Effect of hydroxyapatite tubes on the lag screw intraoperative insertion torque for the treatment of intertrochanteric femoral fractures.

BACKGROUND: Hydroxyapatite (HA) augments are frequently used in orthopedic surgery. However, the effectiveness of HA augments on the treatment of intertrochanteric femoral fractures remains unknown. This study aimed to investigate whether the use of HA tubes affects the intraoperative insertion torque of the lag screw during intertrochanteric femoral fracture surgery. METHODS: From January 2016 to October 2020, 58 patients with intertrochanteric femoral fractures were included and divided into the HA treatment group (HA group, n = 29) and non-HA treatment group (N group, n = 29). Patients with intertrochanteric femoral fractures were treated using the Gamma3 nail system® with or without two HA tubes. HA tubes were inserted into the femoral head through the lag screw hole before the insertion of the lag screw. The mean and maximum intraoperative insertion torques of the lag screw, bone mineral density (BMD) of the uninjured opposite side femoral neck, and tip apex distance (TAD) of the lag screw on postoperative radiographs were assessed. To assess the loss of reduction after the surgery, we investigated the amounts of telescoping of the lag screw and the changes in the neck shaft angle. RESULTS: The mean and maximum insertion torques were correlated with BMD in the HA and N groups, respectively. The mean and maximum insertion torques were not correlated with TAD in the HA and N groups, respectively. The mean torque/BMD ratio was significantly higher in the HA group than in the N group (p = 0.03). There were no significant differences in the maximum torque/BMD ratio between HA and N groups (p = 0.06), while the maximum torque/BMD ratio tended to be higher in the HA group than in the N group. The amounts of telescoping of the lag screw in the HA group were significantly lower than that in the N group (p = 0.04), while there were no significant differences in the changes in the neck shaft angle between two groups (p = 0.32). CONCLUSION: Our results strongly suggest that the use of HA tubes increases the intraoperative lag screw insertion torque/BMD ratio and may improve the lag screw fixation by strengthening the bone/metal thread interface in the treatment of intertrochanteric femoral fractures.

Mithramycin has inhibitory effects on gliostatin and matrix metalloproteinase expression induced by gliostatin in rheumatoid fibroblast-like synoviocytes.

OBJECTIVES: Gliostatin (GLS) has angiogenic and arthritogenic activities and enzymatic activity as thymidine phosphorylase. Aberrant GLS production has been observed in the synovial membranes of patients with rheumatoid arthritis (RA). Matrix metalloproteinases (MMPs) are involved in joint destruction. Promoters of GLS and some MMP genes contain Sp1 binding sites. We examined the inhibitory effect of the Sp1 inhibitor mithramycin on GLS-induced GLS and MMP expression in cultured fibroblast-like synoviocytes (FLSs). METHODS: Synovial tissue samples were obtained from patients with RA. FLSs pretreated with mithramycin were cultured with GLS. The mRNA expression levels of GLS and MMP-1, MMP-2, MMP-3, MMP-9, and MMP-13 were determined using reverse transcription polymerase chain reactions. Protein levels were measured using enzyme immunoassay and gelatin zymography. RESULTS: GLS upregulated the expression of GLS itself and of MMP-1, MMP-3, MMP-9, and MMP-13, an effect significantly reduced by treatment with mithramycin. GLS and mithramycin had no effect on MMP-2 expression. CONCLUSIONS: Mithramycin downregulated the increased expression of GLS and MMP-1, MMP-3, MMP-9, and MMP-13 in FLSs treated with GLS. Because GLS plays a pathological role in RA, blocking GLS stimulation using an agent such as mithramycin may be a novel approach to antirheumatic therapy.

The Sp1 transcription factor is essential for the expression of gliostatin/thymidine phosphorylase in rheumatoid fibroblast-like synoviocytes.

