# RF-035 — Transformation phenotypes and tumors after transplanting exposed fibroblasts

Why this matters
Cells given prolonged, high-dose laboratory exposure later formed tumours when transplanted into mice with weakened immune defences. This is a consequential endpoint to investigate. One assay used a tumour-promoting chemical, and unclear cell histories prevent an RF-alone claim. The recipient mice were not RF-exposed.

Id: RF-035

Author: Ding et al.

Full Authors: Zhen Ding; Xiaoyong Xiang; Jintao Li; Shuicai Wu

Year: 2022

Title: Molecular Mechanism of Malignant Transformation of Balb/c-3T3 Cells Induced by Long-Term Exposure to 1800 MHz Radiofrequency Electromagnetic Radiation (RF-EMR)

Journal: Bioengineering

Citation: Ding Z, Xiang X, Li J, Wu S. Molecular Mechanism of Malignant Transformation of Balb/c-3T3 Cells Induced by Long-Term Exposure to 1800 MHz Radiofrequency Electromagnetic Radiation (RF-EMR). Bioengineering. 2022;9(2):43. doi:10.3390/bioengineering9020043.

Doi: 10.3390/bioengineering9020043

Pmid: 35200397

Topic: Cell transformation and tumorigenicity

Verification Group: Original text reviewed

Record Role: Original text reviewed

Featured: False

Exposure: 1.8-GHz continuous wave; culture average SAR 8 W/kg, 4 h/day for 40 or 60 days, sXc-1800 waveguide system. Authors selected high culture SAR to accelerate transformation. Fans/air-temperature monitoring and medium-response assessment described; alarm threshold for temperature difference 0.1°C. This is not a measurement of human-limit compliance.

Design: Sham/exposed Balb/c-3T3 cultures passaged together; experiment and analysis blinded. Reporting describes triplicate experiments with triplicate samples but does not clearly distinguish independent biological batches from subsamples. Focus assay: 30-day post-exposure culture; TPA 0.1 μg/mL for 24 h on days 1, 4 and 7 in sham and exposed cultures. Transplantation: 2×10^6 cells/mouse, 4-week observation; HeLa positive control. Soft agar: 4 weeks; HeLa positive control. Student t tests; no multiple-testing adjustment stated.

Finding: Original results report transformation foci, soft-agar colonies, and visible tumors four weeks after transplanting 40- or 60-day exposed Balb/c-3T3 cells into SCID mice; sham cultures lacked foci/colonies and mice receiving sham cells lacked tumors. The focus assay included TPA treatment of all groups. Exact effect sizes, mouse denominators and culture-lineage independence were not adequately specified for a quantitative risk estimate.

Boundary: Distinct endpoint beyond a transient biomarker, but donor-cell passage/TPA history before transplantation and soft agar is not explicit, and mouse group size/biological replicate structure are unclear. Thus describe reported tumorigenicity of exposed-cell preparations, not proved RF-alone cancer initiation or spontaneous cancer in RF-exposed mice. Only one high culture SAR; no dose-response series or independent replication established. Pathway enrichment does not establish causal mediation.

Related: Separate Shenzhen/Beijing programme from NTP, Ramazzini, Newcastle and Lund. Culture phenotyping and transplanted-cell tumors are components of the same study, not independent replications. No linked preprint/duplicate version located.

Protection Question: Would reproducible transformation and tumour formation from exposed-cell preparations strengthen a cancer-hazard inference? High culture dose, chemical-promoter use and unclear donor-cell histories prevent an RF-alone initiation claim here.

Access: Original open-access publisher/PMC article passages retrieved via indexed primary records; Methods 2.1-2.6 and 2.10, Results 3.1-3.4 and disclosures checked.

Locator: Methods sections 2.1-2.3 exposure/sham/TPA; 2.5-2.6 transplantation/soft agar; 2.10 statistics; Results sections 3.1, 3.3, 3.4 and Figures 2, 4, 5; Funding and Conflicts of Interest.

Notice: PubMed, PMC/publisher primary records and targeted DOI/title notice search checked 20 Oct 2026; no correction, retraction or concern found. This does not certify that no notice exists.

Funding: Shenzhen High-level Hospital Construction Fund; Shenzhen Key Medical Discipline Construction Fund SZXK013; Sanming Project of Medicine in Shenzhen SZSM201612063.

Conflicts: Authors declare no conflict of interest. Ethics approval: North China University of Technology (2017014, 7 March 2017). Data available from corresponding author on reasonable request.

Source Url: https://doi.org/10.3390/bioengineering9020043

Retrieval Links: https://doi.org/10.3390/bioengineering9020043 | https://pmc.ncbi.nlm.nih.gov/articles/PMC8869874/ | https://www.mdpi.com/2306-5354/9/2/43 | https://www.mdpi.com/2306-5354/9/2/43/pdf?version=1642492243 | https://pubmed.ncbi.nlm.nih.gov/35200397/

Verification Date: 2026-10-20