This study provides evidence that in addition to overt necrosis, a subset of myocytes undergo apoptosis during ischemia-reperfusion injury. Apoptosis may provide a new target for cardioprotection during evolving AMI in humans.

We investigated the role of cardiomyocyte apoptosis in the remodeling of the left ventricle from 24 h to 12 wk after myocardial infarction in the rat. Infarct size planimetry, quantification of cardiomyocyte apoptosis, terminal deoxynucleotide transferase-mediated dUTP nick-end labeling (TUNEL) methodology, and echocardiography (left ventricular diastolic diameter and ejection fraction) were performed. Sham-operated animals showed low rates of cardiomyocyte apoptosis (0.03%) and no change in diastolic diameter or ejection fraction during the study. Twenty-four hours after infarction, TUNEL positivity was high in the infarct areas (1.4%) and border zones (4.9%). It declined to 0.34% (P < 0.01 vs. sham) at 4 wk and 0.10% at 12 wk in the border zones. In the remote myocardium, cardiomyocyte apoptosis increased to 0.07% (P = 0.03 vs. sham) on day 1 and remained on the same level up to 4 wk. The increase in diastolic diameter 1-4 wk after infarction correlated (r = 0.60, P < 0.01) with cardiomyocyte apoptosis in the noninfarcted myocardium, which quantitatively contributed most (>50%) to the apoptotic cell loss by 4 wk.

Purpose: A novel [68 Ga]-labeled DOTA-4-amino-1-carboxymethyl-piperidine-D-Phe-Gln-Trp-Ala-ValGly-His-Sta-Leu-NH 2 peptide (BAY86-7548) having high affinity to bombesin receptor subtype II to detect primary and metastatic prostate carcinoma using positron emission tomography/computed tomography (PET/CT) was synthesized and evaluated for prostate cancer. Experimental Design: In this first human study with BAY86-7548, 14 men scheduled for radical prostatectomy (n ¼ 11) or with biochemical recurrence after surgery or hormonal therapy (n ¼ 3) were enrolled. The patients received an intravenous injection of BAY86-7548 followed by over 60-minute dynamic imaging of prostate gland (n ¼ 10) and/or subsequent whole-body imaging (n ¼ 14). The visual assessment of PET/CT images included evaluation of intraprostatic (12 subsextants) and pelvic nodal uptake of BAY86-7548 in 11 surgical patients and detection of potential metastatic foci in all patients. In patients with biochemical recurrence, results were compared with those of eitherWe found a sensitivity, specificity, and accuracy of 88%, 81% and 83%, respectively, for detection of primary PCa and sensitivity of 70% for metastatic lymph nodes using histology as gold standard. BAY86-7548 correctly detected local recurrence in prostate bed and showed nodal relapse in accordance with

Recent studies indicate that the specificity of p38 mitogenactivated protein kinase (MAPK)-mediated cellular stress responses is determined by the expression pattern of the distinct p38 isoforms. Here, we have analysed the function of distinct p38 isoforms in the growth and invasion of head and neck squamous cell carcinomas (HNSCCs). Activation of p38 MAPK by arsenite resulted in inactivation of the ERK1,2 signaling pathway by dephosphorylation of MEK1,2 in primary human epidermal keratinocytes (HEKs), whereas in HNSCC cells this p38-mediated inhibition of the ERK1,2 pathway was absent. Quantitation of p38 pathway component mRNA expression in HNSCC cell lines (n ¼ 42) compared to HEKs (n ¼ 8) revealed that p38a and p38d isoforms are predominantly expressed in both cell types and that MKK3 is the primary upstream activator expressed. Inhibition of endogenous p38a or p38d activity by adenoviral delivery of corresponding dominant-negative p38 isoforms potently reduced MMP-13 and MMP-1 expressions, and suppressed the invasion of HNSCC cells through collagen. Dominantnegative p38a and p38d inhibited squamous cell carcinoma (SCC) cell proliferation and inhibition of p38a activity also compromised survival of SCC cells. p38a and p38d were predominantly expressed in HNSCCs (n ¼ 24) and nonneoplastic epithelium in vivo (n ¼ 6), with MKK3 being the primary upstream activator. Activation and expression of p38a and p38d by tumor cells was detected in HNSCCs in vivo (n ¼ 16). Adenoviral expression of dominantnegative p38a or p38d in cutaneous SCC cells potently inhibited their implantation in skin of severe combined immunodeficiency mice and growth of xenografts in vivo. Our results indicate that p38a and p38d specifically promote the malignant phenotype of SCC cells by regulating cell survival, proliferation and invasion, suggesting these p38 MAPK isoforms as potential therapeutic targets in HNSCCs.

Cardiomyocyte apoptosis is a consistent feature of end-stage heart failure in man and appears to be quantitatively related to the clinical severity of deterioration in dilated cardiomyopathy. Increased expression of Bcl-2 in cardiomyocytes indicates activation of an antiapoptotic response. These observations suggest that cardiomyocyte apoptosis is a clinically relevant and potentially modifiable pathophysiological phenomenon in severe heart failure.

