Yoshinobu Ohsaki

Serum Osteopontin Levels are Highly Prognostic for Survival in Advanced Non-small Cell Lung Cancer: Results from JMTO LC 0004

Background: The Japan-Multinational Trial Organization (JMTO) lung cancer (LC) 0003 was a prospective randomized phase III trial investigating advanced non-small cell lung cancer comparing paclitaxel (P) plus carboplatin (C) versus vinorelbine (V), gemcitabine (G) followed by docetaxel (D). This trial was conducted with Southwest Oncology Group (SWOG) 0003 using a common arm of PC. An analysis of SWOG 0003 samples showed that low osteopontin (OPN) plasma levels were highly prognostic for a better outcome. We performed an independent investigation to validate these results using samples from Japanese patients enrolled in the JMTO LC 0004, a correlative study associated with JMTO LC 0003. Methods: A total of 20 ml of blood was collected before treatment from patients enrolled in JMTO LC 0003. Serum concentrations of OPN and basic fibroblast growth factor (bFGF) were measured by enzyme-linked immunosorbent assay. Effects of OPN and bFGF levels on tumor response, progression-free survival (PFS), and overall survival (OS) were examined. Results: Seventy-one samples were obtained, including 32 specimens from the PC arm and 39 from the VGD arm. There were no significant relationships between either OPN or bFGF levels with patient characteristics. In an analysis of clinical outcome, low OPN levels correlated with better OS and progression-free survival (hazard ratio [HR] = 0.57; 95% confidence interval [CI], 0.33–0.97; p = 0.037, HR = 0.42; 95% CI, 0.25–0.70; p = 0.001, respectively) and high bFGF levels correlated with better OS (HR = 0.53; 95% CI, 0.31–0.90; p = 0.018). Conclusion: Consistent with the findings from SWOG 0003, low OPN serum levels were significantly associated with a favorable prognosis in the JMTO LC 0004. Additionally, high bFGF levels were associated with improved survival.

Expression of syndecan-1 is common in human lung cancers independent of expression of epidermal growth factor receptor

In order to determine syndecan-1 expression in lung cancer, we examined 115 lung cancer specimens and 17 lung cancer cell lines. Syndecan-1 was immunohistochemically stained with a polyclonal antibody in 115 paraffin-embedded specimens; 84 cases out of 97 non-small cell lung cancer (NSCLC) and eight cases out of 18 small cell lung cancer (SCLC) were positively stained. Simultaneously, epidermal growth-factor receptor (EGFR) was stained; 47 cases out of 97 NSCLC and one case of 18 SCLC were positively stained. No significant correlation was shown between EGFR and syndecan-1 expression (P=0.68). Syndecan-1 mRNA was detectable in 16 of 17 lung cancer cell lines and EGFR mRNA in nine of 17. Eight cell lines had syndecan-1 mRNA as well as EGFR mRNA. PR-39 (1 microM) and 80 pM transforming growth factor-beta(1) (TGF-beta(1)), did not increase expressions of syndecan-1 mRNA and EGFR in five lung cancer cell lines. We concluded that lung cancer had detectable syndecan-1; however, expression of syndecan-1 protein did not correlate with survival time of lung cancer patients.

Sarcoidosis during infliximab therapy for Crohn’s disease

Tumor necrosis factor‐α (TNF‐α) antagonists are effective for inflammatory diseases, such as Crohn’s disease, rheumatoid arthritis (RA) and psoriasis. Although TNF‐α antagonists are also useful for sarcoidosis, paradoxical occurrence of sarcoidosis or sarcoidal reaction may be observed. We report a Crohn’s disease patient, who developed sarcoidosis during infliximab therapy. A 35‐year‐old man had been receiving infliximab for 7u2003months for Crohn’s disease. He developed cough and fever, accompanied by an infiltrated erythematous plaque on his right knee. The chest radiography, skin biopsy and laboratory findings were all consistent with sarcoidosis.

