Expression of keratinocyte growth factor and its receptor in odontogenic keratocysts.

BACKGROUND: The mitotic activity of the epithelial cells of odontogenic keratocysts (OKCs) is greater than that of other odontogenic jaw cysts, and the mitotic activity of the epithelial cells decreases after marsupialization. Keratinocyte growth factor (KGF) interacts with its specific receptor (KGFR), and elicits the proliferation and/or differentiation of the various types of epithelial cells. The aim of this study was to investigate the expression of KGF/KGFR in OKCs before and after marsupialization. METHODS: The expression of KGF was immunohistochemically detected in the specimens of 16 OKCs and 11 dentigerous cysts before and after marsupialization. The expression of KGF mRNA was measured in the fibroblasts isolated from OKCs by real-time PCR. RESULTS: KGF was expressed in the epithelial cells and fibroblasts of 12 and seven of 16 OKC specimens, respectively. The intensity of the KGF expression in both the epithelial cells and the fibroblasts significantly decreased after marsupialization. KGFR was expressed throughout the epithelium in 15 of 16 OKC specimens, but the intensity of the KGFR expression did not change after marsupialization. The expression of KGF was detected in the epithelium of two of 11 dentigerous cyst specimens, but not in the fibroblasts before marsupialization. Real-time PCR revealed that recombinant human interleukin (IL)-1alpha increased the expression of KGF mRNA in the fibroblasts isolated from OKCs. CONCLUSION: KGF/KGFR signaling may play a crucial role in the epithelial cells of OKCs. Furthermore, the expression of KGF in the fibroblasts of OKCs is regulated by IL-1alpha.

Serum intact parathyroid hormone levels predict hospitalisation for heart failure.

OBJECTIVE: To assess whether circulating levels of intact parathyroid hormone (intact PTH) in outpatients predict hospitalisation for heart failure (HF). METHODS: Eighty-eight consecutive outpatients with HF were enrolled in the study. The independent association between intact PTH and hospitalisation for HF was assessed using Cox regression analysis. RESULTS: Mean (SD) serum intact PTH levels significantly increased as New York Heart Association classes increased (I: 40 (21), II: 55 (24), III: 76 (46), IV: 131 (45) pg/ml). The receiver operating characteristic (ROC) curves showed intact PTH levels >or=47 pg/ml to be the optimal cut-off points for hospitalisation for HF, with sensitivity 87%, specificity 71% and area under the ROC curve 0.82 (95% CI 0.72 to 0.91). After adjustment for variables accepted to be predictors for hospitalisation due to HF (age, gender, hypertension, diabetes mellitus, atrial fibrillation, ischaemic heart disease, left ventricular ejection fraction, B-type natriuretic peptide, estimated glomerular filtration rate and cardiac drugs), intact PTH levels >or=47 pg/ml were associated with a hazard ratio of 7.13 for hospitalisation for HF (95% CI 1.79 to 28.4). CONCLUSION: Serum intact PTH levels obtained in outpatients with HF were shown to be an independent predictor of hospitalisation for HF.

Epidermal growth factor inhibits Fas-mediated apoptosis in salivary epithelial cells of patients with primary Sjögren's syndrome.

OBJECTIVES: Cell death is detected in the ducts of labial salivary glands (LSG) of patients with primary Sjögren's syndrome (pSS). However, the counter-mechanism to inhibit the apoptotic process remains unclear. In this study, we studied the ability of epidermal growth factor (EGF) to activate the PI3K-Akt pathway and NF-kB in primary cultured salivary gland epithelial cells (SGEC) of pSS patients. METHODS: SGEC, obtained from 2 female pSS patients, were cultured and used for Hoechst staining and deoxynucleotidyltransferase-mediated dUTP nick end-labeling (TUNEL) assay. The frequency of apoptosis, detected by Hoechst staining, was quantified, and statistical significance was determined through unpaired student's t-test. RESULTS: Following twelve hours of stimulation, both PI3K inhibitors and anti-Fas antibody failed to induce apoptosis in primary cultured SGEC. However, the combination of anti-Fas antibody, along with LY294002 or Bay 11-7082, induced apoptosis which was statistically more significant than apoptosis found in the control cells (p < 0.01). Interestingly, the apoptosis induced by anti-Fas antibody along with LY294002 was clearly inhibited by the addition of 10 ng/ml EGF. Furthermore, the results of the TUNEL assay clearly indicated apoptosis through stimulation with anti-Fas antibody and LY294002 or Bay 11-7082. Furthermore, the apoptosis was completely blocked by the addition of EGF. CONCLUSION: Our results suggest that salivary epithelial cells are protected from Fas mediated apoptosis, through cell survival factors including either the PI3K-Akt pathway or NF-kB.

