Nicotinic acetylcholine receptors expressed in the ventralposterolateral thalamic nucleus play an important role in anti-allodynic effects

BACKGROUND AND PURPOSE

Much interest is currently being focused on the anti-nociceptive effects mediated by nicotinic acetylcholine (nACh) receptors, including their location and mechanism of action. The purpose of this study was to elucidate these issues using 5-iodo-3-(2(S)-azetidinylmethoxy)pyridine (5IA), a nACh receptor agonist, and [(125)I]5IA.

EXPERIMENTAL APPROACH

We partially ligated the sciatic nerve of Sprague-Dawley rat to induce neuropathic pain [Seltzer's partial sciatic nerve ligation (PSL) model]. We then examined the changes in nACh receptor density in the CNS using [(125)I]5IA autoradiography and the involvement of nACh receptors in anti-nociceptive effects in the region where changes occurred.

KEY RESULTS

Autoradiographic studies showed that the accumulation of [(125)I]5IA and the number of nACh receptors in the thalamus of PSL rats were increased about twofold compared with those in the sham-operated rats. No change was observed in other brain regions. Rats injected in the ventral posterolateral thalamic nucleus (VPL) with 5IA demonstrated a significant and dose-dependent anti-allodynic effect and this effect was completely antagonized by mecamylamine, injected with 5IA, into the VPL. The blockade of nACh receptors in the VPL by mecamylamine decreased by 70% the anti-allodynic effect of 5IA, given i.c.v. Moreover, mecamylamine given intra-VPL by itself, induced significant hyperalgesia.

CONCLUSIONS AND IMPLICATIONS

Our findings suggest that the nACh receptors expressed in the VPL play an important role in the anti-allodynic effects produced by exogenous and endogenous agonists.

Polymorphisms of the ICAM-1 exon 6 (E469K) are associated with differentiation of colorectal cancer

Background

Genetic factors are thought to play a role in development for colorectal carcinogenesis. ICAM-1 is a polymorphic gene, thus, the present study investigated the relationship between the polymorphisms of ICAM-1 and the susceptibility and phenotypical characteristics of colorectal cancer (CRC).

Methods

The polymorphisms at ICAM-1 exon 4 (G241R) and exon 6 (E469K) were detected by PCR with sequence-specific primers. The relationship between specific genotypes of ICAM-1 and differentiation of CRC was evaluated by the histological grade.

Results

We showed only GG genotype of ICAM-1 individuals in either CRC or normal controls. The KK genotype of ICAM-1 K469E was found more frequently than in the controls (P < 0.05). Patients with well-differentiated CRC displayed the KK more frequently than those of poor differentiation (P < 0.05).

Conclusion

The findings indicate that polymorphisms of G241R are rare in Chinese population and that KK genotype of ICAM-1 K469E is significantly associated with well differentiation of CRC.

Impact of number of resected and involved lymph nodes (LN) at the time of surgical resection on the survival of non-small cell lung cancer (NSCLC)

7514

Background: Total number of lymph-nodes has recently proven prognostic in early breast and colorectal cancer. In this study we retrospectively evaluated the prognostic impact of the number of resected and involved lymph-nodes on the survival of stage I-III NSCLC. Methods: A series of 928 consecutive NSCLC pts who underwent complete lobectomy, bilobectomy or pneumonectomy with lymph-nodes dissection from 1/2000 to 11/2007 at Tokyo Medical University was eligible. Log rank and Cox proportional hazard model was used to estimate survival rates and relative risks. Results: Demographics are as follows: median age: 65.0 (22–87yrs), sex: 547 males and 381 females, median follow-up time: 2.5 yrs, clinical stage: 765 stage I, 84 stage II and 76 stage III, histology: 684 adenocarcinoma, 182 squamous cell carcinoma, and 62 others, operation: 870 lobectomy, 42 bilobectomy and 16 pneumonectomy, mean number of resected LN: 15 (1–49), mean number of involved LN: 0.9 (0–22). We observed a statistically significant increasing trend in overall survival (OS) between 0–3 and 4 and more of number of involved LN (P<0.001). Although a significant increasing in OS of 0–9 of number of resected LN cases compared with 10 and more was observed in all stages (P=0.024), no significant differentiation was observed in clinical stage I cases. Conclusions: This data suggests that there is a significant decrease in OS with 10 and more number of resected LN examined at surgery in NSCLC pts. However, there is no significant different in stage I pts, which implies that selected LN sampling is enough in clinical stage I cases. Further study such as LN dissection vs LN sampling in clinical stage I will be needed.

No significant financial relationships to disclose.

