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Cancer cells increase lipid metabolism by up-regulation lipogenic enzymes such as stearoyl-CoA desaturase 1 (SCD1). It is the rate-limiting enzyme in the de novo synthesis of fatty acids (FAs), catalyzing the conversion and biosynthesis of saturated fatty acids (SFAs) into monounsaturated fatty acids (MUFAs). We developed SSI-4, a novel highly specific SCD1 inhibitor. The anti-tumor activity ofSSI-4 was examined against different cholangiocarcinoma (CCA) models that included human and mouseCCA cell lines, CCA patient-derived xenografts (PDX) NOD SCID gamma (NSG) mouse models, and CCA PDX derived organoids. Using cell proliferation assay, we examined twelve CCA cell lines and 4 were very sensitive to SSI-4 (1-40 nM IC50). The remaining CCA cell lines showed moderate to no sensitivity to SSI-4. Studies at the protein level have shown that SCD1 is present in both sensitive and non-sensitive cells. Thus, SCD1 must be present in sensitive cells but is not predictive of response to an SCD1 inhibitor. In an effort to identify biomarkers predicting response to therapy, we performed assays, such as lipid, lactate, or energy phenotype which identified elevated lactate and unsaturated fatty acid levels as well as a glycolytic energy phenotype. In vivo, CCA PDX models have demonstrated that SSI-4strongly inhibited tumor growth. Immunohistochemical analysis of CCA tumors revealed elevated glycolytic genes in sensitive cells and thus, a potential predictive biomarker. We are currently pursuing a better understanding of the relationship between glycolysis and fatty acid synthesis/metabolism. We are also testing novel combination therapy of SSI-4 with the standard of care and other drugs to develop novel treatments for CCA. Using CCA PDX derived organoids showed synergistic antitumor activity of SSI-4in combination with cancer standard of care drugs such as gemcitabine and cisplatin. Collectively, we expect to develop a biomarker-driven selection of CCA patients sensitive to SCD1 inhibitors and novel SSI-4 combination therapy leading to improved patient survival. Citation Format: Justyna J. Gleba, Laura A. Marlow, Erin E. Miller, James L. Miller, Aylin Alasonyalilar-Demirer, Yi Guo, Kabir Mody, Lewis R. Roberts, Steven R. Alberts, Mark J. Truty, Tushar C. Patel, John A. Copland. Defining stearoyl-CoA desaturase 1 as a molecular therapeutic target against cholangiocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1004.

Ovarian cancer remains a challenging disease, with an average 5 year survival rate of 46%. At time of diagnosis, over 70% of patients have advanced metastatic disease, for which there are no effective treatment options. Of patients with metastatic disease, more than 70% of patients develop peritoneal carcinomatosis, making the peritoneum one of the main areas of dissemination. We have previously found that expression of the serine protease inhibitor Kazal type 1 (SPINK1) by ovarian cancer cells drives anoikis resistance, allowing the tumor cells to circumvent apoptosis protocols and facilitating tumor cell metastasis. For this new study we focused on ovarian clear cell carcinoma (OCCC), a histotype of ovarian cancer that has particularly poor prognosis if diagnosed in late stage. Using OCCC cell lines, we found that knockdown of SPINK1 reduces cell survival and stimulates apoptotic pathways in OCCC cells, when cultured under attachment-free conditions to mimic metastatic disease. We then identified Interleukin-6 (IL-6) as an upstream regulator of SPINK1 expression and a potential therapeutic target for metastatic OCCC: we showed that IL-6 silencing reduced SPINK1 mRNA expression and cell survival, while treatment with recombinant IL-6 increased SPINK1 expression and attachment-free survival. We developed a new OCCC mouse model and showed that knockdown of SPINK1 results in significant reduction of metastatic lesions, highlighting the impact of SPINK1 on OCCC metastasis. In ongoing studies we are testing intraperitoneal injections of FDA approved IL-6 inhibitors in a preclinical model to assess impact on abdominal dissemination of tumor cells. By targeting the IL-6 – SPINK1 signaling axis, we aim to develop therapeutic approaches to reduce the metastatic burden and peritoneal carcinomatosis of late stage disease, resulting in better prognosis and survival of patients with ovarian clear cell carcinoma. Citation Format: Christine Mehner, Erin Miller, Mathew A. Coban, Alexandra Hockla, Derek C. Radisky, Evette S. Radisky. Targeting ovarian cancer induced peritoneal carcinomatosis by inhibition of signaling axis between Interleukin-6 (IL-6) and serine protease inhibitor Kazal type 1 (SPINK1) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3758.

