Unit 6.1. Restriction enzymes are and how they are used in biotechnology.
2. Gene mutations, including deletions, insertions, and substitutions. 3. Genes that regulate the cell cycle and cancer. |
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Restriction Enzymes when applied to the HIV Virus:
Restriction Enzymes come from bacteria. They are extremely useful because they cut at very specific sequences of Bacterial DNA. PLasmid full of HIV protein and you grow it in E Coli, place it back into a cell and see the components of an HIV cell on a less dangerous scale. If you were to study one specific protein of HIV, you could take the sequence of genes from that protein of HIV and place it into an E Coli Plasmid at the restriction sites. When the Plasmid is completed with the fragment, the HIV protein placed in the Ecoli plasmid, you can then place it back into a cell and see how the HIV enters a cell and how the viral proteins interact with receptors. Possible AIDS Vaccine: Another application of recombinant DNA technology is in an experimental vaccines against AIDS. Currently, one example is a viral protein manufactured by yeast cells, which is then recombined with viral genes. The vaccine is safe because it contains no viral particles. (CliffsNotes) Gene mutations, including deletions, insertions, and substitutions. Mutations: The CCR5-delta32 mutation results in a smaller protein that isn't on the outside of the cell anymore. Most forms of HIV cannot infect cells if there is no CCR5 on the surface. People with two copies of the CCR5 delta32 gene (inherited from both parents) are virtually immune to HIV infection. This occurs in about 1% of Caucasian people.(Stanford School of Medicine) Deletions: Dr Khalili’s lab engineered a 20-nucleotide strand of gRNA (which aids in deletion and insertion) to target the HIV-1 DNA and paired it with a DNA-snipping enzyme called Cas9. Which they then used it to edit the human genome. (Temple University) Insertions: Once HIV conquers a human cell, it will stay there forever. The virus inserts its deadly genome permanently into its victims’ DNA, forcing them to require medical treatment for the rest of their life.(Temple University) Substitution: When the Viral DNA enters the host cell's nucleus, it begins by cutting the host cell's DNA and substituting itself inside, causing the host cell to transcribe new viral mRNA. |
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Cervical Cancer
Cervical cancer is cancer that begins in the uterine cervix, the lower end of the uterus. Cervical Cancer is correlated to the HIV virus because it is considered one of three "acquired immunodeficiency syndrome (AIDs)-defining cancers" (cancer.gov). Cervical cancer starts in the cells lining the cervix -- the lower part of the uterus (womb). This is sometimes called the uterine cervix. The cervix has two different parts and is covered with two different types of cells. These cells do not suddenly change into cancer. Instead, the normal cells of the cervix first gradually develop pre-cancerous changes that turn into cancer.
- The part of the cervix closest to the body of the uterus is called the endocervix and is covered with glandular cells.
- The part next to the vagina is the exocervix (or ectocervix) and is covered in squamous cells Most cervical cancers begin in the cells in the transformation zone. (Cancer.org)
Genes that Regulate the Cell Cycle and Cancer
- In normal cells, hundreds of genes control the process of cell division. Normal growth requires a balance between the activity of those genes that promote cell growth and suppress it. It also relies on the activities of genes that signal when damaged cells should undergo cell death. Cells become cancerous after mutations. P53 genes act as tumor suppressors, meaning they suppress cancer. another gene is P21 is located in the G1 phase of the cell cycle and links damaged DNA to cell cycle arrest. When these two suppressor genes fail to work, the cell cycle begins a mass production of unregulated cells.
