H epatocellular carcinoma (HCC) is the fifth most common human cancer and third most frequent cause of cancer death worldwide. 1 Although over 80% of new HCC cases will occur in Eastern Asia and subSaharan Africa, 2 the startling increase in HCC incidence in the United States over the past 20-25 years and the typically high mortality from this disease have established HCC as an important health concern in this country. [2][3][4][5][6] The clinical management of HCC is complicated by typically late-stage disease at presentation and prevalent underlying liver dysfunction that can render patients ineligible for potentially curative surgical therapies, which are generally suitable for only 20%-30% of HCC patients. 3,5,7 Although regional therapies, such as transarterial embolization and percutaneous treatments, are used in patients with nonresectable disease, their success is curtailed by recurrence as locally advanced or metastatic disease. For these patients, systemic therapy is indicated but has been largely unsuccessful. 3,4,[8][9][10] Thus, a clear need exists to develop effective, life-prolonging therapeutic strategies for the large number of HCC patients with advanced disease.A major challenge in the systemic treatment of HCC is cellular resistance to conventional cytotoxic agents, which, at

Tamoxifen is a mainstay in the treatment of estrogen receptor (ER) -positive breast cancer patients. Although the efficacy of tamoxifen has been attributed to induction of tumor cell growth arrest and apoptosis by inhibition of ER signaling, recent evidence indicates that tamoxifen possesses ER-independent antitumor activities. Here, we use OSU-03012, a small-molecule inhibitor of phosphoinositide-dependent protein kinase-1 (PDK-1) to address the hypothesis that PDK-1/Akt signaling represents a therapeutically relevant target to sensitize ER-negative breast cancer to tamoxifen. OSU-03012 sensitized both ER-positive MCF-7 and ER-negative MDA-MB-231 cells to the antiproliferative effects of tamoxifen in an ER-independent manner. Flow cytometric analysis of phosphatidylserine externalization revealed that this augmented suppression of cell viability was attributable to a marked enhancement of tamoxifen-induced apoptosis by OSU-03012. Mechanistically, this OSU-03012-mediated sensitization was associated with suppression of a transient tamoxifen-induced elevation of Akt phosphorylation and enhanced modulation of the functional status of multiple Akt downstream effectors, including FOXO3a, GSK3A/B, and p27. The growth of established MDA-MB-231 tumor xenografts was suppressed by 50% after oral treatment with the combination of tamoxifen (60 mg/kg) and OSU-03012 (100 mg/kg), whereas OSU-03012 and tamoxifen alone suppressed growth by 30% and 0%, respectively. These findings indicate that the inhibition of PDK-1/Akt signaling to sensitize ER-negative breast cancer cells to the ER-independent antitumor activities of tamoxifen represents a feasible approach to extending the use of tamoxifen to a broader population of breast cancer patients. Considering the urgent need for novel therapeutic strategies for ER-negative breast cancer patients, this combinatorial approach is worthy of continued investigation.

We examined the effects of the quinolone antibacterial agents pefloxacin (PFLX) and ofloxacin (OFLX) on the Achilles tendon of Sprague-Dawley rats. A single oral administration of PFLX 300 and 900 mg/kg or OFLX 900 mg/kg induced edema with mononuclear cell infiltration mainly in the inner sheath of the inner Achilles tendon just proximal to the tuber calcanei in rats killed on the next day. Cell infiltration was also seen in the adjacent synovial membrane and joint space. With progression of severity, the lesions extended to the surface tendon tissue, wherein irregularly arranged collagen bundles were detached from each other and nuclei of fibroblasts were pyknotic and fragmented. After 2-wk repeated administration, these lesions were replaced by fibrotic foci with regenerated tendon fibroblasts, and the incidence and severity were reduced in the OFLX but not PFLX groups. Coadministration of cyclosporin A with OFLX 300 mg/kg induced these lesions despite the fact that neither induced lesions alone. The tendon lesions were induced in juvenile rats (4 wk of age) but not in young adults (12 wk). The articular cartilage of juvenile rats showed focal degeneration and/or cavitation in the tarsal joints after a single and 2-wk administration of PFLX or OFLX. Hydrocortisone slightly increased the incidence of OFLX-induced lesions in both the tendon and cartilage after a 2-wk administration. The occurrence of the tendon lesions is different from that of the Achilles tendon disorders reported in older humans, but they are thought to be a useful model for them.