Introduction: CD4+ and CD8+ T cells are important effector cells in the adaptive immune response against cancers. In premalignant proliferative breast tissues, the role of the immune system remains relatively undefined. In this study, we sought to investigate and quantify the presence of CD4 and CD8 expressing immune cells in benign breast tissues and their association with breast cancer risk. Method: Archived breast tissue samples from women with benign breast disease (BBD) or no clinical breast disease [Komen Tissue Bank (KTB)] were obtained for this age-matched case-control study. BBD samples included BBD cases (subsequently developed breast cancer) and BBD controls). Tissue sections were characterized for non-proliferative or proliferative disease and degree of lobular involution. CD4+ and CD8+ cell densities (cells/mm2) were obtained by digital image quantitation for up to 10 individual lobules per sample and a per-sample estimate of cell density was calculated as the median cell density across lobules within a sample. Statistical analysis was performed using Wilcoxon signed-rank and Kruskal-Wallis tests. Results: Among 267 women (median age 52, range 35-75) comprising 89 age-matched triplets, 2417 lobules were evaluated [783 KTB, 804 BBD case, 830 BBD control]. 1372 (57%) lobules were normal and 1045 (43%) were fibrocystic. CD4+ cells were present in 1903 (79%) lobules while CD8+ cells were present in 2214 (92%) lobules. CD4 and CD8 densities showed a moderate positive correlation (r = 0.39) with each other, but overall, lobules showed a lower density of CD4+ than CD8+ cells (mean difference -54 cells/mm2, 95% CI: -68 to -39 cells/mm2). At the per sample level (see Table), BBD controls showed significantly higher levels of both CD4+ (p=0.009) and CD8+ cells (p=0.0001) compared to KTB samples. In contrast, the BBD cases only showed elevated CD8 (p=0.007) and not CD4 (p=0.21) cell infiltrates compared to KTB samples. Comparing BBD cases to BBD controls, BBD cases showed significantly lower CD8 cell density as compared to BBD controls (p=0.002) and cases had lower CD4 cell density but the difference was not significant (p=0.07). Despite these differences in the cell densities, the ratio of CD4:CD8+ cells did not differ significantly across groups (p=0.83). The CD4:CD8+ ratio also did not differ significantly by histologic impression (p=0.74), degree of involution (p=0.27), or age (p=0.32). KTBBBD ControlsBBD CasesMedian (IQR)(n=89)(n=89)(n=89)CD4+ cells/mm240 (17-95)60 (25-124)49 (21-92)CD8+ cells/mm285 (49-131)157 (84-225)134 (80-168)Ratio (CD4:CD8)*0.45 (0.14-0.96)0.41 (0.15-0.81)0.40 (0.19-0.70)*Ratio is missing for n=7 samples (3 KTB, 2 BBD control, 2 BBD case) with undefined ratio due to zero CD8+ cells for all lobules in the sample. Conclusion: Our findings suggest that BBD is associated with increased infiltration of T cells into the breast tissue. Furthermore, these immune responses appear more robust in BBD patients at lower risk of developing breast cancer. Citation Format: Pena Jimenez A, Hoskin TL, Arshad MA, Visscher DW, Brahmbhatt RD, Miller EE, Stallings Mann ML, Carter JM, Murphy LM, Winham SJ, Radisky DC, Denison LA, Knutson KA, Degnim AC. CD4 and CD8 T cell densities are increased in benign breast disease compared to normal breast tissue. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-04-09.

