4.1/2 APPLIED LEC Flashcards
kinetochore vs non kinetochore microtubules
- kinetochore microtubules attach to the kinetochore regions of centromeres and will separate chromosomes during mitosis
- non-kinetochore microtubules create a cage like network to open up and elongate the cell
laser beam experiment
researchers fluorescently labelled dna and microtubules separately and photobleached a section of the microtubules to visualize how microtubules shorten. First image shows metaphase- photobleached microtubules and connected chromosomes
second image: shows anaphase: where proteins of centromeres have been broken down and sister chromatids separate
hypothesize that photobleached area will remain as microtubules shorten.
Photobleached area remains showing microtubules shorten at one end on the kinetochore side (the poles) of the cell
how do microtubules move chromosomes
kinetochore motor proteins attach to and pull microtubule through them, tubulin sub units come out the other end and can be recycled.
Johnson and Rao cell fusion experiment
fused cells at different mitotic phases to see if certain cellular cues influenced the other cell
- fused cell in mitotic phase and interphase and observed interphase chromosomes thickening, meaning there is a cellular cue in the mitotic cell communicating to the interphase cell to elicit that response
Markert and Masui microinjection experiment
injected M phase cytoplasm into interphase cell and noticed the formation of centromeres and mitotic spindles
in injecting interphase cytoplasm into the another interphase cell, the cell stayed in interphase (CONTROL)
conclude that mphase cytoplasm must have m phase regulatory molecules that induce m phase in interphase cells
cancer in the cell cycle and canadian stats
knowledge of cell cycle helps our understanding of uncontrolled cell division in cancer
cancer is leading cause of death in canadians
- ASIR (age-standardized incidence rate) and ASMR (age-standardized moratlity rate) suspected to decrease slightly (increase in liver, intrahepatic bile duct cancer, kidney cancer, melanoma, and non-Hodgkin
lymphoma)
cancer journey
prevention - screening - diagnosis - treatment - survivorship/ recovery OR end of life care
also: psychosocial or palliative care
characteristics of cancer cells
- abnormally shaped nuclei
- divide abnormally and disorganized, faster and uncontrolled
- different size and shape of cell
- loss of normal cellular features
- unregulated cell cycle and checkpoints are disrupted
limited growth vs cancer cells
normal cells will only grow one layer covering the petri dish, when they reach the parameter, their growth is stunted in whats known as density dependant inhibition
normal cells also anchor themselves to the base of the petri dish. if scientists scraped away some of the cells the remain cells with divide and fill in the gap, then stop dividing
cancer cells have unlimited growth, and divide much beyond one layer, forming a clump of cells. Cancer cells have no density dependant inhibition. Cancer cells don’t exhibit anchorage dependance.
stages of cancer
stage 1- tumour is small and hasn’t grown out of the organ it started in
stage 2- tumour hasn’t spread to nearby tissues, and is larger than in stage one
stage 3 - tumour is large and has spread to nearby tissues and lymph nodes
stage 4 - tumour has spread through blood or lymphatic system to distant site in the body
chemotherapy drugs
vincristine:
-extract from rosy periwinkle
taxol:
- extract from pacific yew tree bark
- ecological concerns because when bark is removed tree dies and ecosystems are effected
both: anti microtubule agents that inhibit microtubule formation and stops mitosis, disrupting uncontrolled cell division
steve jobs legacy
- 1955 - 2011
- mac products
- rare pancreatic cancer
- had his whole genome sequenced
- led to identification of Pim1 biomarker for rare pancreatic cancer
- led to developments in comparing therapies, the knowledge for Afinitor chemotherapy used to treat pancreatic cancer
- advancements in pancreatic cancer immunotherapy which allows seeks out and kills cancer cells
cancer research in hamiltion
juravinski cancer centre
CAR-T cell therapy
approved by health Canada in 2018, in use at clinics
Dr. Ronan Foley of Juravinski cancer center: says this treatment is a new care approach for patients who cannot undergo chemotherapy, radiation and surgery.
How CAR-T cell therapy works
- harnesses bodys own immune system
- extract t cells of patients from blood
- make CAR-T cells in lab
- grow millions
- infuse CAR-T cells into patient
- CAR-T cells bind to and kill cancer cells
major advancement in immuno-based cancer strategies
alcohol and cancer
- ethanol in alcohol is broken down into acetaldehyde which is toxic and if accumulates (body cant break it down fast enough, too much ingested) can cause dna damage and lead to cancer (bowel cancer)
- consuming large amounts of alcohol can cause circulating oestrogen levels to rise, which can lead to breast cancer in women because of dna damage, increased cell division and rearrangement, and abnormal development
- alcohol can act as a solvent, other carcinogens can be more easily absorbed by the body and leads to mouth, throat, and esophageal cancers
