CD133/prominin-1 is a potential therapeutic target for antibody-drug conjugates in hepatocellular and gastric cancers (original) (raw)

Anti-CD133 Monoclonal Antibody CMab-43 Exerts Antitumor Activity in a Mouse Xenograft Model of Colon Cancer

Monoclonal Antibodies in Immunodiagnosis and Immunotherapy, 2019

Cancer stem cells contribute to tumorigenesis, metastasis, recurrence, and chemoresistance. CD133/prominin-1-a pentaspan membrane glycoprotein-has been used as a stem cell biomarker for the isolation of stemlike cells from a variety of normal and pathological tissues. In our previous studies, we developed several anti-CD133 monoclonal antibodies using Cell-Based Immunization and Screening (CBIS) methods, followed by characterization of their efficacy by flow cytometry, western blotting, and immunohistochemical analyses. One of the 100 clones, CMab-43 (IgG 2a , kappa), demonstrated a sensitive and specific reaction against colon cancer cells. This study aimed to investigate the antitumor activity of CMab-43. Caco-2 cells (human colon cancer cell line) were subcutaneously implanted into the flanks of nude mice. CMab-43 and control mouse IgG were injected three times into the peritoneal cavity of mice. Tumor formation was observed in the control and CMab-43-treated mice of Caco-2 xenograft models. CMab-43 significantly reduced tumor development of Caco-2 xenograft in comparison with the control mouse IgG on days 12, 14, and 17. Our results cumulatively suggest that CMab-43 is useful for antibody therapy against CD133expressing colon cancers.

Optimization of post-insertion method to conjugate Doxil with anti-CD133 monoclonal antibodies: Investigating the specific binding and cytotoxicity to colorectal cancer cells in vitro

Saudi Pharmaceutical Journal

In this paper, Doxil coupled with anti-CD133 monoclonal antibodies made by either routine or optimized post-insertion technique, were compared with respect to their size, drug leakage, release pattern and the number of antibodies conjugated per single liposome. The results demonstrated that the number of antibodies conjugated per liposome in the optimized post-insertion technique was almost two times more than those in the routine post-insertion method. However, the drug release and leakage pattern was almost similar between the two methods. Furthermore, anti-tumor activity and therapeutic efficacy of the preferred CD133-targeted Doxil with Doxil was compared in terms of their in vitro binding, uptake, internalization and cytotoxicity against HT-29 (CD133+) and CHO (CD133-) cells. Flow cytometry analyses and confocal laser scanning microscopy results exhibited a significantly higher cellular uptake, binding and internalization of CD133-targeted Doxil in CD + 133 cells relative to Doxil. Cytotoxicity results revealed a lower in vitro inhibitory concentration for CD133-targeted Doxil compared to Doxil. However, CHO (CD133-) cells displayed a similar uptake and in vitro cytotoxicity for both CD133-Doxil and non-targeted Doxil. Therefore, the results of this study can exhibit that specific recognition and binding of antibodies with CD133 receptors on HT-29 cells can result in enhanced cellular uptake, internalization and cytotoxicity. The research suggests further investigation for in vivo studies and may offer proof-of-principle for an active targeting concept.

Establishment of CMab-43, a Sensitive and Specific Anti-CD133 Monoclonal Antibody, for Immunohistochemistry

Monoclonal antibodies in immunodiagnosis and immunotherapy, 2017

CD133, also known as prominin-1, was first described as a cell surface marker on early progenitor and hematopoietic stem cells. It is a five-domain transmembrane protein composed of an N-terminal extracellular tail, two small cytoplasmic loops, two large extracellular loops containing seven potential glycosylation sites, and a short C-terminal intracellular tail. CD133 has been used as a marker to identify cancer stem cells derived from primary solid tumors and as a prognostic marker of gliomas. Herein, we developed novel anti-CD133 monoclonal antibodies (mAbs) and characterized their efficacy in flow cytometry, Western blot, and immunohistochemical analyses. We expressed the full length of CD133 in LN229 glioblastoma cells, immunized mice with LN229/CD133 cells, and performed the first screening using flow cytometry. After limiting dilution, we established 100 anti-CD133 mAbs, reacting with LN229/CD133 cells but not with LN229 cells. Subsequently, we performed the second and third ...

