To clarify the roles of vitamin D and calcium as potential chemopreventive agents against colorectal cancer in humans, and to develop "treatable", pre-neoplastic, phenotypic biomarkers of risk for colorectal neoplasms, we estimated the effects of supplemental vitamin D3 (1,000 IU/day [25 μg/day]) and calcium (1,200 mg/day), alone and in combination, on biomarkers of proliferation (mib-1), differentiation (p21), and apoptosis (bax [apoptosis-promoting] and bcl-2 [apoptosis-inhibiting]), in the normal-appearing rectal mucosa in a subsample of participants (n = 104) in a larger randomized, double-blind, placebo-controlled clinical trial among colorectal adenoma patients.
We found that the HIF-1α gene expression, HIF-1α protein concentration, and IHC expression of HIF-1α, GLUT-1, Ki-67, and Bcl-2 were not systematically affected by either the fixation or freezing delay of the tissue, the perioperative ischemia time, or the total ischemia time (perioperative ischemia+delay of fixation or freezing) in colorectal tumors.
Loss of pSer70 Bcl-2 expression is closely linked to biological aggressiveness in colorectal tumors and represents a statistically significant molecular index for prognosis of patients with these tumors.
Loss of pSer70 Bcl-2 expression is closely linked to biological aggressiveness in colorectal tumors and represents a statistically significant molecular index for prognosis of patients with these tumors.
The aim of this study was to determine the frequency of apoptosis in colorectal neoplasms and to examine its relationship to a number of pathological parameters, to the presence of mutations in the p53 tumor suppressor gene, and to overexpression of the bcl-2 oncoprotein.