Alexei F. Kisselev, Ph.D.
Associate Professor of Pharmacology & Toxicology
Pharmacology & Toxicology
Moscow State University, Moscow, Russia, MS 1991
Norris Cotton Cancer Center
Pharmacology and Toxicology Graduate Program
Program in Experimental and Molecular Medicine
7936 Rubin 632, One Medical Center Drive
Norris Cotton Cancer Center
Dartmouth Medical School
Lebanon NH 03756
proteasome different active sites as drug targets especially in cancer; development of site-selective proteasome inhibitors and their use for research and therapeutic purposes; ribosome-interacting proteasome and their role in proteostasis.
My laboratory works on fundamental and translational aspects of proteasome pharmacology, biochemistry, and cell biology. Proteins in all living cells are constitutively synthesized and degraded. The 26S proteasome is a large (2.5MDa) ATP-dependent proteolytic machine, which is responsible for the majority of protein degradation in mammalian cells. The majority of its substrates are damaged and misfolded proteins. Cancer cells, especially those which produce large amounts of proteins (e.g., antibody-secreting multiple myeloma cells), generate excessive amounts of abnormal proteins resulting in a high load on proteasome in these cells and making cancer cells highly sensitive to proteasome inhibitors. Peptide boronate inhibitor of proteasome Velcade (bortezomib) is being used for the treatment of multiple myeloma and mantle cell lymphoma, and five other proteasome inhibitors are now undergoing clinical trials.
The translational aspects of our work are aimed at defining the roles of the proteasome’s different active sites as drug targets in cancer and using this information to develop a more potent proteasome inhibitor for the treatment of cancer. Each proteasome has three pairs of active sites, the chymotrypsin-like, trypsin-like, and caspase-like. Bortezomib and second-generation proteasome inhibitors were developed as inhibitors of the chymotrypsin-like sites, but most co-inhibit one or both of the other two sites. To clarify whether co-targeting of the other two sites is important for the anti-neoplastic activity of inhibitors, we developed highly specific inhibitors of all three sites and showed that specific inhibition of chymotrypsin-like sites is not sufficient to induce cytotoxicity. We also showed that co-inhibition of the caspase-like or, even better, of the trypsin-like sites is needed to induce maximal cytotoxicity in multiple myeloma cells. We further discovered that certain unique cell-permeable inhibitors of trypsin-like sites that we developed selectively sensitize multiple myeloma and breast cancer cells to bortezomib and carfilzomib (a proteasome inhibitor in phase III trials). Our goals for the next five years are to validate these finding in mice, identify molecular markers of response and develop approaches to selectively target inhibitors to tumors. Selective targeting will also allow us to achieve two important goals: (1) decrease toxicity of inhibitors and (2) increase inhibition of the proteasome to the levels needed to increase clinical response in myeloma and achieve it in solid tumors. We set the latter goal because we found that current clinically achievable levels of proteasome inhibition are cytotoxic to neither the majority of multiple myeloma cells lines nor to all solid tumor cell lines we have tested.
The site-specific inhibitors we have developed will also be excellent tools for studying the role of proteasome active sites in the physiological processes regulated by the ubiquitin-proteasome pathway (e.g., antigen presentation). We are pursuing this research in collaboration with other laboratories.
Our fundamental research on proteasome biochemistry is built upon our unexpected discovery that a fraction of proteasomes in mammalian cells associates with polysomes. We found that certain mRNAs are enriched in these complexes and that proteasomes association with polysomes increase upon heat shock. Based on these findings, we hypothesize that polysome-associated proteasomes are involved in co-translational protein degradation of specific substrates.
