Grp78 is required for intestinal Kras-dependent glycolysis proliferation and adenomagenesis.

In development of colorectal cancer, mutations in are often followed by mutations in oncogene The latter changes cellular metabolism and is associated with the Warburg phenomenon. Glucose-regulated protein 78 () is an important regulator of the protein-folding machinery, involved in processing and localization of transmembrane proteins. We hypothesize that targeting in and ()-mutant intestines interferes with the metabolic phenotype imposed by mutations.

Translation initiation factor eIF2Bε promotes Wnt-mediated clonogenicity and global translation in intestinal epithelial cells.

Modulation of global mRNA translation, which is essential for intestinal stem cell function, is controlled by Wnt signaling. Loss of tumor supressor APC in stem cells drives adenoma formation through hyperactivion of Wnt signaling and dysregulated translational control. It is unclear whether factors that coordinate global translation in the intestinal epithelium are needed for APC-driven malignant transformation.

Driver mutations of the adenoma-carcinoma sequence govern the intestinal epithelial global translational capacity.

Deregulated global translation is an emerging feature of cancer cells. Oncogenic transformation in colorectal cancer (CRC) is driven by mutations in , , , and , known as the adenoma-carcinoma sequence (ACS). Here we introduce each of these driver mutations into intestinal organoids to show that they are modulators of global translational capacity in intestinal epithelial cells.

Expression of UPR effector proteins ATF6 and XBP1 reduce colorectal cancer cell proliferation and stemness by activating PERK signaling.

The unfolded protein response (UPR) acts through its downstream branches, PERK-eIF2α signaling, IRE1α-XBP1 signaling and ATF6 signaling. In the intestine, activation of the UPR through the kinase PERK results in differentiation of intestinal epithelial stem cells and colon cancer stem cells, whereas deletion of XBP1 results in increased stemness and adenomagenesis. How downstream activation of XBP1 and ATF6 influences intestinal stemness and proliferation remains largely unknown.

Heterozygosity of Chaperone Grp78 Reduces Intestinal Stem Cell Regeneration Potential and Protects against Adenoma Formation.

Deletion of endoplasmic reticulum resident chaperone Grp78 results in activation of the unfolded protein response and causes rapid depletion of the entire intestinal epithelium. Whether modest reduction of Grp78 may affect stem cell fate without compromising intestinal integrity remains unknown. Here, we employ a model of epithelial-specific, heterozygous deletion by use of mice and organoids.

Induction of endoplasmic reticulum stress by deletion of Grp78 depletes Apc mutant intestinal epithelial stem cells.

Intestinal epithelial stem cells are highly sensitive to differentiation induced by endoplasmic reticulum (ER) stress. Colorectal cancer develops from mutated intestinal epithelial stem cells. The most frequent initiating mutation occurs in Apc, which results in hyperactivated Wnt signalling.