Cancer
Macrophages
"Eat" pathogens
Because mutations in proto-oncogenes are those that allow the cell to gain a new function, they are often referred to as
"gain of function" mutations
Progression of Cancer
1. A cell or small group of cells disregards its genetic programming. 2. A cell or small group of cells begins dividing uncontrollably. 3. A tumor is formed 4. Tissues and organs are impacted from the excess cell growth
Gene Expression
1. DNA within the nucleus serves as a template 2. mRNA is processed before leaving the nucleus to a ribosome within the cytoplasm 3. tRNAs carry amino acids to the mRNA 4. The amino acids bond together to form a growing protein chain 5. The protein chain and mRNA molecule break off from the ribosome 6. The protein chain is further modified and the mRNA strand is used again
Place the following three terms in order to describe the central dogma of biology
1. DNA, 2. RNA, 3. Protein
Which indicated portion of the diagram is the active site
3
- Mammogram
A specific type of X-ray used to screen for and diagnose breast cancer
Identify the mode of action of alkylating agents
Alkylating agents: chemicals that integrate into the DNA, causing it to break at specific points; general and so can cause long-term side effects including other cancers.
Which of the following helps regulate the speed at which the cell cycle progresses
All of the above - how quickly the cell moves through the checkpoints that regulate the phases of the cell cycle, proto-oncogenes that may be present and help accelerate the progression of the cell cycle, presense of growth factors that initiate transcription of proto-oncogenes
- Which of the following statements best describes the benefits of radiation therapy?
All of the choices are correct - radiation damages the DNA within cancer cells, either slowing down cell division or stopping it altogether. Radiation therapy can be directed against specific cells and tissues within the body. Radiation therapy may shrink tumors, making them easier to remove surgically. Radiation therapy can be combined with other therapies, including chemotherapy.
Benign Tumor
An abnormal growth that usually does not grow larger, multiple layers of abnormal cells, cells closely resemble those in surrounding tissues
The growth of capillaries to tumors in order to supply them with oxygen and nutrients is called
Angiogenesis
Infer the reason why cancer cells increase the rate of angiogenesis
As tumor cells grow, they require oxygen and nutrients. Angiogenesis occurs as growth factors are released and capillaries grow toward the tumor.
Cancer and Homeostasis
As tumors grow, they take up space, crowding out other organs, preventing their proper functioning. As angiogenesis occurs, blood and nutrients are rerouted from healthy organs to the tumor, causing the organs to lose function. When cancer causes organs to not function, it may change blood chemistry As tumors impact organs, their lack of function disrupts homeostasis As tumors grow, they may block ducts or vessels, preventing their ability to transport materials necessary for homeostasis
- For example, ____ is a gene known to be associated with some forms of breast and ovarian cancer
BRCA1
Compare the results of a normal blood test with that of an individual with cancer
Blood tests called complete blood counts (CBCs) look at the presence of normal blood cells and basic blood chemistry. Cancers may elevate the number of white blood cells and tumor cells may even be present in the blood. Changes in blood calcium, enzymes, or ion concentrations may also indicate that cancer is interrupting the function of an organ. Specific proteins associated with cancer can be tested for in blood, including CA 15-3 and CA 125.
Outline the general characteristics of cancer cells
Cancer cells are different from typical cells as they: look different (irregular shape, larger nuclei with more genetic material). are immortal (because of telomerase enzyme that repairs telomeres). lose the ability to specialize. Masses of unspecialized cells are called tumors. They can be benign or malignant.
Stages 0 and 1 of Cancer
Cancer cells are restricted to very small areas. Tumor is less than 2cm and has not spread to any lymph nodes.
Define the term cancer
Cancer is a disease that is caused by the inability of the body to control the division of cells.
Which of the following statements best describes the occurrence and function of checkpoints during the cell cycle
Checkpoints occur during the G1, G2, and mitotic phases of the cell cycle and help regulate the rate at which the cell moves through the different phases of the cell cycle
Define the term chemotherapy
Chemotherapy is the use of drugs to treat disease. In the case of cancer, chemotherapy works by targeting the cell cycle to prevent cell division in rapidly dividing cells. Chemotherapy affects all cells of the body, so it can be effective in treating and preventing metastasis, but also has many negative side effects.
