Transcript Issues in Biotechnology

Issues in Biotechnology:
The Way We Work With Life
Dr. Albert P. Kausch
life edu.us
Medical Biotechnology
Lecture 31
Part IVb. Cancer Biology and
Emergent Treatments: Applications of
Biotechnology in Cancer Treatment
© life_edu
Issues in Biotechnology:
The Way We Work With Life
Dr. Albert P. Kausch
Kimberly Nelson
OnCampus Live
BCH 190, MIC 190, AFS 190, NRS 190, PLS 190
OnLine BCH 190
A Sweeping General Survey on Life and Biotechnology
A Public Access College Course
The University of Rhode Island
Issues in Biotechnology:
Biotechnology, Our Society and Our Future
life
edu.us
Issues in Biotechnology:
The Way We Work With Life
Dr. Albert P. Kausch
life edu.us
BCH 190
Section II.
The Applications of
Biotechnology
A Sweeping General Survey on Life and Biotechnology
© life_edu
The University
of Rhode Island
Issues in Biotechnology:
The Way We Work With Life
Dr. Albert P. Kausch
life edu.us
Medical Biotechnology
Lecture 31
Part IVb. Cancer Biology and
Emergent Treatments: Applications of
Biotechnology in Cancer Treatment
© life_edu
Emergent Technologies in Cancer Treatment
Cancer Basics, and the Application of
Biotechnology to Treat Disease
Cancer: Presentation Overview - Part 2
Fundamentals of Oncology
• Socio-economic burden of cancer
• Origins of cancer (carcinogenesis)
• Pathophysiology and Molecular pathology
• Contemporary target discovery/validation
Applications of Biotechnology in Cancer Treatment
• A brief history of cancer chemotherapy
• Three Case Studies - New Drugs Making a Difference
• Issues and opportunities for doing even more
DNA Microarray
A technology that is reshaping molecular biology
Microarrays consist of ordered
sets of DNA fixed to solid surfaces
provide pharmaceutical firms with
a means to identify drug targets.
In the future, the emerging
technology promises to help
physicians decide the most
effective drug treatments for
individual patients.
The complex interaction between a microbial pathogen and a host is the underlying basis of
infectious disease. By understanding the molecular details of this interaction, we can identify
virulence-associated microbial genes and host-defense strategies and characterize the cues to
which they respond and mechanisms by which they are regulated.
This information will guide the design of a new generation of medical tools.
How Does Chip Technology Work?
RNA expression
Disease free
Metastases
Nature 415: 530-536 2002
Pharmacogenomics
• Genetic causes of interpatient variability in phenotype
• Relationship between patient phenotype and genotype
Phenotype:
Genotype:
Responders
Clinical symptoms
Pharmacokinetic variability
Response to drug
- efficacy
- side effects
A genetic marker(s) distinguishing
specific variations within a DNA
sequence
Non-responders
Pharmacogenomics
Human Genetics
• SNPs
• Haplotypes
• Sequencing
Expression Profiling
• Specific transcript levels
• Total RNA profiling
Phenotype
Proteomics
• Specific biochemical
markers
• Protein profiling
• Drug response
• Disease
Prediction
Whan that Aprill, with her shoures soote
The droghte of March is perced to the roote
And bathed every veyne in swich licour,
Of which vertu engendred is the flour;
Whan Zephirus eek with his sweete breeth
Inspired hath in every holt and heeth
The tendre croppes, and the yonge sonne
Hath in the Ram his halfe cours yronne,
And smale foweles maken melodye,
And slepen al the nyght with open eye(So priketh hem Nature in hir corages);
Thanne longen folk to goon on pilgrimages
