Link Between RNA Gene and Melanoma Could Lead to Improved Treatment

A non-coding RNA gene has been linked to malignant melanoma and could improve diagnostic tools and treatment for skin cancer.

A large screening study published in the journal Nature studied the expression of many IncRNAs across different cancer types. The screening was able to identify the gene SAMMSON as a melanoma-specific IncRNA.

“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,” said co-study author Pieter Mestdagh. “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.”

The results of the study confirmed that SAMMSON was expressed in more than 90% of human malignant melanoma clinical samples. Furthermore, SAMMSON demonstrated that it is activated by the melanoma-specific transcription factor SOX10.

Researchers also saw a dependency of melanoma cells on SAMMSON expression. In fact, it was concluded as a ‘SAMMSON addiction’ because massive amounts of cancer cells died off rapidly once the presence of SAMMSON was reduced in the melanoma cultures.

“In both in vitro and pre-clinical studies in mice, we have proven that blocking SAMMSON through targeted antisense molecules drastically reduces the growth of melanoma,” said Jean-Christophe Marine. “Importantly, we have 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 we can combat through targeted therapy, without affecting the normal cells from the host or patient.”

Since the SAMMSON gene is not expressed in benign melanoma, its occurrence could be a key factor in the development of new diagnostic tools that could drastically improve prognosis for melanoma patients.

However, in order to solidify that SAMMSON could serve as a biomarker of melanoma malignancy, additional research is needed, the study concluded. Currently, researchers are initiating talks with different industrial players to explore mutually beneficial future collaborations.