Rapid selection and proliferation of cd133(+) cells from cancer cell lines: Chemotherapeutic implications

PLoS ONE, 2010

Cancer stem cells (CSCs) are considered a subset of the bulk tumor responsible for initiating and maintaining the disease. Several surface cellular markers have been recently used to identify CSCs. Among those is CD133, which is expressed by hematopoietic progenitor cells as well as embryonic stem cells and various cancers. We have recently isolated and cultured CD133 positive [CD133(+)] cells from various cancer cell lines using a NASA developed Hydrodynamic Focusing Bioreactor (HFB) (Celdyne, Houston, TX). For comparison, another bioreactor, the rotary cell culture system (RCCS) manufactured by Synthecon (Houston, TX) was used. Both the HFB and the RCCS bioreactors simulate aspects of hypogravity. In our study, the HFB increased CD133(+) cell growth from various cell lines compared to the RCCS vessel and to normal gravity control. We observed a (+)15-fold proliferation of the CD133(+) cellular fraction with cancer cells that were cultured for 7-days at optimized conditions. The RCCS vessel instead yielded a (2)4.8-fold decrease in the CD133(+)cellular fraction respect to the HFB after 7-days of culture. Interestingly, we also found that the hypogravity environment of the HFB greatly sensitized the CD133(+) cancer cells, which are normally resistant to chemo treatment, to become susceptible to various chemotherapeutic agents, paving the way to less toxic and more effective chemotherapeutic treatment in patients. To be able to test the efficacy of cytotoxic agents in vitro prior to their use in clinical setting on cancer cells as well as on cancer stem cells may pave the way to more effective chemotherapeutic strategies in patients. This could be an important advancement in the therapeutic options of oncologic patients, allowing for more targeted and personalized chemotherapy regimens as well as for higher response rates.

CD133 induces tumour-initiating properties in HEK293 cells

Tumor Biology, 2013

The pentaspan protein CD133 (Prominin-1) is part of the signature of tumour-initiating cells for various cancer entities. The aim of the present study was to investigate the impact of ectopic CD133 expression on tumourigenic properties of otherwise CD133-negative, nontumourigenic cells in vitro and in vivo. CD133 was stably transfected into human embryonic kidney 293 (HEK293) which was then sorted for the expression of CD133. The effects of CD133 on cell proliferation were assessed upon standard cell counting of sorted cells at various time points. Severe combined immunodeficient (SCID) mice (n030) were injected with HEK293 CD133 high and CD133 low transfectants (5×10 3 , 1×10 5 , or 5×10 6 cells per injection). The expression of CD133, Ki67, CD44s, CD44v6, and EpCAM was analysed upon immunohistochemical staining of cryosections with specific antibodies. In vitro, ectopic expression of CD133 did influence neither cell proliferation nor cell cycle distribution of otherwise CD133-negative HEK293 cells. However, CD133 high cells generated tumours in vivo in SCID mice with at least 1,000-fold increased frequency compared to CD133 low cells. Tumour load was also significantly increased in CD133 high cells as compared to those tumours formed by high numbers of CD133 low cells. Immunohistochemistry stainings disclosed no changes in Ki67, CD44s, CD44v6, or EpCAM once tumours were formed by either cell type. CD133 induces tumour-initiating properties in HEK293 cells in vivo and is potentially involved in the regulation of tumourigenicity. Future research will aim at the elucidation of molecular mechanisms of CD133-induced tumourigenicity. Keywords CD133. HEK293. Tumourigenic potential. Mouse model Martin Canis and Axel Lechner have equally contributed.

CD133 antisense suppresses cancer cell growth and increases sensitivity to cisplatin in�vitro

Experimental and Therapeutic Medicine, 2012

The increased incidence of cancer in recent years is associated with a high rate of mortality. Numerous types of cancer have a low percentage of CD133 + cells, which have similar features to stem cells. The CD133 molecule is involved in apoptosis and cell proliferation. The aim of this study was to determine the biological effect of CD133 suppression and its role in the chemosensitization of cancer cell lines. RT-PCR and immunocytochemical analyses indicated that CD133 was expressed in the cancer cell lines B16F10, MCF7 and INER51. Downregulation of CD133 by transfection with an antisense sequence (As-CD133) resulted in a decrease in cancer cell viability of up to 52, 47 and 22% in B16F10, MCF-7 and INER51 cancer cell lines, respectively. This decreased viability appeared to be due to the induction of apoptosis. In addition, treatment with As-CD133 in combination with cisplatin had a synergic effect in all of the cancer cell lines analyzed, and in particular, significantly decreased the viability of B16F10 cancer cells compared with each treatment separately (3.1% viability for the combined treatment compared with 48% for 0.4 µg As-CD133 and 25% for 5 ng/µl cisplatin; P<0.05). The results indicate that the downregulation of CD133 by antisense is a potential therapeutic target for cancer and has a synergistic effect when administered with minimal doses of the chemotherapeutic drug cisplatin, suggesting that this combination strategy may be applied in cancer treatment. Materials and methods Cell culture. The B16F10 murine melanoma and MCF7 breast cancer cell lines were obtained from the American Type Culture Collection (ATCC, Manassas, VA, USA) and the INER51 lung cancer cell line was obtained from the National Institute of Respiratory Diseases (INER) in Mexico City, Mexico.