Suramin Inhibits the Growth of Non-Small-Cell Lung Cancer Cells That Express the Epidermal Growth Factor Receptor

The epidermal growth factor (EGF) is a potent growth factor that is believed to enhance the proliferation of cancer cells by a paracrine or autocrine mechanism. EGF transduces various signals and finally stimulates cell proliferation upon binding to cell surface receptors. Prevention of the association of this peptide with its receptors might lead to the development of new modalities for treatment of lung cancer. Several investigators have reported that suramin has antiproliferative activity against cancer cells that express EGF receptors (EGF-R), and that it acts by blocking the binding of the ligand to its receptor. In this study, we analyzed the antitumor effect of suramin using two lines of lung cancer cells (A549 and PC-13), which express EGF-R, and a variety of assays. Receptor-binding assays confirmed that A549 and PC-13 cells have cell surface receptors for EGF. Suramin inhibited the binding of EGF to these receptors. EGF and fetal bovine serum (FBS) stimulated the proliferation of cells, but suramin inhibited these effects in a dose-dependent fashion. Suramin at 200 microg/ml reduced the growth of A549 and PC-13 cells by 25 and 15%, respectively, in medium that contained 1% FBS. Paradoxically, the concentrations of suramin that inhibited cell proliferation were lower than those that were effective in inhibiting the binding of EGF to its receptor. Although expression of c-fos and c-myc mRNA increased when cells were stimulated by EGF or FBS, suramin at 200 microg/ml did not markedly alter such expression. Suramin partially blocked the EGF-induced progression of the cell cycle from the G0/G1 to the S phase. These results suggest that suramin partially blocks EGF signal transduction. Suramin probably inhibits cell proliferation by inhibiting intranuclear enzymes, as well as by partial blockage of EGF signal transduction.

Down-regulation of protein kinase C potentiates atrial natriuretic peptide-stimulated cGMP accumulation in vascular smooth-muscle cells.

It has been reported that atrial natriuretic peptide (ANP) produces inositol phosphates and diacylglycerol in vascular smooth muscle cells (VSMC). The purpose of this study is to investigate whether diacylglycerol produced by ANP affects ANP-induced cyclic GMP (cGMP) accumulation through the activation of protein kinase C. Short-term (15 min) treatment of rat aortic VSMC with protein kinase C activating phorbol 12-myristate 13-acetate (PMA, 100 nM) decreased ANP (100 nM)-induced cGMP accumulation by 34.7% in the presence of IBMX (0.5 mM). However, the long-term (24 h) treatment to decrease the activity of protein kinase C led to an enhancement of the cGMP accumulation by 69.6% compared with that of control VSMC. There were no significant differences in Bmax and Kd for ANP and ANP-dependent particular guanylyl cyclase activity between long-term PMA-treated and control VSMC. In the present study, we show that the activation of protein kinase C attenuates the cGMP accumulation induced by ANP and that down-regulation of protein kinase C results in an enhancement of the cGMP accumulation. These data are consistent with the role of protein kinase C as a negative regulator in ANP-receptor/guanylyl cyclase pathway.

Pentoxifylline Potentiates the Antitumor Effect of Cisplatin and Etoposide on Human Lung Cancer Cell Lines

The effect of pentoxifylline (PENT) on the sensitivity of two human lung adenocarcinoma cell lines, PC-9 and PC-14, to cisplatin (CDDP) and etoposide (ET) was studied. PENT at 0.5 and 1 mM enhanced the cytotoxicity of CDDP and ET on PC-14 and PC-9, respectively. Isobologram analyses of IC50 data, as well as combination index calculations, revealed that PENT had an additive or a synergistic effect when applied in combination with CDDP or ET, respectively. PENT potentiated the antitumor effect of ET in a nude-mouse xenograft model using PC-14 cells, when PENT was administered at 150 mg/kg subcutaneously for 6 days. Flow cytometry revealed that PENT decreased the accumulation of cells in the G2+M phase caused by CDDP when using PC-9 cells. However, PENT did not remarkably alter the accumulation of cells in G2+M caused by ET. These results suggest that PENT enhanced the antitumor effects of CDDP additively and those of ET synergistically. The enhancement mechanism probably differs between CDDP and ET. PENT needs more study to elucidate its potency as a new agent for combination chemotherapy.

Transforming growth factor-β1 proliferated vascular smooth muscle cells from spontaneously hypertensive rats

To clarify whether the growth inhibitors, transforming growth factor-β1 (TGF-β1), heparin, and interferon-γ (IFN-γ) contribute to the development of vascular hypertrophy in spontaneously hypertensive rats (SHR), the growth of vascular smooth muscle cells (VSMC) was evaluated both for cell numbers over a period of 4 days, and [3H]thymidine incorporation over 24 h. Heparin and IFN-γ inhibited the proliferation of VSMC from SHR and Wistar-Kyoto (WKY) rats. TGF-β1 enhanced SHR-VSMC proliferation by 16.6 ± 8.9%; in contrast TGF-β1 inhibited WKY-VSMC proliferation by 60.5 ± 7.4%. There was no difference in affinity, number of binding sites, or subtype expression of TGF-β1 receptor between SHR-VSMC and WKY-VSMC. This evidence suggests that the signal transduction system of TGF-β1 either the receptor itself or downstream signaling molecules, may be altered in SHR-VSMC versus WKY-VSMC. This abnormal responsiveness to TGF-β1 is involved in the proliferative characteristics of SHRVSMC. Therefore, TGF-β1 could contribute to the development of hypertension or vascular hypertrophy in SHR.

