Molecular Medicine

Dr Catherine Flynn

Consultant Haematologist

St James’s Hospital

October 22nd 2009

Molecules

DNA mRNA ProteinTranscription Translation

Cell CycleStem Cells/ Quiescence

Do different cancer stem cells have the same Achilles' heel ???

Molecules… at the bench…..

DNA mRNA ProteinTranscription Translation

Micro array

SNP

Proteomics

Short Inhibitory RNA

………….To The Bedside• What is the biology of acute myeloid

leukaemia?

• What is the best treatment for chronic myeloid leukaemia?

• Which Patient should have a transplant?

Haematopoiesis

Morphology

Karyotype

Molecular Diagnostics

Leukaemia Diagnosis

• Modify Diagnosis

• Counsel patient and family better re prognosis

• Recommend specific treatment

DNA mRNA Protein

Symptoms and Signs Laboratory Findings

Haematopoiesis

Leukaemia

• An Acquired Cancer– (rare inherited leukaemias reported)

Differentiation Arrest

Mutations disrupt genes controlling Proliferation

uncontrolled growth of an immature clone of cells

Hematology 2007;2007:509-520

Model of leukaemogenesis with two cooperating classes of mutations

Risk Factors?

Frohling S and Dohner H. N Engl J Med 2008;359:722-734

Structure of a Human Chromosome

Frohling S and Dohner H. N Engl J Med 2008;359:722-734

Chromosomal Abnormalities in Human Cancer

Acute Myeloid Leukaemia

Abnormalities seen in at least 50 %of cases

Karyotype is of major prognostic significance

Used in planning treatment

Acute Myeloid Leukaemia

Favourable Intermediate Poor

t(8;21) AML1/ETO

Normal Karyotype

Complex karyotype ( >3)

inv(16) inv(3) or t(3;3)

t(15;17)

Survival from CR by MRC Cytogenetic Risk Group

100

75

50

25

0

FavourableIntermediate Poor

0 1 2 3 4 5

Years from randomisation

68%

44%

18%2P <0.00001

% s

till

ali

ve

Similar results in SWOG/EGOG study (Slovak et al, 2000 ) and CALGB (Byrd et al, 2002)

Karyotypic Normal AML

• "Should I recommend an allogeneic stem-cell transplant, or not?"

Graft versus Leukaemia/ Potential Cure

Toxicity/Mortality

Copyright ©2007 American Society of Hematology. Copyright restrictions may apply. Maslak, P. ASH Image Bank 2007;2007:7-00028

Figure 2. Cells with multiple Auer rods (arrow) may be appreciated

Acute Promyelocytic Leukaemia (APML)

Copyright ©2009 American Society of Hematology. Copyright restrictions may apply.

Lazarchick, J. ASH Image Bank 2009;2009:8-00163

Figure 1. A "faggot" cell present on the peripheral smear from a patient with acute promelocytic leukemia is shown

Myeloid Maturation

Differentiation Arrest in APML

Licht J. N Engl J Med 2009;360:928-930

Countering PML/RARα with All-trans Retinoic Acid

RARα

PML

Encourages Self Renewal

Blocks differentiation

The karyotype of patients with Acute Myeloid Leukaemia can be helpful. PML/RARα translocation is found in AML called acute promyelocytic leukaemia (APML). This fusion

protein……….

is re

spons

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is c

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20% 20% 20%20%20%A. is responsible for the

response to Retinoic Acid/ATRA

B. is caused by a translocation between chromosomes 15 and 19

C. is associated with a poor outcome

D. predicts age of onsetE. is only seen in the elderly

Chronic Myeloid Leukaemia

A Paradigm for Malignancy

2 3 4 51

7 8 9 10

11 126

13 14 15 16 17 18

The Philadelphia Chromosome

Philadephia Chromosome

The Ideal Target for Molecular Therapy

Present in the majority of patients with the disease

Determined to be the causative abnormality

Has unique activity that is

- Required for disease induction

- Dispensable for normal cellular function

Courtesy of BJ Druker, MD

Bcr-Abl as a Therapeutic Target for CML

Bcr-Abl is detected in 95% of patients with CML

Bcr-Abl is the causative abnormality of CML

Bcr-Abl tyrosine kinase is constitutively activated

intracellularly

Tyrosine kinase activity is required for CML cell

function

Abl null mice are viable

(From Novartis Pharma)

(C(C3030HH3535NN77SOSO44))

NN

NN

NN

HH

NN

HH

NNNN

NN

OO

NN

Imatinib mesylateImatinib mesylate (STI571 - Glivec(STI571 - Glivec®®))

Goldman J and Melo J. N Engl J Med 2001;344:1084-1086

Mechanism of Action of STI571/Glevec/Imatinib

Goldman, J. M. et al. N Engl J Med 2003;349:1451-1464

Signal-Transduction Pathways Affected by BCR-ABL

Druker B et al. N Engl J Med 2006;355:2408-2417

Kaplan-Meier Estimates of the Cumulative Best Response to Initial Imatinib Therapy

Chronic Myeloid Leukaemia

Janet Rowley Receives Presdential Medal of Freedom August 2009

Chronic Myeloid Leukaemia

STI 571/Gleevec/Imatinib was developed in the late 1990s to treat CML.

Its mode of action is in ………

DNA m

ethyl

atio

n

Cel

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kinas

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Pro

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iffer

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20% 20% 20%20%20%A. DNA methylation

B. Cell cycle arrest

C. Tyrosine kinase inhibitor

D. Protein destruction

E. Inhibition of cell differentiation