INTRO TO LEUKEMIA Flashcards
▪ a disease of the blood-forming tissues, predominantly the bone marrow
LEUKEMIA
• adults:
bone marrow
• children or newborns who develop early leukemic stages:
liver and spleen
▪ a malignant neoplasm characterized by disorderly (different maturation stages affected or arrested), purposeless (unwanted/unneeded response), and uncontrolled proliferation of one or more of the hematopoietic cells (due to gene mutation/oncogene activation and other factors affecting uncontrolled wbc production)
LEUKEMIA
▪ mutation of gene at a certain stage of [?] in a cell cycle
DNA encoding
▪ also caused by [?] in a cell cycle
low or inhibition or regulatory cells/substances
: regulates or suppresses activity of mutated gene/s or cells
▪ regulatory substances
: key regulators for cell proliferation
• p27 and p53
- very low levels or defective: mutated gene are allowed to proliferate
• p27 and p53
- leads to genetic mutation leading to leukemia
• p27 and p53
: master control during the transition stage of a primitive precursor cell until maturation
▪ GATA2
: arrests/halts cell maturation on a blast stage
• GATA2 mutation
: • causes the normal cells to be cancerous when mutated
Proto-oncogenes
Proto-oncogenes
• functions to encode proteins which stimulates:
- cell division
- cell differentiation
- cell death (minimized or inhibit if unnecessary)
• normal gene controlling essential cell functions such as signaling pathways, cell proliferation, differentiation, and apoptosis that, on mutation, may become an oncogene
Proto-oncogenes
• group of genes that causes the normal cells to become cancerous when mutated
Proto-oncogenes
Oncogene
• upon activation: exhibits increased production of an encoded protein which causes
- increased cell division
- decreased cell differentiation
- inhibition of cell death (apoptosis)
No cell death occurs with blast cells, allowing proliferation; no elimination of abnormal cells
Oncogene
Oncogene e.g.,
DNMT3A
MEIS1
(proto-oncogene; caused by viral infection)
DNMT3A
(oncogene; triggers leukemia)
MEIS1
• viruses have the capability to carry their own oncogene and mutating it to an individual’s proto-oncogene to their oncogenes with the use of triggers
MEIS1
- viruses integrate their RNA to our cells (nucleus) and their oncogene causes our proto-oncogene to become oncogene
MEIS1
IMPLICATED/ASSOCIATED CONDITIONS
- HEREDITY/GENETIC
- CHROMOSOMAL ABNORMALITY/CONGENITAL FACTORS
- CHEMICAL AGENTS
- IONIZING RADIATION ]
- VIRUSES
- IMMUNOLOGICAL DEFECTS
- NEOPLASIA
▪ All lines of the offspring may inherit the gene and demonstrate leukemia decelopment
- HEREDITY/GENETIC
- CHROMOSOMAL ABNORMALITY/CONGENITAL FACTORS Examples:
• Trisomy 21
• Philadelphia (Ph) chromosome
• Chromosome 8 and 14 arm defects
: most popular
- Ph1 chromosome
ch22 abnormality
- Ph1 chromosome
some part of ch9 is transferred to ch22 (modification)
- Ph1 chromosome
usually seen mostly in CML and sometimes in ALL
- Ph1 chromosome
- CHEMICAL AGENTS
benzene
chloramphenicol
most widely known to depress bone marrow
benzene
antibiotic with major side effects or reversible bone marrow depression, aplastic anemia, and leukemia
chloramphenicol
▪ used in chemotherapies to kill cancer cells
- IONIZING RADIATION
• not specific (usually systemic) and kills healthy cells thus aggravating the leukemic condition of a patient
- IONIZING RADIATION
▪ implicate the leukemic condition of a patient due to their mode of replication
- VIRUSES
• integrates their viral RNA causing the mutation or activation of proto-oncogene into oncogene in an infected individual
- VIRUSES
▪ most known virus to trigger leukemia
• Epstein-Barr virus (EBV)
• Human T-lymphotropic virus (HTLV) - HTLV-I - HTLV-II
▪ breakdown (decreased capacity) of the immunosurveillance that normally keeps neoplastic growths, aggravating the leukemic condition
- IMMUNOLOGICAL DEFECTS
▪ usually seen in acute lymphocytic leukemia (ALL = prone to viral infections) and lymphoma
- IMMUNOLOGICAL DEFECTS