Neoplasia Flashcards
What is parenchyma?
Gives rise to neoplastic cellular component
What is stroma?
Gives rise to the supportive cellular component (skeleton) upon which parenchyma resides
Malignancy in parenchyma =
Carcinoma
Malignancy in stroma =
Sarcoma
Benign tumor of mesenchymal origin?
Fibroma or lipoma
Malignant tumor of mesenchymal origin?
Fibrosarcoma or liposarcoma
Benign tumor of epithelial lining of glands/ducts?
Adenoma, papilloma, cystadenoma
Malignant tumor of epithelial lining of glands/ducts?
Adenocarcinoma, papillary carcinoma, cystadenocarcinoma
Describe mixed tumor
Can be benign or malignant… come from ONE germ cell layer (but have more than one type of neoplastic cell type)
Describe teratoma
More than one neoplastic cell type from MORE THAN ONE germ cell layer
How do tumor cells get their start?
They are all derived from the same single founding transformed cell (its a stem cell)
(comes to clinical attention after it has already divided many times)
4 types of regulatory genes affected in cancers
- Growth-promoting proto-oncogenes
- Growth-inhibiting tumor suppressor genes
- Genes regulating apoptosis
- DNA-repair genes
What does DNA methylation do?
Silences gene expression
What does histone modification do?
Either enhances or dampens gene expression
PDGF-b chain
POG: PDGFB
MoA: Overexpression
Astrocytoma
Fibroblast growth factors
POG: HST1
MoA: Overexpression
Osteosarcoma
Fibroblast growth factors
POG: FGF3
MoA: Amplification
Stomach, Bladder, Breast cancer + melanoma
TGF-a
POG: TGFA
MoA: Overexpression
Astrocytoma
HGF
POG: HGF
MoA: Overexpression
Hepatocellular carcinoma + thyroid cancer
EGF receptor family
POG: ERBB1 (EGFR)
MoA: Mutation
Adenocarcinoma of lung
EGF receptor family
POG: ERBB2 (HER)
MoA: Amplification
Breast carcinoma
ALK receptor
POG: ALK
(2 MoAs)
MoA: Translocation, fusion gene formation
Adenocarcinoma of lung, lymphomas
MoA: Point mutation
Neuroblastoma
GTP-binding proteins
KRAS, NRAS, HRAS, GNAQ, GNAS
POG: KRAS
MoA: Point Mutation Colon, lung and pancreatic tumors 90% pancreatic adenocarcinomas/cholangiocarcinomas 50% colon cancers 30% lung adenocarcinomas
POG: HRAS
MoA: Point Mutation
Bladder and kidney tumors
POG: NRAS
MoA: Point Mutation
Melanomas and hematologic malignancies
30% myeloid leukemias
POG: GNAQ
MoA: Point Mutation
Uveal melanoma
POG: GNAS
MoA: Point Mutation
Pituitary adenoma and other endocrine tumors
Nonreceptor TK
POG: ABL
(2 MoAs)
MoA: Translocation
CML
MoA: Point Mutation
ALL
RAS signal transduction
POG: BRAF
MoA: Point Mutation/translocation
Melanomas (60%), leukemias, colon carcinoma, others
100% hairy cell leukemias
What is BRAF?
Serine/threonine protein kinase sitting atop cascade of other serine/threonine kinases of MAPK family
Function of hedgehog pathway?
Major path transmitting info to embryonic cells for proper differentiation
Pathologies linked to hedgehog pathway?
- Holoprosencephaly and cyclopia
- Many cancers
Cancers associated w/ hedgehog pathway?
- BCC (most common cancer dx)
- Brain
- Lung
- Mammary gland
- Prostate
- Skin
Mechanism of development of hedgehog cancers?
- Adult stem cells transformed into cancer stem cells
Relationship of WNT to HH?
Signal transduction pathways that are similar, but distinct from HH
Cancers associated w/ Beckwith-Wiedemann syndrome?
- Wilms tumor
- Hepatoblastoma
- Pancreatoblastoma
- Adrenocortical tumors
- Rhabdomyosarcomas
What 2 pathways are medulloblastomas associated with?
- WNT and SHH
Transcriptional activators
POG: MYC
MoA: Translocation
Burkitt’s lymphoma
Transcriptional activators
POG: NMYC
MoA: Amplification
Neuroblastoma
What does MYC do?
Activates many genes involved w/ cell growth
- It is rapidly and transiently induced by RAS/MAPK
Function of CDK; D cyclins
Phosphorylates RB, thus allowing it to progress through G1
Function of CIP/KIP (p21 and p27)
Block cell cycle by binding CDK-cyclin complexes
What induces p21?
p53
What does p27 respond to?
