title: Whole genome sequencing reveals potential targets for therapy in patients with refractory KRAS mutated metastatic colorectal cancer.
abstract: BACKGROUND
  The outcome of patients with metastatic colorectal carcinoma (mCRC) following first line therapy is poor, with median survival of less than one year. The purpose of this study was to identify candidate therapeutically targetable somatic events in mCRC patient samples by whole genome sequencing (WGS), so as to obtain targeted treatment strategies for individual patients.
  
  
  METHODS
  Four patients were recruited, all of whom had received > 2 prior therapy regimens. Percutaneous needle biopsies of metastases were performed with whole blood collection for the extraction of constitutional DNA. One tumor was not included in this study as the quality of tumor tissue was not sufficient for further analysis. WGS was performed using Illumina paired end chemistry on HiSeq2000 sequencing systems, which yielded coverage of greater than 30X for all samples. NGS data were processed and analyzed to detect somatic genomic alterations including point mutations, indels, copy number alterations, translocations and rearrangements.
  
  
  RESULTS
  All 3 tumor samples had KRAS mutations, while 2 tumors contained mutations in the APC gene and the PIK3CA gene. Although we did not identify a TCF7L2-VTI1A translocation, we did detect a TCF7L2 mutation in one tumor. Among the other interesting mutated genes was INPPL1, an important gene involved in PI3 kinase signaling. Functional studies demonstrated that inhibition of INPPL1 reduced growth of CRC cells, suggesting that INPPL1 may promote growth in CRC.
  
  
  CONCLUSIONS
  Our study further supports potential molecularly defined therapeutic contexts that might provide insights into treatment strategies for refractory mCRC. New insights into the role of INPPL1 in colon tumor cell growth have also been identified. Continued development of appropriate targeted agents towards specific events may be warranted to help improve outcomes in CRC.
authors.forename: Vijayalakshmi
authors.initials: V
authors.lastname: Shanmugam
authors.forename: Ramesh K
authors.initials: RK
authors.lastname: Ramanathan
authors.forename: Nicole A
authors.initials: NA
authors.lastname: Lavender
authors.forename: Shripad
authors.initials: S
authors.lastname: Sinari
authors.forename: Manpreet
authors.initials: M
authors.lastname: Chadha
authors.forename: Winnie S
authors.initials: WS
authors.lastname: Liang
authors.forename: Ahmet
authors.initials: A
authors.lastname: Kurdoglu
authors.forename: Tyler
authors.initials: T
authors.lastname: Izatt
authors.forename: Alexis
authors.initials: A
authors.lastname: Christoforides
authors.forename: Hollie
authors.initials: H
authors.lastname: Benson
authors.forename: Lori
authors.initials: L
authors.lastname: Phillips
authors.forename: Angela
authors.initials: A
authors.lastname: Baker
authors.forename: Christopher
authors.initials: C
authors.lastname: Murray
authors.forename: Galen
authors.initials: G
authors.lastname: Hostetter
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Von Hoff
authors.forename: David W
authors.initials: DW
authors.lastname: Craig
authors.affiliation: Translational Genomics Research Institute (TGen), 445 N Fifth Street, Phoenix, AZ 85004, USA. jcarpten@tgen.org.
authors.forename: John D
authors.initials: JD
authors.lastname: Carpten
mesh_terms: D000368:Aged; D015153:Blotting, Western; D049109:Cell Proliferation; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D056915:DNA Copy Number Variations / Q000235:genetics; D020868:Gene Silencing; D020022:Genetic Predisposition to Disease; D015894:Genome, Human / Q000235:genetics*; D045325:HCT116 Cells; D057809:HEK293 Cells; D006801:Humans; D054643:INDEL Mutation / Q000235:genetics; D008297:Male; D008875:Middle Aged; D058990:Molecular Targeted Therapy; D009154:Mutation / Q000235:genetics*; D009362:Neoplasm Metastasis; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000072183:Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000235:genetics; D016283:Proto-Oncogene Proteins p21(ras); D034741:RNA, Small Interfering / Q000378:metabolism; D017422:Sequence Analysis, DNA; D015398:Signal Transduction / Q000235:genetics; D018631:ras Proteins / Q000235:genetics
chemical_list: C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D034741:RNA, Small Interfering; D019869:Phosphatidylinositol 3-Kinases; D010744:Phosphoric Monoester Hydrolases; C098706:INPPL1 protein, human; D000072183:Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins