Profiling Circulating miRNA Without PCR for Early Detection of Pancreatic Cancer

DESCRIPTION provided by applicant Pancreatic cancer PaC has a poor prognosis in most cases due to the lack of early detection owing to its nonspecific asymptomatic nature An effective inexpensive screening tool is needed for early diagnosis within years of tumor initiation It is well accepted that genomic instability is a hallmark of cancer Recent research indicates that less than hundred microRNA miRNA sequences specifically generated by tumors are sufficient for early detection of PaC and other cancers for effective intervention with excellent prognosis MiRNA can be extracted from urine and blood using standard kits The key challenge is to detect specific biomarkers in the thousand fold large background of miRNA sequences that body normally produces While quantitative reverse transcribe polymerase chain reaction qRT PCR is an effective tool for miRNA profiling it is prohibitively expensive fo screening A microarray is an inexpensive alternative However due to the small size of miRNA a conventional microarray is not reliable due to large background from nonspecific binding A disruptive technology is needed to read microarrays of miRNA at high specificity with minimal background from the normal miRNA sequences and high sensitivity to avoid PCR amplification Owing to the small size of miRNA PCR is an added expensive complexity It is well known that electrochemical detection has excellent specificity with virtually no background from nonspecific binding of targets to microarray of probes The key limitations of this active detection method are a only one target sequence per electrode can be detected and b the redox current decreases as the sensor electrode size diminishes making multiplexing difficult A method developed in Sarafandapos s lab at the University of Nebraska Lincoln can electrochemically andquot readandquot microarray spots on a monolith electrode by simply scanning a laser with a beam size of m to quantitatively measure the local redox current Published studies indicate that Scanning Electrometer for Electrical Double layer SEED has conservative responsivity of andlt atto moles Vajra Instruments has licensed the patent for SEED from UNL and built a commercializable microscope size prototype Using a spot microarray preliminary results indicate a sensitivity of pico molar pM with no signal from non specific binding at consistency The goal in Phase I will be to achieve pM sensitivity to detect copies of tumor specific miRNA extracted from ml of serum or plasma using standard commercial kits The study will target five miRNA sequence from deidentified human serum plasma samples of pancreatic patients without using PCR The success will be based on the pM sensitivity with to fold copies of background miRNA and quantitative comparison with qRT PCR the gold standard The proof of concept Phase I study will be organized into two specific aims Quantification of SEED performance using synthetic miRNA and SEED analysis on serum plasma samples Phase II will attempt to bring SEED to market by validating the technology for early detection of PaC by targeting circulating miRNA from blood PUBLIC HEALTH RELEVANCE Profiling Circulating miRNA Without PCR for Early Detection of Pancreatic Cancer Narrative MicroRNA circulating in blood have the potential to effectively diagnose pancreatic cancer and other cancers before clinical signs appear The key is to detect less than miRNA sequences in the midst of thousand fold large background of other miRNA sequences that the body normally produces The current technologies are either difficult to multiplex or too expensive to be used for screening The proposed proof of concept study is to directly measure the tumor specific miRNA extracted from about ml of serum or plasma using a disruptive technology called SEED Measurement by SEED is virtually blind to non specific binding with consistency Owing to its electrochemical nature the binding time of targeted miRNA to the probe will reduce from hours for conventional microarray methods to below one hour