Non-Invasive Gene Mutation Detection in Lung Cancer Patients

Abstract

A system and method for the detection of saliva biomarkers in bodily fluids is described. In particular, the system is suitable for detecting biomarkers of lung cancer in a subject. The system includes an electrochemical sensor chip having at least one well, wherein the at least one well contains a working electrode coated with a conducting polymer functionalized with at least one capture probe, and at least one labeled detector probe. When the at least one labeled detector probe is mixed with a sample of the subject containing a biomarker of lung cancer and added to the at least one well, an electric current is applied to the sample, such that when at least some of the biomarker binds to the capture probe, a measurable change in electric current in the sample is created that is indicative of lung cancer.

What is claimed is: 
     
         1 . A device for detecting lung cancer in a subject, comprising:
 an array of units on a substrate, each unit comprising an electrode chip including a working electrode, a counter electrode, and a reference electrode;   wherein the working electrode of at least one unit is coated with a conducting polymer embedded or functionalized with a capture probe which binds to a first marker of lung cancer.   
     
     
         2 . The device of  claim 1 , wherein the working electrode, counter electrode, and reference electrode are comprised of a conductive material. 
     
     
         3 . The device of  claim 1 , wherein the conducting polymer comprises pyrrole. 
     
     
         4 . The device of  claim 1 , wherein the conducting polymer is electropolymerized on the working electrode by applying a cyclic square-wave electric field to the device. 
     
     
         5 . The device of  claim 1 , wherein the first marker of lung cancer is a nucleic acid. 
     
     
         6 . The device of  claim 1 , wherein the capture probe is a nucleic acid that hybridizes to a nucleic acid sequence encoding mutant EGFR in a sample. 
     
     
         7 . The device of  claim 6 , wherein the nucleic acid encoding mutant EGFR encodes a EGFR mutant selected from the group consisting of E746-A750 deletion mutant of EGFR and L858R point mutation of EGFR. 
     
     
         8 . The device of  claim 1 , wherein the capture probe is a nucleic acid that hybridizes to a nucleic acid sequence encoding wild-type EGFR in a sample. 
     
     
         9 . The device of  claim 1 , wherein the capture probe comprises a nucleotide sequence selected from the group consisting of SEQ ID NO: 1 and SEQ ID NO: 3. 
     
     
         10 . A method of detecting lung cancer in a subject comprising:
 obtaining a sample of the subject;   mixing a first portion of the sample with a solution comprising a labeled detector probe;   adding the mixture to a first electrode chip on a device, the electrode chip comprising a working electrode, a counter electrode, and a reference electrode; wherein the working electrode is coated with a conducting polymer embedded with a capture probe capable of binding to first marker associated with lung cancer in the sample; and   measuring the current in the electrode chip, wherein a change in current is correlated to the presence of the first marker associated with lung cancer in the sample.   
     
     
         11 . The method of  claim 10 , further comprising applying a cyclic square-wave electric field to the electrode chip during the adding step. 
     
     
         12 . The method of  claim 10 , wherein the first marker comprises a variable region comprising a nucleic acid sequence harboring a mutation associated with lung cancer, and at least one of the detector probe and capture probe hybridizes to the variable region. 
     
     
         13 . The method of  claim 10 , wherein the first marker associated with lung cancer comprises a nucleic acid encoding mutant EGFR. 
     
     
         14 . The method of  claim 13 , wherein the nucleic acid encoding mutant EGFR encodes a EGFR mutant selected from the group consisting of E746-A750 deletion mutant of EGFR and L858R point mutation of EGFR. 
     
     
         15 . The method of  claim 13 , wherein the capture probe comprises a nucleotide sequence selected from the group consisting of SEQ ID NO: 1 and SEQ ID NO: 3. 
     
     
         16 . The method of  claim 13 , wherein the labeled detector probe comprises a nucleotide sequence selected from the group consisting of SEQ ID NO: 2 and SEQ ID NO: 4. 
     
     
         17 . The method of  claim 13 , wherein the sample is a saliva sample. 
     
     
         18 . The method of  claim 13 , wherein the sample is a blood sample. 
     
     
         19 . A system for detecting lung cancer in a subject, comprising:
 an electrochemical sensor chip having at least one well, wherein the at least one well contains a working electrode coated with a conducting polymer functionalized with at least one capture probe; and   at least one labeled detector probe;   wherein, when the at least one labeled detector probe is mixed with a sample from the subject containing a first marker of lung cancer and added to the at least one well, an electric current is applied to the sample in the at least one well, such that when at least some of the first marker binds to the capture probe, a measurable change in electric current in the sample is created that is indicative of lung cancer.   
     
     
         20 . The system of  claim 19 , wherein the first marker is a nucleic acid encoding mutant EGFR. 
     
     
         21 . The system of  claim 19 , wherein the change in current in the sample is measurable within 10 minutes after the sample has been loaded into the well. 
     
     
         22 . The system of  claim 19 , wherein the first marker comprises a variable region comprising a nucleic acid sequence harboring a mutation associated with lung cancer, and at least one of the detector probe and capture probe hybridizes to the variable region. 
     
     
         23 . The system of  claim 20 , wherein the nucleic acid encoding mutant EGFR encodes a EGFR mutant selected from the group consisting of E746-A750 deletion mutant of EGFR and L858R point mutation of EGFR. 
     
     
         24 . The system of  claim 19 , wherein the capture probe comprises a nucleotide sequence selected from the group consisting of SEQ ID NO: 1 and SEQ ID NO: 3. 
     
     
         25 . The system of  claim 19 , wherein the labeled detector probe comprises a nucleotide sequence selected from the group consisting of SEQ ID NO: 2 and SEQ ID NO: 4.