Decrease In Metastasis Research Articles

An exploratory study on the effect of kynurenine metabolites on sEnd-2 endothelioma cells.

Cancer is the second leading cause of mortality worldwide. The development of anticancer therapy plays a crucial role in mitigating tumour progression and metastasis. Epithelioid hemangioendothelioma is a very rare cancer, however, with a high systemic involvement. Kynurenine metabolites which includel-kynurenine, 3-hydroxykynurenine, 3-hydroxyanthranilic acid and quinolinic acid have been shown to inhibit T-cell proliferation resulting in a decrease in cell growth of natural killercells and T cells. Furthermore, metabolites such as l-kynurenine have been shown to inhibit proliferation of melanoma cells in vitro. Considering these metabolite properties, the present study aimed to explore the in vitro effects of l-kynurenine, quinolinic acid and kynurenic acid on endothelioma sEnd-2 cells and on endothelial (EA. hy926 cells) (control cell line). The in vitro effect at 24, 48, and 72 h exposure to a range of 1-4 mM of the respective kynurenine metabolites on the two cell lines in terms of cell morphology, cell cycle progression and induction of apoptosis was assessed. The half inhibitory concentration (IC50), as determined using nonlinear regression, for l-kynurenine, quinolinic acid and kynurenic acid was 9.17, 15.56, and 535.40 mM, respectively. Optical transmitted light differential interference contrast and hematoxylin and eosin staining revealed cells blocked in metaphase, formation of apoptotic bodies and compromised cell density in l-kynurenine-treated cells. A statistically significant increase in the number of cells present in the sub-G1 phase was observed in l-kynurenine-treated sample. To our knowledge, this was the first in vitro study conducted to investigate the mechanism of action of kynurenine metabolites on endothelioma sEnd-2 cells. It can be concluded that l-kynurenine exerts an antiproliferative effect on the endothelioma sEnd-2 cell line by decreasing cell growth and proliferation as well as a metaphase block. These hallmarks suggest cell death via apoptosis. Further research will be conducted on l-kynurenine to assess the effect on cell adhesion in vitro and in vivo as cell-cell adhesion has been shown to increase metastasis to distant organs therefore, the inhibition of adhesion may lead to a decrease in metastasis.

Abstract SoA3-01: SERMs versus SERDs for targeting ESR1 mutations

Abstract Estrogen receptor positive (ER+) breast cancers are effectively treated with adjuvant endocrine therapies, with or without the addition of CDK4/6 inhibitors. However, many patients develop resistance and progress to ER+ metastatic disease (MBC). Acquired mutations in ESR1, which encodes estrogen receptor alpha (ERa), contribute to 20-40% of endocrine therapy resistant MBC. An emerging, unanswered and controversial question is the best choice of ER-targeted therapy for ET-resistant mutant ER+ MBC, recognizing that for most patients, a balance between compliance, effectiveness and quality of life are competing issues. To partially address some of these issues, we have tested and compared a relatively nontoxic SERM, lasofoxifene, to a complete estrogen receptor antagonist (CERAN), OP1250, in a mutant ERa (MCF-7 Y537S ERa) MBC endocrine therapy resistant xenograft tumor model (MIND = Mammary intraductal) to examine the efficacy of both drugs in a metastatic context in which a frequently observed, aggressive mutant ERa is expressed. As single agents, both Lasofoxifene and OP1250 inhibited primary tumor growth as well as metastasis to the lung, liver, brain and bone, with greater effect at higher doses of each drug, and both were substantially more effective than fulvestrant, the current gold standard for treating progressive disease. When combined with palbociclib, an additional decrease in metastasis was observed, compared to lasofoxifene, OP1250 or palbociclib as single agents. In total, these results demonstrate that lasofoxifene, a SERM, is as effective as OP-1250, a complete ER antagonist and SERD in a xenograft MIND model of mutant ER+ metastatic breast cancer. The potential use of lasofoxifene or OP1250, both alone and in combination with CDK4/6 inhibitors, to reduce tumor growth and metastasis in patients with ET-resistant metastatic breast cancer, is being tested in clinical trials to determine whether either drug is a preferred therapy versus current standard of care for mutant ER+ MCB. Citation Format: G. Greene. SERMs versus SERDs for targeting ESR1 mutations [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr SoA3-01.

Abstract 2738: XON7, a new Glyco-Humanized Polyclonal Antibody, first in class immunotherapy against several solid tumors

