scholarly journals Promising potential of [177Lu]Lu-DOTA-folate to enhance tumor response to immunotherapy—a preclinical study using a syngeneic breast cancer model

Author(s):  
Patrycja Guzik ◽  
Klaudia Siwowska ◽  
Hsin-Yu Fang ◽  
Susan Cohrs ◽  
Peter Bernhardt ◽  
...  

Abstract Purpose It was previously demonstrated that radiation effects can enhance the therapy outcome of immune checkpoint inhibitors. In this study, a syngeneic breast tumor mouse model was used to investigate the effect of [177Lu]Lu-DOTA-folate as an immune stimulus to enhance anti-CTLA-4 immunotherapy. Methods In vitro and in vivo studies were performed to characterize NF9006 breast tumor cells with regard to folate receptor (FR) expression and the possibility of tumor targeting using [177Lu]Lu-DOTA-folate. A preclinical therapy study was performed over 70 days with NF9006 tumor-bearing mice that received vehicle only (group A); [177Lu]Lu-DOTA-folate (5 MBq; 3.5 Gy absorbed tumor dose; group B); anti-CTLA-4 antibody (3 × 200 μg; group C), or both agents (group D). The mice were monitored regarding tumor growth over time and signs indicating adverse events of the treatment. Results [177Lu]Lu-DOTA-folate bound specifically to NF9006 tumor cells and tissue in vitro and accumulated in NF9006 tumors in vivo. The treatment with [177Lu]Lu-DOTA-folate or an anti-CTLA-4 antibody had only a minor effect on NF9006 tumor growth and did not substantially increase the median survival time of mice (23 day and 19 days, respectively) as compared with untreated controls (12 days). [177Lu]Lu-DOTA-folate sensitized, however, the tumors to anti-CTLA-4 immunotherapy, which became obvious by reduced tumor growth and, hence, a significantly improved median survival time of mice (> 70 days). No obvious signs of adverse effects were observed in treated mice as compared with untreated controls. Conclusion Application of [177Lu]Lu-DOTA-folate had a positive effect on the therapy outcome of anti-CTLA-4 immunotherapy. The results of this study may open new perspectives for future clinical translation of folate radioconjugates.

2019 ◽  
Vol 2 (4) ◽  
pp. 83-98 ◽  
Author(s):  
André De Lima Mota ◽  
Bruna Vitorasso Jardim-Perassi ◽  
Tialfi Bergamin De Castro ◽  
Jucimara Colombo ◽  
Nathália Martins Sonehara ◽  
...  

Breast cancer is the most common cancer among women and has a high mortality rate. Adverse conditions in the tumor microenvironment, such as hypoxia and acidosis, may exert selective pressure on the tumor, selecting subpopulations of tumor cells with advantages for survival in this environment. In this context, therapeutic agents that can modify these conditions, and consequently the intratumoral heterogeneity need to be explored. Melatonin, in addition to its physiological effects, exhibits important anti-tumor actions which may associate with modification of hypoxia and Warburg effect. In this study, we have evaluated the action of melatonin on tumor growth and tumor metabolism by different markers of hypoxia and glucose metabolism (HIF-1α, glucose transporters GLUT1 and GLUT3 and carbonic anhydrases CA-IX and CA-XII) in triple negative breast cancer model. In an in vitro study, gene and protein expressions of these markers were evaluated by quantitative real-time PCR and immunocytochemistry, respectively. The effects of melatonin were also tested in a MDA-MB-231 xenograft animal model. Results showed that melatonin treatment reduced the viability of MDA-MB-231 cells and tumor growth in Balb/c nude mice (p <0.05). The treatment significantly decreased HIF-1α gene and protein expression concomitantly with the expression of GLUT1, GLUT3, CA-IX and CA-XII (p <0.05). These results strongly suggest that melatonin down-regulates HIF-1α expression and regulates glucose metabolism in breast tumor cells, therefore, controlling hypoxia and tumor progression. 


2019 ◽  
Vol 65 (5) ◽  
pp. 760-765
Author(s):  
Margarita Tyndyk ◽  
Irina Popovich ◽  
A. Malek ◽  
R. Samsonov ◽  
N. Germanov ◽  
...  

