Serum HOTTIP expression is upregulated in nasopharyngeal carcinoma patients and predicts poor prognosis

Nasopharyngeal Carcinoma (NPC) is a tumor with ethnic and geographic distribution characteristics. HOXA Transcript at the distal Tip (HOTTIP) has been confirmed to have cancer-promoting effects in various tumors. The aim of this study was to investigate the clinical significance of HOTTIP in the development of NPC and its role in prognostic assessment.

Reverse transcription real-time PCR was used to analyze the expression of HOTTIP in the serum of 122 NPC patients before treatment, 35 controls and 30 NPC patients after treatment, and the relationship between HOTTIP expression and the clinicopathological features and prognosis of NPC patients was analyzed. The NPC cell lines CNE1 and HNE1 stably overexpressing HOTTIP were constructed using the retroviral method. Plate clone formation assays, MTT assays, flow cytometry, and Transwell migration and invasion assays were used to investigate the effects of HOTTIP overexpression on the colony-formation ability, cell proliferation ability, apoptosis, and migration and invasion abilities of CNE1 and HNE1 cells, respectively.

HOTTIP was highly expressed in NPC serum and cells compared with the control group; serum HOTTIP expression in NPC patients after treatment was significantly lower than that before treatment; Kaplan-Meier survival curve revealed that the Progression-Free Survival (PFS) and Overall Survival (OS) of the HOTTIP low-expression group were both better than those of the HOTTIP high-expression group; COX proportional hazard models showed that high HOTTIP expression was an independent risk factor for PFS in NPC patients. The overexpression of HOTTIP promoted the proliferation, migration and invasion abilities of CNE1 and HNE1 NPC cells and inhibited cell apoptosis in vitro cell experiments.

Increased HOTTIP expression in serum indicates a poor prognosis and may be used as a molecular marker and therapeutic target in NPC.