[Bacterial infection and production of immunoglobulin in the tonsil]

Immunoglobulin (Ig) isotype switching is the process whereby B cells initially expressing IgM and/or IgD on their surface switch to other Ig heavy-chain loci. We demonstrated that TGF-beta, IL-10 and VIP in the presence of CD40 mAb, can induce isotype switching for IgA in human tonsillar B cells by the generation of switch circular DNA (S alpha/S mu), the induction of alpha germ-line transcripts and a significant amount of IgA production. IgA is the predominant immunoglobulin effector molecule of mucosal immunity that functions as the first line of specific immunologic defense against many microbial pathogens. However, IgA causes IgA nephropathy. We investigated here, whether tonsillar mononuclear cells from patients with IgA nephropathy produce HP-specific IgA and/or IgA-related cytokines by stimulation with components of HP outer membranes (OMHP). HP-specific IgA was predominately induced by tonsillar mononuclear cells of IgA nephropathy, compared to those from chronic tonsillitis. Production of IL-10 and TGF-beta was enhanced by stimulation with OMHP in tonsillar mononuclear cells from IgA nephropathy. These results suggested that local infection of HP and HP-specific IgA induction in the tonsil are associated with pathogens in IgA nephropathy.

Expression of p27 is associated with Bax expression and spontaneous apoptosis in oral and oropharyngeal carcinoma

p27Kip1, a cyclin-dependent kinase inhibitor, is a negative regulator of the cell cycle, and apoptosis is a genetically encoded program of cell death. To clarify the relationship between the cell cycle and apoptosis, we investigated expression of p27, cyclin D1 and apoptosis-related proteins (p53, Bax, Bcl-2 and c-Myc) in 60 cases of oral and oropharyngeal squamous-cell carcinoma (SCC) using an immuno-histochemical approach, and evaluated spontaneous apoptosis in vivo. Our most notable finding was that spontaneous apoptosis in the p27-positive group was significantly higher than that in the p27-negative group (p = 0.028). In addition, the percentage of p27-positive cells was clearly correlated with that of Bax-positive cells (gamma = 0.288, p = 0.028) and with that of cyclin D1-positive cells (gamma = 0.416, p = 0.002). Expression of p27 was inversely associated with the clinical stage of total tumor progression (p = 0.027). However, no correlation was found between p27 expression and the following parameters: gender, tumor size, lymph node metastasis, overall survival and disease-free survival. Our results give evidence that the action of the cell-cycle regulator p27 is closely linked with apoptosis in clinical samples from patients and indicate that over-expression of p27 might induce apoptosis in cancer cells through elevation of Bax expression, thereby acting on tumor progression.

Decreased expression of Bax is correlated with poor prognosis in oral and oropharyngeal carcinoma

We investigated the expression of apoptosis-related factors, p53, Bax, Bcl-2, and spontaneous apoptosis in 57 cases of oral and oropharyngeal squamous cell carcinoma (SCC) by immunochemical staining and ApopTag kit. Positive expression of Bax was inversely associated with advanced tumor stage (P = 0.0225), lymph node metastasis (P = 0.0225), clinical stage (P = 0.0083) and poor prognosis (P = 0.0478). Positive expression of p53 was related to poor prognosis (P = 0.0445) and was associated with negative expression of Bax (P = 0.0439). The apoptosis index did not correlate with clinical outcome. These results suggest that abnormality of Bax expression plays an important role in tumor progression in oral and oropharyngeal SCC.

Homology modeling of gelatinase catalytic domains and docking simulations of novel sulfonamide inhibitors

