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Slackers Guide to Hematologic Cancers. Mike Ori. Disclaimer. These represent my understanding of the subject and have not been vetted or reviewed by faculty. Use at your own peril. I can’t type so below are common missing letters you may need to supply e r l
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Disclaimer • These represent my understanding of the subject and have not been vetted or reviewed by faculty. Use at your own peril. • I can’t type so below are common missing letters you may need to supply • e r l • I didn’t use greek letters because they are a pain to cut and paste in.
Evasion of apoptosis • Insensitivity to anti-growth signals • Self sufficiency of growth signals • Limitless replication potential • Sustained Angiogenesis • Tissue invasion and metastasis
It is the observation that cancer cells rely more heavily on glycolysis than on oxidative phosphorylation even in the presence of adequate oxygen supplies. Thus it is believed that the glycolysis is better suited to meet the metabolic demands of cancer cells.
What is epigenetics • List a few epigenetic mechanisms in the cell
Epigenetics refers to reversible but inheritable changes in gene expression that occur without mutations. Examples include • Methylation • Histone acetylation • Both examples limit the access of promoter regions to their respective promoters.
miRNA are small (~22bp) RNA strands that function at the post transcriptional level to silence specific genes. Each miRNA may interact with multiple genes and thus can serve as an off switch post transcriptionally. • Some oncogenes control the expression of miRNA.
DNA replications “spell checker”. It makes sure A-T and G-C go together.
P53 is a tumor suppressor gene. • It activates DNA repair genes • It can arrest the cell cycle at G1/S checkpoint • It can initiate apoptosis
An epithelial growth factor receptor whose gene is amplified in 25% of breast cancers. • Self-sufficiency in growth signals
Trastuzumab is a monoclonal antibody directed against her2/neu/Erb b2. • It functions by binding to and disrupting erb b2
BCR-ABL is a unique protein that from t(9:22) translocation that results in the fusion of the BCR promoter to the ABL tyrosine kinase in such a way that the kinase no longer requires a ligand for activation. • ABL is a proliferative kinase that is active in hematopoietic cells
B-catenin is a cell proliferation enzyme that is sequestered by APC. • The deletion of one APC allele causes familial adenomatouspolyposis, an autosomal dominant condition that predisposes to colon cancer in early adulthood • Mutations in APC can lead to attenuated colon cancer forms
Follicular • Expansion of B cells • Paracortical • Expansion of T cells • Sinus histiocytes • Surgical drainage
What is the common gene involved with lymphoma translocation
DNA cleavage is an important part of maturation of immune cells. This presents opportunity for abnormal joining.
Translocations • Inherited • Downs, neurofibromatosis • Viruses • HTLV, EBV, HHV-8 • Environmental agents • Iatrogenic • Radiation
Lymphocytic leukemias evolve to lymphomas late. Similarly, lymphomas may transform into lymphocytic leukemias.
Common indolent lyphoma • Back to back follicles • T(14:18) BCL-2 • Anti-apoptotic • May transform into diffuse large cell lymphoma
Large round lymphocytes • Alterations in BCL-6 • Germinal center formation disrupted
Rapidly aggressive lymphoma • T(8:14) c-myc oncogene • Association with EBV • Starry sky pattern due to histiocytes
Associated with MALT in gut • Chronically inflamed tissue • H. pylori • Indolent but may transform to diffuse B-cell
Common cancer of young adults • Orderly progression from local nodes to spleen to liver to bone marrow • Reed-sternberg cells
T cell lymphoma • CD4+ • Band like infiltrates in dermis • Flat erythematous rash -> plaques -> tumor nodules • TX with local control early • Sezary syndrome • Widespread rash • Blood and lymph node involvement • Poor prognosis
Granulocytes • Neutrophils • Eosinophils • Basophils • Monocytes • Erythrocytes • Megakaryocytes