And especially from every shires ende
to room 10, in CBLS they wende,
Whan that Aprill, with her shoures soote
The droghte of March is perced to the roote
And bathed every veyne in swich licour,
Of which vertu engendred is the flour;
Whan Zephirus eek with his sweete breeth
Inspired hath in every holt and heeth
The tendre croppes, and the yonge sonne
Hath in the Ram his halfe cours yronne,
And smale foweles maken melodye,
And slepen al the nyght with open eye(So priketh hem Nature in hir corages);
Thanne longen folk to goon on pilgrimages
And especially from every shires ende
to room 10, in CBLS they wende,
When in April the sweet showers fall
That pierce March’s drought to the root
And bathed every vein in sweet liquor
That has power to generate therein and sire the flower;
When Zephyr also has with his sweet breath
Filled again, in every holt and heath,
The tender shoots and leaves, and the young sun
His half-course in the sign of the Ram has run,
And many little birds make melody
That sleep through all the night with open eye
(So Nature pricks them on to ramp and rage)
Then folk do long to go on pilgrimages
And especially from every shire’s end
Of URI they to 271 Chaffee they went
Variation in Phenotype
is
Variation in Genetics
X
Variation in Environment
Vp = Vg X Ve
Complex (Multifactorial) Phenotypes: What can
we expect?
Genei
I. Few Genes each contributing large risk
• ls> 4.0
Genen
Expression of
Phenotype =
Gi + Gn + E
Environment
II. Many genes each contributing small risk
• ls< 2.0
Gi
Gi
Gi
Gi
E
Gi
Phenotype
Genetics
X
Environment
What Causes Cancer?
Genetics
Environment
What Causes Cancer?
Genetics
Mutations Oncogenes Anueploidy Chromosomal Rearrangements
Human Cancer Genes:
Genes Causally Linked to Oncogenesis
About 290 genes have been linked to cancer by identification of
mutation in primary human tumors. Changes include…
Point mutations
Activating (ex. Ras in pancreatic cancer)
Inactivating (ex. p53 in ~50% of all cancers)
Translocations
Aberrant fusion proteins (ex. bcr/abl in CML)
High Expression (ex. erbB2 in breast cancer)
Deletions/insertions/frame shifts (ex. APC in colon cancer)
Point mutations
Frame shift mutations
Deletions
Insertion
Translocations
Additional gene copies
Anueploidy
Chromosomal
rearrangements
Oncogene activations
Viruses (e.g. HPV)
Step-wise (ordered) Genetic Changes in
Colon Tumorigenesis
“Full Blown” Tumorigenesis requires 4-17 events (mutations)
Kinzler and Vogelstein Cell 1996
What Causes Cancer?
Environment
Carcinogens (Too many to name)
Toxic compounds (everywhere)
Sunlight (UVb)
Tobacco smoking
Radiation
Emergent Technologies in Cancer Treatment:
Lecture Overview
Fundamentals of Oncology
• Socio-economic burden of cancer
• Origins of cancer (carcinogenesis)
• Pathophysiology and Molecular pathology
• Contemporary target discovery/validation
Emergent Technologies in Cancer Treatment
Applications of Biotechnology in Cancer Treatment
• A brief history of cancer chemotherapy
• Three Case Studies - New Drugs Making a Difference
• Issues and opportunities for doing even more
Emergent Technologies in Cancer Treatment:
Lecture Overview
Fundamentals of Oncology
• Socio-economic burden of cancer
• Origins of cancer (carcinogenesis)
• Pathophysiology and Molecular pathology
• Contemporary target discovery/validation
Applications of Biotechnology in Cancer Treatment
• A brief history of cancer chemotherapy
• Three Case Studies - New Drugs Making a Difference