Abstract Introduction: Cancer immunotherapy has recently generated much excitement after the success of the immunomodulating anti-CTLA-4 and anti-PD-1 antibodies against various types of cancers. However, for many cancers, there is still a lack of effective treatment that can result in long-term cancer-free survival and lower metastatic and relapse risks. The emergence of cancer resistance could be minimized by drug combination or by multi-targeting of tumor cells. Polyclonal antibodies can target several tumor-associated antigens simultaneously and would be more efficient than a conventional mAbs. Here we evaluate the safety and efficacy of XON7, a first in class glyco-humanized polyclonal antibody (GH-pAb), in cancer preclinical models. Material and Methods: XON7 ability to induce Complement Dependent Cytotoxicity (CDC) and apoptosis was tested in a panel of cancer cell lines and PBMC. XON7 was also evaluated in sphere formation assay to predict its effects on cancer resistant. Specific binding to human tumors and healthy tissues was assessed by immunochemistry on tissue micro-array. Cross-cancer activity was evaluated on biopsies from patients with solid tumor such as CRC, NSCLC, osteosarcoma, and breast cancers. In vivo XON7 efficacy was evaluated in NMRI nude mice using A549: NSCLC, HCT-116: colon cancer, LNCaP: prostate cancer and MDA-MB-231: breast cancer cells. A human NSCLC chorio-allantoic membrane (CAM) model was used to evaluate the efficacy of XON7 + anti PD-1 on tumor growth and metastasis. Pharmacokinetics and safety of this drug were assessed in marmoset after single and repeated IV dosing up to 60mg/kg. Results: XON7 showed a potent in vitro antitumor activity in a panel of cancer cell lines, it induced specific tumor cell CDC (EC50=50ug/mL) and apoptosis (IC50= 100ug/mL). it was able to kill up to 100% of the cancer cells without affecting PBMC. In addition, it induced a striking decrease of tumor sphere formation in HCT116, A549 and MDA-MB-231 cancer cell lines. XON7 showed preferential recognition of tumor cells as compared to normal cells, it demonstrated cross-reaction to tumor patient biopsy without staining of the healthy tissues. In vitro XON7 potency was translated into in vivo efficacy in different mice xenograft models. XON7 induced a significant reduction of tumor growth ranging from 40 to 90% across several tested tumors. Furthermore, it showed, significant increase of anti-tumor response rate and decrease of metastasis when it is associated with anti PD-1 in vivo CAM model (>90%, p=0.001). XON7 was also characterized by high tolerance and satisfactory exposure in marmoset. Conclusion: Based on its safe toxicity profile and potent activity, XON7 appeared as a novel and promising cancer immunotherapy to fight against recurrent solid tumor, it is now aimed to reach clinical development, FIH in patients is planned to start before the end of 2023. Citation Format: Carine Ciron, Gwenaelle Evanno, Pierre Morice, Pierre-Joseph Royer, Françoise Shneiker, Odile Duvaux, Bernard Vanhove, Firas Bassissi. XON7, a new Glyco-Humanized Polyclonal Antibody, first in class immunotherapy against several solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2738.

Abstract 6527: Fucosyltransferase 5 promotes immune evasion in ovarian cancer by suppressing double negative T cells

Abstract Emerging evidence suggests that aberrant glycosylation in cancer impact on various stages in the disease progression including immunomodulation, but the underlying mechanisms remain poorly understood. Our previous data demonstrated that fucosyltransferase 5 (FUT5), a glycosyltransferase responsible for the terminal step in synthesizing Lewis antigens, may contribute to peritoneal metastasis of ovarian cancer. In this study, using clinical samples of high grade serous ovarian cancer (HGSOC), the most common subtype, we found that high expression of FUT5 is associated with a worse outcome. By employing multiplex immunohistochemistry (IHC) to examine T cell subsets, we found a significant decrease in CD3+CD4−CD8− (double negative, DN) T cells in FUT5high (n=10) compared to FUT5low samples (n=10), while there is no difference in the abundance of CD8+ cytotoxic T cells, CD4+ helper T cells or CD4+Foxp3+ regulatory T cells. Tumor-infiltrating DN T cells has been shown to mediate potent anti-tumor response. In addition to their cytotoxic capabilities, DN T cells largely exhibit modulatory functions on other T cell subsets. To further investigate, we performed additional IHC staining and observed a significant increase in proliferating (Ki67+) CD8+ tissue resident memory cells, which are known to be important for cancer immunity. In addition, we observed a decrease in metastases in the FUT5 knockdown group, accompanied by an increase in DN T cells in ascites and omental metastatic tumors in humanised mice, as revealed by flow cytometry, confirming a direct immunomodulatory role of FUT5. Together, these findings reveal a novel role of FUT5 in promoting immune evasion by suppressing anti-tumor DN T cells, which could provide novel insights for immunotherapy in HGSOC, which has a low response rate to immune checkpoint inhibitors (This research is supported by RGC SRFS2223-7S05, HMRF 08192286 and LSCCB under the Health@InnoHK Program launched by ITC, HKSAR). Citation Format: S. W. Fung, Sally K. Y. To, A. A. Hassan, Phillip P.C. Ip, Alice S. T. Wong. Fucosyltransferase 5 promotes immune evasion in ovarian cancer by suppressing double negative T cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6527.