Summarize how information is stored within the chemical structure of a DNA molecule
DNA (deoxyribonucleic acid) is a nucleic acid that stores genetic information. DNA consists of units called nucleotides. Each nucleotide contains: A 5-carbon deoxyribose sugar, a phosphate group, and a nitrogen-containing base. Adenine (A) always pairs with thymine (T); guanine (G) always pairs with cytosine (C). It is the order of the nitrogen bases in DNA that stores the genetic information for the cell. The sum of all genetic information in a cell is called the genome. Genes are units of genetic information that provide instructions for making proteins.
Tumor suppressor genes code for proteins that examine DNA before cell division to ensure it is undamaged. They work at the ____ checkpoint in the cell cycle
G1
Outline the stages of gene expression from DNA to functional protein
Gene expression occurs in 2 stages: transcription and translation.
Summarize the process of gene editing
Genome editing targets specific sequences in DNA for editing. Clustered regularly interspaced short palindromic repeats (CRISPR) is most commonly used. Enzyme CAS9, uses an RNA molecule to identify and bind to specific complementary sequences of DNA. PAM regulatory regions help make sure CAS9 has the correct sequence. CRISPR can remove nucleotides, inactivating the gene, or insert new nucleotides, changing the function of the gene. CRISPR has been used in cancer treatments to inactivate cell-cycle control genes that are nonfunctioning. Trials have been successful with genes for fusion proteins, oncogenes that get stuck.
- Immunotherapy works on the basis of
Helping the body distinguish "self" cells from "non-self" cells and to destroy only the "nonself" cells
The body's ability to regulate internal conditions within a narrow range is called
Homeostasis
Infer how cancer may disrupt organ function and body chemistry
Homeostasis is often regulated by negative feedback loops. Cancer disrupts homeostasis by interfering with the body's ability to maintain homeostasis. Tumors take up space in organs and block blood and lymphatic vessels and ducts, so organs cannot function. Tumors require oxygen and nutrients, depriving nearby tissues.
Summarize the importance of homeostasis in a living organism
Homeostasis is the body's ability to maintain a constant internal environment, including pH, temperature, and blood chemistry.
Which of the following genotypes would result in a nonfunctional tumor suppressor gene
Homozygous recessive (mm)
- CT Scan (Computerized Tomography)
Imaging scan that gives a multi-dimension view of organs and can be useful in detecting if cancer is spreading to other organs
The cell cycle consists of
Interphase (orange) - The majority of the cell's time; normal functions occur - Consists of G1 (growth), S (synthesis), and G2 (growth) phases. M phase (blue) - the portion where cell division occurs; consists of mitosis and cytokinesis.
Characteristics of cancer cells
Lack of specialization, become immortal, appear irregular in shape, loses function compared to surrounding tissue, have large dark nuclei
Plasma
Liquid portion of blood that contains water and dissolved nutrients
Which of the following is true concerning the checkpoints in the cell cycle
Mitosis stops if chromosomes are not properly aligned
Outline the criteria associated with staging cancer
Most doctors use a number system to grade cancers based on - Size of tumor. Has tumor spread to nearby tissues. Has cancer spread to nearby lymph nodes. Has cancer moved to other organs
Infer how mutations change the information content of a DNA molecule
Mutations are any changes to the nucleotide sequence of DNA. Mutations can be caused by chemicals (called carcinogens), radiation exposure, or viruses. Mutations may or may not impact protein structure.
Cancer Progression
New mutations arise. A single cell has the ability to start a tumor. Cancer in situ. The tumor is at its place of origin. One cell in the tumor mutates further. Cancer cells now have the ability to invade both lymphatic vessels and blood vessels, allowing them to travel throughout the body. New metastatic tumors are found some distance from the primary tumor.
Malignant Tumor
Possesses the ability to spread, unspecialized and do not resemble other cells of the tissue, multiple layers of abnormal cells
Identify how mutations in proto-oncogenes may lead to cancer
Proto-oncogenes speed up the cell cycle. Associated with signaling pathways: growth hormones interact with target cell receptors, proto-oncogenes are activated, cell division is promoted. Proto-oncogenes become oncogenes when mutations caused them to be "stuck" on. Only a single mutation is required for this. Examples associated with breast cancer include ERBB2.
