Distribution and Variable Expression of Secretory Pathway Protein Reticulocalbin in Normal Human Organs and Non-neoplastic Pathological Conditions

Abstract

Reticulocalbin (RCN) is one member of the Ca2+-binding proteins in the secretory pathway and is localized in the endoplasmic reticulum. RCN may play a role in the normal behavior and life of cells, although its detailed role remains unknown. Overexpression of RCN may also play a role in tumorigenesis, tumor invasion, and drug resistance. The new antibody for human RCN is used in the distribution of RCN in normal human organs of fetuses and adults with or without inflammation. Immunohistochemical examination demonstrated a broad distribution of RCN in various organs of fetuses and adults, predominantly in the endocrine and exocrine organs. However, RCN expression was heterogeneous in each constituent cell of some organs. Among non-epithelial organs, vascular endothelial cells, testicular germ cells, neurons, and follicular dendritic cells showed strong staining. Plasma cells were the only RCN-positive cells among hematopoietic and lymphoid cells. In inflammatory conditions, RCN expression was enhanced in both epithelial and non-epithelial cells. Heterogeneous expression of RCN indicates that the amount of RCN needed for cell behavior and life may be variable, depending on each cell type and, therefore, RCN may be helpful in establishing the cell origin of neoplasms in some organs. However, further study is needed to establish the significance of RCN in tumorigenesis and in some peculiar features of neoplasms.

Analysis of Pax6 Contiguous Gene Deletions in the Mouse, Mus musculus, Identifies Regions Distinct from Pax6 Responsible for Extreme Small-Eye and Belly-Spotting Phenotypes

“…Figure 4 (Ozawa and Muramatsu 1993;Weis et al 1994;Ozawa 1995a,b;Tachikui et al 1997). Rcn1 has been shown to be expressed in a number of tissues (Fukuda et al 2007), including the eye (present study). Linkage between Pax6 and Rcn1 has been conserved among mouse, man, and fish (Kent et al 1997;Miles et al 1998;Kleinjan et al 2008).…”

Time Series Proteome Profiling To Study Endoplasmic Reticulum Stress Response

“…36 More recent studies have suggested that overexpression of RCN may play a role in tumor progression, invasiveness and resistance to chemotherapy. 37 In this investigation, RCN-3 was the most affected protein, with a 7-fold down-regulation after 24 h treatment with Thp. Conversely, RCN-1, which shares 58% sequence homology with RCN-3 (Supplemental Figure 1), was only down-regulated by a factor of 1.65 ± 0.12.…”

Microarray analysis of perichondral and reserve growth plate zones identifies differential gene expressions and signal pathways

“…Although described previously in primary osteoblasts and osteoclasts, it has not yet been reported in the growth plate [23]. Reticulocalbin (Rcn1), which is distributed predominantly in endocrine and exocrine organs, is one member of the Ca 2+ -binding proteins in the secretory pathway [24]. Carnitinine palmitoyltransferase 1A (Cpt1a) is the key regulatory enzyme of hepatic long-chain fatty acid β-oxidation [25].…”