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The selection of effective therapeutic agents is critical for improving the survival of patients with renal cell carcinoma (RCC). The aim of the present study was to develop an ex vivo drug testing assay using patient-derived tumor organoid (TO) cultures. For this purpose, surgical tumor specimens were obtained from 20 patients with RCC. TOs were developed ex vivo from freshly resected RCC tumors, and their histopathological and molecular characteristics were evaluated using histological staining and whole-exome sequencing (WES). Using a cell viability assay, the therapeutic efficacy of standard of care tyrosine kinase inhibitors in RCC TOs was determined. It was found that TOs recapitulated the histological features of primary RCC tumors. Using WES, a strong concordance was identified at the genetic level between the primary tumors and their corresponding TOs. Using patient-derived TO models, a prototype of an ex vivo drug testing assay was developed, and it was found that RCC TOs exhibited differential responses to sunitinib, pazopanib, cabozantinib, axitinib and sorafenib treatment. On the whole, although the predictive value of the current assay has to be tested and validated in future clinical studies, the findings of the present study demonstrate a novel approach for ex vivo drug testing in patient-derived TO models, which may have potential for use in the personalized treatment of cancer patients.

Glycogen Synthase Kinase-3β (GSK-3β), a serine/threonine protein kinase, has been implicated as a potential therapeutic target in human cancer. The objective of the present study was to evaluate aberrant expression of GSK-3β as a potential biomarker in human breast and head and neck cancers. Nuclear/cytosolic fractionation, immunoblotting and immunohistochemical staining was used to study the expression of GSK-3β in human breast and head and neck cancer. Aberrant nuclear accumulation of GSK-3β in five human breast cancer cell lines was demonstrated and in 89/128 (70%) human breast carcinomas, whereas no detectable expression of GSK-3β was found in benign breast tissue. Nuclear GSK-3β expression was associated with HER-2 positive tumors (P=0.02) and non-triple negative breast carcinomas (P=0.0001), although nuclear GSK-3β was observed in some samples across all breast cancer subtypes. Aberrant nuclear expression of GSK-3β was found in 11/15 (73%) squamous cell head and neck carcinomas, whereas weak or no detectable expression of GSK-3β was found in benign salivary gland and other benign head and neck tissues. These results support the hypothesis that aberrant nuclear GSK-3β may represent a potential target for the clinical treatment of human breast and squamous cell carcinoma.

Glycogen synthase kinase-3β (GSK-3β), a serine/threonine protein kinase, is a complex regulator of numerous cellular functions. GSK-3β is a unique kinase which is constitutively active in resting and nonstimulated cells. GSK-3β has been implicated in a wide range of diseases including neurodegeneration, inflammation and fibrosis, noninsulin-dependent diabetes mellitus, and cancer. It is a regulator of NF-κB–mediated survival of cancer cells, which provided a rationale for the development of GSK-3 inhibitors targeting malignant tumors. Recent studies, many of them reported over the past decade, have identified GSK-3β as a potential therapeutic target in more than 15 different types of cancer. Whereas only active GSK-3β is expressed in cancer cell nucleus, aberrant nuclear accumulation of GSK-3β has been identified as a hallmark of cancer cells in malignant tumors of different origin. This review focuses on the preclinical and clinical development of GSK-3 inhibitors and the potential therapeutic impact of targeting GSK-3β in human cancer. Clin Cancer Res; 23(8); 1891–7. ©2017 AACR.

Glycogen synthase kinase-3 beta (GSK-3β), a serine/threonine kinase, has been identified as a potential therapeutic target in human bladder cancer. In the present study, we investigated the antitumor effect of a small molecule GSK-3β inhibitor, 9-ING-41, currently in clinical studies in patients with advanced cancer, in bladder cancer cell lines. We found that treatment with 9-ING-41 leads to cell cycle arrest, autophagy and apoptosis in bladder cancer cells. The autophagy inhibitor chloroquine potentiated the antitumor effects of 9-ING-41 when tested in combination studies. Our findings also demonstrate that 9-ING-41 enhanced the growth inhibitory effects of gemcitabine or cisplatin when used in combination in bladder cancer cells. Finally, we found that 9-ING-41 sensitized bladder cancer cells to the cytotoxic effects of human immune effector cells. Our results provide a rationale for the inclusion of patients with advanced bladder cancer in clinical studies of 9-ING-41.

