Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pathology A - General Pathology > [A] 1.72 Carcinogenesis (chemical and physical agents) > Flashcards

[A] 1.72 Carcinogenesis (chemical and physical agents) Flashcards

1
Q

Carcinogenesis/oncogenesis: Overview

A
  1. Origin is a non-lethal genetic change in the cell
  2. Neoplastic transformation → Inheritance by daughter cells
  3. Genetic damage in tissue stem cells (→ Immortalise)
  4. Monoclonal tumour cells can mutate further (Genetic heterogeneity)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

It is hypothesised in carcinogenesis/oncogenesis that…

A

The mutation of a cell is in the background

  • The tumour is monoclonal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Give the steps of carcinogenesis

A
  1. Initiation
  2. Promotion
  3. Progression
  4. Malignant cell population develops
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Carcinogenesis: Initiation phase

A
  • Mutation of a single cell
  • Proliferation ability increases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Carcinogenesis: Promotion phase

A
  • Reversible effects on cells
  • Rapid growth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Carcinogenesis: Progression phase

A
  • Initiated cell becomes malignant
  • Increased proliferation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Proper carcinogen

A

Able to induce all the steps of carcinogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Incomplete carcinogen

A

Initiator

  • Can trigger only the initiation phase of carcinogenesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Natural promotional effects initiating carcinogenesis

A
  • Oestrogen (Endometrial & mammary gland tumours)
  • Mediators of chronic inflammation (NFκB signal pathway)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

DNA mutation during carcinogenesis can be either…

A
  • Somatic / Germinal
  • Spontaneous / Induced
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

DNA damage can be induced by…

A
  • Chemical agents
  • Radiation/physical agents
  • Microbial agents
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Chemical carcinogens

A

Approximately 10 million exist

2 mechanisms:

  • Direct carcinogens
    • Without metabolic transformation
    • E.g Chemotherapeutic agents
  • Indirect carcinogens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Indirect carcinogenic agents can be caused by…

A
  • Metabolic transformation
  • Polycyclic carbohydrates
  • Aromatic amines
  • Plant & microbial metabolites
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Indirect carcinogenic cause: Metabolic transformation

A
  • Individual difference in the activity of CYP450
  • Individual sensitivity to chemical carcinogens
  • Carcinogenesis in dose and exposition time-dependent
    • Accumulation of small doses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Indirect carcinogenic agent: Polycyclic carbohydrates

A
  • Fossil fuels
  • Benzoprien: Tobacco burn, cooked animal fat, smoked meat
  • Epoxides: Covalent bond to DNA, RNA & proteins
  • Smoke & Tar
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Indirect carcinogenic agent: Aromatic amines

A

β-naphthol amines: Paint industry (bladder tumours)

17
Q

Indirect carcinogenic agent: Plant & microbial metabolites

A

Aflatoxin: Aspergillus flavus B1

(Hepatocellular carcinoma)

18
Q

Indirect carcinogenic agent: Other miscellaneous

A
  • Vinyl-chloride: Coolant
  • Hormones
  • Asbestos
  • Arsenic, nickel, chromium
  • Insecticides, fungicides, Biphenyl
  • Food preservatives
19
Q

Indirect carcinogenic agents: Mechanism of action

A
  • Damage to oncogens
  • Damage to tumor suppressor genes (E.g P53)
20
Q

What can increase the effect of indirect carcinogenic agents?

A

Promotors

  • Hormones
  • Phenols
  • Some drugs

Acting against the DNA-repair mechanisms

21
Q

Radiation & physical agents causing carcinogenesis

A
  • UV light
  • Radiation
  • Nuclear fission
  • Ionising radiation
22
Q

UV light as a cause of carcinogenesis

A
  • Melanoma - Intermittent, intensive exposure (sunbathing)
  • Basal cell & squamous cell carcinoma - Cumulative
  • Squamous cell carcinoma in animals
23
Q

Nuclear fission as a cause of carcinogenesis

A

Radionucleotides

  • Miners of radioactive elements - 10x more likely to get lung cancer
  • Hiroshima/Nagasaki atomic bomb/Chernobyl
    • Myeloid leukaemia
    • Thyroid gland carcinoma
    • Mammary gland carcinoma
    • Colonic carcinoma
    • Lung carcinoma
24
Q

Ionising radiation as a cause of carcinogenesis

A

E.g X-rays

  • Chromosome fragmentation
  • Translocation
  • Mutatuon
25
Q

UV rays as a cause of carcinogenesis

A

Nucleotide excision repair damage → Pirimidine dimers

Can induce further mutations

Pathology A - General Pathology (85 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions