Blue Light Special: Killing Cancer With “Light Activation”

A new platinum-based compound that is activated by blue light offers a cancer-killing potency that is up to 80 times higher than that of current platinum-based anti-cancer drugs, according to research led by the University of Warwick.

Working in conjunction with researchers at Ninewells Hospital Dundee and the University of Edinburgh, the Warwick team hopes the new compound will improve cancer treatment effectiveness for a wide variety of cancers. According to Professor Peter Sadler, University of Warwick Department of Chemistry:

“This compound could have a significant impact on the effectiveness of future cancer treatments. Light activation provides this compound’s massive toxic power and also allows treatment to be targeted much more accurately against cancer cells.”

This assertion is backed up by initial tests performed at Ninewells Hospital Dundee. Here, a team tested the effectiveness of the new compound on killing cultivated esophageal cancer cells. The results of these studies were encouraging, with 50 percent of all cancer cells killed by a small concentration of 8.4 micro moles per liter of the compound.

Additional research for the compound is set to begin on ovarian and liver cancer cells.

Previous platinum-based compounds have been engineered to react to ultraviolet light. However, the narrow wavelength of ultraviolet rays has limited its real-world potential. Since the new compound reacts directly with visible blue light (as well as green light), it is expected to deliver a broader range of applications.

Researchers also report that the new compound is stable and easily administered. Additionally, it is water soluble, meaning that it simply dissolves and flushes from the body following treatment.

Peter Sadler explains that “light activation generates a powerful cytotoxic compound that has proven to be significantly more effective than treatments such as cisplatin.” As a result, the team has hopes that the new compound will offer effective treatment options for cancer types that do not traditionally respond well to platinum-based chemotherapy.

Source:
http://www.news-medical.net/news/20101210/Researchers-find-new-light-activated-platinum-based-compound-to-kill-cancer-cells.aspx

Could RNA Interference be the Key to Shutting Down Cancer?

Each individual cancer cell displays a multitude of genetic mutations. Among the hundreds of these potentially hazardous mutations, scientists believe that the alteration of one to twelve could be enough to render a caner cell impotent and effectively shut it down within the body. The method currently being proposed to achieve this potentially landmark procedure is known as RNA interference.

RNA interference is a naturally occurring cellular phenomenon. In normal cell division, DNA must be transported from the nucleus to the ribosomes. However, RNA can disrupt this path by intercepting small snippets of genetic material en route. This unique type of RNA is specifically referred to as short interfering RNA (siRNA).

As Dr. Daniel Anderson of the David H. Koch Institute for Integrative Cancer Research at MIT explains, this method of interference “offers the potential to turn off essentially any gene in the cell.”

To bring this new theory of cancer treatment into practice, two factors must be addressed. The first is identifying which specific cancer mutations to target for interference. On the top of the list for researchers are those genes that cause cancer cells to divide and replicate quickly. In some cases, such genes have already been identified. However, it should be noted that different kinds of cancer might require different targets for RNA interference.

The second factor that needs to be addressed is finding a way to safely deliver siRNA to cancer cells without overly affecting healthy tissues. According to Steven Dowdy of the University of California, San Diego, delivery of this siRNA is the “number one hurdle” associated with RNA interference treatment.

Presently, the leading candidate for delivery of siRNA is via a fatty molecule called a lipidoid. With RNAi hidden within the lipidoid, the molecule can slip into a cell’s membrane and allow the RNA to go to work. Researchers at MIT have already shown that such a process can be effective in shutting off specific genes within the livers of mice. They have also made progress in reducing ovarian cancer tumor growth in mice via the procedure.

A number of additional steps are required before lipidoid transmission is ready for clinical trials. Most notably, is the fact that lipidoid molecules are fairly large in comparison to RNA data. As a result, the transmission could be hindered.

Another issue is the potential for the lipidoid to enter a normal cell. If such a scenario occurs, the DNA of a healthy cell could be abnormally damaged. To address this issue, scientists are toying with the idea of engineering lipidoids that are peppered with specific proteins. These proteins serve as a homing device of sorts by being drawn to binding proteins present on the exterior of cancer cells.

Currently, experts on the subject such as Dr. Dowdy believe patient-specific RNA interference could be readily available within ten to 20 years. As he sees it, future patients will have their tumors genetically sequenced to discover which cancer-causing genes have been activated. Once this information is known, a specific siRNA treatment can be implemented to effectively shut off the cancer’s ability to proliferate.

Source:
http://web.mit.edu/newsoffice/2010/targeting-cancer2-1116.html

50 Percent of Cancer Patients May Benefit From Oxygen-Carrying Compounds

Engineered proteins that help carry oxygen to cancer tumors may improve the odds of successful treatment for approximately half of all cancer patients. Scientists have long known that low levels of oxygen are a main source of a tumor’s resistance to radiation.

It is estimated that 50 percent of all cancer patients have tumors that exhibit insufficient oxygen levels (a state referred to as hypoxia). Now, a small startup based out of San Francisco known as Omniox is working to improve the effectiveness of current radiation treatments through the use of oxygen-carrying compounds.

Previous studies suggest that the vast majority of cancer tumors exhibit hypoxic regions. These oxygen-starved regions occur due to the rapid growth of tumor cells. As the tumor grows, it requires higher and higher levels of oxygen-rich blood to properly feed the growth of cells. To accomplish this, the tumor stimulates the growth of new blood vessels.