Preexisting and acquired resistance to epidermal growth factor receptor (EGFR) inhibitors limits their clinical usefulness in patients with advanced non-small cell lung cancer (NSCLC). This study characterizes the efficacy and mechanisms of the combination of gefitinib or erlotinib with OSU-03012, a celecoxib-derived antitumor agent, to overcome EGFR inhibitor resistance in three NSCLC cell lines, H1155, H23, and A549. The OSU-03012/EGFR inhibitor combination induced pronounced apoptosis in H1155 and H23 cells, but not in A549 cells, suggesting a correlation between drug sensitivity and basal phospho-Akt levels independently of EGFR expression status. Evidence indicates that this combination facilitates apoptosis through both Akt signaling inhibition and upregulation of endoplasmic reticulum (ER) stress-induced, GADD153-mediated pathways. For example, ectopic expression of constitutively active Akt significantly attenuated the inhibitory effect on cell survival, and small interfering RNAmediated knockdown of GADD153 protected cells from undergoing apoptosis in response to drug cotreatments. Furthermore, the OSU-03012/EGFR inhibitor combination induced GADD153-mediated up-regulation of death receptor 5 expression and subsequent activation of the extrinsic apoptosis pathway. It is noteworthy that the ER stress response induced by this combination was atypical in that the cytoprotective pathway was not engaged. In addition, in vivo suppression of tumor growth and modulation of intratumoral biomarkers were observed in a H1155 tumor xenograft model in nude mice. These data suggest that the concomitant modulation of Akt and ER stress pathways with the OSU-03012/EGFR inhibitor combination represents a unique approach to overcoming EGFR inhibitor resistance in NSCLC and perhaps other types of cancer with elevated basal Akt activities. [Cancer Res 2008;68(8):2820-30]

Fluoroquinolone antibacterial agents have been reported to induce tendon lesions in juvenile rats. In the present study, we characterized fluoroquinolone-induced Achilles tendon lesions by comparing the effects of 10 fluoroquinolones and examining the potential of one of these antimicrobial agents, pefloxacin, to induce tendon lesions when coadministered with one of nine anti-inflammatory compounds. Among the 10 fluoroquinolones tested, fleroxacin and pefloxacin were the most toxic, inducing lesions at a dose of 100 mg/kg of body weight or more, while lomefloxacin, levofloxacin, and ofloxacin or sparfloxacin and enoxacin induced lesions at 300 mg/kg or more and 900 mg/kg, respectively. In contrast, norfloxacin, ciprofloxacin, and tosufloxacin had no effect even at the high dose of 900 mg/kg. The severity of the Achilles tendon lesions appeared to correlate with the structure of the substituent at the seventh position. Furthermore, pefloxacin-induced tendon lesions were inhibited by coadministration with dexamethasone and N-nitro-L-arginine methyl ester. Phenidone (1-phenyl-3-pyrazolidinone) and 2-(12-hydroxydodeca-5,10-diynyl)3,5,6-trimethyl-1,4-benzoqui none (AA861) also decreased the incidence of tendon lesions. In contrast, catalase, dimethyl sulfoxide, indomethacin, pyrilamine, and cimetidine did not modify these tendon lesions. These results suggest that nitric oxide and 5-lipoxigenase products partly mediate fluoroquinolone-induced tendon lesions.

