GMS 6552 EXAM 2 : PRINCIPLES OF MEDICAL MICROBIOLOGY
AND IMMUNOLOGY | QUESTIONS AND ANSWERS | LATEST EXAM
UPDATE
Oncogene - CORRECT ANSWER - A gene that causes or contributes to the
development of cancer
Hallmarks of Cancer - CORRECT ANSWER - Sustaining proliferative
signaling
Evading growth suppressors
Activating invasion and metastasis
Enabling replicative immortality
Inducing angiogenesis
Resisting cell death
In vivo oncogenic evidence - CORRECT ANSWER - Cause cancer when
activated in a transgenic animal
Render nontumorigenic cells tumorigenic
Knock down or knock out in tumorigenic cells renders the cells nontumorigenic
Activation/overexpression of the oncogene is strongly correlated with human
cancer
In vitro oncogenic evidence - CORRECT ANSWER - Causes anchorage-
independent growth in soft agar (protection from anoikis)
Causes focus formation (loss of contact inhibition)
Renders cell growth factor independent
Oncogenes in Cancer - CORRECT ANSWER - Aberrant expression of proto-
oncogenes that increases cell proliferation/survival
,First identified in cancer-causing viruses
Typically a dominant mechanism
Oncogene activation is usually limited to somatic tissue, but more cases of
inherited oncogene mutations are being found
Biochemical functions of oncogenes - CORRECT ANSWER - G-proteins
(Ras)
Protein Kinases (Raf, Akt)
Lipid Kinases (PI3-Kinase)
Transcription Factors (Myc)
Binding and inactivating apoptotic proteins (BCL2)
Protein Kinase regulatory subunits (Cyclins A, E, D)
Transcriptional coactivators (B-Catenin, YAP, TAZ)
Five Ways to Activate Oncogenes - CORRECT ANSWER - 1. Mutation of
gene to make it overactive
2. Amplification of a normal gene
3. Chromosomal Rearrangement
4. Promoter/enhancer insertion
5. Hypomethylation of oncogene
Amplification - CORRECT ANSWER - Multiple gene copies = too much
transcript and protein
DNA sequencing, DNA-PCR
RNA sequencing, RNA-PCR
Protein: Western
Chromosomal Rearrangement - CORRECT ANSWER - Affects regulatory
region of oncogene
, Cytogenetics
PCR using primers
Promoter/Enhancer Insertion - CORRECT ANSWER - From retroviral
integration near oncogene
Gene expression activated from the viral promoter
Should activate oncogenes or disrupt tumor suppressors
Can find new genes
Hypomethylation of Oncogenes - CORRECT ANSWER - Ex. N-ras is
activated in liver cancer due to under-methylated promoter, allowing gene
expression
Directly measure methylation using methyl-sensitive restriction
enzyme/genomic DNA,, bisulfite genomic sequencing, or methylation specific
PCR
measure RNA/protein level
Oncogenes in medical practice - CORRECT ANSWER - Specific diagnosis,
sub-classification of tumor type, and/or prognosis can be based on certain gene
involvement
EGFR Inhibitors - CORRECT ANSWER - Sustaining proliferative signaling
Cyclin-dependent kinase inhibitors - CORRECT ANSWER - evading growth
suppressors
Immune activating anti-CTLA4 mAb - CORRECT ANSWER - avoiding
immune destruction
Telomerase inhibitors - CORRECT ANSWER - enabling replicative
immortality
AND IMMUNOLOGY | QUESTIONS AND ANSWERS | LATEST EXAM
UPDATE
Oncogene - CORRECT ANSWER - A gene that causes or contributes to the
development of cancer
Hallmarks of Cancer - CORRECT ANSWER - Sustaining proliferative
signaling
Evading growth suppressors
Activating invasion and metastasis
Enabling replicative immortality
Inducing angiogenesis
Resisting cell death
In vivo oncogenic evidence - CORRECT ANSWER - Cause cancer when
activated in a transgenic animal
Render nontumorigenic cells tumorigenic
Knock down or knock out in tumorigenic cells renders the cells nontumorigenic
Activation/overexpression of the oncogene is strongly correlated with human
cancer
In vitro oncogenic evidence - CORRECT ANSWER - Causes anchorage-
independent growth in soft agar (protection from anoikis)
Causes focus formation (loss of contact inhibition)
Renders cell growth factor independent
Oncogenes in Cancer - CORRECT ANSWER - Aberrant expression of proto-
oncogenes that increases cell proliferation/survival
,First identified in cancer-causing viruses
Typically a dominant mechanism
Oncogene activation is usually limited to somatic tissue, but more cases of
inherited oncogene mutations are being found
Biochemical functions of oncogenes - CORRECT ANSWER - G-proteins
(Ras)
Protein Kinases (Raf, Akt)
Lipid Kinases (PI3-Kinase)
Transcription Factors (Myc)
Binding and inactivating apoptotic proteins (BCL2)
Protein Kinase regulatory subunits (Cyclins A, E, D)
Transcriptional coactivators (B-Catenin, YAP, TAZ)
Five Ways to Activate Oncogenes - CORRECT ANSWER - 1. Mutation of
gene to make it overactive
2. Amplification of a normal gene
3. Chromosomal Rearrangement
4. Promoter/enhancer insertion
5. Hypomethylation of oncogene
Amplification - CORRECT ANSWER - Multiple gene copies = too much
transcript and protein
DNA sequencing, DNA-PCR
RNA sequencing, RNA-PCR
Protein: Western
Chromosomal Rearrangement - CORRECT ANSWER - Affects regulatory
region of oncogene
, Cytogenetics
PCR using primers
Promoter/Enhancer Insertion - CORRECT ANSWER - From retroviral
integration near oncogene
Gene expression activated from the viral promoter
Should activate oncogenes or disrupt tumor suppressors
Can find new genes
Hypomethylation of Oncogenes - CORRECT ANSWER - Ex. N-ras is
activated in liver cancer due to under-methylated promoter, allowing gene
expression
Directly measure methylation using methyl-sensitive restriction
enzyme/genomic DNA,, bisulfite genomic sequencing, or methylation specific
PCR
measure RNA/protein level
Oncogenes in medical practice - CORRECT ANSWER - Specific diagnosis,
sub-classification of tumor type, and/or prognosis can be based on certain gene
involvement
EGFR Inhibitors - CORRECT ANSWER - Sustaining proliferative signaling
Cyclin-dependent kinase inhibitors - CORRECT ANSWER - evading growth
suppressors
Immune activating anti-CTLA4 mAb - CORRECT ANSWER - avoiding
immune destruction
Telomerase inhibitors - CORRECT ANSWER - enabling replicative
immortality
