Expression of glucose regulated protein 78 (GRP78) determines colorectal cancer response to chemotherapy

BACKGROUND: Colorectal cancer (CRC) is an important health problem all over the world. A great improvement in the screening and early detection of CRC has been achieved. However, a new molecular prognostic marker is largely required. Glucose regulated protein 78-kDa (GRP78) is the central regulator of the endoplasmic reticulum (ER) and has an important role in the proliferation, differentiation and resistance to chemotherapy in cancer cells. OBJECTIVE: The aim of the present study was to investigate the impact of elevated level of GRP78 on CRC prognosis and chemosensitivity. METHODS: Sixty eight CRC tissue samples were collected and protein expression of GRP78 was evaluated using immunohistochemistry. The clinicopathological factors of the patients were correlated with GRP78 level. RESULTS: GRP78 expression increased with the progression from early to advanced CRC stages. In addition, GRP78 level was increased with the progression from early T1-2 to late T3-4 tumor localization (p < 0.05). Moreover, a significant association was found between GRP78 expression and response to chemotherapy (p < 0.05). Association between GRP78 expression and patient's clinical characteristics including lymph node involvement and metastasis was not significant. CONCLUSIONS: Results suggest the possibility to use GRP78 as a biomarker for progression of CRC and its chemosensitivity to therapy.