Modified ELISPOT assay may predict T-cell hyporesponsiveness to non-inherited maternal antigens

Clinical reports have suggested the existence of immunological tolerance to noninherited maternal antigens (NIMA) in human leukocyte antigen (HLA) mismatched allogeneic stem cell transplantation (allo-SCT). We studied the T-cell reactivity using IFN-gamma enzyme-linked immunospot (ELISPOT) assay in three HLA fully matched allo-SCT cases and one healthy volunteer family case. In HLA fully matched allo-SCT cases, ELISPOT assay could detect the hyporesponsiveness of T cells from donors to the B cells from recipients. Moreover, ELISPOT assay showed that the T cells from an individual responded to B cell from his mother significantly weakly than those from an unrelated HLA-haploidentical individual. These observations suggest that our IFN-gamma ELISPOT assay-based method may predict the presence of immunological tolerance to NIMA.

MBL2 single nucleotide polymorphism diversity among four ethnic groups as revealed by a bead-based liquid array profiling

In the present work we established a rapid, cost-effective and high-throughput method for genotyping using a multiplexed microsphere-based suspension array platform - Luminex xMAP which enabled us to analyze 3 SNPs in the MBL2 gene promoter and 5' UTR, and 3 coding SNPs exon 1 haplotypes, associated with different levels of MBL2 expression. Using this system MBL2 diversity in four different ethnic groups, namely, Asian (Japanese), Caucasian, Hispanic and African-American-assessed. Results showed significant variability in terms of allele, genotype, and haplotype distribution. Characteristic MBL haplotype patterns were defined for each ethnic group. A prevalence of haplotypes coding functional proteins capable of complement activation and pathogen opsonization was observed. Regardless of the significant diversity of individual haplotypes, a high, almost similar (25-28%) proportion of haplotypes associated with MBL deficiency was found in the four ethic groups. The proportion of individuals homozygous for the haplotypes resulting in complete MBL2 deficiency was also significant (2-10%). Considering the role of MBL2 in innate immunity and as a clinically relevant marker, the genotyping approach developed and the knowledge of the genetic variation in different ethnic groups will be relevant to future medical genetic studies.

Immunogenic HLA class I epitopes identified by humoral response to pregnancies

The main objective of this study was to understand the humoral immunity against HLA so that this knowledge can be applied clinically. We investigated the various factors resulting in antibody production by 128 mothers against the child's inherited paternal alleles. Among 128 mother-child pairs, 39 different mismatch antigens were observed. Of these, 19 resulted in antibody production against the specific mismatched antigen. The 20 mismatched antigens that did not result in a humoral immune reaction were excluded from this study. We performed epitope analysis by testing 45 allo-antisera from mothers. We compared the amino acids that define these epitopes in the mother's HLA with those in the immunogen's HLA. The positions of the mismatched amino acids between them were determined to be the immunogenic amino acid positions of mismatched HLA. We found that the immunogenic epitopes were located mainly on the alpha 1 helix. Mothers who have different immunogens were shown to have different class II alleles. Epitope analysis of this study indicated the possibility that immunogenic amino acid positions exist for each of the different mismatching alleles. Mismatching at these immunogenic positions did not always result in the antibody production, and it is thought that the differences are due to the efficiency of class II alleles in presenting the mismatched alleles.

Epitopes of HLA antibodies found in sera of normal healthy males and cord blood

This chapter defines epitopes targeted by antibodies in the sera of two populations of healthy normal males and in cord blood samples from a third population. These epitopes are accessible for antibody binding on either the intact or dissociated forms of recombinant HLA class I single antigens. Sixty percent of these epitopes are defined by hidden amino acids, and are therefore designated as cryptic epitopes. All sera were tested in parallel, using single antigen beads that bore either intact or dissociated recombinant HLA antigens. Ninety-six HLA class I epitopes were characterized as epitopes of these antibodies. More than half were private epitopes, and the rest were shared by two-to-18 HLA antigens. Fifty-eight (60%) epitopes were accessible on dissociated HLA antigens. Of these, 41 were defined by hidden amino acids, 13 by at least one hidden amino acid in addition to exposed amino acids, and four were defined by exposed amino acids. Almost all epitopes were found exclusively on either A-, B-, or C-locus antigens--except for one inter-locus epitope. Antibodies with nearly identical specificities were found in all three of the tested populations. Most of these antibodies target epitopes that are accessible only on the dissociated forms of the HLA class I antigens. Specificities of such antibodies are unavoidably detected when testing for specificities of alloantibodies so it may be necessary to clearly differentiate the two forms of antibody. The relevance of these antibodies in transplantation is not yet known. But even if they are shown to be irrelevant to graft rejection, awareness of the newly identified epitopes could prove useful in avoiding unnecessary exclusion of potential transplant donors.

