Aptamers are oligonucleotide or peptide molecules that bind to a target molecule with high affinity and specificity. The present study aimed to evaluate the target specificity and applicability for in vivo molecular imaging of an aptamer labeled with a radioisotope. The human epidermal growth factor receptor 2 (HER2/ErbB2) aptamer was radiolabeled with ¹⁸F-fluoride. HER2-positive tumor cell uptake of the aptamer was evaluated in comparison to negative controls by flow cytometry and confocal microscopy. Using ¹⁸F-labeled HER2-specific aptamer positron emission tomography (PET), in vivo molecular images of BT474 tumor-bearing mice were taken at 60, 90 and 120 minutes after injection. In flow cytometric analysis, HER2 aptamer showed strong binding to HER2-positive BT474 cells, while binding to HER2-negative MDA-MB231 cells was quite low. Likewise, in confocal microscopic images, the aptamer was bound to HER2-positive breast cancer cells, with minimal binding to HER2-negative cells. In vivo PET molecular imaging of BT474 tumor-bearing mice revealed significant higher uptake of the ¹⁸F-labeled HER2 specific aptamer into the tumor compared to the that of HER2-negative cell tumor(p = 0.033). HER2 aptamer was able to preferentially bind to HER2-positive breast cancer cells both in vitro and in vivo, by recognizing HER2 structure on the surface of these cells. The ¹⁸F-labeled aptamer enabled appropriate visualization of HER2 expression by human breast cancer cells. The results suggest that a radiolabeled HER2 aptamer could potentially be applied in the development of treatment strategies or in targeted therapy against HER2-positive breast cancer cells.

BACKGROUND AND PURPOSE: The association of perivascular spaces in the centrum semiovale with amyloid accumulation among patients with Alzheimer disease–related cognitive impairment is unknown. We evaluated this association in patients with Alzheimer disease–related cognitive impairment and β-amyloid deposition, assessed with [¹⁸F] florbetaben PET/CT. MATERIALS AND METHODS: MR imaging and [¹⁸F] florbetaben PET/CT images of 144 patients with Alzheimer disease–related cognitive impairment were retrospectively evaluated. MR imaging–visible perivascular spaces were rated on a 4-point visual scale: a score of ≥3 or <3 indicated a high or low degree of MR imaging–visible perivascular spaces, respectively. Amyloid deposition was evaluated using the brain β-amyloid plaque load scoring system. RESULTS: Compared with patients negative for β-amyloid, those positive for it were older and more likely to have lower cognitive function, a diagnosis of Alzheimer disease, white matter hyperintensity, the Apolipoprotein E ε4 allele, and a high degree of MR imaging–visible perivascular spaces in the centrum semiovale. Multivariable analysis, adjusted for age and Apolipoprotein E status, revealed that a high degree of MR imaging–visible perivascular spaces in the centrum semiovale was independently associated with β-amyloid positivity (odds ratio, 2.307; 95% CI, 1.036–5.136; P = .041). CONCLUSIONS: A high degree of MR imaging–visible perivascular spaces in the centrum semiovale independently predicted β-amyloid positivity in patients with Alzheimer disease–related cognitive impairment. Thus, MR imaging–visible perivascular spaces in the centrum semiovale are associated with amyloid pathology of the brain and could be an indirect imaging marker of amyloid burden in patients with Alzheimer disease–related cognitive impairment.

Role of LOXL2 in the epithelial-mesenchymal transition and colorectal cancer metastasis Role of LOXL2 in the epithelial-mesenchymal transition and colorectal cancer metastasis

To determine whether persisting cervical fluorodeoxyglucose (FDG) uptake after concurrent chemoradiotherapy (CCRT) for cervical cancer can reflect residual malignancy.

Supradiaphragmatic lymph node metastases (SdLNM) are frequently identified using 18F-FDG positron emission tomography/computed tomography (PET/CT) in advanced epithelial ovarian cancers (AEOC). This study aimed to determine the prognostic significance of SdLNM detected by PET/CT in patients with AEOC. Medical records of patients diagnosed with AEOC were retrospectively registered from January 2009 to July 2015. Patients were categorized according to PET/CT stage: PET/CT stage III, PET/CT stage IV with SdLNM, and PET/CT stage IV with other metastases. Clinicopathologic characteristics, recurrence patterns, survival outcomes were compared according to PET/CT stage. Anatomical distribution of SdLNM and effect of thoracic debulking surgery were estimated. A total of 295 patients were identified, including 176 patients who underwent primary debulking surgeries (PDS). Progression-free (P = 0.671) and overall (P = 0.525) survival did not differ significantly between patients with PET/CT IV with SdLNM and PET/CT IV with other metastases; however, patients with PET/CT IV with SdLNM had significantly poorer progression-free (P < 0.001) and overall (P = 0.016) survival than those with PET/CT stage III. Recurrence patterns were similar in all groups; intraperitoneal metastasis was the most common (78.8%) and thoracic recurrence alone accounted for less than 10%. Debulking of SdLNM lesions did not improve progression-free survival (P = 0.425) or overall survival (P = 0.465) of patients with AEOC. SdLNM detected using preoperative PET/CT are a negative prognostic factor in AEOC. Resection of suspicious SdLNM may not have effect to survival of patients with AEOC.