The advent of tyrosine kinase inhibitors as molecular target therapy has resulted in a marked change in the laboratory process for the diagnosis and therapeutic monitoring of chronic myelogenous leukemia. This includes defining the molecular typing of BCR-ABL1 to establish the diagnosis, a quantitative and/or high quality assay for minimal residual disease to evaluate the molecular response, and mutation analysis and chromosomal examination to assess its resistance to inhibitors. These processes should be used where appropriate for each patient. In the ongoing development and clinical use of novel agents for treatment of the leukemia, the quality assurance of each process of molecular-genetic testing, such as specimen handling, measurement, and reporting, has become increasingly important in the quality care of patients.

Recent studies have uncovered molecular pathways of colorectal cancer, including the chromosomal instability pathway and microsatellite pathway. In addition, according to genetic and epigenetic profiles, colorectal cancer can be subclassified into 3 distinct groups, named the CpG island methylator phenotype (CIMP) 1, CIMP2, and CIMP negative. CIMP1 is characterized by MSI and BRAF mutations and rare KRAS and p53 mutations. CIMP2 is associated with KRAS mutations and rare MSI, BRAF, or p53 mutations. CIMP negative cases have a high rate of p53 mutations and lower rates of MSI or mutations of BRAF or KRAS. Regarding genetic testing for personalized medicine for colorectal cancer, uridine disphosphate glucuronosyl transferase 1(UGT1) and KRAS tests are available. Irinotecan is one of the most effective chemotherapeutic agents in the treatment of metastatic colorectal cancer. The prodrug irinotecan is biotransformed by carboxylesterase into its active metabolite SN-38, which is inactivated by UGT1 into the inactive compound SN-38G. Here we discuss UGT1A1 gene polymorphism as a predictor of toxicity. The epidermal growth factor (EGFR) plays an important role in the development and progression of colorectal cancer. KRAS serves as a mediator between extracellular ligand binding and intracellular transduction of signals from EGFR to the nucleus. Activating KRAS mutations has been identified as a predictor of resistance to EGFR-directed antibodies such as cetuximab. Here we discuss the current understanding of KRAS mutations and the therapeutic effect of cetuximab.

Significant targeted molecules for breast cancer treatment are hormone receptor and HER2. Since the concept of an "intrinsic subtype" was proposed, breast cancers have been treated according to subtypes including Luminal A, B, HER2 and triple negative. In this article, gene testing useful as a prognostic factor and to predict the chemotherapeutic effect on ER-positive breast cancers will be introduced, although it has not been approved in Japan. Gene testing is useful but expensive so far; therefore, it will be used in parallel to conventional tools, i.e. HE-stained sections and immunohistochemical methods.

Genetic tests for individualized cancer therapy are now expanding their repertoire as pharmacogenomics biomarkers, coupled with advances in molecular targeted therapy. These tests were considered special in the 1990s, because they were almost entirely limited to hematopoietic tumors and other rare tumors. Molecular targeted therapy has been applied to common solid tumors as well as hematopoietic tumors in the first decade of the 21st century, leading to a breakthrough in genetic tests. In this symposium, recent advances in genetic tests for molecular targeted therapy are being presented on breast cancer, lung cancer, colorectal cancer and hematopoietic tumors by 4 speakers.

We report a case of a female in her 80s who was diagnosed with recurrent lung adenocarcinoma after primary surgery. She was treated with a systemic chemotherapy regimen consisting of carboplatin plus paclitaxel until the disease showed progression. On detection of epidermal growth factor receptor(EGFR)mutations, we administered gefitinib, an EGFR tyrosine kinase inhibitor, at a dosage of 250 mg daily. After 6 months of gefitinib therapy, laboratory findings revealed elevated serum aspartate aminotransferase(AST)and alanine aminotransferase(ALT)levels(grade 2), indicative of hepatotoxicity. Gefitinib was discontinued and erlotinib was initiated at a dosage of 50 mg daily. She continued the therapy for 3 years, during which her disease stabilized without any further complications or hepatotoxicity. Thus, low-dose erlotinib may be effective and well tolerated by patients with non-small cell lung cancer harboring EGFR mutations who are intolerant to gefitinib.

