Heritability of Cancer

Last year, one of my professors made the statement that "You cannot inherit cancer". This seems very contradictory to what I grew up with; most cancer patients I've met have a family history of cancer, which is also why I am pretty sure I'll get it one day, between the prevalence on either side of my family and the frequent exposure to carcinogens.

The truth of the statement tends to be easier to grasp once you go down into developmental biology. Cancer at its root is the unregulated growth of cells. This is a stark contrast to development, which is the process of a highly specific differentiation of cells. Starting from a relatively spherical egg, a human being begins to form "front-sides" and "back-sides", ending up with different organs, which contin highly specialized cells types: nerve cells, skin cells, muscle cells, etc. Without regulation, not only will there be too many cells, the functions that is needed for survival of a human would no arise. If an individual can proceed through development without trouble, then there must have been changes that occurred after the germ cells left the two parents.

So why are descendent of people with cancer are more likely get cancer themselves? It is because of the high amount of genetic mutations that need to occur before a cell becomes cancerous. Without a whole slew of these mutations, cells are not cancerous. So someone can pass on a lot of these mutations, but until the individuals obtain more mutations, s/he will not have cancer.

This entry, and I'm suspecting the next, will be describing some of the mutations necessary.

First off, comes telomeres. Telomeres are a bunch of repeating nucleotides, the building blocks of DNA, at the end of strands of DNA. At first it seems that they are relatively useless, as they do not code for any functions - TTAGGG, TTAGGG, TTAGGG, so on and so on. They can't be read to make proteins, which provide most of the functions of a cell. It turns out, when DNA is replicated, in one direction, the cell machinery can read all the way through, but in the other, the machinery needs to start and stop all the time. Everytime it starts, it needs some preformed short fragments of nucleic acids, RNAs, from which the additional DNAs can attach to. After replication, the machinery goes along and replace all the RNA fragments with DNA. One downfall of this technology is that it needs DNA pieces of the other side of the fragment in order to replace the RNA. The last bits of RNA will be by themselves, and will not be able to replace to DNA, before they are just chewed up and destroyed. So everytime new cells are formed, their DNA becomes just a bit shorter. At some point, the "useless" DNAs are gone, and every time a cell replicates, it starts losing bits of genetic information that are necessary for the functions of the cell. These changes can be to imoprtant for the survivals of the cell, or in some cases, gives just enough damage that it'll push the cell towards being cancerous. One thing that a potential cancer cell will need to do is somehow stop this limit (See Hayflick limit) on the amount of replications a cell can undergo before it stops being able to survive. To accomplish this, they need to borrow technology from one of the few cell types that are constantly dividing - germ line cells.

With the Hayflick limit, each cell can usually undergo 40~60 divisions before stopping division, but humans definitely had more than 60 generations. It is because germ lines, embryonic stem cells, immune cells, and a few rare others have an enzyme called telomerase that would reverse the effect of the shortening DNA by adding more TTAGGG sequences back into the code. The gene that encodes for this enzyme is in all cells, but it is only active in a few rare ones. Without being able to reactivate this gene, even the most potent mutations, the mutated cells will eventually die off.

Welcome post for David

As you might have noticed, the last entry was posted by our guest David. Lifted directly off his profiles, he describes himself as "... a cancer patient advocate who cares very much about the well-being of people not only diagnosed with cancer but also their families and those who are in remission. We can beat this disease together. Keep up the fight".

He has asked to post about a few things regarding the benefits of support groups and physical exercise, and how they affect both patients and loved ones alike. I am very glad for his initiative, as cancer has always been a big story in my life.

As a result of this, I'll be tackling cancer from a scientific (mostly biochemical) perspective, and hopefully the synergistic nature of this will lead to some interesting readings. I'll planning on posting on Wednesday, with potentially an unrelated updates on the weekends. Until then, take care of yourself and your loved ones, and I hope you'll enjoy what's to come =).

How Much Does Exercise Benefit Cancer Patients?

It has long been proven that more active adults are less likely to develop health problems over time; exercise and physical activity every day can lower the risk of developing immune diseases, heart attacks, and other complications from aging. But can exercise also affect those who have just been diagnosed with cancer or who are in remission from it? Recent research suggests that yes, healthy, active adults are much less at risk for developing certain kinds of cancers than others and that regular exercise for patients undergoing treatment and after treatment ends can have positive effects on the health as well.

While the link between exercise and rare cancers like malignant mesothelioma hasn’t been explored as extensively, the link between exercise and colorectal, breast, and endometrial cancers have been reported on. Specifically in regards to colon cancer, physical activity has been known to positively affect metabolism, insulin regulation, and energy in active adults.

