Introduction Present State The RITA CEPA Knowledge Base Benefit Members RITA CEPA at the 1999 ESVP Meeting Sample Photo Guide: Liver Contact Links to related Web sites

Introduction

Carcinogenesis is a complex multistage process. The rate, duration and characteristics of cell replication and cell death are significant if not critical factors in the development of neoplasia, especially with regard to non-genotoxic compounds. Growth alterations caused by these substances may play a key role by enhancing the rate of mutation, increasing the survival of mutated cells, and giving mutated cells a preferential growth advantage.

Mechanistic information including cell proliferation data are requested increasingly by the regulatory authorities. However, such studies are currently performed without any regulatory guidelines and may be interpreted with little or no experience. Establishment of cell proliferation studies is a scientific and technical challenge for most companies and laboratories at the present time.

The quality of Cell Proliferation Data depends on the procedures and protocols in these labour-intensive studies. Inter-laboratory work in this area should be coordinated, so that expenditure of substantial resources will yield a cohesive data base.

Therefore, participants from 16 European companies and organizations established the RITA-associated group for Cell Proliferation and Apoptosis with the primary goal

of assisting its members to perform
cell proliferation studies, to compare
and to interpret the results according
to standardized protocols, which will
be established within the group,
and to create and operate a
data base.

Among the RITA CEPA members, experience with cell proliferation studies covers a variety of areas. Due to close cooperation and by sharing available data, the group has information on subjects for which examples are listed in the following table:

Markers:	BrdU, 3H-Thymidine, PCNA, Ki 67, AgNOR
Species:	Various strains of rats and mice
Organs/ tissues:	liver, gallbladder, kidney, urinary bladder, nasal cavity, larynx, trachea, lung, esophagus, stomach, intestine, thyroid gland, exocrine/endocrine pancreas, pituitary gland, mammary gland, skin/epidermis, testis, and tumors
Equipment:	automated immunostainer, image analysis systems
Data on compounds such as:	hormones, cytotoxic substances, immunosuppressors, peroxisome proliferators, etc.

Present State

Since February 1998, the following topics have been addressed, some are close to finalization and others are complete:

• Extensive literature searches have been performed on liver, gallbladder, endocrine and exocrine pancreas, stomach, intestine, kidney, urinary bladder, thyroid gland, adrenal gland, pituitary gland, testis, lung, trachea, larynx, nasal cavity, mammary gland and skin (rat, mouse, hamster, Guinea pig and human).
• Measurement strategies have been discussed and agreed for liver, kidney, duodenum, adrenal gland and endocrine pancreas.
• Staining protocols for BrdU are harmonized and have involved inter-company staining assessments and quality evaluations.
• Inter-company evaluations to assess stained slides (BrdU) and to compare the results (i.e., labelling indices obtained) have been conducted for liver, kidney, duodenum and lung.

While organ-specific topics are handled by working groups, the goal of the RITA CEPA members is to amalgamate all experience within the project in order to harmonize methods and procedures across organ systems as widely as possible.

For the future it is planned

• To finalize the discussions on measurement strategies for all organs.
• To continue the preparation of documents for each organ, including data derived from the literature search, proposed measurement strategies, results of the comparative evaluations, approved staining protocols, and references (see the Example for the liver).
• To enter data from control animals into a data base.
• To harmonize PCNA staining.
• To discuss measurement strategies for the evaluation of apoptosis.

The RITA CEPA Knowledge Base

In order to make the knowledge and experience, gained so far within the RITA CEPA group, available to all project members, a member Web site has been established. Present in this knowledge base is the following information:

• The harmonized staining protocol
• Results from the inter-company evaluations
• Organ-specific trimming and tissue preparation guides
• Organ-specific measurement strategies
• Organ-specific photo guides
• All results from the literature reviews
• The minutes of all meetings
• Contact addresses of all members
• And much more ...

Benefit

The standardization of techniques, overview of the current literature, quality assessments, the collection of data on control animals and later of treated animals are the focus of the RITA CEPA project. CEPA offers a broad scientific knowledge and technical advice to its members. Due to the joint initiative of experts from many companies and organizations, the project will soon provide powerful, up to date, and persuasive information on chemicals, agrochemicals and pharmaceuticals, which will be to the benefit of all members, whether they are well experienced in this area already or taking their first steps.

Contact

If you are interested in more information on the project, or if you are interested in joining, please contact:

Dr. Rupert Kellner Fraunhofer Institute of Toxicology and Experimental Medicine Department of Databases and Information Systems Nikolai-Fuchs-Str. 1 D-30625 Hannover Germany Phone: +49 (0) 511 - 535 0106 Fax:     +49 (0) 511 - 535 0155 e-mail: rupert.kellner@item.fraunhofer.de

Links to related Web sites

The following list shows some links to Web sites which are related to the current topic.

RITA: Registry of Industrial Toxicology Animal-data
Standardized Organ Sampling and Trimming Guides
Web site of the European Society of Toxicologic Pathology, ESTP: www.eurotoxpath.org
DevTox: The Developmental Toxicology Web site (www.devtox.org)