Background: IRAK4, a serine/threonine kinase, was identified as a therapeutic target in hematological malignancies. IRAK4-mediated activation of NF-kappaB could play an important role in NF-kappaB-regulated survival and chemoresistance of cancer cells. CA-4948, a first-in-class small molecule inhibitor of IRAK4, has been tested in Phase 1 clinical trial with evidence of clinical activity in Non-Hodgkin's Lymphoma (NHL) patients. To support the development of companion diagnostic for CA-4948, we developed an immunohistochemical (IHC) assay and explored expression of potential biomarkers of response to CA-4948 in tumor biopsy samples obtained from NHL patients. Materials and Methods: IHC assay was developed and used for analysis of NF-kappaB p-p50 and p-IRAK1 expression in tumor biopsy samples obtained from 14 patients with NHL. Patients were defined according to their clinical response to CA-4948 treatment: stable disease (SD), 6 cases and progressive disease (PD), 8 cases. Results: We found nuclear and/or cytoplasmic expression of NF-kappaB p-p50 in all 6 SD cases treated with 50 mg QD (2 cases, tumor regression), 50 mg BID (1 case), 200 mg BID (1 case, tumor regression) and 400 mg BID (2 cases). Expression of NF-kappaB p-p50 was not detected in 7 of 8 cases with PD including patients treated with 50 mg QD (1 case), 100 mg QD (1 case), 100 mg BID (3 cases), 200 mg BID (1 case) and 400 mg BID (1 case). We found statistically significant correlation between expression of NF-kappaB p-p50 in tumor biopsy and SD in NHL patients treated with CA-4948 (p Conclusions: Although the cohort size is small, our findings suggest that expression of NF-kappaB p-p50 can serve as biomarker to predict SD in response to the treatment with IRAK4 inhibitor CA-4948 in NHL patients. NF-kappaB p-p50 selection strategy might be used in future clinical trials to identify NHL patients which are most likely to respond to CA-4948 in combination with chemotherapy or targeted therapeutics. Citation Format: Andrey Ugolkov, Maria Samson, Rosanna Hok, Reinhard von Roemeling, Robert Martell. Identification of NF-kappaB phospho-p50 as a predictive biomarker for IRAK4 inhibitor CA-4948 in patients with non-Hodgkin's lymphoma [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 385.

Glycogen Synthase Kinase-3β (GSK-3β), a serine/threonine protein kinase, is an emerging therapeutic target in the treatment of human breast cancer. In this study, we demonstrate that the pharmacological inhibition of GSK-3 by two novel small molecule GSK-3 inhibitors, 9-ING-41 and 9-ING-87, reduced the viability of breast cancer cells but had little effect on non-tumorigenic cell growth. Moreover, treatment with 9-ING-41 enhanced the antitumor effect of irinotecan (CPT-11) against breast cancer cells in vitro. We next established two patient-derived xenograft tumor models (BC-1 and BC-2) from metastatic pleural effusions obtained from patients with progressive, chemorefractory breast cancer and demonstrated that 9-ING-41 also potentiated the effect of the chemotherapeutic drug CPT-11 in vivo, leading to regression of established BC-1 and BC-2 tumors in mice. Our results suggest that the inhibition of GSK-3 is a promising therapeutic approach to overcome chemoresistance in human breast cancer, and identify the GSK-3 inhibitor 9-ING-41 as a candidate targeted agent for metastatic breast cancer therapy.

The histone deacetylases (HDACs) occur in 11 different isoforms, and these enzymes regulate the activity of a large number of proteins involved in cancer initiation and progression. The discovery of isoform-selective HDAC inhibitors (HDACIs) is desirable, as it is likely that such compounds would avoid some of the undesirable side effects found with the first-generation inhibitors. A series of HDACIs previously reported by us were found to display some selectivity for HDAC6 and to induce cell-cycle arrest and apoptosis in pancreatic cancer cells. In the present work, we show that structural modification of these isoxazole-based inhibitors leads to high potency and selectivity for HDAC6 over HDAC1-3 and HDAC10, while unexpectedly abolishing their ability to block cell growth. Three inhibitors with lower HDAC6 selectivity inhibit the growth of cell lines BxPC3 and L3.6pl, and they only induce apoptosis in L3.6pl cells. We conclude that HDAC6 inhibition alone is insufficient for disruption of cell growth, and that some degree of class 1 HDAC inhibition is required. Moreover, the highly selective HDAC6Is reported herein that are weakly cytotoxic may find use in cancer immune system reactivation.

