Genetic mutations are really important when it comes to causing cancer. They change how certain genes work, and this can lead to the growth of tumors. A tumor is an unusual mass of tissue that grows too much. Some tumors are harmless (benign), while others are dangerous (malignant). Knowing how genetic mutations cause cancer helps doctors diagnose, treat, and prevent these diseases.
There are different types of genetic mutations, including:
Point Mutations: This type involves changing just one part of the DNA. This can mess up how proteins function. For example, the KRAS gene, which is changed in about 30% of all cancers, often has point mutations that help cancer grow.
Insertions and Deletions: These mutations either add or remove pieces of DNA, which can change how the gene is read. If three pieces of DNA are deleted from the MET gene, it can lead to certain kinds of lung cancer.
Copy Number Variations: This means that parts of the genetic material can be duplicated or lost. This can cause certain genes, like MYC, to be overactive and contribute to cancer.
Chromosomal Translocations: This is when pieces of chromosomes swap places. This can create new proteins that can cause cancer, like the BCR-ABL fusion found in many patients with chronic myeloid leukemia.
Oncogenes are changed versions of normal genes called proto-oncogenes. When oncogenes are active, they can help cancer cells grow and survive. Some key points are:
Gain-of-function mutations: These changes make certain genes too active. For example, the HER2/neu gene is found in 20-30% of breast cancers, leading to faster cancer growth.
Constitutively active proteins: These mutated genes can create proteins that are always on, ignoring normal checks. About 90% of pancreatic cancers have changes in the KRAS gene, making cells grow non-stop.
Tumor suppressor genes act like brakes on cell growth and can help lead cells to die when they are not needed. When these genes are changed, their protective role is lost, which can lead to cancer.
Loss-of-function mutations: These mutations can stop the genes from controlling cell growth. For example, around 50% of all cancers have changes in the TP53 gene, which stops cells from dividing uncontrollably.
Two-hit hypothesis: Introduced by a scientist named Knudson in 1971, this idea is important for certain inherited cancers, like retinoblastoma. In these cases, a person gets one bad copy of the RB1 gene from a parent, and then a second change happens that leads to cancer.
More than 90% of cancers are caused by changes that happen during a person’s life, rather than being passed down from parents. Things like smoking cause about 30% of cancer deaths because they change important genes like TP53.
On average, a person with cancer has about 33 to 66 mutations in their tumors, but this number can vary depending on the type of cancer and the person's genes.
Cancers that start in epithelial cells (called carcinomas) often have specific patterns of mutations. For example, lung cancers usually have mutations caused by the damage from smoking.
In conclusion, genetic mutations are key players in how tumors form. They change how oncogenes and tumor suppressor genes work, which sets off a chain reaction that can lead to cancer. Research in genetics and how cells work is really important for creating better cancer treatments. Understanding these changes helps doctors know more about how cancer develops and how to treat it effectively.
Genetic mutations are really important when it comes to causing cancer. They change how certain genes work, and this can lead to the growth of tumors. A tumor is an unusual mass of tissue that grows too much. Some tumors are harmless (benign), while others are dangerous (malignant). Knowing how genetic mutations cause cancer helps doctors diagnose, treat, and prevent these diseases.
There are different types of genetic mutations, including:
Point Mutations: This type involves changing just one part of the DNA. This can mess up how proteins function. For example, the KRAS gene, which is changed in about 30% of all cancers, often has point mutations that help cancer grow.
Insertions and Deletions: These mutations either add or remove pieces of DNA, which can change how the gene is read. If three pieces of DNA are deleted from the MET gene, it can lead to certain kinds of lung cancer.
Copy Number Variations: This means that parts of the genetic material can be duplicated or lost. This can cause certain genes, like MYC, to be overactive and contribute to cancer.
Chromosomal Translocations: This is when pieces of chromosomes swap places. This can create new proteins that can cause cancer, like the BCR-ABL fusion found in many patients with chronic myeloid leukemia.
Oncogenes are changed versions of normal genes called proto-oncogenes. When oncogenes are active, they can help cancer cells grow and survive. Some key points are:
Gain-of-function mutations: These changes make certain genes too active. For example, the HER2/neu gene is found in 20-30% of breast cancers, leading to faster cancer growth.
Constitutively active proteins: These mutated genes can create proteins that are always on, ignoring normal checks. About 90% of pancreatic cancers have changes in the KRAS gene, making cells grow non-stop.
Tumor suppressor genes act like brakes on cell growth and can help lead cells to die when they are not needed. When these genes are changed, their protective role is lost, which can lead to cancer.
Loss-of-function mutations: These mutations can stop the genes from controlling cell growth. For example, around 50% of all cancers have changes in the TP53 gene, which stops cells from dividing uncontrollably.
Two-hit hypothesis: Introduced by a scientist named Knudson in 1971, this idea is important for certain inherited cancers, like retinoblastoma. In these cases, a person gets one bad copy of the RB1 gene from a parent, and then a second change happens that leads to cancer.
More than 90% of cancers are caused by changes that happen during a person’s life, rather than being passed down from parents. Things like smoking cause about 30% of cancer deaths because they change important genes like TP53.
On average, a person with cancer has about 33 to 66 mutations in their tumors, but this number can vary depending on the type of cancer and the person's genes.
Cancers that start in epithelial cells (called carcinomas) often have specific patterns of mutations. For example, lung cancers usually have mutations caused by the damage from smoking.
In conclusion, genetic mutations are key players in how tumors form. They change how oncogenes and tumor suppressor genes work, which sets off a chain reaction that can lead to cancer. Research in genetics and how cells work is really important for creating better cancer treatments. Understanding these changes helps doctors know more about how cancer develops and how to treat it effectively.