Growth suppressors, like TGF-b
Function of INK4/ARF family (CDKN2A-C)
specifically INK4
p16/INK4 binds cyclin D-CDK4 and promotes inhibitory effects of RB
Function of INK4/ARF family (CDKN2A-C)
specifically ARF
p14/ARF increases p53 levels by inhibiting MDM2 activity
What does RB do?
Binds E2F Tfs in hypophosphorylated state (PREVENTS G1-S transition)
What does p53 do?
- Acts via p21 to arrest cell cycle
- Induces apoptosis by inducing transcription of pro-apop. genes (BAX)
- MDM2 negatively regulates via feedback loop
- Required for G1-S transition
APC
Adenomatous polyposis coli protein
Fxn: Inhibitor of WNT signaling
Familial: familial colonic polyps and carcinomas
Sporadic: stomach, colon, pancreas carcinoma + melanoma
NF1
Neurofibromin-1
Fxn: Inhibitor of RAS/MAPK signaling
Familial: Neurofibromatosis 1 (neurofibromas and malignant peripheral nerve sheath tumors)
Sporadic: neuroblastoma, juvenile myeloid leukemia
NF2
merlin
Fxn: cytoskeletal stability and Hippo signaling pathway
Fam: Neurofibromatosis 2 (acoustic schwannomas and meningiomas)
Sporadic: Schwannoma and meningioma
PTCH
patched
Fxn: Inhibitor of HH signaling
Fam: Gorlin syndrome (BCC, MB, several benign tumors)
Sp: BCC, MB
PTEN
phosphatase and tensin homologue
Fxn: Inhibitor of PIK3/AKT signaling
Fam: Cowden syndrome (variety of benign skin, CNS, GI growths + breast, endometrial and thyroid carcinomas)
Sp: Diverse cancers (carcinomas and lymphoid tumors)
SMAD2, SMAD4
Fxn: Component of TGF-b signaling pathway (repressors of MYC and CDK4 exp. and inducers of CDK inhibition)
Fam: Juvenile polyposis
Sp: Colonic and pancreatic carcinomas
RB
Fxn: Inhibitor of G1/S transition
Fam: familial retinoblastoma syndrome (retinoblastoma and osteosarcoma)
Sp: retinoblastoma, osteosarcoma and carcinomas of lung, colon, breast
CDKN2A
p14/ARF and p16/INK4
Fxn: p14 is indirect activator of p53 and p16 is negative regulator of CDK
Fam: familial melanoma
Sp: pancreatic, breast and esophageal carcinoma
VHL
von Hippel Lindau protein
Fxn: Inhibitor of hypoxia induced Tfs (HIF1a)
Fam: Von Hippel Lindau syndrome (cerebellar hemangioblastoma, retinal angioma, renal cell carcinoma)
Sp: RCC
CDH1
E-cadherin
Fxn: Cell adhesion, inhibition of cell motility
Fam: familial gastric cancer
Sp: gastric carcinoma and lobular breast carcinoma
TP53
Fxn: cell cycle arrest and apoptosis d/t DNA damage
Fam: Li-Fraumeni
Sp: almost all cancers
BRCA1/BRCA2
Fxn: repair of ds-DNA breaks
Fam: familial breast/ovarian carcinomas, male breast cancer + chronic lymphocytic leukemia (BRCA2)
MSH2, MLH1, MSH6
Fxn: DNA mismatch repair
Fam: hereditary nonpolyposis colon carcinoma
Sp: colonic and endometrial carcinomas
WT1
Fxn: Tf
Familial Wilms tumor
MEN1
menin
Fxn: Tf
Multiple Endocrine Neoplasia-1 (PT, pituitary and pancreatic tumors)
How is normal cell cycle regulation lost?
Loss of one of 4 key regulators:
- p16/INK4
- Cyclin D
- CDK4
- RB
How does HPV harm RB?
E7 binds Rb, not allowing E2F to bind Rb, thus E2F is able to cause cell cycle progression
Where is p53 located?
17p13.1
Where is RB located?
13q14
Cancers with wild-type p53?
- Testicular teratocarcinomas
- Childhood ALL
Cancers with mutated p53?
- Lung and colorectal cancers
How does HPV harm p53?
E6 binds p53 and causes its degradation
Most common cancers in Li-Fraumeni?
- Sarcomas
- Breast cancer
- Leukemias
- Brain tumors
- Carcinomas of adrenal cortex
What’s interesting about cancers associated with WT1?
- in Wilms tumor, WT1 acts as tumor suppressor (thus it is down regulated in Wilms tumor)
- in leukemias and breast cancers, it is overexpressed (acting as a proto-oncogene here)
- d/t changes in epigenetics
Translocation for CML?