In vivo anti-tumor effects of XON7 in association with ICIs.

e14520 Background: The advent of immune checkpoint inhibitors (ICIs) has rapidly transformed the treatment paradigm for multiple cancer types. This remarkable shift has been driven in large part by unprecedented durability that is characteristic of ICIs responsiveness. However, ICIs promote tumor cell immune escape; indeed, the response rate to single agent PD-1 blockade in unselected patients ranges from 40 to 70% in some diseases, while the response rates in most other approved diseases is limited to 10–25%. These observations support the need to strengthen immunotherapy and bring additional benefits for patients. XON7, is a glyco-humanized polyclonal antibody (GH-pAb) targeting multiple tumor antigens and active in vitro and in vivo in several solid tumors and hematological malignancies. Methods: A human lung carcinoma chorio-allantoic membrane (CAM) model was used to evaluate the efficacy of XON7 + anti PD-1 treatment. Fertilized white Leghorn eggs were incubated until Day 9, then inoculated in the upper CAM with 1.106 H460 cells. Treatments were administrated at E10, E12, E14, E15 and E17. Two groups were included: control group (n=20) received a non-immune GH-pAb + anti-PD-1 (10 mg/kg + 2,5 mg/kg respectively); treated group (n=20) received XON7 and anti-PD-1 at the same doses. Upper CAM, lower CAM and brain were collected from the embryos at E18. Tumor growth was evaluated by tumor weight using one-way ANOVA. Metastasis were quantified by qPCR for Alu sequences. Immune cell infiltration was analyzed by RT-qPCR with specific primers for chicken CD3, CD4 and CD8 sequences, with GAPDH as reference gene expression. Results: Significant reduction in tumor growth (~30%, p=0.02) and metastasis (>90%, p=0.001) was observed in both the brain and the lower CAM in the XON7+ICI group compared to control group. No differences in lymphocyte infiltrates (CD3, CD4, and CD8) were observed between groups. However, a significant increase in the M1/M2 ratio was observed in the XON7 + anti-PD-1 group over control. No toxicity from the treatment appeared in this model. Conclusions: In vivo data showed a significant increase of response rate and decrease of metastasis when XON7 is associated with anti PD-1. Combination of GH-pAb with ICI could constitute an immunotherapy combination likely to overcome resistance to anti-PD1.

Future trends in incidence and long-term survival of metastatic cancer in the United States

BackgroundPrevious studies have demonstrated epidemiological trends in individual metastatic cancer subtypes; however, research forecasting long-term incidence trends and projected survivorship of metastatic cancers is lacking. We assess the burden of metastatic cancer to 2040 by (1) characterizing past, current, and forecasted incidence trends, and (2) estimating odds of long-term (5-year) survivorship.MethodsThis retrospective, serial cross-sectional, population-based study used registry data from the Surveillance, Epidemiology, and End Results (SEER 9) database. Average annual percentage change (AAPC) was calculated to describe cancer incidence trends from 1988 to 2018. Autoregressive integrating moving average (ARIMA) models were used to forecast the distribution of primary metastatic cancer and metastatic cancer to specific sites from 2019 to 2040 and JoinPoint models were fitted to estimate mean projected annual percentage change (APC).ResultsThe average annual percent change (AAPC) in incidence of metastatic cancer decreased by 0.80 per 100,000 individuals (1988–2018) and we forecast an APC decrease by 0.70 per 100,000 individuals (2018–2040). Analyses predict a decrease in metastases to liver (APC = −3.40, 95% CI [−3.50, −3.30]), lung (APC (2019–2030) = −1.90, 95% CI [−2.90, −1.00]); (2030–2040) = −3.70, 95% CI [−4.60, −2.80]), bone (APC = −4.00, 95% CI [−4.30, −3.70]), and brain (APC = −2.30, 95% CI [−2.60, −2.00]). By 2040, patients with metastatic cancer are predicted to have 46.7% greater odds of long-term survivorship, driven by increasing plurality of patients with more indolent forms of metastatic disease.ConclusionsBy 2040, the distribution of metastatic cancer patients is predicted to shift in predominance from invariably fatal to indolent cancers subtypes. Continued research on metastatic cancers is important to guide health policy and clinical intervention efforts, and direct allocations of healthcare resources.

Tumor necroptosis-mediated shedding of cell surface proteins promotes metastasis of breast cancer by suppressing anti-tumor immunity

Necroptosis is a form of regulated necrosis and is executed by MLKL when MLKL is engaged in triggering the rupture of cell plasma membrane. MLKL activation also leads to the protease, ADAMs-mediated ectodomain shedding of cell surface proteins of necroptotic cells. Tumor necroptosis often happens in advanced solid tumors, and blocking necroptosis by MLKL deletion in breast cancer dramatically reduces tumor metastasis. It has been suggested that tumor necroptosis affects tumor progression through modulating the tumor microenvironment. However, the exact mechanism by which tumor necroptosis promotes tumor metastasis remains elusive. Here, we report that the ectodomain shedding of cell surface proteins of necroptotic cells is critical for the promoting effect of tumor necroptosis in tumor metastasis through inhibiting the anti-tumor activity of T cells. We found that blocking tumor necroptosis by MLKL deletion led to the dramatic reduction of tumor metastasis and significantly elevated anti-tumor activity of tumor-infiltrating and peripheral blood T cells. Importantly, the increased anti-tumor activity of T cells is a key cause for the reduced metastasis as the depletion of CD8+ T cells completely restored the level of metastasis in the Mlkl KO mice. Interestingly, the levels of some soluble cell surface proteins including sE-cadherin that are known to promote metastasis are also dramatically reduced in MLKL null tumors/mice. Administration of ADAMs pan inhibitor reduces the levels of soluble cell surface proteins in WT tumors/mice and leads to the dramatic decrease in metastasis. Finally, we showed the sE-cadherin/KLRG1 inhibitory receptor is the major pathway for necroptosis-mediated suppression of the anti-tumor activity of T cells and the promotion of metastasis. Hence, our study reveals a novel mechanism of tumor necroptosis-mediated promotion of metastasis and suggests that tumor necroptosis and necroptosis-activated ADAMs are potential targets for controlling metastasis.

