Cancer / Oncology/Colorectal cancer
Gastrointestinal · type
Colorectal cancer
Clinical / Scientific
Colorectal tumorigenesis classically follows APC–Wnt initiation, then KRAS, TP53 and SMAD/TGF-β events, with a parallel MSI-high hypermutated path. Metabolic, inflammatory -2 and angiogenic programmes are prominent. Immune checkpoint benefit concentrates in mismatch-repair-deficient disease.
Molecular / histological subtypes
Core Biological Drivers
APC / Wnt
Initiating event in most sporadic CRC.
KRAS / BRAF
-pathway mutations in subsets.
TP53
Later adenoma–carcinoma event.
MMR / MSI
Hypermutation and immune visibility.
COX-2 inflammation
PGE2-supported epithelial proliferation.
Key Pathways
Scientific explanation
Canonical Wnt signalling stabilizes β-catenin, driving TCF/LEF . APC loss is a classic colorectal initiating event; the pathway also contributes to stemness in several tissues.
Scientific explanation
RAS GTPases and RAF kinases are frequent oncogenic nodes. KRAS, NRAS and BRAF mutations lock mitogenic signalling on in a ligand-independent way in many tumours.
Scientific explanation
The RAS–RAF–MEK–ERK cascade transmits mitogenic RTK signals to programmes for proliferation and differentiation.
Scientific explanation
TP53 encodes a stress-responsive factor controlling cell-cycle arrest, and metabolic adaptation. Loss or mutation is among the most common cancer events.
Scientific explanation
TGF-β is cytostatic in intact epithelium but later supports , immune suppression and stromal . Context switches its role during progression.
Scientific explanation
-2–PGE2 signalling can promote , immune suppression and epithelial proliferation, notably in colorectal neoplasia.
Scientific explanation
family ligands drive endothelial sprouting and vascular permeability, a canonical tumour axis.
Scientific explanation
Aerobic (Warburg metabolism) supports ATP, biomass and redox buffering even when oxygen is available. Hexokinase, PKM2 and lactate export are frequent nodes.
Scientific explanation
PD-1 on T cells engaging PD-L1/PD-L2 restrains cytotoxic function. Tumour or myeloid PD-L1 is a canonical adaptive immune-evasion axis.
Scientific explanation
EGFR is an ERBB-family tyrosine . Ligand activation or mutation (notably NSCLC exon 19/L858R) drives and signalling.
Scientific explanation
HER2/ERBB2 amplification or overexpression produces ligand-independent ERBB signalling, classically in a subset of breast and gastroesophageal cancers and rarely in colorectal cancer.
Scientific explanation
Epithelial–mesenchymal plasticity, driven by TWIST/SNAIL/ZEB and TGF-β/Wnt/Notch inputs, reduces adhesion and increases motility and stem-like features.
Pathway Convergence
Target → pathway → downstream effect → biological consequence. Shared intersections are mechanistic maps, not protocols.
Growth-factor signalling
Ligand or mutation-driven RTK input feeds PI3K/AKT and mTORC1, supporting anabolic growth. This is a map of signalling, not a treatment protocol.
Hypoxia to vessels
Low oxygen stabilizes HIF-1α, inducing VEGF and endothelial sprouting. Anti-angiogenic pharmacology intersects this axis but does not erase the tumour ecosystem.
Inflammatory survival
Chronic cytokine tone activates NF-κB and STAT3 transcriptional programmes that favour survival, invasion and sometimes immune evasion.
Energy stress
Energetic stress activates AMPK, which can restrain mTORC1. Biguanides and related tools map onto this axis in models.
Metabolic Vulnerabilities
Aerobic supports ATP, biomass and acidification even when oxygen is available. Extent varies by tumour and remains a vulnerability hypothesis rather than a uniform target.
Glutamine anaplerosis and nucleotide nitrogen demand are prominent in MYC-high and rapidly proliferating tumours. Dependence is heterogeneous.
Tumor Microenvironment
Disordered vasculature creates , HIF-1α stabilization, induction and immune-suppressive adenosine/lactate milieus.
Tumour-associated macrophages and myeloid-derived suppressor cells secrete cytokines that support invasion and blunt cytotoxic T cells.
Microbiome-derived metabolites modulate epithelial and immune tone.
Metastasis Module
, protease-mediated invasion, , circulating tumour-cell survival and organ-specific colonization form the metastatic cascade. Pre-metastatic niches and vascular permeability influence tropism.
Resistance Biology
EGFR-antibody resistance via RAS/BRAF/HER2; adaptive ; and efflux.
Cancer Stemness
Lgr5+ intestinal stem programmes and Wnt-high fractions support regeneration and therapy tolerance in models.
Mechanism-Based Adjunctive Strategies
Compounds appear only where a mechanistic overlap exists for this cancer. Evidence tiers are not equivalent. Nothing here is a treatment recommendation.
Target / Mechanism
uncoupler in cestodes; mammalian models report , Wnt/β-catenin and modulation. Those host-signalling findings are investigational/preclinical.
Cancer relevance
Models report Wnt/β-catenin, and effects. Host signalling findings remain investigational.
