Expression of telomere related molecules and DNA repair enzymes in human gastric cancer : Expression of telomeric repeat binding facor 1 and 2 and TRF1-interacting nuclear protein 2 in human gastric carcinomas Expression of MRE11 complex (MRE11,Rad50,NBS1) and hRAP1 and its relation with telomere regulation, telomerase activity in human gastric carcinomas