intrinsic-factor and Adenocarcinoma

Primary gastric cancer remains one of the most prevalent malignancies worldwide. Often patients remain asymptomatic until it is detected at an advanced stage with a poor prognosis. Thus, it's characteristically difficult to initially diagnose until it becomes late stage, at which point prognosis becomes poor. Pernicious anemia is a classic risk factor for the development of primary gastric cancer, but is uncommonly seen in clinical practice. Over time, patients who produce the autoantibodies to intrinsic factor that cause pernicious anemia typically will present initially with clinically significant megaloblastic anemia and peripheral neuropathy. However, patients can also present with more nonspecific signs and symptoms. Thus, clinicians should remain vigilant as circulating anti-intrinsic factor antibodies only worsen the disease over time and increase the risk of developing primary gastric cancer. This report not only presents the rare concurrent diagnosis of pernicious anemia and gastric cancer, but also aims to increase clinical awareness of these two conditions' classic association because early diagnosis and treatment significantly impacts morbidity and mortality.

Topics: Adenocarcinoma; Anemia, Pernicious; Autoantibodies; Humans; Intrinsic Factor; Stomach Neoplasms

Pancreatic adenocarcinoma (PDAC) is mostly refractory to immunotherapies. In this issue of Immunity, Li et al. (2018) generate a library of clonal PDAC tumors to examine the tumor-intrinsic features shaping the anti-tumor immune response and find that tumor cell-derived CXCL1 directly blunts T cell infiltration and reduces responsiveness to immunotherapy.

Topics: Adenocarcinoma; Carcinoma, Pancreatic Ductal; Humans; Immune Evasion; Immunotherapy; Intrinsic Factor; Pancreatic Neoplasms; Yin-Yang

Human colon adenocarcinoma (Caco-2) cells express both intrinsic factor-cobalamin receptor and transcobalamin II (TC II). The expression of these activities began to rise by day 6 and reached peak levels between 10 and 15 days in culture. The postconfluent Caco-2 cell membranes bound approximately 30-35 fmol of intrinsic factor (IF) [57Co]Cbl/mg protein. The size of the mature receptor expressed in the apical brush border had a relative molecular mass of 230 kDa. The intracellular form of TC II had a Mr of 43, 5 higher than the secreted form of TC II. TC II was secreted unidirectionally via the basolateral direction when Caco-2 cells were grown on culture inserts. When grown on culture inserts, the Caco-2 cells were polarized (electrical resistance greater than 200 omega/cm2) and transcytosed [57Co]Cbl bound to IF from apical-to-basal but not from basal-to-apical direction. Under these conditions, [57Co]Cbl complexed to haptocorrin was not transported. These cells also transcytosed free [57Co]Cbl, although less efficiently. The [57Co]Cbl transcytosed using either IF[57Co]Cbl or free [57Co]Cbl as ligands was bound exclusively to TC II. Intracellular [57Co]Cbl decreased during transcytosis with a slow (t1/2 = 4 h) transfer of [57Co]Cbl from IF to TC II. These results show that the transport of Cbl in Caco-2 cells is very similar to the human enterocyte system.

Topics: Adenocarcinoma; Biological Transport; Cell Line; Colonic Neoplasms; Electrophoresis, Polyacrylamide Gel; Humans; Intrinsic Factor; Kinetics; Methionine; Molecular Weight; Sulfur Radioisotopes; Transcobalamins; Vitamin B 12

Topics: Adenocarcinoma; Anemia; Anemia, Pernicious; Biological Assay; Blood; Cobalt Isotopes; Gastrectomy; Gastric Acidity Determination; Geriatrics; Histamine; Humans; Intrinsic Factor; Lactobacillus; Liver; Lymphoma; Schilling Test; Stomach Neoplasms; Urine; Vitamin B 12