Introduction: The role of macrophages in the tumor microenvironment is of increasing interest for tumor progression and invasion. Here we investigated the difference in CD68+ cell density in tissue samples from women with Benign Breast Disease (BBD) and women with no clinical breast disease from the Komen Tissue Bank (KTB) at Indiana University. Method: Archived breast tissue samples from women with BBD and no clinical breast disease were obtained for this age-matched case-control study. BBD samples included cases [later got Breast Cancer (BC)] and controls (did not get BC). Samples were characterized via H&E stain for epithelial proliferation [normal (N), fibrocystic non-proliferative (NP), proliferative (P), or atypia (A)]. CD68+ cell density was obtained by digital image quantitation on a per lobule basis (Total CD68+ cells/mm2). Statistical analysis was performed with mixed effects regression. Results: Among 276 women (median age 53, range 35-79) comprising 92 age-matched triplets, 2508 lobules were evaluated [789 KTB, 839 BBD case, 880 BBD control]. 1407 (56%) lobules were normal and 1101 (44%) were fibrocystic {NP [613 (56%)], P [448 (41%)] and A [40 (4%)]}. Out of 2508 lobules analyzed, 2362 (94%) had CD68+ cells, while 146 (6%) showed zero CD68+ cells [19 (2%) BBD cases, 20 (2%) BBD controls, 107 (14%) KTB, p Conclusion: CD68+ cells are more frequent in breast lobules from women with BBD compared to normal donors. This finding in premalignant breast tissues is consistent with inflammation as a driver of tumorigenesis. BBD case (n = 92 patients)BBD control (n = 92 patients)KTB(n = 92 patients)n lobulesMedian (IQR)n lobulesMedian (IQR)n lobulesMedian (IQR)Overall839313 (165 - 538)880299 (164 - 527)789136 (55 - 272)By Lobule TypeNormal344310 (177 - 557)434331 (177 - 567)629128 (55 - 255)All non-normal/fibrocystic lobules combined495314 (157 - 527)446274 (152 - 478)160159 (58 - 393)Fibrocystic non-proliferative231319 (153 - 543)263274 (140 - 496)119163 (71 - 359)Fibrocystic proliferative246295 (153 - 496)169277 (153 - 478)33128 (30 - 385)Atypia18484 (313 - 739)14260 (223 - 375)8216 (0 - 493)IQR - Interquartile range (25th percentile - 75th percentile) Citation Format: Muhammad A. Arshad, Daniel W. Visscher, Tanya L. Hoskin, Rushin D. Brahmbhatt, Alvaro Pena Jimenez, Melody L. Stallings Mann, Erin E. Miller, Linda M. Murphy, Jodi M. Carter, Stacey J. Winham, Keith L. Knutson, Derek C. Radisky, Amy C. Degnim. CD68+ immune cells show different infiltration patterns in tissue samples from women with no clinical breast disease and those who have benign breast disease. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2364. doi:10.1158/1538-7445.AM2015-2364

Introduction: Histologic characteristics of nonmalignant breast tissues (epithelial proliferation and involution) are associated with future breast cancer (BC) risk. We evaluated immune infiltration (lobulitis) in benign breast lobules and its association with features of BC risk. Methods: We analyzed archived nonmalignant breast tissue samples from 81 women in age-matched groups of varying cancer risk: 27 with benign breast disease (BBD) who later developed BC (cases), 27 with BBD without subsequent BC (controls), and 27 normal women without clinical breast disease from the Komen Tissue Bank at Indiana University (KTB). Up to 10 lobules in each sample were characterized by H&E for lobulitis, involution (none, partial, complete), and fibrocystic (FC) status (normal, nonproliferative, proliferative). Lobulitis was defined by H&E staining as lymphocyte nuclei in the intralobular stroma at low magnification and between adjacent acini at high magnification. Data was analyzed by mixed effects logistic regression. Results: Median age was 57 years (range 37-70). Among 81 breast tissue samples, 750 lobules were evaluated: 249 in BBD Cases, 265 in BBD Controls, and 236 in KTB donors. 56% of lobules were normal and 44% were FC, with 87% of FC lobules occurring in BBD samples. Lobulitis was present in 44% of lobules and varied according to subject age and individual lobule features. Younger women were more likely to have lobulitis (p=0.002); among women Conclusion: Lobulitis is common in normal and benign breast tissue lobules but varies with age, involution status, and epithelial abnormality. Further work is needed to understand the role of immune infiltrates in breast cancer risk. Citation Format: Rushin D. Brahmbhatt, Daniel W. Visscher, Tanya L. Hoskin, Derek C. Radisky, Linda M. Murphy, Melody L. Stallings Mann, Erin Miller, Vernon S. Pankratz, Lynn C. Hartmann, Marlene H. Frost, Amy C. Degnim. Immune infiltration of normal and benign breast lobules varies in breast tissues based on cancer risk. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1652. doi:10.1158/1538-7445.AM2014-1652