Doxorubicin-induced DNA intercalation and scavenging by nuclear glutathione S-transferase pi.

Glutathione S-transferase (GST) functions in xenobiotic biotransformation and drug metabolism. Increased expression of GSTpi, an isozyme of GST, has been found in cancer cells resistant to doxorubicin hydrochloride (DOX) or cis-diamminedichloroplatinum (II) (CDDP), and this increase was believed to be correlated with drug resistance of cancer cells. GST is mainly expressed in the cytoplasm; GSTpi in the nucleus has been reported in cancer cells, but the meaning of this result is not known. Here, we studied changes in the amount of nuclear GSTpi after exposure of cancer cells to anticancer drugs, and role of the nuclear GSTpi in drug resistance. We found nuclear GSTpi in cancer cells resistant to DOX, and the amount of nuclear GSTpi was enhanced by treatment of the cancer cells with DOX or CDDP. We also found that a mushroom lectin, an inhibitor of nuclear transport, inhibited the nuclear transfer of GSTpi, suggesting the existence of a specific transport system for the nuclear transfer of GSTpi. Nuclear GSTpi protected DNA against damage by anticancer drugs. These results suggest a possible role of GSTpi in the acquisition of resistance to anticancer drugs by cancer cells.

Localization in situ of specific RNA by electron microscopy.

To better understand the metabolism of RNA in nuclei, the analysis of precise nuclear distribution of specific RNA would be essential. For this purpose, nonradioactive electron microscopic (EM) in situ hybridization may be the most appropriate technique while the details required for the technique have not been fully established. In the present study, we attempted to localize 28S and 18S rRNAs in the nuclei of mouse Sertoli cells by EM in situ hybridization as a model system. After various preliminary experiments we chose the pre-embedding method; fresh-frozen sections of mouse testis were fixed with a mixture of 4% paraformaldehyde and 0.1% glutaraldehyde, digested with 10 microg/ml of proteinase K and hybridized with thymine-thymine (T-T) dimerized oligodeoxynucleotides (oligo-DNA) complementary to a part of 28S and 18S rRNAs. Then, the T-T dimers were detected enzyme-immunohistochemically with horseradish peroxidase (HRP) labeled anti-T-T dimer. After osmification of HRP products, the sections were embedded in Epon resin, cut into 100 nm ultra-thin sections and observed under a transmission electron microscope. As a result, we successfully localized both 28S and 18S rRNAs in the dense fibrillar and granular components of the nucleolus, showing the usefulness of nonradioactive EM in situ hybridization in the nuclear localization of specific RNA.

Expression of fas/fas ligand (fasL) and its involvement in infiltrating lymphocytes in hepatocellular carcinoma (HCC).

