The ability of a replication-deficient adenovirus vector to transfer a foreign gene into neural cells of adult rats in vivo has been analysed. A large number of neural cells (including neurons, astrocytes and ependymal cells) expressed an E. coli lacZ transgene for at least 45 days after inoculation of various brain areas. Injecting up to 3 x 10(5) pfu in 10 microliters did not result in any detectable cytopathic effects--these were only observed for very high titres of infection (> 10(7) pfu 10 microliters-1). Adenovirus vectors therefore appear to be a promising means for in vivo transfer of therapeutic genes into the central nervous system.

The deregulated expression of cyclin E as measured by the overexpression of its low molecular weight (LMW) isoforms is a powerful predictor of poor outcome in patients with breast cancer. The mechanism by which these LMW forms give tumor cells a growth advantage is not known and is the subject of this article. In this article, we provide the pathobiological mechanisms of how these LMW forms are involved in disease progression. Specifically, we show that overexpression of the LMW forms of cyclin E but not the full-length form in MCF-7 results in (a) their hyperactivity because of increased affinity for cdk2 and resistance to inhibition by the cyclin-dependent kinase inhibitors p21 and p27, (b) resistance to the growth inhibiting effects of antiestrogens, and (c) chromosomal instability. Lastly, tumors from breast cancer patients overexpressing the LMW forms of cyclin E are polyploid in nature and are resistant to endocrine therapy. Collectively, the biochemical and functional differences between the full-length and the LMW isoforms of cyclin E provide a molecular mechanism for the poor clinical outcome observed in breast cancer patients harboring tumors expressing high levels of the LMW forms of cyclin E. These properties of the LMW forms cyclin E suggest that they are not just surrogate markers of poor outcome but bona fide mediators of aggressive disease and potential therapeutic targets for patients whose tumors overexpress these forms.

Motor neuron diseases such as amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy cause progressive paralysis, often leading to premature death. Neurotrophic factors have been suggested as therapeutic agents for motor neuron diseases, but their clinical use as injected recombinant protein was limited by toxicity and/or poor bioavailability. We demonstrate here that adenovirus-mediated gene transfer of neurotrophin-3 (NT-3) can produce substantial therapeutic effects in the mouse mutant pmn (progressive motor neuronopathy). After intramuscular injection of the NT-3 adenoviral vector, pmn mice showed a 50% increase in life span, reduced loss of motor axons and improved neuromuscular function as assessed by electromyography. These results were further improved by coinjecting an adenoviral vector coding for ciliary neurotrophic factor. Therefore, adenovirus-mediated gene transfer of neurotrophic factors offers new prospects for the treatment of motor neuron diseases.

Cyclin E and its co-activator, phosphoecyclin-dependent kinase 2 (p-CDK2), regulate G 1 to S phase transition and their deregulation induces oncogenesis. Immunohistochemical assessments of these proteins in cancer have been reported but were based only on their nuclear expression. However, the oncogenic forms of cyclin E (low molecular weight cyclin E or LMW-E) in complex with CDK2 are preferentially mislocalized to the cytoplasm. Here, we used separate nuclear and cytoplasmic scoring systems for both cyclin E and p-CDK2 expression to demonstrate altered cellular accumulation of these proteins using immunohistochemical analysis. We examined the specificity of different cyclin E antibodies and evaluated their concordance between immunohistochemical and Western blot analyses in a panel of 14 breast cell lines. Nuclear versus cytoplasmic staining of cyclin E readily differentiated fulllength from LMW-E, respectively. We also evaluated the expression of cyclin E and p-CDK2 in 1676 breast carcinoma patients by immunohistochemistry. Cytoplasmic cyclin E correlated strongly with cytoplasmic p-CDK2 (P < 0.0001), high tumor grade, negative estrogen/progesterone receptor status, and human epidermal growth factor receptor 2 positivity (all P < 0.0001). In multivariable analysis, cytoplasmic cyclin E plus phosphorylated CDK2 (as one variable) predicted breast cancer recurrence-free and overall survival. These results suggest that cytoplasmic cyclin E and p-CDK2 can be readily detected with immunohistochemistry and used as clinical biomarkers for aggressive breast cancer. (Am J Pathol 2016 http://dx