BBS Faculty Member - Karen Cichowski

Karen Cichowski

Division of Genetics

Harvard Medical School
BWH Genetics, NRB Rm. 458D
77 Avenue Louis Pasteur
Boston, MA 02115
Tel: 617-525-4722
Fax: 617-525-4705
Lab Members: 7 postdoctoral fellows, 2 students, 1 research assistant

The focus of my laboratory is to elucidate how deregulated cell signaling drives cancer. To achieve this we have been taking a multi-faceted approach; combining mouse modeling techniques with basic biochemical and cell biological studies. One of the most commonly deregulated signaling pathways in human cancer is the Ras pathway. Mutations can occur in Ras itself, upstream regulators, or downstream effectors. Therefore we have been focusing on how this pathway promotes nervous system, lung, prostate, and breast cancers. We have also been using our mouse models and insight to develop novel therapies, several of which have been developed into clinical trials.

A new family of tumor suppressors:
One rapidly evolving area of research in my laboratory relates to identifying a new family of human tumor suppressors. While mutations in
RAS genes are common in many cancers, RAS mutations are conspicuously rare in breast, prostate and brain tumors, suggesting that Ras is activated via alternative mechanisms. We have recently identified several members of the RasGAP gene family, that function as human tumor and metastasis suppressors. These RasGAPs normally function to turn off Ras, therefore their inactivation results in unrestricted Ras signaling. Moreover, we have found that these proteins often serve as signaling scaffolds, integrating Ras with other important signaling pathways, thus explaining their robust tumor and metastasis suppressing activity.

Therapeutic development:
There has been significant progress in developing targeted therapies for cancers driven by mutations in genes that encode enzymes (e.g. kinases). However, developing effective therapies for cancers that are driven by mutations that do not directly affect a targetable protein represents a major challenge in cancer research. Ras-driven cancers represent an important example of this challenge. We have been taking innovative approaches to develop novel combination therapies for Ras driven tumors and have recently made important advances in developing potential therapies for nervous system malignancies and lung cancer.

Epigenetics and the Ras pathway:
The deregulation of epigenetic processes is rapidly becoming appreciated as an important regulator of cancer. We have recently discovered that the Ras pathway can be regulated by and can cooperate with epigenetic enzymes. Thus, in addition to unraveling new mechanisms that contribute to tumorigenesis, these findings reveal additional genes/proteins that represent new potential therapeutic targets.

The NF1 tumor suppressor:
NF1 was the first RasGAP gene shown to function as a human tumor suppressor. It is inactivated in a common familial cancer syndrome, affecting 1 in 3500 individuals. NF1 patients can develop numerous peripheral nervous system tumors and are also predisposed to developing brain tumors, myeloid malignancies, and cognitive deficits. However, we and others have found that the NF1 gene is also mutated in a variety of sporadic cancers, including glioblastoma. We have been focusing on understanding how this enigmatic tumor suppressor functions on a cellular level in tumors that develop in NF1 patients, and sporadic tumors, and have been exploiting this insight to develop new targeted cancer therapies.

Last Update: 8/6/2015


For a complete listing of publications click here.



Min J, Zaslavsky A, Fedele G, McLaughlin SK, Reczek EE, De Raedt T, Guney I, Strochlic DE, Beroukhim R, Bronson RT, Ryeom S, Hahn WC, Loda M, Cichowski, K. An oncogene-tumor suppressor cascade drives metastatic prostate cancer by coordinately activating Ras and NF-kB. Nature Medicine (2010) 16(3):286-94. PMCID: PMC2903662

De Raedt T, Walton Z, Lucas J, Li D, Chen Y, Maertens O, Jeong SM, Bronson RT , Normant E, Marcia C. Haigis MC, Manning BD, Wong KK, Macleod KF and
Cichowski K. Exploiting cancer cell vulnerabilities to develop a combination therapy for Ras-driven cancers Cancer Cell (2011) 20(3):400-13. PMCID: PMC3233475

Maertens O, Johnson B, Hollstein P, Frederick DT, Cooper ZA, Messiaen L, Bronson RT, McMahon M,Granter S, Flaherty K, Wargo JA, Marais R,
Cichowski K. Elucidating distinct roles for NF1 in melanomagenesis, Cancer Discov. 2013 Mar;3(3):338-49. Epub 2012 Nov 21. PMCID: PMC3595355 .

McLaughlin SK, Olsen SN, Dake B, De Raedt T, Lim E, Bronson RT, Beroukhim R, Polyak K, Brown M, Kuperwasser C,
Cichowski K. The RasGAP gene, RASAL2, is a tumor and metastasis suppressor. Cancer Cell. 2013 Sep 9;24(3):365-78. PMCID: PMC3822334.

PRC2 loss amplifies Ras-driven transcription and confers sensitivity to BRD4-based inhibitors. De Raedt T, Beert E, Pasmant E, Luscan A, Brems H, Ortonne N, Helin K, Hornick JL, Mautner V, Kehrer-Sawatzki H, Clapp W, Bradner J, Vidaud M, Upadhyaya M, Legius E,
Cichowski K. Nature. 2014 Oct 9;514(7521):247-51. Epub 2014 Aug 13. PMID: 25119042 [PubMed - indexed for MEDLINE]

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