The paper presents the results of the research on the antitumor activity of a new drug - atomic clusters of silver (ACS), the colloidal solution of nanostructured silver bisilicate Ag6Si2O7 with particles size of 1-2 nm in deionized water. In vitro studies to evaluate the effect of various ACS concentrations in human tumor cells cultures (breast cancer, colon carcinoma and prostate cancer) were conducted. The highest antitumor activity of ACS was observed in dilutions from 2.7 mg/l to 5.1 mg/l, resulting in the death of tumor cells in all studied cell cultures. In vivo experiments on transplanted Ehrlich carcinoma model in mice consuming 0.75 mg/kg ACS with drinking water revealed significant inhibition of tumor growth since the 14th day of experiment (maximally by 52% on the 28th day, p < 0.05) in comparison with control. Subcutaneous injections of 2.5 mg/kg ACS inhibited Ehrlich's tumor growth on the 7th and 10th days of the experiment (p < 0.05) as compared to control.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1844-1844
Author(s):  
John Richards ◽  
Myriam N Bouchlaka ◽  
Robyn J Puro ◽  
Ben J Capoccia ◽  
Ronald R Hiebsch ◽  
...  

AO-176 is a highly differentiated, humanized anti-CD47 IgG2 antibody that is unique among agents in this class of checkpoint inhibitors. AO-176 works by blocking the "don't eat me" signal, the standard mechanism of anti-CD47 antibodies, but also by directly killing tumor cells. Importantly, AO-176 binds preferentially to tumor cells, compared to normal cells, and binds even more potently to tumors in their acidic microenvironment (low pH). Hematological neoplasms are the fourth most frequently diagnosed cancers in both men and women and account for approximately 10% of all cancers. Here we describe AO-176, a highly differentiated anti-CD47 antibody that potently targets hematologic cancers in vitro and in vivo. As a single agent, AO-176 not only promotes phagocytosis (15-45%, EC50 = 0.33-4.1 µg/ml) of hematologic tumor cell lines (acute myeloid leukemia, non-Hodgkin's lymphoma, multiple myeloma, and T cell leukemia) but also directly targets and kills tumor cells (18-46% Annexin V positivity, EC50 = 0.63-10 µg/ml) in a non-ADCC manner. In combination with agents targeting CD20 (rituximab) or CD38 (daratumumab), AO-176 mediates enhanced phagocytosis of lymphoma and multiple myeloma cell lines, respectively. In vivo, AO-176 mediates potent monotherapy tumor growth inhibition of hematologic tumors including Raji B cell lymphoma and RPMI-8226 multiple myeloma xenograft models in a dose-dependent manner. Concomitant with tumor growth inhibition, immune cell infiltrates were observed with elevated numbers of macrophage and dendritic cells, along with increased pro-inflammatory cytokine levels in AO-176 treated animals. When combined with bortezomib, AO-176 was able to elicit complete tumor regression (100% CR in 10/10 animals treated with either 10 or 25 mg/kg AO-176 + 1 mg/kg bortezomib) with no detectable tumor out to 100 days at study termination. Overall survival was also greatly improved following combination therapy compared to animals treated with bortezomib or AO-176 alone. These data show that AO-176 exhibits promising monotherapy and combination therapy activity, both in vitro and in vivo, against hematologic cancers. These findings also add to the previously reported anti-tumor efficacy exhibited by AO-176 in solid tumor xenografts representing ovarian, gastric and breast cancer. With AO-176's highly differentiated MOA and binding characteristics, it may have the potential to improve upon the safety and efficacy profiles relative to other agents in this class. AO-176 is currently being evaluated in a Phase 1 clinical trial (NCT03834948) for the treatment of patients with select solid tumors. Disclosures Richards: Arch Oncology Inc.: Employment, Equity Ownership, Other: Salary. Bouchlaka:Arch Oncology Inc.: Consultancy, Equity Ownership. Puro:Arch Oncology Inc.: Employment, Equity Ownership. Capoccia:Arch Oncology Inc.: Employment, Equity Ownership. Hiebsch:Arch Oncology Inc.: Employment, Equity Ownership. Donio:Arch Oncology Inc.: Employment, Equity Ownership. Wilson:Arch Oncology Inc.: Employment, Equity Ownership. Chakraborty:Arch Oncology Inc.: Employment, Equity Ownership. Sung:Arch Oncology Inc.: Employment, Equity Ownership. Pereira:Arch Oncology Inc.: Employment, Equity Ownership.


Blood ◽  
1962 ◽  
Vol 20 (4) ◽  
pp. 432-442 ◽  
Author(s):  
ROBERT SCHREK ◽  
STANLEY L. LEITHOLD ◽  
IRVING A. FRIEDMAN ◽  
WILLIAM R. BEST

