Hotspots of MLV integration in the hematopoietic tumor genome.

Extensive research has been performed regarding the integration sites of murine leukemia retrovirus (MLV) for the identification of proto-oncogenes. To date, the overlap of mutations within specific oligonucleotides across different tumor genomes has been regarded as a rare event; however, a recent study of MLV integration into the oncogene Zfp521 suggested the existence of a hotspot oligonucleotide for MLV integration. In the current review, we discuss the hotspots of MLV integration into several genes: c-Myc, Stat5a and N-myc, as well as ZFP521, as examined in tumor genomes. From this, MLV integration convergence within specific oligonucleotides is not necessarily a rare event. This short review aims to promote re-consideration of MLV integration within the tumor genome, which involves both well-known and potentially newly identified and novel mechanisms and specifications.

ZFP521 contributes to pre-B-cell lymphomagenesis through modulation of the pre-B-cell receptor signaling pathway.

ZFP521 was previously identified as a putative gene involved in induction of B-cell lymphomagenesis. However, the contribution of ZFP521 to lymphomagenesis has not been confirmed. In this study, we sought to elucidate the role of ZFP521 in B-cell lymphomagenesis. To this end, we used a retroviral insertion method to show that ZFP521 was a target of mutagenesis in pre-B-lymphoblastic lymphoma cells. The pre-B-cell receptor (pre-BCR) signaling molecules BLNK, BTK and BANK1 were positively regulated by the ZFP521 gene, leading to enhancement of the pre-BCR signaling pathway. In addition, c-myc and c-jun were upregulated following activation of ZFP521. Stimulation of pre-BCR signaling using anti-Vpreb antibodies caused aberrant upregulation of c-myc and c-jun and of Ccnd3, which encodes cyclin D3, thereby inducing the growth of pre-B cells. Stimulation with Vpreb affected the growth of pre-B cells, and addition of interleukin (IL)-7 receptor exerted competitive effects on pre-B-cell growth. Knockdown of BTK and BANK1, targets of ZFP521, suppressed the effects of Vpreb stimulation on cell growth. Furthermore, in human lymphoblastic lymphoma, analogous to pre-B-cell lymphoma in mice, the expression of ZNF521, the homolog of ZFP521 in humans, was upregulated. In conclusion, our data showed that the ZFP521 gene comprehensively induced pre-B-cell lymphomagenesis by modulating the pre-B-cell receptor signaling pathway.

A case of maxillary sarcoma in a chimpanzee (Pan troglodytes).

Oral malignancy is rare in chimpanzees. A 34-year-old female chimpanzee (Pan troglodytes) at Kumamoto Sanctuary, Japan, had developed it. Treatment is technically difficult for chimpanzees while malignant neoplasm is seemingly rising in captive populations. Widespread expert discussion, guidelines for treatment, especially for great apes in terminal stages is urgently needed.

Interferon-γ/CCR5 expression in invariant natural killer T cells and CCL5 expression in capillary veins of dermal papillae correlate with development of psoriasis vulgaris.

BACKGROUND: There have been extensive studies regarding which types of T lymphocytes are involved in psoriasis vulgaris (PV). However, it has remained unclear which types of T lymphocytes might directly contribute to psoriasiform epidermal and vascular hyperplasia. OBJECTIVES: To understand the role of T-cell receptor (TCR)Vα24+ invariant natural killer (iNK)T cells in the development of PV. METHODS: Seventeen patients were enrolled in this study. Using biopsy samples of PV plaques, TCRVα24(+) iNKT cells were investigated regarding their cytokine production to understand their roles in development of disease. RESULTS: The number of interferon (IFN)-γ+ iNKT cells correlated with the length of the psoriasiform hyperplasia rete ridge and the Psoriasis Area and Severity Index. IFN-γ+ iNKT cells in psoriatic skin exhibited higher C-C chemokine receptor (CCR)5 expression, and the amount of C-C chemokine ligand (CCL)5, a ligand for CCR5, was increased in capillary veins of psoriasis plaques. CCR5+ iNKT-cell numbers significantly correlated with the number of capillary vein endothelial cells expressing CCL5 in PV. Furthermore, the number of CCL5+ capillary veins correlated with the maximum rete ridge length. CONCLUSIONS: IFN-γ/CCR5 expression in iNKT cells and CCL5 expression in vessels of dermal papillae correlate with the development of psoriasiform hyperplasia and microabscess. We propose that these iNKT cells may become useful targets for development of novel therapeutic approaches to PV.

