Cancer + Stem Cells

Vocabulary flashcards related to cell cycle, stem cells, and cancer.

G₁ Phase

Phase between M and S phase where the cell continuously grows.

G₂ Phase

Phase where energy stores are built up and proteins for mitosis and cytokinesis are produced.

M-Phase

Phase involving mitosis and cytokinesis lasting 1-2 hours. No interphase

S-Phase

Phase involving synapsis and duplication, lasting 24 hours. Longest phase

Cancer Therapy

Involves targeting CDKs with CDIs, and radio/chemo leading to cell death in both cancer and normal cells.

ESC (Embryonic Stem Cell) Cycle

Rapid cell division with a short G1 phase.

Stem Cell Properties

Ability to expand through self-renewal and differentiate.

Quiescent (G₀) Phase

Cells exit G1 phase to a quiescent state where they no longer proliferate; some cease division completely.

Checkpoints (G1)

Examine cell size, nutrients, molecular signals, and DNA integrity.

Checkpoints (G2)

Examine DNA integrity and replication.

CDKs

Power cell cycle and formed by cyclin D and CDK 4/6; phosphorylates Rb proteins.

CKIs (CDK Inhibitors)

Negative regulators and cancer treatment targets.

Symmetric Division

Division resulting in two daughter cells with stem characteristics.

Somatic Cells

Having a prolonged gap G0 phases, like hematopoietic stem cells.

IPSCs (Induced Pluripotent Stem Cells)

Reprogramming fibroblasts by inducing transcription factors like Oct4, Sox2, KLF4 and c-Myc

Mesenchymal Stem Cells (MSCs)

Quiescent in bone marrow and body fat; activation allows differentiation and migration to damaged tissues.

Homing capacity

Ability of MSCs to migrate to sites of tissue damage.

Hematopoietic Stem Cells (HSCs)

Quiescent in bone marrow, slow and no differentiation; regenerative for whole blood reconstitution. Can regenerate to hematopoietic cells

Retinoblastoma Protein (Rb)

Transcription factor, regulated by phosphorylation, blocks S-phase and cell growth.

p53 Protein

Transcription factor that halts division and triggers cell cycle arrest and apoptosis when most potent.

Asymmetric Division

Division resulting in one daughter with stem characteristics and one with differentiation.

Stem Cell Regulatory Network

Core set of transcription factors including KLF4, Myc, and LIN28.

Myc

Regulates cell expression.

LIN28

Regulates mRNA translation.

Totipotent

The ability to differentiate into any cell type.

Pluripotent (ESCs)

Cells from the blastocyst that can differentiate into almost any cell type.

iPSCs (Induced Pluripotent Stem Cells)

Genetically changed adult stem cells, such as induced pluripotent stem cells (iPSCs).

Multipotent

Limited differentiation within a specific lineage.

Unipotent

Can only differentiate into one cell type.

Limitations of Stem Cell Applications

Immunological rejection and ethical concerns involving the destruction of human embryos.

Cancer Stem Cells

Can lead to self-renewal and proliferation, resistance to treatment, tumorigenesis, metastasis, and tumor heterogeneity.

Origin of Cancer Stem Cells

De-differentiation from normal or cancer stem/progenitor cells or fusion of stem and cancer cells.

Cancer Cells Characteristics

Unlimited self-renewal, tumorigenic, dysregulated differentiation and less mitotically active.

Somatic Characteristics

Limited self renewal, regular differentiation, quiescent and organogenic