Biomedical subjects

Rajgopal Govindarajan

Publications and source records attributed to Rajgopal Govindarajan.

3 recordsLinked to original sources

PubMed2005

Characterization of a new antibody raised against the NH2 terminus of P-glycoprotein.

PURPOSE: Cancers exposed to chemotherapy develop multidrug resistance, a major cause for chemotherapy failure. One mechanism of multidrug resistance development is due to overexpression of P-glycoprotein (Pgp) in these cancer cells. Thus, a prechemotherapy evaluation of Pgp in cancer cells aids in the design of alternative regimens that can circumvent such failure. As few Pgp-specific antibodies are available in detecting low levels of Pgp, there is a need for preparing an antibody that allows the detection of Pgp by various immunologic methods. EXPERIMENTAL DESIGN: We selected the amino acid stretch 11 to 34 in the cytoplasmically located NH2 terminus of Pgp as antigen, which was chemically synthesized and used to raise an antibody in a rabbit, termed NH2 11 antibody. We compared the properties of NH2 11 antibody with that of the well-characterized Pgp-specific antibody, C219, by Western blotting, immunoprecipitation, immunocytochemistry, and immunohistochemistry. RESULTS: Immunoblotting analysis suggested that NH2 11 antibody efficiently interacts with both recombinant and constitutively expressed Pgp in cancerous and noncancerous human cells. Immunoprecipitation reactions indicated that the NH2 11 antibody selectively immunoprecipitates Pgp. Immunocytochemical analyses indicated that the NH2 11 antibody detects Pgp in drug-resistant breast cancer cells as well as in human prostate and breast adenocarcinoma tissue sections. CONCLUSION: As the NH2 11 antibody detects Pgp present in cells and tissues, we conclude that the amino acid sequence to which this antibody was raised is highly antigenic and the antibody is useful in the detection of Pgp by a variety of immunologic methods.

ATP Binding Cassette Transporter, Subfamily B↗

PubMed2005

Cancer--an ayurvedic perspective.

An integrated approach is needed to manage cancer using the growing body of knowledge gained through scientific developments. Thousands of herbal and traditional compounds are being screened worldwide to validate their use as anti-cancerous drugs. The science of Ayurveda is supposed to add a step on to the curative aspects of cancers that have resemblance with clinical entities of arbuda and granthi mentioned in Sushrutha samhita. Hence, an attempt is made in this review to discuss about the pathology and therapeutic management of various cancers described in Ayurveda. Review of literature on anticancer drugs of plant origin revealed identification of newer ayurvedic drugs that are not mentioned in the ancient texts. These new findings add up to ayurvedic science that has been developed through ages. In addition, details of experimental and clinical studies conducted on single and compound ayurvedic preparations for their anticancer efficacy strongly emphasize ayurvedic therapy as a scientifically driven one and not simply unconventional.

Antineoplastic Agents, Phytogenic↗

PubMed2002

Impaired trafficking of connexins in androgen-independent human prostate cancer cell lines and its mitigation by alpha-catenin.

Gap junctions, composed of connexins, provide a pathway of direct intercellular communication for the diffusion of small molecules between cells. Evidence suggests that connexins act as tumor suppressors. We showed previously that expression of connexin-43 and connexin-32 in an indolent prostate cancer cell line, LNCaP, resulted in gap junction formation and growth inhibition. To elucidate the role of connexins in the progression of prostate cancer from a hormone-dependent to -independent state, we introduced connexin-43 and connexin-32 into an invasive, androgen-independent cell line, PC-3. Expression of these proteins in PC-3 cells resulted in intracellular accumulation. Western blot analysis revealed a lack of Triton-insoluble, plaque-assembled connexins. In contrast to LNCaP cells, connexins could not be cell surface-biotinylated and did not reside in the cell surface derived endocytic vesicles, in PC-3 cells, suggesting impaired trafficking to the cell surface. Intracellular accumulation of connexins was observed in several androgen-independent prostate cancer cell lines. Transient expression of alpha-catenin facilitated the trafficking of both connexins to the cell surface and induced gap junction assembly. Our results suggest that impaired trafficking, and not the inability to form gap junctions, is the major cause of communication deficiency in human prostate cancer cell lines.

Biotinylation↗