CVX-045: A novel thrombospondin-1 (TSP-1) mimetic CovX-Body that potentiates chemotherapy in preclinical colon cancer models

14011 Background: TSP-1 reduces angiogenesis and tumor growth in vivo, and induces endothelial cell apoptosis in vitro. CVX-045 was produced by fusing a peptide derived from TSP-1, known to have anti-vascular activity, to a proprietary monoclonal antibody. CVX-045 possesses the potency and specificity of the TSP-1 mimetic peptide, along with the advantageous PK of an antibody. Methods: Anti-tumor activity of CVX-045 was evaluated in A549, A431, and HT-29 human adenocarcinoma xenograft models. Cells were implanted SC in female nu/nu mice, and tumors were staged to 300–400 mm3 prior to initiation of weekly treatments: CVX-045 IV 10–30 mg/kg; 5-FU or CPT-11 IP 100 mg/kg. Results: CVX-045 (10 mg/kg) significantly reduced A549 and A431 tumor growth 73% (day 49) and 51% (day 22), respectively, but was not effective in the HT-29 xenograft (10 or 30 mg/kg). CVX-045 demonstrated significant anti-vascular activity, reducing tumor microvessel density 51% in A549, 49% in A431, and 36% in HT-29 xenografts. CVX-045 (30 mg/kg) plus 5- FU significantly decreased HT-29 tumor growth 70% and microvessel density 61.2% on day 30 (both P<0.01), effects significantly greater than either agent alone. Co-treatment with CVX-045 (30 mg/kg) plus CPT-11 decreased HT-29 tumor volume 91% on day 28 (P<0.001), also significantly greater than either agent alone. As a surrogate measurement of survival, mice remained on treatment until tumors reached 2000 mm3. CPT-11 alone extended the time to reach tumor load from day 28 to day 39, while the combination of CPT-11 with CVX-045 extended this further to day 60. Conclusions: CVX-045 exhibits significant anti-angiogenic activity in several tumor models and enhances anti-tumor activity in combination with standard chemotherapies in a highly aggressive colon tumor model. No significant financial relationships to disclose.

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Blockade of the CD47/SIRPα Checkpoint Potentiates the Anti-Tumor Efficacy of Tafasitamab

Blood ◽

10.1182/blood-2020-139582 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 11-12

Author(s):

Doris Mangelberger ◽

Christian Augsberger ◽

Karin Landgraf ◽

Christina Heitmüller ◽

Stefan Steidl

Keyword(s):

