GRP78 Protein Expression as Prognostic Values in Neoadjuvant Chemoradiotherapy and Laparoscopic Surgery for Locally Advanced Rectal Cancer.

PURPOSE: We investigated the relationships between biomarkers related to endoplasmic reticulum stress proteins (glucose-regulated protein of molecular mass 78 [GRP78] and Cripto-1 [teratocarcinoma-derived growth factor 1 protein]), pathologic response, and prognosis in locally advanced rectal cancer. MATERIALS AND METHODS: All clinical stage II and III rectal cancer patients received 50.4 Gy over 5.5 weeks, plus 5-fluorouracil (400 mg/m(2)/day) and leucovorin (20 mg/m(2)/day) bolus on days 1 to 5 and 29 to 33, and surgery was performed at 7 to 10 weeks after completion of all therapies. Expression of GRP78 and Cripto-1 proteins was determined by immunohistochemistry and was assessed in 101 patients with rectal cancer treated with neoadjuvant chemoradiotherapy (CRT). RESULTS: High expression of GRP78 and Cripto-1 proteins was observed in 86 patients (85.1%) and 49 patients (48.5%), respectively. Low expression of GRP78 protein was associated with a significantly high rate of down staging (80.0% vs. 52.3%, respectively; p=0.046) and a significantly low rate of recurrence (0% vs. 33.7%, respectively; p=0.008) compared with high expression of GRP78 protein. Mean recurrence-free survival according to GRP78 expression could not be estimated because the low expression group did not develop recurrence events but showed a significant correlation with time to recurrence, based on the log rank method (p=0.007). GRP78 also showed correlation with overall survival, based on the log rank method (p=0.045). CONCLUSION: GRP78 expression is a predictive and prognostic factor for down staging, recurrence, and survival in rectal cancer patients treated with 5-fluorouracil and leucovorin neoadjuvant CRT.

GRP78 Protein Expression as Prognostic Values in Neoadjuvant Chemoradiotherapy and Laparoscopic Surgery for Locally Advanced Rectal Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: We investigated the relationships between biomarkers related to endoplasmic reticulum stress proteins (glucose-regulated protein of molecular mass 78 [GRP78] and Cripto-1 [teratocarcinoma-derived growth factor 1 protein]), pathologic response, and prognosis in locally advanced rectal cancer. MATERIALS AND METHODS: All clinical stage II and III rectal cancer patients received 50.4 Gy over 5.5 weeks, plus 5-fluorouracil (400 mg/m2/day) and leucovorin (20 mg/m2/day) bolus on days 1 to 5 and 29 to 33, and surgery was performed at 7 to 10 weeks after completion of all therapies. Expression of GRP78 and Cripto-1 proteins was determined by immunohistochemistry and was assessed in 101 patients with rectal cancer treated with neoadjuvant chemoradiotherapy (CRT). RESULTS: High expression of GRP78 and Cripto-1 proteins was observed in 86 patients (85.1%) and 49 patients (48.5%), respectively. Low expression of GRP78 protein was associated with a significantly high rate of down staging (80.0% vs. 52.3%, respectively; p=0.046) and a significantly low rate of recurrence (0% vs. 33.7%, respectively; p=0.008) compared with high expression of GRP78 protein. Mean recurrence-free survival according to GRP78 expression could not be estimated because the low expression group did not develop recurrence events but showed a significant correlation with time to recurrence, based on the log rank method (p=0.007). GRP78 also showed correlation with overall survival, based on the log rank method (p=0.045). CONCLUSION: GRP78 expression is a predictive and prognostic factor for down staging, recurrence, and survival in rectal cancer patients treated with 5-fluorouracil and leucovorin neoadjuvant CRT.

The Molecular Chaperone GRP78/BiP as a Therapeutic Target for Neurodegenerative Disorders: A Mini Review.

