Browsing by Author "Priya, S"

Now showing 1 - 2 of 2
  • Item
    Estrogen-dependent cell signaling and apoptosis in BRCA1-blocked BG1 ovarian cancer cells in response to plumbagin and other chemotherapeutic agents
    (ANNALS OF ONCOLOGY, 2008) Thasni, KA; Rakesh, S; Rojini, G; Ratheeshkumar, T; Srinivas, G; Priya, S
    Background: Cellular response to chemotherapeutic drugs in the absence of BRCA1 either completely or partially had drawn less attention. The present study evaluated whether there is a differential inhibition of cell growth by selected compounds with respect to BRCA1 status in estrogen receptor (ER)-positive ovarian cancer cells. Materials and methods: The BG1 ovarian cancer cells used in the experiments were antisensely blocked with BRCA1 gene. Growth inhibition and apoptotic induction were analyzed to evaluate the cytotoxic effects. Small interfering RNA (SiRNA) transfection, western blot analysis, RT-PCR analysis and molecular modeling were carried out to analyze the estrogen-dependent action of plumbagin. Results: Although we found that all the compounds studied induce apoptosis, the induction was in the order of plumbagin > doxorubicin > tamoxifen > cisplatin. Plumbagin can bind to the active site of ER-alpha. Plumbagin, however, induced ER-alpha 46 kDa truncated isoform, which was found abundantly preempted in the cytoplasm compared with a 66-kDa full-length isoform. The truncated isoform is known to inhibit classical ER-alpha signaling pathways. SiRNA-transfected cells for ER-alpha exhibited lower cytotoxicity upon plumbagin treatment than the control-transfected cells. Conclusion: Taken together, this study indicates that plumbagin has chemotherapeutic potential in BRCA1-mutated/defective ER-positive cancers.
  • Item
    Growth of gold nanoparticles in human cells
    (LANGMUIR, 2005) Anshup; Venkataraman, JS; Subramaniam, C; Kumar, RR; Priya, S; Kumar, TRS; Omkumar, RV; John, A; Pradeep, T
    Gold nanoparticles of 20-100 nm diameter were synthesized within HEK-293 i human embryonic kidney), HeLa (human cervical cancer), SiHa (human cervical cancer), and SKNSH (human neuroblastoma) cells, Incubation of 1 mM tetrachloroaurate solution, prepared in phosphate buffered saline (PBS), pH 7.4, with human cells grown to similar to 80% confluency yielded systematic growth of nanoparticles over a period of 96 h. The cells, stained due to nanoparticle growth, were adherent to the bottom of the wells of the tissue culture plates, with their morphology preserved, indicating that the cell membrane was intact. Transmission electron microscopy of ultrathin sections showed the presence of nanoparticles within the cytoplasm and in the nucleus, the latter being much smaller in dimension. Scanning near field microscopic images confirmed the growth of large particles within the cytoplasm. Normal cells gave UV-visible signatures of higher intensity than the cancer cells. Differences in the cellular metabolism of cancer and noricancer cells were manifested, presumably in their ability to carry out the reduction process.