Malignant melanoma is insensitive to chemotherapy, and standard therapy for metastatic melanoma has been dacarbazine for years. Molecular abnormalities of malignant melanoma, mainly of MAP kinase signals such as BRAF mutation, have been clarified, and molecular target therapy for melanoma has been developed recently. Vemurafenib, an inhibitor for mutated BRAF, has shown its efficacy for the first time, with response rate of more than 50%, and an overall improvement in survival compared with dacarbazine in a phase III study. Skin toxicities including squamous cell carcinoma, are the most severe adverse events. Another BRAF inhibitor, dabrafenib, and a MEK inhibitor, trametinib, have shown excellent efficacy in clinical studies. Melanoma also has high immunogenicity, and cytokines or cell immunotherapy have shown some efficacy. Recently, the importance of immune checkpoints which adjust T-cell activation, such as the cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), -B7 or the programmed cell death protein-1(PD1)-PD1 ligand(PDL1), have been clarified. Targeting those immune checkpoints is expected to be effective for enhancing tumor immunity. CTLA-4 antibody ipilimumab has been reported to improve overall survival in two phase III studies. Major adverse events were autoimmune response such as colitis, eruption, liver dysfunction and endocrineopathies. Antibodies to PD1 or PDL1 have shown a higher response rate than those of ipilimumab, and seem to accompany fewer autoimmune responses in phase I studies. These two types of targeting therapy are expected to be standard therapies for melanoma.

A 47-year-old man was found to have abnormal findings on chest radiography. Chest computed tomography (CT) and magnetic resonance imaging (MRI) showed that he had a pulmonary arteriovenous malformation. He had experienced epistaxis when he was a junior high school student, and since then, the symptom had frequently recurred. Further, he had telangiectasia on the lips. Thus, he was given a diagnosis of hereditary hemorrhagic telangiectasia (HHT). Endoscopy revealed gastric telangiectasia, and in addition, his colon had many juvenile polyps. When he was 49 years of age, he underwent genetic analysis for HHT. A diagnosis of juvenile polyposis-HHT combined syndrome (JP-HHT) was made since a heterozygous germline 4-base deletion in exon 9 of SMAD4 was detected. To the best of our knowledge, this is the first case of JP-HHT associated with SMAD4 mutation in Japan.

Human T-cell leukemia virus type 1 (HTLV-1) belongs to Delta Retorviridae, and induces a malignancy of CD4+CD25+ T-cells, adult T-cell leukemia (ATL), and several chronic inflammatory diseases, such as HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) and HTLV-1 uveitis. A nationwide survey of HTLV-1-infected subjects, which was recently conducted by Japanese government, revealed that the numbers of HTLV-1 carriers and patients with HTLV-1-associated diseases have not decreased much over the last two decades in Japan. In contrast, novel findings on HTLV-1 dynamics in vivo and molecular mechanisms of its pathogenesis are accumulating by detailed analysis of newly identified viral and cellular factors, novel technologies such as next-generation sequencing, and appropriate animal models for HTLV-1 research. In this review, we summarize the recent progress of HTLV-1 research.

Cancer therapies are changing from general chemotherapeutic agents to drugs that target specific proteins and signaling pathways. Target therapies, which attack specific cancer cells without harming normal cells, have the potential to treat cancers with fewer side effects than conventional therapies. This article reviews mechanisms of resistance to targeted agents, including genetic resistance, bypass track resistance, and defect growth arrest/apoptosis. Secondary mutations reduce the biologic effects of inhibiting the driver oncoprotein. Interaction and cross signaling from targeting receptor to other growth factor receptors may potentially contribute to therapeutic resistance. They explain why solid tumors develop resistance to target therapies in a highly reproducible fashion.