BACKGROUND: This study was conducted to examine the expression of Fas/Fas ligand (FasL), to elucidate its relationship with tumor-infiltrating lymphocytes (TILs), and to detect possible gene mutation of Fas/FasL in patients with hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC). METHODS: Indirect immunohistochemical staining was performed on formalin-fixed, paraffin-embedded sections of liver biopsy and surgery specimens from five normal livers, and from the livers of 30 patients with HCC. Fas/FasL mRNA-expressing cells and apoptotic cells were detected by in situ hybridization and DNA nick end labeling (TUNEL), respectively. We also performed polymerase chain reaction (PCR)-amplifying and direct sequencing for the Fas/FasL gene. RESULTS: Fas/FasL and its mRNA were localized on the membrane or in the cytoplasm in some HCC cells, as well as hepatocytes. Their expression was enhanced in areas with infiltrating inflammatory cells in the noncancerous regions of liver tissue and on the margins of the cancerous tissue. The positivity rate for TUNEL was elevated along these margins. The labeling index of Fas/FasL was lower in the cancerous liver tissue than in the surrounding noncancerous region (P < 0.01), and tended to decrease in proportion to the malignancy of tumor cells; Fas/FasL expression was not found on poorly differentiated type cancer cells. Fas(-)/FasL(+), FasL-mRNA(+) HCC cells were seen in one specimen of moderately differentiated type. Some CD8+T lymphocytes were TUNEL-positive around the cancerous region. In this study, cancerous and noncancerous tissues in HCC revealed no genetic mutations in any exons of Fas/FasL. CONCLUSIONS: These findings suggest that Fas/FasL expression was decreased in proportion to the malignancy of tumor cells, and that infiltrating CD8+ T lymphocytes play a role in apoptosis in HCC. The apoptosis in HCC could be regulated by the suppression of Fas/FasL expression, or, sometimes, by the enhancement of FasL expression.

Expression of metallothionein in colorectal cancers and synchronous liver metastases.

The aim of this study is to clarify whether the expression of metallothionein (MT) is related with the malignant potential in primary colorectal cancer and/or synchronous liver metastasis. Immunohistochemical staining for MT was performed on the specimens of adenocarcinoma of the colon and rectum and its liver metastases in 34 patients treated with curative surgery, respectively. Expression of MT was compared with clinicopathological variables and patient survival. In patients with primary colorectal cancer, positive expression was found in 7 of 34 (20.6%) patients, but MT was not detected in any of the cases of liver metastases (0%; p = 0.0111). In the primary tumor, positive MT expression was significantly associated with a higher degree of lymph node involvement (mean +/- SD: 48.4 +/- 33.8 vs. 18.6 +/- 24.4% in MT-positive and MT-negative tumors, respectively; p = 0.0122). The survival rate in the patients with MT-negative tumors was significantly better than that in those with MT-positive tumors as primary sites (p = 0.0198). MT expression in colorectal cancer may be a potential marker affecting lymph node metastases and may be a predictor of a poor prognosis, particularly in patients with synchronous liver metastases.

Fas/FasL mediated apoptosis of thyrocytes in Graves' disease.

We examined in the present study the possible involvement of Fas and its ligand (FasL) in the process of Graves' disease. Immunohistochemical analysis showed that few normal thyrocytes expressed Fas but many thyrocytes in Graves' disease expressed this molecule. The percentage of FasL-positive thyrocytes in Graves' thyroids was, however, less than in normal thyroids. Several apoptotic thyrocytes and infiltrating mononuclear cells (MNCs) were detected scattered throughout Graves' thyroid tissues and abundant proliferating cell nuclear antigen (PCNA)-positive thyrocytes were present. Apoptotic cells, as well as PCNA-positive cells, were scarcely detectable in normal thyroid glands, however. In vitro treatment of thyrocytes by IL-1beta a cytokine found to be expressed in Graves' thyroid glands, increased Fas but reduced FasL expression. IL-1beta-stimulated thyrocytes became sensitive to apoptosis by anti-Fas IgM monoclonal antibody (mAb). Activated T cells, which strongly expressed FasL, showed cytotoxic activity toward IL-1beta-stimulated thyrocytes but not toward unstimulated thyrocytes. This cytotoxic activity involved the Fas/FasL pathway. Importantly, unstimulated thyrocytes could kill activated, but not resting, T cells. IL-1beta-stimulated thyrocytes, with down-regulated FasL expression, could not efficiently kill activated T cells. The cytotoxic activity of unstimulated thyrocytes toward activated T cells was inhibited by anti-FasL mAb. Interestingly, unstimulated thyrocytes induced apoptosis in IL-1beta-stimulated thyrocytes but not in unstimulated thyrocytes. These interactions were also blocked by anti-FasL mAb. Our results suggest that the apoptotic cell death of both thyrocytes and infiltrating MNCs found in Graves' thyroid glands is regulated by IL-1beta through Fas/FasL interactions.

Enhanced expression of complement C5a receptor mRNA in human diseased kidney assessed by in situ hybridization.

