Endocrine secretory granules (ESGs) are morphological characteristics of endocrine/neuroendocrine cells and store peptide hormones/neurotransmitters. ESGs contain prohormones and ESG-related molecules, mainly chromogranin/secretogranin family proteins. However, the precise mechanism of ESG formation has not been elucidated. In this study, we experimentally induced ESGs in the non-neuroendocrine lung cancer cell line H1299. Since repressive element 1 silencing transcription factor (REST) and prospero homeobox 1 (PROX1) are closely associated with the expression of ESG-related molecules, we edited the REST gene and/or transfected PROX1 and then performed molecular biology, immunocytochemistry, and electron and immunoelectron microscopy assays to determine whether ESG-related molecules and ESGs were induced in H1299 cells. Although chromogranin/secretogranin family proteins were induced in H1299 cells by knockout of REST and the induction was accelerated by the PROX1 transgene, the ESGs could not be defined by electron microscopy. However, a small number of ESGs were detected in the H1299 cells lacking REST and expressing pro-opiomelanocortin (POMC) by electron microscopy. Furthermore, many ESGs were produced in the REST-lacking and PROX1- and POMC-expressing H1299 cells. These findings suggest that a lack of REST and the expression of genes related to ESG content are indispensable for ESG production and that PROX1 accelerates ESG production.

Trial registration: Not applicable.

内分泌分泌颗粒 (ESG) 是内分泌/神经内分泌细胞的形态特征，并储存肽激素/神经递质。ESG 包含激素原和 ESG 相关分子，主要是嗜铬粒蛋白/分泌粒蛋白家族蛋白。然而，ESG形成的确切机制尚未阐明。在这项研究中，我们在非神经内分泌肺癌细胞系 H1299 中通过实验诱导 ESG。由于抑制元件 1 沉默转录因子 (REST) 和 prospero 同源框 1 (PROX1) 与 ESG 相关分子的表达密切相关，我们编辑了REST基因和/或转染PROX1，然后进行分子生物学、免疫细胞化学以及电子和免疫电子显微镜测定以确定ESG相关分子和ESG是否在H1299细胞中被诱导。尽管通过敲除REST在 H1299 细胞中诱导嗜铬粒蛋白/分泌粒蛋白家族蛋白PROX1转基因加速了诱导，电子显微镜无法确定ESG。然而，通过电子显微镜在缺乏 REST 并表达阿黑皮质素原 (POMC) 的 H1299 细胞中检测到少量 ESG。此外，在缺乏 REST 和表达 PROX1 和 POMC 的 H1299 细胞中产生了许多 ESG。这些发现表明，缺乏 REST 和与 ESG 含量相关的基因表达对于 ESG 的产生是必不可少的，并且 PROX1 加速了 ESG 的产生。

试用注册：不适用。