An Update on Anti-CD137 Antibodies in Immunotherapies for Cancer

International Journal of Molecular Sciences

The selective expression of CD137 on cells of the immune system (e.g., T and DC cells) and oncogenic cells in several types of cancer leads this molecule to be an attractive target to discover cancer immunotherapy. Therefore, specific antibodies against CD137 are being studied and developed aiming to activate and enhance anti-cancer immune responses as well as suppress oncogenic cells. Accumulating evidence suggests that anti-CD137 antibodies can be used separately to prevent tumor in some cases, while in other cases, these antibodies need to be co-administered with other antibodies or drugs/vaccines/regents for a better performance. Thus, in this work, we aim to update and discuss current knowledge about anti-cancer effects of anti-CD137 antibodies as mono- and combined-immunotherapies.

Therapeutic Antitumor Efficacy of Anti-CD137 Agonistic Monoclonal Antibody in Mouse Models of Myeloma

Clinical Cancer Research, 2008

Purpose: Eradication of post-treatment residual myeloma cells is needed to prevent relapses and immunostimulatory monoclonal antibodies (mAbs) such as anti-CD137, CTLA-4, CD40, etc, that enhance the immune response against malignancies represent a means of achieving this purpose. This study explores anti-CD137 mAbs for mutiple myeloma (MM) treatment in preclinical models of the disease because they safely augment tumor immunity and are in clinical trials for other cancers.

Potent Anticarcinoma Activity of the Humanized Anti-CD70 Antibody h1F6 Conjugated to the Tubulin Inhibitor Auristatin via an Uncleavable Linker

Clinical Cancer Research, 2008

Purpose: The antitubulin agent monomethyl auristatin F (MMAF) induces potent antitumor effects when conjugated via protease cleavable linkers to antibodies targeting internalizing, tumor-specific cell surface antigens. Humanized 1F6 (h1F6) is a humanized monoclonal antibody targeting CD70, a member of the tumor necrosis factor family that is expressed on hematologic malignancies and carcinomas. Here, we tested h1F6^maleimidocaproyl (mc) MMAF conjugates, consisting of an uncleavable mc linker, for their ability to interfere with the growth of CD70-positive carcinomas. Experimental Design: To evaluate the optimal drug per antibody ratio, we conjugated either four or eight MMAF molecules to the cysteines that comprise the interchain disulfides of h1F6 and determined antitumor activities in vitro and in xenografted mice. The tumor types tested included glioblastoma, patient-derived renal cell carcinoma (RCC) cell isolates, and standard RCC tumor cell lines. Results: All h1F6-mcMMAF conjugates potently interfered with the growth of all carcinomas in vitro and resulted in complete responses of RCC tumors implanted orthotopically or s.c. in mice. In vitro, h1F6-mcMMAF(8) was generally more potent than h1F6-mcMMAF(4). However, h1F6-mcMMAF(4) displayed equal or better efficacy than h1F6-mcMMAF(8) when administered to tumor-bearing mice. Conclusions: We showed that h1F6-mcMMAF conjugates inhibited the growth of human carcinomas and that increased drug loading, while improving potency in vitro, did not substantially affect the pharmacodynamic and pharmacokinetic properties in vivo. Based on these findings, h1F6-mcMMAF(4), designated SGN-75, has been identified as a potential antibody-drug conjugate for clinical development.

Boosting Cancer Immunotherapy with Anti-CD137 Antibody Therapy

Clinical Cancer Research, 2015

In the last five years, immunomodulatory antibodies have revolutionized cancer immunotherapy. CD137, a member of the tumor necrosis factor receptor superfamily, represents a promising target for enhancing anti-tumor immune responses. CD137 helps regulate the activation of many immune cells, including CD4 + T cells, CD8 + T cells, dendritic cells and natural killer cells. Recent studies indicate that the anti-tumor efficacy of therapeutic tumor-targeting antibodies can be augmented by the addition of agonistic antibodies targeting CD137. As ligation of CD137 provides a co-stimulatory signal in multiple immune cell subsets, combination therapy of CD137 antibody with therapeutic antibodies and/or vaccination has the potential to improve cancer treatment.