Quantifying HMGB3 in Cancer Research: How ELISA Advances Biomarker Studies

Introduction

High Mobility Group Box 3 (HMGB3) is a non-histone chromatin binding protein in the HMGB family, involved in DNA architecture, transcription, replication, and repair. Increasing evidence indicates that aberrant expression of HMGB3 correlates with cancer initiation, progression, metastasis, treatment resistance, and poor prognosis in several malignancies. Measuring HMGB3 levels—especially circulating HMGB3 in serum or plasma—is therefore emerging as a promising biomarker in oncology.

This article reviews:

1. The evidence that HMGB3 is emerging as a biomarker in leukemia, breast cancer, and gastric cancer.

2. Why and how ELISA (enzyme-linked immunosorbent assay) is a technically advantageous method for quantifying circulating HMGB3 compared with Western blotting or qPCR.

3. How quantification of HMGB3 has been used to correlate with clinical parameters: tumor stage, treatment response, prognosis.

HMGB3 as a Biomarker in Specific Cancers

Leukemia

• HMGB3 is strongly expressed in hematopoietic stem cells (HSCs), where it regulates the balance between immature and mature blood lineages. Loss or dysregulation of HMGB3 alters differentiation and is implicated in leukemogenesis. PNAS+2Frontiers+2

• A recent study “HMGB3: A Novel Regulator of Leukemia Proliferation” (ASH / Blood) shows overexpression of HMGB3 protein in leukemia, where knockdown reduces cell proliferation and affects MAPK pathway activation. Ash Publications+1

• HMGB3 is also involved in certain fusion oncogenes in leukemia (e.g. HMGB3-NUP98 fusions), showing its role at genetic alteration level. PMC+1

Breast Cancer

• In breast cancer, several studies show overexpression of HMGB3 in tumor tissues compared to adjacent non-malignant tissues, and correlation of higher HMGB3 with poorer prognostic factors (e.g. lymph node metastasis). PLOS+2ResearchGate+2

• HMGB3 has been considered a marker of therapeutic resistance (e.g. to chemotherapy, etc.) in preclinical settings. There is less published data to date on circulating HMGB3 in serum/plasma in breast cancer (compared to tissue expression).

Gastric Cancer

• In gastric cancer (GC), HMGB3 overexpression has been shown in GC tissues; Tang et al. (2012) reported that HMGB3 overexpression associates with disease onset and progression. PMC

• A more recent study (Ke et al., 2022) used cancer-associated fibroblasts (CAFs) co-cultured with GC cell lines and measured HMGB3 by qRT-PCR, Western blot, and ELISA; in the co-culture medium, HMGB3 released by CAFs is elevated. Higher HMGB3 correlates with poorer survival in stomach adenocarcinoma (STAD) patients. Journal of Gastrointestinal Oncology

Methods of Quantification: ELISA vs qPCR vs Western Blot

To use HMGB3 as a biomarker in clinical or translational research, reproducible, sensitive, and high-throughput measurement is essential. Below is a technical comparison.

Technical Details of ELISA for HMGB3

• Commercial ELISA kits exist to detect human HMGB3 in serum, plasma, and cell culture supernatants. For example, RayBiotech offers a Human HMGB3 ELISA kit that works with plasma, serum, and cell culture supernatants. raybiotech.com

• Assay Genie offers a sandwich ELISA kit (catalog HUEB0526) with sensitivity in the 0.11-0.19 ng/mL range, ranges ~0.3-20 ng/mL, good recovery in serum and plasma, intra- and inter-assay coefficients of variation (CV) < ~10%. assaygenie.com+1

• Important validation steps: standard curve linearity, limit of detection (LOD), limit of quantification (LOQ), inter-assay and intra-assay variability, recovery (spiking known HMGB3 into serum/plasma), dilution linearity, and potential interference from hemolysis, lipemia, etc.

Applications: Correlations with Tumor Progression, Treatment Response, Prognosis

Here are examples and proposed uses of quantifying HMGB3 in oncology.