• Issues and opportunities for doing even more
The Bari Myth
• USS John Harvey, an American ship in Bari Harbor, carried a highly classified
load of 2,000 100-lb mustard bombs
• Dec 2, 1943 - A German raid damaged 17 ships, including the Harvey
• Fire on the Harvey caused a mustard-laden smoke that spread quickly
• 617 Mustard gas poisoning cases among troops and merchant marine seamen,
with a 14% fatality rate (3-fold higher that of World War I)
• Commonly cited as the key observation that led to Goodman and Gilman’s
pioneering work on the use of nitrogen mustards in cancer chemotherapy
R. Joy, HISTORICAL ASPECTS OF MEDICAL DEFENSE AGAINST CHEMICAL WARFARE
The Bari Myth (cont’d)
After World War I, researchers were highly aware of the human
effects of mustard gas—it destroyed lymphatic tissue and bone
marrow. It was broadly reasoned that mustards could also kill
cancer cells in the lymph nodes.
It was not until 1942, more than a year before the Bari raid,
however, that two young assistant professors in Yale’s new
Department of Pharmacology, Louis S. Goodman, M.D., and Alfred
Gilman, Ph.D., were commissioned by the Defense Dept. to study
nitrogen mustard and its derivatives. Their pre-clinical studies in
mice produced dramatic regressions of lymphomas.
In December of 1942, a 48-year-old patient with terminal
lymphosarcoma was given 10 consecutive doses of nitrogen
mustard, a 10th of a milligram to a milligram per kilogram of body
weight, roughly 2.5 times what became the standard dose.
Within two days a softening of the tumor masses was noted. By the
end of treatment the tumors disappeared. A month later, however,
the patient relapsed, and subsequent courses of treatment were less
effective. Nevertheless the scientists were encouraged.
The clinical trials remained a classified military secret, even from
caregivers, until 1946—the first Yale patients’ charts said only, “0.1
mg. per kg. compound X given intravenously.”
From Humble Beginnings…
R Ruddon, Anticancer Drugs
Goodman and Gilman usher in 60 years
of cytotoxic chemotherapy
R Ruddon, Anticancer Drugs
Cytotoxic Drugs in 2012 - Still Among
Standards of Care in Cancer Chemotherapy
1st Line
2nd Line
Breast Ca
Adriamycin+ Cytoxan +/- Taxol
Cytoxan + 5FU+methotrexate
Cytoxan + Adriamycin + 5FU
Taxol + Herceptin (erbB2+ only)
Tamoxifen
Taxol
Xeloda
Herceptin
Taxotere
NSCLC
Taxol and carboplatin
Gemcitabine + CDDP
Tarceva, Taxotere
Etoposide, Navelbine
Colorectal
Camptosar + 5FU+ leucovorin
Oxaliplatin + 5FU+leucovorin
Xeloda
Irinotecan
Prostate
LHRH analog (Lupron/Zoladex)
+/- antiandrogen
Casodex+mitoxantrone+pred
-nisone
Hodgkins Lymphoma
ABVD: doxorubicin+bleomycin+
vinblastine+ dacarbazine
The key limitation of cytotoxic chemotherapy…
How fast is the tumor growing?
Tumor Type
Burkitt's lymphoma
Testicular cancer
Ewings' sarcoma
Small cell lung cancer
Colon cancer
Breast cancer
Lung cancer
Doubling time (days)
2 - 5 days
21
22
81
96
129
134
Populations of committed stem cells in normal tissues
(bone marrow; epithelium of GI tract) have doubling
times < 1 day
Cancer: Presentation Overview
Fundamentals of Oncology
• Socio-economic burden of cancer
• Origins of cancer (carcinogenesis)
• Pathophysiology and Molecular pathology
• Contemporary target discovery/validation
Applications of Biotechnology in Cancer Treatment
• A brief history of cancer chemotherapy
• Three Case Studies - New Drugs Making a Difference
• Issues and opportunities for doing even more
Inhibition of Angiogenesis as a Target