Monoclonal Antibody ◽

Tumor Growth ◽

B Cell ◽

Tumor Model ◽

B Cell Lymphoma ◽

Checkpoint Blockade ◽

Subcutaneous Tumor ◽

Anti Tumor Activity

Introduction Tafasitamab (MOR208) is an Fc-enhanced, humanized, monoclonal antibody that targets CD19 and has shown promising clinical activity in patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL). CD19 is homogeneously expressed among different B-cell malignancies, and the binding of tafasitamab to CD19 directly mediates cell death, induces antibody-dependent cellular cytotoxicity and antibody-dependent cellular phagocytosis. Aiming to potentiate the tafasitamab-mediated "eat me" signal, we tested a combination with a CD47-directed monoclonal antibody (mAb) to inhibit the CD47/SIRPα "don't eat me" signal and further enhance macrophage-mediated phagocytosis. Preclinical studies demonstrated that blocking the CD47/SIRPα checkpoint in combination with antibodies, such as rituximab, increased phagocytosis by macrophages, resulting in effective anti-tumor effects in non-Hodgkin lymphoma (NHL) (Chao, et al. 2010). Additionally, the combination of the anti-CD47, magrolimab, and the anti-CD20, rituximab, demonstrated beneficial outcomes for patients with refractory NHL (Advani, et al. 2019). Here, we present in vitro and in vivo data on the combinatory effect of tafasitamab and an anti-CD47 mAb in preclinical models of Burkitt's lymphoma (BL). Methods During in vitro studies, CD14+ monocytes were isolated from the whole blood of healthy volunteers and differentiated with 50 ng/mL M-CSF for 6 days. ADCP was analyzed by flow cytometry in co-culture experiments with Ramos cells (BL) after 3 hours of treatment with tafasitamab and anti-CD47 mAb (clone B6H12). In vivo, the combination of tafasitamab with an anti-CD47 mAb was tested in a Ramos disseminated survival and subcutaneous tumor model in SCID and NOD-SCID mice, respectively. In both models, tafasitamab was administered therapeutically twice a week either at 3 mg/kg (disseminated) or 10 mg/kg (subcutaneous) for max. 4 weeks. The anti-CD47 mAb was administered at 4 mg/kg three times per week. Main study readouts were to assess animal survival and any delays in tumor growth. Results The combination of tafasitamab + CD47/SIRPα checkpoint blockade enhanced ADCP activity of primary M2 macrophages on BL-derived Ramos cells, in comparison with the anti-CD47 mAb or tafasitamab monotherapies (Figure 1A). In vivo, a significant increase in anti-tumor activity was observed with the combination of tafasitamab + anti-CD47 mAb. In the Ramos disseminated survival model, the combination showed an increased life span (ILS) of >182% compared with tafasitamab monotherapy control, with an overall survival of all animals treated with the combination (15/15) until the end of the study (Day 99 post-cell injection). Additionally, pronounced anti-tumor efficacies were detected in the Ramos subcutaneous tumor model. Here, the combination resulted in a significant delay in tumor growth compared with the tafasitamab or anti-CD47 mAb monotherapies (ILS >175% tafasitamab and ILS >72% anti-CD47 mAb vs tafasitamab + B6H12) (Figure 1B). Conclusions The ADCP activity of primary macrophages was increased by combining tafasitamab with an anti-CD47 mAb in vitro, resulting in enhanced anti-tumor activity compared with tafasitamab or anti-CD47 mAb monotherapies in vivo. Overall, results indicate the combination of tafasitamab with a CD47/SIRPα checkpoint blockade may be a promising novel combination approach for lymphoma therapy. Disclosures Mangelberger: MorphoSys AG: Current Employment. Augsberger:MorphoSys AG: Current Employment. Landgraf:MorphoSys AG: Current Employment. Heitmüller:MorphoSys AG: Current Employment. Steidl:MorphoSys AG: Current Employment.

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A Targeted-Covalent Inhibitor of 17β-HSD1 Blocks Two Estrogen-Biosynthesis Pathways: In Vitro (Metabolism) and In Vivo (Xenograft) Studies in T-47D Breast Cancer Models

Cancers ◽

10.3390/cancers13081841 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1841

Author(s):

Donald Poirier ◽

Jenny Roy ◽

René Maltais

Keyword(s):

Breast Cancer ◽

Tumor Growth ◽

Therapeutic Potential ◽

Tumor Model ◽

Growth Effect ◽

Mouse Tumor ◽

Cancer Models ◽

Model Cell

17β-Hydroxysteroid dehydrogenase type 1 (17β-HSD1) plays an important role in estrogen-dependent breast tumor growth. In addition to being involved in the production of estradiol (E2), the most potent estrogen in women, 17β-HSD1 is also responsible for the production of 5-androsten-3β,17β-diol (5-diol), a weaker estrogen than E2, but whose importance increases after menopause. 17β-HSD1 is therefore a target of choice for the treatment of estrogen-dependent diseases such as breast cancer and endometriosis. After we developed the first targeted-covalent (irreversible) and non-estrogenic inhibitor of 17β-HSD1, a molecule named PBRM, our goal was to demonstrate its therapeutic potential. Enzymatic assays demonstrated that estrone (E1) and dehydroepiandrosterone (DHEA) were transformed into E2 and 5-diol in T-47D human breast cancer cells, and that PBRM was able to block these transformations. Thereafter, we tested PBRM in a mouse tumor model (cell-derived T-47D xenografts). After treatment of ovariectomized (OVX) mice receiving E1 or DHEA, PBRM given orally was able to reduce the tumor growth at the control (OVX) level without any observed toxic effects. Thanks to its irreversible type of inhibition, PBRM retained its anti-tumor growth effect, even after reducing its frequency of administration to only once a week, a clear advantage over reversible inhibitors.