Deletion of entire HLA-A gene accompanied by an insertion of a retrotransposon

Unusual HLA-A'null' alleles because of an entire gene deletion were found in three apparently unrelated Japanese families with leukemia patients. Inclusion of the entire HLA-A gene in the deletion was confirmed by polymerase chain reaction direct sequencing of the surrounding regions of HLA-A. Further localization of the breakpoints of the HLA-A deletion at the centromeric and telomeric sides was performed, and these families were shown to possess the identical deletion. We then determined the genomic sequence of the HLA-A-deleted haplotype. Surprisingly, the haplotype turned out to carry an insertion of an SVA (SINE-VNTR-Alu) retrotransposon of 2 kb as well as the 14 kb deletion that included the entire HLA-A gene.

A pediatric case of transfusion-related acute lung injury following bone marrow infusion

TRALI is a rare but serious complication associated with transfusion, and known to occur following infusion of all types of plasma-containing blood products. However, only one adult case of TRALI after allogenic marrow graft has been reported. In this study, we present a pediatric case possibly associated with allogenic marrow infusion. A 10-yr-old girl was referred to our hospital for the treatment of acute myeloid leukemia. She underwent allogenic bone marrow transplantation from her HLA-2-loci-mismatched mother. During conditioning, she suffered from bacterial sepsis, but it had improved with antibiotics until day 0 of transplantation. Two h after starting the marrow infusion, she developed severe hypoxia. We discontinued the infusion and started steroids, which improved her respiratory condition. However, she developed respiratory failure again after resuming infusion of the graft. Despite intensive care with mechanical ventilation, the patient died of endotoxin shock five days after transplantation. Although we could not identify the antibody which might have been involved in the respiratory distress, the clear temporal relationship between marrow infusion and respiratory distress suggested that similar acute lung injury to TRALI might have occurred following allogenic marrow infusion in the present case.

High-risk HLA allele mismatch combinations responsible for severe acute graft-versus-host disease and implication for its molecular mechanism

In allogenic hematopoietic stem-cell transplantation, an effect of HLA locus mismatch in allele level on clinical outcome has been clarified. However, the effect of each HLA allele mismatch combination is little known, and its molecular mechanism to induce acute graft-versus-host disease (aGVHD) remains to be elucidated. A total of 5210 donor-patient pairs who underwent transplantation through Japan Marrow Donor Program were analyzed. All HLA-A, -B, -C, -DRB1, -DQB1, and -DPB1 alleles were retrospectively typed in all pairs. The impacts of the HLA allele mismatch combinations and amino acid substitution positions in 6 HLA loci on severe aGVHD were analyzed. A total of 15 significant high-risk HLA allele mismatch combinations and 1 HLA-DRB1-DQB1 linked mismatch combinations (high-risk mismatch) for severe aGVHD were identified, and the number of high-risk mismatches was highly associated with the occurrence of severe aGVHD regardless of the presence of mismatch combinations other than high-risk mismatch. Furthermore, 6 specific amino acid substitution positions in HLA class I were identified as those responsible for severe aGVHD. These findings provide evidence to elucidate the mechanism of aGVHD on the basis of HLA molecule. Furthermore, the identification of high-risk mismatch, that is, nonpermissive mismatch, would be beneficial for the selection of a suitable donor.

The relationship between RASSF1A aberrant methylation and survival in small sized lung adenocarcinoma

7199

Background: Aberrant methylation of CpG islands in promoter regions of tumor cells is one of the major mechanisms for silencing of tumor suppressor genes. The RAS association domain family 1A (RASSF1A) gene was isolated from the 3p21.3 region homozygously deleted in lung cancer cell lines, and it was shown to be inactivated by hypermethylation of the promoter region in lung cancers. In this study, we investigated the clinicopathological significances of RASSF1A methylation in the development and/or progression of small-sized (less than 2.0cm) lung adenocarcinoma. It is important to identify a marker for high-risk early stage patients who should benefit from new investigational adjuvant therapies. Methods: Surgically resected specimens from 77 cases of small-sized primary lung adenocarcinoma. We determined the frequency of aberrant promoter methylation of the RASSF1A genes in small-sized adenocarcinoma. Aberrant promoter methylation was examined using methylation-specific PCR (MSP). Results: Twenty-five of 77 (32.5%) tumors showed RASSF1A methylation. RASSF1A methylation was dominantly detected in smoker (P < 0.03). There was no significant correlation of RASSF1A methylation with gender, age, T stage, N stage and pathological stage. RASSF1A methylation correlated with adverse survival by univariate analysis (P < 0.005) as well as multivariate analysis (P = 0.0062; RR 4.251; 95% C.I., 1.507–11.993). Furthermore, RASSF1A promoter hypermethylation in resected stage I small-sized lung adenocarcinoma was associated with impaired patient survival (P < 0.01). Conclusions: Aberrant promoter methylation of the RASSF1A was present in 25 of 77 (32.5%) of small-sized lung adenocarcinoma by MSP assay. These results indicated that epigenetic inactivation of RASSF1A plays an important role in the progression of small-sized lung adenocarcinoma, and that RASSF1A hypermethylation appears to be a useful molecular marker for the prognosis of patients with small-sized and stage I lung adenocarcinoma. RASSF1A is a potential tumor suppressor gene that undergoes epigenetic inactivation in lung adenocarcinoma through hypermethylation of its promoter region. RASSF1A methylation was significantly related to unfavorable prognosis in small-sized lung adenocarcinoma.

