Constarium
← Search

Omics · study · 2026

Alternative End-Joining Activation by miR-21-5p Confers Radiation Resistance in Oral Squamous Cell Carcinoma [RNA-seq of SUGH-OSCC patient tumors]

Listed in NCBI GEO

Marked heterogeneity in radiosensitivity is a major challenge in the treatment of oral squamous cell carcinoma (OSCC), often resulting in poor outcomes for radioresistant tumors.

Description

The underlying molecular drivers of this resistance remain elusive. Here, we identify a novel mechanism in which miR-21-5p promotes radiation resistance by selectively activating the error-prone DNA double-strand break (DSB) repair pathway alternative end-joining (Alt-EJ).

Integrative miRNA profiling, multi-omic analyses, and functional assays demonstrate that miR-21-5p upregulation coupled with suppression of its target gene signature increases Alt-EJ dependence for DSB repair. This Alt-EJ reliance enhances genomic instability, increases tumor mutational burden and microhomology-mediated indels, and confers pronounced radiation resistance in OSCC models, while correlating with poor radiotherapy response in patients.

Read the rest (2 more)

Importantly, pharmacological or genetic inhibition of Alt-EJ components, including PARP1 and POLQ, restores radiosensitivity in vitro and in vivo, with PARP1 inhibition specifically reversing miR-21-5p-mediated resistance in a syngeneic mouse model. Further RNA-seq analyses of these mice tumors confirmed that PARP inhibitor induced selective radiosensitization effects for miR-21-5p-overexpressing tumors were accompanied by a pronounced reduction in alt-EJ expression.

Collectively, these findings establish the miR-21-5p/Alt-EJ axis as a key driver of radiation resistance in OSCC and support Alt-EJ targeting as a promising approach for precision radiosensitization.

Links

Topics

From keywords
Life Sciences
Inferred from text
Cancer 65% · RNA sequencing 65%
Provenance · 1 source records, 9 field assertions
SourceKeyLast seenRaw
NCBI GEOGSE30457910 d agoJSON v1
FieldAssertionExtractorEvidence
access_levelsource · NCBI GEOconnector:ncbi_geo@1.0.0
concepts[disease].local:disease:cancerenrichment · NCBI GEOkeyword-concept-rules@1.0.0title+description (65%)
concepts[field].local:field:life-sciencesmapping · NCBI GEOconnector:ncbi_geo@1.0.0
concepts[method].geo_series_type:expression-profiling-by-high-throughput-sequencingsource · NCBI GEOconnector:ncbi_geo@1.0.0/gdstype
concepts[modality].local:modality:rna-seqenrichment · NCBI GEOkeyword-concept-rules@1.0.0title+description (65%)
concepts[organism].NCBITaxon:9606source · NCBI GEOconnector:ncbi_geo@1.0.0/taxon
descriptionsource · NCBI GEOconnector:ncbi_geo@1.0.0/summary
publication_datesource · NCBI GEOconnector:ncbi_geo@1.0.0
titlesource · NCBI GEOconnector:ncbi_geo@1.0.0/title