INTRODUCTION: Gliostatin/thymidine phosphorylase (GLS/TP) has angiogenic and arthritogenic activities, and aberrant GLS production has been observed in the active synovial membranes of rheumatoid arthritis (RA) patients. The human GLS gene promoter contains at least seven consensus binding sites for the DNA binding protein Sp1. Here we examined whether Sp1 is necessary for GLS production in RA. We also studied the effects of the Sp1 inhibitor mithramycin on GLS production in RA fibroblast-like synoviocytes (FLSs). METHODS: FLSs from RA patients were treated with specific inhibitors. The gene and protein expression of GLS were studied using the quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and an enzyme immunoassay. Intracellular signalling pathway activation was determined by western blotting analysis, a luciferase assay, a chromatin immunoprecipitation (ChIP) assay and a small interfering RNA (siRNA) transfection. RESULTS: The luciferase and ChIP assays showed that Sp1 binding sites in the GLS promoter were essential for GLS messenger RNA (mRNA) expression. GLS production was suppressed in FLSs by siRNA against Sp1 transfection. Mithramycin decreased GLS promoter activity, mRNA and protein expression in FLSs. Tumour necrosis factor-α (TNF-α) significantly increased GLS expression in RA FLSs; this effect was reduced by pre-treatment with cycloheximide and mithramycin. CONCLUSIONS: Pretreatment of mithramycin and Sp1 silencing resulted in a significant suppression of GLS production in TNF-α-stimulated FLSs compared to controls. GLS gene expression enhanced by TNF-α was partly mediated through Sp1. As physiological concentrations of mithramycin can regulate GLS production in RA, mithramycin is a promising candidate for anti-rheumatic therapy.

E7080 suppresses hematogenous multiple organ metastases of lung cancer cells with nonmutated epidermal growth factor receptor.

While epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors improve the prognosis of patients with EGFR mutant lung cancer, the prognosis of patients with nonmutant EGFR lung cancer, especially those with metastases, is still extremely poor. We have assessed the therapeutic efficacy of E7080, an orally available inhibitor of multiple tyrosine kinases including VEGF receptor 2 (VEGFR-2) and VEGFR-3, in experimental multiple organ metastasis of lung cancer cell lines without EGFR mutations. E7080 markedly inhibited the in vitro proliferation of VEGF-stimulated microvascular endothelial cells. Intravenous inoculation into natural killer cell-depleted severe combined immunodeficient mice of the small cell lung cancer cell lines H1048 (producing low amounts of VEGF) and SBC-5 (producing intermediate amounts of VEGF) resulted in hematogenous metastases into multiple organs, including the liver, lungs, kidneys, and bones, whereas intravenous inoculation of PC14PE6, a non-small cell lung cancer cell line producing high amounts of VEGF, resulted in lung metastases followed by massive pleural effusion. Daily treatment with E7080 started after the establishment of micrometastases significantly reduced the number of large (>2 mm) metastatic nodules and the amount of pleural effusion, and prolonged mouse survival. Histologically, E7080 treatment reduced the numbers of endothelial and lymph endothelial cells and proliferating tumor cells and increased the number of apoptotic cells in metastatic nodules. These results suggest that E7080 has antiangiogenic and antilymphangiogenic activity and may be of potential therapeutic value in patients with nonmutant EGFR lung cancer and multiple organ metastases.

FK506 inhibition of gliostatin/thymidine phosphorylase production induced by tumor necrosis factor-α in rheumatoid fibroblast-like synoviocytes.

Gliostatin/thymidine phosphorylase (GLS/TP) is known to have angiogenic and arthritogenic activities. The purpose of this study was to determine the inhibitory effects of FK506 (tacrolimus) on GLS production in rheumatoid arthritis (RA). We investigated the modulation of serum GLS by FK506 therapy and the effect of FK506 on the production of GLS in fibroblast-like synoviocytes (FLSs). Serum samples were collected from 11 RA patients with active disease at baseline and after 12 weeks of FK506 treatment. Serum concentrations of GLS and matrix metalloproteinase (MMP)-3 were measured by ELISA and found to be down-regulated in responders evaluated with a disease activity score. Patient FLSs were cultured and stimulated by tumor necrosis factor (TNF)-α with or without FK506. The expression levels of GLS were determined using reverse transcription-polymerase chain reaction (RT-PCR) and enzyme immunoassay and shown to be significantly increased. GLS levels in TNF-α-stimulated FLSs were reduced by FK506 treatment. Our data show a novel mechanism for the action of physiological concentrations of FK506 in RA that regulates the production of GLS in FLSs.