The challenge of acute rejection in intestinal transplantation.

Early diagnosis and treatment of acute cellular rejection (ACR) after intestinal transplantation (ITx) is challenging. We report the outcome of three patients: two presented mild ACR improved with steroids. One presented steroid-resistant severe rejection, improved after rabbit anti-thymocyte globulin (r-ATG), but unfortunately died for encephalitis caused by opportunistic infections.

Small bowel transplantation using grafts from living-related donors. Two case reports.

A living-related small bowel transplantation (SBT) was performed in two pediatric patients with short bowel syndrome. In both cases, the donor was the patient's mother. The distal ileum (100 cm, 120 cm) was harvested and the ileocolic vessels, ileocecal valve, and terminal ileum were left intact. The two donors were discharged from the hospital on postoperative days 15 and 6, respectively. Recipient 1 was a 2 year 6 month-old boy with short bowel syndrome who underwent SBT due to loss of venous access. The graft vein was anastomosed to the recipient's infrarenal inferior vena cava. Despite triple immunosuppression (tacrolimus, steroid, and azathioprine), there were four episodes of rejection. The patient had been on total parenteral nutrition for almost his entire posttransplant course. He died from Pneumocystis carinii pneumonia 16 months after the transplantation. Recipient 2 was a 4 year 5 month-old girl with short bowel syndrome who underwent an isolated small bowel transplantation because of recurrent line sepsis. Her pretransplant bilirubin was 8.0 mg/dl and a biopsy showed severe fibrosis. The graft vein was anastomosed to the recipient's inferior mesenteric vein. After transplantation, her bilirubin level became normal within 10 days. Triple immunosuppression (tacrolimus, steroid, and cyclophosphamide) together with a 3-day course of OKT-3 made her post-transplant course feasible. After overcoming a single episode of rejection she left the hospital 4 months after SBT. The patient is currently (10 months after transplantation) hospitalized due to rejection, which is being successfully controlled, and she is off total parenteral nutrition. From our experience, harvesting of the distal ileum for use as a bowel graft can be safely performed. The advantages of living-related grafts, optimal graft length, and choice of vascular reconstruction in SBT are yet to be explored.

ras and p53 genes are infrequently involved in N-nitroso-N-butylurea (NBU)-induced rat leukemia.

Chemically-induced rodent tumor models help us to understand a series of genetic changes during carcinogenesis. In this study, we present N-nitroso-N-butylurea (NBU)-induced rat leukemia and compare it with the genetic alterations found in 7,12-dimethylbenz[a]anthracene (DMBA)-induced erythroblastic leukemias which consistently have an A to T transversion at the second base of codon 61 in N-ras. By continuous NBU treatment for 120-150 days, 14 primary leukemias were induced in Long-Evans rats. Myeloblastic leukemia cells predominantly increased in all rats except in one case which predominantly had erythroblastic leukemia cells. Point mutations of Ha-, Ki-, N-ras and p53 were determined after RNA was transcribed into cDNA and this cDNA was used as a substrate for polymerase chain reaction (PCR) which was eventually sequenced. No abnormalities in exons 1 and 2 of Ha-, Ki- and N-ras were detected in all leukemias. In the p53 gene, an A to C transition was found at the second base of codon 198 (Asn-Thr) in one leukemia, but others had no mutation. These results suggest that ras and p53 genes are infrequently involved in NBU-induced leukemias. The genetic target of NBU during leukemogenesis seemed to be different from that of DMBA.