Cancer Flashcards
What is a malignant neoplasia known as?
Cancer
Abnormal growth of tissues resulting from loss of responsiveness to growth control signals
Neoplasm
Cancer of the blood stream (WBCs) is known as:
Leukemias
Malignant neoplasms of mesenchymal origin is known as:
What is considered mesenchymal tissue?
- Sarcomas
- fat, bone, muscle
Cancer of epithelial origin is known as:
- Carcinomas
Cancer at the site of the lymph nodes is known as:
- Lymphomas
Suffix -oma indicates that abnormal cells are:
- Benign
Suffix -carcinoma & -sarcoma indicate the growth/cells are:
- Malignant
An increase in the number of a cells is known as:
- Hyperplasia
Some cellular and nuclear changes (loss of differentiation) leading to loss of cell uniformity and abnormal tissue architecture is known as:
Dysplasia
Undifferentiated cells, variable in size and shape; numerous and atypical mitoses, lack of organized tissue architecture is known as:
- Anaplasia
What are 3 characteristics of benign neoplasms:
- well differentiated
- well demarcated (no invasion of surrounding tissue)
- no distant metastases
3 characteristic of malignant neoplasms:
- lack of differentiation (anaplasia)
- locally invasive, infiltrating surrounding tissues
- distant metastases
T/F: Normal cells proliferate.
True : cell proliferation is limited to certain types of cells and processes
Which cells/processes in the body under NORMAL conditions can go under cell proliferation?
- BM myeloblasts
- Immune cells
- Epidermal cells
- Epithelial cells (gut)
- Regenerating tissues
Cell damage or perturbation in the cell cycle leads to:
- Apoptosis (programmed cell death)
List the 7 factors/processes that characterize a Cancer Cell:
- Self sufficiency in growth signals
- Insensitivity to growth inhibitory signals
- Evasion of apoptosis
- Limitless replicative potential
- Sustained angiogenesis
- Ability to invade & metastasize
- Evasion of host immune response
An increase in growth factors, increase in transcription factors, increase in the number of signal-transducing proteins, increased receptor gene signaling or gene signaling not being turned off all can lead to:
- Stimulation of cell proliferation
___________ encodes proteins that normally stimulate cell proliferation.
Proto-oncogenes
Altered or mutated forms of proto-oncogenes is known as:
- Onco-genes
In cancers, ________ have sustained gain of function alterations resulting from changes in the ________.
- Onco-genes
- Genome
Mutations of proto-oncogenes arise ________ and are _________.
- Somatically
- Dominant (meaning only one allele has to be effected for uncontrolled proliferation to occur)
Proto-oncogenes: Growth Factor Receptors
Mutated forms of receptors have __________ activity.
In addition to, over expression of ______ ________.
- Constitutive ( meaning the receptors are always on)
- Growth Factors (over expression of ERBB2 (HER2) in breast cancer)
Proto-oncogenes: Growth Factors
Oncogenes cause over expression of ___________ growth factors.
- Autocrine (dominant defect - one allele affected and causing uncontrolled proliferation)
What are 2 ways in which a cell can undergo uncontrolled growth?
- increase the number of receptors
- the receptor is constantly activated (on)
When GTP is hydrolyzed (converted) to GDP this signals the receptor to __________.
- turn off
Proto-oncogenes: Signal Transducing Proteins
RAS encodes for _______ which transmits a mitogenic signal for activated growth factor receptors that causes a cascade of _____________ that act on the ________. (this is a normal process)
- p21 G protein
- Transducing proteins
- Nucleus
RAS mutation:
Mutations affecting __________ lead to constitutive activation of the mitogenic cascade.
GTP hydrolysis
What is the most common abnormalities in human cancer (particularly high incidence in colon and pancreatic cancers)
- RAS mutations
Proto-oncogenes: Signal-Transducing Proteins
Proto-oncogenes stimulate expression of several growth-related genes, including _______________.
- Cyclin-dependent kinases (CDKs)
MYC as a proto-oncogene is known for normal growth -> MYC activates _____________ genes -> to increase growth
- growth related
_______ is most commonly involved in human cancer.
- MYC
Proto-oncogenes: Signal-Transducing Proteins
MYC in its altered form continues to activate _______.
An increase in MYC leads to an _______ cell growth.
- CDKs
- Increase
MYC in breast, lung and other cancers is overexpressed due to ____ ____________.
- Gene amplification
Progression of the cell cycle is driven by ______ and __________.
- Cyclins
- Cyclin-dependent kinases (CDKs)
The cell cycle is tightly controlled by _____________.
- CDK inhibitors
Dysregulation of ______ and _____ expression or their mutation occur often in cancer cells and promote proliferation.
- Cyclin
- CDK
The most common insults affect proteins involved in ______ transition
- G1-S
_____ ___________ _____ encode proteins that normally inhibit cell proliferation or stimulate apoptosis upon cell damage.
