Slug is a fast-turnover transcription factor critical for controlling cell fate and cancer cell invasion and metastasis. LncRNA SNHG15 transcription is upregulated in a variety of human cancers according to The Cancer Genome Atlas. Ectopic expression of SNHG15 promoted colon cancer cell migration in vitro, accelerated xenografted tumor growth in vivo, and elevated levels of SNHG15 were associated with poor prognosis for colon cancer patients. Mechanistically, SNHG15 maintains Slug stability in living cells by impeding its ubiquitination and degradation through interaction with the zinc finger domain of Slug.