According to one study by The National Cancer Institute, exercise has been found to be beneficial for cancer survivors after treatment. The effects of exercise after treatment and into recovery for these common cancers has been positive, with many patients who are physically active being much less likely to have a recurrence or to die from complications afterwards.

Maintaining a healthy lifestyle after diagnosis is important in regards to quality of life. The benefits to the body are numerous, as well as benefits to one’s emotional state and self-perception. Exercise can improve mood, reduce fatigue brought on by treatment, and generally bolster self esteem as recovering patients become stronger again. All of these things can influence how a patient recovers and lives during and after major illnesses.

Patients must be careful not to overdo exercising. But if recovering patients are able, taking small steps just after recovery can set up good habits for continuing the exercise in the future. For instance, walking longer distances every day or taking the stairs instead of the elevator in buildings are small things one can do to add exercise into a daily routine. However, all patients and healthy adults alike should remember to consult a doctor before starting a new exercise regimen.

The link between exercise and the risk of certain cancers has been studied extensively in the last ten years. With guidance, any patient’s quality of life can be improved with regular exercise.

One yellow daffodil at a time

On the commute back from work, the trains are split into the ones going towards the city, and going towards the airport. Generally I like dividing my train ride in two; get on the airport-bound train and get off half way through, so I have two small wait periods instead of one big one. One day as I got off the airport-bound train, a man rushed up the escalator, but was a few seconds too late. He looked dejected as he asked me which train that was.

When I informed him that it was the airport train, there was a hint a relief in his features. It was the equivalent of finding change in your couch as we go through the biggest economic crisis of our lifetime. I wanted to give the man a hug - he had lots of anxiety, his appearance was disheveled, and despite me being a chemist who's robbed of the majority of his olfactory factory, there was a familiar sweet scent about him.

"I'm going to be late, goddamnit I'm going to be late, she's going to kill me," he repeated over and over.

"The train will be here in a few minutes," I offered, "and the duration of the ride to the end won't be that long," but he wasn't having it.

Then the small talk began

"Were you coming from school?"

Work. Pharmaceutical.

"So you hand out drugs at the pharmacy?"

Make. Lab.

"This train's a beaut isn't she"

Olympics. Satisfied.

I had been waiting, but before long, he revealed that his wife was being discharged from the hospital from her first round of chemo, and that she was currently stuck with her mother. I've learned from experience that at this moment, the conversation's his - no OMGs, no I'm sorrys, no anecdotes - it was his story to tell.

"I'm complaining too much, God, why am I so selfish."

"Because it's tough on you too. In the next while she's going to need you to be there for her, and right now, for the one second, you need someone to be there for you"

Hospital cots, gift shops, bad coffee

"You sound like you understand"

Been there, done that, cried a bit

"Does it get easier?"

"There is nothing easy about watching your love ones fighting for their lives, with their lives, while you sit on the sidelines, where there's literally nothing you can do to contribute to the fight."

If you take away all the hateful messages, a little bit of me could understand what Christie Blanchford was getting at here. Our society has been shaped by men who don't cry in front of others, so when it does happen, it has the same effect as an unseen left hook.

After he recovered, he became a little more composed.

"Can you smell the alcohol on me?"

Gum was offered

"I usually don't drink, but that seems like it's all I've been doing for the past week"

"No more?"

"No more."

The duration of the ride between the second to last to last station was a silent one. He started getting antsy again. I put my hold on the side of his arm.

Godspeed, and good luck.

Stuck in time

I've been working in industry for almost 8 months now as a synthetic chemistry intern for a pharmaceutical. I'm trying to figure out if I like it more than academic, if I like Chemistry as a career, or if I want to go some different direction entirely. My biggest problem is that it's rare that I would be doing something only to experience the "I love this; this is what I want to be doing for the rest of my life". Although the most recent time I've felt that, it turned out to be one of the greatest mistakes.

I've been called an old man a few times now because of my job. Social life comes in bursts; never often enough, never long enough. Part of it is it's now crunch time, and everyone's either doing their thesis, working, or trying to take over the(ir) world.

I constantly have a feeling that I'm stuck, with no clear path to follow, and my past running at the speed of light trying to catch up with me. I need to enjoy some escapism. Last year, being in the musical helped me put my combined honours degree in a box in the back of my mind. This year, I'm trying to complete my last work term somewhere away from here; Germany, Switzerland, San Francisco, anywhere that'll take me. I do hope that I do hear back, and that the escape will be everything I hoped for and more.