Key Points From Lecture: -some types of cancer have a high mortality rate, and for these cancers the incidence rates and mortality rates are usually linked (ie: a dip in one causes a dip in the other, etc).    -other cancers have lower mortality rates and the incidence rates may not be as closely linked as others (eg a sharp rise in incidence may not lead to a sharp rise in mortality).   -different cancers contribute to the total statistics more so than others (eg male prostate vs male lung cancer deaths)   -cells in our bodies respond to a variety of cues to balance cell fate decisions such as death vs survival and growth vs no growth.    -cancerous cells (as we will see in future lectures) typically find ways to circumvent the cues that would prevent a cell from improperly growing and/or circumvent death cues to remain immortal.

Key Points From Lecture: -Transcription is the process of converting DNA into RNA, which will later be used to build a polypeptide (aka protein) in a different process. While DNA is double stranded (mostly for structure) only one strand - known as the template strand - is read by an enzyme called RNA polymerase. This enzyme binds to the DNA of a gene at a promoter site and follows base pairing rules (As bind only to Ts, Cs only to Gs, etc.) to copy the DNA into a strand of RNA. Only a region of DNA sequence within a gene, known as the RNA coding region or RNA coding sequence is copied. The DNA is read in a specific direction, similar to how one reads left to right, and the RNA is copied over one base at a time. Note that RNA does not contain T, in place it uses U. This means that while DNA uses A, T, G, C bases RNA uses A, U, G, C bases.    -Translation is the process of converting an RNA sequence into a series of amino acids known as a polypeptide. An amino acid is a building block of polypeptides, containing a similar backbone structure, with a variable R group which can vary in properties (eg: hydrophilic or hydrophobic for water soluble vs water insoluble). An RNA strand - often referred to as mRNA at this point (m for messenger...since it is carrying information on how to build a specific protein) is sandwiched between two subunits or halves of a very complex machine known as a ribosome. The ribosome provides an area for molecules called tRNA to interact with the mRNA strand, 3 base pairs at a time; known as a codon. The tRNA both holds a single amino acid and has the capacity to interact with a codon of RNA. If the region on the tRNA known as an anticodon can form base pairs (using base pair rules) with a codon on the mRNA strand then it will contribute the amino acid it is holding. If not then another  tRNA will attempt to form base pairs until one matches. There is one tRNA for every codon in the genetic code. As tRNAs progressively form base pairs to the RNA strand they will build a longer and longer polypeptide, one amino acid at a time.  Once finished (ie all of the RNA has been read by the ribosome and tRNA the polypeptide will bunch up or assemble or "fold" into a fully functional protein.

allele One of two or more alternative forms of a single gene. Different alleles of a gene each have a unique nucleotide sequence, and their activities are all concerned with the same biochemical and developmental process, although their individual phenotypes may differ. amino acids The building blocks of proteins. There are 20 different amino acids. angiogenesis Development of a blood supply to a tissue. apoptosis Programmed cell death. Regulated process involving cell deterioration and ultimately its destruction. base pairs Two complementary nucleotide bases joined together by chemical bonds. benign Refers to a tumour that contains cells which closely resemble normal cells. Benign tumours are characteristically contained by the basal lamina. cancer Diseases characterized by the uncontrolled and abnormal division of eukaryotic cells and by the spread of the disease (metastasis) to disparate sites in the organism. carcinogens Several natural and artificial agents, mostly chemicals and types of radiation, that increase the frequency with which cells become cancerous. cell division A process whereby one cell divides to produce two cells. chromosome The genetic material of the cell, complexed with protein and organized into a number of linear structures. It literally means "colored body," because the threadlike structures are visible under the microscope only after they are stained with dye codon A group of three adjacent nucleotides in a RNA molecule that specifies either one amino acid in a protein chain or the termination of protein synthesis. deletion (deficiency) A chromosomal mutation resulting in the loss of a segment of the genetic material and the genetic information contained therein from a chromosome. deoxyribonucleic