Array-based comparative genomic hybridization (array CGH) enables us to detect the genomic copy number alterations of cancers with high resolution. Our established array CGH platform consists of 2,304 BAC/PAC clones covering the whole genome at 1.3-mega base resolutions. Using this technique, we were thus able to reveal disease-specific genomic alterations and the candidate target genes in various lymphomas. We herein report the characteristic genomic alterations of malignant lymphomas including diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL) and adult T cell lymphoma/leukemia (ATLL). The combined use of the array CGH data with gene expression profiling and specific gene rearrangement analyses further delineated the subtype-specific genomic alterations. For instance, we revealed that activated B-cell-like DLBCL is characterized by a gain of chromosome 3, 18q and loss of 9 p21, whereas the germinal center B-cell-like DLBCL is characterized by a gain of 2p15, 7q, and 12q. Among these genomic alterations,we found the 9 p21 loss (p16INK4a locus) to be the most aggressive type of DLBCL. Comparisons of the genome profiles of FL,both with and without BCL2 rearrangement, also revealed the existence of a unique subgroup: trisomy 3 FL. Comparison of genome profiles between acute type and lymphoma types of adult T cell lymphoma also demonstrated that acute and lymphoma types are genomically distinct subtypes, and thus may develop tumors via distinct genetic pathways. In addition to identifying disease-specific genomic alterations, we also discovered several target genes of the genomic gains and losses. Furthermore,we developed a computer algorithm to classify lymphoma diseases or subtypes on the basis of copy number gains and losses. We applied the algorithm to the classifications of DLBCL and MCL diseases and ABC and GCB subtypes. The method correctly classified the DLBCL and MCL diseases at 89%, and ABC and GCB subtypes at 83%. These results demonstrate that copy number gains and losses detected by array CGH could be used for classifying lymphomas into biologically and clinically distinct diseases or subtypes. The genomic copy number alterations detected by array CGH are therefore considered to have the potential to help diagnose or classify different disease entities and tumor subtypes.

A 43-year-old female was admitted with therapy-resistant pancreatitis and an abdominal tumor around the pancreatic head. Laboratory data revealed leukocytosis with a white blood cell count of 18200/microl, 25% atypical cells and an LDH of 13410 IU/l. The bone marrow was comprised of 78.4 percent lymphoblastoid cells which were positive for CD10, CD19 and CD20, and the cytogenetic study of which demonstrated the presence of t(8;14) (q24;q32) and t(14;18) (q32;q21) in the same clone. The patient was diagnosed as having Burkitt's lymphoma (BL) with t(8;14) and t(14;18). Although CODOX-M and IVAC therapy combined with rituximab achieved complete remission, she died of rapid progressive disease during whole brain irradiation before autologous peripheral blood stem cell transplantation. Even if the intensive chemotherapy with rituximab is given adequately, durable remission may not be achieved in BL with translocation of t(8;14) and t(14;18). A more effective therapy remains to be established for the treatment of this disease.

We report herein on two rare cases of newly diagnosed chronic myeloid leukemia, which developed early blastic transformation within a year of imatinib treatment. Case 1 is a 22-year-old Japanese female, who underwent gradual blastic transformation with the increase of a resistant clone, which cytogenetically evolved right after she reached complete hematologic remission. Case 2 is a 24-year-old Japanese male, who underwent sudden transformation after 8 months treatment with imatinib mesylate following complete cytogenetic response. Although a sudden blastic transformation is extremely rare, the occurrence of such events even among the low-risk, good responding patients highlights the need for continued, rigorous monitoring by sensitive analysis, such as quantitative PCR. In order to accomplish the early eradication of minimal residual disease, the therapeutic strategy for chronic myeloid leukemia has to be defined in the era of imatinib, considering the application of allogeneic stem cell transplantation, which is currently the only curative treatment.

Until now reduced estrogen level has been considered to affect some psychiatric symptoms, because there are sex differences in onset of Schizophrenia and Alzheimer's disease. Estrogen is associated with cognitive functions, and it has been reported to protect oxidative damage of DNA related to base excision repair (BER). Some patients with Xeroderma Pigmentosum, who have normal BER and impaired nucleotide excision repair (NER), are known to be suffering from mental retardation. Therefore we hypothesized that impaired NER was partly associated with pathology of mental disorder and investigated the effects of estrogen on NER for ultraviolet-induced DNA damage. The N2a neuroblastoma cell line was used as a representative of neuronal cells and 17p-estradiol was selected as one of the most active estrogen derivatives. There were no significant effects of 17p-estradiol on prevention of DNA damage, promotion of DNA repair, or cell survival at the concentration of 0-0.1 microM 17p-estradiol (below cytotoxicity level). These results described that estrogen might not directly affect NER except through another DNA repair system.

Progress in translational research for lung cancer achieved during the last 10 years was reviewed. Since the discovery of oncogenes in 1980s, evidences of molecular basis of human cancer were rapidly accumulated and since the determination of draft sequences of human genome, the progress was further accelerated. With these molecular knowledge, it is now possible to comprehensively and extensively analyze human cancer using deoxyribonucleic acid (DNA) chips. The most remarkable event in this field was discovery of mutations of the epidermal growth factor receptor (EGFR) gene in a subset of patients with pulmonary adenocarcinoma with a high response to EGFR tyrosine kinase inhibitor. In the next 10 years, individualization of cancer treatment especially by targeted drugs based on molecular characteristics of each tumor using patients' tissue will be increasingly more important.

Tumor suppressor p53 protein is activated by a variety of cellular stresses through several pathways and transactivates its downstream genes, including regulators of cell cycle, apoptosis and DNA repair. The loss of p53 function by TP53 gene mutations therefore fails to activate these genes and is thought to be a critical cause of carcinogenesis and/or tumor progression. TP53 is one of the most frequently mutated genes in human cancer. TP53 mutations are found in about 50% of human cancers, although the frequency of TP53 mutations differs among tumor types. However, the degree of functional disorder of mutant p53 varies according to the type of TP53 mutation. And the effects of p53 on cancer formation and/or progression are influenced by the degree of p53 dysfunction. So it is important to analyze the effects of TP53 mutations carefully according to the oncogenicity of each mutation from the molecular epidemiological point of view. Here, together with some cautions needed for analyzing and interpreting the significance of TP53 gene mutations, we present some examples of the identified specific mutation spectrum and the correlation between the prognosis and TP53 mutation in some cancers.