E7080, a multi-tyrosine kinase inhibitor, suppresses the progression of malignant pleural mesothelioma with different proangiogenic cytokine production profiles.

PURPOSE: Malignant pleural mesothelioma (MPM) is a biologically heterogeneous malignant disease with a poor prognosis. We reported previously that the anti-vascular endothelial growth factor (VEGF) antibody, bevacizumab, effectively inhibited the progression of VEGF-high-producing (but not VEGF-low-producing) MPM cells in orthotopic implantation models, indicating the need for novel therapeutic strategies to improve the poor prognosis of this disease. Therefore, we focused on the multi-tyrosine kinase inhibitor E7080 and assessed its therapeutic efficacy against MPM cells with different proangiogenic cytokine production profiles. EXPERIMENTAL DESIGN: The efficacy of E7080 was assayed in orthotopic implantation of severe combined immunodeficient mouse models with three human MPM cell lines (MSTO-211H, NCI-H290, and Y-MESO-14). RESULTS: With regard to proangiogenic cytokine production profiles, MSTO-211H and Y-MESO-14 cells were MPM cells producing high levels of fibroblast growth factor-2 and VEGF, respectively. NCI-H290 cells produced low levels of fibroblast growth factor-2 and VEGF compared with the other two cell lines. E7080 potently suppressed the phosphorylation of VEGF receptor-2 and FGF receptor 1 and, thus, inhibited proliferation of endothelial cells, but not that of the MPM cell lines, in vitro. Orthotopically inoculated MSTO-211H cells produced only thoracic tumors, whereas NCI-H290 and Y-MESO-14 cells also developed pleural effusions. Treatment with E7080 potently inhibited the progression of these three MPM cell lines and markedly prolonged mouse survival, which was associated with decreased numbers of tumor-associated vessels and proliferating MPM cells in the tumor. CONCLUSIONS: These results strongly suggest broad-spectrum activity of E7080 against MPM with different proangiogenic cytokine production profiles in humans.

A bone metastasis model with osteolytic and osteoblastic properties of human lung cancer ACC-LC-319/bone2 in natural killer cell-depleted severe combined immunodeficient mice.

Lung cancer is commonly associated with multiple-organ metastasis, and bone is a frequent metastatic site for lung cancer. Lung cancer frequently develops osteolytic, and less frequently osteoblastic, metastasis to bone. Osteolytic metastasis models of lung cancer have been reported, but no osteoblastic metastasis model is available for lung cancer. In the present study, we established a reproducible model of human lung cancer with both osteolytic and osteoblastic changes in natural killer cell-depleted severe combined immunodeficient mice. Intravenous inoculation of ACC-LC-319/bone2 cells resulted in the development of metastatic colonies in the lung, liver, and bone of the mice. As assessed sequentially by X-ray photographs, osteolytic bone lesions were observed by day 28, and then osteoblastic lesions were detected by day 35. Histological examination revealed the presence of bony spurs, a hallmark of osteoblastic bone metastasis, where osteoclasts were hardly observed. Treatment with an anti-human vascular endothelial growth factor antibody, bevacizumab, as well as zoledronate, inhibited the number of experimental bone metastases, including osteoblastic changes produced by ACC-LC-319/bone2 cells. These results indicate that our bone metastasis model by ACC-LC319/bone2 might be useful to understand the molecular pathogenesis of osteolytic and osteoblastic metastasis, and to identify molecular targets to control bone metastasis of lung cancer.

Intensification therapy with anti-parathyroid hormone-related protein antibody plus zoledronic acid for bone metastases of small cell lung cancer cells in severe combined immunodeficient mice.