Three-dimensional models for the catalytic domain of gelatinases (MMP-9 and -2) have been constructed based on the X-ray crystal structure of MMP-3. Conformations of the loop segment which forms the bottom half of the S1' subsite but shows conformational diversity among the crystal structures of other MMPs have been explored by simulated annealing of each gelatinase model complexed with two highly potent "probe" inhibitors. Representative catalytic domain models have been selected for each gelatinase from the set of generated conformations based on shape complementarity of the loop to the probe inhibitors. The single model selected for MMP-9 was utilized to explain the structure-activity relationship of our novel sulfonamide inhibitors. Molecular dynamics (MD) simulations of the complex models revealed important features of the binding mechanism of our inhibitors: (i) the ligand carboxylate group coordinating to the catalytic zinc ion and hydrogen bonding to the Glu219 side chain, (ii) one of the sulfonyl oxygens forming hydrogen bonds with the main chain NHs (Leu181 and Ala182), (iii) the sulfonyl substituent making extensive hydrophobic contact with the S1' subsite. The gauche conformation exclusively adopted by the sulfonamide C-N-S-C torsion plays an important role in achieving the third binding feature by properly directing the substituent into the S1' subsite. Improvement of the inhibitory activity according to straight elongation of the sulfonyl substituent was attributed to an increase of the hydrophobic contact between the substituent and the S1' subsite. Structural modifications which alter the straight shape of the substituent lead to deterioration of the activity. On the other hand, the two candidate models selected for MMP-2 differ in the bottom shape of the S1' subsite: one with a channel-like subsite and the other with a pocket-like subsite resembling that of the MMP-9 model. The bottom shape was experimentally probed by chemical synthesis of inhibitors having elongated sulfonyl substituents whose terminal alkyl groups were shown by MD simulations to protrude from the S1' subsite bottom into the solvent. Gelatinase assays of these inhibitors showed that elongation of the substituent significantly reduces activity against MMP-9 while retaining activity against MMP-2, consequently increasing the selectivity between MMP-2 and -9. The results confirm that MMP-9 has a pocket-like S1' subsite with a floorboard and MMP-2 has a channel-like S1' subsite.

Expression of protein p27 is associated with progression and prognosis in laryngeal cancer

OBJECTIVE

A cyclin-dependent kinase inhibitor, p27kip1, is recognized as a negative regulator of the cell cycle. To clarify whether immunohistochemical detection of p27 might provide prognostic information, we investigated the expression of p27 in laryngeal squamous cell carcinoma (SCC).

STUDY DESIGN

A retrospective study of patients was performed in 109 cases of laryngeal SCC. In addition, we investigated the expression of p53 and granulocyte colony-stimulating factor receptor (GCSF-R) to examine the prognostic significance of them in the same samples.

METHODS

Immunohistochemical staining by specific monoclonal antibodies was performed using the avidin-biotin-peroxidase complex technique.

RESULTS

Advanced tumor size and clinical stage and the occurrence of lymph node metastasis were associated with the absence of p27 expression, but not correlated with p53 expression and GCSF-R expression. The overall 5-year survival rate in the p27-positive group was significantly higher than that in the p27-negative group. In the Cox proportional hazard model, p27 was demonstrated to be the most powerful prognostic factor among gender, tumor size, lymph node metastasis, stage of disease, and p53 and GCSF-R expression.

CONCLUSIONS

We concluded that assessment of p27 expression is useful as a prognostic factor for laryngeal SCC and of value in selecting patients with laryngeal SCC for aggressive therapy.

Molecular and serological characterization of adenovirus genome type 7h isolated in Japan

In 1996, three adenovirus type 7 (Ad7) strains were isolated from children with fever and upper respiratory diseases in Japan. Restriction endonucleases (REs) analysis and PCR amplification of the E3 7.7 kDa ORF revealed that these strains were genotype Ad7h and closely related to an Argentine Ad7h strain, which has been reported to be highly virulent and so far predominant only in South America. These strains showed weak cross-neutralizing activity and specific haemagglutination-inhibition activity to Ad3 antiserum. The present findings suggest that Ad7h in South America has spread to other parts of the world. Since the seroprevalence to Ad7 in the current Japanese population is very low due to the absence of Ad7 circulation in Japan for decades, Ad7 outbreak as a typical case of re-emerging infectious diseases is a cause for serious concern.

Staining of interleukin-10 predicts clinical outcome in patients with nasopharyngeal carcinoma

BACKGROUND

Interleukin-10 (IL-10) has been implicated as an important modulator of lymphoid cells, and its sequence is homologous to an open reading frame in the Epstein-Barr virus (EBV) genome. Nasopharyngeal carcinoma (NPC) is a representative tumor related to EBV infection.