BACKGROUND: Anaphylatoxin C5a mediates inflammatory responses through interaction with a specific C5a receptor (C5aR), the expression of which is thought to be restricted to peripheral blood leukocytes. Although the presence of C5aR on cultured mesangial cells and tubular epithelial cells has recently been documented, the tissue distribution of C5aR in diseased kidney has not yet been determined. METHODS: Immunohistochemistry and nonradioactive in situ hybridization for C5aR were performed in 34 tissue samples of kidneys from patients with various renal diseases, including 4 with minimal change nephrotic syndrome (MCNS), 5 with membranous nephropathy (MN), and 25 with mesangial proliferative glomerulonephritis (mesGN; 15 patients with IgA nephropathy, 5 with non-IgA mesGN, and 5 with lupus nephritis). Normal portions of surgically resected kidney served as the control. RESULTS: In normal kidneys, C5aR protein was detected in tubular epithelial cells, while C5aR mRNA was detected in a few glomerular cells, tubular epithelial cells, and vascular endothelial and smooth muscle cells. In MCNS, the distribution of C5aR protein and mRNA was similar to that in normal kidneys. In MN and mesGN, C5aR protein and mRNA were detected in mesangial cells, glomerular epithelial and endothelial cells, Bowman's capsule cells, tubular cells, infiltrating cells, and vascular endothelial and smooth muscle cells. The glomerular expression of C5aR mRNA and protein correlated positively with the degree of mesangial hypercellularity and mesangial matrix expansion in mesGN. In the tubulointerstitium, interstitial expression of C5aR mRNA correlated positively with the degree of tubular atrophy and interstitial broadening in mesGN. Furthermore, the interstitial expression of C5aR mRNA correlated positively with the level of serum creatinine. CONCLUSIONS: Our results indicate that renal cells produce C5aR and that activation of C5a/C5aR pathway on renal cells may be involved in tissue injury in mesGN.

Importance of NF-kappaB in rheumatoid synovial tissues: in situ NF-kappaB expression and in vitro study using cultured synovial cells.

OBJECTIVES: To examine whether inhibition of NF-kappaB induces apoptosis of human synovial cells stimulated by tumour necrosis factor alpha (TNFalpha), interleukin 1beta (IL1beta), and anti-Fas monoclonal antibody (mAb). METHODS: The expression of proliferating cell nuclear antigen (PCNA), NF-kappaB, and the presence of apoptotic synovial cells were determined in synovial tissues. Apoptosis of cultured synovial cells was induced by inhibition of NF-kappaB nuclear translocation by Z-Leu-Leu-Leu-aldehyde (LLL-CHO). The activation of caspase-3 and expression of XIAP and cIAP2 in synovial cells in LLL-CHO induced apoptosis was also examined. RESULTS: Abundant PCNA+ synovial cells were found in rheumatoid arthritis (RA) synovial tissue, though a few apoptotic synovial cells were also detected in the RA synovial tissues. Nuclear NF-kappaB was expressed in RA synovial cells. Electrophoretic mobility shift assay showed that treatment of cells with TNFalpha or IL1beta significantly stimulated nuclear NF-kappaB activity. A small number of apoptotic synovial cells expressing intracellular active caspase-3 were found after treatment of cells with LLL-CHO. Although treatment of RA synovial cells with TNFalpha or IL1beta alone did not induce apoptosis, apoptosis induced by LLL-CHO and caspase-3 activation were clearly enhanced in TNFalpha or IL1beta stimulated synovial cells compared with unstimulated synovial cells. Furthermore, induction of apoptosis of synovial cells with caspase-3 activation by anti-Fas mAb was clearly increased by LLL-CHO. The expression of cIAP2 and XIAP in synovial cells may not directly influence the sensitivity of synovial cells to apoptosis induced by LLL-CHO. CONCLUSION: The results suggest that NF-kappaB inhibition may be a potentially important therapeutic approach for RA by correcting the imbalance between apoptosis and proliferation of synovial cells in RA synovial tissue.

Prolonged survival of rat cardiac allograft with proinflammatory cytokine inhibitor.