Successful Combined Treatment of a Patient with Borderline Resectable Liver Metastasis of Colorectal Cancer

Aim: to present the value of interventional radiology techniques in the treatment of a patient with liver metastasis of colorectal cancer.Key points. In 2013, a 60-year-old patient with stage IIIB sigmoid colon cancer, pT3N2M0 underwent resection of the sigmoid colon with the formation of hardware rectosigmoanastomosis, 6 courses of adjuvant chemotherapy were performed. In 2015, a control examination revealed metastatic liver damage. Liver resection could not be performed due to the small future residual volume, and systemic chemotherapy was not effective. The patient underwent 3 cycles of regional chemotherapy. Taking into account the pronounced positive dynamics, in the form of a decrease in tumor size and a decrease in cancer markers, the patient managed to perform an extended right-sided hemihepatectomy. No progression of the tumor process was detected during the follow-up.Conclusion. Modern possibilities of X-ray endovascular methods allow to achieve results in the treatment of patients with colorectal cancer metastases in the liver such as a decrease in metastases in size, that make liver resection possible.

Preliminary Study on Natural Killer Cell Activity for Interferon-Gamma Production after Gamma Knife Radiosurgery for Brain Tumors.

High-dose radiation is well known to induce and modulate the immune system. This study was performed to evaluate the correlation between clinical outcomes and changes in natural killer cell activity (NKA) after Gamma Knife Radiosurgery (GKS) in patients with brain cancer. We performed an open-label, prospective, cross-sectional study of 38 patients who were treated with GKS for brain tumors, including metastatic and benign brain tumors. All of the patients underwent GKS, and blood samples were collected before and after GKS. NKA was measured using an enzyme-linked immunosorbent assay kit, to measure interferon-gamma (IFNγ) secreted by ex vivo-stimulated NK cells from whole blood. We explored the correlations between NK cell-produced IFNγ (NKA-IFNγ) levels and clinical parameters of patients who were treated with GKS for brain tumors. NKA-IFNγ levels were decreased in metastatic brain tumor patients compared to those with benign brain tumors (p<0.0001). All the patients who used steroid treatment to reduce brain swelling after GKS had an NKA-IFNγ level of zero except one patient. High NKA-IFNγ levels were not associated with a rapid decrease in brain metastasis and did not increase after GKS. The activity of NK cells in metastatic brain tumors decreased more than that in benign brain tumors after GKS.

Abstract 1618: OP-1250 prevents tumor spread in a model of metastatic mutant ERα+ breast cancer

Abstract Estrogen receptor positive (ER+) breast cancers represent about 70-75% of all breast cancer. In general, these cancers are effectively treated with adjuvant endocrine therapies, with or without the addition of CDK4/6 inhibitors. However, many patients develop resistance and eventually progress to metastatic disease (MBC). Acquired mutations in ESR1, which encodes estrogen receptor alpha (ERα), contribute to 20-40% of endocrine therapy resistant MBC. In patients, breast cancer metastasis occurs in the liver, lungs, brain and bone. OP-1250 is a novel compound that is a complete ERα antagonist (CERAN). Previous studies have shown that OP-1250 effectively blocks both the AF-1 and AF-2 activation functions of ERα. In the current study, we used a mutant ERα MBC endocrine therapy resistant xenograft model to examine the efficacy of OP-1250 in a metastatic context. MCF7 cells engineered to express one of the most common and aggressive ERα mutations, Y537S, were labeled with luciferase and injected via the nipple (mammary intraductal MIND model) into NSG mice. Mice were treated with 3 and 10 mg/kg of OP-1250 alone or in combination with palbociclib at 70mg/kg and tumor growth was monitored via a Xenogen IVIS imager. At study end point, mice were sacrificed and excised organs were imaged ex-vivo and further processed for immunohistology analysis. OP-1250 at both doses inhibited primary tumor growth as well as metastasis to the lung, liver, brain and bone, with greater effect at 10 mg/kg, and was significantly more effective than Faslodex. When combined with palbociclib at 70 mg/kg, an additional significant decrease in metastasis was observed, compared to OP-1250 or palbociclib alone. Our results also suggest that the efficacy seen in the combination study was driven primarily by OP-1250. In total, these results demonstrate the potential use of OP-1250, both alone and in combination with a CDK4/6 inhibitor, to inhibit tumor growth and metastasis in a model of aggressive mutant ER+ MBC. Citation Format: Muriel Laine, Marianne E. Greene, Tiffany Leng, Sophia Li, Gopinath S. Palanisamy, Cyrus L. Harmon, Leslie Hodges-Gallagher, Peter J. Kushner, Geoffrey L. Greene. OP-1250 prevents tumor spread in a model of metastatic mutant ERα+ breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1618.

