cell biology

• ch15 EMS
• Stem cells


  Cells able to make an animal (embryonic stem cells) or make and replenish a tissue (adult stem cells)
• Stem cell differentiation


  1. Stem cell

  2. Proliferating precursor cells

  3. Terminally differentiated cells
• Types of stem cells

  • Embryonic stem cells
  • Adult stem cells
• Embryonic stem (ES) cells

  • Totipotent- They can generate all of the tissues of the body
• Adult stem cells


  • Multipotent-They can generate several tissues
  • Unipotent-generate one type of tissue
• Where embryonic stem cells come from

  1. Early embryo (blastocyst)

  2. Inner Cell Mass (ICM) cells develop into the fetus

  3. Trophoblast: feeder cells that provides support for the ICM cells
• Blastocyst


  Early developing embryo that is just a few days old
• Generating embryonic stem (ES) cells

  1. Culture cells with different growth factors

  2. Regenerated blastocyst in a culture dish

  3. Culture cells under specific conditions

  4. Blastocyst placed in foster mother

  5. New organism
• Cells generated from ES cells

  • Beating heart cells
  • Neuronal cells
• Regenerative medicine


  Using stem cells to treat diseases like Parkinson's, Alzheimer's, diabetes, muscular dystrophy, immunodeficiency disorders
• Significant problems for therapeutics using ES stem cells are ethical issues and immune system rejection
• Generating stem cells by nuclear transfer


  1. Remove and discard the nucleus of the oocyte

  2. Replace it with nucleus of an adult somatic cell

  3. Early embryo placed in foster mother

  4. Cloned organism

  
• Induced pluripotent stem (iPS) cells


  Mature cells can be reprogrammed to become pluripotent
• Adult stem cells


  • Hematopoietic stem cells
  • Epidermal stem cells
• Cancer is a serious health threat, with high incidence and mortality rates
• Major types of cancer

  • Carcinoma
  • Sarcoma
  • Lymphoma and leukemia
  • Germ cell tumor
  • Blastoma
• Development of cancer (carcinoma)

  1. Cell migration

  2. Dividing cells in basal layer

  3. Penetrate underlying tissue

  4. Further mutation and ability to invade
• Development of cancer - Invasion and Metastasis

  1. Cancer cells invade surrounding tissues and blood vessels

  2. Cancer cells are transported by the circulatory system to distant sites

  3. Cancer cells reinvade and grow at new location
• Cancer cell migration in a blood vessel can be visualized directly in living animals
• Melanoma cells can travel through the bloodstream to the liver and brain, making cancer fatal
• Characteristics of cancer cells

  • Reduced dependence on signals for growth
  • Proliferate indefinitely
  • Genetically unstable – increased mutation rate
  • Abnormally invasive
  • Avid for nutrients
  • Survive and proliferate in abnormal localizations
• Cancer is fundamentally a genetic disease caused by accumulation of mutations
• Cancer cells often have highly abnormal chromosomes, reflecting genetic instability
• Oncogenes


  Genes that encode proteins that function to promote cell growth, invasion and proliferation
• Tumor suppressor genes


  Genes whose expression suppress cancer
• What causes cancer


  1. Inherited from parents

  2. Errors that occur as cells divide

  3. Damage to DNA caused by chemicals, radiations, virus or bacteria infection
• Standard cancer treatments


  • Surgery
  • Chemotherapy
  • Radiation therapy
  • Immunotherapy
• Immunotherapy


  Anti-PD-1 and anti-PD-L1 antibodies that interrupt the immunosuppression mediated by the PD-1/PD-L1 pathway
• Content and format of final exams