Wnt / STAT3 signalling models. Convergence: Wnt/β-catenin, JAK/STAT, mTOR.
Celecoxib
Target / Mechanism
Selective -2 reducing PGE2. Relevant to -associated epithelial neoplasia; cardiovascular risk and lack of broad anticancer approval constrain interpretation.
Cancer relevance
-2/PGE2 biology is relevant in some epithelial neoplasias. Cardiovascular risk and lack of broad anticancer approval apply. Do not equate polyp or biomarker studies with tumour cure.
Inflammation-associated epithelial neoplasia research. Convergence: COX / inflammatory signalling, Angiogenesis.
Target / Mechanism
Modest complex I inhibition raises AMP:ATP, activating and restraining hepatic and -linked anabolism. Direct antineoplastic efficacy is not established from that pharmacology alone.
Cancer relevance
activation and restraint provide a metabolic rationale in - and -linked tumours. Human data are mixed and do not establish metformin as cancer therapy.
Metabolic adjunctive research context. Convergence: AMPK, mTOR, Glycolysis.
Curcumin
Target / Mechanism
Polyphenol with promiscuous in-vitro NF-κB, and ROS effects. Bioavailability is poor; dish activity does not establish clinical anticancer efficacy.
Cancer relevance
In-vitro NF-κB/ effects are frequent. Poor bioavailability and absence of robust clinical anticancer efficacy keep this pathway-level.
Inflammatory-signalling dish models. Convergence: NF-κB, JAK/STAT.
Statins (HMG-CoA reductase inhibitors)
Target / Mechanism
Inhibit HMG-CoA reductase, depleting mevalonate-pathway isoprenoids needed for RAS/RHO prenylation and some sterol-dependent growth programmes. Observational oncology signals are mixed and not a licence to treat cancer with statins.
Cancer relevance
Mevalonate-pathway blockade can affect prenylation of RAS-family GTPases. Observational human signals are mixed and confounding is substantial.
Mevalonate / prenylation mechanistic overlap. Convergence: RAS/RAF, Fatty-acid metabolism.
Target / Mechanism
Benzimidazole that binds β-. Mammalian disruption, mitotic arrest and related signalling in cancer models are preclinical and are not an approved anticancer use.
Cancer relevance
disruption can trigger mitotic stress and in cell and animal models. This is not an established oncology use.
Experimental antimitotic / microtubule stress. Convergence: Apoptosis, p53.
Berberine
Target / Mechanism
Isoquinoline alkaloid that can inhibit complex I and activate in metabolic models, with additional -independent reports. Not an approved antineoplastic.
Cancer relevance
Complex I / pharmacology overlaps metformin-like energy stress in models. Bioavailability and lack of oncology indication keep this mechanistic.
Metabolic energy-stress hypothesis. Convergence: AMPK, mTOR, Mitochondrial oxidative phosphorylation.
Omega-3 fatty acids
Target / Mechanism
EPA/DHA alter eicosanoid balance and membrane signalling. Cachexia and hypotheses exist; they are not cytotoxic oncology drugs.
Cancer relevance
Eicosanoid rebalancing and cachexia/ research. Not cytotoxic oncology.
Inflammation / cachexia supportive research. Convergence: COX / inflammatory signalling, Immune suppression.
Sulforaphane
Target / Mechanism
Isothiocyanate that can activate NRF2 via KEAP1 modification and has epigenetic HDAC-related reports in models. Chemoprevention hypotheses exceed proven oncology treatment.
Cancer relevance
KEAP1/NRF2 activation and epigenetic reports in models. Chemoprevention hypotheses are not treatment proof.
NRF2 / chemoprevention research. Convergence: NRF2, Oxidative stress.
EGCG
Target / Mechanism
Green-tea catechin with in-vitro effects on RTKs, epigenetic enzymes and redox. Clinical anticancer efficacy is not established.
Cancer relevance
Catechin effects on RTKs and redox in vitro. Clinical anticancer efficacy is not established.
RTK / redox dish models. Convergence: EGFR, PI3K/AKT.
Research Context
- CRC adenoma-carcinoma. Fearon ER, Vogelstein B. A genetic model for colorectal tumorigenesis. Cell. 1990;61(5):759-767. https://doi.org/10.1016/0092-8674(90)90186-I
- CRC TCGA. The Cancer Genome Atlas Network. Comprehensive molecular characterization of human colon and rectal cancer. Nature. 2012;487(7407):330-337. https://doi.org/10.1038/nature11252
- NF-κB. Karin M. NF-κB as a critical link between inflammation and cancer. Cold Spring Harb Perspect Biol. 2009;1(5):a000141. https://doi.org/10.1101/cshperspect.a000141
- Checkpoints. Pardoll DM. The blockade of immune checkpoints in cancer immunotherapy. Nat Rev Cancer. 2012;12(4):252-264. https://doi.org/10.1038/nrc3239
This oncology atlas is educational. Pathway maps, adjunctive strategies, and compound listings describe mechanistic relevance. They do not establish clinical efficacy, do not recommend treatment, and are not a substitute for oncology care. Evidence tiers are not equivalent.