RADT-06. IDENTIFICATION OF NEW RADIATION RESPONSE PREDICTOR GENES FOR GLIOBLASTOMACRUCIAL CONTRIBUTION OF THE LUNATIC FRINGE GENE (LFNG)

Abstract Glioblastoma (GBM) is adults’ most common aggressive primary intracranial tumor. The current standard of care involves maximal safe surgery followed by radiochemotherapy. OBJECTIVE our study was to identify genes that predict response to radiochemotherapy. MATERIALS AND METHODS We collected molecular and clinical data, including primary glioma mRNA expression, from two international online databases - TCGA and CCGA. A total of 76 cases were examined, with 41 patients in the TCGA cohort and 35 in the CCGA cohort. The patients were divided into two groups before assessing the data. Group 1 included patients who were alive at the time of the analysis, and Group 2 included patients who had passed away. Then, we performed a single-center Moroccan transcriptomic study involving 28 cases to assess the impact of the individualized gene in our environment. RESULTS The following genes, namely SRPX, S100A16, LFNG, CD5, CMBL, and TCTN2, are among the top genes co-overexpressed in TCGA and CGGA patients. We conducted a multivariate COX survival test, taking into account known prognostic clinical parameters, and found that the LFNG gene is the only marker of poor prognosis independent of other clinical markers in TCGA and CGGA patients treated with radiotherapy. Our results indicate that patients who overexpress LFNG have elevated IFNg levels and low granzyme B levels, while the levels of perforin and granzyme A remain unaffected by LFNG variation. Furthermore, our results demonstrate positive correlations between LFNG gene expression and four immune checkpoints (PD1, PDL1, CTLA4, and VISTA), but negative correlations only with TIM3. CONCLUSION Our findings suggest that LFNG could serve as a useful biomarker for identifying patients with poor prognosis and that LFNG expression may be associated with specific immune checkpoint expression patterns. These results have important implications for the development of new therapeutic approaches in the treatment of TCGA and CGGA patients.