52 research outputs found

    Sclerotium rolfsii Lectin Induces Stronger Inhibition of Proliferation in Human Breast Cancer Cells than Normal Human Mammary Epithelial Cells by Induction of Cell Apoptosis

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    Sclerotium rolfsii lectin (SRL) isolated from the phytopathogenic fungus Sclerotium rolfsii has exquisite binding specificity towards O-linked, Thomsen-Freidenreich (Galβ1-3GalNAcα1-Ser/Thr, TF) associated glycans. This study investigated the influence of SRL on proliferation of human breast cancer cells (MCF-7 and ZR-75), non-tumorigenic breast epithelial cells (MCF-10A) and normal mammary epithelial cells (HMECs). SRL caused marked, dose-dependent, inhibition of proliferation of MCF-7 and ZR-75 cells but only weak inhibition of proliferation of non-tumorigenic MCF-10A and HMEC cells. The inhibitory effect of SRL on cancer cell proliferation was shown to be a consequence of SRL cell surface binding and subsequent induction of cellular apoptosis, an effect that was largely prevented by the presence of inhibitors against caspases -3, -8, or -9. Lectin histochemistry using biotin-labelled SRL showed little binding of SRL to normal human breast tissue but intense binding to cancerous tissues. In conclusion, SRL inhibits the growth of human breast cancer cells via induction of cell apoptosis but has substantially less effect on normal epithelial cells. As a lectin that binds specifically to a cancer-associated glycan, has potential to be developed as an anti-cancer agent

    A rapid preparative method for the purification of vitamin E acetate by kinetic reverse phase chromatography

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    Alpha-tocopherol or vitamin E is an essential food ingredient. Due to high purity requirement in food applications, it is majorly produced in the acetate form through chemical routes. However, the isolation of food grade vitamin E acetate (VEA) is critical due to the co-generation of close characteristic impurities in the production processes. The work undertaken here provides a new kinetic chromatography method for production of food grade VEA. In this work, suitable adsorbent for chromatography separation was selected based on shallow-bed binding–elution characteristics. Loading conditions were identified by frontal adsorption behavior. Kinetic parameters and bed height for the purification was predicted by establishing the relationship between bed height, purity and the relative separation factor (RSF). The RSF of 2.8 and corresponding bed height is predicted from the established relationship for the separation of VEA from impurities. The bed height of 170 cm with isocratic mobile phase of 2% (wt/wt) water in methanol provides 98 wt.% purity of VEA with recovery of 90%. This work has highlighted methodology based on kinetic parameters for the separation of close characteristic impurities from target molecule. This work also provided the application of simple handy tools like RSF and dual wavelength detection for the rapid development of preparative separation process for VEA and other such valuable components from unknown impurities

    Pentoxifylline modulates cell surface integrin expression and integrin mediated adhesion of B16F10 cells to extracellular matrix components

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    Our previous studies demonstrated that Pentoxifylline (PTX), a phosphodiesterase inhibitor could inhibit the lung homing of B16-F10 melanoma cells in C57BL/6 mice. In this study we have looked at the effect of PTX on cell surface integrin expression and integrin mediated adhesion of B16-F10 melanoma cells. B16F10 cells treated with PTX when injected through the tail vein of mice showed a 75% reduction in pulmonary nodules as compared to control untreated cells. PTX brought about a significant reduction in the integrin mediated adhesion of F10 cells to Fibronectin and Vitronectin (58.75% + 3.4 S.E and 60% + 1.7 S.E respectively if control was considered as 100 %). This inhibition in adhesion was evident upto 4 hours only and treatment for 24 hours brought about an increase in adhesion (135.5 % + 0.5 S.E). Flow cytometric analysis showed higher surface expressions of αv, α5 and αIIb integrin subunits in B16-F10 as compared to the low metastatic cell line B16-F1 suggesting a role for these integrins in determining the metastatic potential. PTX brought about a significant decrease in the cell surface expression of α5, αIIb and β1integrin subunits but not that of the αv subunit on B16-F10 cells. PTX also brought about a reduction in the total cellular protein levels of β1 and αv integrin subunits. Various isoforms of Protein Kinase C (PKC) has been shown to regulate integrin expression, localization and activity. Hence we looked at the effect of PTX on total cellular PKC activity. PTX brought about a significant reduction in total cellular PKC activity (82.66 + 0.593). Collectively our results indicate that the antimetastatic action of PTX is mediated, at least in part through its effects on adhesion and the surface expression of specific integrin receptors

    Searching for the initiating site of the major capsid protein to generate virus-like particles for a novel laboratory mouse papillomavirus.