METHODS

The authors investigated the expression of IL-10 in 21 primary NPCs by using an immunohistochemical approach to examine its prognostic significance.

RESULTS

IL-10 staining was positive in 12 of 21 primary NPCs (57%). There was no association between IL-10 expression and gender, tumor size, the occurrence of lymph node metastases, clinical stage, or recurrence. However, there was a significant difference in overall survival between the negative expression and positive expression of IL-10 (P = 0.0348). Although 87.5% of the IL-10 negative group survived for 5 years, only 15.6% of IL-10 positive patients survived for that length of time by the Kaplan-Meier method. IL-10 expression was significant as an independent prognostic indicator of overall survival by multivariate analysis using the Cox proportional hazards model (odds ratio, 26.64; P = 0.0019).

CONCLUSIONS

The results imply that expression of IL-10 is a prognostic factor in patients with NPC and may prove valuable in selecting patients with NPC who are candidates for aggressive therapy.

Correlation of antiangiogenic and antitumor efficacy of N-biphenyl sulfonyl-phenylalanine hydroxiamic acid (BPHA), an orally-active, selective matrix metalloproteinase inhibitor

The antiangiogenic activity and antitumor efficacy of a newly developed matrix metalloproteinase (MMP) inhibitor were examined. N-biphenyl sulfonyl-phenylalanine hydroxiamic acid (BPHA) potently inhibits MMP-2, -9, and -14, but not MMP-1, -3, or -7. In contrast, (-)BPHA, an enantiomer of BPHA, was inactive against all MMPs tested. Daily oral administration of 200 mg/kg BPHA, but not (-)BPHA in mice resulted in potent inhibition of tumor-induced angiogenesis, primary tumor growth, and liver metastasis. The growth inhibition activity of BPHA was 48% and 45% in a B16-BL6 melanoma and F2 hemangio-endothelioma model, respectively. BPHA also showed 42% inhibition of the liver metastasis of C-1H human colon carcinoma cells. These results indicate that selective MMP inhibition is correlated with antiangiogenic and antitumor efficacy and that the selective MMP inhibitor BPHA has therapeutic potential.

Granulocyte-colony-stimulating factor enhances invasive potential of human head-and-neck-carcinoma cell lines

Granulocyte-colony-stimulating factor (G-CSF), a hematopoietic cytokine, regulates the proliferation and differentiation of granulocytic progenitor cells and functionally activated mature neutrophils. G-CSF also affects nonhematopoietic tumor cells by the binding of G-CSF to its specific receptor (G-CSFR) on the cells. In this study, we investigated the effect of G-CSF on the invasive potential of head-and-neck carcinoma cells, and explored the intracellular events initiated by the binding of G-CSF in tumor cells. In vitro treatment of head-and-neck-carcinoma cell lines, IMC-2, IMC-3, KB, Ca9-22, SCCKN and SCCTF, with recombinant G-CSF (rG-CSF) significantly augmented their invasive potential in dose- and time-dependent manners. Among these cancer cells, IMC-2, IMC-3, KB and Ca9-22 cells produced little G-CSF, while large amounts of G-CSF were produced by SCCKN and SCCTF cell lines. Anti-G-CSF antibody (Ab) abrogated the rG-CSF-enhanced invasiveness to the control level of that in untreated cancer cell lines. Immunocytochemical staining and Western blotting using anti-G-CSFR monoclonal antibody (MAb) revealed the expression of G-CSFR on head-and-neck-cancer cell lines exhibiting the enhancement of invasive activity by rG-CSF. IMC-2 cells, having the highest invasive ability among the cell lines used, showed augmentation of G-CSFR expression on stimulation with rG-CSF. Furthermore, stimulation of IMC-2 cells with rG-CSF induced rapid activation of tyrosine-phosphorylated JAK1, suggesting that the G-CSF signal may be transduced into the cells through G-CSFR. Moreover, the gelatinolytic activity of IMC-2 cells was enhanced by stimulation of rG-CSF, and the enhanced invasiveness was inhibited on addition of the tissue inhibitors of metalloproteinases (TIMPs). These results suggest that exogenous rG-CSF may increase the risk of metastasis and/or local recurrence in patients with G-CSFR-positive head-and-neck squamous-cell carcinoma, via an invasive mechanism.