BACKGROUND: Proinflammatory cytokines, such as tumor necrosis factor (TNF-alpha) and interleukin-1 (IL-1), play important roles in acute allograft rejection. FR167653 is an inhibitor of these cytokines that acts through inhibition of the mitogen-activated protein kinase p38 pathway. We examined the effect of FR167653 on allograft rejection. METHODS: We used Brown-Norway and Lewis rats as donors and recipients, respectively. We performed heterotopic cardiac transplantation. The control group consisted of untreated rats. In the experimental groups, recipients were intraperitoneally injected with FR167653 just after operation, followed by daily injection of the drug from Day 1 to 10. We divided 20 rats into 5 groups, which received varying doses of FR167653, ranging from 75 to 300 mg/kg/day. RESULTS: In the control group, the mean graft survival was 6.8 +/- 0.3 days. FR167653 at 150 mg/kg/day significantly prolonged the survival period (up to 12.1 +/- 1.5 days, p = 0.002). Histologically, FR167653 markedly suppressed cellular infiltration on Day 5 post-transplantation. The serum level of TNF-alpha in the control group was persistently elevated from 9.3 +/- 3.9 pg/ml to 11.3 +/- 3.8 pg/ml, whereas FR167653 significantly suppressed the level to <1.4 +/- 1.4 pg/ml. CONCLUSIONS: FR167653 prolonged rat cardiac allograft survival by suppressing the action of proinflammatory cytokines.

Partial tolerance of subcutaneously transplanted xenogeneic tumour cell graft by Fas-mediated immunosuppression.

Certain anti-Fas antibodies, such as RMF2, induce apoptosis of Fas-expressing cells. We applied the Fas/anti-Fas system to induce killing of Fas-expressing immunocytes with resultant immunosuppression. W7TM-1 tumour cells, a rat T-cell line, were inoculated subcutaneously in BALB/c mice and tumour growth was monitored in untreated mice and in mice treated with RMF2. Prior to treatment with RMF2, we examined the expression of Fas in isolated splenocytes and in tumour-infiltrating lymphocytes by flow cytometry and immunohistochemistry, respectively. There was a remarkable increase in Fas-positive lymphocytes, including natural killer (NK) cells, among splenocytes at day 5 after tumour cell inoculation. The number of Fas-positive infiltrating lymphocytes also increased markedly, from day 5 to day 10. We then examined whether RMF2 could induce apoptosis of Fas-positive activated lymphocytes isolated from the spleen at day 5 in vitro. Terminal deoxy (d) -UTP nick end labelling (TUNEL) and Annexin V staining methods showed apoptosis of isolated cells when incubated with RMF2, and typical apoptotic features were confirmed by 4',6-diamidino-2-phenylindole dihydrochloride (DAPI) staining. Furthermore, suppression of cellular and humoral immunity was noted in RMF2-treated mice by mixed lymphocyte reaction and assay of serum levels of immunoglobulin G, respectively. Finally, treatment of animals with RMF2 daily from day 5 to day 9 could maintain the tumour size, while the tumour mass began to diminish in untreated mice immediately after reaching a maximum size. We confirmed the enhancing effects of long-term treatment with RMF2, through the induction of immunosuppression, on the growth of unvascularized xenogeneic tumour cell grafts.

Antimicrobial susceptibility of Staphylococcus intermedius isolated from healthy and diseased dogs.

A total of 90 strains of Staphylococcus intermedius isolated from dogs were examined for antimicrobial susceptibility. There were no significant differences in the distribution patterns of MICs between strains from 1982 to 1985 and those from 1999, and between strains from healthy dogs and those from diseased dogs. All of the strains were susceptible to ABPC, DMPPC, CEX, TDM, ERFX, BFLX, and FF at concentrations of 0.05 to 6.25 microg/ml. The MICs of OTC, KM, EM, AIV-TS, and LCM were distributed in a broad range of 0.1 to >100 microg/ml, indicating the existence of resistant as well as susceptible populations of S. intermedius. Thirty-three strains (36.7%) were resistant to one or more anitmicrobial agents such as OTC (n=32), KM (n=9), EM (n=7), AIV-TS (n=7), and LCM (n=7).

Intraglomerular synthesis of complement C3 and its activation products in IgA nephropathy.

