At the time of its construction in the 1950s, the central dogma of molecular biology was a useful model that represented the current state of knowledge for the flow of genetic information after a period of prolific scientific discovery. Unknowingly, it also biased many of our assumptions going forward. Whether intentional or not, genomic elements not fitting into this paradigm were deemed unimportant and emphasis on the study of protein-coding genes prevailed for decades. The phrase “Junk DNA,” first popularized in the 1960s, is still used with alarming frequency to describe the entirety of noncoding DNA. It has since become apparent that RNA molecules not coding for protein are vitally important in both normal development and human malignancy. Cancer researchers have been pioneers in determining noncoding RNA function and developing new technologies to study these molecules. In this review, we will discuss well known and newly emerging species of noncoding RNAs, their functions in cancer, and new technologies being utilized to understand their mechanisms of action in cancer. Cancer Res; 1–10. ©2018 AACR.
Lessons from the Crypt: HMGA1—Amping up Wnt for Stem Cells and Tumor Progression
High mobility group A1 (HMGA1) chromatin remodeling proteins are enriched in aggressive cancers and stem cells, although their common function in these settings has remained elusive until now. Recent work in murine intestinal stem cells (ISC) revealed a novel role for Hmga1 in enhancing self-renewal by amplifying Wnt signaling, both by inducing genes expressing Wnt agonist receptors and Wnt effectors. Surprisingly, Hmga1 also “builds” a stem cell niche by upregulating Sox9, a factor required for differentiation to Paneth cells; these cells constitute an epithelial niche by secreting Wnt and other factors to support ISCs. HMGA1 is also highly upregulated in colon cancer compared with nonmalignant epithelium and SOX9 becomes overexpressed during colon carcinogenesis. Intriguingly, HMGA1 is overexpressed in diverse cancers with poor outcomes, where it regulates developmental genes. Similarly, HMGA1 induces genes responsible for pluripotency and self-renewal in embryonic stem cells. These findings demonstrate that HMGA1 maintains Wnt and other developmental transcriptional networks and suggest that HMGA1 overexpression fosters carcinogenesis and tumor progression through dysregulation of these pathways. Studies are now needed to determine more precisely how HMGA1 modulates chromatin structure to amplify developmental genes and how to disrupt this process in cancer therapy. Cancer Res; 78(8); 1–8. ©2018 AACR.


