Bio of Cancer

Homeostasis

Maintenance of a stable internal environment. At the tissue level, cell division, differentiation, and cell death are balanced to preserve normal structure and function.

Hyperplasia

Increase in the number of cells in a tissue. The cells generally retain normal appearance and tissue organization.

Metaplasia

Replacement of one differentiated cell type with another that is not normally found at that location.

Dysplasia

Abnormal cellular growth and differentiation, characterized by irregular nuclear appearance, increased mitotic activity, and disrupted tissue architecture. May precede cancer.

Neoplasia

Abnormal, relatively autonomous proliferation of cells producing a neoplasm. Can be benign or malignant.

Anaplastic

Describes tumor cells that have lost normal differentiated characteristics, making their tissue of origin difficult to identify microscopically.

Invasiveness

Ability of cancer cells to penetrate normal tissue boundaries and grow into surrounding tissues

Metastasis

Spread of malignant cells from the primary tumor to a distant location, where they establish secondary tumors.

-oma

Suffix indicating a tumor or mass. Often used for benign tumors, such as lipoma, but some malignant tumors also end in -oma, such as melanoma.

Carcinoma

Malignant tumor originating from epithelial cells.

Sarcoma

Malignant tumor originating from mesenchymal tissues such as bone, muscle, or connective tissue

Leukemia

Cancer involving blood-forming cells, typically affecting bone marrow and circulating blood.

Lymphoma

Malignancy of lymphocytes, often forming tumors in lymph nodes or other lymphatic tissues

Neuroectodermal tumors

Tumors originating from cells derived from neuroectodermal tissues.

Leiomyoma

Benign tumor of smooth muscle.

Myeloma

Malignancy of plasma cells, which normally produce antibodies.

Monoclonal cancer

Cancer originating from one ancestral transformed cell whose descendants accumulate additional changes

Polyclonal cancer

A tumor or cancerous population containing cells derived from more than one independently originating clone

Mutations

Changes in DNA sequence that may alter gene expression or protein function.

Somatic mutations

Acquired mutations occurring in non-germline cells during an individual's lifetime. Generally not inherited by offspring.

Inherited mutations

Germline mutations transmitted from a parent and present throughout the offspring's body.

Carcinogens

Agents that increase cancer risk through DNA damage or other cancer-promoting mechanisms

Virus

Infectious agent containing genetic material that replicates using host cells. Some viruses contribute to cancer, such as HPV.

Lifestyle

Behavioral or environmental exposures that influence cancer risk, such as tobacco use, alcohol consumption, and UV exposure

Tumorigenesis

Multistep process through which normal cells develop into tumor cells.

Point mutation

Change affecting a single nucleotide or nucleotide pair.

Frameshift mutation

Insertion or deletion of nucleotides not divisible by three, shifting the reading frame and often creating a premature stop codon.

Translocation

Chromosomal rearrangement involving transfer or exchange of genetic material between chromosomes.

Gene amplification

Increase in the number of copies of a gene, often resulting in increased protein production.

Autocrine

Cell releases a signaling molecule that acts on itself or nearby cells of the same type.

Paracrine

Signaling molecule acts on neighboring cells over a relatively short distance.

Endocrine

Hormone travels through the bloodstream to affect distant target cells.

Ectopic hormone

Hormone produced by a tissue or tumor that does not normally produce it.

Proto-oncogene

Normal gene that promotes regulated growth, division, or survival and can become oncogenic when activated abnormally.

Oncogene

Activated or dysregulated gene that promotes malignant transformation or uncontrolled growth.

Tumor suppressor

Gene whose normal function limits inappropriate proliferation, maintains genomic integrity, or promotes cell death.

Growth factor receptor

Protein that recognizes extracellular growth signals and initiates intracellular responses.

Receptor kinases

Receptors with kinase activity, such as receptor tyrosine kinases, that phosphorylate proteins after activation.

Signal transduction

Conversion of an extracellular or intracellular signal into a cellular response through molecular signaling events.

Signal transduction factors

Molecules that relay or regulate signaling pathways, such as Ras, RAF, MEK, and ERK.

Protein kinases

Enzymes that transfer phosphate groups from ATP to target proteins, changing their activity or interactions.

Transcription factors

Proteins that regulate transcription by binding DNA or interacting with transcriptional machinery.

RNA transcription

Synthesis of RNA using DNA as a template

RNA processing

Modifications to primary RNA transcripts, including splicing, 5′ capping, and polyadenylation in eukaryotic mRNA.

Gene expression

Production of functional RNA or protein from genetic information.

Control of gene expression

Regulation of when, where, and how much RNA or protein a gene produces.

Cell cycle

Ordered sequence of events through which a cell grows, replicates DNA, and divides: G1, S, G2, and M phases.

Cyclins/CDKs

Cyclins are regulatory proteins that activate cyclin-dependent kinases, which phosphorylate proteins controlling cell-cycle transitions.

G1/S checkpoint

Control point before DNA synthesis that helps prevent inappropriate entry into S phase.

G2/M checkpoint

Control point before mitosis that helps ensure DNA replication is complete and major DNA damage has been addressed.

Totipotent

Able to generate embryonic and extraembryonic tissues needed to form an entire organism.

Pluripotent

Able to generate cell types from all three embryonic germ layers, but not independently form an entire organism.

Multipotent

Able to differentiate into multiple related cell types within a restricted lineage. Example: hematopoietic stem cells.

Differentiation

Process through which cells acquire specialized structure and function.

Dedifferentiation

Process through which a differentiated or committed cell acquires a less specialized state or renewed developmental potential.

Stem cells

Cells capable of self-renewal and producing differentiated descendants.

Cancer stem cells

Subpopulation of cancer cells capable of sustained self-renewal and generating tumor cell populations, often implicated in recurrence and treatment resistance.