The glucose regulated protein 78 (GRP78), also known as BiP, is the endoplasmatic reticulum (ER) homologue of HSP70, which plays a dual role in the ER by controlling protein folding, in order to prevent aggregation, and by regulating the signaling of the unfolded protein response (UPR). Most neurodegenerative disorders including Parkinson's, Alzheimer's diseases and progressive retinal degeneration are characterized by activation of the UPR and modified expression of GRP78. The expression levels and activity of GRP78 are altered with age raising the question of whether the lack of GRP78 could be a predisposing factor for many neurodegenerative disorders associated with age including PD, Alzheimer and Age-related macular degeneration. Attempts to induce or upregulate GRP78 in animal models of neurodegeneration have recently been made with the help of pharmacological BiP protein Inducer X (BIX) and GRP78 cDNA delivery via adeno-associated virus (AAV) vectors. The results of these studies validate GRP78 as a new therapeutic target for treatments of forebrain ischemia, Parkinson disease and retinal degeneration. These data, together with the results from age-related studies, highlight the importance for developing drugs to induce elevation of endogenous GRP78 in order to increase cellular survival and extend functional longevity.

Ischemic preconditioning in the protection of global cerebral ischemia in rats by reducing endoplasmic reticulum stress / 国际脑血管病杂志

Objective To investigate the effect of inhibition of endoplasmic reticulum stress (ERS) in ischemic preconditioning-induced cerebral ischemia tolerance.Methods A total of 120 adult male SpragueDawley rats were randomly allocated into three groups:sham operation,global cerebral ischemic and ischemic preconditioning groups (ischemic preconditioning for 3 minutes,and global cerebral ischemia for 15 minutes after 2 days).Three time points (day 1,day 3 and day 7) were set.Sugawara method was used to observe the changes of neurological behavior in rats.TUNEL staining was used to observe the conditions of cortical neuronal apoptosis.Immunofluorescence staining and Western blot analysis were used to detect the expression levels of ERS-related protein CHOP,GRP78,and caspase-12.Results The neurological behavior score showed that the sham operation group did not have neurological deficits.Both the global cerebral ischemic group and the ischemic preconditioning group had obvious neurological deficits,and they improved gradually with the passage of time,but after modeling,the neurological scores at each time point in the global cerebral ischemic were significantly lower than those in the ischemic preconditioning group:at day 1∶11.00 ±0.63 vs.14.33 ±0.33 (t =21.74,P＝0.001); at day 3∶ 12.17±0.31vs.15.17±0.48 (t=27.93,P =0.000); at day 7:14.67±0.49 vs.16.33 ±0.33 (t =7.81,P=0.020).TUNEL staining showed that at day 7 after ischemia,the positive cell count per mm2 in the sham operation,global cerebral ischemic and ischemic preconditioning groups were 4.83 ±1.85vs.395.67± 43.43 and 146.17± 27.38 respectively (F=23.62,P=0.001).The ischemic preconditioning group was significantly lower than that in the global cerebral ischemic group (P =0.001).Immunofluorescence staining showed that at day 7 after ischemia,the numbers of positive cells of CHOP (26.50±3.89vs.82.33±4.25; P=0.000),GRP78 (15.00±2.02vs.35.67±2.99; t=0.000),and caspase-12 (22.33 ± 2.76 vs.66.50± 7.25; P=0.000) in the ischemic preconditioning group were significantly less than those in the global cerebral ischemic group.Western blotting showed that at day 7 after ischemia,the expression levels of CHOP (1.22 ± 0.38 vs.3.22 ± 0.51; t =24.50,P =0.001),GRP78 (1.78 ± 0.45 vs.3.16 ± 0.76; t =14.29,P =0.005),and caspase-12 (2.89 ± 0.53 vs.5.96 ± 0.67; t =77.73; P =0.000) in the ischemic preconditioning group were significantly lower than those in the global cerebral ischemic group.Conclusions Ischemic preconditioning demonstrated a neuroprotective effect for the second lethal ischemia,its mechanism may be associated with the relief of ERS and downregulation of ERS-related protein.