Genetic and epigenetic alterations are induced during gastric carcinogenesis. Infection by H. pylori markedly increases induction of both alterations, and inflammation triggered by the infection is critical for induction of aberrant DNA methylation (epigenetic alterations). Oncogenes, such as PIK3CA, CTNNB1, KRAS, and ERBB2, are activated by point mutations and gene amplification. Tumor-suppressor genes, such as TP53, CDH1, CDKN2A, and MLH1, are inactivated by mutations, and more frequently by aberrant methylation if they have promoter CpG islands. The information on the activated signaling pathway, such as the ERBB2-MAPK signaling pathway, is now becoming useful for patient stratification. Comprehensive analysis of genetic and epigenetic alterations in gastric cancers is expected to lead to more occasions of translation.

Recent advances in lung cancer research have enabled significant progress in our understanding of the molecular pathogenesis and treatment for lung cancer. For example, EGFR tyrosine kinase inhibitors have been developed, and a subset of patients show marked therapeutic responses to this treatment. Subsequently, this super-response was revealed to be associated with an EGFR mutation that was identified in 2005. Currently, EGFR tyrosine kinase inhibitors are available for first-line treatments of patients with advanced non-small-cell lung cancer when the tumor is positive for an EGFR mutation. More recently, similar marked responses to an ALK inhibitor in patients with ALK fusion lung cancers were demonstrated. In this article, we review such recent advances in lung cancer, focusing on EGFR mutation and ALK fusion..

Quantitative analysis of the leukemia fusion gene by real-time PCR is a sensitive method to monitor minimal residual disease; the data obtained are very useful to evaluate the disease stage and prognosis, contributing to the clinical practice of hematology. However, there is no standard laboratory procedure for leukemia genetic testing. Therefore, this genetic testing has some problems related to precision management. To minimize analytical error factors, normalization by an internal control gene is necessary. Additionally, it is important to choose a gene suitable for leukemia gene expression analysis because the expression of an internal standard gene changes due to various factors. In this study, we examined analytical error factors (RNA extraction efficiency, reverse transcription reaction efficiency) and evaluated an internal control gene. As a result, in RNA extraction, the extraction efficiency of the acid-guanidium-phenol-chloroform (AGPC) method was high compared to the silica method. The reverse transcription reaction efficiency was significantly different with each reaction reagent. Furthermore, since three kinds of gene (18s rRNA, GUS, beta-actin) had few differences between samples, they were considered to be suitable as internal standards.

Although human T cell leukemia virus type I (HTLV-I) is undoubtedly involved in the immortalization and leukemogenesis of infected cells, mechanistic underpinnings of its molecular pathophysiology in long latent period of Adult T-cell leukemia (ATL) remain to be elucidated. One of the most significant recent advances in biomedical research has been the discovery of small noncoding RNAs designated microRNA (miRNA), which affect the field of virology including HTLV-1 research. Mounting evidence indicates that viruses use these miRNAs to manipulate both cellular and viral gene expression. Viral infection also can exert a profound impact on the cellular miRNA expression profile. Some studies have demonstrated that some deregulations of miRNA are involved in the pathogenesis of HTLV-1. Furthermore, global analyses of ATL patient samples have provided a conceptual progress that Polycomb family induces miR-31 silencing, resulting in overexpression of NF- kappaB inducing kinase (NIK) following NF-kappaB activation. Given that miRNAs act as pleiotropic molecules essential in all cellular events, deregulation of miRNA signature caused by HTLV-1 infection strongly involves the imbalance of molecular network of lymphocytes. Recognition and understanding of the widespread molecular applicability of miRNAs will increasingly have much effect on the development of novel strategies to treat the HTLV-1-associated diseases. Here we discuss our current knowledge of viral miRNAs and virally influenced cellular miRNAs and their relationship to ATL.

The clinical significance of KRAS gene testing prior to using anti-epidermal growth factor receptor(EGFR)antibodies for colorectal cancer patients has been established in past randomized clinical trials. Thus, testing for the 7 most common mutations of KRAS codons 12 and 13 is now recommended as a clinical practice. However, pooled analysis of randomized controlled studies in Western countries in patients treated with cetuximab has suggested that patients with tumors showing the KRAS p. G13D mutation[a glycine(G)to aspartate(D)transition mutation] have longer overall survival and progression-free survival when compared to patients with other KRAS mutations. Furthermore, even among patients whose tumors are wild-type for KRAS codons 12 and 13, response rates are only 13~17% for anti-EGFR antibody monotherapy. These facts suggest that additional activating mutations in the RAS-RAF-MAPK or PI3K-AKT-mTOR pathways may also confer resistance to anti-EGFR antibody therapies. Indeed, recent retrospective studies have shown that mutations in KRAS codon 61 and 146, BRAF, NRAS, and PIK3CA may also predict resistance to anti-EGFR antibodies in colorectal cancer patients. On the other hand, the continuous use of anti-EGFR therapies for KRAS wild-type patients may lead to secondary resistance. Acquired EGFR or KRAS mutations have occasionally been detected among specimens from these patients. We review the latest personalized therapy available for colorectal cancer patients using KRAS mutational testing. We also illustrate future perspectives for patient selection using KRAS, BRAF, NRAS, PIK3CA, and other mutations.