Normal haemopoiesis

ABNORMALITIES IN THE HEMOPOIETIC SYSTEM CAN LEAD TO HEMOGLOBINOPATHIES HEMOPHILIA DEFECTS IN HEMOSTASIS/THROMBOSIS HEMATOLOGICAL MALIGNANCY

MUTATIONS AND DNA VARIOUS TYPES OF MUTATIONS CAN OCCUR LEADING TO DISEASE PHENOTYPE POINT MUTATIONS INSERTIONS OR DELETIONS TRANSLOCATIONS COMPLEX CHROMOSOMAL REARRANGEMENTS

EXAMPLE OF COMMON MUTATIONS IN HUMAN DISEASE

Sickle cell disease

Sickle cell disease, morphology and molecular

VARIABILITY IN GENETIC DISEASES ONE DISEASE, ONE GENE, ONE MUTATION ONE DISEASE, ONE GENE, MANY MUTATIONS ONE DISEASE, MORE THAN ONE GENE, MANY MUTATIONS

HAEMOPHILIA X LINKED RECESSIVE DISORDER HAEMOPHILIA A – MUTATIONS IN FACTOR VIII GENE HAEMOPHILIA B – MUTATIONS IN FACTOR IX GENE SIMPLE AND COMPLICATED MUTATIONS THE FLIP TIP MUTATION

F8A E1 E22 E23 E26 F8A E1 E22 E23 E26 TEL CEN TEL INVERSION 22 E1E22E23 E26 A B C FIGURE 4 THE IVS 22 MUTATION IN HAEMOPHILIA A. F8B

Genetic factors and deep vein thrombosis FACTOR V LEIDEN MUTATION PROTHROMBIN MUTATION ? OTHER FACTORS IN THE PROTEIN C PATHWAY FVL LEADS TO SIGNIFICANT INCREASE IN RISK OF DVT, PARTICULARLY IN ASSOCIATION WITH OTHER ENVIRONMENTAL FACTORS EG OCP

CANCER DEVELOPMENT: ITS IN THE GENES

HOW DOES A CELL BECOME TUMORIGENIC? THREE PROCESSES ARE INVOLVED IMMORTALISATION TRANSFORMATION METASTASIS

IMMORTALISATION PROCESS BY WHICH THE CELLS ARE INDUCED TO GROW INDEFINITELY

TRANSFORMATION CELLS ARE NOT CONSTRAINED IN TERMS OF GROWTH CHARACTERISTICS AND TEND TO BECOME FACTOR INDEPENDENT

METASTASIS CANCER CELLS GAIN THE ABILITY TO INVADE NORMAL TISSUE AND ESTABLISH OTHER FOCI OF MALIGNANCY

WHAT CAUSES CELL TRANSFORMATION? ENVIRONMENTAL CARCINOGENS(INITIATORS AND PROMOTERS) GENETIC SOMATIC MUTATIONS MENDELIAN INHERITANCE

ONCOGENES NORMAL CELLULAR COUNTERPARTS(PROTO- ONCOGENES) MUTATION/ACTIVATION LEADS TO TUMOR FORMATION HUNDREDS OF ONCOGENES IDENTIFIED GAIN OF FUNCTION

Tumour suppressor genes Originally known as recessive oncogenes Need to have both copies of the gene affected to promote a malignant phenotype Knudsons 2 hit hypothesis First mutation makes cells susceptiple to development of cancer 2 nd hit leads to a malignant phenotype

TRANSLOCATIONS AND CANCER SEEMS PARTICULARLY RELEVANT IN HEMATOLOGICAL MALIGNANCIES CHRONIC MYELOID LEUKEMIA ACUTE PROMYELOCYTIC LEUKEMIA BURKITTS LYMPHOMA NON HODGKINS LYMPHOMA

Leukaemia, the current hypothesis Defect in maturation of white blood cells May involve a block in differentiation and/or a block in apoptosis Acquired genetic defect Initiating events unclear Transformation events involve acquired genetic changes Chromosomal translocation implicated in many forms of leukaemia

Chronic Myeloid Leukaemia Malignancy of the haemopoietic system Transformation of the pluripotent stem cell 9;22 translocation giving rise to the Philadelphia (Ph’) chromosome Creation of a leukaemia specific mRNA (BCR- ABL) Resistance to apoptosis, abnormal signalling and adhesion Molecular diagnostics Molecular and cellular therapeutics

Cytogenetic Abnormality of CML: The Ph Chromosome xY

The Ph Chromosome: t(9;22) Translocation 22 bcr abl Ph ( or 22q-) bcr-abl FUSION PROTEIN WITH TYROSINE KINASE ACTIVITY 9 9 q+

Prevalence of the Ph Chromosome in Haematological Malignancies Leukaemia% of Ph+ Patients CML95 ALL (Adult)15–30 ALL (Paediatric)5 AML2 Faderl S et al. Oncology (Huntingt). 1999;13:

bcr-abl Gene and Fusion Protein Tyrosine Kinases Adapted from Melo JV. Blood. 1996;88: p210 Bcr-Abl p185 Bcr-Abl 2-11 Chromosome 9 c-bcr Chromosome 22 c-abl Exons Introns CML Breakpoints ALL Breakpoints

NON HODGKINS LYMPHOMA B CELL FOLLICULAR LYMPHOMA t(14;18)(q21;q14) BCL 2 AND IMMUNOGLOBULIN GENES INVOLVED DYSREGULATION OF BCL 2 FAILURE OF APOPTOSIS

Detecting Cancer – where to begin?

Detecting cancer, the need for a marker of disease

Detecting Cancer – different markers for different diseases?

Cancer Molecular Diagnostics – discriminating cancers at the gene level

How Cancer Molecular Diagnostics? Chromosome analysis Gene analysis Gene expression analysis Protein analysis Gene chip analysis

Leukaemia diagnostics Morphology Cytogenetics Fluorescent In Situ Hybridisation (FISH) Immunophenotyping PCR of chromosomal translocations

New developments in Cancer Molecular Diagnostics The Gene Chip

The Gene Chip, a Molecular snap shot of the cell

MOLECULAR MEDICINE A new approach to medicine New Diagnostics New Therapeutics A number of agents now in clinical trials Molecular medicine will help identify new targets and permit rational drug development