Bone metastases occur in more than one-third of patients with advanced lung cancer and are difficult to treat. We showed previously the therapeutic effect of a third-generation bisphosphonate, minodronate, and anti-parathyroid hormone-related protein (PTHrP) neutralizing antibody on bone metastases induced by the human small cell lung cancer cell line, SBC-5, in natural killer cell-depleted severe combined immunodeficient mice. The purpose of our current study was to examine the effect of the combination of PTHrP antibody and zoledronic acid, which has been approved to treat bone metastases, against bone metastases produced by SBC-5 cells expressing PTHrP. Treatment with PTHrP antibody and/or zoledronic acid did not affect the proliferation of SBC-5 cells in vitro. Repeated treatments with either PTHrP antibody or zoledronic acid inhibited the formation of osteolytic bone metastases of SBC-5 cells but had no effect on metastases to visceral organs. Importantly, combined treatment with PTHrP antibody and zoledronic acid further inhibited the formation of bone metastases. Histologic assays showed that, compared with either PTHrP antibody or zoledronic acid alone, their combination decreased the number of tumor-associated osteoclasts and increased the number of apoptotic tumor cells. These findings suggest that this novel dual-targeting therapy may be useful for controlling bone metastases in a subpopulation of small cell lung cancer patients.

Lysophosphatidic acid stimulates the proliferation and motility of malignant pleural mesothelioma cells through lysophosphatidic acid receptors, LPA1 and LPA2.

Lysophosphatidic acid (LPA) is one of the simplest natural phospholipids. This phospholipid is recognized as an extracellular potent lipid mediator with diverse effects on various cells. Although LPA is shown to stimulate proliferation and motility via LPA receptors, LPA(1) and LPA(2), in several cancer cell lines, the role of LPA and LPA receptors for malignant pleural mesothelioma (MPM) has been unknown. MPM is an aggressive malignancy with a poor prognosis and the incidence is increasing and is expected to increase further for another 10-20 years worldwide. Therefore, the development of novel effective therapies is needed urgently. In this study, we investigated the effect of LPA on the proliferation and motility of MPM cells. We found that all 12 cell lines and four clinical samples of MPM expressed LPA(1), and some of them expressed LPA(2), LPA(3), LPA(4) and LPA(5). LPA stimulated the proliferation and motility of MPM cells in a dose-dependent manner. Moreover, LPA-induced proliferation was inhibited by Ki16425, an inhibitor of LPA(1), and small interfering RNA against LPA(1), but not LPA(2). Interestingly, LPA-induced motility was inhibited by small interfering RNA against LPA(2), but not LPA(1), unlike a number of previous reports. These results indicate that LPA is a critical factor on proliferation though LPA(1), and on motility though LPA(2) in MPM cells. Therefore, LPA and LPA receptors, LPA(2) as well as LPA(1), represent potential therapeutic targets for patients with MPM.

Novel dual targeting strategy with vandetanib induces tumor cell apoptosis and inhibits angiogenesis in malignant pleural mesothelioma cells expressing RET oncogenic rearrangement.

Malignant pleural mesothelioma (MPM) is an aggressive malignancy with a poor prognosis, therefore development of novel effective therapies is urgent. In the present study, we investigated the therapeutic efficacy of vandetanib (ZD6474), an inhibitor of VEGFR-2, EGFR and RET tyrosine kinases, in an orthotopic model of MPM. We found that a human MPM cell line, EHMES-10, expressed RET/PTC3 oncogenic rearrangement and a large amount of VEGF. Vandetanib induced the apoptosis and inhibited the proliferation of EHMES-10 cells in vitro (IC(50)=0.3 microM). Once-daily oral treatment with vandetanib inhibited tumor angiogenesis, and reduced significantly the growth of thoracic tumors and the production of pleural effusions, resulting in the prolonged survival of mice in EHMES-10 orthograft model. In contrast, the selective EGFR tyrosine kinase inhibitor, gefitinib, had no effect against EHMES-10 cells both in vitro and in vivo. Our results suggest that using vandetanib to target RET-dependent tumor cell proliferation and survival and VEGFR-2-dependent tumor angiogenesis may be promising against MPM expressing RET oncogenic rearrangement and VEGF.

Follistatin suppresses the production of experimental multiple-organ metastasis by small cell lung cancer cells in natural killer cell-depleted SCID mice.

