By Tan Ee Lyn
HONG KONG, July 7 |
HONG KONG, July 7 (Reuters) - Liver cancers are embedded with a type of super cancer stem cells that make them resistant to chemotherapy, spread to other body parts and stage a comeback even after they are surgically removed, researchers in Hong Kong reported on Thursday. The discovery, published this week in the journal Cell Stem Cell, is important because it means experts can target these stem cells in their fight against liver cancer, a major blight in China and southeast Asia.
These cancer stem cells have a unique surface protein called CD24 and patients with high counts of CD24 tend to have poorer chances of survival, said lead researcher Irene Ng, pathology professor and director of the State Key Laboratory for Liver Research at the University of Hong Kong.
"CD24 is like a button, a switch on some cancer stem cells. Once they are switched on, they activate a protein in the cell called STAT3," Ng told a news conference.
Her colleague Terence Lee said: "STAT3 goes into the nucleus of the cells and carries out its functions, which are to form tumours, spread and be drug resistant. If we inhibit the function of STAT3, we block the function of cancer stem cells."
Stem cells are master cells found throughout the body and they are special because they can transform into different cell types and multiply and self-renew.
Liver cancer stem cells are therefore troublesome because they are responsible for growing tumours, making them spread, drug-resistant and so hardy that they recur even after they have been surgically removed.
In their experiment, Ng and colleagues found that mice that were implanted with liver cancer enriched with CD24 cancer stem cells were resistant to chemotherapy.
They then injected two colonies of liver cancer cells - one with CD24 stem cells and the other without - into separate parts of the liver of the same mouse.
"That part of the liver with CD24 cancer stem cells grew cancer and the cancer spread to the lungs. But not the other part of the liver without CD24 cancer stem cells," Lee said.
They went back to human liver cancer patients and found that those with high concentrations of CD24 had a 67 percent chance of cancer recurrence in the first year after surgery, compared to 21 percent recurrence in those with low CD24 count.
Those with high CD24 count had a 80 percent chance of their cancer spreading to other body parts, compared to 32 percent chance of spreading in patients with low D24 count.
Ten percent of China's population carry the hepatitis B virus, a key cause of liver cancer. There are 500,000 new cases of liver cancer worldwide a year, over 50 percent in China. (Editing by Sanjeev Miglani)
(Created by Ee-lyn Tan
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Insulin resistance was associated with a lower cure rate of patients with Hep C
A study in the latest issue of Alimentary Pharmacology & Therapeutics investigates insulin resistance and sustained virological response in hepatitis C.
A higher baseline homeostasis model assessment of insulin resistance (HOMA-IR) score has sometimes predicted a poorer sustained virological response rate to peginterferon/ribavirin therapy in treatment-naïve chronic hepatitis C patients.
Dr Romero-Gómez and colleagues from Spain perform a meta-analysis to evaluate the impact of HOMA-IR on SVR in hepatitis C.
Relevant studies were identified by searching Medline and EMBASE.
The research team identified 17 publications that addressed the influence of insulin resistance on sustained virological response.
Sustained virological response was higher with HOMA-IR less than 2 in all genotypes
Alimentary Pharmacology & Therapeutics
The researchers found that normal insulin sensitivity was associated with a higher rate of sustained virological response in comparison with insulin resistance.
Moreover, in separate analysis by genotype selecting studies that used HOMA-IR more than 2 as cut-off defining insulin resistance, sustained virological response was higher in patients with HOMA-IR less than 2 in all genotypes.
Studies reporting no association between HOMA and sustained virological response included easy-to-cure cohorts, analyzed variables strongly related with insulin resistance like body mass index, steatosis, hyper γGT, age and fibrosis and reported differences in handling and interpretation of HOMA-IR.
Dr Romero-Gómez and colleagues concluded, "Elevated HOMA-IR was associated with a lower cure rate of patients with hepatitis C treated with Peg-IFN-α/ribavirin irrespective of genotype, and the more difficult-to-treat cohort, the better the HOMA-IR prediction."
"HOMA-IR is, as a surrogate marker of insulin resistance, susceptible to some biases derived from both handling and interpretation."
Aliment Pharmacol Ther 2011: 34(3): 297–305
07 July 2011
Non-alcoholic fatty liver disease and non-alcoholic steatohepatitis is increasing
The most recent issue of the Alimentary Pharmacology & Therapeutics reports on the epidemiology and natural history of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis in adults.
Non-alcoholic fatty liver disease (NAFLD) is a common cause of chronic liver disease, and its worldwide prevalence continues to increase with the growing obesity epidemic.
Dr Younossi and colleagues from Virginia, USA assessed the epidemiology of NAFLD in adults based on clinical literature published over the past 30 years.
The researchers reviewed epidemiology and natural history of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis in adults based on clinical literature published over the past 30 years.
An in-depth search of PubMed was based on 5 search terms: ‘non-alcoholic fatty liver disease’ OR ‘non-alcoholic steatohepatitis’ OR ‘fatty liver’ OR ‘steatosis’ AND ‘incidence’ OR ‘prevalence’ OR ‘natural history’.
Studies of paediatric cohorts were excluded.
NAFLD is the most common cause of elevated liver enzymes
Alimentary Pharmacology & Therapeutics
Articles were categorized by topic and summarized, noting generalizations concerning their content.
The team found that 4 study categories included NAFLD incidence, prevalence, risk factors and natural history.
Studies related to NAFLD prevalence and incidence indicate that the diagnosis is heterogeneous and relies on a variety of assessment tools, including liver biopsy, radiological tests such as ultrasonography, and blood testing such as liver enzymes.