Background: We have previously identified Glycogen Synthase Kinase-3 beta (GSK-3β) nuclear accumulation as a hallmark of pancreatic ductal adenocarcinoma (PDAC) and demonstrated the antitumor effects of GSK-3β tool compound inhibitors in vivo (Ougolkov, Clin Cancer Res 2006). 9-ING-41 (Actuate Therapeutics Inc), a first-in-class, small-molecule potent selective GSK-3β inhibitor, has significant preclinical antitumor activity in PDAC. 9-ING-41 is synergistic with gemcitabine (GEM) in significantly reducing PDAC cell proliferation via impairment of ATR/Chk1 DNA damage response (Ding, Clin Cancer Res 2019). These data provided the rationale for inclusion of patients with PDAC in the 1801 phase 1/2 study evaluating 9-ING-41 alone and in combination with chemotherapy, including GEM and GEM plus nab-paclitaxel. Methods: Parts 1 and 2 of the 1801 phase 1/2 study evaluate the safety and tolerability of 9-ING-41 in patients with refractory malignancies. Part 1 establishes the recommended phase 2 study dose (RP2D) for 9-ING-41 monotherapy, while Part 2 assesses 9-ING-41 in combination with chemotherapies. For Part 1, patients received twice-weekly IV infusions of 9-ING-41 (21-day cycle). Based on prior treatment, Part 2 for those with PDAC consists of 9-ING-41 plus GEM (1000 to 1250 mg/m2 days 1 and 8; 21-day cycle) or 9-ING-41 plus GEM and nab-paclitaxel (125 mg/m2). Part 3 (Simon 2-stage phase 2 at the RP2D) will assess clinical benefit in patients with refractory PDAC treated with 9-ING-41-based combinations at the RP2D established in Part 2. Response is defined by response evaluation criteria in solid tumors (RECIST) criteria in evaluable lesions. The study is opening in 25 sites globally and will accrue approximately 300 patients. Results: To date, the study has accrued 34 patients with advanced solid tumors (n=33) or hematologic malignancies (n=1). Four dose levels (1, 2, 3.3, and 5 mg/kg) have been completed without dose-limiting toxicities (DLT). Part 2 of the study evaluating combination of 9-ING-41 with chemotherapy agents has been activated. Six patients with advanced PDAC have enrolled. One patient has completed 5 cycles of treatment with 9-ING-41 (1mg/kg) with stable disease (SD) as the best response. Another patient with SD as the best response has completed 6 cycles and now is joining the arm combining 9-ING-41 with GEM after disease progression. Four additional patients are awaiting first response assessment with enrollment ongoing. 9-ING-41-attributable AE to date are Grade 1 transient visual changes (color perception). Conclusions: 9-ING-41 is well tolerated. Preclinical data support the inclusion of patients with advanced PDAC on clinical studies of 9-ING-41. Citation Format: Benedito A. Carneiro, Malika Dhawan, Brittany Borden, Ludimila Cavalcante, Howard Safran, Andrey Ugolkov, Andrew P. Mazar, Daniel D. Billadeau, Francis J. Giles, Pamela Munster. GSK-3β blockade with 9-ING-41 in pancreas cancer: The 1801 phase 1/2 study [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr B09.

Glycogen synthase kinase-3beta (GSK-3β) is a serine/threonine protein kinase that has been established as a therapeutic target in a broad spectrum of human malignancies. We have previously identified aberrant GSK-3β nuclear expression in bladder cancer (BC), and demonstrated that GSK-3β positively regulated BC cell survival and proliferation. Our objective was to evaluate the antitumor effects of the clinically viable agent 9-ING-41, a maleimide-based ATP-competitive GSK-3 inhibitor, which has broad spectrum antitumor activity and marked activity in reversing chemoresistance in a variety of pre-clinical models of human cancers. We used flow cytometry, Western immunoblotting, quantitative RT-PCR, BrDU incorporation and MTS assays to examine antitumor activity of 9-ING-41 in BC (T24, HT1376, RT4 cell lines). Additionally, we studied combination therapy of 9-ING-41 with gemcitabine and cisplatin, standard agents used for the treatment of patients with advanced BC, with cabozantinib, a multi kinase inhibitor, and with chloroquine, an autophagy inhibitor. A dose-dependent decrease in cancer cell proliferation was observed by MTS assay and BrdU incorporation assay with GI50 0.7μM (T24), 4.7 μM(HT1376), 2.2μM(RT4). Treatment with 9-ING-41 induced prominent cell cycle arrest (predominantly G2 arrest) in BC cells. Expression of cell cycle related proteins, including Cyclin D, and anti-apoptotic proteins, such as XIAP and Bcl-2, were significantly decreased as detected by Western immunoblotting and real time RT-PCR. Treatment with 9-ING-41 significantly potentiated the growth inhibitory effect of cisplatin and gemcitabine in cultured cells. In addition, combination therapy with 9-ING-41 and cabozantinib or chloroquine, significantly potentiated the effect of either single agent. Our data proved that a single treatment using 9-ING-41 is effective in BC cells. Combination treatment of 9-ING-41 with standard chemotherapeutic drugs or novel agents may provide a new therapeutic approaches in BC. These data provide a rational for the inclusion of patients with advanced BC in clinical studies of 9-ING-41. Citation Format: Hiroo Kuroki, Tsutomu Anraku, Vladimir Bilim, Masayuki Tasaki, Daniel Schmitt, Andrew Mazer, Francis J. Giles, Andrey Ugolkov, Yoshihiko Tomita. 9-ING-41, a novel inhibitor of glycogen synthase kinase-3beta (GSK-3β), is active as a single agent and within combination therapies in bladder cancer cell lines [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 4812.