Granulocyte-colony-stimulating factor enhances invasive potential of human head-and-neck-carcinoma cell lines

Granulocyte-colony-stimulating factor (G-CSF), a hematopoietic cytokine, regulates the proliferation and differentiation of granulocytic progenitor cells and functionally activated mature neutrophils. G-CSF also affects nonhematopoietic tumor cells by the binding of G-CSF to its specific receptor (G-CSFR) on the cells. In this study, we investigated the effect of G-CSF on the invasive potential of head-and-neck carcinoma cells, and explored the intracellular events initiated by the binding of G-CSF in tumor cells. In vitro treatment of head-and-neck-carcinoma cell lines, IMC-2, IMC-3, KB, Ca9-22, SCCKN and SCCTF, with recombinant G-CSF (rG-CSF) significantly augmented their invasive potential in dose- and time-dependent manners. Among these cancer cells, IMC-2, IMC-3, KB and Ca9-22 cells produced little G-CSF, while large amounts of G-CSF were produced by SCCKN and SCCTF cell lines. Anti-G-CSF antibody (Ab) abrogated the rG-CSF-enhanced invasiveness to the control level of that in untreated cancer cell lines. Immunocytochemical staining and Western blotting using anti-G-CSFR monoclonal antibody (MAb) revealed the expression of G-CSFR on head-and-neck-cancer cell lines exhibiting the enhancement of invasive activity by rG-CSF. IMC-2 cells, having the highest invasive ability among the cell lines used, showed augmentation of G-CSFR expression on stimulation with rG-CSF. Furthermore, stimulation of IMC-2 cells with rG-CSF induced rapid activation of tyrosine-phosphorylated JAK1, suggesting that the G-CSF signal may be transduced into the cells through G-CSFR. Moreover, the gelatinolytic activity of IMC-2 cells was enhanced by stimulation of rG-CSF, and the enhanced invasiveness was inhibited on addition of the tissue inhibitors of metalloproteinases (TIMPs). These results suggest that exogenous rG-CSF may increase the risk of metastasis and/or local recurrence in patients with G-CSFR-positive head-and-neck squamous-cell carcinoma, via an invasive mechanism.

IL-10 expression is associated with the expression of platelet-derived endothelial cell growth factor and prognosis in oral and oropharyngeal carcinoma

We investigated the expression of IL-10 in oral and oropharyngeal squamous cell carcinoma (SCC) specimens by an immunohistochemical technique. Of 58 SCC, 13 (22%) and 35 (60%) cases showed intense and moderate positive staining of IL-10, respectively. There was no association between the staining of IL-10 and clinicopathological features. However, the patients with intense staining of IL-10 had a significantly lower overall survival rate than those with moderate or negative staining of IL-10 (P = 0.019). In addition, the patients with intense staining of IL-10 had the highest score of platelet-derived endothelial cell growth factor (PD-ECGF), which is established as a poor prognostic indicator (P = 0.0105). These results suggested that IL-10 contributes to the clinical outcome of oral and oropharyngeal SCC.

Inhibition of N-linked glycosylation by tunicamycin enhances sensitivity to cisplatin in human head-and-neck carcinoma cells