Gastric Cancer

• In the Ke et al. (2022) co-culture study, ELISA was used to quantify HMGB3 released into culture medium by CAFs co-cultured with gastric cancer cell lines. This release was elevated when CAFs were exposed to GC cells. The elevated extracellular HMGB3 correlated with more aggressive phenotypes (proliferation, invasion) and poorer survival in patient data. Journal of Gastrointestinal Oncology

• The tissue overexpression studies (e.g. Tang et al.) show that gastric cancer patients with high HMGB3 expression in tumor tissue have worse disease-free survival and overall survival. PMC

Leukemia

• The study “HMGB3: A Novel Regulator of Leukemia Proliferation” (2024) demonstrates that HMGB3 overexpression in leukemia is associated with higher proliferation; knockdown reduces proliferation and impacts key signaling (MAPK). Though this is mostly cell/tissue based, it suggests that measuring HMGB3 at the protein level could reflect disease burden. Ash Publications

• In murine models, Hmgb3 regulates HSC differentiation; overexpression is linked to undifferentiated phenotype, which is relevant to acute leukemias. PNAS

Breast Cancer

• Breast cancer tissue studies: overexpression of HMGB3 correlates with lymph node status, higher tumor grade, more aggressive subtypes and shorter survival. ResearchGate+2PLOS+2

• Potentially, measuring circulating HMGB3 (if secreted or released into bloodstream) could serve for monitoring; however as of now there are fewer published data measuring HMGB3 in serum/plasma in breast cancer patients compared to tissue or cell lines. (This is a gap to fill.)

Why ELISA for Circulating HMGB3 Is Especially Useful

• Reproducibility & Standardization: ELISA kits with defined capture and detection antibodies, known concentrations of standard, allow results across labs to be compared if protocol harmonised.

• High Throughput: One can process tens to hundreds of samples per run (96-well plates), enabling studies of large patient cohorts.

• Quantitative Protein Measurement: Circulating protein is closer to functional role of secreted / released HMGB3, rather than just mRNA expression. Particularly relevant when HMGB3 is released by tumor cells or stromal cells (e.g. CAFs).

• Sensitivity: Good ELISA kits can detect low concentrations (ng/mL to sub-ng/mL), enabling detection even when circulating levels are modest.

• Feasibility with Serum/Plasma: Unlike Western blot (which requires large protein amounts, etc.), ELISA works with small volumes of biofluids; better suited for longitudinal sampling.

Challenges & Comparison to Other Methods

• Correlation with mRNA: Because ELISA measures protein, sometimes differences in mRNA (qPCR) do not translate into proportional changes in secreted or soluble protein levels. Posttranscriptional regulation, protein stability, secretion, or release must be considered.

• Specificity of Antibodies: ELISA depends on antibodies recognizing HMGB3 specifically (vs other HMGB proteins, or isoforms). Cross-reactivity can produce false positives.

• Matrix Effects: Serum and plasma contain many proteins, inhibitors, proteases; potential interference, need for proper controls (spiking, dilution, blocking).

• Dynamic range: ELISA kits must have sufficient dynamic range to capture both low basal HMGB3 in healthy controls and elevated HMGB3 in advanced disease. Saturation of capture/detection must be avoided.

• Alternative Techniques:

  • Western blot: useful for assessing size, modifications, verifying antibody specificity, checking isoforms. Not suited for quantifying low abundance soluble protein in large scale.

  • qPCR (RT-PCR): measures mRNA; useful in tissues/cells; lower material cost; high sensitivity; but does not directly measure protein or secretion.

Examples / Studies Using Circulating HMGB3 Measured by ELISA

• In hepatocellular carcinoma (HCC) (not breast or gastric but informative), Zheng et al., 2018: used ELISA to measure serum HMGB3 in cohorts (normal controls, chronic hepatitis, cirrhosis, HCC). Serum HMGB3 was significantly elevated in HCC vs benign disease; it had better diagnostic performance (ROC, AUC) than AFP especially in small tumors (<3 cm). Semantic Scholar

• In gastric cancer via co-culture medium, the Ke et al. 2022 study described above used ELISA to measure HMGB3 in culture supernatants/coculture media, showing elevated release from CAFs when co-cultured with GC cells. That suggests HMGB3 may be released into extracellular space and possibly into circulation. Journal of Gastrointestinal Oncology

• To date, explicit large clinical studies measuring circulating HMGB3 in serum/plasma in leukemia, breast or gastric cancer patients with ELISA are limited; many studies focus on tissue or cell line expression, or preclinical models. This is an active area under development.

