Histone deacetylase (HDAC)-1, −2, −4 and −6 expression in human pancreatic adenocarcinoma: associations with clinicopathological parameters, tumor proliferative capacity and patients’ survival

BACKGROUND: Histone deacetylases (HDACs) have been associated with malignant tumor development and progression in humans. HDAC inhibitors (HDACIs) are currently being explored as anti-cancer agents in clinical trials. The present study aimed to evaluate the clinical significance of HDAC-1, −2, −4 and −6 protein expression in pancreatic adenocarcinoma. METHODS: HDAC-1, −2, −4 and −6 protein expression was assessed immunohistochemically on 70 pancreatic adenocarcinoma tissue specimens and was statistically analyzed with clinicopathological characteristics and patients’ survival. RESULTS: Enhanced HDAC-1 expression was significantly associated with increased tumor proliferative capacity (p = 0.0238) and borderline with the absence of lymph node metastases (p = 0.0632). Elevated HDAC-4 expression was significantly associated with the absence of organ metastases (p = 0.0453) and borderline with the absence of lymph node metastases (p = 0.0571) and tumor proliferative capacity (p = 0.0576). Enhanced HDAC-6 expression was significantly associated with earlier histopathological stage (p = 0.0115) and borderline with smaller tumor size (p = 0.0864). Pancreatic adenocarcinoma patients with enhanced HDAC-1 and −6 expression showed significantly longer survival times compared to those with low expression (p = 0.0022 and p = 0.0113, respectively), while a borderline association concerning HDAC-2 expression was noted (p = 0.0634). CONCLUSIONS: The present study suggested that HDACs may be implicated in pancreatic malignant disease progression, being considered of clinical utility with potential use as therapeutic targets.