Cracking the code of cancer cells

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CHICAGO -- Personalized cancer care. Beyond a biopsy. Looking deep within a cancer cell to determine what went wrong -- then stopping the chain of events that leads to tumor growth. It’s research that’s already making a difference in patients’ lives.

Imagine being able to decode a cancer cell, determine why the cell has gone awry and why it won’t die. It’s a mystery some have already solved.

“I’ve been practicing for over 25 years now, and really what we’ve been able to be successful at is trying to decode this DNA sequence," said Dr. Ravi Salgia, a University of Chicago medical oncologist.

Humans are built by DNA – and so are the individual cells inside our bodies. When doctors sequence a tumor, they can see where its DNA structure is abnormal. The jumbled sequence can lead to faulty cell structure and function – in other words, cancer.

“What happens in cancer is the cancer cells refuse to die. That’s the problem. And so, what these genetic sequences are telling the cancer cells ‘keep reproducing.’ We know it’s the DNA sequence that leads to these abnormalities," Salgia said.

Decoding the abnormal DNA sequence is the first step in what’s called precision medicine. The process starts with a tissue sample – taken from a patient’s actual tumor.

"We take the tumor tissue and then we cut them up, isolate the DNA, then we sequence them. We have lots of tools to analyze the sequences themselves, and then we put it together and say, ‘Oh, these are the genetic abnormalities that have occurred," Salgia said.

These are lung cancer cells Dr. Salgia grew in his lab. Taken from tumor tissue samples, some are growing, multiplying and on the move -- some are dying.

“This is way beyond just the sequencing," he said.

Lung cancer was once divided into two types. But now doctors know much more about the genetic makeup of tumors.

“Now when I see a patient we talk about non-small cell lung cancer with adenocarcinoma, with an EGFR mutation that’s an L858R that’s developed a resistant mutation with a TC90-M. That’s how complex and detailed this becomes, but it really helps us determine what to do," Salgia said.

Ultimately the goal is to develop drugs that target the altered DNA. The science has already made its way out of the lab and to patients.

“I ended up having probably one of the best mutations you can have," said lung cancer patient Meghan O’Brien, lung cancer patient:

Thirty-two-year-old Meghan O’Brien was diagnosed with lung cancer in 2012.

“It was one thing that I had cancer, but to wrap my head around the fact that I had lung cancer, I was just, I don’t know. And then they came back in and later that night and said, ‘You have stage 4 lung cancer," O'Brien said.

At the time of diagnosis, the cancer that began in Meghan’s lungs had already spread to her spine. Eventually it would travel to her brain and liver. But first, Meghan found Dr. Salgia.

“He was the one that was really all about, you know, let’s get her tumor cells off to the lab and get this genetic testing done," O'Brien said.

Meghan has what’s called an ALK translocation. In simpler terms...

“It causes this type of lung cancer, and it causes it to proliferate, that is to grow faster, and to metastasize faster. What led to that mutation is an important question. And you know, a lot of non-smokers may have this mutation as an example, and we don’t understand what the cause of that may be," Salgia said.

But doctors do have something. As a result of tumor sequencing, there are drugs developed to target Meghan’s specific mutation – and they’ve helped extend her life.

“That gene mutation – that ALK gene mutation – and this medicine that was created specifically for it is what ended up turning my life around and kind of bringing me to more of my new normal. You know, there’s that hope. There’s a lot of hope out there," Salgia said.

He continued: “There are only a handful of genetic changes that we can target at this moment in time for lung cancer. But that’s clearly what we’re working towards, to try to identify the genetic changes and can you tailor the therapy based on the genetic changes.”

Patients often develop drug resistance to the gene mutation inhibitors. That’s why Dr Salgia says there is still much work to be done. There are also clinical trials to determine if the targeted therapies can outsmart early stage cancers.

To learn more about Dr Salgia’s work at the University of Chicago Medicine, go to:

http://www.uchospitals.edu/specialties/cancer/lung/

http://www.uchospitals.edu/news/features/lung-targeted-therapies.html

 http://www.uchospitals.edu/specialties/cancer/lung/video/index.html

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2 comments

  • Martin

    There’s already a cure for cancer. The abnormality that causes a cell to become a cancerous cell is a lack of oxygen. You want to cure cancer, get hyperbaric oxygen therapy. When did cancer suddenly become so popular? Now everyone and their mom has cancer or knows someone with cancer. Prior to the 90s cancer was being treated with oxygen, but then investors started investing in drug companies because their return was much larger than oxygen therapy and that was that. For the skeptics, hyperbaric oxygen therapy is much less expensive then “traditional” cancer treatment, so honestly you have nothing to lose. Try it for yourself.