No significant financial relationships to disclose.

Fetal-maternal microchimerism: impact on hematopoietic stem cell transplantation

Reciprocal cell traffic between mother and fetus during pregnancy gives rise to postpartum fetal-maternal lymphohematopoietic microchimerism, which is frequently detected in blood or tissue from healthy individuals. Although such microchimerism has been implicated in the pathogenesis of autoimmune diseases and tissue repair, recent clinical experiences have suggested the association of microchimerism with acquired immunologic hyporesponsiveness to non-inherited maternal HLA antigens (NIMAs) or inherited paternal HLA antigens (IPAs); T cell-replete HLA-haploidentical hematopoietic stem cell transplantation from a microchimeric IPA/NIMA-mismatched donor confers relatively lower incidence of severe graft-versus-host disease. The underlying mechanisms by which fetal-maternal microchimerism contributes to IPA/NIMA-specific tolerance are still elusive, although emerging experimental evidence suggests an involvement of the central deletion of IPA/NIMA-reactive T cells, the induction of peripheral regulatory T cells, and affinity-dependent modulation of NIMA-reactive B cells.

Successful non-T-cell-depleted nonmyeloablative hematopoietic stem cell transplantation (NST) from an HLA-haploidentical 2-loci-mismatched sibling in a heavily transfused patient with severe aplastic anemia based on the fetomaternal microchimerism

A 37-year-old Japanese man with systemic hemochromatosis due to multiple transfusions was referred to us for the treatment of severe aplastic anemia (SAA), from which he had been suffering for 24 years. The patient had diabetes arising from the hemochromatosis, chronic anal fissures, and a kidney abscess due to neutropenia. He was treated with a nonmyeloablative preconditioning regimen followed by non-T-cell-depleted (non-TCD) allogeneic peripheral blood stem cell transplantation (PBSCT) from his human leukocyte antigen (HLA)-haploidentical 2-loci-mismatched sibling. Prompt engraftment of granulocytes and platelets was observed, and graft-versus-host disease was easy to control. Noninherited maternal antigens in the donor were confirmed prior to PBSCT, and they were also detected in small quantities in the recipient. This report describes the first successful nonmyeloablative hematopoietic stem cell transplant in a heavily transfused SAA patient from an HLA-haploidentical 2-loci-mismatched sibling donor. The result suggests that a long-term fetomaternal microchimerism-positive sibling can be a second-line donor if an alternative HLA-identical donor is not available.

Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia Rescued with a Second Allogeneic Stem Cell Transplantation from a Haploidentical Mother after Relapse following Cord Blood Transplantation

A 32-year-old female patient who had Philadelphia chromosome-positive acute lymphoblastic leukemia underwent cord blood transplantation while in her second remission. However, she had a hematological and central nervous system relapse 3 months later. After reinduction with imatinib mesylate, unmanipulated peripheral blood stem cell transplantation was performed from the patient's haploidentical mother with a reduced-intensity conditioning regimen. Rabbit antithymocyte globulin, tacrolimus, and methylprednisolone were used for prophylaxis of graft-versus-host disease. Engraftment of neutrophils was observed on day 12, and complete donor chimerism was obtained by day 24. The posttransplantation course was uneventful. Although the patient had a relapse 10 months later, this case demonstrated that transplantation from a haploidentical donor is clearly a feasible alternative for patients who desperately need rescue transplantation.

Second Transplantation from HLA 2-Loci-Mismatched Mother for Graft Failure Due to Hemophagocytic Syndrome after Cord Blood Transplantation

A 7-year-old girl with acute myelogenous leukemia with multilineage dysplasia received unrelated cord blood transplantation but developed hemophagocytic syndrome (HPS) after sepsis with methicillin-resistant coagulase-negative staphylococci before engraftment. Bone marrow aspiration on day 20 revealed a markedly increased number of activated macrophages showing hemophagocytosis. The presence of donor-type chimera in the bone marrow was confirmed at that time. We therefore quickly started immunosuppressive and antibacterial treatment. Although her condition gradually improved, the patient suffered graft failure due to HPS. She received peripheral blood stem cell transplantation from her HLA 2-loci-mismatched mother on day 54 and continued in complete remission 12 months after the second transplantation. The results in this case suggested that because of fetomaternal microchimerism it may be useful to select an HLA-haploidentical mother as a backup donor for stem cell transplantation.