DOTA-NOC (DOTA-[Nal3]-octreotide)

DOTANOC (DOTA-[Nal3]-octreotide) is an octreotide-derived peptide containing a DOTA chelator and a 1-naphthylalanine substitution at position 3. The peptide-chelator complex forms a somatostatin analog ligand that binds strongly to SSTR2, SSTR3 and SSTR5, which are somatostatin receptors often overexpressed in neuroendocrine tumors (NETs). When labeled with radionuclides (e.g., Ga-68, Lu-177, Y-90), the ligand becomes a radioligand used in PET/CT imaging of NETs and peptide receptor radionuclide therapy (PRRT). This dual theranostic use makes DOTA-NOC a valuable agent in oncology.

Produced by JPT Peptide Technologies, a leader in custom peptide synthesis and oncology research reagents.

DOTA-NOC (DOTA-[Nal3]-octreotide), precursor for radiolabeled DOTA-NOC and ligand for somatostatin receptors. Can be bound to radionuclides for development of cancer treatment and diagnosis. For research use only!

DOTA-NOC (DOTA-[Nal3]-octreotide) - Specifications

• Peptide sequence: DPhe-Cys-1Nal-DTrp-Lys-Thr-Cys-Thr-ol (cyclic disulfide)
• Amount: 2 mg (20 x100µg)
• Purity: >95% (HPLC-MS)
• Delivery Format: Freeze-dried in glass vial
• Application(s): Nuclear medicine
• Condition(s)/Topic(s): Cancer
• Standard Delivery Time: approx. 3 weeks

JPT Peptide Technologies provides the DOTA NOC peptide in a range of aliquot sizes, ensuring flexibility for diverse research applications. For any special requirements, please contact our customer support: peptide@jpt.com

Radiolabeled DOTA-NOC variants and their applications:

As a precursor of its radiolabeled variants, DOTA NOC can carry various radionuclides via its DOTA chelator and generate radioligands essential for imaging and treating neuroendocrine tumors (NETs). For example:

• Ga-68-DOTA-NOC is clinically used for high-resolution PET/CT visualization of NETs by binding to somatostatin receptors and emitting positrons that enable precise tumor imaging.
• Lu-177-DOTA-NOC and Y-90-DOTA-NOC are applied in peptide receptor radionuclide therapy (PRRT), in which deadly beta radiation is delivered to tumor cells.
• Ac-225-DOTA-NOC, a recently developed alpha-emitting variant, is being investigated for resistant or advanced tumors, providing highly localized and potent DNA damage that induces cell death.

These applications underscore the pivotal role of DOTANOC radioligands in tumor imaging and therapy, while emphasizing the need for continued research to expand their therapeutic potential in oncology.

We also offer customized DOTANOC tailored to your research needs (non-radioactive variants). More information is available on our website!

Custom Options for DOTA Peptides and other Radioligands

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Research areas and applications of DOTA NOC, CAS: 619300-53-7:

• NET diagnosis and staging research: Investigated for highly sensitive PET/CT imaging to detect primary and metastatic tumors.
• Receptor profiling studies: Used to explore SSTR2, SSTR3, and SSTR5 expression for potential guidance of individualized therapy.
• PRRT treatment studies: Evaluated for identifying suitable patients and predicting therapeutic response.
• Treatment monitoring research: Studied for its role in tracking disease progression, therapeutic efficacy, and recurrence.
• Exploration in other SSTR-positive tumors: Researched in cancers expressing somatostatin receptors, including meningiomas, medullary thyroid carcinoma, and small cell lung cancer.
• Theranostic investigations: Examined as a model for integrating diagnostics (PET/CT) with therapy (PRRT).
• Alpha therapy research: Studied with alpha-emitting constructs (e.g., Ac-225-DOTANOC) and novel conjugates for enhanced therapeutic outcomes.
• Biodistribution studies: Applied in research assessing pharmacokinetics, tracer distribution, and tumor uptake.
• Radionuclide-drug conjugate research: Investigated as a platform for developing dual-purpose imaging and therapeutic agents.

Benefits of DOTANOC (DOTA-[Nal3]-octreotide) and its radiolabeled variants:

• High sensitivity: Detects even small or early lesions often missed by conventional imaging.
• Functional imaging: Visualizes receptor activity, providing biological as well as anatomical information.
• Broad receptor affinity: Binds strongly to SSTR2, SSTR3, and SSTR5, improving detection across heterogeneous tumors.
• Theranostic versatility: Combines PET/CT imaging with radionuclide therapy within one molecular platform.

Key Concepts

What are radionuclides and radioligands?

Radionuclides are unstable, radioactive isotopes that emit radiation as they decay and are widely used in medicine for tumor imaging and therapy. Depending on the radiation type, they can either provide high-resolution diagnostic images (positron or gamma emitters) or destroy tumor cells through localized radiation damage (beta- and alpha-emitters).

When a radionuclide is attached to a molecule that specifically binds to certain receptors or cells, the resulting compound is called a radioligand. Radioligands combine the targeting ability of the ligand with the functional effects of the radionuclide, enabling precise tumor imaging and targeted treatment.

What is Peptide Receptor Radionuclide Therapy?

Peptide Receptor Radionuclide Therapy (PRRT) is a targeted molecular therapy primarily applied in the treatment of neuroendocrine tumors (NETs) that overexpress somatostatin receptors. In this strategy, somatostatin analogs such as octreotide derivatives are conjugated to a radionuclide (most commonly lutetium-177 or yttrium-90) via the DOTA chelator. Following intravenous administration, the radiolabeled peptide ligand exhibits high affinity binding to somatostatin receptors on tumor cells and undergoes receptor-mediated internalization.

This process enables the radionuclide to deliver localized ionizing radiation directly to malignant tissue while largely sparing surrounding healthy structures. Through this receptor-targeted mechanism, PRRT facilitates tumor regression and disease stabilization, and has emerged as an effective therapeutic option for patients with advanced, or metastatic NETs.

What is a DOTA chelator?

A DOTA chelator (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) is a macrocyclic compound that forms highly stable complexes with metal ions, including diagnostic and therapeutic radionuclides such as Ga-68, Lu-177, and Y-90. By acting as a molecular cage, DOTA ensures that the radionuclide remains securely bound to the peptide in vivo, preventing premature release and minimizing off-target radiation. This stability is crucial for both effective tumor targeting and patient safety, as it allows the radioligand to circulate intact until it reaches receptor-expressing tumor sites.

Impact of Nal3 Substitution on Receptor Affinity

The 1-naphthylalanine (Nal3) substitution in DOTA-NOC replaces the third amino acid of octreotide with a bulky aromatic side chain. This modification strengthens hydrophobic interactions with somatostatin receptors and markedly increases binding affinity, particularly for SSTR2, SSTR3, and SSTR5. As a result, DOTANOC achieves broad receptor coverage and strong tumor binding.

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