Navigation Links
Repeated Liver Cell Proliferation, a Cause for Liver Cancer

According to researchers at the University of California, San Diego (UCSD) School of Medicine, liver cancer can possibly be caused by cycles of liver cell// death and renewal – liver cell proliferation.

The research, appearing online the week of June 19 in advance of publication in the journal Proceedings of the National Academy of Sciences, underscores the importance of JNK1-mediated cell death and compensatory proliferation. The findings by Michael Karin, Ph.D., professor pharmacology in UCSD?|s Laboratory of Gene Regulation and Signal Transduction, and colleagues strongly suggest that the control of tissue renewal through the IKK and JNK pathways plays a key role in liver cancer in mouse models.

One link between inflammation and cancer is known to involve the NF-kB pathway, which regulates gene expression. In research published in the journal Cell in 2005, Karin and his colleagues at UCSD implicated the pathway's activator, IKK , in chemically induced liver cancer. However, the surprising outcome of those studies was the finding that while NF-??B activation in hepatocytes (liver cells) prevents liver cancer, its activation in inflammatory cells, such as tissue macrophages, promotes tumor development.

In their latest work, the research team studied what precedes inflammation ?V the injury of hepatocytes caused by toxic chemicals, which sets in motion the inflammation process.

Their research showed that the absence of IKK?ò in hepatocytes led to increased c-Jun N-terminal kinase (JNK) activation after exposure to a chemical carcinogen used to elicit liver cancer in mice. Importantly, deletion of the gene that codes for the major isoform of JNK in liver cells, JNK1, prevented the development of liver cancer and reversed the tumor-enhancing effect caused by ablation of IKK?ò.

"We found that long-term JNK activation leads to cell death; if activated briefly, it stimulates proliferation of pre-malignant and cancerous tu mor cells," said Karin. Blocking JNK prevents liver injury but also inhibits liver regeneration, so the timing and context of activation are very important, he added.

"In this research, we set out to identify what causes inflammation in response to liver injury, as well as what stimulates the proliferation of surviving hepatocytes," said Karin. "Since we previously knew that JNK activity is required for normal liver cell proliferation, we wondered if the same activity is required for production of liver cancer in carcinogen-exposed mice. The results were clear JNK1 is critical for tumor development."

The scientists genetically removed JNK1 to test if its increased activation, caused by the absence of IKK?ò, was responsible for accelerated tumor development. When JNK1 was removed, the number and size of cancerous liver tumors decreased, and the tumors grew more slowly. Increased JNK1 activation was found in diseased liver and tumors when compared to normal tissue.

Hepatocellular carcinoma (HCC), the most common form of liver cancer, is the third leading cause of cancer deaths worldwide. Its major risk factors are persistent infection with hepatitis B and C viruses, and exposure to toxic chemicals, including alcohol ?V all of which cause chronic liver injury and inflammation. Although not common in the United States., the incidence of HCC is on an upward trajectory, with little hope for treatment or cure through chemotherapy, radiation or other traditional cancer treatments.

"We now understand development of liver cancer in mice. Since inflammation drives both damage and regeneration in liver tissue, it is the repeating cycle of damage, inflammation and regeneration that leads to liver cancer," said Karin. "However, this knowledge is not satisfactory until we find out if it applies to humans."

Source: Eurekaert
'"/>




Related medicine news :

1. New Findings for Repeated Miscarriages
2. Repeated checking causes memory distrust
3. Repeated Heart Surgery with Older Blood Transfusion Pack More Death Risk
4. Repeated Weight loss Messages Have No Effect On Couch Potatoes
5. Genes May Trigger Repeated Premature Birth In Blacks
6. Blood Cells Capable of Regenerating Liver
7. Liver donors can thrive after transplant
8. Heavy Drinking Raises Risk of Liver Cancer
9. Arthritis Drug May Cause Liver Damage
10. Liver transplant oversight urged
11. Liver key to extending life
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/27/2016)... ... June 27, 2016 , ... ... its strategic partnership with Connance, a healthcare industry leader providing predictive analytics ... proprietary technology combine to provide health systems, hospitals and ambulatory surgical centers ...
(Date:6/26/2016)... ... , ... Pixel Film Studios Released ProSlice Levels, a Media Slicing Effect ... a whole new perspective by using the title layers in ProSlice Levels to ... ProSlice Levels contains over 30 Different presets to choose from. FCPX users ...
(Date:6/25/2016)... ... June 25, 2016 , ... Austin residents seeking Mohs surgery ... of Mohs Surgery and to Dr. Russell Peckham for medical and surgical dermatology. , ... for skin cancer. The selective fellowship in Mohs Micrographic Surgery completed by Dr. Dorsey ...
(Date:6/25/2016)... ... June 25, 2016 , ... ... non-athletes recover from injury. Recently, he has implemented orthobiologic procedures as a method ... —Johnson is one of the first doctors to perform the treatment. Orthobiologics are ...
(Date:6/24/2016)... ... , ... June 19, 2016 is World Sickle Cell Observance Day. In an ... of holistic treatments, Serenity Recovery Center of Marne, Michigan, has issued a ... Cell Disease (SCD) is a disorder of the red blood cells, which can cause ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... June 24, 2016 According to ... Type (Standard Pen Needles, Safety Pen Needles), Needle Length ... Growth Hormone), Mode of Purchase (Retail, Non-Retail) - Trends ... report studies the market for the forecast period of ... USD 2.81 Billion by 2021 from USD 1.65 Billion ...
(Date:6/23/2016)... , June 23, 2016 Research and ... Global Market - Forecast to 2022" report to their ... treatment method for the patients with kidney failure, it replaces ... fluid from the patient,s blood and thus the treatment helps ... and chloride in balance. Increasing number of ...
(Date:6/23/2016)... 2016 Research and Markets has announced ... Analysis 2016 - Forecast to 2022" report to their ... contains up to date financial data derived from varied research ... trends with potential impact on the market during the next ... which comprises of sub markets, regional and country level analysis. ...
Breaking Medicine Technology: