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H Bukawa

Publications and source records attributed to H Bukawa.

At least 19 recordsLinked to original sources
PubMed2006

Ubiquitous mitochondrial creatine kinase downregulated in oral squamous cell carcinoma.

In this study, we performed two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption/ionisation time of fly mass spectrometry to identify the protein(s) associated with the development of oral squamous cell carcinomas (OSCCs) by comparing patterns of OSCC-derived cell lines with normal oral keratinocytes (NOKs), and found that downregulation of ubiquitous mitochondrial creatine kinase (CKMT1) could be a good candidate. Decreased levels of CKMT1 mRNA and protein were detected in all OSCC-derived cell lines examined (n=9) when compared to those in primary normal oral keratinocytes. Although no sequence variation in the coding region of the CKMT1 gene with the exception of a nonsense mutation in exon 8 was identified in these cell lines, we found a frequent hypermethylation in the CpG island region. CKMT1 expression was restored by experimental demethylation. In addition, when we transfected CKMT1 into the cell lines, they showed an apoptotic phenotype but no invasiveness. In clinical samples, high frequencies of CKMT1 downregulation were detected by immunohistochemistry (19 of 52 (37%)) and quantitative real-time RT-PCR (21 of 50 (42%)). Furthermore, the CKMT1 expression status was significantly correlated with tumour differentiation (P<0.0001). These results suggest that the CKMT1 gene is frequently inactivated during oral carcinogenesis and that an epigenetic mechanism may regulate loss of expression, which may lead to block apoptosis.

Apoptosis↗
PubMed2006

Overexpression of stathmin in oral squamous-cell carcinoma: correlation with tumour progression and poor prognosis.

Stathmin is an intracellular phosphoprotein that is overexpressed in a number of human malignancies. Our previous study using proteomic profiling showed that significant upregulation of stathmin occurs in oral squamous-cell carcinoma (OSCC)-derived cell lines. In the current study, to determine the potential involvement of stathmin in OSCC, we evaluated the state of stathmin protein and mRNA expression in OSCC-derived cell lines and human primary OSCCs. A significant increase in stathmin expression was observed in all OSCC-derived cell lines examined compared to human normal oral keratinocytes. In immunohistochemistry, 65% of the OSCCs were positive for stathmin, and no immunoreaction was observed in corresponding normal tissues. Real-time quantitative reverse transcriptase-polymerase chain reaction data were consistent with the protein expression status. Moreover, stathmin expression status was correlated with the TNM stage grading. Furthermore, we found a statistical correlation between the protein expression status and disease-free survival (P=0.029). These results suggest that expression of stathmin could contribute to cancer progression/prognosis, and that stathmin may have potential as a biomarker and a therapeutic target for OSCC.

Aged↗
PubMed2005

Monitoring of circulating tumour-associated DNA as a prognostic tool for oral squamous cell carcinoma.

Frequent allelic imbalances (AIs) including loss of heterozygosity and microsatellite instability on a specific chromosomal region have been identified in a variety of human malignancies. The objective of our study was to assess the possibility of prognostication and monitoring of oral squamous cell carcinoma (SCC) by microsatellite blood assay. DNA from normal and tumorous tissues and serum DNA obtained at three time points (preoperatively, postoperatively, and 4 weeks postoperatively) from 64 patients with oral SCC was examined at nine microsatellite loci. In all, 38 (59%) DNA samples from tumorous tissues and 52% from serum showed AIs in at least one locus. Patterns of AIs in the serum DNA were matched to those detected in tumour DNA. Of them, AIs were frequently detected preoperatively (44%, 28 of 64), and postoperatively (20%, 13 of 64). Moreover, among 12 cases with AIs during the postoperative period, six had no evidence of an AI 4 weeks postoperatively, and they had no recurrence and were disease free. In contrast, six patients with AI-positive DNA 4 weeks postoperatively have died with distant metastasis within 44 weeks. Thus, our results suggest that the assessment of microsatellite status in the serum DNA could be a useful predictive tool to monitor disease prognosis.