Downregulated microRNA-149-3p triggers malignant development and predicts worse prognosis in oral squamous cell carcinoma

ObjectiveAccumulating evidence reveals that aberrant expression of microRNAs contributes to the tumorigenesis and development of diverse human cancers. In the current study, we aimed to evaluate the functional role and prognostic value of miR-149-3p in oral squamous cell carcinoma (OSCC). MethodsReal-time polymerase chain reaction (PCR) analysis was performed to detect the expression of miR-149-3p in 70 OSCC patients (64.10 ± 11.97 years; 31 males and 39 females). The prognostic ability of miR-149-3p in OSCC patients was assessed by Kaplan–Meier survival analysis. Transwell assays and cell adhesion assays were used to investigate the impact of miR-149-3p on cell migration and invasion. The regulation of MMP2 expression by miR-149-3p was determined by real-time PCR, western blotting and dual luciferase reporter assay. ResultsOur results revealed a lower level of miR-149-3p in OSCC tissues than in adjacent normal tissues. Downregulation of miR-149-3p was correlated with malignant development and poor outcomes in patients with OSCC. MiR-149-3p repressed the migratory and invasive abilities of OSCC cells. We confirmed that miR-149-3p targeted the 3'-untranslated region of MMP2 mRNA to suppress MMP2 expression. Moreover, the miR-149-3p-mediated decrease in metastasis was reversed by overexpression of MMP2 in OSCC cells. ConclusionOur findings provide an important molecular mechanism by which miR-149-3p inhibits OSCC cell migration and invasion via negative regulation of MMP2 and implicate miR-149-3p as a prospective biomarker and therapeutic target for OSCC.

Anti-cancer immunoprotective effects of immunization with hydatid cyst wall antigens in a non-immunogenic and metastatic triple-negative murine mammary carcinoma model

Cancer vaccines have gained lots of attention as the future of cancer treatment. However, poor immunogenicity of tumor-associated antigens often fails to induce an efficient immune response against the tumor. Strange anti-tumor immune responses at the parasite-infected patients due to cross-reactivity have been reported in various studies. Therefore, parasite antigens with significant immunogenicity and high epitope homology with cancer antigens may activate a strong immune response against cancer cells. Herein, the sera of immunized rabbits with the hydatid cyst wall (HCW) antigens were incubated with 4 T1 mammary carcinoma cells to investigate cross-reactivity between the HCW antigens antisera and surface antigens of the breast cancer cells. Also, the SDS-PAGE profile of HCW antigens was prepared and incubated with the breast cancer patients’ sera and considerable reactivity was observed between their sera and a specific band (~27/28 kDa) according to Western blotting analyzes. Then, the protein bands with cross-reactivity with breast cancer patients’ sera were utilized for prophylactic immunizations of Balb/c mice. The immunoprotective effect of immunization with the HCW antigens caused significant inhibition of 4 T1 breast tumor growth, decrease of metastasis, and enlargement of the tumor-bearing mice survival time in comparison with PBS and pure immune adjuvant injected groups. Mass spectrometry analysis showed that the ~ 27/28 kDa band has numbers of proteins/polypeptides with a high degree of homology with cancer cells antigens which can be the reason for this cross-reactivity and anti-tumor immune response. Taking together, immunization with HCW antigens would be a promising approach in cancer immunotherapy after further investigations.

Macrophages Mediate the Antitumor Effects of the Oncolytic Virus HSV1716 in Mammary Tumors.

Oncolytic viruses (OV) have been shown to activate the antitumor functions of specific immune cells like T cells. Here, we show OV can also reprogram tumor-associated macrophage (TAM) to a less immunosuppressive phenotype. Syngeneic, immunocompetent mouse models of primary breast cancer were established using PyMT-TS1, 4T1, and E0771 cell lines, and a metastatic model of breast cancer was established using the 4T1 cell line. Tumor growth and overall survival was assessed following intravenous administration of the OV, HSV1716 (a modified herpes simplex virus). Infiltration and function of various immune effector cells was assessed by NanoString, flow cytometry of dispersed tumors, and immunofluorescence analysis of tumor sections. HSV1716 administration led to marked tumor shrinkage in primary mammary tumors and a decrease in metastases. This was associated with a significant increase in the recruitment/activation of cytotoxic T cells, a reduction in the presence of regulatory T cells and the reprograming of TAMs towards a pro-inflammatory, less immunosuppressive phenotype. These findings were supported by in vitro data demonstrating that human monocyte-derived macrophages host HSV1716 replication, and that this led to immunogenic macrophage lysis. These events were dependent on macrophage expression of proliferating cell nuclear antigen (PCNA). Finally, the antitumor effect of OV was markedly diminished when TAMs were depleted using clodronate liposomes. Together, our results show that TAMs play an essential role in support of the tumoricidal effect of the OV, HSV1716-they both host viral replication via a novel, PCNA-dependent mechanism and are reprogramed to express a less immunosuppressive phenotype.