BACKGROUND: Complement activation is thought to be pathologically important in IgA nephropathy (IgAN). Although C3 deposition in the mesangium is found in IgAN, the origin of C3 is not clear. We recently demonstrated intraglomerular C3 synthesis in the human kidney; however, the activation and pathological role of locally synthesized C3 remains unclear. Here we performed nonradioactive in situ hybridization for C3 mRNA and immunohistochemistry for C3 and its activation products, such as C3d and membrane attack complex (MAC), to determine whether locally produced C3 in glomeruli was activated in IgA nephropathy. METHODS: Renal samples from 14 patients with IgAN and 5 with minimal change nephrotic syndrome (MCNS) were examined. Uninvolved portions of surgically removed kidneys with tumors served as normal controls. RESULTS: C3 mRNA was not detected in glomeruli in control tissue and MCNS, but was strongly expressed in resident glomerular cells of IgAN, including mesangial cells, glomerular epithelial cells and the cells of Bowman's capsule. Examination of serial sections disclosed that more than 70% of cells positive for C3 mRNA were also stained for C3 protein, C3d, and MAC. Double staining for in situ hybridization and immunohistochemistry also revealed that those C3 mRNA signals were present in intraglomerular cells positive for C3. The expression of C3 mRNA and MAC in glomeruli correlated significantly with the degree of mesangial matrix expansion. CONCLUSIONS: Our results demonstrated that locally synthesized C3 is activated in the glomeruli of IgAN and that its expression correlated with the severity of mesangial matrix expansion. These findings suggest that activation of C3 may be involved in tissue injury in IgAN through the formation of membrane attack complex.

Expression of Fas and Fas ligand in normal and ischemia-reperfusion testes: involvement of the Fas system in the induction of germ cell apoptosis in the damaged mouse testis.

Apoptosis of germ cells is very common in normal and injured mammalian testes. The aim of this study was to examine the possible involvement of the Fas and Fas ligand (FasL) system in the induction of germ cell apoptosis in normal and ischemia-reperfusion testes of adult mice. Apoptosis was assessed by the TUNEL method and by DNA gel electrophoresis. Fas and FasL mRNAs were detected by Northern blotting and reverse transcription polymerase chain reaction techniques, and proteins were analyzed by Western blotting and immunohistochemistry. Apoptosis of germ cells was identified in the normal testis especially around stages XI and XII, whereas the expression of Fas and FasL was largely confined to Leydig cells and Sertoli cells, respectively. However, in the testes reperfused after 1 h of ischemia, a high number of TUNEL-positive cells were identified in parallel with increased Fas-positive germ cells, whereas FasL expression in Sertoli cells was almost constant irrespective of the duration of reperfusion. Moreover, i.p. injection of anti-Fas antibody, which blocks the interaction between Fas and FasL, inhibited apoptosis, as indicated by the reduced number of TUNEL-positive cells, except for apoptosis at stages XI and XII. Our results indicate that the Fas/FasL system mediates apoptosis of spermatogenic cells in the injured testis but not spontaneous apoptosis in the normal testis.

Role of the Fas system in liver regeneration after a partial hepatectomy in rats.

Apoptosis is involved in the homeostatic control of organs. The aim of this study was to define the in vivo role of apoptosis-related proteins including the Fas system and Bcl-2 in liver regeneration following a partial hepatectomy (PH). We used 70% hepatectomized rats which were serially sacrificed from 12 h to 28 days. The expressions of Fas, Fas ligand, and Bcl-2 were examined by semiquantitative RT-PCR and immunohistochemistry. Liver regeneration, as examined by PCNA staining, peaked from 24 h to day 3, and declined from day 5. On the other hand, hepatocyte apoptosis, as examined by TUNEL staining, was seldom observed until 24 h, but increased from 1 week after PH. In the RT-PCR study, Fas showed an early decline by 24 h, followed by a later peak from days 3 to 5, and then a constant expression thereafter. Meanwhile, the Fas ligand was also low until day 3, but showed a remarkable increase from days 5 to 7, followed by a gradual decrease. On the other hand, Bcl-2 showed an early peak until 24 h, followed by a decline from day 5. In an immunohistochemical study, the time courses of these protein expressions were almost synchronous with their mRNAs in the RT-PCR study. We thus conclude that the coordinated interplay between these apoptosis-related proteins and hepatocyte apoptosis suggests the possible involvement of these proteins in the course of liver regeneration.