Adult↗
PubMed2005

Aberrant expression of RAB1A in human tongue cancer.

This study was designed to identify specific gene expression changes in tongue squamous cell carcinomas (TSCCs) compared with normal tissues using in-house cDNA microarray that comprised of 2304 full-length cDNAs from a cDNA library prepared from normal oral tissues, primary oral cancers, and oral cancer cell lines. The genes identified by our microarray system were further analysed at the mRNA or protein expression level in a series of clinical samples by real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis and imuunohositochemistry. The microarray analysis identified a total of 16 genes that were significantly upregulated in common among four TSCC specimens. Consistent with the results of the microarray, increased mRNA levels of selected genes with known molecular functions were found in the four TSCCs. Among genes identified, Rab1a, a member of the Ras oncogene family, was further analysed for its protein expression in 54 TSCCs and 13 premalignant lesions. We found a high prevalence of Rab1A-overexpression not only in TSCCs (98%) but also in premalignant lesions (93%). Thus, our results suggest that rapid characterisation of the target gene(s) for TSCCs can be accomplished using our in-house cDNA microarray analysis combined with the qRT-PCR and immunohistochemistry, and that the Rab1A is a potential biomarker of tongue carcinogenesis.

Aged↗
PubMed2003

Novel OK-432-conjugated tumor vaccines induce tumor-specific immunity against murine tongue cancer.

Priming with tumor antigens is one of the most important strategies in cancer immunotherapy. To enhance tumor antigenicity, OK-432, a streptococcal preparation, was coupled to squamous cell carcinoma (KLN-205) by means of a 0.2% glutaraldehyde method. The purpose of this study was to investigate whether OK-432-conjugated tumor vaccines could induce tumor-specific immunity. Our originally developed mouse tongue cancer model was used throughout this work for the analysis of antitumor effects. Prepared OK-432-conjugated KLN-205 vaccines were immunized 3 times to DBA/2 mice. The results showed that the KLN-205 vaccines induced cytolytic activity and strongly suppressed both KLN-205 tumor incidence and growth, and survival of the mice was improved. Moreover, the histological results showed that a greater number of lymphocytes had infiltrated around tumor cells by 24 hours after tumor inoculation in the vaccine group. These results suggest that immunizations with KLN-205 vaccines increase the antitumor effects against tongue cancer.

Animals↗
PubMed2000

Rectal and vaginal immunization with a macromolecular multicomponent peptide vaccine candidate for HIV-1 infection induces HIV-specific protective immune responses.

An effective vaccine for human immunodeficiency virus (HIV) is needed to stimulate the immune response of the genital mucus to prevent mucosal transmission of the virus. We have developed a macromolecular multicomponent peptide vaccine candidate, VC1. Both rectal and vaginal immunization of VC1 mixed with cholera toxin (CT) induced HIV-1-specific IgA antibody in mouse fecal extract solution and vaginal wash. These antibody productions were enhanced by the combination with IL-4 or GM-CSF expressing plasmids. Either fecal extract or vaginal wash solution from immunized mice inhibited production of HIV-1IIIB p24 protein. The mononuclear cells from spleen, intestinal lymph nodes, or Peyer's patches from VC1- and CT-immunized mice released IFN-gamma or IL-4, when these cells were co-cultured with VC1 antigen. In addition, the regional lymphoid cells from rectal and vaginal region of mice immunized with VC1 and CT also elicited a substantial level of HIV-1-specific cytotoxic T cell (CTL) response. This CTL response was enhanced by the addition of IL-12 expressing plasmid. Our results clearly demonstrated that both rectal and vaginal immunization could induce systemic and mucosal immunities specific for HIV-1.

AIDS Vaccines↗
PubMed2000

Rapid tumor necrosis induced by electrochemotherapy with intratumoral injection of bleomycin in a hamster tongue cancer model.

