Abstract: The present invention provides genomic loci which are hypermethylated and differentially expressed in drug resistant cells compared to non-drug resistant cells. These genomic loci are homologous to the rab6 locus but map to a different chromosomal position. The present invention also provides nucleic acids isolated from these genomic loci by Methyl-Differential Display (MDD) methods, including genomic DNAs and cDNAs. The present nucleic acids are useful as probes for detecting mutations and the methylation patterns of the newly identified genomic loci, and of homologous nucleic acids. Nucleic acids of the present invention are also useful for detecting expression of mRNA from herein identified genes, for measuring expression of those and homologous genes sequences, and for determining suitability of therapeutic treatment. The disclosed nucleic acids and their homologs are useful for inhibition of multiple drug resistance.

Abstract: The present invention provides Methyl- (or Mutant-) Differential Display (MDD) methods and nucleic acid probes for detecting mutations and the methylation patterns of nucleic acids. Regions of the genome are differentially methylated or mutated in different cell types, including cancerous cell types. The TSP50 gene is thereby identified and found to be differentially expressed in breast cancer cells. The present invention provides methods and compositions for identifying aberrant expression of the TSP50 gene and of tsp50 protein. Antibodies of the present invention can be used for diagnosis and treatment of diseases characterized by aberrant tsp50 expression.

Abstract: The present invention provides Methyl- (or Mutant-) Differential Display (MDD) methods and nucleic acid probes for detecting mutations and the methylation patterns of nucleic acids. The methods of the present invention are particularly useful for detecting and isolating genomic DNA fragments which are near coding and regulatory regions of genes and which are differentially mutated or methylated relative to the corresponding DNA from normal cells. Genes are frequently not methylated in the cells where they are expressed but are methylated in cell types where they are not expressed. Moreover, tumor cell DNA is frequently methylated to a different extent and in different regions than is the DNA of normal cells. The present invention is used for identifying which regions of the genome are methylated or mutated in different cell types, including cancerous cell types.

Abstract: The present invention provides Methyl- (or Mutant-) Differential Display (MDD) methods and nucleic acid probes for detecting mutations and the methylation patterns of nucleic acids. The methods of the present invention are particularly useful for detecting and isolating genomic DNA fragments which are near coding and regulatory regions of genes and which are differentially mutated or methylated relative to the corresponding DNA from normal cells. Genes are frequently not methylated in the cells where they are expressed but are methylated in cell types where they are not expressed. Moreover, tumor cell DNA is frequently methylated to a different extent and in different regions than is the DNA of normal cells. The present invention is used for identifying which regions of the genome are methylated or mutated in different cell types, including cancerous cell types.