Male germ cell death in mouse testes: possible involvement of Fas and Fas ligand.

Loss of germ cells is very common during various stages of mammalian spermatogenesis. Although cell death, particularly apoptosis, has been implicated, our understanding of the mechanisms underlying germ cell death is still limited. In order to elucidate the extent and mechanism of germ cell death, this review first covers what is known of germ cell degeneration in the normal testes of fetal, neonatal, and adult mice from electron microscopy (EM) and from terminal dUTP nick-end labeling (TUNEL) staining. The issue of whether the Fas and Fas ligand (FasL) system is involved in the induction of germ cell apoptosis in normal and damaged testes is then addressed, including consideration of both the ischemia-reperfusion model of testicular torsion and the estrogen-treated testis model of environmental endocrine disruption. Finally, this review proposes that different molecular pathways may be triggered to induce male germ cell apoptosis, depending upon the physiological and pathological states of the germ cells.

Eradication of breast cancer xenografts by hyperthermic suicide gene therapy under the control of the heat shock protein promoter.

To investigate the usefulness of heat shock protein (HSP) promoter for breast cancer gene therapy, hyperthermia and HSV thymidine kinase (tk) suicide gene combination therapy was examined with mouse mammary cancer cell line FM3A. HSP promoter activity was markedly increased after heat shock (41-45 degrees C), with maximum activation (about 400-fold) at 3 hr. An in vitro cytotoxic assay showed that HSP-tk-transduced FM3A cells became more sensitive (more than 50,000 times) to ganciclovir (GCV) with heat shock, but untreated cells showed no increased cytotoxic sensitivity to GCV compared with control FM3A cells. In addition to promoter-oriented selective cell killing, a "chemosensitization effect" as a bystander effect was demonstrated by hyperthermia and suicide gene combination therapy, using a non-heat-inducible promoter. Immunohistochemical analysis revealed that this synergistic killing effect was dependent on apoptotic cell death with upregulation of both Fas and FasL (Fas ligand) expression. We also examined the efficacy of HSP-tk gene therapy in vivo by implanting breast cancer in subcutaneous and intraperitoneal models of BALB/c nude mice targeted by the HVJ-anionic liposome method. Significant tumor regression was observed in HSP-tk-transduced tumors followed by hyperthermia therapy, but no such inhibition was noted in either the mock vector transfection or hyperthermia group compared with control tumor-bearing mice. Our results demonstrate that this combination system is synergistically effective in mediating Fas-dependent apoptosis for a specific gene therapy targeting HSP-expressing mammary carcinomas, even in advanced and heat-resistant breast cancer.

Expression of mitochondrial thioredoxin-dependent antioxidant protein, SP-22, in normal human and inflammatory mouse placentae.

The aim of this study was to elucidate whether a novel mitochondrial antioxidant protein, SP-22, is localized in placenta and whether its expression is induced in placenta of lipopolysaccharide (LPS)-exposed mouse. Western blot analysis of normal human placenta indicated that the SP-22 protein was located in the mitochondrial fraction. Immunohistochemical analysis of SP-22 in normal placenta showed that immunoreactive SP-22 was distributed mostly in cytotrophoblastic cells but with almost no signal in syncytiotrophoblasts. The positive signals were also detected in the decidual cells and stromal cells in stem villi of normal placenta. We also examined LPS-mediated inflammatory placenta on day 13 of pregnancy at various time points after LPS injection (50 microg/kg, intraperitoneally). Western blot analysis indicated that LPS approximately quadrupled the expression of SP-22 in placenta of LPS-exposed mouse. When the SP-22 protein was localized immunohistochemically, the decidua and the diploid trophoblasts in the basal zone were intensively stained in placenta of LPS-exposed mouse compared to the control. The localization and inducible expression of SP-22 protein in placenta suggest a possible role in antioxidant system in mitochondria of normal and inflammatory placentae.