5^th International conference on Predictive, Preventive and Personalized Medicine & Molecular Diagnostics December 01-02, 2016 Valencia, Spain

Biography:

Hassan Ashktorab has completed his PhD from Utah State University and Postdoctoral studies from Indiana and University of Florida School of Medicine. He is the Director of Microarray and GI research group. He has published more than 95 papers in reputed journals and has been serving as an Editorial Board Member of repute journals. He has received the Outstanding Researcher Award in 2011 in Howard University College of Medicine. He is a Member of PLoS One and Digestive Diseases and Science Editorial Boards and past Editorial Board Member of Gut. He has been Member of different NIH study sections since 2002. He was awarded Visiting Professorship from Jiangsu University, China in 2015.

Abstract:

Background & Aim: Several driver mutations have been discovered in colorectal cancer (CRC) progression including KRAS and BRAF that have practical significant therapeutic and prognostic value. Whole exome sequencing (WES) is revolutionizing screening for pathogenic single nucleotide variants (SNV) in complex disorders such as CRC. Little or no studies have comprehensively examined the association between somatic genetic variants in signaling pathways and risk of CRC in African Americans (AA). We aimed to determine somatic variants that drive colorectal carcinogenesis in AA.

Methods: WES was carried out on genomic DNA from 12 normal-tumor pairs of frozen biopsies from AA patients with CRC. For WES, base call quality recalibration, realignment around Indels, SNV calling and variants call recalibration were carried out using GATK (Genome Analysis Tool Kit) and normative population databases (e.g., 1000 Genomes SNP database, dbSNP and HapMap) provided the capability to filter genetic variants from putative mutations. Variants were then annotated using Annova. Sanger sequencing was used for validation of SNV.

Results: WES uncovered somatic mutations alteration in many genes that are known targets in CRC including APC, BRAF, KRAS, Notch1, PIK3C2A and NDRG4. We discovered a number of novel SNVs in EID3, RGS3, HNRNPF, GNAS and APC in tumor samples. We detected several rare and unique alterations in the known Wnt pathway gene: APC, MSH3 and ARID1. In addition, all three of these variants, APC4664, APC3418 and APC3862, are located in exon 15, which is the portion of APC most highly associated with CRC risk.

Conclusion: This work provides insight into identification of novel somatic mutations in APC, MSH3 and PIK3CA from both Caucasian and African Americans with CRC. Our data suggest an association between specific genes in the Wnt signaling pathway and risk of CRC. The precise cancer genomes approaches may be effective in detecting CRC based on personalized medicine as a guide to develop more effective way for reducing cancer morbidity and mortality.

Biography:

Professor Mittra obtained his medical degree from University of Delhi and is a Fellow of the Royal College of Surgeons of England and holds a PhD degree from University of London. He did his post-doctoral training with Dr Renato Dulbecco, Nobel Laureate, at the Imperial Cancer Research Laboratories in London.  Professor Mittra is a multi-faceted personality. He is a breast cancer surgeon while at the same time being deeply involved in public health and basic research in cancer.  Professor Mittra’s current research interests lie in the area of biology of extracellular nucleic acids and their role in ageing, inflammation, degenerative disorders and initiation and metastatis of cancer.

Abstract:

Several hundred billion to a trillion cells die in the adult human body daily, and a considerable amount of fragmented cell-free nucleic acids (cfNAs) from dying cells are released into the circulation.  Our research has shown that circulating cfNAs can freely enter into healthy cells, accumulate in their nuclei, trigger a DNA damage repair response (DDR) and integrate into host cell genomes by an unique mechanism.Similarly, at the tissue level, locally generated cfNAs from dead cells can be taken-up by healthy bystander cells to induce DDR that facilitates their integration into recipient cell genomes. Genomic integration of cfNAs leads to dsDNA breaks, inflammation, chromosomal instability, senescence and apoptosis of recipient cells. cfNAs from cancerous cells can cause oncogenic transformation of NIH3T3 cells which are tumourigenic in immune-deficient mice. These findings raise a new hypothesis of cancer metastasis which posits that metastasis arises from de novo oncogenic transformation of cells of target organs induced by cfNAs arising from apoptotic circulating tumour cells (CTCs). This hypothesis challenges the current dogma that metastasis are produced by growth of CTCs that are lodged in distant organs.