ABSTRACT. Five racehorses in apparently normal condition succumbed to sudden cardiac death (SCD) during or shortly after intensive training exercise. Cardiopathologic examination was performed. In 1 of the 5 horses, the use of an electrocardiogram (ECG) recording taken continuously for 440 sec enabled us to analyze some of the arrhythmias in the terminal event of SCD. The ECG tracing exhibited the R-on-T phenomenon following a pair of ventricular premature contractions (VPCs). The phenomenon rapidly degenerated into ventricular fibrillation, which led to cardiac arrest. In all 5 horses cardiopathologic examination revealed the following lesions: (i) foci of myocardial fibrosis in the right atrium located close to the sinoatrial (SA) node, (ii) fibrotic and/or fibroplastic changes in the upper portion of the interventricular septum, including the atrioventricular (AV) conduction system, and (iii) arterio-and arteriolosclerosis of the SA and AV node vessels. Pathogenetically, the process by which the focal lesions of myocardial ischemia secondary to vascular sclerosis progressed into fibrosis and/or fibroplasia could play a major role in the genesis of arrhythmias. Presumably the fibrotic and/or fibroplastic changes in the area of the AV bundle and its bundle branches are closely related to the onset of fatal ventricular arrhythmias such as VPCs, deteriorating into ventricular fibrillation. SCD in training and racing Thoroughbred horses appears to be due to arrhythmia.-KEY WORDS: arrhythmia, equine, heart, pathology, sudden death.J. Vet. Med. Sci. 61(8): 921-928, 1999 matter what conclusions have been drawn thus far about human SCD, the precise relationship between the prodromal signs (including fatal arrhythmias) and the pathologic condition is still controversial [3,5,8,9,11,23,26,36]. This paper reports the cardiopathologic changes found in 5 racehorses that had been in apparently normal condition when they succumbed to SCD or instantaneous death during or shortly after intensive training exercise. It also describes the terminal electrocardiographic events in 1 of the 5 animals. MATERIALS AND METHODSNecropsy of the 5 racehorses in this study (Table 1) was performed as soon as possible after SD, usually within 3 hr. Fortuitously, when horse 1 fell and lay down suddenly shortly after a training exercise, it was possible to record an electrocardiogram (ECG). For the ECG recording, a baseapex lead was used [29]; the positive electrode was positioned over the apex-beat area of the heart and the negative electrode over the cardiac base. The recording was performed continuously over the 400-sec terminal event of the SD, at a paper speed of 25 or 50 mm/sec. So that we could analyze the arrhythmias, the onset of the R-on-T phenomenon was set up as a 0-sec point, and the beginning point of the recording was calculated back to 370 sec (Table 2). For measurements of the Q-T interval, 5 successive intervals with sinus rhythm were randomly taken from the ECG tracing, mainly at a paper speed of 50 mm/sec. The corrected Q-...

The phosphoinositide-dependent kinase 1 (PDK1)/Akt pathway is an important regulator of multiple biological processes including cell growth, survival, and glucose metabolism. In light of the mechanistic link between Akt signaling and prostate tumorigenesis, we evaluated the chemopreventive relevance of inhibiting this pathway in the transgenic adenocarcinoma of the model prostate (TRAMP) mouse with OSU03012, a celecoxib-derived, but COX-2-inactive, PDK1 inhibitor. Beginning at ten weeks of age when prostatic intraepithelial neoplasia (PIN) lesions are well developed, TRAMP mice received OSU03012 via daily oral gavage for 8 weeks. The drug treatment significantly decreased the weight of all 4 prostate lobes as well as the grade of epithelial proliferation in the dorsal and lateral lobes compared to vehicle-treated control mice. The incidences of carcinoma and metastasis were decreased, although not to statistically significant levels. Treated mice lost body fat and failed to gain weight independent of food intake. This change and periportal hepatocellular atrophy can be linked to sustained PDK1 inhibition through downstream inactivation of glycogen synthase. Centrilobular hepatocellular hypertrophy and necrosis of Type II skeletal myofibers were also compound-related effects. We conclude that targeting of the PDK1/Akt pathway has chemopreventive relevance in prostate cancer and causes other in vivo effects mediated in part by an alteration of bioenergetic signaling.

Wormwood, Artemisia absinthium, is a very bitter plant, and its extract has been used as food additives such as seasonings for food and drinks. A 13-week repeated dose toxicity study of wormwood extract was performed in both sexes of Wistar Hannover (GALAS) rats. Rats were divided into 4 groups consisting of 10 males and 10 females each, and were given water containing 0, 0.125, 0.5, or 2% wormwood extract. All rats had survived at the end of the study, and no changes indicating obvious toxicities that are attributable to the treatment of wormwood extract were observed in the body weights, hematological and serum biochemical examinations, organ weights, and histopathological examinations. Based on the results of the present study, the NOAEL (no-observed-adverse-effect-level) of wormwood extract of Wistar Hannover rats was estimated to be 2% (equivalent to 1.27 g/kg/day in males and 2.06 g/kg/day in females) or more.