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Inhibition of B-NHL Tumor Xenografts Following Treatment with Galiximab (Anti-CD80 mAb) and Potentiation When Combined with Chemotherapy

Blood ◽

10.1182/blood.v120.21.4873.4873 ◽

2012 ◽

Vol 120 (21) ◽

pp. 4873-4873

Author(s):

Mario I Vega ◽

Hari Hariharan ◽

Peter Chu ◽

Tracey Murphy ◽

Dana Clanton ◽

...

Keyword(s):

Tumor Growth ◽

Phase I ◽

Overall Response Rate ◽

Response Rate ◽

Tumor Model ◽

Chemotherapeutic Drugs ◽

Overall Response ◽

Anti Tumor Activity

Abstract Abstract 4873 The non-Hodgkin's lymphomas (NHLs) are a group of lymphoproliferative malignancies with divergent clinical courses. Although the NHLs have historically been treated with radiation therapy and/or chemotherapy, the standard of care has evolved to incorporate the use of rituximab, a mAb that is directed against the CD20 antigen expressed on the surface of transformed B-lymphocytes. However, there are subsets of patients who do not initially respond or become refractory to further treatments. Hence, there is a need for new therapeutic strategies for these patients. CD80 is constitutively expressed on the surface of many B-cell lymphomas. When cell-surface CD80 is cross-linked with anti-CD80 antibodies, cell proliferation is inhibited, proapoptotic molecules are upregulated and antibody-dependent cell cytotoxicity (ADCC) is induced. These findings provide the rationale for using an anti-CD80 mAb to treat lymphoma. Galiximab is a primatized monoclonal antibody that targets CD80 expressed on malignant B cells and is being studied in the clinic as a potential treatment for follicular NHL. Galiximab is a primatized anti-CD80 mAb that has been tested as monotherapy in phase I/II clinical trials involving patients with relapsed/refractory follicular lymphoma (FL), producing an overall response rate of 11% and tumor reductions in 46% of patients. In a recent phase I/II clinical trial involving patients with relapsed or refractory FL, combined therapy with galiximab and rituximab yielded an overall response rate of 66% and a median progression-free survival of 12.1 months at the recommended phase II dose of galiximab (500 mg/m2). We have recently reported that galiximab signals B-NHL cells in vitro and inhibits cell growth and sensitizes resistance tumor cells to apoptosis by chemotherapeutic drugs. The present finding was designed to validate the in vitro findings in in vivo in mice. Thus, we examined in vivo the anti-tumor activity of galiximab used alone and in combination with chemotherapeutic agents in SCID mice bearing human lymphoma xenografts. The in vivo anti-tumor effects of galiximab used alone and in combination with fludarabine or doxorubicin were determined in solid and disseminated human B-lymphoma tumors grown in SCID mice. Galiximab monotherapy in vivo demonstrated significant anti-tumor activity in a Raji lymphoma solid tumor model and in an SKW disseminated lymphoma tumor model. There was significant inhibition in tumor growth and prolongation of survival in both models. In vitro, galiximab sensitized Raji cells to apoptosis by both fludarabine and doxorubicin. Tumor growth inhibition was significantly enhanced when the mice were treated with the combination of galiximab and fludarabine. These findings support the potential clinical application of galiximab in combination with chemotherapeutic drugs for the treatment of CD80-expressing hematologic malignancies. Disclosures: No relevant conflicts of interest to declare.