Abstract A recently developed slide-chamber method was used to test the radiosensitivity of blood lymphocytes from 80 patients with chronic lymphocytic or lymphosarcoma-cell leukemia. The objective of this study was to determine whether these in vitro tests on sensitivity to x-rays had any clinical significance. Two objective criteria were used to measure the clinical reactions of the leukemic patients. The first was the duration of survival of patients following the in vitro test. The second was the minimal leukocyte count of a patient following x-ray therapy; the minimal count was expressed as a percentage of the count before therapy. The in vitro radiosensitivity was measured by the 10 per cent survival time of lymphocytes irradiated with 1000 r. Blood lymphocytes from non-leukemic individuals were highly radiosensitive with indices of 1.1 to 2.2 days. In initial tests, the lymphocytes of 61 leukemic patients had the same high sensitivity to x-rays as lymphocytes from non-leukemic individuals. In contrast, the lymphocytes of 19 leukemic patients were radioresistant to irradiation with indices of 2.5 to 11 days. The 61 patients with radiosensitive lymphocytes had a median survival time of 22 months after the in vitro test. In contrast, the 19 patients with radioresistant lymphocytes had a median survival time of only 4 months. Clinical x-ray therapy caused a greater decline in leukocyte counts in patients with radiosensitive lymphocytes than in those with radioresistant cells. A significant index of 0.60 was obtained for the correlation of in vitro radiosensitivity of lymphocytes and the in vivo decrease in leukocyte counts of patients after x-ray therapy. It is concluded that an in vitro finding of radioresistant lymphocytes is correlated with a poor response of the leukocyte count to x-ray therapy and a short survival time of the patient.


BMC Cancer ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Ethan P. Metz ◽  
Erin L. Wuebben ◽  
Phillip J. Wilder ◽  
Jesse L. Cox ◽  
Kaustubh Datta ◽  
...  

Abstract Background Quiescent tumor cells pose a major clinical challenge due to their ability to resist conventional chemotherapies and to drive tumor recurrence. Understanding the molecular mechanisms that promote quiescence of tumor cells could help identify therapies to eliminate these cells. Significantly, recent studies have determined that the function of SOX2 in cancer cells is highly dose dependent. Specifically, SOX2 levels in tumor cells are optimized to promote tumor growth: knocking down or elevating SOX2 inhibits proliferation. Furthermore, recent studies have shown that quiescent tumor cells express higher levels of SOX2 compared to adjacent proliferating cells. Currently, the mechanisms through which elevated levels of SOX2 restrict tumor cell proliferation have not been characterized. Methods To understand how elevated levels of SOX2 restrict the proliferation of tumor cells, we engineered diverse types of tumor cells for inducible overexpression of SOX2. Using these cells, we examined the effects of elevating SOX2 on their proliferation, both in vitro and in vivo. In addition, we examined how elevating SOX2 influences their expression of cyclins, cyclin-dependent kinases (CDKs), and p27Kip1. Results Elevating SOX2 in diverse tumor cell types led to growth inhibition in vitro. Significantly, elevating SOX2 in vivo in pancreatic ductal adenocarcinoma, medulloblastoma, and prostate cancer cells induced a reversible state of tumor growth arrest. In all three tumor types, elevation of SOX2 in vivo quickly halted tumor growth. Remarkably, tumor growth resumed rapidly when SOX2 returned to endogenous levels. We also determined that elevation of SOX2 in six tumor cell lines decreased the levels of cyclins and CDKs that control each phase of the cell cycle, while upregulating p27Kip1. Conclusions Our findings indicate that elevating SOX2 above endogenous levels in a diverse set of tumor cell types leads to growth inhibition both in vitro and in vivo. Moreover, our findings indicate that SOX2 can function as a master regulator by controlling the expression of a broad spectrum of cell cycle machinery. Importantly, our SOX2-inducible tumor studies provide a novel model system for investigating the molecular mechanisms by which elevated levels of SOX2 restrict cell proliferation and tumor growth.


Blood ◽  
1990 ◽  
Vol 75 (3) ◽  
pp. 638-645 ◽  
Author(s):  
FM Uckun ◽  
L Souza ◽  
KG Waddick ◽  
M Wick ◽  
CW Song

Abstract The purpose of this study was to investigate the in vivo radioprotective effects of recombinant human granulocyte colony stimulating factor (rhG-CSF) in lethally irradiated BALB/c mice. We initially analyzed the effects of increasing doses of rhG-CSF on survival of mice receiving 700 cGy (LD100/30) single dose total body irradiation (TBI). While 1 microgram/kg to 100 micrograms/kg doses of rhG-CSF were not radioprotective, a dose-dependent radioprotection was observed at 200 micrograms/kg to 4,000 micrograms/kg rhG-CSF. We next compared four different rhG-CSF treatment regimens side by side for their radioprotective effects in LD100/30 irradiated mice. One hundred percent of control mice receiving phosphate buffered saline died within 21 days after TBI with a median survival of 14 days. The median survival was prolonged to 20 days and the actuarial 60-day survival rate was increased to 27% when mice received 2,000 micrograms/kg rhG- CSF 24 hours before TBI (P = .0002; Mantel-Peto-Cox). Similarly, the median survival time was prolonged to 24 days and the actuarial 60-day survival rate was increased to 33%, when mice were given 2,000 micrograms/kg rhG-CSF 30 minutes before TBI. Optimal radioprotection was achieved when 2,000 micrograms/kg rhG-CSF was administered in two divided doses of 1,000 micrograms/kg given 24 hours before and 1,000 micrograms/kg given 30 minutes before TBI. This regimen prolonged the median survival time of LD100/30 irradiated mice to more than 60 days and increased the actuarial 60-day survival rate to 62% (P = .0001; Mantel-Peto-Cox). By comparison, no survival advantage was observed when mice received rhG-CSF 24 hours post-TBI. Similar radioprotective effects were observed when mice were irradiated with 650 cGy (LD80/30). The presented findings provide conclusive evidence that rhG-CSF has significant in vivo radioprotective effects for mice receiving LD100/30 or LD80/30 TBI.