- Tumor suppressor genes
Tumor suppressor genes are _________ in cancer cells by mutations, truncation, deletions or methylation, leading to _______________.
- Inactivated
- Uncontrolled growth
Proto-oncogenes -> _____ __________.
Tumor suppressor genes -> _____ _______.
- Favors growth
- Inhibit growth
Mutations of tumor suppressor genes are usually _________.
- Recessive (meaning 2 alleles must be altered to lose their function)
__________ ________ develop earlier in age than sporadic malignancies and often arise in multiple locations.
- Hereditary cancers
Tumor suppressor genes- p53 -> controls ____ __________ and ________: it detects cellular stress and prevents propagation of damaged cell.
- Cell proliferation
- Apoptosis
Under normal conditions, p53 is bound ________ ______ -> which causes its degradation and short half-life
- MDM2 gene
Upon cellular stress _____ is released from the complex with ______ -> which increases its half-life and activates it ___________ ______ activity
- p53
- MDM2
- transcription factor
Active p53 stimulates transcription of ____ __________ (p21) -> which leads to _____ growth arrest: simulataneously DNA repair systems are activated (GADD45)
- CDK inhibitor (p21)
- G1
____ is the most commonly mutated genes in human cancer (over 70%)
- p53
Mutations or loss of p53 leads to _________ and _________ of mutated and damaged cells.
- Accumulation
- Propogation
p53 functional form is a _______.
- Tetramer
p53 protein is a _____________ ______ -> which binds to DNA sequence of genes encoding proteins responsible for cell cycle arrest and ________.
- Transcription factor
- Apoptosis
In this scenario, the mutant p53 does not interfere with the actions of the wild type allele.
- Loss of function
In this scenario, the mutant p53 forms a complex with the wild type allele and prevents its binding to the target gene promoters.
- Dominant negative mutant
In the scenario, the mutant p53 binds to different DNA sequences and activates different target genes -> which leads to cell proliferation
- Gain of function
T/F: DNA repair genes usually are NOT directly involved in cell cycle regulation.
- True
Lack of DNA repair facilitates mutations in genes including _________ and _____ __________.
- Oncogenes
- Tumor suppressor genes
In regards to breast cancer, both ______ and ______ encode for nuclear proteins involved in response to DNA damage and in DNA repair.
- BRCA1
- BRCA2
Deregulation of apoptotic mechanism leads to:
- Propagation of damaged, mutated cells
___________ is an enzyme, which in stem cells maintain normal telomere length preventing their senescence.
- Telomerase
In most cancers _________is up-regulated which allows for _________ cell divisions.
- Telomerase
- Unlimited (limitless replicative potential)
_______________ - the growth of capillary blood vessels -> tumor growth and metastasis depend on this.
- Angiogenesis
Perfusion supplies nutrients, growth factors and oxygen, preventing _______-___________ apoptosis.
- Hypoxia-induced
What is the Angiogenic switch?
- scale is tipped so more pro-angiogenic factors exist than anti-angiogenic factors (= more angiogenesis -> tumor growth)
Invasion and metastasis occurs by invasion of the ___________ ______, which is mediated by ________ motility factors and stimulated by _______________.
- Extracellular matrix
- Autocrine
- Chemoattractants
Name 3 main players in cellular effectors of anti-tumor immunity:
- CD8 T cells
- NK cells
- Macrophages
Name 3 ways a tumor can escape the immune response of the host:
- selective outgrowth of antigen negative cells
- loss of expression of MHC-1
- secretion of immunosuppressants
Factors that can cause cancer:
- Viruses/Bacteria
- Chemicals
- Radiation
Viruses can contribute to cancer development by:
- synthesizing proteins inactivating human genes involved in the cell cycle (HPV)
- expression of proteins stimulating cell proliferation (EBV, HBV)
- tissue injury leading to induction of regeneration processes (HBV)
Tumor progression occurs d/t deregulation of DNA replication causes genomic instability -> cancer. Name the 3 alterations in the process that causes this to occur.
- Altered cell checkpoints
- Altered apoptosis
- Altered DNA repair
Non specific signs of tumor progression:
- unexplained weight loss
- fever
- fatigue
- pain
- skin changes
Why do we die of cancer?
- Cytokine- induced cancer symptoms
Cancer diagnosis can be determined by:
- imaging (xray, CT, MRI, PET)
- biopsy (histopathological analysis)
- immunocytochemistry
This technique for diagnosing cancer detect tumor cells by using antibodies against tumor-specific antigens
- immunocytochemistry
Tumors are complex tissues containing:
- tumor cells
- fibroblasts
- immune cells
- blood vessels (endothelial cells)
- lymphatic vessels
Cancer therapy consists of:
- surgery
- chemotherapy
- radiation
Chemotherapy and radiotherapy target _______ ________ cells.
- rapidly dividing
- (these therapies target all proliferating cells in the body)
Inherited mutations of the ______ _________ ______ contribute to familial cancers.
- tumor suppressor genes
