Expression and subcellular localization of menin in human cancer cells

Abstract

Abstract. The aim of this study was to elucidate the expression and localization of menin, a protein encoded by the multiple endocrine neoplasia type I (MEN1) gene, in 13 human cancer cell lines. Reverse transcription-polymerase chain reaction (RT-PCR) was used to determine the expression of the menin gene. The localization of the menin protein was detected by immunofluorescence microscopy. Western blotting was used to determine the quantity of menin in the nucleus, cytosol and membrane of the cells. RT-PCR revealed that menin was expressed in all the cell lines examined in this study. Immunofluorescence microscopy revealed that menin was located primarily in the nucleus. In the GES-1 (transformed human gastric epithelium), MCF-7 (breast cancer), SGH44 (brain glioma) and HeLa (cervical cancer) cell lines, menin was also found to be localized to the membrane, cytosol and nucleus. Moreover, in SGH44 cells more menin was located in the cytosol than the nucleus. Similar findings were obtained by western blotting. In the GES-1 and MKN-28 cells undergoing octreotide treatment, cytoplasmic menin was significantly increased compared with the control groups. Therefore, we suggest that menin is expressed in a number of human cancer cell lines and that the cytosolic distribution increases when the cells undergo octreotide treatment, indicating a new role for menin.

Neuroendocrine Breast Carcinomas Share Prognostic Factors with Gastroenteropancreatic Neuroendocrine Tumors: A Putative Prognostic Role of Menin, p27, and SSTR-2A

“…This case study and our observation of menin in the poor local RFS of NEBC patients suggest a putative role of menin and ESR1 mutations in the development of DOI: 10.1159/000493348 drug resistance. While data on menin in NEBC are lacking, Ren et al [44] reported that the luminal breast cancer cell lines expressed mainly cytoplasmic menin, similar to this study. Based on the previous preclinical data and our results on NEBC, we suggest that the prognostic value of menin expression should be evaluated in ER-positive breast cancer in a prospective setting.…”

Menin Immunoreactivity in Secretory Granules of Human Pancreatic Islet Cells

“…In situ analysis performed by several groups also demonstrate nuclear localization of the protein, although the results depend on the particular antibody and/or technique employed (immunohistochemistry versus immunofluorescence) and the biological source of the sample (mouse versus human) (35, 38-40). Alternatively, some published IHC reports describe cytoplasmic menin staining or a shuttling of the protein amongst cellular compartments (41-43). …”

Updates on the Role of Molecular Alterations and NOTCH Signalling in the Development of Neuroendocrine Neoplasms

“…The menin protein is usually located in the nucleus, cytoplasm and around telomeres. However, its specific biological role has not yet been described [26].…”