Surreal illustration of interconnected nodes in cancerous and healthy colon tissue.

Cracking the Code: How a Tiny Loop Could Revolutionize Colorectal Cancer Treatment

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Jordan Keane in Health & Wellness October 2026 • 3 min read.

"Scientists Discover a Key Feedback Loop in Colorectal Cancer Development, Offering New Avenues for Targeted Therapies"


Colorectal cancer (CRC) remains a significant health challenge worldwide. While treatments have improved, the need for more effective and targeted therapies is ever-present. Recent research has shed light on a fascinating feedback loop within cancer cells that could pave the way for new treatment approaches.

A team of scientists has identified a critical link between several key proteins within colorectal cancer cells: c-MYC, NAMPT, and SIRT1. This loop appears to be activated in the early stages of both major pathways leading to CRC, offering a potential target for intervention.

This article explores the details of this discovery, explaining the role of each protein and how their interaction contributes to cancer development. We'll also delve into the potential therapeutic implications, including the possibility of developing drugs that specifically target this feedback loop.

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CRC’s Global and U.S. Burden

The 2020 statistics cited in a review report that colorectal cancer accounted for 10.0% of the world’s 19.3 million new cancer cases and 9.4% of the 9.9 million cancer deaths, ranking second among causes of cancer death. In the United States, colorectal cancer is the fourth most common cancer in men and women, excluding some kinds of skin cancer, and the fourth leading cause of cancer-related deaths. A study examined c-MYC gene copy-number gain in 367 consecutive patients with primary colorectal cancer, investigating its incidence and clinicopathological significance.

The c-MYC/NAMPT/SIRT1 Loop: What is it and Why Does it Matter?

Surreal illustration of interconnected nodes in cancerous and healthy colon tissue.

At the heart of this discovery lies a positive feedback loop involving three key proteins: c-MYC, NAMPT, and SIRT1. Understanding the function of each is crucial to grasping the significance of the loop:

Let's break down the roles and interaction:

  • c-MYC: This is a well-known proto-oncogene, meaning it has the potential to cause cancer when it is abnormally activated. It regulates cell growth, proliferation, and metabolism.
  • NAMPT (Nicotinamide Phosphoribosyltransferase): An enzyme crucial for producing NAD+, a vital molecule for cellular energy and function. NAMPT is also implicated in cancer development and progression.
  • SIRT1 (Silent Information Regulator 1): A protein deacetylase involved in various cellular processes, including stress resistance, DNA repair, and metabolism. SIRT1 has been shown to promote cancer cell survival.
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NAMPT and c-MYC as Research Targets

A review reports that NAMPT can be inhibited, making it a subject of cancer-treatment research. Research in murine serrated intestinal tumorigenesis suggests NAMPT and SIRT1 may represent therapeutic targets in colorectal cancers driven by serrated BRAF or KRAS alterations, as well as by the WNT pathway. These findings identify potential research directions; the supplied sources do not establish these targets as treatments for patients.

The study reveals that c-MYC increases the levels of NAMPT, which leads to higher NAD+ production and, consequently, increased SIRT1 activity. SIRT1, in turn, further enhances c-MYC activity, creating a self-amplifying loop that fuels cancer cell growth and survival.

A Promising Future for Colorectal Cancer Therapy

This study's findings offer a compelling rationale for exploring therapies that target the c-MYC/NAMPT/SIRT1 feedback loop. By inhibiting NAMPT or SIRT1, it may be possible to disrupt this loop, suppress cancer cell growth, and improve treatment outcomes, especially in the serrated subtype of colorectal cancer.

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c-MYC’s Prognostic and Treatment Relevance

Whether c-MYC predicts colorectal cancer prognosis remains debated, according to a review that examined studies on the association. A separate review describes colorectal cancer as the third most common cancer worldwide and the second deadliest, after lung cancer, and says surgery remains the mainstay of treatment. In a study of 121 patients with RAS- and BRAF-wild-type metastatic colorectal cancer treated with anti-EGFR plus Folfiri, researchers evaluated c-MYC expression before treatment; they also assessed expression in 33 subsequent metastases collected during targeted therapy or during resistance.

Emerging Treatment Approaches

A 2025 review describes CAR-T cell therapies, oncolytic viruses, and immune checkpoint inhibitors as emerging approaches in colorectal cancer treatment. Its authors frame these modalities as part of a transformative era in oncology, while the supplied summary does not specify their clinical effectiveness. A 2024 review also notes that advances in surgery and chemotherapy have improved disease-free and overall survival compared with three decades earlier.

Precision Care and Treatment Decisions

A 2026 review describes colorectal cancer care as moving toward dynamic precision oncology and reports that immunotherapy has become standard first-line and perioperative treatment for patients with mismatch repair-deficient or microsatellite instability-high disease. A separate research topic focuses on how emerging targeted therapies interact with surgical management, including their effects on clinical decision-making, treatment sequencing, and outcomes in real-world settings. These sources highlight both disease-specific treatment advances and the practical questions involved in coordinating them with surgery.

