Anticancer drugs docetaxel and vinorelbine suppress cell growth by altering microtubule assembly and activating the proapoptotic signal pathway. Vinorelbine and docetaxel have been approved for treating several advanced cancers. However, their efficacy in the management of advanced hormone-refractory prostate cancer remains to be clarified. Microtubule damage by some anticancer drugs can activate the ERK survival pathway, which conversely compromises chemotherapeutic efficacy. We analyzed the effect of ERK inhibitors PD98059 and U0126 on vinorelbine-and docetaxelinduced cell growth suppression of androgen-independent prostate cancer cells. In androgen-independent C-81 LNCaP cells, inhibition of ERK by PD98059, but not U0126, plus docetaxel resulted in enhanced growth suppression by an additional 20% compared to the sum of each agent alone (p < 0.02). The combination treatment of docetaxel plus PD98059 also increased cellular apoptosis, which was in part due to the inactivation of Bcl-2 by increasing phosphorylated Bcl-2 by more than 6-fold and Bax expression by 3-fold over each agent alone. At these dosages, docetaxel alone caused only marginal phosphorylation of Bcl-2 (10%). Docetaxel plus U0126 had only 20% added effect on Bcl-2 phosphorylation compared to docetaxel alone. Nevertheless, both U0126 and PD98059 exhibited an enhanced effect on docetaxel-induced growth suppression in PC-3 cells. No enhanced effect was observed for vinorelbine plus PD98059 or U0126. Thus, the combination therapy of docetaxel plus PD98059 may represent a new anticancer strategy, requiring lower drug dosages compared to docetaxel monotherapy. This may lower the cytotoxicity and enhance tumor suppression in vivo. This finding of a combination effect could be of potential clinical importance in treating hormone-refractory prostate cancer. © 2003 Wiley-Liss, Inc. Key words: prostate cancer; ERK inhibitor; apoptosis; chemotherapyProstate carcinoma is the most common malignancy and second leading cause of cancer death in men in the United States. 1 Approximately 180,400 new cases of prostate cancer are diagnosed each year. 2 Prostate cancers generally respond to androgen ablation therapy. However, such treatment is not curative, and the disease progresses to an androgen-independent stage. 3 Effective treatment for advanced hormone-refractory cancers remains a significant challenge. Conventional chemotherapy is usually ineffective because of the low proliferation rate of prostate cancer cells and the significant drug toxicity. 4 Thus, novel approaches are needed to serve this patient population.A wide range of anticancer drugs induce apoptosis in malignant cells. 5-7 DNA fragmentation, nuclear condensation and cell shrinkage are the typical markers of apoptosis. 8 The Bcl-2 family of proteins represents a critical checkpoint within most apoptotic pathways. 9 At least 15 family members have been identified in mammalian cells. These proteins form heterodimers of anti-and proapoptotic members to inhibit one another's function. 9 The ratio of ...

Background-We tested the hypothesis that intracoronary delivery of an adenovirus encoding adenylyl cyclase type VI (Ad.AC VI ) would be associated with increased left ventricular (LV) function in pigs with congestive heart failure. Methods and Results-Pigs (52Ϯ6 kg; nϭ16) underwent placement of pacemakers, LV pressure transducers, and left atrial and aortic catheters. Physiological and echocardiographic studies were obtained from conscious animals 13 days later, and pacing was initiated (220 bpm). Seven days later, measures of LV function were reduced, documenting severe LV dysfunction and dilation. Pigs then received intracoronary Ad.AC VI (1.4ϫ10 12 vp; nϭ7) or saline (PBS; nϭ9) (randomized, blinded), with concomitant infusion of nitroprusside (50 g/min, 6.4 minutes) to increase gene transfer. Pacing was continued for 14 days, and final studies were obtained. The a priori key end point was change in LV dP/dt during isoproterenol infusion (pre-Ad.AC VI value minus value after 21 days of pacing). Pigs receiving Ad.AC VI showed a smaller decrease in both LV ϩdP/dt (Pϭ0.0014) and LV ϪdP/dt (Pϭ0.0008). Serial echocardiography showed that Ad.AC VI treatment was associated with increased LV function and reduced LV dilation and that end-systolic wall stress was reduced. AC-stimulated cAMP production was increased 1.7-fold in LV samples from Ad.AC VI -treated pigs (Pϭ0.006), and B-type natriuretic peptide was reduced (0.035). Gene transfer was confirmed by polymerase chain reaction. Conclusions-AC