Required for tumor
metastasis & growth
beyond 1-2 mm3
Limited role in adults
Broad spectrum of
activity
May circumvent
acquired drug resistance
Folkman: Angiogenesis is Necessary
Angiogenesis and Tumors
Blood vessels grow toward
and into tumors
VEGF
Vascular Epithelial Growth Factor
DNA Technology
And Small Molecule
Drug Design
Precise treatments for:
Cancers
Cardiovascular diseases
Inflammation
Behavior
Obesity
Depression
Schizophrenia
Small Molecule Cancer Drug Design
Small Molecule Cancer Drug Design
Gleevec: Imatinib, is a drug used to treat certain cancers. It is marketed by
Novartis as Gleevec (USA) or Glivec (Europe/Australia/Latin America) as its
mesylate salt, imatinib mesilate (INN).
Imatinib is the first of a new class of drugs that act by specifically inhibiting a
certain enzyme – a receptor tyrosine kinase – that is characteristic of a particular
cancer cell, rather than non-specifically inhibiting and killing all rapidly dividing
cells.
Recombinant DNA And
New Cancer Drugs
DNA Technology
and Pharmaceuticals
Allows precise treatments for:
Cancers
Cardiovascular diseases
Inflammation
Behavior
Obesity
Depression
Schizophrenia
Genetic Constructs Now Make Proteins
That Are New Cancer Drugs
Promoter
Coding Sequence
Terminator
Your favorite gene
Controlled expression
“making protein”
Erbitux
Herceptin
Avastin
Rituxan
TM
TM
TM
TM
Stop transcription
Message stability
Advance 1: AvastinTM (Bevisizumab)
Why an Antibody to VEGF?
Ferrara: VEGF is Necessary for Angiogenesis
Antibodies for targeted therapy
Advantages





