ABSTRACT
The disorder of mitochondrial functions plays a key role in oncogenesis. It is known that TSPO (18-kDa translocator protein) lies in a peculiar location at the interface between the mitochondria and the cytosol. TSPO is found in many types of tissues and is associated with multiple cellular processes, including apoptosis, cell proliferation and the regulation of mitochondria. However, the involvement of TSPO in hepatocellular carcinoma (HCC) remains unclear. In this study, we found that TSPO is upregulated in HCC tissue and is associated with poor differentiation and poor survival. Multivariate analyses showed that TSPO was an independent predictive factor for poor prognosis in HCC patients. For the first time, we provided evidence that TSPO knockdown suppressed HCC cell proliferation in vitro. Hence, TSPO knockdown-induced apoptosis by disturbing mitochondrial function by enhancing the formation of reactive oxygen species (ROS) and decreasing the mitochondrial membrane potential (ΔΨm). An assay exploring the underlying mechanism revealed that TSPO knockdown modulated apoptotic regulatory proteins by regulating the ERK signaling pathway. Through a functional assay and an in vivo mouse model, the anti-cancer effect of PK11195, a specific ligand of TSPO, on HCC was revealed. In summary, TSPO may potentially serve as a prognostic biomarker, and TSPO might be a potential therapeutic target for HCC.
ABSTRACT
BACKGROUND: This study aimed to compare the sensitivity of 99mTc-MIBI SPECT/CT, 99mTc-MIBI planar scintigraphy and ultrasonography (US) in patients with secondary hyperparathyroidism (SHPT), and to explore the factors that affect the sensitivity of 99mTc-MIBI SPECT/CT. METHODS: In this retrospective study, forty-six patients with SHPT who underwent 99mTc-MIBI planar scintigraphy, 99mTc-MIBI SPECT/CT and US were enrolled. They underwent surgery within 1 month. We compared the sensitivity of the different imaging methods based on the lesions according to the pathological results. The parathyroid lesions on 99mTc-MIBI SPECT/CT images were divided into missed diagnosis group (MDG) and non-missed diagnosis group (NMDG). We compared the lesion to background ratio (LBR), maximum diameter, volume, the mean CT Hounsfield unit values (CTmean) and location of lesions between MDG and NMDG. RESULTS: The sensitivity of 99mTc-MIBI SPECT/CT, 99mTc-MIBI planar scintigraphy and US were 70.30% versus 48.48% versus 61.82%, respectively. The sensitivity of 99mTc-MIBI SPECT/CT combined US was 79.39%, which was higher than 99mTc-MIBI SPECT/CT with significant difference (P = 0.000). On 99mTc-MIBI SPECT/CT images, the LBR, maximum diameter and volume of lesions in MDG was smaller than those in NMDG with significant difference (P < 0.001). The average LBR, maximum diameter and volume of lesions in MDG and NMDG were 3.42 ± 1.28, 9.32 ± 2.69 mm, 208.51 ± 163.22 mm3 versus 6.75 ± 5.08, 15.03 ± 4.94 mm and 863.85 ± 1216.0 mm3, respectively. CONCLUSIONS: 99mTc-MIBI SPECT/CT exhibited the highest sensitivity among the three methods. When 99mTc-MIBI SPECT/CT combined with US, the sensitivity can be further improved. Lesions with lower MIBI uptake and smaller lesions on 99mTc-MIBI SPECT/CT images were easily missed.