Plenary Lecture

Plenary Lecture

Studies on a Promising Anticancer Molecule of Marine Origin. Results of an Interdisciplinary Study

Professor Carla Falugi
Universita di Genova - Dipartimento di Biologia
Laboratory of Experimental Embryology and Cytotoxicology
Viale Benedetto XV, N5 - I-16132 Genova, Italy

Abstract: Since the first 80s, we found that some tumour types present over expression of cholinesterase activities, and in particular of acetylcholinesterase (AChE, E.C: 3.1.17).
AChE is an enzyme associated to the cholinergic signal system, whose classic role is to remove acetylcholine (ACh) from the receptors. Nevertheless, the protein is also involved in cell-to-cell communication driving embryonic development, by mechanisms yet largely unknown, possibly related to the intracellular dynamics evoked by ACh signalling, and in morphogenetic cell movements, related to AChE function as a cell-substrate adhesion molecule (SAM), through the affinity for laminin. Moreover, this molecule is affected by a number of natural and synthetic inhibitors, including environmental contaminants. For this reason, the activity of AChE was found to be a good biomarker for environmental toxicity, related to the role played by ACh in inflammation.
During studies on environmental toxicants, such as organophosphate pesticides, we found that a low AChE inhibition promotes apoptosis in human cultured cells, and decreases cell movements, causing embryonic anomalies such as cardia bifida in chick embryos. Apoptosis is one of the good cell responses against tumour, and preventing cells migration is a bad feature for embryonic development, but a good feature for metastasis spreading prevention.
In particular, Non Small Cell Lung Cancer (NSCLC) biopsies and cultured cell lines present enhanced AChE activity, and possess a complete set of molecules related to cholinergic signal system, including vesicular ACh transporter, ACh biosynthetic enzyme, and receptors. Thus, our hypothesis was that down-regulation of this signalling system, in a natural-like and non-toxic way would help in enhancing anti-cancer cell features.
A natural anti-AChE complex compound, belonging to the class of polymeric alkylpyridinium salts (poly-APS), is produced by the Mediterranean sponge, Reinera sarai, to avoid infestation from other marine organisms. Poly-APS were found to be a mixture of two of 3-octylpyridinium polymers, including 29 and 99 monomeric units, and were demonstrated to exert strong AChE-inhibitory activity in vitro. Colleagues of the CNR-ISMAR demonstrated the neurotransmitter/neuromodulator role of AChE in living organisms and the non toxic and reversible activity of poly-APS. This confirmed the requested features of the compound, that was used on NSCLC cells for a preliminary battery of tests, in order to check selective apoptosis among NSCLC and healthy cells.
On exposure to low poly-APS doses, a high percentage of the cancer cells underwent apoptosis, in a significant amount vs normal lymphocytes, used as a healthy control (P<0.05). Then, a complex series of experiments was begun, both in vitro and in vivo, in cooperation with the Institute for the Study of cancer (IST), who supplied cells and operated on mice for pre-clinical experiments. In living mice, the low toxicity of poly-APS on normal cells was confirmed by injection in the caudal vein. No overt effects on health parameters, such as weight gain and physical behaviour, were observed, and histological analysis of major organs did not reveal differences between the treated animals as compared to controls. A series of synthetic homologs of poly-APS molecules were performed and tested, in order to choose the more promising substances to be used for further pre-clinical experiments. The results of this work are the object of this presentation.

Brief Biography of the Speaker:
Carla Falugi, born in Seggiano (GR) 12/10 1943, is full professor since 1999; graduated in Natural Science, the 21st November 1968, with thesis evaluation 110/110, performed didactic and research tasks since 1970 (MPI grant for didactic and scientific training up to 1972; MPI research contract up to 1976; assistant professor since 1977; professor with didactic charge of Comparative Anatomy from 1977 to 1983)
After 1983, she was teacher of Cytology and Histology; Experimental Embryology and Morphology, Developmental Biology. At present she teaches 4 courses: Developmental Biology (since 1990); Cytotoxicology; Environemntal Toxicology and Biomarkers of environmental damage.
Her research, since 1970, regards the functions of signal molecules, belonging to the cholinergic neurotransmitter system, and their receptors in regulation of cell-to-cell and cell-environment communication promoting differentiation (induction, ion flux, membrane depolarisation etc.)during early developmental stages, from fertilisation. The model mainly used for this basic study has been represented by marine invertebrates, and in particular embryonic and larval development of sea urchin up to metamorphosis and juvenile stages. This model has been found very sensitive to environment interaction. In the latest years, the interst on neurogenesis and neural functioning was carried out by the use of two human in vitro models: the NTERA2 cells (classic and well known neurogenic model) able to differentiate towards cholinergic neurons and olygodendrocyte co-culture, and preadipocyte from lipoaspirate primary cultures, appropriately differentiated towards hMADS (human Multipotent Adipose-Derived Stem cells). These two models offer a tool system to investigate cell differentiation/functioning in a manner pertinent to embryogenesis, that also retain interactions between glial cells and neurons.
Based on this experience. Since 1987 she has undergone a study on the effects of xenobiotics, able to interact in the correct reception of signal molecules, in order to establish the effects of these substances on correct embryonic development and cell differentiation and at the same time to select alternative models, to use for obtaining biomarkers of environmental state. In this context, she is member of the Italian Platform for Alternative Models (IPAM).



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