A25 - Carcinogenesis (biological agents)

Question 1

What is carcinogenesis?

Answer 1

It is the process where normal and healthy cells transform into cancer cells - The tumour will form.

Include something called Neoplastic transformation

Question 2

What is Neoplastic transformation ?

Answer 2

It is a process which carcinogenic chemical, oncogenic viruses or radiation change the genotype and phenotype of the cell, making the cell able to form progressively growing tumours

Neoplastic transformation has 4 steps

Question 3

Name the 4 steps of Neoplastic transformation

Answer 3

1. Initiation
2. Promotion
3. Progression
4. Malignant cell poopulation

The two first steps can be reversible !!
Proper carcinogenic agents will induce of all the steps. Incomplete carcinogenic agents, called iniciator, can trigger the initiation phase only

Question 4

What is initiation?

Answer 4

The mutation of one single cell and the proliferation ability increases

Question 5

What is the promotion?

Answer 5

The reversible feects ont he cells will fasten the growth

Question 6

What is progression?

Answer 6

Initiated cell becomes malignant and we see an increases proliferation

Question 7

What is malignant cell proliferation?

Answer 7

The tumour will develop and proliferate further

Question 8

Name some natural promotional agents

Answer 8

1. Oestrogen: Causing mammary gland tumours

2. Mediators of chronic inflammation: The induce the promotion and progression in case of initiated cells

Question 9

What is meant by biological agents?

Answer 9

Bacteria, viruses, fungi and parasites which produces carcinogenesis

Question 10

Fungi, as biological agent

Answer 10

The mycotoxins are hepatotoxic in high doses, most importantly the Aspergillus flavus B1 aflatoxin

Question 11

Plants, as biological agents

Answer 11

The Eagle fern can cause chronic bleeding and inflammatgion in the bladder, which can be transformed into neoplastic diseases. In chronic cases it can develop into papilloma or carcinoma

Question 12

Viruses, as biological agents

Answer 12

In the host there is a protooncogenic activity, due to the viral induction, the protooncogenic activity increases and there will be an uncontrolled oncoprotein prodiction induced due to the viral exposition - Leading to cell prolfieration, typically caused by Retroviruses

Question 13

Parasites, as biological agents

Answer 13

1. Spirocerca lupi: Will induce granulomas, and if NOT killed, the granulomas will be a chronic effect to the esophagus and theu can develop into soft tissue granulomas and is already a malignant turmour

2. Eimeria stiedae: If the parasite is not killed, can lead to biliary papillomatosis (Seen in rabbits)