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    Correctly folded virus-like particles (VLPs) of papillomavirus (PV) display conformationally dependent epitopes that are type specific, maintained on authentic virions, and induce neutralizing antibodies. Alignment of the L1 amino acid (aa) sequences of 84 PVs revealed that the lengths of their N-termini are diverse and that multiple, possible initiation methionine (met) codons exist. The L1 gene of MusPV (MmuPV1), that naturally infects immunodeficient laboratory mouse strain (NMRI-Foxn1(nu)/Foxn1(nu)), has four met codons at the 1st, 2nd, 28th, and 30th aas from its N-terminus. Of these, the 3rd and 4th mets, that are at the 28th and 30th aa position from the N-termius, respectively, are located at the position where most PVs have their first met. These two mets, located at the 9th and 11th from the YLPP conserved aas of most PVs, should be considered as consensus initiation codons of PV L1s. Three L1 proteins of MusPV, starting from the 2nd, 3rd, and 4th mets, were expressed using a baculovirus expression system and characterized for their ability to self-assemble into VLPs. While MusPV L1 proteins starting from the 2nd met expressed an L1 protein that did not fold into VLPs, the L1s starting from the 3rd and 4th mets generated correct VLPs in abundant quantities. We now conclude that the highest quantity and best quality VLPs are made from the consensus L1 met of MusPV. Exp Mol Pathol 2014 Jan 2; 96(2):155-161

    Induction of lymphomas on implantation of human oral squamous cell carcinomas in nude mice

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    111-118<span style="font-size: 15.0pt;mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">Cancer cells from five oral cancer patients and pleomorphic adenoma cells from one individual were inoculated as single cell suspension in to subcutis of 30 Swiss nude mice and tail vein of additional 30 mice. Further, tumor tissue pieces from three oral cancer patients were xenografted sc in 18 nude mice, and 10 mice were kept as controls. In animals implanted with tumor pieces, 7/18 (39%) mice, developed squamous cell carcinoma at the site of inoculation within 8-15 days, while tumors were not observed in mice inoculated with single cell suspension, up to 60/90 days. In 8/68 (12%) mice, <span style="font-size: 15.0pt;mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">white foci were observed in several tissues, with hepatomegaly and splenomegaly noted in 27/68 (39%) mice. Histopathological examination of various tissues revealed presence of large cell lymphoma in several organs in 14/68 (2 1 %) mice. No regional or distant metastasis of the implanted oral tumor cells was detected. Mice injected with cells from pleomorphic adenoma, also demonstrated large cell lymphoma in 2/10 (20%) mice, whereas none of the 10 control animals showed any gross abnormalities or microscopic abnormalities in several organs. 2/16 (12%) lymphomas exhibited positive reaction with mouse B cell antibodies illustrating the murine origin of the lymphomas, and these were immunophenotyed as <span style="font-size: 15.0pt;mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">B cell lymphomas. The lymphomas were also examined with mouse T cell antibodies and none reacted positively with the mouse T cell antibodies. The lymphomas also failed to react with human T cell, B cell and human Leucocyte common antigen (LCA) antibodies, indicating that the induced lymphomas were not of human origin. The tumor specimens from seven of eight oral cancer patients and the pleomorphic adenoma patient induced lymphomas in nude mice. Thus it appears that xenografting oral tumor cells into nude mice may cause induction of the murine lymphomas, and this needs further investigation. </span

    Validating theoretical model-predictive (HBO) - slow growth during therapy – Using Experimental Data from graph 2D.

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    <p>Validating theoretical model-predictive (HBO) - slow growth during therapy – Using Experimental Data from graph 2D.</p
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