Purpose: Basal-like breast tumors are typically (ER/PR/HER2) triple-negative and are associated with a high incidence of brain metastases and poor clinical outcomes. The molecular chaperone αB-crystallin is predominantly expressed in triple-negative breast cancer (TNBC) and contributes to an aggressive tumor phenotype in preclinical models. We investigated the potential role of αB-crystallin in brain metastasis in TNBCs. Experimental Design: αB-crystallin expression in primary breast carcinomas and brain metastases was analyzed by immunohistochemistry among patients with breast cancer with brain metastases. αB-crystallin was overexpressed or silenced in two different TNBC cell lines. The effects on cell adhesion to human brain microvascular endothelial cells (HBMEC) or extracellular matrix proteins, transendothelial migration, and transmigration across a HBMEC/astrocyte coculture blood–brain barrier (BBB) model were examined. In addition, the effects of overexpressing or silencing αB-crystallin on brain metastasis in vivo were investigated using orthotopic TNBC models. Results: In a cohort of women with breast cancer brain metastasis, αB-crystallin expression in primary breast carcinomas was associated with poor overall survival and poor survival after brain metastasis, even among patients with TNBC. Stable overexpression of αB-crystallin in TNBC cells enhanced adhesion to HBMECs, transendothelial migration, and BBB transmigration in vitro, whereas silencing αB-crystallin inhibited these events. αB-crystallin promoted adhesion of TNBC cells to HBMECs, at least in part, through an α3β1 integrin–dependent mechanism. αB-crystallin overexpression promoted brain metastasis, whereas silencing αB-crystallin inhibited brain metastasis in orthotopic TNBC models. Conclusion: αB-crystallin is a novel regulator of brain metastasis in TNBC and represents a potential biomarker and drug target for this aggressive disease. Clin Cancer Res; 20(1); 56–67. ©2013 AACR.

Purpose: Although recent studies have shown glycogen synthase kinase-3β (GSK-3β), a serine/threonine kinase, as a positive regulator of pancreatic, colon, and kidney cancer cell survival and proliferation, the role of GSK-3 in bladder cancer remains unknown. Our objectives were to determine the subcellular localization of GSK-3β and to evaluate the effect of GSK-3 inhibition in bladder cancer. Experimental Design: We used immunohistochemical staining and nuclear/cytosolic fractionation to determine the expression pattern of GSK-3β in human urothelial carcinomas. To study the effect of GSK-3 inhibition on bladder cancer cell proliferation and survival, we used pharmacologic inhibitors of GSK-3, RNA interference, MTS assay, bromodeoxyuridine incorporation assay, quantitative reverse transcriptase-PCR, and Western blotting. Results: We found aberrant nuclear accumulation of GSK-3β in 62% (43 of 69) and 91% (21 of 23) of noninvasive and invasive human urothelial carcinomas, respectively. GSK-3β nuclear staining was significantly associated with high-grade tumors (P < 0.001), advanced stage of bladder cancer (P < 0.05), metastasis (P < 0.05), and worse cause-specific survival (P < 0.05) in bladder cancer patients. Moreover, we found that pharmacologic inhibition or genetic depletion of GSK-3β resulted in decreased viability of bladder cancer cells. Conclusions: Our results suggest nuclear accumulation of GSK-3β as a novel prognostic marker in bladder cancer, show that GSK-3 contributes to urothelial cancer cell proliferation and survival, and identify GSK-3 as a potential therapeutic target in human bladder cancer. Clin Cancer Res; 16(21); 5124–32. ©2010 AACR.