How the proposed loop fits with related evidence

Related cell-line analyses found greater sensitivity in serrated-route than classical Wnt-driven colorectal cancer lines to a SIRT1 inhibitor only at very high concentrations. This comparison narrows the claim: the reported difference depended on the concentration tested and came from cell-line analysis.[1]

The cited work reports elevated c-MYC, NAMPT, and SIRT1 in human BRAF- or KRAS-associated serrated adenomas, while also noting NAMPT expression in healthy intestinal epithelium. Together, these observations place the proteins in both normal tissue and tumor-associated findings, so expression alone does not distinguish cancer-specific activity.[1]

A review of NAMPT-directed cancer approaches describes inhibitors, combinations, dual inhibitors, and antibody–drug conjugates as having experimental or clinical results. This is a broad treatment-research landscape, not evidence that a particular approach is effective for colorectal cancer patients.[2]

What remains unresolved about the loop

  • Does the proposed loop operate similarly across colorectal cancer routes, given that the reported inhibitor sensitivity comparison depended on very high concentrations and differed between cell-line groups?[1]
  • Can the proposed feedback-loop approach extend beyond colorectal cancer? The cited discussion raises broader tumor types, but some of the supporting work it mentions is unpublished.[1]

Sources

  1. Targeting c-MYC through Interference with NAMPT and SIRT1 and Their Association to Oncogenic Drivers in Murine Serrated Intestinal Tumorigenesis (2019)
  2. Review of various NAMPT inhibitors for the treatment of cancer (Frontiers in Pharmacology, 2022)

About this Article -

Written with AI assistance from published research, and reviewed by the Mystum team. See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1007/s12032-018-1225-1, Alternate LINK

Title: The C-Myc/Nampt/Sirt1 Feedback Loop Is Activated In Early Classical And Serrated Route Colorectal Cancer And Represents A Therapeutic Target

Subject: Cancer Research

Journal: Medical Oncology

Publisher: Springer Science and Business Media LLC

Authors: Lydia Brandl, Nina Kirstein, Jens Neumann, Andrea Sendelhofert, Michael Vieth, Thomas Kirchner, Antje Menssen

Published: 2018-11-20

Everything You Need To Know

1

What is the c-MYC/NAMPT/SIRT1 feedback loop, and why is it important in the context of colorectal cancer?

The research identifies a positive feedback loop involving c-MYC, NAMPT, and SIRT1. Specifically, c-MYC elevates NAMPT levels, boosting NAD+ production and subsequently enhancing SIRT1 activity. SIRT1 then amplifies c-MYC activity, establishing a self-perpetuating cycle that promotes cancer cell growth and survival. This loop is significant because it is activated in the early stages of colorectal cancer development, making it a potential target for therapeutic intervention.

2

Can you explain the individual roles of c-MYC, NAMPT, and SIRT1 within the identified feedback loop?

c-MYC is a proto-oncogene involved in cell growth, proliferation, and metabolism. NAMPT, or Nicotinamide Phosphoribosyltransferase, is an enzyme that produces NAD+, essential for cellular energy and function and also implicated in cancer progression. SIRT1, or Silent Information Regulator 1, is a protein deacetylase involved in stress resistance, DNA repair, and metabolism, promoting cancer cell survival. Together, they form a loop where each protein enhances the activity or production of the others, driving cancer development.

3

How could targeting NAMPT or SIRT1 potentially lead to new colorectal cancer therapies?

Targeting NAMPT or SIRT1 could disrupt the c-MYC/NAMPT/SIRT1 feedback loop. Inhibiting NAMPT would reduce NAD+ production, limiting SIRT1 activity. Similarly, inhibiting SIRT1 directly would prevent it from further enhancing c-MYC activity. Breaking this loop could suppress cancer cell growth and improve treatment outcomes, especially in specific colorectal cancer subtypes like the serrated subtype. This strategy focuses on starving the cancer cells by disrupting their energy and growth pathways.

4

What are the limitations of the study's findings, and what areas require further research to translate these discoveries into clinical applications?

The study doesn't delve into the specifics of drug development or clinical trials. It also doesn't explore the potential side effects of targeting NAMPT or SIRT1, or how these therapies might interact with existing cancer treatments. Further research is needed to understand the long-term effects and optimal strategies for targeting this loop in different patient populations and cancer stages. It's important to know if inhibiting NAMPT or SIRT1 would have adverse effects on healthy cells.

5

Besides the c-MYC/NAMPT/SIRT1 loop, what other factors contribute to colorectal cancer development, and how might they interact with this loop?

While the study highlights the c-MYC/NAMPT/SIRT1 loop, other signaling pathways and genetic mutations also contribute to colorectal cancer. For instance, mutations in genes like APC, KRAS, and TP53 are known drivers of CRC. The interplay between these factors and the c-MYC/NAMPT/SIRT1 loop is complex. Future research should investigate how these pathways interact and whether targeting the c-MYC/NAMPT/SIRT1 loop can synergize with other therapeutic approaches that address these additional genetic and molecular drivers of CRC. Also immune evasion could be at play and isn't discussed in this context.

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