The Epel Lab
... at Hopkins Marine Station!Recently Departed....
Till Luckenbach
Some cancer cells have a remarkable ability to resist a medical treatment with cell toxic drugs. This resistance is mediated by cellular transporters that remove the chemicals and thus prevent them from accumulating in the cell and affecting it. These cellular pumps recognize a large number of chemically unrelated compounds, which is why this broad resistance is called multidrug resistance (mdr) or multixenobiotic resitance (mxr).
Mxr transporters are also found in some marine organims which help them to defend themselves against toxic agents in the environment. Due to its broad specificity mxr pumps can also recognize "new" chemicals like for instance man-made pollutants. Though this seems advantageous there may also be a downside, because pollutants can inhibit the transporter activity by overwhelming the capacity of the pumps. Consequently, the transporters do not work properly and toxic substrates can now accumulate in the cell and affect it..
The goal of my research is to investigate the potential of pollutants to increase the toxicity of other compounds by interfering with mxr transporters. I focus mainly on artificial fragrances that are used in soaps, washing detergents and so forth. In many of these products synthetic musks are used as fragrances. These chemicals can be found in aquatic environments where they are very persistent accumulate in the organisms. Though they are considered low toxic they could be harmful by compromising the cellular defense system associated with mxr and thus increase the toxicity of other chemicals.
Rebecca Vega
Todd Ciche 
Todd has accepted a post-doc position at Cal Tech and will continue his earlier work on nematodes there.
Many strains of disease-causing bacteria have become resistant to antibiotics, leading those in the medical profession to search for new sources of drugs. The marine world that may provide the pharmaceutical industry with the next generation of medicines. Seemingly simple marine creatures, such as squid, are inspiring ideas on how to design these much-needed new medicines. Recent studies have shown that female squid inoculate their eggs with a bacterial paste. Without this protective coating, the eggs likely would fall prey to fungi, bacteria and parasites during their one-month incubation exposed bare on the seafloor.
Using a new technique, Drs. Epel and Ciche have discovered about eight previously unknown kinds of bacteria in the market squid's egg sheath. Only one of the10 bacterial species was shown to produce antibacterial compounds. Based on this, the scientists hypothesize that the group of bacteria work in concert, communicating through chemical signals, to produce antibiotic and anti-fungal compounds. Thus, although most bacteria may not directly produce protective compounds, they may play a key role in signaling other bacteria to produce them.
In subsequent experiments,
Drs. Epel and Ciche have characterized the bacteria in the egg coatings
of two other species of squid --- one native to Hawaii and the other native
to the Mediterranean Sea. Remarkably, they found that these two species
have several bacteria in common with the market squid. The finding suggests
that these bacteria are involved in a common biological process and that
the bacteria and their protective function have remained unchanged during
the many millions of years it took for the different squid species to
evolve.
25+ years as Dave's assistant:
Photography
Electron microscopy
Microinjection
Web site design
Animation
Programming
Equipment fabrication
Problem solvingNow full time for the station
