Cancer Biology and Molecular Genetics

Comprehensive vocabulary flashcards covering cancer pathology, molecular biology of DNA/RNA, and genetic mutation mechanisms based on lecture transcripts.

Neoplasm

A tumor, an abnormal mass of cells within tissue without physiological function.

Benign Tumor

Tumor remains within confined location and tissue of origin, slow-growing, and well differentiated (such as warts).

Malignant Tumor

Cells that spread, leaving tissue of origin and breaking free from original mass, often via the bloodstream, more haphazard and chaotic, and poorly differentiated.

Metastases

A malignant tumor that has traveled elsewhere in the body and formed a new mass, competing with other healthy tissue; also known as secondary tumors.

Metazoic Organism

A multicellular organism.

Carcinoma

Cancers that arise from epithelial cells, which are the most common and responsible for most deaths.

Sarcoma

A non-epithelial cancer that arises from connective tissue.

Leukemia

A non-epithelial cancer that arises in cells responsible for producing blood; this cancer does not produce a typical mass or tumor.

Lymphoma

A non-epithelial cancer that occurs in immune organs and immune-system tissue, deriving from B cells and T cells.

Neural Cancer

Cancers that arise from cells of the nervous system, which are difficult to cure.

Anaplastic Tumors

Dedifferentiated cancerous cells that have lost all identification, making it difficult for a pathologist to identify their origin.

Genomic Heterogeneity

Different mutations such as small nucleotides, polymorphisms, insertions, and rearrangements within a tumor.

Epigenetic Heterogeneity

Different methylation and acetylation patterns between the same genes.

Nucleic Acids

Molecules composed of C, O, H, N, and P, consisting of nucleotides that have a nitrogen base, pentose sugar, and a phosphate group.

Purines

Adenine and Guanine, which are large 2-ring bases.

Pyrimidines

Cytosine, Thymine, and Uracil, which are smaller 1-ring bases.

Phosphodiester Bond

A covalent bond where polymerases synthesize to connect nucleotides together to create nucleic acid.

Watson-Crick Model

The model of complementarity where Adenine pairs with Thymine and Guanine pairs with Cytosine.

Base Stacking

A force in base pairing where the hydrophobic base orients itself to the inside of the molecule to avoid exterior water while the phosphate group is hydrophilic.

Anti-Parallel Strands

Strands inverted so that horizontally $5'$ matches across from $3'$ and $3'$ matches across from $5'$, allowing replication to be bi-directional ($5'$ to $3'$).

Semi-conservative Replication

The process where both resulting DNA strands contain half of the parent strand.

Topoisomerase

An enzyme that relaxes the tightening region of DNA as the strand is pulled tighter while being unraveled.

Replication Protein-A

Coats ssDNA to protect exposed bases, prevent annealing, keep separation, and signal replication.

Primase

An RNA polymerase that forms RNA primers, which are the starting pieces for building nucleic acid to begin DNA synthesis.

DNA polymerase $\alpha$

The enzyme that begins synthesizing the new DNA strand before falling off.

DNA polymerases $\delta$ and $\epsilon$

Enzymes that take over and synthesize the rest of the DNA strand, aided by Proliferating Cell Nuclear Antigen.

DNA Replication Bubbles

Places where the MCM complex has removed hydrogen bonds, separating DNA into two strands.

Leading Strand

The daughter strand synthesized continuously in the direction of the MCM complex.

Lagging Strand

The daughter strand synthesized in pieces in the opposite direction of the MCM complex.

Ribosomal RNA (rRNA)

A type of RNA needed to form ribosomes for protein synthesis.

Small Nuclear RNA (snRNA)

RNA needed for pre-mRNA splicing and ligation.

TATA Box

A promoter region for RNA synthesis with the sequence $5'-TATA(A/T)A-3'$.

Enhancers

Regulatory elements that increase the level of transcription.

Antisense Strand

The strand of DNA that the RNA strand binds to; also called the Template Strand or non-coding Strand.

Sense Strand

The strand of DNA that is NOT read by the RNA; also called the Non-Template Strand or Coding Strand.

Introns

DNA sequences that do not code for proteins.

Exons

DNA sequences that contain protein coding information.

5'-Cap

A 7-methylguanosine cap added to the $5'$ end of mRNA through a $5'$ to $5'$ linkage for recognition and protection.

Poly(A) Tail

A long string of adenine residue added to the $3'$ end, needed for mRNA to leave the nucleus and for protection.

AUG

The start codon which codes for Methionine.

Stop Codons

UAA, UAG, and UGA, which signify the termination phase of translation.

Chaperones

Proteins that help newly synthesized proteins fold into active proteins.

Aggregate

A nonfunctional, misfolded polypeptide that is very dangerous to the cell.

Mutagens

Any substance that promotes unwanted changes in DNA sequence, classified as endogenous (internal) or exogenous (external) threats.

Silent Mutation

A base-pair substitution that results in no change in the amino acid.

Missense Mutation

A non-silent mutation that results in a change in amino acids.

Nonsense Mutation

A non-silent mutation that produces a stop codon, resulting in a truncated protein.

Frameshift Mutations

Insertions or deletions that effectively destroy a gene because all downstream codons are altered.

Reciprocal Translocation

A mutation where breaks occur in 2 different chromosomes and genetic material is mutually exchanged.

Ploidy

The number of sets of chromosomes in a cell.

Aneuploidy

Cells that do not contain a multiple of 23 chromosomes.

Oncogenes

Tumor-causing genes.

Tumor Suppressor Genes

Genes that code for proteins that dampen cell division or promote DNA repair, balancing proto-oncogenes.

Two-Hit Hypothesis

The theory that both alleles of a tumor suppressor gene must be mutated or inactivated to cause cancer.

Driver Mutations

Mutations that directly influence transformation, typically affecting tumor-suppressor genes or proto-oncogenes.

Passenger Mutations

Have no direct influence on tumorigenesis

Robertsonian Translocation

Short arms (p-arms) of 2 different chromosomes are lost and remaining long arms fuse to form a single chromosome