Castration-resistant prostate cancer

Subtype of Prostate cancer

Clinical / Scientific

CRPC continues AR signalling via amplification, mutations, splice variants or adrenal/intratumoral androgens, with and DNA-repair subsets. It is still usually adenocarcinoma, not automatically neuroendocrine.

Core Biological Drivers

AR amplification / variants

Ligand-independent or hypersensitive AR.

PI3K

PTEN-loss cooperation.

Key Pathways

Androgen receptor

Scientific explanation

AR is a nuclear factor required for most prostate adenocarcinoma growth. Resistance can occur through AR amplification, splice variants, or lineage plasticity.

PI3K/AKT

Scientific explanation

phosphorylates PIP2 to PIP3, recruiting . supports growth, survival, glucose uptake and mTORC1 input. Pathway activation is common via PIK3CA mutation, PTEN loss or -tyrosine- signalling.

mTOR

Scientific explanation

mTORC1 integrates growth-factor and nutrient signals to drive protein synthesis, lipid synthesis and suppression. It sits downstream of PI3K/AKT and amino-acid sensing.

PARP / DNA repair

Scientific explanation

Homologous-recombination defects (BRCA1/2 and related) create dependence on PARP-mediated repair. Mismatch-repair deficiency creates hypermutation and immune visibility.

Wnt/β-catenin

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.

Drug efflux

Scientific explanation

ABC transporters such as ABCB1/P-gp, ABCC1 and ABCG2 export structurally diverse drugs and contribute to multidrug-resistance phenotypes.

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.

Receptor tyrosine kinase
↓
PI3K/AKT
↓
mTOR
↓
Protein synthesis / growth

Inflammatory survival

Chronic cytokine tone activates NF-κB and STAT3 transcriptional programmes that favour survival, invasion and sometimes immune evasion.

Cytokines
↓
NF-κB / STAT3
↓
Survival and invasion genes
↓
Therapy-tolerant phenotype

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.

Lipogenesis and glucocorticoid- bypass in some clones.

Tumor Microenvironment

Tumour-associated macrophages and myeloid-derived suppressor cells secrete cytokines that support invasion and blunt cytotoxic T cells.

Metastasis Module

Bone-dominant with increasing visceral risk in later clones.

Resistance Biology

ARSI resistance via AR variants and lineage plasticity.

Cancer Stemness

Wnt, Notch, Hedgehog, ALDH and CD44-associated programmes can mark stem-like fractions with quiescence and therapy tolerance. These markers are not interchangeable across tumour types.

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.

Metformin

Clinical / Human EvidenceIn VivoIn VitroMechanistically Plausible

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.

Niclosamide

In VitroIn VivoMechanistically Plausible

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.

Itraconazole

Early ClinicalIn VivoIn Vitro

Target / Mechanism

Azole antifungal; off-target reports include Hedgehog-pathway antagonism and anti-angiogenic endothelial effects in experimental and early clinical settings. Not a licensed antineoplastic.

Cancer relevance

Hedgehog antagonism and anti-angiogenic endothelial reports exist, including early clinical probes. Not a licensed antineoplastic.

Hedgehog / angiogenesis research. Convergence: Hedgehog, Angiogenesis.

Statins (HMG-CoA reductase inhibitors)

Clinical / Human EvidenceIn VitroMechanistically Plausible

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.

Mebendazole

In VitroIn VivoMechanistically Plausible

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.

Research Context

  1. NEPC. Beltran H, et al. Divergent clonal evolution of castration-resistant neuroendocrine prostate cancer. Nat Med. 2016;22(3):298-305. https://doi.org/10.1038/nm.4045
  2. Resistance. Holohan C, Van Schaeybroeck S, Longley DB, Johnston PG. Cancer drug resistance: an evolving paradigm. Nat Rev Cancer. 2013;13(10):714-726. https://doi.org/10.1038/nrc3599

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.