Detection of codon 61 point mutations of the K-ras gene in lung and colorectal cancers by enriched PCR

Low-dose metronomic cyclophosphamide treatment mediates ischemia-dependent K-ras mutation in colorectal carcinoma xenografts

“…Thus, a rapid accumulation of mutant cells was facilitated in tumors exposed to LDM-induced hypoxia. Using similar PCR-RFLP approaches (modified from Toyooka et al, 2003;Shahrzad et al, 2005), we further examined K-ras mutations at codon 61 in the xenografts. We found no evidence for de novo development of mutation at this additional codon in either control or treatment group of the xenografted tumors (Supplementary Figure 1).…”

“…DNA was extracted from cultured cells and xenografted tissues, and K-ras mutation status at codon 13 and 61 was determined as described (Toyooka et al, 2003;Shahrzad et al, 2005). For codon 13, if there is a mutation in either of the first two bases, the mutant PCR fragment will not be cut by XcmI, and will remain at its original size of 165 bp.…”

“…Mutated K-ras was confirmed and identified by sequencing. K-ras codon 61 letter 1 and 2 mutations were determined by a two-step PCR-RFLP analysis, and letter 3 mutations were determined by a singlestep PCR-RFLP (modified from Toyooka et al, 2003;Shahrzad et al, 2005).…”

Tissue sampling for mutation analysis in colorectal cancer: K-ras is homogeneously distributed throughout the tumor tissue

“…The standard methodology involves analysis of very limited areas of the colorectal tumors, using one or a few biopsies (9,11,(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)24,26,(39)(40)(41)(42). However, these tumors generally display a morphological mosaiclike pattern, representing different intratumoral subclones of tumor development, ultimately affecting the results of studies of tumor markers as point mutations (43,44), allelic imbalance (21,45), as well as aneuploidy (11,46,47) and methylation status (48). As a rule, histological invasiveness directly affects the results in terms of 'molecular morbidity' (29)(30)(31).…”

Genetic alterations in lung adenocarcinoma with a micropapillary component

“…The KRAS mutations in codons 12 and 13 were examined using PCR-based direct sequencing on an ABI PRISM 3130xl Genetic Analyzer (Applied Biosystems), as previously reported (17)(18)(19). ALK IHC.…”