Biology was the first subject that
actually got a 10 year old me fascinated when I first learnt the science behind
heart attack. Having seen so many people suffer from such attacks given my
family’s medical history led to me deciding to look for a cure. However, small
and insignificant this episode may seem but it was enough to ignite in my mind
the curiosity of the intricacies of human body. Little did I know that one
class lecture would throw me into this enthralling and mystifying world of
biological sciences. All through school
with every class, I was only persuaded to delve deep into the subject.
This insatiable thirst for the subject
propelled me to go for a Bachelors in Science in one of the biological
subjects. The choice of course wasn’t difficult to make. Francis Crick was
right when he said that it was the molecule that has the glamour, not the
scientist. The study of molecules sustaining life had to be the key to get to
the core of the subject and unravel biology in a different way altogether.
The undergraduate program was a new
avenue where I got exposed to various fields of study. It was gratifying to
finally be able to get at the core of the mere facts that we were presented
with at the school. The two modules that garnered my engrossment were cell
biology and molecular biology.
Through long, the double helical
structure held together by specific pairing between the bases on two strands
became one of the iconic images of science. However, it was only later in our
molecular biology lectures that I realized that this molecule is a lot more
sophisticated than it looks. Moreover, learning that the modest image of a
typical cell with organelles is extravagantly dynamic had me overwhelmed.
Thus, complexity of mechanisms
involved in cell biology and molecular biology presents a particularly
compelling drama and one only gets filled with plenty of remaining mysteries.
The contribution of molecular biology
and cell biology to the scientific revolution has been immense. From production
of vast amount of rare drugs and vaccines, tracing evolution, creating instant
test for a host of illness, to identification of criminals. Together these two
fields have virtually encompassed the entire spectrum of science from physics
and chemistry to biology and medicine. I feel, this field would allow me to
study life on every level from individual molecules to the interrelated webs of
earth’s organisms. Above all, I believe this is one of the most challenging and
potentially rewarding fields.
Next comes the daunting task to get at
a specific area from these two vast fields. The discipline that I felt would
perfectly straddle these two areas is cancer and epigenetics.
Siddharta Mukherjee in his book ‘The
Emperor of All Maladies’, described cancer as an infinitely resourceful
adversary. This statement definitely struck a chord. Cancer is a global
adversary no doubt but to describe it as resourceful is what was unique and
made me realize the research potential of this globally occurring phenomenon.
Cancer is an amalgam of many diseases
sharing a common feature of abnormal growth. Researchers all over the world
thus have come up with different approaches to tackle it.
One such approach that seemed
quintessential to my interest is epigenetics. Epigenetic
mechanisms act to change the accessibility of chromatin to transcriptional
regulation locally and globally via modifications of the DNA and by
modification or rearrangement of nucleosomes. Global
changes in the epigenetic landscape are a hallmark of cancer. DNA methylation usually
takes place at the 5? position of the cytosine ring within CpG dinucleotides,
and its consequence is the silencing of genes and noncoding genomic
Histone modification such as acetylation and
methylation are important in transcriptional regulation. Noramally, about
70-80% of all CG dinucleotides in the genome are methylated and the remainder
CG dinucleotides occur in clusters known as CpG islands near the 5′ end of
genes and are protected from methylation. So, Cpg island hypermethylation and
genome wide hypomethylation are common epigenetic features of cancer cells. Too
much methylation in CpG island can lead to activation of nearby oncogens and
too little methylation across the genome can lead to silencing of tumor
suppressor genes. Moreover, cancer cells also have a histone cancer signature
caused by deacetylation of some lysine resuides.
Thus if given an opportunity I would
want to work in this field to study and identify epigenetic markers on cancer
cells. This is highly important since identification of specific epigenetic
profiles of types and subtypes of cancer can be used as a diagnostic tool and
identification of the stage of development of cancer in patients.