The aim of this study was to determine whether mRNA levels of thymidylate synthase (TS), excision repair cross-complementing -1 (ERCC-1), excision repair cross-complementing-2 (ERCC-2) and methylenetetrahydrofolate dehydrogenase( MTHFD) mRNA in the primary tumor could predict a tumor response in patients with unresectable liver metastasis from colorectal cancer treated with mFOLFOX6 therapy as a first-line treatment. Eighteen patients with unresectable liver metastasis from colorectal cancer treated with mFOLFOX6 therapy as a first-line treatment were enrolled in this study. There were no significant differences between the response rate and these enzymes mRNA levels. In ERCC-1 and MTHFD mRNA expression, the progression-free survival time tended to be longer in patients with low levels than in patients with high levels( ERCC-1: p=0.08, MTHFD: p=0.07). The progression-free survival time was significantly longer in patients with both ERCC-1 and MTHFD mRNA were low levels than in patients with other( p=0.03). The levels of ERCC-1 and MTHFD were low in patients who could perform a conversion therapy. There were no significant differences between an overall survival time and these enzymes mRNA levels. In this study, the ERCC-1 and MTHFD mRNA expression may be useful for the prediction of progression-free survival time in patients with unresectable liver metastasis from colorectal cancer treated with mFOLFOX6 therapy.

A man in his 60s was given an emergency operation 15 years ago for abdominal bleeding. His tumor of small intestine was resected and diagnosed as small intestinal leiomyosarcoma. He came to our hospital because of his abdominal masses 15 years after the initial operation. CT scan showed a 15 cm-sized solid and cystic tumor in the pelvic cavity. The tumor was diagnosed as GIST by PET-CT and MRI. The tumor was resected, and pathological findings led to the diagnosis of GIST with this tumor. Previous tumor cells were slightly-positive for kit immunohistological examination, but did not resemble this tumor cells morphologically. So genetic tests were performed and revealed two tumors had same mutations of c- kit. Finally, we could diagnose the tumor was recurrent metastases of small intestinal GIST 15 years after the initial surgery. kit mutation analysis was useful for a diagnosis of recurrences and predictions of the clinical response to imatinib in GISTs.

The NADP+-dependent isocitrate dehydrogenases 1 and 2 (IDH1/2) catalyze the oxidative decarboxylation of isocitrate into α-ketoglutarate (α-KG). IDH1 and IDH2 mutations have been frequently found in some types of gliomas (low-grade diffuse gliomas WHO grade II, anaplastic gliomas WHO grade III, and secondary glioblastomas WHO grade IV), and have received significant attention because of their specificity to single codons. Since the unveiling of IDH1/2 mutations, many studies have investigated their clinical impact on gliomas. While the favorable influence of these mutations in high-grade gliomas has been well established, their prognostic impact on low-grade diffuse gliomas is much less clear. While the mechanism of IDH1/2 mutations in gliomagenesis remains to be clarified, its elucidation might lead to novel therapeutic strategies against gliomas.

Clinical studies overseas using the therapeutic anti-EGFR monoclonal antibodies, cetuximab or panitumumab against metastatic colorectal cancer(mCRC), have revealed KRAS mutations as a negative predictive marker of response. Accordingly, the Ministry of Health, Labour and Welfare in Japan approved medical reimbursement of the KRAS mutation test in April 2010. Anti-EGFR monoclonal antibody therapies are now used as first-line treatment for patients with mCRC. To advance the simple high-throughput KRAS mutation test, we established a high-throughput screening system for detecting KRAS mutations utilizing Luminex(xMAP)technology(the fluorescent bead-based multiplex analyte profiling method), in combination with the polymerase chain reaction-reverse sequence-specific oligonucleotide method. Here we evaluated the basic performance of our system and confirmed its high specificity and reproducibility in detecting KRAS mutations at codons 12 and 13 in both plasmid DNAs carrying mutant KRAS genes and formalin-fixed paraffin-embedded tissues from mCRC patients. We demonstrated the KRAS mutation status in paraffin-embedded tissues of mCRC and confirmed that the results were comparable to those of the direct sequencing method. Our high-throughput method has an advantage in simultaneous analysis of multiple mutations in one well of 96-well PCR plates, and will advance the KRAS mutation test in clinical laboratories.

Genomic imprinting is an epigenetic marking and a stable transmission of monoallelic gene expression patterns in a parent of- origin-specific manner. Aberrant imprinting has been linked to a number of human genetic disorders, including congenital abnormalities, childhood cancer, behavior disorders, and cancer in adults. Imprinted genes play roles in carcinogenesis. Recently, progress in researched on epigenetic mechanisms of imprinted genes, in edition to analysis of the pathology of the oncogenetic mechanisms, has begun to be clinically applied to diagnostic methods, prevention, and cancer drug development.

Epidermal growth factor receptor (EGFR) is a transmembrane tyrosine kinase receptor that, on ligand binding, triggers the RAS-RAF-MAPK signaling pathway which is mainly associated with cell proliferation. Drugs targeting EGFR have recently entered clinical practice and have proven to be effective in providing clinical benefits. However, the presence of mutated KRAS alleles in cancer is a predictive marker of anti-EGFR drug resistance. Similarly, alterations of other members of the RAS-RAF-MAPK signaling pathway may also be such predictive markers, especially the BRAF mutation in colorectal cancer. Therefore, the identification of KRAS and BRAF mutations may be important in predicting resistance to EGFR-targeted therapies. We looked at the Tm analysis for simultaneous detection of KRAS and BRAF mutations using a quenching probe. The oligonucleotide probes modified with certain fluorescent dyes at 5'-end cytosine are quenched by their interaction with a uniquely positioned guanine. When the probe is hybridized with target DNA, its fluorescence is quenched by the guanine in the target DNA. However, as the temperature is raised, perfect match probes and miss match probes dissociate at different temperatures. Dissociated probes generate fluorescence. This simple and rapid method for simultaneous detection of these mutations is useful in clinical practice.