Checkpoints function to
Regulate the speed at which the cell moves through the cell cycle. Ensure the cell is ready for cell division. If a cell is not ready for cell division, it will be put into G0 phase to attempt to repair its DNA. If that is not possible, the cell may undergo apoptosis.
Stages of Cancer (Breast Cancer)
Stages 0-1 cancer - Tumor is limited to a very small area and only nearby lymph nodes, if any, are involved. Stage 2 - Tumor has become invasive and has grown, but is still located entirely within the breast, lymph nodes may be involved. Stage 3 - Tumor has moved out of the breast tissue, but has not spread to distant organs, lymph nodes are involved. Stage 4 - Cancer has fully metastasized and spread to organs outside the breast, the cancer is incurable.
- Topoisomerase Inhibitors
Target cells during the S phase, disable the topoisomerase enzyme, preventing DNA replication, prevent cell division, either directly or indirectly
Summarize the series of events in the cell cycle and the location of the major checkpoints
The cell cycle describes the organized series of events required for cell division.
- PCR (polymerase chain reaction)
The cellular DNA, usually from a patient's blood sample, is sequenced many times to look for mutations in known cancer-related genes. A genetic test usually used if the person has a family history of cancer.
Identify the types of immune cells that may be used to treat cancer
The immune system functions to identify "self" vs. "non-self" and then target any "non-self" cells for destruction. Immunotherapy involved convincing the body's immune system to identify and eliminate cancer cells as "non-self" instead of "self." Involves identifying atigen differences between "self" and cancer cells. Cancer vaccines use modified viruses to initiate an immune response against cancer cells. Monoclonal antibodies can be created to target specific cancer antigens.
Distinguish between alpha, beta, and gamma radiation
The shorter the wavelength, the more energy present. Radiation therapy uses high-energy gamma rays and X-rays or particles, including alpha and beta particles.
Stage 3 of Cancer
The tumor has been found in at least 4 lymph nodes but has not spread to distant organs.
Stage 4 of Cancer
The tumor has fully metastasized and spread to distant organs
Stage 2 of Cancer
The tumor is between 2 and 5cm but has not spread to any lymph nodes. The cancer is considered invasive, has grown in size, but is still located completely within the organ of origination
How do tumor suppressor genes work to prevent the onset of cancer within cells
They synthesize proteins that inhibit the cell cycle and proteins that promote apoptosis
Mutations in proto-oncogenes are examples of recessive mutations because it requires both proto-oncogenes to be mutated in order for the mutation to be physically expressed
True
What activates the expression of tumor suppressor genes
Tumor suppressor genes are activated by the presense of signals outside of the cell that binds to receptors on the cell surface, initiating a signal pathway
Identify how mutations in tumor suppressor genes may lead to cancer
Tumor-suppressor genes prevent unregulated cell growth by slowing down the progression of the cell through the cell cycle. Most code for proteins that survey DNA for damage during the G1 checkpoint. Examples associated with breast cancer include p53 and BRCA1.
During translation
Within the cytoplasm, mRNA moves to a ribosome. tRNA reads codons (3 nucleotides) of the mRNA. For each codon, the corresponding amino acid is brought to the ribosome by tRNA and assembled. The polypeptide is released and the ribosome and mRNA may be used again.
During transcription
Within the nucleus, RNA polymerase exposes the nucleotide bases of the DNA to be transcribed. A copy of mRNA is made from the DNA strand. Uracil (U) is used instead of thymine (T). mRNA is edited and leaves the nucleus.
- Biopsies
a surgical procedure when tissue is removed from the patient and examined under a microscope to determine if cancerous cells are present
Choose the characteristics that best describe normal cellular function
ability to differentiate, ability to undergo apoptosis, ability to regulate cell division
Growth factors work as signaling molecules. When they bind to receptors on target cells, they function to
activate proto-oncogenes, stimulating cell division
____ are chemotherapeutic drugs, meaning they are used to fight cancer. They integrate into the DNA, usually causing it to break
alkylating agents
Which of the following statements best describe how alkylating agents work as chemotherapy
alkylating agents work to prevent the cell from replicating its genetic material, preventing cell division
Which of the following statements is NOT correct in describing the physiology of the human body
all of the answer choices are correct (groups of organs that collectively work together are called organ systems, different tissues are organized into organs, which perform a specific function within the body, cells with a similar function are organized together into tissues)
Which of the following statements best describes the benefits of radiation therapy
all of them - radiation damages the DNA within cancer cells, either slowing down cell division or stopping it altogether, radiation therapy can be directed against specific cells and tissues within the body, radiation therapy may shrink tumors, making them easier to remove surgically, radiation therapy can be combined with other therapies, including chemotherapy.
In the thymus gland, any T cell that has the potential to destroy the body's own cells undergoes _______, which destroys the cell
apoptosis
Cytokines, secreted by helper T cells, function to
attract cells of the immune system, stimulate the cloning of T and B cells, stimulates phagocytosis by cells
Which of the following are methods used to detect the presence of cancer? Select all that apply
biopsies, blood tests to look at enzymes or nutrient levels, MRIs, CT and PET scans, and mammograms, blood tests to look at blood cell counts
Select all of the following organs and parts within the body that can get cancer
blood; soft tissue, including muscles, tendons, and blood vessels; brain; skin; bone
Stomach
breaks down food and mixes it with digestive juices and enzymes
- Blood test
can be useful as a first test when looking cancers related to bone marrow or specific proteins produced by tumors
Red blood cells
carry oxygen
Angiogenesis contributes to carcinogenesis because it
causes blood vessels to grow into the tumor
The life cycle of a cell as it grows, develops, and divides can be called the
cell cycle
Platelets
cell fragments that function to clot blood
Of the following list, select only those that are known to cause mutations
certain chemicals, such as benzene; ultraviolet radiation from the sun; viruses; x-rays
The collective term for drugs that aid in the treatment of cancer is
chemotherapy
The body maintains a relatively ______ internal environment by adjusting its physiological processes
constant
____ T cells are responsible for a cellular response to virus-infected and cancer cells
cytotoxic
The following list describes ways that CRISPR may be used to treat cancer. Which of the following describes immunotherapy instead of CRISPR therapy
cytotoxic T cells may be stimulated, creating an immune response against cancer cells and shrinking tumors.
White blood cells
defend the body from foreign substances
- Individuals with family histories of these cancers can be tested to see if they carry copies of this gene. If the results show a _____ variation, it is associated with breast cancer; if the results show a ____ variation, it either is not believed to be associated with breast cancer
deleterious, polymorphism
Select all of the following that describe the structure of a molecule of DNA
double helix, contains a phosphate group, contains four nitrogenous bases (adenine, thymine, guanine, and cytosine)
DNA
double-stranded, stores genetic information, functions within the nucleus, contains thymine bound to adenine
The purpose of checkpoints within the cell cycle is to
ensure that cell division is occurring correctly and regulate how quickly cell division occurs
The use of X-rays or gamma rays to externally target cancer within the body is called
external radiation
The only treatment options for stage 3 cancer are chemotherapy or surgery
false
There are no treatment options available for stage 2 cancers
false
There are no treatment options for stage 4 cancers
false
Treatment options exist only for stage 1 cancer
false
Though all of these _______ somewhat, they do not go beyond a certain range. If they do, _____ result
fluctuate, illness
From the following list, select those types of radiation that are used for the treatment of cancer
gamma rays, alpha and beta particles, x-rays
The insertion of genetic material into human cells for the treatment of a genetic disorder is called
gene therapy
- Blood is drawn and the ______ of interest are copied via techniques including polymerase chain reaction (PCR) and sequencing
genes
- Recall that cancer can have genetic causes, especially if individuals carry one or more _____ that predispose them to cancer
genes
During mitosis, cells divide to produce
genetically identical cells, two daughter cells
____ are external signals received at a cell's plasma membrane that promote cell division
growth factors
Topolsomerase is an enzyme that
helps unwind the two strands of DNA during replication
The growth of cells is typically a _____ process
highly controlled
An individual's body chemistry is tightly regulated in order to maintain a constant internal environment, also known as
homeostasis
- Alkylating Agents
integrate into DNA, causing it to break, can have long-term negative impacts, prevent cell division, either directly or indirectly
When radioactive materials are introduced into the body to treat cancer, it is called
internal radiation
Select the 2 correct answer choices from the list below. The spindle serves two roles in mitotic cell division
it separates sister chromatids and elongates the cell
There are three major parts within each DNA nucleotide. Of these three, which is responsible for the storage of genetic information
its four nitrogen bases
Cytotoxic T cells
kill virus-infected and cancer cells
The longer the wavelength of a form of radiation, the ____ energy is present
less
When cancer strikes, the body ___ the ability to control this process
loses
Select all of the following that are types of cancer
lymphoma, leukemia, prostate tumor, tumor in breast tissue
A tumor that invades surrounding tissue is called a(n)
malignant tumor
Although cancer may originate in many regions of the body, many patients die from cancerous growth in the lungs, lymph glands, or liver. This is most readily explained as
metastasis occurring more commonly in organs that have a filter effect.
