1st Department of Propaupedic Internal Medicine, Endocrine Oncology Unit, Laiko Hospital, National and Kapodistrian University of Athens, Athens, Greece.
Department of Surgery, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
Endocrine. 2020 May;68(2):438-447. doi: 10.1007/s12020-020-02228-1. Epub 2020 Feb 29.
BACKGROUND/AIMS: We assessed the levels of autophagy and mitophagy, that are linked to cancer development and drug resistance, in well differentiated pancreatic neuroendocrine neoplasms (PanNENs) and correlated them with clinico-pathological parameters.
Fluorescent immunostaining for the autophagy markers LC3Β and p62/or LAMP1 was performed on 22 PanNENs and 11 controls of normal pancreatic tissues and validated through Western blotting. Autophagy quantitative scoring was generated for LC3B-positive puncta and analysed in relation to clinico-pathological parameters. TOMM20/LC3B qualitative assessment of mitophagy levels was undertaken by fluorescent immunostaining. The presence of autophagy/mitophagy was validated by transmission electron microscopy.
Autophagy levels (LC3B-positive puncta/cell) were discriminative for normal vs. NEN pancreatic tissue (p = 0.007). A significant association was observed between autophagy levels and tumour grade (Ki67 < 3% vs. Ki67 ≥ 3%; p = 0.021), but not functionality (p = 0.266) size (cut-off of 20 mm; p = 0.808), local invasion (p = 0.481), lymph node- (p = 0.849) and distant metastases (p = 0.699). Qualitative assessment of TOMM20/LC3B demonstrated strong mitophagy levels in PanNENs by fluorescent immunostaining as compared with normal tissue. Transmission electron microscopy revealed enhanced autophagy and mitophagy in PanNEN tissue. Response to molecular targeted therapies in metastatic cases (n = 4) did not reveal any patterns of association to autophagy levels.
Increased autophagy levels are present in primary tumours of patients with PanNENs and are partially attributed to upregulated mitophagy. Grade was the only clinico-pathological parameter associated with autophagy scores.
背景/目的：我们评估了与癌症发展和耐药性相关的自噬和线粒体自噬水平，这些水平存在于分化良好的胰腺神经内分泌肿瘤（PanNEN）中，并将其与临床病理参数相关联。
对 22 例 PanNEN 和 11 例正常胰腺组织对照进行了自噬标志物 LC3B 和 p62/或 LAMP1 的荧光免疫染色，并通过 Western blot 进行了验证。生成了 LC3B 阳性斑点的自噬定量评分，并与临床病理参数进行了分析。通过荧光免疫染色进行了 TOMM20/LC3B 对线粒体自噬水平的定性评估。通过透射电子显微镜验证了自噬/线粒体自噬的存在。
自噬水平（LC3B 阳性斑点/细胞）可区分正常胰腺组织与 NEN 胰腺组织（p=0.007）。自噬水平与肿瘤分级（Ki67<3%与 Ki67≥3%；p=0.021）之间存在显著相关性，但与功能（p=0.266）大小（20mm 界限；p=0.808）、局部侵袭（p=0.481）、淋巴结转移（p=0.849）和远处转移（p=0.699）无关。与正常组织相比，荧光免疫染色显示 PanNEN 中的 TOMM20/LC3B 表现出强烈的线粒体自噬水平。透射电子显微镜显示 PanNEN 组织中存在增强的自噬和线粒体自噬。对转移性病例（n=4）进行的分子靶向治疗反应并未显示出与自噬水平相关的任何模式。
PanNEN 患者的原发肿瘤中存在自噬水平升高，部分归因于上调的线粒体自噬。分级是与自噬评分相关的唯一临床病理参数。