Background: Recurrent/metastatic head and neck squamous cell carcinoma (SCCHN) and salivary gland malignancies are difficult to treat with limited standard of care options at the present time. Glycogen Synthase Kinase-3beta (GSK-3beta), a serine/threonine protein kinase, has been implicated as a potential therapeutic target in human cancer. Our in vivo studies demonstrated that our novel GSK-3 inhibitors significantly potentiated the effects of conventional chemotherapy in patient-derived xenograft models of glioblastoma and breast cancer leading to regression of tumors. In order to develop a rationale to test our novel GSK-3 inhibitors in head and neck (H&N) malignancies, we evaluated the expression pattern of GSK-3beta in human H&N benign tissue and malignant tumors. Methods: We used immunohistochemical staining of H&N tumor tissue Microarray (TMA), 48 total cases (20 benign tissues, 28 malignant), to study the expression pattern of GSK-3beta. GSK-3beta nuclear accumulation was defined as positive staining of more than 50% of cancer cell nuclei throughout the tumor regardless of cytoplasmic staining. Results: Of the 20 malignant H&N samples (15 SCCHN, 1 nasopharyngeal and 5 other histology), 13 (65%) were found to have aberrant nuclear accumulation of GSK-3beta. Amongst SCCHN, 73% (11 of 15 samples) had aberrant nuclear accumulation of GSK-3beta. In contrast, none (0%) of the 11 benign non-salivary H&N tissue showed detectable expression of GSK-3beta. Of interest, 60% of salivary adenoid cystic carcinoma specimens and 44% of benign salivary gland tissue showed GSK-3beta expression. Conclusions: Our results demonstrate for the first time, that there is aberrant nuclear expression of GSK-3beta in SCCHN. This finding supports further exploring of our novel GSK-3beta inhibitor as a potential therapeutic target for recurrent/metastatic SCCHN and also, as a potential prognostic and predictive biomarker for risk of recurrent disease and chemo- or radio-resistance. Its role in salivary gland malignancies requires further studying. Citation Format: Maria Matsangou, Andrey Ugolkov, Timothy J. Taxter, Sandeep Samant, Andrew P. Mazar, Francis J. Giles. Aberrant nuclear expression of GSK-3beta in human head and neck carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1127. doi:10.1158/1538-7445.AM2017-1127

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer death, with a 5-year overall survival rate Histopathological comparison of sections from PDX tumor, organoids, and primary PDAC from a 63-year-old female patient were performed on paraffin embedded tissue. H&E and immunohistochemical staining for cytokeratins (CK7, CK20), p53, Claudin-4, and CEA were performed. DNA and mRNA sequencing was performed. Both PDX and organoids exhibited histopathological features remarkably consistent with the original patient tumor including the histologic grade (moderately differentiated), cytological appearance (irregular nuclear membranes, open chromatin and prominent nucleoli), mitotic activity (5 -7/10 HPF), and immunohistochemical profile. The PDX and organoids demonstrated diffuse moderate-to-strong positivity for CK7, CEA, p53, and Claudin-4 and focal weak positivity for CK20 - all similar to the primary tumor. The immunohistochemical staining pattern was consistent with mRNA sequencing of the primary tumor which showed that CEA, Claudin-4 and p53 expression were ∼960-fold, ∼27-fold and ∼3 fold higher respectively (vs. benign pancreatic tissue). DNA sequencing revealed somatic mutations in KRAS and TP53 genes seen in >90% and ∼70% of PDACs respectively, and a few rare somatic mutations, such as a sodium leak channel (NALCN) mutation, seen in ∼3% of PDAC. Both PDX and organoid models of PDAC maintain key histological features, immunohistochemical profile and basic gene expression pattern akin to the primary tumor. These findings suggest that PDXs and organoids have the potential to serve as reliable pathophysiological models for optimizing individual therapy for patients with PDAC. Citation Format: Isabel Romero Calvo, Ashwin Akki, Andrey Ugolkov, Mary M. Buschmann, Samantha M. Sparrow, Teresa Barry, Margaret Eber, Tongjun Gu, Shuang Qin Zhang, Hedy Kindler, William Dale, Kevin Roggin, Andrew P. Mazar, Kevin P. White, Christopher R. Weber. Organoids and patient-derived tumor xenograft of pancreatic adenocarcinoma share morphological and genetic features with the primary tumor. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4272.

Glycogen Synthase Kinase-3beta (GSK-3beta), a serine/threonine protein kinase, has been demonstrated to be potential therapeutic target in human breast cancer. Our objective was to evaluate novel GSK-3 inhibitors alone and in combination with chemotherapeutic drugs for the targeted therapy of breast cancer. Using a short-term treatment, we found that the GSK-3 inhibitor 9ING41 significantly potentiates the antitumor effects of CPT-11, cisplatin and 5-FU to inhibit breast cancer cell growth. We established hormone-refractory BC-1 and BC-2 patient-derived xenograft (PDX) tumor models from metastatic pleural effusions that were obtained from breast cancer patients. We considered BC-1 and BC-2 PDX tumors as chemoresistant, because metastatic disease progressed in both cases in despite of the fact that patients received many cycles of chemotherapy. Although we found that BC-1 and BC-2 PDX tumors express estrogen receptor (ER), both PDX tumors carried activating mutations in ESR1. These mutations confer ligand-independent activity of the ER in tamoxifen-resistant breast tumors. We found that BC-1 and BC-2 PDX tumors grew without estradiol supplementation in immunodeficient mice, which suggests a hormone-refractory nature of these tumors. We found that GSK-3 inhibitor 9ING41 potentiates the effects of chemotherapeutic drug CPT-11, and leads to the regression of BC-1 and BC-2 breast PDX tumors. Our results demonstrate inhibition of GSK-3 as a promising therapeutic approach to overcome breast cancer chemoresistance, and identify GSK-3 inhibitor 9ING41 as a drug candidate for the targeted therapy of human breast cancer. Citation Format: Andrey Ugolkov, Irina Gaisina, Kevin White, Alan Kozikowski, Thomas O’Halloran, Andrew Mazar. GSK-3 inhibitor 9ING41 potentiates the antitumor effects of CPT-11 in human breast cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3078.

