Patent ID: 7993826
Filing Date: 2011-08-09
Classification: C12Q

Abstract:
1. A method for determining whether disseminated cancer cells are present in a blood sample from a human subject having or suspected of having cancer, wherein the method comprises: (a) obtaining a blood sample from a human subject having or suspected of having cancer, collecting from the blood sample a cell fraction that comprises mononuclear cells (MNC fraction), removing a fraction of the MNC fraction to obtain test fraction A′, passing the remaining MNC fraction through a screen with a mesh or pore width of 17-27 μm, and collecting cells from the screen to obtain test fraction C; (b) isolating mRNA from test fraction A′ and test fraction C to obtain mRNA samples; (c) measuring in each of the mRNA samples obtained in step (b) the expression level of manganese superoxide dismutase (MNSOD) mRNA that encodes a protein having the amino acid sequence of SEQ ID NO:13 or an allelic variant thereof, thioredoxin reductase (TXNRD1) mRNA that encodes a protein having the amino acid sequence of SEQ ID NO:15 or an allelic variant thereof, and glutathione peroxidase (GPX1) mRNA that encodes a protein having the amino acid sequence of SEQ ID NO:17 or an allelic variant thereof, wherein said measuring is by reverse transcription into cDNA and PCR; (d) determining the expression ratio of MNSOD, TXNRD1, and GPX1 from test fraction C to test fraction A′; and (e) comparing the expression ratio for each of MNSOD, TXNRD1, and GPX1 determined in step (d) to a control limit for expression for each of MNSOD, TXNRD1, and GPX1 in blood samples of healthy human subjects, and wherein an expression ratio determined in step (d) higher than the control limit of expression of at least one of MNSOD, TXNRD1 and GPX1 indicates the presence of disseminated cancer cells in the blood sample from a human subject having or suspected of having cancer.