Ideal for extracellular targets
Small molecule approaches successful for “beautiful” binding sites,
but generally limited for all others
– Non-enzymes
– Non-receptors
– Shallow pocket enzymes
Opportunity for exquisite selectivity
– Enzymatic selectivity for targets with promiscuous binding sites
IGF-1R & Insulin receptor
– Eliminates potential for chemotype-based toxicities associated
with small molecules
Relatively long duration of coverage over target
– T 1/2 for human antibodies (weeks vs. hours for drugs)
Antibodies for targeted therapy
Potential Issues/Risks

Distribution of Abs may limit activity relative to small molecules
– Distribution: potential for limited tumor penetration
Single chain variable fragments may improve penetration
–
Potential for immunogenicity
Fully human antibodies may mitigate risk



Manufacturing more complicated; high COG
Long T1/2: Little opportunity to limit exposure if toxic
– Points to advantage for small molecule, or Ab fragments
Human Abs rarely x-react with rodents: preclinical modeling is
challenging
– Efficacy modeling for anti-angiogenesis targets
– Estimates of TI in the efficacy species
Therapeutic Antibodies for Cancer


Antibodies already a key weapon in the Cancer arsenal
Regulatory approvals for Abs in solid tumor indications are on the rise
Product
Target
Company
Indication
Approval date
RituxanTM
CD20
IDEC/Roche/
Genentech
NHL
11/97
HerceptinTM
erbB2
Genentech/
Roche
Metastatic BC
9/98
AvastinTM
VEGF
Genentech
1st line CRC
2/2004
ErbituxTM
EGFR
ImClone/BMS
2nd line CRC
2/2004
Additional Benefit from Avastin
Breast Cancer:
Phase III study of Avastin plus paclitaxel in first-line metastatic breast
doubled the duration of surviving without cancer progression
compared to chemotherapy alone
Median progression-free survival was 11 months for patients treated with
Avastin plus chemotherapy, compared to six months for patients
treated with chemotherapy alone
In patients with measurable disease, the overall response rate was 28
percent (93/330) in the Avastin plus chemotherapy arm, vs. 14
percent (45/316) observed in the chemotherapy alone arm
KD Miller, ASCO 2005
Lung Cancer:
Phase III study of Avastin plus paclitaxel and carboplatin chemotherapies
in first-line non-small cell lung cancer (NSCLC) patients showed a
30
percent improvement in overall survival (12.5 months vs. 10.2
months)compared to patients who received chemotherapy alone
AB Sandler, ASCO 2005
Advance 2: HerceptinTM (traztuzumab)
EGF
TGF-
Amphiregulin
Betacellulin
HB-EGF
Heregulins
NRG2
NRG3
Heregulins
Betacellulin
AEV
Extracellular Ligandbinding Domain
Tyrosine
Kinase
Domain
ErbB-1 (EGFR)
5’
v-erbB v-erbA
ErbB-2
ErbB-3
3’
ErbB-4
erbB2 as a Cancer Target
• erbB2 (HER2) is a member of the epidermal growth factor receptor
(EGFR) family of transmembrane tyrosine kinases
• Amplification (an excess number of gene copies) or over-expression
(excess production of protein) confers on the affected cancer cell aggressive
behavioral traits, including enhanced growth and proliferation, increased
invasive and metastatic capability, and stimulation of angiogenesis
• Patients with breast cancer in which HER2 is amplified (FISH-positive
tumors) or HER2 is over-expressed are likely to have poorly differentiated
tumors with a high proliferative rate, positive axillary lymph nodes, and
decreased expression of estrogen and progesterone receptors
NE J Med 353: 1734 (2005)
Gabriel N. Hortobagyi, M.D.
erbB2 as a Target: Checklist
HerceptinTM (traztuzumab)
1.
2.
3.
4.
5.
6.
Is the target a ‘gain-of-function’ gene that provides
a key advantage to the tumor:
•
Progression and expression are linked?
•
Inhibition of gene function restores normal
homeostasis?
Is the target gene differentially expressed in tumor
vs. normal cells (plausible basis for a TI?)
Can the target be measured in biopsy material to
select patients for clinical treatment?
Can modulation of the target after Rx be monitored
by a relatively non-invasive technique (biomarker)?
Does target structure/function indicate a plausible
basis for therapeutic attach (Is it an enzyme? A
receptor?)
Is it plausible that inhibition of the target would
combine with other known Rx?
/?
/?
Herceptin (anti-erbB2)
Monoclonal Antibody:
Biological Effects
ErbB-2
LA Emens, Amer J Therapeutics 12: 243 (2005)
Herceptin: Clinical Activity in Advanced Breast Cancer
LA Emens, Amer J Therapeutics 12: 243 (2005)
Herceptin – Activity in Improving Survival
(D + C, TX =/- trastuzumab)
Romond et al., NE J Med 353: 1673 (2005)
“On the basis of these results, our care of patients with HER2-positive breast
cancer must change today. Certainly, patients with lymph-node–positive,
HER2-positive breast cancer should receive trastuzumab as part of optimal
adjuvant systemic therapy… Since most HER2-positive tumors have other
adverse prognostic factors, this risk–benefit scenario is likely to apply to
many patients with node-negative breast cancer.”
NE J Med 353: 1734 (2005)
Gabriel N. Hortobagyi, M.D.
Issues in Biotechnology
One of the standards of care in cancer
treatments include the use of chemotherapy.
Many of the drugs used in modern
chemotherapy are:
(A) carcinogenic
(B) cytotoxic
(C) not developed by large pharmaceutical
companies
(D) free of any side-effects
(E) deadly
Therapeutic Antibodies for Cancer