However, the growth of new blood vessels often has difficulty keeping up with the growth of the tumor. Such a fact reduces the effectiveness of radiation – a treatment option that relies heavily on the flow of oxygen.

Radiation therapy works by generating free radicals within the body that damage and kill tumor cells. Since free radicals require oxygen to survive, a hypoxic region often receives insufficient damage to completely kill off the tumor.

The issue of improving oxygen flow to tumors has been studied since the 1950s. Unfortunately, a variety of attempted solutions have proven unsuccessful. Omniox hopes to reverse this trend with the introduction of oxygen-carrying proteins.

These proteins have been augmented to cling to oxygen molecules and hold onto them until they have arrived inside hypoxic tissue. These proteins differ from previous oxygen-carrying options in that the proteins are not based on hemoglobin. Hemoglobin has previously been identified as unsuccessful because nitric oxide (an oxygen-killing material) also clings to such molecules.

Previous studies have shown that Onniox’s proteins effectively accumulate in the tumors of living animals and serve to improve oxygen levels in hypoxic regions.

The National Cancer Institute is working in conjunction with Omniox to further develop and research the oxygen-carrying proteins. The NCI recently awarded the startup with $3 million in funding.

Source:
http://www.technologyreview.com/biomedicine/26772/page2/

Altered Voltage in “Instructor Cells” May Contribute to Cancer Growth

Unique “instructor cells” recently identified by biologists at Tufts University have been shown to spur melanoma-like growth in pigment cells when membrane voltage is altered. According to researchers, this voltage change triggers a series of events that directly leads to the abnormal growth of melanocytes within stem cells.

The new findings could eventually lead to successful treatment and prevention regimens for a variety of cancers, as well as vitiligo and certain birth defects.

Details of the study are reported in the October 19 issue of Disease Models and Mechanisms. The study involved the manipulation of voltages felt across cell membranes of in vivo frog tadpole “instructor cells.” Based on specific voltage levels, researchers were able to predict which cells would eventually exhibit signs of aggressive melanoma with remarkable accuracy.

According to lead researcher Michael Levin, melanoma symptoms were directly linked to the do-polarization of cells.

Interestingly, the “instructor cells” are not housed within the stem cells themselves. Rather, they communicate with stem cells via serotonin transport-based pathways. This fact – that distant cells can directly induce alterations in other cells – is a fairly novel discovery.

The research raises questions about how such regenerative treatments as stem cell therapy may potentially result in the development of cancer. This is due to the fact that electrical stimulation has been previously linked as a key component for regeneration (Levin and colleagues previously showed how amputated tadpole tails could be induced to regenerate via use of electrical current).

Presently, the widespread importance of electrical manipulation is in question. Some experts on the subject, such as regenerative biophysicist Richard Borgens of Purdue University, suspect that electrical activity only plays a role in a small set of cancer types.

Regardless, the identification of melanoma instructor cells suggests that similar, though wholly different, triggers may be present in other types of cancer. As Levin suggests, the next step is to look for and identify additional instructor cells that may be used to better understand the formation of other cancers.

Sources:

http://www.the-scientist.com/news/display/57754/

http://www.eurekalert.org/

http://www.genengnews.com/

biologic

Calorie-Balanced Diet May Prevent Cancer

Mounting research suggests that adhering to an energy-balanced diet (consuming only as many calories as you burn) may reduce your risk for cancer. Additionally, the American Institute for Cancer Research (AICR) identifies 12 common cancers that may be spurred by unhealthy diet, insufficient physical activity and improper weight management. These 12 cancers are:

  • Endometrial
  • Esophageal
  • Oral
  • Stomach
  • Colon
  • Pancreatic
  • Breast
  • Lung
  • Kidney
  • Gallbladder
  • Liver
  • Prostate

The most recent evidence that links diet to cancer involves observational studies that asked individuals between the ages of 30 and 60 to answer an in-depth questionnaire regarding weight, diet, physical activity level and other health factors. The participants were then followed for several decades to monitor the development of cancer.

Alarmingly, the AICR reports that as much as 69 percent of esophageal cancers, 45 percent of colon cancers and 38 percent of breast cancers may be directly related to poor diet and improper weight management. Statistically significant percentages were also found for the nine other cancer types.

Previous studies have already suggested that an energy-balanced diet improves cancer treatment outcomes and lowers the risk for cancer to return. However, this is the first study to indicate that healthy diet and lifestyle may actually help prevent the onset of cancer.

Based on these findings, the AICR recommends a variety of health-conscious eating habits. Some eating habits that may decrease risk of cancer include:

  • Lowering intake of red meat and processed meat (these foods are associated with colo-rectal cancer)
  • Increasing intake of fruits and non-starchy vegetables (may reduce risk of esophageal cancer)
  • Consuming no more than one alcoholic beverage each day for women or two alcoholic beverages for men (alcohol increases caloric intake and may increase risk of breast cancer)
  • Take steps to reduce excess body fat, particularly around the waist (linked to lowered risk of liver, gallbladder and endometrial cancer)
  • Exercise daily for at least 30 minutes (wide-ranging health benefits)

Source:

http://www.curetoday.com/index.cfm/fuseaction/article.show/id/2/article_id/1548