AAV (adeno-associated virus) vectors are considered to be promising gene-delivery vehicles for gene therapy, because they are derived from non-pathogenic virus, efficiently transduce non-dividing cells, and cause long-term gene expression. Appropriate AAV serotypes are utilized depending on the type of target cells. Among various neurological disorders, Parkinson's disease (PD) is one of the most promising candidates of gene therapy. PD is a progressive neurodegenerative disorder that predominantly affects dopaminergic neurons in the substantia nigra. One of the major approaches to gene therapy of PD is the intrastriatal expression of dopamine (DA)-synthesizing enzyme genes. As for the initial step of clinical application, AAV vector-mediated AADC (aromatic L-amino acid decarboxylase; the enzyme converting L-DOPA to DA) gene transfer in combination with oral administration of L-DOPA would be appropriate, since DA production can be regulated by adjusting the dose of L-DOPA. Second, intramuscular injection of AAV vectors is appropriate to protein-supplement gene therapy. Monogenic diseases such as hemophilia and Fabry disease are suitable candidates. Regarding cancer gene therapy, AAV vectors may be utilized to inhibit tumor angiogenesis, metastasis, and invasion. When long-term transgene expression in stem cells is needed, a therapeutic gene should be introduced with a minimal risk of insertional mutagenesis. To this end, site-specific integration into the AAVS1 locus on the chromosome 19 (19q13.4) by using the integration machinery of AAV would be particularly valuable.

Gemtuzumab ozogamicin (GO) is a humanized anti-CD33 monoclonal antibody conjugated to calicheamicin, that is rapidly internalized after binding to CD33. This is followed by intracellular release of calicheamicin, which induces double-stranded DNA breaks, cell cycle arrest, and apoptosis. So GO is a more selective agent for acute myeloid leukemia (AML), because the CD33 antigen is expressed on AML, while it is not expressed on normal hematopoietic stem cells and nonhematopoietic tissues. However, some studies indicated that this agent showed resistance to refractory AML cells via various mechanisms, and that there were no potent effects. In this study, we report a 76-year-old female with recurrent AML who responded to single therapy with GO, achieving complete remission for more than 1 year after the start of administration, although additional remission induction was impossible. The response to GO can be stratified with reference to the response to conventional chemotherapy.

Recently it is considered that there is a small population of cells with stem cell property not only in leukemia but also in solid cancer.These cells show the ability of self-renewal and multi-potential differentiation, and can initiate and maintain a tumor. The origin of cancer stem cells might be their normal stem cells, progenitor cells, or bone marrow-derived cells. It is still difficult to isolate cancer stem cells in solid cancer. There are three possible methodologies to isolate or identify cancer stem cells; the use of a surface marker, use of cells cultured in a specific condition (sphere), or the use of side population cells identified by FACS. The gold standard assay that fulfills the definition of cancer stem cell may be serial transplantation in animal models. Cancer stem cells are likely to be responsible for disease relapse or metastasis, and also for resistance to radiation or conventional chemotherapy. The stem cell niche plays an important role on maintaining cancer stem cells. The novel promising therapies against cancer stem cells are considered, including antibody-based therapy, signal inhibitors, overcoming radiation and drug resistance, or differentiation therapy. Another interesting therapy targeting the niche may also be considered.

Molecular mechanism of thyroid carcinogenesis has been well studied through the discovery of genetic abnormalities such as RET/PTC rearrangement and BRAF mutation, both of which constitutively activate MAP kinase pathway and are frequently found in papillary thyroid cancer. The TP53 mutation is thought to play a critical role in transformation of differentiated thyroid cancer into anaplastic thyroid cancer. Besides these genetic alterations, cancer stem cell theory has recently been applied to thyroid field. A better understanding of thyroid cancer stem cell may not only ameliorate our comprehension of thyroid cancer biology, but also open the possibility of innovative diagnostic procedures and development of novel targeted therapies. In this article, we mainly review thyroid carcinogenesis based on the evidence of radiation-induced cancer and cancer stem cell hypothesis.