Abstract 1103: Aspirin reduces the incidence of metastasis in a preclinical study of Braf mutant colorectal cancer

Abstract Background. Aspirin is a well-studied chemopreventive agent for the prevention of conventional colorectal adenomas and cancer. Post hoc analyses of cardiovascular prevention trials demonstrate a long-term reduction in colorectal cancer incidence and mortality with aspirin treatment. Randomized controlled trials have shown a long-term benefit for reducing colorectal cancer incidence in patients with Lynch Syndrome, a form of hereditary colorectal cancer. These findings have led to the recommendation of aspirin as a chemopreventive for colorectal cancer by the U.S. Preventive Services Task Force and Cancer Council Australia. However, future research questions have noted a lack of knowledge of the differential benefits of aspirin in preventing sessile serrated lesions versus conventional adenomas and cancer. In our study, we hypothesized that aspirin will be an effective long-term treatment for the prevention of colorectal cancer resulting from sessile serrated lesions. We aimed to investigate this in a preclinical study utilizing a murine model of Braf mutant serrated neoplasia with a primary end-point investigating cancer incidence. Methods. BrafV637E/+/Villin-CreERT2/+ mice were injected with tamoxifen (i.p. 75mg/kg) at 2 weeks of age to activate the Braf mutation within the intestine, then commenced on an aspirin-supplemented (n=78) or control standard (n=83) diet at wean. Aspirin was supplemented into the diet and provided ad libitum, at a human equivalent dose of 80-120mg per day, until sacrifice at 14 months. The gastrointestinal tract was excised and evaluated for the presence of carcinoma. In addition, the peritoneal and thoracic cavities were inspected for metastatic disease. A gastrointestinal pathologist (CL) assessed all histology sections. Results. At sacrifice, 14 months post induction of mutant Braf, all mice developed murine serrated lesions reminiscent of human sessile serrated lesions. We observed a carcinoma incidence of 31% (26/83) of which 35% (9/26) had metastasized to the liver or peritoneal cavity. When mice were treated with an aspirin-supplemented diet there was no significant reduction in carcinoma incidence (22/78, 28%, P = 0.7315). However, there was a significant reduction in the incidence of metastasis (1/22, 5%, P = 0.0134). Mice in the control group had lesions of a significantly greater size when compared to aspirin treated mice (P=0.0032). Conclusions. Aspirin resulted in a 7-fold decrease in metastases. This study demonstrates that the benefit of aspirin in preventing Braf mutant serrated neoplasia occurs at the carcinoma-metastasis phase of colorectal carcinogenesis. This could have potential clinical benefit in reducing recurrence and mortality. Citation Format: Alexandra Kane, Cheng Liu, Lochlan Fennell, Diane McKeone, Jennifer Borowsky, Barbara Leggett, Vicki Whitehall. Aspirin reduces the incidence of metastasis in a preclinical study of Braf mutant colorectal cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1103.

Therapeutic potential of FLANC, a novel primate-specific long non-coding RNA in colorectal cancer

ObjectiveTo investigate the function of a novel primate-specific long non-coding RNA (lncRNA), named FLANC, based on its genomic location (co-localised with a pyknon motif), and to characterise its potential as...

Abstract 5061: TET inhibits prostate cancer tumor growth, progression and metastasis in TRAMP mice

Abstract Introduction: Prostate cancer (PCa) is the 2nd most common malignancy in USA. Novel agents for treatment of advanced PCa are warranted. Transgenic adenocarcinoma of the mouse prostate (TRAMP) is an autochthonous mouse model exhibits both histological and morphological features that mimic human prostate carcinogenesis. Herein, for the first time, we evaluated the in vivo effects of TET, a derivative of Tetrandrine in TRAMP model. Methods: Beginning 12 weeks of age, male TRAMP mice were administrated with TET (30 mgm/kg body weight, orally, alternative days) in PBS or PBS alone (Control) till 30 weeks of age. Body weight (B) of animals was recorded weekly. At various time points animals were euthanized, genitourinary tract (G) were weighed. Prostate tissue was subjected to immunohistochemical analyses for SV40-TAg, epithelial-mesenchymal transition (EMT), proliferation, neuroendocrine differentiation (NED) and apoptosis. Multiple organs were examined for drug toxicity and lungs were analyzed for metastasis. Results: TRAMP mice exhibit to high-grade prostatic intraepithelial neoplasia (PIN) by 12 weeks and progresses to poorly differentiated adeno-carcinoma by 30 weeks with distant metastasis to lungs. TET feeding did not show any considerable difference body weight loss profiles during the entire treatment regimen. At the time of necropsy, there was no evidence of edema, abnormal organ size or appearance in non-target organs. TET gavage group showed (p&amp;lt;0.005) lower G/B ratio compared to the PBS treated group. These findings clearly indicate that TET dosing is non-toxic and restricts the abnormal growth of the prostate in TRAMP mice. TET repress the EMT as well as NED transition and inhibits cell proliferation (p&amp;lt;0.005) by Ki-67 staining. Oral administration of TET inhibits PCa growth and progression by increases (p&amp;lt;0.005) apoptosis in tumor tissues. Further, TET inhibited metastasis as there was significant (p&amp;lt;0.005) decrease in metastasis to lungs in TET treated animals. Conclusion: Human achievable dose of TET treatment to TRAMP mice bearing prostate tumor, exhibited no-observed-adverse-effect-level in toxicology evaluations and also significantly inhibited tumor growth, progression, local invasion and distant metastasis involving suppression of tumor, and thus could have potential against human PCa. Citation Format: Hari K. Koul, Prakash Srinivasan Timiri Shanmugam, Praveen K. Jaiswal, Sweaty Koul. TET inhibits prostate cancer tumor growth, progression and metastasis in TRAMP mice [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 5061. doi:10.1158/1538-7445.AM2017-5061