The incidence of cutaneous squamous cell carcinoma (cSCC) is increasing globally. We have studied the expression of complement system components in cSCC. Expression profiling of cSCC cell lines (n=8) and normal human epidermal keratinocytes (n=5) with Affymetrix and quantitative real-time PCR (qPCR) revealed upregulation of complement factor H (CFH) and factor H-like protein-1 (FHL-1) in cSCC cell lines. The expression of CFH and FHL-1 mRNAs was also significantly higher in cSCC tumors (n=6) than in normal skin (n=11). Analysis of CFH and FHL-1 expression in vivo in invasive cSCCs (n=65), in situ cSCCs (n=38), and premalignant lesions (actinic keratoses, n=37) by immunohistochemistry showed that they were specifically expressed by tumor cells in cSCCs and the staining intensity was stronger in cSCCs than in in situ cSCCs and actinic keratoses. The expression of CFH by cSCC cells was upregulated by IFN-γ and the basal CFH and FHL-1 expression was dependent on extracellular signal-regulated kinase (ERK)1/2 and p38 signaling. Knockdown of CFH and FHL-1 expression inhibited proliferation and migration of cSCC cells and inhibited basal ERK1/2 activation. These results provide evidence for a role of CFH and FHL-1 in cSCC progression and identify them as progression markers and potential therapeutic targets in SCCs of skin.

f Cell migration is a fundamental biological function, critical during development and regeneration, whereas deregulated migration underlies neurological birth defects and cancer metastasis. MARCKS-like protein 1 (MARCKSL1) is widely expressed in nervous tissue, where, like Jun N-terminal protein kinase (JNK), it is required for neural tube formation, though the mechanism is unknown. Here we show that MARCKSL1 is directly phosphorylated by JNK on C-terminal residues (S120, T148, and T183). This phosphorylation enables MARCKSL1 to bundle and stabilize F-actin, increase filopodium numbers and dynamics, and retard migration in neurons. Conversely, when MARCKSL1 phosphorylation is inhibited, actin mobility increases and filopodium formation is compromised whereas lamellipodium formation is enhanced, as is cell migration. We find that MARCKSL1 mRNA is upregulated in a broad range of cancer types and that MARCKSL1 protein is strongly induced in primary prostate carcinomas. Gene knockdown in prostate cancer cells or in neurons reveals a critical role for MARCKSL1 in migration that is dependent on the phosphorylation state; phosphomimetic MARCKSL1 (MARCKSL1 S120D,T148D,T183D ) inhibits whereas dephospho-MARCKSL1 S120A,T148A,T183A induces migration. In summary, these data show that JNK phosphorylation of MARCKSL1 regulates actin homeostasis, filopodium and lamellipodium formation, and neuronal migration under physiological conditions and that, when ectopically expressed in prostate cancer cells, MARCKSL1 again determines cell movement. M ARCKS-like protein 1 (MARCKSL1) is an actin binding protein that is predominantly expressed in immature brain (1, 27). The MARCKSL1 homologue MARCKS has been more extensively studied and has been shown to bind actin with a stoichiometry of 1:2, thereby facilitating cross-linking (56; reviewed in reference 39). Binding to actin occurs via an effector domain (ED) that is 87% identical to the corresponding domain of MARCKSL1. Surprisingly, however, full-length MARCKSL1 does not cross-link F-actin (49; reviewed in reference 39), although the MARCKSL1 effector domain alone interacts with actin. This indicates that in a physiological context, another level of regulation is required for MARCKSL1 to regulate actin bundling. The only known critical function of MARCKSL1 is in early development of the nervous system, as genetic disruption of MARCKSL1 results in neural tube closure defects (5, 51), events that depend on coordinated control of actin functions, cell shape, and cell migration. MARCKSL1 is also associated with cell spreading (23); however, the mechanism whereby MARCKSL1 regulates F-actin in a cellular context has remained obscure.c-Jun N-terminal kinase 1 (JNK1) and JNK2, like MARCKSL1, are required for neural tube closure (20,36). However, the identity of the JNK effectors mediating this event remains unresolved. JNK activity is highly elevated in neuronal cells (8,42), and although initially unexpected (7,8,53), it is now accepted that a number of important physiological substrates fo...

Six monoclonal antibodies identify a 210 kDa polypeptide which shows a cell cycle specific redistribution from the nucleus to the mitotic spindle. In interphase cells this polypeptide was localized in the nucleus and behaved during differential cell extraction as a component of the nuclear matrix. It accumulated in the centrosome region at prophase, in the pole regions of the mitotic spindle at metaphase and in crescents at the poles in anaphase, and reassociated with the nuclei as they reformed in telophase. Due to its staining pattern we call the protein the Spindle Pole‐Nucleus (SPN) antigen. The localization of SPN antigen during mitosis was dependent on the integrity of the spindle since treatment of cells with nocodazole resulted in the dispersal of SPN antigen into many small foci which acted as microtubule organizing centres when the drug was removed. The SPN antigen was present in nuclei and mitotic spindles of all human and mammalian cell lines and tissues so far tested. When microinjected into the cytoplasm or nuclei of HeLa cells, one antibody caused a block in mitosis. Total cell number remained constant or decreased slightly after 24 h. At this time, about half the cells were arrested in a prometaphase‐like state and revealed aberrant spindles. Many other cells were multinucleate. These results show that the SPN antigen is a protein associated with mitotic spindle microtubules which has to function correctly for the cell to complete mitosis.