Katja Pokrovskaja Tamm Group

Novel targeted therapies in cancer to overcome drug resistance

The aim of our research is to find novel therapeutic approaches to overcome primary and secondary resistance to anti-cancer therapy. Anti-cancer treatment often activates cellular protective mechanisms. Two of such mechanisms are induction of autophagy and activation of transcription factor STAT3. We aim at understanding the role of autophagy in drug resistance and at targeting autophagy for anti-cancer therapy using novel compounds against a lipid kinase Vps34 developed by several companies including Sprint Bioscience. In mouse studies, this compound is shown to activate chemokine secretion and to reprogram cold into hot inflamed tumors improving the anti-PD-1/PD-L1 immunotherapy. Our goal is to reveal the mechanisms behind and to develop novel combination treatments using these compounds. STAT3 activation can underlie resistance to therapy, for example to the tyrosine kinase inhibitors, and we are using novel approaches that we have developed for targeting STAT3. There is a cross-talk between autophagy and STAT3 pathway, and we explore whether simultaneous targeting of both pathways can be beneficial, in particular, in the treatment of acute leukemia (ALL). In collaboration with Mats Heyman and Anna Nilsson at KBH, we support a large sample collection of live-frozen cells purified from bone marrow and peripheral blood of pediatric patients with ALL. Our goal is to identify novel biomarkers and novel targets for therapy in specific genetic sub-groups of ALL with a focus on pre-clinical validation of targeting autophagy/lysosomal pathway and STAT3 pathway. We collaborate with Päivi Östling’s group and Rozbeh Jafari’s at SciLifeLab Solna,  Martin Enge’s group at BioClinicum and Sprint Bioscience, Huddinge.


Autophagy in anti-cancer therapy
Molecular mechanisms underlying pediatric leukemia development and treatment
STAT3 as a target in anti-cancer therapy


  • Swedish Cancer Society
    • STAT3 and autophagy as targets for therapy in pediatric acute leukemia
  • Stiftelsen för Internationellt Onkologiskt Samarbete
    • Targeting Autophagy as a therapeutic strategy in pediatric acute lymphoblastic leukemia
  • The Cancer Society in Stockholm
    •  Targeting STAT3 and autophagy in pediatric acute leukemia
  • Karolinska Institutet's research funds
    • Novel targeted therapy in acute leukemia

Group members

Katja Pokrovskaja Tamm, PI, PhD, Docent
Henri Colyn Bwanika, M.Sc., Research assistant
Asimina Talanti, M.Sc., Research assistant


Angelo de Milito, Associate Professor (docent), Director Tumor Biology and Therapeutics, Sprint Bioscience, Huddinge


Linda Vidarsdottir, PhD, University of Iceland
Yasmin Yu, Senior scientist, Sprint Bioscience, Huddinge

Selected publications

PTENP1-AS contributes to BRAF inhibitor resistance and is associated with adverse clinical outcome in stage III melanoma.
Vidarsdottir L, Azimi A, Das I, Sigvaldadottir I, Suryo Rahmanto A, Petri A, Kauppinen S, Ingvar C, Jönsson G, Olsson H, Frostvik Stolt M, Tuominen R, Sangfelt O, Pokrovskaja Tamm K, Hansson J, Grandér D, Egyházi Brage S, Johnsson P
Sci Rep 2021 May;11(1):11023

Irreversible TrxR1 inhibitors block STAT3 activity and induce cancer cell death.
Busker S, Qian W, Haraldsson M, Espinosa B, Johansson L, Attarha S, Kolosenko I, Liu J, Dagnell M, Grandér D, Arnér ESJ, Tamm KP, Page BDG
Sci Adv 2020 03;6(12):eaax7945

Silencing of CEBPB-AS1 modulates CEBPB expression and resensitizes BRAF-inhibitor resistant melanoma cells to vemurafenib.
Vidarsdottir L, Fernandes RV, Zachariadis V, Das I, Edsbäcker E, Sigvaldadottir I, Azimi A, Höiom V, Hansson J, Grandér D, Egyházi Brage S, Pokrovskaja Tamm K
Melanoma Res 2020 10;30(5):443-454

STAT3 is activated in multicellular spheroids of colon carcinoma cells and mediates expression of IRF9 and interferon stimulated genes.
Edsbäcker E, Serviss JT, Kolosenko I, Palm-Apergi C, De Milito A, Tamm KP
Sci Rep 2019 01;9(1):536

Targeting autophagy by small molecule inhibitors of vacuolar protein sorting 34 (Vps34) improves the sensitivity of breast cancer cells to Sunitinib.
Dyczynski M, Yu Y, Otrocka M, Parpal S, Braga T, Henley AB, Zazzi H, Lerner M, Wennerberg K, Viklund J, Martinsson J, Grandér D, De Milito A, Pokrovskaja Tamm K
Cancer Lett 2018 10;435():32-43

Metabolic reprogramming of acute lymphoblastic leukemia cells in response to glucocorticoid treatment.
Dyczynski M, Vesterlund M, Björklund AC, Zachariadis V, Janssen J, Gallart-Ayala H, Daskalaki E, Wheelock CE, Lehtiö J, Grandér D, Tamm KP, Nilsson R
Cell Death Dis 2018 08;9(9):846

Identification of novel small molecules that inhibit STAT3-dependent transcription and function.
Kolosenko I, Yu Y, Busker S, Dyczynski M, Liu J, Haraldsson M, Palm Apergi C, Helleday T, Tamm KP, Page BDG, Grander D
PLoS One 2017 ;12(6):e0178844

Cell crowding induces interferon regulatory factor 9, which confers resistance to chemotherapeutic drugs.
Kolosenko I, Fryknäs M, Forsberg S, Johnsson P, Cheon H, Holvey-Bates EG, Edsbäcker E, Pellegrini P, Rassoolzadeh H, Brnjic S, Larsson R, Stark GR, Grandér D, Linder S, Tamm KP, De Milito A
Int J Cancer 2015 Feb;136(4):E51-61

An activated JAK/STAT3 pathway and CD45 expression are associated with sensitivity to Hsp90 inhibitors in multiple myeloma.
Lin H, Kolosenko I, Björklund AC, Protsyuk D, Österborg A, Grandér D, Tamm KP
Exp Cell Res 2013 Mar;319(5):600-11

Glucocorticoid-induced cell death is mediated through reduced glucose metabolism in lymphoid leukemia cells.
Buentke E, Nordström A, Lin H, Björklund AC, Laane E, Harada M, Lu L, Tegnebratt T, Stone-Elander S, Heyman M, Söderhäll S, Porwit A, Ostenson CG, Shoshan M, Tamm KP, Grandér D
Blood Cancer J 2011 Jul;1(7):e31

Activation of STAT1 is required for interferon-alpha-mediated cell death.
Arulampalam V, Kolosenko I, Hjortsberg L, Björklund AC, Grandér D, Tamm KP
Exp Cell Res 2011 Jan;317(1):9-19

Cell death induced by dexamethasone in lymphoid leukemia is mediated through initiation of autophagy.
Laane E, Tamm KP, Buentke E, Ito K, Kharaziha P, Khahariza P, Oscarsson J, Corcoran M, Björklund AC, Hultenby K, Lundin J, Heyman M, Söderhäll S, Mazur J, Porwit A, Pandolfi PP, Zhivotovsky B, Panaretakis T, Grandér D
Cell Death Differ 2009 Jul;16(7):1018-29