Prognostic significance of Bcl-2, Bcl-xL/S, Bax and Bak expressions in colorectal carcinomas.

Expression of apoptosis-related markers and clinical outcome in patients with advanced colorectal cancer

“…The last finding prompted us to investigate the information provided by bax, an apoptosis promoter, with that provided by bcl-2, an apoptosis suppressor. Previous reports on colorectal carcinoma established an association between bcl-2 positive staining and good prognosis (Ofner et al, 1995;Baretton et al, 1996), suggesting that bcl-2 promoted cell survival in slowly growing tumours, which was recently confirmed by Ogura et al (1999) and is in keeping with results obtained in other solid tumours (Silvestrini et al, 1994). All these studies, however, referred to patients with operable colorectal cancer submitted to surgery as the only therapeutic approach.…”

“…In both studies bax expression and/or mutational status proved to be significantly related to clinical outcome. In fact, in these studies involving 58 (Ogura et al, 1999) and 41 (Sturm et al, 1999) patients, those with high bax protein expression had a longer survival than patients with low bax expression, and this finding was especially evident for patients with wild-type p53 liver metastases (Sturm et al, 1999). However, in a group of patients submitted to preoperative radiochemotherapy for locally advanced rectal carcinoma Tannapfel et al (1998) did not find any correlation between the level of bax expression and the degree of clinical-to-pathological downstaging or the frequency of tumour recurrence.…”

“…Among the different approaches to evaluate cell susceptibility to the activation of apoptosis, we focused on the expression of two negative and positive regulatory proteins, bcl-2 and bax, whose immunocytochemical determination proved to be feasible on archival specimens and associated with tumour progression and treatment response in different clinical situations involving various tumour types (Krajewski et al, 1995;Barretton et al, 1996;Apolinario et al, 1997;Bonetti et al, 1998;Silvestrini et al, 1998;Tai et al, 1998;Daidone et al, 1999;Ogura et al, 1999;Sturm et al, 1999). Bax represents a pro-apoptotic member of the bcl-2 family which controls important checkpoints during the apoptotic process and whose transcriptional activation is induced by wild-type p53.…”

“…To our knowledge only two studies have evaluated the prognostic relevance of the apoptosis promoter bax in patients with resectable primary colorectal cancer (Ogura et al, 1999) and liver metastases from colorectal cancer (Sturm et al, 1999) submitted to surgery without any adjuvant treatment. In both studies bax expression and/or mutational status proved to be significantly related to clinical outcome.…”

Overexpression of hRFI inhibits 5-fluorouracil-induced apoptosis in colorectal cancer cells via activation of NF-κB and upregulation of BCL-2 and BCL-XL

“…Finally, the apoptosis regulators are known to be closely related to both chemosensitivity and prognosis in colorectal cancer (Kahlenberg et al, 2003). In particular, the expression of Bcl-2 family proteins is an important determinant of the chemosensitivity to 5-FU in colorectal cancer cells (Maurer et al, 1998;Ogura et al, 1999;Nita et al, 1998Nita et al, , 2000Violette et al, 2002). We have revealed in this study that hRFI overexpression in colorectal cancer cells elicits an increase of IC 50 values towards 5-FU as well as the specific upregulation of Bcl-2 and Bcl-XL.…”