Swaney JS, Patel HH, Yokoyama U, Lai NC, Spellman M, Insel PA, Roth DM. Adenylyl cyclase activity and function are decreased in rat cardiac fibroblasts after myocardial infarction. Am J Physiol Heart Circ Physiol 293: H3216-H3220, 2007. First published September 14, 2007; doi:10.1152/ajpheart.00739.2007.-Myocardial infarction (MI) results in left ventricular remodeling (e.g., ventricular hypertrophy, dilatation, and fibrosis). Fibrosis contributes to increased myocardial stiffening, impaired ventricular filling and function, and reduced cardiac output. Adenylyl cyclase (AC) expression and activity are reduced in animal models of heart failure. Stimulation of AC can inhibit extracellular matrix production in isolated cardiac fibroblasts; however, a role for reduced AC expression and activity in fibrosis associated with cardiac remodeling after chronic MI has never been determined. We tested the hypothesis that AC expression and activity are reduced in cardiac fibroblasts after chronic (18 wk) MI. Rats underwent coronary artery ligation or sham surgery (control), and echocardiography was used to assess left ventricular remodeling 1, 3, 5, 7, 10, 12, and 18 wk after surgery. Cardiac fibroblasts were isolated from the noninfarcted myocardium and compared for differences in AC activity and collagen synthesis. End-diastolic dimension was increased [control: 0.76 Ϯ 0.02 cm and MI: 1.0 Ϯ 0.02 cm (means Ϯ SE), P Ͻ 0.001] and fractional shortening was decreased (control: 44 Ϯ 2% and MI: 17 Ϯ 2%, P Ͻ 0.001) in MI compared with control rats. Basal and forskolin-stimulated cAMP production were decreased by 90% and 93%, respectively, and AC5/6 expression was decreased 39% in fibroblasts isolated from MI rats compared with sham controls. Serum-stimulated collagen production was increased twofold and forskolin-mediated inhibition of collagen synthesis was reduced in fibroblasts from MI rats compared with controls. Our data demonstrate that AC expression and activity are reduced and collagen production is increased in cardiac fibroblasts of rats after MI.CONGESTIVE HEART FAILURE (CHF) is a leading cause of morbidity and mortality in the United States. CHF was believed to result primarily from systolic dysfunction; however, it is recognized that diastolic dysfunction, or an inability of the heart to fill during diastole, is also an underlying mechanism in many patients with heart failure (29). Myocardial fibrosis, a key contributor to cardiac dysfunction during CHF, reflects hyperplasia and increased deposition of extracellular matrix (ECM) material into the interstitial and perivascular space (5). Exaggerated ECM deposition results in myocardial stiffening and decreased relaxation of the heart, ultimately leading to cardiac dysfunction (19,20).The myocardium is composed of cardiac myocytes and nonmyocytes, which include endothelial cells, vascular smooth muscle cells, and fibroblasts (34). Cardiac fibroblasts (CFs), an abundant cell type in the heart (comprising ϳ2/3 of the total cell population) are responsible for basal ECM ho...

Introduction Statins inhibit HMG‐CoA reductase and are used to lower low‐density lipoprotein‐cholesterol (LDL‐C) for cardiovascular disease (CVD) prevention. Besides the benefits of reducing CVD‐related morbidity and mortality, adverse events have been reported by the FDA. Statin‐induced skeletal myopathy is the most reported statin adverse event. While the precise mechanism is undefined, there is considerable evidence that a statin‐induced impairment of oxidative phosphorylation within mitochondria is involved. We and others have previously shown that Atorvastatin (Ator) administration induces mitochondria alterations. Rational Because observational studies report a high incidence of statin‐myopathy and females seem to be more susceptible to statin adverse events, we aimed to generate a mouse model mimicking statin‐induced muscular side effects. Methods 8‐week‐old male (M) and female (F) C57BL6J mice received either Ator (5mg/kg/day) or vehicle (Veh, 10% EtOH in water,) by daily oral gavage (4 groups, M+Ator, F+Ator, M+Veh, and F+Veh, n= 9–11 each). Body weights (BW) were recorded in two‐week intervals. 3‐month(m) post statin administration a lipid panel, liver enzymes, and creatine kinase (CK) was analyzed (n=8 each). Voluntary home cage activity was assessed 4‐m post statin treatment. Results A) M+Veh mice presented higher total‐C and high‐density lipoprotein (HDL)‐C serum levels than F+ Veh mice (total‐C mg/dl, Mean ± SEM; M+Veh 131.4 ± 7.4, F+Veh 90.5 ± 4.8, M+Veh vs F+Veh, * p<0.0004, and HDL‐C mg/dl, Mean ± SEM; M+Veh 82.8 ± 3.3, F+Veh 58.6 ± 3.4, M+Veh vs F+Veh, * p<0.0002). Long‐term Ator administration; B) induced lower BW (g) in male mice, but not in females starting at 1m post Ator administration (6m post body weight, Mean ± SEM; M+Veh 32.9g ± 0.8, M+Ator 28.4g ± 0.7, M+Veh versus M+Ator * p<0.0005; F+Veh 23.2g ± 0.6, F+Ator 22.7g ± 0.4, F+Veh vs F+Ator, not significant (ns)), C) reduced LDL‐C serum levels in M+Ator, but not in F+Ator mice (LDL‐C direct, Mean ± SEM; M+Veh 8.25 ± 0.41, M+Ator 7.12 ± 0.29, M+Veh versus M+Ator * p<0.04; F+Veh 9.25 ± 0.45, F+Ator 8.38 ± 0.56, F+Veh vs F+Ator, ns), D) did not alter total‐C or HDL‐C levels, E) elevated alkaline phosphatase levels in M+Ator but not in F+Ator mice, 5) did not alter CK serum levels, F) induced the development of gray hair only in M+Ator, and G) reduced voluntary cage activity in M+Ator and F+Ator mice, when compared to M+Veh and F+Veh. Conclusion Long‐term Ator administration reduced LDL‐C serum levels and BW in male mice but not in female mice. Although CK‐serum levels, a marker for skeletal muscle damage, were not significantly changed, voluntary cage activity was reduced in male and female Ator treated mice when compared to Veh treated controls. We suggest for the first time that long‐term Ator administration can induce a mouse‐model of statin‐induced myopathy. Support or Funding Information Veterans Medical Research Foundation Pilot Project Award: Alice Zemljic‐Harpf (PI), University of California, San Diego, ANES Research Seed Award 2019:...