This study evaluated the effects of electrochemotherapy (ECT) with intratumoral injection of bleomycin (BLM) on the chemically induced tongue cancer model in the hamster. Intratumoral injection of BLM followed by high-voltage electrical treatment induced rapid necrosis of the tumor within 48 hours and subsequent rapid tumor volume reduction. Three weeks after the ECT with BLM, 3 of the 6 animals showed no palpable tumor, while no antitumor effects were observed in the control groups. Because of the remarkable antitumor effect with no major observed side effects, we concluded that ECT combined with intratumoral injection of BLM has the potential to enhance treatment results for tongue cancer.

Analysis of Variance↗
PubMed1999

In vivo antitumor effects of electrochemotherapy in a tongue cancer model.

PURPOSE: This study investigated the in vivo antitumor effects of electrochemotherapy (ECT) using electroporation and bleomycin in a hamster tongue cancer model to assess its clinical applicability. MATERIALS AND METHODS: Twenty animals with chemically induced tongue cancer were divided into four experimental groups designated B-E-, B-E+, B+E-, and B+E+. The B+E+ and B+E- groups received an intraperitoneal injection of 100 microg bleomycin. Fifteen minutes after the injection, the B+E+ animals received electric pulses. The B-E+ group received only electric pulses. The B-E- group received neither bleomycin nor electric pulses. Each group received the same treatment twice. The antitumor effects were assessed based on tumor volume reduction and histologic findings. RESULTS: The B+E+ group showed remarkable tumor volume reduction, decreasing an average to 8.8% of its original volume 14 days after the treatment. Complete loss of the protruding tumor was observed in two of the five animals. Histologically, the tumors of the B+E+ group consisted of severely degenerated tumor cells and desquamative keratinizing cells. No living cancer cells were detected in three animals. The B+E-, B-E+, and B-E- groups showed progressive tumor growth, exceeding 200% of initial tumor volume during the experimental period. CONCLUSION: The current study showed remarkable antitumor effects of ECT with bleomycin in the hamster tongue cancer model. ECT with bleomycin may be clinically applicable to the treatment of oral cancer.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1999

Comparison between hockey stick and reversed hockey stick incision: gently curved single linear neck incisions for oral cancer.

Hockey stick incision (HSI) and reversed-HSI are known to be useful incisions for lymph node dissections of the neck. Both are gently curved single linear incisions without three-point suture line junctions, but are different at the base of the skin flap. The HSI allows the elevation of a superiorly-based single cervical skin flap and the reversed-HSI allows for an inferiorly-based flap. We compared the viability of the skin flaps, exposure of the operation field and cosmetic results to evaluate the characteristics of each incision. HSI appeared to be the suitable incision for radical neck dissection due to adequate exposure of the operation field while rendering excellent cosmetic results. Reversed-HSI was applied in combination with block resection of parts of the oral cavity because it provided much better exposure of the operation field than HSI, while still achieving acceptable cosmetic results. Using this technique, a small area of marginal necrosis was occasionally seen at the apex of the skin flap due to poor blood supply.

Aged↗
PubMed1997

Strong augment effect of IL-12 expression plasmid on the induction of HIV-specific cytotoxic T lymphocyte activity by a peptide vaccine candidate.