Neuroblastoma is a devastating pediatric cancer and most patients older than 18 months present with multi-organ metastatic disease. High grade or recurrent disease is refractory to treatment with chemotherapy and almost uniformly fatal. Because GSK-3beta has been shown to be a positive regulator of NF-kappaB-mediated survival and chemoresistance in cancer cells, we hypothesize that the inhibition of GSK-3 may have potential therapeutic effects in neuroblastoma. To test this premise we used small molecule inhibitors, Western blotting, apoptotic and MTS assays to study the effect(s) of GSK-3 inactivation in neuroblastoma cell lines SK-N-DZ and SK-N-BE(2). Using chemically distinct GSK-3 inhibitors (AR-A014418, TDZD8 and 9-ING-41), we found that pharmacological inhibition of GSK-3 led to a decrease in proliferation and survival of neuroblastoma cells. We observed that inhibition of GSK-3 results in decreased expression of the anti-apoptotic molecules Bcl-XL and XIAP (NF-kappaB target genes) and a subsequent increase in neuroblastoma cell apoptosis. Moreover, we show that our novel GSK-3 inhibitor 9-ING-41 enhances the antitumor effects of irinotecan in neuroblastoma cells. Our results demonstrate that GSK-3 positively regulates neuroblastoma cell survival and proliferation and suggest that the inhibition of GSK-3 is a promising new approach for the treatment of neuroblastoma. Citation Format: Oleksii Dubrovskyi, Andrey Ugolkov, Irina Gaisina, Gennadiy Bondarenko, Luigi Strizzi, Naira Margaryan, Thomas O'Halloran, Alan Kozikowski, Mary Hendrix, Andrew Mazar. Targeting GSK-3: a new approach for the treatment of neuroblastoma. [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 3287. doi:10.1158/1538-7445.AM2015-3287

Patient-derived xenograft (PDX) tumor models have emerged as new and effective models for developing novel anticancer therapies and personalized use of chemotherapeutic drugs. The PDX approach is based on the transplantation of primary or metastatic human tumors into highly immunodeficient NOD scid gamma (NSG) mice followed by continuous propagation of the established engrafment in mice. Clinicians can evaluate the effects of cancer drugs on their patients’ personalized tumor grafts enabling them to select the best treatment for the cancer patient. Here, we report that PDX tumors engrafted in NSG mice are susceptible to formation of B-cell lymphomas. We xenografted primary or metastatic human tumor fragments into NSG mice and found that tumors generated from patients’ samples of breast (1 out 3 cases), colon (2 out of 6 cases), pancreatic (1 out of 3 cases), bladder (1 out of 2 cases) and renal (1 out of 2 cases) cancer were histologically similar to lymphoid neoplasm. Moreover, we found that the first passage (F1) of some breast and pancreatic cancer PDX tumors could grow as a lymphoid neoplasm in one mouse and as an adenocarcinoma in another mouse after initial transplantation of the pieces from the same human tumor graft (F0). Whereas subcutaneous PDX tumors resembling primary human carcinoma histology were slow growing and non-metastatic, we found that subcutaneous PDX lymphoid neoplasms were fast growing and formed large metastatic lesions in lymph nodes, liver, lungs and spleen of the mouse. Immunohistochemical staining confirmed that lymphoma cells express human leucocyte common antigen CD45 and B-cell antigen CD19/20. By using Epstein-Barr Virus-encoded RNA (EBER) in situ hybridization, we found that PDX lymphoma cells were EBER-positive. Because B-cells are typically present in any solid malignant tumor, B-cell PDX lymphomas may evolve in a wide range of PDX tumor models. Our results suggest that histolopathological evaluation and lymphoid marker testing should be performed as part of the initial model characterization in order to exclude B-cell lymphomas during the development of PDX tumor model from solid human carcinoma. Citation Format: Gennadiy Bondarenko, Andrey Ugolkov, Piotr Kulesza, Stephen M. Rohan, Oleksii Dubrovskyi, Demirkan Gursel, Jeremy V. Mathews, Thomas V. O'Halloran, Jian-Jun Wei, Andrew P. Mazar. Patient-derived tumor xenograft are susceptible to formation of B-cell lymphoma after initial transplantation of human carcinoma to immunodeficient mice. [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 1464. doi:10.1158/1538-7445.AM2015-1464