Tunicamycin (TM), a naturally occurring antibiotic, blocks the first step in the biosynthesis of N-linked oligosaccharides in cells. In this study, we investigated whether changes in N-linked glycosylation affect the sensitivity of head-and-neck carcinoma cell lines to cis-diaminedichloroplatinum(II) (cisplatin) in vitro and in vivo. In vitro treatment of the IMC-3 and KB cell lines with TM significantly decreased the 50% inhibitory concentration (IC50) of cisplatin, as determined by the MTT assay (24.15 to 10.97 microg/ml, p < 0.05). In addition, TM significantly decreased the IC50 of cisplatin against established cisplatin-resistant IMC-3/CR cells (>100 to 14.4 microg/ml, p < 0.05) to levels similar to those against parental IMC-3 cells. TM treatment decreased the number of Con A- and L-PHA-binding sites on the surface of tumor cells but had no effect on the intracellular platinum concentration. Induction of apoptosis in vitro by TM plus cisplatin in combination was increased compared with that by cisplatin alone. Furthermore, in vivo administration of TM plus cisplatin in combination significantly inhibited local tumor growth in the cisplatin-resistant in vivo C3H/He mouse model as compared with the control group (p < 0.05) and increased in vivo apoptosis of tumor cells. Our results suggest that the manipulation of glycosylation by TM in tumor cells might be a useful therapeutic strategy for successful chemotherapy using cisplatin against head-and-neck cancer.

Granulocyte-colony-stimulating factor enhances invasive potential of human head-and-neck-carcinoma cell lines

Granulocyte-colony-stimulating factor (G-CSF), a hematopoietic cytokine, regulates the proliferation and differentiation of granulocytic progenitor cells and functionally activated mature neutrophils. G-CSF also affects nonhematopoietic tumor cells by the binding of G-CSF to its specific receptor (G-CSFR) on the cells. In this study, we investigated the effect of G-CSF on the invasive potential of head-and-neck carcinoma cells, and explored the intracellular events initiated by the binding of G-CSF in tumor cells. In vitro treatment of head-and-neck-carcinoma cell lines, IMC-2, IMC-3, KB, Ca9-22, SCCKN and SCCTF, with recombinant G-CSF (rG-CSF) significantly augmented their invasive potential in dose- and time-dependent manners. Among these cancer cells, IMC-2, IMC-3, KB and Ca9-22 cells produced little G-CSF, while large amounts of G-CSF were produced by SCCKN and SCCTF cell lines. Anti-G-CSF antibody (Ab) abrogated the rG-CSF-enhanced invasiveness to the control level of that in untreated cancer cell lines. Immunocytochemical staining and Western blotting using anti-G-CSFR monoclonal antibody (MAb) revealed the expression of G-CSFR on head-and-neck-cancer cell lines exhibiting the enhancement of invasive activity by rG-CSF. IMC-2 cells, having the highest invasive ability among the cell lines used, showed augmentation of G-CSFR expression on stimulation with rG-CSF. Furthermore, stimulation of IMC-2 cells with rG-CSF induced rapid activation of tyrosine-phosphorylated JAK1, suggesting that the G-CSF signal may be transduced into the cells through G-CSFR. Moreover, the gelatinolytic activity of IMC-2 cells was enhanced by stimulation of rG-CSF, and the enhanced invasiveness was inhibited on addition of the tissue inhibitors of metalloproteinases (TIMPs). These results suggest that exogenous rG-CSF may increase the risk of metastasis and/or local recurrence in patients with G-CSFR-positive head-and-neck squamous-cell carcinoma, via an invasive mechanism.

Expression of hMSH2 correlates with in vitro chemosensitivity to CDDP cytotoxicity in oral and oropharyngeal carcinoma

We investigated the expression of hMSH2, a human mutS homologue from chromosome 2p, in oral and oropharyngeal squamous cell carcinoma (SCC) by an immunohistochemical technique and performed tumor in vitro chemosensitivity testing. In 58 oral and oropharyngeal SCC, the hMSH2 positive score was inversely associated with tumor size, but not with other clinical parameters. Among five anticancer drugs (cisplatin (CDDP), 5-FU, peplomycin, mitomycin C and doxorubicin), only for CDDP was sensitivity to cytotoxicity correlated with the hMSH2 positive score. The susceptibility of hMSH2-positive tumors to CDDP killing was significantly higher than that of hMSH2-negative tumors. Immunohistochemical results regarding hMSH2 are promising in the evaluation of the sensitivity of cancer cells to CDDP cytotoxicity and enable one to select patients for adjuvant chemotherapy for oral and oropharyngeal SCC.

