ABSTRACT
DNA is double helical macromolecule which carries all the genetic information and it is usually found enveloped inside a nucleus. The DNA helix relaxes and supercoils itself frequently in order to derive information from the genes during processes like transcription, condensation, replication and recombination, which require mutable or immutable alterations to cause the separation of the two DNA strands. Due to problems caused by the helical structure of DNA, these topoisomerase enzymes perform the required DNA uncoiling. Their role in cell cycle is also significant as their mutation leads to failure of anaphase separation (1, 2). In the present review, the important roles of DNA topoisomerases and their inevitable role in cell growth and cell cycle are discussed viz. how they function in cell proliferation and what are the results when different inhibitors are added to the cells, affecting cell cycle at various checkpoints .
ABSTRACT
Electrical charge is an indicator of the cellular state of health. In cells, the cell membrane is a leaky dielectric. Capacitors are composed of two conducting sheets separated by a thin layer of insulating material known as a dielectric. Cells contain several forms of biological capacitors, which consist of an insulating material (the membrane) covered on both sides by collection of charged dissolved minerals, which serve the function similar to a conducting metal plate. This means that any condition, illness or change in dietary intake that affects the composition of the cell membranes and their associated minerals can affect and alter cellular capacitance. Healthy cells have a higher whole cell and cytoplasm conductivity and higher membrane capacitance than the malignant cells. The electric charge of cell membranes of mammals is negative at physiological pH. It is well-known that surface of cancer and tumor cells carry negative charge in excess to that of normal cells which is responsible for their increased mobility and invasiveness. The high negative surface charge on malignant cells and trophoblasts may mediate the lack of immune rejection of these cells. Thus, neutralizing or removing the tumor cell negative charge may allow negatively charged lymphocytes to approach and destroy them and thereby, the viability and survival of the cancer cells may be affected at least in vitro. The present study serves to - test this hypothesis on invasive human breast carcinoma cell line MDA-MB-231 (ER ) using specially designed and constructed combination of circuits. Preliminary results showed that out of the 8 designed circuits, sets 1, 2 and 7 were able to produce significant growth inhibition of MDA cells in vitro. The application of electrostatic field through specially designed circuits is unique and has never been reported previously. Our long-term goal is to develop a minimally invasive device that will selectively target and destroy both metastatic and non-metastatic cancer cells in humans. Better understanding of effect of decreasing surface charge density of tumor cells may lead to device effective treatment strategy of human tumors in future.
ABSTRACT
A protocol has been developed for induction of somatic embryogenesis from whole inflorescence explants of Chamomilla recutita L. (chamomile). Chamomile is a well-known medicinal plant from the Asteraceae family often referred to as the “star among medicinal species.” Nowadays, it is a highly favoured medicinal plant in folk and traditional medicine. Its multitherapeutic, cosmetic and nutritional values have been established through the years of traditional and scientific use and research. Chamomile has an established domestic (Indian) and international market, which is increasing day by day. Among the various major constituents, α-bisabolol and chamazulene have been reported to be more useful than others. Chamazulene occurs in the capitula of the flowers in minute quantities and has been demonstrated to exert antiinflammatory activity in-vivo. Moreover, chamomile is a seasonal 4-5 months winter crop in India but is extensively required in various medicinal applications. Therefore, to increase the overall yield of this plant, its in-vitro propagation is needed. In the present study, somatic embryos were developed from capitulum explants after 2-4 weeks of culture on MS medium supplemented with 26.8 µM NAA and 11.5 µM Kin. The somatic embryos were further subcultured in-vitro, where new plantlets regenerated from embryos. It is concluded that in-vitro propagation is possible in case of chamomile and can be used to increase the overall yield of chamazulene present in the capitula of flowers as well as augment the overall yield of this important plant, which is conventionally propagated by seeds.