Rola weryfikacji histopatologicznej, trudności terapeutyczne i leczenie przeciwzakrzepowe w paliatywnej chemioterapii chorej z niedoborem antytrombiny oraz rakiem jelita grubego i rakiem macicy w wywiadzie

Palliative chemotherapy in patients with thrombophilia is a challenge for clinical oncologists. On one hand the optimal treatment should be very safe for patient, on the other hand – as effective as possible. That therapy is also connected with proper thromboprophylaxis. The incidence of multiple cancers is a serious problem of modern oncology. In patients whose medical history includes two or more cancers, it is essential to obtain histopathological diagnosis before the administration of treatment of disseminated disease. It allows to avoid improper therapy which is often toxic. The article presents the case of a patient with antithrombin deficiency and two cancers in medical history: colon cancer and endometrial cancer. The treatment of the patient because of the metastatic cancer was started after the histopathological diagnosis. In metastatic lymph node the endometrial cancer was recognized. The carboplatin and paclitaxel were used in the therapy. The treatment was conducted in four course chemotherapy. It revealed considerable polyneuropathy and hematologic toxicity limiting from further therapy. Treatment allowed to obtain biochemical response, decrease of metastases and the condition of a patient improved. During the systemic therapy thromboprophylaxis with acenocumarol was used. The incidence of venous thromboembolism or bleeding complications were not noticed.

Abstract B20: Development of metastatic patient-derived xenografts (PDXs) for accurate assessment of anti-metastatic therapeutics in pre-clinical settings

Abstract Background: Although advances in treating early stage breast cancers have increased the overall survival rate, once the disease has metastasized treatment options subside to palliative care. The limited access to metastatic biopsies and disease-relevant pre-clinical models to test new therapeutics targeted against advanced metastatic cancers limits progress and translation of investigational therapeutics to the clinic. Methods: To address this deficiency we developed a collection of metastatic patient derived xenograft models via direct transplantation of metastatic biopsy or residual surgical material in immunocompromised mice. We successfully collected and established triple negative as well as ER/PR positive patient xenografts which are available for collaborative research. We further characterized and utilized the PDXs to assess the efficacy of new combination therapy to treat distant metastases. Results: The efficacy of Aurora A kinase inhibition by small molecule inhibitor MLN8237 (Alisertib) as monotherapy and in combination with microtubule targeting drug, eribulin, on different stages of metastasis and potential mechanisms of its action was defined. Our work using PDX models indicates that Alisertib does not limit growth of the primary tumor. These findings are similar to the results of clinical trials with Alisertib in breast cancer. Importantly, we found that Alisertib dramatically decreases growth of the established metastases and prevents further dissemination via inactivation of AKT and activation of cytotoxic autophagy. Combination of Alisertib with eribulin led to a synergistic decrease in metastases to distant organs and provided additional local control of mammary tumor growth. Conclusion: Metastatic PDX models provide new, accurate assessment of anti-metastatic regiment's efficacy. MLN8237 plus eribulin combination shows synergistic inhibition of metastatic spread, growth of established metastases and prolongs overall survival. Future clinical trials are needed to further test this regiment in clinic to improve survival of metastatic cancer patients. Citation Format: Ryan Ice, Anna Kiseleva, Yuriy Loskutov, Matthew Smolkin, Adham Salkeni, Hannah Hazard, Ginger Layne, Elena Pugacheva{Authors}. Development of metastatic patient-derived xenografts (PDXs) for accurate assessment of anti-metastatic therapeutics in pre-clinical settings. [abstract]. In: Proceedings of the AACR Special Conference: Patient-Derived Cancer Models: Present and Future Applications from Basic Science to the Clinic; Feb 11-14, 2016; New Orleans, LA. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(16_Suppl):Abstract nr B20.

