Long Intergenic Non-Coding RNAs in HNSCC: From “Junk DNA” to Important Prognostic Factor

SIMPLE SUMMARY: Head and neck squamous cell carcinoma (HNSCC) has one of the highest incidence and mortality rates among all cancers. Diagnostic process and treatment results are far from satisfactory. These are the main reasons behind studying the microenvironment of the tumor and finding the connection between the aberrant expression levels of non-coding RNAs and patients’ outcomes. In this paper, we tried to present the function and the promising diagnostic potential of long intergenic non-coding RNAs (lincRNAs). We proved that a multitude of them play a pivotal role in the different processes involved in the progression of the disease—e.g., proliferation, migration, and the epithelial-to-mesenchymal transition. Even though there is a lot of work ahead of us, lincRNAs could become unique and valuable biomarkers or future targets for personalized medicine. ABSTRACT: Head and neck squamous cell carcinoma is one of the most common and fatal cancers worldwide. Even a multimodal approach consisting of standard chemo- and radiotherapy along with surgical resection is only effective in approximately 50% of the cases. The rest of the patients develop a relapse of the disease and acquire resistance to treatment. Especially this group of individuals needs novel, personalized, targeted therapy. The first step to discovering such solutions is to investigate the tumor microenvironment, thus understanding the role and mechanism of the function of coding and non-coding sequences of the human genome. In recent years, RNA molecules gained great interest when the complex character of their impact on our biology allowed them to come out of the shadows of the “junk DNA” label. Furthermore, long non-coding RNAs (lncRNA), specifically the intergenic subgroup (lincRNA), are one of the most aberrantly expressed in several malignancies, which makes them particularly promising future diagnostic biomarkers and therapeutic targets. This review contains characteristics of known and validated lincRNAs in HNSCC, such as XIST, MALAT, HOTAIR, HOTTIP, lincRNA-p21, LINC02487, LINC02195, LINC00668, LINC00519, LINC00511, LINC00460, LINC00312, and LINC00052, with a description of their prognostic abilities. Even though much work remains to be done, lincRNAs are important factors in cancer biology that will become valuable biomarkers of tumor stage, outcome prognosis, and contribution to personalized medicine.