MRI features of pituitary adenoma apoplexy and their relationship with hypoxia, proliferation, and pathology

Abstract

Objective We aim to study the MRI features of pituitary adenoma (PA) apoplexy and their relationship with hypoxia, proliferation, and pathology. Methods Sixty‐seven patients with MRI signs of PA apoplexy were selected. According to the MRI signs, they were divided into the parenchymal group and the cystic group. The parenchymal group had a low signal area on T2WI without cyst >2 mm and this area was not significantly enhanced on the corresponding TW1 enhancement. The cystic group had a cyst >2 mm on T2WI, and the cyst showed liquid stratification on T2WI or high signal on T1WI. The relative T1WI (rT1WI) enhancement value and relative T2WI (rT2WI) value of non‐apoplexy areas were measured. Protein levels of hypoxia‐inducible factor‐1 (HIF‐1α), pyruvate dehydrogenase kinase 1 (PDK1), and Ki67 were detected with immunohistochemistry and Western blot. Nuclear morphology was observed with HE staining. Results The rT1WI enhancement average value, rT2WI average value, Ki67 protein expression level, and the number of abnormal nuclear morphology of non‐apoplexy lesions in the parenchymal group were significantly lower than those in the cystic group. The protein expression levels of HIF‐1α and PDK1 in the parenchymal group were significantly higher than those in the cystic group. HIF‐1α protein was positively correlated with PDK1 but negatively correlated with Ki67. Conclusion When there is PA apoplexy, the ischemia and hypoxia of the cystic group are lesser than those of the parenchymal group, but the proliferation is stronger.

Hypoxia effect on proliferative activity of cells in orthotopic xenograft of hepatocellular carcinoma of the liver in the experiment

“…Гипоксия также может вызывать остановку роста раковых клеток, замедление пролиферации и, в последующем, их гибель. Было показано, что факторы, индуцируемые гипоксией, непосредственно влияют на пролиферативную активностью опухолевых клеток [5]. Самый широко используемый маркер пролиферации как в нормальных, так и в опухолевых клетках -белок Ki-67.…”