6. Tumour Suppressor Genes (Retinoblastoma and the two hit hypothesis, p53)

The genes that are mutated in cancers can be divided into two groups - tumour suppressor genes and proto-oncogenes.

Tumour suppressor genes are genes that produce proteins that are involved in stopping mutated cells from dividing, and also act as the brakes on the cell cycle at its various checkpoints.

The retinoblastoma gene is a gene that is involved in stopping cells from crossing the G1 checkpoint in the cell cycle, preventing cells from entering S phase and replicating their DNA in preparation for cell division.

For the retinoblastoma gene to be rendered inactive, it needs a mutation in both of its copies (alleles). This is explained by the 'two hit hypothesis'.

P53 is another example of a significant tumour suppressor gene. It is active during the cell cycle, acting by halting damaged cells at the checkpoints and then ordering the cell to destroy itself by the process of apoptosis.

[nannasrensen]

Don't you mean that the tumor supressor genes are dominant? If you only need one working one? The tumor supressor-inactivating mutation must be the one that's considered recessive? Or am I just comfused?

[theoneh]

I have my exam in 2 days, and have struggled with getting my head around this for months. Thank you so much!!!

[dr.paddlesmack]

this is amazing. don't worry about some of the negative comments. this has definitely made my understanding a lot more clear

[guljafari]

thank you so much ... however I think the sniffing sound in the headphone gets a little irritating ...

[ilovepathologyVijayPatho]

you have really made this simple.! loved it

[dr.adilkhaliq]

very Impressive and perfect. Thank you for this effort.

[ldyelphinium]

do u mind adding captions? the video is very helpful but i cant understand some parts due to ur pronounciation

[joory_a]

Thank you very much for making this so so simple

loved the video! Every video has being more improved!!!!

[thirva]

Sir this cleared all my doubts, thank you :)

[emmayoung]

Dude sounds like Alan Davies. Thanks, i have a biochem exam tomorrow!

[cucuruto]

Hei dude, can you take subtitles english generation? That form stay easy to understand tks

[missyfford]

i have rb and currently undergoing radiothearapy to treat it (: mine is very rare as im 12 and i have it, when its usually found in babies!

[tinekerocks]

great video. Thank you for the review.

[Maryam]

Thanks for making it that simple =D
I'll definitely go check your other videos while I study Pathology

[fajitaboys]

Why are the tumor supressor genes recessive and not dominant if they both need to be mutated in order to be taken out and thus allow for cancer??

[dragomirflavius]

❤❤❤❤i have a test on this an you saved me

[workhard]

Have you watched Dr najeeb lectures, sounds like animated content of Dr najeeb videos.

[jaju]

RB protein is pRb right, whereas RB is just the gene? Diagram might have got that wrong I think, should say pRb rather than RB.

[enterURLhere]

that tumour was sitting in the backseat of the car and the car was driving backwards???