How to present a scientific paper Dr. Rebecca B. Riggins Department of Oncology, Georgetown...
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Transcript of How to present a scientific paper Dr. Rebecca B. Riggins Department of Oncology, Georgetown...
How to present a scientific paper
Dr. Rebecca B. Riggins
Department of Oncology, Georgetown University
Outline
• Preliminary thoughts on the assigned reading
• Typical structure of a scientific paper– Differences dictated by journal in which it is
published
• Discussion of Zhao et al., with comparisons to Schafer et al.
• Final thoughts on the assigned reading
‘A scientific paper is like an hourglass’
Introduction
(Materials and Methods)
Results
Discussion
Abstract = mini hourglass
‘The width of the hourglass is inversely proportional to importance’
• RESULTS and the HYPOTHESIS/RATIONALE are key when it comes to presenting a scientific paper
• The Introduction is useful for background
• The Discussion is a useful summary
Introduction
(Materials and Methods)
Results
Discussion
Zhao et al.: ErbB2, glycolysis, and breast cancer growth
• Key words in the title will be better described in theIntroduction section• This should guide you in preparing 3 or 4 slides to introduce the paper and why the study is important…
Cancer cell metabolism
• Normal cells and cancer cells differ in how they derive energy from glucose
• Normal: aerobic
• Cancer: anaerobic
• Cancer cell glycolysis dependence = Warburg effect
• Explain this graphically using simple images
O2+glucose glycolysis oxidative phosphorylation 38 ATP
glucose glycolysis only 2 ATP
A simple diagram of glycolysis vs. oxidative phosphorylation
http://www.nutritionaloncology.org/images/aerobicGlycolysis.jpg
• Multiple molecules and pathways can regulateglycolysis• Some of these include:
• Ras, PI3K, mTOR, Src
•These are all targets ofthe receptor tyrosine kinase ErbB2
Please cite your source!
The full ErbB family signaling pathway
E
rbB
1
E
rbB
1
c-FosElk1 c-Jun
mTOR
PDK1
HBEGF
PLC-
PKC
Nck
Ras
Raf
MEK1/2
ERKs
p38
JNK
PI3K
p70S6K
Akt/PKB
PAK
CDC42
Anti-Apoptosis
E
rbB
1
E
rbB
2
Er
bB3
ErbB4
TGFEGFAreg
Btc
Ereg
Nrg1,2
MKK3/6
GR
B2
SOS
SHC
Nrg3,4
TranslationTranslation
Gene ExpressionGene Expression
Er
bB3
Er
bB3
GSK3
FKHR
ErbB4
ErbB4
ErbB4
ErbB4
E
rbB
1
ErbB4
ErbB3
E
rbB
2
2009ProteinLounge.com 2009ProteinLounge.com
C
Relevant ErbB family signaling
E
rbB
1
E
rbB
1
c-FosElk1
c-Jun
mTOR
PDK1
HBEGF
Ras
Raf
MEK1/2
ERKs
p38
JNK
PI3K
p70S6K
Akt/PKB
PAK
CDC42
Anti-Apoptosis
E
rbB
1
E
rbB
2
TGFEGFAreg
Btc
Ereg
Nrg1,2
MKK3/6
GR
B2
SOS
SHC
TranslationTranslation
Gene ExpressionGene Expression
GSK3
FKHR
ErbB3
E
rbB
2
2009ProteinLounge.com 2009ProteinLounge.com
C
Ligands
Receptors
Intracellularsignaling
Translation
How might ErbB2 regulate glycolysis?
• Lactate dehydrogenase A (LDH-A) is a key glycolytic enzyme, and its expression is increased in mouse mammary epithelial cells that overexpress a form of ErbB2
• Heat shock factor 1 (HSF1) is a transcription factor that regulates glucose metabolism which is itself regulated by Ras (a target of ErbB2)
• Does ErbB2 regulate glycolysis through these molecules?
Experimental results
• Select key figures that illustrate the important points– These are often positive, but if there is room
for criticism please provide it
• Do NOT attempt to describe every panel of every figure
Overexpression of Erb2 promotes glycolysis in breast cancer cells
O2 consumption
http://www.nutritionaloncology.org/images/aerobicGlycolysis.jpg
Overexpression of ErbB2 increases LDH-A and HSF1
…and knockdown of ErbB2 reduces LDH-A expression and glycolysis
Downregulation of HSF1 = reduced LDH-A and glycolysis
Use of Hsf1 -/- cells is a wayto confirm siRNA results
Glycolysis inhibitors, ErbB2, and cancer
http://www.nutritionaloncology.org/images/aerobicGlycolysis.jpg
2DG = glucose analog that cannot undergo glycolysis
Oxamate = inhibitor of LDH, which converts pyruvate to lactate
Oligomycin = inhibitor of oxidative phosphorylation
• Are ErbB2 overexpressing cells more sensitive to glycolysis inhibitors (and less sensitive to oxidative phosphorylation inhibitor)?
Overexpression of ErbB2 = sensitivity to glycolysis inhibitors, and sensitivity to oxidative phosphorylation inhibitors
Glycolysis inhibitor Oxidative phosphorylation inhibitor
Similar results with 2DG in anothercell line overexpressing ErbB2
Downregulation HSF1 inhibits ErbB2 effects on glycolysis and sensitivity to inhibitors
Again, use of Hsf1 -/- cells is a wayto confirm siRNA results
Summary of Results
E
rbB
1
E
rbB
2
Upregulation of HSF1 protein
Increased LDH-A expression, enzyme activity
E
rbB
1
E
rbB
2
E
rbB
1
E
rbB
2
Increased glycolysis
Increased cell growth
Glycolysis inhibitors
ErBB2 siRNA
HSF1 siRNA
Discussion section
• This is a summary of the major findings, and their importance for the field of study
• The first paragraph is the summary
• Subsequent paragraphs elaborate on the key findings and place them in context
Thank you for your attention!
• Questions?
• If you would like an electronic copy of this presentation, you can download it here:
http://openwetware.org/wiki/Riggins_Lab• Under Resources, click ‘Lectures’
• Click ‘How to present a scientific paper’