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

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.

The aim of the present study was to investigate the impact of elevated level of GRP78 on CRC prognosis and chemosensitivity.

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.

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.

Results suggest the possibility to use GRP78 as a biomarker for progression of CRC and its chemosensitivity to therapy.