We previously reported that repeated inoculation of VC1, a macromolecular multicomponent peptide vaccine emulsified with Freund's adjuvant (VC1-F), induced high cytotoxic T lymphocyte (CTL) levels and a substantial level of multivalent antibodies which neutralized various human immunodeficiency virus type 1 (HIV-1) isolates. In the present study, we report that inoculation of VC1-F plus interleukin (IL)-12 expression plasmid can induce a higher antigen-specific CTL response compared to that with VC1-F alone. VC1-F plus IL-12 expression plasmid or VC1-F alone were inoculated to BALB/c mice twice at interval of 2 weeks. Two weeks after the second inoculation, spleen effector cells from these mice were examined. Stronger CTL responses against target cells were observed from the inoculation of VC1-F plus IL-12 plasmid than from that with VC-1F alone, but there was no difference in antibody induction. The inoculation of VC1 plus IL-12 plasmid also produced higher CTL activity than the inoculation of VC1 alone. These augmented CTL activities were not observed using target cells pulsed with non-HIV-specific peptides and different class I haplotype cells. These data demonstrate that co-inoculation of cell-mediated immune potent antigen and IL-12 plasmids can enhance the antigen-specific CTL response. This may be a potential approach for the induction of cellular immunization against HIV-1 and other diseases.

AIDS Vaccines↗
PubMed1997

DNA vaccination followed by macromolecular multicomponent peptide vaccination against HIV-1 induces strong antigen-specific immunity.

The induction of a strong and long-lasting immunity characterized by both a humoral and cell-mediated immune (CMI) response is one of the most important considerations in developing an effective HIV vaccine. In previous studies, we have independently developed both DNA vaccine and macromolecular multicomponent peptide vaccine (VC1) candidates. In the present study, we attempted to optimize the vaccination protocol using mice, guinea pigs, rabbits and Macaca fuscata monkeys. Repeated vaccination with VC1 induced a substantial level of multivalent antibodies which neutralized various HIV-1 strains, as determined using a p24 inhibition assay. On the other hand, repeated immunization with DNA vaccine induced and sustained high levels of cytotoxic T lymphocytes (CTLs). In addition, when DNA vaccination was followed by multicomponent peptide vaccination, levels of both humoral immunity and CMI increased, and this effect continued for at least 10 months. These data clearly demonstrate that for inducing HIV-1 specific immunity, immunization with DNA vaccine followed by VC1 boosting produces better results than immunizing with either vaccine alone.

AIDS Vaccines↗
PubMed1997

HIV-1-specific cell-mediated immunity is enhanced by co-inoculation of TCA3 expression plasmid with DNA vaccine.

We developed a candidate DNA vaccine designated pCMV160IIIB with pcREV (pCMV160IIIB/REV) that encodes gp160 of human immunodeficiency virus (HIV)-1IIIB and Rev driven by the cytomegalovirus (CMV) promotor. This vaccine induced both HIV-1-specific antibodies and cytotoxic T lymphocyte (CTL) activity. In the present study, we inoculated the TCA3 expression plasmid into mouse skeletal muscle with pCMV160IIIB/REV to determine whether this cytokine expression plasmid was able to modify the immune response. Results of a delayed-type hypersensitivity (DTH) assay using footpad swelling as well as those of a CTL assay clearly demonstrated that cell-mediated immunity (CMI) elicited by co-inoculation of pCMV160IIIB/REV with the TCA3 expression plasmid was markedly enhanced compared with that obtained using pCMV160IIIB/REV alone. When TCA3 expression plasmid was inoculated with anti-TCA3 antibody, enhancement of the DTH response was suppressed below the level of that obtained with pCMV160IIIB/REV alone. The titre of HIV-1-specific IgG2a was slightly high when pCMV160IIIB/REV was co-inoculated with this plasmid, suggesting that T-helper 1 (Th1) response was predominant in TCA3-inoculated mice. Infiltration of mononuclear cells was seen in the muscles at sites where TCA3 expression plasmid had been inoculated. Our present data suggest that TCA3 expression plasmid has potent adjuvant activity that results in an augmented CMI response.

AIDS Vaccines↗
PubMed1997

Genetic control of immune responses to HIV-1 env DNA vaccine.

