NEO212, temozolomide conjugated to NEO100, exerts superior therapeutic activity over temozolomide in preclinical chemoradiation models of glioblastoma.

Background: The chemotherapeutic standard of care for patients with glioblastoma (GB) is radiation therapy (RT) combined with temozolomide (TMZ). However, during the twenty years since its introduction, this so-called Stupp protocol has revealed major drawbacks, because nearly half of all GBs harbor intrinsic treatment resistance mechanisms. Prime among these are the increased expression of the DNA repair protein O6-guanine-DNA methyltransferase (MGMT) and cellular deficiency in DNA mismatch repair (MMR).

Activation of Epstein-Barr Virus' Lytic Cycle in Nasopharyngeal Carcinoma Cells by NEO212, a Conjugate of Perillyl Alcohol and Temozolomide.

The Epstein-Barr virus (EBV) is accepted as a primary risk factor for certain nasopharyngeal carcinoma (NPC) subtypes, where the virus persists in a latent stage which is thought to contribute to tumorigenesis. Current treatments are sub-optimal, and recurrence occurs in many cases. An alternative therapeutic concept is aimed at triggering the lytic cycle of EBV selectively in tumor cells as a means to add clinical benefit.

Inhibition of autophagy and induction of glioblastoma cell death by NEO214, a perillyl alcohol-rolipram conjugate.

Glioblastoma (GBM) is the most aggressive primary brain tumor, exhibiting a high rate of recurrence and poor prognosis. Surgery and chemoradiation with temozolomide (TMZ) represent the standard of care, but, in most cases, the tumor develops resistance to further treatment and the patients succumb to disease. Therefore, there is a great need for the development of well-tolerated, effective drugs that specifically target chemoresistant gliomas.

Enhanced brain entry of checkpoint-inhibitory therapeutic antibodies facilitated by intraarterial NEO100 in mouse models of brain-localized malignancies.

Objective: Immune checkpoint-inhibitory therapeutic antibodies have shown striking activity against several types of cancers but are less effective against brain-localized malignancies, in part due to the protective effect of the blood-brain barrier (BBB). The authors hypothesized that intraarterial (IA) delivery of a novel compound, NEO100, has the potential to safely and reversibly open the BBB to enable brain-targeted therapeutic activity of checkpoint-inhibitory antibodies.

Methods: Immunocompetent mice with syngeneic glioblastoma or melanoma cells implanted into their brains were subjected to a single IA injection of NEO100 to open their BBB.

NEO212, a Perillyl Alcohol-Temozolomide Conjugate, Triggers Macrophage Differentiation of Acute Myeloid Leukemia Cells and Blocks Their Tumorigenicity.

Many patients with acute myeloid leukemia (AML) are still dying from this disease. In the past, the alkylating agent temozolomide (TMZ) has been investigated for AML and found to be partially effective; however, the presence of O6-methylguanine DNA methyltransferase (MGMT; a DNA repair enzyme) in tumor cells confers profound treatment resistance against TMZ. We are developing a novel anticancer compound, called NEO212, where TMZ was covalently conjugated to perillyl alcohol (a naturally occurring monoterpene).

Potentially Curative Therapeutic Activity of NEO212, a Perillyl Alcohol-Temozolomide Conjugate, in Preclinical Cytarabine-Resistant Models of Acute Myeloid Leukemia.

Despite progress in the treatment of acute myeloid leukemia (AML), the clinical outcome remains suboptimal and many patients are still dying from this disease. First-line treatment consists of chemotherapy, which typically includes cytarabine (AraC), either alone or in combination with anthracyclines, but drug resistance can develop and significantly worsen prognosis. Better treatments are needed.

Developing a clinically relevant radiosensitizer for temozolomide-resistant gliomas.

The prognosis for patients with glioblastoma (GB) remains grim. Concurrent temozolomide (TMZ) radiation-the cornerstone of glioma control-extends the overall median survival of GB patients by only a few months over radiotherapy alone. While these survival gains could be partly attributed to radiosensitization, this benefit is greatly minimized in tumors expressing O6-methylguanine DNA methyltransferase (MGMT), which specifically reverses O6-methylguanine lesions.

Cytotoxic impact of a perillyl alcohol-temozolomide conjugate, NEO212, on cutaneous T-cell lymphoma .

Background: Mycosis fungoides (MF) and Sézary syndrome (SS) are subtypes of primary cutaneous lymphomas and represent complex diseases regarding their physiopathology and management. Depending on the stage of the disease, different treatment regimens are applied, but there is no consensus on an optimal approach. Prognosis for patients with early stage MF is favorable, but significantly worsens in advanced disease and in SS, where patients frequently relapse and require multiple therapies.

