Cancer Is A Death ?
Cancer is not a new dub for people, breathing exercises in the 21st century. This is repeated, and our daily activities. Each year approximately one million new cancer cases diagnosed worldwide. Most people lose their lives to cancer. Treatment is available but not yet 100% guarantee of recovery from cancer. Cancer affects nearly every organ of the human body to become ruins the later stages.
In fact it appears the cancer is not a disease but a heterogeneous group of disorders characterized by a normal cell to lose control of cell division. Cancer cells divide rapidly and continuously leads to the formation of tumors that eventually form a tissue. These cells from cell proliferation to travel all healthy cells to produce tumors. The most common form of cancer among breast, lung, prostate, blood, colon, rectum, pancreas, liver, etc.
Generation of tumor
Basically, normal cells grow, divide, mature and die for the treatment of complex internal and external signals. A normal cell can be both excitatory and inhibit signals responsible for this growth, proliferation and maturation. In the case of cancer cells, these signals disrupted, the cell is divided into unusually high speeds. After removal of normal controls, the cancer cell loses its normal shape and form of separate lots, which we call “cancer.” When the cancer cells remain localized described as “benign tumor”, but when cells penetrate the tissue, the tumor has been described as “cancer.” The journey of the cells in other parts of the body, forming secondary tumors and underwent ” mark “.
The genetic aspect of cancer
Cancer is the culmination of abnormal cell growth, so the demand for public and scientific attention. Several theories have been compared to cancer, but scientists now know that most if not all cancers are caused by defects in DNA> Former perspective suggest a genetic origins of cancer. Many substances, such as ionizing radiation, chemotherapy, we see an episode of the result of mutations that cause cancer. Some tumors are often syndicated with chromosomal abnormalities, about 90% of people with chronic myeloid leukemia is a reciprocal trans-location between chromosome 22 and chromosome 9> These observations are consistent with the genetic traces of the origin of cancer. In 1971, Alfred Knudson proposed model to determine the genetic basis of cancer. The model of S is described as “Knutson multi-step model of cancer”, he studied with retinoblastoma, a cancer that develops in only one eye, but sometimes it happens so> Knutson states that cancer is a multistep process that requires multiple mutations, mutations inherited additional mutations also required to disclose cancer and cancer runs in families. The model has been confirmed today.
Beginning with a history of mutations of cancer cells and abnormal results of development. This cell divides to form a clone of cells each with the same mutation. Another mutation that occurs in some cell clones can be further improved virtuosity of these cells to germinate and cells can be either dominant mutations. In the process, shows that the clonal evolution of tumor cells are more mutations that allow them to become aggressive on their breeding grounds. The speed depends on the frequency of new mutations in clonal evolution. The regulators of DNA repair genes that were also mutated in progressive cancer and hereditary diseases in DNA repair is usually made of reinforced incidence of cancer. Typically, DNA repair mechanisms to eliminate many of the mutants, but cells defective DNA repair system is more likely that the mutated genes that regulate cell division. Many of aneuploid cells and thus accelerate the development of cancer.
Are environmental factors responsible for cancer?
Smoking is a good example of environmental factor facing cancer greatly. Other environmental factors include certain chemicals such as benzene (industrial solvent), benzo [a] pyrene (cigarette smoke), PCBs (transformers and capacitors). Ultraviolet light, ionizing radiation, viruses, other carcinogens to cancer. Most of the environmental factors that may cause somatic mutations of rapid cell division.
The genes that contribute to cancer
Signals that regulate cell division can be divided into two categories: particles that accelerate cell division and others that hinder them. Since cell division is not inconsistent with these two agents, cancer causing mutations in one of these two factors. Mutations in genes usually dominated by the tone and known as “oncogenes.” Oncogenes first identified cancer-causing genes Peyton Rous discovered the 1909th Michael Bishop, Harold Varmus and colleagues in 1975 found that all the genomes of normal cells to DNA sequences closely related to viral oncogenes. These cellular genes called protoncogenes. It is doomed to basic cellular functions of normal cells, but when mutated oncogenes and produce tumors. Many oncogenes have been identified by experiments in which segments of DNA selectted added to cells in culture.
Tumor suppressor genes is more difficult than what we saw oncogenes, such as prevention of cancer and is reccessive in action. One of the first tumor suppressor gene discovery was that the volume of the retina in 1985, Raymond White and Webster Cavenne.
Structure and Change in the number of chromosomes, and cause cancer
Most mutations occur during development. It is now clear that mutations in the chromosome appears to be the incidence of cancer. At least three types of chromosomal reorganization, deletions, inversions and trans-sites can be linked to cancer. Deletions can cause loss of tumor suppressor genes in one or more. Invert and trans sites of tumor suppressor genes, can destroy the function and the production of fusion proteins that can stimulate in treating the symptoms. Fusion protein consisting mainly of myeloid leukemia is a leukemia effect of bone marrow cells. The third method, which can cause cancer of chromosomal reorganization, the carcinogenic potential of gene transfer to a new position, the opening sequences, such as Burkitt’s lymphoma is common.
These viruses cause cancer
About 95% of cervical cancer in women infected with the virus of human papiloma (HPV). Also, infection with the virus that causes hepatitis B, the growth of liver cancer. Epstein-Barr virus mononucleosis caused by lymphoma, including Burkitt. There is little retrovirus that causes cancer in humans. Other human cancers associated with DNA viruses, retroviruses such as integrated into the host chromosome, but the donot pöördtranskriptsiooniahela unequal retroviruses.
Changes in DNA methylation is often associated with cancer
In many cancer cells, DNA methylation seems to have become the decoration. In some cases the DNA of cancer cells, the methylated (hypermethylated) or undermethylated (hypomethylated). Hypermethylation seems to help silence the expression of tumor suppressor genes in cancer. However, hypomethylation contributes to cancer requires further investigation. The role of DNA methylation is an interesting, not to other genetic changes in DNA methylation is reversible. This type of irreversible genetic changes called epigenetic processes.
Cancer treatment is currently available, including chemotherapy, bone marrow transplant, radiation, etc., but the point is still 100% free preponderated cancer.
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