The tiny RNA molecules of the microRNA, which consist of only about 20 building blocks, do not contain instructions for building proteins, but assume, according to experts, control tasks in the cell. For this purpose, they "bind directly to appropriate sequences of protein-encoding mRNA molecules, which can no longer be translated into a protein", explains the DKFZ in its current communication. With a special microRNA, a known cancer gene can be blocked, thus inhibiting the invasion of skin cancer cells.
MicroRNAs influence cancer growth
"In many cancers, the tumor cells form a pattern of microRNAs which differs from the healthy cells," explains DKFZ scientist Stefan Eichmüller. Depending on which genes block the microRNAs in the cell, cancer growth can either be driven or braked. Thus the microRNAs "have a great influence on how the diseases are going", emphasizes the expert. The research team around Stefan Eichmüller has now investigated whether microRNAs also affect the malignant properties of melanoma( black skin cancer).The cancer form is, according to the experts, particularly feared, since the tumors form early metastases. The invalidity and mobility of these cancer cells is a good indicator of their malignant properties, which the researchers concentrated on their current studies, reports the DKFZ.
Within the scope of their study, the scientists equipped a human melanoma cell line according to the random principle with a single of the approximately one thousand known microRNAs. They then were able to compare the effect of the different mircoRNAs by examining the distances between the cells in a specific gel, the DKFZ explains. As expected, a wide range of hiking trails had been identified. These differed "depending on whether the respective cell had a microRNA caught that promoted or inhibited its malignant properties," according to the DKFZ.Among those cells that only moved slightly, the team had finally identified the microRNA miR-339-3p, which blocked the migration of the cells significantly. This is the proof that the molecule actually affects the invasiveness of the cells. However, miR-339-3p had almost no effect on the viability of the cells.
Cancer gene MLC1 is blocked
According to data from the DKFZ, several melanoma cell lines showed significantly less miR-339-3p than normal melanocytes from the skin, and when the researchers fitted these cell lines with additional miR-339-3p, they lost invasiveness, The investigations with bioinformatic methods have shown that miR-339-3p in the melanoma cells inter alia blocks the known cancer gene MLC1.This promotes the survival of cancer cells and its overexpression is associated with poor prognosis in melanoma. According to Stefan Eichmüller, "miR-339-3p obviously blocks a key key molecule that promotes many of the malignant properties of melanoma cells."
Less lung metastases formed
In experiments with mice, the researchers were able to demonstrate that a transfer of melanoma cells equipped with miR-339-3p actually resulted in the formation of fewer lung metastases in mice than in the case of conspecificates carrying untreated cancer cellshad been. Previous studies have already identified microRNAs that inhibit the formation of MCL1 in other cancers and thus can reduce the invasive capacity of the cells."With miR-339-3p, we have now also discovered a real new tumor suppressor for melanoma," said Eichmüller. In further investigations it should now be examined whether miR-339-3p is also suitable as a diagnostic marker, with which the aggressiveness of melanomas can be assessed.(fp)
A special microRNA can slow down the invasion of skin cancer cells and thus reduce the risk of lung metastases. Scientists from the German Cancer Research Center( DKFZ) have discovered the microRNA, which blocks a known cancer gene and thus suppresses the invasiveness of black skin cancer cells. In experiments with mice, the use of melanoma cells with this microRNA has led to fewer animals developing lung metastases, the DKFZ reports. The results of the researchers were published in the specialist magazine "Cancer Research".