Expression of inositol polyphosphate 4-phosphatase type II and the prognosis of oral squamous cell carcinoma

Inositol polyphosphate 4-phosphatase type II (INPP4B) is a phosphoinositide phosphatase that plays complex roles in the pathogenesis of different tumors. We aimed to explore the expression, clinicopathological significance, and prognostic value of INPP4B in oral squamous cell carcinoma (OSCC). Tissue microarrays that included samples from 176 primary OSCCs, 42 normal mucosae, and 69 dysplastic tissues were used for immunostaining analyses of INPP4B protein. Aperio ScanScope CS scanner and aperio quantification software were used to scan the microarrays and score the staining, respectively. We also evaluated the correlation between INPP4B expression and clinical parameters, pathological grades, node-positive status, and immune-related markers. Expression of INPP4B was statistically significantly upregulated in human primary OSCC tissues compared with dysplastic and normal tissues. Additionally, we found that patients with strong expression of INPP4B had a statistically significantly poorer overall survival than patients with weak expression of INPP4B. Furthermore, our study indicated that expression of INPP4B in OSCC was positively associated with expression of p-S6^Ser235/236 , p-CAD^Ser1859 , and certain immune checkpoints (B7-H4, Galectin-9). Therefore, INPP4B may be an independent prognostic indicator for patients with OSCC, in which it might function as an oncoprotein.