The Cacalano Lab
The Cacalano lab studies the effects of aberrant signal transduction and gene regulation in tumor cells on resistance to radiotherapy, metastatic behavior, and stem-like properties in cancer. In particular, we are interested in how constitutively activated receptor tyrosine kinases and Wnt signaling promote tumor growth, spread, and resistance to therapy. Our interests also include how epigenetic silencing of kinase inhibitors such as the Suppressors of Cytokine Signaling (SOCS) dysregulates kinase activation, the function of STAT transcription factors and chemokine production, creating an immunosuppressive and tumor-promoting microenvironment. We currently apply these approaches to cancers of the brain, prostate, pancreas and lung.
Nicholas A. Cacalano, PhD
Byeong Cheol Lee, PhD, Visiting Scholar
Our Current and Past Research
Epigenetic Regulation of SOCS genes and Radiation Responses
SOCS1 and SOCS3 have been implicated as potential tumor suppressors in cancers of diverse tissues such asliver, breast, and pancreas. We determined that the SOCS1 gene was epigenetically repressed by CpG islandmethylation in human glioblastoma multiforme (GBM) whereas the SOCS3 gene was not repressed. Wedetermined that re-introduction of the SOCS1 gene sensitized GBM cell lines to ionizing radiation (IR),demonstrating that SOCS1 repression increases resistance to radiotherapy and therefore represents a selectiveadvantage to tumor cells. Further, we determined that SOCS3- deficient fibroblasts were more radiosensitive thanWT fibroblasts and that SOCS3-deficient fibroblasts failed to undergo radiation-induced G1 arrest and accumulatein the G2/M phase of the cell cycle. At the molecular level, we found that SOCS3 knockout cells phosphorylatedp53 and H2AX normally in response to radiation but failed to upregulate p21 expression, and that p21 activation andG1 arrest can be restored in SOCS3 KO cells by expression of WT SOCS3 or a dominant-negative mutant of STAT3.Our results indicate that SOCS gene expression is dysregulated in GBM and that SOCS3 plays a role in thecontrol of genome stability by controlling STAT3-mediated inhibition of radiation-induced p21 expression.
ROR1 expression and function in Organoids and primary tumor samples from prostate cancer patients: assessing the efficacy of anti-ROR1 therapeutic antibodies for cancer treatment. The ROR1 pseudokinase, which is a receptor for Wnt5a, promotes metastasis and stem-like properties via non-canonical Wnt signaling and is overexpressed in several cancers, including chronic lymphocytic leukemia (CLL), as well as prostate, lung, and pancreatic cancer. Accordingly, a novel antibody-based ROR1-targeting therapeutic, Cirmtuzumab, has been developed to treat CLL and may have potential to treat solid tumors as well. Our lab is currently interrogating the role of the ROR1 pseudokinase signaling pathway in establishing and maintaining the metastatic niche in solid tumors, identifying the major ROR1-dependent signaling pathways in cell lines and organoids derived from primary tumor samples, and examining the effect of Cirmtuzumab on tumor cell growth, migration, invasion, spheroid formation, and the expression of epithelial-to-mesenchymal (EMT) and stemness gene signatures.
SOCS3-STAT3-CXCL1-signaling axis in pancreatic ductal adenocarcinoma (PDA). The STAT3 transcription factor is often overexpressed or constitutively activated in pancreatic cancer, suggesting that STAT3-targeted therapies would be effective treatments for PDA. However, our laboratory has found that responses to STAT3 inhibitors may be more complex than previously thought. We have shown that the gene encoding suppressor of cytokine signaling (SOCS)-3, an endogenous STAT3 inhibitor, is epigenetically silenced in some PDA cell lines but not others. Re-introduction of SOCS3 into these cells resulted in STAT3 inhibition and derepression of the CXCL1 gene, which increased tumor cell aggressiveness in vivo. Our data suggest that STAT3-targeted therapies may inhibit tumor growth in some cases of PDA but promote metastasis in tumors that silence SOCS3. We are currently interrogating this pathway to determine if stratifying PDA tumors on the basis of SOCS3 gene methylation can predict responsiveness to anti-STAT3 therapies. Further, we are exploring possible mechanisms for CXCL1-driven tumor aggressiveness, such as recruitment of tumor-associated neutrophils (TANs) that can promote metastasis.
