Oestrogen changes neuroblastoma cells into neurons

The female sex hormone oestrogen can perform an important role in neuroblastoma, a form of cancer mainly affecting young children. In laboratory experiments, researchers at Karolinska Institutet in Sweden demonstrate that oestrogen treatment and overexpression of the oestrogen receptor cause malignant neuroblastoma cells to mature into neuron-like cells.

Neuroblastoma forms in the peripheral nervous system and is one of the most common forms of solid cancer in young children. The disease mainly affects babies and young children, and while in some cases the tumours can disappear of their own accord, the majority are aggressive, metastasising cancer tumours that are resistant to modern combinations of surgery, radiotherapy and intensive chemotherapy.

The most aggressive forms of neuroblastoma are often associated with a more active MYCN gene, which drives tumour cell growth and spread and inhibits the maturation of the cells. Researchers focus on the activity of this gene and how it relates to neuroblastoma. MYCN is often seen only as a marker for a poor prognosis, but it's critical to the disease and is a possible target for new drugs.

In a previous study, the group discovered that activation of MYCN results in the formation of specific microRNAs, which are relatively small RNA molecules that regulate proteins. Some of these microRNAs disable the oestrogen receptor ERalpha. The present study shows that the inhibition of these microRNA molecules or oestrogen therapy in combination with an overexpression of the oestrogen receptor can cause aggressive neuroblastoma cells with MYCN activation to mature into neuron-like cells which behave more like normal cells.

The researchers studied tumour tissue from patients, cultivated human tumour cells and tumours in mouse models for neuroblastoma. In the mice, the neuron-like cells did not grow as quickly as the original cancer cells, and analyses of the tumour tissue from patients show that those with a high level of the oestrogen receptor have a better survival rate than those with a low. Oestrogen could be a therapeutic method for patients who express high levels of the oestrogen receptor. Another therapy could involve deregulating MYCN or upregulating the oestrogen receptor and then treating with oestrogen.
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Using viruses to fight viruses

Researchers at The Ottawa Hospital and the University of Ottawa have discovered that the Maraba virus, or MG1, can target and destroy the kind of HIV-infected cells that standard antiretroviral therapies can't reach. Daily medications keep the level of HIV virus in the blood low, there is currently no way to totally eliminate dormant HIV-infected cells from the body. If a person living with HIV stops taking antiretroviral medications, these hidden viruses rapidly rebound.

These latently HIV-infected cells are hard to target because they are not distinguishable from normal cells. Dr. Jonathan Angel and his team tried a new approach of identifying these dormant cells by using the MG1 virus. This virus attacks cancer cells that have defects in their interferon pathway, which makes the cells more vulnerable to viruses. Dr. Angel and his team previously found that latently HIV-infected cells also have defects in this pathway.

Using a number of laboratory models of latently HIV-infected cells, the researchers found that the MG1 virus targeted and eliminated the infected cells, and left healthy cells unharmed.
While most of these cells in patients are in the lymph nodes and other organs, a tiny number are found in the blood. When the researchers added MG1 to relevant blood cells taken from HIV-positive individuals, the levels of HIV DNA in the sample dropped. This indicated that the HIV-infected cells had been eliminated.
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How cancer spreads

A research study led by University of Minnesota engineers gives new method of how cancer cells move based on their ability to sense their environment.

The researchers discovered that cells have the ability to sense the stiffness of their environment and their ability to move is depend on their environment ranging from bone tissue to fatty tissue and muscle tissue.

Researchers compared cells from human brain cancer to mobile but normal cells from embryonic chick brains. They did five different experiments that included environments with six different stiffnesses.

The researchers slowed the cancer cells down in a petri dish in the lab by following the predictions of their computer models, which were based on an understanding the mechanics of the cancer cell movement.

Cells are like cars, they have motors that generate force, and a clutch to transfer that force to structures that grip the tissue along which they move. When the environment is good like a paved road, they can move into higher gear, with the engine spinning faster and the clutch transferring more force to the parts that, like wheels, get more grip.

They discovered that the combination of the two drugs they tested inhibit the motor and clutch functions of cancer cells and therefore hindered their movement.

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