Dr Premila and Dr. Muthuraman
Areas of research interest
The lead investigators of this group are Dr. Premila Abraham and Dr. Muthuraman
1. Elucidation of mechanism(s) of organ toxicities of anticancer drugs (methotrexate and cyclophosphamide) and ways to minimise them
Gastrointestinal toxicity of methotrexate
Currently, intestinal toxicity is the major dose-limiting factor for methotrexate (MTX ) administration, and MTX induced intestinal mucositis represents a significant burden to patients. Despite all the efforts being made to ameliorate MTX-induced intestinal damage, there is no satisfactory therapeutic intervention so far that prevents this side effect. This is due, at least in part, to the lack of understanding of the mechanisms by which MTX induces intestinal impairment. We have been investigating the mechanism of MTX induced gastrointestinal toxicity using rat model and have demonstrated that increased oxido-nitrosative stress, protein tyrosine nitration and cysteine nitrosylation and PARP overactivation, enterocyte mitochondrial damage and respiratory chain defects, and epithelial cell apoptosis and necrosis play important roles.
Proliferation and differentiation of surviving crypt stem cells are necessary for recovery from MTX induced gastrointestinal (GI) injury. Notch -1 signalling pathway is critical for crypt stem cell survival. Intestinal crypt organoids are a new robust model to investigate intestinal regeneration and to screen for therapeutic interventions. Using crypt organoid culture, we are currently investigating the role of Notch-1 signaling pathway in MTX induced intestinal mucositis. We will also evaluate the effect of valproate, a Notch activator in mitigating MTX induced GI syndrome [ Ongoing ICMR funded project: Crypt organoid usage in the elucidation of the mechanism of methotrexate induced intestinal mucositis; study on the effect of methotrexate on crypt repair and regeneration and Notch-1 signaling pathway, and the protective effect of valproic acid (VPA), an inducer of the Notch-1 signaling pathway, in vivo in MTX -induced intestinal injury, mortality and morbidity in mice ]
As we have demonstrated that overproduction of peroxynitrite contributes to MTX induced GI toxicity, we are interested in finding whether ebselen, a peroxynitrite scavenging drug can prevent MTX induced GI toxicity [ Ongoing DST SERB funded project: Investigation of the ‘in vitro’ and ‘in vivo’ protective effect of SPI-1005 (Ebselen) , a peroxynitrite scavenging , clinically safe investigational new drug in methotrexate induced small intestinal injury; investigation of its effect on peroxynitrite induced cell death signal transduction pathways]
2. Urotoxicity of cyclophosphamide
Cyclophosphamide-induced hemorrhagic cystitis remains a prevalent important clinical problem today in the setting of treatment of a multitude of oncologic and rheumatologic conditions. Although highly effective, the use of MESNA and forced saline diuresis does not completely prevent HC in patients receiving high‑dose cyclophosphamide.Hence, there is a need for novel agents that could be useful to prevent adverse urologic effects during CP therapy. Our previous research findings demonstrated that the administration of cyclophosphamide (CP ) to rats enhanced the production of reactive oxygen species (ROS)and reactive nitrogen species (RNS), and depleted the antioxidant enzymes in bladder . However, the consequence of over production of ROS and RNS and their down stream targets is not known. Recent studies have shown that ROS and RNS overactivation can activate the development of endoplasmic reticulum (ER) stress induced apoptotic pathway and inflammatory pathway. Our preliminary studies using human urothelial cell lines have shown CP induces increased protein expression of ER stress markers- GRP78, PDI and caspase12, as well increased apoptosis [Completed ICMR funded project: A study on the possible role of endoplasmic reticulum stress in cyclophosphamide induced damage to human urothelial cell line]. Currently we are interested in investigating in detail the role of ER stress induced apoptosis and inflammation in CP induced urotoxicity and whether the administration of ER stress inhibitors, sodium phenylbutyrate and tauroursodeoxycholic acid can prevent CP induced ER stress and apoptosis in HUC4449 cells and hemorrhagic cystitis in rats [ Submitted to DBT for funding]
3. Targetting cancer stem cells for the treatment of endometrial cancer
Endometrial cancer (EC) is one of the most common female malignancies worldwide. Cisplatin is one of the most commonly used agents in the post curative surgery in patients with EC. Although cisplatin is recognized as the first-line chemotherapy agent for patients with EC, its efficiency remains a major problem. Cancer stem-like cells (CSCs) are thought to be the root cause of chemotherapy-resistance and radio-resistance, ultimately leading to treatment failure in patients with advanced disease. With the emergence of the CSC theory, there is a growing need for developing therapeutic agents which can potentially target them. Cancer stem cells are increasingly preferred as a target to prevent disease recurrence or to circumvent therapeutic resistance. Recent evidence suggests that aspirin, curcumin and silibinin are able to target cancer stem-like cells (CSCs). These include breast, pancreatic, prostate and colorectal cancers. However, the effect of these agents on endometrial cancer stem cells has not been investigated yet. Currently we are investigating the anticancer effects of aspirin ,curcumin and silibinin individually on cancer stem-like populations derived from endometrial cancer cell lines-Ishikawa and HEC-1-B cell line.
Ongoing Intramural fluid funded projects
1. Effect of curcumin on cancer stem like cells in human endometrial cancer cell line
2. Does aspirin inhibit cancer stemness in endometrial cancer ?
3. Effect of silibinin on stemness properties, tumour suppressing properties in human endometrial cancer cell line-HEC1B
4. Effect of silibinin on PI3K/ Akt signalling in endometrial cancer stem cells derived from HEC1B
4. Biotin and gestational diabetes
Diabetes during pregnancy is associated with an increased risk of maternal and neonatal morbidity. In pregnancies complicated by diabetes, hyperglycemia and lipid metabolism alterations are associated with both maternal and fetal complications. Pharmacological concentrations of biotin reduce serum glucose, triglycerides and cholesterol . Biotin is important for normal embryonic growth . We investigated the beneficial effect of megadoses of biotin in streptozotocin-induced gestational diabetes mellitus in rats. Hyperglycemia and hypercholesterolemia were observed in the diabetic rats. Treatment with biotin normalised these values. Biotin treatment improved maternal reproductive performances as well fetal outcomes. [ Completed CSIR funded project -Mechanism of hypoglycemic and hypolipidemic effects of mega doses of biotin in rat model of gestational diabetes]. We are currently analysing biotin status and its association with serum markers of glucose and lipid homeostasis in women with gestational diabetes [ Ongoing intramural fluid funded project: Analysis of biotin levels and its association with markers of glucose and lipid homeostasis in gestational diabetes mellitus]