Impaired cell death is a characteristic of cancer cells, determining their resistance to apoptotic signals, (Adams and Cory 2007, Hartman and Czyz 2013) which is one of the six essential alterations in cell biological capabilities acquired during the multistep development of human tumours (Hanahan and Weinberg 2011, Hartman and Czyz 2013) and remains critical in effective cancer treatment strategies (Adams and Cory 2007). Two major apoptotic paths have been defined; death receptor (extrinsic) and mitochondrial (intrinsic) pathway and they are usually switched on in a stimulus-dependent manner (Steel, Doherty et al. 2004, Adams and Cory 2007, Hartman and Czyz 2013).Such that extra-cellular death inducing signals via Fas receptors and various intra cellular signals result in activation of caspases (Du, Fang et al. 2000) (caspase 8 and 9) respectively. Intrinsic apoptotic pathway is widely implicated as a barrier to cancer pathogenesis than extrinsic apoptosis pathway (Hanahan and Weinberg 2011).
Tumour suppressor genes are genes that slow cell division down and cause them to die. (lungcancer.aboutCom) Lung cancer is when there is an malignant growth of the lung. There were many genes and chromosomes associated with lung cancer but two genes that affect it the most are p53 tumour suppressor and ras oncogenes. Ras genes are the most important gene out of all the oncogenes. This gene is located on the 11th chromosome and its job is to act as a switch which relays signals.
The underlying genetic cause of prion diseases is under investigation to understand how polymorphisms, host factors and mutations in the prion protein gene (PRNP) lead to severe physiological impairments and ultimately death, exemplified by Creutzfeldt-Jakob Disease and Familial Fatal Insomnia (Capellari et al., 2011). In humans there are multiple phenotypes associated with prion diseases the most common of which are acquired Creutzfeldt-Jakob disease, inherited (also called familial) Creutzfeldt-Jakob disease, sporadic Creutzfeldt-Jakob disease and Familial Fatal Insomnia (Puoti et al., 2012). The gene PRNP encodes the normal prion protein specifically called prion protein cellular (PrPC) in humans (Capellari et al., 2011). Located on chromosome 20, the PRNP sequence is composed of two exons, which amount to a protein called PrPC of approximately 200-250 amino acids after post-translational modifications. One such modification is the addition of a glycosylphosphatidylinositol unit used as an attachment function, most-likely to attach to a neuron (Araújo, 2013).
According to Sarkar, mutations that cause Hutchinson-Gilford progeria syndrome result from the defective Lamin A protein. This alteration creates an unstable nuclear envelope there by damaging the nucleus. Cellular instability leads to the process of premature aging A newborn with Progeria disease typically appears healthy at birth. It affects both males... ... middle of paper ... ...day with this fatal disease. A mutation in the Lamina A protein cell results in rapid aging, ultimately affecting how one lives their life.
But somatic mtDNA mutations may have great effects on aging and cancer. (Hartmann A, 2008) Leber hereditary optic neuropathy (LHON) is caused by mtDNA mutations and is a maternally inherited disorder... ... middle of paper ... ...net, 48, 935-942. 9) Huoponen K, VilkkiJ, Aula P, Nikoskelainen E, Savontaus M (1991) Am. J. Hum. Genet, 48, 1147-1153.
thymine). This can lead to uncontrolled cell division. When genes are abnormal (or have been mutated) they are called oncogenes (onkos means tumour), about a hundred of which have been discovered. Cancerous cells will divide uncontrollably and repeatedly forming clones of genetically identical cells. Therefore, thought the mutation may start off in only one cell, it can be passed on to the cells decedents, so the daughter cells will too have the mutated gene.
Abstract: The main goal of this paper is to explain what Cystic Fibrosis is and also to explain what the causes of Cystic Fibrosis are. Cystic Fibrosis is caused by a mutation in a gene called Cystic Fibrosis Transmembrane Conductance Regulator (CFTR). Cystic Fibrosis is known as one of the most common life-shortening disease. More that 1,000 mutations in the CFTR gene have been found in people with Cystic Fibrosis. Most of these mutations change single protein amino acids in the CFTR protein and it deletes a small amount of DNA from the CFTR gene.
Proto-oncogenes for instance, when mutated, activates the oncogene (altered version) which causes an acceleration and an increase in cell division and soon is out of control and leads to cancer (ACS, 2011). When mutations occur in tumor suppressor genes, as said by Katherine M. Hyland (n.d.), they deactivate the ability to fix DNA mistakes and cancer develops as well. The National Cancer Institute (2014) states that the original role of the BRCA gene is to produce proteins that help develop breasts, fix damaged DNA, and prevent rapid cell growth. For this same reason, the BRCA1 and BRCA2 genes belong in the category of tumor suppressor genes (Kluger and Park, 2013). Mutations in these genes are related to breast cancer because most of the BRCA genes are found in the breast tissue, declared by Kluger and Park (2013), and when mutations occur, the accumulation of cancer cells begins-breast cancer develops.
Acute Myeloid Leukemia (AML) is the most common type of acute leukemia in adults. AML is a heterogeneous disease which results from genetic alterations in normal hematopoietic stem cells. These alterations induce differentiation arrest and/or excessive proliferation of abnormal leukemic cells or blasts . Recent genomic studies have identified that recurrent somatic mutations in patients with AML blocks differentiation and/or enhance self-renewal by altered transcription factors [2,3]. The genetic or the epigenetic changes acquired by AML cells disrupt the key growth regulatory pathways and changes will make the normal cells to attain certain malignant characteristics which include inappropriate proliferation in the absence of normal growth signals, indefinite self-renewal in a manner analogous to a stem cell, escape from programmed cell death, inhibition of differentiation, aberrant cell cycle checkpoint control and genomic instability .
The regulator proteins produced are involved in inhibiting cell production and survival. With the loss of TSGs and lack of regulatory proteins, the tumor progression can eventually lead to many types of cancer. Overview of VHL Disease The von Hippel-Lindau disease is an autosomal dominant inheritance disorder that is associated with the loss and mutation of VHL tumor suppressor gene (2). VHL disease is a hereditary cancer that appears in 1 in 36,000 live births. Germline VHL gene mutations of this rare disorder are a predisposition to many cancers that can produce benign or malignant tumors due to a loss of the wild-type VHL allele given by the unaffected parents (3).