Solitary fibrous tumor of the pleura: Apparent diffusion coefficient (ADC) value and ADC map to predict malignant transformation

Solitary fibrous tumors (SFTs) of the pleura are rare soft‐tissue tumors that are presumed to be of mesenchymal origin. Most SFTs are histologically benign, but up to 20% of SFTs may be malignant. In addition, malignant transformation may occur within histologically benign SFTs, though it is rare. However, it is difficult to diagnose malignant SFTs of the pleura by means of conventional computed tomography and magnetic resonance imaging (MRI). In this article we present the first case of malignant SFT of the pleura in an 81‐year‐old man in which the apparent diffusion coefficient (ADC) value and ADC map based on diffusion‐weighted MRI were very useful for identifying malignant transformation. J. Magn. Reson. Imaging 2007;26:155–158.

Alterations in penicillin binding protein gene of Streptococcus pneumoniae and their correlation with susceptibility patterns

Penicillin binding protein (pbp) gene alterations of 328 clinical isolates of Streptococcus pneumoniae were examined for a correlation with their antibiotic-resistance. The frequency of penicillin G (PEN-G) resistance was determined to clarify susceptibility to several antibiotics, namely PEN-G, ampicillin, sulbactam/ampicillin, cefozopram, panipenem (PAPM), clarithromycin (CLR), azithromycin (AZM) and levofloxacin (LVX). Oligonucleotide primers for three pbp genes (pbp1a, pbp2x and pbp2b) were used to detect mutations in pbp. Of the strains, 25.9% were classified as Pen-Gs, 68.0% as Pen-Gir and 6.1% as Pen-Gr. The polymerase chain reaction product for wild-type pbp1a was found in 185 isolates, that for wild-type pbp2x was found in 66 isolates and that for wild-type pbp2b was found in 213 isolates. None of these three genes was detectable in 100 isolates while all of them were detected in 64 isolates (1aw/2xw/2bw). Of those 64 isolates with 1aw/2xw/2bw, the minimum inhibitory concentration (MIC) of PEN-G was < or =0.06 mg/l for 54 isolates and 0.12 mg/l for 10 isolates. Of the 272 strains for which the MIC of PAPM was < or =0.03 mg/l, there were 85 Pen-Gs, 184 Pen-Gir and three Pen-Gr isolates. Three strains for which the MIC of LVX was > or =4.0 mg/l included one Pen-Gs and two Pen-Gir isolates. The MICs of CLR correlated significantly with those of AZM. The MIC of CLR was > or =1 mg/l for 216 isolates, and the MIC of AZM was > or =1 mg/l for 244 of them. These data suggested that PAPM may be effective against S. pneumoniae infection, although acquisition of resistance should be considered. LVX also seemed to be effective against S. pneumoniae.

Doxapram stimulates the carotid body via a different mechanism than hypoxic chemotransduction.

To determine if doxapram stimulates the carotid body through the same mechanism as hypoxia, we compared the effects of doxapram and hypoxia on isolated-perfused carotid bodies in rabbits. Doxapram stimulated the carotid body in a dose-dependent manner. In Ca(2+)-free solution, neither doxapram nor hypoxia stimulated the carotid body. Although, doxapram had an additive effect on the carotid body chemosensory response to hypercapnia, a synergistic effect was not observed. Also, we investigated the various K(+) channel activators on the response to doxapram and hypoxia: pinacidil and levcromakalim as ATP-sensitive K(+) channel activators; NS-1619 as a Ca(2+)-sensitive K(+) channel activator; and halothane as a TASK-like background K(+) channel activator. The hypoxic response was partially reduced by halothane only, while pinacidil, levcromakalim and NS-1619 had no effect. Interestingly, the effect of doxapram was partially inhibited by NS-1619. Neither pinacidil nor levcromakalim affected the stimulatory effect of doxapram. We conclude that doxapram stimulates the carotid body via a different mechanism than hypoxic chemotransduction.