Glioblastoma (GBM) is, in essence, an incurable cancer, with most patients surviving 12-15 months following initial diagnosis. Previously published studies identified Glycogen Synthase Kinase-3 (GSK-3) as a new therapeutic target in GBM. Because GSK-3beta is a positive regulator of NF-kappaB-mediated survival and chemoresistance in cancer cells, we hypothesize that the inhibition of GSK-3 may overcome NF-kappaB-mediated chemoresistance to conventional drugs in human GBM. Using IVIS imaging of live mice, we found that: 1) NF-kappaB is constitutively active in orthotopic GBM patient-derived xenograft (PDX) tumors expressing an NF-kappa luciferase reporter; and 2) a single intravenous injection of our novel GSK-3 inhibitor 9-ING-41 (25 mg/kg) significantly reduced NF-kappaB transcriptional activity in orthotopic GBM PDX. Using 3 different orthotopic GBM PDX- tumor models, enabled for bioluminescence imaging through luciferase modification, we evaluated antitumor effects of 9-ING-41, alone as well as in combination with irinotecan, CCNU and temozolomide. Our in vivo results revealed that treatment with a combination of 9-ING-41 and irinotecan delays GBM PDX tumor growth, relative to either agent as a monotherapy, and, even more promising, 9-ING-41+CCNU leads to a complete tumor regression. Histological evaluation of mouse brain confirmed the absence of cancer cells and a formation of cyst at the location of intracranial tumor in mice treated with 9-ING-41+CCNU. Our results provide a rationale to advance 9-ING-41 for clinical evaluation in treating GBM, especially when combined with CCNU cytotoxic therapy. Citation Format: Andrey Ugolkov, Oleksii Dubrovskyi, Irina Gaisina, Alex Yemelyanov, Gennadiy Bondarenko, Charles James, James Chandler, Thomas O'Halloran, Alan Kozikowski, Jeffry Raizer, Andrew Mazar. Targeting GSK-3: a novel approach to enhance glioblastoma chemosensitivity. [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 2699. doi:10.1158/1538-7445.AM2015-2699

NF-kappaB is known to regulate human breast cancer progression, metastasis and chemoresistance. Glycogen Synthase Kinase-3beta (GSK-3beta), a serine/threonine protein kinase, is an essential positive regulator of NF-kappaB transcriptional activity and thereby GSK-3beta may represent a potential therapeutic target in human breast cancer. Our objectives were to determine the expression pattern of GSK-3beta in human breast cancer, to assess the effect of GSK-3 inhibition on breast cancer cell proliferation, survival and chemoresistance, and to evaluate our lead GSK-3 inhibitors alone and in combination with chemotherapeutic drugs for the targeted therapy of breast cancer. Using nuclear/cytosolic fractionation, Western immunoblotting and immunohistochemical staining, we observed aberrant nuclear accumulation of GSK-3beta in five breast cancer cell lines and in 7 of 8 primary human breast carcinomas and corresponding lymph node metastases whereas no detectable expression of GSK-3beta was found in benign breast tissue. Pharmacological inhibition of GSK-3 led to a decrease in proliferation and survival of breast cancer cells. Our in vitro comparison studies demonstrated that our lead GSK-3 inhibitor 9-ING-41 was significantly (30 times) more effective than GSK-3 inhibitor LY2090314 (Eli Lilly), currently in mid-stage clinical trials, in terms of growth inhibition of breast cancer cells. Inhibition of GSK-3 resulted in decreased expression of the NF-kappaB target genes Bcl-2 and XIAP and induction of apoptosis. Moreover, our lead GSK-3 inhibitor 9-ING-41 and doxorubicin acted synergistically to suppress growth of breast cancer cells. Our preliminary in vivo experiments demonstrated that monotherapy with our lead GSK-3 inhibitor 9-ING-41 (20 mg/kg) for 48 hours inhibited proliferation (as shown by BrDU assay) and induced apoptosis (as shown by TUNEL assay) in MDA-MB-468 orthotopic xenograft tumors. Moreover, in vivo toxicology study demonstrated that intravenous injections of 9-ING-41 did not adversely affect mouse complete blood counts or cause overt pathological changes in mouse organs. Our results identify GSK-3beta as a new potential drug target in breast cancer and suggest that inhibition of GSK-3 is a novel therapeutic approach to overcome NF-kappaB-mediated chemoresistance in breast cancer. Citation Format: Andrey Ugolkov, Irina Gaisina, Dmitry Malin, Peter Kulesza, Alan Kozikowski, Vincent Cryns, Andrew Mazar. Inhibition of GSK-3: A novel therapeutic approach for breast cancer treatment. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr B068.