Antibodies already a key weapon in the Cancer arsenal
Regulatory approvals for Abs in solid tumor indications are on the rise
Product
Target
Company
Indication
Approval date
RituxanTM
CD20
IDEC/Roche/
Genentech
NHL
11/97
HerceptinTM
erbB2
Genentech/
Roche
Metastatic BC
9/98
AvastinTM
VEGF
Genentech
1st line CRC
2/2004
ErbituxTM
EGFR
ImClone/BMS
2nd line CRC
2/2004
Issues in Biotechnology
Antibodies have some distinct advantages over
old school chemotherapies for treating cancer
because they:
(A) all of these reasons
(B) are ideal for extracellular targets involved
with tumor growth
(C) eliminate potential for chemotype-based
toxicities associated with small molecules
(D) have a relatively long duration of coverage
over the tumor target
Advance 3: TarcevaTM (erlotinib)
EGFR
(erbB1)
Why Target EGFR for Anti-tumor Drug
Discovery ?
• Over-expression of EGFR can transform cells in a liganddependent manner
• EGFR or TGFa are frequently over-expressed in
carcinomas, for example 42% of Lung Cancers over-express
EGFR and many express EGF or TGFa
• EGFR “Knockout” Mice are viable and hematopoietic cells
lack EGFR
The Use of Mouse As
A Human Cancer Model
The Use of Mouse Genomics As
A Human Cancer Model
OncoMouse
OncoMouse
Pharmacological Selectivity - Among
close oncogene kindreds
O
HN
O
O
O
O
HN
O
N
N
O
CP-358774
erbB2 kinase: 1714 nM
EGFR kinase: 2 nM
857x selective for EGFR
N
N
erbB2 kinase: 43 nM
EGFR kinase: 18 nM
represents >500000x
shift in selectivity!
O
O
N
OMe H
N
H
N
O
HN
HN
N
N
N
CP-724714
erbB2 kinase: 8 nM
EGFR kinase: 6173 nM
772x selective for erbB2
N
erbB2 kinase: 40 nM
EGFR kinase: 5998 nM
N
Tarceva
Antibodies Advantages




Extracellular targets
Small molecules
successful for
“beautiful” binding sites
Opportunity for exquisite
selectivity
Relatively long duration
of coverage over target
– T 1/2 for human
antibodies (weeks vs.
hours for drugs)






Intracellular targets
Tyrosine Kinases active
sites
Exquisite selectivity
(500,000-fold vs. erbB2)
Relatively long duration
of coverage over target
– T 1/2 in humans ~12
hours… q.d. oral
dosing (strong patient
preference)
High tumor penetration
Low COG
New Frontiers - Tumor Stem Cells

BCRP/ABCG2 (breast cancer resistance protein)

