Head and neck squamous cell carcinoma remains the sixth most common cancer worldwide (Chu & Kim, 2008). Although great progress has made in the treatment for laryngeal squamous carcinoma, the overall survival rate still remains low. The overall 1‐ and 2‐year survival rates for laryngeal squamous cell carcinoma patients without treatment are only 56.4% and 26.5%.
Recurrence and metastasis contribute a lot to the successful treatment; which of laryngeal squamous cell carcinoma (Rudolph, Dyckhoff, Becher, Dietz, & Ramroth, 2011). Hence, it is urgent to understand the underlying mechanisms of laryngeal squamous cell Cancer stem cells (CSCs); hence are a small group of cancer cells with self‐renewal capabilities and tumorigenicity. CSCs lead the resistance to radiotherapy and chemotherapy. Increasing evidence report that CSCs are present in laryngeal squamous cell carcinoma.
Human laryngeal squamous cell
For instance, CSCs were directly isolate from resected laryngeal squamous cell carcinoma tissues. CSC‐like cells were identify from primary cultured. human laryngeal squamous cell carcinoma epithelia. Therefore, investigating CSC‐like properties could help to elucidate the laryngeal squamous cell carcinoma development. Long noncoding RNAs (lncRNAs) are RNAs with longer than 200 nucleotides in length. LncRNAs can play crucial roles in many biological processes.
In addition, lncRNAs can function as tumor suppressors or tumor oncogenes such as lung cancer, bladder cancer and osteosarcoma. In laryngeal squamous cell carcinoma, lncRNA CCAT1 can promote cell proliferation and invasion. LncRNA Dleu2 can affect laryngeal carcinoma cells progression through regulating microRNA‐16‐1. In there current study, they aim to investigate whether DiGeorge syndrome critical region gene 5 (DGCR5) was involve in CSC‐like phenotypes of Hep‐2R cells.
DGCR5 was greatly increase while miR‐506 was decrease in Hep‐2R cells. Knock down of DGCR5 was able to inhibit the stemness and promote the radiosensitivity of Hep‐ 2R cells. miR‐506 was predict as a target of DGCR5. Therefore, they speculat that DGCR5 could promote CSC‐like properties in human laryngeal carcinoma cells by sponging miR‐506.
Cellular processes in cancer
Increasing evidence has prove that non coding RNAs are involve in many cellular processes in cancer, including the existence of CSCs. In there current study, they observe that CSC‐like properties were highly enrich in Hep‐2R cells compare with Hep‐2 cells. In addition, DGCR5 was obviously increase in Hep‐2R cells while miR‐506 was decreased. Inhibition of DGCR5 repress stemness of Hep‐2R cells through upregulating miR‐506.
For another, over expression of miR‐506 also increase radio sensitivity of Hep‐2R cells and restraine the CSC‐like traits. miR‐506 was predict as a target of DGCR5 by using informatics analysis and the direct correlation between them was confirm in there study. Meanwhile, Wnt signaling pathway was highly inactivate by knockdown of DGCR5 and miR‐506 mimics. Subsequently, in vivo experiments were conduct to validate that DGCR5 contribute to stemness of Hep‐2R cells via modulating miR‐506 and Wnt signaling in vitro.
In conclusion, there findings support that DGCR5 exert a crucial role in the CSC‐like characteristics of human laryngeal carcinoma cells. These data suggest knockdown of DGCR5 inhibited CSC‐like phenotypes of Hep‐2 cells by sponging miR‐506 and inhibiting Wnt signaling.