HEYL-mediated activation of LAMA3 influences radiotherapy response in esophageal cancer

Esophageal cancer (EC) is a major cause of cancer-related mortality. This study aims to investigate how hairy/enhancer-of-split is related to YRPW motif-like protein (HEYL), which regulates laminin subunit alpha 3 (LAMA3) and its impact on EC radiotherapy via the epithelial-to-mesenchymal transition (EMT) pathway.

Differentially expressed genes (DEGs) related to radiotherapy sensitivity in EC cells were screened. Radioresistant cells were constructed using X-ray treatment at different doses. LAMA3 expression in radioresistant and parental cells was validated using RT-qPCR and Western blot (WB). γ-H2AX phosphorylation levels were identified to confirm the successful establishment of radioresistant cells. WB and immunofluorescence were performed to detect KI67 and EMT markers (E-cadherin, Slug, and Vimentin). Transwell, wound healing, cell counting kit-8 (CCK-8), and 5-Ethynyl-2'-deoxyuridine (EdU) assays were conducted to assess the response of radioresistant cells to LAMA3 expression alteration. Transcription factors of LAMA3 were predicted and verified. An in vivo model was established to confirm the role that HEYL and LAMA3 played in EMT and radioresistance.

LAMA3 was shown to induce the EMT pathway and reduce radiotherapy efficacy in radiation-resistant OE19R and TE-1R cells. HEYL bound to the LAMA3 promoter, activating its expression. In vitro and in vivo rescue experiments confirmed that HEYL transcriptionally activated LAMA3 to confer resistance to radiotherapy via the EMT pathway in EC.

In conclusion, HEYL activates the transcription of LAMA3, which in turn reduces EC radiosensitivity via the EMT pathway.