The urokinase plasminogen activator receptor (uPAR) has been implicated in the progression of metastatic disease in a number of different solid tumor types including breast cancer. We have developed a therapeutic monoclonal antibody, ATN-658, that targets uPAR in a novel manner. ATN-658 does not inhibit the binding of uPA to uPAR but appears to have pleiotropic effects on other uPAR interactions including those with various integrins. In the present study, we utilized 231LM2-4H2N, a novel highly metastatic variant of the triple negative breast cancer cell line cell line, MDA-MB-231, to evaluate the effect of ATN-658 on metastasis. This variant has been transfected to also express HER2 and metastases in this model are resistant to targeted treatments such as trastuzumab and sunitinib. Orthotopic 231LM2-4H2N xenograft tumor spontaneously metastasizes to lung and liver and forms large macroscopic metastases that lead to death. We transfected 231LM2-4H2N cells with dTomato and Luc2 to allow for real time assessment of metastatic progression using IVIS imaging. Primary orthotopic tumors were staged to 500 mm3, at which time they were resected and the mice followed using bioluminescence to detect metastases, which typically appear in the lungs within 2-3 weeks post-resection. Mice were randomized once lung metastases were visible and treatment was initiated using vehicle control, lapatanib (30 mg/kg QD), ATN-658 (10 mg/kg Q3D) or the combination of lapatanib and ATN-658. Growth of metastases was estimated using average radiance measurements. ATN-658 inhibited metastatic progression by ∼90% and doubled median survival compared to the vehicle control in this study. Lapatanib had no effect on the size of the metastases or survival and the combination of ATN-658+lapatanib inhibited metastatic progression and survival to the same extent as ATN-658 monotherapy. The activation of ERK was significantly inhibited by ATN-658 in vivo although this alone was insufficient to inhibit tumor growth since lapatanib also inhibited ERK to the same extent suggesting the other effects were being mediated by ATN-658. The effect of ATN-658 monotherapy on metastatic tumor growth was much greater in the 231LM2-4H2N model than in the parental MDA-MB-231 model. In order to probe the reason for this difference in effect, we analyzed the expression of uPAR in the various MDA-MB-231 variants. uPAR expression was significantly upregulated in HER2-transfected MDA-MB-231 breast cancer cells suggesting that the level of uPAR expression may dictate the degree of response to ATN-658. If this hypothesis can be validated, this would provide a patient enrichment strategy for the humanized version of ATN-658, huATN-658, which is getting ready to go into the clinic. Citation Format: Irawati Kandela, Andrey Ugolkov, Giulio Francia, Shafaat Rabbani, Robert S. Kerbel, Andrew P. Mazar. Inhibition of breast cancer metastaticprogression by a novel uPAR targeted monoclonal antibody, ATN-658, correlateswith the uPAR expression. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 863. doi:10.1158/1538-7445.AM2013-863

Patient-derived xenograft (PDX) tumor models have emerged as a new approach to evaluate the effects of cancer drugs on patients’ personalized tumor grafts enabling to select the best treatment for the cancer patient and providing a new tool for oncology drug developers. Here, we report that human tumors engrafted in immunodeficient mice are susceptible to formation of B-and T-cell PDX tumors. We xenografted human primary and metastatic tumor samples into immunodeficient mice and found that a fraction of PDX tumors generated from patients’ samples of breast, colon, pancreatic, bladder and renal cancer were histologically similar to lymphocytic neoplasms. Moreover, we found that the first passage of breast and pancreatic cancer PDX tumors after initial transplantation of the tumor pieces from the same human tumor graft could grow as a lymphocytic tumor in one mouse and as an adenocarcinoma in another mouse. Whereas subcutaneous PDX tumors resembling human adenocarcinoma histology were slow growing and non-metastatic, we found that subcutaneous PDX lymphocytic tumors were fast growing and formed large metastatic lesions in mouse lymph nodes, liver, lungs, and spleen. PDX lymphocytic tumors were comprised of B-cells which were Epstein-Barr virus positive and expressed CD45 and CD20. Because B-cells are typically present in malignant solid tumors, formation of B-cell tumor may evolve in a wide range of PDX tumor models. Although PDX tumor models show great promise in the development of personalized therapy for cancer patients, our results suggest that confidence in any given PDX tumor model requires careful screening of lymphocytic markers.