Wednesday, December 24, 2014

Experimental anti-cancer drugs PF-04691502 and PD-0325901 excel against colorectal cancer models





Genes make proteins and proteins tell your body's cells what to do: one talks to the next, which talks to the next, and to the next. Like a game of telephone, researchers call these "signaling pathways". Abnormalities in these signaling pathways can cause the growth and survival of cancer cells. Commonly, mutations or rearrangements of genes in the MAPK signaling pathway create cancer's fast growth, and alterations in the PI3K signaling pathway allow cancer cells to survive into virtual immortality.

Of course, researchers have extensively targeted these two signaling pathways, designing drugs that turn on or off genes in these pathways, thus interrupting the transmission of cancer-causing signals. Unfortunately, these pathways have proven difficult to drug and also it has been difficult to show the effectiveness of drugs that successfully interrupt the transmission of signals along these pathways.

A study by the University of Colorado Cancer Center published in the journal PLoS ONE and concurrent phase I clinical trial is examining a new strategy: targeting both these important cancer-causing pathways simultaneously.

"Well, these two pathways are mutated frequently in cancer. Why not hit both of them? It was as simplistic as that," says Todd Pitts, MS, research instructor in the Program for the Evaluation of Targeted Therapies, and the study's first author.

The study used colorectal cancer tumors grown on mice from samples of patient tumors, called "patient-derived xenograft" models. To these tumors, Pitts and colleagues added the experimental anti-cancer drugs PF-04691502 (left structure) and PD-0325901 (right structure), the first of which mutes a link in the PI3K signaling pathway and the second of which mutes a link in the MAPK signaling pathway. In this case, the combination was greater than the sum of the parts - alone, PF-04691502 and PD-0325901 modestly inhibit the growth and survival of colorectal cancer in these models; after 30-day exposure to the combination, colorectal cancer cells were killed much more effectively than by either drug alone, and even more effectively than if you added together the cells killed by each drug alone.

Tuesday, December 23, 2014

Cimetidine drug could be one of many common over-the-counter medicines to treat cancer

Cimetidine2DACS.svg

We know that, Cimetidine INN (/sɨˈmɛtɨdn/ or /sˈmɛtɨdn/) is a histamine H2-receptor antagonist that inhibits stomach acid production. It is largely used in the treatment of heartburn and peptic ulcers. It has been marketed by GlaxoSmithKline (which is selling the brand to Prestige Brands) under the trade name Tagamet (sometimes Tagamet HB or Tagamet HB200). Cimetidine was approved in the UK in 1976 and was approved in the US by the Food and Drug Administration for prescriptions starting January 1, 1979.

Now, it has been concluded that, a popular indigestion medication can increase survival in colorectal cancer, according to research published in ecancermedicalscience. But in fact, scientists have studied this for years - and a group of cancer advocates want to know why this research isn't more widely used.

"Cimetidine is an interesting drug as it's very safe, very well-known, and has clinical results in cancer that have been confirmed in a number of trials," says Pan Pantziarka, lead author of the paper and member of the Repurposing Drugs in Oncology (ReDO) project.

Cimetidine treats indigestion by blocking histamine receptors in the gut, which decreases the production of gastric acid. It also appears to block histamine receptors in cancer cells, as well as supporting the immune system's defences against cancer.

Cimetidine has been shown to have positive effects in colorectal and gastric cancer, melanoma, and renal cell carcinoma.

"Cimetidine is one of the most interesting examples of repurposed drugs in oncology - a drug with an extensive history of pre-clinical and clinical evidence of efficacy in a range of different cancers and with multiple mechanisms of action at work," says Pantziarka.

Cimetidine drug could be one of many common over-the-counter medicines to treat cancer

Friday, November 28, 2014

Bacterial protein flagellin can prevent and cure rotavirus infection

Activation of the innate immune system with the bacterial protein flagellin could prevent and cure rotavirus infection, which is among the most common causes of severe diarrhea, says a Georgia State University research team that described the method as a novel means to prevent and treat viral infection.


The team's findings are to be published in Science on Nov. 14.
Rotavirus is most problematic in infants and young children, who can become severely dehydrated and require hospitalization. Rotavirus causes about 500,000 deaths annually worldwide in children younger than five years of age, according to the Centers for Disease Control and Prevention.

