Radioactive Bacteria:1 – Pancreatic Cancer:0

Years ago, when I was just starting my healthcare career, I worked with a team specializing in the management of patients with pancreatic cancer.  Despite the dedication and compassion of our team, revolutionary surgical techniques, and top-notch palliative care, all too often our patients died. Even today, some 30 years later, pancreatic cancer has a poor prognosis. It’s seldom detected in its early stages, and often spreads rapidly. Signs and symptoms frequently don’t appear until the disease is advanced and surgical removal isn’t possible.

Pancreatic cancer touches so many people. It killed my childhood mentor and one of my best friends. It’s taken the lives of many household names, from astronauts to actors, entrepreneurs to opera singers.  For example, Patrick Swayze, Randy Pausch, Luciano Pavarotti, Dizzy Gillespie, Count Basie, Michael Landon, Joan Crawford, Sally Ride and of course, Apple CEO – Steve Jobs.

So, I was excited to hear about new research into a targeted anti-cancer therapy that promised limited side effects. The study, published April 22 in the Proceedings of the National Academy of Sciences found that treating mice with an attenuated, radioactively labeled bacteria –  Listeria monocytogenes – drastically reduced the number of metastases, while leaving normal tissue unscathed.

The notion of using bacteria to attack tumors is not new. Robert Hoffman, a cancer biologist at the University of California, San Diego, who was not involved in the current study, has shown that Salmonella can kill mouse cancer cells, including metastases of pancreatic cancer.

Other research has shown that a Listeria strain known as CRS-207 has the ability to stimulate an immune response in Phase 1 and 2 trials.

In the new study, researchers at Albert Einstein College of Medicine have paired this technique with a radioactive isotope to selectively kill tumor cells, focusing on the metastatic cells that so often elude current treatment regimens.

It’s this combination of approaches that synergistically target metastases, that’s new. Claudia Gravekamp, an immunologist at Albert Einstein College of Medicine who led the study with nuclear medicine researcher Ekaterina Dadachova had previously demonstrated that an attenuated strain of Listeria monocytogenes, a type of bacterium that penetrates host cells during infection, selectively killed breast cancer cells without damaging normal tissue. The bacteria’s ability to target only diseased cells raised the possibility that it could be used to treat metastatic cancer by both directly killing cells and by carrying anti-tumor therapies—like radiation—to cancer cells.

Gravekamp and Dadachova tested the bacteria against highly metastatic pancreatic cancer in mice. First, they demonstrated that the bacteria proliferated well in the animals’ metastases, but poorly in the primary tumor, and not at all in normal tissues like spleen, suggesting the bacteria would be good candidates for delivering a therapy to far-flung metastases.

Then, the researchers armed the Listeria with the Rhenium-188, a radionuclide that kills cells by releasing DNA-damaging. Sure enough, regular injections of the Rhenium-188 labeled bacteria decreased metastases by 90% versus controls.

While this implies that bacteria have to potential to be used to deliver therapeutic radiation doses to metastases, the bacteria were administered before metastases were established, notes Donald Buchsbaum, a radiation biologist at the University of Alabama at Birmingham who was not involved in the study.  “So to some extent it’s a prevention model.”

Future work will need to focus on targeting established metastases, possibly by exploring other radioisotope options.  Gravekamp and Dadachova are currently refining their protocol and examining alternative radioisotopes to achieve a 100% reduction of metastases, but have high hopes for their bacteria.

Though primary tumors are often removed surgically, even small pieces left behind can produce new metastases. It might be possible that one day radioactive Listeria could be part of an “early second-line treatment after surgery to prevent further metastases,” says Gravekamp.

Which is great news in the war against cancer and not a bad deal for the Listeria bacteria which normally gets a bad rap for causing the infection listeriosis  – the leading cause of death among food-borne bacterial pathogens – responsible for approximately 2,500 illnesses and 500 fatalities annually in the United States.

Exciting stuff!

Long, long sneezy days of summer

Seems it’s not just polar bears and politicians who need to be concerned about global warming. According to a new study, allergy sufferers are going to be in for a hard time too.  Researchers from the US Department of Agriculture have discovered that ragweed pollen levels are rising along with the temperatures.

The team of researchers, who analyzed ragweed pollen counts from Texas to Saskatoon over a 15-year period , also concluded that the length of the ragweed season, which is dependent on warm temperatures, would increase in northern latitudes.

From 1995 – 2009, Madison  and LaCrosse, WI saw an increase in their ragweed season of 12 and 13 days respectively while Minneapolis, MN and Fargo, ND, saw their ragweed season increase in length by 16 days. Further north, in Winnipeg and Saskatoon the ragweed seasons lengthened  by 25 – 27 days.

Better news though for those in the South.  The ragweed season  in Texas and Arkansas actually decreased by three or four days although the amount of allergen in the air during the season increased.

“This study is a confirmation of what the Intergovernmental Panel on Climate Change has been projecting. We’ve gone from a theoretical projection of changes in the timing of ragweed season, to boots on the ground starting to see it happen,” said study author Lewis Ziska, a plant physiologist at the Agricultural Research Service.

This all adds up to a lot of summer suffering. At least 1 in every 10 people in the United States is sensitive to ragweed and the pollen is the culprit in more than a quarter of all allergy cases.

SRxA’s teams of expert Allergy and Ocular Advisors are on hand to help pharmaceutical companies educate physicians and patients  on this latest aspect of global warming.

Slimming Shades!

Drawing your drapes, or closing your blinds before going to bed, may do more than shutting out the bogey man or your neighborhood voyeur!

According to a study published this week in the Proceedings of the National Academy of Sciences, persistent exposure to light at night may lead to weight gain, even without changing physical activity or eating more food.

Researchers found that mice exposed over an eight week period to even dim light at night gained 50% more weight than mice that lived in a standard light-dark cycle.

“Although there were no differences in activity levels or daily consumption of food, the mice that lived with light at night were getting fatter than the others,” said Laura Fonken, lead author of the study and a doctoral student in neuroscience at Ohio State University.

Which begs the question, if the mice are not less active or eating more, what’s causing the bigger weight gain?

It turns out that mice living with light at night eat at times they normally wouldn’t. “Something about light at night was making the mice in our study want to eat at the wrong times,” said Randy Nelson, professor of neuroscience and psychology at Ohio State.

Food for thought?  While you, dear reader, digest this information, we at Word on Health are off to order our blackout shades!