Cancer researchers Unrecognized anti-cancer protein discovered

Researchers identify previously unknown anti-cancer protein

The treatment options for cancers vary greatly depending on the type of tumor and the stage of the disease. In the case of hepatocellular carcinoma, the chances of a cure for those affected have so far often been rather poor, which, on the one hand, is related to the often delayed diagnosis and, on the other hand, is due to the limited therapeutic options. However, scientists have now discovered a protein that could be helpful in both the early diagnosis and treatment of liver cell cancer.

The international research team led by Professor Michael N. Hall from the Biozentrum, University of Basel, has identified "a new anti-cancer protein". The protein LHPP prevents the unrestrained proliferation of cancer cells in the liver. In addition, the protein is suitable as a biomarker for the diagnosis and prognosis of liver cell cancer, according to the Communication of the University of Basel. The researchers have published their research results in the journal "Nature".

According to recent study results, the protein LHPP plays a decisive role in liver cancer. This finding opens up new approaches to early diagnosis and therapy. (Image: blueringmedia / fotolia.com)

Incidence of liver cancer is increasing

According to the researchers, the incidence of liver cancer has risen steadily in recent years. In Switzerland, for example, the number of diseases has almost doubled in the last twenty years. Often, the chances of recovery for those affected are rather poor, because the cancer - in the absence of symptoms in the early stages - discovered late and the liver is already severely damaged, the scientists report.

Crucial importance of tumor suppressors

"Liver tumors develop from previously damaged cells that grow uncontrollably and proliferate indefinitely," explain the experts. However, so-called tumor suppressors (special proteins) prevent excessive cell growth. However, these anti-cancer proteins are often defective in cancer cells. The LHPP now identified forms one of these tumor suppressors. In the current study, the researchers were able to demonstrate "that the loss of LHPP promotes tumor growth and reduces the chance of survival of cancer patients."

More than 4,000 proteins studied

According to the University of Basel, the research team developed a mouse model of hepatocellular carcinoma in which they activated the growth protein mTOR in the liver. Subsequently, they analyzed a total of more than 4,000 proteins and compared these in healthy and in cancerous tissue. In the context of the investigations, an enzyme has emerged as particularly promising - the histidine phosphatase LHPP, according to the Communication of the University of Basel.

LHPP was missing in tumor samples

"It was very noticeable that LHPP occurs only in healthy tissue and is completely absent in the tumor samples," says first author Sravanth Hindupur in the university's press release on the study results. In the animals, which were reinstated the genetic information for LHPP, no tumors had arisen and their liver function was preserved. "Similar to the mouse model, we were able to see markedly reduced LHPP levels in tumors of patients with liver cancer," Hindupur continues.

Often, liver cancer is discovered only at an advanced stage, which significantly limits the therapeutic options. (Image: magicmine / fotolia.com)

Better diagnosis and prognosis of the course of the disease possible?

The researchers also found that both the severity of the disease and life expectancy are directly related to the amount of LHPP. "With a complete loss of the anti-cancer protein, cancer patients die on average two years earlier," reports the University of Basel. Thus, the protein would also be useful as a biomarker for diagnosis and prognosis of the disease process. LHPP forms a phosphatase, which removes from proteins all those phosphate groups that are attached to a histidine, the scientists explain the function of LHPP. Histidine, like all amino acids, is one of the basic building blocks of proteins.

New level of tumorigenesis made visible

So far, the so-called histidine phosphorylation of proteins "hardly explored because there were no suitable tools," report the experts. For the current research, however, "Tony Hunter of the Salk Institute in the US has provided new tools" with which "we could now make a completely new level of tumor development visible," emphasizes Hindupur. It has become clear that the deficiency of the anti-cancer protein LHPP causes the proteins to be phosphorylated beyond the normal level on histidine. This promotes uncontrolled cell growth and thus the development of tumors. Presumably, LHPP also plays a role in other cancers, the researchers concluded. (Fp)