Chemo cycle # 7

Today is the day of my penultimate cycle of chemotherapy. I was moved from Mondays to Tuesdays because of the bank holiday. I had tried to get back on Mondays but the chemo nurse was rather, um, anal in this matter - I used to believe I was the Queen of Anal Behaviour before that, she made me look like a complete amateur. Not that it matters much of course. I have to admit that I'm not looking forward to today. I'm not that bothered about the treatment per se, and I'm quite sure the side effects will not be too bad. I simply hate the place. On top of that I'm fully aware that I'm reaching the end of chemotherapy and my mind is getting very impatient, which means I find being pragmatic more and more difficult. I want it to end. Still, in three weeks time I'll getting the last lot and that will be the worst over as far as overall treatment goes, hopefully. Obviously I'm not looking forward to surgery either but at least there'll only be the one of that.



I managed to overdo it last week again and I haven't quite recovered yet. I went to see The Last King of Scotland - very good film, Forest Whitaker was worryingly convincing as Amin but some of the scenes, notably the torture, were simply impossible to watch as far as I was concerned. Then filled with the happiness of being out of the house I decided to go shopping. I got home, had to go and lie down and that's more or less how I've spent the past four days. I had planned to go for a blood test - yes, my silly blood count was again low last week - and/or go and see Miss Potter - mainly for the Lake District scenery, which I love (photo of me above Rydal Water below taken in June 2006) - yesterday but I couldn't do either. Thankfully we're able to see some of the Australian open on the BBC so I've been able to enjoy this from the comfort of my bed.






The weight is now definitely on the way up. The main culprits are likely to be the steroids and/or the chemo drug as they're the main things to have changed recently and the kilos have only piled on since starting them. I'm not particularly fussed - there's nothing I can do about it. The only problem is trousers - it's getting to that point where it's a choice between wearing jeans/trousers and breathing. That's when you know you've lost the battle. My 'hair', on the other hand, is growing reasonably quickly. I've done a bit of reading on the topic and it will probably take up to six months for my hair to be back to normal. At least it's not growing back grey and I'm still waiting to see whether it will be curly/wavy. It looks very thin and even though there's a reasonably large amount of it I'm not sure how it'll look. I'm getting quite impatient - typical - and I'm debating whether to dye it red with one of those dyes that washes out easily. A sort of midlife crisis if you want.



And now for my first instalment of Nerdy Corner. I've kept it simple - my brain can't cope with anything too demanding - but I can never guarantee that I'm making sense. I'm adding visual aids for those who just want to skip this part.



*** NERDY CORNER ALERT ***



Chemo drugs target rapidly dividing cells by targeting, among other things no doubt but in my case, enzymes and other proteins involved in the cell cycle. Very broadly speaking (and purists can cut me some slack here) the cell cycle can be divided into two stages:



1. DNA replication - Because a cell gives rise to two daughter cells the DNA needs to be duplicated so that each daugther cell gets a full copy of all the genes of a particular organism.



2. Cell division - Here the two sets of DNA are segregated at opposite poles of the cell and the nucleus is then divided in two. This results in the formation of two daughter cells.

Both stages are highly regulated and if problems occur mechanisms are in place to trigger cell suicide and prevent errors to be transmitted to daughter cells. This of course is only valid in the case of healthy cells. Cancer cells somehow managed to bypass the control mechanisms and replicate despite such errors.



Right, I've been subjected to three chemo drugs, administered in two times four cycles in the following way:



1. Adriamycin (also known as doxorubicin) and cyclophosphamide - These drugs effectively prevent DNA replication by binding to an enzyme called topoisomerase II. When DNA is being replicated it needs to be unwound and separated for the process to take place. In turn this leads to increased tensions in other areas and generates coils and supercoils (sorts of loops) in the DNA, making replication much more difficult. Topoisomerase II removes these coils by cutting both strands of DNA, allowing them to rotate and sealing the DNA strands again. Adriamycin and cyclophosphamide, however, bind to topoisomerase II once it has cut the strands, thereby stabilising it and preventing it from sealing the strands again. This leads to the cell's inability to replicate its DNA and cell suicide follows.


2. Taxotere - This drug affects the stage of cell division but also leads to cell suicide. Once the DNA has been replicated, what is known as the mitotic spindle forms. This enables the segregation of chromosomes at opposite poles of the cell and is made of microtubules, themselves formed of tubulin (a type of protein) segments, which run along the length of the cell in a number of 'strands'. The movement of chromosomes along the microtubules depends on two mechanisms: motor proteins and the microtubules themselves. Basically Taxotere inhibits microtubule function. Microtubules are in what is called dynamic instability - tubulin is constantly being added and removed from the microtubules, and it is this process which generates force/movement (don't ask me to elaborate this bit). Taxotere binds to the microtubule-bound tubulin and prevents it from being removed. This in turn leads to an accumulation of microtubules within the cell and an inappropriate supply of tubulin. This ultimately triggers the beginning of cell suicide. A less important function of Taxotere is the blocking of the bcl-2 oncoprotein which prevents cell suicide from occuring. More on this when I tackle the genetics of cancer - something for you all to look forward to.

*** END OF NERDY CORNER ***

I hope this has made a little sense at least. If not please let me know. And now it is time for me to go and get prepared for my long day - I can't avoid the blood test today, which means a very long day lies ahead. I hope you are all well and I'll leave you with my current favourite song: 'Where's ya moped, where's ya moped, where's ya moped Petr Cech? Where's ya moped, Petr Cech?'