ELAPOR1, also known as KIAA1324, is an evolutionarily conserved protein containing a mannose-6-phosphate receptor (M6PR) domain. It is a target of the transcription factor MIST1 and plays a crucial role in secretory granule maturation. ELAPOR1 is specifically expressed in zymogenic cells in the stomach and is involved in the regulation of secretory vesicle trafficking [1].

In vivo, Elapor1-/-mice showed defective secretory granule maturation in zymogenic cells, demonstrating its essential function in this process [1]. In cancer research, high ELAPOR1 levels are associated with favorable disease-free and overall survival in colorectal cancer patients. Overexpression of ELAPOR1 significantly inhibits cell proliferation and invasion in CRC cell lines, while ELAPOR1-shRNA promotes these processes [2]. In pancreatic cancer, diminished ELAPOR1 expression is linked to high histological grade, advanced disease stage, and reduced patient survival. ELAPOR1 transgene expression inhibits migration and invasion of PDAC cells and induces characteristics of the classical/progenitor subtype [3].

In conclusion, ELAPOR1 is essential for normal secretory granule maturation in zymogenic cells. Its loss-of-function models, such as the Elapor1-/-mice, have revealed its importance in maintaining exocrine cell architecture. In cancer, ELAPOR1 shows potential as a prognostic indicator and a therapeutic target, with its reduced expression associated with more aggressive disease phenotypes in colorectal and pancreatic cancers [1,2,3].

References:

1. Cho, Charles J, Park, Dongkook, Mills, Jason C. 2021. ELAPOR1 is a secretory granule maturation-promoting factor that is lost during paligenosis. In American journal of physiology. Gastrointestinal and liver physiology, 322, G49-G65. doi:10.1152/ajpgi.00246.2021. https://pubmed.ncbi.nlm.nih.gov/34816763/

2. Huang, Anzhong, Qin, Chunzhi, Wu, Mengting, Wu, Guangbin, Sun, Peilong. . ELAPOR1 suppresses tumor progression in colorectal cancer and indicates favorable prognosis. In Cancer biomarkers : section A of Disease markers, 37, 279-288. doi:10.3233/CBM-220285. https://pubmed.ncbi.nlm.nih.gov/37334577/

3. Ohara, Yuuki, Liu, Huaitian, Craig, Amanda J, Ambs, Stefan, Hussain, S Perwez. 2024. ELAPOR1 induces the classical/progenitor subtype and contributes to reduced disease aggressiveness through metabolic reprogramming in pancreatic cancer. In International journal of cancer, 155, 569-581. doi:10.1002/ijc.34960. https://pubmed.ncbi.nlm.nih.gov/38630934/