Selective Toxicity Of Anti Cancer Agents Biology Essay

discriminating Toxicity Of Anti Cancer Agents Biology EssayCancer is know to be ca uptake by a large radical of various distempers, all told involved in boothular malfunction. It dates back to about 1600 BC when it was get-go found in an Egyptian papyrus (Wu et al, 2006) and thought to be incur fit till surgery and radiation became the means of discourse in the mid-1900s. afterwards many years it was realised that using either or faction of manipulation, metastatic pubic louse could non be controlled and in order to pass water therapeutic effect, the therapy had to reach every organ of the body. Research in medicate discovery and get downment now focuses on using chemformer(a)apy particularly those that be selectively toxic e.g. antimetabolites (Thurston, 2007). It is not fully understood why they ar selectively toxic but they argon more effective on tumour cells because they ar able to divide faster that healthy cells. selective perniciousness was defined as materi als that atomic number 18 able to defame approximately types of cells and not the others (Albert, 1951). Even though mortality rate has not change much, characteristics and path elans of cells in different tumours have been identified so as to develop therapies for specific tumour. The therapies developed either target protein that cause or be involved in development of tumour directly or by targeting drugs to the tumour.Examples of new drugs that have resulted from advances in drug discovery argon (Narang Desai, 2009) Imatinib (Gleevec) inhibits cover version of protein (BCR-ABL) which is found in CML tumour cells.Gefitinib (Iressa1) inhibits epidermal growth factor receptors. It is utilise to treat lung crabby person.Trastuzumab (Herceptin1) is another monoclonal antibody that binds the cell surface HER2/neu (erbB2) receptor and is used in treating erbB2+ breast crabmeat.This report will focus on principles and challenges of selective toxicity of chemotherapy, how the y blend, the limitations of the current chemotherapy and ways to improve drugs.MECHANISM OF transactionChemotherapy drugs are able to move throughout the body to get to where they are intended by entering the bloodstream through an injection, a throw away which are usually through a vein or as capsules and tablets. For chemotherapy to work it is important to understand cell cycle, this is because chemotherapy drugs work mainly on vigorously reproducing cells in the body where some drugs attack special phases of the cell cycle like the S phase. In cancerous cells, the checkpoints are change create the cancer cells to continue to grow out of control. Chemotherapy works by damaging the genes present in military position the nucleus of cells. Some drugs work by damaging cells when they are beginning to divide or while copies are being made. Chemotherapy drugs cause the cancerous cells to think that their lifespan has finished which leads to apoptosis. on that point are different classes of selective toxicity drugs which have different methods for kill cancerous cells, some of which are below(ACS, 2013)Alkylating agents (e.g. busulfan) are selectively toxic to DNA, where they damage DNA so as to prevent cancer cells from reproducing. Active in all the phases of cell cycle and are used to treat a wide variety of cancer like leukaemiaAntimetabolites(5-fluorouracil), these agents alter DNA and ribonucleic acid growth by replacing building blocks normally present in DNA and RNA. They work in the S phase and are used to treat breast cancer.Anti-tumour antibiotics/Anthracyclines (Doxorubicin) are also important as they dissemble the enzymes that contribute to DNA replication.Other cancer drugs- these are not sort out as chemotherapy drugs and they are still new. There are different types, the active and passive where active stimulates the immune organization to attack the disease and passive(monoclonal antibody, e.g. Rituximab which binds to particular substanc es) uses antibodies that were made synthetically. In 2010, the first vaccine for cancer called the Provenge for prostate cancer was approved by the FDA (ACS, 2013).Below Figure 1 shows the new selectively toxic agents that target specific sites and how they influence those sites.Figure Shows new group of anti-cancer agents designed to target specific protein that contributes to growth of tumour (Wu et al, 2006).PRINCIPLESChemotherapy drugs that are selectively toxic have been the first choice of treatment for many cancers and on that point are over 100 drugs in the market today (ACS, 2013) used alone or with other treatments.It is also important to understand how these drugs work so doctors (oncologists) can predict which drugs can be combined with them and how a great deal each drug can be administered to perseverings.There are troika key goals of these chemotherapy treatment (ACS, 2013)The most important goal of chemotherapy is to cure cancer where the cancer/tumour is cleare d from the system. There are no guarantees with this treatment as it competency even take years for a patient to be cured of cancer.In a situation where cure is not possible it is important to control the disease by shrinking cancer or stopping it from growing or spreading. This is also important as it gives the possibility of a longer life because it is controlled like a disease that is chronic like diabetes.Last is palliation, which is important when cancer is at an mod stage. Chemotherapy drugs in this case can be used to relieve symptoms or improve the patients quality of life.LIMITATIONSNormal cells that divide rapidly are modify by these chemotherapeutic agents because they cannot differentiate between cell reproducing normal meanders and cancer cells as they are not highly selective therefore causing the following side personal effects (Salmon Sartorelli, 1998).Bone marrow suppression because the atomic number 76 marrow cells normally divide quicklyAlopecia because hair follicle cells are able to divide frequently as wellGI disturbances (Nausea and Vomiting) due to mucosal cells dividing rapidlySome of these agents cause serious side effects which whitethorn lead to permanent damage to a vital organ (liver, lungs) in the body, cause infertility, heart problems or disrupt the central nervous system by causing damage. Another big problem is the development of shelter of chemotherapy drugs to treating different tumours which can occur before treatment with drug or over time after treatment. In some cases continuous/ extended exposure to one chemotherapy drug can cause exemption to other compounds with similar structures (Akhdar, 2012). Resistance can also develop if the drug slow-wittedness in the patient is reduced due to diminished cellular spreading or increased drug efflux.Chemotherapy treatment is also expensive and might take a couple of years before the disease is eradicated. In some cases the treatment does not work or may not destroy the cancer completely. Lastly, it makes the immune system very weak.Ways to advance DrugA way of improving drug or avoiding resistance is using a combination of variety of cytotoxic agents as it allows fast attack of different biological targets therefore increasing the effect of the treatment (Thurston, 2007) or with other agents that act as sensitizers to these cytotoxic agents (Narang Desai, 2009).Another way is developing new cookings that can prevent the severe side effects associated with a particular drug e.g. Doxorubicin caused cardiotoxicity but with new formulations like the liposomal formulation there are decreased side effects that are teachable and due to the selectivity of the new drug it works better than the conventional anthracycline.The use of adjuvants can minimize toxicity of anticancer drugs, therefore reducing the side effects of some of the drugs.A better diet is also advised, especially with avoiding food that cause inactivation of the drugs. Vitamin C found in citrous fruit fruits like oranges have been found to influence anticancer drugs and reduce toxicity to the body (Salmon Sartorelli, 1998).ConclusionIt can be concluded that there are three important factors to consider in selective toxicity of a drug, they are the tumour, drug and most especially the host. There have been a lot of improvement with using chemotherapy to manage cancer even though they cause severe side effects and resistance. Other challenges faced are the cost, time involved and the high mortality rate. This has brought about increase in effort of scientists to search for ways for the body to fight cancer tissue and find better cytotoxic agents to fight cancer cells.