Complete nucleotide sequence and genetic organization of Aichi virus, a distinct member of the Picornaviridae associated with acute gastroenteritis in humans

The complete nucleotide sequence of a novel enteric virus, Aichi virus, associated with nonbacterial acute gastroenteritis in humans was determined. The Aichi virus genome proved to be a single-stranded positive-sense RNA molecule with 8,251 bases excluding a poly(A) tail; it contains a large open reading frame with 7,302 nucleotides that encodes a potential polyprotein precursor of 2,433 amino acids. The genome contains a 5' nontranslated region (NTR) with 712 bases and a 3' NTR with 240 bases followed by a poly(A) tail. The structure of the genome, VPg-5' NTR-leader protein-structural proteins-nonstructural proteins-3' NTR-poly(A), was found to be typical of a picornavirus. The VP0-VP3 and VP3-VP1 cleavage sites were determined to be Q-H and Q-T, respectively, by N-terminal amino acid sequence analyses using purified virion proteins. Possible cleavage sites, Q-G, Q-A, and Q-S, which cleave P2 and P3 polyproteins were found to be similar to those of picornaviruses. A dendrogram based on 3Dpol proteins indicated that Aichi virus is genetically distinct from the known six genera of picornaviruses including entero-, rhino-, cardio-, aphtho-, and hepatovirus and echovirus 22. Considering this together with other properties of the virus (T. Yamashita, S. Kobayashi, K. Sakae, S. Nakata, S. Chiba, Y. Ishihara, and S. Isomura, J. Infect. Dis. 164:954-957, 1991), we propose that Aichi virus be regarded as a new genus of the family Picornaviridae.

Expression of platelet-derived endothelial cell growth factor in oral and oropharyngeal carcinoma

Platelet-derived endothelial cell growth factor (PD-ECGF) was isolated as an endothelial cell mitogen from platelets. In this study, we investigated the expression of PD-ECGF and counted microvessels in 58 oral and oropharyngeal squamous cell carcinoma (SCC) specimens by an immunohistochemical technique to examine their prognostic significance and performed tumor in vitro sensitivity to 5-fluorouracil (5-FU) and cisplatin as determined by a bioluminescence assay of the ATP values of tumor cells after continuous exposure. The percentage of PD-ECGF-positive tumor cells (PD-ECGF score) was correlated with the frequency of the recurrence of disease (P=0.0043) but not with sex, tumor size, metastasis, or clinical stage. Overall survival of the high PD-ECGF expression group (>40% PD-ECGF score) was shorter than the low expression (<40%) group (P=0.0365). Vessel count was correlated with lymph node metastasis and clinical stage. The survival of patients with hypervascularity (more than the median of intratumor vessel counts, >82) was shorter than that of those with hypovascularity (vessel count <81, P=0.0446). However, there was no association between PD-ECGF expression and vessel count. Cox proportional multivariate analysis showed that PD-ECGF expression was the most significant independent prognostic indicator for overall survival. The susceptibility to 5-FU cytotoxicity in the extremely high PD-ECGF expression groups (>70% of PD-ECGF score) was significantly higher than that in the low group, whereas there was no difference in their sensitivity to cisplatin. These results showed that carcinoma cells with high PD-ECGF expression were sensitive to 5-FU in spite of poor prognosis. These data provide further information when deciding on adjuvant therapy for oral and oropharyngeal SCCs.

Expression of multidrug resistance-associated protein (MRP) in head and neck squamous cell carcinoma

We investigated the expression of multidrug resistance-associated protein (MRP) in 115 cases of head and neck squamous cell carcinoma (H&NSCC) by immunohistochemistry and examined the relationship between MRP expression and clinical factors. Thirty-four (30%) of 115 cases of H&NSCC had expression of MRP. The clinical stage was inversely associated with the expression of MRP (P = 0.0090), but not with age, sex, tumor size, metastasis, recurrence, death from disease or overall survival rate for 5 years. In vitro chemosensitivity to five chemotherapeutic agents (cis-diamminedichloroplatinum, 5-fluorouracil, peplomycin, mitomycin C and Adriamycin) was tested by ATP assay and no correlation between the sensitivity of tumor cells to the cytotoxicity of any drug and MRP expression was found. These results suggest that the resistance to anticancer drugs is not dependent only on the expression of MRP in H&NSCC.