Vitamin K(2) has dual actions, stimulates osteoblastic functions, for synthesis of osteocalcin, osteonectin and other matrix bone proteins, in addition, new finding, in stem cell culture found osteoblast producing gene expression of collagen type 1, the other action, vitamin K(2) contains mild antiresorpion by inducing the osteoclastic apoptosis. Our study found that postmenopausal and elderly women have high risk of vitamin K(2) deficiency, comparing to the normal value of young, reproductive females. The efficacy of vitamin K(2) will be fulfill benefit after 6 months of administration, prolong use will enhance of bone quality that prevent fracture.

A 60-year-old man was admitted with muscle weakness and numbness in the extremities. Based on the existence of monoclonal gammopathy of the IgG-lamda type, a slight increase of plasma cells in the bone marrow, and an elevated level of serum vascular endothelial growth factor (VEGF), the diagnosis of POEMS syndrome was made. After peripheral blood stem cell collection by etoposide and G-CSF, the patient received high dose melphalan (200 mg/m2) therapy supported by autologous peripheral blood stem cell transplantation (autoPBSCT). After high-dose chemotherapy with autoPBSCT, the serum VEGF level normalized and the monoclonal IgG-lamda, disappeared. The patient gradually recovered from a bedridden state and at the time of writing has no impairment in his activities of daily life. After the autoPBSCT, monoclonal IgG-kappa, protein was detected transiently in serum. The new monoclonal immunoglobulin was considered to be due to normal immune reconstitution after myeloablation rather than alteration of the abnormal plasma cell clone, similarly as oligoclonal immunoglobulins occur in multiple myeloma after autoPBSCT. AutoPBSCT with high-dose chemotherapy should be considered among the treatments of choice for POEMS syndrome.

Twenty-three patients with acute myelogenous leukemia (AML) have received autologous hematopoietic stem cell transplantation (autoHSCT) in our institute from 1997 to 2005. Among them, 3 patients relapsed, and the other 4 patients (17%) showed cytogenetic abnormalities after the autoHSCT. In these 4 patients with AML1/MTG8 or CBFbeta/MYH11 AML, RT-PCR findings using bone marrow cells were all negative when a cytogenetic abnormality was detected. Myelodysplasia was not detected in the bone marrow and no abnormal findings were seen in the peripheral blood. Cytogenetic abnormalities were detected 12-48 months after AutoHSCT, which disappeared in three patients and decreased in the remaining one patient with a median follow up time of 51 months (30-72 months) after their detection. We present our finding together with a review of the literature on post-autoHSCT cytogenetic abnormalities not related to relapse or secondary leukemia/myelodysplastic syndrome.

Orchiopexy is one of the most frequently used surgical procedures for cryptorchidism and has been shown to have a beneficial effect on fertility. However, orchiopexy, especially for bilateral cryptorchidism, does not always guarantee subsequent fertility and paternity. Compared with a control group, paternity was significantly compromised in men with previous bilateral, but not unilateral cryptorchidism. Recent techniques of assisted reproductive technology, especially testicular sperm extraction with intracytoplasmic sperm injection (TESE-ICSI), have brought revolutionary changes in clinical therapy for infertiliy. If spermatozoa exists in testis of infertile men, logically there is a possibility of paternity. However, our study demonstrated that about 20% of pubertal boys who had had orchiopexy, were predicted to have lost their future paternity potential even if TESE-ICSI were conducted, because they were predicted to have no spermatozoa in the testis. To prevent or reverse the damage of spermatogenesis at prepuberty or puberty, we should not take a wait-and-see attitude but should consider a countermeasure for the pubertal boys who had had bilateral orchiopexy in childhood, especially when the serum follicle stimulating hormone level is elevated and testicular volume is lowered, before paternity is lost. In this review, we discuss the potential approaches including epidermal growth facter therapy, gene therapy and stem-cell therapy for cryptorchid patients in the future.

The discovery of tissue stem cells has launched the current boom in the field of regenerative research, which is tremendously exciting and holds enormous therapeutic potential. However, despite such optimism, recent findings have tempered the potential for medical practice especially in case of anatomically complicated and functionally sophisticated organs such as kidney and lung. This article reviews recent findings on renal stem cells and their possible application in therapeutic intervention for acute renal failure, as well as the intensive attempts to build a functional kidney de novo for chronic renal failure, which may truly progress the next stage from "regenerative medicine" to "regenerative therapy".