The research, performed in mice, was led by Dr. Andrew Gewirtz and Dr. Benyue Zhang of the Institute for Biomedical Sciences at Georgia State, and included collaborators at Emory University School of Medicine, Baylor College of Medicine, Vanderbilt University School of Medicine, Genentech Inc. and the Pennsylvania State University.

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The researchers expect the specific method used in their work, using flagellin or the IL-22 and IL-18 proteins it elicits, might be effective against a range of chronic viral infections of the digestive system such as norovirus and hepatitis C virus. The team is now planning studies in humans to test this hypothesis. The general model of activating innate immunity to combat viral infection should prove an effective means of slowing down most any virus and could be a temporary means to deal with a broad range of viral infections until more specific solutions could be developed, Gewirtz said.

Thursday, November 27, 2014

Smart drug Modafinil can impair cognitive performance in healthy students

It is claimed one in five students have taken the 'smart' drug Modafinil to boost their ability to study and improve their chances of exam success. But new research into the effects of Modafinil has shown that healthy students could find their performance impaired by the drug. 
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The study carried out by Dr Ahmed Dahir Mohamed, in the School of Psychology at The University of Nottingham Malaysia Campus, and published today, Wednesday 12 November 2014, in the open access journal PLOS ONE, showed the drug had negative effects in healthy people.

Dr Mohamed said: "We looked at how the drug acted when you are required to respond accurately and in a timely manner. Our findings were completely opposite to the results we expected."

In a randomised double blind study, 'Modafinil increases the latency of response in the Hayling Sentence Completion Test in Healthy Volunteers: A Randomised Controlled Trial', they administered 32 participants with the drug and 32 with a placebo. All the participants were given a famous neuropsychological task known as the Hayling Sentence Completion Test in which they were asked to respond both quickly and accurately. Dr Mohamed found the drug slowed down reaction times, impaired their ability to respond in a timely manner and failed to improve their performance of the task.

Wednesday, November 26, 2014

Breakthrough in flexible electronics enabled by inorganic-based laser lift-off




A research team led by Prof. Keon Jae Lee of KAIST provides an easier methodology  to  realize  high  performance flexible electronics by using the  Inorganic-based Laser  Lift-off  (ILLO),  which  enables    nanoscale processes  for   high   density   flexible   devices and    high temperature processes that were previously difficult to achieve on plastic substrates.


Chaetocin synergistic with TKIs against CML cells

Chaetocin (structure below), a mycotoxin that increases oxidative stress, can complement the activity of tyrosine kinase inhibitors (TKIs) in chronic myeloid leukaemia (CML) by overcoming innate resistance mediated by secreted bone marrow stromal cytokines and growth factors (BMSFs), researchers report.

The authors explain that CML–leukaemic stem cells (CML–LSCs), which exhibit innate resistance to TKIs, are crucial for the maintenance of CML. And add that BMSFs are implicated in this innate resistance, and are also known to increase the levels of reactive oxygen species (ROS).

“Higher ROS levels in CML-LSCs exposed to BMSFs might render them susceptible to ROS-mediated damage by exogenous ROS-generating agents”, hypothesises the team inOncogenesis.

Chaetocin significantly reduced the viability and colony forming capacity of CML–LSK cells, and increased apoptosis. These effects of chaetocin were enhanced in the presence of BMSFs.
Moreover, treatment with both chaetocin and imatinib overcame BMSF-mediated imatinib resistance, and resulted in increased cytotoxicity and apoptosis induction as well as a complete loss of colony formation.

Although treatment with either chaetocin or BMSFs resulted in increased ROS levels in CML–LSKs, when the two were used in combination, ROS levels were significantly higher than when either was used alone. Interestingly, chaetocin-mediated cytotoxicty was inhibited when the cells were pretreated with an antioxidant, N-acetyl-cysteine.

This “strongly suggested” that chaetocin activity against CML–LSKs, and its potentiation by BMSFs, was mediated by the increased ROS, say the researchers.