Expression of granulocyte colony-stimulating factor receptor correlates with prognosis in oral and mesopharyngeal carcinoma

Granulocyte colony-stimulating factor receptors (G-CSFRs) have been observed on the surface of not only hematopoietic cells but also several cancer cells. The stimulation of G-CSF has been demonstrated to induce proliferation and activation of G-CSFR-positive cells. In this study, we investigated the expression of G-CSFR on the surface of tumor cells and G-CSF production in oral and mesopharyngeal squamous cell carcinoma (SCC) by an immunohistochemical approach. Of 58 oral and mesopharyngeal SCCs, 31 cases (53.4%) and 36 cases (62.1%) were positive for G-CSFR and G-CSF, respectively. There was no association between G-CSFR expression and G-CSF staining. In the group positive for G-CSFR expression, relapse was significantly more likely after primary treatment (P = 0.0069), whereas there was no association between G-CSFR expression and age, sex, tumor size, lymph node metastasis, and clinical stage. Also, the G-CSFR-positive groups had a significantly lower disease-free and overall survival rate than the G-CSFR-negative groups (P = 0.0172 and 0.0188, respectively). However, none of the clinical markers correlated significantly with G-CSF staining, nor did the status of G-CSF production influence the overall survival. The results imply that assessment of G-CSFR may prove valuable in selecting patients with oral and mesopharyngeal SCC for aggressive therapy.

Highly selective and orally active inhibitors of type IV collagenase (MMP-9 and MMP-2): N-sulfonylamino acid derivatives

Various N-sulfonylamino acid derivatives were synthesized and evaluated for their in vitro and in vivo activities to inhibit type IV collagenase (MMP-9 and MMP-2). When the amino acid residue and the sulfonamide moiety were modified, their inhibitory activities were greatly affected by the structure of the sulfonamide moiety. A series of aryl sulfonamide derivatives containing biaryl, tetrazole, amide, and triple bond were found to be potent and highly selective inhibitors of MMP-9 and MMP-2. In addition, these compounds were orally active in animal models of tumor growth and metastasis. These results revealed the potential of the N-sulfonylamino acid derivatives as a new type of candidate drug for the treatment of cancer.

Expression of P-glycoprotein in inner ear capillary endothelial cells of the guinea pig with special reference to blood-inner ear barrier

Expression of P-glycoprotein (P-gp) was detected immunohistochemically in the guinea pig inner ear using mouse anti-P-gp monoclonal antibody C219. P-gp was found only in the capillary endothelial cells of the cochlea and vestibule. The pattern of P-gp immunostaining in the inner ear was similar to that of the brain. The present investigation suggested that P-gp expression in inner ear capillary endothelial cells might play an important role in the blood-inner ear barrier by acting as an extrusion pump.

Purification and characterization of a glutamic-acid-specific endopeptidase from Bacillus subtilis ATCC 6051; application to the recovery of bioactive peptides from fusion proteins by sequence-specific digestion

Screening cultures of nonpathogenic microorganisms led us to a glutamic-acid-specific endopeptidase from Bacillus subtilis ATCC 6051, which we purified and named BSase. The nucleotide sequence encoding BSase, with a molecular mass of 23,894 Da, completely agreed with that of the mpr gene, which had been reported by Rufo Jr. and Sloma et al. to encode a metalloprotease [J Bacteriol (1990) 172: 1019-1023 and 1024-1029 respectively]. However, enzymatic characterization revealed it to have the catalytic triad of a serine protease and not the consensus sequence of a metalloprotease, and it was inhibited by diisopropylfluorophosphate. We therefore consider BSase (mpr) to be a serine protease. In the alignment of the acidic-amino-acid-specific proteases, the proteases from bacilli have a highly conserved histidine residue, which is most important in the histidine triad in the proteases from streptomycetes. Furthermore, Ca2+ was necessary for its activity and stability. BSase cleaved the C-terminal glutamic acid with high specificity and was very stable over a wide pH range. On the basis of these properties, we tried to retrieve a bioactive peptide from a fusion protein by sequence-specific digestion, and succeeded in obtaining the bioactive peptide. BSase was found to be very useful as a tool for selective cleavage.

