The Dual Face of Gingival Mesenchymal Stem Cell Paracrine Signalling in Oral Squamous Cell Carcinoma: A Pro-Tumour Transcriptional Programme and a Hypothesis-Generating Drug-Repurposing Screen.

Background

In our companion study, the gingival mesenchymal stem cell (GMSC) secretome suppresses oxidative stress and induces apoptosis in primary oral squamous cell carcinoma (OSCC) cells, where those wet-lab results are themselves reported as preliminary; here we ask whether it also engages a proliferation × migration programme in patient tissue. The two arms differ in read-out type (apoptosis and redox there, transcript abundance here), not in opposed function.

Methods

Primary OSCC cells received GMSC-conditioned medium (GMSC-CM) or indirect Transwell co-culture, assayed by RT-qPCR (VEGFA, TGFB1, MMP9, CXCL12, CCND1, PCNA, MYC, EGFR), MTT, and scratch-wound migration. Thirteen computational layers plus a GeoMx spatial verify-and-decide layer were applied to public data: TCGA-HNSC, GEO, CPTAC, single-cell inference, prognostic modelling, DepMap and LINCS L1000.

Results

All eight transcripts were raised in all three arms (16 of 24 comparisons significant), indicating a pro-tumour transcriptional shift; metabolic activity was unchanged and wound closure was reduced under conditioned medium (p < 0.01). Of 1358 genes significant in all three modalities, 1219 (89.8%, 95% CI 88.0-91.3%) share direction against 25.0% expected by chance (3.59-fold; exact binomial p below machine precision). The pre-registered oral-cavity signature did not validate externally (GSE41613; C = 0.562), and no ligand-receptor pair survived permutation calibration.

Conclusions

GMSC paracrine exposure induces a pro-tumour transcriptional programme in primary OSCC cells that replicates at patient level, without demonstrated functional or therapeutic consequence; gefitinib is nominated only as a hypothesis-generating candidate. The evidence rests on three primary cultures (n = 3), one GMSC donor preparation, one 24 h time point, a single reference gene, no cell-line authentication and no test of gefitinib; the study programme has concluded, and these experiments cannot be performed now.