Most breast cancer deaths are the consequence of metastasis from the primary site. In order to metastasize, tumor cells must escape the physical barriers that contain the growing primary tumor, enter the vascular system, exit the vascular system at a distant point, and colonize a distant organ. An important mediator of metastasis is matrix metalloproteinase-9, a member of the MMP family that has been found to be upregulated both in breast cancer cells and in the surrounding tumor stroma. Studies using animal models have sometimes produced apparently contradictory findings, due in part to methodology in which MMP-9 expression is suppressed throughout the host organism and throughout the course of tumor initiation and progression. To define the specific role of tumor cell-produced MMP-9 in metastasis of human breast cancer, we implemented a bioluminescent imaging animal model of metastasis in which luciferase-expressing MDA-MB-231 cells, infected either with control nontarget lentivirus (MDA-MB-231-NT) or with shRNA lentivirus targeting MMP-9 (MDA-MB-231-MMP9-KD), were orthotopically implanted into the mammary fat pads of immunocompromised mice. Tumor growth and development of lung metastases were assessed over 10 weeks using an IVIS imager. At 11 weeks mice were sacrificed, and tumor progression was assessed by ex vivo lung imaging and by immunohistochemical processing of the tumors and the lungs. Imaging studies revealed that primary tumors developing from MMP-9 knockdown cells grew more slowly throughout the course of the study (ranging from 25% to 50%), and that while the majority of the control group developed lung metastases, none of the mice injected with MDA-MB-231-MMP9-KD cells showed metastatic progression. After sacrifice, the measured tumor weight showed a median of 99 mg for the MDA-MB-231-MMP9-KD and 158 mg for the MDA-MB-231-NT tumors, showing that knockdown of MMP-9 inhibited tumor growth. Ex vivo imaging of the lungs confirmed the in vivo studies: no metastases were detected from MDA-MB-231-MMP9-KD cells, while all lungs of the MDA-MB-231-NT injected mice had detectable metastases (p=0.0079). Similarly, a single level immunohistochemical correlate found no metastases in the MDA-MB-231-MMP9-KD mice, while 3 of 4 mice with the non-target control cells showed large metastases (median 7×103 μm2). Our results demonstrate that expression of MMP-9 by human breast cancer cells plays a significant role in the progression of tumor growth and metastasis and provide insight into the potential of MMP-9 as a target for therapeutic intervention. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1497. doi:10.1158/1538-7445.AM2011-1497

During development, epithelial cells acquire mesenchymal characteristics through a process known as epithelial-mesenchymal transition (EMT). Substantial evidence now exists that EMT-related processes play a major role in tumor progression. EMT is a focus of interest in lung cancer as loss of E-cadherin expression confers increased resistance to several types of chemotherapy. In previous studies, we found that matrix metalloproteinase-3 (MMP3) induced EMT in mouse mammary epithelial cells through induction of Rac1b, an alternatively spliced isoform of Rac1. We now show that exposure to MMPs stimulates Rac1b and induction of EMT markers in human lung cancer cell lines, and that knockdown of Rac1b blocks MMP induced EMT. We also show that Rac1b expression levels in human lung tumor biopsies is predictive of patient outcome, and that Rac1b and MMP expression levels are correlated in these samples, suggesting a direct relationship. We also describe the generation of new transgenic mouse models for which MMP3 or Rac1b is inducibly expressed in lung epithelial cells; activation of kRAS in these mice reveals that expression of MMP3 or Rac1b promotes increased tumor number, size, and progression to adenocarcinoma as well as increased expression of EMT markers vimentin, sm-actin, col1a1, and Snail. We also show that expression of Rac1b in lung epithelial cells leads to spontaneous adenocarcinoma formation. These results demonstrate a direct linkage between induction of EMT and tumor progression, implicate Rac1b as a key mediator of these processes, and demonstrate that MMPs can directly stimulate all of these events. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2318.