Rotations and Thesis Projects:
1. Proteasome inhibitors for the treatment of triple-negative breast cancers.
2. Molecular markers of tumors response to proteasome inhibitors.
3. Testing site-specific proteasome inhibitors in animal models of multiple myeloma and solid tumors.
4. Development and in vivo testing of third generation proteasome inhibitors.
5. Development of second generation of site-specific proteasome inhibitors.
6. Selective targeting of proteasome inhibitors to tumors.
7. Mechanisms of tumors resistance to proteasome inhibitors.
8. Role of different active active sites in protein breakdown by proteasomes.
9. Combining proteasome inhibitors with novel anti-neoplastic agents.
10. Regulation of proteasome inhibitor specificity by post-translational modifications of proteasomes.
11. Proteasome-ribosome supercomplexes in co-translational protein degradation.
12. Potential role of miRNA in targeting proteins for co-translational degradation.
RO1 CA124634-01A1; NCI; Kisselev (PI); 07/20/07-05/31/12
Different active sites of the proteasome as drug targets in cancer
The goal of this project is to test the hypothesis that all three active sites are drugâ€™s molecular targets in multiple myeloma, inhibition of at least two sites is required to achieve optimal cytotoxicity, the therapeutic window of proteasome inhibitors depends on which active sites they target, and the exact pathways by which proteasome inhibitors induce apoptosis in myeloma cells depends on which active sites they target.
Investigator Initiated Research Grant Susan G. Komen for the Cure
P.I.: Alexei Kisselev 05/18/10-05/17/13
Site-specific proteasome inhibitors for the treatment of triple-negative breast cancers
The goal of the project is to test the hypothesis that combining proteasome inhibitors with DNA-damaging chemotherapeutic agents that cause double-strand breaks in DNA may be especially beneficial for the treatment of triple-negative breast cancers (TNBCs), and that site-specific proteasome inhibitors will be better, less-toxic, sensitizers of TNBCs to DNA-damaging agents than are bortezomib and other inhibitors with broad active-site specificity.
Multiple Myeloma Research Foundation Senior Research Award;
P.I.: Alexei Kisselev; 03/01/11-02/28/13
Molecular mechanisms of intrinsic resistance of myeloma cells to bortezomib
The goal of this project is to determine mechanism of differential sensitivity of myeloma cells to bortezomib revealed upon clinically relevant short exposure to this agent.
PEMM101; Medical Pharmacology; PEMM131; Pharm133
Dr. Kisselev was born and grew up in Moscow, Russia. He received his Masters degree in Chemistry (with Honors) from the Moscow State University in in 1991. He received a Ph.D. his bioorganic chemistry in 1995 form the same University for research on HIV protease carried out at the Max-von-Pettenkofer Institute at the University of Munich in Germany. He moved to the USA in 1995 and did his postdoctoral work with Prof. Alfred Goldberg at Harvard Medical School where he received fellowship awards from the Medical Foundation and the Leukemia and Lymphoma Society.
Albershardt TC, Salerni BL, Soderquist RS, Bates DJ, Pletnev AA, Kisselev AF, Eastman A
Mirabella AC, Pletnev AA, Downey SL, Florea BI, Shabaneh TB, Britton M, Verdoes M, Filippov DV, Overkleeft HS, Kisselev AF
Screen M, Britton M, Downey SL, Verdoes M, Voges MJ, Blom AE, Geurink PP, Risseeuw MD, Florea BI, van der Linden WA, Pletnev AA, Overkleeft HS, Kisselev AF
Florea BI, Verdoes M, Li N, van der Linden WA, Geurink PP, van den Elst H, Hofmann T, de Ru A, van Veelen PA, Tanaka K, Sasaki K, Murata S, den Dulk H, Brouwer J, Ossendorp FA, Kisselev AF, Overkleeft HS
Verdoes M, Willems LI, van der Linden WA, Duivenvoorden BA, van der Marel GA, Florea BI, Kisselev AF, Overkleeft HS
Geurink PP, Liu N, Spaans MP, Downey SL, van den Nieuwendijk AM, van der Marel GA, Kisselev AF, Florea BI, Overkleeft HS
Britton M, Lucas MM, Downey SL, Screen M, Pletnev AA, Verdoes M, Tokhunts RA, Amir O, Goddard AL, Pelphrey PM, Wright DL, Overkleeft HS, Kisselev AF
van Swieten PF, Samuel E, Hernandez RO, van den Nieuwendijk AM, Leeuwenburgh MA, van der Marel GA, Kessler BM, Overkleeft HS, Kisselev AF
Kisselev AF, Callard A, Goldberg AL