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Derivatives of Deoxypodophyllotoxin Induce Apoptosis Through Bcl-2/Bax Proteins Expression

Anti-Cancer Agents in Medicinal Chemistry ◽

10.2174/1871520620999200730160952 ◽

2020 ◽

Vol 20 ◽

Author(s):

Ya-Nan Li ◽

Ni Ning ◽

Lei Song ◽

Yun Geng ◽

Jun-Ting Fan ◽

...

Keyword(s):

Annexin V ◽

Mtt Method ◽

Anthriscus Sylvestris ◽

Anti Tumor Activity ◽

Derivatives Of ◽

Toxicity In Vitro ◽

Ht 29 ◽

Mcf 7

Background: Deoxypodophyllotoxin, isolated from theTraditional Chinese Medicine Anthriscus sylvestris, is well-known because of its significant antitumor activity with strong toxicity in vitro and in vivo. Objective: In this article, we synthesized a series of deoxypodophyllotoxin derivatives, and evaluated their antitumor effectiveness.Methods:The anti tumor activity of deoxypodophyllotoxin derivatives was investigated by the MTT method. Apoptosis percentage was measured by flow cytometer analysis using Annexin-V-FITC. Results: The derivatives revealed obvious cytotoxicity in the MTT assay by decreasing the number of late cancer cells. The decrease of Bcl-2/Bax could be observed in MCF-7, HepG2, HT-29 andMG-63 using Annexin V-FITC. The ratio of Bcl-2/Bax in the administration group was decreased, which was determined by the ELISA kit. Conclusion: The derivatives of deoxypodophyllotoxin could induce apoptosis in tumor cell lines by influencing Bcl-2/Bax.

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A Novel Bispecific Antibody Targeting EGFR and VEGFR2 Is Effective against Triple Negative Breast Cancer via Multiple Mechanisms of Action

Cancers ◽

10.3390/cancers13051027 ◽

2021 ◽

Vol 13 (5) ◽

pp. 1027

Author(s):

Nishant Mohan ◽

Xiao Luo ◽

Yi Shen ◽

Zachary Olson ◽

Atul Agrawal ◽

...

Keyword(s):

Endothelial Cells ◽

Tumor Growth ◽

Mechanisms Of Action ◽

Breast Cancers ◽

Single Chain ◽

Cancer Cell Growth ◽

Anti Tumor Activity ◽

Enhance Tumor Growth

Both EGFR and VEGFR2 frequently overexpress in TNBC and cooperate with each other in autocrine and paracrine manner to enhance tumor growth and angiogenesis. Therapeutic mAbs targeting EGFR (cetuximab) and VEGFR2 (ramucirumab) are approved by FDA for numerous cancer indications, but none of them are approved to treat breast cancers. TNBC cells secrete VEGF-A, which mediates angiogenesis on endothelial cells in a paracrine fashion, as well as promotes cancer cell growth in autocrine manner. To disrupt autocrine/paracrine loop in TNBC models in addition to mediating anti-EGFR tumor growth signaling and anti-VEGFR2 angiogenic pathway, we generated a BsAb co-targeting EGFR and VEGFR2 (designated as anti-EGFR/VEGFR2 BsAb), using publicly available sequences in which cetuximab IgG backbone is connected to the single chain variable fragment (scFv) of ramucirumab via a glycine linker. Physiochemical characterization data shows that anti-EGFR/VEGFR2 BsAb binds to both EGFR and VEGFR2 in a similar binding affinity comparable to parental antibodies. Anti-EGFR/VEGFR2 BsAb demonstrates in vitro and in vivo anti-tumor activity in TNBC models. Mechanistically, anti-EGFR/VEGFR2 BsAb not only directly inhibits both EGFR and VEGFR2 in TNBC cells but also disrupts autocrine mechanism in TNBC xenograft mouse model. Furthermore, anti-EGFR/VEGFR2 BsAb inhibits ligand-induced activation of VEGFR2 and blocks paracrine pathway mediated by VEGF secreted from TNBC cells in endothelial cells. Collectively, our novel findings demonstrate that anti-EGFR/VEGFR2 BsAb inhibits tumor growth via multiple mechanisms of action and warrants further investigation as a targeted antibody therapeutic for the treatment of TNBC.