We investigated the genetic control of immunoglobulin production and the delayed-type hypersensitivity (DTH) response produced by an HIV-specific DNA vaccine using several strains of mice. Murine antigen-specific immunoglobulin production was determined by ELISA. The DTH response was assessed in terms of the footpad swelling reaction. All strains of mice, except for B10.RIII and B10.T(6R), exhibited strong immunoglobulin production and footpad swelling in response to the DNA vaccine. In vitro treatment of lymphoid cells with monoclonal antibodies showed that the footpad swelling response was mediated by CD4+8- and Ia- T cells. However, CD8+ T cells did not suppress footpad swelling. There was no difference in the induction of HIV-specific immunoglobulin production or DTH response induced by the DNA vaccine among the strains, suggesting that HIV-specific DNA vaccine is useful for immunizing various populations against HIV-1.

AIDS Vaccines↗
PubMed1995

A macromolecular multicomponent peptide vaccine prepared using the glutaraldehyde conjugation method with strong immunogenicity for HIV-1.

The immunogenicity of a newly constructed macromolecular multicomponent peptide vaccine candidate against human immunodeficiency virus type 1 (HIV-1) was compared with that of previously reported vaccine candidates. This vaccine candidate is composed of a macromolecular multicomponent peptide complex consisting of three V3 region peptides, one Gag region peptide, and CD4-binding site peptide and was constructed using the multiple-antigen peptide and glutaraldehyde methods. Sera from rabbits immunized with this newly constructed vaccine showed strong antibody titers against each constituent peptide antigen. Furthermore, these antibodies exhibited strong neutralizing and antifusion activity toward HIV-1IIB, HIV-1MN, and fresh isolates from Japanese HIV-seropositive individuals. These results show that this new vaccine candidate has the capacity to induce strong, polyvalent immunogenicity and therefore may prove to be a powerful peptide vaccine against HIV-1 infection.

AIDS Vaccines↗
PubMed1995

Neutralization of HIV-1 by secretory IgA induced by oral immunization with a new macromolecular multicomponent peptide vaccine candidate.

Control of pandemic infection of human immunodeficiency virus type 1 (HIV-1) requires some means of developing mucosal immunity against HIV-1 because sexual transmission of the virus occurs mainly through the mucosal tissues. However, there is no evidence as yet that the secretory immunoglobulin A (IgA) antibody induced by immunization with antigens in experimental animals can neutralize HIV-1. We demonstrate here that oral immunization with a new macromolecular peptide antigen and cholera toxin (CT) induces a high titre (1:2") of gut-associated and secretory IgA antibody to HIV-1. Using three different neutralizing assays, we clearly demonstrate that this secretory IgA antibody is able to neutralize HIV-1IIIB, HIV-1SF2 and HIV-1MN. Our new approach may prove to be important in the development of a mucosal vaccine that will provide protection of mucosal surfaces against HIV-1.

AIDS Vaccines↗
PubMed1995

Induction of potent humoral and cell-mediated immune responses following direct injection of DNA encoding the HIV type 1 env and rev gene products.

DNA vaccines have the potential of giving rise to a potent cell-mediated immune response by inducing intracellular synthesis and subsequent antigenic presentation of encoded antigens. We have tested a DNA vaccine specific for human immunodeficiency virus type 1 (HIV-1) by the injection of animals with expression plasmids encoding the HIV-1 envelope protein and the Rev regulatory protein. Injection of both plasmids into mice, rabbits, or macaques was found to induce high levels of specific antibodies capable of efficiently inhibiting both HIV-1 infection and envelope-mediated cell fusion. A readily detectable delayed-type hypersensitivity (DTH) response was demonstrable in injected mice and lymphocytes derived from these proliferated in response to an HIV-1 envelope V3 loop-specific peptide. Interestingly, the injected mice or macaques also developed a strong cytotoxic T lymphocyte (CTL) response against target cells pulsed with the V3 peptide. Taken together, these data demonstrate that injection of HIV-1 gene expression plasmids can induce potent humoral and cell-mediated immune responses and suggest that DNA vaccines may prove to be significantly beneficial as a means of immunizing against HIV-1.

Animals↗