Childhood cancers defy current understanding

Cancer is still surprising researchers, making the pathway to urgently-needed new treatments more difficult to predict. Researchers in Sydney have made an unexpected discovery that transforms our thinking about one of the ‘universal features’ of cancer.

A combined team of scientists from Sydney Children’s Hospitals Network (SCHN) and Children’s Medical Research Institute (CMRI) studied an aggressive category of neuroblastoma, which is the most common solid cancer of childhood.

For many years, the presence of a telomere lengthening mechanism has been considered essential for the growth of essentially all cancers. Dr Loretta Lau (SCHN) and Professor Roger Reddel (CMRI), who jointly led the research team and collaborated with Professor Michelle Haber’s team at Children’s Cancer Institute (CCI), have now shown this isn’t always the case. They found that 11% of high-risk neuroblastomas can keep growing without any method to lengthen their telomeres.

Telomeres can be found at both ends of all chromosomes, the bundles of DNA found in most cells. In normal cells, telomeres gradually become shorter, and this limits the number of times normal cells can multiply. In cancer, cancerous cells need to find a way to lengthen telomere DNA—to allow it to keep multiplying, and therefore for the cancer to keep growing.

Previously, researchers have believed that because something has gone wrong, probably during a child’s very early development, some cells have had abnormally long telomeres, so long that the cancer can keep on growing aggressively even though the cancer cells’ telomeres keep on shortening.

The new finding means that cancer biologists need to re-evaluate their understanding that the presence of a telomere lengthening process is a universal feature of cancer. Already, there is evidence from researchers in Belgium that a similar principle applies to melanomas, a common skin cancer which can also be very aggressive.

The study was recently published in Cell Reports.

In 2013, ACRF awarded CMRI $2 million in funding to develop the ACRF Telomere Analysis Centre. This funding was given to support an internationally unique consortium of telomere research groups to better understand the differences in telomere biology between normal and cancerous cells.

ACRF has supported cancer research at CMRI by awarding three research grants, in total $15.2 million, towards cutting edge research technology. ACRF has also awarded CCI three grants, in total $5.2 million.

This news post was originally published on the CMRI website.