The research team found that the prevalence of NAFLD is highest in populations with pre-existing metabolic conditions such as obesity and type II diabetes.
Many studies investigating the natural history of NAFLD verify the progression from NASH to advanced fibrosis and hepatocellular carcinoma.
Dr Younossi's team concludes, "Non-alcoholic fatty liver disease is the most common cause of elevated liver enzymes."
"Within the NAFLD spectrum, only NASH progresses to cirrhosis and hepatocellular carcinoma."
"With the growing epidemic of obesity, the prevalence and impact of NAFLD continues to increase, making NASH potentially the most common cause of advanced liver disease in coming
Aliment Pharmacol Ther 2011; 34: 274–285
06 July 2011
Viral Dominance in HBV/HCV Dual Infection
Asian ethnicity is a significant independent predictor of HBV-dominant disease in people with HBV/HCV dual infection. With undetectable HBV viral load, HCV dominance is more common in non-Asians.
Pharmaceuticals
FDA Warns Cadila Over Incompetent Microbiologists
Yet another facility run by an Indian drugmaker has been tagged by the FDA. The latest belongs to Cadila Healthcare, which was cited by the FDA for failing to follow good manufacturing practices at a new facility designed to make injectable meds for sale in the US. More specifically, a June 21 warning letter cited problems with microbiologists failing to follow basic procedures.
For instance, microbiologists reported that were no problems with microbiological plates when, in fact, a colony-forming unit - which is a measure of viable bacterial or fungal numbers - was found. And a microbiological growth was incorrectly identified and reported as a typical microorganism when compared with an in-house library of typical environmental flora... Continue Reading...
Bayer Is Scolded For Tweeting Medicines
To Tweet or not to Tweet? That is a question that Bayer Healthcare will be pondering for some time. The drugmaker was upbraided by the UK’s Prescription Medicines Code of Practice Authority for recently Tweeting about two medicines, which was deemed to be a cause for concern since the information went directly to the public.
What were the Tweets about? In April, the @BayerUKIreland Twitter account wrote this concerning Levitra: “First & only melt-in-the-mouth erectile dysfunction treatment launched by Bayer today http://tinyurl.com/6hfxymf.” And last year, Bayer tweeted: “Sativex® launched in UK for the treatment of spasticity due to Multiple Sclerosis http://tiny.cc/kiz2y,” according toInPharm.....Continue Reading...
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Off The Cuff
Doctors' Challenge: How Real Is That Pain?
Melinda Beck
(The Wall Street Journal, New York, July 5, 2011)
"Despite decades of research, doctors have few tools to measure pain objectively…Evaluating patients' pain is posing a greater dilemma than ever for doctors, given two colliding health-care trends. On the one hand, opioid painkillers…have become a major drug of abuse. With prescriptions up 48% since 1999, opioids are now the nation's second-leading cause of accidental death, after car crashes, according to the Office of National Drug Control Policy. On the other hand, the Institute of Medicine [IOM], which advises the government on health issues, reported last week that pain is all too often undertreated in the U.S. For many of the 116 million Americans afflicted with chronic pain, help is delayed, inaccessible or inadequate, the IOM found. Many patients feel stigmatized even asking for help."
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A Drugstore within: Mesenchymal Stem Cells Protect and Heal
Released: 7/6/2011 4:00 PM EDT
Embargo expired:
Source:
Newswise — A stem cell that can morph into a number of different tissues is proving a natural protector, healer and antibiotic maker, researchers at Case Western Reserve University and their peers have found.Source:
Mesenchymal stem cells reaped from bone marrow had been hailed as the key to growing new organs to replace those damaged or destroyed by violence or disease, but have failed to live up to the billing.
Instead, scientists who’d been trying to manipulate the cells to build replacement parts have been finding the cells are innately potent antidotes to a growing list of maladies.
The findings are summarized in the July 8 issue of Cell Stem Cell.
The cell, referred to as an MSC, “is a drugstore that functions at the local site of injury to provide all the medicine that site requires for its successful regeneration,” said Arnold Caplan, professor of biology at Case Western Reserve, and lead author of the paper.
Here’s how:
MSCs sit on every blood vessel in the body. When a blood vessel is injured or enflamed, the cells detach and jump into action.
“From the front end, the cell puts up a curtain of molecules which stop an overaggressive immune system from sending in cells to survey the damage – which, if successful, would mount an autoimmune response,” he said. “The back face of the MSC secretes molecules that set up a regenerative microenvironment so that the damaged tissue can repair itself and not make scar tissue.”
Researchers around the world have been using the cells in a broad range of preclinical animal models of disease and injury and in clinical trials during the last decade.
By injecting MSCs into damaged tissue or infusing them into the blood stream, the therapy appears to have muted damage or cured such diverse conditions and disorders as acute heart attack, stroke, kidney failure, tendonitis, juvenile diabetes, radiation syndrome, arthritis, amyotrophic lateral syndrome, burns, wounds and more.
The researchers have found that MSCs from one human do not cause an immune response in another, nor in animals injected with human MSCs.
Most of the research has been done using cells culled from bone marrow, but results using cells extracted from fat, placenta, umbilical cord and muscle have shown similar but not identical potential.
Which source of cell is the best for each disease or injury requires further investigation.
Recent work, led by the University of San Francisco scientists, shows the cell’s arsenal is even greater. They found the cells produce a protein that kills bacteria including E. coli and Staphylococcus aureus, and enhance clearance of the microbes from the body.
Because MSCs are showing themselves capable of far more than a foundation for tissue engineering, Caplan suggests the acronym should now stand for medicinal signaling cells.
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