From bioinformatic screening of genetic markers to low invasive lymph node metastases diagnosis in patients with cervical cancer

Abstract

Background. The problem of lymph nodes metastases diagnosing in cervical cancer remains relevant and not fully resolved. The last decade studies results have shown the great potential of molecular markers in lymph nodes metastasis prediction, however, additional studies for their implementation in clinical practice are required.
 Aim. Bioinformatic and laboratory screening of molecular markers of cervical tumors regional metastasis for its low invasive diagnosis.
 Material and methods. The study was performed on 400 patients with cervical cancer and 40 donors without oncological pathology. To identify potential molecular markers of lymph node metastatic lesions, the Cancer Genome Atlas database was initially analyzed. The identified markers were validated by the Real-Time-polymerase chain reaction in tumor cell samples (extracted using laser microdissection) and extracellular deoxyribonucleic acid (DNA). The MannWhitney test was used to assess the differences; the Bonferroni correction was used to account for multiple comparisons.
 Results. At the bioinformation stage, the change in the copy number of 5493 genes was analyzed, of which 79 genes were selected that most often change their copy number. During the data validation, it was found that primary tumor cells and tumor cells of metastases from the lymph nodes differ from normal cervix cells in the level of gene copies. The copy number of the CCND1 and PPARGC1A genes has the highest potential for regional lymph nodes metastases diagnosing in patients with cervical cancer; the PIK3CA, SPEN, ERBB3, APC, MUC4, CASP8, HLA-A, IGSF1 and TMTC1 loci have a lower potential. The EP300, TTN, DMD, DST, LAMP3, TORC2, TP53 and FOXO3 genes can be used to diagnose cervical cancer, whether metastatic or not. Additional validation of markers was carried out on extracellular DNA of blood plasma of cervical cancer patients and conditionally healthy donors. The presence of a differential copy number of PIK3CA, SPEN, ERBB3, APC, CCND1, HLA-A, TTN, MUC4, DST, PPARGC1A genes was found in two groups of patients with cervical cancer with and without metastatic lesions of the lymph nodes.
 Conclusion. The study made it possible to form a list of potential molecular markers for low invasive diagnostics of cervical cancer in general (EP300, LAMP3, TORC2, FOXO3, TP53) and cervical cancer with metastatic lesions of regional lymph nodes (PIK3CA/DST, APC/PPARGC1A, ERBB3/HLA-A and LAMP3/MUC4).