The epidermal growth factor receptor (EGFR) triggers a downstream signaling cascade such as the RAS-RAF-MAPK and PI3K-AKT pathways, which are involved in cell proliferation, differentiation, survival and invasion. Two monoclonal antibodies (moABS) targeting EGFR, cetuximab and panitumumab, are established to be a new treatment for metastatic colorectal cancers. Among activating mutations in the downstream of EGFR, the KRAS gene mutation has shown to be predictive biomarker for resistance to anti-EGFR antibody therapy. This review focuses on the current status of chemotherapy with anti-EGFR antibody for colorectal cancers. The identification of patients who are likely to benefit from EGFR-targeted moABS is increasingly crucial for improving therapeutic strategies.

We established a strategy as follows to identify oncoantigens and HLA-restricted epitope peptides, which can be applied as cancer vaccine therapy; i) To identify genes overexpressed in solid tumors using the cDNA microarray, ii) To validate the clinicopathological significance of their protein expression by tissue microarray covering thousands of human cancers, iii) To verify whether they are essential for the cell growth by siRNAs, iv) To screen for the epitope peptides recognized by human HLA-A* 0201/A* 2402-restricted cytotoxic T lymphocyte by ELISPOT assay. We identified dozens of epitopes derived from oncoantigens. In clinical trials, the cancer vaccine therapy against lung cancer using a combination of peptides demonstrated safety and good immunogenicity, and warrants further studies.

Wilms' tumor gene WT1 encodes a transcription factor and functions as an oncogene. WT1 gene product WT1 protein is a promising par-tumor-associated antigen. WT1 peptide-based immunotherapy has been performing for more than six hundred patients with leukemias and various types of solid tumors. This immunotherapy is safe and has clinical benefit especially for leukemia, glioblastoma multiforme, advanced pancreatic cancer, and ovarian cancer. As a new strategy for cancer treatment, it should be recommended to initiate immunotherapy that had a potential of eradication of cancer stem cells before surgery, chemo- and radio-therapy.

The development of a carrier for the delivery of siRNA is a factor in the realization of RNA interference (RNAi) therapeutics. Modification of siRNA carriers with polyethylene glycol, i.e., PEGylation, is a general strategy for stabilizing a particle in the blood stream and delivering it to tissue or cells. However, it is well-known that, when a carrier is modified by PEGylation, it results in a significant inhibition of both cellular uptake and the endosomal escape process. In a previous study, we reported on the development of a multifunctional envelope-type nano device (MEND) for delivering siRNA and peptide-based functional devices for overcoming the effects conferred by PEGylation and succeeded in the delivery of siRNA to tumor tissue. In this study, we noticed that the pH-sensitive property, changing from neutral to cationic in response to a decrease in pH, could avoid the inhibition caused by PEGylation and succeeded in synthesizing a pH-sensitive cationic lipid, YSK05. The YSK05-MEND had a higher fusogenicity and potency for endosomal escape than other MENDs containing conventional cationic lipids. The PEGylated YSK05-MEND induced efficient gene silencing and avoided the inhibition of endosomal escape caused by PEGylation followed by optimization of the lipid composition. Furthermore, the intratumoral injection of the PEGylated YSK05-MEND resulted in a more efficient gene silencing compared with MENDs containing conventional cationic lipids. Thus, the YSK05-MEND is a promising siRNA carrier for avoiding the inhibition in intracellular trafficking caused by PEGylation both in vitro and in vivo.

Epstein-Barr virus (EBV)-associated gastric carcinoma (GC), comprising nearly 10% of all cases of GC, is the monoclonal growth of EBV-infected epithelial cells, which express a limited number of EBV-latent genes(latency I program). The primary molecular abnormality in EBV-associated GC is the epigenetic abnormality, that is, global CpG island methylation in the promoter region of many cancer-related genes. Experimental infection of EBV induced this EBV-specific epigenotype in addition to gastric cancer epigenotype in gastric cancer cells. Viral latent membrane protein 2A (LMP2A) is partly responsible for the promotion of DNA methylation, through STAT3-mediated up-regulation of DNMT1. Such a mechanism may be the overdrive of interaction between virus and infected cells.