Heat Shock Proteins and Cancer.

Heat shock proteins (HSPs) constitute a large family of proteins involved in protein folding and maturation whose expression is induced by heat shock or other stressors. The major groups are classified based on their molecular weights and include HSP27, HSP40, HSP60, HSP70, HSP90, and large HSPs. HSPs play a significant role in cellular proliferation, differentiation, and carcinogenesis.

Tyrosine phosphorylation of HSC70 and its interaction with RFC mediates methotrexate resistance in murine L1210 leukemia cells.

We previously identified and characterized a 66-68 kDa membrane-associated, tyrosine phosphorylated protein in murine leukemia L1210 cells as HSC70 which is a methotrexate (MTX)-binding protein. In order to further characterize the functional role of HSC70 in regulating MTX resistance in L1210 cells, we first showed that HSC70 colocalizes and interacts with reduced folate carrier (RFC) in L1210 cells by confocal laser scanning microscopy and Duolink in situ proximity ligation assay. The tyrosine phosphorylation status of HSC70 found in the membrane fraction was different from the parental L1210/0 and cisplatin (CDDP)-MTX cross resistant L1210/DDP cells.

Oligonucleotides and G-quadruplex stabilizers: targeting telomeres and telomerase in cancer therapy.

Cancer is a leading cause of death worldwide and an estimated 1 in 4 deaths in the United States is due to cancer. Despite recent advances in cancer treatment, adverse effects related to cancer therapy remain a limiting factor for many patients. The ideal cancer treatment would selectively target cancerous cells while sparing normal, healthy cells to offer maximal therapeutic benefit while minimizing toxicity.