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Knockdown of LncRNA LINC00958 Inhibits the Proliferation and Migration of NSCLC Cells by MiR-204-3p/KIF2A Axis

Cell Transplantation ◽

10.1177/09636897211025500 ◽

2021 ◽

Vol 30 ◽

pp. 096368972110255

Author(s):

Qing Wang ◽

Kai Li ◽

Xiaoliang Li

Keyword(s):

Lung Cancer ◽

Cell Proliferation ◽

Tumor Growth ◽

Tumor Model ◽

Luciferase Reporter ◽

Cell Proliferation And Migration ◽

And Migration ◽

Proliferation And Migration

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. Increasing evidence suggests that long non-coding RNAs (lncRNAs) function in the tumorigenesis of NSCLC. LINC00958, a newly identified lncRNA, has been reported to be closely linked to tumorigenesis in several cancers. However, its specific role in NSCLC remains unclear. In this study, we determined the expression of LINC00958 in NSCLC by RT-qPCR analysis and evaluated cell proliferation and migration by CCK-8 and transwell assays, respectively. We established a xenograft tumor model to examine the effect of LINC00958 on tumor growth in vivo. Luciferase reporter assays were performed to determine the interaction between LINC00958 and miR-204-3p and the interaction between miR-204-3p and KIF2A. We found that LINC00958 was up-regulated in NSCLC tissues and cell lines. Down-regulation of LINC00958 inhibited cell proliferation and migration in vitro and suppressed tumor growth in vivo. Besides, miR-204-3p was identified as a target of LINC00958 and miR-204-3p inhibitor could reverse the inhibitory effect of LINC00958 knockdown on proliferation and migration of NSCLC cells. We also validated that KIF2A, a direct target of miR-204-3p, was responsible for the biological role of LINC00958. KIF2A antagonized the effect of miR-204-3p on NSCLC cell proliferation and migration and was regulated by LINC00958/miR-204-3p. Taken together, these data indicate that the LINC00958/miR-204-3p/KIF2A axis is critical for NSCLC progression, which might provide a potential therapeutic target of NSCLC.

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Anti-Tumor Activity of the Aurora a Inhibitor MLN8237 in Diffuse Large B-Cell Lymphoma Preclinical Models.

Blood ◽

10.1182/blood.v112.11.1592.1592 ◽

2008 ◽

Vol 112 (11) ◽

pp. 1592-1592 ◽

Cited By ~ 1

Author(s):

Jessica J Huck ◽

Mengkun Zhang ◽

Marc L Hyer ◽

Mark G Manfredi

Keyword(s):