In vitro effect of hyperthermia on chemoenhancement and uptake of cisplatin in human pharyngeal carcinoma KB cells

The purpose of this study was to assess the efficacy of hyperthermia (42 or 44 degrees C) as a modifier of cis-diamminedichloroplatinum (II) (CDDP) cytotoxicity and platinum incorporation in human pharyngeal carcinoma KB cells. To maximize the interactive effect, we examined the time sequence of high (above 43 degrees C) or low (below 43 degrees C) hyperthermia and CDDP. Within the dose range of CDDP studied, there was a marked synergism between the effects of heating at 44 degrees C and subsequent CDDP exposure for 5 h. Pretreatment at 44 degrees C for 30 min or at 42 degrees C for 4 h enhanced CDDP cytotoxicity more than posttreatment at 44 degrees C for 30 min or at 42 degrees C for 4 h. However, the chemoenhancement ratio of pretreatment at 44 degrees C for 30 min was higher then that of pretreatment at 42 degrees C for 4 h, although the thermal isotoxic dose decreased the cell count to 60% under both conditions. There was a significant increase in CDDP uptake after hyperthermia at 44 degrees C. These results indicate that high hyperthermia effectively enhances subsequent CDDP cytotoxicity in human pharyngeal carcinoma KB cells.

[Successful combination chemotherapy for a post-operative gastric cancer patient with multiple liver metastases and elevated CEA]

A 75-year-old male was admitted one year after surgery for advanced gastric cancer. He was diagnosed as having multiple liver metastases with elevated serum CEA level. Combination chemotherapy consisting of THP-ADM, MMC and 5'-DFUR was done in the outpatient clinic. As a result, both multiple metastatic liver tumors and serum CEA level showed a remarkable response.

Involvement of intracellular glutathione in induction of apoptosis by cisplatin in a human pharyngeal carcinoma cell line

We investigated the effect of intracellular glutathione (GSH) levels on apoptosis in KB cells induced by cisplatin (CDDP). The mode of cell death, apoptosis or necrosis, was evaluated by biochemical and morphological criteria. The treatment of KB cells with D,L-buthionine-(S,R)-sulfoximine (BSO, a gamma-glutamyl cysteine synthetase inhibitor) decreased GSH level to 1/7th of that of control cells, and augmented cell death induced by CDDP via a necrotic rather than apoptotic process (the ratio of necrosis to apoptosis; n/a>14). In contrast, treatment with 2-oxothiazolidine-4-carboxylic acid (OTZ, a precursor of cysteine) increased GSH levels 1.7 fold compared with that of untreated cells, inhibited cell death induced by CDDP and switched the mode of cell death from necrosis to apoptosis (n/a<0.8, similar to untreated cells). These results suggest that the GSH level affects the cytotoxicity of CDDP and plays an important role in switching the mode of cell death induced by CDDP.

A dose-response relationship between the frequency of p53 mutations and tobacco consumption in lung cancer patients

Mutations of the p53 tumor suppressor gene are frequent in lung cancers. It is suggested that p53 mutations are associated with smoking-induced lung carcinogenesis. We examined p53 mutations in 53 lung cancers by analyzing reverse transcription-polymerase chain reaction-single strand conformation polymorphism (RT-PCR-SSCP) to ascertain the association between p53 mutations and smoking. Twenty-five (47%) of 53 lung cancers carried p53 mutations. A discriminant analysis showed that the Brinkman index (0.156) and gender (0.140) significantly influenced p53 mutations. Furthermore, there was a dose-response relationship between the quantity of cigarettes consumed and the frequency of p53 mutations in lung cancer patients (P < 0.001). In patients with adenocarcinoma, the frequency of p53 mutations correlated with the amount of the tobacco smoked (P < 0.05). We suggest that the p53 gene is a target of particular carcinogen in tobacco smoke.