Immunohistochemical analysis of PDK1, PHD3 and HIF-1α expression defines the hypoxic status of neuroblastoma tumors

Abstract

Neuroblastoma (NB) is the most common solid tumor during infancy and the first cause of death among the preschool age diseases. The availability of several NB genomic profiles improves the prognostic ability, but the outcome prediction for this pathology remains imperfect. We previously produced a novel prognostic gene signature based on the response of NB cells to hypoxia, a condition of tumor microenvironment strictly connected with cancer aggressiveness. Here we attempted to further define the expression of hypoxia-modulated specific genes, looking at their protein level in NB specimens, considering in particular the hypoxia inducible factor-1α (HIF-1α), the mitochondrial pyruvate dehydrogenase kinase 1 (PDK1), and the HIF-prolyl hydroxylase domain 3 (PHD3). The evaluation of expression was performed by Western blot and immunocytochemistry on NB cell lines and by immunohistochemistry on tumor specimens. Stimulation of both HIF-1α and PDK1 and inhibition of PHD3 expression were observed in NB cell lines cultured under prolonged hypoxic conditions as well as in most of the tumors with poor outcome. Our results indicate that the immunohistochemistry analysis of the protein expression of PDK1, PHD3, and HIF-1α defines the hypoxic status of NB tumors and can be used as a simple and relevant tool to stratify high-risk patients.

Hypoxia Predicts Poor Prognosis in Neuroblastoma Patients and Associates with Biological Mechanisms Involved in Telomerase Activation and Tumor Microenvironment Reprogramming

“…NB-hop genes are known from the literature to be modulated by hypoxia and encode proteins that are involved in key biological processes associated with the response to hypoxia [3,17,[101][102][103][104][105][106][107][108][109]. Expression of these genes has been previously reported to represent a marker of hypoxia in NB cell lines [3,102,105] and tumors [102], and to correlate with NB bone marrow metastases and poor patient outcome [3,101]. The expression of NB-hop genes correlates with HIF-1a expression, which is one of the most important regulators of the cellular response to hypoxia [16].…”

Intravenous Bone Marrow Mononuclear Cells Transplantation in Aged Mice Increases Transcription of Glucose Transporter 1 and Na+/K+-ATPase at Hippocampus Followed by Restored Neurological Functions

“…By co-culture with BM-MNCs, increased transcription of PHD3, PDK1, and Glut1 was observed in HUVECs in vitro. The activation of Hif-1α is regulated by post-translational modifications (Ke and Costa, 2006), and the transcription of PHD3 and PDK1 is known to be increased after activation of Hif-1α (Ognibene et al, 2017). Activation of Hif-1α is also known to upregulate Glut1 transcription (Lokmic et al, 2012).…”

miR-210 and miR-152 as Biomarkers by Liquid Biopsy in Invasive Ductal Carcinoma

“…In BC samples, this study found increased levels of HIF-1α expression and decreased levels of VHL. In neuroblastoma tumors, Ognibene et al also observed that most hypoxic tumors present high expression of HIF-1α, which is a prognostic indicator to stratify high-risk patients [ 24 ]. In renal carcinoma cells, densitometry analysis revealed that the protein expression of VHL in cancerous tissue was lower when compared to normal adjacent tissue of the patients [ 25 ].…”