Tuesday, November 25, 2014

Isis Pharmaceuticals announces initiation of ISIS-SMN Rx Phase 3 study in children with SMA

Isis Pharmaceuticals, Inc. (NASDAQ: ISIS) announced  the initiation of a pivotal Phase 3 study evaluating ISIS-SMNRx in approximately 120 non-ambulatory children with spinal muscular atrophy (SMA). SMA is a severe and rare genetic neuromuscular disease characterized by muscle atrophy and weakness. The Phase 3 study, CHERISH, is the second Phase 3 study Isis has initiated in a global late-stage clinical development program for ISIS-SMNRx. Isis earned a $27 million milestone payment from its development partner, Biogen Idec, for the dosing of the first patient in this study. Isis is also evaluating ISIS-SMNRx in the Phase 3 study, ENDEAR, in infants with SMA. Isis is conducting both Phase 3 studies with agreement from the U.S. Food and Drug Administration (FDA) for special protocol assessments, or SPAs.

University of Leeds researchers make new synthetic anti-cancer molecule

Researchers at the University of Leeds have made a new synthetic anti-cancer molecule that targets two key mechanisms in the spread of malignant tumours through the body. A study published in the journal PLOS ONE today reports that the synthetic molecule JK-31 blocks the signalling of a "growth factor" chemical that promotes the creation of networks of blood vessels to feed tumours.

But the researchers also found that the new molecule intervened directly in the growth of the cancer itself, inhibiting a protein that controls the division and proliferation of malignant cells.
Dr Vas Ponnambalam, Reader in Human Disease Biology in the University of Leeds' Faculty of Biological Sciences, said: "The ability to mount this two-pronged attack on cancerous growths is exciting. There is a great need for better drugs against cancer than what we currently have and JK31 may represent an important addition to the toolkit for drug makers developing the next generation of drugs."

The researchers observed the effect of the synthetically produced molecule, JK-31, on the growth and proliferation of a model human breast cancer cell line and found that it effectively blocked the protein cyclin-dependent kinase 1 (CDK1), which plays a key part in the process of the division of cancer cells, and therefore inhibited the proliferation of the cells.

In a separate laboratory experiment, they found the same JK-31 molecule also blocked a specific growth factor (VEGF-A) produced by the cancer to attract the growth of blood vessels.

Other molecules exhibiting similar dual effects are known but JK-31 is the only compound so far shown to successfully target CDK1 and block VEGF-A.

Monday, November 24, 2014

New drug combination shows promise as effective, safe treatment for rheumatoid arthritis

A new drug combination for rheumatoid arthritis treats the disease just as well as other intensive treatment strategies but with less medication and fewer side effects at a significantly lower cost. Doctoral researcher Diederik De Cock (KU Leuven) describes the strategy in a new study published in Annals of Rheumatic Diseases.

Rheumatoid arthritis (RA) is a chronic auto-immune disease that causes pain and stiffness in the joints, fatigue, bone damage and, eventually, loss of mobility. RA afflicts around 1% of people in the western world; in Belgium, 80,000 to 100,000 people currently live with the disease.

Because there is no known cure for RA, physicians focus treatment on suppressing disease activity. Therapies have improved in recent years, and clinical studies show that intensive treatment of early RA can prevent joint damage and improve patients' quality of life.

In the two-year study, called 'CareRA' (Care in early RA), researchers and clinicians in the rheumatology unit at University Hospitals Leuven examined various therapies for early RA. Their goal: to find the optimal combination and dosage of three commonly prescribed antirheumatic drugs (methotrexate, sulfasalazine and leflunomide) in combination with glucocorticoids (a class of steroid hormones).

The researchers divided 290 early RA patients into three treatment groups. Each group received a different combination therapy: 'COBRA Classic' (methotrexate, sulfasalazine and a high first dose of glucocorticoids), 'COBRA Slim' (methotrexate and a moderate dose of glucocorticoids) or 'COBRA Avant-Garde' (methotrexate, leflunomide and a moderate dose of glucocorticoids).

Friday, November 21, 2014

Sulindac drug can protect against oxidative damage due to AMD

In continuation of my update on Sulindac

Scientists at Florida Atlantic University's Charles E. Schmidt College of Science, as well as the Charles E. Schmidt College of Medicine, have found that sulindac, a known anti-inflammatory drug, can protect against oxidative damage due to age-related macular degeneration (AMD), one of the primary causes of vision loss in the elderly. Their findings were released today in an article titled "Pharmacological protection of retinal pigmented epithelial cells by sulindac involves PPAR-α" in the prestigious Proceedings of the National Academy of Sciences.