Correlation of Musashi-1, Lgr5, and pEGFR expressions in human small intestinal adenocarcinomas

Recent studies have revealed that Musashi-1 and Lgr5 (leucine-rich-repeat-containing G-protein-coupled receptor 5) were putative stem cell genes. The epidermal growth factor receptor (EGFR) has also been extensively studied; it was known as an oncogenic driver in cancers. Overexpressions of Musashi-1, EGFR, and Lgr5 have been reported in some tumor tissues and cell lines. In this study, we used immunohistochemical analysis to investigate the expression pattern of Musashi-1, Lgr5, and pEGFR in 38 small intestinal adenocarcinomas (SIAs) resection specimens, 20 matched normal specimens and tried to analyze the correlations among them. The positive rate of Musashi-1, Lgr5, and pEGFR in SIAs, respectively, was 71 % (27/38), 55 % (21/38), and 45 % (17/38). Compared with the adjacent normal small intestinal mucosa, Musashi-1, Lgr5, and pEGFR protein were overexpressed in SIAs (P< 0.05). Furthermore, Musashi-1 and Lgr5 expressions were significantly correlated with the depth of wall invasion (P = 0.0011, P = 0.0017, respectively). Musashi-1 expression was closely correlated with Lgr5 (P = 0.015, r = 0.392). However, pEGFR expression was not associated with age, gender, tumor size, differentiation, depth of invasion, lymphatic metastasis, TNM stage, and pEGFR expression was not correlated with Musashi-1 or Lgr5 (P > 0.05, r = 0.064; P > 0.05, r = 0.307, respectively). Thus, we suggest that Musashi-1, Lgr5, and pEGFR are overexpressed in human SIAs and may play roles in human SIA carcinogenesis and progression.