Development of anticancer drugs targeting cancer stem-like cells
Funding: State Research Programme "The development of novel biomedical tecnologies and tools for prevention, treatment and diagnosis to improve the pablic health"
Project leader: Dr. biol. Aija Linē
Project coleaders: Dr. Pēteris Trapencieris (LOSI), prof. Mārcis Leja (LU/RAKUS), Dr. Gunta Purkalne (PSKUS), Dr. med. Jekaterina Ērenpreisa
To develop a novel approach for personalised anticancer therapy based on targeting zinc enzymes in cancer stem-like cells (CSLC).
- To design and synthesize novel zinc enzyme inhibitors;
- To determine the enzyme specificity and cytotoxic activity of the compounds against cancer cell lines and fibroblasts;
- To establish a bio-bank of primary cell cultures, paired cancerous and normal tissues and blood samples from breast, lung and gastric cancer patients;
- To isolate and characterize putative CSLC populations from primary tumour cell cultures;
- To establish the expression pattern of zinc-enzymes in the primary cancer tissues and putative CSLC populations, and to investigate the functional significance of the candidates in CSLC biology;
- To test the effects of the lead compounds on the CSCL populations.
The existence of subpopulations of cells with self-renewing capacity that are responsible for tumour maintenance, chemoresistance and metastasis, called cancer stem-like cells (CSLC) has been demonstrated in a wide variety of solid and hematopoietic malignancies and has attracted a great attention as novel cellular targets for anticancer therapy. Zinc enzymes are metalloproteins comprising more than 300 representatives of all major enzyme classes, including carbonic anhydrases (CAs), matrix metalloproteinases (MMPs) and histone deacetylases (HDACs). A number of them are overexpressed in various cancer types and play a role in the regulation of various cancer-promoting processes (proliferation, apoptosis, migration, epithelial-mesenchymal transition, hypoxia and DNA damage response), and may serve as anticancer drug targets. However, so far their role in CSLC biology has not been systematically studied. This project aims to explore the role of CAs, MMPs and HDACs in CSLC biology and to access their relevance as drug targets. The mRNA expression pattern of the selected zinc enzymes is analysed by Q-RT-PCR array in breast, lung and gastric cancers and paired normal tissues, and the putative CSLC populations isolated from the primary cell cultures based on their sphere-forming capacity and chemoresistance. The functional relevance of the candidate genes in the self-renewal capacity, proliferation, apoptosis, migration, adaptability to hypoxic environment and chemoresistance will be studied by knock-down and overexpression in CSLC populations. In parallel, novel hydroxamic acid derivatives capable of binding in the catalytic sites of zinc enzymes are designed and synthesized. Their inhibitory activity and selectivity for various zinc enzymes are tested using in vitro enzymatic assays. Cytotoxic activity against cancer cell lines and fibroblasts is tested using proliferation assays. Finally, the effects of the lead compounds on the CSLC biology will be studied.
Accomplishments up to day:
- Two novel schemes for the synthesis of coumarine analogues with hydroxamic acid and sulphonamide functionalities are developed resulting in the production of more than 20 compounds with MMP and CA inhibitory activity.
- The standard operating procedures for the collection, processing and storage of tissues and blood specimens are elaborated and the clinical information database is established.
- A methodology for the disintegration of tissues, removal of microflora and establishment of multicellular spheroid and adherent cultures from primary tumour tissues is developed.
- A novel putative mechanism of chemo and radioresistance of cancer cells has been discovered and currently is being characterised.
- Design and synthesis of novel pharmacologically active compounds targeting CSLCs in new classes of heterocycles with known and newly developed Zn binding groups.
- The bio-bank of primary cell cultures, paired cancerous and normal tissues and blood samples from breast, lung and gastric cancer patients.
- The methodology for isolation and cultivation of CSLCs that provides a platform for discovering CSLC-associated drug targets and developing personalized medicine.
- Established frequency of CA, MMP and HDAC overexpression in human breast, lung and gastric cancers and CSLC populations.
- Deeper understanding of the functional significance of CAs, MMPs and HDACs in the self-renewal capacity, proliferation, apoptosis, migration, adaptability to hypoxic environment and chemoresistance of CSLCs.
Dr. biol. Jekaterina Ērenpreisa
The aim of Subproject is to clarify the mechanisms of tumor resistance to therapy and involved regulators. We have planned:
- to characterize the activation of germ cell program in tumour cells after genotoxic treatment and it’s relationship to the tumour resistance;
- to investigate this program’s role in tumour cells to resist therapy-induced cell senescence and involved regulatory molecules;