Scientific Officers: M.A. Indap, Ph.D. (Officer-in-charge), R.P. Gude, Ph.D.
Anti-cancer drug testing facility: A.S. Juvekar, Ph.D. (In-charge)

Research Fellows: P.Y. Dua.

While chemotherapy forms an important modality for treating cancer, there are still several hurdles to achieving 100% success in this field. The Chemotherapy group is therefore addressing issues responsible for the incomplete success of chemotherapy, such as multi-drug resistance, excessive toxicity to normal cells, insufficient amount of drug reaching the target cells, angiogenesis, metastasis, etc. The group is also providing service to screen new, synthetic and natural products for their in vitro / in vivo anti-cancer activity using internationally approved test systems.

Establishment of a national facility for in vitro / in vivo anti-cancer drug screening

Research institutes, universities and pharmaceutical companies abroad and in India routinely synthesize new drugs, extract novel compounds from plant material and design new formulations of existing drugs. However, few facilities exist in India to test the effectiveness of such compounds / formulations. Since 1998, CRI has been offering its services on a charge basis, for testing the in vitro / in vivo anti-cancer activity of new compounds or formulations using 20 human malignant cell lines and 5 murine tumour models. So far, the Centre has tested compounds received from Chittaranjan National Cancer Institute (Kolkata) and the following Mumbai-based organisations: SIRO Research Foundation, University Department of Chemical Technology, Kelkar Education Trust’s Scientific Research Centre, Bharat Serums and Vaccines, Vedic Life Sciences, Themis Medicare and Quest Institute for Life Sciences. It is now planned to introduce human tumour xenografts in nude/SCID mice and establish a state of the art ‘National Facility’ for in vitro / in vivo anti-cancer drug testing in this institute.

Screening of novel potential anti-cancer drugs in vivo (Council of Scientific and Industrial Research)

The Council of Scientific and Industrial Research has formed drug discovery groups to speed up the identification of lead compounds from plant extracts and formulations of Arya Vaidya Shala that are used to treat various diseases including cancer. Under this project, initial in vitro testing of plant extracts on human malignant cell lines has been conducted at Regional Research Laboratory (RRL), Jammu. Extracts showing positive effect in vitro have to undergo in vivo testing in the centre - first on murine tumour models and later on human tumour xenografts in nude mice. Twenty plant extracts have been tested on murine tumour models, viz. P388, L1210 (both leukaemia), Lewis lung carcinoma, Colon 26 and Ca51 (both colon carcinoma). Of these, four extracts show tumour inhibitory activity in Ca51 tumour, while one extract shows activity in P388 murine leukaemia. These compounds will be tested on a spectrum of human tumour models and human tumour xenografts in nude / SCID mice to obtain efficacy data.

Synthesis and assessment of in vitro anti-cancer activity of metal complexes on a spectrum of human malignant cell lines (Department of Biotechnology)

Cisplatin has proved successful in the treatment of various solid tumours and is the drug of choice as the first line treatment of ovarian cancer. However, in view of its observed renal and neurotoxic effects, there has been an on-going search to design and develop a substitute to cisplatin. Several metal complexes of cisplatin with platinum, gold, cadmium and nickel have been under development. In this project, 25 water-insoluble and 5 water-soluble copper (I) complexes have been tested on 10 human malignant cell lines in vitro using sulforhodamine-B assay. Of these, 11 water-insoluble complexes and 1 water-soluble complex show consistent in vitro cytotoxicity on a spectrum of cell lines. These compounds are to be examined in vivo in animal tumour models for their LD50 anti-cancer activity, and mechanism of action, and also in human tumour xenografts.

Development of carrier systems for novel compounds and in vitro / in vivo therapeutic study of new formulations

Development of targeted anti-cancer drugs allows dose escalation of cytotoxic compounds to overcome drug resistance and reduce peripheral toxicity. Recent efforts in design of cancer selective drugs have utilized various carrier systems as well as encapsulation. In this study, 3 non-steroidal anti-inflammatory drugs (NSAIDs), viz. aspirin (ASA), ibuprofen and nimesulide, have been found to exert preferential cytotoxicity against actively proliferating human MCF7 breast cancer cells, the effect being dose and time dependent. The IC50 obtained with ASA is 5 µg/ml whereas that with ibuprofen and nimesulide is 13.5 µg/ml and 28 µg/ml, respectively. Free ASA as well as its cyclodextrin inclusion complex arrest cells at the G1 phase of the cell cycle. ASA is more effective on MCF7 cell line than on K562 erythroleukaemia cell line, and death due to apoptosis is not observed in both the cell lines. In the chick chorioallantoic membrane model, ASA-loaded pellets release sufficient ASA to produce vascular regression and inhibition of angiogenesis. The anti-angiogenic property of ASA needs to be examined on a panel of solid tumours. The therapeutic utility of sodium butyrate (NaB) is also being investigated by studying inhibition of K562 cells in culture. Amongst the polyphenolic compounds included in these studies, curcumin shows the lowest IC50. NaB with quercetin is found to be an effective combination in vitro. Brief exposure of S180 ascites tumour cells to curcumin arrests S180 cell proliferation. In view of the short half-life of NaB, liposomal encapsulation is warranted.

Anti-metastatic role of pentoxifylline and related compounds in a murine metastatic tumour model (Council of Scientific and Industrial Research)

Despite advances in diagnosis and treatment of cancer by surgery, chemotherapy and radiation therapy, its spread to distant target organs remains a major concern. This project therefore examines the use of anti-metastatic agents to inhibit circulating tumour cells dissociated from the primary localised tumour from homing or anchoring to a distant target organ and forming metastatic foci there. Data reveal that in vitro treatment of B16F10 melanoma cells with pentoxifylline, caffeine and theophylline leads to the following ultrastructural changes: degenerating, swollen mitochondria with loss of cristae, vacuole formation, fragments of endoplasmic reticulum with free ribosomes scattered in the cytoplasm, condensation and margination of nucleolus, hypertrophy of nucleus with indentation of nuclear membrane and large amount of hyperchromatin deposited on the periphery of the nucleus. The efficacy of these 3 agents has further been determined, in relation to oxidative effect, on B16F10 and B16F1 melanoma cell lines. The concentration of glutathione is found to be higher in B16F10 melanoma cell line, compared to B16F1 cell line. Treatment with methylxanthine derivatives leads to depletion of glutathione, up-regulation of glutathione S-transferase activity and elevated lipid peroxidation.

Role of matrix metalloproteases in angiogenesis

Solid tumours secrete numerous soluble factors that induce endothelial cell growth directed towards the localised tumour or recruit host cells to release cytokines that enhance endothelial cell proliferation and migration, leading to angiogenesis. The role of matrix metalloproteases (MMP) and their action on micro-environmental conditions are closely linked to angiogenesis. This project therefore examines inhibitors of MMP, which can delay the process of angiogenesis. The intra-dermal assay of angiogenesis has been standardised and a pilot study on the anti-angiogenic activity of suramin has been carried out on tumor induced growth of B16F10 melanoma in C57BL6 mice. Future plans include studying the activity of conventional chemotherapeutic drugs at low concentration in combination with pentoxifylline and other methylxanthine derivatives in B16F10 melanoma and Lewis lung carcinoma models. Changes in the levels of specific cell surface molecules on melanoma cells and endothelial cells will also be examined.