Telomerase

Oct4

Nanog

Stat3

Aldehyde Dehydrogenase

CXCR4/SDF-1
Cancer: Summary for Part 2
• Targeted therapies, those abrogating the key molecular advantages of
tumor cells, are adding importantly to patient survival
• These approaches offer the promise of less morbidity and higher quality of
life
• Monoclonal antibodies have ‘credentialed’ targeted therapies; small
molecule drugs are now emerging as well
• The future is likely to be focused on understanding ‘systems biology’ vs.
individual gene targets, on tumor stem cells vs. their diverse (and somewhat
less talented) progeny, and on novel combinations of targeted agents where
patient survival will be measured in decades, not months
No Walls
The Clear bead at the center changes everything
There are no edges to my being now
I have heard it said that there is a window
That opens from one mind to another
But where there are no walls
There is no need for a window, or fitting a latch.
Rumi 1279 AD
11. There have been genes that have been identified to be
associated with certain types of cancer. Microarrays or
biochips have been used to examine differences in RNA
population in cancer vs. non-cancerous cells. Human cancer
genes of special interest are:
(A) genes that are causally linked to cancer development or
oncogenesis
(B) those that have been introduced by genetic engineering
(C) now being investigated in cloned humans who have had
these genes removed from their genome
(D) only simple somatic cell mutations
(E) currently only those involved with breast cancer
12. One of the standards of care in cancer treatments include
the use of chemotherapy. Many of the small molecule chemical
drugs still used in modern chemotherapy are:
(A) carcinogenic
(B) cytotoxic (kill fast growing cells)
(C) not currently developed by large pharmaceutical
companies
(D) free of all side-effects
(E) only placebos
13. Biopsy and histology has been an effective tool for the staging of
colon cancer using Dukes’ staging. This type of staging works well only
for very good / very poor prognosis patients (Dukes’ stage A and D), but
it is not very informative when predicting long-term outcomes of
intermediate prognosis patients (Dukes’ stage B and C). A bigger
problem is that a biopsy and a Dukes’ classification provides a only
single snapshot in time… within the long natural history of a colon
tumor (until the day of biopsy). Molecular staging in colon cancer may
have the following implications:
(A) there will be an increase of misdiagnosis
(B) molecular staging will be in the control of the big pharmaceutical
companies who will prefer to keep it secret because it will decrease the
sales of their most effective chemotherapies and decrease sales
(C) molecular staging itself may cause cancer
(D) molecular staging may provide more accurate and early
predictions of patient outcome than is currently possible with clinical
staging
(E) directly cause an increase in health care costs and therefore be
prohibitive
14. Progression of cancer development is thought to be due to
both genetic and non-genetic changes at the molecular level.
The result of clonal progression in carcinogenesis is:
(A) a fortunate event because it signals programmed cell
death of the tumor
(B) a clone of cells that is unresponsive to normal growth
controls, and is able to expand indefinitely
(C) means that the cancer is untreatable
(D) a result of a gain in function of the tumor suppressor
genes
(E) what renders some cancers as not dangerous
15. The USS John Harvey, an American ship in Bari Harbor,
carried a highly classified load of 2,000 100-lb mustard bombs
on Dec 2, 1943 when a German raid damaged 17 ships,
including the Harvey. Fire on the Harvey caused a mustard
gas-laden smoke that spread quickly. 617 mustard gas
poisoning cases among troops and merchant marine seamen
occurred. Studies of mustard gas by two young assistant
professors in Yale’s new Department of Pharmacology, Louis
S. Goodman, M.D., and Alfred Gilman, Ph.D had already
shown interesting biological effects of mustard gas that
eventually lead to the development of:
(A)
(B)
(C)
(D)
(E)
radiation therapy
chemotherapy
molecular staging
gene therapy
stem cell therapy
16. Going from a microscopic view of the histological
appearance of tumors in biopsies to a molecular view of
analyzing the genes that are expressed or not expressed in
tumors can be done now by:
(A) generating a molecular profile on a GeneChip
(microarray)
(B) sequencing all of the genes in the patient
(C) comparing all the genes of a patient to a healthy
individual
(D) doing a ‘Southern blot’ on the patient’s DNA
(E) electron microscopy
17. The growth of blood vessels is known to have a strong
influence on tumor growth. AVASTIN is a very effect anticancer recombinant DNA drug that as an antibody reacts with
VEGF to inhibit tumor:
(A)
(B)
(C)
(D)
(E)
angiogenesis
DNA synthesis
transcription
protein production
origins
18. Herceptin is an antibody based drug that is produced from
cloned DNA that has been introduced into cells so that it can
be produced in large quantities. Herceptin binds to erbB2 and
is very effective against what type of cancer?
(A)
(B)
(C)
(D)
(E)
brain cancer
herceptin treats all of these cancer types effectively
breast cancer
prostate cancer
lung cancer
19. Antibodies have some distinct advantages over old school
small molecule chemotherapies (such as mustard gas) for
treating cancer because they:
(A) are highly specific
(B) are ideal for extracellular targets involved with tumor
growth
(C) eliminate potential for chemotype-based toxicities
associated with small molecules
(D) have a relatively long duration of coverage over the tumor
target
(E) all of these reasons
20. Avastin is a humanized antibody that binds the peptide
factor VEGF with a half-life in humans of 17-21 days. This
drug is produced from a cloned segment of DNA that has been
introduced into cell culture to make a stable transgenic cell
line. These cells are then grown in large fermenters that are
then harvested and the antibody is then purified through
biomanufacturing processes. This purified antibody is sold as
the drug Avastin which when introduced into the patient will
cause:
(A) the neutralization of VEGF that reduces or eliminates the
ongoing angiogenesis in tumors
(B) tumors to stop replicating their DNA
(C) metastasis
(D) debilitating side effects, such as paralysis
(E) a shortened death process