Cancer Cell Biology and Genetics Review

Vocabulary flashcards based on lecture notes covering the biology, genetics, clinical statistics, pharmacology, and mechanisms of programmed cell death (apoptosis) in cancer.

Cancer (ACS Definition)

A group of diseases characterized by uncontrolled growth and spread of abnormal cells.

Hallmarks of Cancer

Six biological capabilities acquired during the multistep development of human tumors, including loss of growth control and evading the immune system.

Contact Inhibition

A property of normal cells where they stop growing once they form a monolayer; this property is lost in cancer cells.

Anchorage Independence

The ability of cancer cells to grow without being attached to a solid surface or plastic tissue-culture dish.

Hayflick Limit

The finite capacity of normal human and animal cells to undergo a limited number of cell divisions.

Bevacizumab (Avastin)

A $VEGF$ antagonist that binds to vascular endothelial growth factor and prevents it from interacting with receptors ($Flt-1$ and $KDR$) on endothelial cells.

Dedifferentiation

The loss of normal specialized cell features, often observed as a microscopic property of cancer cells.

Mutagenic compounds

Carcinogenic chemicals that are either directly mutagenic or converted to mutagenic compounds by cellular enzymes to cause $DNA$ damage.

HPV E6 Protein

A protein from the human papillomavirus that inhibits the $p53$ tumor suppressor.

HPV E7 Protein

An oncogene product of human papillomavirus that inhibits the Retinoblastoma ($Rb$) tumor suppressor.

HPV E5 Protein

A protein from the human papillomavirus that causes sustained activation of the $PDGF$ receptor, leading to enhanced proliferation.

Tumorigenesis

A multistep process involving multiple mutations and genetic instability, the risk of which increases with the age of the person.

Tumor Suppressor Genes

Genes that encode proteins that restrain cell growth and prevent malignancy when present.

p53 (TP53)

A cellular stress sensor and transcription factor that ensures $DNA$ integrity; mutations in this gene account for $50\%$ or more of all human cancers.

Retinoblastoma (Rb) Protein

A tumor suppressor that binds to transcription factor $E2F$; its phosphorylation by $CDK4/6$-cyclin $D1$ allows the cell to transition from $G1$ to $S$ phase.

Proto-oncogene

A normal cellular gene encoding a protein involved in the regulation of cell growth or differentiation.

Oncogenes

Mutant forms or excessive quantities of proto-oncogenes that promote loss of growth control and acting as accelerators of cell proliferation.

Imatinib (Gleevec)

A small molecule drug that blocks the $ATP$ binding site of the tyrosine kinase active site for targets such as $Bcr-Abl$, $c-Abl$, $c-Kit$, and $PDGFR$..

Trastuzumab (Herceptin)

A monoclonal antibody and $HER2$ receptor antagonist that binds to $HER2$ on the cell surface and induces receptor internalization.

Epigenetic Alterations

Acquired changes like $DNA$ methylation and histone modifications that affect gene expression without altering the $DNA$ sequence.

Cancer Stem Cells

Cells capable of self-renewal and aberrant differentiation that are responsible for initiating and sustaining tumor growth.

Circulating Tumor Cells (CTCs)

Cells shed from a primary tumor into the blood or lymph, used as a "liquid biopsy" to reveal metastasis in action.

CellSearch System

The only $FDA$ cleared methodology for the enumeration of $CTCs$ in whole blood; unfavorable results are defined as $>5\,CTC/7.5\,mL$ for breast/prostate or $>3\,CTC/7.5\,mL$ for colon cancer.

Necrosis

Passive cell death resulting from gross injury or tissue damage, marked by cell swelling and the release of cellular contents.

Apoptosis

Programmed cell death actively driven by the cell, marked by shrinking, membrane blebbing, and fragmentation into apoptotic bodies.

Caspases

$C$-terminal Aspartic Acid Proteases known as the "executioners" of apoptosis.

Bcl-2 Family

A group of proteins that includes pro-apoptotic members ($Bax$, $Bad$) and anti-apoptotic members ($Bcl-2$, $Bcl-xl$).

Venetoclax (Venclexta)

A selective inhibitor of the anti-apoptotic protein $BCL-2$ used to treat chronic lymphocytic leukemia ($CLL$) and restore the apoptotic process.

BCL-2 Mutation

B-cell lymphoma

CYCD1 Mutation

Carcinoma of breast

NEU/HER2 Mutation

Adenocarcinoma of breast, ovary, and stomach

H-RAS Mutation

Carcinoma of colon, lung, and pancreas; melanoma

K-RAS Mutation

Acute myeloid and lymphoblastic leukemia; carcinoma of thyroid; melanoma

N-RAS Mutation

Carcinoma of GI tract and thyroid

Cyclin D1 Proto-oncogene

Proteins that control cell cycle

Bcl-2 Proto-oncogene

Proteins that affect apoptosis

Ras Proto-oncogenes

Protein kinases or proteins that activate protein kinases

PDGF Proto-oncogene

Growth factors

HER2 Proto-oncogene

Growth Factor Receptor

MYC Proto-oncogene

Transcription factors

RB Function

Tumor suppressor gene that binds E2F to prevent retinoblastoma

p53 Function

Transcription factor (cell cycle and apoptosis)

BRCA1 Function

TRanscription factor, DNA repair in double-stand breaks