____ are part of the cytoskeleton of the cell. They help compose spindle fibers, which are active during mitosis to pull apart sister chromatids and elongate the cell
microtubules
Any of these substances that are known to cause mutations are called____, and when they are known to cause specific forms of cancer, they are called_____
mutagens, carcinogens
Which of the following is true about mutations
mutations are changes in the nucleotide sequence of DNA
This control of the internal environment is called homeostasis, and can be observed through the _____ range of the body's pH, temperature, and blood glucose
narrow
Any changes to the ____ sequence of DNA are called mutations
nucleotide
Mutations can change the ___ sequence of DNA, which may result in changes to the resulting ____
nucleotide
- Once sequenced, the pattern of _______ can be compared to databases to determine if mutations exist
nucleotides
DNA is found inside the
nucleus
Within eukaryotic cells, DNA is found inside the membrane-bound nucleus in the form of condensed chromosomes
nucleus
A small structure within a cell that carries out a particular function for the cell is a(n)
organelle
Cancer is named based on the types of cells or tissues where it
originates
A technique that uses the enzyme DNA polymerase to produce millions of copies of a particular piece of DNA is called the
polymerase chain reaction
What is the name of the technique used to amplify small amounts of DNA
polymerase chain reaction
- Antimetabolites
prevent cell division, either directly or indirectly, can also be called antibiotics and interfere with enzymes involved in DNA replication or transcription, integrate into DNA, preventing DNA replication
- Alkaloids and Taxanes
prevent spindle formation during mitosis, can have long-term negative impacts, prevent spindle formation during mitosis
T cells
produce cytotoxic and helper T cells
Liver
produces bile and cholesterol, filters out toxins from blood, regulates blood sugar
Genes that code for proteins that promote the cell cycle and inhibit apoptosis are called
pronto-oncogenes
Skin
protects the body, helps regulate body temperature
The ____ may have no change, may be abnormally formed, or may be incomplete
protein
Heart
pumps blood throughout the body
The movement of energy in the form of waves or particles is called____
radiation
Cancer is a disorder in which some cells have lost the ability to control their
rate of cell division
Cancer can impact many locations in the body. For example, melanoma impacts the ___, while lymphomas impact the ____
skin, immune system
Internal radiation therapy
small deposits of radioactive material are placed in the body. Interstitial brachytherapy- seeds placed in direct contact with tumor. Intracavitary brachytherapy - seeds placed in nearby body cavities. Low-dose treatments - seeds are left inside patient after treatment. High-dose treatment - seeds are removed after treatment.
Cell specialization refers to the ability of embryonic cells to
specialize and differentiate into any cell within the body
When functioning properly, photo-oncogenes tend to ____ the cell cycle
speed up
Tumor ____ genes code for proteins that inhibit the cell cycle
suppressor
Lungs
takes in oxygen and expels carbon dioxide
Homeostasis can best be described as
the body's ability to maintain constant internal conditions
RNA
transcribes and translates genetic information into proteins, contains uracil bound to adenine, single-stranded, functions within the nucleus, as well as the cytoplasm
Cells that pile on top of each other in multiple layers form a
tumor
Which of the following is a gene that normally codes for a protein that suppresses cell division
tumor suppressor gene
- Mammograms
use x-rays to examine breast tissue for cancer
External radiation therapy
uses X-rays or gamma rays to target a specific area of the body.
- Magnetic Resonance Imaging (MRI)
uses radio waves and magnets to generate detailed images of the body
- Positron Emission Tomography (PET) scans
uses radioactive tracers to look at the uptake of sugar by cells
These mutations can be caused by chemicals, radiation, or
viruses
- Computerized tomography (CT) scans
x-rays take pictures of organs from different angles and computer assemble them into 3-D models