Abstract 5095: Hic-5 modulation of the stromal matrix is required for mammary tumor progression

Abstract Primary tumors grow and invade into surrounding tissues/stroma, frequently resulting in metastasis to distant organs. Tumor cell-stroma crosstalk plays a crucial, but incompletely understood role during tumor progression and metastasis. For example, increased stromal matrix density and/or rigidity correlates with poor prognosis in human breast cancer patients. Previous studies have implicated Hic-5, a focal adhesion scaffold protein, in tumor cell invasion, proliferation and metastasis. To investigate the role of Hic-5 in mammary tumor progression, Hic-5 -/- mice were generated and crossed with mice expressing Polyoma Middle T Antigen (PyMT) driven by the MMTV promoter. The PyMT mouse is a well-established model for human breast cancer progression. Tumors from the Hic-5 -/- PyMT mice demonstrated an increased latency and had reduced growth as compared to Hic-5 +/- PyMT controls. The absence of Hic-5 did not affect the progression of the tumor to a carcinoma stage, but there was a decrease in metastasis to the lungs. Immunohistochemical analysis showed that Hic-5 is primarily expressed in the cancer associated fibroblasts (CAFs) and the Hic-5 -/- PyMT tumor stroma exhibits reduced extracellular matrix (ECM) deposition. Furthermore, 3D cell-derived matrices (CDM) generated in vitro using isolated CAFs, confirmed that Hic-5 -/- PyMT CAFs do not efficiently deposit and organize ECM. The organization of the stromal matrix has been shown previously to increase the rigidity of the tumor, which in turn promotes FAK Y397 phosphorylation in the tumor cells to promote cell invasion and proliferation. Accordingly, the Hic-5 -/- PyMT tumors exhibited a reduction in FAK phospho-Y397 staining and attenuation of downstream ERK activation, suggesting that their stromal matrix is not optimally organized for tumor cell signaling. Taken together, these data demonstrate that Hic-5 expression in CAFs is important for stromal matrix organization/remodeling during tumor progression and that the loss of the organization of the ECM in the Hic-5 -/- tumor stroma may contribute to the reduced tumor growth and metastasis observed in these animals. Supported by NIH CA163296 to CET, NS066071 to EO and Carol M. Baldwin Breast Cancer Fund to CET. Citation Format: Gregory J. Goreczny, Jessica Ouderkirk, Eric Olson, Mira Krendel, Christopher Turner. Hic-5 modulation of the stromal matrix is required for mammary tumor progression. [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 5095.

Abstract 1629: Novel interaction of MUC16 with FAK activate EMT process and metastasis of pancreatic ductal adenocarcinoma

Abstract Introduction: MUC16 is a heavily glycosylated, type I transmembrane mucin, which is over expressed in different cancers. We have previously shown that significant overexpression of MUC16 in human PDAC tissues with disease progression compared to normal pancreas. However, the functional consequences of MUC16 and their role in PDAC is poorly understood. Based on this our hypothesis is that MUC16 can drive pancreatic cancer metastasis through FAK-mediated Akt and ERK/MAPK signaling activation and altering EMT markers. Methods: We have developed MUC16 knockdown Capan1 and Colo-357 PDAC cells to study the functional impacts. Congenic cell survival, soft-agar colony formation, and trans-well chamber assays were performed to determine the in vitro tumorigenicity. Orthotopic implantation was carried out using capan-1 and colo-357 PDAC cells to determine the oncogenic and metastatic potential of MUC16. Binding assay was performed to determine the cell adhesion property of MUC16 in colo-357 cells. The physical interaction between MUC16 and mesothelin, galectin-3 and FAK were evaluated by confocal and immunoprecipitation analysis. Immunoblot analyses were performed to determine the downstream signaling in MUC16 knockdown cells. Results: MUC16 knockdown in capan-1 and colo-357 PDAC cell lines resulted in significantly decreased cell proliferation (P&amp;lt;0.05), colony formation (P&amp;lt;0.01), and migration (P&amp;lt;0.01) in vitro. Further, MUC16 knockdown capan-1 and colo-357 cells significantly decreases the tumor formation (P&amp;lt;0.05) and metastasis (liver P&amp;lt;0.05, spleen P&amp;lt;0.001, intestinal wall P&amp;lt;0.01, diaphragm P&amp;lt;0.01 and peritoneum P&amp;lt;0.001) in orthotopic xenograft mouse model. Adhesion assay displays decreased cell attachment of MUC16 knockdown cells with recombinant galectin-1 and galectin-3 proteins. Immunoprecipitation and immunofluorescence studies confirmed that MUC16 interaction with mesothelin and galectin-3 in PDAC cells. Co-immunoprecipitation revealed a novel interaction between MUC16 and FAK in PDAC cells. Interestingly, we observed decreased expression of mesenchymal markers (N-cadherin and Zeb1) and increased expression of epithelial markers (E-cadherin and CK18) in MUC16 silenced PDAC cells, correlating with the decrease in metastasis. Moreover, MUC16 knockdown show decreased FAK-mediated Akt and ERK/MAPK activation in PDAC cells. Conclusion: Overall our study concludes that MUC16 interacts with FAK leads to the activation of EMT markers for enhancing pancreatic cancer metastasis. Citation Format: Sakthivel Muniyan, Dhanya Haridas, Satyanarayana Rachagani, Imayavaramban Lakshmanan, Suprit Gupta, Seema Chugh, Parthasarathy Seshacharyulu, Moorthy P. Ponnusamy, Surinder K. Batra. Novel interaction of MUC16 with FAK activate EMT process and metastasis of pancreatic ductal adenocarcinoma. [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 1629.