(9;22)(q34;q11)
Gene for CML?
ABL 9q34
BCR 22q11
Translocation for AML?
(8;21)(q22;q22)
15;17)(q22;q21
Translocation for Burkitt lymphoma
(8;14)(q24;q32)
Translocation for mantle cell lymphoma
(11;14)(q13;q32)
Translocation for follicular lymphoma
(14;18)(q32;q21)
What do microRNAs (miRs) do?
Mediate sequence-specific inhibition of mRNA translation via RNA-induced silencing complex
What do long noncoding RNAs do?
Modulate gene expression
DNMT3A gene
Fxn: DNA methylation
Tumor: AML (20%)
MLL1 gene
Fxn: histone modification
Tumor: AL in infants (90%)
MLL2 gene
Fxn: histone modification
Tumor: Follicular lymphoma (90%)
CREBBP/EP300
Fxn: histone acetylation
Tumor: diffuse large B cell lymphoma (40%)
ARID1A
Fxn: Nucleosome positioning/chromatin remodeling
Tumor: Ovarian clear cell carcinoma (60%) and endometrial carcinoma (30-40%)
SNF5
Fxn: Nucleosome positioning/chromatin remodeling
Tumor: malignant rhabdoid tumor (100%)
PBRM1
Fxn: Nucleosome positioning/chromatin remodeling
Tumor: renal carcinoma (30%)
HTLV-1
- T cell leukemia/lymphoma
Encodes Tax protein, which turns on pro-survival pathways (PI3K/AKT, NFKB) leading to polyclonal T cell expansion
EBV
Burkitt lymphoma, B cell lymphomas in T-cell immunosuppressed pts.
*also nasopharyngeal carcinoma (China/Africa)
HBV and HCV
- hepatocellular carcinomas d/t chronic inflammation and hepatocellular injury
MCV (Merkel cell polyomarvirus)
- Merkel cell carcinoma (skin cancer)
HHV-8
Kaposi sarcoma
H pylori
Gastric adenocarcinoma and MALT lymphomas
Cushing syndrome associated cancers
- Small cell carcinoma of lung
- Pancreatic carcinoma
- Neural tumors
- via ACTH
SIADH associated cancers
- Small cell carcinoma of lung
- Intracranial neoplasias
- via ADH or ANP
Hypercalcemia
- Squamous cell carcinoma of lung
- Breast carcinoma
- Renal carcinoma
- Adult T-cell leukemia/lymphoma
- via PTHRP, TGFa, IL-1
Hypoglycemia
- Ovarian carcinoma
- Fibrosarcoma
- Mesenchymal sarcomas
- via insulin
Polycythemia
- Renal carcinoma
- Cerebellar hemangioma
- Hepatocellular carcinoma
- via erythropoietin
Myasthenia
- Bronchogenic carcinoma
- Thymic neoplasms
- Immunologic
Acanthosis nigricans
- Gastric carcinoma
- Lung carcinoma
- Uterine carcinoma
- Immunologic/EGF
Hypertrophic osteoarthropathy/clubbing of fingers
- Bronchogenic carcinoma
- Thymic neoplasms
- Unknown cause
DIC
- Acute promyelocytic leukemia
- Prostate carcinoma
- tumor factors activating clotting
Venous thrombosis
- Pancreatic carcinoma
- Bronchogenic carcinoma
- Tumor products (mucins activating clotting)
HCG associated cancers
- Trophoblastic tumors, nonseminomatous testicular tumors
Calcitonin associated cancers
- Medullary carcinoma of thyroid
Catecholamine and metabolites associated cancers
- Pheochromocytoma
a-fetoprotein associated cancers
- Liver cell cancer
- Nonseminomatous germ cell tumors of testicle
Carcinoembryonic antigen associated cancers
- Carcinomas of colon, pancreas, lung, stomach and heart
Prostatic acid phosphatase associated cancers
- Prostate cancer
Neuron-specifc enolase associated cancers
- Small cell cancer of lung
- Neuroblastoma
Igs associated cancers
- Multiple myeloma and other gammopathies
CA-125 mucin associated cancers
Ovarian cancer
CA-19-9 mucin associated cancers
Colon, pancreatic cancers
CA-15-3 mucin associated cancers
Breast cancer
TP53, APC, RAS mutants in stool/serum
Colon cancer
TP53, RAS mutants in stool/serum
Pancreatic cancer
TP53, RAS mutants in sputum and serum
Lung cancer
TP53 mutants in urine
Bladder cancer
What are tumor markers best used for?
- Detecting recurrences
- lack specificity and sensitivity for early detection