Natural Killer (NK) Cell Responses to Cancer Stem Cells
In a joint project with collaborators in the Department of Dentistry at UCLA, we have characterized distinct activation states of natural killer (NK) cells that mediate either cytotoxicity toward tumor targets or differentiation of cancer stem cells via secretion of cytokines such as interferon-gamma (IFN-g) and tumor necrosis factor (TNF). NK cells can preferentially target poorly differentiated, stem-like cells in the tumor that are known to be the source of metastasis and resistance to chemotherapy and radiation. In addition, the cytotoxic activity and cytokine production of NK cells from normal donors as well as from cancer patients could be greatly enhanced by co-culture with a combination of bacterial products and target cells. This finding has therapeutic implications, as NK cells from cancer patients are known to be greatly impaired in both cytotoxicity and cytokine secretion. Ex-vivo-activated natural killer cells have been shown to target stem-like cells from pancreatic tumors, as well as glioblastoma and head and neck cancer, suggesting that NK-based immunotherapy may be generally applicable to tumors from a variety of tissues. Further, this approach has been validated in a murine pancreatic cancer model in mice with a reconstituted human immune system. The long-term goal of this work is to re-activate autologous NK cells from cancer patients ex-vivo as a therapy to potentiate anticancer immunity by increasing cytotoxicity toward stem cells and inducing stem cell differentiation to a less aggressive phenotype that is more easily eliminated with chemotherapy and radiation.
Lee S, Mendoza TR, Burner DN, Muldong MT, Wu CCN, Arreola-Villanueva C, Zuniga A, Greenburg O, Zhu WY, Murtadha J, Koutouan E, Pineda N, Pham H, Kang SG, Kim HT, Pineda G, Lennon KM, Cacalano NA, Jamieson CHM, Kane CJ, Kulidjian AA, Gaasterland T, Jamieson CAM.(2022) Novel Dormancy Mechanism of Castration Resistance in Bone Metastatic Prostate Cancer Organoids. Int J Mol Sci. 2022 Mar 16;23(6):3203. doi: 10.3390/ijms23063203.
Lee S, Burner DN, Mendoza TR, Muldong MT, Arreola C, Wu CN, Cacalano NA, Kulidjian AA, Kane CJ, Jamieson CAM (2020) Establishment and Analysis of Three-Dimensional (3D) Organoids Derived from Patient Prostate Cancer Bone Metastasis Specimens and their Xenografts. J Vis Exp. Feb 3;(156). doi: 10.3791/60367.PMID: 32065165
Kaur K, Kozlowska AK, Topchyan P, Ko MW, Ohanian N, Chiang J, Cook J, Maung PO, Park SH, Cacalano N, Fang C, Jewett A. Probiotic-Treated Super-Charged NK Cells Efficiently Clear Poorly Differentiated Pancreatic Tumors in Hu-BLT Mice. Cancers (Basel). 2019 Dec 24;12(1):63. doi: 10.3390/cancers12010063.PMID: 31878338
Kozlowska AK, Tseng HC, Kaur K, Topchyan P, Inagaki A, Bui VT, Kasahara N, Cacalano N, Jewett A. Resistance to cytotoxicity and sustained release of interleukin-6 and interleukin-8 in the presence of decreased interferon-γ after differentiation of glioblastoma by human natural killer cells. Cancer Immunol Immunother. 2016 Sep;65(9):1085-97. doi: 10.1007/s00262-016-1866-x. Epub 2016 Jul 20.PMID: 27439500
Tseng HC, Inagaki A, Bui VT, Cacalano N, Kasahara N, Man YG, Jewett A. Differential Targeting of Stem Cells and Differentiated Glioblastomas by NK Cells. J Cancer. 2015 Jul 16;6(9):866-76. doi: 10.7150/jca.11527. eCollection 2015.PMID: 26284138
Kim MH, Kim MS, Kim W, Kang MA, Cacalano NA, Kang SB, Shin YJ, Jeong JH. (2015)
Suppressor of cytokine signaling (SOCS) genes are silenced by DNA hypermethylation and histone deacetylation and regulate response to radiotherapy in cervical cancer cells. PLoS One. 10(4):e0123133.
Sitko, J, Zhou, H, Takaesu, G, Yoshimura, A, McBride, WH, Jamieson, CAM, Jewett, A,
Cacalano, NA. (2008) SOCS3 regulates p21 expression and cell cycle arrest in response to DNA damage. Cellular Signalling 20: 2221-2230.
Zhou, H, Miki, R, Eeva, M, Fike, FM, Seligson, D, Yang, L, Yoshimura, A, Teitell, MA, Christina A.M. Jamieson, CAM, Cacalano, NA (2007) Reciprocal regulation of SOCS1 and SOCS3 enhances resistance to ionizing radiation in glioblastoma multiforme Clin. Cancer Res.13:2344-2353.
Sitko JC, Guevara CI, Cacalano NA (2004) Tyrosine-phosphorylated SOCS3 interacts with the Nck and Crk-L adapter proteins and regulates Nck activation. J Biol Chem. 2004 Sep 3;279(36):37662-9. doi: 10.1074/jbc.M404007200. Epub 2004 Jun 1.