10779/rcsi.10789751.v1 Steven Carberry Steven Carberry Beatrice D'Orsi Beatrice D'Orsi Naser Monsefi Naser Monsefi Manuela Salvucci Manuela Salvucci Orna Bacon Orna Bacon Joanna Fay Joanna Fay Markus Rehm Markus Rehm Deborah A. McNamara Deborah A. McNamara Elaine W. Kay Elaine W. Kay Jochen H M Prehn Jochen H M Prehn The BAX/BAK-like protein BOK is a prognostic marker in colorectal cancer. Royal College of Surgeons in Ireland 2019 bcl2-Associated X Protein colorectal cancer Physiology Medical Physics 2019-11-22 16:52:58 Journal contribution https://repository.rcsi.com/articles/journal_contribution/The_BAX_BAK-like_protein_BOK_is_a_prognostic_marker_in_colorectal_cancer_/10789751 <p>The intrinsic or mitochondrial apoptosis pathway is controlled by the interaction of antiapoptotic and pro-apoptotic members of the BCL-2 protein family. Activation of this death pathway plays a crucial role in cancer progression and chemotherapy responses. The BCL-2-related ovarian killer (BOK) possesses three BCL-2 homology domains and has been proposed to act in a similar pro-apoptotic pathway as the pro-apoptotic proteins BAX and BAK. In this study, we showed that stage II and III colorectal cancer patients possessed decreased levels of BOK protein in their tumours compared to matched normal tissue. BOK protein levels in tumours were also prognostic of clinical outcome but increased BOK protein levels surprisingly associated with earlier disease recurrence and reduced overall survival. We found no significant association of BOK protein tumour levels with ER stress markers GRP78 or GRP94 or with cleaved caspase-3. In contrast, BOK protein levels correlated with Calreticulin. These data indicate BOK as a prognostic marker in colorectal cancer and suggest that different activities of BOK may contribute to cancer progression and prognosis.</p>