acid (DNA) A polymeric molecule consisting of deoxyribonucleotide building blocks that in a double-stranded, double-helical form is the genetic material of most organisms. dominant An allele or phenotype that is expressed in either the homozygous or the heterozygous state. E-cadherin A protein that is found on the cell surface and is important for adhering cells together. enzyme A protein that facilitates a biochemical reaction in a cell. frameshift mutation A mutational addition or deletion of a base pair in a gene that disrupts the normal reading frame of an RNA, which is read in groups of three bases. gene The determinant of a characteristic of an organism. Genetic information is coded in the DNA, which is responsible for species and individual variation. A gene’s nucleotide sequence specifies a protein or RNA and is subject to mutational alteration. genetic code The base-pair information that specifies the amino acid sequence of a protein genotype The complete genetic makeup of an organism growth factor A protein that must be present in the extracellular environment (culture medium or animal body) for the growth and normal development of certain types of cells. heparan Structure which surrounds normal cells and helps to hold tissue together heparanase Enzyme which degrades heparan. heterozygous A term describing a diploid organism having different alleles of one a gene. homozygous A term describing a diploid organism having the same alleles of one a gene. malignant Refers to a tumour that invades normal surrounding tissues and/or undergo metastasis metastasis The spreading of malignant tumor cells throughout the body so that tumors develop at new sites. mutagen Any physical or chemical agent that significantly increases the frequency of mutational events above a spontaneous mutation rate. mutant allele Any alternative to the wild-type allele of a gene. Mutant alleles may be dominant or recessive to wild-type alleles. N-CAM Neural cell adhesion molecule, a protein that is found on the cell surface and is important for adhering cells together. nitrogenous bases A nitrogen-containing base that, along with a sugar and a phosphate, is one of the three parts of a nucleotide, the building block of RNA and DNA. nucleic acid One of the family of molecules which includes the DNA and RNA molecules. nucleotide A subunit of RNA and DNA that consists of three distinct parts: a sugar (ribose in RNA, deoxyribose in DNA), a nitrogenous base, and a phosphate group. oncogene A gene whose action promotes cell proliferation. Oncogenes are altered forms of proto-oncogenes. pedigrees Simple diagrams of a family's genealogy that shows family members' relationships to each other and how a particular trait or disease has been inherited. phenotype The observable properties of an organism that are produced by the genotype and its interaction with the environment. plasmin A type of proteinase. plasminogen Inactive form of plasmin. Converted to active form by plasminogen activator. protein One of a group of high-molecular weight, amino acid-containing compounds of complex shape and composition. proteinase Enzyme which breaks down other proteins. recessive An allele or phenotype that is expressed only in the homozygous state. regulatory proteins Proteins active in the activation or repression of transcription of the gene. replication The process of making an identical copy of a section of duplex (double-stranded) DNA, using existing DNA as a template for the synthesis of new DNA strands retroviruses Single-stranded RNA viruses that replicate via double-stranded DNA intermediates. The DNA integrates into the host’s chromosome where it can be transcribed. ribonucleic acid (RNA) A usually single-stranded polymeric molecule consisting of ribonucleotide building blocks. RNA is chemically very similar to DNA. RNA performs an essential role in protein synthesis (translation). somatic mutation A mutation that occurs in a somatic cell (in multicellular organisms). The mutant characteristic affects only the individual in which the mutation occurs, and is not passed on to the succeeding generation. telomere Specific structure at the end of chromosomes. Protects chromosomes from loss and degradation. telomerase Protein/enzyme which forms and maintains telomeres. thrombospondin An inhibitor of angiogenesis. transcription Formation of RNA from a DNA template. transfection Experimental introduction and expression of foreign DNA in cells. translation Production of a protein from RNA. tumour A mass that forms within otherwise normal tissue, caused by the uncontrolled growth of a transformed cell. tumour suppressor genes Genes in normal cells that encode products that suppress uncontrolled cell proliferation. VEGF Vascular endothelial growth factor, an inducer of angiogenesis.