CD45RO+TILs: cellular biomarkers for larynx squamous cell carcinoma outcome

OBJECTIVE

The prognostic importance of Tumor-Infiltrating Lymphocytes (TILs) in the tumor microenvironment of various cancers is increasingly recognized. In the present study, we aimed to investigate the prognostic value of CD3+, CD4+, CD8+, and CD45RO + TILs and their relation to histopathological features in larynx squamous cell carcinoma.

METHODS

Formalin-Fixed and Paraffin-Embedded (FFPE) samples from 63 primary larynx squamous cell carcinoma patients were immunostained for CD3, CD4, CD8, and CD45RO expression. Positive cells in micrographs from Invasive Margin (IM) and Tumor Center (CT) of tissue specimens counted by ImageJ software and their correlation with disease outcome were analyzed.

RESULTS

The expression level of TILs subpopulations was associated with clinicopathological markers as well as Overall Survival (OS) and Disease-Free Survival (DFS). In multivariate analysis, high frequency of CD45RO + cells in IM were confirmed as an independent prognostic marker for DFS (p = 0.007, HR = 4.968) and OS (p = 0.007, HR = 4.957). Similar findings were observed in the multivariate analysis of the combined frequency of CD45RO+cells in IM and CT.

CONCLUSION

TILs are associated with patients clinicopathological features. Also, our findings indicate that CD45RO + TILs are a valuable marker for risk prediction in larynx SCC and could predict patients' outcomes.

HOX genes: potential candidates for the progression of laryngeal squamous cell carcinoma

Laryngeal squamous cell carcinoma (LSCC) is a very aggressive cancer, considered to be a subtype of the head and neck squamous cell carcinoma (HNSCC). Despite significant advances in the understanding and treatment of cancer, prognosis of patients with LSCC has not improved recently. In the present study, we sought to understand better the genetic mechanisms underlying LSCC development. Thirty-two tumor samples were collected from patients undergoing surgical resection of LSCC. The samples were submitted to whole-genome cDNA microarray analysis aiming to identify genetic targets in LSCC. We also employed bioinformatic approaches to expand our findings using the TCGA database and further performed functional assays, using human HNSCC cell lines, to evaluate viability, cell proliferation, and cell migration after silencing of selected genes. Eight members of the homeobox gene family (HOX) were identified to be overexpressed in LSCC samples when compared to normal larynx tissue. Quantitative RT-PCR analysis validated the overexpression of HOX gene family members in LSCC. Receiver operating characteristic (ROC) statistical method curve showed that the expression level of seven members of HOX gene family can distinguish tumor from nontumor tissue. Correlation analysis of clinical and gene expression data revealed that HOXC8 and HOXD11 genes were associated with the differentiation degree of tumors and regional lymph node metastases, respectively. Additionally, siRNA assays confirmed that HOXC8, HOXD10, and HOXD11 genes might be critical for cell colony proliferation and cell migration. According to our findings, several members of the HOX genes were overexpressed in LSCC samples and seem to be required in biological processes involved in tumor development. This suggests that HOX genes might play a critical role in the physiopathology of LSCC tumors.

Alterations of p14 ARF , p15 INK4b , and p16 INK4a Genes in Primary Laryngeal Squamous Cell Carcinoma

The 9p21 gene cluster, harboring growth suppressive genes p14 ^ARF , p15 ^INK4b , and p16 ^INK4a , is one of the major aberration hotspots in head and neck cancers. We try to elucidate specific aberrations affecting this region, throughout methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) assay. Methylation of the gene was investigated by MS-MLPA in a well-characterized series of 27 laryngeal squamous cell carcinomas and 20 samples of healthy mucosa. Aberrant promoter hypermethylation was confirmed using and methylation-specific. All samples studied except 3 (11 %) presented losses at 9p21 segment. The most common finding was the small deletion (exon 1α) of the p16 ^INK4a locus (44 %). Deletion of the 9p21 gene cluster was identified in 5 cases (18 %). We only found methylation in 8 samples (30 %) for p15 ^IK4b -exon 1. Promoter methylation of p14 ^ARF , p15 ^IK4b and p16 ^INK4a was not detected in any tumor sample. Methylation-specific polymerase chain reaction confirmed the results. Our data indicate that there may be a subgroup of patients in which epigenetic regulation of 9p21 segment might have little relevance. Nevertheless, MS-MLPA could not be suitable for the study of methylation at this region and further research is required.

Utility of MS-MLPA in DNA methylation profiling in primary laryngeal squamous cell carcinoma

OBJECTIVES

Methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) assay is a method that has rarely been exploited in DNA methylation profiling of laryngeal squamous cell carcinoma (LSCC).

MATERIAL AND METHODS

Methylation of the gene was investigated by MS-MLPA in a well-characterized series of 53 LSCC and 30 samples of healthy mucosa. Aberrant promoter hypermethylation was confirmed using bisulfite pyrosequencing, and methylation-specific.

RESULTS

Promoter hypermethylation was observed in 36 of the 53 patients (68%). CDKN2B (28%), APC (17%), RARβ (15%), DAPK1 (11%) and CHFR (11%) were most frequently hypermethylated. Aberrant methylation of CHFR was mainly a late-stage event. Methylation-specific polymerase chain reaction and bisulfite pyrosequencing confirmed aberrant methylation for CDKN2B, APC and DAPK1.

CONCLUSION

Promoter methylation profiling of LSCC using MS-MLPA identified CDKN2B, DAPK1, RARβ, APC, and CHFR as frequent epigenetic events. The clinical implications of these genes as biomarkers are highly relevant as attractive targets for cancer therapy, given the reversible nature of epigenetic gene silencing.