Long non-coding RNA addiction in melanoma skin cancer

Long non-coding RNA addiction in melanoma skin cancer

Researchers revealed a remarkable link between malignant melanoma and a non-coding RNA gene called SAMMSON. The SAMMSON gene is specifically expressed in human malignant melanoma and, strikingly, the growth of aggressive skin cancer is highly dependent on this gene. The conclusions could pave the way for improved diagnostic tools and skin cancer treatment. 

"Our research showed that the long non-coding RNA gene SAMMSON is specifically expressed in human melanomas and duplicated or amplified in about 10% of the cases. In addition, SAMMSON was nowhere to be found in melanocytes, the normal melanin-producing cells, nor in any other normal adult tissue. This unique expression profile of SAMMSON led us to hypothesize that this gene might play an important role in the etiology of melanoma," said the author.

Further research confirmed that SAMMSON is expressed specifically in more than 90% of human malignant - and not in benign - melanoma clinical samples. In addition, they showed that the SAMMSON gene is activated by the melanoma-specific transcription factor SOX10, explaining its melanoma specific expression pattern.

Scientists discovered a remarkable dependency of melanoma cells on SAMMSON expression. When reducing the presence of SAMMSON in melanoma cultures, cancer cells rapidly and massively die off, irrespective of the type of melanoma. This led to the key conclusion of a 'SAMMSON addiction', reflected in the Nature paper's title: "Melanoma addiction to the lineage-restricted lncRNA gene SAMMSON".

They also discovered that SAMMSON is recruited to mitochondria, an organelle that provides energy to the cancer cells. By promoting degradation of SAMMSON, these antisense molecules disrupt the vital mitochondrial activity, which stops the tumor's growth. In other words: SAMMSON addiction is a clear vulnerability that can be used to combat through targeted therapy, without affecting the normal cells from the host or patient.

Further research will be necessary to firmly establish the study's hypothesis that SAMMSON can serve as a biomarker of melanoma malignancy. As the SAMSSON gene is not expressed in benign melanoma, its occurrence could be a key factor in developing new diagnostic tools that may dramatically improve melanoma prognosis.