PURPOSE: Follistatin (FST), an inhibitor of activin, regulates a variety of biological functions, including cell proliferation, differentiation, and apoptosis. However, the role of FST in cancer metastasis is still unknown. Previous research established a multiple-organ metastasis model of human small cell lung cancer in natural killer cell-depleted SCID mice. In this model, i.v. inoculated tumor cells produced metastatic colonies in multiple organs including the lung, liver, and bone. The purpose of this study is to determine the role of FST in multiple-organ metastasis using this model. EXPERIMENTAL DESIGN: A human FST gene was transfected into the small cell lung cancer cell lines SBC-3 and SBC-5 and established transfectants secreting biologically active FST. The metastatic potential of the transfectants was evaluated using the metastasis model. RESULTS: FST-gene transfection did not affect the cell proliferation, motility, invasion, or adhesion to endothelial cells in vitro. I.v. inoculated SBC-3 or SBC-5 cells produced metastatic colonies into multiple organs, including the lung, liver, and bone in the natural killer cell-depleted SCID mice. FST transfectants produced significantly fewer metastatic colonies in these organs when compared with their parental cells or vector control clones. Immunohistochemical analyses of the liver metastases revealed that the number of proliferating tumor cells and the tumor-associated microvessel density were significantly less in the lesions produced by FST transfectants. CONCLUSIONS: These results suggest that FST plays a critical role in the production of multiple-organ metastasis, predominantly by inhibiting the angiogenesis. This is the first report to show the role of FST in metastases.

Current status and perspective of angiogenesis and antivascular therapeutic strategy: non-small cell lung cancer.

Lung cancer is the leading cause of cancer death worldwide, and most patients die of metastatic disease. Angiogenesis, namely, neovascularization from preexisting vasculature, is necessary for tumor growth in both primary and distant organs to supply oxygen and nutrition. Angiogenesis consists of sprouting and nonsprouting (the enlargement, splitting, and fusion of preexisting vessels) processes, and both can occur concurrently. The growth of non-small cell lung cancer (NSCLC), which accounts for more than 80% of all lung cancers, is usually dependent on angiogenesis, which is regulated by complex mechanisms in the presence of various angiogenesis-related molecules. Vascular endothelial growth factor (VEGF), also known as vascular permeability factor (VPF), is one of the most potent angiogenic molecules, while also regulating both angiogenesis and vascular permeability and hence promoting tumor progression and the development of malignant pleural effusions in NSCLC. Recent clinical trials showed that the anti-VEGF antibody bevacizumab, combined with standard first-line chemotherapy, provided a statistically and clinically significant survival advantage with tolerable toxicity. In addition, the combined use of the anti-VEGF antibody with an inhibitor of epidermal growth factor receptor (EGFR) has also shown favorable antitumor efficiency. These successes proved the validity of an antivasculature strategy for NSCLC. Furthermore, a large number of antivasculature agents have been shown to be effective against multiple targets. The efficiency of these compounds is currently being investigated in clinical trials for NSCLC.

Restored expression of the MYO18B gene suppresses orthotopic growth and the production of bloody pleural effusion by human malignant pleural mesothelioma cells in SCID mice.

Malignant pleural mesothelioma (MPM) is closely related to exposure to asbestos, and a rapid increase in the number of MPM patients is therefore estimated to occur from 2010 to 2040 in Japan. Because MPM is refractory to conventional chemotherapy and radiotherapy, the prognosis of MPM patients is extremely poor. MYO18B, a novel member of the myosin family, is a tumor suppressor gene isolated from a homozygously deleted region at 22q12.1 in a lung cancer cell line. The inactivation of the MYO18B gene plays an important role in several malignant diseases. However, the role of MYO18B in the progression of MPM is still unknown. Six different human MPM cell lines were used in this study. Western blot revealed that none of the cell lines expressed a detectable level of MYO18B protein. One of the MPM cell lines, EHMES-10, was transfected with the MYO18B gene. We found that a restored expression of the MYO18B protein in EHMES-10 cells resulted in the inhibition of their anchorage-independent growth and motility in vitro. In addition, it also inhibited their ectopic (subcutaneous space) and orthotopic (thoracic cavity) growth in SCID mice, in association with an increased degree of cell apoptosis. Furthermore, it also suppressed the production of bloody pleural effusion after orthotopic injection. These findings suggest that the restored expression of MYO18B may be a useful therapeutic strategy for the treatment of locally advanced MPM in humans.