2011 ◽  
Vol 308 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Gengyun Wen ◽  
Michael A. Partridge ◽  
Bingyan Li ◽  
Mei Hong ◽  
Wupeng Liao ◽  
...  

Author(s):  
Suresh Kumar Ananda Sadagopan ◽  
Nooshin Mohebali ◽  
Chung Yeng Looi ◽  
Mohadeseh Hasanpourghadi ◽  
Ashok Kumar Pandurangan ◽  
...  

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 925-925 ◽  
Author(s):  
Andreas Lundqvist ◽  
Kristy Greeneltch ◽  
Maria Berg ◽  
Shivani Srivastava ◽  
Nanae Harashima ◽  
...  

Abstract Killer IgG like receptor (KIR) inactivation of NK cells by self HLA molecules has been proposed as a mechanism through which malignant cells evade host NK cell-mediated immunity. To overcome this limitation, we sought to develop a method to sensitize the patient’s tumor to autologous NK cell cytotoxicity. The proteasome inhibitor bortezomib has recently been shown to enhance the activity of tumor death receptors. We found that exposure of a variety of different leukemia, lymphoma and solid tumor cancer cell lines to sub-apoptotic doses of bortezomib sensitized tumor cells in vitro to lysis by allogeneic NK cells. Importantly, this sensitizing effect also occurs with autologous NK cells normally rendered inactive via tumor KIR ligands; NK cells expanded from patients with metastatic renal cell carcinoma were significantly more cytotoxic against the patient’s own autologous tumor cells when pretreated with bortezomib compared to untreated tumors. This sensitization to autologous NK cell killing was also observed in vivo in two different murine tumor models. A significant delay in tumor growth in C57BL/6 mice bearing LLC1 tumors (figure) and a delay in tumor growth and a significant prolongation (p&lt;0.01) in survival were observed in RENCA tumor bearing Balb/c mice treated with bortezomib and syngeneic NK cell infusions compared to untreated mice or animals treated with bortezomib alone or NK cells alone. An investigation into the mechanism through which NK cell cytotoxicity was potentiated revealed bortezomib enhanced the activity of tumor death receptor-dependent and -independent apoptotic pathways. More specifically, bortezomib sensitized human and murine tumor cells to TRAIL and perforin/granzyme mediated NK cell cytotoxicity respectively. These observations suggest that pretreatment of malignant cells with bortezomib could be used as a strategy to override NK cell inhibition via tumor KIR ligands, thus potentiating the activity of adoptively infused autologous NK cells. A clinical trial evaluating the safety and anti-tumor efficacy of adoptively infused autologous NK cells in patients with advanced malignancies with and without tumor sensitization using bortezomib is currently being explored. Figure: Tumor growth in LLC1 bearing C57BL/6 mice. Fourteen days following s.c. injection of 3x105 LLC1 tumor cells, mice received 15μg (i.p) bortezomib and/or an adoptive infusion of 1x106 NK cells from C57BL/6 mice (i.v) given on day 15. Each dot represents the tumor volume of individual mice measured on day 28 post tumor injection. Tumors were significantly smaller in mice treated with bortezomib followed by NK cells compared to controls or mice that received either NK cells alone or bortezomib alone (p&lt;0.04 for all groups). Figure:. Tumor growth in LLC1 bearing C57BL/6 mice. . / Fourteen days following s.c. injection of 3x105 LLC1 tumor cells, mice received 15μg (i.p) bortezomib and/or an adoptive infusion of 1x106 NK cells from C57BL/6 mice (i.v) given on day 15. Each dot represents the tumor volume of individual mice measured on day 28 post tumor injection. Tumors were significantly smaller in mice treated with bortezomib followed by NK cells compared to controls or mice that received either NK cells alone or bortezomib alone (p&lt;0.04 for all groups).


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