A Novel Venom-Derived Peptide for Brachytherapy of Glioblastoma: Preclinical Studies in Mice.

We developed a bacterial expression system to produce a recombinant disintegrin, vicrostatin (VCN), whose structure is based on a natural disintegrin isolated from southern copperhead snake venom. Our goal is to develop VCN for potential clinical translation as an anti-cancer agent. VCN is a peptide of 69 amino acids with a single tyrosine residue.

Rare Stochastic Expression of O6-Methylguanine- DNA Methyltransferase (MGMT) in MGMT-Negative Melanoma Cells Determines Immediate Emergence of Drug-Resistant Populations upon Treatment with Temozolomide In Vitro and In Vivo.

The chemotherapeutic agent temozolomide (TMZ) kills tumor cells preferentially via alkylation of the O6-position of guanine. However, cells that express the DNA repair enzyme O6-methylguanine-DNA methyltransferase (MGMT), or harbor deficient DNA mismatch repair (MMR) function, are profoundly resistant to this drug. TMZ is in clinical use for melanoma, but objective response rates are low, even when TMZ is combined with O6-benzylguanine (O6BG), a potent MGMT inhibitor.

Multimeric disintegrin protein polymer fusions that target tumor vasculature.

Recombinant protein therapeutics have increased in number and frequency since the introduction of human insulin, 25 years ago. Presently, proteins and peptides are commonly used in the clinic. However, the incorporation of peptides into clinically approved nanomedicines has been limited.

Development of a chimeric recombinant disintegrin as a cost-effective anti-cancer agent with promising translational potential.

Vicrostatin (VCN) is a chimeric recombinant disintegrin generated in Origami B (DE3) Escherichia coli as a genetic fusion between the C-terminal tail of a viperid disintegrin echistatin and crotalid disintegrin contortrostatin (CN). The therapeutic modulation of multiple integrin pathways via soluble disintegrins was previously shown by us and others to elicit potent anti-angiogenic and anti-metastatic effects in several animal cancer models. Despite these favorable attributes, these polypeptides are notoriously difficult to produce recombinantly in significant quantity due to their structure which requires the correct pairing of multiple disulfide bonds for biological activity.

Vicrostatin - an anti-invasive multi-integrin targeting chimeric disintegrin with tumor anti-angiogenic and pro-apoptotic activities.

Similar to other integrin-targeting strategies, disintegrins have previously shown good efficacy in animal cancer models with favorable pharmacological attributes and translational potential. Nonetheless, these polypeptides are notoriously difficult to produce recombinantly due to their particular structure requiring the correct pairing of multiple disulfide bonds for biological activity. Here, we show that a sequence-engineered disintegrin (called vicrostatin or VCN) can be reliably produced in large scale amounts directly in the oxidative cytoplasm of Origami B E.

The use of pepsin in receptor internalization assays.

For internalization experiments that use fluorescent antibody (Ab) staining to distinguish between inside versus outside cellular localization of various receptor targeting ligands, it is critical that there be efficient removal of all residual surface-bound fluorescent Ab. To achieve this, a fluorescent Ab removal technique is commonly employed in receptor internalization assays that utilizes low pH glycine-based buffers to wash off the residual non-internalized fluorescent Ab retained on cell surfaces. In this study, we highlight the shortcomings of this technique and propose an alternative in situ proteolytic approach that we found to be non-deleterious to the cells and significantly more effective in removing the residual fluorescence resulting from non-internalized surface-bound Ab.

Development of a novel recombinant disintegrin, contortrostatin, as an effective anti-tumor and anti-angiogenic agent.

Contortrostatin (CN) (Mr 13,500 Da) is a novel homodimeric disintegrin isolated from the venom of Agkistrodon contortrix contortrix (Southern Copperhead) snake and displays two RGD motifs (one on each chain), which modulate its interaction with integrins on tumor cells and angiogenic vascular endothelial cells. In previous studies, we have shown that native CN administered in a liposomal formulation exhibits potent anti-angiogenic and tumor growth inhibitory activities. Current isolation of the protein from crude venom is difficult and prohibitively expensive for translation into the clinic.

Intravenous liposomal delivery of the snake venom disintegrin contortrostatin limits breast cancer progression.

Despite significant research in this area, metastatic breast cancer remains a disease with a poor prognosis. Until an effective therapy is developed, it is imperative that new treatment modalities be investigated. In this report, we describe an effective method for delivery of a novel snake venom disintegrin, contortrostatin (CN), in an orthotopic, xenograft model of human mammary cancer in immunodeficient mice.