Defects in apoptotic signal transduction in cisplatin-resistant non-small cell lung cancer cells.

Non-small cell lung cancer (NSCLC) often shows intrinsic multidrug resistance, which is one of the most serious problems in cisplatin-based adjuvant chemotherapy. Anticancer drugs exert at least part of their cytotoxic effect by triggering apoptosis. In order to understand the molecular alterations leading to heterogeneous cisplatin sensitivity and apoptosis inducibility in NSCLC cells, we analyzed various apoptotic pathways, including the activation of caspase-8, -9 and -3, the release of cytochrome c from mitochondria and the expression levels of pro- and anti-apoptotic proteins such as Bax, Bad, Bcl-2, Bcl-xL, Fas and p53 using heterogeneously apoptosis-sensitive cells (Ma-10, Ma-31 and Ma-46). Cisplatin treatment induced the activation of caspase-8, -9 and -3 and the release of cytochrome c in apoptosis-sensitive Ma-46. The expression of Bcl-xL was the highest and p53 was not expressed in apoptosis-resistant Ma-31, and Fas was not expressed in Ma-46. These expression levels were not correlated with the apoptosis inducibility of the three cell lines. These results suggest that blockage of the apoptotic signal from mitochondria is responsible for apoptosis resistance in NSCLC cell lines. Our findings also indicate that anti-apoptotic Bcl-xL and pro-apoptotic p53 are necessary but not sufficient for resistance to cisplatin-induced apoptosis in NSCLC cells.

Expression of multidrug resistance proteins and accumulation of cisplatin in human non-small cell lung cancer cells.

In order to understand and overcome multidrug resistance (MDR) of human non-small cell lung cancer (NSCLC), mRNA and protein expression levels of P-glycoprotein (MDR1), multidrug resistance-associated protein 1 (MRP1), and lung resistance-related protein (LRP) were investigated and compared with the chemosensitivity and the intracellular/intranuclear cisplatin accumulation of three NSCLC cell lines (Ma-10, Ma-31, and Ma-46). Ma-31 was more resistant than Ma-10 and Ma-46 to cisplatin, carboplatin, etoposide, and paclitaxel. The mRNA level of MDR1 was extremely low, and MDR1 protein was not detected in all cell lines. MRP1 mRNA expression was highest in Ma-31 and lowest in Ma-10, but there was no notable difference between the MRP1 protein expression in three cell lines. LRP mRNA/protein was equally expressed in Ma-10 and Ma-31, but was nominal in Ma-46. The intracellular/intranuclear cisplatin accumulation of the cells was determined to be Ma-31>Ma-46>Ma-10. Thus, MDR1, MRP1, and LRP mRNA and protein expression levels were not correlated with the chemosensitivity or the intracellular/intranuclear cisplatin accumulation of each cell line. The present results indicate that MDR proteins (MDR1, MRP1, and LRP) may not play an important role in the chemoresistance and drug efflux of NSCLC cells.

Overexpression of constitutive signal transducer and activator of transcription 3 mRNA in cisplatin-resistant human non-small cell lung cancer cells.

Non-small cell lung cancer (NSCLC) often shows intrinsic multidrug resistance, which is one of the most serious problems in cisplatin-based adjuvant chemotherapy. Recently, the constitutive activation of signal transducer and activator of transcription (STAT) factors has been found in a variety of human cancers. In the present study, the mRNA expression of STATs in various human NSCLC cell lines was investigated by quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) to determine whether STATs can be implicated in cisplatin resistance and apoptosis inducibility. Cisplatin triggered apoptosis in Ma-46 based on biochemical and morphological findings, but not in Ma-31. The mRNA expression of STAT3 was highest in cisplatin-resistant Ma-31 and lowest in cisplatin-sensitive Ma-46. A 6-hour exposure of cancer cells to cisplatin failed to stimulate STAT3 mRNA expression. Therefore, an increased transcriptional level of constitutive STAT3 may be related to the suppressive regulation of the apoptotic pathway in intrinsically chemo-resistant NSCLC cells.