theory says the selective pressure on the CCR5 Delta 32 mutation has been caused by smallpox instead of the bubonic plague(Galvani and Slatkin, 2003). - Render the alignment into a box-shaded diagram. Identify the position of the mutation on the multiple sequence alignment. Can you deduce anything from these data Check that your sequences are appropriately gapped . 3'-AA/860 bp insert : 5'-TTTCATGA----- //----- TCATGAAA-3' 3'-AAAGTACT----- //----- AGTACTTT-5' 3'-TT/860 bp insert : 5'-AATCATGA----- //----- TCATGATT-3' 3'-TTAGTACT----- //----- AGTACTAA-5' 3'-CC/860 bp insert : 5'-GGTCATGA----- //----- TCATGACC-3' 3'-CCAGTACT----- //----- AGTACTGG-5' 3'-GG/860 bp insert : 5'-CCTCATGA----- //----- TCATGAGG-3' 3'-GGAGTACT----- //----- AGTACTCC-5' Note that for each respective PCR product, the last eight bases at each 3'-end of the DNA are identical. Also note that only the first two and the last two base pair positions vary between the four PCR products. The PCR products were designed in this way to directly measure the effect of 3'-base composition on blunt vector and T-vector efficiency (Novy, Yaeger, and Kolb, 2008). From the human protein sequence, present any Prosite motif and conserved sequence domains in a sequence diagram. Identify the position of the mutation on the diagram. Can you deduce anything from these data Representative Sequence Length Mass (Da) A2QKA5 Checksum: FF7C4CB42EEB5629 385 41,846 10 20