Tumor Growth ◽

Growth Inhibition ◽

Tumor Model ◽

B Cell Lymphoma ◽

Tumor Growth Inhibition ◽

Aurora A ◽

Hct 116 ◽

Xenograft Models

Abstract Aurora A kinase is a serine/threonine protein kinase that is essential for normal transit of cells through mitosis. In many tumor types the Aurora A gene is amplified and/or the protein is over-expressed. The Aurora A small-molecule inhibitor MLN8237 demonstrated robust tumor growth inhibition in xenograft models of solid tumors grown subcutaneously (S.C.) in immunocompromised mice. Here we explored the antitumor activity of MLN8237 in models of diffuse large B-cell lymphoma (DLBCL) both in vitro and in vivo. In vivo three established DLBCL xenograft models (OCI-Ly7, OCI-Ly19, and WSU-DLCL2; all cells expressing luciferase) and a primary DLBCL tumor model PHTX-22-06 were tested using MLN8237 at different doses. Rituximab, an anti-CD20 monoclonal antibody that is active against CD20+ malignant B cells and is a standard of care agent was used for comparison. Using these model systems, tumor cells were injected either I.V. (to evaluate disseminated disease), or S.C. in severe combined immunodeficient mice (SCID). Animals were dosed orally for 21 days with MLN8237 (QD or BID) at various doses, or Rituximab dosed at 10mg/kg IV (once/week) and tumor growth inhibition was monitored using either bioluminescent imaging for the disseminated models or vernier calipers for the S.C. models. Tumor growth inhibition by MLN8237 was dose dependent with 20 mg/kg bid being the most efficacious dose (TGI>100% in both disseminated OCI-Ly19 and WSU models). All animals in the OCI-Ly19 disseminated model 20 mg/kg BID treatment group demonstrated regressions and remained disease free until the end of the study, day 65. In this study the Rituximab treated animals were euthanized on day 31 due to a high level of tumor burden. In the primary tumor model, PHTX-22-06, MLN8237 dosed at 20 mg/kg BID was also the most efficacious with a TGI of 95%. Moreover, tumor growth inhibition was durable as determined by prolonged tumor growth delay (>50 days). Significant efficacy was achieved in all models tested, whether grown as disseminated or subcutaneous models. A noted increase in durability of response was observed with MLN8237 treatment when compared with previous data from solid tumor models. In vitro, MLN8237 treatment increased levels of apoptosis in the OCI-Ly19 cells in comparison to the solid tumor cell line HCT-116 (colon). Greater Annexin V positive cells and greater cleaved PARP and Caspase-3 signals were detected in the MLN8237 treated OCI-Ly19 cells when compared to HCT-116 cells. The demonstration of robust and durable anti-tumor activity in preclinical models treated with MLN8237 provides the basis for its clinical evaluation as a treatment option for DLBCL. MLN8237 is currently in multiple Phase I clinical trials.

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Kruppel-like factor 6 suppresses growth and invasion of hepatocellular carcinoma cells in vitro and in vivo

International Journal of Immunopathology and Pharmacology ◽

10.1177/0394632016655171 ◽

2016 ◽

Vol 29 (4) ◽

pp. 666-675 ◽

Cited By ~ 2

Author(s):

Pei-Hao Wen ◽

Dong-Yu Wang ◽

Jia-Kai Zhang ◽

Zhi-Hui Wang ◽

Jie Pan ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Cell Proliferation ◽

Tumor Growth ◽

Tumor Model ◽

Carcinoma Cells ◽

Tumor Suppressive Function ◽

Xenograft Tumor Growth ◽

Hcc Cells

Kruppel-like factor 6 (KLF6) as a novel tumor suppressive gene participates in multiple biological behaviors and plays an important role in regulating tumor cell growth and invasion. However, the functions of KLF6 in hepatocellular carcinoma (HCC) remain poorly understood. The expression level of KLF6 was examined by immunohistochemical assay in human HCC tissues, and KLF6-overexpressed HCC cells (SMCC-7721 and HepG2) were used for evaluating cell proliferation and invasion by MTT and Transwell assays. A subcutaneous HCC tumor model was established for assessing tumor growth in vivo. Our results showed that the expression of KLF6 was significantly downregulated in HCC tissues compared with the adjacent non-cancerous tissues (50.0% vs. 72.0%, P = 0.034) and negatively associated with the lymph-vascular space invasion (LVSI) in HCC patients ( P = 0.003). Furthermore, overexpression of KLF6 reduced cell proliferation and weakened the cell invasive potential followed with the decreased expression of PCNA and MMP-9 in HCC cells. The in vivo experiment indicated that KLF6 overexpression suppressed the xenograft tumor growth. Therefore, our findings show that KLF6 suppresses growth and invasion of HCC cells in vitro and in vivo, suggesting a tumor suppressive function in HCC and provides the potential therapeutic target for the treatment of HCC.

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