Screening of mutations in the additional sex combs like 1, transcriptional regulator, tumor protein p53, and KRAS proto-oncogene, GTPase/NRAS proto-oncogene, GTPase genes of patients with myelodysplastic syndrome

Genetic and methylation status of CDKN2A (p14ARF/p16INK4A) and TP53 genes in recurrent respiratory papillomatosis

Recurrent respiratory papillomatosis (RRP) is a rare and chronic disease affecting the upper airway with papillomatous lesions caused by the human papillomavirus (HPV) infection, especially HPV-6 and/or HPV-11 types. Little is known about the genetic and epigenetic drivers in RRP pathophysiology. For this purpose, we analyzed 27 papillomatous lesions from patients with RRP to evaluate somatic mutations and methylation status in CDKN2A (p14^ARF/p16^INK4A) and TP53, which are key tumor suppressor genes for the cell cycle control. Sanger sequencing analysis revealed one somatic mutation in TP53 (c.733_734insA) and four mutations in CDKN2A (c.-30G > T, c.29_30insA, c.69delT, and c.300C > A). These mutations were observed in 10 patients, 6 of which carried double mutation. Furthermore, 50% (5/10) of these patients carrying somatic mutations had RRP severity, representing 62.5% (5/8) of the severity cases in this study, albeit no significant association was found between somatic mutations and disease severity. Methylation-specific polymerase chain reaction assays revealed p14^ARF promoter hypermethylation in 100% of cases, followed by TP53 (96.3%) and p16^INK4A (55.6%), suggesting the influence of HPV in the DNA methylation machinery. In conclusion, somatic mutations were not common events identified in patients with RRP. However, epigenetic modulation by high methylation rates, particularly for the p14^ARF/TP53 pathway, seems to be in the course of RRP development.

Screening and identification of key candidate genes and pathways in myelodysplastic syndrome by bioinformatic analysis

Myelodysplastic syndrome (MDS) is a heterogeneous hematologic malignancy derived from hematopoietic stem cells and the molecular mechanism of MDS remains unclear. This study aimed to elucidate potential markers of diagnosis and prognosis of MDS. The gene expression profiles GSE19429 and GSE58831 were obtained and downloaded from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) in MDS were screened using GEO2R and overlapped DEGs were obtained with Venn Diagrams. Then, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway functional enrichment analyses, protein–protein interaction network establishment and survival analyses were performed. Functional enrichment analysis indicated that these DEGs were significantly enriched in the interferon signaling pathway, immune response, hematopoietic cell lineage and the FOXO signaling pathway. Four hub genes and four significant modules including 25 module genes were obtained via Cytoscape MCODE. Survival analysis showed that the overall survival of MDS patients having BLNK, IRF4, IFITM1, IFIT1, ISG20, IFI44L alterations were worse than that without alterations. In conclusion, the identification of these genes and pathways helps understand the underlying molecular mechanisms of MDS and provides candidate targets for the diagnosis and prognosis of MDS.

Mutation profiling in the PIK3CA, TP53, and CDKN2A genes in circulating free DNA and impalpable breast lesions

Breast impalpable lesions have become a clinical dilemma because they are small, presenting a heterogeneous cellular phenotype. The aim of this study was to evaluate the mutational profile of the PIK3CA, TP53, and CDKN2A genes, comparing the mammary tissue with the respective circulating free DNA (cfDNA). The PIK3CA, TP53, and CDKN2A genes were sequenced (PCR-Sanger) in 58 women with impalpable lesions (49 malignant and 9 benign) with the respective cfDNA. The chi-square or Fisher's exact test was used to evaluate statistical significance between the clinical variables and mutational profile. A total of 51 out of 58 samples generated successful mutation profiles in both breast lesion and cfDNA. Of the 37 mutations detected, 10 (27%) and 16 (43%) mutations were detected in benign and malignant breast lesions, respectively, while 2 (5%) and 9 (24%) were found in cfDNA of women with benign and malignant lesions, respectively. The lymph node involvement with mutations in the PIK3CA in malignant lesions (P = 0.001), and the relationship between mutations in PIK3CA, comparing ductal tumors with benign lesions (P = 0.05), were statistically significant. This study detected different mutations in PIK3CA, TP53, and CDKN2A genes, which represent, in part, the heterogeneity of impalpable lesions. The results confirm that more studies should be conducted on the functional role of cfDNA in the impalpable lesions.