Search PubMed⌕ Search

Biomedical subjects

C K Banerjee

Publications and source records attributed to C K Banerjee.

At least 55 records · Page 3Linked to original sources
PubMed1981

Biochemical markers in colon tumorigenesis: retinoic acid and dihydrotestosterone-binding proteins.

A specific retinoic acid-binding protein (RABP) and a dihydrotestosterone-binding protein (DHTBP) appeared in colon tumors as well as in tissues surrounding the the tumors, but the proteins were nondetectable in normal adult human colon tissues. We have analyzed a total of 105 human colon tumors and related specimens for the presence of RABP and DHTBP as possible biochemical markers in colon tumorigenesis. The tissue or tumor extracts after incubation with (3H) retinoic acid or (3H) dihydrotestosterone were sedimented on sucrose gradients, and the binding proteins were detected from the 2S (RABP) or 6-7S (DHTBP) radioactive peaks. The overall results of the analysis illustrate that about 78% of the 74 human colon, rectum, cecum, and colorectum tumors analyzed contained RABP in detectable amounts. Thirty percent of the 20 colon tissues isolated from subjects suspected for colon cancer and 18% of the 11 normal colon tissues from autopsies contained detectable amounts of the binding protein. A comparative study on the quantitative amounts of RABP and DHTBP in colon tumors and related tissues indicates that the amount of retinoic acid or dihydrotestosterone bound per mg protein ranged from 0.8 to 5.1 pmoles in the binding protein-positive specimens. However, the relative amounts of the two binding proteins in these tissues were not in the same proportions. Appearance of RABP and/or DHTBP in the surrounding tissues of colon tumors correlated with the amounts of the binding protein(s) in the tumors. RABP of human colon tumor shared the same ligand specificity and other physicochemical characteristics as RABP of other species.

Androgen-Binding Protein↗
PubMed1980

The presence of binding proteins for retinoic acid and dihydrotestosterone in murine and human colon tumors.

Retinoic acid-binding protein (RABP), which is distinctly present in embryonic colon and lung, is below the limits of detection in adult mouse colon and lung. The binding protein is present in malignant murine colon tumors as well as in lungs of animals bearing subcutaneously implanted tumors. Primary cell cultures from 1 g of colon tumor 26 gave rise to about 10(7) tumor cells and yielded 30 mg of extractable protein. The lower limit for detection of RABP, based on the appearance of its specific 2S peak after sucrose density gradient sedimentation, was 0.1 mg of protein, which corresponds to 3.3 x 10(4) tumor cells. After subcutaneous implantation of colon tumor 26 in mice, no RABP peak was evident in the lung extracts up to the fourth day. From the fifth day onwards, RABP appeared in lung extracts, possibly as a consequence of pulmonary metastasis. Fragments of mouse lungs containing the metastatic tumor foci were reimplanted subcutaneously and produced tumors that contained RABP at levels comparable to those in colon tumor 26. The primary subcutaneous tumors and pulmonary metastatic tumors showed the same histologic appearance--an undifferentiated carcinoma. On the 15th day of subcutaneous implantation of colon tumor 26 in mice, RABP was detected in lung and brain but in none of the other tissues where the protein is normally undetectable. After intraperitoneal implantation of colon tumor 26 in mice, no well-defined RABP peaks were detected from their liver extracts. None of the three normal human colon extracts analyzed for RABP or a dihydrotestosterone-binding protein (DHTBP) contained any detectable amounts of either of the binding proteins. However, 70% of the human colon tumors contained RABP and 90% contained DHTBP. Both of these binding proteins were evident in the two human colon tissues adjoining colon tumors.

Adenocarcinoma↗
PubMed1980

Cellular uptake of retinoic acid in vitro.

Incubation of chick embryo skin and mouse colon tumour 26 with [3H]retinoic acid resulted in the formation of a complex of retinoic acid and its cellular binding protein both in cytosol and in nuclei. Formation of the ligand--protein complex was temperature-dependent and increased with increases in retinoic acid concentration in the incubation medium. About 3--8% of the ligand present in the cytosol was associated with the nuclei.

Animals↗
PubMed1980

Purification and properties of retinol- and retinoic acid-binding proteins from a transplantable mouse colon tumor.

Cellular retinol-binding protein and retinoic acid-binding protein, the possible mediators of the action of retinoids in epithelial differentiation and control of tumorigenesis, have been reproducibly purified from mouse colon tumor 26, and some of their properties were studied. The main steps of purification involved acid-precipitation, DEAE-Sephadex, CM-cellulose and Sephadex G-100 chromatography. About 2 mg of the binding proteins were isolated from 60 g tumor. The purified preparations showed only two protein bands on polyacrylamide gel electrophoresis. The two binding proteins were partially resolved by sedimentation equilibrium technique; but was completely separable by preparative electrophoresis in the presence of sodium dodecyl sulfate. The retinol- and retinoic acid-binding proteins are presumably monomers with molecular weights of 15,500 and 14,600, respectively, as determined by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. On gel filtration however, both the binding proteins retarded to the same molecular size of 17,800. On preparative columns, both the proteins expressed the same isoelectric pH, 4.5. Both proteins of the tumor possessed functional thiol groups. The mercurial inhibition of the binding capacity of the proteins for their ligands was reversible upon treatment with thiol compounds.

Animals↗
PubMed1978

Purification and properties of retinoic acid-binding protein from chick-embryo skin.

Retinoic acid-binding protein, which is considered to mediate the biological function of retinoic acid in epithelial differentiation and in the possible control of tumorigenesis, was reproducibly purified from chick-embryo skin by using DEAE-Sephadex and Sephadex G-100 column chromatography and isoelectric focusing. About 1mg of protein was isolated from 60g of skin. The purified protein-ligand complex was found to be homogeneous by electrophoresis on polyacrylamide gels. The binding protein has mol.wt. 17800 and pI 4.5. The binding of [3H]retinoic acid to the protein was completely inhibited by mercury compounds. The inhibition is reversible on treatment without dithithreitol; about 50% of the retinoic acid-binding capacity of the mercury-compound-treated protein is restored by chromatography on Sephadex G-25. iodoacetamide treatment of the protein irreversibly inhibits about 50% of retinoic acid binding.

4-Chloromercuribenzenesulfonate↗
PubMed1978

Determination of binding affinities of retinoids to retinoic acid-binding protein and serum albumin.

Binding affinities of retinoic acid and its synthetic analogues to intracellular retinoic acid-binding protein, which is a possible candidate for mediating their biological function, and to serum albumin, the plasma transport protein, were evaluated. A quantitative method involving elimination of interfering serum albumin by immunoprecipitation was developed to measure the binding efficiency of these retinoids, some of which are active in modifying epithelial differentiation and preventing tumorigenesis. Two cyclopentenyl analogues of retinoic acid and 13-cis-retinoic acid showed, like retinoic acid, a binding efficiency of 100% for the cellular binding protein. With the phenyl, dichlorophenyl and trimethylmethoxyphenyl analogues of retinoic acid, the binding efficiency increased as the substituents on the aromatic ring increased; thus the trimethylmethoxyphenyl analogue binds almost as efficiently as retinoic acid itself. However, the trimethylmethoxyphenyl analogue with a sulphur atom on the side chain has a much decreased binding affinity. The correlation noticed between the binding efficiency of these retinoids and their biological activity in differentiation and/or in the control of tumorigenesis particularly enhances the confidence in the present method of determining the relative binding efficiencies. None of the vitamins, hormones and cofactors tested, showed appreciable affinity for the retinoic acid-binding site. Studies on binding of retinoic acid and its analogues to serum albumin indicate that no correlation exists between binding affinity for albumin and their biological potency.

Animals↗
PubMed1977

Fatal proliferative glomerulonephritis in lepromatous leprosy.

A patient of lepromatous leprosy with recurrent erythema nodosum leprosum developing acute renal failure proving fatal within 8 weeks is reported. The renal lesion demonstrated acute proliferative glomerulonephritis. Its pathogenesis in relation to ENL is discussed.

Acute Kidney Injury↗