Clinical/Translational Uses: Tumor Stage, Treatment Response, Prognosis

Quantifying HMGB3 (especially circulating) could be useful in several ways:

1. Early detection / diagnosis
   When HMGB3 is elevated in serum/plasma, may differentiate cancer from benign conditions, or detect early stage disease. Example: HCC study where HMGB3 levels distinguished HCC vs cirrhosis/chronic hepatitis. Semantic Scholar

2. Monitoring progression or metastasis
   Tissue expression of HMGB3 in gastric, colorectal, breast cancers correlates with lymph node metastasis, serosal invasion, higher TNM stage. PLOS+2PMC+2

3. Predicting treatment response / resistance

   • In ovarian cancer, high HMGB3 correlates with resistance to PARP inhibitors; knockdown sensitizes cells. Nature

   • In gastric cancer, HMGB3 release by CAFs promotes chemoresistance in GC cells (cisplatin IC50) in co-culture models. Journal of Gastrointestinal Oncology

   • In leukemia, controlling HMGB3 levels may affect proliferation and response to therapy (still being studied).

4. Prognostic value
   High HMGB3 expression (tissue and possibly higher circulating levels) often associated with worse overall survival, disease-free survival. In gastric cancer Tang et al. 2012, in breast cancer (as above), in HCC as well. PLOS+3PMC+3PMC+3

5. Risk stratification
   Could help classify patients by risk (e.g. HMGB3 high vs low) for decision making (e.g. more aggressive treatment, monitoring).

Suggestions for Future Research / Best Practices

• Clinical cohort studies measuring circulating HMGB3 in serum/plasma of leukemia, breast cancer, and gastric cancer patients: correlating with staging, metastasis, treatment response, survival. Use of ELISA for those cohorts.

• Longitudinal sampling (pre-treatment, during therapy, and post-treatment) to assess changes in HMGB3, to see if changes correlate with response or relapse.

• Standardization of ELISA protocols, including choice of kit, sample handling, storage, quality control.

• Comparison studies pairing ELISA measurement of HMGB3 with qPCR (mRNA) and Western blot (protein) to establish correlation, discordance, understand what is captured by each method.

• Validation of assay specificity: confirm that antibodies used do not cross-react with HMGB1, HMGB2 or other HMGB family members, or closely related isoforms.

• Regulatory grade validation if moving toward clinical diagnostics: reproducibility, sensitivity, specificity, limits of detection, possibly CLIA or equivalent.

• Investigate mechanisms of release: is HMGB3 secreted actively or released passively (e.g. via cell death, exosomes)? Knowing mechanism helps interpret circulating HMGB3 levels.

Conclusion

HMGB3 is an increasingly well‐supported biomarker candidate in oncology, especially in leukemia, breast cancer, and gastric cancer. Elevated HMGB3 expression in tissues is associated with aggressive disease, metastasis, poor survival, and therapeutic resistance. To translate these observations to clinically useful biomarkers, measuring circulating HMGB3 protein via ELISA offers distinct technical advantages over qPCR and Western blot: higher throughput, better quantitation of secreted/soluble protein, suitability for serum/plasma samples, and reproducibility.

While existing studies (e.g. HCC, GC CAF-co-culture, ovarian cancer) illustrate how ELISA measurement of HMGB3 can correlate with clinical parameters, there remains need for more large clinical cohort ELISA studies in leukemia, breast, and gastric cancer to validate diagnostic, prognostic, and predictive utility. With careful assay validation and standardized sampling, quantifying HMGB3 could contribute significantly to cancer biomarker panels, liquid biopsy strategies, and precision oncology.

References / Links to Key Papers & Resources

• Tang HR et al., “High mobility group-box 3 overexpression is associated with gastric cancer disease onset and progression.” PMC (USA) article. PMC

• Zheng W et al., “High mobility group box 3 as an emerging biomarker in hepatocellular carcinoma …” PMC article. PMC

• Ke Y et al., “Interfering HMGB3 release from cancer-associated fibroblasts … gastric cancer.” JGO / AMEGROUPS. Journal of Gastrointestinal Oncology

• Ma H et al., “HMGB3 promotes the malignant phenotypes and stemness … epithelial ovarian cancer …” BMC / BioSignaling. BioMed Central+1

• Swenson et al., Blood, “HMGB3: A Novel Regulator of Leukemia Proliferation”. Ash Publications

• RayBiotech, Human HMGB3 ELISA Kit product description. raybiotech.com

• Assay Genie HMGB3 ELISA Kit specification document. assaygenie.com